US3733968A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brake pedal travel limiter for hydraulic brake booster
Assignee: Bendix Corp
•
Filing: 1971-10-01
•
Granted: 1973-05-22
•
Expires: 1991-10-01
Abstract
Abstract A hydraulic boost device for brakes having a housing with a bore therein in communication with an inlet and an outlet. A booster piston is slidably received in the housing so that one end of the piston communicates with a pressure chamber which is in fluid communication with the bore. Valve means is slidably located in the bore for controlling fluid communication between the inlet, outlet and pressure chamber. Brake pedal operated means including a push rod and ratio changer levers are interconnected with the booster piston and the valve means so that brake pedal and push rod travel during a normal braking operation with hydraulic power assist will always be at some predetermined ratio to piston travel. Should a hydraulic failure occur in the boost device during a brake application, means effectively restricts push rod movement with respect to the booster piston thereby minimizing pedal travel.
Inventors
- 👤 L Bach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:47
CPC Classifications
B; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/16; B60T13/161; B60T13/162
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
118 words
In a hydraulic boost device including a housing having a pressure chamber and valve means for controlling the pressure in said chamber and a piston having one end exposed to the chamber pressure and operator-operated means comprising a force transmitting assembly including a push rod and a ratio changer lever means connecting respectively said piston and said valve means, the improvement which comprises: mechanism effective upon malfunction of the device for controlling the travel of the push rod with respect to the piston; said mechanism including a hydraulic fluid cavity in the piston into which the push rod projects, and means for capturing the fluid in said cavity to form a hydraulic connection between the rod and piston.
Claim 2
Dependent Claim
118 words
In a hydraulic boost device including a housing having a pressure chamber and valve means for controlling the pressure in said chamber and a piston having one end exposed to the chamber pressure and operator-operated means comprising a force transmitting assembly including a push rod and a ratio changer lever means connecting respectively said piston and said valve means, the improvement which comprises: mechanism effective upon malfunction of the device for controlling the travel of the push rod with respect to the piston; said mechanism including a hydraulic fluid cavity in the piston into which the push rod projects, and means for capturing the fluid in said cavity to form a hydraulic connection between the rod and piston.
Claim 3
Dependent Claim
47 words
The improvement in claim 1 wherein said means for capturing the fluid in the cavity includes a passage in the push rod communicating the cavity with the pressure chamber, and a sleeve slidably carried by the push rod to be moved into closing relationship to the passage.
Claim 4
Dependent Claim
29 words
The improvement in claim 2 wherein said sleeve is spring preloaded to uncover the passage during normal actuation so that the push rod can move freely in the cavity.
Claim 5
Dependent Claim
25 words
The improvement in claim 3 wherein said sleeve is provided with laterally disposed axially extending arms having slots therein for engagement with said lever means.
Claim 6
Dependent Claim
157 words
A hydraulic boost device, which comprises: a housing having a bore therein with inlet and outlet ports opening thereinto; a chamber in the housing in fluid communication with said bore; a piston slidably positioned in the housing and having an end extending into the chamber; valve means in the bore for controlling communication between the inlet and outlet ports and the chamber; and operator-operated means including a force transmitting assembly having a push rod drivably connected to the piston and ratio changer lever means operatively connecting said force transmitting assembly to said valve means; said operator-operated means further comprising a fluid cavity in that end of the piston which extends into the chamber for slidably receiving the push rod, and mechanism effective during an actuation if the chamber pressure is inadequate to move the piston for limiting the sliding movement of said push rod with respect to the piston so that manual assist is more quickly effected.
Claim 7
Dependent Claim
157 words
A hydraulic boost device, which comprises: a housing having a bore therein with inlet and outlet ports opening thereinto; a chamber in the housing in fluid communication with said bore; a piston slidably positioned in the housing and having an end extending into the chamber; valve means in the bore for controlling communication between the inlet and outlet ports and the chamber; and operator-operated means including a force transmitting assembly having a push rod drivably connected to the piston and ratio changer lever means operatively connecting said force transmitting assembly to said valve means; said operator-operated means further comprising a fluid cavity in that end of the piston which extends into the chamber for slidably receiving the push rod, and mechanism effective during an actuation if the chamber pressure is inadequate to move the piston for limiting the sliding movement of said push rod with respect to the piston so that manual assist is more quickly effected.
Claim 8
Dependent Claim
47 words
A hydraulic boost device, as recited in claim 5, wherein said push rod is provided with a passage communicating the cavity with said chamber, and a sleeve is slidably mounted on the push rod for controlling the flow of hydraulic fluid between the cavity and the chamber.
Claim 9
Dependent Claim
45 words
A hydraulic boost device, as recited in claim 6, wherein said sleeve is spring preloaded to uncover the passage during normal actuation and slidable against said preloaded spring in the event of a malfunction in the device to cause the sleeve to cover the passage.
Claim 10
Dependent Claim
29 words
A hydraulic boost device, as recited in claim 7, wherein said sleeve is operatively connected to said lever means at a point between the ends of said lever means.
Claim 11
Dependent Claim
16 words
A hydraulic boost device, as recited in claim 5, wherein said mechanism comprises a control valve.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |