Oval frame razor
US7178243B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 2004 |
| Grant date | Feb 20, 2007 |
| Priority date | — |
| Expiry date | Nov 10, 2024 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB26B21/44
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A razor blade unit for safety razor has optimized shape and dimensions for body shaving, especially the regions of the axillae. The blade unit has an elongate blade with a rectilinear sharpened edge, and a skin contacting surface at which the length is 1 to 4 times the width and not greater than 60 mm, preferably 40 to 45 mm. The skin contacting surface has a footprint area of at least 450 mm2, preferably 600 to 750 mm2, and a circularity which is not less than the lower of (i) 65%, and (ii) the circularity of a rectangle with the same length and width as the skin contacting surface and with corner radii of 30% of the width. In a plane perpendicular to the blade edge the skin contacting surface is convex and shaped to make at least three point contact with an imaginary circumscribing circle with a radius of 15 to 70 mm, preferably 25 mm. Guard cap surfaces in front of and behind the blade edge each have a skin contact area of at least 140 mm2, and their combined area is preferably at least 400 mm2, e.g. 450 to 500 mm2. A preferred shape is rectangular with semi-circular ends.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.