Abstract: The improved grinder of this invention is provided with a non-circular peripheral surface encompassing an output shaft. The non-circular peripheral surface is arranged to receive a mating hole in a grinder wheel guard. The grinder wheel guard is positioned on the grinder by means of a threaded fastener or the like and is sufficiently large to house an appropriate grinder wheel. The arrangement between the non-circular peripheral surface on the grinder and the mating hole in the grinder wheel guard provides a means for transferring any load imposed on the grinder wheel guard directly into the body or housing of the grinder.

Abstract: An improved latching mechanism for retaining bits, such as chisels, chippers or scalers in reciprocating impact tools. The improved latching mechanism includes a latch member that is located in the hollow nose of the tool and is rotatable between latched and unlatched positions. A split spring encircles the nose and engages the latch member to prevent inadvertent rotation of the latch member and to retain the latch member in the nose. The latch member extends into the hollow nose and, when in the latched position, engages the bit to retain the bit in the tool while permitting limited reciprocating movement of the bit. When in the unlatched position, the latch member frictionally engages the bit to inhibit inadvertent discharge of the bit, while permitting intentional insertion and removal of the bit.