Claims:CLAIMS

We claim:

1. A multi pot multi plate hydraulic braking system for agricultural tractors and like vehicles comprising of
a piston (1),
a. brake housing (2),
a sealing ring (3),
a wiper seal (4),
an inlet port (5),
a cover plate (6),
a splined shaft (7),
friction plates (8),
intermediate plates (9),
two or more pot bores (10) and
a parking brake piston (11)
characterised in that the wiper seal (4) made of rubber is placed in the groove of the pot bore (10) near the open face of the pot bore (10), and sealing ring (3) made of rubber is placed in a special chamfered groove of the pot bore (10) next to the wiper seal (4) groove, the piston (1) being placed in the pot bore (10) within the wiper seal (4) and sealing ring (3), the sealing ring (3) and the chamfered groove of the pot bore (10) being designed such that, when the piston (1) moves out, it travels along with the sealing ring (3) by deflecting the rubber upto a distance ‘X’ value.

2. A multi pot multi plate hydraulic braking system as claimed in Claim 1, wherein each pot bore (10) has an inlet port (5) for fluid entry from the actuation system to build the required hydraulic pressure.

3. A multi pot multi plate hydraulic braking system as claimed in Claim 1, wherein the brake housing (2) is fixed to the cover plate (6), the cover plate (6) being fixed to vehicle, the splined shaft (7) consisting of external splines, which are connected to the vehicle transmission through gears.

4. A multi pot multi plate hydraulic braking system as claimed in Claim 1, wherein the friction plates (8) consists of a core metal plate with both faces or one face lined with friction material, and the intermediate plates (9) are metal plates, the friction plates (8) and intermediate plates (9) being sequentially placed between the brake housing (2) and cover plate (6), either the friction plates (8) or the intermediate plates (9) having internal splines which are fixed on the splined shaft (7).

5. A multi pot multi plate hydraulic braking system as claimed in Claim 1, wherein when the friction plates (8) rotate with the splined shaft (7) the intermediate plates (9) are held stationary and when the intermediate plates (9) rotate along with the splined shaft (7) the friction plates (8) are held stationary, the friction plates (8) and the intermediate plates (9) being able to slide along the axis of the splined shaft, there being a running clearance between each friction plate (8) and intermediate plate (9), the sum of the running clearances between all the friction plates (8) and intermediate plates (9) being less than or equal to value of ‘X’ of the sealing ring (3).

6. A multi pot multi plate hydraulic braking system as claimed in Claim 1, wherein the parking brake piston (11) moves on the axis of the splined shaft (7) and is connected to the mechanical linkages of the parking brake handle, there being a clearance between the parking brake piston (11), friction plates (8) and intermediate plates (9) when the parking brake handle is at rest condition.

7. A multi pot multi plate hydraulic braking system as claimed in Claim 1 and working thereof, wherein in the service brake applied condition, when fluid pressure is applied on the pistons (1) through the inlet port (5), it pushes out the piston (1) along with the sealing ring (3) by deflecting the rubber to a distance ‘X’ due to the chamfer groove design of the pot bore (10), thereby restricting the piston (1) to slide over the sealing ring (3), the pistons (1) in-turn pushing the intermediate plates (9) and friction plates (8) towards the cover plate (6) to generate the required frictional force since one of the plates are stationary and the other is rotating, this frictional force generating the required braking torque onto the splined shaft (7) thereby generating a brake force on the wheels through the transmission, this braking force being used to stop, slow down or steer the vehicle as per the driver’s requirement.

8. A multi pot multi plate hydraulic braking system as claimed in Claim 1 and working thereof, wherein in the brake released condition, when the fluid pressure is released, the sealing ring (3) is pulled back, along with the pistons (1) to ‘X’ distance providing the required running clearance between the intermediate plates (9) and friction plates (8), the splined shaft (7) starting to rotate along with the friction plates (8) or intermediate plates (9) which are fixed to it.

9. A multi pot multi plate hydraulic braking system as claimed in Claim 1 and working thereof, wherein when the friction plates (8) wears, the brake running clearance increases, the piston (1) traveling more than ‘X’ value to close the clearances between the friction plates (8) and intermediate plates (9) to generate the required braking, the sealing ring (3) deflecting till the distance ‘X’ due to chamfer groove design of pot bore (10), the piston (1) then sliding over the sealing ring (3) to close the clearances between the friction plates (8) and intermediate plates (9) for necessary braking, the piston (1) is pulled back to a distance ‘X’ by the deflected sealing ring (3) when fluid pressure is released.

10. A multi pot multi plate hydraulic braking system as claimed in Claim 1 and working thereof, wherein in the parking brake applied condition, when the parking brake is applied, the mechanical linkages moves parking brake piston (11) towards the cover plate (6), the parking brake piston (11) in turn pushing the intermediate plates (9) and friction plates (8), the intermediate plates (9) and friction plates (8) coming in contact and generating braking force to the transmission through splined shaft (7), mechanical linkages pulling out parking brake piston (11) to home position and the parking brake being released.

Dated this 10th day of September 2015

N. Surya Senthil – IN/PA-736
For JUS MAXIMA LAW OFFICES
To (Agent for Applicant)
The Controller of Patents
Patent Office in Chennai

, Description:TITLE
MULTI POT MULTI PLATE HYDRAULIC BRAKING SYSTEM FOR AGRICULTURAL TRACTORS AND LIKE VEHICLES

FIELD OF THE INVENTION

This invention relates to mechanical engineering, specifically automobile engineering and relates to a brake system. This invention relates to a multi pot multi plate hydraulic braking system for agricultural tractors and like vehicles.

BACKGROUND OF THE INVENTION

In the present scenario mechanical brakes with mechanical actuation is widely used in tractor brake applications. Whilst attractive from a cost view point, its efficiency is low due to design limitations. With continued usage and time, its efficiency decreases due to corrosion, build-up of dirt on the pivots and wear on operating shaft, unless periodical maintenance is carried out. As the lining wears, regular brake adjustment leads to an angle effect (Sine Angle) in the input rod linkages which further reduces the efficiency.

Therefore it is the need of the hour is to develop a effective and simple hydraulic multi plate multi pot brake for agricultural tractors and like vehicles for enhanced performance.

Some of the prior art in this field reveal various improvements made over the years in the art in tractor disc brakes for better working and efficacy.

Indian Patent 131979 claims a disc brake for a tractor or like vehicle comprising a stationary housing having a radial braking surface, a rotatable friction disc mounted on a shaft within the housing and a hydraulic actuator for forcing the friction disc into contact with the radial braking surface, in which the hydraulic actuator comprises a pair of co-operating annular cylinder and piston members having a sliding seal therebetween, one of the members comprising a metal shell of channel section held against rotation relative to the housing and the other member being axially movable to apply pressure to the friction disc and being keyed to the shell so that torque taken by the movable member on application of the brake is transmitted through the shell to the housing.

Indian Patent Application No: 2053/KOLNP/2010 claims a braking system for farm tractors and similar vehicles, comprising a differential braking system and a hydraulic system for the braking assistance forming a system unit (H) which includes two circuit branches (H1,H2), each circuit branch operating the braking with respect of one side of the vehicle. According to the invention, to said system unit (H) are applied, through connection interfaces (36,37), two control units (C1,C2), each control unit including an electrovalve (20) and a distributor (24) operated by said electrovalve, each said distributor (24) controlling the operation of the system unit (H) with respect to one of the circuit branches (H1,H2), and each said electrovalve (20) being singularly controlled by an electronic control circuit (EL) provided with sensors (V,R,P,A) of the main vehicle parameters, such as a sensor (V) of the vehicle speed, sensors (R) of the speed of singular wheels, sensors (P) of the positions of the braking pedals and a sensor (A) of the position of the accelerator pedal. In this manner the vehicle is equipped with a function of regulation of the slip in traction (ASR), or with a function preventing the wheel blockage in braking (ABS), or with a function of stability control (ESP), or with several of these and other functions, having a great utility to the aim of security when the vehicle runs on road at a high speed.

Indian Patent Application No: 5771/DELNP/2010 discloses a brake and steer-by-braking (SBF) pedal arrangement (10) for tractors. The pedal arrangement (10) includes: - a right pedal (11) and a left pedal (12) operating synchronously or diachronically; and at least one hydraulic or pneumatic circuit connected to one master cylinder (13) activated by at least one of the pedals (11, 12). The pedal arrangement (10) also has potentiometers (17, 20) connected electronically to an electronic central control unit (CL); the potentiometers (17, 20) determine the distance between the pedals (11, 12); and the electronic central control unit (CL) determines, on the basis of data received from the potentiometers (17, 20), whether or not to activate the steer-by-braking function (SBF).

Indian Patent Application No: 2262/MUM/2011 describes a hydraulic braking system of Tractor trailer or similar vehicle, this system is capable of Braking the trailer without affecting the hydraulic operation of tractor. At the same time this valve also maintains its priority for braking over other application. Also prevent power loss of tractor when NO trailer or trolley is attached

Indian Patent Application No: 2464/MUM/2011 claims a brake control system for trailer vehicle adapted to be hitched on tractor vehicle comprising of pressure control system, quick joiner coupling, a connector, brake cylinder box structure and wheel brake drum. The pressure control system is operated by pressing the lever for providing adequate pressurized oil present in the inbuilt hydraulic system to trolley brake system. Quick joiner coupling carries hydraulic oil to trolley control system & for lifting the trolley from the notch. Spring pipe is a connection between tractor section and trolley section. Brake cylinder box structure is having two cylinders such as master cylinder for delivering pressurized brake fluid to the rear wheel & front wheel brake system and hydraulic cylinder for providing brake fluid to the master cylinder of the trailer respectively. Wheel brake drum applies brakes by pushing the rods to increase additional pressurized oil by touching brake shoes assembly. The present embodiment is a cost effective, more efficient maintainance free brake control system for trailer.

Indian Patent Application No: 3104/MUM/2012 claims a hydraulic Trailer braking system for trailer along with combination power saving and anti pressure adding valve. The Anti pressure addind valve prevent the system pressure to increasing at the pump discharge end and in all three the condition i.e 1. Only Brake operated 2. Only Auxiliary equipment operated 3. Both Brake and Auxillary operated.

Indian Patent Application No: 1893/MUM/2013 describes an invention wherein the oil (Hydraulic Oil) which is pumped by the hyd pump connected to the tractor normally flows from the brake valve and enters into the existing hydraulic system of tractor. whenever the auxiliary operation is to be done by the tractor the pressure from the line is prevented to enter the brake cylinder because of the check valve provided after the anti pressure adding valve (say pressure p1) when the brakes are applied by used of master cylinder on the tractor the same oil (brake oil) is used as a pilot to actuate the brake valve and the hydraulic oil enters the trailer brake cylinder and pressurizes the same the max pressure can be set using the anti pressure adding valve device, this device has two function a) this device control brake pressure when brakes are operated b) in case the back pressure is exerted by the auxiliary equipment, then this valve is operated by the back pressure and nullifies the brake pressure and so only the master pressure of the auxiliary system is exerted, thus the pressure adding on the line before the brake valve is prevented, as soon as the pressure increases the pressure p1 the oil is by-passed and returns in the hydraulic system of the tractor and thus the other operation is also possible at the same time. if the load on the hydraulic system of the tractor exceeds p1 then depending upon the load the p1 also varies up to the pressure setting of tractor hydraulics and thus when the load reduced below P1 the brake pressure does not come below P1. However none of the existing prior art discloses any multi pot multi plate hydraulic braking system for agricultural tractors and like vehicles.

Therefore it is the need of the hour in the industry to develop a multi pot multi plate hydraulic braking system for agricultural tractors and like vehicles. This invention eventually addresses the above and proves to be performance efficient, cost effective and eases the assembly.

Further it will be apparent to those skilled in the art that the objects of this invention have been achieved by providing a novel multi pot multi plate hydraulic braking system for agricultural tractors and like vehicles which is unique in nature unlike existing braking systems for agricultural tractors as described in the above prior art. Various changes may be made in and without departing from the concept of the invention. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing and modifying other methods and structures for carrying out the same purpose of the present invention. Further, features of some stages disclosed in this application may be employed with features of other stages. Therefore, the scope of the invention is to be determined by the terminology of the following claims and the legal equivalents thereof.

OBJECTIVES OF THE INVENTION

This invention may be summarized, at least in part, with reference to its objects.

The foremost object of the present invention is to present a novel, compact multi pot multi plate hydraulic braking system for agricultural tractors and like vehicles.

The object of the present invention is to provide a multi pot multi plate hydraulic braking system that is easy and simple to meet new regulations and customer requirements.

Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention.

SUMMARY OF THE INVENTION

The present invention embodies a multi pot multi plate hydraulic braking system for agricultural tractors and like vehicles. The present invention relates to the service brake application through two or more pistons and one or more number of friction plates and intermediate plates to stop, slow down or steer assist the moving agricultural tractors and similar vehicles by actuating a single brake in field applications and latched brake in haulage applications. All these pistons have a self adjusting mechanism to provide consistent braking by compensating for liner wear. A parking brake mechanism is built into the same system through mechanical linkages.

DESCRIPTION OF THE DRAWINGS

The advantages and features of the present invention will be more readily apparent by persons skilled in the art when considered in reference to the following description and when taken in conjunction with the accompanying drawings listed below

Figure 1 is a cross sectional view illustrating the present invention multi pot multi plate hydraulic braking system when the service brake is off.
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Figure 2 is a cross sectional view illustrating the present invention multi pot multi plate hydraulic braking system during sealing ring deflection when the service brake is on.

Figure 3 is a cross sectional view illustrating the present invention multi pot multi plate hydraulic braking system when the service brake is on.

Figure 4 is a cross sectional view illustrating the present invention multi pot multi plate hydraulic braking system when the parking brake is on.

Figure 5 depicts the working procedure of the present invention.

DETAILED DESCRIPTION

The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of particular applications of the invention and their requirements. The present invention can be configured as follows:

The present invention is a multi pot multi plate hydraulic braking system operated through a hydraulic actuation system consisting of two master cylinders coupled separately with two brake pedals independently operated during field applications and with a latched pedal during haulage applications.

Construction

As shown in Figure 1, the present multi pot multi plate hydraulic braking system invention components are as follows:
1. Piston
2. Brake Housing
3. Sealing Ring
4. Wiper Seal
5. Inlet Port
6. Cover Plate
7. Splined Shaft
8. Friction Plates
9. Intermediate Plates
10. Pot Bore
11.Parking Brake Piston

According to a preferred embodiment of the present invention, as depicted in Figure 1, the brake housing (2) consists of two or more pot bores (10). A wiper seal (4) made of rubber is placed in the groove of the pot bore (10) near the open face of the pot bore (10). Sealing ring (3) made of rubber is placed in a special chamfered groove of the pot bore (10) which is next to the wiper seal (4) groove. The piston (1) is placed in the pot bore (10) with-in the wiper seal (4) and sealing ring (3). The sealing ring (3) and the sealing ring groove chamfer of pot bore (10) is designed so that, when the piston (1) moves out, it travels along with the sealing ring (3) by deflecting the rubber to a distance ‘X’ value as can be seen in Figure 2. This phenomenon restricts the piston (1) to slide over the sealing ring (3) till a distance of ‘X’ value. Each pot bore (10) has an inlet port (5) for fluid entry from the actuation system to build the required hydraulic pressure. The brake housing (2) is fixed to the cover plate (6). The cover plate (6) is fixed to vehicle. The splined shaft (7) consisting of external splines, are connected to the vehicle transmission through gears. The friction plates (8) and intermediate plates (9) are sequentially placed between the brake housing (2) and cover plate (6). The no. of friction plates (8) and intermediate plates (9) can vary according to the brake requirement. The friction plate (8) consists of a core metal plate with both faces or one face lined with friction material. The intermediate plates (9) are metal plates. Either the friction plates (8) or the intermediate plates (9) have internal splines which are fixed on the splined shaft (7) and rotate along with it. When the friction plates (8) rotate with the splined shaft (7) the intermediate plates (9) are held stationary. When the intermediate plates (9) rotate along with the splined shaft (7) the friction plates (8) are held stationary.

According to a preferred embodiment of the present invention, as depicted in Figure 1, the friction plates (8) and the intermediate plates (9) can slide along the axis of the splined shaft. When the vehicle moves the transmission rotates the splined shaft (7) along with either the friction plates (8) or the intermediate plates (9). There is a running clearance between each friction plate (8) and intermediate plate (9). The sum of the running clearances between all the friction plates (8) and intermediate plates (9) is less than or equal to value of ‘X’ of the sealing ring (3).

According to a preferred embodiment of the present invention, as depicted in Figure 1, there is a parking brake piston (11) which moves on the axis of the splined shaft (7). This is connected to the mechanical linkages of the parking brake handle. There is a clearance between the parking brake piston (11), friction plates (8) and intermediate plates (9) when the parking brake handle is at rest condition.

Working Principles

According to a preferred embodiment of the present invention, as depicted in Figure 3, in the service brake applied condition, when fluid pressure is applied on the pistons (1) through the inlet port (5), it pushes out the piston (1) along with the sealing ring (3) by deflecting the rubber to a distance ‘X’ (Refer Fig - 2) due to the chamfer groove design of the pot bore (10). This phenomenon restricts the piston (1) to slide over the sealing ring (3). The pistons (1) in-turn push the intermediate plates (9) and friction plates (8) towards the cover plate (6) to generate the required frictional force since one of the plates are stationary and the other is rotating. This frictional force generates the required braking torque onto the splined shaft (7) thereby generating a brake force on the wheels through the transmission. This braking force is used to stop, slow down or steer the vehicle as per the driver’s requirement.

According to a preferred embodiment of the present invention, as depicted in Figure 1, in the brake released condition, When the fluid pressure is released, the sealing ring (3) is pulled back, along with the pistons (1) to ‘X’ distance providing the required running clearance between the intermediate plates (9) and friction plates (8). The splined shaft (7) starts to rotate along with the friction plates (8) or intermediate plates (9) which are fixed to it.

According to a preferred embodiment of the present invention, as depicted in Figure 2, the auto adjuster mechanism working is as follows: when the friction plates (8) wears, the brake running clearance increases. To cater for this increased running clearance, the piston (1) has to travel more than ‘X’ value to close the clearances between the friction plates (8) and intermediate plates (9) to generate the required braking. As the piston (1) moves, the sealing ring (3) deflects till the distance ‘X’ due to chamfer groove design of pot bore (10), then the piston (1) slides over the sealing ring (3) to close the clearances between the friction plates (8) and intermediate plates (9) for necessary braking. When fluid pressure is released, the piston (1) is pulled back to a distance ‘X’ by the deflected sealing ring (3), thereby the running clearance is automatically adjusted for friction plate wear. This phenomenon of self adjustment of piston (1) provides consistent braking from new to worn out lining condition at all applications.

According to a preferred embodiment of the present invention, as depicted in Figure 4, in the parking brake applied condition, When the parking brake is applied the mechanical linkages moves parking brake piston (11) towards the cover plate (6). The parking brake piston (11) in turn pushes the intermediate plates (9) and friction plates (8). Now the intermediate plates (9) and friction plates (8) comes in contact and generates braking force to the transmission through splined shaft (7). When the parking brake is released mechanical linkages pulls out parking brake piston (11) to home position and the brake is released.

While there has been shown and described what is considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.

It will be apparent to those skilled in the art that the objects of this invention have been achieved by providing the above invention. However various changes may be made in the structure of the invention without departing from the concept of the invention. Therefore, the scope of the invention is to be determined by the terminology of the following claims and the legal equivalents thereof.

Dated this 10th day of September 2015

N. Surya Senthil – IN/PA-736
For JUS MAXIMA LAW OFFICES
(Agent for Applicant)
To :

The Controller of Patents
Patent Office in Chennai