Patent GB-671787-A (GB)
Title: Improvements in or relating to machines for manufacturing coiled springs
IPC: B21F3/06
Filed: 1950-05-22
Abstract: 671,787. Coiling. STEWO GES. May 22, 1950 [Oct. 31, 1949], No. 12772/50. Class 83 (iv). Straightening; shearing adjuncts.-A spring coiling machine with an abutment for determining the spring diameter and with pitch means each controlled by cams has means for zeroizing each cam after performance of a spring making cycle independently of the rotation of the cams. Feed rolls 34, 35 driven by gears 25, 16 from a motor-driven shaft 12 pull wire 135 through straightening rolls 136 and through a spring-pressed guide 91 to a bending roll 72 on a lever 69 actuated by a cam 63. The coil passes a pitch lever 84 moved axially, Fig. 3 (not shown), by a cam 64. On the shaft 12 a clutch member 13 is coupled by dogs 37, 104 with a member 17 driving the feed rolls and a member 103 carrying a switch actuator 134 and a blade operating eccentric sheave 100. A shaft 42 rotated from the powershaft carries an arm 43 on which is mounted a member 46 clutched to a member 48 when a cone cam 52 is moved axially by a shaft 57. The member 48 carries a stop 60 urged to zero position against a stop 61 by a spring 58 and is keyed to a shaft 62 carrying the cams 63, 64, 68. An electromagnet 113 when excited moves a rod 114 axially and by dog 115' raises the locking lever 109 to release the dog 104 of the coupling 103. A block 118 on the rod 114 turns a shaft which operates a fork 40 and also moves axially the cone 52. A switch 124 in the circuit of the electromagnet 113 has an operating lever 125 urged to closed position by a spring 126 and moved to open position by an electromagnet 127. Pins 129, 130 engage a lever 131 operated by the cam 68. Operation. At the beginning of the cycle the electromagnet 113 is de-energized and the dog 37 is spring-pressed towards the member 13. When the main shaft 11 rotates the dog 37 is moved by the dog 14 to rotate the gear 16 and the feed-rolls. The core 52 is moved to the right, Fig. 2, to clutch members 42, 48 together and rotate the cam-shaft 62. A latch 111 of the lever 109 is spring-pressed into a groove 106 to engage and withdraw the dog 104. The wire 135 is fed against the roll 72 and coiled and is pitched by the finger 84 and the cams 63, 64 rotated to control the diameter and pitch of the coil and the spring 58 is wound up. When the cam 68 strikes the lever 131 it is displaced from the pin 129 and the spring 126 moves the lever 125 to close the switch 124. The electromagnet 113 is thus excited to withdraw the dog 37 to stop the feed rolls and the cone 52 is moved to the left, Fig. 2, to unclutch the member 41 and allow the spring 58 to restore the cams. On excitation of the electromagnet 113 the latch 111 is raised to allow a spring 105 to project the dog 104 to clutch it to the member 13. An eccentric 102 is rotated to reciprocate a shear blade 96 against a fixed blade 97 to shear the wire. The dog 134 temporarily closes the switch to excite the electromagnet 127 which operates the lever of the switch 124. The lever 131 then drops to lock the switch in the off position. The lever 109 with latch 111 is moved to push back the dog 104 to disengage the shear. On de-excitation of the electromagnet 113 the clutches for the feed rolls and the cams are brought into operation to start the cycle for the next spring.