Patent ID: 6435318
Filing Date: 2002-08-20
Classification: B60T,B62L,F16D

Abstract:
A bicycle disk brake assembly adapted to be mounted on a fork of a bicycle for braking a brake disk of a wheel, said bicycle disk brake assembly comprising:a caliper body adapted to be attached fixedly to the fork and having a vertical passage adapted to permit extension of the brake disk of the wheel therein, and a fluid reservoir replete with a hydraulic fluid; two brake pads mounted within said vertical passage in said caliper body and operably associated with said reservoir in such a manner that when an external pressure is applied on the fluid in said reservoir, said brake pads will move toward each other; and a pressure-reducing cylinder including an outer chamber in fluid communication with said reservoir in said caliper body, an inner chamber, a partition fixed in said cylinder between said inner and outer chambers and having an inflow passage and an outflow passage, which are formed therethrough, each of said inflow and outflow passages having an inner end that is in fluid communication with said inner chamber, and an outer end that is in fluid communication with said outer chamber, an inner check valve for limiting flow of the fluid from said outer chamber to said inner chamber, said inner check valve being biased to close said inner end of said inflow passage when the fluid pressure in said outer chamber is smaller than a first predetermined value and being activated to open said inner end of said inflow passage when the fluid pressure in said outer chamber reaches the first predetermined value, an outer check valve for limiting flow of the fluid from said inner chamber to said outer chamber, said outer check valve being biased to close said outer end of said outflow passage when the fluid pressure in said inner chamber is smaller than a second predetermined value, said outer end of said outflow passage being opened when the fluid pressure in said inner chamber reaches the second predetermined value, a piston disposed movably and sealingly within said inner chamber and movable inward within said inner chamber when the fluid flows from said outer chamber to said inner chamber, and a resilient member for urging said piston outwardly so as to bias the fluid to flow from said inner chamber to said outer chamber and subsequently to said reservoir when the fluid pressure in said inner chamber reaches the second predetermined value and when the external pressure is released from the fluid in said reservoir.