Resilient type sealing member for sealing a push rod member of a railway type vehicle brake cylinder

An improved resilient type sealing member for use at least in a railway application which requires both sealing of an annular space located between an inner surface of a brake cylinder member and an adjacent outer surface of a piston member at least partially disposed for reciprocal movement within such brake cylinder member and for providing a required amount of support for such piston member during such reciprocal movement, said improved resilient type sealing member comprising:

• (a) a generally uniformly round resilient disc-like member having each of a first predetermined diameter and a including a pair of radially opposed and substantially flat parallel side portions, said predetermined diameter being uniform along said predetermined thickness from a point closely adjacent a first side of said pair of radially opposed and substantially flat parallel side portions to a point closely adjacent a second side of said pair of radially opposed and substantially flat parallel side portions;
• (b) a first groove, having a first predetermined shape and a first predetermined depth, formed in a first one of said pair of said radially opposed and substantially flat parallel side portions of said resilient disc-like member, said first groove being disposed closely adjacent an outer edge of said resilient disc-like member, said first groove beginning at said first one of said pair of substantially flat parallel side portions and extending inwardly therefrom toward a second one-of said pair of substantially flat parallel side portions;
• (c) a second groove, having a second predetermined shape and a second predetermined depth, formed in said second one of said pair of said radially opposed and substantially flat parallel side portions of said resilient disc-like member, said second groove being disposed closely adjacent said outer edge of said resilient disc-like member, said second groove beginning at said second one of said pair of substantially flat parallel side portions and extending inwardly therefrom toward said first one of said pair of substantially flat parallel side portions, said second groove being substantially radially opposed to said first groove;
• and
• (d) a generally uniformly cylindrical aperture sealingly engageable with such adjacently disposed outer surface of such piston member, having a second predetermined diameter, formed substantially through a center of said resilient disc-like member.