Patent US3732749A successfully refreshed from Google Patents.
US3732749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lever mechanism with variable mechanical advantage
Assignee: Worcester Valve Co Ltd
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Filing: 1972-03-08
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Granted: 1973-05-15
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Expires: 1992-03-08
Abstract
Abstract A lever mechanism for exerting variable torque about the axis of a valve spindle in which a stationary abutment member, a movable abutment member rotatable with the spindle, and a pivot pin are mounted on a valve with a lever arm which provides an initial mechanical advantage between the lever and the spindle until after some rotation has occurred, spindle and lever move in unison with a final mechanical advantage, the initial mechanical advantage being greater than the final mechanical advantage.
Inventors
- 👤 R Thatcher
- 👤 A Ediss
- 👤 B Wheeler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:31
CPC Classifications
F; F16; F16K; F16K31/00; F16K31/44; Y; Y10; Y10T; Y10T74/00; Y10T74/20; Y10T74/20558; Y10T74/2057
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
149 words
Means for exerting variable torque about the axis of a valve spindle, comprising a first abutment mounted stationarily and radially spaced from said axis a moving abutment mounted for rotation with said spindle and radially off-set therefrom a pivot mounted for rotation with said spindle and also radially off-set therefrom and a lever mounted on for pivotal movement about said pivot such that when the spindle is in one limiting position, the lever when forced in one sense of direction abuts the first abutment which then acts as a fulcrum so that a torque is applied to thE spindle via the pivot with an initial mechanical advantage whilst when some rotation of said lever and said spindle has occurred said lever abuts said moving abutment so as to directly rotate the spindle with a final mechanical advantage wherein the initial mechanical advantage is greater than the final mechanical advantage.
Claim 2
Dependent Claim
149 words
Means for exerting variable torque about the axis of a valve spindle, comprising a first abutment mounted stationarily and radially spaced from said axis a moving abutment mounted for rotation with said spindle and radially off-set therefrom a pivot mounted for rotation with said spindle and also radially off-set therefrom and a lever mounted on for pivotal movement about said pivot such that when the spindle is in one limiting position, the lever when forced in one sense of direction abuts the first abutment which then acts as a fulcrum so that a torque is applied to thE spindle via the pivot with an initial mechanical advantage whilst when some rotation of said lever and said spindle has occurred said lever abuts said moving abutment so as to directly rotate the spindle with a final mechanical advantage wherein the initial mechanical advantage is greater than the final mechanical advantage.
Claim 3
Dependent Claim
27 words
Means according to claim 1 in which said pivot and said moving abutment are carred by a member which is fixed to the spindle for rotation therewith.
Claim 4
Dependent Claim
25 words
Means according to claim 2 in which said first abutment is carried on a further member which is fixed to the body of the valve.
Claim 5
Dependent Claim
37 words
Means according to claim 3 in which said first abutment is shaped so that the position of contact between said lever and said first abutment moves when said lever moves to provide a varying initial mechanical advantage.
References Cited (Backward Citations)
US2188783A
Cited
US2600499A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-14 | 1976-11-13 | 1977-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-14 | 1980-11-13 | 1981-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-14 | 1984-11-13 | 1985-05-15 | $7700.00 | Window Closed / Lapsed |