GB2355966A

GB2355966A - Vehicle power take-off apparatus

Info

Publication number: GB2355966A
Application number: GB9929444A
Authority: GB
Inventors: William Robert Winton; Robert Mcgladdery
Original assignee: WINTON ENGINEERING Ltd
Current assignee: WINTON ENGINEERING Ltd
Priority date: 1999-11-05
Filing date: 1999-12-10
Publication date: 2001-05-09
Also published as: GB9926334D0; GB9929444D0

Abstract

A power take-off apparatus for use on vehicles comprises a pulley 15, such as a timing belt pulley, driven directly or indirectly by a vehicle engine crankshaft and a clutch 22 mounted on the pulley 15 to drive the power take-off. The clutch comprises a clutch plate or set of clutch plates fixed to the pulley and a unit movable to engage and disengage the clutch plate or set of clutch plates. The clutch may be electrically operated or controlled by a Bowden cable. If electrically operated there may be a switch arrangement to prevent the clutch being engaged if the vehicle is in gear or the handbrake released. The clutch unit is mounted on a mounting plate 20 supported by pillars 18 connected to the vehicle engine block. Drive means for taking power from the clutch unit are mounted on the mounting plate, taking the form of a drive pulley or a hydraulic or pneumatic pump 24 to provide fluid under pressure to energise an external fluid operated motor acting as a prime mover for equipment such as a close-coupled compressor, generator or water pump.

Description

2355966 POWER TAIKE-OFF APPARATUS This invention relates to a power

take-off apparatus for use in a vehicle. 5 Power take-off apparatuses in general are sold for fitting to vehicles such as trucks or fire engines. Known apparatuses of this kind are bulky and unsuitable for fitting to lighter vehicles such as light lorries, cars and utility vehicles such as vans or those vehicles sold under the registered trade marks Land Rover and Range Rover.

According to the present invention there is provided a power take-off apparatus comprising a pulley connectable directly or indirectly to a vehicle engine crankshaft; a clutch mounted on said pulley, said clutch comprising a clutch plate or set of clutch plates fixed to said pulley and a clutch unit movable to engage and disengage the clutch plate or set of clutch plates; a clutch control arrangement which, when operated, engages said clutch; and drive means for taking power from the clutch unit.

Such an apparatus can readily be mounted on a vehicle because all that it is necessary to do is to replace one of the external pulleys, e.g. the pulley on the crankshaft or a pulley driven by a timing belt or the like, by the pulley of the present invention. Accordingly the present invention allows a power take-off apparatus to be fitted on a wide range of vehicles including light lorries, cars and utility vehicles.

Preferably, the clutch plate or set of clutch plates is mounted in a recess in said pulley. This provides a very compact arrangement for the power take-off apparatus making it more suitable for application to a small vehicle. The compactness can be further enhanced by the clutch unit is positioned at least in part within said recess in said pulley.

The drive means for taking power from the clutch unit maybe a pneumatic or hydraulic pump mounted adjacent said pulley to provide fluid under pressure, when the clutch is engaged, for energising an external fluid-operated motor acting as a prime mover for equipment, for example a close coupled compressor, generator or water pump. Alternatively, the output from the pump could be via pipes or hoses themselves provided with hose connectors mounted in a readily accessible position on the exterior of the vehicle, for example near to the bonnet or hood of the vehicle. Alternatively the drive means may be a drive pulley.

The clutch can take many forms including a remotely controlled system operated, for example, by a Bowden cable. Preferably, however, it is an electrically operated 10 clutch and the control arrangement is a control circuit.

Preferably, the electrical control circuit includes switch arrangement connectable to the vehicle gearbox selector and/or the vehicle handbrake so as to prevent the clutch being engaged when the vehicle is being driven. 15 Desirably, said clutch unit is mounted on a mounting plate, the mounting plate itself being supported by pillars extending past the clutch and pulley and connectable to the vehicle engine block.

In order that the present invention may more readily be understood, the following description is given, merely by way of example, reference being made to the accompanying drawings in which:

Fig. I is a schematic side elevational view, partly in section, of a power take-off 25 which is a first embodiment to the present invention; and Fig. 2 is a similar view of a power take-off which is a second embodiment of the present invention.

A first embodiment is illustrated in Fig. I connected to an engine block 10 of an engine of any suitable vehicle. This may be an in-line engine or a transverse engine.

Nearly all engines will have a timing belt cover and such a cover 12 is illustrated.

As can be seen in the half section, mounted on an end portion 14 of the crankshaft is a pulley 15 which may itself act as the timing belt pulley for the engine. The outer periphery of the pulley 15 is adapted to receive a belt. The pulley 15 is formed with annular spacer 19 inside its outer periphery. The annular spacer 19 acts a vibration damper and is formed from rubber or some other suitable material. The spacer 19 is in itself conventional and not essential to the invention. The pulley 15 is modified as compared to a normal timing belt pulley. It includes a fixed clutch plate 16, which is fixed to the pulley so as to rotate when the pulley 15 itself rotates. Alternatively a plurality of clutch plates 16 may be provided A clutch unit 22 is positioned adjacent the fixed clutch plate 16 which is mounted on the pulley 15. The clutch unit 22 is mounted on the inner side of a mounting plate 20. The mounting plate 20 is supported by three pillars 18, only two of which can be seen in the drawing, which extend past the clutch unit 22 and the pulley 15 and are connected to the engine block 10.

The clutch unit 22 is an electrically operated dog clutch and may have a moving clutch plate or set of plates. It is movable in a direction parallel to the rotational axis of the pulley 15 to engage and disengage the fixed clutch plate 16, whereby the clutch unit 22 and fixed clutch plate 16 together constitute a clutch. The movement of the clutch unit 22 is controlled by a control circuit 21. An electrical (or electromagnetic) clutch is preferred, although other forms of clutch are contemplated.

The clutch could simply be manually operated or operated remotely by Bowden cable.

As can be seen in Fig. 1, the clutch plate 16 is mounted in a recess 17, within the centre of the pulley 15 in particular on the base of the recess 16. The clutch unit is also positioned partly within the recess 17. This provides a compact arrangement for the clutch.

The pulley 15 may be manufactured from a conventional pulley in the following way. If, necessary, the recess 17 is formed or enlarged, for example by turning on a lathe. The clutch plate 16 is then mounted within the recess by bolts I I or any other suitable fixing. 5 Mounted on the right-hand side of the mounting plate 20 is a hydraulic pump 24, the input drive shaft of which is connected to the clutch unit 22 through a bearing in a bearing housing 23. It has been found that when attached to the engine of a normal car, a hydraulic pump of up to 5kW can comfortably be mounted on the mounting plate 20.

It will be appreciated, therefore, that when the clutch unit 22 is operated, the clutch unit 22 will engage against the fixed clutch plate 16 and will thereby be driven from the vehicle engine by the keyway of the pulley 15, this in turn driving the hydraulic pump 24.

Output hoses (not shown) can be connected from the hydraulic pump 24 to an external hydraulic motor (not shown) which may be used, upon engagement of the clutch, to drive any piece of equipment such as a close coupled compressor, a generator or water pump by way of example. In this way, the hydraulic pump acts as a drive means to take power from the clutch unit 22.

Reference has been made in this description to a hydraulic pump and hydraulic motor. These could, of course, be replaced by a pneumatic pump and motor.

The control circuit 21 associated with the electrically operated clutch will include a control switch for turning the clutch on and off. It will preferably also include a switch arrangement which is connectable to the vehicle gearbox selector and either additionally or alternatively to the vehicle handbrake, whereby the circuit remains open unless the vehicle gearbox is in neutral and the handbrake is on. In this way operation of the apparatus of the invention is prevented unless the vehicle is "51 stationary.

A second embodiment is illustrated in Fig. 2 and comprises in most part elements which are indentically constructed and arranged to the first embodiment. The same reference numerals are used for like elements and a detailed description of the common elements is omitted for brevity. The only difference is that the hydraulic pump 24 of the first embodiment is replaced by a toothed drive pulley 25 for taking power from the clutch unit 22. A belt (not shown) may be arranged around the drive pulley to drive external equipment when the clutch is engaged. The drive pulley 25 and belt may be used to drive an external hydraulic (or pneumatic) pump itself connected to drive an external hydraulic (or pneumatic) motor for driving further equipment. This is a particularly advantageous arrangement when driving a hydraulic pump which is too large to mount on the mounting plate 20.

Claims

1. A power take-off apparatus comprising a pulley connectable directly or indirectly to a vehicle engine crankshaft, a clutch mounted on said pulley, said clutch comprising a clutch plate or set of clutch plates fixed to said pulley and a clutch unit movable to engage and disengage said clutch plate or set of clutch plates; a clutch control arrangement which, when operated, engages said clutch; and drive means for taking power from the clutch unit.

2. An apparatus according to claim 1, wherein said drive means is a pneumatic or hydraulic pump mounted adjacent said pulley to provide fluid under pressure, when said clutch is engaged, for energising an external fluid-operated motor acting as a prime mover for equipment.

3. An apparatus according to claim 1, wherein said drive means is a drive pulley.

4. An apparatus according to any one of the preceding claims, wherein said clutch is an electrically operated clutch and wherein said control arrangement comprises a control circuit.

5. An apparatus according to claim 4, wherein said control circuit includes a switch arrangement which is connectable to the vehicle gearbox selector and/or the vehicle handbrake so as to prevent the clutch being engaged when the vehicle is being driven.

6. An apparatus according to any one of the preceding claims, wherein said clutch unit is mounted on a mounting plate, the mounting plate itself being supported by pillars extending past the clutch and pulley and connectable to a vehicle engine block.

7. An apparatus according to any one of the preceding claims, wherein the clutch plate or set of clutch plates is mounted in a recess in said pulley.

8. An apparatus according to claim 7, wherein the clutch unit is positioned at least in part within said recess in said pulley.

9. An apparatus according to anyone of the preceding claims, wherein said pulley is mounted directly on the crankshaft of an engine.

10 10. An apparatus according to any one of the preceding claims, wherein said pulley is arranged in use to drive an engine timing belt.

11. A power take-off apparatus constructed substantially as hereinbefore 15 described with reference to the accompanying drawings.

12. A pulley connectable directly or indirectly to vehicle engine crankshaft and having a clutch plate or set of clutch plates fixed thereto for engagement with a clutch unit to take power from the crankshaft. 20

13. A pulley constructed substantially as hereinbefore described with reference to the accompanying drawings.