GB2477600A

GB2477600A - Bag emptying apparatus

Info

Publication number: GB2477600A
Application number: GB1022019A
Authority: GB
Inventors: David Norris; Stephen Manson
Original assignee: DC Norris and Co Engineering Ltd
Current assignee: DC Norris and Co Engineering Ltd
Priority date: 2010-02-03
Filing date: 2010-12-23
Publication date: 2011-08-10
Anticipated expiration: 2030-12-23
Also published as: GB2477600B; GB201022019D0; GB201001758D0

Abstract

Apparatus for evacuating a bag containing a flowable product, especially a flowable food product, comprises a cutting device 27 for forming a slit in a bag placed on a support bed 8. A traction device 10 draws the bag through a nip between the jaws 20, 22 of a stripping device 19 so as to expel the contents of the bag though the slit in the bag. A receptacle 6 disposed at a level beneath that of the bag for collects the contents of the bag. A platen 31 may press upon the bag to increase its rigidity when being cut by cutting device 27.

Description

* BAG OPENING APPARATUS This invention relates to an apparatus for opening bags containing a flowable product, in particular food products.

A flowable food product, such as stew or baked beans, may be supplied to a food processing plant in a plastic bag which is sealed at the neck by a clip or other fastening; the bag weighing seven kilograms, for example.

The bag may be cooled in a chiller to a temperature of about four degrees Celsius before being opened, conventionally, by slitting it with a knife.

The bag is then squeezed manually to expel its contents through the slit.

This is a time consuming and messy exercise, and some of the contents of the bag may remain in it and be wasted.

To overcome these problems, the present invention seeks to provide a method and apparatus for evacuating such a bag mechanically. Although primarily intended for use in connection with the food industry, the invention may be employed in other fields in which it is necessary to open bags containing a flowable substance.

According to one aspect of the invention, the contents of a bag are expelled, conveniently into a receptacle, by bringing a cutting device into contact with the bag so as to form an opening therein, engaging a traction device with a clip or other fastening at the neck of the bag, and using the traction device to draw the bag along a predetermined path and through a nip between the jaws of a stripping device. The bag may be slit open either before displacement commences, or while it is undergoing movement.

According to another aspect of te invention, apparatus for evacuating such a bag comprises a cutting device, a traction device for drawing the bag through the apparatus, a stripping device comprising jaws for engagement with the bag and serving to expel the contents of the bag though an opening formed by the cutting device in the bag wall as the bag is drawn through the stripping device. A receptacle may be provided for collecting the contents of the bag.

According to a further aspect of the invention, a traction device has gripping members which in a rest condition of the apparatus project between the jaws of a stripping device to facilitate engagement of the gripper members with a fastening for the neck of the bag.

During the stripping operation and prior thereto the bag may rest on a support bed which may comprise an array of spaced apart horizontal bars extending parallel to the path to be followed by the bag through the apparatus. Herein, the direction in which a bag is drawn through the apparatus is referred to as being the forward direction, and vice versa.

The product escaping from the bag may drain through gaps between the bars of the support bed into a receptacle provided below the support bed.

The construction of the support bed may differ from that described above, provided that it allows the product to pass through it into the receptacle, or is otherwise adapted to channel the product to the receptacle.

Although a receptacle may be positioned wholly beneath the plane of the support bed, it lies within the scope of the invention for the side and rear walls of the receptacle to extend upwards beyond the plane of the support bed, provided that they do not obstruct passage of the bag.

* The bag may follow a substantially horizontal path from the support bed into the nip between the jaws of the stripping device. One of the jaws of the stripping device (in general, the lower one of the two jaws) may take the form of a stationary anvil towards which the other jaw may be urged by operating means; although it falls within the scope of the invention for both jaws to be movable. A movable jaw upper may be retracted into a position in which a gap is formed between the jaws for a purpose to be explained hereinafter. Preferably at least one of the jaws is chevron-like in shape when viewed perpendicularly to the plane of the support bed.

This arrangement of the jaws is found to be more effective in expelling product from the corners of the bag than jaws arranged at right angles to the direction of movement of the bag.

The traction device, which is located forwardly of the stripping device, may incorporate rearwardly extending gripper members. The gripper members may be movable by operating means from an open position into a closed position in which they engage with the fastening at the neck of the bag in such a way as to make possible the application of tractive force to the bag. The gripper members may be movable by further operating means so as to project through the gap formed between the jaws of the stripping device when the movable jaw is in an upper, retracted position.

This arrangement makes it easier for the operator to engage the neck fastening with the gripper members. It falls within the scope of the invention for one gripper member to be movable and the other to be stationary.

The stroke of the traction device is preferably at least equal to the length of the longest bag to be processed by the apparatus. When the traction device reaches the end of its forward stroke and the bag has been emptied, the gripper members aid the movable jaw or jaws are retracted and release the bag which falls into a chute for disposal.

A cutting device may be positioned to the rear of the stripping device and incorporate a knife blade which is brought into contact with the bag and serves to form one or more openings in the bag during its passage through the apparatus. A blade may be arranged to form an opening in the bag before it is entrained by the traction device, and may be advanced towards the rear end of the bag. Because a bag containing a flowable food product may not be sufficiently firm as to resist penetration of such a cutting device so as to achieve a satisfactory cut, a platen may be brought to bear on the bag so as to increase its firmness.

Accordingly the invention also provides a cutting device for use in apparatus for evacuating a bag containing a flowable product, especially a flowable food product, said device comprising a blade having a pointed projection at substantially the mid-point of its leading end, cutting edges flanking said projection, means to advance and retract the blade, and means to apply pressure to the bag during the cutting operation so as to increase its firmness. The blade may be of substantially deltoid shape, wherein trailing edges of the blade also serve as cutting edges.

Preferably, pneumatic or hydraulic piston and cylinder units are employed, firstly to displace the traction device, secondly to advance, retract, open and close its gripper members, and thirdly to displace the movable jaw or jaws of the stripping device, and fourthly to displace the cutting device; although other types of operating means may be used instead. Operation takes place automatically using electronic control means.

Having regard to the foregoing, it will be appreciated that a still further aspect of the invention provides apparatus for evacuating a bag containing a flowable product, especially a flowable food product, comprising, a support structure, a receptacle mounted on the support structure, a support bed mounted on the support structure, the support bed being adapted to allow the flowable product to pass to the receptacle, a stripping device at one end of the support bed, the stripping device incorporating a pair ofjaws, at least one of which is movable between a retracted position and a position proximate the other jaw, a traction device movable along a path extending forwardly from the stripping device through a distance substantially corresponding to the length of bags to be evacuated, the traction device incorporating gripper members, at least one of which is movable towards and away from the other, the gripper members being extendable through a gap between the jaws of the stripping device when the or each of its movable jaws is a retracted position, and preferably a cutting device for forming an opening in the bag. If the apparatus is arranged such that the bag is slit open manually, then this last mentioned device may be omitted.

In the drawings: Figure 1 is a diagrammatic elevational view of an embodiment of the apparatus with components located as at the commencement of operation, Figure 2 is a plan view to a larger scale, depicting the gripper members and jaws, Figure 3 is an end view of the grippers,

I

Figure 4 is an isometric view of part of the stripping device, including its jaws, and Figure 5 is a plan view of a blade used to slit the bag, Referring to the drawings, an apparatus for evacuating bags of flowable food product comprises a support structure including a forward section 2 and a rearward section 4. Herein, the direction towards the right hand end of the apparatus as viewed in Figures 1 and 2 is taken to be the forward direction. Mounted beneath the rearward section of the support structure is a receptacle 6 for receiving the contents of the bags. A support bed 8 overlies the receptacle. The support bed is formed from a plurality of spaced-apart, horizontal bars or tubes, each of which extends from left to right as viewed in Figures 1 and 2. Conveniently each of the bars or tubes is of circular cross-section.

The support bed is provided with a cover 5 (only part of which is shown) which may be raised to permit a bag to be positioned on the support bed, and thereafter lowered to cover the support bed during operation. The receptacle 6 may have an outlet duct through which the contents of the bags may be led to containers or to a processing plant. Other possible arrangements may be employed, including, for example, the use of replaceable receptacles which may be removed from the apparatus when full, and their contents tipped into an inlet of the processing plant.

Arranged beneath the forward section 2 of the support structure is a chute for receiving discarded bags. Supported by the forward section above the chute, in alignment with the centre line of the apparatus, is a traction device 10 which is movable by piston and cylinder unit 12 from a rearward position into a forward position adjacent the forward end of the support structure,.e. at the right hand end of Figure 1. The traction device incorporates a pair of rearwardly facing gripper members 14 which are extendable relative to the body of the traction device towards the rear by a piston and cylinder unit 16. The gripper members are movable towards and away from each other by a piston and cylinder unit 18. The gripper members are so shaped that in their closed positions as illustrated in Figures 2 and 3 they are capable of engaging behind the clip which is conventionally used to close the neck of such a bag whereby, as the gripper members are displaced in the forwards direction, at least the neck of the bag is carried with them between the jaws 20, 22.

The neck of the bag is released by the gripper members when they are moved into their open positions.

Located at the forward end of the support bed 8 is a stripping device 19 including a fixed, lower jaw 20 which is chevron-shaped when viewed in plan, the apex of the chevron being in line with, and facing towards, the traction device. Arranged above the fixed jaw 20 is an upper jaw 22, also chevron-like, and corresponding in shape to the fixed jaw. The jaw 22 is movable vertically under the action of a piston and cylinder unit 24 between an upper retracted position in which a gap is formed between the jaws, and a lower position adjacent to the fixed jaw in which a nip is formed between the jaws. In its lower position the movable jaw may be urged resiliently against the fixed jaw 20.

Mounted at the rear of the apparatus is a cutting device 27 which includes a deltoid shaped, flat blade 28 shown in Figure 5 which is arranged in a horizontal plane above the support bed. On the centre line * of its leading end the blade is provided with a forwardly extending pointed projection 29 flanked on both sides by cutting surfaces 30.

Cutting surfaces 30A are also provided at each side of the trailing edges of the blade. The blade may be made in one piece, or have separate cutting edges and a pointed projection attached to a delta shaped base member. A piston and cylinder unit 26 is arranged to advance and retract the blade. In its inoperative, retracted position the blade 28 is shielded by a protective cover (not shown) to avoid injury to the operator.

A platen 31 is positioned ahead of the blade 28 and may be lowered by a piston and cylinder unit 32 to press on a bag positioned on the support bed.

Operation of the apparatus may be arranged to take place semi-automatically under the control of an electronic control system.

At the commencement of operation, the movable jaw 20 of the stripping device is in its upper retracted position so that a gap exists between the jaws 20, 22. The traction device is located in its rearward position in which the gripper members 14 are in a closed condition and project rearwardly through the gap between the jaws of the stripping device.

An operator opens the cover 5 and places a bag containing a flowable food product on the support bed with its neck facing forwardly. The neck of the bag is placed between the gripper members 14 with the clip which seals the neck of the bag being located forwardly of the gripper members. Attachment of the bag to the gripper members by the operator at this stage of the operation is facilitated by the fact that the gripper members project through the gap between jaws 20, 22 and are therefore located to the rear of the stripping device, and are therefore readily accessible. The cover 5 is closed and the control system actuated to initiate the cycle of operations to be performed by the apparatus.

Automatic operation commences with the platen 31 descending and squeezing the bag so as to increase its firmness. The blade 28 is advanced and the pointed projection 29 cuts a pilot opening in the rear of the bag. The cutting edges 30 serve to enlarge the opening as they penetrate the bag. The blade is then retracted, and, the cutting surfaces 30A cut away any material that resists rearward movement of the blade, so that the bag is not pulled to the rear by the blade. The traction and stripping devices then proceed to carry out the sequences of operation as described above.

The unit 16 operates to retract the gripper members 14 relative to the body of the traction device and through the gap between the jaws 20, 22 of the stripping device. The neck of the bag is thus carried through the gap between the jaws into a position just forwardly of the jaws where it remains during a brief pause. The unit 24 now operates to cause the movable jaw 22 of the stripping device to descend and create a nip within which the neck end of the bag is located. With the above-mentioned components in their operating positions, the unit 12 operates to move the traction device towards its forward position, the gripper members drawing the remaining part of the bag through the nip between the jaws.

The chevron-like shapes of the jaws ensure that accumulations of product are driven out of the corners of the bag.

When the traction device 10 reaches its forwardmost position, in which the entire length of the bag has passed between the jaws 20, 22 of the stripping device, the gripper members are opened, the upper jaw 22 raised, and the empty bag discarqed to fall into the chute 40. The traction device is returned to its rearmost position, the gripper members 14 moved into their closed positions relative to each other, and extended so as project though the gap between the jaws of the stripping device.

The cutting device is withdrawn so that it does not interfere with positioning of a subsequent bag. The steps of displacing the gripper members in the rearward direction relative to the traction device and moving them to their closed positions may take place simultaneously or sequentially as desired.

Modifications may be made to the apparatus described above. For example, the fixed jaw 20 of the stripping device may be replaced by a plate serving as an extension of the support bed, the plate having a flat upper surface which cooperates with a movable jaw of chevron-like shape. Such a plate (and other components adapted to cooperate with the movable jaw) are to be regarded as jaws for the purposes of the present invention. The movable jaw 22 may be arranged to press against the fixed jaw through the material of the bag, resiliently resisting the bag being drawn through the nip between the jaws, or may be made to descend through a limited distance so as to form a nip of a defined size.

Also, in accordance with the invention, both jaws may be movable towards and away from each other. It also falls within the scope of the invention for one or both of the jaws to take the form of elongate rollers.

According to a wider aspect of the invention, the automatic cutting device may be omitted and an opening made in the bag manually after it has been positioned on the support bed. Although the apparatus shown in the drawings is designed for use with bags which have their necks closed by a clip, the apparatus may be adapted for use with bags in which the neck * is knotted, or provided with other means to which the gripper members may be coupled.

The apparatus may be modified to open rectangular bags which are sealed along a bottom edge and closed by two (or more) clips applied to an upper edge. In such a modification the apparatus would be provided with * two (or more) sets of grippers and jaws arranged at appropriate distances apart. The cutting device may be used in conjunction with an apparatus which does not employ the stripping and traction devices described herein. Although the apparatus described above is so arranged that the bag follows a horizontal path, it also falls within the scope of the invention for it to have an inclined path, the support bed, traction and stripping devices and their operating systems being arranged accordingly.

L

Claims

O CLAIMS1. Apparatus for evacuating a bag containing a flowable product, especially a flowable food product, comprising a traction device for drawing the bag through the apparatus, and a stripping device comprising jaws for engagement with the bag and serving to expel the contents of the * bag though an opening in the bag wall.
2. Apparatus as claimed in claim 1, wherein at.least one of the jaws is substantially chevron-shaped.
3. Apparatus as claimed in claim I or claim 2, wherein at least one of the jaws is movable towards and away from the other under the action of operating means.
4. Apparatus as claimed in claim 3, wherein the operating means comprises a piston and cylinder unit.
5. Apparatus as claimed in any of claims 1 to 4, wherein the traction device is provided with gripper members movable from an open position into a closed position for gripping engagement with the closed neck of a bag.
6. Apparatus as claimed in claim 5, wherein the traction device is disposed forwardly of the stripping device and includes means for displacing the gripper members through a gap formed between the jaws of the stripping device when at least one of the jaws is in a retracted position.
7. Apparatus as claimed in claim 6, including first operating means for displacing the gripper members through said gap and second operating means for moving the grippers between open and closed positions.
8. Apparatus as claimed in claim 7, wherein each of said operating means comprises a piston and cylinder unit.
9. Apparatus as claimed in any of claims 1 to 8, further including a support bed for a bag upstream of the stripping device.
10. Apparatus as claimed in claim 9, wherein the support bed extends horizontally and comprises spaced apart elongate support members extending parallel to the direction of movement of a bag through the apparatus, the traction device being arranged to travel along a path extending parallel to the support members.
11. Apparatus as claimed in any of claims 1 to 10, wherein a cutting device is movable into contact with the bag, the cutting device serving to slit a bag open as it is drawn through the apparatus under the action of the traction device.
12. Apparatus as claimed in any of claims ito 10, including means for applying pressure to a bag supported on a support bed, and a cutting device provided with a blade movable to penetrate a bag from the rear.
13. Apparatus for evacuating a bag containing a flowable product, especially a flowable food product, comprising, a support structure, a receptacle mounted on the support structure, a support bed mounted on the support structure, the support bed being adapted to allow flowable product evacuated from a bag to drain therethrough into the receptacle, a stripping device at one end of the support bed, the stripping device incorporating a pair of jaws, at least one of which is movable between a retracted position and a position proximate the other jaw, a traction device movable along a path extending away from the stripping device through a distance substantially corresponding to the length of bags to be evacuated, the traction device incorporating gripper members movable between the jaws of the stripping device, at least one of which gripper members is movable towards and away from the other, and a cutting device movable into a position for engagement with a bag resting on the support bed.
14. A method of evacuating a bag containing a flowable product, especially a flowable food product, including coupling a traction device to a fastening at the neck of the bag, bringing a cutting device into contact with the bag so as to form an opening therein, the traction device entraining the bag and drawing it along a predetermined path in a forwards direction so that the bag passes through a nip between the jaws of a stripping device during such, movement, thereby to expel the contents of the bag through said opening.
15. A method as claimed in claim 14, wherein gripper members of the traction device extend between the jaws when at least one of the jaws is in a retracted position to facilitate engagement of the gripper members with the neck fastening, thereby to position said neck on the forward side of the stripping device preparatory to jaws of the stripping device being closed about the bag, and the bag being drawn through the apparatus by the traction device.
16. Apparatus for evacuating a bag containing a flowable product, especially a flowable food product, comprising a traction device for drawing the bag through the apparatus, the bag passing between the jaws of a stripping device whereby the contents of the bag are expelled though an opening in the bag wall, a cutting device movable into contact with the bag, thereby to form the opening in the bag, said opening being formed as the bag is drawn through the apparatus or prior to the bag being drawn through the apparatus.
17. A cutting device for use in apparatus according to claim 9 or any claim appended thereto, said device comprising a blade having a pointed projection at substantially the mid-point of its leading end, cutting edges flanking said projection, means to advance and retract the blade, and means to apply pressure to the bag during the cutting operation so as to increase its firmness.
18. A cutting device as claimed in claim 17, wherein the blade is of substantially deltoid shape, trailing edges of the blade being cutting edges; the blade being aanged ma plane parallel to that of the suppo bed.
19. Apparatus for evacuating a bag comprising a traction device having gripping members which in a rest COfldjtjo of the apparatt..js project between the jaws of a Stripping device to facilitate engageme of the gripper membe with a fastening at the neck of the bag, the gripping members being withdrawn from the gap before it is closed, in preparation for the traction device being displaced to draw the bag through the apparatus.