GB2052944A - Power transmission apparatus - Google Patents

Abstract

Power transmission apparatus 1 is provided for coupling between the power take-off shaft of a tractor and a piece of ancillary belt-driven equipment, without the usual problems of weight support and careful alignment during the coupling operation. The apparatus comprises a drive shaft 4 rotatably supported in a bearing 3 having a crossbar 2 with means 24 for permitting the load arms of the tractor to engage and lift the crossbar, and the apparatus, one end of the drive shaft 4 being adapted for coupling-to the tractor power take-off shaft, the other end thereof being connected to a belt pulley 5 to drive the same. <IMAGE>

Description

SPECIFICATION Power transmission apparatus This invention relates to power transmission apparatus for coupling between the power take-off shaft of a tractor and a piece of ancillary belt-driven equipment.

Since ancillary belt-driven equipment is often, in use, located to the rear of the driving tractor or towed thereby, it is convenient to drive such equipment by a drive belt passing around a driving pulley whose pulley axis is disposed transversely of the tractor. Therefore, a commonly-used transmission apparatus comprises a drive shaft connected at one of its ends via bevel gearing to a drive pulley, the other end being adapted for direct coupling to the power take-off shaft of a tractor, the whole being additionally adapted for fixed attachment to the tractor body with freedom for the drive shaft, bevel gearing and pulley to rotate.

Such apparatus is ponderous, and as the usual method of attachment thereof to a tractor is manual, the operation presents some difficulty. Thus the weight of the apparatus has to be supported while the operator fixes the attachment means (bolts and nut), at the same time taking care that the drive shaft is in a correct spatial relationship to the tractor power take-off shaft for coupling thereto. Coupling is usually direct or non-articulated, so that the drive shaft must be in exact axial alignment with the power take-off shaft if it is to be coupled thereto, causing further difficulty in attachment.

The removal of mitigation of these difficulties is among the objects of the invention.

The invention therefore provides power transmission apparatus for coupling between the power take-off shaft of a tractor and a piece of ancillary belt-driven equipment, which power transmission apparatus comprises a drive shaft, means for coupling one end of the drive shaft to the power take-off shaft of the tractor, means for operatively connecting a belt pulley to the other end of the drive shaft, a bearing for rotatably supporting the drive shaft, a crossbar mounted on the bearing, and means on the crossbar for permitting the load arms of the tractor to engage and lift the crossbar, and the apparatus.

Preferably the belt pulley axis runs transversely of the drive shaft axis. Preferably the means for coupling one end of the drive shaft to the tractor power take-off shaft includes a universal joint. Preferably the length of the drive shaft can be altered, e.g. a telescopically extendible drive shaft may be employed.

An embodiment of the invention will now be described by way of example, with reference to the accompanying drawings, in which Figure 1 is a three-quarter front perspective view of a power transmission apparatus; Figure 2 is a three-quarter rear perspective view of the apparatus of Fig. 1; Figure 3 is a front detail from Fig. 1, on an enlarged scale; Figure 4 is an exploded view of the detail of Fig. 3; Figure 5 is an exploded view of the apparatus of Fig. 2; and Figure 6 is a view of the apparatus of Fig. 2 mounted on the rear of a tractor.

Referring now to the drawings, a power transmission apparatus 1 comprises a crossbar 2, a bearing sleeve 3, a drive shaft 4, a belt pulley 5 and a gearbox 6. The gearbox 6 and the crossbar 2 have correspondingly perforated mounting plates 61, 21 respectively.

The plate 21, together with the adjacent end of the drive shaft 4, together comprise the aforesaid means for operatively connecting a belt pulley to said end of the drive shaft. The drive shaft end is adapted for engagement with the gear train in the gearbox 6. The drive shaft 4 terminates in a universal joint 45 with a tightener 46. The crossbar 2 terminates in wings 22 each have a set of holes 23, and a lift pin 24. The mounting plate 21 bears a swivelling shackle 25. The bearing sleeve 3 bears a covered lubrication port 31.

The drive shaft 4 comprises a telescoping inner member 41 and outer tubular member 42, having longitudinal ridges 43 on the one and matching longitudinal grooves 44 on the other. The crossbar 2 and mounting plates 21 and 61 are all perforated with suitable voids 27 to permit the passage of the outer tubular member 42 of the drive shaft 4 into the bearing sleeve 3, and its rotation therein. The gearbox 6 contains a set of bevel gears (not shown) to establish a driving connection between the drive shaft 4 and the belt pulley 5.

Each lift pin 24 can be fixed at will in a selected one of the holes 23 on the respective wing 22. The mounting plates 61, 21 are bolted face to face by bolt and nut units 26 to assemble the apparatus.

In use of the apparatus 1, a tractor 7 having a power take-off shaft 71 and conventional front or rear lift arms 72 is driven into close proximity with the apparatus, and the lift arms 72 are aligned with the wings 22 thereof. Each lift arm 72 is then engaged with a respective lift pin 24 and secured thereto by means of a cotter, a split pin or the like. The telescoping drive shaft 4 is manually extended and the universal joint 45 thereof coupled to the power take-off shaft 71 and fixed thereto by the tightener 46.

The piece of ancillary belt-driven equipment (not shown) is stationed so that its belt pulley is aligned with the belt pulley 5. (This piece of equipment may additionally be coupled to the tractor body for towing by the tractor in use).

The apparatus 1 is then raised to a desired working height by operation of the tractor hydraulic system to raise the lift arms 72 and hold or lock them at the said height. A drive belt 73 is fitted on to the aligned belt pulleys.

The power take-off is then operated to drive the ancillary equipment.

It will be appreciated that the entire coupling operation is effected manually without any manual weight-lifting and without appreciable physical strain on the operator. The swivelling shackle 25 is provided merely for mechanical hoisting of the apparatus 1 for transport and storage of the latter, but is not involved in the above-described coupling operation.

The gearbox 6 and belt pulley 5 together comprise a unit which is commercially available. Thus the apparatus of the invention may include or omit the said unit, which latter may be acquired separately by the user and bolted to the plate 21 for use.

Claims (11)

1. Power transmission apparatus for coupling between the power take-off shaft of a tractor and a piece of ancillary belt-driven equipment, which power transmission apparatus comprises a drive shaft, means for coupling one end of the drive shaft to the power take-off shaft of the tractor, means for operatively connecting a belt pulley to the other end of the drive shaft, a bearing for rotatably supporting the drive shaft, a crossbar mounted on the bearing, and means on the crossbar for permitting the load arms of the tractor to engage and lift the crossbar, and the apparatus.

2. Apparatus as claimed in claim 1, wherein the belt pulley axis runs transversely of the drive shaft axis.

3. Apparatus a claimed in claim 1 or 2 wherein the means for coupling one end of the drive shaft to the tractor power take-off shaft includes a universal joint.

4. Apparatus as claimed in any of claims 1 to 3 wherein the length of the drive shaft can be altered.

5. Apparatus as claimed in claim 4 wherein the drive shaft is telescopically extendible.

6. Apparatus as claimed in claim 5 wherein the drive shaft comprises inner and outer tubular members having at least one longitudinal ridge on the one and a matching longitudinal groove in the other.

7. Apparatus as claimed in any of claims 1 to 6 wherein the means for operatively connecting a belt pulley to the other end of the drive shaft includes a gearbox containing a set of bevel gears to establish driving connection between the drive shaft and the belt pulley.

8. Apparatus as claimed in any of claims 1 to 7 wherein the means for permitting the load arms of the tractor to engage and lift the crossbar, and the apparatus, comprises a pair of wings mounted at opposite ends of the crossbar, and a pair of lift pins mounted one on each of said wings.

9. Apparatus as claimed in claim 8 wherein each wing bears a plurality of perforations as a set of matched pairs, one member of each pair being located in either wing, and wherein each said perforation is adapted to retain a lift pin removably and interchangeably.

10. Apparatus as claimed in any of claims 7 to 9 which apparatus includes the gearbox and the belt pulley and is assembled ready for use.

11. Apparatus as claimed in any of claims 7 to 9 which apparatus does not include the gearbox or the belt pulley, but includes means for mounting the gearbox and the belt pulley.

1 2. Power transmission apparatus as claimed in claim 1, substantially as herein decribed with reference to or as illustrated in the accompanying drawings.

1 3. Any novel feature or combination of features described herein.