Writing implement
US4952089A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 5, 1988 |
| Grant date | Aug 28, 1990 |
| Priority date | — |
| Expiry date | Oct 5, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB43K5/1845
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A writing implement for use in numerically controlled drafting machines has a tip with a front end face which is maintained at a distance of a fraction of one millimeter from the surface of a sheet of paper or another carrier of information by a portion of a ball which is rotatably mounted in a socket extending rearwardly from the front end face so that the surface of the carrier and the front end face define a capillary gap. This gap draws ink from the socket which receives ink from a channel extending into a reservoir in the housing of the implement. The channel contains several rib-shaped back supports each of which is in mere point contact with the adjacent confined major portion of the ball in the socket so as to center the ball in the socket whereby the confined major portion of the ball and the surface surrounding the socket define a capillary clearance, and to provide paths for the flow of ink from the channel into the socket. The width of the lines to be drawn on the surface of the carrier is determined by the diameter of the front end face of the tip. The front end face of the tip can be formed with radially outwardly extending capillary grooves which promote the flow of …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.