Patent · US Expired

Oil pump

US4801253A · kind A · utility

9Cited by
13References
8Claims
0Family size

Assignee

Inventor

Key dates

Filing dateOct 31, 1986
Grant dateJan 31, 1989
Priority date
Expiry dateOct 31, 2006

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB27B17/12
  • WIPO fieldMachine tools
  • WIPO sectorMechanical engineering

Abstract

Instead of a hand-operated oil pump for supplying extra oil to the chain of a motor saw, two pumps according to the invention are disposed on the same shaft. The first one works always, while the second one can be switched on and off. The switching is effected by choking the feed of oil partly or completely to the second one. Both the pumps are controllable by decreasing the piston stroke.

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