GB2283139A

GB2283139A - A braking device for an electrically driven vehicle

Info

Publication number: GB2283139A
Application number: GB9321870A
Authority: GB
Inventors: Jose Manuel Rodriguez-Ferre
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-05-18
Filing date: 1993-10-22
Publication date: 1995-04-26
Also published as: CN1035866C; GB9321870D0; CN1102161A; BR9301924A

Abstract

In a braking arrangement for a child's toy vehicle, such as driven by a battery powered electric motor, on operation of an actuating member, such as, a brake pedal 2, 3, an electrical switch 5 disconnects the motor from the power supply and short-circuits the motor to provide an electromagnetic braking effect. Additionally a mechanical brake 13, (16, Fig 3), 17 may be operated by the brake pedal 2, 3. In a further aspect such a braking arrangement includes a band brake, 13, (16, Fig 3), 17 operated by the brake pedal 2, 3, via a Bowden cable 6, 7. A still further aspect relates to a mechanical brake 13, (16, Fig 3), 17 which is operated by an actuating member such as the brake pedal 2, 3 when a switch 5 also operated by the actuating member disconnects the motor from the power supply. <IMAGE>

Description

DESCRIPTION OF INVENTION Title: "A braking device for an electrically driven vehicle' THE PRESENT INVENTION relates to a braking device for an electrically driven vehicle, for example for a toy vehicle for children, of the type driven by the child himself, and powered by an electric motor having a battery as power source.

According to one aspect of the invention there is provided a braking device for a vehicle driven by an electric motor supplied with current from a current source, said braking device including switch means which, on operation of an actuating member of the braking device, disconnects the motor from said current source and short circuits the motor so that the motor acts as an electromagnetic retarder.

Preferably the device additionally includes a mechanical brake which is operated by operation of said actuating member, so as to provide a retardation additional to that provided by the electric motor functioning as an electromagnetic retarder.

In a preferred embodiment, the braking device comprises a brake pedal through operation of which the motor is disconnected from the battery and is shortcircuited and thereafter a mechanical braking action is achieved.

The electric motor is disconnected from the battery and is short-circuited by way of a switch operated by a brake lever carrying the brake pedal. The mechanical brake is of the type comprising a fixed surface designed for application to a rotating disc or drum attached to the wheel, and in which friction constrains the rotation of the moving portion, the absorbed energy being converted into heat.

In its preferred form the braking device comprises three groups of components, namely: I. A box containing the operating mechanism and electrical brake.

II. A transmission member.

III. A receiving member and mechanical brake.

Group I comprises the brake pedal; the switch, and an anchorage for a force transmitting member operating the mechanical brake. When the brake pedal is operated, before the mechanical braking effect is produced, the electrical effect occurs thanks to the switch, which disconnects the motor from the battery and short-circuits the motor.

Group II comprises a protective sheath with attachment terminals and an inner braided cable with a metal attachment terminal at one end and a threaded stud at the other end, for facilitating tensioning adjustment by way of a nut and locknut.

Group III comprises a disc or drum fixedly attached to the wheel, provided with a peripheral groove for housing a brake band in the form of a rubber ring. An open ring is mounted on the disc and is connected to the transmission member which is caused to tighten about the rubber ring when the brake pedal is operated, braking the disc, and thus the wheel.

The preferred embodiment of the present invention is described below by way of example, with reference to the accompanying drawings, in which: FIGURE 1 is a general view, partly in section, of the preferred embodiment, FIGURE 2 is a view of the box containing the operating mechanism and electric brake operating switch, in cross section on the line II-II in Figure 1, and FIGURE 3 is a view in cross section of the mechanical brake, seen on the line III-III in Figure 1.

With reference to the Figures, a braking device embodying the invention comprises a box 1 containing an operating mechanism and switching means operable to cause the electric motor (not shown) of the associated battery powered vehicle (not shown), to act as an electric, or electromagnetic, brake. The operating mechanism consists of an iron lever 2, terminating in a bent portion, forming a pedal, which carries a plastics protective member 3 on which the foot of the child driver of the vehicle rests, said lever having a shaft 4 passing transversely through the box, and on which shaft the lever pivots. Inside the box there is a switch 5 which disconnects the electric motor of the vehicle from the battery and short-circuits the motor when the lever pedal 2, 3 is operated, so that before a mechanical braking effect takes place, an electrical or electromagnetic braking effect is produced.

The lever 2 is provided with a formation for attachment of one end of a transmission member in the form of the inner 7 of a Bowden cable, having an outer sheath 6. A spring 8 restores the lever pedal 2, 3 to its rest position when the lever is released.

The cable inner 7 terminates at its end remote from lever 2 in a threaded stud 10 carrying an adjuster nut 11 and locknut 12 to facilitate adjustment of the tensioning of the cable. The end of the outer sheath 6 of the cable nearer the lever 2 is received in a socket 9 fixed within the box 1.

The mechanical brake consists of a disc or drum 13 mounted centrally on a wheel (not shown) of the vehicle by way of screws passing through holes 14, into the wheel. On the outer periphery of the disc or drum 13, the latter is provided with a circumferential groove or throat 15 in which there is mounted a rubber ring 16. Around the disc 13, radially outwardly of ring 16, there is mounted a broken or open ring 17, forming a band having two outwardly extending tabs or lugs 18 and 19 at the two ends of said band, the lugs 18 and 19 having through holes for attachment of the transmission member.Thus, the tab 18 has a hole through which the stud 10 passes while the tab 19 has a hole through which the cable inner 7 passes but which is too small for the cable outer sheath 6 to pass, and has an adjoining recess or socket which forms an abutment for the end of the Bowden cable remote from the lever 2. A recovery spring 20, disposed between the lugs 18 and 19, urges these apart when the brake is not operated. The ring 17 is provided with a retaining lug 21 for attachment to the vehicle chassis by way of a stay (not shown).

When the brake lever 2 is moved anti-clockwise in Figure 1, the cable inner 7 is pulled to the left relative to the sheath 6, forcing the lug 18 closer to the lug 19 and thus tightening the ring or band 17 about the drum 13.

Thus, if the ring 16 is constrained to rotate with the disc 13, a frictional retarding force arises between the ring 16 and the ring 17, whereas if the ring 16 is constrained to remain stationary with respect to ring 17 a frictional retarding force arises between the ring 16 and the drum 13, and in either case the drum 13 and thus the wheel to which it is attached, is mechanically braked. The ring 16 could, if desired, be dispensed with if the materials for the drum 13 and ring 17 were appropriately selected.

It will be appreciated that in some instances an appreciable braking force will be exerted by the electric motor and the associated drive train when the motor is simply disconnected from the battery without being shortcircuited. Accordingly, in such instances the switch associated with the brake pedal may simply be arranged, when operated, to disconnect the motor from the battery without short-circuiting the motor.

Claims

1. A braking device for a vehicle driven by an electric motor supplied with current from a current source, said braking device including switch means which, on operation of an actuating member of the braking device, disconnects the motor from said current source and short circuits the motor so that the motor acts as an electromagnetic retarder.

2. A braking device according to claim 1 additionally including a mechanical brake which is operated by operation of said actuating member, so as to provide a retardation additional to that provided by the electric motor functioning as an electromagnetic retarder.

3. A braking device for a battery-powered children's vehicle, comprising an electric motor supplied by a battery, the braking device comprising three groups consisting respectively of: a box (1) housing the operating mechanism and electrical disconnecter; a transmission member; and a receiving member and mechanical brake; the first of the groups comprising a lever-pedal (2, 3) with pivot shaft (4) and a switch (5), which in combination, disconnect the electrical portion and shortcircuit the motor, prior to the mechanical braking effect; in that the transmission group comprises a protective sheath (6) of an inner braided cable (7) with a metal attachment terminal at one end (9), for connection to a key of the brake lever and at the other end a threaded stud (10) with a tensioning device which may be associated with the mechanical braking receiving member; and in that the mechanical brake group comprises a disc (13) fixedly attached to the wheel, provided with a peripheral throat for housing a resilient material ring (16), said disc being surrounded by a second open ring (17), having a key (21) for attachment to the chassis, provided with tabs (18, 19) for attachment to the corresponding end of the transmission member and a recovery spring for said ring, which acts on the disc, braking it by a throttling action.

4. A braking device for a vehicle driven by an electric motor supplied with current from a current source, the braking device including a mechanical brake which is operated by operation of an actuating member, said braking device further including switch means which, on operation of the actuating member of the braking device, disconnects the motor from said current source.

5. A braking system substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

6. Any novel feature or combination of features described herein.