Patent GB-1113159-A (GB)
Title: Sawing machine
IPC: B23D49/00
Filed: 1966-09-30
Abstract: 1,113,159. Sawing. KEURO MASCHINENBAU G.m.b.H. & CO. KOMM. GES. 30 Sept., 1966 [14 Oct., 1965]. No. 43741/66. Heading B5L. A sawing machine for cross-cutting of workpieces comprises two saw blades 4 mounted in the same plane with their cutting edges facing each other on a rigid substantially rectangular frame 1, 2 which is adapted to reciprocate in the direction of its longitudinal frame members 1, each blade being clamped to a pair of slide carriages 3, 3<SP>1</SP> which are movable along the transverse frame members 2, and the two pairs of slide carriages being movable towards each other for the cutting strokes of the blades and away from each other for the idle strokes of the blades. The longitudinal frame members 1 consist of cylinders which are slidable on pistons secured to tubular piston rods 6 carried by brackets 14 on the bed of the machine. The ends of the cylinders are interconnected by the transverse members 2 along which are movable the slide carriages 3, 3<SP>1</SP> for the saw blades 4. The carriages are shiftable along the members 2 by spindles 12, 13, 12<SP>1</SP>, 13<SP>1</SP>, the spindles associated with each blade being interconnected by gear-boxes 10 joined to shafts 11. Each pair of slide carriages 3, 3<SP>1</SP> is movable by an hydraulic motor driving through bevel gears spur gears 19, Fig. 4, on the spindles 12, 13, 12<SP>1</SP>, 13<SP>1</SP>. Each -spur gear is rotatably mounted on short shafts 20, 20<SP>1</SP> axially moved by racks 22, 22<SP>1</SP> engaging pinions 21, 21<SP>1</SP>. The pinions are interconnected by levers 25, 25<SP>1</SP> and a link 24, and the lever 25 is rigidly connected to a further lever 26 having its other end slidable along a rail 27 which is mounted at one end on a pivot 28 to the machine frame and is angularly adjustable by rotation of a threaded spindle 29. In operation, the frame 1, 2 is reciprocated by hydraulic fluid supplied by a reversible pump controlled by limit switches to alternate sides of the pistons in the cylinders 1. The saw blades are moved towards each other to engage a workpiece 9 by the hydraulic motors and gear units 10 shifting the slide carriages 3, 3<SP>1</SP> along the members 2. The saws may be moved independently and engage the workpiece at different pressures by controlling the motors. Alternately, the motors may be shunted together so that the blades engage the workpiece at the same pressure. During reciprocation of the frame, the lever 26 slides along the rail 27 and causes oscillation of the pinions 21, 21<SP>1</SP> so that the racks 22, 22<SP>1</SP> and hence the spindles and carriages are axially reciprocated, the spindles associated with each blade moving in opposite directions so that the blades move with arcuate cutting strokes and move towards each other on the cutting stroke and away from each other on the return stroke, the degree of curvature being determined by the inclination of the rail 27. With the rail 27 adjusted to be parallel to the direction of reciprocation of the frame, the blades effect straight cutting strokes. In other embodiments, the spindles are replaced by chains, racks or the like, and the hydraulic drive may be replaced by an electric system. The teeth of one of the blades are staggered with respect to those of the other so that the blades can completely sever the workpiece without engaging one another.