GB1174138A - Improvements in or relating to Saws - Google Patents

Abstract

1,174,138. Sawing. ETABS. GUILLIET. 11 Dec., 1967 [14 Dec., 19661, No. 56185/67. Heading B5L. A system for conveying wood for band saws when required as halving saws or slab-cutting saws comprises a feed guide member 9 and a feed roller 16 arranged one on each side of the plane of the blade 5 and movable towards each other transversely in relation to this plane, the shaft 17 of the roller carrying two articulated arms 35, 36 staggered in height, each provided with a feeding wheel 42, 43 and urged by elastic members towards the plane of the saw blade such that during slab-cutting, the slab is gripped on one side at three non-aligned points situated at different heights. The band saw 5 runs over pulley 3, 8 and through a worktable 7. The feed guide member 9 is disposed on one side of the saw blade and consists of a motordriven belt or roller 9 protruding from the open side of a casing 11 carried by a sleeve 12 slidable in a frame 29 on the work-table 7. The feed guide member 16 is disposed on the opposite side of the saw blade and consists of an interrupted roller comprising a set of gear-wheels 15 mounted on a shaft 17 and driven by a motor 63. The shaft is mounted in a casing 18 which is movable about a pivot 19 on the work-table and extends through a slot 37 in the table and engages a fork 21 on a rod 22 extending transversely to the plane of the blade. The rod is formed with a rack 27 engaging a pinion 24 which also engages a rack 28 on the sleeve 12. The guide member 9 and feed roller 16 can be moved to positions equidistant from the plane of the blade by jacks 31, 33 and the pinion can be moved axially by a further jack 26 from a position out of mesh with the racks to an engaged position so that the guide member 9 and feed roller 16 are maintained equidistant from the blade when the saw is used for halving timber. When the saw is used for slab cutting, the pinion 24 is disengaged from the racks and the sleeve 12 moved against a stop 71, the feed roller 16 urging the workpiece against the guide member 9. The arms 35, 36 are pivotable about the shaft 17, each arm rotatably carrying a feed wheel 42, 43 interconnected by a universally-jointed shaft 47 and driven from the motor 63. The arms are pulled in the direction F by springs 51, 52 attached to a strut 54 mounted on a pivot 55 on the work-table, a slot 56 in the casing permitting movement thereof about pivot 19. The opposite end of strut 54 has a bore 57 which can be engaged, when a jack 58 is extended, by a peg 59 which is mounted in a bore 61 on arm 35 and extends through a bore 62 in arm 36. The end of the strut also engages a cam 60 on the casing 18. When the peg 59 engages the bores 61, 62 and 57, the pivots 19, 55, peg 59 and shaft 17 act as the pivots of a parallelogram linkage -so that when the saw is used for halving timber, the operative edges of the feed roller 16 and gearwheels 42, 43 -are maintained during movement towards and-away from the band saw in a plane parallel to the plane of the band saw. During slab cutting the peg 59 is withdrawn -from the bores 57, '62 so that the arms 35, 36 can pivot individually about the shaft 17 to engage the wheels 42, 43 with an uneven surface of a balk D of timber to be cut. The various jacks are controlled by an electro-hydraulic circuit.