US3774370A

US3774370A - Merchandise bagging device and method

Info

Publication number: US3774370A
Application number: US00150989A
Authority: US
Inventors: S Fried
Original assignee: SPEEDCHECK SYSTEMS Inc
Current assignee: SPEEDCHECK SYSTEMS Inc
Priority date: 1971-06-08
Filing date: 1971-06-08
Publication date: 1973-11-27
Anticipated expiration: 1990-11-27
Also published as: LU65481A1; ZA723577B; CH550685A; AR192648A1; DE2227752A1; BR7203652D0; FR2141237A5; BE784599A; NL7207524A; IT956107B

Abstract

The bagging apparatus can be used in supermarkets, department stores, etc. to increase the speed at which merchandise can be checked out of the store without having to hire a separate employee to bag the merchandise. The check-out employee places the merchandise in a horizontal receptacle. When the receptacle is full, a bag is slipped over the receptacle. Then, a button is pushed and the bagging device automatically withdraws the receptacle from the bag horizontally, and the bag with its merchandise then supported by a transfer platform just below. The transfer platform has a relatively short upwardly-extending flange. The transfer platform is rotated so as to turn the bag upright. The flange has dimensions such that it supports the bag and prevents it from falling off of the platform until the bag is transferred onto a moving conveyor belt. The conveyor belt pulls the bag and maintains the bag upright. The platform then returns upwardly to its initial horizontal position. The receptacle then is returned to its initial position and is ready for use in filling another bag. The full bags are accumulated on the conveyor until removed by the customer. The retraction and return of the receptacle, and the movement of the transfer platform from horizontal to vertical and back again are controlled by a single cam having two followers on opposite sides, one follower operating the transfer platform and the other operating the receptacle. The cam is shaped so that each cam portion serves a dual purpose and synchronizes correctly the operation of the various components with respect to one another.

Description

[ 4] MERCHANDISE BAGGING DEVICE AND METHOD [75] Inventor: Sidney Fried, Ridgefield, Conn.

[73] Assignee: Speedcheck Systems, Inc., Ridgefield Park, NJ.

[22] Filed: June 8, 1971 [21] Appl. No.: 150,989

[52] US. Cl. 53/255, 53/391 [51] Int. Cl B65b 67/04, B65b 5/06 [58] Field of Search 53/35, 255, 258,

[56] References Cited UNITED STATES PATENTS 2,463,576 3/ 1949 Strickler 53/255 2,850,855 9/1958 Ofiutt 53/258 X 2,958,990 11/1960 Kerker 53/258 X 3,237,365 3/1966 Koulakoff et al. 53/55 3,388,527 6/1968 Vadas 53/258 X 3,417,546 12/1968 Irwin 53/190 3,480,114 11/1969 Shoffner 53/384 X 3,530,644 9/1970 Kapare 53/ 187 3,546,829 12/1970 bonergan 53/258 X 3,579,957 5/1971 Mills, Jr. et al 53/190 Primary ExaminerTravis S. McGehee Assistant Examinerl'lorace M. Culver Attorney-Curtis, Morris & Safford [57] ABSTRACT The bagging apparatus can be used in supermarkets,

[ Nov. 27, 1973 department stores, etc. to increase the speed at which merchandise can be checked out of the store without having to hire a separate employee to bag the merchandise. The check-out employee places the merchandise in a horizontal receptacle. When the receptacle is full, a bag is slipped over the receptacle. Then, a button is pushed and the bagging device automatically withdraws the receptacle from the bag horizontally, and the bag with its merchandise then supported by a transfer platform just below. The transfer platform has a relatively short upwardly-extending flange. The transfer platform is rotated so as to turn the bag upright. The flange has dimensions such that it supports the bag and prevents it from falling 011' of the platform until the bag is transferred onto a moving conveyor belt. The conveyor belt pulls the bag and maintains the bag upright. The platform then returns upwardly to its initial horizontal position. The receptacle then is returned to its initial position and is ready for use in filling another bag. The full bags are accumulated on the conveyor until removed by the customer. The retraction and return of the receptacle, and the movement of the transfer platform from horizontal to vertical and back again are controlled by a single cam having two followers on opposite sides, one follower operating the transfer platform and the other operating the receptacle. The cam is shaped so that each cam portion serves a dual purpose and synchronizes correctly the operation of the various components with respect to one another.

11 Claims, 8 Drawing Figures Patented Nov. 27, 1973 3,774,370

3 Sheets-Sheet .L

INVENTOR.

Patented Nov. 27, 1973 3 Sheets-Sheet 2 INVENTOR. jaclnad HIE/C Amm f W Patented Nov. 27, 1973 :5 Sheets-Sheet y.

1 MERCHANDISE BAGGING DEVICE ANDMETI-IOI) This invention relates to machines and methods for packaging articles, and specifically to machines and methods for bagging merchandise such as groceriesor goods purchased in other retail stores.

Various different suggestions have been made in the past for equipment to either automatically or semiautomatically bag groceries. Examples of such prior suggestions are shown in U. S. Pat. Nos. 2,958,990 to Kerker; 3,270,485 to Knepper; 3,161,003 to Grin'tz; and 2,924,053 to Bisen. Each of these priordevices-has significant disadvantages which are believed to have been instrumental in preventing any of them from becoming successful in the marketplace. Some of the mechanisms are very complicated, expensive and, it is believed, unreliable. Others are believed .to be clumsy and slow to use. It is believed that others would operate in a manner which would tend to frighten customers.

Accordingly, it is an object of the present invention to provide a relatively simple, reliable and inexpensive device and method for the bagging of merchandise; a device and method which are capable of significantly reducing the cost of high-speed merchandise checkout, thus increasing the productivity of the check-out employees and decreasing the cost of doing business for the stores.

It is a further object to provide such a device which is not unduly noisy, is attractive in appearance, and is compact enough in size to avoid the necessity of increasing the size of the usual check-out counter.

It is another object to provide such a device and method which are safe to operate and do not frighten the customer or cause him to be overly worried about his goods being damaged.

The co-pending U. S. Patent application entitled Automatic Bag Checkout Counter, filed Mar. 3, 1971, in the names of Sidney Fried and Siegfried S. Green, shows a machine and method which intended to solve a portion of the foregoing problems. It is another object of the present invention to provide a bagging device and method which constitute distinct improvements over those shown in the co-pending patent application, and substantially fully meet the foregoing objectives.

In accordance with the present invention, the foregoing objectives are met by the provision of a merchandise bagging device and method in which the merchandise is placed in a receptacle, a bag is fitted over the stationary receptacle by hand, the receptacle is withdrawn from the bag horizontally, and the bag is supported by a transfer platform which then moves to deposit the filled bag upright on a moving conveyor. A short flange on the platform holds the bag and prevents it from slipping off the platform during its movement, but permits it to tip off of the platform and onto the belt at the proper time. The retraction and return of the receptacle and the transfer movement of the transfer platform are controlled by a single cam with oppositely positioned rollers which drives the transfer platform and the receptacle.

Further objects and advantages of the invention will be set forth in or apparent from the following description and drawings. In the drawings;

FIG. 1 is a perspective, partially broken-away view of a supermarket check-out counter incorporating the bagging device of the present invention;

FIG. 2 is a partially perspective, ,partially brokenaway and partially schematic view of the operating components of the bagging device shown :in FIG. 1;

Each of FIGS. 3, 4, 5, and -6 is a schematic view of some of the operational components shown in FIG. 2 in various different operational positions;

FIG. 7 is an elevation view of aportion of the equipment shown in FIGS. 1 and 2 and;

FIG. 8 is an electrical schematic circuit diagram of the electrical elements of the equipment shown in FIGS. 1 through 7.

GENERAL DESCRIPTION The check-out station 10 shown in FIG. 1 includes a cash register 12, andia check-out unit including a lower base housing-1&5 and :an upper housing 14. In the upper away to show a portion of the bagging mechanism 18. Grocery bags 24 filled with merchandise 36 are moved away from the mechanism 18 and towards an end wall 37 by a conveyor belt 22. The filled bags are stored on the belt 22 until the customer removes them.

Referring now to FIGS. 2 through 7 as well as FIG. 1, the bagging mechanism includes an elongated metal receptacle 30 with an open end, and a transfer platform 32 positioned immediately below the receptacle. As shown in FIG. 1, the upper housing 14 has an inner wall facing the operator with an edge 26 which is slightly behind the front edge of the receptacle 30, so that the operator easily can fit a bag in place over the receptacle, and yet will be protected by the inner wall from contact with the mechanism. The opposite wall extends substantially further at 28 in order to give aditional protection to the customer and to shield some of the mechanism from view.

With the components of the mechanism 18 motionless and in the positions shown in FIG. 2, the check-out operator loads the merchandise 36 into the receptacle as each item is rung-up on the cash register 12. The itemspreferably are placed in the receptacle on their sides so that they will be upright when placed in the grocery bag. Preferably, the heaviest items are stacked near the open end of the receptacle 30 so that the heaviest items will be at the bottom of the filled bag. When the receptacle 30 is full of groceries, the operator slips an open grocery bag over the receptacle, and then pushes a button which starts an automatic bagging cycle which is illustrated in FIGS. 3 through 6.

FIG. 3 shows the mechanism 18 when the receptacle 30 has been almost completely withdrawn from the bag 24. The receptacle has a U-shaped cross section, and moves horizontally through appropriately-shaped slots 38 (see FIG. 2) in a vertical wall 34 of the upper housing 14. This wall retains. the merchandise in the bag while the receptacle is being withdrawn. FIG. 3 also shows the bag dropping gently onto the transfer platform 32, which remains motionless at this time.

FIG. 4 shows the mechanism 18 in the condition in which the receptacle 30 has been completely withdrawn from the bag and through the wall 34, and the transfer platform 32 has started to pivot clockwise upon its axle 80. The platform 32 has a relatively short flange 116 at its front edge which prevents the bag 24 from slipping off of the platform 32 when it is tilted (see FIG. 4). When, however, the platform reaches a position just short of vertical, the center of gravity of the bag is located such that it tips off of the platform and its leading edge moves onto the moving conveyor belt 22 just below.

As is shown in FIG. 6, the belt 22 grips the leading edge of the bottom of the bag 24,'and slides the bag gently off the flange 116 and moves it quickly away from the bagging mechanism so that the platform 32 can return to its initial horizontal position. The full bag 24 is moved by the conveyor belt 22 for a short distance, and then the belt stops. The receptacle 30 moves back to its initial horizontal position, the bagging mechanism 18 stops, and it is ready to receive another load of groceries for bagging.

As it will be explained in greater detail below, the flanged transfer platform and associated mechanism is an advantageous feature of the present invention. The platform is simple in structure, and yet it quickly and safely delivers the bag upright to its proper position on the conveyor belt 22.

DRIVE SYSTEM The system for driving the bagging mechanism is another advantageously simple feature of the present invention.

Referring to FIG. 2, the input conveyor belt 16 is conventional and is driven by a conventional drive system including a motor 40, a speed reducer 42, a drive chain 44 with mating sprockets driving a drive roller 46 which moves the belt 16 around an idler roller 48.

The conveyor belt 22 is driven by a drive motor 50 and a speed reducer 52 through a chain 54. This drive system turns a roller 56 which drives the belt 22 over an idler roller 59 at the opposite end, and over an intermediate idler 58. As it will be explained in greater detail below, each of the conveyor belts l6 and 22 can be operated independently upon the command of the operator. Also, the belt 22 moves automatically as part of the bagging mechanism of the machine.

The drive system for retracting and returning the receptacle 30 and for the transfer and return movement of the transfer platform 32 includes a drive motor 60, and a speed reducer 62 driving a first sprocket 68 through a dynamic brake 64. Sprocket 68 drives a larger sprocket 70 by means of a chain 66. Coupled to the sprocket 70 by means of a shaft 72 is a cam 74 which drives two oppositely-positioned

cam follower rollers

76 and 78. The roller 78 is rotatably mounted on an actuating lever 92 which is pivoted on the framework (not shown) of the machine at one end 94. At the other end is an elongated slot 96 in which rides a roller 98 which is secured to the receptacle 30.

The roller 76 is moved by the cam 74 to operate a linkage which rotates the shaft 80 and, hence, turns the platform 32 first clockwise to transfer a bag 24 to the output conveyor 22, and then counterclockwise to return the platform to its initial position. The linkage coupling the roller 76 to the shaft 80 includes a relatively short swing link 82 securedat its upper end to one end of the shaft 80. Pivoted at the other end of link 82 is a pusher link 84 which is pivotably connected to the idler 76 at its other end. Also rotatably connected at the other end of the pusher link 84 is a second swing link 86 which is pivotably connected to a support member 90 forming part of the frame of the machine.

A tension spring 88 is connected between the stationary support member 90 and the lower end of the swing link 82. A similar spring is connected between the frame of the machine and the middle portion of the lever 92. Springs 88 and 100 serve the purpose of simultaneously holding the

followers

76 and 78 against the outer edge of the cam 74 and pulling on the linkage and levers in a manner such as to return the receptacle 30 and the platform 32 to their initial horizontal positions shown in FIG. 2.

As is shown in FIGS. 3 through 6, the cam 74 is somewhat heart-shaped. It has a dwell region 106 of substantially constant radius, two regions and 112 of rapidly decreasing radius, and an indentation 108 formed between the two

regions

110 and 112. The

followers

76 and 78 are positioned at an angle of with respect to one another about the axle 72 of the cam 74. Thus, as one follower is going through various radial excursions, the other follower will be riding on the dwell portion 106 of substantially constant radius and will not be moved by the cam.

When the bagging mechanism is at rest, the follower or roller 78 normally rests in the indentation 108 of the cam 74 so that the lever 92 will be as far forward as it can be, and the receptacle 30 will be extended as far forward as possible. This condition is shown in FIG. 2. FIG. 3 shows the position of the mechanism immediately after the follower 78 has traversed the portion 112 of the cam 74. The receptacle 30 is retracted almost all the way, and the roller 78 is approaching the dwell region 106. Rotation of the cam 74 is in the direction of the arrows shown in FIGS. 3 through 6.

FIG. 4 shows the components of the bagging mechanism when the follower 78 has reached the dwell region 106 of the cam, and the follower 76 is resting on the portion 1 10 of the cam. This causes the follower 76 to move to the left (under the influence of the spring 88) and rotates the platform 32 on its axle 80.

FIG. 5 shows the components of the mechanism when the follower 78 has reached the indentation 108 of the cam. At this point, the platform 32 is substantially vertical. FIG. 6 shows the cam after it has rotated somewhat further so that the cam 76 reaches the region 112 of the cam and is returning the platform 32 to its horizontal position. The receptacle 30 is still in its retracted position which it reached as shown in FIG. 4 when the lever 92 reached its position furthest left. Subsequently, when the follower 78 reaches the indentation 108, the mechanism will stop and be ready for the start of another cycle.

FIG. 7 shows some of the details of the receptacle 30 and the transfer platform 32. The receptacle 30 has side walls whose right ends 122 and 124 are bent slightly inwardly. Also, the top edges of the

portions

122 and 124 are angled somewhat downwardly. This shaping of the open end of the receptacle 30 facilitates the fitting of a bag over the receptacle.

The transfer platform 32 has two

side portions

126 and 128 which form a relatively small angle with horizontal. The central portion of the platform 32 is substantially flat. The flange 116 extends upwardly only from the central portion. Its height above the base of the platform 32 is less than the distance from the platform 32 to the bottom 132 of the receptacle 30. This provides a clearance space between the receptacle bottom 132 and the flange 116 so that a paper bag can be inserted over the receptacle 30 reIatively easy.

The beauty of the flange 116 is that it is extremely easy to fabricate, and yet is short enough to permit the platform 32 to be relatively close'to the bottom of the receptacle 30 so as to minimize the distance the bag 24 must drop when the receptacle is retracted. All thisis accomplished while still providing a clearance space for fitting the bag over the receptacle, and yet providing enough flange 116 to hold the bag onto the platform until the proper time for it to be released.

FIG. 7 also illustrates typical mounting elements 130 which are used to attach the shaft 80 to the metal framework 131 of the bagging equipment. An appropriate guideway with rollers (not shown) is provided for guiding the receptacle during retraction and return. The mounting elements 130 include appropriate bearings. It should be understood that there are bearings for all shafts. However, since the frame and bearings are conventional, they are not shown except in an exemplary manner in FIG. 7 in order to clarify the drawings.

CONTROL CIRCUIT The control circuit for this invention is relatively simple, as is apparent from FIG. 8 of the drawings. A double-pole double-throw line switch 138 is used to connect two

input lines

140 and 142 to a source 160 of common household 60 Hz. AC current. A normallyclosed Stop switch 134 and a normally open Start switch 136 are connected in series with the coil of a first relay 144. This combination is connected between the

power lines

140 and 142. Connected in a'shunt path around the Start switch is the series combination of a normally-closed microswitch 104 and a normallyopen contact 144 (a) of the relay 144. Relay 144 also includes a pair of normally closed contacts 144 (b) and a pair of normally open contacts 144 (0). Normally closed contacts 144(b) connect a red indicator lamp 148 between

lines

140 and 142 so that when the machine is not running through a bagging cycle, the red light is lighted. This indicates that the machine is in the Stop condition.

When the start button 136 is pressed, it completes a series path through the coil of relay 144. This causes contacts 144 (a) and 144 (c) to close, and contact 144 (b) to open. The closing of contact 144 (a) acts as a latch to hold the energization of the coil of relay 144 until either microswitch 104 opens or Stop switch 134 is pushed. The energization of relay 144 turns off the red Stop lamp 148 and turns on the green Run lamp 150, and also energizes the coil of a relay 152 which has two normally-open contacts 152 (a) and 152 (b). The closing of these contacts energizes the drive motor 60 which rotates the cam 74 to operate the retracting and transfer mechanism.

The drive motor 40 for the input conveyor 16 is energized through a pair of contacts 146 (a) and 146 (b) of a relay 146 whose coil is energized by means of a wellknown foot-operated switch 147. Thus, the input conveyor belt motor 14 can be operated at any time, as long as the line-switch 138 is closed, and regardless of whether the Start button 136 has been pressed.

The accumulator belt drive motor 50 is energized through a pair of contacts of 154 (a) and 154 (b) of a relay 154 whose coil is energized either by a normallyopen microswitch 158 during the bagging cycle, or by an overriding foot-operated switch 155 which is coupled mechanically to the microswitch 158. Thus, the

motor 50 can be operated manuallyby the operator as well as automatically during the-bagging cycle.

Each of the

motors

40, 50 and 60 is energized through an appropriate pair of fuses 156.

Referring again to FIGS. 2 through 6, the microswitch 104 is shown in itsfixed relation to the frame of the system. It is secured to the frame by mounting means which is not shown, for the sake of clarity. A metal patch 102 is secured to the surface of the cam in a position and has a thickness such that the patch 102 will actuate (open) the microswitch 104 when it passes by. When the system is at rest as shown in FlG. 2,the patch 102 is located somewhat clockwise from the switch 104. The patch does not actuate the switch 104 until the patch has made one complete revolution and another bagging cycle'has been completed.

The .microswitch 1 158 which automatically operates the transfer belt is located slightly below and to the side of the transfer platform 32 so that the platform 32 closes the switch 158 justafter leaving the horizontal position, holds the switch closed during its further downward and upward travel, and then releases the switch just prior to the return of the platform to the horizontal position. This function is illustrated in FIGS. 4 through 6. Using the platform motion to actuate the switch 158 ensures that the belt will be moving when the bag tips onto the belt 22, and that it will move at least a desired distance away from the transfer platform 32, but will not move any further than is necessary to provide clearance for return of the platform to its horizontal position. However, if the operator wishes to move the bag 24 further down the conveyor, he or she can operate the foot-switch 155 to over-ride the switch 158, and thus operate the belt 22 for as long as desired.

The use of the dynamic brake 64 to stop the drive motor 60 ensures an accurate, smooth and rapid stop of the bagging mechanism 18.

The

motors

40, 50 and 60 are conventional. A typical example of a useful motor is a volt AC motor with an operating speed of 1750 rpm..Each of the speed reducers reduces the output speed to approximately 43 The merchadise bagging system and method described above is believed to meet the objects set forth at the beginning of this description. It is relatively simple in construction so as to minimize manufacturing cost, and yet it operates rapidly and smoothly so as to provide a substantial increase in the productivity of the check-out employee. The bagging device is quite compact, so that it isbelieved that the check-out counter using it need not be any longer than most conventional check-out counters currently in use. Furthermore, it is believed that some of the frightening or potentially frightening aspects of prior proposed automatic bagging systems have been-avoided or eliminated. There are no parts of the system which rise above the top of the check-out counter. Furthermore, most of the mechanism is hidden from view by the housing 14. Also, many of the more familiar aspects of the physical appearance of the conventional check-out counter are retained so that the strangeness of the appearance of the counter is minimized. These features promote customer acceptance of this new labor-saving device.

The above description of the invention is intended to be illustrative and not limiting. Various changes or modifications in the embodiments described may occur to those skilled in the art and these can be made without departing from the spirit or scope of the invention.

I claim:

1. In a grocery bagging machine, a horizontallyaligned receptacle having a bottom wall, two upright side walls and an open end shaped to receive a bag thereover, means from horizontally moving said receptacle from a first grocery-receiving position to a second position which is at least the length of one bag distant from said first position, means for holding the groceries and bag while said receptacle is moving from said first.

to said second position so as to completely withdraw said receptacle from a bag encircling said groceries and said end of said receptacle, a pivotably-mounted platform immediately below said bottom wall of said receptacle, means for rotating said platform to upright and discharge a loaded bag therefrom onto a surface beneath said platform, and means for rotating said platform back to its original position, and returning said receptacle back to its first position for receipt of further groceries, an input conveyor system for moving groceries to a bagging station, said receptacle being under said input conveyor when in said second position.

2. Apparatus as in claim 1 in which said platform has angular sections forming an essentially curved surface for cradling a bag when lying on its side on the platform.

3. Apparatus as in claim 1 including switch means actuated by movement of said platform for starting said drive means during movement of the platform to an upright position, and for stopping said drive means during return of said platform.

4. In a merchandisebagging machine including a retractable receptacle and a platform for receiving the bag when separated from said receptacle, the improvement comprising motive means for retracting and returning said receptacle and tipping and returning said platform to move said bag to an upright position, said motive means including a single cam and two followers, one follower being connected to said receptacle, and the other to said platform, said cam having an indented portion opposed by a portion of substantially constant radius greater than that of said indented portion, said followers being located opposite one another with respect to said cam.

5. Apparatus as in claim 4 including drive means for driving said cam through one revolution upon receipt of a start signal, and a dynamic brake for stopping said cam.

6. In a merchandise bagging machine including a retractable receptacle and a platform for receiving the bag when separated from said receptacle, motive means for retracting and returning said receptacle and tipping and returning said platform to move said bag to an upright position, said motive means including cam means having a single cam with a first portion of relatively small radius and another portion of relatively larger radius, and followers and linkages for following the surface of said cam and retracting said receptacle, turning and returning said platform, and restoring said receptacle to its initial position.

7. Apparatus as in claim 6 in which said platfonn is rotatably mounted for tipping and returning, said linkages including a crank arm and a push-rod pivoted to said crank arm, said cam follower being coupled to a push-rod and said crank arm being secured to rotate said platform, and a lever with a longitudinal slot in one end, pivotably mounted at the other end, with a second cam follower mounted between the ends of said lever, and a pin on said receptacle slidably engaging said slot.

8. Apparatus as in claim 7 including springs connected to pull upon said followers and hold them against the surface of said cam.

9. A machine as in claim 1 in which said surface is the surface of a conveyor belt to carry the loaded grocery bag to a bag storage station.

10. A machine as in claim 9 in which said platform has a short flange at one end to hold said bag against slipping off during the first part of its rotation, but then is allowed to tilt and fall of gently onto said conveyor surface.

11. Apparatus as in claim 10 in which said flange extends upwardly from said platform by a distance less than the distance between said platform and the receptacle bottom so as to allow the wall of a bag to pass between said platform and said flange when the bag is being drawn over the receptacle.

Claims

1. In a grocery bagging machine, a horizontally-aligned receptacle having a bottom wall, two upright side walls and an open end shaped to receive a bag thereover, means from horizontally moving said receptacle from a first groceryreceiving position to a second position which is at least the length of one bag distant from said first position, means for holding the groceries and bag while said receptacle is moving from said first to said second position so as to completely withdraw said receptacle from a bag encircling said groceries and said end of said receptacle, a pivotably-mounted platform immediately below said bottom wall of said receptacle, mEans for rotating said platform to upright and discharge a loaded bag therefrom onto a surface beneath said platform, and means for rotating said platform back to its original position, and returning said receptacle back to its first position for receipt of further groceries, an input conveyor system for moving groceries to a bagging station, said receptacle being under said input conveyor when in said second position.

4. In a merchandise bagging machine including a retractable receptacle and a platform for receiving the bag when separated from said receptacle, the improvement comprising motive means for retracting and returning said receptacle and tipping and returning said platform to move said bag to an upright position, said motive means including a single cam and two followers, one follower being connected to said receptacle, and the other to said platform, said cam having an indented portion opposed by a portion of substantially constant radius greater than that of said indented portion, said followers being located opposite one another with respect to said cam.

7. Apparatus as in claim 6 in which said platform is rotatably mounted for tipping and returning, said linkages including a crank arm and a push-rod pivoted to said crank arm, said cam follower being coupled to a push-rod and said crank arm being secured to rotate said platform, and a lever with a longitudinal slot in one end, pivotably mounted at the other end, with a second cam follower mounted between the ends of said lever, and a pin on said receptacle slidably engaging said slot.