AU6278694A - Clamp for bin lifter - Google Patents

Description

"CLAMP FOR BIN LIFTER" TECHNICAL FIELD This invention relates to a clamp for a bin lifter and has been devised particularly though not solely for use with an articulated lifting arm attached to a refuse collection vehicle for the lifting of refuse bins to be unloaded into the vehicle.

BACKGROUND ART

It is known to use vehicles for the collection of refuse or recyclable materials which are placed into large wheeled bins and left at the kerbside or in other similar locations for collection. An articulated arm is connected to the vehicle adapted to be engaged with the bin to lift the bin and invert the bin, discharging the contents into a hopper or chute in an upper part of the vehicle. The empty bin is then returned to ground level by the articulated arm.

Many different ways have been proposed for engaging the bin with the end of the articulated arm including the use of hydraulic clamps and the use of suction or vacuum cups engageable with a flat side of the bin so that when suction is applied to the cup, the bin is securely engaged with the end of the lifter arm. The suction cups are commonly used in combination with a ledge or comb engageable beneath an outwardly protruding flange around the upper perimeter of the bin so that the comb takes most of the weight of a laden bin when engaged under the flange, and the suction cups secure the side wall of the bin to the end of the lifter arm. Configurations of this type have been reliable in use when the bins are clean, dry and not misshapen as the suction cups can then get a good grip on the side of the bin. In many situations however when the bin is distorted or wet, and particularly in cold regions where the bin can become frozen, the suction cup cannot adequately grip the side of the bin and as a result the bin is prone to slide off the suction cup and become disengaged from the lifter arm once elevated and tilted for unloading of the bin contents into the vehicle.

Other types of clamping mechanisms have used large hydraulically operated clamping arms to mechanically clamp the upper periphery of a bin to the end of the lifter arm before the lifting and inversion operation takes place, but such clamping mechanisms require accurate alignment with the upper perimeter of the bin and furthermore can cause considerable damage to a bin due to the forces imposed on the clamping arms by the hydraulic actuation mechanism.

DISCLOSURE OF INVENTION The present invention therefore provides a clamp for a bin lifter of the type having an arm extending from a vehicle and being engageable with a bin by way of a comb engageable under a flange around the upper periphery of the bin and a suction cup engageable with a side of the bin below the comb, said clamp comprising a short finger clamp moveably mounted to the arm adjacent the comb, connected to actuation means operable to move the finger between an engaged position resting on the flange of the bin in juxtaposition to the comb, and a disengaged position clear of the flange allowing the bin to be engaged or disengaged from the comb.

Preferably the finger clamp is pivotally mounted to the arm.

Preferably the pivotal mounting is by way of a pivot pin, and the actuation means causes the finger clamp to rotate about the pivot pin in use.

Preferably the actuation means comprises a pneumatic piston and cylinder assembly.

Preferably the piston and cylinder assembly is operated by vacuum applied to the cylinder at the same time, and from the same source, as vacuum applied to the suction cup. BRIEF DESCRIPTION OF DRAWINGS

Notwithstanding any other forms that may fall within its scope, one preferred form of the invention will now be described by way of example only with reference to the accompanying drawings, in which:-

Fig. 1 is a front elevation of an articulated bin lifter arm incorporating a clamp according to the invention; Fig. 2 is a side elevation of the construction shown in Fig. 1; and

Fig. 3 is a similar view to Fig. 1 showing a bin engaged with the articulated arm in a partially raised position. MODES FOR CARRYING OUT THE INVENTION

In the preferred form of the invention a clamp for a bin lifter is provided for use in combination with a suction cup engagement mechanism attached to an articulated arm of the type shown in the attached drawings, although it will be appreciated that the clamp can be applied for use with any other type of lifter arm.

The articulated lifter arm 1 is mounted to a vehicle, e.g. to the side of a collection truck by any suitable means but typically by way of a retractable boom 2 (Fig. 3) so that the base 3 of the arm can be moved outwardly from the side of the vehicle to a suitable position for engagement with a refuse or recyclable bin 4. The arm typically has a number of pivotally engaged links operable by a hydraulic piston and cylinder assembly 5 so that the end portion 6 of the arm is movable between a retracted position as shown in Fig. 1 where it can be engaged with a bin, and an elevated position (not shown) where the bin is lifted and inverted for discharge into a rubbish collection vehicle. The upper arm portion 6 is typically provided with a ledge or comb 7 which may have fragmented portions as can be seen in Fig. 2 adapted to be engaged under a peripheral flange 8 extending around the upper portion of the bin 4 which also typically has a lid 9 hinged to the body of the bin around a hinge pin 10. The bin is typically of large capacity, e.g. 240 litres and mounted on wheels 11. The outer arm portion 6 is also provided with at least one suction cup 12 which is connected to a vacuum line operated from the vehicle so that when the comb 7 is engaged under the flange 8 of the bin 4, vacuum is applied to the suction cup causing the cup to be firmly engaged with the side of the bin for the lifting and inversion of the bin.

In order to overcome problems of unintended release of the suction cup 12 under adverse conditions, the lifter arm according to the present invention is provided with a short finger clamp 13 pivotally mounted to the arm portion 6 by way of a pivot pin 14 adjacent to the comb 7 and movable about the pivot pin by suitable actuation means between an engaged and a disengaged position.

The actuation means typically comprise a pneumatic piston and cylinder assembly diagrammatically represented in the accompanying drawings by long chain line 15 connected between a pivot point 16 on arm portion 6 and a further pivot pin 17 on a portion of a bell crank arm 18 on which the short finger 13 is mounted. Operation of the air cylinder 15 therefore causes the bell crank arm 18 to pivot between the disengaged position shown in Fig. 1 where the finger clamp 13 is elevated, and the engaged position shown in Fig. 3 where the finger clamp is moved to a lowered position, lightly clamping the flange 8 of the bin between the finger clamp and the comb 7. It has been found in use that failure of the suction cup 12 to firmly engage the bin 4 has usually been by a sliding motion of the face of the bin across the suction cup, eventually causing disengagement of the cup from the side of the bin and then the bin from the entire lifter arm. It has surprisingly been found by the inventor that the application of a small clamping pressure on top of the flange 8 in the vicinity of the comb 7 is sufficient to prevent transverse movement of the bin across the suction cup 12, resulting in the suction cup remaining engaged with the bin even when the bin is wet or dirty or in an extreme situation even when the side of the bin has become wet and frozen in sub-zero conditions.

Because the finger clamp is actuated by a pneumatic piston and cylinder assembly rather than by a hydraulic clamp, there is a degree of "give" in the engagement of the finger clamp with the flange 8 due to the compressible nature of the air within the pneumatic cylinder assembly thus allowing the clamping action to take place without exerting excessive pressure on the flange of the bin which would otherwise be destructive.

Hydraulic clamping mechanisms formerly used for clamping bins to lifter arms (normally without the suction cup 12) can seriously damage a bin due to the unyielding engagement of a hydraulic clamp, whereas the small finger clamp used in the present invention, in combination with pneumatic operation, results in a yieldable clamping operation which provides sufficient friction to securely engage the bin with the lifter arm without damaging the bin in most normal circumstances. Although the yieldable clamping operation is most easily achieved by pneumatic operation, it will be appreciated that it can also be achieved by other equivalent means, for example by a hydraulically operated mechanism incorporating a spring or a flexible link to provide a degree of "give" in the operation.

Claims (7)

CLAIMS : -

1. A clamp for a bin lifter of the type having an arm extending from a vehicle and being engageable with a bin by way of a comb engageable under a flange around the upper periphery of the bin and a suction cup engageable with a side of the bin below the comb, said clamp comprising a short finger clamp moveably mounted to the arm adjacent the comb, connected to actuation means operable to move the finger between an engaged position resting on the flange of the bin in juxtaposition to the comb, and a disengaged position clear of the flange allowing the bin to be engaged or disengaged from the comb.

2. A clamp as claimed in claim 1 wherein the finger clamp is pivotally mounted to the arm.

3. A clamp as claimed in claim 2 wherein the pivotal mounting is by way of a pivot pin, and the actuation means causes the finger clamp to rotate about the pivot pin in use.

4. A clamp as claimed in any one of the preceding claims wherein the actuation means comprises a pneumatic piston and cylinder assembly.

5. A clamp as claimed in claim 4 wherein the piston and cylinder assembly is operated by vacuum applied to the cylinder at the same time, and from the same source, as vacuum applied to the suction cup.

6. A clamp as claimed in any one of claims 1 to 3 wherein the finger clamp is so arranged that upon moving to the engaged position any further operation of the actuation means is absorbed by flexibility in the clamp.

7. A clamp as claimed in claim 6 wherein the flexibility in the clamp is provided by a spring or other flexible link.