US20120199582A1

US20120199582A1 - Lid for a pan, plate, bowl or the like

Info

Publication number: US20120199582A1
Application number: US12/931,638
Authority: US
Inventors: Edward Z. Cai
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-02-07
Filing date: 2011-02-07
Publication date: 2012-08-09
Also published as: EP2673209A1; KR20140064716A; CA2825633A1; WO2012108952A1

Abstract

A vacuum seal lid for turning existing containers including plate, bowl, pan and even cutting board into a vacuum storage container comprises a top plate having an opening, a sidewall, sealing means for preserving vacuum, and a knob adapted to be at a first position in which it is above the opening to facilitate evacuation and handling, a second position in which it is at least partly below the opening to facilitate stacking and storage and a third position between the first and second positions in which the vacuum is released. The top plate may further comprise a first plate in which the opening is located and a second plate having an elastic membrane and a smooth lower surface constituting part of the sealing means for sealing containers smaller than the lid. The sealing means also comprises a sealing membrane located below the bottom surface or on the outer surface of the sidewall for sealing containers larger than the lid. To improve the seal, the sealing membrane is separable or apart from the bottom or outer surface of the sidewall. To improve the seal further, at least part of the sealing membrane is sloped at an angle relative to a horizontal plane. The knob has a knob head, a valve opening, and a valve sealer adapted to clean the valve opening by moving the knob head to improve the reliability of the lid.

Description

FIELD OF THE INVENTION

This invention relates to a lid or cover for a container such as a pan, plate or bowl, particularly to a lid that forms an airtight seal, and more particularly to a lid that forms a vacuum seal to the container.

BACKGROUND OF THE INVENTION

Lids or covers have been ubiquitously used for pans and plates, and typically adopt dome shape and have a knob or handle for easy handling. Since the seal between the lid and the pan or plate is typically not airtight, such lids are not well suited for storage. In addition, the protruded handle prevents the containers covered by the lids from stacking over each other to save space.
Numerous vacuum seal lids, as known in FoodSave® and Seal-A-Meal vacuum containers or taught in exemplar U.S. Pat. Nos. 5,969,632, 6,619,493 and 7,131,550, were invented for specially made containers. For unknown reasons, however, few airtight lids were invented to fit the existing containers such as pans and plates. Among such airtight lids, Piccioni taught in US publication number 2009/0173735 a bell shaped glass lid fitted with a U-shaped soft structure 4 to seal to dish, Hsieh taught in US publication number 2009/0101535 a dome shaped lid having a top valve for allowing a pump to evacuate air and a bottom gasket 30 for sealing to the container, and the applicant taught in U.S. Pat. No. 7,594,586 and US publication numbers 2006/0032852 and 2010/0018169 a lid having a disc shape that can vacuum seal nearly all containers.
Picconi's lid is susceptible to air leakage since the plastic structure 4 may be too rigid to conform to the topography of the dish to form a complete seal. Hsieh's lid is similar to that commercialized by Royal Sovereign International Inc and is also susceptible to leakage, especially after the lid was washed in dishwasher or when the vacuum level is low. The leakage was possibly caused by insufficient conformation of the gasket 30 to the small indents or protrusions on the surface of most dish plates or by the food residue or dust caught between the circular seal 293 and the slot surface of the groove 61 and vent hole 63 of the top valve which is difficult to reach by normal washing. The applicant's lid, commercialized under Keepeez® brand, conforms well to the topography of the container to form a complete seal, but still has some drawbacks such as not working well with plates or with containers larger than the lid.
The present invention is to provide a new lid to simplify the process of preparing and storing products such as food and solve the problems with the prior lids described above.

SUMMARY OF THE INVENTION

A vacuum seal lid is provided to turn existing containers including plate, bowl, pan and even cutting board into a vacuum storage container. The lid comprises a top plate having an opening, a sidewall, sealing means for preserving vacuum, and a knob connected to the top plate and adapted to be at a first position in which it is above the opening to facilitate evacuation and handling, a second position in which it is at least partly below the opening to facilitate stacking and storage and a third position between the first and second positions in which the vacuum is released. In a first embodiment of the invention, the top plate comprises one rigid plate to which the knob is hosted. In a second embodiment of the invention the top plate comprises a first plate in which the opening is located and a second plate having an elastic membrane to which the knob is attached and a smooth lower surface constituting part of the sealing means for sealing containers smaller than the lid. The elastic membrane of the second embodiment is affixed to the sidewall by a membrane lock having a first and second ridges separated only by the second plate or elastic membrane and received by two channels on the side wall and first plate to prevent potential detachment of the membrane.
The sealing means further comprises an elastic sealer having an elastic sealing membrane located at least party below the bottom surface or on the outer surface of the sidewall for sealing containers larger than the lid. To improve the seal, the sealing membrane is separable or apart from the bottom or outer surface of the sidewall. To improve the seal further, at least part of the sealing membrane is sloped at an angle relative to a horizontal plane. In one embodiment of the invention, the elastic sealer is attached to the bottom of the sidewall and the sealing membrane has one end connected to the bottom of the elastic sealer and the other end movable relative to the bottom of the elastic sealer. In another embodiment of the invention, the sealing membrane comprises a part of the second plate or elastic membrane located below the bottom surface or on the outer surface of the sidewall. In yet another embodiment of the invention, the sidewall comprises an inner sidewall and an outer sidewall and the sealing membrane is sloped at an angle preferably larger than 30 degrees and most preferably larger than 50 degrees between the inner and out sidewalls.
The knob, in one embodiment of the invention, comprises a knob head, a body fitted frictionally to the opening, a valve chamber having a tubular opening for frictionally receiving a tube of an evacuation device and a valve opening on its bottom plate, and a valve sealer for covering the valve opening and having a stem body and a head extended above the tubular opening. In another embodiment of the invention, the knob comprises a knob head, a valve opening, and a valve sealer frictionally fitted into the valve opening and adapted to clean the valve opening by moving the knob head to improve the reliability of the lid. A loss or partial loss of the frictional fit results in an air passage for the valve opening. The knob has a motion sealing distance, which is the maximum distance the valve sealer may move without causing any air passage, between about 0.5 mm to 15 mm, preferably between 1 mm and 7 mm, to prevent leakage.
The present invention further provides a method of use comprising placing the lid on a container, pressing or pushing the knob head down to form a first air passage to evacuate the container, thus vacuum sealing the lid to the container, and pulling the knob head up to form a second air passage to release the vacuum, thus lifting the lid away from the container.

DESCRIPTION OF THE DRAWING

The accompanying drawing illustrates diagrammatically non-limitative embodiment of the invention, as follows:

FIG. 1 is a section view of a lid or cover on a dish showing a knob in a protruded position;

FIG. 1 a is a section view of the lid of FIG. 1 showing the knob in a recessed position;

FIG. 2 is a section view of a first modified version for the lid of FIG. 1 showing the knob in a protruded position;

FIG. 2 a is a section view of the lid of FIG. 2 showing the knob in a recessed position;

FIG. 2 b is a section view of an evacuation device for connecting the lid to a vacuum pump (not shown);

FIG. 3 is a section view of a second modified version for lid of FIG. 1 when not in use or prior to being applied to a plate larger than the lid;

FIG. 3 a is a section view of the lid along line A-A of FIG. 3;

FIG. 3 b is a section view of the lid along line B-B of FIG. 3;

FIG. 3 c is a section view of the lid along line C-C of FIG. 3;

FIG. 3 d is a section view of an improved membrane lock for the lid of FIG. 3.

FIG. 3 e is a section view of the lid along line E-E of FIG. 3 d.

FIG. 4 is a section view of the lid of FIG. 3, where the knob is pressed to evacuate the container;

FIG. 4 a is a section view of the lid of FIG. 3, showing the position of knob after vacuum is formed;

FIG. 4 b is a section view of the lid of FIG. 3, where the knob is pulled up to release the vacuum;

FIG. 4 c is a section view of the lid of FIG. 3 after being sealed to a bowl smaller than the lid;

FIG. 4 d is a section view of the lid of FIG. 3 with the evacuation device of FIG. 2 b, where the container has been evacuated by a vacuum pump (not shown) connected to the device;

FIG. 5 is a section view of a third modified version for the lid of FIG. 1 when not in use or prior to being applied to a plate larger than the lid;

FIG. 5 a is a section view of the lid of FIG. 5, where the knob is pressed to evacuate the container;

FIG. 5 b is a section view of an evacuation device for connection to the lid of FIG. 5;

FIG. 5 c is a section view of a first modified version for the elastic sealer 10 of FIG. 5;

FIG. 5 d is a section view of a second modified version for the elastic sealer 10 of FIG. 5;

FIG. 6 is a section view of a fourth modified version for the lid of FIG. 1 vacuum-sealed to a plate;

FIG. 7 is a section view of a fifth modified version for the lid of FIG. 1 when not in use or prior to being applied to a bowl larger than the lid;

FIG. 7 a is a section view of the lid along line A-A of FIG. 7;

FIG. 7 b is a section view of the lid along line B-B of FIG. 7;

FIG. 7 c is a section view of the lid of FIG. 7, showing the lid vacuum-sealed to the bowl;

FIG. 7 d is a section view of an improved version of the lid of FIG. 7;

FIG. 8 is a section view of a sixth modified version for the lid of FIG. 1;

FIG. 8 a is a section view of the lid of FIG. 8 vacuum-sealed to a bottle;

FIG. 8 b is a section view of an alternative elastic sealer for the lids of FIGS. 7 and 8;

FIG. 9 is a section view of a seventh modified version for the lid of FIG. 1;

FIG. 9 a is a section view of the lid of FIG. 9 when the knob is pressed to evacuate a container;

FIG. 9 b is a section view of the lid of FIG. 9 when device of FIG. 2 b is inserted into the knob.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 and 1 a show a round lid or cover 1 for sealing food 20 in a dish plate 21 having a rim 24 and interior surface 23. Lid 1 comprises a top plate 30, an elastic sealer 10 to seal to interior surface 23 to form a closed chamber 22 between the top plate and dish, a sidewall 29, and a knob 50 for facilitating the removal of the lid. Sidewall 29 comprises a body 28, an outwardly protruded upper end 6, and a lower end having a bottom surface 15, a lower outwardly protruded ridge 14 and an upper outwardly protruded ridge 27 to receive elastic sealer 10. Upper end 6 is received in a skirt 4 of top plate 30, and the skirt is bended at its lower end by heat or pressure to form a horizontal ring 5 to lock sidewall 29 to top plate.
Elastic sealer 10 has three sealing planes 16, 17 and 18 formed on the bottom of the elastic sealer. Sealing plane 18 is horizontal and sealing plane 17 is about 20 degrees. Sealing plane 16 tilts more upwards than plane 17 from the inner to outer periphery of the elastic sealer and is about 40 degrees relative to a horizontal surface or the bottom surface of the dish plate. Sealing planes 16 and 17 are formed at the bottom of an outward protruded ring 25 of the sealer 10 to allow them to slope more upward when interior surface 23 is more vertical. A ring-shaped gap 26 is formed between ring 25 and sidewall 11 of the sealer 10 to enable the sealing planes to be able to tilt even more upward. Elastomer and rubber materials have a durometer (shore A) of 20 to 60, preferably 25 to 45 measured according to ASTM D-2240, are used for the sealer 10. Bottom surface 15 and ridges 15 and 27 convey a weight force of the lid or a vacuum force, which is to be discussed in FIG. 3, to sealing planes 16, 17 and 18 in a controlled and gradually increased way to achieve airtight seal to interior surface 23 of the dish.
It was found that conventional gasket having either flat or round sealing surface or the gasket taught by Hsieh in US publication number 2009/0101535 having downwardly sloped sealing surface caused vacuum loss in days or even minutes when sealed to some dish plates, especially when the vacuum level in the closed chamber 22 is low. The lid 10 with elastic sealer 10 was found to maintain vacuum seal for much longer time, up to weeks and even months.
Knob 50 comprises a cylindrical body 73 received in an opening 34 formed on a recessed central section 75 of the top plate, an attachment screw 77 having a base plate 56 to prevent knob 50 from moving out of the opening 34, a knob head 60 having horizontal protrusion 59 on the top end of body 73, and a O-ring 78. The cylindrical body 73 fits frictionally in opening 34. After placing the lid on a dish plate, one can move the knob downward by pressing head 60, and can hold the protrusion 59 to pull the knob up. The friction fit keeps the knob in the up position (FIG. 1) without falling down to make the knob head readily accessible. When knob 50 in the down position as shown in FIG. 1 a, O-ring 78 seals the opening 34 and the knob mostly hides below the top plate in closed chamber 22 to allow another dish plate 21 to stack on or over the top plate 30 as shown in FIGS. 1 and 1 a.
The ability to hide the knob when not needed not only helps saving storage space in refrigerator and pantries but also enables a host or hostess for an outdoor party or a waiter or waitress in a restaurant to carry several dishes at one time to speed up service and reduce work load. The airtight seal by the lid also provides other benefits such as keeps food fresher, keeps cooked food warm and prevent spill.
It is appreciated that in this and later embodiments of the invention, besides pans and plates, the lid or cover 1 can be used to seal other containers such as bowls, cups, bottles, canisters, chambers, cutting boards, and surfaces on or in which other items may be supported. Besides food, other products such as household, commercial and industrial items may be sealed in the container. It also appreciated that besides being round as in this and later embodiments, lid 1 may also adopt square, oval, rectangular or other shape. It also appreciated that the term top plate simply means that the plate is above the bottom of the container and may have any shape such as round, square, rectangular, ring, heart or oval shape. It further appreciated that the movable knob 50 may be used in existing glass or stainless lids for pans and other cooking devises to allow the hiding of the knob for storage and stacking.
In FIGS. 2 and 2 a, a first modified version of lid 1 of FIG. 1, showing only the upper half of the lid, is provided. The modified Knob comprises body 73 a capped by head 60 a and connected by a screw 77 having a base plate to a depressible protruded section 85 a of top plate 30, a valve chamber 35 having a base plate 129 and a valve opening 125, a elastic or rubbery valve sealer 127 above the base plate to cover the valve opening, a valve tube 74 fitted into the valve chamber to fix a rim 32 of the sealer 127 to prevent the sealer from being pulled out of the valve chamber, and a tubular opening 53 for receiving an evacuation device 84 shown in FIG. 2 b. Device 84 has a tube 83, and cut 87 at the lower end of tube 83 and a horizontal tube 76 connected to a vacuum pump (not shown). Valve sealer 127 has stem body 73 b and head 60 b extended above opening 53 to be readily accessible. Tubular opening 53 is dimensioned to fit tightly to tube 83 of device 84 to prevent tube 83 from falling or moving during evacuation. Head 60 b and stem 73 b of valve sealer 127 are dimensioned to be receivable inside the tube 83. Part of the rim 32 of the sealer 127 is not fixed by valve tube 74 to allow one to pull the head 60 b to move the unfixed part of the valve sealer up 10 to 100 degrees, preferably 30 to 75 degrees to wash or clean the space between base plate 129 and sealer 127.
Unlike the lids in Seal-A-Meal® or FoodSave® vacuum containers where one's hand has to hold an evacuation device steady during evacuation, lid 1 enables hand-free evacuation. One inserts tube 83 of the device 84 into the tubular opening 53 to fit tightly and the stem body 73 b and head 60 b are automatically received inside tube 83. The vacuum pulls valve sealer 127 up to open valve opening 125 and cause the closed chamber 22 to the evacuated (FIG. 2 a). As vacuum develops in chamber 22, depressible protruded section 85 a is pulled down by vacuum to form a recessed section 85 b to receive and hide knob 50 below the top plate 30, allowing another dish plate (not shown) to sit on or stack over the top plate. After device 84 is removed, sealer 127 falls to base plate 129 to seal valve opening 125 to prevent vacuum loss in the closed chamber 22. To release the vacuum, one just pulls head 60 b upward to open valve opening 125.
The depressible protruded section 85 a may be designed to stay in the protruded form when there is no external force, enabling a small vacuum to be generated in closed chamber 22 by pressing knob head 60 a. When the knob head is pressed, the protruded section 85 a becomes recessed section 85 b and a positive pressure is produced in the closed chamber to push elastic sealer 127 up to release the pressure. When the knob head is released, the recessed section 85 b tries to go back to the protruded form and produce a vacuum, which in turn pulls the valve sealer down to close the valve opening 125 and prevents the recessed section 85 b from returning to the protruded form 85 a.
Although the lid of FIG. 2 has addressed most problems of existing lids discussed in the Background of the Invention, it still has several problems. First, the valve opening 125 sealed by elastic sealer 127 often leaks because of food debris or dusts trapped between the valve sealer and the base plate 129. Second, only about 60 to 70% amount of air in closed chamber 22 may be removed even with evacuation device 84 since the affordable pumps can only remove 60 to 70% of air. Third, the top plate 30 and sidewall 29 need to be thick and strong to stand the vacuum without breakage, making the lid heavy and expensive to make. Forth, the lid cannot seal containers smaller than the lid.
FIGS. 3 to 3 c show a second modified version for the lid of FIG. 1 to resolve the above problems. The improved lid comprises a first top plate 30 a having an opening 34 and lip 33, a second top plate comprising an elastic membrane 30 b adapted to generate a vacuum in closed chamber 22 and to convert the vacuum to a downward force to apply to the elastic sealer 10 to preserve the airtight seal and vacuum, a knob 50 connected to the second plate 30 b and movable in opening 34 among various positions shown in FIGS. 4 to 4 d, and a membrane lock 31 for locking a peripheral section 7 of the elastic membrane to sidewall 29. The opening 34 is large enough to allow a hand to pass through to move knob 50 from a position below the top plate to a position above the plate, which is to be discussed later in FIGS. 4-4 d. The top surface of the second plate or elastic membrane 30 b is in contact with the first plate 30 a when the knob is not in use or at a top position. Such contact makes the first and second plates look and function as one plate in dishwashers to prevent foreign matters from entering between the plates. An unexpected benefit for such contact is that the product life and the ability of the lid to maintain the vacuum over the life were significantly increased.
In the lids (Keepeez®) based on applicant's U.S. Pat. No. 7,594,586, it was found that the elastic membrane tended to separate from the side wall or rigid rim. Membrane lock 31 has resolved this problem, and it comprises a first lock formed on top plate 30 a and having a first ridge 8 and a first channel 2 for receiving the elastic membrane and a second lock formed on sidewall 29 and having a second ridge 3 and second channel 9 also for receiving the elastic membrane. The second ridge 3 is adapted to fit into the first channel 2, and the first ridge 8 is adapted to fit into the second channel 9. The first and second ridges are adjacent to each other and separated only by a vertical section of the elastic membrane 30 b. It is believed that the dimensional variations of elastic membrane 30 b, sidewall 29 and plate 30 a, which are believed to cause the membrane separation from the rigid rim in the lids based on U.S. Pat. No. 7,594,586, become canceled out in the membrane lock 31, thus avoiding the membrane separation problem.
Knob 50 comprises knob body 73 having a base 45, a cylindrical chamber 51 and a sidewall 35, an inner body 37 having a base 36 and sidewall 43 adapted to fit tightly into chamber 51 to sandwich the elastic membrane between sidewalls 35 and 43 and between bases 36 and 45, a knob head 60 having horizontal protrusion 59, a first tube receiving opening 54 and a recession 57 above to reduce the height of the opening 54, a valve shaft 55 having a top end affixed to the knob head and a lower end connected to a valve sealer 42, a pair of plate-shaped springs 61 a and 61 b, each having one end connected to sidewall 35 and another end connected to the valve shaft, and a valve opening 80 formed in inner body 37 for communicating the closed chamber 22 with atmosphere. Protrusion 41 on the valve shaft prevents the valve sealer 42 from slipping out. One or more air channels 44 are formed on base 36 to direct air to valve opening 80 when knob 50 reaches the food. The base 45 fits into opening 33 of the first top plate snugly to stabilize the knob, and the knob is prevented from moving out of the opening 33 by lip 34.
A protrusion 46 on the inner surface of sidewall 35 fits into a corresponding recession on the outer surface of sidewall 43 to prevent the sidewalls 35 and 43 from separation. A membrane scar 49 is formed at an edge of the elastic membrane 30 b to cause the membrane to be permanently affixed to sidewalls 35 and 43. The scar 49 is formed by producing a hole on a section of the elastic membrane above inner body 37, and heating the membrane around the edge of the hole to cause the membrane to bead and progress to the area or junction where the sidewall 43 of inner body 37 meets the sidewall 35 of knob body 73.
Valve opening 80 has a valve sidewall 79 dimensioned to form a frictional fit to the valve sealer to cause an airtight seal between the valve sidewall and valve sealer to allow the valve sealer to completely close the valve opening. Valve sealer 42 is adapted to move up and down frictionally in valve opening 80, and cleans the valve sidewall 79 as it moves. A cylindrical extension 40 is formed above the valve sidewall for receiving and guiding the movement of the valve sealer. Three vertical channels 47 (FIGS. 3 & 3 a) are formed on the sidewall 38 of the extension 40 to reduce the friction when the valve sealer moves from the valve opening into the extension. When the valve sealer moves from the valve opening into extension 40, a partial loss of the frictional fit is resulted, which in turn forms an air passage 58 at the bottom end of channel 47 to allow atmospheric air to enter chamber 22 via an opening 53 on the plate-shaped spring 61 b, a ring-shaped chamber 48, and valve opening 80 (FIG. 4 b).
Unlike the valve in the prior art lid or in FIG. 6, the tube receiving openings 53 and 54 of the knob are positioned upstream of the valve opening 80 and open up the space above the valve sealer 42 for direct access to cleaning liquid or water and does not create any dead or difficult to clean space in the valve 50. Tube receiving openings 53 and 54 are dimensioned to receive tube 83 of the evacuation device 84 of FIG. 2 b to allow a vacuum pump to evacuate the closed chamber 22. The opening 54 is sized to allow device 84 to interact and push knob head 60 down, therefore moving valve shaft 55 and valve sealer 42 down, to cause at least partial loss of the friction fit and the formation of air passage 81 (FIG. 4 d) when tube 83 of the device is inserted into the openings 53 and 54. Opening 53 fits to tube 83 tightly to lock the position of the knob head.
An opening 67 is formed on the top wall 66 of the cylindrical extension 40 and dimensioned to receive and allow movement of the shaft 55 therein. An opening 69 is formed between the plate-shaped springs 61 a and 61 b, and also dimensioned to receive and allow movement of the shaft 55 therein, which causes the valve shaft and thus the valve sealer 42 to be connected to the springs 61 a and 61 b. A space or gap 68 is between the springs 61 a and 61 b to enable independent movement of the springs 61 a and 61 b. A stop plate 68 is formed on shaft 55 to sandwich springs 61 a and 61 b between the bottom of the knob head 60 and the stop plate as well as to enable the knob head to pull the springs 61 a and 61 b upwards as shown in FIG. 4 b to open the valve opening 80 and produce the air passage 58. A seal sleeve 62 is attached around the top end of the sidewall 35 to seal to the knob head 60 when the knob head is pushed down as shown in FIG. 4 d.
The springs 61 a and 61 b are sufficiently long to allow the valve shaft to move sufficient distance to cause the valve sealer 42 either to move out of the valve opening 80 to lose all the frictional fit between the valve sealer and the valve sidewall 79 and produce an air passage 81 as shown in FIG. 4 or lose part of the frictional fit to produce air passage 58 as shown in FIG. 4 b. The springs are also sufficiently strong to overcome the friction force of the frictional fit to cause the valve sealer to return into the valve opening 80 after the valve sealer is moved to cause the loss or partial loss of the frictional fit to produce the air passage 81 or 58. The valve opening 80 may have a diameter between about 2 mm and 20 mm, preferably between 5 mm and 10 mm. To prevent leakage during the storage due to aging, accidental contact or touching, the motion sealing distance of the valve sealer 42, which is the maximum distance the valve sealer can move in the valve opening 80 towards the container without causing any air passage to form between the closed chamber and atmosphere, is normally between about 0.5 mm to 15 mm, and preferably longer than 1 mm and 7 mm.
Knob 50 in FIGS. 3-9 has several unique features compared with other valves. First, the valve sealer 42 keeps the valve opening 80 sealed even when the valve sealer or valve shaft is moved a certain distance as long as the distance is smaller than the motion sealing distance, thus making knob 50 much less prone to leakage than other valves that leak fluid even with a very slight move of the valve sealer. Second, the valve sealer 42 swipes off any dust, food or other foreign matters on the sidewall 79 of the valve opening, i.e. on the sealing surface, when the sealer moves up or down during normal use. This enables the knob or valve to be self-cleanable, which is critical to the reliability of the lid. Third and also importantly, the valve sealer is allowed to move among a first position in which the valve sealer forms an airtight seal to the valve opening 80, a second position in which the valve sealer is at least partially above the valve opening to form a first air passage 58 between the closed chamber and atmosphere, and a third position in which the valve sealer is at least partially below the valve opening to form a second air passage 81 between the closed chamber and atmosphere. The knob head 60 of the lid allows one to press to move the valve shaft 55 and thus the valve sealer 42 down to form the air passage 58 to allow air to be removed from closed chamber 22. The knob head 60 also allows one to pull to move the valve shaft 55 and thus the valve sealer 42 up to form air passage 58 to allow air to enter the closed chamber to facilitate the removal of the lid from the container.
In FIG. 3 and other exemplar embodiments of the invention, it is appreciated that an extension similar to the cylindrical extension 40 may be formed at the lower end of the valve opening 80. It is also appreciated that the openings 67 and 69, the horizontal cross section of the valve shaft 55 and the valve opening 80 may have oval, square or other non-circular shape to prevent any mis-alignment between openings 53 and 54. It is also appreciated that the knob may adapt any shapes such as oval, triangular, square, rectangular, star and heart shapes besides the round shape. It is further appreciated that the first plate 30a may adapt a ring shape and the opening 34 is larger than base 45 of the knob body 73. It is still further appreciated that knob head 60 and other non-essential parts may be minimized or even removed and the knob work just as a valve with its sealing surface self-cleanable during use.
To use lid 1, one checks whether the container is larger or smaller than the lid. If the container is larger, one holds knob 50 to place elastic sealer 10 on interior surface 23 of the container. Before use, the knob is above opening 34 of plate 30 a with the base 45 resting therein in a first or a non-use position (FIG. 3), thus being readily accessible for handling and air evacuation through the knob. To produce vacuum to preserve food 20, one presses knob head 60 to move knob 50 in opening 34 downward to a second or a storage position below or partly below opening 34 shown in FIGS. 4 and 4 a. The base 45 of the knob pushes the second plate or elastic membrane 30 b connected to the knob down to force air above food 20 out via air passage 81, opening 80, channel 47, chamber 48 and openings 53 and 54. Pressing knob head 60 causes springs 61 a and 61 b to bend and valve sealer 42 at the end of valve shaft to move against the friction fit out of valve opening 80 to produce passage 81 (FIG. 4). When the knob head I released, springs 61 a and 61 b pushes the knob head, valve shaft and the valve sealer up to close valve opening 80 to set the knob at the storage position as shown in FIG. 4 a to preserve the vacuum in the chamber 22. To open the valve opening 80, one simply pulls knob head 60 upwards to move the knob to a third position, causing springs 61 a and 61 b to bend and the valve shaft 55 and valve sealer 42 to move up into cylindrical extension 40 to produce air passage 58 (FIG. 4 b). While the knob is at the third position, which is between the first and second positions, air continues to enter chamber 22 via passage 58 and as a result causes the third position of the knob to change until the knob reaches the first position.
If the container is smaller than the lid (FIG. 4 c), one places the top plates 30 a and 30 b over the rim 24 of container 21. The bottom surface of the elastic membrane 30 b is smooth and has a peripheral section 7 accessible to the container to form an airtight seal to rim 24, enabling the lid to seal containers smaller than the lid. To remove air and create vacuum, one presses the knob 60 in a way similar to that shown in FIG. 4. To release the vacuum and remove the lid, one pulls the knob in a way similar to that shown in FIG. 4 b. The knob 50 in this and other embodiments of the invention may be pressed down more or less to remove more or less air, thus creating higher or lower vacuum level. The positions of the knob relative to the opening 34 or lip 34 of the plate 30 a therefore indicate the vacuum level below the lid. For examples, when knob head 60 is positioned far above lip 33, the vacuum level is low, when it is leveled with the lip, the vacuum level is medium, when it is far below the lip, the vacuum level is high.
Unlike existing vacuum lids where the lid can not change shape and dimension, the lids in FIG. 3, FIGS. 5 and 7 have the second top plate 30 b adapted to conform to the shape of the food, thus allowing a lot more air above the food to be evacuated by evacuation device 84 connected to a vacuum pump (not shown). To use, one insert the tube 83 of the device into the tube receiving openings 53 and 54 to push the knob head 60 down, which in turn bends the springs 61 a and 61 b and moves the valve shaft 55 and valve sealer 42 down to form air passage 81. The seal sleeve 62 seals the valve body 73 to knob head 60, and the tight fit between the tube 83 and tube receiving opening 53 prevents the knob head from moving up by the springs 61 a and 61 b. As the vacuum pump draws air out of the closed chamber 22 via passage 81, valve openings 80, channel 47, chamber 48 and tube 83, the elastic membrane becomes stretched and moves down to cover and conform to the shape of the food 20 (FIG. 4 d).
In FIG. 3 d, an improved membrane lock 31 is provided for the lid 1 of FIG. 3. Only part of sidewall 29 and part of the first and second plates 30 a and 30 b are shown. The sidewall 29 is tilted inwardly toward the center of lid and the membrane lock 31 is protruded inwardly from the sidewall 29 towards the center of the lid to enable a plurality of the same size lids to stack into each other. A small opening 162 is formed on the first plate located near the sidewall 29 and apart from the opening 34 and knob 50 to allow fluid such as water or air between the first and second plates to pass through. The improved membrane lock 31 comprises a first lock 165 formed on top plate 30 a and having a first ridge 171 and a first channel 163 for receiving elastic membrane 30 b and a second lock 167 formed on sidewall 29 and having a second ridge 164 and second channel 166 for receiving the elastic membrane. The second ridge 164 is adapted to fit into the first channel 163, and the first ridge 171 is adapted to fit into the second channel 166. The first channel 163 causes the bottom part of the first plate to be wrapped by the elastic membrane to prevent the membrane from moving out of channel 163. Like the membrane lock in FIG. 3, to prevent the elastic membrane from separation from the lock 31, the first and second ridges are separated only by a vertical section of the elastic membrane 30 b.
The first channel 163 on plate 30 a is a continuous round channel. But there are a plurality of second channels 166 on sidewall 29 around the second ridge 164 and a plurality of first ridges 171 on plate 30 a around the first channel 163 adapted to enter the plurality of second channels 166 when the second ridge 164 enters the first channel 163. Each first ridge 171 comprises a left ridge 171 a having a hooked end 170 a, a right ridge 171 b having a hooked end 170 b, and a gap 172 between the left and right ridges (FIG. 3 e). A side channel 168 is formed below each second channel 166 for receiving the hooked ends of the first ridge. The width of each second channel 166 is smaller than the width of each side channel 168, and is sized to require the left and right ridges 171 a and 171 b to bend toward each other in order for the hooked ends 170 a and 170 b to pass through. At least one of the first ridge 171, second channel 166 and side channel 168 may have sharp elements to break a part of the elastic membrane 30 b when the first ridges 171 are forced into the second channels 166. The breaking of the elastic membrane is found to prevent the separation of the membrane from the membrane lock. It is appreciated that it is possible to form the second channel and ridge on the first lock 165 and form the first channel and ridge on the second lock 167.
FIGS. 5 to 5 c provides a third modified version of the lid of FIG. 1 with an improved elastic sealer 10 having mini gaskets 93 connected to sealing planes 16, 17 and 18. Though the elastic sealer of FIG. 1 forms longer lasting seal than other lids, the seal is not enough for since most kitchen containers have minor indented or protruded areas on their interior surface 23 and are not perfectly round. In addition, even if a container is perfectly round, it still appears oval or non-round to the lid if the lid is not centered in it. Mini gasket 93 comprises a sealing membrane 94 located below and apart from the bottom of the elastic sealer and having a first end 105 connected to the bottom surface of the elastic sealer and a second end 106 movable relative to the elastic sealer. The sealing membrane 94 is sloped or tilted at an angle between about 1 to 89 degrees, preferably about 2 to 80 degrees, to the horizontal plane to achieve long lasting seal. Here the sealing membrane adapts the shape of a sloped letter I. It is found even longer lasting seal is achieved by sloping or tilting the sealing membrane outwards so that the second end 106 is closer to the outer periphery of the elastic sealer than the first end 105 (FIG. 5). Part of the sealing membrane may be sufficiently thin to cause it collapse and a part of it to touch the bottom surface of the elastic sealer by the weight of lid when the lid stands on the container, thereby facilitating the vacuum formation.
FIG. 5 c shows an improved version of the mini gasket 93 in which the sealing membrane 94 has a sealing rim 124 at the second end 106. The sealing rim is thicker or fatter than the sealing membrane or at least than the part of the sealing membrane adjacent to the sealing rim. In FIG. 5 d, sidewall 29 has a sloped bottom surface 15 so that the inner face of the sidewall is taller than the outer face, which was found to prevent food from entering between sidewall 29 and elastic sealer during use. FIG. 5 d also shows another improved mini gasket 93 in which the sealing membrane 94 comprises a leg 123 and a foot 122 to seal to the interior surface 23 of the container. Here the sealing membrane 94 adapts letter L shape. It is appreciated by tilting leg 123 of FIG. 5 c, the sealing membrane 94 adapts a sloped V shape; by curving leg 123 and foot 122, the sealing membrane adapts C shape; by moving the foot 122 about 50% to the left of leg 123, the sealing membrane adapts an inverted T shape; by moving the foot 122 about 50% to the left of leg 123 and curving the foot 122, the sealing membrane adapts an inverted Y shape; by adding a leg to the second end 106, the sealing membrane adapts a letter U shape. Since the combination and variation of leg 123 and foot 122 has the effect of a sloped sealing membrane, the above L, sloped V, C, inverted T, inverted Y, and U shaped sealing membranes 94 are all considered generally sloped. It is also appreciated that the sealing membrane may be formed on or attached to the bottom of a plastic or metal ring to form the elastic sealer. It is also appreciated that elastic sealer 10 may need only one mini gasket or sealing membrane to achieve enough seal to the interior surface 23. It is further appreciated at least part of the sealing membrane designed to contact interior surface 23 is made sufficiently thin to conform to the minor indents and protrusions on the interior surface, and has a thickness less than about 1.5 mm, preferably less than 0.75 mm, and most preferably less 0.5 mm.
The sidewall 29 is formed from a stainless steel sheet and the top plate 30 a is made from glass. A channel 88 is formed at the top part 97 of sidewall 29 to receive a ring 90 and to sandwich the peripheral section 7 of the elastic membrane. Glass plate 30 a is placed over ring 90 and the top end 91 of the sidewall is rolled over glass plate 30 a to affix the elastic membrane with scar 92 formed at the periphery of the membrane. Like knob 50 of FIG. 3, the modified knob comprises knob head 60, knob body 73 and inner body 37 for sandwiching the elastic membrane there between. Knob body 73 has a top chamber 57 to receive knob head 60. A recession 52 is formed on the rim of chamber 57 to facilitate the evacuation of closed chamber 22 by pressing the knob head. Knob head has a sidewall 102 received and movable in the ring-shaped chamber 48. A first spring 100 is compressed between the top wall 66 of cylindrical extension 40 and the valve sealer 42 for moving the valve shaft 55 and valve sealer 42 down and a second spring 101 is compressed between the knob head and top wall 66 for moving the valve shaft and valve sealer up. The first and second springs are selected to keep the valve sealer in the valve opening 80 during storage or when the lid is not in use. The first spring 101 is preferably stronger or has a larger spring force constant than the second spring 100 to increase the sealing reliability of the knob 50 and lid during vacuum storage.
Besides glass plate 30 a and elastic membrane 30 b, top plate 30 further has a shield 143 below and connected to the base 36 of inner body. The shield is in contact with the elastic membrane prior to use and moves away or more apart from the elastic membrane as the air in the closed chamber 22 is being evacuated (FIG. 5 a). It is larger than base 45 of the knob body and has a plate 144 and a plurality of openings 146. The shield was found to prevent the elastic membrane from being damaged by sharp bones or shells in the food when one presses knob to push the membrane against the food or when the lid is connected to a vacuum pump. An unexpected benefit of the shield 143 is that it prevents the elastic membrane 30 from damages by microwave oven, especially when lid 1 covers food containing tomato sauce or oil, which has been a major problem associated with Keepeez® lids taught by applicant in U.S. Pat. No. 7,594,586. The shield is preferably smaller, most preferably 5 mm to 40 mm smaller, than the sidewall 29 to facilitate the cleaning of the lid.
To use, one simply presses the knob head 60 to compress the second spring 101, thus moving the valve shaft 55 and valve sealer 42 down to produce air passage 81,and to push the elastic membrane 30 downward to force air out of the closed chamber 22 via the air passage 81 (FIG. 5 a). The downward movement of the elastic membrane causes the shield 143 connected to the membrane and knob 50 to move down with the membrane as air is removed from chamber 22. If one desires to remove more air for the food, an evacuation device 84 (FIG. 5 b), which has a tube 83 to seal to the top chamber 57 and the a pin 107 to push the knob head 60, may be inserted into the top chamber 57 of the knob 50.
FIG. 6 shows a fourth modified version of the lid of FIG. 1. Compared to lid of FIG. 5, the top plate 30 here has only one layer and the inner body 37 functions as knob body 73 and is formed directly on the top plate. A tubular channel 112 is formed in valve shaft 55 with a top end connected to a chamber 115 and lower end 111 connected to closed chamber 22. Tube receiving opening 54 is formed on a disc 117 sealed to chamber 115. A ball sealer 120 is pushed against disc 117 by a spring 116 to close opening 54. The sidewall 29 is made from stainless steel or plastics and has a plurality of elastic pleats 119 a and 119 b adapted to collapse or change in height when pressed to expel air out of the chamber 22 and to have a memory to rebound or return to its original height when not pressed, thus generating vacuum in the closed chamber.
Similar to the lid of FIGS. 5 and 5 a, one presses the knob head 60 to push the valve shaft 55 and valve sealer 42 down produce air passage 81 (not shown). The knob head 60 and spring 101 convey the pressing force to the sidewall 29 via knob body 37 and top plate 30 to compress the elastic pleats 119 a and 119 b to force air out of chamber 22 via the air passage 81 (not shown). When not pressed, the knob head 60 is pushed up by spring 101 to cause the shaft 55 and valve sealer 42 to move up and close the valve opening 80; the compressed elastic pleats try to expand, thereby producing a vacuum in closed chamber 22. To release vacuum and lift up the lid 1, similar to that shown in FIG. 4 b, one holds the protruded part 59 or knob head 60 and pulls the knob up, which causes the valve shaft 55 and valve sealer 42 to move up into the cylindrical extension 40 to produce air passage 58 (not shown) to allow air to enter chamber 22 and the compressed pleats to expand and return to its original height.
To evacuate air with evacuation device 84 of FIG. 2 b, one inserts tube 83 into tube receiving opening 54 to push ball sealer 118 down to evacuate air from the closed chamber 22 via channel 112.
A fifth modified version of the lid of FIG. 1 is presented in FIGS. 7 to 7 c. The improved lid comprises a first plate 30 a, a sidewall 29 connected above the first plate and having bottom surface 15 about in the same plane as the bottom surface of the first plate and a channel 2, and a second plate or elastic membrane 30 b. Membrane 30 b comprises a peripheral section 7 having a smooth lower surface for enabling the lid to form a seal to the rim 24 of container 21 in a way similar to that shown in FIG. 4 c. The peripheral section 7 has a mostly flat section 18 that covers or wraps bottom surface 15 of the sidewall 29 to form elastic sealer 10 for enabling the lid to form an airtight seal to the interior surface 23 of container 21. This means, like lid of FIGS. 3 and 5, the lid can seal containers both smaller and larger than the lid. It, however, has much lower cost than the lid of FIGS. 3 and 5 since its elastic sealer 10 is just a peripheral section of the elastic membrane 30 b and its sidewall 29 is just a part of the first plate 30 a. The peripheral section 7 located close to sidewall 29 is sloped or tilted downward from sidewall 29 to knob 50 at an angle relative to a horizontal plane when the lid is not in use or not applied to a container (FIG. 7). The lower surface of the first plate 30 a is also tilted downward from sidewall 29 to the center. The angle or slope is about 5 to 75 degrees, preferably 10 to 60 degrees. Such slope was found to improve the seal to the rim 24 of the container, enables the elastic membrane to seal to the interior surface 23 when the slope or angle is large, and help removing fluid between the plates 30 a and 30 b.
The peripheral section 7 also has a sloped part 17 that covers a predetermined height of the outer surface of the sidewall 29 and is accessible to the interior surface 23 of the container to improve the seal to the container. The most outer part of peripheral section 7 is affixed to channel 2 by a ring 82 and has scar 92 formed at the periphery of the membrane. A fluid gap 19 is formed between the sloped part 17 and the sidewall 29 to contain a layer of fluid such as air or liquid to further improves the seal of the elastic membrane to interior surface 23 of the container. The distance between the sidewall 29 and the sections 17 and 18 of the elastic sealer 10 of the elastic membrane 30 b contacting the bottom surface 15 and covering of the outer surface of the sidewall 29 is adapted to be changeable to enable the sections 17 and 18 of the elastic membrane to better conform to the interior surface 23 of the container to further improve the airtight seal.
The elastic membrane 30 b is stretched 1% to 50%, preferably 5% to 30% when or before the membrane is attached to the sidewall 29 by ring 82 during the production or assembly of the lid, and is maintained in the stretched and tensioned condition when the lid is not in use or not applied to a container. Such stretching facilitates the expelling of fluid such as air and water if present between the first and second plates 30 a and 30 b when the knob moves from a vacuum storage position in which the knob is partly below the opening 34 or plate 30 a to a non-use position in which the knob is above or mostly above the opening 34.
A problem discovered with the lid taught in applicant's U.S. Pat. No. 7,594,586 is that after extensive heavy uses for months, a small percent of lids (e.g. about 4% depending on the age of the lids) developed small leakage. It was tried to resolve this problem by doubling the thickness of the membrane, for example from 0.05 mm to 0.1 mm. Only some limited success was achieved. In average, the percent of lids that developed leakage was reduced by about 30%, i.e. from about 4% to about 3% when the membrane thickness is doubled. It was found with surprise when the one elastic membrane were replaced by two identical elastic membranes in lid 1, the percent of lids that developed leakage was reduced by almost 250%, i.e. from about 4% to about 1.5%. The improvement is almost 10 times better than expected. As a result, it is preferred that the elastic membrane 30 b comprises a plurality of elastic membranes in one stack with their peripheral sections connected together to the sidewall 29. Even more surprisingly, when the two membranes in lid lwere bonded together by heat, no leakage was found in almost 200 lids after extensive heavy uses. This means the bonding process resolved the leakage problem, and bonded membranes with 2 or more elastic membranes bonded together by a bonding process such as calendaring, heat or pressing bonding, laminating or extrusion coating are preferred in lid 1.
The improved knob 50 of FIG. 7 is simplified by removing the ring-shaped chamber 48 of the knob in FIGS. 3 and 5, and comprises knob body 73 having an rim 109 for preventing the knob body from being pushed below the opening 34, inner body 37 having valve opening 80 and cylindrical extension 40 open to atmosphere via tubular openings 72 and 53 directly below tubular opening 54 on knob head 60, a valve sealer 42, and springs 100 and 101 adapted to keep the valve sealer at least partly in the valve opening 80 even when there is vacuum below the knob as long as the knob head 60 is not pressed or pulled. Cylindrical extension 40 is covered by top wall 66 of knob body 73 having opening 67 to receive valve shaft 55. Knob body 73 has is only slightly smaller than opening 34 to allow the knob to move up and down in the opening and to prevent foreign solids from entering the space between the first and second plates 30 a and 30 b. After the knob is moved to a lower position in opening 34, a layer of static air 120 is formed between the first and second plates to provide heat insulation for the product 20 in closed chamber 20 (FIG. 7 c). It is appreciated that the first plate 30 a may be connected to the upper part of sidewall 29 and is apart and above the second plate or elastic membrane 30 b. It is also appreciated that an airtight seal may be formed between the opening 34 and knob body 73 by an O-ring or seal gasket to preserve a vacuum between the first and second plates 30 a and 30 b after knob 60 is moved from a first unused position (FIG. 7) to a second sealed storage position.
To use, if the container 20 is larger than the lid 1, one places the elastic sealer 10 on the interior surface 23 and press the knob head 60 to produce air passage 81 to evacuate air in chamber 22 (FIG. 7 c) and release the knob head to allow valve sealer 42 to return into valve opening and allow a vacuum to form in the chamber. To remove the lid, one pulls the knob head in a similar way shown in FIG. 4 b. If the container is smaller than the lid, one places elastic membrane 30 b over the rim 24 of the container in a similar way shown in FIG. 4 c. To evacuate via a pump, one insert the tube 83 of device 84 of FIG. 2 b into openings 54, 53 and 72 to press knob head 60 down. Tube 84 fits frictionally to openings 53, 54 and 72 to keep knob head down to cause O-ring 108 to seal opening 67 during the evacuation even after one releases knob head.
An improved lid of FIG. 7 is shown is FIG. 7 d. The channel 2 of the improved lid faces sideways to allow a plastic or metal sleeve 82 to be pushed in to sandwich and affix the peripheral section of the elastic membrane to the sidewall 29, therefore makes all of the sloped section 17 of the elastic membrane readily accessible to the interior surface of the container for improved sealing. A shield 143 having a disc plate 144 below the base plate 45 of the knob 50 is connected to inner body 37 for protecting the elastic membrane in a similar way as the shield of FIG. 5. The shield also has a rim 121 to sit on countertop or table surface when lid is not in use. The base plate 45 is smaller than the opening 34 to expose part of the elastic membrane 30 b to facilitate cleaning. The elastic membrane 30 b is tilted or sloped first downward and then upward from sidewall 29 to the center of the lid. A chamber 128 is formed below the base plate 45 and disc plate 144. The top end of the spring 101 is immobilized to the bottom end of the knob head 60 and the lower end of the spring 101 is immobilized to plate 66 of the knob body so that the spring 101 is not only able to pull the valve sealer 42 back into the valve opening after the knob head is pressed but also able to push the valve sealer back into the valve opening after the knob head is pulled up. Such immobilization of the spring's ends not only saves the cost of spring 100 but also allows the knob to be shorter to facilitate stacking and storage.
In FIGS. 8 and 8 a, a sixth modified version of the lid of FIG. 1 is provided. Here the sidewall comprises an outer sidewall 28 a and an inner sidewall 28 b located a predetermined distance from the outer sidewall. The sloped section 17 of the elastic sealer 10, i.e. the peripheral section of the elastic membrane 30 b, is positioned between the outer and inner sidewalls 28 a and 28 b. The membrane lock 31 has a channel 9 and ridge 8 to sandwiching the outer part of the membrane. A stainless steel cover 149 covers the sidewall 29 and has a top cover 30 c to cover the first plate 30 a, an opening 141 on the top cover for immobilizing a elastomer or rubber ring 199 in tubular opening 53 to increase the friction to tube 83 when device 84 of FIG. 2 b is inserted, and a bottom cover 148 rolled over the bottom of outer sidewall 28 a. A passage 162 is formed in first plate 30 a to allow air to enter and leave the fluid gap 19 to facilitate the sealing of the inner surface 23 to the sloped section 17 of the elastic sealer 10. To use, one inserts the sloped section 17 of the elastic sealer 10 into the container 21, press the knob head 60 to push the valve shaft 55 and valve sealer 42 out of valve opening 80 to produce an air passage to evacuate air in the container, and release the knob head to allow the valve sealer to close the valve opening to maintain the vacuum in the container (FIG. 8 a). To remove the lid, one just pulls the knob head up as described in FIGS. 3 to 7.
When testing the lid of FIG. 8, it was discovered that the sloped section 17 of the elastic sealer 10 could form a long lasting airtight seal to the container even when the knob 50 is removed. Without knob 50, one just inserts the sloped section 17 of the elastic sealer 10 into a container and presses the top plate 30 c to deform the sloped section 17 till most or all of the sloped section 17 of the elastic sealer has entered the container. It is discovered that the lid works the best when the sloped section 17 is sloped or tilted at an angle larger than 15degrees, preferably larger than 45 degrees and most preferably more than 60 degrees relative to a horizontal plane or to the horizontal plate 30 a. The lid was found to rebound a little after being released, and such rebounding is reduced or eliminated when the passage 162 is present and/or the slope angle is about 60 degrees or more. It is appreciated that the lids of FIGS. 7 and 7 d can also form a long lasting airtight seal to the container without knob 50. It is also appreciated that elastic membrane 30 b of FIG. 8 may be replaced by an elastic gasket or sealer 10 adapted to fit between the outer and inner sidewalls 28 a and 28 b and comprises a horizontal top base 120 for contacting top plate 30 a and sidewall 29, a bottom ring 18 and thin sealing membrane 17 connected to the top base and bottom ring (FIG. 8 b). The sealing membrane 17 is sloped at an angle of preferably larger than 15 degrees, more preferably larger than 45, and most preferably larger than 60 degrees relative to a horizontal plane or the horizontal top base 120. The sealing membrane 17 is preferably less than 1.5 mm and more preferably less than 0.7 mm to improve the airtight seal to the interior surface 23 of a container.
In FIGS. 9 to 9 b, a seventh modified version of the lid of FIG. 1 is provided. This modified lid is similar to that of FIG. 8 but has a revised knob 50 with a smaller knob head 60. The revised knob comprises a body 37 having valve opening 80 and a chamber 150, a knob head 60 have a tubular body 151 fitted to and movable in chamber 150, an outward protrusion 152 to prevent the knob head from moving out of the chamber 150, a tubular opening 54, an inwardly protruded top lip 155 and a recession 52 on the top lip, and a valve shaft 55 having a top cylinder 156 movable within the tubular body 151 and a lower end 41 to affix valve sealer 42. The top cylinder 156 is prevented from moving out of the tubular body 151 by the inward protrusion 155 and has a through opening 158.
To vacuum seal, one inserts the sloped section 17 of the elastic sealer 10 of the elastic membrane 30 b into container 21 to seal to its interior surface 23, press the knob head 60 to cause valve shaft to push valve sealer 42 out of the valve opening 80 to produce air passage 81 to evacuate air (FIG. 9 a), and release the knob to allow the spring 100 to return the valve sealer into the valve opening 80 to seal and maintain the vacuum. To vacuum more air with a pump, one inserts the tube 83 of device 84 of FIG. 2 b into opening 54 to press top cylinder 156 and valve shaft 55 to push valve sealer 42 out of the valve opening 80 to produce air passage 81 (FIG. 9 b). When the tube 84 is removed, spring 100 pushes top cylinder 156 up to return valve sealer 42 into valve opening 80 to seal and preserve the vacuum in the container. To release vacuum, one presses knob head 60 just enough to push the valve sealer 42 out of the valve opening 80. It is appreciated that a protrusion 59 of FIG. 8 may be formed on knob head 60 of FIG. 9 to allow one to pull the knob head up to release the vacuum and lift the lid off the container.
The scope of the invention is obviously not restricted or limited to the embodiments described by way of examples and depicted in the drawings, there being numerous changes, modifications, additions, and applications thereof imaginable within the purview of the claims.

Claims

1. A lid for sealing a container comprising:

a top plate;

a sidewall connected to the top plate;

a knob for facilitating the removal of the lid from the container;

wherein at least one of said top plate and sidewall is adapted to seal to the container to form a closed chamber between said top plate and the container; and

wherein at least part of said knob is adapted to change position relative to the container after the lid is applied to the container.

2. A lid as defined in claim 1 wherein said knob comprises a body, a base plate to prevent said body from separating from the top plate, and a head protruded out of said body horizontally for one to hold and move said knob between a first position in which said knob is at least partly above said top plate to make said knob readily accessible and a second position in which said knob is at least partly below said top plate to allow a second container to sit on said top plate, thereby allowing stacking of containers.

3. A lid as defined in claim 2 wherein said top plate comprises at least one of a recessed section and a depressible section to which said knob is connected.

4. A lid as defined in claim 1 wherein said top plate comprises an opening adapted to allow said knob to move in said opening between a first position in which said knob is at least partly above said opening and a second position in which said knob is at least partly below said opening.

5. A lid as defined in claim 4 wherein said top plate comprises a first plate on which said opening is formed and a second plate to which said knob is connected, said knob being adapted to move in said opening between said first and second positions.

6. A lid as defined in claim 5 wherein said second plate is in contact with said first plate when said knob is at said first position to prevent foreign matters from entering between said first and second plates.

7. A lid as defined in claim 6 wherein said second plate comprises an elastic membrane and said first plate has a lower surface adapted to cause at least the peripheral section of said membrane to slope downward at a direction from said sidewall to knob, thereby improving the seal to the container.

8. A lid as defined in claim 6 wherein said second plate comprises an elastic membrane in a stretched and tensioned condition prior to applying the lid to a container to facilitate the expelling of fluid including at least one of air and water between said first and second plates when said knob moves from said second position to said first position.

9. A lid as defined in claim 5 wherein at least part of said knob is sufficiently large to close said opening and allow a layer of air to form between said first and second plates to provide heat insulation for a product in said closed chamber when said knob is at said second position.

10. A lid as defined in claim 5 wherein said first plate further comprises a second opening located close to said sidewall and apart from said knob to allow fluid between said plates to pass through.

11. A lid as defined in claim 5 wherein said knob comprises a valve opening and a valve sealer for closing said valve opening during storage when said knob is at said second position, said valve sealer being adapted to open said valve opening when said knob is at a third position, said third position being between said first and second positions.

12. A lid as defined in claim 5 wherein said opening is sufficiently large to allow a hand to pass through and move said knob from said second position to said first position.

13. A lid as defined in claim 5 wherein said opening is adapted to prevent said knob from completely moving out of said opening at least in one of the upward and downward movements of said knob.

14. A lid as defined in claim 5 further comprising a seal gasket between said opening and knob body to maintain a vacuum between said first and second plates after said knob is moved from said first to said second position.

15. A lid as defined in claim 1 wherein said top plate comprises an elastic membrane having a peripheral section and a membrane lock comprising a first lock having a first ridge and a first channel for receiving said peripheral section and a second lock having a second ridge and a second channel also for receiving said peripheral section, wherein said first ridge is adapted to end said second channel when said second ridge enters said first channel to lock said peripheral section to said sidewall.

16. A lid as defined in claim 15 wherein said first and second ridges are separated only by a vertical section of said peripheral section of said membrane to prevent said membrane from moving out of said channels.

17. A lid as defined in claim 15 wherein said second channel has a plurality of channels around said second ridge and said first ridge has a plurality of ridges around said first channel, each of said plurality of ridges having a wider end adapted to pass through each of said plurality of channels, said lock further comprising a side channel sized to receive said wider end of each of said plurality of ridges, wherein at least one of said side channel, said first ridge and said second channel is adapted to break said elastic membrane.

18. A lid as defined in claim 1 wherein said top plate further comprises a first plate having a channel and a second plate having an elastic membrane, said channel being adapted to cause said elastic membrane to wrap the bottom surface of said first plate to prevent said elastic membrane from moving out of said channel.

19. A lid as defined in claim 1 wherein said top plate comprises an elastic membrane and a membrane lock for locking said elastic membrane to said sidewall, said sidewall being tilted toward the center of the lid to allow a plurality of said lids to stack into each other, said sidewall comprising an inward protrusion at its top end for hosting said membrane lock, thereby facilitate said stacking.

20. A lid as defined in claim 1 wherein said top plate comprises an elastic membrane, said membrane comprises a scar at an edge of said membrane to facilitate the attaching of said membrane to at least one of said sidewall and side knob.

21. A lid as defined in claim 1 further comprises an elastic sealer connected to said sidewall and adapted to form an airtight seal to an interior surface of a container.

22. A lid as defined in claim 21 wherein said top plate comprises an elastic membrane adapted to generate a vacuum in said closed chamber and further adapted to convert the vacuum to a downward force applied to said elastic sealer to maintain said airtight seal.

23. A lid as defined in claim 22 wherein said elastic membrane has a smooth lower surface accessible to a container to seal to the rim of the container, whereby said membrane allows the lid to seal containers smaller than the lid and said elastic sealer allows the lid to seal containers larger than the lid.

24. A lid as defined in claim 21 wherein said elastic sealer comprises a plurality of sealing planes having different angles relative to a horizontal surface, the outer sealing plane being adapted to tilt more upwards from the inner to outer periphery of said sealer than the inner sealing plane.

25. A lid as defined in claim 21 wherein said sidewall has a bottom surface in contact with said elastic sealer to apply a force to said sealer to cause said airtight seal, said bottom surface being adapted to be so sloped that the inner face of said sidewall is taller than the outer face.

26. A lid as defined in claim 21 wherein said top plate comprises an elastic membrane, said elastic membrane having a smooth lower surface for enabling the lid to seal to the rim of a container and an outer section that covers at least part of the bottom surface of said sidewall to form said elastic sealer for enabling the lid to seal to the interior surface of a container.

27. A lid as defined in claim 21 wherein said sidewall is adapted to change in height when the lid pressed to expel air out of said closed chamber and to have a memory to return to its original height when the lid is not pressed, thereby generating a vacuum in the closed chamber.

28. A lid as defined in claim 21 wherein said elastic sealer comprises at least one mini gasket connected to said elastic sealer to improve said airtight seal, said mini gasket comprising a sealing membrane located below and apart from the bottom surface of said elastic sealer.

29. A lid as defined in claim 28 wherein said sealing membrane is adapted to collapse to cause at least part of it to touch said bottom surface when the lid stands on the container.

30. A lid as defined in claim 1 wherein said top plate comprises an elastic membrane and a shield below said membrane, said shield being adapted to move away from said elastic membrane as air in said closed chamber is being removed.

31. A lid as defined in claim 1 wherein said knob comprises a valve opening for communicating said closed chamber with atmosphere and a valve sealer, said valve opening having a valve sidewall of a predetermined length adapted to form a frictional fit to said valve sealer to cause an airtight seal, said valve sealer being adapted to move in said valve opening to cause at least a partial loss of said frictional fit to form an air passage between said closed chamber and atmosphere.

32. A lid as defined in claim 1 wherein said knob comprises a valve opening for communicating said closed chamber with atmosphere and a valve sealer, said valve sealer being adapted to move among a first position in which said valve sealer forms an airtight seal to said valve opening, a second position in which said valve sealer is at least partly above said valve opening to form a first air passage between said closed chamber and atmosphere, and a third position in which said valve sealer is at least partly below said valve opening to form a second air passage between said closed chamber and atmosphere.

33. A lid as defined in claim 32 wherein said knob further comprises a knob head adapted to be pressed to move said valve sealer to form said second air passage, thereby allowing air in said closed chamber to be evacuated, and to be pulled to move said valve sealer to form said first air passage to release the vacuum in said closed chamber, thereby allowing the lid to be removed from the container.

34. A lid as defined in claim 1 wherein said top plate comprises a plurality of elastic membranes in one stack with their peripheral sections connected together to said sidewall.

35. A lid as defined in claim 34 wherein said plurality of elastic membranes was bonded together by a bonding process to prevent the leakage of the elastic membrane after extended heavy uses.

36. A lid for sealing a container comprising:

a top plate;

a sidewall connected to the top plate;

wherein at least one of said top plate and sidewall comprises an elastic sealer to seal to the container to form a closed chamber between said top plate and container; and

wherein said elastic sealer comprises a sealing membrane adapted to contact and seal to an interior surface of the container, at least part of said sealing membrane being generally sloped at an angle relative to a horizontal plane when the lid is not in use or not applied to the container.

37. A lid as defined in claim 36 wherein said top plate comprises an elastic membrane adapted to cover at least part of a bottom surface of said sidewall, said sealing membrane comprising the part of said elastic membrane below said bottom surface of said sidewall.

38. A lid as defined in claim 37 wherein the distance between said sealing membrane and said sidewall is adapted to be changeable to improve said airtight seal.

39. A lid as defined in claim 36 wherein said top plate comprises an elastic membrane adapted to cover a predetermined height of an outer surface of said sidewall, said sealing membrane comprising the part of said elastic membrane outside said outer surface of said sidewall.

40. A lid as defined in claim 38 further comprising a layer of fluid including at least one of air and a liquid between said sealing membrane and said outer surface of said sidewall.

41. A lid as defined in claim 36 wherein said elastic sealer further comprises a top base adapted to contact at least one of said sidewall and top plate, said sealing membrane being connected to said top base at an angle larger than 15 degrees relative to the horizontal plane.

42. A lid as defined in claim 36 wherein said top plate comprises a first plate and an elastic membrane below said first plate, said elastic membrane being adapted to cover at least part of said side wall and at least part of the bottom surface of said first plate near said sidewall, said sealing membrane comprising the part of said elastic membrane that covers said sidewall or bottom surface of said first plate near said sidewall.

43. A lid as defined in claim 42 wherein at least part of said sealing membrane is sloped at an angle of at least 5 degrees relative to the horizontal plane when the lid is not in use or not applied to a container.

44. A lid as defined in claim 42 wherein at least part of said sealing membrane is sloped at an angle of at least 45 degrees relative to the horizontal plane when the lid is not in use or not applied to a container.

45. A lid as defined in claim 36 wherein said sidewall comprises a first sidewall and a second sidewall located a predetermined distance from said first sidewall, said sealing membrane being sloped between said first and second sidewalls at said angle relative to the horizontal when the lid is not in use.

46. A lid as defined in claim 36 wherein said elastic sealer is connected to said sidewall, said sealing membrane being sloped and located below and apart from the bottom surface of said elastic sealer.

47. A lid as defined in claim 46 wherein said sealing membrane has a first end connected to said elastic sealer and a second end movable relative to the bottom surface of said elastic sealer.

48. A lid as defined in claim 47 wherein said second end of said sealing membrane is positioned closer to the outer edge of said elastic sealer than said first end.

49. A lid as defined in claim 47 wherein said second end of said sealing membrane comprises a sealing rim thicker than the part of said sealing membrane adjacent to said sealing rim.

50. A lid as defined in claim 46 wherein said sealing membrane approximately adapts one of L, C, sloped V, inverted T, inverted Y, U and sloped I shapes, at least part of said sealing membrane designed to contact the interior surface of the container being sufficiently thin and elastic to conform to the indents or protrusions on the interior surface.

51. A lid as defined in claim 36 wherein said side wall has at least one elastic pleat adapted to collapse when the lid is pressed, thereby expelling air out of said closed chamber, and to have a memory to rebound to its original height when the lid is not pressed, thus generating vacuum in the closed chamber.

52. A lid for sealing a container comprising:

a top plate;

a sidewall connected to the top plate;

a knob located on said top plate;

wherein at least one of said top plate and sidewall is adapted to seal to the container to form a closed chamber between said top plate and container; and

wherein said knob comprises a valve opening for communicating said closed chamber with atmosphere and a valve sealer, said valve opening having a valve sidewall of a predetermined length adapted to form a frictional fit to said valve sealer to cause an airtight seal, said valve sealer being adapted to move in said valve opening to cause at least a partial loss of said frictional fit to form an air passage between said closed chamber and atmosphere.

53. A lid as defined in claim 52 wherein said knob further comprises an extension to said valve sidewall, said extension having a channel to cause said at least partial loss of said frictional fit to produce said air passage when said valve sealer moves into said extension.

54. A lid as defined in claim 52 wherein said knob is adapted to have a motion sealing distance for said valve sealer between about 0.5 mm and 15 mm to prevent leakage during storage due to accidents or aging.

55. A lid as defined in claim 52 wherein said knob further comprises a spring sufficiently strong to overcome the friction force of said frictional fit and cause said valve sealer to return into said valve opening after said valve sealer is moved to cause said at least partial loss of said frictional fit to produce said air passage.

56. A lid as defined in claim 55 wherein said spring comprises a plate having a first end connected to the body of said knob and a second end connected to said valve sealer, said plate being adapted to bend sufficiently to cause said valve sealer to move and lose said frictional fit.

57. A lid as defined in claim 55 wherein said spring comprises a first spring for moving said valve sealer down and a second spring for moving said valve sealer up, said first and second springs being adapted to keep said valve sealer in said valve opening during storage.

58. A lid as defined in claim 57 wherein said second spring is stronger than said first spring to increase the sealing reliability of the lid during storage.

59. A lid as defined in claim 55 wherein said knob further comprises a knob head connected to said valve sealer through a valve shaft and a knob body in which said valve sealer is hosted, said spring being adapted to move said valve sealer up and down in said valve opening and having a first end immobilized to said knob head and a second end immobilized to said knob body.

60. A lid as defined in claim 52 wherein said knob further comprises a second opening positioned upstream of said valve opening for receiving an evacuation device connected to a vacuum pump to evacuate said closed chamber and a knob head adapted to interact with the evacuation device to cause said at least partial loss of said friction fit when the evacuation device is received in said second opening.

61. A lid as defined in claim 52 wherein said knob further comprises a knob head, a knob body having a chamber above said valve opening, and a valve shaft connected to said knob head and valve sealer,

62. A lid as defined in claim 52 wherein said valve sealer is adapted to move among a first position in which said valve sealer forms an airtight seal to said valve opening, a second position in which said valve sealer is at least partially above said valve opening to form a first air passage between said closed chamber and atmosphere, and a third position in which said valve sealer is at least partially below said valve opening to form a second air passage between said closed chamber and atmosphere.

63. A lid as defined in claim 62 wherein said knob further comprises a knob head, wherein said valve sealer is adapted to form said second air passage when one presses said knob head, thus the lid, to remove the air from said closed chamber and to form said first air passage when one pulls said knob head to remove the lid from the container.

64. A method of using a lid comprising placing a lid on a container, pressing a knob of the lid down to form a first air passage to evacuate the container, thereby vacuum sealing the lid to the container, and pulling the knob up to form a second air passage to release the vacuum, thereby lifting the lid off the container.