Patent GB-564587-A (GB)
Title: An apparatus for cutting pipes or for marking off pipes preparatory to cutting them
IPC: B23Q35/10
Filed: 1943-01-13
Abstract: 564,587. Mathematical drawing-appliances. WATKINS, W. W. Jan. 13, 1943, Nos. 661 and 18406. [Class 97 (iii)] [Also in Group XXII] A portable apparatus for cutting or marking a pipe in situ to form an oblique end or attaching adjacent lengths obliquely in pipe-lines, comprises a stationary structure fixed to the end of the pipe and extending away therefrom on which is mounted a rotary support carrying a cutter or marker which is movable lengthwise thereof, but restraining against rotations relatively to the support, and an oblique track secured to the structure to control the lengthwise movement of the cutter or marker during the rotary movement. On the pipe 22 is secured by radial screws 30 a chuck 21 provided with a boss 23 having an axial extension 24. On the boss is mounted on ball-bearings 32, the nave 26 of an arm 33 which is rotated by hand-operated bevel gear 61, 60 and to which are secured a pair of channels 34 provided with balls to act as anti-friction guides for a slide comprising a pair of narrow channel members 27 carrying a cutting blow-pipe 29. The blow-pipe is mounted on a block 57 slidable in a graduated quadrant 58 on a radially adjustable bar 54 provided with a scale 56. The slide members 27 which at their rear ends carry a radially adjustable graduated finger 28 provided with a ball 52 are slotted at 48 and pressed rearwardly by springs 45 so as to engage a swash-plate 25 mounted on the extension 24. The swash-plate is provided with a rectangular central slot 36, which fits over the extension 24 and is long enough to permit the swash-plate to be angularly adjusted on a pivot 37 secured in the extension 24 by pairs of blocks 38, 39, 40. Mounted on the block 40 is a protractor 41 slotted at 42 so as to engage a screw and wing nut 43 to lock the swash-plate in any angular position. For cutting thin pipes, the blowpipe may be arranged in the central setting in the quadrant so as to be at right angles to the pipe axis throughout the cutting operation. When cutting a.thick pipe, the blow-pipe is controlled manually so as to move the cutter block in the quadrant as cutting progresses, so that the pipe is cut at a progressively varying angle to the pipe axis. In order that the pipe end face may be in the plane 67 of the oblique end, Fig. 8, the pipe may be marked longitudinally at positions 0, 90, 180, 270 degrees, as indicated by marks 68, 69, 70 which represent 0, 90 and 270 degrees. If desired, marks may also be made at intermediate angles. The cutter may be arranged at mark 68 in the controlled position at right angles to the pipe axis and is moved along the quadrant as cutting progresses to obtain the maximum displacement of the cutter when mark 69 is reached, as indicated at 71, Fig. 9. The direction is then reversed, returning through the central positions at 180 degrees and continuing until the opposite maximum displacement is reached at mark 70, and finally returning to mark 68. If desired, the angle between the cutter and pipe axis may be at an acute angle to the plane 67 so as to provide a V-groove to facilitate welding. In such case, the cutter may be arranged so that the mid-position of the cutter is not the zero mark of the scale 59, but a mark at the desired acute angle thereto. Thus the arrow 73, Fig. 11, indicates the radial direction of cut at mark 69 and 74 indicates the acute angle between .said direction and the plane 67. In operation, two short bridges of uncut metal are left at points 180 degrees apart and are not severed until the apparatus is detached from the pipe. In a modification for marking a pipe a spring- urged pencil 75 may be secured in a holder 76 in a radially adjustable graduated arm 54 carried by a slide 27 which is movable by the swash-plate 25 in bearings 79 in the rotor frame 80. The slide has a radially adjustable doublefingered arm 77 with ball-ended fingers 78 engaging opposite ends of the onset plate. The frame 80 which is rotated by worm gear from a handle 63 has plain central bearings 81 journalled on the stator boss 23 and a journal 85 on the extension 24 thereof.