GB576199A - Tube reducing method and mechanism - Google Patents

Abstract

576,199. Rolling tubes. DEWEY, C. L. April 25, 1944, No. 7720. [Class 83 (iv)] Mandrels; mandrel carriages and supports.-Tubes are reduced by rolls with rounded helical ribs, the tube being fed either in opposition to the feed that the ribs would impart or at a different rate so that the ribs act to apply pressure to cause the metal to flow without grooving the tubes. The tube T is held in a vice 12 on a saddle 11 fed on ways by a piston 14, a mandrel rod 18 being held in a slotted vertically adjustable support 17 with lubricant supply at 26. A conical head 20 is screwed on the rod and has ducts 24 leading to a clearance on part of the conical surface and on the whole of the cylindrical surface 22. The rolls have a rounded helical rib 29 and a plain conical end 32 that acts in conjunction with a pip on the mandrel head finally to smooth out any incipient markings. The rolls have ball bearing mountings 34, 35 in heads carried by slides 48. adjustable in ways on a flanged housing 46 under the control of backing up screws 51. Screws 50 (not shown) provide for clamping after adjustment. Split packing 38 on the roll necks is secured by split retaining members 39 secured by screws. The housing 46 is bolted to a face-plate carried by a spindle 52 belted to a motor. In a modification, conical rolls 54, Fig. 5, are mounted on spindles 55 in ball bearings 63 in a fixed housing 64 with their axes parallel to that of the tube which is carried by a chuck 57 on a ball bearing tailstock spindle 58. The tailstock is fed by a piston 61 and the rolls are driven by pinions meshing with an internal gear 66 on a belt-driven spindle.