GB1565891A - Palletiser - Google Patents

Description

(54) PALLETISER (71) We, MARRYAT HANDLING LIMITED, a British Company of Lombard House, 10, Lombard Road, London SW19 3XR, 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 conveyor assemblies and is primarily concemed with transferring and stacking bales, for example tobacco bales, from conveyor belts onto pallets.

The problem with transferring and stacking bales of shreddable material such as tobacco directly from a conveyor belt onto a pallet is that a certain amount of scuffing of the bale material takes place as the moving bale is forced by the conveyor belt across the pallet and this results in abrasion and consequent loss of tobacco or other material from the bale.

The present invention aims to solve the problem of transferring and stacking bales of tobacco or other shreddable material from a moving conveyor belt to a stationary pallet without any abrasion of the bale taking place.

According to the invention, a conveyor assembly including a unitary structure comprising a hoist mechanism, a boom movable in substantially a horizontal direction to and from a position in which it can at one end overlap a receiving surface located for the purpose of receiving a load when delivered thereto by the assembly, means for moving the boom to and from the said position, flexible conveying means supported by the boom for conveying a load over the boom towards the said one end thereof, means for driving the flexible conveying means with respect to the boom while the boom is being withdrawn from its overlapping position so that the load is deposited on the said surface substantially without abrasion of the load, and said hoist mechanism being arranged to move said boom in a vertical direction whereby the height of said boom can be set to deposit said load on said surface or on top of a load previously positioned on the surface.

The invention will now be further des cribed, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a part-sectioned side elevation of one embodiment of a conveyor assembly according to the invention; Figure 2 is a part-sectioned end elevation of the assembly shown in Figure 1; Figure 3 is a plan view of the assembly shown in Figures 1 and 2; and Figures 4-7 are diagrammatic views showing various steps in the transfer of a bale from a conveyor belt to a pallet.

Referring to the drawings, the conveyor assembly comprises a frame having four bases 1, 2, 3 and 4 and a pair of vertically upright folded plate members 5 extending respectively from the bases 1, 2 and 3, 4. A hoist 6 is located between the upright members 5 and mounted on the hoist 6 are two pairs of friction-tyred wheels 7 arranged to be driven by an electric motor 8. Lower flanges 9 of side members of a boom 10 are arranged to rest on the wheels 7 and the boom is held in place by means of pinch rollers 12 rotatably mounted in stanchions 13 secured top the frame 30 of the hoist 6.

Mounted on one of the upright members 5 is an electric motor 14 which is arranged to drive via bevel gears 15 and 16 a shaft 17 extending between the upright members 5.

The bevel gear 15 is mounted on a shaft 18 the other end of which carries a bevel gear 19 which engages a further bevel gear 2p mounted on a shaft 21 extending between the upright members 5. Mounted on each shaft 17 and 21 are, in each case, a pair of sprockets 22. A respective endless chain 23 extends around each sprocket 22 and around an idler sprocket 22a mounted on a shaft 22b supported at its ends in tensionable bearings 22c. One run of each chain 23 is secured to the associated side of the hoist 6.

A conveyor belt 24 is mounted on the boom 10 by means of a roller 25, 26 at each end of the boom. The lower run of the conveyor belt passes around idler rollers 27, 28 and 29 and around a roller 31 which is arranged to be driven by an electric motor 32 via a chain drive 33 and a pair of sprockets 34, 35 res pectively mounted on the motor shaft and the shaft carrying the roller 31. The rollers 27-31, motor 32, pulleys 34, 35 and the associated shafts are mounted in a frame 30 connected to the hoist 6.

The frame is so arranged that the end of the boom carrying the roller 25 can be located adjacent to a feeder conveyor 36 having a conveyor belt 37 movably mounted thereon.

The other end of the boom 10 is arranged to be adjacent to a track consisting of two guide rails 38 on which a wheeled pallet 39 can be guided or, alternatively, a static pallet can be placed directly on the floor.

In use, the boom is first arranged as shown in Figure 4, with the roller 25 located adjacent the end of the conveyor belt 37 with the upper run of the conveyor belt 24 located at the same height as the upper run of the conveyor belt 37. The motor 32 is arranged to drive the belt 24 at the same speed and in the same direction as the conveyor belt 37 whereby a bale 40 can be transferred from the belt 37 to the belt 24 without any scuffing or abrasion of the material of the bale occuring. Once the bale is located in a pre determined position on the conveyor belt 24, the motor 32 is stopped.

The motor 8 is then started to drive the wheels 7 which, by virtue of their frictional engagement with the flanges 9, are effective to move the boom to the left as shown in the drawings. It will be appreciated that if the conveyor belt were kept stationary during this lateral movement of the boom, the upper run of the belt would move to the left relatively to the frame 30 at twice the speed of the boom itself. Thus, in that case, the bale on the belt would be accelerated relatively to the frame and in some arrangements could reach the end of the boom at which the roller 26 is provided when the boom had completed only part of its horizontal traversing movement.

To prevent this from occurring the motor 32 is started once again but in the reverse direc tion so that the upper run of the conveyor belt 24 is driven by the motor 32 in the reverse direction relatively to the frame 30 at approximately half the speed of the lateral movement of the boom relatively to the frame 30 so that the bale moves along the boom at aproximately the same speed as the boom is moving. By such means, the bale can be arranged to reach the end of the boom at which the roller 26 is provided at the same time as the boom is fully located over the pallet 39. The motor 8 is thereupon stopped This position is indicated in Figure 5 of the drawings. The conveyor belt motor 32 is stopped at the same time as the boom motor 8.

The motor 14 is then started to move the boom down to a vertical postition in which the lower run of the conveyor belt 24 is located marginally above the upper surface of the pallet 39. In one embodiment of the invention, prior to motor 8 starting, the boom is raised by means of the chains 23, which are driven by the sprockets 22 in turn driven by the motor 14 via the shafts 17 and 21 and bevel gears 15, 16, 19 and 20, to the position shown in Figure 6 after which the boom is lowered again by reversing the direction of the motor 14. However, when there is not already a bale on the pallet 39, this step is not essential.

After the boom has been moved to the position at which the lower run of the conveyor belt 24 is marginally above the height of the upper surface of the pallet 39, the motor 8 is started again to drive the boom in the reverse direction, i.e. from left to right in the drawings. Again, if the conveyor belt 24 were not driven, the upper run of the belt would move from left to right at twice the speed of the boom and the bale would move with the belt.

The motor 32 is therefore arranged to drive the conveyor belt in a direction in which the upper run of the belt moves from right to left at the same speed as the boom is being driven from left to right. The belt is therefore effectively "peeled" off the bale and the bale is deposited on the pallet 39 without any scuffing or abrasion of the bale material occuring. The boom is returned to the position shown in Figure 4 of the drawings when the motor 8 is stopped while the motor 32 continues to run. As stated above, the motor 32 drives the belt 24 at the same speed as the conveyor belt 37 whereby the belt 24 can receive a further bale 41.

Once the bale 41 is wholly received on the conveyor belt 24, the motor 32 is stopped and the motor 14 started to hoist the boom to the position shown in Figure 6 of the drawings when the motor 14 is stopped. The boom is then moved laterally to the position shown in Figure 7 of the drawings with the bale 41 being transferred, at the same time, from the right end to the left end of the boom by the conveyor belt 24. The motor 14 is started again to lower the boom to a position in which the lower run of the conveyor belt 24 is marginally above the upper surface of the bale 40 already on the pallet 39.

The boom is then moved to the right from the position shown in Figure 7 and the belt is driven in the opposite direction whereby the bale 41 is deposited on top of the bale 40 in a like manner to that in which the bale 40 is deposited on the pallet 39. Once the bale 41 has left the conveyor belt 24, the boom can be returned to the position shown in Figure 4 of the drawings and the loaded pallet moved away from the apparatus along the guide rails 38 and replaced by an empty pallet. The cycle can then be repeated.

If desired, each pallet may be loaded with only a single bale in which case the hoisting step of the boom may be omitted.

The various movements of the bale on the conveyor belt 24 and the boom conveyor itself are desirably controlled by photo-electric beams which are arranged to control the electric motors 8, 14 and 32 in a conventional manner.

Safety hand rails 42 may be provided to the sides of the apparatus as shown in Figure 3 of the drawings in order to prevent personnel from touching the boom or other components and thus possibly interfering with the operation of the apparatus or injuring themselves when the apparatus is operating.

A manually-operated counter-balanced clamp 43 (Figure 3) may be provided for clamping the pallet in position on the guide rails 38 adjacent to the apparatus. The clamp is operable by a lever 44 located outside the safety railing 42. A manually adjustable pallet stop 45 is mounted on the guide rails 38 for determining the position of the pallet. Finally, an expanding picket type gate 46 may be provided having switch means which prevent the palletising apparatus from operating when the gate is open.

WHAT WE CLAIM IS: 1. A conveyor assembly including a unitary structure comprising a hoist mechanism, a boom movable in substantially a horizontal direction to and from a position in which it can at one end overlap a receiving surface located for the purpose of receiving a load when delivered thereto by the assembly, means for moving the boom to and from the said position, flexible conveying means supported by the boom for conveying a load over the boom towards the said one end thereof, means for driving the flexible conveying means with respect to the boom while the boom is being withdrawn from its overlapping position so that the load is deposited on the said surface substantially without abrasion of the load, and said hoist mechanism being arranged to move said boom in a vertical direction whereby the height of said boom can be set to deposit said load on said surface or on top of a load previously positioned on the surface.

2. A conveyor assembly according to Claim 1, in which the flexible conveying means is an endless belt developing the boom longitudinally and arranged to travel over rollers mounted on axes fixed with respect to the boom, and in which the means for driving the flexible conveying means with respect to the boom comprise a motor connected for causing the belt to circulate about the boom.

3. A conveyor assembly according to Claim 2, in which the belt is arranged to receive a load at the end of the boom remote from the said one end and to deliver the load to the said one end while the boom is being driven to overlap the said surface, the motor being arranged during such movement of the boom to drive the upper run of the belt relatively to the frame in the reverse direction to that of the boom and at a speed such that the load reaches the said one end substantially simultaneously with the completion of the overlapping movement of the boom.

4. A conveyor assembly according to Claim 2 or Claim 3, in which the motor is arranged to cause the endless conveyor to move while said boom is being withdrawn from said overlapping position by causing the upper run of the belt to move at the same speed as the boom is being withdrawn from its overlapping position, but in the opposite direction.

5. A conveyor assembly according to any one of the preceding claims, in which the means for moving the boom to and from the said position comprises power driven friction wheels.

6. A conveyor assembly according to any one of Claims 1 to 5 comprising a feeder conveyor arranged to deliver loads in succession to the end of said beam remote from said one end thereof, and means for positioning pallets in succession to provide receiving surfaces for receiving loads from the flexible conveying means.

7. A conveyor assembly substantially as decribed with reference to the accompanying drawings.

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

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. step of the boom may be omitted. The various movements of the bale on the conveyor belt 24 and the boom conveyor itself are desirably controlled by photo-electric beams which are arranged to control the electric motors 8, 14 and 32 in a conventional manner. Safety hand rails 42 may be provided to the sides of the apparatus as shown in Figure 3 of the drawings in order to prevent personnel from touching the boom or other components and thus possibly interfering with the operation of the apparatus or injuring themselves when the apparatus is operating. A manually-operated counter-balanced clamp 43 (Figure 3) may be provided for clamping the pallet in position on the guide rails 38 adjacent to the apparatus. The clamp is operable by a lever 44 located outside the safety railing 42. A manually adjustable pallet stop 45 is mounted on the guide rails 38 for determining the position of the pallet. Finally, an expanding picket type gate 46 may be provided having switch means which prevent the palletising apparatus from operating when the gate is open. WHAT WE CLAIM IS:

1. A conveyor assembly including a unitary structure comprising a hoist mechanism, a boom movable in substantially a horizontal direction to and from a position in which it can at one end overlap a receiving surface located for the purpose of receiving a load when delivered thereto by the assembly, means for moving the boom to and from the said position, flexible conveying means supported by the boom for conveying a load over the boom towards the said one end thereof, means for driving the flexible conveying means with respect to the boom while the boom is being withdrawn from its overlapping position so that the load is deposited on the said surface substantially without abrasion of the load, and said hoist mechanism being arranged to move said boom in a vertical direction whereby the height of said boom can be set to deposit said load on said surface or on top of a load previously positioned on the surface.

2. A conveyor assembly according to Claim 1, in which the flexible conveying means is an endless belt developing the boom longitudinally and arranged to travel over rollers mounted on axes fixed with respect to the boom, and in which the means for driving the flexible conveying means with respect to the boom comprise a motor connected for causing the belt to circulate about the boom.

3. A conveyor assembly according to Claim 2, in which the belt is arranged to receive a load at the end of the boom remote from the said one end and to deliver the load to the said one end while the boom is being driven to overlap the said surface, the motor being arranged during such movement of the boom to drive the upper run of the belt relatively to the frame in the reverse direction to that of the boom and at a speed such that the load reaches the said one end substantially simultaneously with the completion of the overlapping movement of the boom.

4. A conveyor assembly according to Claim 2 or Claim 3, in which the motor is arranged to cause the endless conveyor to move while said boom is being withdrawn from said overlapping position by causing the upper run of the belt to move at the same speed as the boom is being withdrawn from its overlapping position, but in the opposite direction.

5. A conveyor assembly according to any one of the preceding claims, in which the means for moving the boom to and from the said position comprises power driven friction wheels.

6. A conveyor assembly according to any one of Claims 1 to 5 comprising a feeder conveyor arranged to deliver loads in succession to the end of said beam remote from said one end thereof, and means for positioning pallets in succession to provide receiving surfaces for receiving loads from the flexible conveying means.

7. A conveyor assembly substantially as decribed with reference to the accompanying drawings.