Portable post driving apparatus
US8640787B2 · kind B2 · utility
Inventor
Key dates
| Filing date | Dec 30, 2009 |
| Grant date | Feb 4, 2014 |
| Priority date | — |
| Expiry date | Jan 30, 2031 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE04H17/263
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An improved valve for a portable post driver. The post driver has an inner hollow cylinder open at both ends and adapted to receive a post through a lock clamp located at its lower end. An outer hollow cylinder having a closed upper end, and slightly larger in diameter than the inner cylinder, is located in sliding engagement over the inner cylinder. First and second power cylinders are attached to upper and lower surfaces of the outer cylinder in alignment with each other. A common piston rod connects the pistons of the power cylinders. A stationary fastening pin attached to the piston rod extends through a slot in the wall of the outer cylinder and is attached to the wall of the inner cylinder. The valve has a reciprocating valve piston which alternately communicates the two power cylinders to a source of fluid under pressure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.