GB1402050A - Tube expander - Google Patents

Abstract

1402050 Tube expanders TRIDAN TOOL & MACHINE Inc 31 Dec 1973 60301/73 Heading B3J A tube expander comprises a rod 37, Fig. 2, with an enlarged head 57 for moving through and expanding a tube 22, e.g. into engagement with fins 21, jaws 39, 40 for gripping an end of the tube and being opened by the head 57 in its retracted position, and means for moving the rod. In a first form, Figs. 1 and 2, for expanding a pair of tubes simultaneously, the pivoted jaws 39, 40 are closed on both tubes by a spring 44, and a pair of expanding rods 37, 38 is provided. These are connected to pistons in cylinders 24, 25 which extend between a head 28, into which fluid may be introduced for retracting the rods, and a back plate 31. Hollow plungers 73, 74 close the rear-ends of the cylinders and extend to a plate 32 where they are connected to nozzles 33, 34 for supplying fluid to advance the pistons. Guide rods 26, 27 to which back plate 31 is adjustably fixed by screws 90 extend the length of the apparatus, carrying a bracket 35 for the jaws. The rods 37, 38 pass to each side of the bracket and through loose bearings 55 with inclined surfaces 56 which cam open the jaws upon movement by the heads 57. Handles 29, 30 are provided. The head 57 may have periperipheral slots (92), Fig. 8 (not shown), to permit air to escape when U-shaped pipes are being expanded, or a modified head may be used, Fig. 9 (not shown), in which air passes through a hollow fastener (93) securing the head (94). The expander may be adapted for a single, or more than two, tubes. In another form, Figs. 10 and 11, the rods 103, 104 are driven by toothed gears 125, 126, 133, 134 which have peripheral grooves 137, 138 to receive the rods. The gears 125, 126 are driven, through gears 115, 115<SP>1</SP>, a shaft 116 and clutches 123, 128, 124, 129, by an hydraulic motor 112. A shaft 132 supporting the gears 133, 134, is pressed down by screws and springs 141, 142, 143, 144. Stops 107, 108 on the rods 103, 104 coact with a plate 105 carried by rod supports 101, 102. In a final form, Fig. 15, each rod 225, 226 is driven by two pairs of grooved gears 232-235 the drive to which from an hydraulic motor is through a chain and two clutches on a central shaft 210. The clutches drive gears 213, 214 meshing with the grooved gears. Sleeves 251, 252 in the jaws limit rearward movement of the rods.