GB2512405A

GB2512405A - Bag emptying system

Info

Publication number: GB2512405A
Application number: GB1308309.2A
Authority: GB
Inventors: David Alan Norris; Stephen Manson
Original assignee: DC Norris and Co Engineering Ltd
Current assignee: DC Norris and Co Engineering Ltd
Priority date: 2013-03-28
Filing date: 2013-05-08
Publication date: 2014-10-01
Anticipated expiration: 2033-05-08
Also published as: GB2512503A; GB2512405B; GB201308309D0; GB2512503B; GB201406003D0; GB201321953D0

Abstract

A system for opening and emptying bags containing a flowable substance such as a food product includes a conveying device arranged to rotate about an upwardly extending axis 7 and entrain bags from a chute 10 over an array of slitting blades 40 and through a bag stripping station 60 provided with bars and at which the contents of a bag are discharged under pressure through slits formed in the bag by the blades. Also claimed is a stripping station comprising an array of baffles separated by a sinuous gap through which bags travel.

Description

BAG EMPTYING SYSTEM

This invention relates to a system for emptying bags containing a flowable product, in particular but not exclusively a food product.

A flowable food product, such as soup, stew or baked beans, may be supplied to a food processing plant in plastics bags which are sealed at the neck by clips or other fastenings. Such a bag, including its contents, may weigh between two and ten kilograms. The bag may be cooled in a chiller to a temperature of about plus four degrees Celsius before being opened, conventionally by slitting the bag with a knife. 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.

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.

Our patent specification GB No 2 477 600A discloses a system for emptying such a bag comprising a traction device for drawing the bag through the system, and a stripping device comprising jaws for engagement with the bag and serving to expel the contents of the bag though a slit. Herein, where used, the term "stripping" is to be taken to mean applying pressure to the exterior of a bag which has been slit open to evacuate its contents.

Although very effective, the system disclosed in the above-mentioned specification does suffer from several problems. In particular, the system has a horizontal bed on which bags must be laid out one at a time preparatory to slitting, so that the system occupies a substantial floor area.

Provision also needs to be made for a number of steps to take place under automatic control, including utilising a pneumatic system to operate jaws, grippers and a platen which applies pressure to the bag. The bags are slit by a blade which is applied to the exposed upper side ofthe bag, with possible health and safety rcpercussions.

The present invention seeks to providc a system which is of simple construction and provides for increased throughput in comparison with the system disclosed in our above-mentioned specification, and in a practical construction to enable losses to be restricted to less than one per cent by weight, in comparison with the losses of seven to nine per cent in the case of the conventional manual approach.

According to a first aspect of the present invention, a system for emptying bags includes a conveying device which in use rotates about an upwardly extending axis and serves to entrain or propel a bag along a curvilinear path with which is associated fir St means for slitting the bag and second means for causing the contents ofthe bag to be evacuated through a slit or slits formed by the first means. In operation the bag may be drawn over cutting blades with which the first means may be provided, and then drawn through the second means at which pressure is applied to the slit bag. The path to be followed by the bag may be defined by a channel which extends around the syslem, delimited on one side by a guide wheel. The channel may receive the neck of the bag, which is held in place by the clip, and conveys the bag to the various means in turn. In a practical system the conveying device is rotatable about a vertical axis, although a degree of tolerance is acceptable, subject to its being compatible with satisfactory operation of the system. Herein the term "system" comprehends any apparatus, machine, device or other means for performing the invention.

A system in accordance with the invention may further incorporate a third means which is disposed at a loading station for delivering a bag into the said path, such that it is taken up or captured by theconveying device; and fourth means by which a bag which has been acted upon by the first and second means may vacate the system. The third means may include or be associated with a delivery chute into which bags may be stowed ready for feeding into the system.

The conveying device may be arranged to rotate continuously during operation so that bags may be fed into the system one after the other, without the system having to be brought to a halt. Alternatively the system may be started and stopped at intervals under the control of the operator or an automatic means.

The conveying device may be in the form of a rotary disc, wheel, thum or be of other rotor-like form, for example that of a star wheel having arms which rotate from a hub. The conveying device may be provided on or adjacent to its periphery or circumference with means for coupling it temporarily to a bag ofthe type which is closed at the neck by a clip or other attachment. Such coupling means may take the form of at least one groove, cut-out, notch or indentation in or associated with the conveying device and into which the neck of the bag may be manually engaged at the bag loading location, in preparation for being introduced into the channel mentioned below. The clip which closes the neck of the bag may be positioned above the upper surface of the conveying means such as to prevent the neck of the bag becoming disengaged from the groove or other coupling means. A channel which extends around the system may be arranged to receive the neck of the bag and guide it during rotation.

When such a system is used with heat sealed bags which do not have a clip or the like closing the neck, the conveying device may take the form of a wheel shrouded on both sides and provided with teeth or the like for engagement with a convenient portion of the bag.

A handle or lever may be positioned at the loading station so as to be displaced by an operator and press the neck of the bag against a peripheral edge ofthe conveying device and bring about the capture and entrainment of the bag by the conveying device.

The first means may comprise a structure on which at least one cutting blade is supported, the blade or blades being presented to the bag as it is drawn over and across the blade or blades.

The second mcans may comprise a structure having juxtaposed surfaces which converge in the downstream direction, the bag being drawn between the surfaces in order to progressively squeeze its contents through the slit or slits previously formed in the bag by the first means.

Other devices, such as rollers or shaped jaws, may be used as alternatives to pressure-applying surfaces for this purpose.

The contents of the bag which are expelled by the second means may be collected in a built-in hopper in the lower part of the system.

Alternatively, a vessel such as a tote bin may be removably positioned beneath the second means or in some other location and be extracted from the system when fill.

The rotary parts of the system may be driven in rotation from a vertically extending shaft coupled to a motor mounted in or on an upper part of the system and driven electrically, pneumatically or hydraulically. The shaft may also be used to drive a scraper or wiper used to clean the inner S surface of a hopper or a lower part of the system.

Tt is recognised that bags fed to the system may contain constituents in the form of large pieces of food product such as meat or rigid peppers, which may obstruct the passage of bags through means applying pressure to the bags. Also, certain food products may exhibit a degree of additional stifthess when very cold, and in either case may lead to the system becoming jammed.

According to another aspect of the invention, a system for emptying bags which follow a path through an emptying system includes an array of baffles or other obstacles which bear on the bags and cause them to follow a sinuous, wavy or zig-zag course, whereby pressure is applied to alternate sides of the bag, thereby promoting the break up or dislodging of such food products.

In the drawings Figure 1 is a side elevation ofa preferred embodiment of the invention, Figure 2 is a perspective view of the preferred embodiment, with some minor modifications, Figure 3 is a view similar to Figure 2, but with part of the casing removed, Figure 4 is a plan view of the system omitting a stator ring with which the system is provided, and with an operating handle shown in its withdrawn or inoperative position, ) Figure 5 is view similar to Figure 4 with the stator ring in place, and the handle in its inoperative position, Figure 6 is a view similar to Figure 5 but with the handle in it operative position, Figure 7 is a perspective view of the lower part Of the system with thc upper part of the casing and certain other components omitted, Figure 8 is a perspective view of a slitting blade assembly and device for compressing bags, viewed from within, Figure 9 shows the slitting blade assembly of Figure 8 seen from an alternative viewpoint, Figure 10 shows a device for compressing bags, Figure 11 shows a device for compressing bags, incorporating an array or stack of baffles, Figure 12 shows a component of the baffle array of Figure 11, Figure 1 shows a single baffle of an alternative type, Figure 14 shows the locations of baffles of the type shown in Figure 12, Figure 15 illustrates cutting and compression assemblies of an alternative construction, Figure 16 shows three alternative constructions of baffle, and Figure 17 shows a bag for use with the system of the invention.

Referring to Figures ito 3 of the drawings, a bag opening and emptying system incorporates a casing assembled from a dished, lower casing part 1 supported on legs, a domed, upper casing part 2, and an intermediate, cylindrical wall 3. Located at the centre of the upper casing part is an electric motor 4 and gearbox 5. Figures 1 and 3 show the motor and gearbox within a casing, whereas Figure 2 shows the motor and gearbox uncased. The motor and gearbox serve to drive in rotation a vertically extending main shaft 7 which is located centrally of the system and is visible in Figure 7. It will be understood that a degree o 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 description. References herein to the shaft being vertical are to be understood in this general sense.

For the convenience of an operator working at a loading station, several bags of food product awaiting opening may be stowed in a chute 10 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 fi.irther bag along the chute. The casing is perforated to allow product to drain.

The system is adapted to entrain bags of fàod product along an arcuate path within the casing and draw them over a slitting means and through at least one compressing means adapted to apply pressure to the bags.

The mechanism used to entrain the bags will now be described with reference to Figures 4 to 6.

Each of Figures 4 to 6 is a cross-sectional view taken at a respective level through the system, and/or depicting a different stage in the operation of its drive mechanism. Referring first to Figure 5, a stator ring Ii extends in an arc from a counter-clockwise facing end which is adjacent to the chute to a clockwise facing end indicated at 1 lain Figure 5. The stator ring 11 is positioned with its radially outer edge closely adjacent to a radially inner surface portion of the casing, and may be mounted on the casing or supported by way of other support structure.

Positioned concentrically within the stator ring and at the same level as that ring is a rotatable, guide ring 13. The stator and guide rings are spaced from each other by a narrow channel 15 which widens out to terminate at its clockwise end 1 la a short distance shy of the chute 10.

An exit opening 17 through which empty bags may be ejected from the system is located beyond the end I la of the stator ring and may consist in part of the metal mesh 22a. The outlet 17 may open into a discharge chute 18 shown in Figure 2.

Referring now to Figure 4, a cam wheel 19 is disposed beneath the radially inner edge ofthe stator ring 11 and is concentric with and coupled to the guide ring 13 as by welding. Struts 20 radiate from the drive shaft 7 and are made fast with the guide ring and cam wheel assembly. Nylon pads 21 are provided around the circumference of the cam wheel 19 as best illustrated in Figure 4 to prevent metal on metal contact between the cam wheel and the stator ring. An indentation or blind groove 23 is provided in the radially outer edge of the cam wheel and provides for a camming action as will be described below. Preferably several such indentations are provided in the cam wheel. Guard pieces 22a and 22b of metal mesh are located beneath any moving parts or positioned so as to close off any untoward spaces, in order to catch escaping food product and simplit' cleaning, as by hosing down after use.

An arcuate handle 25, shaped at 29 for ease of manipulation, is mounted above the delivery chute 10 at the loading station and is arranged to swivel about a pivot axis 27 between an inoperative, withdrawn position shown in Figure 4 and an operative position shown in Figure 6. When the handle is in its operative position it bears against the cam wheel and a recess 31 in the handle aligns with the channel 15. In this position the handle also extends the end 1 lb of the stator ring, In its inoperative or withdrawn position the handle is spaced from the cam ring.

At the commencement of a cycle of operation, the handle is set in its inoperative position. The motor is started so as to drive the guide and cam ring assembly in rotation in the clockwise direction with reference to Figures 4 to 6. A bag such as that shown in Figure 1 7is pushed along the delivery chute 10 into an accessible position and its neck introduced into the recess 3 1. With the earn and guide wheels in rotation the handle is turned in the counter-clockwise direction with respect to Figures 4 to 6 so that it bears against the cam wheel. As the cam wheel rotates, the indentation 23 (or one of the indentations) in its side comes into alignment with the handle. The neck and clip enter the indentation 23 and the bag neck becomes trapped in the channel 15 between the stator and guide rings, whereby the bag is drawn around the system, across the slitting blades and through at least one bag compression assembly until it is released by the channel and leaves the system through the outlet 17 and chute 18 Figure 7 is a perspective view of the interior of the lower casing part, omitting the internal components save for the main shaft 7, a bag slitting assembly 40, a first bag compression assembly 50, a second bag compression assembly 60, and an optional ramp 80 leading to the outlet 17. The contents of the bags drop into the bottom of the lower casing part. Arms 71 extending from the shaft 7 carry scrapers and!or wiper blades 73 for scraping or wiping the inner surface of the lower casing part, and directing accumulated food product to the outlet 74 in the base of the casing, so that it is discharged into a hopper or a vessel such as tote bin. The lower part of the casing may serve as a hopper in this respect.

A framework 75 extends from the support legs for holding in place such a vessel Figure 7 also shows an additional compressing assembly 60 shortly to be described with reference to Figure 11 which serves to work on, loosen or crush products which offer greater resistance than the compression assembly 50 can readily act on alone. It falls within the scope of the invention for assembly 60 to be used to back up assembly 40, or for it to be used in place of the latter, or for two identical assemblies 60 to be used.

As shown, the slitting assemblies are positioned at approximately sixty degrees relative to each other. However, it may be advantageous to position the slitting assemblies closer together, say at twenty degrees spacing, as this provides for there to be a wider opening so that the bags drop onto the mesh guard more reliably without interfering with the entry chute.

To provide ready access to the various assemblies shown in the drawings for replacement or cleaning, the casing is provided with rectangular IC openings over which support plates may be mounted with an overlap.

Each of the assemblies may be mounted on the inner side of the plate and project through the opening.

In the case of the slitting and compression assemblies 40 and 50 respectively, both assemblies are mounted on one and the same support plate 44 and held in place by a retaining strap 43 having inwardly bent ends. The compression assembly 50 is mounted above the slitting assembly 40.

Referring to Figures 8 and 9, the slitting assembly incorporates a vertical plate 46 defming an opening across which extends a bar 48 for supporting a set of three slitting blades or knives 47. It has been found, however, that better results may be obtained using five blades. The compression assembly 50 incorporates shoulders 51 between which is defined a gap through which the bag passes after being slit by the blades 47. The arrangement is such that bags drawn through the system are compelled to pass through the gap of the bag compression assembly, the gap narrowing in the direction of travel of the bag, and cannot pass over it.

Figure 10 shows a device 50 for compressing bags and illustrates the arrangement for mounting assemblies of various types in conjunction with openings in the casing by means of a metal strap 51 which is bent round at its ends to grasp the edges of the opening in the wall of the system.

Referring to Figures 11 and 12, the compression device shown therein incorporates an array of baffles adapted to resist the passage of a bag and thereby bear on, 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 is assembled from a plurality of rectangular panels 60, each provided with a pair of parallel slots 62 and screw holes 63 to enable the baffles to be fastened together at their lower ends. At their upper ends the free ends of the legs of the panels are received in openings 66 in a pair of plates 64, the facing edges of which are separated by a sinuous groove 65. The assembly is mounted on a plate 67 to fit over an opening in the casing wall, and held in place by strap 68. As the bag is drawn over the plates 64, the bag is pulled down between them and through the array, the plates preventing the bag escaping upwards.

Figure 13 shows an alternative baffle design which may be employed in place of the baffles of the array just described. The baffle has a projecting top-piece 71 to restrain bags from escaping over the heads of the baffles. Figure 14 shows the baffles of Figure 13 in plan, defining the path to be followed by a bag relative to the baffles of this construction, again providing for buffeting the bag as it passes between them.

Figure 15 shows alternative slitting and compressing assemblies respectively. The blades 90 of the slitting assembly are mounted at the end of a support track 92 to be followed by the bags. The blades are mounted on a horseshoe shaped support 91. The compression assembly also incorporates a horseshoe shaped assembly 95 shaped to apply pressure to the bags as they proceed through it. The structure has a turned back end piece 96 to provide more effective operation.

It will be understood that modifications may be made to the system described above and that the groove or indentation in which the neck of the bag is received may take any convenient fonn, consistent with the function it has to perform, and be provided in any convenient number.

Claims

CLAIMS.I. A system for emptying bags including a conveying device adapted to rotate about an upwardly cxtending axis and entrain or propel a bag along s a curvilinear path, a first means associated with said path for slitting the bag, and a second means associated with said path for causing the contents of the bag to be evacuated through a slit or slits formed by the first means.
2. A system as claimed in claim 1, further comprising third means for delivering a bag into the path such as to be entrained therealong by the conveying device, and fourth means for providing an outlet for a bag which has acted upon by the first and second means.
3. A system as claimed in claim 2, wherein the third means is associated with a chute for the introduction of bags into the system.
4. A system as claimed in any preceding claim, wherein the conveying device is adapted to rotate continuously when in operation, whereby bags are capable of being admitted in sequence into the system, without the system being brought to a halt.
5. A system as claimed in any preceding claim, wherein the conveying device comprises a rotor provided on or in the vicinity of its periphery or circumference with means for coupling the rotor to a bag.
6. A system as claimed in claim 5, wherein the last-named means comprises at least one groove, cut-out, notch or indentation.
7. A system as claimed in claim 6, including a handle or lever for urging part of the bag into such groove, cut-out, notch or indentation.
8. A system as claimed in claim 6 or claim 7, wherein the groove, cut-S out, notch or indentation is in the radially outer peripheral edge of a cam wheel.
9. A system as claimed in any preceding claim, wherein said first means comprises at least one cutting blade across which a bag is adapted to be drawn by the conveying device.
10. A system as claimed in any preceding claim, wherein said second means comprises juxtaposed surfaces which converge in the direction of movement of a bag through the system, whereby in operation the bag is drawn between the said surfaces such as to progressively compress the bag and squeeze its contents out through a slit or slits formed in the bag by the first means.
11. A system as claimed in any preceding claim, wherein said path lies through an array of baffles which in use apply pressure to alternate sides of the bag.
12. A system as claimed in claim 11, wherein in use bags are arranged to follow a sinuous path through the array of baffles.
13. A system as claimed in any preceding claim, wherein rotary components of the system are drivable in rotation from a shaft coupled to drive means mounted on a cover for the system.
14. A system as claimed in claim 13, wherein the shaft is coupled to a scraper or other means for cleaning inner parts of the system.
15. A system for emptying bags of flowable food product including a conveying device arranged to rotate about an upwardly extending axis and entrain bags along a curvilinear path from a bag loading station and through a bag slitting station and a bag stripping station, at which latter station the contents of a bag are discharged under pressure through a slit or slits formed in the bag at the slitting station.
16. A system as claimed in claim 15, including an array of baffles or other obstructions to bags travelling along said path, and causing bags to follow a sinuous path whereby pressure is applied to alternate sides of the bags.
17. A system as claimed in any preceding claim, wherein means for slitting or compressing bags are mounted on support plates fitted over openings in a casing for the system.
18. An array of baffles mounted on support plates separated by a sinuous gap through which bags are compelled to travel as they pass through a system for emptying such bags.
19. Apparatus for emptying bags including a conveying device arranged to rotate about an upstanding axis and entrain bags along a path through, sequentially, a bag loading station, a bag slitting station and a bag stripping station, at which latter station the contents of a bag are discharged under pressure through slits formed in the bag at the slitting station. *
20. Apparatus as claimed in claim 19, wherein the conveying device is arranged to rotate continuously.
21. Apparatus as claimed in claim 19 or 20, in which the conveying device is in the form of a rotary wheel, the peripheral edge of which is provided with means for engagement with the neck of the bag at the loading station.
22 Apparatus as claimed in claim 21, wherein said means comprises a cut-out, notch or indentation in the rim of the wheel. **

*
23. Apparatus as claimed in any of claims 19 to 22, wherein the slitting 15 station comprises a structure on which at least one cutting blade is supported and slits the bag as it is drawn over the blade or blades.
24. Apparatus as claimed in any of claims 19 to 22, further comprising a ri a lever or handle at the loading station for displacement by an operator so as to press the neck of the bag against the edge of the disc and bring about its capture.
25. A system substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.