US20080017663A1

US20080017663A1 - Bag Lifting and Emptying System

Info

Publication number: US20080017663A1
Application number: US11/780,978
Authority: US
Inventors: Behrokh Khoshnevis
Original assignee: University of Southern California USC
Current assignee: University of Southern California USC
Priority date: 2006-07-20
Filing date: 2007-07-20
Publication date: 2008-01-24
Also published as: WO2008011159A2; WO2008011159A3

Abstract

A bag lifting and emptying system may include a rupture mechanism for the bag, an attachment mechanism for the bag, and a hoist connectable to the attachment mechanism. The rupture mechanism may be configured to rupture a bottom portion of the bag, when the bag is lowered onto the rupture mechanism, so as to cause the contents of the bag to be transferred from the bag into a receptacle. The attachment mechanism may be configured to releasably attach to the bag. The hoist may be configured to lift the bag and subsequently lower the bag onto the rupture mechanism.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon, and claims the benefit of priority under 35 U.S.C. § 119(e) from, U.S. Provisional Patent Application Ser. No. 60/807,867, filed on Jul. 20, 2006, entitled “Lifting And Emptying System For Bagged Materials,” attorney docket no. 28080-212. The content of this provisional application is incorporated herein by reference in its entirety as though fully set forth.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

This work was funded in part by ONR Grant No. N00014-05-1-0850.

BACKGROUND

A number of applications require that bags of heavy material, such as concrete by way of example, be lifted, and their contents emptied into a container such as the hopper of a mixer. Commercially available mixers, produced by different manufacturers, generally require manual lifting and emptying of bags of material.
Systems and methods that can eliminate the laborious task of manually lifting the heavy bags (which usually may be over 50 pounds) would be desirable.

SUMMARY

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B, 1C, 1D, 1E, and 1F illustrate a bag lifting and emptying system, in accordance with one embodiment of the present disclosure.
FIGS. 2A and 2B illustrate in more detail an attachment mechanism for a bag, in a bag lifting and emptying system in accordance with the present disclosure.
FIGS. 3A, 3B, 3C, and 3D illustrate in more detail a bag rupture mechanism, in a bag lifting and emptying system in accordance with the present disclosure.
FIG. 4A illustrates a pendent control for a hoist, in a bag lifting and emptying system in accordance with one embodiment of the present disclosure.
FIG. 4B illustrates an operator using a pendent to control the operation of a hoist.
FIG. 5 illustrates an embodiment of a bag lifting and emptying system that includes a dust enclosure.
FIGS. 6A and 6B illustrate an alternate embodiment of a bag lifting and emptying system, in which the bag is made to enter the hopper from the top.
FIGS. 7A, 7B, 7C, and 7D provide actual three-dimensional views of a bag lifting and emptying system in operation.

DETAILED DESCRIPTION

Systems and methods are described for lifting bags of materials, such as concrete, and emptying them into a container. The systems and methods described below are applicable to a large number of scenarios, including but not limited to building construction.
FIGS. 1A-1F illustrate a bag lifting and emptying system 100, during various stages of lifting and lowering a bag 105, and emptying the bag of its contents. The bag lifting and emptying system 100 may include an attachment mechanism 110 that can releasably attach to the bag 105; a rupture mechanism 120; and a hoist 130. The rupture mechanism 120, shown in FIG. 1E, may be configured to rupture the bottom portion of the bag 105 when the bag 105 is lowered thereon, causing the contents of the bag to spill out of the bag. In the illustrated embodiment, the hoist 130 may be connectable to the attachment mechanism 110, for example by a cable 135, and may be configured to lift the bag 105, then lower the bag 105 into a hopper 137 and onto the rupture mechanism 120 which tears open the bag 105 so that the material inside the bag 105 is transferred from the bag into the hopper.
FIGS. 1A and 1B illustrate the lifting action of the hoist 130. After elevating the bag 105, and once the bag 105 passes a certain elevation point, an inlet 136 to the hopper 136 may be opened, for example manually. The bag 105 may then be lowered into the hopper 137 through the inlet 136. FIG. 5C illustrates the bag 105 approaching the open inlet 136 of the hopper 137, while FIG. 1D illustrates the bag 105 entering the inlet 136. As the bag 105 is further lowered into the hopper 137, its lower part may be ruptured by the rupture mechanism 120 (described further below), so that the material inside the bag 105 is transferred into the hopper 137.
FIG. 1E illustrates the rupture mechanism 120 onto which the bag 105 is lowered, after entering through the inlet 136 of the hopper 136. As seen in FIG. 1E, the rupture mechanism 120 may include a triangular blade 121 that ruptures the bag 105, as further described in conjunction with FIGS. 2A, 2B, and 2C. Once the bag 105 is emptied of its contents, the empty bag 105 may be elevated once more by the hoist 130 and removed, after which the hoist 130 may be lowered so that it immediately attaches to, and lifts, the next bag.
FIG. 1F illustrates the hoist 130 as being comprised of two separate modules, 130-a and 130-b. These modules are easily transportable and may be place on top of mixer equipment. The hoist 130 may be an electrically (i.e. automatically) controlled hoist, with an electric cable 135, as in the above embodiments illustrated in FIGS. 1A-1F. The electrically controlled, motorized hoist 130 may be powered by a regular power network (e.g., 110V), or may be powered by a rechargeable battery.
Alternatively, the hoist 130 may be a manually controlled hoist. Such a manually controlled hoist may include a rope and pulley combination. An operator using such a manually controlled hoist may pull downward, by hand, the rope that is positioned over a pulley on top, the pulley substituting for motorization for the hoist. In a different embodiment, the manually controlled hoist may include a rope, wheel and drum combination. In this combination, the operator may turn the wheel that winds the rope around the drum. In a manually controlled hoist, a ratchet mechanism may be used to prevent reverse motion. The latch of the ratchet mechanism may be released after emptying the lifted bag.
FIGS. 2A and 2B illustrate in more detail an exemplary attachment mechanism 200 that attaches to or grasps a bag 205 and permits the bag 205 to be lifted and lowered by a hoist in a bag lifting and emptying system described above, in accordance with one embodiment of the present disclosure. As shown in FIGS. 2A and 2B, the attachment mechanism 200 may include a spear 210, i.e. a straight rod with sharp conical tips 212 and 214 at its ends. The spear 210 may be configured to pierce through a top portion of a bag 205 and be inserted therethrough, so as to cause the bag 205 to be lifted when an upward force is applied to the spear 210, and lowered when the upward force is removed. The sharp conical tips 212 and 214 can easily pierce holes on the bag 205 and be inserted into the top section of the bag 205. The two open ends of the spear 210 may provide reliable lifting points to be connected to an electric cable hoist such as the hoist 130 shown in FIGS. 1A-1E. A cable 220 may connect the spear 210 to the hoist 130, and transmits the upward force to the bag 205.
To prevent tearing the bag 205 by a sudden lift action of the hoist, one or more springs may be used, as shown in FIGS. 2A and 2B. In the illustrated embodiments, two springs 240-a and 240-b are shown as being used, together with another horizontal rod 245, separate from the spear 210. While one spring may be used at the end of the cable 220, the use of two springs may shorten the overall height of the attachment mechanism 200 or bag grasping module. The springs 240-a and 240-b may extend vertically between the spear 210 and the rod 245. One end of each spring may be attached to the spear, and the remaining end of each spring may be attached to the rod 245. The springs 240-a and 240-b may provide tensioning, i.e. may be configured to absorb at least some of the upward force transmitted from the hoist 130 to the bag 205 through the cable 220, so as to substantially prevent tearing of the bag 205 by a sudden lift action of the hoist.
FIGS. 3A, 3B, 3C, and 3D illustrate in more detail an exemplary rupture mechanism 300 for a bag 305, in accordance with one embodiment of the present disclosure. As shown in FIGS. 3A and 3B, the rupture mechanism 300 may include one or more blades 310 that terminate in a pointed vertex. While only one blade is shown in FIGS. 3A-3D, there may be a plurality of blades in other embodiments of the present disclosure. The blade 310 may have a substantially triangular shape. The blades may be positioned substantially vertically, i.e. with their vertices directed substantially upward, so as to rupture the bag 305 when the bag 305 is lowered onto them.
FIG. 3C illustrates an embodiment in which the blade 310 is attached to a lateral actuator 320. The lateral actuator 320 may move the blade 310 laterally after the blade 310 has pierced the bag 305, thus increasing the tear that they make on the bottom of the bag 305. In turn, this may increase the speed at which the bag's contents are emptied and may ensure that the bag's contents are completely removed. The lateral actuator 320 may be manually operated or automatically operated. The lateral actuator 320 may include a handle 322, which may be moved reciprocally, manually by hand or automatically by a motor, to facilitate the opening of hard-to-cut bags. FIG. 3D is an actual three-dimensional view of a bag rupture mechanism described above.
FIG. 4A illustrates a pendent control 400 for an electrically controlled hoist, in a bag lifting and emptying system in accordance with one embodiment of the present disclosure. The control of the lifting and lowering operation for the bag may be performed by a pendent, which may be any one of many types of pendents typically offered with commercial electric hoists. The pendents may have up-down and possibly speed control buttons and knobs. FIG. 4B illustrates an operator using the pendent 400 to control the lifting and lowering of bags of material.
In one embodiment, the bag lifting and emptying system described in the present disclosure may include a dust enclosure for substantially preventing or minimizing the escape of dust while the material contained within the bag is being transferred onto the hopper. FIG. 5 illustrates an embodiment of a bag lifting an emptying system 500 that includes a dust enclosure 510 that is configured to prevent dust from escaping while the bag's contents are spilling out of the bag. The dust enclosure 510 may seal the area onto which the contents of the bag are transferred, and may include a sealable opening through which the bag may be inserted into the enclosure. In the embodiment illustrated in FIG. 5, the sealable opening may be a half-conical rubber, which is shown to be mounted around the outlet of the loader to allow for snug fit with the barrel to contain the dust upon emptying the bag's contents. In general, the loader in a bag lifting and emptying system may have a different design to fit barrel mixers in which the barrel is tilted to about 45 degrees, the degree of tilt in all barrel mixers being adjustable. As shown in FIG. 5, the loader may be mounted on adjustable legs 560, to make it possible to align its outlet with the inlet of the barrel of the mixer. Other forms of sealable opening may be used for the dust enclosure 510, including but not limited to a closable shoot and collapsible flaps.
FIGS. 6A and 6B illustrate an alternate embodiment of a bag lifting and emptying system 600. As illustrated in FIGS. 6A-6B, the bag lifting and emptying system 600 may be designed so that the bag is made to enter the hopper from an inlet 636 on the top of the hopper, rather than from an inlet located on the side of the hopper that is manually opened and shut, as shown in FIGS. 1A-1D. FIG. 6A illustrates the lifting action of the hoist, while FIG. 6B illustrates the bag entering the inlet 636 on the top of the hopper. The inlet 636 of the hopper may be opened, for example, when the bag pushes on two spring-loaded flaps. The design illustrated in FIGS. 6A-6B may have the advantage of not requiring manual interference to open the hopper inlet. Another advantage of the design illustrated in FIGS. 6A-6B may be that it is easier to raise the fully or partially emptied bag is easier in this configuration, because the cable direction is perfectly vertical and no force is exerted in a slant direction to possibly jam the bag.
FIGS. 7A, 7B, 7C, and 7D provide actual three-dimensional views of a bag lifting and emptying system in operation. The bag lifting and emptying system may be operated by piercing the top of a bag 705 with a spear 710 so as to attach the bag 705 to a hoist 730, as shown in FIG. 7A. The hoist 730 may be operated (either electrically, as shown in FIGS. 7A-7D, or manually) to cause the bag 705 to be lifted, as shown in FIG. 7B. The inlet 736 of a hopper may be opened, and the bag 705 lowered into the hopper, as shown in FIGS. 7C-7D. Once the bag 705 has been substantially emptied of its contents, the bag 705 may be removed from the spear 710. The process described above may be repeated to empty other bags. The material that is removed from the bag(s) may be mixed with fluid and/or other material. Any one of numerous commercially available mixers may be used.
While a dust enclosure is not explicitly shown in FIGS. 7A-7D, in an embodiment that includes a dust enclosure, a sealable opening in the dust enclosure may be opened, when the bag is ready to be lowered into the hopper. The hoist may then be operated to lower the bag within the dust enclosure. The sealable opening may be closed, after which the hoist may continue to lower the bag onto the bag rupture mechanism. After the bag has been substantially emptied of its contents, the sealable opening in the dust enclosure may be opened again, and the bag may continue to be hoisted out of the dust enclosure.
In sum, systems and methods have been described that allow the process of lifting and emptying heavy bags of material to be automated. In this way, the laborious task of lifting and lowering the heavy bags may be eliminated, while containing dust generated during the process.
While certain embodiments have been described of systems and methods for lifting, lowering, and emptying a bag, it is to be understood that the concepts implicit in these embodiments may be used in other embodiments as well. The protection of this application is limited solely to the claims that now follow.
In these claims, reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference, and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”

Claims

1. A bag lifting and emptying system, comprising:

a rupture mechanism configured to rupture a bottom portion of a bag when the bag is lowered onto the rupture mechanism, so as to cause the bag's contents to be transferred from the bag;

an attachment mechanism configured to releasably attach to the bag; and

a hoist connectable to the attachment mechanism, the hoist configured to lift the bag and subsequently lower the bag onto the rupture mechanism.

2. The bag lifting and emptying system of claim 1, wherein the rupture mechanism comprises one or more blades, each blade terminating in a pointed vertex; and

wherein the blades are positioned substantially vertically, so that the pointed vertices of the blades are directed substantially upward so as to rupture the bag when the bag is lowered onto them.

3. The bag lifting and emptying system of claim 2, further comprising a lateral actuator attached to the blades, the lateral actuator configured to move the blades laterally after the blades have pierced the bag so as to increase tear made by the blades in the bag.

4. The bag lifting and emptying system of claim 1,

wherein the attachment mechanism includes a spear configured to pierce through a top portion of the bag and be inserted therethrough, so as to cause the bag to be lifted when an upward force is applied to the spear and lowered when the upward force is removed; and

wherein the hoist includes a cable connectable to the spear and configured to transmit to the bag the upward force.

5. The bag lifting and emptying system of claim 4, wherein the attachment mechanism further includes:

a horizontal rod attachable to the cable of the hoist;

at least one tension spring extending vertically between the spear and the rod, a first end of the spring attachable to the spear and a second end of the spring attachable to the rod; and

wherein the spring is configured to absorb at least some of the upward force so as to substantially prevent tearing of the bag by a sudden lift action of the hoist.

6. The bag lifting and emptying system of claim 4,

wherein the cable comprises an electric cable; and

wherein the hoist comprises at least one of: a manually operated hoist; and an electrically controlled hoist.

7. The bag lifting and emptying system of claim 1, further comprising a pendent operable to implement a lifting and a lowering operation of the hoist; and

wherein the pendent includes at least one of:

an up-down control knob operable to control the lifting and lowering operation of the hoist; and

a speed control know operable to control a speed of the lifting and lowering operation of the hoist.

8. The bag lifting and emptying system of claim 1, further comprising a dust enclosure configured to seal an area onto which the bag's contents are transferred, thereby substantially preventing dust from escaping while the contents of the bag are being transferred from the bag.

9. The bag lifting and emptying system of claim 8, wherein the dust enclosure includes a sealable opening through which the bag can be inserted into the dust enclosure.

10. The bag lifting and emptying system of claim 2, wherein at least some of the blades are substantially triangular in shape.

11. A bag lifting and lowering system, comprising:

an attachment mechanism for a bag, the attachment mechanism including a spear configured to pierce through a top portion of the bag and be inserted therethrough, so as to cause the bag to be lifted when an upward force is applied to the spear and lowered when the upward force is removed; and

a hoist connectable to the spear, the hoist configured to lift and lower the bag as a result of lifting and lowering the spear.

12. The bag lifting and lowering system of claim 11,

wherein the hoist includes a cable connectable to the attachment mechanism and configured to transmit to the bag the upward force.

13. The bag lifting and lowering system of claim 11, wherein the hoist comprises a manually operated hoist; and

wherein the manually operated hoist includes at least one of:

a rope and pulley combination;

a rope, wheel, and drum combination; and

a ratchet mechanism.

14. The bag lifting and lowering system of claim 11, wherein the hoist comprises an electrically controlled hoist; and

wherein the cable comprises an electric cable.

15. The bag lifting and lowering system of claim 11, wherein the attachment mechanism further includes:

a horizontal rod attachable to the cable of the hoist;

at least one spring extending between the spear and the rod, a first end of the spring attachable to the spear and a second end of the spring attachable to the rod; and

16. The bag lifting and lowering system of claim 11,

wherein the spear has a first end and a second end, each end having a pointed conical tip that facilitates piercing of the spear through the top portion of the bag; and

wherein the at least one spring comprises a first spring and a second spring, the first spring connected to the spear near the first end of the spear and a second spring connected near the second end of the spear.

17. A bag emptying system, comprising:

a bag rupturing mechanism for rupturing a bag so as to cause its contents to spill out of the bag; and

a dust enclosure configured to substantially prevent dust from escaping while the bag's contents are spilling out of the bag, the dust enclosure including a sealable opening through which the bag can be inserted into the dust enclosure.

18. The bag emptying system of claim 17, wherein the sealable opening of the dust enclosure comprises at least one of:

a closable shoot; and

one or more collapsible flaps.

19. A method of lifting and emptying a bag containing a material, the method comprising:

piercing a portion of the bag with a spear so as to attach the bag to a hoist;

operating the hoist so as to lift the bag, then to lower the bag onto a rupture mechanism within a container; and

rupturing the bag so as to allow its contents to be transferred into the container.