GB2403781A

GB2403781A - Freewheel mechanism for golf cart drive unit

Info

Publication number: GB2403781A
Application number: GB0316130A
Authority: GB
Inventors: Martin Phillip Roberts-Jones
Original assignee: GREAVES BEST DESIGN
Current assignee: GREAVES BEST DESIGN
Priority date: 2003-07-10
Filing date: 2003-07-10
Publication date: 2005-01-12
Anticipated expiration: 2023-07-10
Also published as: GB0316130D0; GB2403781B

Abstract

A drive and freewheel assembly for a vehicle comprises a motor 1 connected through a gearbox 2 to a drive shaft 6 of a ground engaging wheel 8 of the vehicle. A first gear member 12 is driven by the motor 1 and a second gear member 14 is driven by the first gear member 12 and is connected to impart rotation to a drive shaft 6 of the ground engaging wheel 8 of the vehicle through a freewheel mechanism 4. The gearbox 2 and freewheel mechanism 4 are positioned together within a housing. The freewheel mechanism 4 is formed of a ratchet made up of a disc 18, and teeth 19 aching on the second gear member 14.

Description

DRIVE AND FREEWHEEL MECHANISM FOR VEHICLES

This invention relates to a drive and freewheel mechanism for vehicles; more especially, the invention concerns a drive and freewheel mechanism for powered golf trolleys used to carry a golf bag holding clubs around a course.

Golf trolleys are widely used by golfers to transport golf clubs retained within a bag around a course. These trolleys are often battery powered with the user normally walking behind the trolley and directing its movement through a handle. Conventionally, a powered trolley will include some form of clutch to disengage the motor from the driven wheels when it is necessary to manhandle the trolley with the motor switched off. A trolley will also generally include some form of differential to enable the driven wheels to turn at different speeds when cornering.

To achieve these objectives, slipping clutches are conventionally fitted in each trolley wheel. These slipping clutches require lubrication which in turn requires seals and other parts.

In one aspect, the invention provides a drive and freewheel assembly for a vehicle which comprises a motor connected through a gearbox to a drive shaft of a ground engaging wheel of the vehicle, a first gear member driven by the motor, a second gear member driven by the first gear member and connected to impart rotation to a drive shaft of the ground engaging wheel of the vehicle through freewheel means, the gearbox and freewheel means being positioned together within a housing.

In another aspect, there is provided a drive and freewheel assembly for a powered vehicle, the assembly comprising a motor connected to a drive shaft of a ground engaging wheel of the vehicle through a gearbox, the gearbox including a driving gear member connectable to the motor and a driven gear member which cooperates with the driving gear member to impart rotation to the drive shaft through freewheel means.

In a further aspect, there is provided a powered golf trolley having a gearbox and freewheel means housed within a common casing.

The invention will now be described by way of example only with reference to the diagrammatic drawings, in which: Figures 1 and 2 are respectively front and rear perspective views of a gearbox and freewheel assembly in accordance with the invention; Figure 3 is a part sectional view of the gearbox and freewheel assembly shown in Figures 1 and 2; and Figure 4 is a second part sectional view of the gearbox and freewheel assembly shown in Figures 1 and 2.

For ease of description, the assembly shown in the drawings will be described with reference to a battery powered golf trolley. It is to be understood, however, that the illustrated assembly can form part of other similarly powered vehicles.

The illustrated assembly includes a battery driven motor 1 mounted on a housing 2 of a gearbox 3 and associated freewheel mechanism 4.

The gearbox housing 2 is supported from drive shaft casings 5 which house drive shafts 6 of the assembly. Each drive shaft 6 is connected at its end remote from the gearbox housing 2 to a hub 7 of one or two ground engaging wheels 8 of a powered golf trolley.

The drive shaft casings 5 carry upstanding brackets 9 to which an elongate handle for guiding the trolley and a golf bag supporting apparatus can be secured. The handle includes an on-off switch for the motor 1.

As will be seen from Figures 3 and 4, the motor 1 has a drive shaft 11 formed with a worm shaft 12. The teeth of the worm shaft 12 inter- engage teeth formed in the circumference of a gear wheel 14. The gear wheel 14 is connected to impart rotation through the freewheel mechanism 4 to the drive shafts 6 and the wheels 8. Each freewheel mechanism 4 includes a stub shaft 15 having a shaped end 16 which engages within an adjoining end of the respective drive shaft 6. The internal surface of the drive shaft end is shaped to complement the external shaping of the stub shaft thereby enabling drive to be transmitted to the drive shaft.

Each stub shaft 15 carries a ratchet mechanism comprising a disc 18 from the periphery of which project a plurality of spring loaded teeth 19 of generally triangular configuration. The spring loading operates to urge the teeth outwardly from the surface of the disc. These teeth 19 locate within an annular ring 21 forming part of the gear wheel 14. The internal periphery of the ring 21 is formed with an annular array of indents 22 each comprising an inclined section 23 terminating in a stop 24. As will be seen from Figure 3, the teeth 19 are shaped to define a snug fit within the indented inner surface of the ring 21. The stops 24 of the ring 21 cooperate with risers of the spring loaded teeth 19 to enable drive to be imparted by the gear wheel 14 to the drive shaft 6 when the gear wheel is rotating in the direction of arrow A of Figure 3. This is the direction in which the gear wheel is driven by the motor 1 and worm shaft 12. Each stub shaft 16 is supported within bearings 25, the end of each drive shaft remote from the gearbox housing being supported within bearings 26. The bearings may be of any conventional design and may comprise roller or plain bearings.

When the motor is switched off, drive to the gear wheel 14 is discontinued. Accordingly, the gear wheel 14 and the worm shaft 12 come to rest. Manual movement of the trolley in the direction in which the trolley was propelled by the motor imparts rotation to the drive shafts 6 and to the discs 18 through the stub shafts 15. Rotation of the discs 18 in the direction of arrow A causes the spring loaded teeth 19 to move inwardly through their engagement with the now stationary inclined sections 23 of the rings 21 effectively to disengage the drive shafts from the motor.

Manual movement of the trolley in the opposite direction causes the spring loaded teeth to engage the stops 24 to impart rotation to the gear wheel 14, the worm shaft 12 and the motor. Movement of the trolley in this direction is against the resistance of the motor.

As will be seen from Figure 4, the freewheel mechanisms 4 are connected one to the other through an idler shaft 27 which passes through a central bore of the gear wheel 14. The idler shaft therefore acts as a differential to enable each drive shaft 5 to rotate independently of one another when the trolley wheels travel in the direction of arrow B. In normal use, the golf trolley is powered by the motor 1 to drive the wheels 8 with the trolley user normally following the trolley and controlling its direction and drive through the handle connected to the assembly through the brackets 9.

On occasions when, for example, the trolley needs to be manually manipulated, the motor is switched off. The trolley can then be manoeuvred without being impeded by the drag of the motor.

It will be appreciated that the foregoing is merely exemplary of drive and freewheel assemblies in accordance with the invention and that various modifications can readily be made thereto without departing from the true scope of the invention disclosed above. Thus, other freewheel and drive assemblies can be employed and the assembly can readily be used or be adapted for use with other vehicles.

Claims

1. A drive and freewheel assembly for a vehicle which comprises a motor connected through a gearbox to a drive shaft of a ground engaging wheel of the vehicle, a first gear member driven by the motor, a second gear member driven by the first gear member and connected to impart rotation to a drive shaft of the ground engaging wheel of the vehicle through freewheel means, the gearbox and freewheel means being positioned together within a housing.

2. A drive and freewheel assembly for a powered vehicle, the assembly comprising a motor connected to a drive shaft of a ground engaging wheel of the vehicle through a gearbox, the gearbox including a driving gear member connectable to the motor and a driven gear member which cooperates with the driving gear member to impart rotation to the drive shaft through freewheel means.

3. An assembly as claimed in claim 1 or claim 2 wherein the motor is battery driven.

4. An assembly as claimed in any one of the preceding claims wherein the gear housing is supported from drive shaft casings which house drive shafts of the assembly.

5. An assembly as claimed in Claim 4 wherein each drive shaft is connected at its end from the gearbox housing to a hub of a ground engaging wheel of the vehicle.

6. An assembly as claimed in any one of the preceding claims wherein the first gear member comprises a gear wheel formed with teeth in its circumference, the teeth of the worm gear cooperating with the . teeth of the gear wheel to impart rotation to the drive shaft of the ground engaging wheel of the vehicle.

7. An assembly as claimed in any one of the preceding claims wherein the freewheel means includes a stub shaft having a shaped end which engages within an adjoining end of the drive shaft, the internal surface of the drive shaft end being shaped to complement the external shaping of the stub shaft.

8. An assembly as claimed in claim 7 wherein the stub shaft carries a ratchet mechanism comprising a disc from the periphery of which periphery of which project a plurality of spring loaded teeth.

9. An assembly as claimed in claim 7 wherein the teeth locate within an annular ring member which forms part of the second gear member, the annular ring member being formed with an annular array of indents and comprising an inclined section terminating in a stop.

10. An assembly as claimed in claim 8 or claim 9 in which the spring loaded teeth are formed integrally with the disc.

11. An assembly as claimed in any one of the preceding claims wherein the vehicles is a powered golf trolley.

12. A powered golf trolley having a gear box and freewheel means housed together within a common casing.

13. A drive and freewheel assembly for a vehicle substantially as herein described and as described with reference to Figures 1 to 4- of the accompanying drawings.