Foot element and cooperable strut element for use in a roof support mechanism

In adjustable roof support mechanism for supporting the roof of a mine which includes a front shield, a rear shield, an elongated foot element and a cooperable strut element, the improvement wherein said elongated foot element has a front end and a rear end and opposite side walls which extend along a portion of its length, said side walls having facing surfaces that contain aligned guide grooves, said aligned guide groove including elongated entry portions that are sloped downwardly as they extend toward the rear end of said foot element and enlarged terminal portions;

• and the extendable strut includes a tubular body and two cams which respectively extend away from opposite sides of the tubular body near a lower end thereof, each of said cams including a side portion which is cylindrical and a side portion which is flat, each said flat surface portion extending in the longitudinal direction of said tubular body;
• said cams fitting within and being movable along the respective elongated entry portions of the guide grooves in the facing sides of the side walls of the foot element when the strut is being mounted on or removed from said foot element, and when located in the terminal portions of the grooves, are rotatable therein to enable said strut element to be oriented in a use position yet prevent unintentional separation from said foot element.