Patent GB-596840-A (GB)
Title: Improvements in or relating to the manipulation of wire
IPC: B21F3/00
Filed: 1945-11-22
Abstract: 596,840. Making wire articles ; coiling. SPORING, P. A., PURSE, J. W., and TELEGRAPH CONDENSER CO., Ltd. Nov. 22, 1945, No. 31495. [Class 83 (iv)] In forming bent wire units comprising a helix having one or more convolutions and a stem substantially coaxial with the helix, the wire is first bent intermediate its length substantially at right angles and one side wound into a helix, whilst the other forms the stem. The machine comprises side plates 3, 4, Fig. 4, supported on feet 6 and spaced apart by members 5 ; a further cross-plate 7, Fig. 3, providing a mounting for a bracket 9 carrying a tubular guide 8 through which the wire is fed. A sleeve 10, mounted in a bearing 12 surrounds the guide and has a pinion 11 integral to engage a gear 74, which is driven intermittently through a Geneva mechanism and bevels, meshing with a common drive shaft 21. A carrier 14 is secured to the sleeve by a screw 13 and has a slide 15 adjustable by a screw 16 ; said slide carrying a freely rotatable roller 17. A mandrel 18 arranged coaxial with the guide tube is supported by a carrier 23 slidable on rods 24 so that when the wire is fed forward the mandrel can be retracted through pairs of links 33, 35, rod 31 and a lever 28 operated by a cam 26 on shaft 21 ; a spring 36 returning the mandrel to operative position. In operation, assuming one unit to have been completed and cut off, the projecting length of the wire which is to form the helix of the next unit is bent slightly off centre and as the mandrel returns a lever 63, having a shoulder piece 65 abutting the carrier, performs the function of bending this part of the wire substantially at right angles so that the bend engages a slot 66 in the end of the guide. The end of the mandrel is reduced in diameter to correspond with the internal diameter of the helix and the roller 17 operated through the sleeve 10 and Geneva mechanism revolves around the end of the mandrel wrapping the wire around it. The motion is anti-clockwise and the bar 63 can be knocked out of the way as the roller rotates in this direction. The mandrel is now retracted and the wire fed forward by a pair of feed wheels 37, 38 having raised peripheral portions co-operating to give the correct feed length. Wheel 37 is mounted on shaft 21 together with a pinion 39, the latter driving the pinion 40 connected to wheel 38, which is mounted on a bar 41 pivoted at 42. The wheels are normally held in engagement by the pressure of a spring plunger 43 on bar 41, which may be lifted by hand in order that the engaging portions of the feed wheels may be relatively adjusted to vary the feed length. A shaft 56 rotated by bevel gears meshing on shaft 21 has a roller 58 supported in arms 57 which knocks the end 59 of a shear blade 49 co-operating with a stationary blade 48 to sever the helix unit. The stationary blade is located to one side of the axis of the guide so that before the wire is cut it is bent slightly at the parting point, this bend being engaged by the bar 63 as the mandrel returns so that the free end of the wire which is to form the next unit is bent further out at right angles and located in slot 66 prior to the wrapping operation on the mandrel. The shear blades are mounted on a bracket 50 which is adjustable by means of a hand nut 51, and screw 60 in a slot in plate 4 so that the length of wire left projecting, and hence number of coils of the helix can be varied. The drive shaft 21 may be operated through a clutch which is adapted to slip and prevent damage in case of faults or jamming of the machine.