US3552720A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Balancing apparatus for hoists
Assignee: Individual
•
Filing: 1968-09-30
•
Granted: 1971-01-05
•
Expires: 1988-09-30
Abstract
Abstract A hoist having a lifting cable for raising and lowering a pneumatic balancing attachment and a load with respect to a suspended position is disclosed. The balancing attachment allows the load to be manually, vertically positioned by a fingertip effort between suspended positions without vertically moving the cable.
Inventors
- 👤 Lorne J Mckendrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:18
CPC Classifications
B; B66; B66D; B66D3/00; B66D3/18
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
142 words
An apparatus for converting a hoist into a balancer wherein the hoist includes a fluid pressure system and means selectively actuated by said fluid pressure system for raising and lowering a load, said apparatus being mounted intermediate said fluid pressure actuated means and said load and comprising a cylinder, a piston slidably supported in said cylinder and operable to vary the vertical distance between said fluid pressure actuated means and said load at any given vertical position of said load as produced by said hoist and a fluid pressure system connected with said cylinder to provide pressure to one side of said piston and to exhaust fluid from the other side of said piston in a manner which produces balancing of the load so that the load can be manually positioned throughout the vertical distance provided by the stroke of said piston.
Claim 2
Independent Claim
142 words
An apparatus for converting a hoist into a balancer wherein the hoist includes a fluid pressure system and means selectively actuated by said fluid pressure system for raising and lowering a load, said apparatus being mounted intermediate said fluid pressure actuated means and said load and comprising a cylinder, a piston slidably supported in said cylinder and operable to vary the vertical distance between said fluid pressure actuated means and said load at any given vertical position of said load as produced by said hoist and a fluid pressure system connected with said cylinder to provide pressure to one side of said piston and to exhaust fluid from the other side of said piston in a manner which produces balancing of the load so that the load can be manually positioned throughout the vertical distance provided by the stroke of said piston.
Claim 3
Dependent Claim
58 words
The apparatus as defined in claim 1 and in which said hoist includes a cable adapted to be connected with the load and movable up and down to vary the position of the load and said balancer is adapted to be mounted on the end of said cable and includes means for connecting said piston to said load.
Claim 4
Dependent Claim
30 words
The apparatus as defined in claim 1 and in which the fluid pressure system for said balancer is adapted to Be connected to the fluid pressure system of said hoist.
Claim 5
Dependent Claim
134 words
In combination with a hoist which is only capable of raising and lowering a load, a balancing apparatus carried by said hoist and operable to provide balancing of the load over a limited vertical distance, said hoist including a load-supporting member and fluid pressure means for raising and lowering said load-supporting member, said balancing apparatus including a cylinder connected at the end of said load-supporting member, a piston disposed within said cylinder and having means for connecting said piston to the load whereby the load and the piston move together with and also independently of movement of said load-supporting member and fluid pressure means connected with said cylinder to act upon said piston to produce balancing of said load over the range of movement of the load provided by the stroke of said piston.
Claim 6
Dependent Claim
134 words
In combination with a hoist which is only capable of raising and lowering a load, a balancing apparatus carried by said hoist and operable to provide balancing of the load over a limited vertical distance, said hoist including a load-supporting member and fluid pressure means for raising and lowering said load-supporting member, said balancing apparatus including a cylinder connected at the end of said load-supporting member, a piston disposed within said cylinder and having means for connecting said piston to the load whereby the load and the piston move together with and also independently of movement of said load-supporting member and fluid pressure means connected with said cylinder to act upon said piston to produce balancing of said load over the range of movement of the load provided by the stroke of said piston.
Claim 7
Dependent Claim
28 words
The combination as defined in claim 4 and in which the fluid pressure means of said hoist is connected with the fluid pressure means of said balancing apparatus.
References Cited (Backward Citations)
US2500879A
Cited
US2949894A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |