Patent GB-379166-A (GB)
Title: Improvements in pipe cutting apparatus
IPC: B23K7/00
Filed: 1931-11-30
Abstract: 379,166. Dividing by fusion. TRIGGS, W. W., 57, Lincoln's Inn Fields, London.- (Douglass Bros. Co. ; 352, Whiting Street, Chicago, U.S.A.) Nov. 30, 1931, No. 33166. [Class 83 (iv).] In a machine for flame cutting pipes, particularly for preparing the ends for making welded joints in tees and crosses of pipes of the same or different diameters and also in elbows and multiple piece bends, the torch is supported so as to move through a closed non-circular orbit, the angular position of the torch being automatically changed so as to maintain a predetermined angular relation to the pipe surface. For joints as shown in Fig. 20, the opening cut in the pipe A is bevelled at 29 and unbevelled at 28 and the end of the pipe B has an unbevelled cut. For a joint as shown in Fig. 22 in pipes of the same diameter the cut in the pipe A<1> is bevelled throughout and the cut in the pipe Bl is bevelled at 30 and unbevelled at parts at 90‹ with respect thereto. Cuts may also be effected in pipes as shown at 34, 35, 36, Fig. 9, for elbow bends &c., and as at 32, 33 for straight cuts. For making double bevel cuts for angle bends a torch with two jets 86, Fig. 26, may be used. The torch body 73, Fig. 17, is mounted at the end of a rotating and reciprocating hollow shaft 7. A torch may be provided at each end of the shaft so that the co-operating pipes of a T or cross may be cut simultaneously or in turn. The torch after cutting the branch pipe B may be used for cutting pipes for angle bends &c. The torch bodies are connected by parallel links 74, 75 to levers 71, 67 on a frame 50 which has a scale and is radially adjusted in and secured to a bracket 46 attached to the shaft 7. The body may be fixed in position by a pin passing through a hole 81 in the lever 67 and one of a number of holes 80 in the support for making unbevelled cuts or cuts with fixed bevels. In order to effect cuts of varying bevels the lever 67 has a sector 69 engaging a worm 70 on a slidable shaft 62, which is rotated by bevel gear 65, 48 from a shaft 49 journalled coaxially within the shaft 7 and rotated relatively thereto as controlled by cam slots 146, 147, Fig. 12, in fixed plates 133, 134, Fig. 2. For this purpose the shaft 49 is keyed to a pinion 118, Fig. 14, mounted in ears 114, 115 passing through a slot in the shaft 7 and screwed to a casing 110 secured to a sleeve 106 in which the shaft 7 is keyed at 108, Fig. 3. The pinion 118 meshes with a pinion 120 engaging the inner teeth of a ring 122, the outer teeth of which engage reciprocating racks 132 mounted in slideways on the casing. These racks engage pinions 130 on slidable arms 124, the pinions also engaging fixed racks 131 secured to the casing. The arms are each provided with rollers 126, 127 so as to engage one or other of the cam plates. The cam plates are carried by a slide 135 and can be adjusted into either of their extreme positions or into a neutral position by racks 137 and pinions 138 from a hand crank 141 which may be fixed in set position by a pin 142. The cam plates may be replaced by a plate having an endless cam slot co-operating with a single arm 124. The shaft 7 is rotated by the sleeve 106, which is connected by bevel gear 105, 104 and spur gear 101, 99, 97 to a shaft 98 which also drives the reciprocating mechanism. The shaft 98 is driven by reduction gearing from a motor 13 through speed gear 14 which may be changed according to the size of pipe in order that the linear speed of cutting may be kept substantially constant for pipes of equal thickness. The motor may be reversed by either of the handles 91, 92 so that successive cuts may be effected in opposite directions in order that a part of the cut may be retraced, if necessary, and in order to avoid kinking or twisting of the gas supply tubes which are connected to valve casings situated on the framing near the handles and connected to a common supply. The shaft 7 is reciprocated with a simple harmonic motion by an adjustable crank 150 through a transversely reciprocated slide 160, a rotary table 168 and a carriage 189 rotatably mounted on the shaft 7 between fixed collars 190 thereon. For this purpose the crank block 150 has a roller 153 engaging a lower longitudinal slot in the slide 160, a similar upper slot 167 engaging a roller 183 on the rotary table. The slide has a shaft with pinions 163 engaging fixed racks 162 so as to avoid binding of the slide in its guides. The roller 183 is carried by one of a pair of blocks 179, 180 which are radially adjusted by hand through a right- and left-handed screw 184. The carriage is guided by a fixed rod and has a pair of arms 204 secured to a collar 205 rotatably mounted on the shaft 7. For operating when the branch B is smaller than the main pipe A the block 150 is first adjusted to the diameter of the branch and the block 179 to the diameter of the pipe A, graduated scales being preferably provided on the parts. The block 179 has a stud 187 engaging a slot in the carriage 189, so that for one rotation of the shaft 98 the table makes an oscillation of approximately 180‹ in each direction and so gives two reciprocations in each direction to the shaft 7. One side of the slot consists of a hard metal plate 193 and the other side of a bevelled plate 194 secured to a frame 195 pivoted to the carriage and having a number of arms 198 pressed down by springs 200. When operating on pipes of the same diameter the crank block 150 and block 179 are adjusted into alignment, these parts being locked together by the smooth end of a screw 155 which passes through apertures in the blocks 150, 179. In this case the table makes a complete rotation. When a half rotation has nearly been completed the plate 194 is raised by a pin 188 on the block 180 so that it enters the slot and frees the pin 187, the second reciprocation being then effected by the pin 188. In order to effect only one complete reciprocation of the shaft 7 for each rotation of the shaft 98 in making continuous transverse cuts for angle bends, the screw 155 is retained in the former position, but the pins 187, 188 are removed and the pin 187 replaced by a longer pin 206<1>, Fig. 8, which passes through the transverse slot 203 in the frame 195. The torch body is adjusted to a fixed distance from the inner surface of the pipe so that the jet is directed against the same point on the inner surface in order that the cut will have the same size and configuration although the bevel may be varied by adjustment of the torch. In order to cut pipes of different thicknesses, torch tips of different lengths may be used so that the tip is always positioned at a substantially constant distance from the outer surface of the pipe. The pipes are mounted in the forked ends 22 of adjustable posts 21 fixed in position by pins 23 so that they may be adjusted to a position, in which the axis thereof is in the same horizontal plane as that of the axis of the shaft 7.