GB583141A - Improvements in hollow pipe bending machines - Google Patents

Abstract

583,141. Bending tubes. LAMPE, C. E. Sept. 26, 1944, No. 18370. [Class 83 (iv)] Mandrels.-A pipe-bending machine comprises in combination a rotatable forming wheel, provided with means for clamping the end of the pipe thereto, a sliding form co-operating with the wheel to hold a pipe in position against the wheel and a spinner mandrel which is rotated within the pipe as the pipe is being bent. The forming wheel comprises a concave peripheral portion 23, Fig. 10, a hub 24 and a central web 25 secured by bolts 21 to the flange of a collar 17a secured to a shaft 11. The wheel is also secured to the shaft by means of an axial screw 29 and around part of the wheel periphery is bolted a gear segment 31 adapted to mesh with a rack bar 33 secured to a sliding form 34, Fig. 16, also having a concave face. Shaft 11 extends down through the table 2 of the machine and is adapted to be driven from an air motor 4, Fig. 2, through a reduction gear 5 and gears 6, 7, 9 and 10. In order that the machine may accommodate different sizes of forming wheels, the sliding form 34 is mounted for longitudinal movement in a block 35 which is movable transversely of the machine towards and away from the axis of the shaft 11 by vice mechanism. The bed comprises a base-plate 42 with dovetailed grooves on which slides the block 35 and a vice plate 46. The latter is movable by means of a coarse adjustment screw 56 and may be locked at certain positions along the bed by means of a locking key-plate 60. The block 35 is adjustable relatively to the plate 46 by a fine adjustment screw 52. One portion of the periphery of the forming wheel is cut away to form a relatively thin flat 62 to which is welded a block 63, Fig. 7, with projections 65 adapted to be engaged by the arms of a clamping member 66 having a screw 71 by which the end of the pipe 37 to be bent may be firmly held between the wheel and a clamping block 69. The machine also includes a rotating mandrel adapted to be driven through a shaft 76 from an electric motor 77 mounted on a frame 78 movable transversely of the machine table by a screw 81, Fig. 4. The mandrel comprises a tubular body 21 bolted to a spinner body 9<1>, Fig. 18, carrying a series of longitudinally extending peripheral rollers 10<1>. A frusto-conical body 171 with circumferential rollers 19<1> of frusto-conical form is secured to the front of a body 9<1> by a form of universal joint comprising a rearward projection 16<1> extending into a slot 15<1> and having a transverse opening 24<1> through which passes a pin 25<1> of smaller diameter. In operation, the pipe is passed over the mandrel, the end of the pipe is plugged and clamped to the forming wheel and the block 35 is moved up so that the sliding form closely engages the wheel. The mandrel is rotated and the forming wheel slowly turned, this in turn causing a -longitudinal movement of the member 34.