Description:FIELD OF INVENTION

The present invention relates to a tractor trailer. In particular, the present invention relates to a tractor hauling a single/multi-axle trailer. More particularly, the present invention relates to an electro-hydraulic brake system for a single/multi-axle trailer hauled by a tractor.

BACKGROUND OF THE INVENTION

During the field and haulage operation of a single/multi-axle trailer hauled by a tractor, it is observed that during hauling of a trailer on an upslope or downslope, the tractor becomes unstable due to heavy pull/push forces generated by such trailer, which often leads to severe accidents as a result of the operator losing control of the tractor. In addition, while hauling the trailer on a downslope or a road, on suddenly applying the tractor brakes, the tractor tyres start skidding and the trailer pushes the tractor forward and a roll-over of the tractor and/or trailer may cause a serious accident, because generally, the trailer does not have a brake system of its own.

DESCRIPTION OF THE INVENTION

In accordance with the present invention, an electro-hydraulic brake-system is used on the trailer hauled by a tractor to avoid any accident during the haulage by the trailer over an upslope or downslope. This electro-hydraulic trailer-brake system is also operated by the tractor’s brake pedal.

Whenever the tractor and the trailer attached thereto are being stopped or required to reduce speeds on up/down slopes, the tractor operator can press the tractor’s brake pedal, and a displacement sensor placed on the opposite side of the brake-pedal measures the brake-pedal distance.
Based on the measured brake-pedal distance, the displacement sensor issues an input signal to the controller fitted below the trailer-body. Depending on this input signal, the controller supplies the necessary electric current to operate an electric motor with its pulley wound with a wire cable connected to a lever attached to the master cylinder for the operation thereof.

Once the motor-pulley starts rotating, this wire-cable is wound thereon (at the motor pulling-end) due to the other end of the wire-cable pulling the master cylinder lever toward the direction of rotation of the electric motor. Due to the leverage between the cylinder rod at the first end of the master cylinder, the lever pushes the master cylinder rod to generate a hydraulic-pressure by a pipe connected to the wheel cylinder in the trailer’s brake-drums, whereby its brake-liners expand and the trailer brake is also applied simultaneously with tractor brakes to stop the tractor-trailer combination within a certain distance.

Accordingly, after the tractor operator releases the tractor’s brake-pedal, an ultrasonic/displacement sensor senses and measures the brake-pedal distance and issues a signal to the controller for changing the polarity of the motor, whereupon the electric motor starts rotating in a reversed direction. This causes the master-cylinder to release the braking force on the brake-liners and wheel-cylinder releases the brake-drum to stop the braking action.

For the safety of the electric motor, a respective limit-switch is provided at either ends of the master-cylinder lever (for fully-braked and brake-released conditions) whenever this lever reaches the maximum position thereof.

Based on the signal issued by these limit-switches, the electric motor starts or stops rotating, and the trailer braking action starts or stops without requiring any extra effort by the tractor-operator. The abovementioned electro-hydraulic brake-system is very easy to be installed on any trailer hauled by the tractors.

Such an electro-hydraulic trailer-brake system is fitted on the trailer for the first time and has proved to be very effective during numerous field-trials conducted by the inventors and overcome the disadvantages associated with the conventional tractor brake system discussed in the background section.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:

An object of the present invention is to provide an electro-hydraulic brake system for single/multi-axle trailer hauled/pushed by the tractor over steep gradients.

Another object of the present invention is to provide an electro-hydraulic brake system for single/multi-axle trailer hauled by the tractor to avoid accidents due to tractor’s instability over steep gradients.

Still another object of the present invention is to provide an electro-hydraulic brake system for single/multi-axle trailer hauled by the tractor to avoid accidents due to the slippage of the tractor or trailer tyres on sudden application of brakes .

Yet another object of the present invention is to provide an electro-hydraulic brake system for single/multi-axle trailer hauled by the tractor to avoid accidents due to the tractor and/or trailer roll-over when the operator loses control over it.
These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.

SUMMARY OF INVENTION

In embodiment of the present invention, there is provided an electro-hydraulic brake system for single/multi-axle trailer hauled by tractor, the electro-hydraulic brake system comprises:

• a tractor brake-pedal operating both tractor and trailer brakes;

• an electrical system for sensing and measuring the distance of the brake-pedal and issuing a corresponding signal for supplying electric supply to an electric motor fitted with a pulley for winding/unwinding a wire cable thereon; and

• a hydraulic system for applying or releasing hydraulic pressure on the trailer brakes;

wherein depending on the measured distance of the brake-pedal, the electrical system applies or releases the trailer brakes to control the stop or start operation of the trailer hauling heavy loads on upslopes or downslopes during sudden brake application/release by pressing or releasing the tractor’s brake pedal .

Typically, the electrical system comprises:

• a reversibly operable electric motor, the electric motor mounted with a pulley for winding a wire cable thereon or unwinding a wire cable therefrom;
• an ultrasonic sensor configured as a displacement sensor and fitted opposite the brake-pedal to sense and measure the distance of the brake-pedal and to issue an input signal to a controller fitted below trailer body;

• the controller configured to receive the input signal and supply a corresponding electrical current to the electric motor; and

• the sensor connected to a respective limit switch to issue a corresponding signal to the electric motor when the lever reaches the maximum inward or outward position thereof;

wherein depending on the level reaching the maximum inward or outward position thereof, the controller issues a corresponding output signal to apply the trailer brakes for reducing speed or for stopping the trailer on upslopes or downslopes during sudden brake application or to release the trailer brakes for moving the trailer on upslopes or downslopes by releasing the tractor’s brake pedal.

Typically, the hydraulic system comprises:

• an oil-tank having at least two apertures for facilitating oil-flow therein/therefrom;

• a master cylinder hydraulically connected to the oil-tank via the apertures;

• a connecting rod attached to the piston and passing through the first end of the master cylinder, the connecting rod connected to a lever of the brake pedal;

• a pipeline connected at the other end of the master cylinder for a connection to wheel-cylinders of the trailer-brakes;

• the wheel cylinder connected to the first ends of a respective brake-shoe fitted with a respective brake-liner and hinged together at the other end thereof and disposed within the brake drum of the trailer brake; and

• the brake-shoes are connected to each other by means of a pair of compression springs for keeping them apart in normal condition thereof;

wherein an outward movement of the lever moves the piston forward for generating a hydraulic pressure in the wheel-cylinder for applying a brake force corresponding to the brake-pedal distance sensed and measured by the ultrasonic sensor fitted under the trailer body.

Typically, an inward movement of the lever moves the piston rearward for releasing the hydraulic pressure applied on the wheel-cylinder for relieving the brake force corresponding to the brake-pedal distance sensed and measured by the ultrasonic sensor fitted under the trailer body.

Typically, the ultrasonic sensor issues a corresponding signal to the controller for changing the polarity of the electric motor to be rotated in reversed direction for releasing the wire cable from the pulley.

Typically, the electrical system comprises:

- a diode connected to the controller via a transistor for stepping down the electrical supply 12V voltage to 5V circuit voltage;

- a diode connected to the controller to issue - depending on the distance of the brake-pedal sensed and measured by the ultrasonic sensor - via a transistor for supplying signal/voltage to relay to operate the electrical motor in forward direction;

- a diode connected to the controller to issue - depending on the distance of the brake-pedal sensed and measured by the ultrasonic sensor - via a transistor, to supply signal/voltage to relay to operate the electrical motor in reversed direction;

- a diode connected to the controller via a transistor for supplying signal/voltage to a relay to operate the electrical motor in a forward direction;

- a first limit switch connected between the ultrasonic sensor and the controller; and

- a second limit switch connected between the ultrasonic sensor and the controller;

wherein the first limit switch is actuated to issue a corresponding signal to the electric motor when the lever reaches the maximum inward position thereof and to stop applying the brake force on the brake-pedal; or the second limit switch is actuated to issue a corresponding signal to the electric motor to rotate in a reversed direction, when the lever reaches the maximum outward position thereof and thereby to start applying the brake force on brake-pedal.

In another embodiment of the present invention, the electro-hydraulic brake system comprises:

- an ultrasonic sensor configured as a displacement sensor and fitted opposite the brake-pedal to sense and measure the distance of the brake-pedal and to issue an input signal to a controller fitted below the trailer body;

- the electric motor configured as a reversibly operable electric motor fitted with a pulley for winding/unwinding a wire cable thereon;

- the controller configured to receive the input signal and supply a corresponding electrical current to the electric motor;

- a diode connected to the controller via a transistor for stepping down the electrical supply 12V voltage to 5V circuit voltage;

- a diode connected to the controller to issue - depending on the distance of the brake-pedal sensed and measured by the ultrasonic sensor - via a transistor for supplying signal/voltage to relay to operate the electrical motor in forward direction;

- a diode connected to the controller to issue - depending on the distance of the brake-pedal sensed and measured by the ultrasonic sensor - via a transistor, to supply signal/voltage to relay to operate the electrical motor in reversed direction;

- a first limit switch connected between the ultrasonic sensor and the controller; and

- a second limit switch connected between the ultrasonic sensor and the controller;

wherein the first limit switch is actuated to issue a corresponding signal to the electric motor when the lever reaches the maximum inward position thereof and to stop applying the brake force on the brake-pedal; or the second limit switch is actuated to issue a corresponding signal to the electric motor to rotate in a reversed direction, when the lever reaches the maximum outward position thereof and thereby to start applying the brake force on brake-pedal.

Typically, the electro-hydraulic brake system further comprises:

• an oil-tank having at least two apertures for facilitating oil-flow therein/therefrom;
• a master cylinder hydraulically connected to the oil-tank via the apertures;

• a connecting rod attached to the piston and passing through the first end of the master cylinder, the connecting rod connected to a lever of the brake pedal;

• a pipeline connected at the other end of the master cylinder for a connection to wheel-cylinders of the trailer-brakes;

• the wheel cylinder connected to the first ends of a respective brake-shoe fitted with a respective brake-liner and hinged together at the other end thereof and disposed within the brake drum of the trailer brake; and

• the brake-shoes are connected to each other by a pair of compression springs to keep them apart in normal condition thereof;

wherein an outward movement of the lever moves the piston forward for generating a hydraulic pressure in the wheel-cylinder for applying a brake force corresponding to the brake-pedal distance sensed and measured by the ultrasonic sensor fitted under the trailer body.

In yet another embodiment of the present invention, the electro-hydraulic brake system comprises:

• an oil-tank having at least two apertures for facilitating oil-flow therein/therefrom;

• a master cylinder hydraulically connected to the oil-tank via the apertures;

• a connecting rod attached to the piston and passing through the first end of the master cylinder, the connecting rod connected to a lever of the brake pedal;

• a pipeline connected at the other end of the master cylinder for a connection to wheel-cylinders of the trailer-brakes;

• the wheel cylinder connected to the first ends of a respective brake-shoe fitted with a respective brake-liner and hinged together at the other end thereof and disposed within the brake drum of the trailer brake; and

• the brake-shoes are connected to each other by means of a pair of compression springs for keeping them apart in normal condition thereof;

wherein an outward movement of the lever moves the piston forward for generating a hydraulic pressure in the wheel-cylinder for applying a brake force corresponding to the brake-pedal distance sensed and measured by the ultrasonic sensor fitted under the trailer body.

Typically the electro-hydraulic brake system further comprises:

- a diode connected to the controller via a transistor for stepping down the electrical supply 12V voltage to 5V circuit voltage;

- a diode connected to the controller to issue - depending on the distance of the brake-pedal sensed and measured by the ultrasonic sensor - via a transistor for supplying signal/voltage to relay to operate the electrical motor in forward direction;

- a diode connected to the controller to issue - depending on the distance of the brake-pedal sensed and measured by the ultrasonic sensor - via a transistor, to supply signal/voltage to relay to operate the electrical motor in reversed direction;

- a diode connected to the controller via a transistor for supplying signal/voltage to a relay to operate the electrical motor in a forward direction;
- a first limit switch connected between the ultrasonic sensor and the controller; and

- a second limit switch connected between the ultrasonic sensor and the controller;

wherein the first limit switch is actuated to issue a corresponding signal to the electric motor when the lever reaches the maximum inward position thereof and to stop applying the brake force on the brake-pedal; or the second limit switch is actuated to issue a corresponding signal to the electric motor to rotate in a reversed direction, when the lever reaches the maximum outward position thereof and thereby to start applying the brake force on the brake-pedal.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described in the following with reference to the accompanying drawings.

Figure 1 shows an electric circuit diagram of the electro-hydraulic brake system for single/multi-axle tractor trailer.

Figure 2 shows a schematic arrangement of the electro-hydraulic brake system for single/multi-axle tractor trailer operated by the electrical circuit of Figure 1.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, an electro-hydraulic brake system for a single/multi-axle tractor trailer hauled by tractor and configured in accordance with the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention.
Figure 1 shows an electric circuit diagram of the electro-hydraulic brake system for single/multi-axle tractor trailer. The circuit includes diodes D1, D2, D3; electric motor M; relays RL-1, RL-2, resistances R1, R2, R3; transistors T1, T2, T3; limit switches LS1, LS2; wire cable WC connected to electric motor M operating the tractor’s brake pedal BP; and an ultrasonic sensor US placed opposite tractor brake pedal BP to measure the brake-pedal distance and issue signal to controller C fitted below the trailer-body. Based on this signal, controller C supplies electricity to rotate the electric motor M with its pulley connected to master cylinder C1 operated on pressing a lever by wire cable WC. A respective limit switch LS1, LS2 is provided at either ends of master cylinder C1 for the safety of electric motor M, which actuates the brake pedal P on reaching said lever L reaching the maximum inward or outward position thereof. Here, the diode D1 is connected to a transistor T3 for providing an input voltage to the controller C. Diodes D2 and D3 respectively provide signal/voltage to the Relays RL-1, RL-2 for operating the electric motor M in Forward or Reverse direction as per the sensing and measurement of the brake-pedal distance by the ultrasonic/displacement sensor US and issuing of a signal to the controller C. The terminals L0-L3 on controller C, are provided to connect the wires for receiving the input signal from the sensor US, and from the limit switches LS1, LS2 and the terminals L4 and L5 are provided for sending the output signal to the electric motor M.

Figure 2 shows a schematic arrangement of the electro-hydraulic brake system for single/multi-axle trailer hauled by tractor and configured in accordance with the present invention. This electro-hydraulic brake system is operated by the electrical circuit of Figure 1. The wire cable WC is connected between electric motor M and lever L attached to the brake pedal BP, the operation of which by its leverage actuates the connecting rod CR of the master cylinder C1 hydraulically connected to the oil tank OT via an aperture A1 or A2 on each side of the piston P thereof. The outlet E of master cylinder C1 is connected via a pipeline PL to a wheel-cylinder C2, which actuates the brake shoes BS fitted with friction liners FL on the trailer’s brake drum BD. Once the electric motor M (Figure 1) starts rotating, the wire cable WC starts winding on the motor pulley (not shown) and master cylinder C1 is pushed towards the rotational direction of electric motor M. Due to the leverage, the lever L of the brake pedal BP pushes the connecting rod CR of the master cylinder C1 to create a hydraulic pressure therein (on the LHS in Figure 2) which is transferred through pipeline PL connected to the wheel-cylinder C2 and applied to the brake-drum BD. This pushes the friction liner FL against brake drum BD to apply brake on the trailer wheels and trailer (not shown) is stopped within a predefined distance. Whereas on releasing the tractor’s brake pedal BP, the ultrasonic sensor US senses the brake pedal BP distance again and issues another signal to controller C (Figure 1) for changing the polarity of electric motor M to reverse its rotational direction, whereby master cylinder C1 releases the braking force applied on friction liner FL to release the brakes on trailer wheels by the hydraulic pressure acting against springs S and wheel-cylinder C2 releases trailer’s brake-drums BD and oil returns via pipeline PL into the oil-tank OT.

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

The electro-hydraulic brake system for single/multi-axle trailer hauled by tractor configured in accordance with the present invention offers the following advantages:

• Electro-hydraulic braking system effectively applies brakes on the trailer hauled by tractor for the safety of the tractor operator and avoids accidents due to uncontrollable operating condition of tractor on up/down slopes.

• Overcomes the issues of vehicle control under speed as well as enhances the safety by effectively applying brakes on trailer itself.
• Electro-hydraulically controlled system requires no additional effort for pressing the brakes on the tractor.

• Controller senses the brake-pedal movement to issue a corresponding signal to the electric motor-pulley combination for reducing the trailer speed and precisely matching it with the tractor speed.

• The tractor and trailer brakes are applied gradually and synchronously to eliminate skidding of the tractor or undesirable pushing by the trailer.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments.

It is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation. The exemplary embodiments described in this specification are intended merely to provide an understanding of various manners in which this embodiment may be used and to further enable the skilled person in the relevant art to practice this invention.

Although, the embodiments presented in this disclosure have been described in terms of its preferred embodiments, the skilled person in the art would readily recognize that these embodiments can be applied with modifications possible within the spirit and scope of the present invention as described in this specification by making innumerable changes, variations, modifications, alterations and/or integrations in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies and assemblies, in terms of their size, shapes, orientations and interrelationships without departing from the scope and spirit of the present invention.

The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.

Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to imply including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention.

The description of the exemplary embodiments is intended to be read in conjunction with the accompanying drawings, which are to be considered part of the entire written description. In the description, relative terms such as “lower”, “upper”, “horizontal”, “vertical”, “above”, “below”, “up”, “down”, “top”, and “bottom” as well as derivatives thereof (e.g. “horizontally”, “inwardly”, “outwardly”; “downwardly”, “upwardly” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion.

These relative terms are for convenience of description and do not require that the corresponding apparatus or device be constructed or operated in a particular orientation.

Terms concerning attachments, coupling and the like, such as “connected” and “interconnected”, refer to a relationship, wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. , Claims:We claim:

1. An electro-hydraulic brake system for single/multi-axle trailer hauled by a tractor, said electro-hydraulic brake system comprises:

• a tractor brake-pedal (BP) operating both tractor and trailer brakes;

• an electrical system for sensing and measuring the distance of said brake-pedal (BP) and issuing a corresponding signal for supplying electric supply to an electric motor (M) fitted with a pulley for winding/unwinding a wire cable thereon; and

• a hydraulic system for applying or releasing hydraulic pressure on the trailer brakes;

wherein depending on the measured distance of the brake-pedal (BP), the electrical system applies or releases the trailer brakes to control the stop or start operation of the trailer hauling heavy loads on upslopes or downslopes during sudden brake application/release by pressing or releasing the tractor’s brake pedal (BP).

2. The electro-hydraulic brake system as claimed in claim 1, wherein said electrical system comprises:

- said electric motor is a reversibly operable electric motor (M) mounted with a pulley for winding a wire cable thereon or unwinding a wire cable therefrom;

- an ultrasonic sensor (US) configured as a displacement sensor and fitted opposite the brake-pedal (BP) to sense and measure the distance of said brake-pedal (BP) and to issue an input signal to a controller (C) fitted below the trailer body;

- said controller (C) configured to receive said input signal and supply a corresponding electrical current to said electric motor (M); and

- said sensor connected to a respective limit switch (LS1; LS2) to issue a corresponding signal to said electric motor (M) when said lever (L) reaches the maximum inward or outward position thereof;

wherein depending on said level (L) reaching the maximum inward or outward position thereof, said controller (C) issues a corresponding output signal to apply the trailer brakes for reducing speed or for stopping the trailer on upslopes or downslopes during sudden brake application or to release the trailer brakes for moving the trailer on upslopes or downslopes by releasing the tractor’s brake pedal (BP).

3. The electro-hydraulic brake system as claimed in claim 1, wherein said hydraulic system comprises:

• an oil-tank (OT) having at least two apertures (A1; A2) for facilitating oil-flow therein/therefrom;

• a master cylinder (C1) hydraulically connected to said oil-tank (OT) via said apertures (A1; A2);

• a connecting rod (CR) attached to the piston (P) and passing through the first end of said master cylinder (C1), said connecting rod (CR) connected to a lever (L) of said brake pedal (BP);

• a pipeline (PL) connected at the other end of said master cylinder (C1) for a connection to wheel-cylinders (C2) of the trailer-brakes;

• said wheel cylinder (C2) connected to the first ends of a respective brake-shoe (BS) fitted with a respective brake-liner (FL) and hinged together at the other end thereof and disposed within the brake drum (BD) of the trailer brake; and

• said brake-shoes (BS) are connected to each other by means of a pair of compression springs (S) for keeping them apart in normal condition thereof;

wherein an outward movement of said lever (L) moves said piston (P) forward for generating a hydraulic pressure in said wheel-cylinder (C2) for applying a brake force corresponding to the brake-pedal distance sensed and measured by said ultrasonic sensor fitted under the trailer body.

4. The electro-hydraulic brake system as claimed in claim 3, wherein an inward movement of said lever (L) moves said piston (P) rearward for releasing the hydraulic pressure applied on said wheel-cylinder (C2) for relieving the brake force corresponding to the brake-pedal distance sensed and measured by said ultrasonic sensor fitted under the trailer body.

5. The electro-hydraulic brake system as claimed in claim 4, wherein said ultrasonic sensor issues a corresponding signal to said controller for changing the polarity of said electric motor (M) to be rotated in reversed direction for releasing said wire cable (WC) from said pulley.

6. The electro-hydraulic brake system as claimed in claim 2, wherein said electrical system comprises:

- a diode (D1) connected to said controller (C) via a transistor (T3) for stepping down the electrical supply 12V voltage to 5V circuit voltage;

- a diode (D2) connected to said controller (C) to issue - depending on the distance of said brake-pedal (BP) sensed and measured by said ultrasonic sensor - via a transistor (T2) for supplying signal/voltage to relay (RL-1) to operate said electrical motor (M) in forward direction;

- a diode (D3) connected to said controller (C) to issue - depending on the distance of said brake-pedal (BP) sensed and measured by said ultrasonic sensor - via a transistor (T1), to supply signal/voltage to relay (RL-2) to operate said electrical motor (M) in reversed direction;

- a diode (D2) connected to said controller (C) via a transistor (T2) for supplying signal/voltage to a relay (RL-1) to operate said electrical motor (M) in a forward direction;

- a first limit switch (LS1) connected between said ultrasonic sensor and said controller (C); and

- a second limit switch (LS2) connected between said ultrasonic sensor and said controller (C);

wherein said first limit switch (LS1) is actuated to issue a corresponding signal to said electric motor (M) when said lever (L) reaches the maximum inward position thereof and to stop applying the brake force on said brake-pedal (BP); or said second limit switch (LS2) is actuated to issue a corresponding signal to said electric motor (M) to rotate in a reversed direction, when said lever (L) reaches the maximum outward position thereof and thereby to start applying the brake force on said brake-pedal (BP).

7. The electro-hydraulic brake system as claimed in claim 1, wherein said electro-hydraulic brake system comprises:

- an ultrasonic sensor configured as a displacement sensor and fitted opposite the brake-pedal (BP) to sense and measure the distance of said brake-pedal (BP) and to issue an input signal to a controller (C) fitted below the trailer body;
- said electric motor configured as a reversibly operable electric motor (M) fitted with a pulley for winding/unwinding a wire cable (WC) thereon;

- said controller (C) configured to receive said input signal and supply a corresponding electrical current to said electric motor (M);

- a diode (D1) connected to said controller (C) via a transistor (T3) for stepping down the electrical supply 12V voltage to 5V circuit voltage;

- a diode (D2) connected to said controller (C) to issue - depending on the distance of said brake-pedal (BP) sensed and measured by said ultrasonic sensor - via a transistor (T2) for supplying signal/voltage to relay (RL-1) to operate said electrical motor (M) in forward direction;

- a diode (D3) connected to said controller (C) to issue - depending on the distance of said brake-pedal (BP) sensed and measured by said ultrasonic sensor - via a transistor (T1), to supply signal/voltage to relay (RL-2) to operate said electrical motor (M) in reversed direction;

- a first limit switch (LS1) connected between said ultrasonic sensor and said controller (C); and

- a second limit switch (LS2) connected between said ultrasonic sensor and said controller (C) ;

wherein said first limit switch (LS1) is actuated to issue a corresponding signal to said electric motor (M) when said lever (L) reaches the maximum inward position thereof and to stop applying the brake force on said brake-pedal (BP); or said second limit switch (LS2) is actuated to issue a corresponding signal to said electric motor (M) to rotate in a reversed direction, when said lever (L) reaches the maximum outward position thereof and thereby to start applying the brake force on said brake-pedal (BP).

8. The electro-hydraulic brake system as claimed in claim 7, wherein said electro-hydraulic brake system further comprises:

• an oil-tank (OT) having at least two apertures (A1; A2) for facilitating oil-flow therein/therefrom;

• a master cylinder (C1) hydraulically connected to said oil-tank (OT) via said apertures (A1; A2);

• a connecting rod (CR) attached to the piston (P) and passing through the first end of said master cylinder (C1), said connecting rod (CR) connected to a lever (L) of said brake pedal (BP);

• a pipeline (PL) connected at the other end of said master cylinder (C1) for a connection to wheel-cylinders (C2) of the trailer-brakes;

• said wheel cylinder (C2) connected to the first ends of a respective brake-shoe (BS) fitted with a respective brake-liner (FL) and hinged together at the other end thereof and disposed within the brake drum (BD) of the trailer brake; and

• said brake-shoes (BS) are connected to each other by a pair of compression springs (S) to keep them apart in normal condition thereof;

wherein an outward movement of said lever (L) moves said piston (P) forward for generating a hydraulic pressure in said wheel-cylinder (C2) for applying a brake force corresponding to the brake-pedal distance sensed and measured by said ultrasonic sensor (US) fitted under the trailer body.

9. The electro-hydraulic brake system as claimed in claim 1, wherein said electro-hydraulic brake system comprises:

• an oil-tank (OT) having at least two apertures (A1; A2) for facilitating oil-flow therein/therefrom;

• a master cylinder (C1) hydraulically connected to said oil-tank (OT) via said apertures (A1; A2);

• a connecting rod (CR) attached to the piston (P) and passing through the first end of said master cylinder (C1), said connecting rod (CR) connected to a lever (L) of said brake pedal (BP);

• a pipeline (PL) connected at the other end of said master cylinder (C1) for a connection to wheel-cylinders (C2) of the trailer-brakes;

• said wheel cylinder (C2) connected to the first ends of a respective brake-shoe (BS) fitted with a respective brake-liner (FL) and hinged together at the other end thereof and disposed within the brake drum (BD) of the trailer brake; and

• said brake-shoes (BS) are connected to each other by means of a pair of compression springs (S) for keeping them apart in normal condition thereof;

wherein an outward movement of said lever (L) moves said piston (P) forward for generating a hydraulic pressure in said wheel-cylinder (C2) for applying a brake force corresponding to the brake-pedal distance sensed and measured by said ultrasonic sensor (US) fitted under the trailer body.

10. The electro-hydraulic brake system as claimed in claim 1, wherein said electro-hydraulic brake system further comprises:

- a diode (D1) connected to said controller (C) via a transistor (T3) for stepping down the electrical supply 12V voltage to 5V circuit voltage;

- a diode (D2) connected to said controller (C) to issue - depending on the distance of said brake-pedal (BP) sensed and measured by said ultrasonic sensor (US) - via a transistor (T2) for supplying signal/voltage to relay (RL-1) to operate said electrical motor (M) in forward direction;

- a diode (D3) connected to said controller (C) to issue - depending on the distance of said brake-pedal (BP) sensed and measured by said ultrasonic sensor (US) - via a transistor (T1), to supply signal/voltage to relay (RL-2) to operate said electrical motor (M) in reversed direction;

- a diode (D2) connected to said controller (C) via a transistor (T2) for supplying signal/voltage to a relay (RL-1) to operate said electrical motor (M) in a forward direction;

- a first limit switch (LS1) connected between said ultrasonic sensor (US) and said controller (C); and

- a second limit switch (LS2) connected between said ultrasonic sensor (US) and said controller (C);

wherein said first limit switch (LS1) is actuated to issue a corresponding signal to said electric motor (M) when said lever (L) reaches the maximum inward position thereof and to stop applying the brake force on said brake-pedal (BP); or said second limit switch (LS2) is actuated to issue a corresponding signal to said electric motor (M) to rotate in a reversed direction, when said lever (L) reaches the maximum outward position thereof and thereby to start applying the brake force on said brake-pedal (BP).

Dated this 28th day of March 2023.

Digitally / e-Signed by:

(SANJAY KESHARWANI)
APPLICANT’S PATENT AGENT
REGN. NO. IN/PA-2043.