Telescopic hydraulic hoist apparatus
US5983778A · kind A · utility
9Cited by
7References
20Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 28, 1997 |
| Grant date | Nov 16, 1999 |
| Priority date | — |
| Expiry date | Jul 28, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B15/16
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A telescoping hydraulic hoist formed from a non-corrosive material provides bearings and hydraulic seals about the bottom portion of each intermediate moving stage. The bearings and hydraulic seals are thus always maintained within the hoist and are not exposed to dust or particulate matter from outside the hoist. Air flows into and out of the air spaces between adjacent stages through air breathers. The hoist may also include variable length stroke limiters, and a cushion member which partially closes off the hydraulic inlet as the innermost stage is fully retracted to slow the hoist motion in the final stages of retraction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.