US3704653A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spring-force applying means
Assignee: Siemens Mobility Ltd
•
Filing: 1971-03-11
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Granted: 1972-12-05
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Expires: 1991-03-11
Abstract
Abstract A spring-brake actuator wherein the piston acted upon by the spring is connected to its piston rod via a clutch held disengaged only so long as fluid pressure is effective on the piston to render the spring inoperative to apply the brake.
Inventors
- 👤 Horatio Leslie Higgins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:35
CPC Classifications
B; B60; B60T; B60T17/00; B60T17/08; B60T17/085; B60T13/00; B60T13/10; B60T13/24; B60T13/26; B60T13/38; B61; B61H; B61H13/00; B61H13/005
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
207 words
A spring force applying means comprising a pair of members relative displacement of which in one direction under the influence of a spring causes the spring to apply a force on a force transmitting element and a chamber defined at least in part by the said pair of members to which chamber can be applied a fluid pressure which exerts across the members a force opposing that exerted by the spring to displace the members relatively in the opposite direction to at least partially relieve said force transmitting element of the force otherwise applied thereto by the spring, and wherein the force transmitting element is operatively connected to one of the pair of members through a clutch which engages when the pressure in the chamber is below a predetermined value to cause the spring thereof to apply a force on the element upon the relevant displacement of the members by the spring in said one direction, the clutch being disengaged upon the application of fluid pressure to the chamber when that fluid pressure exceeds said predetermined value, the engagement of said clutch and said force transmitting element including for allowing the said force transmitting element to move freely relative to said clutch when the clutch is disengaged.
Claim 2
Dependent Claim
207 words
A spring force applying means comprising a pair of members relative displacement of which in one direction under the influence of a spring causes the spring to apply a force on a force transmitting element and a chamber defined at least in part by the said pair of members to which chamber can be applied a fluid pressure which exerts across the members a force opposing that exerted by the spring to displace the members relatively in the opposite direction to at least partially relieve said force transmitting element of the force otherwise applied thereto by the spring, and wherein the force transmitting element is operatively connected to one of the pair of members through a clutch which engages when the pressure in the chamber is below a predetermined value to cause the spring thereof to apply a force on the element upon the relevant displacement of the members by the spring in said one direction, the clutch being disengaged upon the application of fluid pressure to the chamber when that fluid pressure exceeds said predetermined value, the engagement of said clutch and said force transmitting element including for allowing the said force transmitting element to move freely relative to said clutch when the clutch is disengaged.
Claim 3
Dependent Claim
44 words
A spring-force applying means as claimed in claim 1, wherein the clutch is constituted by a nut threadedly engaged through a reversible thread with the element, the nut having a clutch face cooperable with a complementary clutch face on said one of the members.
Claim 4
Dependent Claim
48 words
Spring-force applying means as claimed in claim 2, wherein the nut is urged by a second spring in a direction to engage the clutch faces, the value of the spring determining the pre-determined value of pressure in the chamber at which the clutch is engaged or disengaged respectively.
Claim 5
Dependent Claim
49 words
Spring-force applying means as claimed in claim 3, wherein the nut, in operation of the means, is moved against the force exerted by a second spring thereby to disengage the clutch by the fluid pressure in the chamber being applied to a pressure responsive member operative on the nut.
Claim 6
Dependent Claim
35 words
Spring-force applying means as claimed in claim 4, wherein there is interposed between the nut and second spring a first thrust bearing and between the nut and the pressure responsive member a second thrust bearing.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-05 | 1976-06-05 | 1976-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-05 | 1980-06-05 | 1980-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-05 | 1984-06-05 | 1984-12-05 | $7700.00 | Window Closed / Lapsed |