Driver tool
US4168751A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 29, 1976 |
| Grant date | Sep 25, 1979 |
| Priority date | — |
| Expiry date | Sep 29, 1996 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE04H17/263
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A driver tool of the power hammer type is equipped with a compression spring acting on the anvil of the tool and loaded by the weight of the tool and by downcrowding to store energy from the load and from attempted rebound of the anvil which is released to the anvil in a driving direction adding to the driving force of the hammer. The spring has a stiffness and a length effective to maintain a free stroke length for the hammer before impacting the anvil when the tool is loaded or downcrowded sufficiently to maintain the anvil thrusting against the workpiece and to develop and build up vibrations from the hammer blows. The hammer blows are divided into impulses by the vibrations allowing the workpiece to recover from blows of magnitudes beyond the elastic limit of the workpiece material which would otherwise damage the workpiece. The preferred spring is a cylindrical spaced coil helical spring having its bottom coil engaging the anvil in good vibration transferring relation and a top end coil bottomed on the end wall of a slip housing surrounding the spring and anvil. The housing is bottomed on the bottom end face of the tool body. A nonmetallic slip washer is preferably interposed …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.