Patent GB-1482171-A (GB)
Title: Alignment clamp
IPC: B23K37/053
Filed: 1974-10-07
Abstract: 1482171 Welding by fusion; restoring to shape J D McFADDEN 7 Oct 1974 [9 Oct 1973 23 Sept 1974] 43301/74 Headings B3R and B3Q Apparatus for aligning and holding together end-to-end two workpieces such as pipes, piles and I, H or angle beams, in preparation for welding together, comprises a band 10 removaby securable around one of the workpieces, e.g. pipe 12, lever dogs, e.g. 50, pivotably mounted on said band and engageable with the other of the workpieces, e.g. pipe 14, and means cooperating with the band and the dogs for moving the latter radially inwards into engagement with said other workpiece, the dogs being shaped such that, in use of the apparatus, they are radially spaced from the inter-workpiece joint region to permit effecting a circumferential weld which is continuous through 360 degrees. The apparatus may be used for correcting out-ofroundness of the workpieces. In the pipe aligning and clamping apparatus of Figs. 1, 5, the band 10 comprises hinged halves 10a, 10b connectable by an adjustable hook and over-centre lever means operated by a handle 26. The band has adjustable spacing and centering screws 16 engageable with the pipe 12. The dogs 50 are spring-returned first order levers having ends 52 engageable with the pipe 14 and ends 58 acted on by band-mounted hydraulic cylinders and pistons 66, 68 via adjustable screws 62. The screws 16, 62 may be used for connecting out-of-roundness respectively of the pipes 12, 14. The cylinder 66 is energized via a line 69 by a remote hand pump, or, in conjunction with an air boosting cylinder, an hydraulic system. Pressure to such an air boosting cylinder may be regulated to provide an initial reduced grip to permit workpice orientating relative location and subsequently an increased grip for full clamping. In Fig. 12 (not shown) the dog-actuating hydraulic cylinders are adjustably screw-thread mounted on the dogs, the co-operating pistons acting on the band. In Figs. 2, 3 (not shown), the dogs are screwactuated third order levers. In the apparatus of Fig. 4 (not shown), intended for use with vertically aligned pipe piles, the dogs have internally tapered ends 52 and carry screw-adjusted tapered end spacers (88) respectively for guiding an upper pipe into centre and for determining a root pass penetration weld gap until tack welds are effected. In Figs. 6-8 (not shown), the two band halves 10a, 10b are connected by an hydraulic cylinder-and-piston tightened latch, and, for use with non-metallic, e.g. epoxy coated, pipe surfaces, the centering screws act on the pipe 12 via steel backed hard rubber concave shoes. In Figs. 9, 10 (not shown), the band is spaced from the pipe 12 by bars secured to the band internal wall and disposed parallel to the band axis, and by pistons (202) of cylinders (196) adjustably screw-thread mounted radially through the band and disposed adjacent the weld joint edge of the band and circumferentially between the dogs. The parallel bars are aligned with each of the dogs and the spacing pistons (202). The cylinders (196) are fed via the same line as that feeding the dog-actuating cylinders, so as to prevent out-of-roundness of the band due to dog actuation. In the piling H-beam aligning and clamping apparatus of Figs. 13, 15, a band 10<SP>1</SP> is shaped to conform generally with the beam on which it is mounted. The band comprises rigidly connected members 230, 236 and hinged members 240, 242 connectable by hook and overcentre lever means 248, 244 operated by handle 126<SP>1</SP>. The members 230, 240, engage the beam flanges and the member 236 the beam web through spacer bars 264 welded to the members. The member 242 engages the beam web through a bracing bar 260. The member 236 is U-shaped and braced by a bar 252. Dogs 150<SP>1</SP> are first order levers having ends 152<SP>1</SP> engaging the beam flanges and web, and ends 158<SP>1</SP> acted on by band-mounted hydraulic cylinders and pistons 1661, 1681 via adjustable screws 162<SP>1</SP>. The dog ends 152<SP>1</SP> are internally tapered at 180 for guiding an upper pile beam into alignment.