GB671501A - Improvements in or relating to a sanding attachment for a motor - Google Patents

Abstract

671,501. Rotary abrasive tools. WATSON, R. D., and SHAPIRO, J. March 21, 1950, No. 6996/50. Class 60. A sanding attachment for a motor comprises a backing plate having an interiorly screwthreaded socket through its rear face adapted to fit on the end of a motor shaft or an adaptor and having a second screw-threaded socket surrounded by a soft pad through the front face, and a slip clutch for holding a polishing disc against the pad, the clutch comprising a stud screwed into the second socket and a friction ring mounted on the stud for engaging the polishing disc and frictionally pressing it against the pad. A rigid backing plate 7 has a hub 8 with a screw-threaded socket 9 at the rear and a, screwthreaded socket 10 at the front with a web 11 between the sockets. The socket 9 fits the motor shaft 12 or an adaptor so that the backing plate may be screwed down on to the end of the motor shaft on top of the round disc or backing plate 13. A thick resilient annular pad consisting of a canvas foundation 14 with woollen pile threads 15 is secured 'to the backing plate, e.g. by cement. The sand paper or emery cloth disc 16 is clamped against the pad by a steel screw stud 17 and a phosphor bronze slip ring 18. The stud screws into the socket 10; the slip ring has a groove 19 to receive the disc 16 and is rotatably mounted on the hub 20 of the stud beneath the flange 21. A stop member 22 may be screwed into the web 11 at the bottom of the socket 10 to limit the seating of the screw stud; the stop member may be removed or replaced by a thinner stop when the pad becomes worn or compressed. The outer face of the stud 17 may have a knurled or roughened surface or a slot to facilitate turning it. In use, disc 16 rotates with the pad but may be controlled by varying the pressure of the disc against the work whereupon the ring 18 slips on the hub of the stud.