Patent GB-1443490-A (GB)
Title: Wire saw
IPC: B28D5/04
Filed: 1974-12-20
Abstract: 1443490 Wire saws YASUNAGA ENG KK 20 Dec 1974 [29 Dec 1973 30 March 1974] 55277/74 Heading B3D A wire saw having a sawing wire array 9 comprises a roller 2 feeding a single wire while causing a tension in the wire, a take-up roller 15 receiving the wire at a speed faster than the wire paying speed of the roller 2 and ceasing to receive the wire as the tension exceeds a certain magnitude, a plurality of guide rollers 23, 24, 25 around which the wire is turned a number of times so as to form the array 9, and a seesaw means 6 including a seesaw lever 18, one end 5, 7 of the means expanding and shrinking as the lever swings while causing the opposite end 11, 12 to shrink and expand. The wire from the feeding roller 1 is turned around one end 5, 7 of the seesaw means before engaging the guide rollers 23, 24, 25 and from the guide rollers is turned around the opposite end 11, 12 before reaching the take-up roller 15. A driving means oscillator one 23 of the guide rollers to reciprocate the wire, and a swinging means causes the seesaw lever 18 to swing in synchronism with the oscillation of the guide roller to prevent slackening of the wire. The wire from the feeding roller 1 passes over idler rollers 3, 4 and then a number of times over the rollers 5, 7 of the seesaw means, roller 5 being journalled on a shaft fixed to a frame 16 and roller 7 being rotatably carried by one end of the lever 18. From roller 7 the wire passes over an idler roller 8 and then over the guide rollers 23, 24, 25 to form the array for sawing a workpiece 28. The wile then passes over an idler roller 10 and a number of times over the rollers 11, 12 of the seesaw means, roller 12 being rotatably carried by lever 18 and roller 11 being journalled on a shaft fixed to frame 16. Thereafter the wire passes over idler rollers 13, 14 to the take-up roller 15. The swing lever 18 is secured to a shaft 19 which is secured to a swing lever 47 oscillatable about the axis of the shaft and having a notch 48 engaging a shaft 39 of a sprocket 37 which is reciprocatable by movement of a rod 40 connected to a crank 38 driven by a motor 43. The lower part of the sprocket 37 engages the upper run of a chain 36 which is guided over sprockets 34, 35 and a sprocket 30 on a shaft 26 secured to the guide roller 23. The upper part of sprocket 37 engages the lower run of a chain 33 guided over sprockets 31, 32 and a sprocket 44 rotatable by a motor 46. If the upper chain 33 is held stationary, operation of motor 43 causes reciprocation of the sprocket 37 along the runs of the chains, the stationary chain rotating the pulley so that it drives chain 36 to cause to and fro motion of the shaft 26 and guide roller 23 whereby the wire is reciprocated. At the same time, the movement of the sprocket 37 swings the lever 47 and hence the lever 6 to increase and decrease the distance between pulleys, 5 7 and 11, 12 to take up slack in the wire. When motor 46 is operated, rotation of chain 33 causes an additional rotation of sprocket 37 so that the movement of wire in one direction is greater than that in the other to effect a feeding of the wire from feed roller 1 onto take-up roller 15. In another embodiment, the swinging of lever 6, oscillation of guide roller 23 and feed of the wire are effected by a mechanism including planetary gearing.