GB1593149A

GB1593149A - Apparatus for grading articles

Info

Publication number: GB1593149A
Application number: GB4932476A
Authority: GB
Original assignee: Craven & Nicholas Eng Ltd
Current assignee: Craven & Nicholas Eng Ltd
Priority date: 1977-11-10
Filing date: 1977-11-10
Publication date: 1981-07-15

Description

(54) APPARATUS FOR GRADING ARTICLES (71) We, CRAVEN & NICHOLAS (ENGI NEERING) LIMITED, a British Company, of St.

John's Road, Boston, Lincolnshire, 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: The present invention relates to apparatus for grading articles by size.

According to one aspect of the present invention there is provided apparatus for grading articles by size, including a conveyor upon which the articles to be graded are carried from a feed station to a discharge station which extends along a portion of the conveyor, the conveyor being comprised of laterally spaced slats which themselves extend laterally of the conveyor, each slat having a flap which extends radially therefrom and which is arranged for pivotal deflection about an axis extending parallel to the slat for movement from a fully closed position to a fully open position, a linear cam surface which extends along at least that portion of the conveyor run along which the discharge station extends and which in the direction of travel of the conveyor progressively diverges away from the conveyor run, the linear cam surface being located so that the terminal lateral edge of the flaps ride thereon in such manner that progressive pivotal movement thereof from their closed to their open position is caused, and disturbing means for moving articles on the conveyor laterally thereof. In the fully closed position the terminal lateral edge of the flap is preferably conveniently spaced from the adjacent flap.

Conveniently each slat is pivotally connected at either end to a pair of laterally spaced roller chains, the flap associated with each slat being fixedly secured thereto.

Preferably, adjustment means are provided so that the degree of divergence of the cam surface from the run of the conveyor may be varied as desired.

According to another aspect of the invention there is provided an article feed apparatus including a conveyor having an inclined run arranged to move through a store of articles, the conveyor being comprised of laterally spaced slats which themselves extend laterally of the conveyor, each slat having a flap which extends radially therefrom and which is arranged for pivotal deflection from a fully closed position to a fully open position, a linear cam surface extending substantially parallel to the inclined run of the conveyor and which is located to contact the terminal lateral edge of each flap thereby to control the position thereof, and disturbing means for moving articles on the conveyor laterally thereof.

Preferably, adjustment means are provided for varying the position of the cam relative to the inclined run of the conveyor and thereby vary the rate of feed thereof.

Advantageously. another aspect of the invention provides the combination of a feed apparatus defined above and an apparatus for grading articles as defined above.

Reference is now made to the accompanying drawings, in which: Figure I is a schematic side elevation of a grading apparatus according to the present invention; Figure 2 is a more detailed perspective view of part of the apparatus according to the present invention; Figure 3 is a part perspective view of the present apparatus showing in part the disturbing means: and Figure 4 is a part plan view of a modified conveyor.

Referring initially to Figure 1, the apparatus is generally shown at 10 and includes a conveyor II which is comprised of laterally spaced slats 12 which themselves extend laterally over conveyor 11 and which are rotatably supported at either end by a pair of laterally spaced roller chains 14 (as more clearly seen in Figure 2), each slat 12 has a flap 14a which is fixedly secured thereto and which extends radially therefrom. As seen in Figure 1, the conveyor is trained about four sprockets 15, 16, 17 and 18, sprocket 15 being drivingly connected to a motor (not shown) which causes movement of the conveyor.

The conveyor run passes through a feed station 13 and a discharge station 20. The feed station is provided with a hopper 19 into which articles to be graded are stored and the conveyor runs along the bottom of the hopper to pick up articles therefrom. The flaps of the slats as they pass through the feed station are held in a partially closed position by a linear cam 24a and then held in a fully closed position until they reach the discharge station. The position of the cam 24a may be varied so as to vary the spacing between the flaps and adjacent slats so as to vary the rate of pick-up of articles from hopper 19.

Consequently, as a given slat moves through the discharge station its associated flap is permitted to pivotally move in a clockwise direction (as shown in Figure 1) so that the effective space between itself and the adjacent slat is progressively increased.

Chutes 26, 27 and 28 are located below the discharge station to collect articles falling therefrom, to provide, in the present instance, three grade sizes of articles.

As more clearly seen in Figure 2, the apparatus is provided with adjustment means 30 which permit the degree of divergence of the upper cam surface 23 to be varied as desired.

It will be appreciated therefore that the number of grade sizes produced by the present apparatus may be conveniently varied by the choice of the number of chutes located beneath the discharge station 20.

Advantageously. as illustrated in Figures 2 and 3, the apparatus may be provided with disturbing means 40 which are arranged to move articles carried by the conveyor thereon so as to ensure that each article is directly supported by the flaps of the conveyor.

The disturbing means 40 which are illustrated include an actuating link 41 which is pivotally connected at one end to an element 41a which forms part of the frame of the apparatus and at the other end to support link 42 to which are pivotally connected two finger support members 43 which extend longitudinally of the conveyor. The opposite ends of support member 43 are pivotally connected to the frame of the apparatus (not shown). Each finger support member carries a plurality of laterally projecting fingers 44 which project downwards towards the conveyor. Conveniently, the fingers 44 are made of resilient material. for instance. a synthetic or natural elastomer.

The actuating link is pivotally connected to operating link 45 which is connected to a push rod 47. The push rod is biased into engagement with one of the roller chains 14 by spring 42a so as to be intermittently raised to an upper position and then subsequently lowered by spring 42a. Such movement is arranged to cause the actuating link to be pivotally deflected and so causes the finger support members 43 to move laterally to and fro across the conveyor.

Accordingly articles carried by the conveyor are moved laterally of the conveyor and are consequently continually oriented.

This helps to ensure that the articles are evenly distributed over the conveyor and also helps to orient each article so that its minimum dimension is present to the gap defined between a flap and its neighbouring slat.

As an alternative or as an addition such disturbance of the articles carried by the conveyor may be achieved by the modification illustrated in Figure 4 wherein the slats 12 are provided with extensions 12a which project through roller chains 14.

Along each side of the roller chains there is provided two rows 60, 61 of cam heads 62, the cam heads of one row being staggered from those of the other row. Thus as the conveyor 11 is moved, the extensions 12a alternatively engage cam heads of alternate rows 60, 61 and so the slats 12 and associated flaps 14a are caused to oscillate laterally of the conveyor. This motion causes disturbance of the articles carried by the conveyor and helps to ensure that the articles are evenly distributed over the conveyor and also helps to orient each article so that its minimum dimension is presented to the gap defined between a flap and a neighbouring slat. If desired, the cam heads 62 may be of varying sizes so that the amount of lateral displacement of the slats 12 is accordingly varied.

It will be appreciated that the present apparatus may be used for grading of a wide range of materials, for instance, fruit, vegetables or minerals such as coal.

WHAT WE CLAIM IS: 1. Apparatus for grading articles by size, the apparatus including a conveyor upon which the articles to be graded are carried from a feed station to a discharge station which extends along a portion of the conveyor. the conveyor being comprised of laterally spaced slats which themselves extend laterally of the conveyor, each slat having a flap which extends radially therefrom and and which is arranged for pivotal deflection about an axis extending parallel to the slat for movement from a fully closed position to a fully open position, a linear cam

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. rotatably supported at either end by a pair of laterally spaced roller chains 14 (as more clearly seen in Figure 2), each slat 12 has a flap 14a which is fixedly secured thereto and which extends radially therefrom. As seen in Figure 1, the conveyor is trained about four sprockets 15, 16, 17 and 18, sprocket 15 being drivingly connected to a motor (not shown) which causes movement of the conveyor. The conveyor run passes through a feed station 13 and a discharge station 20. The feed station is provided with a hopper 19 into which articles to be graded are stored and the conveyor runs along the bottom of the hopper to pick up articles therefrom. The flaps of the slats as they pass through the feed station are held in a partially closed position by a linear cam 24a and then held in a fully closed position until they reach the discharge station. The position of the cam 24a may be varied so as to vary the spacing between the flaps and adjacent slats so as to vary the rate of pick-up of articles from hopper 19. Consequently, as a given slat moves through the discharge station its associated flap is permitted to pivotally move in a clockwise direction (as shown in Figure 1) so that the effective space between itself and the adjacent slat is progressively increased. Chutes 26, 27 and 28 are located below the discharge station to collect articles falling therefrom, to provide, in the present instance, three grade sizes of articles. As more clearly seen in Figure 2, the apparatus is provided with adjustment means 30 which permit the degree of divergence of the upper cam surface 23 to be varied as desired. It will be appreciated therefore that the number of grade sizes produced by the present apparatus may be conveniently varied by the choice of the number of chutes located beneath the discharge station 20. Advantageously. as illustrated in Figures 2 and 3, the apparatus may be provided with disturbing means 40 which are arranged to move articles carried by the conveyor thereon so as to ensure that each article is directly supported by the flaps of the conveyor. The disturbing means 40 which are illustrated include an actuating link 41 which is pivotally connected at one end to an element 41a which forms part of the frame of the apparatus and at the other end to support link 42 to which are pivotally connected two finger support members 43 which extend longitudinally of the conveyor. The opposite ends of support member 43 are pivotally connected to the frame of the apparatus (not shown). Each finger support member carries a plurality of laterally projecting fingers 44 which project downwards towards the conveyor. Conveniently, the fingers 44 are made of resilient material. for instance. a synthetic or natural elastomer. The actuating link is pivotally connected to operating link 45 which is connected to a push rod 47. The push rod is biased into engagement with one of the roller chains 14 by spring 42a so as to be intermittently raised to an upper position and then subsequently lowered by spring 42a. Such movement is arranged to cause the actuating link to be pivotally deflected and so causes the finger support members 43 to move laterally to and fro across the conveyor. Accordingly articles carried by the conveyor are moved laterally of the conveyor and are consequently continually oriented. This helps to ensure that the articles are evenly distributed over the conveyor and also helps to orient each article so that its minimum dimension is present to the gap defined between a flap and its neighbouring slat. As an alternative or as an addition such disturbance of the articles carried by the conveyor may be achieved by the modification illustrated in Figure 4 wherein the slats 12 are provided with extensions 12a which project through roller chains 14. Along each side of the roller chains there is provided two rows 60, 61 of cam heads 62, the cam heads of one row being staggered from those of the other row. Thus as the conveyor 11 is moved, the extensions 12a alternatively engage cam heads of alternate rows 60, 61 and so the slats 12 and associated flaps 14a are caused to oscillate laterally of the conveyor. This motion causes disturbance of the articles carried by the conveyor and helps to ensure that the articles are evenly distributed over the conveyor and also helps to orient each article so that its minimum dimension is presented to the gap defined between a flap and a neighbouring slat. If desired, the cam heads 62 may be of varying sizes so that the amount of lateral displacement of the slats 12 is accordingly varied. It will be appreciated that the present apparatus may be used for grading of a wide range of materials, for instance, fruit, vegetables or minerals such as coal. WHAT WE CLAIM IS:

1. Apparatus for grading articles by size, the apparatus including a conveyor upon which the articles to be graded are carried from a feed station to a discharge station which extends along a portion of the conveyor. the conveyor being comprised of laterally spaced slats which themselves extend laterally of the conveyor, each slat having a flap which extends radially therefrom and and which is arranged for pivotal deflection about an axis extending parallel to the slat for movement from a fully closed position to a fully open position, a linear cam

surface which extends along at least that portion of the conveyor run along which the discharge station extends and which in the direction of travel of the conveyor progressively diverges away from the conveyor run, the linear cam surface being located so that the terminal lateral edge of the flaps ride thereon in such manner that progressive pivotal movement thereof from their closed to their open position is caused, and disturbing means for moving articles on the conveyor laterally thereof.

2. Apparatus according to Claim 1 wherein each flap is so sized that in the fully closed position the terminal lateral edge of the flap is conveniently spaced from the adjacent flap.

3. Apparatus according to Claim 1 or Claim 2 wherein each slat is pivotally connected at either end to a pair of laterally spaced roller chains, the flap associated with each slat being fixedly secured thereto.

4. Apparatus according to any of Claims 1 to 3 wherein adjustment means are provided so that the position of the cam in relation to the run of the conveyor may be varied.

5. Apparatus according to any of Claims 1 to 4 wherein the disturbing means includes two rows of cam heads, each row extending along a respective side of the conveyor, the slats being mounted for lateral reciprocation and being provided with end extensions for co-operation with the cam heads, the cam heads of one row being staggered in relation to the cam heads of the other row so that on movement of the conveyor the slats are caused to reciprocate.

6. Apparatus according to any of I to 5 wherein the disturbing means includes a plurality of flexible fingers which are spaced along the conveyor and which are mounted for oscillation laterally of the conveyor.

7. Apparatus according to any of Claims I to 6 wherein the conveyor has an inclined run which passes through a store of the articles thereby to pick up and feed articles to said discharge station, and a linear cam surface extending substantially parallel to the inclined run of the conveyor and which is located to contact the terminal lateral edge of each slat thereby to control the position thereof.

8. Apparatus according to Claim 7 wherein adjustment means are provided for varying the position of the cam relative to the inclined run of the conveyor and thereby vary the rate of feed of the conveyor.

9. Apparatus for grading articles by size substantially as herein described with reference to, and as shown in, any of the accompanying drawings.

10. An article feed apparatus including a conveyor having an inclined run arranged to move through a store of articles, the conveyor being comprised of laterally spaced slats which themselves extend laterally of the conveyor, each slat having a flap which extends radially therefrom and which is arranged for pivotal deflection from a fully closed position to a fully open position, a linear cam surface extending substantially parallel to the inclined run of the conveyor and which is located to contact the terminal lateral edge of each flap thereby to control the position thereof, and disturbing means for moving articles on the conveyor laterally thereof.

11. An apparatus according to claim 10 wherein adjustment means are provided for varying the position of the cam relative to the inclined run of the conveyor and thereby vary the rate of feed thereof.