FIELD OF THE INVENTION

The present invention relates to a brake safety system. More particularly, the present invention relates to a system for providing safety in brake shoe assembly used in foundation brakes. The invention also relates to a method of providing safety and ease in assembling brake shoes used in foundation brakes.

BACKGROUND AND THE PRIOR ART

For the same size of front axle, the load ratings are increasing & bearings sizes are becoming bigger. This is reducing the gap between the cam tip & hub OD as there is no change in Brake size. This has initiated the new spring design with offset center bar spring where in the spring center bar is moved out of the gap & taken over the cam head.

Current brake shoe return springs can be fitted in 4 possible ways. One way of fitment is correct where spring center bar is above cam head & towards cam as shown in figure 5. Other 3 ways are incorrect fitment i.e where spring center bar above cam head but away from cam shown in figure 6, where spring center bar is below cam head but towards cam head shown in figure 7 and where spring center bar is below cam head but away from cam head as shown in figure 8.

Field study shows that operator can possible fit the spring in the incorrect ways also which could lead to wheel hub cutting & vehicle jamming, which is a potential safety hazard.

Further from field visit study two issues were observed: Groove formation on hub's main cause is incorrect filament.

US 8245820 discloses automatic Brake Adjuster with flexible reference point wherein one-way lock mechanism and clutch mechanism are integrated in one part and located on the worm shaft with the provision of isolating the one way lock mechanism and regulator worm gear wheel from heavy clutch spring load by a thrust sleeve arrangement for independent function, one-way lock mechanism is meant for sensing the excess lining clearance and adjusting the slack between the brake lining and brake drum whereas the clutch mechanism is to ignore the excess stroke of brake actuator due to elasticity in the foundation brake parts of a vehicular braking system.

In order to address the safety issues the inventors in the present invention have provided a system for providing safety in brake shoe assembly. They have also provided a method which would ease assembling problem in the brakes and take care of the safety of the users.

OBJECTS OF THE INVENTION

One object of the proposed invention is to overcome the disadvantages / drawbacks of the prior art.

A basic object of the present invention is to provide a brake safety system.

Another object of the present invention is to provide a brake safety method.

These and other advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

SUMMARY OF THE INVENTION

The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.

An aspect of the present invention is to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below.

Accordingly, an aspect of the present invention is to provide a system for providing safety in a brake shoe assembly used in foundation brakes, said system comprising; at least two web brake shoes;
a spring assembly operatively engaged in holes provided in the said brake shoes such that the engagement of the spring assembly with the brake shoes provide positive locking of the spring assembly with the said brake shoes; characterized in that said spring assembly comprising a center bar portion with spring elements on its both ends, said center bar portion being essentially rectangular and said spring elements comprising unique hook profiles wherein said center bar portion having an angular relationship with the said hook profile.

Another aspect of the present invention is to provide a spring assembly comprising a center bar portion with spring elements on its both ends, said center bar portion being essentially rectangular and said spring elements comprising unique hook profiles wherein said center bar portion having an angular relationship with the said hook profile.

Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:

Figure 1 illustrates brake assembly for Shoe return spring, Cam head washer & Brake shoe with hole or slot in shoe web.

Figure la illustrates an exploded view of the brake assembly for shoe return spring, cam head washer & brake shoe with hole or slot in shoe web.

Figure 2 illustrates the arrangement of poka yoke spring & cam head washer.

Figures 3 illustrates the arrangement of poka yoke spring in Shoe with hole.

Figure 4 illustrates another view of the arrangement of poka yoke spring in shoe with hole.

Figure 5 illustrates the poka yoke spring.

Figure 6 illustrates brake assembly for right fitment of spring wherein spring center bar is above cam head & towards cam.

Figure 7 illustrates brake assembly for wrong fitment of spring where in spring center bar above cam head but away from cam.

Figure 8 illustrates brake assembly for wrong fitment of spring where spring center bar is below cam head but towards cam head.

Figure 9 illustrates brake assembly for wrong fitment of spring where spring center bar is below cam head but away from cam head.

Figure 10 illustrates shoe return spring.

Figure 10a illustrates cam head washer which prevents the spring from wrong fitment.

Figure 11 illustrates hole in the webs brake shoe.

Figure 12 illustrates hook of shoe return spring locking in web to ensure positive locking of spring.

Figure 13 illustrating the relationship between the hook profile and the center bar portion.

Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.

Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a spring means" includes reference to one or more of such spring means.

By the term "substantially" it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

The present invention relates to a system and a method for providing safety and ease in assembling brake shoes used in foundation brakes.

The system comprises shoe return spring assembly having a unique hook means which holds the brake shoes and capable of holding the center bar position by locating the hook in the hole of the web brake shoe. One end of the hook is designed by rotating 90 degree & increasing the hook length in such a way that the hook on one end locates in the web & locks. This locking of hook in web is ensures positive locking of spring.

The spring assembly comprises pair of spring elements or profiles which is linked to each other by the center bar portion which is essentially rectangular shaped. The center bar portion aids in maintaining right fitment conditions of the spring in the brake system. Components/Parts of the brake assembly;

1. shoe return spring (1),

2. cam head washer (2)

3. hole or slot (3)

4. shoe web (4)

5. hook profile (5)

6. rectangular center bar portion of the spring assembly (6)

7. 90 degree rotated part (7) of the hook (5)

8. Angle between the rectangular center bar portion (6) and the 90 degree rotated part (7)

WE CLAIM:

1. A system for providing safety in a brake shoe assembly used in foundation brakes, said system comprising; at least two web brake shoes; a spring assembly operatively engaged in holes provided in the said brake shoes such that the engagement of the spring assembly with the brake shoes provide positive locking of the spring assembly with the said brake shoes; characterized in that said spring assembly comprising a center bar portion with spring elements on its both ends, said center bar portion being essentially rectangular and said spring elements comprising unique hook profiles wherein said center bar portion having an angular relationship with the said hook profile.

2. The system as claimed in claim 1, comprising two spring elements.

3. The system as claimed in claims 1 and 2, wherein said hook profiles provided in the said spring elements are substantially U shaped.

4. The system as claimed in claims 1 to 3, wherein one of the said hook profiles comprising increased length portion being rotated by about 90 degree or so.

5. The system as claimed in claim 1, wherein said center bar portion makes an angle of about 50 degree with the part of the hook which is rotated by 90 degree as claimed in claim 4.

6. The system as claimed in claim 1, wherein the spring center bar portion is located above cam head and towards the cam providing for right fitment.

7. A spring assembly comprising a center bar portion with spring elements on its both ends, said center bar portion being essentially rectangular and said spring elements comprising unique hook profiles wherein said center bar portion having an angular relationship with the said hook profile.

8. Assembly as claimed in claim 7, wherein said hook profiles provided in the said spring elements are substantially U shaped.

9. Assembly as claimed in claim 7, wherein one of the said hook profiles comprising increased length portion being rotated by about 90 degree or so.

10. Assembly as claimed in claim 7, wherein said center bar portion makes an angle of about 50 degree with the part of the hook which is rotated by 90 degree as claimed in claim 9.