GB2206753A

GB2206753A - Electric motor driven golf trolley

Info

Publication number: GB2206753A
Application number: GB08812658A
Authority: GB
Inventors: Ian Lewis Blair
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-07-10
Filing date: 1988-05-27
Publication date: 1989-01-11
Anticipated expiration: 2008-05-27
Also published as: GB2206753B; GB8716331D0; GB8812658D0

Abstract

A battery-powered golf trolley comprises a wheeled trolley frame for supporting a golf bag, a motor (8) for driving the wheels of the trolley through a gearbox, a battery (2) for powering the motor (8) and hand-operated control means (4,6) between the battery (2) and the motor (8) for controlling the speed of forward movement of the trolley. On enforced rearward movement of the trolley, a reverse drive torque is electromagnetically induced in the motor (8) which brakes the wheels of the trolley. The trolley further includes switch means (10,12) actuation of which disconnects the control means (4,6) from the motor (8) and isolates the motor electrically such that, with said switch means (10,12) actuated and on enforced reverse movement of the trolley, the gearbox imposes a mechanical resistance to reverse rotation of the wheels of the trolley. <IMAGE>

Description

IMPROVED GOLF TROLLEY This invention relates to golf trolleys, and more particularly to battery-powered golf trolleys.

Battery-powered golf trolleys are now commonly available and are a great assistance to golfers particularly when climbing the slopes often met on golf courses.

However, these trolleys, including the battery and the motor, together with the clubs carried thereby, are much heavier than conventional hand-pulled trolleys.

Consequently, when going downhill, these powered trolleys can prove difficult to control if the user maintains the trolley travelling in the forward direction - conventional powered trolleys free-wheel in this forward direction and therefore have a tendency to run away from a user following behind.

It is therefore standard practice to incorporate within the trolleys a dynamic braking system so arranged that, on movement of the trolley in a reverse direction, a reverse drive torque is induced in the motor which serves to brake the wheels of the trolley.

Thus it will be appreciated that, when negotiating a down-slope, the user reverses the direction of movement of the trolley and leads the trolley downhill, the reverse movement of the trolley creating a consequential and inherent braking of the wheels of the trolley which enables control of the trolley to be maintained on even the steepest of hills.

However, the regenerative braking effect induced by the motor on reverse movement of the trolley is of a significant value and is such that, on other than steep inclines, it is often difficult for the user to overcome the braking effect on the wheels of the trolley and to achieve the desired downhill movement of the trolley, particularly at the beginning of such movement.

It would be desirable to be able to provide a battery powered golf trolley having a more flexible braking arrargement than heretofore and such as to enable controlled movement of the trolley down both shallow and steep inclines.

According to the present invention there is provided a battery-powered golf trolley comprising a motor mounted on the trolley and adapted to drive the wheels of the trolley through a gearbox, a battery for powering said motor, and hand-operated control means connected between the battery and the motor for controlling the output from the motor and therefore the speed of forward movement of the trolley, the arrangement being such that, on enforced reverse movement of the trolley, a reverse drive torque is electromagnetically induced in the motor which brakes the wheels of the trolley, characterised in that the trolley further comprises switch means actuation of which disconnects the control means from the motor whereby the motor is electrically isolated, the arrangement being such that, on enforced reverse movement of the trolley with said switch means actuated, the gearbox imposes a mechanical resistance to reverse rotation of the wheels of the trolley.

Thus it will be appreciated that, when negotiating a downhill slope for which the regenerative braking effect electromagnetically induced in the drive motor is too high for the slope in question, the user operates the switch means to isolate the motor electrically and relies upon the relatively moderate braking effect imposed upon the wheels of the trolley by the mechanical gearbox.

The provision of the moderate braking facility is also useful when beginning negotiation of a steep incline, in that initial reverse movement of the trolley down the hill can be more readily achieved without the regenerative braking effect being present. Once movement of the trolley is underway, the regenerative braking effect can be introduced, thereby enabling controlled movement of the trolley down even the steepest of inclines.

Preferably the gearbox comprises a worm reduction gearbox, the arrangement being such that the trolley freewheels when moved in the forward direction but, considered in the reverse direction, the trolley wheels are mechanically locked, enforced movement in said reverse direction causing the drive shaft to the worm gearing to turn and subjecting the wheels of the trolley to a mechanical resistance from the worm gearing.

By way of example only, an embodiment of the invention will now be described in greater detail with reference to the accompanying drawings of which Figs. 1 and 2 are schematic illustrations of control means for a trolley according to the invention in two different operative conditions.

A trolley according to the invention is basically of relatively conventional construction and includes an upright body portion adapted to support thereon a golf bag and associated equipment, the body portion being carried on a pair of rear wheels, one to each end of a rear axle, and a free-wheeling front wheel. A battery mounted on the lower regions of the body portion powers an electric motor which drives the rear wheels through a reduction gearbox.

More particularly, and referring to the drawings, a battery 2 inputs power to an electronic speed control unit 4 the output from which is under the control of a manually-operable rotary control lever 6 mounted on a handle of the trolley at the upper regions of the body portion thereof, the output from the unit 4 being fed to, to control the speed of, a motor 8.

The motor 8 drives the rear axle of the trolley through a mechanical worm reduction gearbox (not shown).

Under normal usage of the trolley, and with the battery 2 electrically connected to the control unit 4, forward movement of the trolley is achieved by appropriate rotation of the manually-controlled lever 6 to actuate the motor 8 to drive the trolley at the desired speed.

The motor 8 may be, for example, a permanent magnet d.c. motor, the control unit 4 serving to switch the battery supply alternately on and off, varying the 'on' period relative to the 'off' period so as to control the motor energy and thereby its speed.

Alternatively, the motor 8 may be an a.c. motor, the control unit 4 producing a variable frequency power supply from the battery 2 the frequency of which controls the speed of the drive motor.

In all cases, the motor 8 is such that, on reverse movement of the trolley, a reverse drive torque is electrically induced in the motor 8 which serves to brake the wheels of the trolley.

Thus, when negotiating a steep down-hill incline where forward movement of the trolley, even in the freewheeling mode, would result in the trolley tending to run-away from the user, the trolley is reversed and is led backwards down the hill by the user, the inherent regenerative braking effect induced in the motor as a result of the reverse movement of the trolley enabling control of the trolley to be maintained.

However, this regenerative braking effect is strong, and is often such as to result in skidding of the trolley and/or difficulty in initiating movement of the trolley when beginning the descent.

The trolley of the invention overcomes these problems by incorporating a switch 10 and a relay 12 in the electrical power supply circuit to the motor 8.

More particularly, the relay 12 is provided between the control unit 4 and the motor 8 and can be switched by the switch 10 between a closed position shown in Fig. 1 associated with normal usage of the trolley as detailed above and an open position shown in Fig. 2.

With the relay 12 in its open position, the motor 8 is disconnected from the control unit 4 and the motor is in open-circuit whereby, on reverse movement of the trolley, no regenerative braking effect is induced in the motor 8 and consequently the wheels of the trolley are not braked by the motor 8.

The trolley is arranged to free-wheel in the forward direction when no power drive is supplied to the rear axle.

However, on rearward movement of the trolley, the gearbox imposes a mechanical resistance to rotation of the rear axle through the reduction gearing therein, and this imposes a moderate braking effect upon the trolley.

More particularly, prior to reverse movement, the trolley wheels are mechanically locked against such movement, subsequent enforced reverse movement causing the drive shaft to the worm gearing to turn and subjecting the wheels of the trolley to a mechanical resistance from the worm gearing.

Thus it will be appreciated that, when negotiating a relatively shallow incline or in other situations where the normal regenerative electrical braking is not required, the user reverses the trolley and operates the switch 10 to introduce the relatively moderate braking effect provided by the gearbox alone.

The provision of this optional moderate braking is also useful when negotiating steep inclines in that moderate braking can be employed until movement downhill has begun, the switch 10 then being released to reintroduce the normal regenerative reverse braking effect once movement is underway.

Although the above trolley is described as incorporating a worm-reduction gearbox, other types of mechanical gearbox providing the required reverse braking effect may be employed.

Thus there is provided a battery-powered trolley providing a more flexible braking system than heretofore and, more particularly, one in which normal electrical braking can be supplemented with, or replaced by, a less severe mechanical brake.

Claims

1. A battery-powered golf trolley comprising a motor mounted on the trolley and adapted to drive the wheels of the trolley through a gearbox, a battery for powering said motor, and hand-operated control means connected between the battery and the motor for controlling the output from the motor and therefore the speed of forward movement of the trolley, the arrangement being such that, on enforced reverse movement of the trolley, a reverse drive torque is electromagnetically induced in the motor which brakes the wheels of the trolley, characterised in that the trolley further comprises switch means actuation of which disconnects the control means from the motor whereby the motor is electrically isolated, the arrangement being such that, on enforced reverse movement of the trolley with said switch means actuated, the gearbox imposes a mechanical resistance to reverse rotation of the wheels of the trolley.

2. A golf trolley as claimed in claim 1 in which the switch means comprises an electrical relay between the control means and the motor, and a switch actuation of which opens the relay to disconnect the motor from the control means whereby said motor is in open-circuit.

3. A golf-trolley as claimed in claim 1 or claim 2 in which the gearbox comprises a worm reduction gearbox, the arrangement being such that the trolley free-wheels when moved in the forward direction but, considered in the reverse direction, the trolley wheels are mechanically locked, enforced movement in said reverse direction causing the drive shaft to the worm gearing to turn and subjecting the wheels of the trolley to a mechanical resistance from the worm gearing.

4. A golf trolley as claimed in any one of claims 1 to 3 in which the motor is a permanent magnet d.c. motor.

5. A golf trolley as claimed in any one of claims 1 to 3 in which the motor is an a.c. motor.

6. A battery-powered golf trolley substantially as described with reference to and as illustrated by the accompanying drawings.