Powder pressing apparatus, punch, method for pressing powder and method for manufacturing the punch
US6413457B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1999 |
| Grant date | Jul 2, 2002 |
| Priority date | — |
| Expiry date | Dec 22, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB30B15/065
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A powder pressing apparatus comprises an upper punch, a lower punch and a die. A compact is formed by pressing a powder loaded in a cavity formed by the upper punch, the lower punch and the die. At least either one of the upper punch and the lower punch has a contacting surface for contact with the compact, formed with grooves. The compact adhering to the upper punch or the lower punch may be sprayed with a liquid such as water. Thereafter, the compact adhering to the upper punch or the lower punch is removed therefrom. Preferably, the grooves should be formed by milling at least at an end portion of the contacting surface, the contacting surface should have a surface roughness Ra=0.05 &mgr;m˜25 &mgr;m, the powder should have an average grain diameter of not greater than 1 &mgr;m, the grooves should be formed at an interval of 0.1 mm˜2.0 mm to a depth of 0.2 &mgr;m˜100.0 &mgr;m.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.