US4028891A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Booster brake unit
Assignee: ITT Inc
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Filing: 1975-11-07
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Granted: 1977-06-14
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Expires: 1995-11-07
Abstract
Abstract A hydraulic transmission is provided between the booster piston and the master cylinder piston which is automatically interrupted if the booster power is not present. In this arrangement, when booster power is not present, a sufficient pressure can be generated with brake pedal effort alone, making use of the full permissible pedal travel.
Inventors
- 👤 Juan Belart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:18
CPC Classifications
B; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/14; B60T13/142; B60T13/143; B60T13/144
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
302 words
A booster brake unit comprising: a master cylinder having a longitudinal axis; at least one master-cylinder piston having a given diameter disposed in said master cylinder coaxial of said axis; a booster housing connected to said master cylinder coaxial of said axis; a booster piston disposed in said booster housing coaxial of said axis for displacing said master-cylinder piston, said booster piston having a diameter greater than said given diameter and an actuation surface at one end thereof remote from said master-cylinder piston; a pressure source; a brake pedal; a pressure-control valve coupled between said source and said actuation surface, said pressure-control valve being coupled to said brake pedal to control pressure applied to said actuation surface from said source by said brake pedal; a pressure chamber disposed within said booster housing coaxial of said axis between adjacent ends of said master-cylinder piston and said booster piston for hydraulic transmission of the force of said booster piston to said master-cylinder piston; a feed chamber disposed in a wall of said booster housing; a two-position valve; and a connection within said booster housing connecting said pressure chamber to said feed chamber via said two-position valve; said two-position valve being held in a closed position by the force of a spring and said pressure of said source; said pressure-control valve including a control housing disposed in said booster piston coaxial of said axis; and a valve spool disposed coaxial of said axis and slideably sealed in said control housing, said valve spool being rigidly connected to said brake pedal; and said two-position valve including a spring-loaded member disposed in said booster piston adjacent the other end thereof coaxial of said axis, said member being in pressure communication with said pressure chamber on one side thereof and said valve spool on the other side thereof.
Claim 2
Dependent Claim
302 words
A booster brake unit comprising: a master cylinder having a longitudinal axis; at least one master-cylinder piston having a given diameter disposed in said master cylinder coaxial of said axis; a booster housing connected to said master cylinder coaxial of said axis; a booster piston disposed in said booster housing coaxial of said axis for displacing said master-cylinder piston, said booster piston having a diameter greater than said given diameter and an actuation surface at one end thereof remote from said master-cylinder piston; a pressure source; a brake pedal; a pressure-control valve coupled between said source and said actuation surface, said pressure-control valve being coupled to said brake pedal to control pressure applied to said actuation surface from said source by said brake pedal; a pressure chamber disposed within said booster housing coaxial of said axis between adjacent ends of said master-cylinder piston and said booster piston for hydraulic transmission of the force of said booster piston to said master-cylinder piston; a feed chamber disposed in a wall of said booster housing; a two-position valve; and a connection within said booster housing connecting said pressure chamber to said feed chamber via said two-position valve; said two-position valve being held in a closed position by the force of a spring and said pressure of said source; said pressure-control valve including a control housing disposed in said booster piston coaxial of said axis; and a valve spool disposed coaxial of said axis and slideably sealed in said control housing, said valve spool being rigidly connected to said brake pedal; and said two-position valve including a spring-loaded member disposed in said booster piston adjacent the other end thereof coaxial of said axis, said member being in pressure communication with said pressure chamber on one side thereof and said valve spool on the other side thereof.
Claim 3
Dependent Claim
13 words
A unit according to claim 1, wherein said member is a sleeve seal.
Claim 4
Dependent Claim
36 words
A unit according to claim 2, further including a compensating bore extending radially through a wall of said booster housing between said pressure chamber and said feed chamber when said unit is in an inactive state.
Claim 5
Dependent Claim
59 words
A unit according to claim 3, further including an extension rigidly secured to an end of said master-cylinder piston adjacent said booster piston, said extension engaging said other end of said booster piston when said unit is in an inactive state and when said pressure of said source is not present when said unit is in an active state.
Claim 6
Dependent Claim
37 words
A unit according to claim 3, further including an intermediate piston disposed between said master-cylinder piston and said booster piston, said intermediate piston being rigidly secured to an end of said master-cylinder piston adjacent said booster piston.
Claim 7
Dependent Claim
258 words
A booster brake unit comprising: a master cylinder having a longitudinal axis; at least one master-cylinder piston having a given diameter disposed in said master cylinder coaxial of said axis; a booster housing connected to said master cylinder coaxial of said axis; a booster piston disposed in said booster housing coaxial of said axis for displacing said master-cylinder piston, said booster piston having a diameter greater than said given diameter and an actuation surface at one end thereof remote from said master-cylinder piston; a pressure source; a brake pedal; a pressure-control valve coupled between said source and said actuation surface, said pressure-control valve being coupled to said brake pedal to control pressure applied to said actuation surface from said source by said brake pedal; a pressure chamber disposed within said booster housing coaxial of said axis between adjacent ends of said master-cylinder piston and said boster piston for hydraulic transmission of the force of said booster piston to said master-cylinder piston; a feed chamber disposed in a wall of said booster housing; a two-position valve; and a connection within said booster housing connecting said pressure chamber to said feed chamber via said two-position valve; said two-position valve being held in a closed position by the force of a spring and said pressure of said source; said two-position valve including a spring-loaded member disposed in said booster piston adjacent the other end thereof coaxial of said axis, said member being in pressure communication with said pressure chamber on one side thereof and said valve on the other side thereof.
Claim 8
Dependent Claim
258 words
A booster brake unit comprising: a master cylinder having a longitudinal axis; at least one master-cylinder piston having a given diameter disposed in said master cylinder coaxial of said axis; a booster housing connected to said master cylinder coaxial of said axis; a booster piston disposed in said booster housing coaxial of said axis for displacing said master-cylinder piston, said booster piston having a diameter greater than said given diameter and an actuation surface at one end thereof remote from said master-cylinder piston; a pressure source; a brake pedal; a pressure-control valve coupled between said source and said actuation surface, said pressure-control valve being coupled to said brake pedal to control pressure applied to said actuation surface from said source by said brake pedal; a pressure chamber disposed within said booster housing coaxial of said axis between adjacent ends of said master-cylinder piston and said boster piston for hydraulic transmission of the force of said booster piston to said master-cylinder piston; a feed chamber disposed in a wall of said booster housing; a two-position valve; and a connection within said booster housing connecting said pressure chamber to said feed chamber via said two-position valve; said two-position valve being held in a closed position by the force of a spring and said pressure of said source; said two-position valve including a spring-loaded member disposed in said booster piston adjacent the other end thereof coaxial of said axis, said member being in pressure communication with said pressure chamber on one side thereof and said valve on the other side thereof.
Claim 9
Dependent Claim
13 words
A unit according to claim 6, wherein said member is a sleeve seal.
Claim 10
Dependent Claim
36 words
A unit according to claim 7, further including a compensating bore extending radially through a wall of said booster housing between said pressure chamber and said feed chamber when said unit is in an inactive state.
Claim 11
Dependent Claim
59 words
A unit according to claim 8, further including an extension rigidly secured to an end of said master-cylinder piston adjacent said booster piston, said extension engaging said other end of said booster piston when said unit is in an inactive state and when said pressure of said source is not present when said unit is in an inactive state.
Claim 12
Dependent Claim
36 words
A unit according to claim 8, further including an intermediate piston disposed between said master-cylinder piston and said boster piston, said intermediate piston rigidly secured to an end of said master-cylinder piston adjacent said booster piston.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-13 | 1980-12-13 | 1981-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-13 | 1984-12-13 | 1985-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-13 | 1988-12-13 | 1989-06-14 | $7700.00 | Window Closed / Lapsed |