A fastener for coupling two relatively thin members having oversized openings therein such as road guard rails which are subject to severe shear loads. The fastener includes a stud having an enlarged head portion and a body portion extending therefrom. The body portion is adapted to pass through the oversized openings and the head is adapted to engage with the surface of the adjacent thin member and is larger than the opening therein. A receptacle is provided which is adapted to interengage and disengage with the stud body between a fastened and unfastened position. At least one spiral cam slot is on the stud body and a corresponding cam surfaces on the receptacle whereby relative rotation between the stud body and receptacle will cause the cam surface to follow the cam slot between the locked and unlocked positions. A spring is positioned to be biased as the cam surface follows the spiral cam slots thereby assisting in drawing the two members into tight interengagement and retaining the stud and receptacle in fastened condition. Finally, a retainer is provided for maintaining proper orientation of the fastener when the members are subjected to a shear load so that the primary load on the fastener is a shear load thereby increasing the load therein capacity of the fastener.

A drill guide for drilling a transverse hole in a patient's knee to intersect a bony ligament tunnel formed in an arthroscopic surgical procedure for replacing the patient's cruciate ligament. The drill guide is U-shaped having spaced apart parallel co-planar legs extend from an arcuate base, one of which legs is solid to fit within the bony ligament tunnel and the other is holed at spaced intervals, the longitudinal axis of which holes point towards the solid leg, a select hole to receive a barrel turned therethrough that was an open longitudinal bore to guide a conventional drill turned therethrough and into the patient's knee to intersect, at a right angle, the bony ligament tunnel.

A slip-on receptacle adapted to be inserted on one of two members to be fastened in alignment with a hole therein and to receive and engage with a stud coupled with the other of the two members so as to fasten the two members together. The receptacle includes a base portion with an opening therein and at least one resilient mounting leg extending from the base into overlying and spaced relationship with respect thereto so as to receive the one member therebetween and mount the receptacle thereon in position with the opening in the base aligned with the opening in the one member. A resilient receptacle leg extends from the base into overlying relationship with respect thereto and is spaced from the base a predetermined distance to permit the one member to be inserted therebetween. The receptacle leg has an opening therein and stud engagement means thereon in position for alignment with the opening in the one member and the base when the receptacle is mounted on the one member to receive the stud coupled with the other member and interengaged therewith to hold the members together. The receptacle leg and each mounting leg are adapted to act independently with the resilient mounting leg accomodating dimensional width variations of the one member and the receptacle leg being a fixed distance from the side of the one member engaged by the base independent of the width diameter of the one member.

A connector for use in builder's scaffolding systems for connecting crossmembers to upright members where the upright members have sockets provided thereon and each of the sockets has an internal clamping face. The connector is coupled to one end of the crossmember. It has an upper and a lower limb spaced apart for receiving the socket therebetween. A generally trapezoidal opening having four sides, two of which are non-parallel, is provided in the two limbs. In engaging the connector, two of the four sides form first and second clamping sides. A wedge coupling member is received within the trapezoidal opening and mounted for clamping engagement with the internal clamping face of the socket and selected portions of the first and second clamping sides. The trapezoidal opening permits connection of the crossmember at a plurality of angles to the upright within the range permitted by the first and second clamping sides. The connector is further provided with an abutment coupling having two spaced-apart arms for permitting at least one of the limbs to be received therebetween. The arms have an aperture through which the wedge member can pass free of clamping action. An abutment face is provided on the abutment coupling for abutting the upright member when the wedge clamping member is in pressure engagement with the first and second clamping sides and the internal clamping face of the socket.

The clamp is of the type which may be actuated by means of an auxiliary actuating member. It consists of two parts, namely a clip (1), whose two branches are connected via a thin part (7) and a slit housing (8) in which an actuating member (2), consisting of a pin with a diameter greater than the diameter of the housing (8) or a cam equipped with a radial arm, is accommodated. The introduction of the pin or, respectively, the rotation of the cam results in closure of the clip, causing the thin part (7) to bend resiliently.