Pin retention system

A releasable retention system for a clevis pin of a clevissed coupling member of heavy engineering equipment, said retention system comprising:

• a male coupling element having an end boss with at least one radially extending projection;
• a female coupling element having first and second flange members, each with an axially extending aperture of a shape complementary to a cross sectional shape of said end boss, said male and female coupling elements in use being slidably and non-rotatably engageable when the at least one radially extending projection on said end boss is extended through said aperture in said first flange member and into said aperture in said second flange member and thereafter by relative coaxial movement between said first flange member and, in combination, said male coupling element and said second flange member, said first and second flange members are fastened to prevent relative rotation between each other by locking means whereby said one or more radially extending projections of said male coupling element engage against a retaining face of said first flange member to prevent withdrawal of said end boss through the aperture of said first flange member, said end boss being circumferentially surrounded by said second flange member for protection against physical damage.

A retention system as claimed in 19 wherein the first flange member is secured to an outer face of said coupling member coaxial with a pin receiving aperture in said coupling member to receive said clevis pin therethrough.