Patent · US Expired

Automatic pencil device for automatic drafting and writing machines

US4809023A · kind A · utility

3Cited by
10References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 5, 1983
Grant dateFeb 28, 1989
Priority date
Expiry dateAug 5, 2003

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB43K21/027
  • WIPO fieldOther consumer goods
  • WIPO sectorOther fields

Abstract

An automatic lead pencil device has a casing which is releasably mountable in a bracket of a drafting machine. Within the casing, there is a clamp sleeve in which a clamping member is axially movable for clamping and releasing a lead during use of the pencil device. An axial movable lead guide tube projects outwardly of the casing in the rest position, and there is a pencil brake within the lead guide tube. The contact zone between the clamping member and the clamp sleeve is constructed so as to be of the non-self-locking type. There is an operative connection between the clamping member and the lead guide tube such that the clamping member is closed when the lead guide tube moves axially inwardly to assume the working position and opens when the lead guide tube moves axially outwardly toward a rest position.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.