Patent · US Expired

Hydraulic fluid replenishment device

US4804023A · kind A · utility

36Cited by
8References
16Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 19, 1987
Grant dateFeb 14, 1989
Priority date
Expiry dateMay 19, 2007

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T29/53743
  • WIPO fieldMachine tools
  • WIPO sectorMechanical engineering

Abstract

A device for automatically replenishing and exchanging hydraulic fluid in the hydraulic system (such as that of a fastener placing tool 31) has a lower reservoir (29) for holding new hydraulic fluid (39) and an upper reservoir (28) for receiving old hydraulic fluid. The device connects with the system to be replenished by means of a single hydraulic fluid connection (17) at the bottom of the lower reservoir (29). An entry port (25) to the second reservoir is positioned opposite the connection (17) at the bottom end of a tube (23) leading to the top of the second reservoir. In use, the device is connected to the hydraulic system through the connection (17) and the system is pressurized. Old hydraulic fluid is forced up through the connection (17) at high speed and passes through the new hydraulic fluid (39) in the lower reservoir (29), through the port (25), up the tube (23) and down into the upper reservoir (28) where it is retained. When the system is depressurized, new hydraulic fluid (39) is drawn down through the same connection (17) into the hydraulic system.

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