The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 14, 1989
Filed:
May. 19, 1987
William H Frearson, Letchworth, GB;
Avdel Limited, British Company, Hertfordshire, GB;
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.