Claims:
1. A hydraulic twin leading shoe (H2LS) brake integrated with parking brake comprising:
plurality of wheel cylinders (124) configured to expand both liners (128) simultaneously for activation of service brakes;
at least one backing plate (130) configured for mounting H2LS floating brake arrangement;
plurality of shoe return spring (122) configured to be individually mounted on each of the brake shoe (126);
plurality of actuation levers/linkages (118A, 118B) configured for simultaneous actuation of brake shoes (126A, 126B);
plurality of parking cable (116A, 116B) configured for simultaneously pulling of the plurality of actuation levers/linkages (118A, 118B);
plurality of pullies (114) with housing (140) configured for routing of said parking cable (116A, 116B) through it;
at least one force applying system configured to apply and transmit the force applied to the parking brake lever (136) to transmit it to parking brakes; and
plurality of auto adjusters (120A, 120B) configured for connecting parking linkages (118A, 118B) and the brake shoe (126B, 126A) respectively.

2. The H2LS brake integrated with parking brake as claimed in claim 1, wherein said plurality of auto adjusters (120A, 120B) are configured for automatically adjusting and maintaining lining gap formed due to wearing of the brake liners (128) to a predetermined gap.

3. The H2LS brake integrated with parking brake as claimed in claim 1, wherein said auto adjuster (120A, 120B) are configured with adjusting levers (132A, 132B) and the ratchets provided on the auto adjuster (120A, 120B) for automatically adjusting and maintaining lining gap formed due to wearing of the brake liners (128) to a predetermined gap.

4. The H2LS brake integrated with parking brake as claimed in claim 1, wherein said one end of auto adjuster (120A) is configured to be mounted on the pivotal end side of the actuation levers/ parking linkage (118A) and the other end configured to be mounted on the brake shoe (126B).

5. The H2LS brake integrated with parking brake as claimed in claim 1, wherein said one end of auto adjuster (120B) is configured to be mounted on the pivotal end side of the actuation levers/ parking linkage (118B) and the other end is configured to be mounted on the brake shoe (126A).

6. The H2LS brake integrated with parking brake as claimed in claim 1, wherein said parking brake levers (118A) is configured to travel in direction of arrow (DA) to move the auto-adjuster (120A) in the direction of arrow (CA) to further move the brake shoe 126B in radial outward direction for applying brake.

7. The H2LS brake integrated with parking brake as claimed in claim 1, wherein said parking brake levers (118B) is configured to travel in direction of arrow (DB) to move the auto-adjuster (120B) in the direction of arrow (CB) to further move the brake shoe 126B in radial outward direction for applying brake.

8. The H2LS brake integrated with parking brake as claimed in claim 1, wherein said auto adjuster (120) is provided with the strut assembly.

9. The H2LS brake integrated with parking brake as claimed in claim 1, wherein said at least one force applying system configured to apply and transmit the force applied to the parking brake lever (136) to transmit it to parking brakes comprising
at least one front cable (102) configured for connecting parking brake lever (136) and an equalizer (138);
at least one intermediate parking cable (104) whose one end is connected to the equalizer (138) and another end is configured to be connected to at least one brake pulley housing pivotally holding at least one brake pulley (114);
at least one rear parking cable (106) configured to be routed through at least one brake pulley (114);
plurality of brake sleeves (134) configured to route both the ends of the rear parking cable (106) to backing plate (130);
at least one bell crank lever (142) configured to be mounted on the rear axle and for routing one end of the rear parking cable (106);
wherein the ends of the rear parking cable (106) on its entry through the backing plate (130) are the parking cable (116A, 116B) configured for connecting to the free ends of the parking linkage/lever (118A, 118B) for simultaneous actuation of brake shoes (126A, 126B) of the H2LS brake assembly.
, Description:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
HYDRAULIC TWIN LEADING SHOE (H2LS) BRAKE INTEGRATED WITH PARKING BRAKE

Applicant:
Tata Motors Limited
A company Incorporated in India under the Companies Act, 1956
Having address:
Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400001, Maharashtra, India

The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
[001] The present subject matter described herein generally relates to a hydraulic brakes and more specifically to hydraulic twin leading shoe (H2LS) brake with integrated parking brake arrangement accompanied by incremental automatic adjuster for service brake.

BACKGROUND
[002] Existing hydraulic twin leading shoe (H2LS) brakes do not have parking brake mechanism. Hence parking brake arrangement needs to be provided on transmission system. Parking brake mechanism is incorporated in existing H2LS brake. Existing hydraulic twin leading shoe (H2LS) brake are without parking arrangement. Hence, additional parking brake arrangement is required to be provided on the transmission.
Prior Arts:
[003] US6766887B2: Dual mode type drum brake device. A brake cable for a dual mode type drum brake functioning as a leading-trailing type during the service brake and as a duo-servo type during the parking brake, may be easily arranged at a lower side of axle. The first and second brake levers (118), (119) of a parking brake actuator (117) have proximal portions (118 a), (119 a) pivotally supported between two ends of a second brake shoe (3) and at a lower end thereof; free ends (118 b), (119 b) extend in opposed direction from the proximal portions (118 a), (119 a) in parallel to face and functionally engage each other; a strut (120) extends between the second brake lever (119) and the pivot lever (16); and a brake cable (23) pulled to activate the free end (118 b) is arranged adjacent to the anchor (7).
[004] US5720367A: Parking and emergency brake operating mechanism for dual mode drum brake assembly. A dual mode drum brake assembly includes a backing plate, a brake drum, and first and second brake shoes supported on the backing plate and movable into frictional engagement with the brake drum. The drum brake assembly further includes a service brake mechanism for selectively moving the brake shoes into frictional engagement with the brake drum, and a rotation preventing abutment secured relative to the backing plate and disposed between and engageable with the brake shoes. A pivot lever is pivotally supported relative to the first brake shoe and is operatively coupled to exert an outward force on the first brake shoe when the parking and emergency brake is actuated. A first strut is disposed adjacent the hydraulic actuator and includes one end coupled to the second brake shoe and opposite end coupled to one end of the pivot lever. A second strut is disposed adjacent the rotation preventing abutment and includes one end coupled to the second brake shoe and an opposite end coupled to an opposite end of the pivot lever. The drum brake assembly further includes an actuation cable having an end portion supported in a generally perpendicular relationship relative to the backing plate, and a parking and emergency brake actuating means carried by the brake assembly and coupled to the actuation cable for mechanically actuating the pivot lever to urge the first brake shoe outwardly into engagement with the brake drum and thereby initiate duo-servo actuation of the parking and emergency brake through one of the first and second struts.
[005] US6739434B1: Linkage for joining a lever to a brake cable. A linkage for connecting a brake cable to a lever in a drum-in-hat park brake assembly. The linkage is defined by a continuous wire that is shaped into a first engagement section that is separated from a second engagement section by a center section. The first engagement section is define by a loop that extends from the center section while the second engagement section is defined by a hook with an end that is spaced apart from the center section a distance that is greater than a radius of the hook such that a resilient force is required to move the end in a plane away from the center section and thereafter receive a loop on the brake cable through which an actuation force is transmitted to move a lever and effect a brake application.
[006] But, existing H2LS brakes in mass production do not have parking brake mechanism. Hence parking brake arrangement needs to be provided on transmission. Proposed invention contains integration of parking brake with existing H2LS brake.
OBJECTS OF THE INVENTION
[007] An object of the present subject matter is to provide a hydraulic twin leading shoe (H2LS) brake integrated with parking brake.
[008] Another object of the present subject matter is to provide a hydraulic twin leading shoe (H2LS) brake integrated with parking brake with a dual parking brake linkages having dual cylinder attached to primary and secondary brake shoe in the parking brake assembly.
[009] Another object of the invention is to replace the cast iron wheel cylinders by aluminum wheel cylinders to improve the service life and to reduce the weight.
[0010] Yet another object of the present subject matter is to provide a hydraulic twin leading shoe (H2LS) brake integrated with parking brake with a dual parking brake linkages wherein each brake shoe is operated by separate parking cables.
[0011] Another object of the present subject matter is to provide a hydraulic twin leading shoe (H2LS) brake integrated with parking brake with a dual auto adjuster mechanism is provided for lining gap adjustment for primary and secondary brake shoes.

SUMMARY
[0012] Before the present system is described, it is to be understood that this application is not limited to the particular machine or device, as there can be multiple possible embodiments that are not expressly illustrated in the present disclosures. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related to H2LS brake with parking brake arrangement, and the aspects are further elaborated below in the detailed description. This summary is not intended to identify essential features of the proposed subject matter nor is it intended for use in determining or limiting the scope of the proposed subject matter.
[0013] The present subject matter describes a H2LS brake with parking brake arrangement for a vehicle. A hydraulic twin leading shoe (H2LS) brake integrated with parking brake comprises plurality of wheel cylinders configured to expand both liners simultaneously for activation of brakes. One backing plate is provided for mounting H2LS floating brake arrangement. Plurality of shoe return spring are provided to be individually mounted on each of the brake shoe. Plurality of actuation levers/linkages are provided for simultaneous actuation of brake shoes. Plurality of parking cable are provided for simultaneously pulling of the plurality of actuation levers/linkages. Plurality of pullies with housing configured for routing of said parking cable through it. At least one force applying system configured to apply and transmit the force applied to the parking brake lever to transmit it to parking brakes and plurality of auto adjusters configured for connecting parking linkages and the brake shoe respectively.
[0014] The auto adjusters are provided for automatically adjusting and maintaining lining gap formed due to wearing of the brake liners to a predetermined gap. The auto adjuster are configured with adjusting levers and the ratchets provided on the auto adjuster for automatically adjusting and maintaining lining gap formed due to wearing of the brake liners to a predetermined gap. One end of auto adjuster is configured to be mounted on the pivotal end side of the actuation levers/ parking linkage and the other end configured to be mounted on the brake shoe.
[0015] The parking brake levers is configured to travel in direction of arrow (DA) to move the auto-adjuster in the direction of arrow (CA) to further move the brake shoe in radial outward direction for applying brake. The parking brake levers is configured to travel in direction of arrow (DB) to move the auto-adjuster in the direction of arrow (CB) to further move the brake shoe in radial outward direction for applying brake. The auto adjuster is provided with the strut assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The foregoing summary, as well as the following detailed description of embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the disclosure, there is shown in the present document example constructions of the disclosure, however, the disclosure is not limited to the specific methods and device disclosed in the document and the drawings. The detailed description is described with reference to the following accompanying figures.
[0017] Figure 1 illustrates an existing H2LS Brake without Parking Arrangement (Prior Art).
[0018] Figure 2 illustrates an isometric view of the H2LS Brake with Parking Arrangement, in accordance with an embodiment of the present subject matter.
[0019] Figure 3 illustrates a front view the H2LS Brake with Parking Arrangement, in accordance with an embodiment of the present subject matter.
[0020] Figure 4 illustrates a front view of the H2LS Brake with Parking Arrangement mounted on chassis, in accordance with an embodiment of the present subject matter.
[0021] Figure 5 illustrates a top view the vehicle chassis mounted with H2LS Brake with Parking Arrangement, in accordance with an embodiment of the present subject matter.
[0022] Figure 6 illustrates a schematic view of the H2LS Brake with Parking Arrangement showing the connections and linkages starting from parking brake lever to the rear drum brakes arrangement, in accordance with an embodiment of the present subject matter.
[0023] Figure 7 illustrates a front view the H2LS Brake with Parking Arrangement, in accordance with an embodiment of the present subject matter.
[0024] Figure 8 illustrates a schematic view of the H2LS Brake with Parking Arrangement showing arrangement of the twin parking cable routing with the brake drum, in accordance with an embodiment of the present subject matter.
[0025] The figure depicts various embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures illustrated herein may be employed without departing from the principles of the disclosure described herein.
REFERRAL NUMERALS:

Element Description Reference Numeral
Front parking cable 102
Intermediate parking cable 104
Rear Parking cable 106
Rear Axle 108
Frame 110
Brake assembly 112
Brake Pulley 114
Parking Cable 116A, 116B
Parking Linkages 118A, 118B
Strut Assembly with Auto adjuster 120A, 120B
Shoe return spring 122
Wheel Cylinder 124
Brake Shoes 126A, 126B
Brake Liner 128
Backing Plate 130
Adjusting Lever 132A, 132B
Sleeve 134A, 134B
Parking brake lever 136
Equilizer 138
Brake pully housing/holder 140

DETAILED DESCRIPTION
[0026] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising", “having”, and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Although any devices and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, devices and methods are now described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
[0027] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated but is to be accorded the widest scope consistent with the principles and features described herein.
[0028] The present subject matter describes the proposed art, H2LS brake with parking arrangement. The H2LS brake with parking arrangement consists of two H2LS floating brake arrangement which consist of two-wheel cylinders due to which both liners are simultaneously expanded with the cylinders. The two separate parking brake mechanical linkages A and B are provided to primary and secondary brake shoe which operates with separate parking cable arrangement. Two separate auto lining gap adjuster are provided for lining gap adjustment for individual shoes in parking brake mechanism to adjust liner wear over time. In addition, individual parking lever of each brake is operated by separate cables.
[0029] Now referring to figure 2, which shows an isometric view of H2LS floating brake arrangement, a parking brake mechanism is incorporated in existing H2LS brake. H2LS brake is floating brake arrangement which consist of two, wheel cylinders (124) due to which both liners (128) are simultaneously expanded with these cylinders (124) during service brake application. Hence two separate mechanical linkages (118a, 118B) are attached to individual brake shoe (126A, 126B) which will be operated with separate parking cable arrangement (116A, 116B). Auto lining gap adjuster is provided in parking brake mechanism to adjust liner wear over time.
[0030] Now referring to figures 3 and 7, a parking brake mechanism is incorporated in existing H2LS brake. H2LS brake is floating brake arrangement which consist of two, wheel cylinders (124) configured to expand both liners (128) simultaneously for activation of brakes. Further, two separate mechanical linkages, the parking brake levers/parking linkages (118A, 118B) are attached to individual brake shoe (126A, 126B) respectively which will be operated with separate parking cable (116A, 116B) arrangement. The auto adjuster (120A, 120B) for automatic adjusting the lining gap is provided in parking brake mechanism to adjust brake liner (128) wear, over time with the help of the adjusting levers (132A, 132B) and the ratchet provided on the auto adjuster (120A, 120B). Further, one end of auto adjuster (120A) is attached to the pivotal end side of the one parking linkage (118A) and the other end of said auto adjuster (120A) is attached to the brake shoe (126B). Similarly, one end of auto adjuster (120B) is attached to the pivotal end side of the parking linkage (118B) and the other end of said auto adjuster (120B) is attached to the brake shoe (126A). The parking cable (116A, 116B) is attached to the free end of the parking brake levers (118A, 118B) such that when there is a pull from the parking cable (116A, 116B) the free end of the parking brake levers (118A, 118B) is pulled against the pivot point on the other end of the parking brake levers (118A, 118B) and in the direction of the parking cable (116A, 116B) as shown in figure 8 with the arrow (DA, DB). The movement of parking brake levers (118A) in direction of arrow (DA) will cause the movement of the auto-adjuster (120A) to move in the direction of arrow (CA) thereby causing the radial outward movement of the brake shoe 126B thereby applying brake. Similarly, the movement of parking brake levers (118B) in direction of arrow (DB) will cause the movement of the auto-adjuster (120B) to move in the direction of arrow (CB) thereby causing the radial outward movement of the brake shoe 126A thereby applying brake. Both these actions take place simultaneously to apply the parking brakes. The Auto adjuster (120) is provided with the strut assembly. The figure also shows a pair of shoe return spring (122) mounted individually on each of the brake shoe (126). The said H2LS floating brake arrangement is mounted on the backing plate (130).
[0031] Now referring to figure 4, a parking brake mechanism is incorporated in existing H2LS brake. H2LS brake is floating brake arrangement which consist of two, wheel cylinders (124) configured to expand both liners (128) simultaneously for activation of brakes. Further, two separate mechanical linkages (118A, 118B) are attached to individual brake shoe (126A, 126B) which will be operated with separate parking cables (116A, 116B) arrangement. Auto adjuster (120) for adjusting the lining gap is provided in parking brake mechanism to adjust brake liner (128) wear over time. The Auto adjuster (120) is provided with the strut assembly. Two separate parking brake lever/linkage (118A, 118B) is assembled for Primary & secondary brake shoe (126A, 126B) in the brake assembly with rivet. Parking lever (118A) is connected to secondary brake shoe (126B) through strut assembly (120A). Parking lever (118B) is connected to primary brake shoe (126A) through strut assembly (120B).
[0032] Now referring to figure 5 and 6, shows a schematic view of the parking brake arrangement on chassis and routing of the parking brake arrangement from parking brake handle till the rear drum brakes respectively. Figure 6 illustrates a top view the vehicle chassis mounted with H2LS Brake with Parking Arrangement, in accordance with an embodiment of the present subject matter. It shows a front cable (102) wherein one end is connected to the parking brake lever (136) and the other end is connected to an equalizer (138). The equalizer (138) is further configured for routing at least one intermediate parking cable (104) whose one end is connected to the equalizer (138) and another end is configured to be connected to at least one brake pulley housing pivotally holding at least one brake pulley (114) to move freely in the housing. At least one brake pulley (114) is configured to route at least one rear parking cable (106) wherein one end of the said rear parking cable (106) is routed through the brake sleeves (134) mounted on a backing plate (130) of the rear brake. The other end of the said rear parking cable (106) is routed through the bell crank lever (142) is mounted on the rear axle and further through the brake sleeves (134) mounted on a backing plate (130) of the rear brake. One end of the said rear parking cable (106) is connected to the free end of one parking linkage/lever (118A) and other end of said rear parking cable (106) is connected to the free end of the other parking linkage (118B) mounted on the backing plate (130) of the H2LS brake assembly with the parking brake arrangement.
[0033] The force applying system is provided to apply and transmit the force applied to the parking brake lever to transmit it to parking brakes comprising
at least one front cable configured for connecting parking brake lever and an equalizer;
at least one intermediate parking cable (104) whose one end is connected to the equalizer (138) and another end is configured to be connected to at least one brake pulley housing pivotally holding at least one brake pulley (114);
at least one rear parking cable (106) configured to be routed through at least one brake pulley (114);
plurality of brake sleeves (134) configured to route both the ends of the rear parking cable (106) to backing plate (130);
at least one bell crank lever (142) configured to be mounted on the rear axle and for routing one end of the rear parking cable (106);
wherein the ends of the rear parking cable (106) on its entry through the backing plate (130) are the parking cable (116A, 116B) configured for connecting to the free ends of the parking linkage/lever (118A, 118B) for simultaneous actuation of brake shoes (126A, 126B) of the H2LS brake assembly.

[0034] Parking Brake Operation:
1. Front parking brake cable (102) is pulled by Cabin parking Lever (136).
2. Force transmitted through equalizer (138) to intermediate parking cable (104) to right-hand and left-hand brake pulleys (114).
3. Individual rear parking brake cables (106) will simultaneously pull the individual brake parking lever/linkage (118A, 118B) attached to each of the shoes (126A, 126B) which transfers the lever action through strut assembly to each of the shoes (126A, 126B).
4. Further application of hand force will actuate each parking brake lever (118A, 118B) to further actuate the brake shoes (126A, 126B) to expand & to apply the parking brake against brake drum to hold/park vehicle.
5. Brake force will be balanced through pulley (114).
6. An auto adjuster (120) along with adjusting lever (132) is incorporated in the braking arrangement to maintain the desired gap for each brake shoe (126).
7. When parking brake is released, brake shoe return spring (122) returns the primary & secondary shoe (126A, 126B) to their retracted position.
[0035] Main features of the hydraulic twin leading shoe (H2LS) brake integrated with parking brake:
1. Provides a dual parking brake linkages having dual cylinder attached to primary and secondary brake shoe in the parking brake assembly wherein each brake shoe is operated by separate parking cables.
2. Dual auto adjuster mechanism is provided for lining gap adjustment for primary and secondary brake shoes.
[0036] Although implementations for the hydraulic twin leading shoe (H2LS) brake integrated with parking brake have been described in language specific to structural features and/or methods, it is to be understood that the appended claims are not necessarily limited to the specific features described. Rather, the specific features are disclosed as examples of implementation for the hydraulic twin leading shoe (H2LS) brake integrated with parking brake.