FORM 2
THE PATENT ACT, 1970,
(39 OF 1970)
&
THE PATENTS RULE, 2003
COMPLETE SPECIFICATION
(SEE SECTION 10; RULE 13)
"PARK BRAKE CABLE ADJUSTMENT SYSTEM FOR A MOTOR VEHICLE"
MAHINDRA & MAHINDRA LIMITED
AN INDIAN COMPANY,
R&D CENTER, AUTOMOTIVE SECTOR,
89, M.I.D.C., SATPUR,
NASHIK - 422 007,
MAHARASHTRA, INDIA.
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES AND ASCERTAINS THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF THE INVENTION:-
Present invention relates to the park brake cable adjustment of automobiles with mechanical park brake system. The Scope of invention is
- to eliminate the cable setting time in vehicle assy line,
- to eliminate cable adjustment in the field during vehicle servicing
- to ensure constant hand brake travel & effort through out the life of the vehicle.
BACKGROUND OF THE INVENTION:-
There are no such automatic adjustment exists for hand operated mechanical park brake system. Various other automatic adjustment are available only on electric park brake mechanism, where in a motor is used to adjust the cable slackness.
This proposed invention has simple mechanical arrangement that could be incorporated for any hand operated, Foot operated - mechanical park brake system for cable adjustment and to eliminate cable setting time in vehicle assembly line.
For all such automatic adjustments, there is one definite common disadvantage in addition to many other technical disadvantages. All of them add a lot of cost to the system more over adopting any of these arrangements into an already existing layout makes the situation very difficult and complicated.
This triggers the need of having a simple and cost effective solution for automatic adjustment of cable. The current invention precisely supports this approach. A major benefit in the present invention as compared to other motorized is a large cost saving and can be adopted with all the vehicles with equalizer mechanism.
SUMMARY OF THE INVENTION:-
This automatic cable adjuster working based on ratchet & slider mechanism. Ref figure 1 for the cable adjuster assembly. First connect front & rear cable ends to the adjuster

holes and then connect the return spring to the cable abutment bracket. After connecting all, apply the park brake lever for the cable to get pulled along with lever.
OBJECT OF INVENTION:-
It is an object of invention to provide the park brake cable adjustment of automobiles
with mechanical park brake system to eliminate the cable setting time in vehicle
assembly line,
It is an another object of invention to provide the park brake cable adjustment of
automobiles with mechanical park brake system to eliminate cable adjustment in the
field during vehicle servicing.
It is another object of invention to provide the park brake cable adjustment of
automobiles with mechanical park brake system to ensure constant hand brake travel &
effort through out the life of the vehicle.
STATEMENT OF INVENTION:-
Accordingly the invention provides the park brake cable adjustment system for a motor vehicle comprises a ratchet plate mounted centrally over a bottom plate provided with a pair of toothed spring slider with engaging teeth of said ratchet held in a guide plate; a top plate rigidly mounted over the said bottom plate so as to enable the said ratchet to move to and fro between said guide plate; a front cabfe assembly mounted on the first abutment bracket; the inner of the said front cable connected to the hole of ratchet; the pair of rear cables assembly mounted on the second abutment bracket; the inner of the said rear cables connected the pair holes at distant and symmetrical; one or more bias spring means provided to keep the said ratchet to move inside the top and bottom plates assembly between the said guide plates.
According another embodiment the park brake cable adjustment system for a motor vehicle comprises a ratchet plate mounted centrally over a bottom plate provided with engaging a pair of toothed wheels with free wheel mechanism at distant; a top plate rigidly mounted over the said bottom plate so as to enable the said ratchet to move to and fro between said guide plate; a front cable assembly mounted on the first abutment bracket ; the inner of the said front cable connected to the hole of ratchet;

the pair of rear cables assembly mounted on the second abutment bracket; the inner of the said rear cables connected the pair holes at distant and symmetrical; one or more bias spring means provided to keep the said ratchet to move inside the top and bottom plates assembly between the said toothed wheels.
DRAWINGS:-
Invention is described with reference to figures of accompanying drawings wherein;
Figure 1 shows the perspective view of ratchet mechanism used in the system
according to invention;
Figure 2 shows exposed view of figure 1 with the details of components;
Figure 3 shows plan view of park brake cable adjusting system using ratchet
mechanism with spring bias to keep rear cables under tension;
Figure 3A. shows plan view of park brake cable adjusting system using ratchet
mechanism with a pair of tension spring bias between front cable abutment bracket
and bottom plate;
Figure 3B shows plan view of park brake cable adjusting system using ratchet
mechanism with a pair of compression spring between rear cables abutment bracket
and bottom plate held in the cable inner;
Figure 3 C shows plan view of park brake cable adjusting system using ratchet
mechanism with a single compression spring between said rear cables abutment
bracket and centre of bottom plate;
Figure 3 D shows plan view of park brake cable adjusting system using ratchet
mechanism with using toothed wheel of free wheel type engaging said ratchet with
spring bias to keep rear cable under tension.
BRIEF DESCRIPTION OF FIGURES:-
Figure: 1 Cable auto adjuster assembly
For first application ratchet will try to pull the rear cable along with the top & bottom plate. While releasing the lever, front cable will try to push the adjuster and rear cables to go back. Here the cable return spring will try to hold the rear cable in position, but the

ratchet with front cable will still go back while sliding on the slider by pushing the spring sliders. Ref figure 3 for adjuster installed in vehicle condition. Along with and, figure 2: for sub parts of the mechanism, ref figure 3, installed view on vehicle.
Figure 2: Cable adjuster sub assembly
(1) Ratchet plate
(2) Slider
(3) Spring slider
(4) Guide plate
(5) Bottom plate
Figure 3: Describes the vehicle installed layout of cable adjuster mechanism. Mount the front cable assembly (9) on the abutment bracket and connect the front inner cable to the ratchet hole. Similarly mount both the rear cable assy (10 - LH/RH) on the abutment bracket and connect the rear inner cable end terminals to the base plate of the adjuster assembly as shown in figure 3.
After connecting all the three end terminals, connect the adjuster return spring (8) to the cable abutment bracket. This return spring will ensure that, both the rear cables are under tension and at the same time this spring load will be less than the threshold load of the brake return spring.
Cable adjustment can be explained in two stages (i.e.) forward & reverse movement. Forward movement:
Pull the park brake lever so that the front cable is pulling the ratchet (2), in turn ratchet will pull the slider (3) & bottom plat (6) and the rear cables. While forward movement, adjuster assemble will move forward and pull both the rear cable and apply the brake. Reverse movement.
While releasing the park brake, adjuster assembly will move back along with the ratchet & front cable, but the adjuster return spring will try to retain the bottom plat with slider and the ratchet will go further back and jumps on the next teeth.

The above mechanism will continue to work whenever park brake is applied and released.
• DIFFERENT CONCEPTS:-
The above said invention can be made workable in the following concepts which is explained the below images.
(1) Spring loaded by tension springs on rear cables (ref fig 3.1)
(2) Fitted with two compression springs on rear cables (ref fig 3.2)
(3) Fitted with one tension springs on front cable {ref fig 3.3)
(4) Concept with toothed wheel mechanism (that is, rachet and paul mechanism) with all the three different spring loading arrangements.
Referring to figures 1, 2, 3 3A, 3B, 3C, and 3D constructional feature of invention as follows:
The park brake cable adjustment system comprises a ratchet plate 2 mounted centrally over a bottom plate 6. The said bottom plate 6 provided with a pair of toothed spring 4 biased slider 3 with engaging teeth of said ratchet held in a guide plate 5. A top plate 1 rigidly mounted over the said bottom plate 6 so as to enable the said ratchet to move to and fro between said guide plate. A front cable 9 assembly mounted on the first abutment bracket. The inner of the said front cable connected to the hole of ratchet. A pair of rear cables assembly mounted on the second abutment bracket 10. The inner of the said rear cables connected the pair holes at distant and symmetrical. One or more bias spring means 8 provided to keep the rear cables inner under tension.
A second embodiment comprises toothed wheel free wheel type in place of spring biased toothed slider and guide plates.
APPLICATIONS:-
This subject invention can be adopted in the following areas,
- Hand brake system with cross pull & conduit reaction system

- Mechanical clutch system with cable arrangement
- Gear shifter with cable arrangement.
- Any other cable operated mechanism which required adjustment.

WE CLAIM:-
1. The park brake cable adjustment system for a motor vehicle comprises a ratchet plate mounted centrally over a bottom plate provided with a pair of toothed spring slider with engaging teeth of said ratchet held in a guide plate; a top plate rigidly mounted over the said bottom plate so as to enable the said ratchet to move to and fro between said guide plate; a front cable assembly mounted on the first abutment bracket; the inner of the said front cable connected to the hole of ratchet; the pair of rear cables assembly mounted on the second abutment bracket; the inner of the said rear cables connected the pair holes at distant and symmetrical; one or more bias spring means provided to keep the rear cables inner under tension.
2. The park brake cable adjustment system for a motor vehicle comprises a ratchet plate mounted centrally over a bottom plate provided with engaging a pair of toothed wheels with free wheel mechanism at distant; top plate rigidly mounted over the said bottom plate so as to enable the said ratchet to move to and fro between said guide plate; a front cable assembly mounted on the first abutment bracket ; the inner of the said front cable connected to the hole of ratchet; the pair of rear cables assembly mounted on the second abutment bracket; the inner of the said rear cables connected the pair holes at distant and symmetrical; one or more bias spring means provided to keep the rear cables inner under tension.
3. The park brake cable adjustment system as claimed in claims 1 and 2 wherein the bias spring means is a pair of tension springs fitted between said first abutment bracket and bottom plate.
4. The park brake cable adjustment system as claimed in claims 1 and 2 .wherein the said bias spring means is a single or a pair compression springs fitted between the said second abutment and bottom plate.

5. The park brake cable adjustment system as claim in claim 4 wherein the said pair of compression fitted through the said inners of the said rear cables.