DESC:FIELD OF THE INVENTION:
The present invention relates to a braking system for vehicles. More particularly, the present invention relates to a pneumatic braking system of lifted wheels.

BACKGROUND OF THE INVENTION:

Currently, the heavy vehicles such as trucks, trailer carriers and load trucks are equipped with a lifted axle or a tandem axle facility to increase the life of tires, increase the fuel efficiency and increase load capacity of the vehicles etc.

A pneumatic braking system is a type of braking which applies brake force on wheels of vehicles by brake application elements such as brake pads, brake drums and brake bands, which are actuated by pressurized air. Heavy vehicles having a lift or tandem axle with the pneumatic braking system, if a brake is applied, the brake application elements are actuated and the braking force is applied on lifted wheels connected with the lift axle. As these wheels are in a non-rotatory condition, the brakes applied on these lifted wheels are considered to be non-useful. The brake is unnecessarily applied on the wheels. The braking elements require pressurized air for applying brake force on the lifted wheels. For applying brakes on these lifted wheels, lot of pressurized air is consumed by the pneumatic braking system. For generating pressurized air, energy is consumed by an air compressor connected with the pneumatic braking system. Hence, lot of energy is wasted due to consumption of pressurized air by the pneumatic braking system for applying brakes to these lifted wheels. .
Further, life of the brake application elements depends upon the number of operation of the braking elements. Due to the unnecessary action of these brake application elements on the lifted wheels for causing braking action, the life of brake application elements will decrease.

Therefore, there is a need of valve or a system for the pneumatic brakes of lifted wheels for preventing unnecessary braking of the lifted wheels.

OBJECT OF THE INVENTION:

An object of the present invention is to provide a pneumatic braking system for the lifted wheels having a valve for preventing unnecessary braking of the lifted wheels.

Yet another object of the present invention is to provide a valve for preventing unnecessary braking of the lifted wheels, thereby reducing air consumption by a pneumatic brake system.

Another object of present invention is to provide a valve for preventing unnecessary braking of the lifted wheels, thereby reducing energy consumption of an air compressor connected with a pneumatic brake system of the lifted wheel axle.

One more object of the present invention is to provide a valve for preventing unnecessary braking of the lifted wheels, which can be retrofitted to a pneumatic braking system of the lifted axle.

One more object of the present invention is to provide a valve for preventing unnecessary braking of the lifted wheels, thereby increasing life of braking elements such as brake pads, brake liners, brake drums and the like.

Further object of the present invention is to provide a valve for preventing unnecessary braking of the lifted wheels, which is simple in construction and economical in operation.

SUMMARY OF THE INVENTION:
According to present invention a valve for regulating supply of pressurized air to a pneumatic braking system of the lifted wheels is provided. A pneumatic system is connected with the pneumatic braking system for supplying pressurized air to the pneumatic braking system to operate the pneumatic braking system. The pneumatic system having an air compressor for supplying pressurized air to the pneumatic braking system. The valve closes the supply of the pressurized air to the pneumatic braking system when the wheels are in a lifted condition and allows flow of the pressurized air to the braking system when the wheels are in a deployed condition. The valve includes a first port, a second port, a third port and a diaphragm. The first port receives pressurized air from the pneumatic system. The second port supplies pressurized air received from the first port to the pneumatic braking system.
The third port receives air from a lift bellow. The lift bellow is provided for lifting a lift axle by filling pressurized air therein. The pressurized air is released from the lift bellow for deploying the wheels on the ground. The diaphragm closes the second port when pressure of received air from the third port is less than pressure of air from the first port, thereby preventing operation of the pneumatic braking system. The diaphragm opens the second port when the pressure of air from the first port is more than pressure of air from the third port, thereby allowing the operation of the pneumatic braking system. The pressure of air from the first port is more than the pressure of air from the third port when the wheels are in the deployed condition. The pressure of air from the third port is more than pressure of air from the first port when the wheels are in the lifted condition.

BRIEF DESCRIPTION OF THE DRAWINGS:
The advantages and features of the present invention will be understood better with reference to the following detailed description and claims taken in conjunction with the accompanying drawings, wherein like elements are identified with like symbols, and in which:
The disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms.
Figure 1 shows a sectional view of a valve for regulating supply of pressurized air to a pneumatic braking system of lifted wheels in accordance with present invention ; and
Figure 2 shows an enlarged view of the valve shown in the figure 1.

DETAILED DESCRIPTION OF THE INVENTION

For thorough understanding of the present invention, reference is to be made to the following detailed description in connection with the above-described drawings. Although the present invention is described in connection with exemplary embodiments, the present invention is not intended to be limited to the specific forms set forth herein. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention. As used throughout this disclosure, the singular forms “a,” “an,” and “the” may include plural reference unless the context clearly dictates otherwise.

The present invention provides a pneumatic braking system having a valve for preventing unnecessary braking of lifted wheels, thereby reducing air consumption by the pneumatic brake system. Also, the valve reduces energy consumption of an air compressor connected with the pneumatic brake system of lifted wheel axle. Further, the valve can be retrofitted to the pneumatic braking system of a lifted axle. Furthermore, the valve increases the life of braking elements such as brake pads, brake liners, brake drums by reducing unnecessary operation of the braking elements of the pneumatic brake system. Also, the valve is simple in construction and economical in operation.

Referring now to figure 1, a sectional view of a braking system for wheels having a valve 100 for regulating supply of pressurized air to the pneumatic braking system 200 of lifted wheels (not shown) in accordance with present invention is illustrated. The braking system includes a pneumatic system for supplying pressurized air for operating a pneumatic braking system 200. The pneumatic braking system 200 is having a brake chamber 204 for actuating braking action on wheels. The brake chamber 204 is attached to a static element such as an axle, a frame (not shown) and the like which is near to the wheels. The brake chamber 204 includes a plunger 210, a plunger spring 230, a plunger diaphragm 220, an inlet port 250, a casing 280 and an attaching member 270. The plunger 210 is connected to the plunger spring 230 and the plunger diaphragm 220. When pressurized air acts on the plunger diaphragm 220, the plunger 210 moves axially forward from a rest position 222. When the pressurized air is released from the brake chamber 204, the plunger diaphragm 220 retracts to the rest position 222 and the plunger 210 moves backward under force of the plunger spring 230.

Further, a distal end 210a of the plunger 210 can be connected to braking elements (not shown), which are capable of applying braking force on a wheel or an axle. The braking elements can be a brake drum, a brake pad, a disc brake or any other braking elements capable to apply brake force on wheels which is obvious to person ordinarily skilled in the art. The plunger 210, the plunger spring 230 and the plunger diaphragm 220 are assembled inside the casing 280. The casing 280 can be attached to the axle or any static element of the wheels of vehicles through an attaching member 270. The attaching member 270 can be a fastener, a rivet, a weld or any other attaching element which is obvious to ordinarily person skilled in the art. The pressurized air enters to the brake chamber 204 through the inlet port 250. A pneumatic system(not shown) is provided for supplying pressurized air for operating the pneumatic braking system 200.The pneumatic system includes an air compressor ( not shown) for supplying pressurized air to the pneumatic braking system 200.

Referring now to figure 2, an enlarged view of the valve 100 connected with the pneumatic braking system 200 for the lifted wheels in accordance with the present invention is illustrated.

The valve 100 is provided for regulating supply of pressurized air to the pneumatic braking system 200 from the pneumatic system. The valve 100 closes the supply of the pressurized air to the pneumatic braking system 200 when the wheels are in a lifted condition and allows flow of the pressurized air to the pneumatic braking system 200 when the wheels are in a deployed condition.

The valve 100 includes a first member 10, a second member 20, a first port 30, a second port 40, a third port 50 and a diaphragm 60. In the present embodiment, the first port 30 is configured in the first member 10. The first port 30 receives pressurized air from the pneumatic system. The first port 30 can be a cylindrical conduit or a passage with any obvious shape of cross section which is obvious to person ordinarily skilled in the art. The first port 30 receives pressurized air from a foot brake valve (not shown). The foot brake valve releases pressurized air from pneumatic system when a brake is applied on a brake pedal (not shown).

The second port 40 is coaxially connected with the inlet port 250 of the brake chamber 204. The second port 40 can be a cylindrical conduit or a passage with any obvious shape of cross section which is obvious to person ordinarily skilled in the art. The first member 10 is connected to the brake chamber 204. The second port 40 and the inlet port 250 of the brake chamber 204 are connected to allow passage of air there through. The second port 40 supplies pressurized air received from the first port 30 to the pneumatic braking system 200.

The third port 50 is configured in the second member 20. The second member 20 is secured to the first member 10. In an alternative embodiment, the first member 10 and the second member 20 can be integral. The third port 50 receives air from a lift bellow (not shown).The lift bellow is provided for lifting a lift axle (not shown) by filling pressurized air therein. The pressurized air is released from the lift bellow for deploying the wheels on the ground. The diaphragm 60 is secured to the second member 20. The diaphragm 60 can be made of elastic elements such as rubber, neoprene, LDPE (low density poly-ethene) and the like. The diaphragm 60 is arranged to move inside a cavity 29 based on a pressure difference created in a first section 12 and in a second section 22.

The diaphragm 60 closes the second port 40 when pressure of received air from the third port 50 is more than pressure of air from the first port 30, thereby preventing operation of the pneumatic braking system 200. The pressure of air from the third port 50 is more than pressure of air from the first port 30 when the wheels are in the lifted condition.

Further, the diaphragm 60 opens the second port 40 when the pressure of air from the first port 30 is more than pressure of air from the third port 50, thereby enabling the operation of the pneumatic braking system 200. The pressure of air from the first port 30 is more than the pressure of air from the third port 50 when the wheels are in the deployed condition.

When the wheels connected with the lift axle are in the deployed condition (resting on ground), the air from the lift bellow is released thereby reducing the pressure from the third port 50. When a vehicle is in motion, the wheels of the lift axle are rotating. If brake is applied through the brake pedal, the foot valve releases pressurized air from the pneumatic system. The pressurized air from the pneumatic system enters to the cavity 29 of the valve 100 through the first port 30. As the pressure of air from the first port 30 is more than the pressure of air from the third port 50, the diaphragm 60 moves towards the second section 22 thereby opening the second port 40. The pressure of air passes to the brake chamber 204 through the inlet port 250 for operating the pneumatic braking system 200. The pneumatic braking system 200 operates to apply brake force to the rotating wheels through braking elements such as brake pads, brake bands and the like, thereby obtaining braking action on the wheels.

When the wheels connected with the lift axle are in the lifted condition, the wheels are in static condition (not rotating) and the lift bellow is (are) filled with pressurized air. As the lift bellow is connected to the third port 50, the third port 50 receives pressurized air from the lift bellow. When the brake is applied, the foot valve releases pressurized air from the pneumatic system. The pressurized air enters to the cavity 29 through the first port 30. When the wheels are in lifted condition, pressure of air in the lift bellow will be more than the pressure of air from the pneumatic system. It may be obvious knowledge to person ordinarily skilled in art to configure elements (lift bellow and related connections) for developing comparatively more pressure in the lift bellow than the pressure of air from the pneumatic system. Hence, the pressure from the third port 50 will be more than the pressure of air from the first port 30. Hence, the diaphragm 60 moves towards first section 12 and closes the second port 40. As the diaphragm 60 closes the second port 40, the pressurized air from the first port 30 could not able to enter the brake chamber 204. Hence, the operation of the pneumatic braking system 200 is prevented.

The valve 100 of the pneumatic braking system 200 for lifted wheels prevents the unnecessary braking of the lifted wheels. As the pressurized air not wasted for unnecessary braking of the lifted wheels, air consumption by the pneumatic braking system 200 is reduced. Further, the valve 100 reduces energy consumption of the air compressor connected with the pneumatic braking system 200 by reducing the air consumption of the pneumatic braking system 200. Furthermore, the valve 100 can be retrofitted to the pneumatic braking system 200 of the lifted axle. The valve 100 increases life of braking elements such as brake pads, brake liners, brake drums and the like by preventing unnecessary operation of the pneumatic braking system 200. Further the valve 100 includes simple mechanical elements such as the diaphragm 60, the first member 10 and the second member 20 with the first port 30, the second port 40 and the third port 50 configured therein, made the valve 100 simple in construction. The valve 100 does not require any external energy source such as electric power or hydraulic power for its operation. Hence, the valve 100 is economical in operation.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.
,CLAIMS:We Claim:
1. A braking system of wheels comprising:
a pneumatic system for supplying pressurized air for operating a pneumatic braking system,
wherein a valve is provided for regulating supply of pressurized air to the pneumatic braking system from the pneumatic system, the valve closes the supply of the pressurized air to the pneumatic braking system when the wheels are in a lifted condition and allows flow of the pressurized air to the pneumatic braking system when the wheels are in a deployed condition.

2. The braking system as claimed in claim 1, wherein the valve comprises:
a first port for receiving pressurized air from the pneumatic system;
a second port for supplying pressurized air received from the first port to the pneumatic braking system;
a third port receiving air from a lift bellow, the lift below is provided for lifting a lift axle by filling pressurized air therein; and
a diaphragm for closing the second port when pressure of received air from the third port is more than pressure of air from the first port, thereby preventing operation of the pneumatic braking system; and opening the second port when the pressure of air from the first port is more than pressure of air from the third port, thereby enabling the operation of the pneumatic braking system.

3. The braking system as claimed in claim 1, wherein the pneumatic system having an air compressor for supplying pressurized air to the pneumatic braking system.

4. The braking system as claimed in claim 2, wherein the pressurized air is released from the lift bellow for deploying the wheels on the ground.

5. The braking system as claimed in claim 2, wherein the pressure of air from the first port is more than the pressure of air from the third port when the wheels are in the deployed condition.

6. The braking system as claimed in claim 2, wherein the pressure of air from the third port is more than pressure of air from the first port when the wheels are in the lifted condition.