GB2078554A

GB2078554A - A Machine for Cleaning and/or Grading Seeds

Info

Publication number: GB2078554A
Application number: GB8115245A
Authority: GB
Original assignee: SIZER RICHARD Ltd
Current assignee: SIZER RICHARD Ltd
Priority date: 1980-05-20
Filing date: 1981-05-19
Publication date: 1982-01-13

Abstract

The machine has a screencase (22) which is reciprocable with respect to a pair of beams (4) which define a support for the screencase. Drive means (28, 30, 32) is provided to reciprocate the screencase. In order to enable the angle of the screencase to be adjusted during its reciprocation the pair of beams (4) are journalled in a frame (2) and actuating means in the form of a piston and cylinder assembly (36) is disposed between the support and the frame. Means (18, 24) are provided for adjusting the angle between the plane of the screencase and the plane of reciprocation to impart a hopping motion to the seeds. <IMAGE>

Description

SPECIFICATION A Machine for Cleaning and/or Grading Seed The present invention relates to a machine for cleaning and/or grading seeds.

A A known cleaning and/or grading machine for seeds has screen-cases which are reciprocally driven along a linear path. The screen-cases carry two screenmeshes one above the other, the upper one having holes larger than the other. Seed, together with impurities is introduced onto the reciprocating screen-case wheren it is graded and cleaned. The dust falls to the bottom of the screen-case, the seed passes through the first mesh but not the second and the large substancesremains on top of the upper screen.

The grading process may be speeded up by changing the speed of the reciprocating screen case and it is advantageous to be able to alter the angle of inclination of the screen-case. With certain types and sizes of seeds it is advantageous to have the seed tray at a shallow angle and with others a steeper angle is preferable.

In the known machine angular adjustment of the screen meshes has been possible, but such adjustment has necessitated stopping the machine to release the meshes from one position and reposition them before restarting the machine. The adjustment of the positions of the screencase can be a matter of trial and error, which necessitates stopping the machine, repositioning the meshes and restarting the machine several times before the optimum angle is found. The adjustment may be required during the grading process when the seed type varies and not just at the start of grading.

It is an object of the present invention to provide a machine for cleaning and/or grading seed in which adjustment of the angle of inclination of the screen-case is more easily achieved.

According to the present invention there is provided a machine for cleaning and/or grading seeds comprising a frame, one or more pairs of beams defining a support for a respective screen case, which support is journalled in the frame and is angularly adjustable thereto, the screencase being carried by the support and being mounted for reciprocal movement with respect to the support, drive means being provided to reciprocate the screen-case, and actuating means being provided to adjust the angular position of the support and the screen-case carried thereby, which angular adjustment may be effected during reciprocal movement of the screen-case.

Preferably the screen-case accommodates a pair of mesh screens, each having a rubber ball cleaning system to keep the screen meshes open and free of seeds. The actuating means to adjust the angular position of the support and screen may comprise a double acting hydraulic piston/cylinder assembly, the cylinder being secured to the frame and a rod of the piston to the screencase support or vice versa. The angular adjustment may conveniently be effected by feeding hydraulic fluid under pressure, generated by a pump, to the assembly by way of a control valve. Other means could be used for example an electro mechanical actuator or manually using a quadrant with a locking device.

In a preferred arrangement the or each beam of the support carries a pair of linear ball bushings, in which are received respective ground shafts secured to the screen-case at the fore and aft ends thereof. A connecting rod secured at one end to the screen-case by way of a pivot pin and at the other end to an eccentric crank pin carried by a pulley wheel provides the reciprocating drive for the screen-case. The pulley wheel is driven from an electric or hydraulic motor, the speed of which is adjustable, by way of a chain or belt.

More preferably two of the ground bearing shafts received in the ball bushing adjacent one end of the screen-case are secured to the screencase by an adjustable mounting whereby the plane of the screen-case may be adjusted with respect to a plane passing through the common axes of the ball bushings, i.e. the plane of reciprocation. A stepping or hopping motion of the seed is thereby produced when the screencase is so adjusted in contrast to a pure linear reciprocating motion, when the plane of reciprocation is parallel with the plane of the screen-case.

The preferred embodiment incorporates both the angular adjustment of the plane of reciprocation, i.e. the support with respect to the frame and angular adjustment of the plane of the screen-case with respect to the plane of reciprocation.

According to another aspect of the invention there is provided a machine for grading and/or cleaning seed comprising a support for a screencase, drive means for reciprocating the screencase with respect to the support, and adjustable attachment means disposed between the screencase and the support whereby the angle between the plane of the screen-case and the plane of reciprocation may be varied.

In a most preferred form of the frame of the machine defines a substantially rectangular periphery and carries two pairs of beams, which define two supports disposed vertically within the frame one above the other. Each support carries a screen-case which preferably has two boats disposed side by side. Each boat has two mesh screens. Alternatively the machine may be provided with only one screen-case or exceptionally more than two.

Conveniently the pulley wheel is mounted on a shaft which extends across the width of the machine, and a second pulley wheel is provided at the eend of the shaft remote from the first pulley wheel. Drive is transmitted by way of a chain or toothed belt to a second drive pulley which carries an eccentric crank pin for reciprocating the second screen-case by way of a second connecting rod. The provision of the chain drive enables the reciprocation of the screen-cases to be balanced.

According to a further aspect of the invention the mesh screens are retained within the screencase by locking means comprising a handle mounted on a shaft which threadingly engages with a block secured to the mesh screen, the shaft carries a locking arm which is in frictional engagement with the shaft and which engages with at least one catch secured to the screencase. The locking arm is free to rotate on the shaft such that when the force acting on the locking arm is greater than the frictional force between the shaft and locking arm the shaft can rotate independently of the locking arm to displace the screen away from the locking arm whereby the reaction force is taken by the catch of the screencase by way of the locking arm.

The present invention will now be described further, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a somewhat diagrammatic view of a machine according to the invention, and Fig. 2 is a cross-sectional view showing the detail of the screen locking mechanism.

A machine for cleaning and/or grading seed is shown in Fig. 1. The machine has a frame 2, carrying seed feed hoppers, a screen-case 22 for cleaning and/or grading the seed and distribution channels for the receiving of graded seed. More particularly a pair of beams 4 interconnected by a tube 8 which define a support for the screen-case 22 are journalled in support bearings 6 in the frame 2. Each end of the pair of beams 4 carries a linear ball bushing 10, 12 within which is received a ground steel shaft 14, 16. The shafts 14, 16 are secured to a respective mounting block 18, 20 which in turn are secured to a screen-case 22.

The pair of mounting blocks 20 are fixedly attached to the screen-case by means of bolts and the pair of mounting blocks 1 8 are secured to a respective mounting pin 24 attached to the screen-case. The mounting blocks 1 8 constitute adjustable attachment lugs and have three bores therein whereby the screen-case may be attached to the beam in any one of three positions such that angle between the plane of the screen-case 22 and the plane of reciprocation may be varied.

A range of angular variations may be achieved by providing a locking device to locate the attachment lug to the screen-case.

One of the mounting blocks 20 carries a pivot pin 26 on which isjournalled one end of a connecting rod 28. The other end of the connecting rod 28 is journalled on a drive pin 30 mounted on a pulley or chain wheel 32. The stroke of the screen-case may be adjusted by arranging that the drive pin 30, of the drive means is adjustably mounted on the pulley wheel 32.

The chain wheel 32 is journalled in the frame and is driven by a motor whose speed is controlled by an adjustable control switch.

Rotation of the chain wheel by the motor generates a reciprocating motion of the screencase with respect to the beam and frame.

The or each beam is provided with an adjustment pin 33 to which is secured one end of a piston rod 34 of an hydraulically actuated piston/cylinder assembly 36. A bracket 38 on the frame receives a mounting for the cylinder body.

The piston/cylinder assembly 36 is double aeting and is fed with hydraulic oil under pressure from a pump by way of a control valve and constitutes actuating means for adjusting the angle of tbe support and hence the screen-case.

In the illustrated embodiment each screencase comprises two boats which accommodate two mesh screens and associated ball and cage cleaning apparatus. Various types of screens are utilised for different types of seeds and it is necessary to be able to release and replace the screens quickly and simply.

Fig. 2 shows a section through a locking device which serves to locate the screen in position.

Each screen has two such devices which serves as both the handle for pulling out the screen and the locking device.

The screen-case 22 has attached thereto two catch members 40 which are formed with a hook portion 42 at the free end. A screen tray 44 has a block 46 attached thereto, which block has a screw threaded bore 48 within which is threadingly received a shaft 50 of a handle 52.

The handle has mounted thereon a locking arm 54 which is gripped on the shaft by a friction washer 56.

The construction is such that in the position shown in Fig. 2 with the handle turned fully anti clockwise the locking arm abuts the catch member and a clamping force urges the screen to the left, against stops locating it positively.

Rotation of the handle 52 in the clockwise direction results in movement of the shaft, handle and locking arm, towards the screen-case 22, to the left in the iilustration to the position shown dotted in Fig. 2, and when the locking arm passes the end face 58 of the hook portion 42 the locking arm rotates with the shaft 50 releasing the connection between the locking arm and catch so permitting withdrawal of the screen-case. The arrangement has the advantage that the unlocking and withdrawal of the screen is achieveu in one operation.

In operation the seed cleaning machine operates as follows: Seed is fed onto the top of the screen-case whilst the screen-case is being reciprocated. The screen-case is inclined with respect to the horizontal and the angle of inclination may be varied and is typically in the range of 5 to 140. The seed appropriately sorted passes from the screen-case into the appropriate distribution channels. The speed of reciprocation is adjustable and the angle of inclination may be adjusted whilst the screen-case is reciprocating.

When the plane of the screen-case 22 is parallel with the plane of reciprocation the seed to be cleaned and/or graded moves substantially linearly to and fro along the mesh screen, usually maintaining rolling or sliding contact with the screen. However, when the plane of the screencase is adjusted by reposition of the adjustable attachment lugs so that it is no longer parallel with the plane of reciprocation, a hopping motion is imparted to the seed. Such a motion leads to improved grading and/or cleaning. The machine inlay be provided with one or more screen-cases which may contain one or more boats. For example in a preferred arrangement the machine has two screen-cases disposed one above the other and each adjustably mounted in the frame on support beams. The construction of the second or further screen-cases, the method of mounting and angular adjustment and its reciprocation being identical with that of the screen-case described with reference to Fig. 1. Where say three screen-cases are provided one above the other, the reciprocating drive may be effected by way of a third drive shaft and corresponding drive pulley, and connecting rod.

Claims

1. A machine for cleaning and/or grading seeds comprising a frame, at least one pair of beams defining a support for a respective screen-case, which support is journalled in the frame and is angularly adjustable thereto, the screen-case being carried by the support and being mounted for reciprocal movement with respect to the support, drive means to reciprocate the screen case, and actuating means operabie during reciprocal movement of the screen-case to adjust the angular position of the support and the screen-case carried thereby.

2. A machine as claimed in claim 1, in which the actuating means comprises a double acting piston and cylinder assembly secured between the support and the frame.

3. A machine as claimed in claim 1, in which the actuating means comprises an adjustable linkage disposed between the support and the frame by means of which angular adjustment of the support is effected.

4. A machine as claimed in claim 3, in which the adjustable linkage comprises an electro mechanical actuator.

5. A machine as claimed in claim 3, in which the adjustable linkage comprises a quadrant and locking device.

6. A machine as claimed in any preceding claim in which the drive means comprises a connecting rod secured between the screen-case and an eccentric pin carried by a rotatable crank, and the screen case is reciprocable with respect - to the support in linear ball bushings.

7. A machine as claimed in claim 6, in which the screen-case has four attachment lugs secured < .thereto, each of which carries a ground shaft associated with a respective one of the linear ball bushings carried by the pair of beams.

8. A machine as claimed in any preceding claim in which the angle of the screen-case is adjustable with respect to the support for producing a hopping motion of the material to be cleaned and/or graded.

9. A machine as claimed in claim 8 when appendent to claim 7, in which at least two of the attachment lugs are adjustably secured to the screencase.

10. A machine as claimed in claim 9, in which the attachment lug or the screen-case has a plurality of bores which may be selectively located in a mounting pin carried by the screencase or the attachment lug, whereby the angle of the screen-case may be adjusted with respect to the support.

11. A machine as claimed in any preceding claim in which the screen-case accommodates at least one seed tray having a pair of mesh screens, the seed tray being retained within the screencase by locking means comprising a handle having a shaft which threadingly engages with the seed tray, and a locking arm which is in frictional engagement with the shaft and which is engagable with catch means secured to the screen-case.

12. A machine as claimed in claim 11, in which cooperation of the locking arm with the catch means upon rotation of the handle generates a force which is greater than the frictional force between the shaft and the locking arm, whereby the shaft rotates independently thereof to displace the seed tray away from the locking arm against a stop.

13. A machine as claimed in any preceding claim having two screen-cases disposed one above the other in the frame, each screen-case being mounted for reciprocal and angular movement with respect to the frame and each screen-case having two releasable seed trays disposed side by side.

14. A machine as claimed in any preceding claim, in which the screen-case has an angle of adjustment in the range 5 to 140 to the horizontal.

1 5. A machine for grading and/or cleaning seed comprising a support for a screen-case, drive means for reciprocating the screen-case with respect to the support, and adjustable attachment means disposed between the screen-case and the support whereby the angle between the plane of the screen-case and the plane of reciprocation may be varied.

1 6. A machine as claimed in claim 15, in which the adjustable attachment means comprises one or more attachment lugs each lug being secured adjustably to the screen-case and each lug cooperating, by way of linear ball bushing, with the support to permit reciprocable movement of the screen-case.

1 7. A machine as claimed in claim 16, in which the attachment lug or the screen-case has a plurality of bores which may be selectively located on a mounting pin carried by the screencase or the attachment lug.

18. A machine as claimed in any of claims 15, 1 6 or 17, in which two non-adjustable attachment lugs are secured to the screen-case and each lug cooperates, by way of linear ball bushing, with the support.

1 9. A machine as claimed in any of claims 1 5 to 18, in which the support is journalled in a frame of the machine and is angularly adjustable with respect thereto by actuating means operable during reciprocation of the screen-case whereby the angular position of the support and the screen-case may be adjusted.

20. A machine as claimed in claim 19, in which the actuating means comprises a double acting piston and cylinder assembly secured between the support and the frame.

21. A machine as claimed in any of claims 15 to 20, in which the screen-case accommodates at least one seed tray having a pair of mesh screens, the seed trays being retained within the screencase by locking means comprising a handle having a shaft which threadingly engages with the seed tray, and a locking arm which is in frictional engagement with the shaft and wbich is engageable with catch means secured to the screen-case.

22. A machine constructed and arranged and adapted to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.