Lock assembly for extension handle

An extension handle apparatus comprising:

• a tubular receiving member presenting an open receiving end and an inner surface;
• an elongated sliding member having a first axial end that protrudes beyond the receiving member, and a second axial end telescopically received within the receiving member through the receiving end for allowing axial extension and retraction of the sliding member relative to the receiving member;
• and
• a lock assembly for releasably locking the sliding member in any selected axial position relative to the receiving member upon relative rotation between the sliding member and the receiving member, the lock assembly including a cam supported on the sliding member within the receiving and including an elongated body defining a longitudinal axis of the cam and possessing a non-circular cross-sectional shape presenting major and minor diameters through the longitudinal axis that are offset from one another by 90 degrees, the major diameter being greater than the minor diameter,
• a shoe of generally C-shaped cross-section supported on the cam body and defining a longitudinal axis, the shoe including an axial opening of non-circular cross-sectional shape corresponding to the cross-sectional shape of the cam body, the opening presenting major and minor diameters through the longitudinal axis of the shoe that are offset from one another by 90 degrees, the minor diameter of the opening being about equal to the minor diameter of the cam body and smaller than the major diameter of the cam body, and
• a retaining means for retaining the shoe on the cam body and preventing relative axial shifting movement between the shoe and the cam,
• the cam body being rotatable relative to the shoe between a locked position in which the major diameter of the cam body is aligned with the minor diameter of the shoe opening, forcing the shoe against the inner surface of the receiving member to lock the sliding member against axial movement, and an unlocked position in which the minor diameter of the shoe opening of the cam body is aligned with the minor diameter on the shoe opening, releasing the locking force on the shoe to allow the sliding member to be extended and retracted
• wherein the cross-sectional shapes of the cam and the shoe permit the cam body to be rotated in one direction to its locked position and to be subsequently rotated in the same direction to its unlocked position.