GB107681A - An Improved Machine for Testing the Straightness of and Straightening Rifle and like Barrels. - Google Patents

Abstract

107,681. Sponsel, C. W. July 31, 1916. Examining and testing. - Consists in detecting curvature in a rifle or machine-gun barrel bv means of an electric contact carried by a wire passing through the barrel, the barrel being then bent straight by means of a treadle-operated lever. The barrel is mounted between centres 12. Figs. 7 and 8, carried by blocks 11 pivoted to levers 10 mounted on supports 9, which are adjustably secured to a slide 4. The latter can be moved along the bed of the machine by means of a rack 5 gearing with a pinion 6 on a spindle 7 turned by a handwheel 8. A wire 19, which is threaded through the barrel and the slotted centres 12, carries a contact 57, and is secured at each end by a gripping lever 20 carried by a block 21 on an arm 22 on a shaft 23. One block 21 can be adjusted in order to stretch the wire 19. Stiffening bars 30 connect the arms 22 to arms 31 also on the shaft 23. If the ends of the barrel rise during bending the levers 10 lift the bars 30, and so prevent injury to the wire. The bending lever 42 carrying the screw 43 is operated from a treadle through toggle links 44. As shown in the diagram, Fig. 3, a primary circuit controlled by a switch 54 supplies current to a transformer 56 which supplies current to the circuit of two lamps 52. One lamp is arranged to be short-circuited when the contact 57 touches the rifle barrel. In order to raise and lower the wire 19, the shaft 23 is rocked by an arm 32, Fig. 7, which rests against an angled nut 33 moved by a spindle 35 rotated by a hand-wheel 36. Rotation of the nut 33 is prevented by a bracket 34. An index-wheel 58, secured to the wheel 36 by a clamp operated by a thumb-screw, indicates the distance through which the wire is raised or lowered and so the curvature of the barrel. Wedges 40 mounted in slides 41 support the barrel during bending.