GB2177783A - Brake pedal mechanism - Google Patents

Description

SPECIFICATION Device in order to developing and increasing a pressure output of a mechanically cylinder The invention relates to a device to develop and/or increase the pressure output of a mechanically actuated cylinder, in particular the brake master cylinder of a vehicle hydraulic braking system where a foot operated lever is used to apply the force to the cylinder piston, which lever is used to apply the force to the cylinder piston.

The usual actuating system of a vehicle is with a pull or push rod, pivoted to the foot lever by a swivel joint connection.

The use of this pull or push rod limits the stroke available for operated the cylinder because of the swivel joint arrangement.

It is an object of the present invention to provide a system where a significantly larger leverage of the foot operated lever is possible.

According to a feature of the present invention the above object is achieved by the piston rod arranging in a guide, which guide is directed essentially or entirely in the longitudinal direction of the cylinder and/or in the direction of the piston moved by the cylinder.

In a further embodiment of the invention there is no or no essentially limitation of a pivot of the lever above mentioned relating to and/or directed to a further pivot of the lever above mentioned.

In an advantageous embodiment of the invention the piston rod is containing a surface where the foot lever applies the force, i.e. the lever and piston rod contact each other but are not connected together with a swivelling joint therefore there is a connection sliding to each other allowing a movement sliding to each other.

Above-mentioned and other features and objects of this invention will become more apparent by reference to the following description taken in conjunction with the acompanying drawing, in which: Figure 1 is a side view of an embodiment of the invention, Figure 2 is a section along the line A-A of Fig. 1.

As can be seen in Fig. 1 and 2, the piston rod 1 of the piston 2 of the brake master cylinder 3 are guided by rings 4 and 5, the piston rod 1 is therefore moveable essentially or entirely in direction parallel to the longitudinal direction of cylinder 3. The ring 4 is arranged into the cylinder 3, the ring 5 being mounted on a convinient part of the vehicle.

A brake foot lever 6 is pivoted on point 9 so that when force is applied at brake pedal 7, the contact point at 8 allows the force to be transmitted to the piston rod 1 slotted to accommoadte the lever 6. A plate spring 10 ensures that the lever 6 remains in contact with the piston rod 1.

A force applied at brake pedal 7 is transmitted to the piston rod 1 moving to the left develops and/or increases the pressure output of the cylinder 3.

It is also possible to arrange the lever point 9 above the piston rod 1 so that the lever 6 can operate in the opposite direction.

As the lever 6 is free to move relative to the piston rod 1 and a pivoting of the piston rod is prohibited essentially or entirely by the guides 4 and 5, the lever 6 can be dimensioned so as to give an almost optimal force intensification relating to the leverage of the lever 6.

1. Device in order to developing and increasing a pressure output of a mechanically cylinder, in particular the master cylinder of a hydraulic braking system of a vehicle, where, at least, a lever is avaible, that is, a lever operated by foot pressure, the lever transmitting force into the piston of a hydraulic cylinder, characterized by a guide (rings 4, 5) for the connection (piston rod 1) between the piston (2) and the cylinder (3), where the lever is available through the connection and/or the piston (2) can move in a predetermined direction.

2. Device according to claim 1, characterized that the guide (rings 4, 5) is holding the connection (piston rod 1) essentially or wholy in the longitudinal direction of the cylinder (3).

3. Device according to claim 1 and/or 2, characterized that, at least in the region of the lever (6) is an arrangement allowing different distance of at least two pivoting or contacting points (8,9) of the lever (6).

4. Device according to claim 1, 2 and/or 3, characterized that, with reference to the relative movements between the connection (piston rod 1) and the lever (6), no or essentially no limitation exists.

5. Device according to claim 3 and/or 4, characterized that there exists an arrangement for the operation of the lever (6) on the connection (piston rod 1) sliding to each other and ollowing a relative movement to each other.

6. Device according to one or more claims 1 to 5, characterize that the guide is formed by stops (rings 4, 5).

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Device in order to developing and increasing a pressure output of a mechanically cylinder The invention relates to a device to develop and/or increase the pressure output of a mechanically actuated cylinder, in particular the brake master cylinder of a vehicle hydraulic braking system where a foot operated lever is used to apply the force to the cylinder piston, which lever is used to apply the force to the cylinder piston. The usual actuating system of a vehicle is with a pull or push rod, pivoted to the foot lever by a swivel joint connection. The use of this pull or push rod limits the stroke available for operated the cylinder because of the swivel joint arrangement. It is an object of the present invention to provide a system where a significantly larger leverage of the foot operated lever is possible. According to a feature of the present invention the above object is achieved by the piston rod arranging in a guide, which guide is directed essentially or entirely in the longitudinal direction of the cylinder and/or in the direction of the piston moved by the cylinder. In a further embodiment of the invention there is no or no essentially limitation of a pivot of the lever above mentioned relating to and/or directed to a further pivot of the lever above mentioned. In an advantageous embodiment of the invention the piston rod is containing a surface where the foot lever applies the force, i.e. the lever and piston rod contact each other but are not connected together with a swivelling joint therefore there is a connection sliding to each other allowing a movement sliding to each other. Above-mentioned and other features and objects of this invention will become more apparent by reference to the following description taken in conjunction with the acompanying drawing, in which: Figure 1 is a side view of an embodiment of the invention, Figure 2 is a section along the line A-A of Fig. 1. As can be seen in Fig. 1 and 2, the piston rod 1 of the piston 2 of the brake master cylinder 3 are guided by rings 4 and 5, the piston rod 1 is therefore moveable essentially or entirely in direction parallel to the longitudinal direction of cylinder 3. The ring 4 is arranged into the cylinder 3, the ring 5 being mounted on a convinient part of the vehicle. A brake foot lever 6 is pivoted on point 9 so that when force is applied at brake pedal 7, the contact point at 8 allows the force to be transmitted to the piston rod 1 slotted to accommoadte the lever 6. A plate spring 10 ensures that the lever 6 remains in contact with the piston rod 1. A force applied at brake pedal 7 is transmitted to the piston rod 1 moving to the left develops and/or increases the pressure output of the cylinder 3. It is also possible to arrange the lever point 9 above the piston rod 1 so that the lever 6 can operate in the opposite direction. As the lever 6 is free to move relative to the piston rod 1 and a pivoting of the piston rod is prohibited essentially or entirely by the guides 4 and 5, the lever 6 can be dimensioned so as to give an almost optimal force intensification relating to the leverage of the lever 6. CLAIMS

1. Device in order to developing and increasing a pressure output of a mechanically cylinder, in particular the master cylinder of a hydraulic braking system of a vehicle, where, at least, a lever is avaible, that is, a lever operated by foot pressure, the lever transmitting force into the piston of a hydraulic cylinder, characterized by a guide (rings 4, 5) for the connection (piston rod 1) between the piston (2) and the cylinder (3), where the lever is available through the connection and/or the piston (2) can move in a predetermined direction.

2. Device according to claim 1, characterized that the guide (rings 4, 5) is holding the connection (piston rod 1) essentially or wholy in the longitudinal direction of the cylinder (3).

3. Device according to claim 1 and/or 2, characterized that, at least in the region of the lever (6) is an arrangement allowing different distance of at least two pivoting or contacting points (8,9) of the lever (6).

4. Device according to claim 1, 2 and/or 3, characterized that, with reference to the relative movements between the connection (piston rod 1) and the lever (6), no or essentially no limitation exists.

5. Device according to claim 3 and/or 4, characterized that there exists an arrangement for the operation of the lever (6) on the connection (piston rod 1) sliding to each other and ollowing a relative movement to each other.

6. Device according to one or more claims 1 to 5, characterize that the guide is formed by stops (rings 4, 5).