Disc for a Disc Brake

Field of the invention

The present invention relates to mechanisms for sensing the speed of a wheel of a two wheeler which has an anti lock brake system or ABS.

Background of the invention

Generally, a signal generating mechanism and a signal receiving device are required to be mounted in the vicinity of wheel of a two wheeler to generate signal for activating speed sensing mechanism. Wheel speed sensing is one of the input for the electronic control unit (ECU) of a ABS vehicle apart from other inputs. The speed sensed by the ECU is used for charging response of other elements of ABS. The wheel speed can be sensed many ways by mounting a sensor and a sensor wheel, where former is stationary and latter is rotating. The sensor unit is a electronic unit with hall effect or other similar arrangement. The signal generator for the sensor to sense is mounted on the rear and front hub of the wheel to close proximity of sensor unit. The sensor works on the principle of change in distance between sensor face and sensor wheel.

In an known conventional technique disclosed in Japanese laid open No- H8 133154 the toner ring is generally provided with teeth since the teeth are relatively long and slender, the toner ring teeth will be subjected to warpage and hence would lead to more machine and labor cost for repairing warpage. In order to address the above said disadvantage as disclosed in 848/MUM/2000, a separate disc mounted along the disc brake disc with rectangular holes on a circular pitch manufactured by a known method of punching and pressing is provided. However this technique demands additional sensor cable routing to align the sensor face with the slot edges, thus leading to increased cost. Further the above said arrangement involves more numbers of parts, for which mounting requires additional bolts. In order to overcome above disadvantages a new way of signal generation and receiving method is disclosed.

Summary of the invention:

The present invention has been devised in view of the above difficulties and it is therefore an object of the present invention is to provide flexibility in mounting orientation of the speed sensing element or sensor such that the sensor's sensing face or edge is parallel to the edge of the slot formed on the toner assembly or wheel hub.

Another objective of the present invention is to facilitate mounting of the sensing element or sensor on the two-wheeler so that obstruction of other components is minimized.

Another objective of the present invention is to facilitate mounting of the sensing element or sensor on the two-wheeler so that wiring (or sensor cable) routing for the sensor is simplified, avoiding unnecessary or excess looping. Another objective of the present invention is to locate the sensor that will render it easy for assembling and servicing.

- Further objective of the present invention is to make the system cost effective and this objective is achieved by reduction in length of sensor cable and other associated advantages in manufacturing.

Brief Description of the Drawings:

The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein

FIG. 1 is a side view of a conventional two wheeler according to this invention FIG. 2 shows the brake disc according to the present invention.

Detailed Description of the Invention:

The present invention relates to wheel speed detecting device for a motorcycle.

Referring to figure. 1, a motorcycle comprises of a frame (101), front fork (102) attached to a pivot tube (103) of the vehicle frame, a front wheel (104) attached to these front forks (102), a handle bar (105) connected to the front forks (102), a fuel tank (106) attached so as to straddle an upper part of the vehicle frame, a seat (107) attached to the upper rear portion of the vehicle frame, an engine unit (108) attached to the lower front section of the vehicle frame, a swing arm (109) attached to a lower rear section of the vehicle frame, suspended by a rear shock absorber (not shown in the drawing) from the vehicle frame and a rear wheel (110) attached to a rear end of swing arm (109). The intake system of the engine comprises of a carburettor, intake duct and an air cleaner. The exhaust system of the engine comprises of exhaust pipe and a muffler. The motorcycle is also provided with a side cover (111) for covering a side section of the vehicle frame, a seat cover for covering a rear section of the vehicle frame below the seat, a front fender (112) for covering an upper part of the front wheel (104), and a rear fender (113) for covering an upper part of the rear wheel (110). The drive from the engine (108) is transmitted from the engine to the driven wheel sprocket mounted on the rear wheel hub mounted on the rear wheel assembly.

To measure the wheel speed, a sensing element (114) (hereinafter is referred to as sensor) is attached to the disc brake mounting structure as a stationary element.

According to one of the embodiments of the present invention and drawing reference to figure 2, the brake disc (201) used in disc brake arrangement is provided with radial grooves (202) having a depth of atleast one-third the thickness of the said disc (201). The sensor detects the said grooves (202) on the disc brake (201)for determining the wheel speed by detecting the change in flux by the Hall effect sensor by change in depth or distance with respect to the sensor. Machining diagonally passing the cutter through the centre of the said disc (201) upto a required depth for the required number of grooves produces the grooves (202). The present arrangement eliminates the use any other means of detecting speed through sensing and thus reduces the cost as well as the part count. Hence it provides an effective design that is not only cost effective but has low maintenance and high durability.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the claims.

We Claim:

1. A disc for a disc brake for a two wheeler comprising:

a disc; and

a plurality of radial grooves on the disc;

wherein the grooves depth is at least one third the thickness of the disc;

2. The disc as claimed in claim 1, wherein the said grooves are in even number.