MXPA98004188A - Brake wear sensor system, with mont brooch - Google Patents

Abstract

The present invention relates to brake wear preceptor for first and second brake bearings mounted to a brake surface of a vehicle brake assembly, the preceptor is designed to be mounted through an aperture slot formed in the surface of the brake surface. brake between the first and second brake pads so that an electrical conduit forming a part of the wear preceptor is rubbed against it by a rotary brake drum when the first and second brake pads reach a thickness less than a predetermined limit, the Wear preceptor comprises: a preceptor housing, a housing cover adapted to fit over a portion of the preceptor housing formed a channel to allow the driver to pass through it, the conductor is disposed in the channel between the preceptor housing and the cover of the housing, a spring clip adapted to retain the cover of the precept housing In an appropriate position relative to the brake surface, the spring clip at least one holding arm engages the brake surface to prevent movement in one direction and at least one preload spring that engages with the brake surface. cover of the housing to prevent movement in an opposite direction, the spring clip thus provides a positive retention of the sensor housing and the housing cover to the surface of the housing.

Description

BRAKE WEAR SENSOR SYSTEM. WITH MOUNTING BROOCH BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wear sensor of the brake shoe and more specifically to a mounting clip for retaining the brake shoe wear sensor and when a plurality of positioning elements are used to secure the sensor to the plate brake. 2. Description of the prior art There are several brake wear sensors in the prior art which typically are shown mounted on the underside of the brake shoe plate and extend within the brake shoe material. It is known to embed an electric sensor in the friction material of the brake shoes to indicate to the operator when brake service is required. One such type of sensor is a single length wire which is eventually worn out by friction of the brake drum when the brake shoe reaches its service limit. Various methods of the prior art have been described for fixing the wire in place within the brake pad friction material. The mounting technologies shown most commonly involve a threaded fastener that is included or formed in the brake wear sensor to place it within a cavity that is in the friction material of the brake shoe. Examples of such mounting systems are described in U.S. Patent Nos. 3,800,278; 2,814,684; 2,731,619; 4,188,613 and 3,297,985. Most of these restraint systems make use of threaded elements to provide a clamping force on the brake plate to hold the sensor in place. Other methods of the prior art for retaining a brake wear sensor include adapters that are subsequently deformed to provide retention in the brake shoe or in the brake plate. Examples of such systems are shown in U.S. Patent Nos. 3,440,604 and 3,689,880. Another known method for retaining a brake wear sensor in the brake plate is to incorporate a snap mechanism in the sensor housing which eliminates the need to provide threads in at least two elements. Examples of such a prior art brooch design are described in U.S. Patent Nos. 4,298,857, 4,869,350; 4,318,457; 4,274,511; 4,344,509 and 5,133,431. The descriptions of which are incorporated herein by reference. A spring clip formed in the sensor housing holds the wear sensor on the brake plate using an interference assembly established by the deformation of the spring clip on the insert. The problem with these fastener systems is primarily a packaging limitation when it is desirable to securely fix a wire circuit between two brake shoes mounted on a common brake plate. It would be desirable to use a clasp that will be placed between the two shoes using a stamped opening in the brake plate does not extend beyond the areas occupied by the brake shoe. It would also be desirable to use a clasp to provide retention and an axial preload on the system.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front elevation view of the brake wear sensor of the present invention; Figure 2 is a top elevation view of the brake wear sensor of the present invention; Figure 3 is a cross-sectional view of the brake wear sensor of the present invention; Figure 4 is a partial cross-sectional view of the brake wear sensor of the present invention mounted on a brake plate; Figure 5 is a partial cross-sectional view of the brake wear sensor of Figure 4, taken along the line V-V; Fig. 6 is a cross-sectional view of the sensor wear of the brake wear sensor of the present invention, - Figure 7 is a side elevational view of the brake wear sensor sensor housing of the present invention, - Figure 8 is an end elevation view of the brake wear sensor sensor housing of the present invention, - Figure 9 is a cross-sectional view of the housing of the brake wear sensor of the present invention, - Figure 10 is a side elevational view of the housing cap of the brake wear sensor of the present invention; the present invention, - Figure 11 is an end elevational view of the housing housing of the brake wear sensor of the present invention, - Figure 12 is a front elevational view of the spring clip of the present invention, - and Figure 13 is a rear elevational view of the spring clip of the present invention; DETAILED DESCRIPTION OF THE PREFERRED MODALITY In order to promote the understanding of the principles of the invention, reference will now be made to the modality illustrated in the drawings and specific language that will be used to describe them. However, it should be understood that it is not intended to limit the scope of the invention, and that such alterations and future modifications in the illustrated device, and that subsequent applications of the principles of the invention as illustrated herein are contemplated as those would normally occur to a person familiar with the technique with which it relates to the invention. Now, with reference to Figure 1, a front elevation view of the housing 12 of the brake wear sensor 2 sensor of the present invention is shown. The sensor housing 12 is molded using a high temperature material suitable for use in a vehicle brake environment. Many suitable materials are known to those familiar with the art. A channel 10 (see Figure 3) is formed within the sensor housing 12 to allow a wire conductor 11 to pass therethrough. The housing cover 17 (see FIG. 2) is fixed to the sensor housing 12 after the installation of the wire conductor 11 in the channel 10. The sensor housing 12 and the housing cover 17 can be manufactured as an array a piece of a sensor mechanism 3 having the channel 10 formed therein. The housing cap 17 secures the wire conductor 11 in position and environmentally protects the wire conductor 11. The mounting lugs 17A and 17B extend from the housing cover 17 to facilitate positioning against the brake plate. The spring clip 6 includes a first front clasp arm 6A and a first rear snap arm 6C, and a second front snap arm 6B and a second rear snap arm or post 6D, which contain the sensor housing 12 and the housing cover 17 for coupling with the brake plate 14 through an opening slot 9 (see FIGS. 4 and 5). The first front clasp arm 6A and the first rear clasp arm 6C can be combined in the first snap arm which engages the brake plate 14 (see Figure 4). In a similar manner, the second front snap arm 6B and the second rear snap arm 6D can be combined in a second snap arm which engages the brake plate 14 (see Figure 4). A first preload spring 7A and a second spring 7B of preload extend from the spring clip 6 and engage the sensor housing 12 so as to apply a compressive force on the sensor housing 12 and the housing cover 17 when the wear sensor 2 is mounted in the groove 9 on the brake plate 14 (see Figure 5).

Figure 2 is a top elevation view of the brake wear sensor 2 of the present invention showing its rectangular shape which is designed to occupy the limited space between the brake shoes 5A and 5B. A rectangular opening slot 9, just larger than the rectangular cross section of the sensor housing 12 is formed in the brake plate 14 oriented to be placed between the brake shoes 5A and 5B (see Figure 4). The brake wear sensor 2 is inserted into this rectangular groove so that the spring-loaded arms 6A and 6B compress it and then expand it to engage the edge of the rectangular groove. At this point, the first and second preload springs 7A and 7B are compressed so that they finally retain the brake wear sensor 2 in position. Preferably, the brake wear sensor 2 is located towards the inner side of the brake plate 14 (see Figure 4) to facilitate an electrical connection. Figure 3 is a view partial cross section of the brake wear sensor 2 of FIG. 4 of the present invention. Figure 3 illustrates more clearly the conductive cavity 10 formed in the sensor housing 12 and by the housing cover 17 when placed on the sensor housing 12. The spring clip 6 is placed on the sensor housing 12 and has a first and second preload springs 7A and 7B which contact the bottom side of the brake plate 14 to apply a load to the brake wear sensor 2 for improved retention and proper positioning in relation to the friction pads 5A and 5B (see Figure 4). The conductor 11 is placed on the conductive cavity 10 and consists of a wire 18 covered by an insulating layer 19. The insulating layer 19 functions to protect the wire 18 from premature wear due to environmental conditions within the vehicle brake. The conductor 11 eventually wears to a point where the wire 18 breaks and is no longer electrically conductive. Now, with reference to Figure 4, a partial cross-sectional view of the brake wear sensor 2 of the present invention mounted on a brake plate 14 of a brake shoe 13 is shown. A spring clip 6 has a first front clasp arm 6A and a second rear snap arm 6B and correspondingly a first rear clasp arm 6C and a second rear snap arm 6D which engage with the brake plate 14 in the opening slot 9 positioned on the inner side of the brake plate 14 and retained in position so as to compress the first and second preload springs 7A and 7B which are formed as part of the spring clip 6. A sensor housing 12 is formed to provide a channel 10 for the wire conductor ll, which will be removed by wear when the brake pads 5A and 5B of the brake wear to the condition of the service limit. The spring clip 6 is housed over and captures the sensor housing 12 and functions to retain it in the brake plate 14 at the proper depth in relation to the brake pads 5A and 5B of the brake which are fixed to the plate 14 of brake and interact frictionally with the brake drum 8. The 5 friction pads 5A and 5B of the brake can be constituted by a single continuous brake friction pad having an opening formed therein on the opening slot 9. A housing cover 17 is adapted to cover the end of the sensor housing 12 and the section 18 of separation of the conductor 11. The housing cover 17 protects the conductor 11 from the elements that can compromise the integrity of the conductor 11, especially the separation section 18. As the friction pads 5A and 5B of the brake wear out to a sufficient degree, the cap also wears 17 of the accommodation. First, the housing cover 17 wears and then the separation section 18 of the conductor 11 wears to the point where the electrical continuity is lost which indicates the need for brake service. Figure 5 is a partial cross-sectional view of the brake wear sensor 2 shown in Figure 4, taken along the line V-V. The first and second preload springs 7A and 7B have been compressed against the sensor housing 12 so they provide a load compressive on the sensor housing 12 and a portion of the housing cover 17 which is important for the durability of the high temperature molded plastics. The first preload spring 7A reacts against the first front snap arm 6A and the first rear snap arm 6C while, in an identical manner, the preload spring 7B reacts against the second front snap arm 6B and the second 6D arm of rear brooch. The clasp arms 6A, 6B, 6C and 6D contact the edge of the opening slot 9 formed in the brake plate 14 and retain the brake wear sensor 2 securely in position, relative to the brake pads 5A and 5B brake. As the brake pads 5A and 5B wear out, the housing cover 17 starts to wear out and finally the conductor 11 is worn through which a service limit indication of the friction pads 5A and 5B can be obtained. Brake. Now, with reference to Fig. 6, a top cross-sectional view of the sensor housing 12 of the brake wear sensor 2 of the present invention is shown. The sensor housing 12 has a rectangular cross-sectional shape to be placed between the friction pads 5A and 5B of the brake in the rectangular opening 9 formed in the brake plate 14. The design provides adequate support for the wire conductor 11 and at the same time minimizes the modification required for the brake shoe 13. The preload spring end 6C and 6D press against the underside of the brake plate 14 to provide a preload on the first and second arms 6A and 6B of the clip for improved retention and axial positioning relative to the friction pads 5A and 5B of the brake. Now, with reference to Figure 7, a side elevation view of the sensor housing 12 is shown where curved sections 12A and 12B are formed in the sensor housing 12 to accommodate the conductor 11. The conductor 11 (not shown) is an electric wire section 18 which has an insulating layer 19. The housing cap 17 and the insulation of the conductor 11 provide protection for the wire, and thereby improve its integrity and prevent premature wear through (by the action of the drum 8) in the harsh environment of a vehicle brake, in where corrosive chemicals can cause premature wear of the conductor 11. Both the housing cover 17 and the insulation are necessary because the conductor 11 is not embedded in the brake pad material and is not supported once the cover 17 of The housing is worn through the brake drum 8. Figure 8 is a rear elevational view of the housing 12 of the sensor of the present invention that more clearly shows the channels 10 through which the conductor 11 passes. Figure 9 is a cross-sectional view of the lid 17 of the present invention in which its intermediate form constitutes the housing of the sensor to form the channel 10. The housing cover 17 adjusts by pressure on the sensor housing 12 after the installation of the conductor 11. Figure 10 is a side elevation view of the housing cover 17 of Figure 9 which shows the relatively thin profile of the housing cover 17 for mounting in the narrow opening slot 9 in the brake plate 14 between the brake friction pads 5A and 5B (see Figure 4). Figure 11 is a rear elevation view of the housing cover 17 of Figure 9 again showing the narrow profile of the housing cover 17 and the mounting lugs 17A and 17B which contact the underside of the plate 14 for restricting the brake wear sensor 2 in the opening slot 9 formed in the brake plate 14 using the spring clip 6. Now, with reference to Figure 12, a front elevation view of the spring clip 6 of the brake wear sensor 2 of the present invention is shown. The spring clip 6 is made of a flexible material such as steel or plastic, any of which can be selected to withstand the environment experienced by a brake shoe without loss of holding force. Four preload clasp arms are clearly shown on the first front snap arm 6A and on the second front snap arm 6B, and the first rear snap arm 6C and the second rear snap arm 6D. The entire snap arms 6A, 6B, 6C and 6D are selected to allow the brake sensor to be inserted and engaged with the brake plate 14. The first and second preload spring 7A and 7B are compressed as the brake sensor 2 is pressed into the brake plate 14 and provides a holding force in the snap arms 6A, 6B, 6C and 6D against the plate 14 of Brake. Now, with reference to Figure 13, a lower elevation view of the spring clip 6 of the brake wear sensor 2 of the present invention is shown. The above description refers to particular embodiments of the present invention and it should be understood that many modifications can be made without departing from the spirit thereof. The embodiments of the invention shown and described in the above specification and the drawings are presented only as examples of the invention. Other embodiments, materials, forms and modifications thereof are contemplated and considered to be within the scope of the present invention, which is limited only by the claims as follows: It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, property is claimed as contained in the following:

Claims (12)

1. A brake wear sensor for a brake mechanism, with a brake plate having at least one brake friction pad attached thereto and having an opening slot formed therein, characterized in that it comprises: sensor, - a housing mechanism having a channel formed therein adapted to pass partially through the opening slot in the brake plate, - a spring clip having at least one preload spring and at least one a snap arm, the snap arm is adapted to be held on the brake plate and the opening slot, and the preload spring makes contact with the sensor housing to apply a compressive force between the sensor housing and the sensor plate. Brake; a conductor positioned within the channel and located in relation to the brake plate to be cut when the brake friction pads wear to a predetermined thickness.

2. The brake wear sensor according to claim 1, characterized in that the opening slot is rectangular.

3. The brake wear sensor according to claim 1, characterized in that the spring clip is constituted by a first front snap arm and a first rear snap arm, and a second front snap arm and a second rear snap arm , wherein the clasp arms engage the brake plate in the opening slot to retain a portion of the housing layer and the sensor body within the preloaded spring and the brake plate.

4. The brake wear sensor according to claim 1, characterized in that the first preload spring extends from the first front snap arm and the first rear snap arm, and a second preload spring extends from the second snap arm. front clasp and the second rear snap arm.

5. The brake wear sensor according to claim 1, characterized in that the housing mechanism is constituted by a sensor housing and a housing cover adapted to be coupled to the sensor housing to form a channel.

6. The brake wear sensor according to claim 4, characterized in that the first preload spring and the second preload spring are leaf springs.

7. A brake wear sensor, for a first and second brake pads mounted to a brake plate of a vehicle brake mechanism, the wear sensor is designed to be mounted through an aperture slot formed in the brake plate. brake between the first and second brake pads so that the electrical conductor part of the wear sensor is rubbed against the rotating brake drum when the first and second brake pads reach a thickness less than a predetermined limit, the wear sensor is characterized in that it comprises: a sensor housing; a housing cap adapted to be placed on a portion of the sensor housing to thereby form a channel to allow the conductor to pass therethrough, - a spring clip adapted to retain the sensor housing of the housing cover in the right position in relation to the brake plate.

8. The brake wear sensor according to claim 7, characterized in that the spring clip is constituted by a first snap arm and a second snap arm which engage the opening slot.

9. The brake wear sensor according to claim 8, characterized in that it further comprises a first preload spring extending from the first snap arm and a second preload spring extending from the second snap arm, the first and second preload springs brake the plate.

10. The brake wear sensor according to claim 8, characterized in that the first snap arm is constituted by a first front snap arm and a first snap back arm, and the second snap arm is constituted by a second snap arm. front clasp and a second rear snap arm.

11. The brake wear sensor according to claim 7, characterized in that the opening slot is located on an inner side of the brake plate.

12. The brake wear sensor according to claim 7, characterized in that the conductor is constituted by a conductive wire coated with an insulating material.