GB1295113A - - Google Patents

Abstract

1295113 Grinding A A HUTCHINS 20 Oct 1970 [9 March 1970] 49717/70 Heading B3D A tool comprises a drum mounted at opposite ends in bearings in a portable body, a motor 14 driving one end of the drum, a sheet 37 of surface treating material extending about the drum through approximately a single complete turn and having opposite end edges 49, 51 terminating near one another, the sheet being connectible to and removable from the drum while the drum is mounted by the bearings, and handles 15, 16 on the body. The motor 14 has a drive shaft 27 which is mounted in bearing 28 in a housing 17 and is connected by gears 33, 34 to a shaft 31 having a screw thread connected to a tubular hub 41 of the drum, the other end of the hub being supported by needle roller bearings on a stub shaft 71 carried by the end wall 72 of a shroud 18 secured to the housing 17. The hub is connected by two thin webs 42, 43 and one thick web 44 to an outer portion 39 which may carry a cylindrical cushion 45 of rubber or the like about which the sheet 37 is carried. The thick web 44 is formed with a recess 54 in which one edge of the sheet of treating material 37, such as sandpaper, is inserted and held by a rod 53 which is carried by springs 55 and can be moved by screws 59 to a position clamping the edge 50 of the sheet against a curved portion of the recess. After clamping the edge 50, the sheet is pulled around the drum and its other edge is held by adhesive 61. The housing 17 is provided with a handle 15 having a switch 24 for controlling an electrical supply or air supply to the motor, and the shroud has a handle 16 which is adjustable about a pivot to extend to the left or right of the tool. The shroud 18 is secured to the housing 17 by screws 74 with a space between the shroud and housing acting as an outlet for cooling air for the motor drawn through an inlet 80, the outlet directing the air away from the drum.