Patent GB-1006247-A (GB)
Title: Improvements in or relating to sanding machines
Inventor: SMITH ORSON WARREN
IPC: B24B21/00
Filed: 1963-12-04
Abstract: 1,006,247. Sanding. SMITHWAY SALES CORPORATION. Dec. 4, 1963, No. 47844/63. Heading B3D. A sanding machine comprises spaced upper and lower housings between which panels may be passed for sanding, a sanding unit mounted in each housing, the units being spaced in longitudinal relationship, means for adjusting  the vertical spacing of the units to accommodate panels of different thickness, means associated with each unit for adjusting the depth of sanding, and a plurality of pairs of feed rolls between which the panels are successively delivered for advancement between the units, the rolls of each pair being spaced to suit panels of different thickness by the vertical adjustment of the units. Sanding units a, b are enclosed in housings H, H<SP>1</SP> vertically spaced to provide a gap through which workpieces, e.g. panels P, are fed. Spaced vertical plates 11, 12 are welded to a base-plate 10, are joined by transverse plates 13 also welded to the base-plate 10 and have a top plate 14 welded thereto. Cylindrical collars 15, 15 welded to the plates 11, 12 have fixed therein the lower ends of columns 16, 17 adjustably supporting the upper housing H<SP>1</SP>. The latter has a top plate 20, an end plate 21, spaced end plates 22, 23 and a bottom plate 23x. Cylindrical collars 24 welded to the plates 22, 23 slidably receive the upper ends of the columns 16, 17. Vertical adjustment of the upper housing H<SP>1</SP> on the columns 16, 17 is effected by hydraulic jacks 62, 62 in the lower housing H supplied by a pump 67 and controlled by a valve 80v. Setting members G are mounted on the end walls of the lower housing H, each member comprising a set of spacer blocks 97 carried by a disc 87 on a shaft 86. The latter is rotated in steps by pawl-and-ratchet mechanism 91, 94 actuated by an air cylinder 88<SP>1</SP> under pushbutton control. A brake hub 92 on the shaft 86 is yieldably engaged by brake blocks 93. The upper housing H<SP>1</SP> having been raised, the shaft 86 is rotated to interpose the desired spacer block 97 between the housings and the housing H<SP>1</SP> is then lowered.  The workpieces are advanced individually from a feed table at the entry end of the machine and discharged at the exit end on to a conveyer. They are advanced through the machine by feed rolls 43 mounted in the lower housing H and driven by an electric motor 49 through belts 49a, 49b and gear-boxes 46. Paired with the feed rolls are spring-loaded pressure rolls 44 mounted in the upper housing H<SP>1</SP>. The sanding units are supported in the housings H, H<SP>1</SP> by horizontal booms 8, 9. The lower boom 9 is mounted by a member 30 received in holes 25, 25<SP>1</SP> in the plates 11, 12. A plate 33 surrounding the hole 25 is secured by bolts 34 to the member 30 and a plate 31 welded to the member 30 engages the plate 12 round the hole 25<SP>1</SP>. An end plate 32 is welded to the member 30. The boom is a box-like structure of plates 35, 36, 37, 38 welded together and to the plates 31, 32. An end plate 39 is welded to the boom. The construction of the upper boom 8 and its mounting in the plates 22, 23 of the upper housing H<SP>1</SP> are similar. Each sanding unit comprises a continuous sandpaper belt 5, slightly wider than the workpieces, trained round a contact roll 40, a driving roll 41 and a tensioning and tracking roll 42 all removably mounted on the respective boom. The contact roll 40 is rotatably mounted in standards 101, 101 fixed at opposite ends of a plate 102 applied against the boom plate 35 and having bevelled edges engaging a hexagonal bar 104 fixed to the plate 35 and a tapered gib 105 which is movable longitudinally to hold the plate 102 against endwise movement or to release it for endwise removal. The driving roll 41 is similarly carried by the boom plate 36 and is belt driven from an electric motor mounted on the respective housing. The roll 42 has trunnions 116, 116<SP>1</SP> rotatable in ball-and-socket bearings 117, 117<SP>1</SP>. Bearing 117 is mounted in a bracket 118 extending from a base-plate 115. The bearing 117<SP>1</SP> is carried by a bell-crank pivoted at 123 on a bracket 118<SP>1</SP> also extending from the base-plate 115. The free end of the bell-crank is pivotally connected to the piston-rod of an air cylinder 127 pivotally mounted on a bracket 129 extending from the bracket 118<SP>1</SP>. The roll 42 is oscillated to cause the sanding belt to move back and forth thereon to avoid longitudinal scoring of the workpieces, the oscillation being limited by adjustable stops 132, 132<SP>1</SP>. The base-plate 115 is removably secured by a plate 144, hexagonal bar 104 and tapered jib, to arms 140, 140 pivotally mounted on the boom plate 38. The base-plate 115 is pivotally connected at 152 to the piston-rod of an air cylinder 150 contained in the boom and pivotally mounted on the boom plate 37, whereby the sanding belt 5 is tensioned. Co-acting with the contact rolls 40 are backup rolls 55 adjustable to control the sanding pressure so as to regulate fully the final thickness of the sanded workpieces. Each roll 55 is rotatably mounted at the ends of arms 57, 57 pivotally carried by a wall w of the housing H or H<SP>1</SP>. Yieldable pressure is applied to the arms by an air cylinder 60 also carried by the wall w. Movement of the roll is adjustably limited by screwthreaded stop shafts 57x supported on the ends of the arms 57 for engagement with abutments 61 formed as projecting lugs on the end supports of the corresponding contact roll 40. The shafts 57x are axially adjustable by a hand wheel 58c through worm gearing and screw-and-nut mechanism. The housings H, H<SP>1</SP> have suction ducts for removing dust. Two pairs of sanding units may be used in tandem.