US3799302A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manual and fluid pressure brake release for hoists
Assignee: Gardner Denver Inc
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Filing: 1972-10-12
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Granted: 1974-03-26
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Expires: 1992-10-12
Abstract
Abstract The release mechanism of a manually actuated brake for a pneumatic hoist includes piston and cylinder type pneumatic actuators interposed in the actuating mechanism for the brake shoes. Actuation of the brake release mechanism when the air supply to the hoise is insufficient to raise or hold a load will result in movement of the actuator piston rods with respect to the cylinders to prevent movement of the brake shoes.
Inventors
- 👤 L Workman
- 👤 J Bos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:27
CPC Classifications
B; B66; B66D; B66D5/00; B66D5/02; B66D5/06; B66D5/08; B66D3/00; B66D3/18; F; F16; F16D; F16D49/00; F16D49/16; F16D59/00; F16D65/00; F16D65/38; F16D65/40; F16D65/42; F16D65/46
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
185 words
In a hoist including a fluid operated motor: means connected to said motor for hoisting a load; releasable brake means for preventing unwanted movement of said means and characterized by a rotatable brake drum, a pair of opposed brake shoes pivotally mounted on said hoist, and biasing means for biasing said brake shoes into engagement with said drum; conDuit means for conveying pressure fluid to operate said motor; control valve means interposed in said conduit means; mechanism including manual actuating means for actuating said control valve and releasing said brake means and characterized by a rotatable control shaft including a cam member; and, fluid actuator means including pressure fluid piston and cylinder means disposed between said cam member and said brake shoes and being connected to receive pressure fluid from said conduit means, said fluid actuator means being operable to prevent movement of said brake shoes to release said brake drum in response to actuation of said manual actuating means when the fluid pressure in said conduit means is insufficient to operate said motor means to raise or hold a load connected to said hoist.
Claim 2
Dependent Claim
185 words
In a hoist including a fluid operated motor: means connected to said motor for hoisting a load; releasable brake means for preventing unwanted movement of said means and characterized by a rotatable brake drum, a pair of opposed brake shoes pivotally mounted on said hoist, and biasing means for biasing said brake shoes into engagement with said drum; conDuit means for conveying pressure fluid to operate said motor; control valve means interposed in said conduit means; mechanism including manual actuating means for actuating said control valve and releasing said brake means and characterized by a rotatable control shaft including a cam member; and, fluid actuator means including pressure fluid piston and cylinder means disposed between said cam member and said brake shoes and being connected to receive pressure fluid from said conduit means, said fluid actuator means being operable to prevent movement of said brake shoes to release said brake drum in response to actuation of said manual actuating means when the fluid pressure in said conduit means is insufficient to operate said motor means to raise or hold a load connected to said hoist.
Claim 3
Dependent Claim
89 words
The invention set forth in claim 1 wherein: said piston and cylinder means comprise a cylinder and piston unit mounted on each of said brake shoes and including a cam follower engageable with said cam member, said cylinder and piston units being disposed for relative movement between said pistons and said cylinders in response to the movement of said cam member when said fluid pressure in said cylinders and said conduit means is insufficient to operate said motor means to raise or hold a load connected to said hoist.
Claim 4
Dependent Claim
28 words
The invention set forth in claim 2 wherein: said piston and cylinder units include adjustable stop means to limit the movement of said pistons relative to said cylinders.
Claim 5
Dependent Claim
44 words
The invention set forth in claim 2 wherein: said cam followers are disposed on said piston and cylinder units for limited relative movement with respect to said brake shoes to provide for limited movement of said control shaft without movement of said brake shoes.
Claim 6
Dependent Claim
173 words
In a hoist including a fluid operated motor; means connected to said motor for hoisting a load; releasable brake means for preventing unwanted movement of said means; conduit means for conveying pressure fluid to operate said motor; control valve means interposed in said conduit means; mechanism including manual actuating means for actuating said control valve and releasing said brake means and characterized by a movable control shaft and a member connected to said shaft and movable in response to the movement of said shaft to release said brake means; and, fluid actuator means connected between said member and said brake means so as to transmit brake releasing force from said member to said brake means and being connected to receive pressure fluid from said conduit means, said fluid actuator means being operable to prevent the release of said brake means in response to the movement of said member when the fluid pressure in said conduit means is insufficient to operate said motor means to raise or hold a load connected to said hoist.
Claim 7
Dependent Claim
173 words
In a hoist including a fluid operated motor; means connected to said motor for hoisting a load; releasable brake means for preventing unwanted movement of said means; conduit means for conveying pressure fluid to operate said motor; control valve means interposed in said conduit means; mechanism including manual actuating means for actuating said control valve and releasing said brake means and characterized by a movable control shaft and a member connected to said shaft and movable in response to the movement of said shaft to release said brake means; and, fluid actuator means connected between said member and said brake means so as to transmit brake releasing force from said member to said brake means and being connected to receive pressure fluid from said conduit means, said fluid actuator means being operable to prevent the release of said brake means in response to the movement of said member when the fluid pressure in said conduit means is insufficient to operate said motor means to raise or hold a load connected to said hoist.
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) | 1977-03-25 | 1977-09-24 | 1978-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-25 | 1981-09-24 | 1982-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-25 | 1985-09-24 | 1986-03-26 | $7700.00 | Window Closed / Lapsed |