Patent GB-756996-A (GB)
Title: Flying saw or circular knife
IPC: B23D45/18
Filed: 1954-06-23
Abstract: 756,996. Shearing. AETNA-STANDARD ENGINEERING CO. June 23, 1954 [Aug. 10, 1953], No. 18408/54. Class 83 (4). [Also in Group XXIII] In a machine for cutting off successive lengths from continuously moving work, such as pipe or rod issuing from a mill, a flying circular knife 9 or saw is moved in a circular orbital path approaching' but not intersecting the path of the moving work 10 and, by means operating in timed relation with the orbital movement, is periodically given an additional movement toward and away from the work. The additional movement may be sufficient to cause the knife to pass completely through the work but preferably the work is also deflected into the path of the knife by a cam 12, in the manner described in Specification 671,534. The knife 9 and its motor 8 are mounted on a carriage 7 rotated in a circular orbital path by cranks 6 and the cranks are carried by a superstructure 4 reciprocated vertically by a pair of eccentrics 105, Fig. 8, each connected by a link 110 to a wrist pin 92 that passes through bearings in bars 88 on the superstructure. In order to guide the superstructure, rollers 93 on the ends of the wrist pins bear on guide posts 95 and, to cushion its downward movement and partially balance inertia forces, air cylinders 124 are connected to the superstructure by piston rods 123. The superstructure is mounted on a secondary structure 2 which is vertically adjustable relative to the base 1 by screw jacks 3 and is guided during this adjustment by cylindrical rods 38a co-operating with grooved rollers 39. The work - supporting cam 12, which is either of circular or pear shape and has a knife notch 11, is mounted on a shaft 13 raised by an eccentric 15 as described in Specification 671,534. A main drive motor 31, driven synchronously with the mill motor, is connected to a main drive shaft 28 through a reduction gear box 30 and infinitelyvariable drive 29. The main shaft 28 is connected to shafts 18 driving the eccentrics 105 for reciprocating the superstructure through a three-speed gear box having gears 155, 156, 157, Fig. 12, on an output shaft 148, a clutch 137, 145, a shaft 135 and bevel gearing 134. The clutch and gear box are controlled from handles 144 by rods 142, 140 and by rods 177,170respecttively, the gearbox ratios being such that the superstructure can be raised and lowered 2, 3 or 4 times for each revolution of the crank arms 6. The clutch element 137 is connected by a rod 181 to a detent 181b which, when the clutch is disengaged, enters a recess in a disc 184 on one shaft 18 and locks the links 110 in a predetermined position. A shaft 17 driving the eccentric 15 for raising the work-supporting cam 12 is driven from the gear box output shaft 148 by a bevel gear 146, shaft 186 and worm gearing 188 and the cam shaft itself is driven from the main shaft 28 by a bevel gear 191, shaft 193 and worm gearing 195. The cranks 6 are also driven from the bevel gear 191 by a shaft 203, Fig. 4, bevel gear 204, shaft 19, gear 47, Fig. 2, and gears 48 on each hollow crank-driving shaft 49; the cranks rotate at the same speed as but in the opposite direction to the cam 12. Each shaft 49 has a balance weight 51 and also an eccentric 50 forming part of a pneumatic balancing system of the kind described in Specification 682,277 [Group XXIII]. To vary the orbit so that the knife, at the cutting position, has the same linear speed as the work, the knife carriage 7 is adjustable along the crank arms by a shaft 20 connected by gears 74, 75, 76 and a'shaft 72 within each crank-driving shaft 49 to an adjusting screw 59 on each crank arm. The shaft 20 is driven at the same speed and in the same direction as the crank-driving shaft 19 by gears 208, 209, 210, Fig. 2, but the drive is through a differential 212 so that, through shaft 35, gear boxes 235, 237. and 240 and a shaft 216, an adjusting motor 32 can rotate the shafts 20 and 72 relative to the crank-driving shafts and thus vary the throw of the cranks while the machine is running. The adjusting motor, through shafts 35, 36 and worm gearing 34, also rotates the four jacks for raising and lowering the secondary structure 2 and controls the adjustment screw of the infinitely variable drive 29 by drives through gear boxes 235, 237 and 244. If desired, a length-of-cut indicator of the kind described in Specification 671,534 may be connected by shafts and gears to the gear box 240. Clutches are provided in the drives for the various adjustments so that adjustments of speed, by means of the infinitely-variable gear, or of the crank throw or of the screw jacks can be made simultaneously or separately, while the machine is running. For cutting small pipes, either the raising of the work-supporting cam 12 or the vertical movement of the superstructure can be eliminated by disconnecting the appropriate drive; in the latter case, the machine operates in substantially the same manner as the machine described in Specification 671,534.