GB189827215A - Improvements in Tube Drawing and Mechanism relating thereto. - Google Patents

Abstract

27,215. Brookes, H. J., Trueman, H. P., and Minton, G. E. Dec. 24. Drawing.-Tubes of constant external diameter but varying internal diameter, as shown in Fig. 8, are produced from uniform blanks by drawing over a mandrel and through a die, the relative positions of the die B and the barrel-shaped end or plug C of the mandrel being adjustable by any suitable means. In the form shown in Fig. 4, the plug is fixed and the die butts against a block D, laterally movable by toggle-levers e, connected to the plate E sliding vertically in the fixed abutment A. In the form shown in Fig. 5, the die is fixed, and a screwed extension I of the mandrel is held in a sleeve J having nuts K<1>, K<2> to limit its sliding movement in a fixed abutment H. End movement between the extension I and the sleeve J is prevented by lock nuts j and a pawl Q on the nut K<1>. A bell-crank lever L, connected to the nut K<1>, is operated at the required intervals by wedge blocks M on a bar N to withdraw the plug C from the die to produce thickened portions in the tube. The bar N is connected by a clutch box 0 and rod P to the carriage G. A block T may be raised by a hand-lever R to lift the lever L clear of the blocks M, and at the same time to release the pawl Q so that the mandrel may be withdrawn for the insertion of a fresh tube. Any suitable form of draw-bench may be used and the die or mandrel may be operated by independent motors.