Patent ID: 6325181
Filing Date: 2001-12-04
Classification: F16D

Abstract:
A piston assembly adapted for use in a wheel cylinder of a drum brake assembly having a pair of brake shoes which arc urged into frictional engagement with a brake drum comprising:a piston body formed from a plastic material and defining an axis, said piston body including an inner face, an outer face, and a stepped opening formed in said outer face and extending toward said inner face, said stepped opening including a first opening and a second opening, said first opening defining a first opening dimension and said second opening defining a second opening dimension less than said first opening dimension, said first opening disposed adjacent said outer face and said second opening disposed between said first opening and said inner face; anda piston insert formed from a non-plastic material, said piston insert including an outer end adapted to engage a brake shoe of the drum brake assembly and an opposite inner end extending into said piston body, said inner end of said piston insert including a first section and a second section, said first section including a first radially outwardly extending flange disposed in said first opening of said piston body to provide a pressure distributing means which is operative to distribute pressure across an associated adjacent surface of said piston body directly adjacent said outer face thereof, wherein said second section of said inner end of said piston insert is generally tapered and said second section including means for securing said inner end of said piston insert to said piston body.