Patent · US Expired

Escapement mechanism and backspace mechanism for a moving paper carriage typewriter having dual pitch capability

US4285605A · kind A · utility

1Cited by
5References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 2, 1979
Grant dateAug 25, 1981
Priority date
Expiry dateJul 2, 1999

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB41J19/58
  • WIPO fieldTextile and paper machines
  • WIPO sectorMechanical engineering

Abstract

A mechanism which will function to allow the escapement of the carriage of a typewriter in one of two predetermined escapement pitches and be capable of backspace operation from a single backspace input for both pitches regardless of which escapement pitch is selected. Escapement ratchets for the two selected pitches are combined, together with a backspace ratchet. Each of the escapement ratchets are engageable by an escapement pawl and the engagement of a pawl with a particular ratchet will determine the pitch within which the escapement system will function. A backspace ratchet is combined with the escapement ratchets and fixedly attached thereto to provide the backspace drive. The backspace ratchet is selectably engageable by the backspace pawl for causing rotation in the opposite direction of that normally utilized for escapement. All motion of the escapement ratchets or backspace ratchet is transmitted through a pinion mounted to the ratchet assembly and, in turn, is transmitted to the paper carriage rack.

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