GB317748A - Improvements in and connected with tube expanders - Google Patents

Abstract

317,748. Stone & Co., Ltd., J., and Jackson, B. May 21, 1928. Tube expanders and flangers.-A tube expander comprises a split bush l fitting inside the tube s and having a conical bore entered by the conical end of a spindle f, the latter passing through a hollow feed screw c and being engaged thereby through the medium of anti-friction bearings j, h. The feed screw is rotatable by means of a tommybar e in a body a which is prevented from rotating by a slotted arm v thereon and an adjustable pin u engaging another tube or a hole in the tube plate t. The bush l may be completely divided into three equal segments or may be partly sawn through, but in each case is ground or machined to be a good fit in the tube when the segments are all in contact with each other in order to avoid the formation of ridges on the interior of the tube during expansion. A stepped flange l<1> on the bush is held to the body a by means of a ring m, and in operation, the spindle f is advanced into the bush without rotation, the grip of the bush in the tube holding the apparatus against end movement. In order to produce a flange or bell mouth s' on the tube a segmental die o is held together on the bush by a spring ring w and is pressed towards the tube-plate, after the bush has been expanded, by means of an undivided disc p and three plungers q slidable in the body a and kept in contact with a handoperated nut r by springs x. Rotation of the body a may be prevented by a holding device engaging a hexagonal or other surface on the exterior thereof. The expander is stated to be particularly suitable for chromium-plated tubes.