Patent ID: 7334968
Filing Date: 2008-02-26
Classification: E21D

Abstract:
1. A yieldable prop having a first end and a second end comprising: a first hollow conduit; a second conduit slidably received in the first hollow conduit; a clamp assembly comprising an engaging collar, the engaging collar having an inner surface, an opposite outer surface, a first end, an opposite second end, a first side extending from the first end to the second end, and a second side extending from the first end to the second end and spaced from the first side to provide a slit in the collar between the first side and the second side, wherein the clamp assembly is in an engaging position when the first side is spaced a first predetermined distance from the second side, and the clamp assembly is in a non-engaging position when the first side is spaced a second predetermined distance from the second side with the first predetermined distance less than the second predetermined distance, the clamp assembly mounted on the outer surface of the second conduit with the inner surface of the engaging collar in facing relationship to the outer surface of the second conduit, wherein with the clamp assembly in the engaging position, the clamp assembly is securely mounted on the outer surface of the second conduit, and the clamp assembly and the second conduit are prevented from sliding relative to one another, and with the clamp assembly in the non-engaging position, the clamp assembly and the second conduit are free to slide relative to one another; and at least one handle having a first end portion fixedly secured to the clamp assembly and a second end portion spaced from the first end portion fixedly secured to the outer surface of the first conduit, wherein with the clamp assembly in the engaging position, the clamp assembly and the second conduit are prevented from sliding relative to one another and the first conduit and the second conduit are prevented from sliding relative to one another, and with the clamp assembly in the non-engaging position the first conduit and the second conduit are free to slide relative to one another, and the first conduit and the portion of the clamp assembly fixedly secured to the first end portion of the at least one handle are in a fixed non-movable position relative to one another.