Institute for Industrial Research and Standards

Mayka Research and Development

Mohammad Afshar

A hand-held grinding device 1, 50, 60 for sharpening the cutting edge 3 of a chisel 4 comprises a housing 5 in which a grinding wheel 6 is mounted and a handle member 7 defining a guide channel 20 for directing the cutting edge 3 to the wheel 6. The grinding wheel 6 is mounted on a shaft 10 with a free end 8 for mounting in the chuck 9 of a power tool 19. The guide channel 20 has a rear end entry 22 and an end exit 21 adjacent to the grinding surface of the wheel 6. The cutting edge 3 of a chisel 4 to be sharpened is urged against the grinding wheel 6 by spring biassing elements 25, 26 extending into the guide channel 20. A forward bridge 30 is provided above the exit 21 and a rearward bridge member 35 is provided above the end entry 22.

Grinding device

A hand held grinding device for sharpening drill bits comprises a pair of bearing members which rotatably support a grinding wheel fast on a shaft. Portion of the shaft is engagable with the chuck of a drill. A guide plate with grooves for various size ranges of drill bits is hingedly connected to the bearing members by a plastics hinge. The grooves direct the drill bit to the grinding wheel at an angle of 59.degree.. By pivoting the guide plate relative to the bearing members, the trailing portion of the cutting edge of the drill bit is relieved.

Growing community of inventors

Dublin, Ireland

Mohammad Afshar