IL36244A

IL36244A - Brake tester for vehicles

Info

Publication number: IL36244A
Application number: IL36244A
Authority: IL
Original assignee: Ben David Y
Priority date: 1971-02-21
Filing date: 1971-02-21
Publication date: 1972-01-27
Also published as: IL36244A0

Description

IMPROVEMENT IN BRAKE TESTER FOR VKHICblSS The present invention concerns a brake tester having a mechanical measurements system, and not a hydraulic or electrical measuring arrangement. In particular the invention conceras a device on such a brake tester which is adapted to measure the reation time of the brake, i.e. the ( moment $ime elapsed between the m^^few^ at which the brake pedal is depressed and the moment at which the wheel first reacts to the power of the brake.

The brake tester having a system of mechanical measurements in use up to now comprises a grooved roller turuable by a motor, the stator of which is provided with a torque arm connected by links and suitable measurement transfer mechanism to a dial which indicates the power required for effecting braking. When a wheel of a motor vehicle is placed onto said roller and the latter is rotated, the wheel is likewise rotated. When the brake pedal of the vehicle is depressed, the force created between the wheel and the roller, is transferred by the torque arm and linkage system to the dial. This type of brake tester will hereinafter be referred to as a brake tester of the kind defined* It is o ten desirable to measure the time required by the wheel to react to the operation of the brake* i.e. the time which lapses between the time at whidh the brake of the vehicle is actuated and the time at which a certain predetermined power is applied by the brake on the wheel* This predetermined power is generally measured in kilograms and may be set at the beginning of the test.

It is thus the object of the present invention to provide a device on a brake tester of the kind defined with - 1a - The invention consists in a device for measuring reaction time on brake testers of the kind defined, comprising a contact provided on the brake pedal of the vehicle adapted, when the pedal is depressed, to close a circuit which actuates - 2 - a timer and a contact provided on said torque arm of the stator of the motor adapted to close a circuit which stops said timer / when a predetermined power is obtained between the wheel and the roller.

The invention is illustrated, by way of example only, in the accompanying drawings, in which Fig. 1 is a schematic front elevation of a brake tester provided with the device according to the invention; Fig. 2 is a schematic side view of the torque arm shown in Fig. 1 .

The brake tester here illustrated comprises, as known per se, a grooved roller 1 mounted in bearings 2 and rotated by a motor 3. On the stator of said motor 3 a torque arm 4 is provided, as known per se, being connected by means of a linkage 5 to the hand of a dial 6· In Fig. 1 only one roller is shown which is associated with dial 6* Dial 6a which is likewise shown, is associated with a second toller (not shown) for testing the co-axial wheel of the vehicle as known per se.

The wheel 7 of a motor-car having a brake pedal 8 is shown resting on rolle 1 · According to the invention, a contact 9 is provided on brake pedal 8 and is adapted to make contact with a second contact (not shown) when said pedal is depressed to effect braking whereby a circuit is closed and a timer dial 10 provided on a panel 1 1 is actuated to indicate the time of the start of the braking. To torque arm 4, which is shown more clearly in Figure 2, a cross-bar 1 2 is attached which carries a contact 1 3. A second contact 14 is provided in the path of contact 1 3. The position of contact 1 3

Claims

to be coordinated to the scale of the dial 6,6a, i.e. to the forces measured by said dial. Owing to the torque of the braking, contact 13 will make contact with contact 14 when a certain predetermined force obtains between the wheel and the roller, so that a circuit which is adapted to stop movement of timer 10 in panel 11 is closed. Thus, the time required from the moment the brake pedal is depressed to the moment at which this force is effected, can be measured* There are a number of variations possible within the ambit of the present claims. Thus, for example, the pedal switch can actuate simultaneously the means for showing the starting time for two aligned wheels, although the reaction time for each wheel is measured separately and shown by separate timers. The contact on the pedal can be mounted adjustably and said pedal can be provided with a spring arrangement of suitable predetermined pressure so that only with a definite and pre-deterrained pressure contact can be made. Furthermore, cross-bar 12 can be adjustably mounted on lever 4. C L A I M S I

1. A device for measuring reaction time on brake testers of the kind defined, comprising a contact provided on the brake pedal of the vehicle adapted, when the pedal is depressed, to close a circuit which actuates a time and a contact provided on said torque arm of the stator of the d .which stops said timer motor, ada tes: to close a circuit/ hen a predete mined power is obtained between the wheel and the roller.

2. A device as claimed in claim 1 , wherein the position of the contact on said torque arm is adjustable.

3. A device as claimed in claim 1 or 2 , wherein the contact on the brake pedal is adjustably mounted.

4. ΛΑ device for measuring reaction time on brake testers of the kind defined, substantially as hereinbefore described and illustrated in the accompanying drawings* Tel-Aviv, .18th February,1971 AGENT FOB APPLICANTS