Lifting device
US4175899A · kind A · utility
Inventor
Key dates
| Filing date | Dec 30, 1977 |
| Grant date | Nov 27, 1979 |
| Priority date | — |
| Expiry date | Dec 30, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S414/13
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A device for raising and lowering sheets of building material utilizes a base support platform on which is attached a support bracket member and a pair of serially connected first and second parallelogram members pivotally joined by a right angle member with the other end of first parallelogram member pivotally connected to the base support platform and the other end of second parallelogram member pivotally connected to an object supporting platform. A spacer arm is pivotally connected to the support bracket and to one leg of the second parallelogram member proximately midway between pivotally connected ends to keep the object supporting platform on a long radius curve or generally straight vertical direction of movement. Hydraulic means are provided for actuating the spacer arm to raise and lower the object supporting platform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.