GB2068466A

GB2068466A - Rotary positive-displacement fluid-machines

Info

Publication number: GB2068466A
Application number: GB8103168A
Authority: GB
Original assignee: TALLERES VALL SA
Current assignee: TALLERES VALL SA
Priority date: 1980-01-31
Filing date: 1981-02-02
Publication date: 1981-08-12
Also published as: ES8100856A1; GB2068466B; ES488091A0; FR2474824A1; FR2474824B1

Abstract

A pump of the sliding-vane type for a pastey material e.g. minced meat, has a casing 1 having an inner concave annular surface 7 whose generatrix is an arc of a circle. A rotor 11 has a part-spherical surface 15 which together with the surface 7 defines an annular working-chamber. Vanes 24 on the rotor extend radially across the working chamber and displace the said material from an inlet 35 to an outlet 32, a fixed partition being placed on the downstream side of the outlet to direct the material into the latter, Fig. 2 (not shown). A part-annular cam 21 secured to the casing lifts the vanes into an operative position after they have passed under the partition in a retracted position. The working chamber may be toroidal, Figs. 3 and 4 (not shown). <IMAGE>

Description

SPECIFICATION Continuous drive mechanism for pastey materials The present invention relates to drive mechanisms for the propulsion in continuous form of substances or materials which occur in the form of a paste or dough.

Atypical example of such a mechanism is found in machinery for the continuous production of sausages, in which minced meat is continually stuffed, through an aperture, into a natural or synthetic sausage-skin.

In known arrangements, this type of mechanism consists of a cylindrical chamber and a rotor revolving inside it such that an annular chamber is formed between the two, which is interrupted at a point on its periphery by a partition fixed to the cylindrical chamber. A series of vanes are mounted on the rotor and fit against the internal surfaces of the annular chamber. The vanes are mounted in such a way that they retract from the cavity to pass the partition. An outlet aperture for the driven material is located directly upstream of the partition, and input of the material is effected through anther aperture situated at any intermediate point on the annular chamber.

This mechanism thus resembles the known vanetype pumps for impelling various fluids.

This type of mechanism, however, presents a difficulty: it is necessary to provide devices which must exert considerable forces in order to urge the vanes from the retracted position in which they are located outside the annular chamber, into the drive position in which they project through the mass of material in order to thrust the material towards the outlet aperture. Moreover, the mechanisms require a large amount of space, so that the mechanism is generally designed in a cylindrical form, in which the vanes move parallel to the axis of the cylinder. This considerably complicates the operations of cleaning the mechanism, is liable to contaminate the meat being processed with residues, and leads to excessively large dimensions.

The present invention seeks to overcome these drawbacks in drive mechanisms and is particularly suitable for use in sausage-making machines. For this purpose, in accordance with the present invention, there is provided a continuous drive mechanism for substances or materials in pastey or doughy form comprising a casing and a rotor which together define an annular chamber having an inlet and an outlet for the driven material, the chamber being interrupted by a partition situated immediately downstream of the outlet, the rotor having a plurality of impeller vanes which retract from the annular cavity to pass the partition, characterised in that the annular chamber is formed such that it has at least one surface of revolution whose generatrices are circular arcs whose centres are located internally relative to the chamber, and which forms at least one guideway for the displacement of the vanes, which vanes are mounted radially on the rotor, between an actuating cam situated adjacent to one edge of the surface of revolution and a boundary surface of the chamber situated adjacent to the opposite edge of the said surface of revolution.

In this way the vanes are driven directly from the corresponding cam, and the space necessary on the rear face of the rotor is limited to precisely that of the drive cam for the vanes. The vanes may have approximately the shape of sectors of a disc or annulus.

In a preferred arrangement the casing has a hemispherical internal surface which bounds the said chamber and with which the rotor is coaxial, the rotor having a generally conical projection which fits the said surface forming the annular chamber, a lower or central space for the drive cam for the vanes, and grooves located in radial planes, the bottoms of which grooves correspond to generatrices of a surface of the rotor, which are circular arcs concentric with those of the said surface of the casing, so that the vanes mounted in the grooves describe a trajectory along a circular arc between the opposing spherical surfaces of the chamber and of the rotor respectively. Consequently the drive cam for the vanes may then be formed by a part like a spherical collar mounted around the central part of the impeller rotor and whose periphery matches the driving profile of the vanes.

In another form of the invention, the casing has a toroidal internal surface which bounds the said chamber, and the rotor has a circumferential edge which coincides with the centres of the generatrices of the toroidal surface, and the vanes are guided by the latter in a rotating movement around the said edge. In this case the cam may be formed by an annular part mounted around the bottom part of the rotor and shaped to fit against the bottom surface of the toroidal casing, and whose periphery matches the driving profile of the vanes.

Two embodiments of the present invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an axial section through an impeller pump for minced meat, having a continuous drive mechanism according to the present invention; Figure 2 is a sectional plan view along the line Il-Il of Figure 1; Figure 3 is a view corresponding to Figure 1 of a pump provided with a toroidal chamber; and Figure 4 is a view corresponding to the Figure 2, showing a sectional plan view along the line IV--IV of Figure 3.

In the first embodiment as shown in Figures 1 and 2, the pump mechanism comprises a main body 1 in the form of a bowl which provides the casing for the drive mechanism and which is extended at the bottom to form a tubular support 2 which ends a suitable mounting device (not shown) as may be most adequate to each case.

Within this body there is mounted a drive shaft 4 rotatable in bearings 3. The drive shaft 4 projects into the bowl and there terminates in a coupling spindle 5. A seal 6 of any conventional type mounted on the shaft 4 immediately above the bearing 3 hermetically seals off the inside of the bowl from the inside of the support 2. The internal surface 7 of the bowl shaped casing is hemispherical, and the aperture of the bowl is closed by a cover 8 which fits on to a conical seat 9 and has a bottom planar surface 10.

A rotor 11 is mounted on the coupling spindle 5 preferably by means of a readily disconnectable coupling, of any conventionai type (not shown) to facilitate removal. This rotor comprises a central hub 12 to which the shaft 4 is coupled by its spindle 5, and a body 13 having a plane upper surface 14. In the operating condition of the pump, the upper surface 14 fits directly adjacent the surface 10 of the cover 8. Below the plane surface the body 13 has a lateral surface 1 5 formed by a hemispherical segment and a second part-spherical surface 16 formed by a hemispherical segment of greater radius. The surfaces 1 5 and 1 6 are separated by a projecting collar part 1 7 which is generally conical.The part 17 extends out to the surface 7, approximately bisecting the arc of the bowl from the shaft 4 to the cover 8. The part 17 constitutes a partition in that It divides the space between the rotor and the bowl into an upper annular chamber around which the meat is driven as wil! be explained below, and a lower annular chamber which accommodates a cam 21.

The part 17 and the lower spherical segment 16 are fluted by a series of slots 1 8 formed within planes which are axial relative to the whole pump.

The slots 18 have bottom edges which are extensions of the upper spherical surface 1 5.

The central part or bottom of the surface 7 has a seat 1 9 in the form of a rectangular step where the bowl adjoins the support 2 and on to which there fits an additional section 20 projecting from the bottom of an annular cam 21. The cam is a collar, surrounding the hub 12 of the rotor. It has a part-spherical upper surface adjacent the surface 16 of the rotor and a part-spherical bottom surface which fits against the surface 7 of the bowl. The cam 21 has a spherical surface which constitutes a cam profile and has parts 22 and 23 which extend radially outwards to different extents. Each of the parts 22 and 23 extends around approximately half the circumference of the cam.The cam 21 can be fixed in the position shown in the drawings by conventional means, for example by means of a stud-and-socket device, which permits easy dismantling for cleaning purposes.

In each of the slots 1 8 there is mounted an impeller vane 24 which is formed by a flat strip having two opposite arcuate edges 25 and 26 which correspond in curvature to the surfaces 7 and 1 5 respectively of the bowl and the rotor.

Each vane has two other opposite edges 27 and 28, the first of which is intended to fit against the surface 10 of the cover, whilst the second includes a part which forms a cam follower which bears constantly against the cam profile formed by surfaces 22 and 23. Thus, as the rotor 11 and shaft 4 rotate, the cam 21 will cause the vanes 24 to be displaced along circular arcs whose centre is the centre of the hemispherical surfaces 7 and 15, between a lower position shown on the left of Figure 1 and an upper position, not shown, in which the top edge 27 lies adjacent the surface of the cover. The position of each vane will depend on the cam section on which the vane in question is bearing. A vane will adopt its lower position when bearing on surface 23 and its upper position when bearing on surface 22.

It may be seen from Figure 2 that the bowl shaped casing has a partition 29- coinciding approximately with the centre of the lower cam surface 23. The partition 29 fits against the surface 10 of the cover, the spherical surface 1 5 of the rotor, and the top conical surface 30 of the part 17 of the rotor, in such a way that the annular chamber formed above the said part 17 is interrupted by this partition 29. An outlet aperture 32 is located immediately in front of the partition 29 (assuming that the rotor rotates in the direction indicated by the arrow 31), the outlet aperture 32 being arranged tangentially to facilitate the discharge of the material. A nozzle 34 is mounted by conventional means such as an annular nut 33 adjacent the outlet aperture 32. On this nozzle 34 would be placed the sausage-skin to take the minced meat driven by the mechanism.The admission of the meat is effected, for example, through a hopper 35, which leads into an opening through the cover 8 at a position diametrically opposite the outlet 32.

Twill thus be appreciated that the bowl-shaped casing and the rotor 11 define between them an annular chamber within which the meat travels. It is bounded by the surface 10 of the cover and surface 3O of the part 17, and by two hemispherical surfaces 7 and 1 5 the respective generatrices of which are both circular arcs having a common centre with the periphery of the casing.

These two surfaces 7, 1 5 constitute guideways for movement of the vanes 24 into and out of the annular chamber. When the vanes pass the partition 29 they encounter a transition ramp 36 from the lower cam surface 23 to the higher surface 22 of the cam, and are thereby urged into their high position in which they divide the annular chamber into a number of independent enclosures and so trap portions of minced meat which are thrust successively round the annular chamber in the direction of the arrow. When the vanes 24 approach the partition 29 which would intercept their passage, they encounter a descending ramp 37 of the cam, which allows them to pass below the partition 29 and being a new drive cycle as described.

In the embodiment of Figures 3 and 4 the principle of operation is the same as in the embodiment of Figures 1 and 2 the only variation being the geometrical form of some of the parts.

Thus the main body 1 provides a casing with an internal surface 7 the shape of which is that of the outer part of a toroidal surface. The rotor 11 a has a cylindrical top lateral surface 15a and a radially projecting part 19a. The grooves 1 8a have a stepped form which defines an intermediately edge 38, around which each of the respective vanes 24a oscillates and on which are centred the circular arcs which are the generatrices of the toroidal surface 7a. In this case the vanes 24a have their upper edge 40 fitting against the cylindrical surface 15a, when raised into the annular chamber, and the edge 28 forming the cam follower as in the previous embodiment. The form of the cam 21 a is somewhat different so as to suit this configuration, and this can be seen clearly from Figure 3. Other parts have the same functions as the corresponding parts of Figure 1 and are indicated by the same reference numerals.

The impeller mechanism according to the present invention is extremely simple. Dismantling it for cleaning purposes is easy and rapid.

Furthermore the height of the unit is only a fraction of that necessary in the known mechanisms for the same capacity.

Claims

1. A continusous drive mechanism for substances or materials in pastey or doughy form comprising a casing and a rotor which together define an annular chamber having an inlet and an outlet for the driven material, the chamber being interrupted by a partition situated immediately downstream of the outlet, the rotor having a plurality of impeller vanes which retract from the annular cavity to pass the partition, characterised in that the annular chamber is formed such that it has at least one surface of revolution whose generatrices are circular arcs whose centre is located internally relative to the chamber, and which forms at least one guideway for the displacement of the vanes, which vanes are mounted radially on the rotor, between an actuating cam situated adjacent to one edge of the surface of revolution and a boundary surface of the chamber situated adjacent to the opposite edge of the said surface of revolution.

2. A continuous drive mechanism according to Claim 1, wherein the casing has a hemispherical internal surface which bounds the said chamber and with which the rotor is coaxial, the rotor having a generally conical projection which fits the said surface forming the annular chamber, a lower or central space for the drive cam for the vanes, and grooves located in radial planes, the bottoms of which grooves correspond to generatrices of a surface of the rotor, which are circular arcs concentric with those of the said surface of the casing, so that the vanes mounted in the grooves describe a trajectory along a circular arc between the opposing spherical surfaces of the chamber and of the rotor.

3. A continuous drive mechanism according to Claim 2 wherein the drive cam for the vanes is formed by a part like a spherical collar, mounted around the central part of the rotor and whose periphery matches the driving profile of the vanes.

4. A continuous drive mechanism according to Claim 1 wherein the casing has a toroidal internal surface which bounds the said chamber, and the rotor has a circumferential edge which coincides with the centres of the generatrices of the toroidal surface, and the vanes are guided by the latter in a rotating movement around the said edge.

5. A continuous drive mechanism according to Claim 4 wherein the drive cam for the vanes is formed by an annular part mounted around the bottom part of the rotor, which fits against the bottom surface of the toroidal casing, and whose periphery matches the driving profile of the vanes.

6. A continuous drive mechanism according to any one of the preceding claims wherein each vane has approximately the shape of a sector of a disc or annular lamina with an edge which is a cricular arc running on the or each said surface of revolution and a radial edge running on the cam.

7. A continuous drive mechanism for pastey materials comprising a casing and a rotor defining therebetween an annular chamber through which said material passes from an inlet to an outlet, a plurality of vanes extending from the rotor to the casing and driven by the rotor to drive said material, and a partition extending across the chamber between the rotor and the casing immediately downstream of the outlet; the vanes being arranged to move between a retracted position to pass the partition and an extended position projecting into the chamber to drive material around it, such movement of the vanes being guided by a surface of the casing which surface is a surface of revolution whose generatrix is an arc whose centre lies inwardly of the surface of revolution, part of which surface forms a surface of the annular chamber, each vane running on a cam outside the chamber.

8. A continuous drive mechanism according to Claim 7, wherein the said surface of the casing forms a hemispherical bowl and the rotor has a part spherical surface having a common centre with the bowl, so that the vanes are guided between the two opposing spherical surfaces of the rotor and the casing.

9. A continuous drive mechanism according to Claim 7 or Claim 8, wherein the cam extends around a part of the rotor, and has a surface extending radially of the rotor and forming a cam track for the vanes.

10. A continuous drive mechanism according to any one of Claims 7 to 9 wherein there is a cover extending from the casing to cover the rotor and forming a surface of the chamber, and said vanes extend to adjacent said cover in their extended position.

11. A continuous drive mechanism according to Claim 7, wherein the chamber has a part-toroidal surface, and the rotor has a circumferential edge coinciding with the centre of the generatrix of tfie part-toroidal surface, the vanes being guided by the part-toroidal surface to pivot about said edge of the rotor.

1 2. A continuous drive mechanism according to Claim 7 or Claim 11, wherein the cam extends around a part of the rotor and has a cam section at least a part of which corresponds to a sector of an annulus concentric with the said generatrix, one edge of said annulus sector forming a cam track for the vanes.

13. A continuous drive mechanism according to Claim 11 or Claim 12 wherein the rotor has a cylindrical surface forming a surface of the chamber and said vanes extend to adjacent said cylindrical surface in their extended position.

14. A continuous drive mechanism according to any one of Claims 7 to 13, wherein the rotor has a circumferential projecting flange having a surface extending from the rotor to the casing and forming a surface of the chamber, there being a plurality of slots in the flange corresponding to the vanes and in which the vanes move.

1 5. A continuous drive mechanism according to any one of Claims 7 to 14, wherein the vanes extend radially of the rotor.

1 6. A continuous drive mechanism for pastey materials substantially as herein described with reference to Figs. 1 and 2 or Figs. 3 and 4 of the accompanying drawings.