Hydraulic booster

Claim 2

A hydraulic booster comprising a booster piston disposed in a slidably sealed relationship in a housing; an annular piston disposed in said booster piston and acting thereon; a central piston disposed in said booster piston in a cooperating relationship with said annular piston to enable said central piston to move relative to said annular piston when actuated by a brake pedal to control pressurized fluid flow in said booster and to enable said central piston and said annular piston to move as a unit when the force of a first spring disposed between said central piston and said booster piston is overcome; a pin disposed in said booster piston subjected to said pressurized fluid, said pin being operated upon by said brake pedal and penetrating said annular piston in a sealed relationship to impart the force of said brake pedal to said central piston; said booster piston accommodating a first chamber bounded by said booster piston and said annular piston; said annular piston bearing against said booster piston in a direction opposite to a brake actuating direction via a resilient means; and said pin bearing against said central piston via a second spring having a higher preload than said first spring.

Claim 3

A booster according to claim 1, wherein said central piston is disposed in said booster piston in a pressure-balanced manner.

Claim 4

A booster according to claim 1, wherein said annular piston is slidably sealed in said booster piston, and said booster piston extends out of said housing in a slidably sealed relationship therewith adjacent said brake pedal.

Claim 5

A booster according to claim 1, further including a tappet to actuate said annular piston, said tappet having one end connected to said brake pedal and the other end fastened axially to said annular piston to enable said tappet to move a given distance relative to said annular piston, said other end of said tappet abutting the adjacent end of said pin.

Claim 6

A booster according to claim 4, wherein the other end of said pin is formed to be retained in said central piston.

Claim 7

A booster according to claim 5, wherein said pin is coaxially retained in said central piston by means of a bayonet-like device.

Claim 8

A booster according to claim 5, wherein said pin includes a head and a shank, and said central piston includes therein a second chamber bounded by an end of said central piston disposed in said first chamber and said head is disposed axially in said second chamber to grip the surface of said end of said central piston in said second chamber.

Claim 9

A booster according to claim 7, wherein said end of said central piston has a central bore therein corresponding to the diameter of said shank through which said shank extends into said second chamber.

Claim 10

A booster according to claim 8, wherein said second spring is disposed in said second chamber acting between said central piston and said head to urge said head into abutment with said surface of said end of said central piston.

Claim 11

A booster according to claim 1, wherein the end of said pin remote from said brake pedal is formed to be retained in said central piston.

Claim 12

A booster according to claim 10, wherein said pin is coaxially retained in said central piston by means of a bayonet-like device.

Claim 13

A booster according to claim 10, wherein said pin includes a head and a shank, and said central piston includes therein a chamber bounded by an end of said central piston adjacent said brake pedal and said head is disposed axially in said chamber to grip the surface of said end of said central piston in said chamber.

Claim 14

A booster according to claim 12, wherein said end of said central piston has a central bore therein corresponding to the diameter of said shank through which said shank extends into said chamber.

Claim 15

A booster according to claim 13, wherein said second spring is disposed in said chamber acting between said central piston and said head to urge said head into abutment with said surface of said end of said central piston.

Claim 16

A hydraulic booster comprising: a booster piston disposed in a slidably sealed relationship in a housing; an annular piston disposed in said booster piston and acting thereon; a central piston disposed in said booster piston in a cooperating relationship with said piston to enable said central piston to move relative to said annular piston when actuated by a brake pedal to control pressurized fluid flow in said booster and to enable said central piston and said annular piston to move as a unit when the force of a first spring disposed between said central piston and said booster piston is overcome; and a pin disposed in said booster piston subjected to said pressurized fluid, said pin being operated upon by said brake pedal and penetrating said annular piston in a sealed relationship to impart the force of said brake pedal to said central piston; said pin bearing against said central piston via a second spring having a higher preload than said first spring.

Claim 17

A hydraulic booster comprising: a booster piston disposed in a slidably sealed relationship in a housing; an annular piston disposed in said booster piston and acting thereon; a central piston disposed in said booster piston in a cooperating relationship with said piston to enable said central piston to move relative to said annular piston when actuated by a brake pedal to control pressurized fluid flow in said booster and to enable said central piston and said annular piston to move as a unit when the force of a first spring disposed between said central piston and said booster piston is overcome; and a pin disposed in said booster piston subjected to said pressurized fluid, said pin being operated upon by said brake pedal and penetrating said annular piston in a sealed relationship to impart the force of said brake pedal to said central piston; said pin bearing against said central piston via a second spring having a higher preload than said first spring.

Claim 18

A booster according to claim 15, further including a tappet to actuate said annular piston, said tappet having one end connected to said brake pedal and the other end fastened axially to said annular piston to enable said tappet to move a given distance relative to said annular piston, said other end of said tappet abutting the adjacent end of said pin.

Claim 19

A booster according to claim 16, wherein the other end of said pin is formed to be retained in said central piston.

Claim 20

A booster according to claim 17, wherein said pin is coaxially retained in said central piston by means of a bayonet-like device.

Claim 21

A booster according to claim 17, wherein said pin includes a head and a shank, and said central piston includes therein a chamber bounded by an end of said central piston adjacent said brake pedal and said head is disposed axially in said chamber to grip the surface of said end of said central piston in said chamber.

Claim 22

A booster according to claim 19, wherein said end of said central piston has a central bore therein corresponding to the diameter of said shank through which said shank extends into said chamber.

Claim 23

A booster according to claim 20, wherein said second spring is disposed in said chamber acting between said central piston and said head to urge said head into abutment with said surface of said end of said central piston.

Claim 24

A hydraulic booster comprising: a booster piston disposed in a slidably sealed relationship in a housing; an annular piston disposed in said booster and acting thereon; a central piston disposed in said booster piston in a cooperating relationship with said annular piston to enable said central piston to move relative to said annular piston when actuated by a brake pedal to control pressurized fluid flow in said booster and to enable said central piston and said annular piston to move as a unit when the force of a first spring disposed between said central piston and said booster piston is overcome; a pin disposed in said booster piston subjected to said pressurized fluid, said pin being operated upon by said brake pedal and penetrating said annular piston in a sealed relationship to impart the force of said brake pedal to said central piston; and a tappet to actuate said annular piston, said tappet having one end connected to said brake pedal and the other end fastened axially to said annular piston to enable said tappet to move a given distance relative to said annular piston, said other end of said tappet abutting the adjacent end of said pin and the other end of said pin is formed to be retained in said central piston.

Claim 25

A hydraulic booster comprising: a booster piston disposed in a slidably sealed relationship in a housing; an annular piston disposed in said booster and acting thereon; a central piston disposed in said booster piston in a cooperating relationship with said annular piston to enable said central piston to move relative to said annular piston when actuated by a brake pedal to control pressurized fluid flow in said booster and to enable said central piston and said annular piston to move as a unit when the force of a first spring disposed between said central piston and said booster piston is overcome; a pin disposed in said booster piston subjected to said pressurized fluid, said pin being operated upon by said brake pedal and penetrating said annular piston in a sealed relationship to impart the force of said brake pedal to said central piston; and a tappet to actuate said annular piston, said tappet having one end connected to said brake pedal and the other end fastened axially to said annular piston to enable said tappet to move a given distance relative to said annular piston, said other end of said tappet abutting the adjacent end of said pin and the other end of said pin is formed to be retained in said central piston.

Claim 26

A booster according to claim 22, wherein said pin is coaxially retained in said central piston by means of a bayonet-like device.

Claim 27

A booster according to claim 22, wherein said pin includes a head and a shank, and said central piston includes therein a chamber bounded by an end of said central piston adjacent said brake pedal and said head is disposed axially in said chamber to grip the surface of said end of said central piston in said chamber.

Claim 28

A booster according to claim 24, wherein said end of said central piston has a central bore therein corresponding to the diameter of said shank through which said shank extends into said chamber.

Claim 29

A booster according to claim 25, further including a second spring is disposed in said chamber acting between said central piston and said head to urge said head into abutment with said surface of said end of said central piston.

Claim 30

A hydraulic booster comprising: a booster piston disposed in a slidably sealed relationship in a housing; an annular piston disposed in said booster and acting thereon; a central piston disposed in said booster piston in a cooperating relationship with said annular piston to enable said central piston to move relative to said annular piston when actuated by a brake pedal to control pressurized fluid flow in said booster and to enable said central piston and said annular piston to move as a unit when the force of a first spring disposed between said central piston and said booster piston is overcome; and a pin disposed in said booster piston subjected to said pressurized fluid flow, said pin being operated upon by said brake pedal and penetrating said annular piston in a sealed relationship to impart the force of said brake pedal to said central piston; said pin including a head and a shank, and said central piston including therein a chamber bounded by an end of said central piston adjacent said brake pedal and said head is disposed axially in said chamber to grip the surface of said end of said central piston in said chamber.

Claim 31

A hydraulic booster comprising: a booster piston disposed in a slidably sealed relationship in a housing; an annular piston disposed in said booster and acting thereon; a central piston disposed in said booster piston in a cooperating relationship with said annular piston to enable said central piston to move relative to said annular piston when actuated by a brake pedal to control pressurized fluid flow in said booster and to enable said central piston and said annular piston to move as a unit when the force of a first spring disposed between said central piston and said booster piston is overcome; and a pin disposed in said booster piston subjected to said pressurized fluid flow, said pin being operated upon by said brake pedal and penetrating said annular piston in a sealed relationship to impart the force of said brake pedal to said central piston; said pin including a head and a shank, and said central piston including therein a chamber bounded by an end of said central piston adjacent said brake pedal and said head is disposed axially in said chamber to grip the surface of said end of said central piston in said chamber.

Claim 32

A booster according to claim 27, wherein said end of said central piston has a central bore therein corresponding to the diameter of said shank through which said shank extends into said chamber.

Claim 33

A booster according to claim 28, further including a second spring is disposed in said chamber acting between said central piston and said head to urge said head into abutment with said surface of said end of said central piston.