Patent GB-166588-A (GB)
Title: Improvements in or relating to the method of producing hairpins and apparatus or machinery therefor
IPC: B21G1/00
Filed: 1919-08-07
Abstract: 166,588. Sparkes, J. S. Aug. 7, 1919. Pins, dress.-A machine for making hair-pins in bulk comprises means for feeding in a number of wires at each side of opposite ends of the machine to centrally-situated forming and actuating mechanism. The wires are drawn by reciprocating grippers through notches in conveyer chains and are held on cylinders during cutting off and the formation of the ends. The blanks then pass to bending stations, after which they fail from the machine ready for coating. The wires X are drawn from reels 71 and pass round rollers 74 and through guide slots to straightening-devices 75 and feeding devices 69 which insert the wires into grooves 44 of chains 40 passing round indexed cylinders 19 and between retaining guides 42, 43. Lengths are cut from the wires by pivoted cutters 38 and are ball or cone pointed by dies acting on the ends of the wires under the control of cam-actuated spring hammers 68. The pointed blanks are conveyed to the bending position and are clamped against arms 27 of a turret former by a resiliently mounted die member 56 whilst reciprocating and laterally swinging members 52 complete the bend. The machine is driven by a central pulley 5 or by an electric motor, transmitting by chains to crank discs 9 bevel geared to cam shafts 17 that index the cylinders 19 through mutilated gearing 21. To reduce shock the driven gears 23 transmit to their shafts 25 through springs 37. To prevent overrunning, levers 35 provided with projections to engage notches in the cylinders are controlled by links connected to levers which also control the cutters 38 and are actuated by cams 64. The levers 35 also clamp the wires during the formation of the points. The crank discs 9 actuate the feed-devices 69 through connecting- rods 11. Each feed-device contains a separate gripping-device for each wire comprising a wedge 86 normally held raised by a spring 87 and sliding on a rib 85 in a guide groove. At the end of the outward stroke the wedge leaves the rib and is pressed down by a spring 90 carried by a bar 91. The bar is pivoted to enable the feed of a whole group of wires to be rendered inoperative, and each spring 90 is pivotally mounted to enable the feed of an individual wire to be stopped. During the inward stroke the rib 85 cams the wedge against the wire X, the intensity of the grip being determined by a stop screw 92. The straightening-devices comprise a series of vertically and horizontally-arranged staggered pins, some of the pins being carried by pivoted members 77 latched at 81 to facilitate introduction of the wires. Some of the pins mav be adjustable, as by mounting on a member 76<2> laterally movable under control of a screw. The hammers 68 are helved and actuated by cams 67<a> preferably arranged to strike a double blow. The turret formers are chain geared at 31<a> to vertical shafts 29 geared to the cylinders 19. A spring bolt 60 engaging countersinks in the turret secures accurate indexings. In a modification the turret formers are replaced by single fixed formers. The dies 52, 56 are carried by slides 50 adjustably linked to levers 47 operated by cams 45 on the shafts 17. Springs 57 provide for the arrest of the die 56 during its clamping action, and bolts 59 ensure complete retraction on the return stroke.