GB2121137A

GB2121137A - Cover for power take-off shaft

Info

Publication number: GB2121137A
Application number: GB08313931A
Authority: GB
Inventors: George Wakeling
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-05-19
Filing date: 1983-05-19
Publication date: 1983-12-14
Also published as: GB2121137B; GB8313931D0

Abstract

A protective cover is disclosed for a power take-off shaft for an agricultural tractor. The shaft (1) will typically be telescopically extensible and have a universal joint (3) at each end thereof. The cover comprises a telescoping pair of tubes (9), one end of each tube having separably attached thereto a funnel-shaped end cover (12) having on the inner surface thereof a bearing ring (14) for engaging a bearing groove (6) on the universal joint. The end cover is slit so as to be resiliently expansible to permit fitting and is held in position by an external clamping ring (16) which is positioned so as at least partially to overlie the bearing ring. <IMAGE>

Description

SPECIFICATION Cover for power take-off shaft This invention relates to a protective cover for a power take-off shaft for an agricultural tractor or the like.

Vehicles such as agricultural tractors are typically provided with a power take-off from the gear-box of the vehicle for use in driving auxiliary equipment which may either be stationary or towed behind the tractor. The take-off is usually in the form of a splined stub-shaft or socket, and the connection with the auxiliary equipment is via a shaft, typically having a pair of universal joints to accommodate movement between the tractor and the auxiliary equipment, the shaft having an end piece mating with the splined stub-shaft or socket.

A similar arrangement may be provided between the auxiliary equipment and the shaft. In addition to the universal joints, relative movement of the tractor and auxiliary equipment is accommodated by constructing the shaft in two relatively telescoping parts.

For safety purposes, and to keep the shaft clean to reduce wear therein, a tubular protective cover is provided around the shaft, the cover also telescoping upon itself to allow for movement of the shaft. The cover is secured against rotation, typically by a short length of chain attached to the tractor. The free end portion of each tube is provided with a bearing surface which engages in a circumferential groove in an end portion of the shaft to hold the cover relative to the shaft and allow rotation of the shaft within the cover. It has also been found, however, that mud, ice and other contaminants can cause the parts of the cover to become locked together, preventing the telescoping action. This can lead to the cover pulling away from one end of the shaft allowing the ingress of dirt and possibly leading to disintegration of the cover.In addition, the bearings are subject to wear in use and are difficult to repiace, when worn. Thus many power take-off shafts are left exposed and constitute a potential hazard when the shaft is in use.

The present invention provides a protective cover for a power take-off shaft for an agricultural tractor, the take-off shaft being telescopically extensible and having a universal joint at each end thereof, the cover comprising a telescoping pair of tubes, one end of each tube having separately attached thereto a funnel-shaped member having on the inner surface thereof a bearing ring for engaging a bearing groove on the universal joint, at least that portion of the funnel-shaped member wherein the bearing ring is located being resiliently expansible, and a clamping ring being located around the external surface of the funnelshaped member at least partially overlying the bearing ring to resist expansion of said member.

Preferably, the inner surface of the outer tube of the pair of tubes is provided with a plurality of ribs extending along the tube and engaging the outer surface of the inner tube of the pair of tubes.

All components of the cover may suitably be formed of plastics materials, the tubes being extruded in high density polyethylene, and the funnel-shaped members being moulded in a polyamide, for example.

The cover of the invention is durable and resistant to failure through exposure to mud and ice. The funnel-shaped members with their bearing surfaces may be readily replaced, if the bearing surfaces are worn, without the need to remove the cover from the shaft.

Reference is made to the drawings, in which: Figure 1 is a part-sectional side view of one end of a power take-off shaft having a cover in accordance with the invention; and Figure 2 is a cross-section through a central portion of the shaft and cover shown in Figure 1.

The power take-off shaft 1 comprises at each end a splined stub-shaft 2 which can engage in mating sockets on the tractor and the auxiliary equipment to be driven, only one end of the shaft and cover being illustrated in Figure 1.

Alternatively, the socket may be provided on the shaft and the stub-shaft on the tractor and equipment, or the ends of the shaft may be different from one another.

Each stub-shaft 2 (or socket) is connected to a universal joint or coupling 3 represented in the drawing schematically. The shaft 1 has two telescoping parts connecting the two universal joints 3. The shaft 1 is provided at each end with a circumferentially grooved bearing ring 6 adjacent to the universal joint 3.

The cover 8 comprises two tubes 9 and 10 (Figure 2) telescoped together and having funnelshaped end covers 12 located around the ends of the take-off shaft 1. The narrow portions 1 2a of the end covers 1 2 locate within the corresponding ends of the tubes 9 and 10 and are each held in place with four spaced self-tapping screws or the like.

As shown in Figure 2, the tubes 9 and 10 are spaced coaxially by longitudinal ribs 13 on the inner surface of the outer tube. The ribs 1 3 engage upon the outer surface of the inner tube 10.

The end covers 1 2 are identical and have therein a bearing ring 14 in the form of a circumferentially-extending rib located at the intersection between the narrow portion 1 2a and the frusto-conical portion 1 2b. The narrow portion 1 2a is reduced in diameter externally to accommodate the tube 9, the ribs 1 3 locating in corresponding grooves. The frusto-conical portion 1 2b ends in a shoulder 1 5 externally, the end of the tube 9 forming an opposing shoulder to accommodate a clamping ring in the form of a screwed hose clip 1 6. A lubrication hole 17, whose position is indicated by a broken line, is provided in each end cover 12 at a position overlying the grease nipple of the universal joint 3, and a slit 1 8 runs from the hole 17 to the end of the portion 1 2a, to allow the portion to be expanded as the end cover 1 2 is brought over the universal joint 3 being being fitted into the end of the tube 9 or 10. The inner tube 10 is increased in diameter adjacent its free end to the same internal diameter as that of the outer tube 9 to facilitate fitting of the end cover 12.

Claims

1. A protective cover for a power take-off shaft for an agricultural tractor, the take-off shaft being telescopically extensible and having a universal joint at each end thereof, the cover comprising a telescoping pair of tubes, one each end of each tube having separably attached thereto a funnelshaped member having on the inner surface thereof a bearing ring for engaging a bearing groove on the universal joint, at least that portion of the funnel-shaped member wherein the bearing ring is located being resiliently expansible, and a clamping ring being located around the external surface of the funnel-shaped member at least partially overlying the bearing ring to resist expansion of said member.

2. A cover according to Claim 1, wherein the inner surface of the outer tube of the pair of tubes is provided with a plurality of ribs extending along the tube and engaging the outer surface of the inner tube of the pair of tubes.

3. A cover according to Claim 1 or 2, wherein the clamping ring is in the form of an externally toothed or grooved flexible band with a screwthreaded rotatable adjusting member for engaging the teeth or grooves to open or close the band.

4. A cover according to Claim 1, 2 or 3, wherein the funnel-shaped member has at least one slit therein to permit the member to be expanded to fit the bearing ring into the bearing groove on the universal joint.

5. A protective cover substantially as described with reference to, or as shown in, the drawings.