US3791627A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pneumatically-operated hoist with automatic control system
Assignee: DW Zimmerman Manufacturing Inc
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Filing: 1971-09-20
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Granted: 1974-02-12
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Expires: 1991-09-20
Abstract
Abstract A pneumatically-operated hoist is operated through an automatic, pneumatic control system. The operation of the hoist is initiated through an external signal for the pneumatic control system by means of which the hoist is automatically directed through a plurality of sequential steps. The hoist preferably has at least two remotely-positioned bleed elements which are operated through the pneumatic control elements to control the hoist pressure at predetermined values in a manner such that an operator can manipulate a load with the hoist in a desired manner without having to operate any manual controls at all. The control system also is equipped with a bleed element which opens to slowly bleed the hoist in the event of air failure, so that a load carried by the hoist can be safely lowered.
Inventors
- 👤 C Stone
- 👤 E Foster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:33
CPC Classifications
B; B66; B66D; B66D3/00; B66D3/18; B66D2700/00; B66D2700/02; B66D2700/026
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
188 words
In combination, a pneumatically-operated hoist comprising a housing, means carrying a cable within said housing and adapted to raise the cable when moved in one direction in said housing and to lower the cable when moved in the opposite direction in said housing, means forming a power chamber in said housing and effective to move said cable-carrying means in said one direction when pressure in said chamber is at least equal to a predetermined amount, said cable-carrying means moving in said opposite direction when the pressure in said chamber is below the predetermined amount, when a given load is carried by the cable, controller means for supplying gas to said chamber, a bleed line communicating with said controller means and extending away from said hoist, at least two automatically-operated bleed elements communicating with said bleed line, and control means for opening and closing said bleed elements in a predetermined sequence for regulating said controller means to supply gas to said power chamber at at least three different pressures to enable loads to be moved up and down without any manual manipulation of said control means and bleed elements.
Claim 2
Dependent Claim
188 words
In combination, a pneumatically-operated hoist comprising a housing, means carrying a cable within said housing and adapted to raise the cable when moved in one direction in said housing and to lower the cable when moved in the opposite direction in said housing, means forming a power chamber in said housing and effective to move said cable-carrying means in said one direction when pressure in said chamber is at least equal to a predetermined amount, said cable-carrying means moving in said opposite direction when the pressure in said chamber is below the predetermined amount, when a given load is carried by the cable, controller means for supplying gas to said chamber, a bleed line communicating with said controller means and extending away from said hoist, at least two automatically-operated bleed elements communicating with said bleed line, and control means for opening and closing said bleed elements in a predetermined sequence for regulating said controller means to supply gas to said power chamber at at least three different pressures to enable loads to be moved up and down without any manual manipulation of said control means and bleed elements.
Claim 3
Dependent Claim
28 words
The combination according to claim 1 characterized further by an emergency bleed element, and means for bleeding said emergency bleed element when the main gas supply is off.
Claim 4
Dependent Claim
22 words
The combination according to claim 1 wherein said control means for actuating said bleed elements includes at least one pneumatic timing element.
Claim 5
Dependent Claim
26 words
The combination according to claim 1 characterized by means for establishing an external signal effective to initiate operation of said control means for said bleed elements.
Claim 6
Dependent Claim
16 words
The combination according to claim 4 characterized further by said external signal means being manually operated.
Claim 7
Dependent Claim
57 words
The combination according to claim 4 characterized further by said external signal means includes said hoist cable having a vacuuM cup for engaging a load, means for establishing a vacuum in said cup when engaged with the load, and means connecting said cup with a component responsive to the vacuum for initiating operation of said control means.
Claim 8
Dependent Claim
149 words
In combination, a pneumatically-operated hoist comprising a housing, means carrying a cable within said housing and adapted to raise the cable when moved in one direction in said housing and to lower the cable when moved in the opposite direction in said housing, means forming a power chamber in said housing, a piston associated with said power chamber and movable with said cable-carrying means according to the pressure in said power chamber, bleed means connected with said hoist and effective to control the pressure in said power chamber according to the degree of bleeding of fluid by said bleed means, means associated with said bleed means for changing the degree of bleeding, and pneumatic control means for actuating said bleed means in a predetermined sequence, whereby the pressure in said power chamber is controlled at different values in a predetermined sequence without any manual manipulation of said bleed means.
Claim 9
Dependent Claim
149 words
In combination, a pneumatically-operated hoist comprising a housing, means carrying a cable within said housing and adapted to raise the cable when moved in one direction in said housing and to lower the cable when moved in the opposite direction in said housing, means forming a power chamber in said housing, a piston associated with said power chamber and movable with said cable-carrying means according to the pressure in said power chamber, bleed means connected with said hoist and effective to control the pressure in said power chamber according to the degree of bleeding of fluid by said bleed means, means associated with said bleed means for changing the degree of bleeding, and pneumatic control means for actuating said bleed means in a predetermined sequence, whereby the pressure in said power chamber is controlled at different values in a predetermined sequence without any manual manipulation of said bleed means.
Claim 10
Dependent Claim
28 words
The combination according to claim 7 characterized further by additional bleed means for automatically reducing the pressure in said power chamber when the main gas supply is off.
Claim 11
Dependent Claim
17 words
The combination according to claim 7 wherein said control means includes at least one pneumatic timing element.
Claim 12
Dependent Claim
22 words
The combination according to claim 7 characterized by means for establishing an external signal effective to initiate operation of said control means.
Claim 13
Dependent Claim
16 words
The combination according to claim 10 characterized further by said external signal means being manually operated.
Claim 14
Dependent Claim
20 words
The combination according to claim 10 characterized further by said external signal means includes means for effecting a pressure change.
Claim 15
Dependent Claim
37 words
The combination according to claim 1 characterized further by said control means actuates said bleed elements so that both of said elements are closed, one of said elements is open, and both of said elements are open.
Claim 16
Dependent Claim
47 words
The combination according to claim 1 characterized by one of the three pressures being at least equal to said predetermined amount, another of said pressures being below said predetermined amount, and the third of said pressures being at an amount between the other two of said pressures.
Claim 17
Dependent Claim
46 words
The combination according to claim 7 characterized further by said bleed means includes at least two automatically-operated bleed valves, and said pneumatic control means actuates said bleed valves to cause pressure in said chamber to be at any of three different values in the predetermined sequence.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |