Fail-resistant hammer assembly for a valveless percussive drill
US8991515B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 31, 2008 |
| Grant date | Mar 31, 2015 |
| Priority date | — |
| Expiry date | Oct 26, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/4984
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
In a valveless percussive drill of the hydraulic type and incorporating a hammer assembly, an “intermediate” shoulder between the head portion and cushion portion of a reciprocating piston engages the end face of a distributor or liner, rather than an interior bearing structure for the piston. This end face can be made harder than the ulterior bearing structure, which may include a surface made of a different material than the piston. Collectively, the result is a percussive drill with the hammer assembly incorporating the piston substantially less susceptible to failure due to galling as the result of contamination in the working fluid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.