Throttle valve construction for a percussion tool
US3939925A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 21, 1974 |
| Grant date | Feb 24, 1976 |
| Priority date | — |
| Expiry date | Jan 21, 1994 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25D2250/265
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A throttle valve construction for a pneumatic paving breaker and other types of percussion tools employing a reciprocating piston to impart blows to a work steel or the like is disclosed, wherein partial movement of the control lever of the tool from a fully depressed position to a partially depressed position permits the throttle valve to shift to a position which substantially reduces the quantity of air under pressure being supplied to the operating cylinder of the tool so that the reciprocation frequency and kinetic energy of the piston are reduced. The amplitude and frequency of the vibrations generated by the tool and transmitted to the operator thereof are likewise substantially reduced when the tool is operating in this mode, and a significant reduction in the level of the sound emitted by the tool is also obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.