GB1559931A

GB1559931A - Press for separating meat and bones

Info

Publication number: GB1559931A
Application number: GB2370677A
Authority: GB
Original assignee: Protecon BV
Current assignee: Protecon BV
Priority date: 1976-06-30
Filing date: 1977-06-03
Publication date: 1980-01-30
Also published as: NL187335C; NL7607187A; NL187335B

Description

(54) A PRESS FOR SEPARATING MEAT AND BONES (71) We, PROTECON B.V., a Dutch limited liability company, of Kromstraat 7-9, OSS, the Netherlands, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:: This invention relates to a press having a piston and press cylinder for putting animal meat and bones under pressure in order to bring the meat into a paste-like condition and to cause it to flow out of a chamber within the press, the press including a slide valve adapted to open and close a large opening in a front face of the chamber so that, after opening the slide valve the bones remaining in said chamber after pressing may be discharged by further movement of the movable piston inside the press cylinder.

Such a press is known from UK Patent Specification No. 1,500,052 in which the large opening, through which the bones may be discharged from the chamber is much smaller in transverse section than the chamber itself, and there are a number of annular bodies positioned within the press cylinder near the slide valve which define a substantially conical opening which becomes narrower towards the slide valve and define an internal surface which smoothly converges from the inner wall of the press cylinder to the discharge opening at the slide valve. Between the annular bodies there are small discharge openings for the meat paste. The discharge of the bones using this known structure requires a great deal of energy and there is the danger that small splinters of bone will leave the press with the meat paste.Moreover much of the paste-like meat has to travel a long path through the mass of bones and meat in order to reach a meat paste discharge opening.

The present invention provides a press comprising a piston and press cylinder, the piston being movable in the cylinder to press animal meat with bones in order to bring the meat into a paste-like condition and to cause it to flow out of a chamber within the press, the press including a slide valve adapted to open and close an opening in a front face of the chamber so that, after pressing the slide valve is opened and the bones remaining in said chamber are discharged through the opening by further movement of the movable piston, a plurality of fine openings connected to passages for allowing passage of meat whilst in a paste like condition being arranged in a surface which extends perpendicular to the direction of movement of the piston, said fine openings communicating with a discharge opening said surface being arranged so that a part of the press will scrape across the fine openings to clean them when the slide valve is moved.

Such fine openings may be present in the slide valve or in the front face of the piston or in both. In the described arrangement whenever opening or closing the slide valve there is a scraping of an edge of the press cylinder and/or of the opening in the slide valve over the openings which cleans them to remove bone splinters, and the material removed will stay in the press chamber or in the opening in the slide valve and be discharged from the chamber with the bones during subsequent movement of the piston after the slide valve has again reached the open position.

If the fine openings are provided in the front face of the piston, said body is adapted to move with said front face into the plane of the front face of the slide valve (only when the slide valve is opened because otherwise the bones present in the chamber would prevent this). Closing the slide valve will slide it across said front face of the piston, so that the edge of the opening in the slide valve will scrape clean the fine openings in the front face of the piston, and the remaining bones will thus be discharged from the chamber by this continued forward movement of the piston body.

If the fine openings are provided in the slide valve these will be scraped clean when the slide valve opens and thus scrapes along an edge of the press cylinder.

If the openings are provided in both parts they can moreover slide across each other so as to be subjected to an additional cleaning action when closing the slide valve.

Where fine openings as indicated above are provided in the front face of the piston, then preferably behind the front face of the piston and within it there is a space connecting with the passages and with the outer peripheral wall of the piston, the piston behind said front face having a clearance with respect to the inner surface of the press cylinder and the space created by said clearance being connected to a discharge for meat paste remote from the slide valve.

The said fine openings, whether provided in the slide valve or in the piston or in both are preferably provided in a disc shape body, supported at its rear by a part of either the slide valve or the piston having passages to allow passage of the meat paste.

Such disc shaped bodies may easily be separated from the slide valve or the piston to be cleaned, inspected or replaced.

It is moreover often preferred to provide a separate annular body in the chamber around the opening adjacent the slide valve, which annular body is guided so as to be at least partially axially slidable in the chamber and is adapted to be pressed by the pressure in the chamber during pressing against the slide valve, the front face of the piston being movable into and out of said annular body with slight clearance between said front part of the piston and said annular body.

In order to obtain a favourable ratio between pressure and capacity it is often desired and preferable to realise the invention in such a way that there is moreover a number of fine openings for allowing passage of meat in the peripheral wall of the chamber which is substantially parallel to the direction of movement of the piston ie in the inner wall of the press cylinder. Where there is also a number of fine openings in the front face of the piston, the meat passing through both sets of openings may have a common discharge adjacent the end of the cylinder opposite the slide valve.

The invention will now be explained in more detail with reference to two preferred embodiments shown in the enclosed drawings. In said drawings: Figure 1 shows the main parts of a press according to a first embodiment of the invention with parts broken away; and, Figure 2 shows a press according to a second embodiment of the invention also with parts broken away.

In Figure 1, 1 is a press cylinder, in which a movable pressing body in the shape of a piston 2 is movable back and forth, the space between the piston 2 and cylinder 1 comprising the press chamber. At the right of the parts shown in the drawing there are conventional driving means (not shown) such as a hydraulic or pneumatic cylinder with piston etc. to move the press piston 2 back and forth. Between said driving means and the part of piston 2 shown in the drawing there is a filling chamber for meat and bones bordered at the left by a wall 8 and having a cover which may easily be opened and closed, and there may also be suitable control and switch means for the piston and other necessary parts, for instance as given in more detail in British Patent Specification 1,500,052 indicated above.

The front part 3 of piston 2 is a sliding fit with the inner wall of the cylinder 1 and behind this front part 3 there is a clearance between the piston 2 and cylinder 1 forming an annular space 4 around the piston, which space 4 connects with a discharge space 5 for meat which in turn is connected to a discharge duct 6.

A sealing ring 7 of rubber or the like is supported against wall 8 bordering the filling chamber and said ring 7 seals between the outer periphery of the piston 2 and the right hand end of the discharge space 5.

At the left side of Figure 1 the cylinder 1 has an annulus 9 sealed by an O-ring 10 against the inner wall of the cylinder, which annulus 9 may slide to limited extent in a horizontal direction to the left and to the right relative to the press cylinder.

The press cylinder 1 has a cover 11 at the left of Figure 1 with a wide discharge opening 12 for the bones having an inner diameter which is equal to or slightly less than the inner diameter of the annulus 9.

This cover 11 is rigidly connected to the press cylinder 1, for instance through a flange connection not shown. Between cover 11 and the front face of the press cylinder 1 is left a slot which in horizontal section has a rectangular shape and which extends vertically entirely through these parts so as to be open at the top and the bottom. A body 13 of a slide valve is guided in this slot. A hydraulic or pneumatic cylinder 14 (only shown in part) is adapted to move the slide valve body 13 up and down in the slot and is of course provided with supply and discharge means and control means for a fluid under pressure in the usual way to move the slide valve up and down when desired.

The slide valve body 13 has a large discharge opening 15 for allowing the bones to pass therethrough, with an inner diameter equal to or almost equal to the inner diameter of the annulus 9 and of the discharge opening 12. In Figure 1 the body 13 is shown in a position in which it closes the chamber within the press cylinder from the discharge opening 12. In the slide valve body 13 a circular body 16 is mounted for discharging meat paste as will be described below. The body 16 is provided with a large number of passages or perforations, so small that bones and splinters cannot pass therethrough, but which are adapted to allow the passage of the meat-which because of the pressure in the chamber becomes paste-like.

The passages in the body 16 may each, as is well known, have a smaller diameter opening where they communicate with the chamber and may be wider behind the fine opening (to the left of Figure 1). For instance their fine openings may have a diameter of 1 mm and they may have a diameter of for instance 3 mm behind the opening and there may be a gradual or a sudden transition from the narrower to the wider part. In this way hard particles entering the fine openings of the passages are less likely to cause clogging or jamming but will be discharged with the meat paste since having passed the fine openings they will reach a wider part of the passages Such passages have been indicated by dot and dash lines 17 in a diagrammatic way in Figure 1.

In its left hand face in Figure 1, the body 16 has a number of concentric annular collecting spaces 18 communicating with passages 19 in the slide valve body 13 so that the meat paste flowing through the passages 17 may flow through said spaces 18 and passages 19 towards a meat paste discharge 20, to which for instance a hose or small discharge pipe may be connected by a screw threaded connection shown.

The front face of the press piston 2 carries a separate body 21 the outer periphery of which seals with the inner surface of the press cylinder as shown at 3 and as described above, and onto this body 21 a front face body 22 is rigidly mounted, having a large number of fine openings and passages 23 corresponding to the fine openings and passages 17 in body 16. The body 22 has a number of annular recesses 24 into which paste-like meat from the chamber is transferred through the passages 23, which meat thereafter may flow through passages 25 in body 21 and from there outwardly into the space 4 and from there to space 5 and discharge 6.

The operation of this press is as follows: the piston 2 is fully retracted to the right in Figure 1 and is not only withdrawn from the press cylinder 1 but also is withdrawn some distance into the filling chamber immediately to the right of wall 8. A quantity of bones with adhering meat is now fed into said filling chamber. These bones may be bones remaining after the trimming of slaughtered animals which have meat remnants remaining attached thereto. Said filling chamber is then closed and piston 2 is moved to the left towards the press cylinder in Figure 1. The slide valve 13 is in the position shown in Figure 1.The piston 2 moves said bones with meat from the filling chamber into the press cylinder I and when the piston 2 has moved forward (to the left) sufficiently and into the chamber, the mass of bones is put under pressure as it is enclosed between said piston, the peripheral wall of the chamber in cylinder 1 and the front face of the body 13 of the slide valve formed by the body 16.

The pressure thus exerted on the mass of bones and meat causes the meat to be brought into a paste-like condition so that it may easily flow and thus leaves the press chamber through the fine openings and passages 17 in body 16 and 23 in body 22 so as to flow towards the discharges 20 and 6 respectively. During this pressing operation the annulus 9 is pressed tightly by the pressure in the chamber against the slide valve 13 to seal the chamber.

When sufficient meat has been removed the pressure on piston 2 is lowered, either by lowering the pressure in the hydraulic or pneumatic cylinder driving piston 2 or by keeping the piston stationary for a short time, during which the pressure in the chamber will gradually decrease by meat flowing out and because of the lower pressure the slide valve 13 is more easily movable. The slide valve 13 is then moved downwardly until opening 15 is aligned with the opening in annulus 9 and the discharge opening 12.

Piston 2 is now moved farther to the left in Figure 1 and will thus discharge the bone cake (ie the bones remaining from which the greater part of the meat has been removed), through opening 15 and opening 12 outwardly. The outer periphery of the body 22 on the front face of the piston and carrying the passages 23 will fit with small clearance into annulus 9.

When slide valve 13 is moved downwardly in this way, the right hand face of the body 16 will slide across the lower part of the opening in annulus 9. Thus this surface is scraped clean and any bone splinters remaining at the openings of the narrow passages 17 will be scraped off and will remain within the annulus 9 in the chamber, and they will be pressed out through openings 15 and 12 in the subsequent discharge of the remaining bones. Thus movement of the slide valve cleans the fine openings of passages 17.

When thus removing the bone cake the press piston 2 may move to the left to such an extent that the front face of the body 22 will be positioned coplanar with the right hand (front) face of the slide valve body 13 and the left hand face of the annulus 9. As the slide valve 13 is closed again by moving it upwardly, the lower part of the edge of the discharge opening 15 will scrape across the front face of body 22, so that the fine openings of passages 23 will be cleaned by scraping off hard parts of such as bone splinters which may have accumulated at the fine openings of such passages. When further moving slide valve 13 upwardly the bodies 16 and 22 will move relative to one another so that their front faces will slide arross each other which further cleans them.

The body 16 in the slide valve may be used without the body 22 on the front face of the piston 2 and the reverse is also possible. If only the passages in the body 16 in the slide valve are utilised, it may be that for part of the meat which has been pressed into a paste-like condition the path back through the mass of bones towards the discharge becomes so long as to be undesirable. In such a case the body 16 in the slide valve with its passages may be combined with discharge openings in the wall of the chamber, for instance as shown in UK Patent Specification 1,500,052, which, however, is only possible in combination with a smaller discharge opening for the bones, which has some disadvantages as compared with the embodiment shown. In Figure 2 of this Specification, another possibility is shown in this respect.

Piston 2 may alternatively comprise a plunger, ie a body not fitting at 3 in the cylinder but leaving a small slot all around its periphery within the cylinder 1, so that meat brought into paste-like condition might pass through said slot into the space 4 as indicated in the above UK Patent Specification. However, when a front face body 22 with fine openings is mounted on the piston as shown in Figure 1, a good and accurate sliding seal at 3 of the piston within the cylinder 1 is preferred.

The body 11 with discharge opening 12 may be omitted if the slide valve 13 is slidably mounted in suitable strong guides at its vertical side edges and in this case the slide valve 13 may itself have a discharge spout, trough or guide for the bones moving up and down therewith. In such a case the body 16 with fine openings may have a meat discharge pipe or holes extending not downwardly as shown but to the left.

Figure 2 shows a vertical section through the axis of the press cylinder of another embodiment of a press according to the invention. In this embodiment there is shown the press cylinder 1, the front part only of the press piston 2 and part of the slide valve 13. Within the press cylinder 1 there are a plurality of rings 26 mounted coaxially and side by side and enclosed between a shoulder 27 in press cylinder 1 near the annulus 9 and a sleeve 28. The rings 26 each have in their right hand radial faces grooves 29 extending radially and evenly distributed around the entire periphery, said grooves forming passages and having either a rectangular or semi-circular section and having a depth (in the axial direction of the press cylinder) of not more than 1 mm, preferably somewhat less.The outer periphery of the rings 26 are crenellated so as to be supported sufficiently within the press cylinder 1 while leaving axial passages 30 for the flow of meat paste. The sleeve 28 has the same crenellated outer surface and, at its right end in Figure 2, is in contact with an end ring 31 enclosed between the end wall 8 and the bottom 32 of the filling chamber and the right hand end face of press cylinder 1. Between end ring 31 and press cylinder 1 there is the space 5 and the connection between the space 5 and the annular space 4 around the piston is formed by local recesses 33 in the left end of end ring 31. An O-ring 34 is positioned between cylinder 1 and end ring 31 to give a good seal while allowing some clearance to allow the end ring 31 to push the rings 26 and the sleeve 28 together and into contact with shoulder 27.The annular space 5 has a meat discharge opening 6 with a suitable duct or pipe as in Figure 1. The sealing ring 7 of Figure 1 in this case is positioned within the end ring 31 as shown.

The slidable annulus 9 at the left end of press cylinder 1 overlaps the cylindrical inner surface of the left most ring 26 over a short distance and has the O-ring 10 positioned as shown between parts 9, 1 and 26.

Helical springs 35, of which only one is shown, push ring 9 into close contact with the slide valve 13. The slide valve 13 has its opening 15 below the body 16 instead of above it as in Figure 1. The body 16 with passages in this case is formed by separate concentric generally coplanar rings 36 engaging with one another by means of an inwardly protruding annular part 37 of each ring engaging behind a corresponding shoulder of the next inner ring, the innermost separate ring 36 having such an annular inward flange engaging behind a central body 38 bolted to the body of the slide valve 13 as shown.The annular inwardly protruding parts 37 are also crenellated to allow passage of meat paste so that this may flow through fine openings and passages 17, formed by crenellated parts on the rings 36, to annular collecting spaces 18, from which the meat paste may flow to passages 19 in a separate body 39 in slide valve 13. From these passages there may be a discharge for the meat paste either upwardly or to the left as shown, or in a similar manner to Figure 1. The slide valve body in this case has a screw-threaded hole 40 at its top for connection with a piston rod of a hydraulic or pneumatic cylinder (not shown) for moving the slide valve up and down in suitable guides (not shown).

At the left end of piston 2 there consist is a body 22 as in Figure 1 but this consists in Figure 2 of separate concentric generally coplanar rings 41 mounted similarly to rings 36 and engaging with one another by means of an inwardly directed flange 42 of each ring engaging behind a corresponding shoulder of the next inner ring and the innermost one of such flanges engaging behind a shoulder in a central body 43 bolted to the piston 2. The fine openings and passages 23 here are also formed by crenellations like the fine openings and passages 17 in body 16 in the slide valve and the flanges 42 also are crenellated to allow the passage of meat paste axially to collecting spaces 42.The meat paste may flow from spaces 42 to spaces 25 in a separate body 21 at the front of the piston, and may leave spaces 25 through radial passages 44 extending radially outwardly into space 4 between piston and cylinder. The body 21 as in Figure 1 forms the piston head which seals with the cylinder, in this case the sleeve 28 and the rings 26 therein along the surface 3. At its front end a conical part 45 of the body 21 is spaced from the inner wall of sleeve 28 and rings 26 and may fit into the conical inside surface of annulus 9 with slight clearance.

The operation of this press is in essence the same as that of the press of Figure 1, but the separate rings 36, 41 and 26 allow easy disassembly and cleaning of the relevant parts. As in Figure 1, moving of the slide valve 13 cleans the fine openings to the passages 17 by the edges 46 of annulus 9, and allows cleaning of the fine openings to the passages 23 in body 22 when these are moved up to the right hand face of slide valve 13 in Figure 2 and the slide valve is closed so that the edge 47 of the opening 15 moves downwardly along and in contact with the openings of passages 23 to clean them. On further closing of the slide valve, the bodies 16 and 22 slide across each other, giving further cleaning.

As described with reference to Figure 1, some of the passages may be omitted by omitting, for instance part of or the entire body 16, part of or the entire body 22 and part of or the entire set of rings 26.

WHAT WE CLAIM IS:- 1. A press comprising a piston and press cylinder, the piston being movable in the cylinder to press animal meat with bones in order to bring the meat into a paste-like condition and to cause it to flow out of a chamber within the press, the press including a slide valve adapted to open and close an opening in a front face of the chamber so that, after pressing the slide valve is opened and the bones remaining in said chamber are discharged through the opening by further movement of the movable piston, a plurality of fine openings connected to passages for allowing passage of meat whilst in a pastelike condition being arranged in a surface which extends perpendicular to the direction of movement of the piston, said fine open ings communicating with a discharge opening, said surface being arranged so that a part of the press will scrape across the fine openings to clean them when the slide valve is moved.

2. A press as claimed in claim 1 in which said fine openings are provided in a front face of the slide valve which closes the chamber during pressing, in use said meat paste passing through said slide valve body to the discharge opening.

3. A press as claimed in claim 1 or claim 2 in which said fine openings are provided in a front face of the piston which front face is movable so as to be positioned in a plane coincident with the front face of the slide valve when the slide valve is open.

4. A press as claimed in claim 3 in which behind the front face of the piston and within it there is a space connecting with the passages and with the outer peripheral wall of the piston, the piston behind said front face having a clearance with respect to the inner surface of the press cylinder and the space created by said clearance being connected to a discharge for meat paste remote from the slide valve.

5. A press according to any of the preceding claims in which the said openings are provided in a disc shaped body, supported at its rear by a part of either the slide valve or the piston having passages to allow passage of the meat paste.

6. A press as claimed in any of the preceding claims in which a separate annular body is provided around said opening adjacent the slide valve which is guided so as to be at least partially axially slidable in the chamber and is adapted to be pressed by the pressure in the chamber during pressing against the slide valve, the front face of the piston being movable into and out of said annular body with slight clearance between said front part of the piston and said annular body.

7. A press as claimed in any of the preceding claims in which there is provided a plurality of openings in the peripheral wall of the chamber which is substantially parallel to the direction of movement of the piston for allowing passage of meat paste.

8. A press as claimed in claim 7 and either claim 3 or claim 4 in which said openings in the peripheral wall are arranged in a separate sleeve arranged within the press cylinder and to provide a space between the outer periphery of the sleeve and the inner periphery of the press cylinder, said space commupicating with at least one discharge opening of meat paste positioned adjacent the end of the chamber opposite the slide valve, said meat discharge opening or openings also serving for the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. one of such flanges engaging behind a shoulder in a central body 43 bolted to the piston 2. The fine openings and passages 23 here are also formed by crenellations like the fine openings and passages 17 in body 16 in the slide valve and the flanges 42 also are crenellated to allow the passage of meat paste axially to collecting spaces 42. The meat paste may flow from spaces 42 to spaces 25 in a separate body 21 at the front of the piston, and may leave spaces 25 through radial passages 44 extending radially outwardly into space 4 between piston and cylinder. The body 21 as in Figure 1 forms the piston head which seals with the cylinder, in this case the sleeve 28 and the rings 26 therein along the surface 3.At its front end a conical part 45 of the body 21 is spaced from the inner wall of sleeve 28 and rings 26 and may fit into the conical inside surface of annulus 9 with slight clearance. The operation of this press is in essence the same as that of the press of Figure 1, but the separate rings 36, 41 and 26 allow easy disassembly and cleaning of the relevant parts. As in Figure 1, moving of the slide valve 13 cleans the fine openings to the passages 17 by the edges 46 of annulus 9, and allows cleaning of the fine openings to the passages 23 in body 22 when these are moved up to the right hand face of slide valve 13 in Figure 2 and the slide valve is closed so that the edge 47 of the opening 15 moves downwardly along and in contact with the openings of passages 23 to clean them. On further closing of the slide valve, the bodies 16 and 22 slide across each other, giving further cleaning. As described with reference to Figure 1, some of the passages may be omitted by omitting, for instance part of or the entire body 16, part of or the entire body 22 and part of or the entire set of rings 26. WHAT WE CLAIM IS:-

1. A press comprising a piston and press cylinder, the piston being movable in the cylinder to press animal meat with bones in order to bring the meat into a paste-like condition and to cause it to flow out of a chamber within the press, the press including a slide valve adapted to open and close an opening in a front face of the chamber so that, after pressing the slide valve is opened and the bones remaining in said chamber are discharged through the opening by further movement of the movable piston, a plurality of fine openings connected to passages for allowing passage of meat whilst in a pastelike condition being arranged in a surface which extends perpendicular to the direction of movement of the piston, said fine open ings communicating with a discharge opening, said surface being arranged so that a part of the press will scrape across the fine openings to clean them when the slide valve is moved.

discharge of meat paste from the openings in the front face of the piston.

9. A press for meat substantially as herein described with reference to and as shown in Figure 1 of the accompanying drawings.

10. A press for meat substantially as herein described with reference to and as shown in Figure 2 of the accompanying drawings.