US4029177A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Overspeed brake for a lift car
Assignee: International Telephone and Telegraph Corp
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Filing: 1976-07-30
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Granted: 1977-06-14
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Expires: 1996-07-30
Abstract
Abstract A rotatable sheave is mounted on one end of a platform lift, enabling the sheave to be turned by friction of guide cables as the platform descends. Dogs attached to the sheave extend themselves due to centrifugal force as the platform moves faster. At a specified speed, the governor dogs impact an activating lever which in turn releases a spring loaded retainer rod assembly. The retainer rod assembly then releases spring loaded push rods that engage brake cam dogs on each end of the platform. The brake cam dogs squeeze the guide cables against clamp bodies halting descent of the platform.
Inventors
- 👤 Robert A. Fiss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:51
CPC Classifications
B; B66; B66B; B66B5/00; B66B5/02; B66B5/04; B66B5/044; B66B5/16; B66B5/18; B66B5/24
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
201 words
A braking system in association with a lift platform having a movable lift cable for translating said lift platform and having at least one stationary guide member separate and spaced apart from said lift cable for aligning said lift platform, said system comprising a governor mounted to said lift platform and operatively engaging said guide member and said governor being coupled through a linkage to brake means, said linkage including a plurality of spring loaded elements locked together by pin means and terminating in said brake means, said brake means including a first cam surface element pivotally mounted to said lift platform and operable by said linkage to lock said guide member between said first cam surface and a second cam surface element fixedly mounted to said lift platform, said governor responding to the translation of said lift platform when the speed of said lift platform relative to said guide member exceeds a predetermined maximum, to release said pin means and permit springs associated with said spring loaded elements to apply a force through said linkage to said brake means thereby to rotate said first cam surface element into engagement with said guide means and stop motion of said lift platform.
Claim 2
Dependent Claim
201 words
A braking system in association with a lift platform having a movable lift cable for translating said lift platform and having at least one stationary guide member separate and spaced apart from said lift cable for aligning said lift platform, said system comprising a governor mounted to said lift platform and operatively engaging said guide member and said governor being coupled through a linkage to brake means, said linkage including a plurality of spring loaded elements locked together by pin means and terminating in said brake means, said brake means including a first cam surface element pivotally mounted to said lift platform and operable by said linkage to lock said guide member between said first cam surface and a second cam surface element fixedly mounted to said lift platform, said governor responding to the translation of said lift platform when the speed of said lift platform relative to said guide member exceeds a predetermined maximum, to release said pin means and permit springs associated with said spring loaded elements to apply a force through said linkage to said brake means thereby to rotate said first cam surface element into engagement with said guide means and stop motion of said lift platform.
Claim 3
Dependent Claim
65 words
The invention as claimed in claim 1, in which the governor includes a sheave supporting a cam dog, and means holding said cam dog in an inoperative state under normal speed conditions of said platform, said cam dog responding to centrifugal force to move into a position to energize said linkage and said brake means when the speed of the platform exceeds said prescribed maximum.
Claim 4
Dependent Claim
61 words
The invention as claimed in claim 1, in which the governor bears a spring biased cam, said cam is responsive to a centrifugal force generated when the platform speed exceeds the prescribed maximum to energize an activating lever forming part of said linkage, and said activating lever includes means to release spring elements in said linkage and operate said brake means.
Claim 5
Dependent Claim
33 words
The invention as claimed in claim 1, in which said guide member is a cable and the first cam surface is enabled to lock said cable between itself and the second cam surface.
Claim 6
Dependent Claim
192 words
A braking system for a lift platform having amovable lift cable for translating said lift platform and having at least one stationary guide member separate and spaced apart from said lift cable for aligning said lift platform, said system comprising a governor mounted to said lift platform and operatively engaging said guide member and said governor being coupled by linkage means to brake means, said linkage means including an activating lever and a plurality of spring loaded elements locked together by pin means and terminating in said brake means, said brake means including a first cam surface element pivotally mounted to said lift platform and operable to lock said guide member between itself and a second cam surface element fixedly mounted to said lift platform, said governor responding to the translation of said lift platform when the speed of said lift platform relative to said guide member exceeds a predetermined maximum to operate said activating lever, causing said pin means to release said spring loaded elements and rotate said first cam surface element into engagement with said guide means thereby to operate said brake means to cause said lift platform to stop.
Claim 7
Dependent Claim
192 words
A braking system for a lift platform having amovable lift cable for translating said lift platform and having at least one stationary guide member separate and spaced apart from said lift cable for aligning said lift platform, said system comprising a governor mounted to said lift platform and operatively engaging said guide member and said governor being coupled by linkage means to brake means, said linkage means including an activating lever and a plurality of spring loaded elements locked together by pin means and terminating in said brake means, said brake means including a first cam surface element pivotally mounted to said lift platform and operable to lock said guide member between itself and a second cam surface element fixedly mounted to said lift platform, said governor responding to the translation of said lift platform when the speed of said lift platform relative to said guide member exceeds a predetermined maximum to operate said activating lever, causing said pin means to release said spring loaded elements and rotate said first cam surface element into engagement with said guide means thereby to operate said brake means to cause said lift platform to stop.
Claim 8
Dependent Claim
72 words
The invention as claimed in claim 5, in which the governor includes a sheave supporting a cam dog, and means holding said cam dog in an inoperative state under normal speed conditions of said platform, said cam dog including a means enabling the cam dog to be flung by centrifugal force into a position to energize said linkage and said brake means when the speed of the platform exceeds said prescribed maximum.
Claim 9
Dependent Claim
61 words
The invention as claimed in claim 5, in which the governor bears a spring biased cam, said cam is responsive to a centrifugal force generated when the platform speed exceeds the prescribed maximum to energize an activating lever forming part of said linkage, and said activating lever includes means to release spring elements in said linkage and operate said brake means.
Claim 10
Dependent Claim
33 words
The invention as claimed in claim 5, in which said guide member is a cable and the first cam surface is operable to lock said cable between itself and the second cam surface.
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) | 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 |