WO2000027212A1

WO2000027212A1 - Method, device and assembly for damping swinging carcasses

Info

Publication number: WO2000027212A1
Application number: PCT/NL1999/000667
Authority: WO
Inventors: Richard Antonius Maria Klein Goldewijk; Hendrik Jan Pardijs
Original assignee: Stork MPS BV
Current assignee: Marel Red Meat BV
Priority date: 1998-11-10
Filing date: 1999-10-28
Publication date: 2000-05-18
Anticipated expiration: 2001-05-10
Also published as: NL1010522C2

Abstract

The invention relates to a method for damping swinging movements of a carcass (4) or a carcass part suspended from a conveyor (2), by the successive steps of: A) moving the carcass (4) or carcass part to at least one engaging element (8) lying in the transport path of the carcass (4) or carcass part, B) placing the carcass (4) or carcass part in contact with the engaging element (8), and C) causing the engaging element (8) to move aside to allow passage of the carcass or carcass part, wherein the engaging element (8) exerts a damping force on the swinging carcass or carcass part. The invention also relates to a device (3) for performing this method and an assembly of such a device and a conveyor (2) for carcasses or carcass parts.

Description

Method, device and assembly for damping swinging carcasses

The invention relates to a method and device for damping swinging movements of a carcass or carcass part suspended from a conveyor. The invention also relates to an assembly of a conveyor for suspended displacement of carcasses and/or carcass parts and at least one device damping swinging movements of carcasses and/or carcass parts transported in suspended manner.

Carcasses and carcass parts are usually displaced hanging from a conveyor. An example hereof is a slaughter line in which the hanging carcasses or carcass parts are displaced between different processing stations so as to undergo successive treatments. As a result of for instance wear to the conveyor (chain, track etc.), changes in transporting direction, decelerations and accelerations the carcasses will begin to swing. This undesirable swinging can be made even worse by so-called resonance effects. Swinging of the carcasses or carcass parts is undesirable because it makes processing thereof more difficult, particularly in the case of automated processing thereof. A uniform presentation of the carcasses and/or carcass parts to the automated processing stations is desirable in order to simplify mutual positioning. Performing of measurements on carcasses or carcass parts is also simplified hereby. Reduced swinging moreover results in a reduced load on conveyors. The measures according to the prior art for cushioning and damping swinging movements consist of guides which are formed by for instance rods or strips and which engage on carcass or carcass part on one or two sides more or less parallel to the transporting direction. A drawback of these guides is that the carcass or carcass part will often bounce against the guide. Another drawback is that the carcass or carcass part encounters resistance from the guide which causes it to hang askew. Yet another drawback is that there is the possibility of the carcass beginning to more or less rotate over the guide.

The French patent application FR 2 663 418 thus describes a weighing device for loads carried by a suspended conveyor. For weighing purposes the loads are carried over a weighing track part which is provided with separate transporting means for further transport of loads over this track section. In order to position a suspended load so that it is as still as possible, the weighing track section is provided with a stabilizer which is embodied such that a load is urged sideways by the stabilizer. The load slides along the stabilizer as it is displaced over the track section. The guide for stabilizing the load is urged with an adjustable bias against the load by an elastic element. In addition to the above described drawbacks of the prior art, such a device has the feature that the centre of gravity of a hanging load is urged laterally out of the transport path to a higher position whereby swinging of the load, particularly in sideways direction, is prevented during engaging of the load. Once the load is released from the stabilizing means the load will swing back sideways to a lower position. Release of the load from the stabilizing means thus results in (renewed) swinging. The stabilizing means engage asymmetrically onto the carcasses. A further drawback of stabilizing by means of stabilizing means as described in the French publication is that a thus stabilized carcass is less easily accessible for the conducting of processes because it is lying against a guide at a position generally relevant for performing slaughtering operations.

The present invention has for its object to provide an improved method and device for damping swinging movements of carcasses or carcass parts suspended from a conveyor which, while retaining the advantages of the prior art, do not have the above stated drawbacks.

The invention provides for this purpose a method of the type stated in the preamble with the successive steps of:

A moving the carcass to at least one engaging element lying in the transport path of the carcass,

B placing the carcass in contact with the engaging element, and

C causing the engaging element to move aside to allow passage of the carcass, wherein the engaging element exerts a damping force on the swinging carcass.

During a subsequent processing step D the engaging element is preferably moved back to a starting position after passage of the carcass. By placing the carcass in contact with the engaging element, which then moves aside, it is possible to stop the swinging movements of a carcass or carcass part without a reaction movement in the form of for instance bouncing back. It is possible to cause the engaging element to move aside under the influence of the force exerted by the carcass or carcass part, but it is also possible to actively control the engaging element using for instance a hydraulic or pneumatic cylinder. It is found in practice that using very simple means this method can bring a carcass or carcass part to a complete or practically complete standstill. The method occupies only a very limited part of the transporting route. Another significant advantage of the method according to the invention is that the position of the carcass or carcass part relative to the conveyor is not important for damping the swinging movement thereof. The above discussed guides for damping the swinging movements operate, with the stated drawbacks, only when the carcass or carcass part is displaced symmetrically of the conveyor. This is the case for instance when the carcass is moved with the back facing forward, the guides can then engage symmetrically on the carcass. It is however usually desired in practice to displace a carcass sideways since the abdomen is then readily accessible for processing stations disposed adjacently of the conveyor. With the method according to the invention a carcass being transported sideways or transversely and swinging can be damped as well as a carcass being transported with the back facing forward.

Known from the European patent application 0 545 501 not cited in the search report is a measuring plate which at first sight displays some resemblance to an embodiment of the device according to the invention. The measuring plate is adapted to move aside with minimal resistance when a hanging carcass exerts a force thereon. The angular displacement of the measuring plate is a measure for the length of the hanging carcass.

The apparent outward similarity between this measuring plate and the device according to the invention is purely coincidental. Other than the measuring plate, an engaging element according to the invention must exert a substantial force on the swinging load to stop the swinging movement. The measuring plate moreover functions differently and the effect sought by means of the invention - the stabilizing of swinging carcasses - is neither realized by the plate nor described as such.

The return movement according to step D preferably takes place in damped manner. The engaging element can thus be prevented from making a rapid return movement after passage of the carcass wherein the engaging element once again engages on the carcass or carcass part. This accelerated return movement could result in renewed swinging of the carcass or carcass part. This is prevented if the return movement after passage of the carcass or carcass part is carried out with some deceleration; an abrupt return movement is cushioned by damping.

The force exerted by the engaging element on the carcass or carcass part during step C preferably increases less than proportionally to the displacement of the engaging element. Still more preferably the maximum force exerted by the engaging element on the carcass or carcass part remains substantially the same as the displacement of the engaging element progresses. It has been found desirable for a good damping that the force exerted by the engaging element on the carcass or carcass part does not increase too much during further displacement thereof. The best results are obtained in practice when during displacement the engaging element exerts a decreasing force on carcass or carcass part.

The engaging element preferably engages the carcass or carcass part close to a freely suspended underside. The travel distance of the swinging movement will generally be greatest on the freely suspended underside, so it is at precisely this position that the carcass must be engaged for an effective damping. Another advantage of engaging on carcass or carcass part close to the freely suspended underside is that the whole object is thereby situated between point of suspension and engaging element. Damping of the swinging movement of the carcass or carcass part will therefore result in damping of the movement of the whole carcass or carcass part. If the engaging element were to engage the carcass or carcass part at a position close to the middle thereof there would be the danger of the remaining freely suspended carcass part under the engaging element continuing to swing. It is also possible to damp swinging movements transversely of the transport path using the method according to the invention.

In yet another preferred application of the method at least one engaging element engages the carcass or carcass part symmetrically relative to a transporting plane running vertically through the transport path. In addition, a subsequent slaughtering process is preferably carried out only after the swinging movements of the carcass or carcass part have been damped. The symmetrical engagement of the engaging element (or engaging elements) has the advantage that when the carcass or carcass part is released from the engaging means no swinging need occur as a result of this release. It is noted here that swinging of a carcass or carcass part consists of two components, a component in the transporting direction and a component perpendicularly of the transporting direction (or, in other words, perpendicularly of the vertical plane through the conveyor). For precise execution of slaughtering processes it is desirable that the carcass or carcass part swings as little as possible during carrying out of the processes. In addition, the carcass or carcass part must be readily accessible, and this is the case when the slaughtering processes are carried out after the stabilizing means have been removed from the carcass or carcass part.

The invention also provides a device for damping swinging movements of a carcass or carcass part suspended from a conveyor, comprising at least one engaging element provided with a contact surface for engaging on the carcass or carcass part, which contact surface is displaceable counter to a bias under the influence of a force exerted on the contact surface by the carcass or carcass part. The device is preferably also provided with biasing means which engage on the contact surface for urging thereof to a starting position. In another preferred embodiment the device is also provided with at least one damper engaging on the contact surface in order to damp a return movement of a contact surface. The above described method can be performed using such a device. The form of the contact surface can be adapted to the form of the carcasses or carcass parts for damping. A contact surface consisting of a plate pivotable counter to bias is found to suffice well in practice.

A variant of the plate-like contact surface is to manufacture the engaging element from a compressible material which, after compression, returns to a starting position in the non- loaded state. Here can be envisaged for instance a compressible foam material which after compression resumes its original shape in the non-loaded state. For good hygiene it will probably be necessary to cover such compressible material with a fluid-tight layer of for instance plastic.

In yet another preferred embodiment the engaging element is embodied as a plate provided with centring means. It is possible here to envisage for instance a plate with a V-shaped contact edge or a plate in concave form. Achievement of stable balance will be enabled even more simply and rapidly by centring of the carcass or carcass part.

The invention also comprises an assembly of a conveyor for suspended displacement of carcasses and/or carcass parts and at least one device for damping swinging movements of carcasses and/or carcass parts transported in suspended manner as described above, wherein the device is placed substantially symmetrically under the conveyor. In a preferred embodiment the device comprises a pivotable engaging element, the rotation shaft of which lies substantially perpendicularly of the transporting direction of the conveyor. An engaging element can thus be placed for instance perpendicularly under the conveyor or pivotable plates can be disposed under the conveyor on either side of the transport path.

In a preferred embodiment this assembly is provided with a device which also comprises at least one processing station which is placed a short distance behind the device in the transporting direction, the distance between assembly and processing station preferably being less than 4 metres and more preferably less than 2 metres. Since swinging of carcasses and carcass parts is particularly inconvenient when processes are to be carried out, it is desirable to damp this swinging movement shortly before a process is to be carried out. It is therefore desirable from this point of view to place a device according to the invention a short distance before a processing station. The carcass or carcass part will then not or practically not be swinging when it reaches the processing station. As processing station can be envisaged for instance a station for opening the abdomen, leaf- fat stripping, cleaving and so on, although a measuring station is also a possible option.

The present invention will be further elucidated with reference to the non-limitative embodiment shown in the following figures. Herein: figure 1 shows a side view of an assembly of conveyor and device for damping swinging carcasses according to the invention, and figure 2 shows a detail side view of the device for damping swinging carcasses as shown in figure 1. Figure 1 shows an assembly 1 of a conveyor 2 and a device 3 for damping swinging movements of a carcass 4 suspended from conveyor 2. In this case the carcass 4 is that of a pig hanging with hind legs 5 from a conveyor track 7 via a suspension bracket 6. Suspension bracket 6 can for instance be displaced in a transporting direction PI by means of a transport chain not shown in this figure.

In order to damp swinging movements of carcass 4 the device 3 is placed under conveyor 2 such that carcass 4 will come up against a pivotable plate 8 which will move aside with continued transport of carcass 4. Pivotable plate 8 is shown in fully swivelled-away position by means of broken lines. For the carcass 4 shown in this figure it is unnecessary for pivotable plate 8 to be rotated as far as shown in this figure. Pivotable plate 8 will be pressed only as far downward by carcass 4 that carcass 4 can be carried past the plate 8.

Plate 8 is connected to a frame 9 for pivoting round a rotation shaft 10, which frame will be further elucidated with reference to figure 3. The pivotable plate is connected to a counterweight 11 situated on the opposite side of rotation shaft 10. The force of gravity on this counterweight 11 thus provides the bias with which pivotable plate 8 is urged against a carcass 4.

Figure 2 is a top view of device 3 which shows clearly that pivotable plate 8 continues beyond rotation shaft 10 and that counterweight 11 is far less wide than plate 8.

Figure 3 shows device 3 in more detail. The height of frame 9 is adjustable by means of a bolt 12 so that the distance between rotation shaft 10 and ground 13 can be adjusted.

The height of device 3 can thus be adjusted depending on the length of the carcasses or carcass parts for processing. Pivotable plate 8 can be locked in a horizontal position using a pin 14 fixed to a chain 15. For this purpose, after pivotable plate 8 has been placed in the horizontal position, the pin 14 is placed in an opening specially arranged therefor in frame 9. In this horizontal position of plate 8 the device 3 allows free passage of carcasses 4. Further arranged on frame 9 is a stopper 16 for bounding an extreme position of plate 8. This position of plate 8 shown with broken lines.

The counterweight 11 connected to pivotable plate 8 can be embodied as a container 20 for partially filling with liquid 21, so that the centre of gravity of the counterweight is shifted when plate 8 is pivoted. In the position of container 20' shown with broken lines the liquid 21' is urged to the outer end of container 20' located furthest away from rotation shaft 10. A centre of gravity 22' of the liquid 21' at which the force of gravity indicated by means of arrow F engages is hereby located at a relatively great distance from rotation shaft 10. When plate 8 and container 20 are displaced to a horizontal position, some of the liquid 21 will displace in the direction of rotation shaft 10. The centre of gravity 22 at which the force of gravity F engages on liquid 21 is hereby likewise displaced in the direction of rotation shaft 10. The figure shows clearly that centre of gravity 22 lies closer to the rotation shaft when plate 8 is situated in a horizontal position than centre of gravity 22' when plate 8' is situated in the position shown with broken lines. The resistance curve of plate 8 is thus such that the force exerted on a carcass 4 by plate 8 decreases as plate 8 approaches closer to the horizontal position. It is further conceivable for the distance between counterweight 11 and rotation shaft 10 to be adjustable, for instance by shifting a counterweight relative to rotation shaft 10 by means of a drive arranged for this purpose. Control of the position of such an intelligent counterweight can be derived for instance from the position of plate 8.

Figure 3 further shows schematically a washing device for cleaning pivotable plate 8 once it has been in contact with a carcass. For this purpose a number of washing apertures connecting onto a washing pipe 17 are provided close to the free end of plate 8 furthest remote from rotation shaft 10. Washing pipe 17 is connected by means of a flexible conduit 18, here shown schematically, to an electric valve 19 with which washing water can be supplied at the appropriate moments. Operation of electric valve 19 can be controlled for instance by means of sensors. A sensor can be incorporated in conveyor 2 or in device 3. Although the invention is elucidated with reference to only a single embodiment, it will be apparent to all that the invention is by no means limited to the described and shown embodiment. On the contrary, many other variations will be possible for the skilled person within the scope of the invention.

Claims

1. Method for damping swinging movements of a carcass or a carcass part suspended from a conveyor, by the successive steps of: A moving the carcass or carcass part to at least one engaging element lying in the transport path of the carcass or carcass part,

B placing the carcass or carcass part in contact with the engaging element, and C causing the engaging element to move aside to allow passage of the carcass or carcass part, wherein the engaging element exerts a damping force on the swinging carcass or carcass part.

2. Method as claimed in claim 1 , wherein during a subsequent processing step D the engaging element is moved back to a starting position after passage of the carcass or carcass part.

3. Method as claimed in claim 2, wherein the return movement according to step D takes place in damped manner.

4. Method as claimed in any of the foregoing claims, wherein the force exerted by the engaging element on the carcass or carcass part during step C increases less than proportionally to the displacement of the engaging element.

5. Method as claimed in claim 4, wherein the maximum force exerted by the engaging element on the carcass remains substantially the same as the displacement of the engaging element progresses.

6. Method as claimed in any of the foregoing claims, wherein the engaging element engages the carcass or carcass part close to a freely suspended underside.

7. Method as claimed in any of the foregoing claims, wherein at least one engaging element engages the carcass or carcass part symmetrically relative to a transporting plane running vertically through the transport path.

8. Method as claimed in any of the foregoing claims, wherein a subsequent slaughtering process is performed after the swinging movements of the carcass or carcass part have been damped.

9. Device for damping swinging movements of a carcass or carcass part suspended from a conveyor, comprising at least one engaging element provided with a contact surface for engaging on the suspended carcass or carcass part, which contact surface is displaceable counter to a bias under the influence of a force exerted on the contact surface by a carcass or carcass part.

10. Device as claimed in claim 9, comprising biasing means which engage on the contact surface for urging thereof to a starting position.

11. Device as claimed in claim 9 or 10, wherein the device also comprises at least one damper engaging on the contact surface in order to damp a return movement of the contact surface.

12. Device as claimed in any of the claims 9-11, wherein the device comprises at least one plate pivotable counter to a bias.

13. Device as claimed in any of the claims 9-11, wherein the engaging element is manufactured from a compressible material which, after compression, returns to a starting position in the non-loaded state.

14. Device as claimed in any of the claims 9-12, wherein the engaging element is embodied as a plate provided with centring means.

15. Assembly of a conveyor for suspended displacement of carcasses and/or carcass parts and at least one device for damping swinging movements of carcasses and/or carcass parts transported in suspended manner as claimed in any of the claims 9-14, wherein the device is placed substantially symmetrically under the conveyor.

16. Assembly as claimed in claim 15, wherein the device comprises a pivotable engaging element, the rotation shaft of which lies substantially perpendicularly of the transporting direction of the conveyor.

17. Assembly as claimed in claim 15 or 16, wherein the device also comprises at least one processing station which is placed a short distance behind the device in the transporting direction.