Machinery safety guards

A machinery safety guard for encircling a tool comprising a mounting ring for application to a non-rotatable part of a drilling machine or the like in generally coaxial relationship with the tool to be carried by such a machine;

• a generally tubular guard body releasably attachable to the said mounting ring;
• resilient, yieldable, retention means attaching the upper end of said guard body to said mounting ring for quick release thereof by an extraction force;
• a guard sleeve slidably mounted on said body and freely movable in the axial direction thereof, the sleeve being adapted and arranged so as to make visible the region of the drilling tool;
• respective access slots in the guard body and guard sleeve each extending upwardly from an open end in the lower edges thereof to facilitate application of the guard body to, and its removal from, the mounting ring in the presence of a drill bit, the open ended slots being of a lesser length than the elements in which the slots are respectively provided;
• at least one pin on the guard body for cooperation with at least one nearly vertical, sharply inclined slit in the sleeve, thereby to impart a rotational motion between the body and guard on relative axial motion therebetween to effect angular displacement, for a distance slightly greater than the width of an access slot, between the said access slots on such axial motion;
• whereby the respective open ended access slots in the guard body and guard sleeve register in radial and axial alignment in the retracted position of the sleeve on the body but are angularly spaced in the peripheral direction of the guard in the operative position of the sleeve to at least partially close the lower said access slot in said guard sleeve during use.