LOAD ADJUSTABLE PARALLEL PROPORTIONING VALVE IN DUAL BRAKING SYSTEM
FIELD OF INVENTION:
[001] The present subject matter described herein, relates to a parallel proportioning valve in dual braking system in a vehicle, and, in particular, to a 5 load adjustable parallel proportioning valve in dual braking system. More specifically, the load adjustment is achieved by integration of magnetic coil in spring receiving plate to modify the proportioning performance based on number of passenger, such as 1, 2, 3, 4 in vehicle for Parallel Proportioning Valve in Dual braking System. 10
BACKGROUND AND PRIOR ART:
[002] US patent US 4203627A discloses a parallel proportioning valve in which both of the proportioning valve assemblies have substantially the same cut-in point of pressure reducing action by absorbing the stroke difference of strokes between the pressure responsive plungers. Further, US patent discloses a parallel 15 proportioning valve which is adapted so that the cut-in point of pressure reducing action increases in one of the valve assemblies when the other valve assembly is not operating due to a breakdown.
[003] Figure. 1 illustrates longitudinally sectioned view showing a parallel proportioning valve of the US patent 4203627A. Referring now to Figure. 1, a 20 casing designated by 10 has fluid chambers 11 and 11' which are parallel to each other. The fluid chambers 11 and 11' have inlets 12 and 12' connected to a pressure source (not shown) such as a tandem master cylinder, and outlets 13 and 13' for transmitting a proportionally reduced pressure to for example, two rear brake cylinders respectively. 25
[004] In the fluid chambers 11 and 11' are incorporated valve assemblies 20 and 20' respectively. The valve assembly 20 is composed of a pressure responsive plunger 21, a valve seat 22 which is opened and closed by the plunger 21, and a plunger guide 24 which pilots a shaft 23 of the plunger. A cut type seal 25 and O-
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ring 26 have the plunger guide 24 fitted therein to provide a liquid-tight seal of the chamber 11.
[005] A washer 27 is fitted in the inner end of the guide 24 to prevent the removal of the cup type seal 25. The other valve assembly 20' constructed exactly the same. The corresponding parts having the same numbers with a prime. 5
[006] The ends of the plungers 21 and 21' are rounded or conically shaped as shown at 28 and 28' and project slightly out of the guides 24 and 24' and pivotally engage recesses 29 and 29' of an abutting plate 30, respectively. A spherical or conically shaped recess 31 is provided on the center of the abutting plate 30, and pivotally engages a projection 32 which is provided on the center of a spring 10 receiving plate 33 which receives a spring 34 mounted between the plate 33 and a cup-shaped cap 35 which closes the end face of the casing 10. The pivotal engagement of the receiving plate 33 and the abutting plate 30 makes possible the equal transmission of the force of the spring 34 to both plungers 21 and 21' since the center of the load of the spring 34 will be kept centered at the abutting portion 15 regardless of the inclination of the abutting plate 30.
[007] At the center of the abutting plate 30 is fixed a pin 36 which is inserted in a hole 37 which is provided in the casing 10 at the center between the chambers 11 and 11'. The pin 36 has an annular notch 38 about the periphery and adjacent to the base portion thereof to form a shoulder 39 which is substantially square to the 20 outer periphery of the pin. Between the pin 36 and the hole 37 is provided a clearance which will be explained hereinafter.
[008] In operation of the parallel proportioning valve of the invention, when the inlet 12 of the chamber 11 has a fluid pressure applied from a pressure source under normal operating conditions wherein both parts of the dual braking system 25 is working, the fluid pressure acts on the effective area corresponding to the sectional area of the shaft 23 of the plunger 21 within the chamber 11 to force the plunger in a leftward direction. However, since the pressure of the spring 34 overcomes the leftwardly biasing force of the fluid on the plunger and the valve
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seat 22 remains open thus permitting the direct release the fluid pressure at the outlet 13.
[009] When the fluid pressure is further increased so that the leftwardly biasing force on the plunger 21 finally overcomes the force of the spring 34, then the plunger 21 is moved in the leftward direction to close the valve seat 22. At that 5 point, a proportionately reduced pressure is transmitted by the vibration of the plunger 21 through the outlet 13. When the fluid pressure is further increased so that the leftwardly biasing force on the plunger 21 finally overcomes the force of the spring 34, then the plunger 21 is moved in the leftward direction to close the valve seat 22. At that point, a proportionately reduced pressure is transmitted by 10 the vibration of the plunger 21 through the outlet 13. The other proportioning valve assembly 20' operates in the same manner as the assembly 20.
[0010] Above described US patent has fixed cutoff point value for the current parallel proportioning valve. In this invention, fixed cutoff value of the valve is decided after multiple level of testing to avoid rear wheel lock even in one (1) 15 passenger load condition. This fixing cutoff value or fixing of cutoff point in one passenger condition leads to underutilization of rear brakes when more than 1 passengers are sitting in the vehicle.
[0011] Figure 2 illustrates the performance graph for the US patent 4203627. In the present graph, a cutoff point 202 is fixed in the load adjustable parallel 20 proportioning valve. The load adjustable parallel proportioning valve is ineffective under more than 1 passengers sitting in the vehicle.
[0012] This known system does not provide effective braking of both front and rear brakes when more than one passenger is sitting in the vehicle. Further, there is more wear and tear in the front brake system due to less use of rear brake 25 system. The front brake system has high load of braking as compare to rear brake system. Therefore, un-even distribution of the brake forces creates in-stability in the vehicle. The other existing known systems are costly and have multiple parts which make the structure complex and heavy. Therefore, a simple and inexpensive load adjustable parallel proportioning valve in dual braking system is 30
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required which can effectively provide effective braking when more than one passenger are sitting in the vehicle.
OBJECTS OF THE INVENTION:
[0013] The principal objective of the present invention is to provide effective braking when more than one passenger is sitting in a vehicle. 5
[0014] Another object of the present subject matter is to provide a simple spring receiving plate integrated with the magnetic coil to change the force required for compression of the spring.
[0015] Yet another object of the present invention is to provide a magnetic coil integrated spring receiving plate which adjusts the cutoff point based on the 10 number of passenger in the vehicle.
SUMMARY OF THE INVENTION:
[0016] The present subject matter disclosed herein relates to a load adjustable parallel proportioning valve in dual braking system in vehicle. The present load adjustable parallel proportioning valve has a spring receiving plate which is 15 integrated with a magnetic coil. Further, the magnetic coil integrated spring receiving plate adjusts the magnetic field around the spring receiving plate based on the number of passengers in the vehicle. Based on the number of passengers, current flow in the magnetic coil is increased which directly increases the magnetic field of the spring receiving plate. Due to change in magnetic force, 20 force required for spring compression changes thus changing the cutoff point in the load adjustable parallel proportioning valve in dual braking system.
[0017] In order to further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative 25 only but not used to limit scope of the present subject matter.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0018] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the 5 accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods in accordance with embodiments of the present subject matter are now described, by way of example, 10 and with reference to the accompanying figures, in which:
[0019] Figure. 1 illustrates longitudinally sectioned view showing a parallel proportioning valve of the US patent 4203627A;
[0020] Figure. 2 illustrates a graph showing fixing of cutoff point for the brakes as known in the art, i.e., US patent 4203627A; 15
[0021] Figure. 3 illustrates the spring and magnetic coil integrated spring receiving plate in the Parallel Proportioning Valve in Dual braking System, in accordance with an embodiment of the present subject matter;
[0022] Figure. 4 illustrates integration of magnetic coil in spring receiving plate to modify the proportioning performance based on number of passenger, such as 1, 20 2, 3, 4 in vehicle for Parallel Proportioning Valve in Dual braking System, in accordance with an embodiment of the present subject matter; and
[0023] Figure. 5 illustrates a graph showing multiple cutoff fixing points based on the number of passengers in the vehicle due to integration of the magnetic coil in the spring sheet. 25
[0024] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and
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methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0025] The subject matter disclosed herein relates to a load adjustable parallel proportioning valve in dual braking system in vehicle. The present load adjustable 5 parallel proportioning valve has a spring receiving plate which is integrated with a magnetic coil. In the present magnetic coil integrated spring receiving plate cut-off point can be adjusted based on the number of passengers. In the present load adjustable parallel proportioning valve in dual braking system, by changing the amount of current passing through magnetic coil integrated in spring receiving 10 plate, magnetic force exerted on the spring changes. Due to change in magnetic force, force required for spring compression changes thus changing the cutoff point. Amount of current passing through magnetic coil can be adjusted by selection knob switch provided in cabin of the vehicle. A knob switch is provided in the cabin of the vehicle which can be adjusted by driver of the vehicle based on 15 number of passenger sitting in the vehicle. Based on the adjustment of the knob switch by the driver, a specified current passes through the magnetic coil surrounds the spring receiving plate. Based on the passed current in the magnetic coil of the spring receiving plate, magnetic forces change accordingly. Therefore, based on the number of passengers in the vehicle, current flow in the magnetic 20 coil of the spring receiving plate can be adjusted to achieve the better braking effects.
[0026] Conventionally, a fixed cutoff point value for the load adjustable parallel proportioning valve in dual braking system. Due to the fixing cutoff value or fixing of cutoff point in one passenger condition, underutilization of rear brakes 25 appears when more than one passenger are sitting in the vehicle.
[0027] According to present subject matter, spring receiving plate is integrated with a magnetic coil which adjusts the magnetic field of the spring receiving plate based on the number of passengers in the vehicle. A knob switch is provided in the cabin of the vehicle which can be adjusted by driver of the vehicle based on 30
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number of passenger sitting in the vehicle. Based on the number of passengers, current flow in the magnetic coil is increased which directly increases the magnetic field of the spring receiving plate. Due to change in magnetic force, force required for spring compression changes thus changing the cutoff point in the load adjustable parallel proportioning valve in dual braking system. 5
[0028] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those 10 skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the 15 concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the 20 following description when considered in connection with the accompanying figures.
[0029] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject 25 matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0030] Figure. 3 illustrates the spring and magnetic coil integrated spring receiving plate in the Parallel Proportioning Valve in Dual braking System, in 30
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accordance with an embodiment of the present subject matter. Figure 3 illustrates the upper portion 300 of the load adjustable parallel proportioning valve in which spring 302 and spring receiving plate 304 is illustrated. The spring 302 is the similar to the spring 34 as illustrated in the figure 1. Similarly the spring receiving plate 304 is same as the spring receiving plate 33 of the figure 1. For clarity in the 5 present invention, the spring 302 and the spring receiving plate 304 is arranged in the same manner as arranged in the figure 1. Therefore, in order to avoid the confusion, explanation of the spring 302 and the spring receiving plate 304 is not described here.
[0031] Figure. 4 illustrates integration of magnetic coil in spring receiving plate to 10 modify the proportioning performance based on number of passenger, such as 1, 2, 3, 4 in vehicle for Parallel Proportioning Valve in Dual braking System, in accordance with an embodiment of the present subject matter. In the present subject matter, the spring receiving plate 304 is integrated with a magnetic coil 304a. Further, the magnetic coil 304a is an electromagnetic coil which is an 15 electrical conductor, such as a wire in the shape of a coil, spiral or helix. When an electric current is passed through the wire of the electromagnetic coil 304a, a magnetic field is generated in the magnetic coil 304a. A current passing through the magnetic coil 304a creates a circular magnetic field around the magnetic coil 304a conductor due to Ampere's law. The advantage of using the coil shape is that 20 it increases the strength of magnetic field produced by a given current. The magnetic fields generated by the separate turns of wire all pass through the center of the coil and add to produce a strong field there. The more turns of wire, the stronger the field produced. Therefore, a magnetic coil is used in the present invention to produce strong magnetic field in reference to current. 25
[0032] The present spring receiving plate 304 is similar to the spring receiving plate 33 of the figure 1. The present spring receiving plate 304 is integrated with a magnetic coil 304a. Due to integration of the magnetic coil 304a on the spring receiving plate 304, cutoff point for the braking can be adjusted based on number of passengers in the vehicle. By changing the amount of current passing through 30
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magnetic coil 304a integrated spring receiving plate 304, magnetic force exerted on the spring 302 can be changed. Due to change in magnetic force, force required for spring 302 compression will change hence cutoff point will change with respect to the current flow. Further, a knob switch is provided in the cabin of the vehicle which can be adjusted by driver of the vehicle based on number of 5 passenger sitting in the vehicle. Based on the adjustment or selection of the knob switch by the driver, a specified current passes through the magnetic coil which surrounds the spring receiving plate 304. Based on the passed current in the magnetic coil 304a on the spring receiving plate 304, magnetic force changes accordingly. Therefore, based on the number of passengers in the vehicle, current 10 flow in the magnetic coil of the spring receiving plate can be adjusted to achieve the better braking effects.
[0033] Magnetic force:
Magnetic force (Fm) generated by the Coil is Fm ∝ I*L where (I = current, L = length of coil) 15
[0034] Total force required to change compress spring (34) = K*x+ Fm where Fm is the magnetic force and K is the spring constant & x is the displacement of the spring. Hence force (Fd) required for spring displacement in normal condition without current Fd = K*x.
[0035] Figure. 5 illustrates a graph showing multiple cutoff fixing points based on 20 the number of passengers in the vehicle due to integration of the magnetic coil in the spring receiving plate. The graph 500 illustrates the cut-off points for the number of person sitting in the vehicle. In the present graph 500, cut-off point 502 illustrates the point for one passenger sitting in the vehicle. Further, 504 illustrate a cut-off point when two passengers are sitting in the vehicle. The cut-off point 25 increases due to increase in the current in the magnetic coil 304a in the spring receiving plate 304. When two passengers are sitting in the vehicle, the driver selects the knob switch for two passengers which allow the passage of current in the magnetic coil of the spring receiving plate corresponding to two passengers. Accordingly, the current flows in the magnetic coil which increases the magnetic 30
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field in the spring receiving plate and spring. Due to change in magnetic force, force required for the spring 302 compression changes hence cut-off point changes with respect to the current flow in the magnetic coil. Similarly point 506 illustrates the cut-off point when 3 or more than three passengers are sitting in the vehicle. 5
[0036] The present magnetic coil integrated spring receiving plate provides different cut-off points based on the number of passengers in the vehicle. The present subject matter increases the optimize utilization of the brake force on the real wheel of the vehicle. Further, the present subject matter decreases the wear and tear of the front brake due to optimum usage of the rear brake in the rear 10 wheel of the vehicle. Upon proper balancing of dual brake system in the vehicle, braking force distribution improved and vehicle stability is also improved.
[0037] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, 15 the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.

We claim:
1. A load adjustable parallel proportioning valve (300) in dual braking system of a vehicle for proportioning performance of the dual braking system based on number of passengers in the vehicle, the load adjustable parallel proportioning valve (300) comprising: 5
a casing (10) having a pair of fluid chambers (11, 11’) each of said chambers having a fluid inlet (12, 12’) for connection to a pressure source;
a pair of plungers (21, 21’) of the pair of fluid chambers (11, 11’) are incorporated in a pair of assembly (20, 20’);
ends of the pair of plungers (21, 21’) are pivotally engaged with an 10 abutting plate (30);
characterized in that
a spring receiving plate (33, 304) provided on the abutting plate (30) to receive a spring (34, 302), wherein the spring receiving plate (304) is integrated with a magnetic coil (304a). 15
2. The load adjustable parallel proportioning valve (300) as claimed in claim 1, wherein the magnetic coil (304a) integrated spring receiving plate (304) receives the spring (302) mounted between the spring receiving plate (304) and a cup shaped cap (35). 20
3. The load adjustable parallel proportioning valve (300) as claimed in claim 1, wherein magnetic force in the magnetic coil (304a) integrated spring receiving plate (304) changes based on the amount of current passing through the magnetic coil (304a) integrated spring receiving plate (304). 25
4. The load adjustable parallel proportioning valve (300) as claimed in claim 1, wherein the load adjustable parallel proportioning valve (300) further comprising a knob switch in cabin of the vehicle which is adjusted to allow passage of a particular amount of current passing through the magnetic coil 30 (304a) integrated spring receiving plate (304).
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5. The load adjustable parallel proportioning valve (300) as claimed in claim 4, wherein the particular amount of current passing through the magnetic coil (304a) integrated spring receiving plate (304) is based on number of passengers in the vehicle.
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6. The load adjustable parallel proportioning valve (300) as claimed in claim 4, wherein the particular amount of current passing through the magnetic coil (304a) integrated spring receiving plate (304) is selected by selecting the knob switch in the cabin. 10
7. The load adjustable parallel proportioning valve (300) as claimed in claim 4, wherein the magnetic coil (304a) integrated spring receiving plate (304) changes force required for the spring (302) compression based on the knob selection.