GB311946A - Improvements relating to the manufacture of sheet metal pipes and the like - Google Patents

Abstract

311,946. Hume, W. R. May 21, 1928. Pipes.-The meeting edges of a curved sheet metal blank for use in the manufacture of a pipe or the like, which are normally flat, are bent slightly inwards as shown in Fig. 2, so that they may spring outwardly into the desired curvature upon release of the pressure. The blank is subsequently pressed against an abutment to bring the edges into contact where they are temporarily secured by tack welding &c. and finally transferred to an arc welding machine. The bending is effected progressively by a reciprocating die 22 having a concave surface with a V-shaped ridge 26 co-operating with a similar recess 81 in. a convex fixed internal die 28. The fixed die is secured by angle irons 33 to thin legs 32, Fig. 7, which pass through the open seam, are braced at 36 and are secured by arms 37 to a bearing 38 adjustable by a screw and hand wheel 43 fixed in adjusted position by a pin 44. The die 22 is secured to a ram 17 reciprocated in guides fixed to a braced framing 6, by an eccentric 16 on a shaft 9 provided with fast and loose pulleys. The cam has a removable cap 18 to facilitate assembly. The pipe rests in adjustable slotted cross bars 51 pivoted to a wheeled carriage 49 which is traversed intermittently on a channel girder 47 by hand or by rack 72 and pinion 71 driven by ratchet mechanism 68, 69 from a weighted lever 66. This lever is put into operation when the ram is raised, by a chain, rod or flexible link adjustably connected thereto and secured to a lever 64 operated by a cam 56 on the shaft 9 through a lever 58, rod 61 and lever 62. The shaped blank is then removed and placed in a channel member 83, Fig. 12, and its edges pressed together by the co-operation of flanges 74, 74<a> of this member with the horizontal flange 75 of an abutment 76. The abutment is adjusted by screws 78 and the flange 75 and part adjacent thereto are perforated at 98 to facilitate tack welding of the edges after pressing them together. The member 83 carries guide members 94 and is pressed upwards by fluid pressure plungers fed from a common supply 89. To ensure that the ends of the pipe are at right angles to the length of the blank, they engage respectively a stop 95 and a wedge driven in between the other end and an inclined stop 97.