GB1137638A - Hand-operated belt sanding machine for wood-working purposes - Google Patents

Abstract

1,137,638. Sanding. EUGEN LUTZ K.G. 19 April, 1966 [24 April, 1965], No. 17144/66. Heading B3D. A portable belt sander comprises a housing 1, a driving motor within the housing for driving at least one of two sanding belt rollers 6, 7, a pressure plate 8 in the housing fixed in relation to the rollers and a guide frame 9 which can be adjusted in height in relation to the housing and pressure plate while remaining parallel to the pressure plate. The guide frame is adjusted by an adjusting screw 21 which swings the frame about shafts 13, 14 on cranks 10, 11 and crank-pins 15, 16. The guide frame is made detachable by use of open bearings 17, 18, the crank-pins being retained in the bearings by spring-clamps 19 while the shafts are retained by spring-clamps (20), Figs. 4, 5 and 6 (not shown). The shaft 14 is rigidly mounted in the housing and the shaft 13 is rigidly mounted in the guide frame as illustrated in Fig. 3 (not shown). The adjusting screw is attached to the shaft 13 by a bearing 22 and is moved axially by a screwed sleeve 24 which is mounted in a cross-piece 25 for swivel movement in the guide frame. An increase in sanding pressure may be applied by hand when handles 2, 3 are pressed downwardly to overcome the pressure of a coil spring 27 in the adjusting mechanism. When sanding is to be effected without the guide frame, the latter is detached and the shaft 14 removed from the housing by shifting it axially to the left (Fig. 4) until keyway (34) in the shaft can clear the head (35) of the retaining screw for the spring- clamp (20) ; if desired, the shaft 14 may be retained by the housing but moved to the right as illustrated in Fig. 7 (not shown), so as to clear the edge (33) of the sanding belt. Figs. 8 and 9 (not shown), illustrate a modified guide frame having a raised edge for use in rabbeting or floor corners. In a modification, Figs. 10 and 11 (not shown), adjustment in height of the guide frame (9a) is effected by an adjusting screw (21a) which moves the frame along inclined surfaces on the bottom of the housing, the surfaces being held together by spring clips (56) which engage in grooves (57) in pins (54). In Fig. 12 (not shown), the cranks are replaced by discs (10c), (llc), adjustment being effected by a push-rod (21c).