Hydraulic spike puller
US9145648B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 14, 2012 |
| Grant date | Sep 29, 2015 |
| Priority date | — |
| Expiry date | Jun 26, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49822
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A pulling tool includes a housing and a tube disposed within the housing, the tube configured to supply hydraulic fluid. The spike puller further includes a piston rod connected to a piston. The piston rod has a hollow axial bore, and the piston and the piston rod are axially moveable relative to the tube. The spike puller has a passage communicating fluid from the tube to the piston. The passage is contained within the housing. The passage is variable between a first configuration in which hydraulic fluid flows at a first restricted flow so as to provide a slower retraction of the piston rod and a second configuration in which hydraulic fluid flows at a second less restricted flow so as to provide a faster retraction of the piston rod.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.