GB2522649A - Bag emptying system - Google Patents

Abstract

A conveying device is adjacent a rubber or plastic block 54 including a slot to receive a blade 56. The conveyor can draw a bag across the block so that the blade splits the bag. There can be multiple blocks 55 with blades 56 mounted on a shank 51 attached to a door 52 of the conveyor casing. A subsequent station 6 on the conveyor can apply pressure to the bag to discharge its contents through the slits. Ideally the blocks are nylon. A conveying device (8, fig 2) passes through a casing. The casing has many openings to provide access for tools to work on the bag. Ideally each opening can be closed by a rectangular door 5, 6 provided with the tool. The tool on one of the doors 5 could to slit the bag while the tool on another 6 could apply pressure to the slit bag. Wipers or scrapers 71 are attachable to a downwardly extending shaft 7.

Description

BAG EMPTYING SYSTEM

This invention relates to bag emptying systems particularly, but not exclusively, for use in emptying bags containing a flowable food products. Herein the term "system" comprehends any apparatus, machine, device or other means for performing the invention.

Certain features described and claimed herein take the form of improvements to the invention which is the subject of our co-pending Patent Application No GB 1308309.2 (Serial No).

A flowable food product, such as soup, stew or baked beans, may be supplied to a food processing plant in plastics bags, typically weighing two to 10 kg, and sealed at the neck by clips or other releasable means of fastening. The bag may be cooled in a chiller before being opened, conventionally by slitting with a knife.

After slitting, the bag may be squeezed manually by being laid out on a support surface and pressed flat with the aid of a roller to expel the contents of the bag through the slit or slits. This is a time consuming and messy exercise, and a significant quantity of the food product may remain in the bag, typically leading to losses of seven to nine per cent by weight.

A problem which may be encountered is that the bag may contain solid constituents which are not readily broken down.

Our co-pending Patent Application referred to above relates to a system for emptying bags which includes a conveying device which rotates about

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a substantially vertical axis and draws a bag along a curvilinear path concentric with the axis. The bag is initially drawn past a first station where it is slit open by the blade or blades of a slitting assembly, and is thereafter drawn past a second station (and possibly further such stations) where pressure is applied to the bag to cause its contents to be evacuated through a slit or slits made at the first station. Devices for slitting open bags and applying pressure to them for the purposes described may be referred to herein as "tools".

An object of the present invention is to provide a bag emptying system with means to facilitate the mounting of such tools relative to the fixed structure of the system.

Accordingly a first aspect of the invention provides a system for emptying bags containing a flowable substance which may be a foodstuff which includes a conveying device adapted to entrain a bag along a path (which may be curvilinear) and a slitting station associated with the path for slitting the bag; said slitting station comprising a plurality of blocks of plastics or rubber, each of which blocks is provided with at least one slot for receiving and retaining a cutting blade positioned for contact with a bag as it is drawn past said station. It will be understood that an arrangement which includes a single such block having one or more slots, each slot being adapted to accommodate a blade, falls within the scope of the invention. Advantages of such a system are that the blades are readily replaceable by inserting a blade into a slot.

The blocks may be injection moulded from nylon or other suitable plastics or rubber material with a slot or slots formed in situ. A face of a block through which a blade protrudes may be bevelled or rounded so as to minimise the risk of the bag snagging on the block.

An alternative method of manufacturing the blocks is to cut the slot or slots after moulding, either by hand or by machine. Preferably a plurality of blocks, each having a slot to receive a respective blade, are bonded or otherwise secured to a metallic support which may be shaped to position the blades appropriately relative to the bag when the bag encounters the blades. To this end the support may have an arcuate or part arcuate shape so as to conform to the profile presented by the bag as it encounters the slitting station.

According to a second aspect of the invention the bags are constrained to follow a path which extends at least partly through a casing for the system. A section of the casing wall is provided with a series of preferably rectangular openings arranged generally lengthwise of the path to be followed by the bag (or part of such path) to enable access to be gained to the tools within the casing. Thus each opening is so positioned as to be close to a respective tool for ease of access.

According to a third aspect of the invention tools are positioned by means of a plurality of separate inserts, each of which incorporates a cover piece from which a shank extends, preferably from the rear face of the cover piece. The cover piece may be plate-like in form and be shaped to conform to the profile of the outer surface of the casing. The shank of each insert is provided or formed with a tool appropriate to the function to be performed at a given location. When the shank is offered up to a respective opening in the wall of the casing, the cover piece overlies the opening and its rim. Thus for one location the tool may take the form of a slitting blade assembly mounted on the rear side of the plate-like cover piece, and for one or more other locations the tool or tools may take the form of a device or devices for applying pressure to the bag, according to the requirements of the system. A number of inserts may be provided with a range of tools for use in applying pressure to the bags, whereby the user is enabled to select and use the most appropriate insert for the task in hand.

The system may be in accordance with our above-mentioned Patent Specification, such that the conveying device is arranged to rotate about a substantially vertical axis, coinciding with that of a main shaft, so that the bag is entrained along a curvilinear path centred on the axis of the main shaft. In this case the cover piece is appropriately curved to conform to the arcuate profile of the casing.

Alternatively the conveying device and the bags may follow a linear path, in which case the cover piece may be planar. A planar cover piece may also be employed if regions of the casing surrounding the openings are shaped so as to be planar.

According to a further aspect of the present invention a system according to our above-mentioned co-pending application may benefit from the incorporation of a number of modifications. In particular, the main shaft may be of circular cross-section but with a downwards extension in the form of a solid, planar bar provided with fittings to enable one-piece wipers or scrapers to be mounted on the bar. In a system in which the path to be followed is preferably curvilinear but may be linear, the bags may be drawn through a baffle assembly which serves to apply pressure to the bag and its contents. A baffle assembly such as that described hereinafter is well adapted to crushing stiff or rigid substances in the bags supplied to the system.

A preferred embodiment of the invention is shown by way of example in the drawings, in which:-Figure 1 is a side view of the preferred embodiment, Figure 2 is a perspective view of the embodiment shown in Figure 1, Figure 3 is a view similar to Figure 2 but with a domed upper casing part removed so as to reveal the principal components of the system in accordance with the invention, Figure 4 is a perspective view of the main shaft with components mounted on a shaft extension, Figure 5 shows a first design of wiper or scraper blade, Figure 6 shows a second design of wiper or scraper blade, Figure 7 shows slitting assembly as it would appear viewed from the exterior of the casing, Figure 8 shows the slitting assembly viewed from the interior of the casing, Figure 9 is a perspective view of a baffle assembly, as viewed in the downstream direction, Figure 10 is a perspective view of a similar baffle assembly as viewed in the upstream direction, Figure 11 shows a component of the baffle assemblies shown in Figures 9 andlO, Figure 12 shows an alternative construction of a baffle assembly, as viewed in the downstream direction, Figure 13 shows the baffle assembly of Figure 12 as it would appear viewed from the exterior of the casing, and Figure 14 is a perspective view of a further baffle assembly as viewed in the downstream direction from within the casing.

Referring to Figures 1 to 3 of the drawings, a preferred embodiment of a bag opening and emptying system is in the form of a mobile unit provided with legs on caster wheels to enable it to be moved from place to place within, for example, an industrial kitchen. The unit includes a casing 1 assembled from a dished, lower casing part 1A, a domed, upper casing part or cover 1B, and an intermediate, cylindrical wall 1C.

Located at the centre of the upper casing part is an electric motor 2 and gearbox 3. Figure 1 shows the motor and gearbox as being mounted within a housing 4 which also houses a control unit, whereas Figure 2 on the other hand shows the motor and gearbox unencased.

The motor and gearbox serve to drive in rotation a substantially vertically extending main shaft 7 best shown in Figure 3 and actuate an entrainment device adapted to be coupled to the neck of a bag and draw it along an arcuate path adjacent the inner surface of the casing wall 1C. Although alluded to herein as being "vertical" it will be understood that a degree of inclination of the main shaft and the parts coupled to it may be acceptable, provided that this does not detract from satisfactory operation of the system in accordance with the following. References herein to the shaft being vertical are therefore to be understood in this general sense.

The design of a mechanism for drawing a bag through the system is within the purview of the typical mechanical engineer and will not be described herein. An example of such a mechanism is, however, to be found in our co-pending Patent Application referred to above.

For the convenience of an operator working at a loading station adjacent to the unit, several bags of food product awaiting opening may be stowed in a chute 8 which extends horizontally away from the casing, and substantially tangentially with respect to it. As each bag is fed into the system, the operator may push a further bag along the chute. The chute is perforated to allow product to drain.

The interior of the casing 1 is shown in Figure 3 to be provided with three stations, each incorporating tools mounted on the inner side of the intermediate wall 1 C, namely a bag slitting stationS and two bag compressing stations 6 for applying pressure to the bag and squeezing its contents out through the slits made at the slitting station. The contents of the bag squeezed out at the bag compressing stations 6 fall into the bottom of the lower casing part lA which serves as a hopper.

Alternatively the contents may be collected in a separate hopper or vessel such as a tote bin, or led direct though pipework to a dispensing device.

The shaft 7 is best seen in Figures 3 and 4 and is provided with tools in the form of a pair of wipers or scrapers 71 for removing food product from the inner surface of the casing and causing it to accumulate at the bottom of the casing. Food product may be removed from the casing through a suitable opening or by way of pipework (not shown), which may be connected to a dispensing device. Pipework (also not shown) may be provided for directing jets of water into the casing for cleaning purposes after use. The shaft 7 has an upper section 72 of circular cross-section driven from the gear box, and is extended downwards in the form of a narrow metal bar 73 of planar cross-section provided with releasable catches 74 for attaching the wipers or scrapers to the bar. This arrangement is best seen in Figures 5 and 6.

The bag slitting station 5 incorporates a tool best shown in Figures 7 and 8 to comprise a shank 51 mounted on the rear side of a rectangular cover piece or plate 52 and held in place on the outer side of the casing wall by interlocking male and female fitments 53, only those on the cover plate being shown. The shank projects through a rectangular opening in the casing wall, both the wall and opening being omitted from the drawings for clarity. The shank 51 is fabricated from a flat bar and extends in a curve away from the cover plate. Bonded to the shank is a row of, for example, five spaced apart nylon or rubber blocks 54, each having a bevelled side 55 formed with a slot dimensioned to receive and grip a blade 56 located so as to slit a bag which encounters the tool. Straps 57 extend from the cover plate to facilitate fixing them in place.

Figure 9 shows a compression device or tool 6 which incorporates an array of baffles 61 adapted to resist the passage of a bag and thereby bear

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on, and loosen or crush the contents of a bag as it is drawn through the array and is buffeted first on one side and then on another by the baffles.

The array of baffles is assembled from a plurality of rectangular panels provided with a pair of parallel slots 62 having bores 63 to receive a rod which fastens the baffles together at their lower ends.

At their upper ends the free ends of the legs of the panels are received in openings 64 in a pair of plates 65, the facing edges of which are separated by a sinuous groove 66, The assembly is mounted on a support piece or plate 67, such as is described above in connection with the slitting assembly, by means of a double plate fixing arrangement 68 and has a turned down portion 69 to prevent bags being lifted over baffle assembly in use. Straps are provided on the support piece or plate to allow the plate to be lifted in position.

Figure 10 shows a slightly modified baffle assembly as viewed in the upstream direction. In use, bags of food or other product are drawn through the system and are slit open as they traverse the slitting assembly and then placed under pressure to force the contents of the bags out through the slits. The sinuous groove guides the neck of the bag along a similarly arranged path so that the bag is buffeted first on one side and then on the other.

Figures 12 and 13 show a modified baffle assembly viewed in the downstream direction and provided with a turned over portion on the right-hand side, as viewed, to prevent bags lifting over the baffle assembly.

Figure 14 shows an alternative baffle construction viewed in the downstream direction comprising a frame 8 which supports a pair of blades 81 moulded from nylon or other suitable plastics material, the blades forming a nip which decreases in width and serves to squeeze the bag as it passes through the nip.

In each of the illustrated embodiments, each cover plate and the tool and the shank which interconnects them, may take the form of an insert, such that that when the cover plate is fitted in place to the external surface of the casing, the tool occupies its correct position within the casing and is presented to the bag drawn along its path. Two of the cover plates, 52 and 67, belonging to the slitting assembly and one of the bag compressing devices, are visible in Figure 1.

The terms "plastics" and "rubber" are used herein in a general sense to include any plastics-like and rubber-like substances which may be moulded or otherwise formed into solid blocks and milled or otherwise slotted, or which may be formed with slots, such as to retain a cutting or slitting blade as described above.

Claims (10)

1. CLAIMSA system for emptying bags containing a flowable product, comprising a conveying device for thawing the bags along a path associated with a slitting station, said station including at least one block formed of plastics or rubber material, and having a slot therein for receiving and retaining a cutting blade.
2. 2. A system as claimed in claim 1 including a plurality of such blocks bonded to or otherwise mounted on a shank extending from a cover plate adapted to close an opening in a casing for the system.
3. 3. A system as claimed in claim 1 or claim 2, wherein the conveying device is arranged to draw the bag past at least one second station adapted to apply pressure to the bag to cause its contents to be evacuated through a slit or slits made at the first station.
4. 4. A system for emptying a bag including means for drawing a bag along a path, at least part of which extends through a casing, the casing being provided with a plurality of openings arranged substantially lengthwise of the path to provide access to tools within the casing for
5. 5. A system as claimed in claim 4 wherein each opening is adapted to be closed by a respective cover piece capable of being mounted on the outer surface of the casing, and wherein the cover piece is connected to a shank capable of being inserted into the opening, the shank being provided with a tool at a location remote from the cover piece.
6. 6. A system as claimed in claim 5, wherein one cover piece is connected to a slitting assembly and at least one other cover piece is connected to means for applying pressure to the bag.
7. 7. A system as claimed in claim 7 wherein the cover pieces are substantially rectangular in shape.
8. 8. A system as claimed in claim 1, wherein the blocks are formed from nylon.
9. 9. A system for emptying bags comprising a vertically extending main shaft extended downwards by a planar bar provided with means for realeasably attaching wipers or scrapers.is
10. 10. A system substantially as hereinbefore described with reference to and as illustrated in the drawings.