US Patent:
20120085090, Apr 12, 2012
Inventors:
Jeffrey S. Gohr - Menomonee Falls WI, US
Vesa Ahola - Oak Creek WI, US
James Dimsey - Elm Grove WI, US
International Classification:
B60T 11/16
Abstract:
Disclosed herein is a hydraulic master cylinder body having a bore defined at least in part by a bore wall, wherein the bore wall includes an opening for hydraulic fluid to be passed into the bore, and a piston assembly situated at least substantially in the bore, the assembly having a piston with a piston body and at least one cup seal situated substantially around the piston body, the cup seal situated adjacent to the bore wall so as to be in sealing engagement therewith, and a back-up ring that is situated about the piston body, wherein the back-up ring is positioned to at least partially cover a portion of the cup seal that is adjacent to the bore wall and to prevent at least a portion of the cup seal from contacting the bore wall and the opening for hydraulic fluid during piston actuation.
