Claims:We claim:

1. An isolation valve in afront wheel annular piston brake for tractors comprising of

a. Body Housing;
a Plunger;
an O-ring;
a Ball;
a Cam Shaft; and
a Knob
characterized in that thefront wheel annular piston brake assembly comprises of Pedals, Two Master cylinders, a Reservoir, a Shuttle valve, the Intelligent Isolation Valvewith a knob facility allowing an ON or OFF function, a Proportioning valve, a Front annular piston brake and a Rear annular piston brake.

2. An isolation valve as claimed in Claim 1 and its working thereof wherein characterized in that the. isolation valve is a directional (ON / OFF) valve, isolating the front foundation brakes from the tractor brake system when the. isolation valve is turned OFF.

3. An isolation valve as claimed in Claim 1 and its working thereof wherein characterized in that the. isolation valve connects the front foundation brakes to the tractor brake system when the. isolation valve is turned ON.

4. An isolation valve as claimed in Claim 1 and its working thereof wherein, at rest condition, when the driver ons the isolation valve using the knob, the plungers push the sealing parts and connect the front foundation brakes with the rest of the tractor brake system.

5. An isolation valve as claimed in Claim 1 and its working thereof wherein, at brakes applied in pedals unlatched condition, the pressure from left hand or right handmaster cylinder is transferred to the corresponding front and rear foundation brake,no pressure being transferred to the other hand foundation brakes.
6. An isolation valve as claimed in Claim 1 and its working thereof wherein, at brakes applied in pedals latched condition, since the front foundation brakes are already connected to the rest of the tractor brake system, the pressure from left hand and right handmaster cylinders are transferred to all foundation brakes.

7. An isolation valve as claimed in Claim 1 and its working thereof wherein, at rest in valve off condition, when the driver turns off the isolation valve using the knob, the spring force push the sealing parts and isolates the front foundation brakes from the rest of the tractor brake system.

8. An isolation valve as claimed in Claim 1 and its working thereof wherein, at brakes applied in pedals unlatched condition, the pressure from left hand or right hand master cylinder is transferred to the corresponding rear foundation brake.

9. An isolation valve as claimed in Claim 1 and its working thereof wherein, at brakes applied in pedals latched condition, the pressure from left hand and right hand master cylinders are transferred to the respective rear foundation brakes, the inner plungers in the isolation valve opening the sealing parts, due to pressure force.

10. An isolation valve as claimed in Claim 1 and its working thereof wherein, at brakes release in pedals unlatched condition, when the pressure in the master cylinders are released, the pressurized fluid, trapped in between the isolation valve and front foundation brakes, pushes the sealing parts against the spring forces and reaches the reservoir through the respective master cylinders.
, Description:TITLE
AN ISOLATION VALVE IN A FRONT WHEEL ANNULAR PISTON BRAKE FOR TRACTORS

FIELD OF THE INVENTION

This invention relates to mechanical engineering, specifically automobile engineering and relates to anannular piston brake system. This invention more specifically relates to an isolation valve in afront wheelannular piston brake for tractor application, with a knob facility for the driver, the front wheel annular piston brake system further containing pedals, master cylinder, reservoir, shuttle valve, proportioning valve, front annular piston brake and rear annular piston brake.

BACKGROUND OF THE INVENTION

Agricultural tractors generally used in India ranges between 25~57 HP. MaximumSpeed of the vehicle varies between 25~35 KPH. Mainly used for ploughing, tilling, disking, harrowing, planting, and similar tasks. These tractors are currently equippedwith brakes in Rear Axle (Dry and Wet MPD brakes with mechanical actuation). Thebrakes are well proven for the above purposes. The maximum achievable decelerationwith current brakes in high mue surfaces is 0.35 to 0.4 g.

The max speed and efficiency of the brakes (w.r.t deceleration) of the Vehiclesother than farm tractors have increased considerably. When the farm tractor is used forhaulage purposes, the max achievable deceleration with 2-wheel braking is not enoughwhen compared to other road/ highway vehicles.

To understand the current brake performance (mechanically actuated Wet MPDbrakes), Performance trials were carried out in current tractor with OIB brake system with existing mechanical actuation to ascertain the maximum achievabledeceleration with 2-wheel braking system, which will be an input for design anddevelopment of 4-wheel braking system.

The usage of farm tractors for haulage purposes needs enhancement inbrakes. To enhance road safety, Europe has revised the norms for tractors with speedsabove 30kmph.

The minimum achievable deceleration should be 0.5g. The maximumachievable deceleration with current 2-wheel brake system in high mue surfaces is 0.35to 0.4 g. Just by increasing the braking force on rear axle will not achieve higherdeceleration. It will only make the rear wheels to lock. To generate higherdeceleration, the braking must be distributed to front axle as well.

Some of the prior art in this field reveal various improvements made over the years in the art, specifically in tractor brakes.

Indian Patent Application No: 2669/MUM/2014 discloses ahydraulic trailer brake system operated by the tractor's own hydraulic system and that, too, without a separate trailer brake control valve. The trailer brake system includes a hydraulic control valve equipped with an isolating valve for prioritizing of fluid flow either to trailer brake outlet or for implement operation. The hydraulic tractor brake system comprises: a hydraulic pump; a brake pedal; a draft lever; the tractor hydraulic system includes a hydraulic control valve, a combination of isolating valve and shut-off valve and a draft plunger; a plurality of linkages are provided for connecting and actuating the brake pedal, the draft plunger, the draft lever and the hydraulic control valve. A gap configured between the draft lever-hydraulic control valve linkage and the hydraulic control valve is adjusted by using draft lever for facilitating the synchronization of the tractor and trailer brake systems.

Indian Patent Application No: 201641037309 claims an all wheel braking system for a two wheel drive tractor to provide higher braking efficiency, comprises of plurality of brake assemblies (105, 106, 108,109), said plurality of brake assemblies (105, 106, 108, 109) actuates simultaneously and thus brake is applied on the dead axle (104) and the live axle (107). This system improves the braking functionality of the braking system by approximately 25~40%.

Indian Patent Application No: 5772/DELNP/2010 discloses a tractor steer-by-braking (SBF) pedal arrangement (10). The pedal arrangement (10) is characterized by having a central brake pedal (11) connected on one side to a right side pedal (12), and on the other side to a left side pedal (13). The central brake pedal (11) acts on a brake system (SBF) to produce the desired braking action. Each of the two side pedals (12, 13), when foot-operated by the driver, generate an activating signal to activate an electronic brake system, which only activates the brake required to steer-by-braking (SBF) in the desired (right or left) direction.

Indian Patent Application No: 1412/KOL/2006 claims an installation of braking device arrangement in the trailer Truck with a synchronization of Tractor brake. The new braking device comprising of installation of new compression with accessories in the tractor and a pneumatic brake attachment with a master cylinder with a provision of a brake fluid container and an additional air tank is provided with the tractor to cater air to air tank of the trailer truck via a flexible air pipe. The trailer equipped with a pneumatic braking device which is controlled by a hand lever by the driver via a control brake - valve of the tractor.

With the foregoing in mind, therefore it is the need of the hour is to developAnisolation valve in a front wheel annular piston brake for tractorsthat offers huge driver benefits, less pedal effort, a compact mechanism, reduce service costs,offer better alignment of the brake housing,and provide a more efficient and speedy brake system for tractors.

The primary purpose of the present invention is to offer an isolation valve in afour wheel annular brake system, as an alternate to the four wheel drive with automatic engagement in a tractor to meet European regulation requirement. By this way, huge cost benefit is accrued at customer end.

This invention eventually addresses the above and proves to be performance efficient, cost effective and eases the assembly.These and other objects of the invention will become more apparent in the course of the ensuing specification and claims when taken with the accompanying drawings.

Further it will be apparent to those skilled in the art that the objects of this invention have been achieved by providing an isolation valve in afront wheel annular piston brake for tractorswhich is unique in nature unlike existing valve systemas 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 an isolation valve in afront wheel annular piston brake for tractorswithknob facility for the driver.

Another object of the present invention is to present an isolation valve in a front wheel annular piston brake for tractors with Hydraulic or mechanical brake actuation.

Another object of the present invention is to providean isolation valve in a front wheel annular piston brake for tractors with enhanced brake efficiency with a maximum deceleration of 0.57g - 35% reduction in stopping distance.

Another object of the present invention isto provide an isolation valve in a front wheel annular piston brake for tractors with a fool proof or mistake proof mechanism for driver intervention.

A further object of the present invention isto provide an isolation valve in a front wheel annular piston brake for tractors that provides a more efficient and speedy Four wheel braking with self adjusted brake system for tractors..

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 an isolation valve in a front wheel annular piston brake for tractors to work as a directional (ON / OFF) valve during service braking.

The Isolation Valve is hydraulically or mechanically actuated in a hydraulic brake system of Tractor having front brake application. It isolates the front foundation brakes from the tractor brake system when this valve is turned OFF. It connects the front foundation brakes to the tractor brake system when this valve is turned ON.

The present invention Isolation Valve provides the knob facility for the driver to turn ON or OFF. It also has a fool proof or mistake proof mechanism if the driver forgets to connect the front foundation brakes during latched condition.

The entire isolation valve assembly comprises of the following parts:

9. Body Housing 12. Ball
10. Plunger 13. Cam Shaft
11. O-ring 14. Knob
15. Spring-ball 16. Plunger-ball

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 detail view of the present invention brake system layout & description.

Figure 2 is layout view of the present invention brake system with isolation valve function.

Figure 3 is a detail view illustrating the working of the present invention brake system pedal latched - isolation valve ON/ OFF condition.

Figure 4 is a cross sectional view illustrating the present invention brake system pedal unlatched - isolation valve ON / OFF condition.

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 an isolation valve in a front wheel annular piston brake for tractors with driver benefits, for lesser pedal effort and for more durability.

Construction

As shown in Figures 1 to 4, the present invention components are as follows:

The entire isolation valve assembly comprises of the following parts:

9. Body Housing 12. Ball
10. Plunger 13. Cam Shaft
11. O-ring 14. Knob
15. Spring-ball 16. Plunger-ball

According to a preferred embodiment of the present invention, as depicted in Figure 1,in addition to the isolation valve, the entire front wheel annular piston brake assembly comprises of the following parts:

1. Pedal
2. Master cylinder
3. Reservoir
4. Shuttle valve
5. Intelligent Isolation Valve
6. Proportioning valve
7. Front APB
8. Rear APB

Two Master cylinders (2) are provided in this system to create fluid pressure when pedal (1) is pressed. Two pairs of Annular piston brakes (7) (8) provided inside Rear Trumpet assembly and Inboard of front wheel assembly. A shuttle valve (4) provided in between MC assembly (2) and Isolation Valve circuit (5). An Intelligent Isolation Valve (5) is provided between Shuttle valve (4) and Front (7) and Rear (8) brake circuit.When pedal is pressed pressurized fluid from Master cylinder (2) pass through Shuttle valve (4) and Isolation valve (5) before reach Front and Rear Brake. When pedal (1) is pressed, all wheel brakes get energized and brake applied.

Working:
I. Valve ON condition:
a) Rest Condition:
According to a preferred embodiment of the present invention, at rest condition, When the driver ON this valve (5) using the knob (14), the plungers (10) push the ball (12) and connect the front foundation brakes with the rest of the tractor brake system.

b) Pedals’ Unlatched Condition:
Brakes Applied Condition:
According to a preferred embodiment of the present invention, at brakes appliedin pedals (1) unlatched condition, the pressure from LH or RH master cylinder (2) is transferred to the corresponding front (7) and rear (8) foundation brake. No pressure is transferred to the other hand foundation brakes.

c) Pedals’ Latched Condition:
Brakes Applied Condition:
According to a preferred embodiment of the present invention, at brakes appliedin pedals (1) latched condition, Since the front foundation brakes (7) are already connected to the rest of the tractor brake system, the pressure from LH and RH master cylinders (2) are transferred to all foundation brakes (7), (8).

II. Valve OFF condition:
a) Rest Condition:
According to a preferred embodiment of the present invention, at rest in valve OFF condition, When the driver switches off this valve (5) using the knob (14), the spring ball (15) force push the ball (12) and isolates the front foundation brakes (7) from the rest of the tractor brake system.

b) Pedals’ Unlatched Condition:
Brakes Applied Condition:
According to a preferred embodiment of the present invention, at brakes appliedin pedals (1) unlatched condition, the pressure from LH or RH master cylinder (2) is transferred to the corresponding rear foundation brake (8). The effective sealing doesn’t allow any pressure transfer to the front foundation brakes (7).

Pedals’ Latched Condition:
Brakes Applied Condition:
According to a preferred embodiment of the present invention, at brakes appliedin pedals (1) latched condition, the pressure from LH and RH master cylinders (2) are transferred to the respective rear foundation brakes. Mean while the plunger-ball (16) in the isolation valve (5), due to pressure force, open the ball (12). Thus pressure is also transferred to the front foundation brakes (7). This is a fool proof or mistake proof mechanism.

Brakes Release Condition:
According to a preferred embodiment of the present invention, at brakes releasein pedals (1) unlatched condition, When the pressure in the master cylinders (2) are released, the pressurized fluid, trapped in between the Isolation valve (5) and front foundation brakes (7), pushes the ball (12) against the spring-ball (15) forces and reaches the reservoir (3) through the respective master cylinders (2).

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.