Patent ID: 8894329

Claim:
An anchor bolt, comprising: a screw member having a head defining a proximal end of the screw member, and an elongate shank extending from the head and terminating at a distal end of the screw member, the shank having a threaded end, the head being or having a feature shaped for coupling with a tool so as to render the tool capable of turning the head about an elongate axis of the screw member, thereby either axially advancing or axially withdrawing the threads of the threaded shank; a wedge member threadably engaged by the threaded portion of the shank; and a cage member defining a cavity through which the threaded end of the shank extends and into which at least a portion of the threadably engaged wedge member is allowed to penetrate, the wedge member being shaped in cooperation with the cavity to force the cavity to undergo a radial expansion as a result of being drawn into the cavity by means of advancing the threads of the threaded shank, the wedge member becoming stuck in the cavity as a result, wherein, for ejecting the wedge member from the cavity, the screw member includes at least one of (1) one or more depressed portions, and (2) one or more projecting portions, defining a step of abruptly increasing radial dimension of the screw, and wherein the cage member includes one or more corresponding step-engaging portions for making an interference contact with said step when the threads have been withdrawn from the cage and wedge members a sufficient amount, so that further withdrawal of the threads ceases to withdraw the threads relative to the cage member while continuing to withdraw the threads relative to the wedge member, thereby forcing the wedge member distally relative to the cavity.