US2702147A - Fluid dispensing unit and pump - Google Patents

Description

F. E. BROWN- FLUID DISPENSING UNIT AND PUMP I v Filed Maren 16', 1951 United States Patent O FLUID DISPENSING UNIT AND PUMP Frank E. Brown, Burbank, Calif., assgnor to Frederick M. Turnbull, Los Angeles, Calif.

Application March 10,-1951, Serial No. 214,989 17\ Claims. (Cl. 222-207) My invention relates to iluid dispensing units and pumps therefor, and more particularly to such units and pumps which are of the displacement type designed to deliver accurately metered increments of a iluid upon manual actuation.

The invention will be particularly exemplified with relation to small pocket-size dispensing units or pumps which eject fixed-volume increments upon relative movement of associated parts, this movement being induced by manual pressure. The invention includes a pump unit usable in itself and also a novel combination of such a pump unit and a container to form a handy pump structure or dispenser unit.

It is often desirable to dispense metered amounts of liquids in small volume increments, each increment being a dose or application of desired volume or a submultiple thereof whereby, in the latter case, a predetermined number of actuations will expel the desired dose or application. Conventional pumps for this purpose which have any semblance of uniformity as to discharged increments have been of the piston type and have employed a check valve near the top of the pump and open on one side to the air. Neither the piston nor a valve of this type can be considered as leak-proof during any prolonged period of use, and manufacturing tolerances often cause such pumps to leak even when new. A valve at an upper air-exposed position gives trouble both because it is diiicult to seal entry of air into the pump and because a portion of the liquid in the valve following use of the pump will progressively evaporate to leave deposits which clog the valve or interfere with its operation or sealing function.

It is an object of the present invention to provide an improved pump unit which overcomes such defects and which is of the diaphragm type; also to provide a pump unit of this type in which a exible diaphragm member is associated with a base member to provide a variablevolume pump chamber.

A further object is to provide a pump unit in which the diaphragm member is flexed between predetermined limiting positions to draw into the pump chamber and expel therefrom volume increments that are substantially equal to each other. Another object is to provide a pump unit in which each actuation expels only a fraction of the liquid in the pump chamber.

A further object is to provide a pump unit in which only a relatively small manual movement is required to expel the volume increment; also to provide a hollow stern structure through which this volume increment is expelled, the stern structure serving as the actuator for the pump unit.

Another important object of the invention is to provide a diaphragm-type pump unit with an outlet check valve which is constantly submerged, as distinct from being exposed to the air. In this connection, another object is to dispose such an outlet check valve means near the junction of the hollow stem structure and the diaphragm member so that it supports and operates against a column of the liquid within the hollow stem structure.

Another object is to provide a pump unit including a ilexible diaphragm member closed by a base member and with outlet and inlet check valve means respectively associated therewith. Other objects include the provision of a pump unit in which the diaphragm and base members are easily assembled; in which these members are positively interlocked; and in which these members become additionally sealed or interlocked because of internal fluid pressure or deformation of the diaphragm member.

The pump unit of the invention can be associated with a container having bottom, side and top walls defining a Huid-containing space, the hollow stem structure extending through an opening in the top wall to form a compact pumping structure or dispensing unit. It is an object of the present invention to provide novel relationships between the pump unit and the container as, for example, novel relationships in spacing, limitation of motion, guiding of the stem structure relative to the opening of the top wall, sealing the junction of this stem structure and the top wall, etc.

The reciprocable stem structure should be sealed relative to the top wall of the container in such way as to prevent leakage of liquid if the pumping structure is inverted. At the same time it is desirable that the sealing junction should admit air to the container to compensate for the volume of liquid displaced. It is an object of the invention to provide a novel sealing junction at this point and to employ dilerent materials in making the top Wall and the reciprocable stem structure.

In this connection, it is an object of the invention to employ an open-topped container with a closure member providing the opening through which a stem member extends and to employ dilerent materials for the closuremember and the stem member. Quite unexpected results have been attained by making one of these members of a waxy-surface plastic material to provide a non-wettable journaling surface for the other member to prevent formation of a continuous iilm of liquid coating the journaling surface. The resulting sealing junction is effective against liquid leakage but permits passage of air into the container upon the existence of minor pressure differentials across the junction. lt is an important object of the present invention to provide a novel junction of this type, irrespective of the constructional details of any pump unit that may be disposed in the container.

Another object of the invention is to provide a closure member made entirely of said waxy-surface plastic material and serving the dual purpose of producing such a `desirable junction and of closing an open-ended container.

Generally speaking, it is an important object of the present invention to provide a relatively simple pump unit or pumping structure with light-weight valve means and with component parts that can be made cheaply. It is an object to provide such a pump unit or pumping structure in which many or all of the parts can be made of molded plastic material so that the pump unit or pumping structure can be easily assembled and dismantled. Another object is to provide a pump unit or pumping structure in which most or all of the operative-parts can be assembled without the use of adhesives or complex attachment means.

Still another object of the invention is to provide a pumping structure which can be constructed so economically that it can be used for marketing small volumes of liquids, the liquid being incrementally dispensable by actuation of the device and the pumping structure being discarded after emptying. Such single-use device is particularly desirable in dispensing medicaments which can be initially packaged under carefully sterilized conditions. ln other instances, however, the invention is well suited to repeated refilling with less critical liquids that are t0 be incrementally dispensed.

Further objects and advantages of the invention will be evident to those skilled in the art from the hereincontained description of exemplary embodiments.

Referring to the drawing:

Fig. 1 is a vertical sectional view of a complete pumping structure;

Fig. 2 is an elevational view partially in section of the pump unit of the invention;

Fig. 3 is a view similar to Fig. 2 showing the pump unit in collapsed or actuated position;

F Fig. 4 is a sectional view taken along the line 4-4 of Fig. is a view taken along the line 5-5 of Fig. 1 and showing one arrangement for holding the intake valve in place;

Fig. 6 is a sectional view taken along the line 6-6 of Fi l' Fig. 7 is a fragmentary sectional view illustrating an alternative way of holding the intake valve in place;

Fig. 8 is a view taken along the line 8-8 of Fig. 7;

Fig. 9 is a fragmentary sectional view of an alternative arrangement for holding the diaphragm member to the stem structure; and

Figs. 10 and l1 are fragmentary sectional views of alternative alignment means disposed near the top of the pumping structure.

Referring particularly to Figs. 2 and 3, the pump unit is indicated generally by the numeral 12 and includes a hollow stem structure 13 to the lower end of which is connected a wall means defining a variable volume pump chamber 14. This wall means preferably includes a diahragm member 15 and a base member 16, the latter seing shown as having a at lower surface 17 which may rest upon any suitable surface 18 at the bottom of a body of liquid 19.

The base member 16 provides an upstanding lip 20 with an inwardly extending projection or shoulder 21 which interlocks with an outwardly extending shoulder 22 of a depending lip 23 of the diaphragm member 1 5. This diaphragm member is preferably formed of flexible material molded in substantially hemispherical form. The material of the lip 23 is sufficiently resilient that it can be deformed to pass through the space below the shoulder 21 and then expand outwardly to lock the members 15 and 16 releasably together. The base member 16 can be formed of rigid or semi-rigid material. The preferred material is polyethylene or some other semi-flexible plastic of sufficient resiliency that the shoulder 21 can be deformed to permit removal of the base member 16 from a mold. l

The base member 16 provides an inlet passage means with which is associated an inlet check valve means 25. A seat member 26 is preferably molded integrally with the base member 16 in a central position and provides a vertical passage, shown enlarged in Fig. 7, including a small portion 27 and a large portion 28 joined by an intermediate tapered portion forming a valve seat 29, the portion 27 meeting the valve seat 29 at a relatively sharp edge 30. In such a vertical passage is mounted an inlet check valve 31 of very light weight to raise in response to minor differences in pressure on opposite sides thereof. This check valve is preferably molded of one of the common plastic materials, preferably a vinyl chloride-acetate copolymer, and provides a pin portion 32 fitting loosely in the small portion 27 of the passage to limit rocking movement of the check valve. The pin portion 32 thus acts as a guide. Above this pin portion is a conical portion 33 having a conical surface which converges downwardly at a lesser angle than the seat 29 so as to establish a line contact with the relatively sharp edge 30 even though the valve 31 should seat with its axis not strictly vertical. This gives a very positive and effective sealing action even though the valve 31 fits quite loosely in the upright passage. The liquid is fed to this upright passage through a lateral passage 35 provided by a radial groove molded in the fiat lower surface 17 and terminating at the periphery of the base member 16.

'lhe valve 31 provides, above the conical portion 33, a cylindrical portion 37 and a head portion 38. To hold the valve 3l in the vertical passage, its upward movement is limited by a suitable stop means. In the embodiments of Figs. l, 2 and 5 this stop means is shown as including peripherally spaced upset portions 39 which can be deformed from the surrounding material by heat and/or pressure, these upset portions extending inwardly above the cylindrical portion 37 to restrain the unseated check valve 3l. In the embodiments of Figs. 7 and 8 this restraint is provided by engagement with a conical shoulder 40 providing an opening 41 which is slightly less in diameter than the cylindrical portion 37. The shoulder 40 can be molded in place, and if a resilient or semi-resilient material is used in making the base member 16, the check valve 31 can be pressed downwardly into place, the conical portion 33 momentarily dilating the opening 41, the shoulder 40 then contracting to confine the later movement of the check valvc 31.

4 Suitable longitudinal grooves may be molded in the cylindrical portion 37 or the conical shoulder 40 to permit passage of the liquid when the check valve is in raised position, such grooves being indicated in the shoulder 40 by the numeral 42.

The diaphragm member 15 can be formed of any suitable flexible material such as rubber, a deformable metal (in bellows form) or one of the well-known exible plastic materials. Polyethylene can be used if the diaphragm member 15 is made sufficiently thin but this material is difficult to mold in thin form. The preferred material is one of the flexible vinyl resins, typically a vinyl chloride-acetate copolymer with a suitable plasticizer, such as Elasticameric Vinilite. The diaphragm member 15 shown should be capable of deformation from its normal or expanded position shown in Fig. 2 into its collapsed or actuated position shown in Fig. 3. It is preferable that the material used should have suficient flexibility or resiliency to return to the position shown in Fig. 2 without the aid of any auxiliary spring, although such spring can be disposed in the pump chamber 14 or at other locations if desired. If, as shown, the lip 23 of the diaphragm member 15 is disposed within the lip 20 of the base member 16 and if the diaphragm member is made of flexible material, the sealing or locks ing action between the lips 20 and 23 will be increased automatically during the pumping operation for two reasons. First, any increase in pressure in the pump chamber 14 during this pumping operation will tend to expand the lip 23 into tighter contact with the lip 20. Second, the lip 23 of a substantially hemispherical diaphragm member 15 will tend to enlarge in size due to internal stresses in the diaphragm member when it is moved toward the collapsed position shown in Fig. 3, thus again tending to spread the lip 23 to form a better seal and lock with the lip 20.

The hollow stem structure 13 is preferably removably connected to the diaphragm member l5 at its lower end to serve as an actuator and move the diaphragm member to its collapsed position shown in Fig. 3 when the hollow stem structure 13 is manually moved downwardly. As shown, the hollow stem structure 13 includes a hollow stem member 44 having a reduceddiameter portion 45 providing a shoulder 46 and includes a valve body 47 of an outlet check valve means 48, this valve body forming the sole connection between the stem member 44 and the diaphragm member 15. The valve body 47 makes a tight press fit with a reduceddiameter portion at the lower end of the stem member 44 and provides a head or seat member 49 terminating at a shoulder 50. The diaphragm member 15 preferably includes a ange 51 having an opening 52 which detachably receives the seat member 49.

In the preferred arrangement, the peripheral surface of this seat member is either cylindrical or diverges downwardly as shown, the opening 52 being of corresponding shape so that the flange 51 of the diaphragm member 15 contracts around the seat member 49 when the latter is forced into the opening 52. This connects the diaphragm member 15 to the hollow stem strtucure 13 after assembly and against any disconnection during the normal pumping operation. At the same time it permits disassembly for cleaning and makes the assembly operation a very simple one in which the seat member 49 is forced into the opening 52 until the flange 5l engages the shoulder 50, this shoulder serving correctly to position the two members.

The seat member 49 is constructed similarly to the seat member 26 to provide an upright passage means including a small portion 54, a large portion 55 and a seat 56, there being an outlet check valve 57 in the passage means and constructed identically with the check valve 3l.

The hollow stem member 44 provides a passage 60 throughout its length which, if desired, may be restricted at its upper end either by being of smaller cross-sectional area or by the use of any suitable dispensing head secured to the upper end of the stem member 44. As best shown in Figs. 2 and 6, the lower end of the passage 50 is preferably constructed to form a bypass around the valve 57 when this valve rises into engagement with the lower end of the stern member 44. The preferred way of accomplishing this is to provide diverging flutes 62 in the lower end of the stem member 44, these flutes providing zones 63 on the lower end of the stem member which act as a stop means for the valve 57. However, as suggested in Fig. 6, even when the valve 57 contacts these zones, the outer portions of the flutes 62 remain open to pass the pumped fluid upwardly into the passage 60. As with the inlet value means 2S, the check valve 57 provides line contact with the edge of the seat member 40 to give a good sealing action even though the valve 57 should seat while its axis is inclined slightly from the vertical. The degree of inclination will be maximized by a pin portion 64 corresponding to the pin portion 32 and loosely fitting in the small portion 54 of the passage.

The pump unit 12 can be lowered into the liquid 19 to bring the fiat lower surface 17 into surface contact with the surface 18. If the valves 31 and 57 are sufficiently light, the pump unit will be self-priming, liquid flowing along the lateral passage 35 and into the pump chamber 14 because of the hydrostatic pressure of the surrounding liquid 19. Air will be displaced from the pump chamber 14 through the check valve 57, and the liquid may rise in the passage 60 to the same level as the surrounding liquid 19 or to a level slightly therebelow.

When the stem member 44 is grasped and manually moved downwardly in the direction of arrow 66 of Fig. 3, a portion of the liquid in the pump chamber 14 will be displaced upwardly past the now-raised check valve 57 to rise in the passage 60 and discharge from the upper end thereof as indicated by arrow 67 of Fig. 3. When the manual pressure is removed, the diaphragm member 15 will move into its position shown in Fig. 2, drawing a fresh increment of liquid through the inlet valve means 2S to refill the pump chamber 14. If the passage 60 is filled with the liquid, as will normally be the case if the check valve 57 is closed, each actuation will displace from the pump chamber 14 a liquid increment of predetermined volume. To insure this result, the seat members 26 and 49 respectively provide inwardly facing stop surfaces 68 and 69 which come into engagement to form a stop means limiting the inward flexure of the diaphragm member 15, as suggested in Fig. 3. Another very important advantage of the construction shown is that the check valve 57 is forced into closed position by the hydrostatic head of the column of liquid in the passage 60. This not only insures positive seating of the check valve 57 but also shields this valve from contact with the air, thus avoiding evaporation which might leave contaminating deposits on the valve surfaces.

The pump unit 12 thus far described is shown in Fig. 1 as a part of a dispensing or pumping structure indicated generally by the numeral 75. This pumping structure includes a container means providing bottom, top and side walls defining a liquid-holding space 76, the stem member 44 extending through the top wall. In the preferred arrangement, the container means includes a container 77 having a cylindrical side wall 78 closed by a bottom wall 79 and having an open top, the container means including a closure member 80 for closing this open end and for journalling the stem member 44 in its reciprocating movement. The closure member is shown as including a shoulder or ange 81 slidably telescoping within the upper end -of the container 77 to a degree permitted by a bead 82.

The closure member 80 provides a wall 83 having an opening 85 which is somewhat larger in diameter than the reduced-diameter portion 45 of the stem member 44 but of insuflicient size to pass the shoulder 46 so that engagement of the shoulder 46 with the closure member 80 determines the maximum position to which the stem member 44 may rise under the action of the diaphragm member 15. The flat lower surface 17 of the base member 16 rests at this time directly on the bottom wall 79. Correspondingly, the pump unit l2 is confined in the container 77 by engagement with the bottom wall 79 and the closure member 80. If desired, the maximum degree of expansion of the diaphragm member 15 may be limited by engagement of the shoulder 46 with the closure member 80 but in the preferred practice such engagement takes place only when the diaphragm member has been expanded to its normal full-shape position.

The invention preferably includes an alignment means for maintaining the stem member 44 accurately aligned with the axis of the opening 85. ln Fig. l this alignment means is at the bottom of the pumping structure and includes a sloping annular wall 87 diverging inwardly to a circular shoulder 88 which co-operates with the bottom wall 79 in providing a recess of such size as to receive the lower portion of the base member 16. This centers the base member relative to the container 77 and aligns the estis of the stem member 44 with the axis of the openmg In the embodiment of Fig. 10, the alignment means is formed as a part of the closure member 80 and includes a conical head 90 molded as a part of the closure member below the wall 83 thereof. This conical head is preferably radially rigidified by radial spokes or webs 92 also molded integrally with the closure member. The conical head 90 provides an opening 93 aligned with the opening 85 to support the stem member 44 in correct alignment. If desired, an annular space 95 may be molded in the closure member 80 between the openings 85 and 93 to provide a space temporarily storing any minute leakage.

In the alternative of Fig. 1l, the alignment means is provided by a separate washerlike member 96 having a flange 97 which frictionally telescopes with the flange 81, the member 96 providing the aforesaid opening 93 which aligns the stem member 44. The member 96 may be shaped to provide an annular space 98 corresponding to the space 95 previously described.

An unexpectedly superior sealing action may be obtained at the junction of the stem member 44 and the closure member 80 by proper selection of materials. In this connection, the members 44 and 80 should be formed ot' dissimilar materials, one of these members being formed of a waxy-surface plastic material of the type having a surface which is substantially non-wettable in the sense that water or other liquid will not form a continuous film along such a surface. Such a material may be polyethylene or a polymerized fluoroethylene material of which polytetrauoroethylene and tritiuorochloroethylene may be cited as examples, these last materials being respectively available under the trade names "Teiion and Kel-F. These materials are characterized by surfaces which have a distinct waxy feel and which are non-wettable to a remarkable extent. When used to provide a journalling surface either on the stern member 44 or the closure member 80 (the other member being of dissimilar material such as a harder plastic, metal or glass), it has been found that liquid will not leak through the junction when the pumping unit is upturned and even though the fit at the junction is quite loose. However, such a junction will permit a small passage of air to maintain the pressure in the container 77 equal to the surrounding pressure as one of these pressures changes relative to the other. The exact reason why this unexpectedly superior action takes place is not definitely known but is believed to be the result of the surface properties of the waxy-surface material which prevents the minute annular space around the stem member 44 and within the opening 85 from being filled with a continuous lm of liquid.

In practice, the closure member 80 is preferably a polyethylene molded element, the ange 81 being of su ch size as to snugly engage the inner wall of the container. While polyethylene Stoppers have been heretofore employed, the unexpected properties of this material in providing an effective seal for a reciprocating part extending through the polyethylene closure member have not previously been known.

The operation of the pumping structure in Fig. 1 will be evident from the description presented hereinbefore as to the operation of the pump unit 12. It should be noted, however, that this type of pumping unit in the container shown provides unique relationships. At the time the stem member 44 is manually moved downwardly, the pressure inside the container 77 lessens due to the decreased overall volume of that portion of the pumping unit 12 which is inside the container. This draws air through the aforesaid junction and also any liquid that may be in the dished top of the closure member 80 because of spillage from prior actuations. Upon release of the stem member 44, liquid flows to the interior of the pump chamber 14 with little or no change in the liquid level in the container 78.

The volume of the pump chamber 14 is preferably several times larger than the volume of the passage 60. In practice, and with any ow-restricting-type head member applied to the upper end of the stem member 44, the unit can be operated in inverted position to give scv eral incremental discharges even though the outer portion of the passage 35 is exposed to the air in the container. v

The passage 35 makes it possible to dispense practically the last drop of solution from the container 77. When the volume of liquid is low, the container can be inclined 8,709, 1&7

7 slightly so that the outer portion of the lateral passage 35 is at the lowest portion of the interior of the container, whereupon the liquid can be substantially completely drained.

If a stronger connection is desired between the seat member 49 and the diaphragm member 15, the arrangement of Fig. 9 can be employed. Here the seat member 49 is counterbored at 100 to receive as a press or screw fit a neck 101 of a securing member 102. This securing member provides a flange 103 which extends beneath the upper portion of the diaphragm member surrounding the seat member, thus tending to prevent withdrawal of the diaphragm member until the securing member 102 is withdrawn from the counterbore 100.

Various changes and modifications can be made without departing from the spirit of the invention as defined in the appended claims.

I claim as my invention:

l. ln a manually actuatable, structure for dispensing a metered increment of a liquid upon each actuation of said pumping structure, the combination of: a container providing bottom and side walls defining an open-topped liquid-holding space; a closure member for closing said open top of said liquid-holding space, said closure member having an opening aligned with an axis of said container', a reciprocating pump unit in said container. said pump unit having a pump chamber. an inlet valve structure communicating between said liquid-holding space and said pump chamber. and an outlet valve structure communicating with said pump chamber; and a stem member aligned with said axis and operatively connected to said outlet valve structure and through it to said pump unit to actuate same, said stem member extending relatively loosely through said opening of said closure member to reciprocate therein. there being a narrow annular space around said stem member within said opening, said members being formed of different materials, one of said materials being a waxy-surface plastic material having a non-wettable iournalling surface forthe other member to` prevent formation of a continuous film of liquid in said narrow annular space and provide a sealing junction resistant to liauid passage but pennitting passage of air into said container upon the existence of minor pressure differentials across said iunction.

2. A pumping structure as said one of said materials is a group consisting of polyethylene, and trifluorchloroethylene.

3. ln a manually actuatable pumping structure for dispensing a metered increment of a fluid upon each actuation of said pumping structure. the combination of: a container providing bottom and side walls defining an open-topped fluid-holding space: a closure member removablyclosing the open top of said fluid-holding space, said closure member being formed of polyethylene and providing an opening bounded by a polyethylene iournalling surface; a reciprocating pump unit; and means for operatively connecting said pump unit within said fluid-holding space of said container, said means including a hollow stem member extending through said opening and movable along the axis of said opening. said hollow stem member being formed of a material different from and harder than said polyethylene and providing an external surface loosely iournalled bv said polyethylene iournalling surface to slide in said opening, and means for operatively connecting said hollow stem member to said pump unit to actuate same and to conduct from said container the fluid pumped by said pump unit.

4. ln a manually actuatable pumping structure for dispensing metered increments of a liquid upon each actuation of said pumping structure, the combination of: a container means providing bottom. top and side walls defining a liouid-holding space.

pocket-size pumping defined in claim l in which material selected from the polytetrauoroethylene said top wall having an opening bounded bv a iournalling surface: a hollowstem structure extending slidably through said opening and providing outer and inner ends respectively outside and inside said container means: wall means within said container means defining a variable-volume pump chamber, said wall means including a flexible diaphragm member attached to said inner end of said hollow stem structure, there being an outlet passage means communicating between the interior of said hollow stern structure and said pump chamber: an outlet check valve in said outlet passage means and adjacent the zone of attachment of said stern structure and said flexible diaphragm member; an inlet check valve for admittin liquid from said container means into said pump chamber through said wall means, reciprocation of said hollow stem structure moving said flexible diaphragm member to draw liquid into said pump chamber past said inlet check valve and expel liquid from said pump chamber past said outlet check valve to said hollow stem structure; and interengaging aligning means on said wall means and said container means and spaced axially from said opening for aligning said stem structure relative t0 the longitudinal axis of said opening.

5. A manually actuatable pumping structure as defined in claim 4 in which the material of said ioumalling surface is a material selected from the group consisting of polyethylene, polytetrauoroethylene and triliuorchloroethylene, and in which said hollow stem structure provides a surface slidably iournalled by said journalling surface and formed of a material dissimilar to said material of said journalling surface. the junction of said stem structure and said top wall forming an air vent for said liquid-holding space.

6. A pumping structure as defined in claim 4 in which said aligning means includes a shoulder on said container means of a size to receive a portion of said wall means forming said variable-volume chamber.

7. A pumping structure as defined in claim 4 wherein said aligning means includes a peripheral wall of a cylindrical recess formed in the bottom wall of said container means and includes a peripheral wall of said wall means adapted to fit into said recess, one of said peripheral walls providing a passage between said peripheral walls for uid communication between the interior of said container means and the underside of said wall means.

8. In a manually actuatable, pocket-size pumping structure for dispensing metered increments of a liquid upon each actuation of said pumping structure, the combination of: a container providing bottom and side walls defining a liquid-holding space; a closure member for said container providing an opening bounded by a polyethylene iournalling surface; a hollow stem structure extending through said opening and loosely iournalled for reciprocating movement by said polyethylene surface, said hollow stem structure providing a iournalling surface formed of a material dissimilar to and harder than polyethylene; a diaphragm member formed of flexible material and removably secured to an inner portion of said hollow stem structure; a base member including means for detachably connecting same to said diaphragm member, said base member and said diaphragm member co-operating in forming a variable-volume pump chamber. said base member constantly engaging said bottom wall of said container; an inlet check valve means controlling the flow of liquid from the interior of said container into said pump chamber; and an outlet check valve means adiacent the iunction of said inner portion of said hollow stem structure and said diaphragm member to control the ow of liauid from said pump chamber into said hollow stem structure, said hollow stem structure being normally filled with a column of the pumped liquid. said outlet check valve means being at the lower end of said column to be normallv retained in closed position by the hydrostatic head of said column, said hollow stem structure providing an outer portion above said closure member and adapted to receive a manual actuating force in an inward direction to deform said diaphragm member, said diaphragm member having sufficient resiliency to return to an undeformed posi and move said hollow stem structure outwardly when the manual actuating force is removed.

9. ln a pump unit, the combination of: a diaphragm member formed of flexible material: a base member connected to and co-operating with said diaphragm member to define a pump chamber variable in volume as said diaphragm member is flexed, said base member providing an inlet passage means for conducting the fluid to be pumped to said pump chamber; an inlet check valve for said inlet passage means and carried by said base member to admit tiuid to said pump chamber but prevent a reverse flow thereof; a tubular valve body having outlet passage means therein extending from one end thereof to the other and providing a valve chamber, one end of said valve body being connected to said diaphragm member with the corresponding end of said outlet passage means in uid communication with said pump chamber; an outlet check valve in said valve chamber of said outlet passage means, said outlet check valve passing fluid from said pump chamber but preventing reversed flow thereof into said pump chamber; and means for limiting the movement of said valve in said valve chamber and for conducting fluid from said valve chamber, said last-named means including a tubular stem member aligned with said valve body and connected to the other end thereof, said tubular stem member providing an open-ended outlet passage therethrough communicating with said outlet passage means through said valve body as the sole outlet for fluid from said pump chamber, said tubular stem member providing shoulder means engageable by said outlet check valve to limit the movement of the latter in said valve chamber.

10. In a pump unit, the combination of: a diaphragm member formed of flexible material; a base member connected to and co-operating with said diaphragm member to define a pump chamber variable in volume as said diaphragm member is flexed, said base member providing an inlet passage means for conducting the fluid to be pumped to said pump chamber, said diaphragm member providing an outlet passage means for conducting said fluid from said pump chamber; an inlet check valve for said inlet passage means and carried by said base member to admit uid to said pump chamber but prevent a reverse ow thereof; an outlet check valve for said outlet passage means, said outlet check valve passing fluid from said pump chamber but preventing a reverse flow thereof into said pump chamber; a first stop member carried by said diaphragm member and having a first stop surface which faces said base member, said first stop member having said outlet passage means therethrough and containing said outlet check valve; and a second stop member carried by said base member in alignment with said first stop member and projecting inwardly from said base member into said pump chamber, said second stop member providing a second stop surface which is engageable by said first stop surface to maximize the inward flexure of said diaphragm member and `thereby to determine the minimum volume of said pump chamber, said second stop member having said inlet passage means therethrough and containing said inlet -check valve.

11. In a pump unit, the combination of: a diaphragm member formed of flexible material; and a base member connected to and co-operating with said diaphragm member to define'a pump chamber variable in volume as said diaphragm member is flexed, said base member providing an inlet passage means for conducting the fluid to-be pumped to said chamber, said diaphragm member providing an outlet passage means for conducting said fluid from said pump chamber, said base member having an annular peripheral flange which extends upwardly therefrom and the height of which is approximately one third of the unflexed height of said diaphragm member, the latter being substantially hemispherical in its unflexed state and having an annular peripheral skirt which is telescoped into said annular peripheral flange, said annular peripheral skirt and said annular peripheral flange respectively having upwardly facing and downwardly facing annular shoulders which are in engagement to retain said peripheral annular skirt within said peripheral annular flange, whereby said peripheral annular skirt is pressed against said peripheral annular flange upon an increase in the pressure in said pump chamber due to inward flexure of said diaphragm member.

l2. In a manually actuatable pumping structure for dispensing metered increments of a liquid upon each actuation of said pumping structure, the combination of a container means providing bottom, top and side walls defining a liquid-holding space, said top wall having an opening bounded by a journalling surface; a hollow stem structure extending slidably through said opening and providing outer and inner ends respectively outside and inside said container means; wall means within said container means defining a variable-volume pump chamber, said wall means including a flexible diaphragm member attached to said inner end of said hollow stem structure, there being an outlet passage means communicating between the interior of said hollow stem structure and said pump chamber; an outlet check valve in said outlet passage means and adjacent the zone of attachment of said stem structure and said exible diaphragm member; and an inlet check valve for admitting liquid from said container means into said pump chamber through said wall means, inward movement of said hollow stem structure collapsing said flexible diaphragm member to expel liquid from said pump chamber past said outlet check valve to said hollow stem structure while simultaneously reducing the pressure in said liquid-holding space, subsequent outward movement of said hollow stem structure taking place when said diaphragm member again expands to draw liquid into said pump chamber past said inlet check valve, said wall means including a lower surface contacting said bottom wall of said container means, said hollow stem structure including a shoulder within said container means and engaging said top wall thereof to limit outward movement of said hollow stem structure in said opening.

13. A small pocket-size dispensing unit for ejectingv small metered increments of a liquid upon relative movement of parts of such unit, said dispensing unit including: a container means comprising one of said parts and providing bottom, top and side walls defining a liquid-holding space, said top wall having an opening bounded by a journalling surface; a hollow stem structure comprising another of said parts, said hollow stem structure extending through said opening and being slidable relative to said journalling surface, said hollow stem structure providing outer and inner ends respectively outside and inside said container means, said stem structure providing a shoulder engaging a portion of said top wall upon outward movement of said stem structure to limit such outward movement of said stem structure relative to said container means; wall means within said container means defining a variable-volume pump chamber, said wall means comprising a lower surface engaging said bottom wall of said container means at all times even when said shoulder engages said portion of said top wall, said wall means including a flexible diaphragm member attached to said inner end of said hollow stem structure, there being an outlet passage means communicating between the interior of said hollow stem structure and said pump chamber, there being an inlet passage means communicating between said liquid-holding space and said pump chamber; an inlet check valve in said inlet passage means admitting liquid from said liquid-holding space into said pump chamber upon expansion of the latter but substantially preventing reverse flow; and an outlet check valve in said outlet passage means admitting liquid fro'm said pump chamber into said hollow stern structure upon contraction of said pump chamber but substantially preventing reverse flow.

14. A dispensing unit as defined in claim 13 in which said bottom wall of said container means provides an upper surface in surface engagement with said lower surface of said wall means, one of such surfaces providing a channel extending from said inlet passage means to the periphery of said lower surface and opening on said liquid-holding space to conduct liquid therefrom to said inlet passage means.

15. In a manually actuatable pumping structure for dispensing metered increments of a liquid upon each actuation of said pumping structure, the combination of: a container means providing bottom, top and side walls defining a liquid-holding space, said top wall having an opening bounded by a journalling surface; a hollow stem structure extending slidably through said opening and providing outer and inner ends respectively outside and inside said container means; wall means within said container means defining a variable-volume pump chamber, said wall means including a base member having an upstanding annular peripheral flange, a diaphragm member formed of flexible material and having a depending lip telescoping within said upstanding annular peripheral flange, said base and diaphragm members including interengaging shoulders preventing separation of such members upon increase in pressure within said pump chamber, there being an outlet passage means communicating between the lower interior of said hollow stem structure and said pump chamber; an outlet check valve in said outlet passage means and adjacent the zone of attachment of said stem structure and said flexible diaphragm member whereby liquid from said pump chamber is admitted into said hollow stem structure through said outlet check valve upon contraction of said pump chamber to form a column of liquid in said hollow stem,

11 the hydrostatic head of said column tending to maintain said outlet check valve closed, said hollow stem structure providing an exit opening communicating with the upper interior thereof from which liquid from said column discharges; an inlet passage means formed in said base member, said base member providing a lower surface shaped to conform to an upper surface of said bottom wall of said container means to lie in surface contact therewith, said inlet passage means providing a valve chamber communicating between said pump chamber and said lower surface of said base member, one of said upper and lower surfaces providing a channel extending from said valve chamber to the periphery of said base member and communicating with said liquid-holding space;

and an inlet check valve in said valve chamber admitting liquid from said channel into said pump chamber upon xpansion of the latter but substantially preventing reverse 16. In a pump unit, the combination of: a molded onepiece base member formed of a somewhat resilient plastic material, said base member having a lower wall, a boss comprising a seat member extending upwardly from said lower wall, and an annular peripheral ange extending upwardly from said lower wall, said ange having an inwardly-extending projection providing a downwardlyfacing shoulder, said boss providing an inlet passage means including an enlarged valve chamber having an upwardlyfacing conical valve seat, the lowermost end of said intake passage means opening below said lower wall; an intake valve positioned movably in said valve chamber and resting against said conical seat to permit ow of a uid upwardly through said valve chamber but substantially prevent reverse ow; a molded arched one-piece diaphragm member made of resilient plastic material providing an upper portion, said diaphragm member including a depending lip telescoping within said annular peripheral ange and providing an enlargement having an upwardly-facing shoulder resting beneath and engageable with said downwardly-'facing shoulder of said annular peripheral ange, said base and diaphragm members cooperating in defining a pump chamber, at least one of said plastic materials being suiciently resilient to permit forcing of the enlargement of the depending lip past said inwardly-extending projection of said peripheral ange, said base member and said diaphragm member being locked together against separation upon increase in pressure within said pump chamber by interengagement of said shoulders; a hollow stem structure providing a lower end connected to said upper portion of said exible diaphragm to contract same upon downward pressure applied thereto through said hollow stem structure, said stem structure providing an exit opening a substantial distance above the zone of connection of said hollow stem structure and said diaphragm member, said hollow stem structure providing an outlet passage means communicating between said pump chamber and the lower interior of said stem structure, said outlet passage means providing a valve seat near said zone of connection of said hollow stem structure and said diaphragm member: and an outlet valve in said outlet passage means permitting upward displacement of uid therethrough upon contraction of said diaphragm member but substantially preventing reverse iiow, said outlet check valve supporting and operating against a column of uid within said hollow stem structure between said outlet valve seat and said exit opening of said hollow stem structure.

17. A small pocket-size dispensing unit for ejecting small metered increments of a liquid upon relative movement of parts of such unit, said dispensing unit including: a'container means comprising one of said parts and providmg bottom, top and side walls defining a li uid-holding space, said top wall having an opening; a ho ow stem structure comprising another of said parts, said hollow stem structure being longitudinally movable in said opening and p roviding outer and inner ends respectively outside and inside said container means', wall means within said container means defining a variable-volume pump chamber, sai d wall means including a base member and an arched diaphragm member, at least the latter being formed of resilient material, said members cooperating in defining a variable-volume pump chamber, said diaphragm member being connected to the inner end of said hollow stem structure; a stop member carried by one of said members and projecting into said pump chamber, said stop member providing a stop surface coaxial with the axis of said hollow stein structure, the other of said members providing another stop surface concentric with said axis and engaging said first-named stop surface upon movement of said diaphragm in a direction to reduce the volume of said pump chamber, thereby positively limiting the contraction of said pump chamber upon each actuation of the dispensing unit; walls defining inlet and outlet passage means respectively communicating between said liquid-holding space and said pump chamber and between said pump chamber and the interior of said hollow stem structure, said outer end of said hollow stem structure providing an exit opening for the expulsion of pumped liquid; an inlet valve in said inlet pasage means admitting liquid from said liquid-holding space into said pump chamber upon expansion of the latter but substantially preventing reverse ow; and an outlet check valve in said outlet passage means admitting liquid from said pump chamber into said hollow stem structure upon contraction of said pump chamber but substantially preventmg reverse ow, said outlet check valve being adjacent the Junction of said hollow stem member and said llexible diaphragm member to support and operate against a column of the liquid within said hollow stem structure.

Relenneel Cited in the le of this patent UNITED STATES PATENTS Germany Apr. 8. 1936

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