GB2065086A - Feed mechanism for rice peeling machines or other cereal processing machines - Google Patents

Abstract

Feed mechanism for rice peeling machines or other cereal processing machines, comprising a feed container which is charged by feed means for the material and which is supported to move in rotation about an axis (7) and possesses an inclined bottom(s) which causes a movement of the centre of gravity of the container plus material during the discharging process, the discharge opening (6) for the material being opened or closed with the aid of a closing means (20) in dependence on the material level and a predetermined external force, supplied, e.g. by spring (10), acting on the feed container. The axis of rotation (7) is placed both above the centre of gravity (S3) of the feed container, when full, and above the inclined bottom (5) and vertically or approximately vertically above the upper end of the inclined bottom (5). <IMAGE>

Description

SPECIFICATION Feed mechanism for rice peeling machines or other cereal processing machines The invention relates to a feed mechanism for rice peeling machines or other cereal processing machines, comprising a feed container which is charged by feed means for the material and which is supported to move in rotation and possesses an inclined bottom which determines the direction of the change in the location of its centre of gravity during the discharging process and is adjoined by a discharge opening for the material which is opened or closed with the aid of a closing means in dependence on the material level and a predetermined external force acting on the feed container.

Mechanisms of this type are used for the purpose of feeding the material to the processing machines, such as roller frames, peeling machines, sorting machines and others, uniformly in the form of a curtain of predetermined width and thickness, for example into the grinding or peeling roller gap; during this process it should be possible to regulate the curtain thickness in dependence on the quantity of material flowing to the feed container and to interrupt the curtain of material flowing out of it. A further purpose is that of forming a certain buffer for the material which ensures that the grinding or peeling rollers of the processing machine are always charged with material over their whole working length. The size of this buffer for the material is determined by appropriately adjusting the external force, in the form of a spring or of a weight, acting on the feed container.

Since, on the one hand, the processing machine is to be charged, if possible, with a constant stream of material and, on the other hand, in practical operation fluctuations occur time and again in the feeding of material to the feed container, an important requirement for such a feed mechanism is that, in this sense, it should have a compensating effect on the stream of material, that is to say, if the supply of material or the contents of the feed container suddenly increase the feed mechanism should open the discharge opening for the material wider only slowly or with a lag, but if the supply of material or the contents of the feed container suddenly decrease it should quickly close the discharge opening for the material.

The mechanisms of the state of the art, known, for example, from German Patents 21 298 and 828 401, are unsatisfactory in this regard since they have an opposite opening and closing characteristic, that is to say with increasing material content the opening moment increases, and thus the discharge opening for the material opens more rapidly, and with decreasing material content the opening moment decreases and thus the discharge opening for the material opens more slowly. Depending on the design of the feed container, in the case of fluctuations in the supply of material in the known mechanisms both factors of the torque acting on the feed container, or only the force, change.

It is the object of the invention to improve feed mechanisms of the type mentioned initially with respect to the desired closing and opening characteristics.

This object is achieved, according to the invention, in that the axis of rotation is placed both above the centre of gravity of the feed container, with maximum material level, and above the inclined bottom and vertically or approximately vertically above its upper end. A preferred constructional embodiment of the novel feed mechanism is characterised, according to the further invention, in that the axis of rotation of the feed container is arranged at the top and close to its one side wall and the discharge opening for the material is arranged at the bottom and close to its opposite, other side wall, and that the inclined bottom is constructed to be inclined downward from approximately the axis of rotation to the discharge opening for the material and its lower edge forms the control edge for changing the part ofthe discharge opening for the material which releases the flow of material, and that the closing means is a cover plate which is fixed in location and which is mounted tangentially to the arc described by the one control edge during the rotation of the feed container and the edge of which which faces the inclined bottom forms the other control edge for changing the opened part of the discharge opening for the material. In this arrangement the cover plate is disposed at a small distance to the feed container discharge opening for the material in order to prevent that the material dammed up on the cover plate flows over its upper edge.In a further development of the feed mechanism, the inclined bottom and the cover plate have been arranged with respect to one another in such a manner that they enclose an angle of 90 or approximately 90 ; this produces a certain directional effect and detrimental layering of the grains of the material with low feeding rates is prevented; in addition, this inclined position of the inclined bottom and the cover plate provides a good prerequisite for adjusting the control edge of the inclined bottom, on the one hand, and the cover plate, on the other hand, to be exactly parallel to an accuracy of 0.1 mm. The parallel adjustment can be facilitated even further by constructing the control edge of the inclined bottom and that of the cover plate, at their ends facing one another, in the shape of knife edges.So that, in the case of wear, the control edges can be easily reworked or exchanged, according to the further invention the cover plate is mounted on a support, in such a manner that it can be removed and adjusted, and the control edge of the inclined bottom is formed by the knife edge of a bar which is constructed in the shape of a knife edge and which is mounted on the inclined bottom in such a manner that it can be removed and adjusted.

The drawing shows an illustrative embodiment of the feed mechanism according to the invention, which is intended for use in a rice peeling machine, which is described in the text which follows.

The Figure shows a longitudinal cross-section through the feed mechanism, in a simplified representation.

The feed mechanism comprises a feed container 1, which is open at the top, with two side walls 2, 3, a rear wall 4 and a front wall, not shown, which is located parallel to the latter, and an inclined bottom 5 which extends obliquely downward from the side wall 2 in the direction of the side wall 3 to the dis charge opening 6 for the material. The feed con tainer 1 is supported on two coaxial axle pins 7 in a housing 8, the longitudinal axes of which form the geometric axis of rotation of the feed container 1.

The axle pins 7 are anchored in the housing 8. The axle pins 7 are arranged in the housing 8, on the one hand, and the bearing holes 9 in the feed container 1, on the other hand, in such a manner that the axis of rotation is located both above the centre of gravity S3 of the feed container, with maximum material content, and above the inclined bottom 5 and vertically or approximately vertically above its upper end or close to the side wall 2 of the feed container 1.

The feed container 1 is supported by a pretensioned tension spring 10 which is stretched between a screw hook 11 and a screw hook 12 which is fixed in a projection 14, mounted at the side wall 3, in such a mannerthat it can be adjusted by a wing nut 13.

The pretension of the tension spring 10 is selected in such a manner that it holds the discharge opening 6 for the material closed until the feed container 1 is filled to a certain degree or contains a certain amount of material, and releases it only after thins predetermined limit is exceeded.

At the lower end of the inclined bottom 5 a bar 17 in the shape of a knife edge is mounted to be removable and adjustable by means of screws 15 and slots 16 and its knife edge forms the one control edge 18 for changing the part of the discharge opening 6 for the material which is opened for the flow of material.

The closing means for the discharge opening 6 of the feed container I is formed by a cover plate 20, which is arranged to be fixed in location at a small distance 19 to the latter and which is mounted in a removable and adjustable manna;, by means ofthe screws 22 and the slots 23, tangentially to the arc described by the one control edge 18 during the rotation of the feed container 1, on a support 21 mounted in the housing 8. The side of the cover plate 20 facing the inclined bottom 5 is formed to a knife edge which forms the other control edge 24 for changing the part of the discharge opening 6 for the material which is opened for the flow of material.The cover plate 22 and the inclined bottom 5 enclose an angle ear which is 90". So that the feed container 1 can be charged with material, a feed pipe 25 opens into it at the top and is fixed to the housing 8 and joined to a pipe line, not shown, for supplying the material.

During the operation ofthe associated rice peeling machine the tension spring 10, which has appropriately designed spring characteristics and is pretensioned, or the closing moment generated by it, holds the feed container discharge opening 6 for the mat erial closed until the material reaches a predeter mined amount or level in the feed container 1, for example the level I, that is to say the feed container 1 with its inclined bottom 5 is rotated toward the cover plate 20 to such an extent that the two control edges 18, 24 are in contact.If, with the appropriate supply of material via the feed pipe 25, the level of material rises above the level I, for example to the level II or the level Ill, the opening moment exceeds the closing moment and the feed container 1 rotates clockwise around its axis of rotation (axle pins 7) to the extent determined by the tension spring 10 and opens a part of the discharge opening 6, in the form of a gap, for the flow of material.The width of the part of the discharge opening 6, or gap, which is opened in each case depends on the material level (level I or II or Ill), or the opening moment, respectively, which is the product of the weight (G or go or G3) acting at the respective centre of gravity (St orS2 or S2) of the feed container and the lever arm (I, or 12 or 12).

As can be seen from the Figure, the lever arm decreases, due to the construction of the feed mechanism in accordance with the invention, with increasing material contents or rising material level, and the increasing weight resulting from this, and increases with decreasing material contents. The opening moments resulting from this, and the closing moments produced by the tension spring 10, provide the feed mechanism with an opening and closing characteristic which causes a certain lag in the rotating movement of the feed container 1 if the material contained therein suddenly increases in quantity, the discharge opening 6 forthe material thus opening only slowly, and with a sudden great decrease in level causes the discharge opening 6 for the material to close rapidly.

The advance achieved with the invention consists in the main in the fact that an opening and closing characteristic has been achieved in feed mechanisms of this type which is better for the requirements of practical operations and that it has been prevented that the feed container frequently swings open and shut, as is the case with customary feed mechanisms; a further essential advantage is the directional effect of the cover plate of the discharge opening for the material, which reliably prevents the detrimental layering of the grains ofthe material in the region of the opened part of the discharge opening for the material.

Claims (8)

1. Feed mechanism for rice peeling machines or other cereal processing machines, comprising a feed container which is charged by feed means for the material and which is supported to move in rotation and possesses an inclined bottom which determines the direction of the change in location of its centre of gravity during the discharging process and is adjoined by a discharge opening for the material which is opened or closed with the aid of a closing means in dependence on the material level and a predetermined external force acting on the feed container, characterised in that the axis of rotation (7) is placed both above the centre of gravity (S3) of the feed container, with maximum material level, and above the inclined bottom (5) and vertically or approximately vertically above its upper end.

2. Feed mechanism according to Claim 1, characterised in that the axis of rotation (7) of the feed container (1) is arranged at the top and close to its one side wall (2) and the discharge opening (6) for the material is arranged at the bottom and close to its opposite, other side wall (3), and that the inclined bottom (5) is constructed to be inclined downward from approximately the axis of rotation (7) to the discharge opening (6) for the material and its lower edge forms the one control edge (18) for changing the part of the discharge opening (6) for the material which releases the flow of material, and that the closing means is a cover plate (20) which is fixed in location and which is mounted tangentially to the arc described by the one control edge (18) during the rotation of the feed container (1) and the edge of which which faces the inclined bottom (5) forms the other control edge (24) for changing the opened part of the discharge opening (6) for the material.

3. Feed mechanism according to Claim 2, characterised in that the cover plate (20) is disposed at a small distance (19) to the discharge opening (6) for the material.

4. Feed mechanism according to Claim 2, characterised in that the inclined bottom (5) and the cover plate (20) enclose an angle of 90" or approximately 90".

5. Feed mechanism according to Claim 2, characterised in that the cover plate (20) is mounted in a removable and adjustable manner on a support (21).

6. Feed mechanism according to Claim 5, characterised in that the side of the cover plate (20) facing the inclined bottom (5) is formed in the shape of a knife edge.

7. Feed mechanism according to Claim 2, characterised in that the edge of the inclined bottom (5) serving as a control edge (18) is formed in the shape of a knife edge.

8. Feed mechanism according to Claim 7, characterised in that the control edge (18) is formed by a knife-edge-shaped bar (17) which is mounted in a removable and adjustable manner on the inclined bottom (5).