Patent · US Expired

Out-of-ink sensing method

US4940997A · kind A · utility

63Cited by
2References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 8, 1989
Grant dateJul 10, 1990
Priority date
Expiry dateAug 8, 2009

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB41J2002/17576
  • WIPO fieldTextile and paper machines
  • WIPO sectorMechanical engineering

Abstract

In an ink-jet printer, a ball check-valve (32) is used over the ink outlet (28) of an ink bag (16) to interrupt the flow of ink and/or air to the ink bladder when the ink supply in the bag falls below a predetermined level (40). The specific gravity of the ball is less than the specific gravity of ink in the bag but greater than the specific gravity of air.

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