Patent GB-1205574-A (GB)
Title: Spring winding machine
IPC: B21F3/04
Filed: 1967-09-26
Abstract: 1,205,574. Winding springs. TORRINGTON MFG. CO. 26 Sept., 1967 [10 Oct., 1966], No. 43658/67. Heading B3E. A spring winding machine comprises a wire feed mechanism adapted intermittently to grip and advance wire longitudinally toward a work station, a laterally extending winding spindle supported at said work station for rotation in one and an opposite direction and for limited axial movement respectively for winding and recoiling of wire about the spindle and for the introduction of pitch during winding, at least one auxiliary mechanism adjacent the work station adapted for operation on an end portion of a spring, and power operating means for said feed mechanism, spindle and auxiliary mechanism, said power operating means including a fast response spindle drive means, engageable and dis-engageable independently of feed and auxiliary mechanism operation selectively to start, stop and reverse the spindle. Wire from a coil 14 is drawn through a straightener 20 by a reciprocating gripper mechanism and is wound around a vertical spindle 28 which is rotatable and movable axially. Also mounted on the work-table 12 and three cam-shafts 29, 30 and 32 which actuate additional tools for forming the spring ends. The feed mechanism and cam-shafts are driven from a motor and variable speed unit 44. The drive passes through an electrically operated brake and clutch. Spindle drive and control mechanism.-The spindle 28 is driven by either of two oppositely rotating motors 170, (172). Each motor drives through an electrically operated clutch and brake. Associated with the motor 170 are the clutch 174 and the brake 176. A pulley 184 on the output shaft of the clutch is connected by a toothed belt with a pulley on the output shaft of the motor 172 and drives a pulley 192 on a cylinder 216. The sleeve is rotatably supported in bearings 218 and 220 and has within it a sleeve 206, which rotates with the cylinder and is axially slidable relative to it. Secured to the sleeve is the spindle 28 on which the spring is wound. Surrounding and in contact with the sleeve are six rollers 230, each of which is rotatable on a pin passing transversely through a shaft 234. Connected to each shaft is an arm 242, the outer end of which carries a roller which engages a cam track formed in a ring 248. Rotation of the ring alters the angle between the axes of the rollers and the sleeve and hence the amount of axial movement of the sleeve for each revolution thereof, thereby controlling the pitch of the winding. At its upper end the sleeve is connected to the piston-rod of a solenoid controlled fluid cylinder assembly 262, which moves the sleeve directly to its starting position. The ring 48 is connected to a gear ring which is rotated by a worm gear on a shaft which terminates in graduated collars 256. The pointer 260 indicates the angle of obliquity of the rollers 230 on a scale 258. Wire feed mechanism.-A slide 110 runs on a dovetail guide, fixed on the work-table 12, and carries a wire gripper. The carriage is driven by a cam 118 which oscillates a bell-crank 124, 128, which in turn, through a link 130, oscillates a lever 132. The lower end of the lever is connected by a bar 136 to the slide 110 at 138. A spring 142 returns the slide. A second cam 120 which controls the opening and closing of the gripper actuates a follower 144 which causes a guideway 146 to move laterally, guided by parallel links 148, 150. The movement of the guideway rocks a cam 151 which turns a wire gripper about its pivot 160. Control and operation.-Mounted on the output shaft of the clutch 176 is a pulse generator 202 which produces two pulse trains, the first train comprising a single pulse/revoluton and the second train comprising 120 pulses/revolution. The control circuit includes four counters A, B, C and D, Fig. 22, the first pulse train being fed to counter A and the second train to counters B, C and D. The counters are pre-set to operate relays KA-KE when a count is reached corresponding to the desired spring parameters. The relays control contacts KA 1 -KE 1  which are connected through potentiometers A-D to a control unit 348 for the spindle clutches 174 and 178. The potentiometers control the degree of engagement of the clutches and hence the spindle speed. A reversing circuit including switches CR 1 -CR 4  is situated between the control unit and the clutches. Spiking circuits 320 and 324 produce a high transient voltage to initiate rapid operation of the brakes on the winding spindle and cam-shaft. At the beginning of a winding operation the counter A closes the relay contacts KA 1  and a high voltage signal, determined by potentiometer A causes tight engagement of the spindle clutch. After a number of turns have been wound at high-speed the contacts KA 1  are opened and counter B closes the contacts KB1 which provides for a lower clutch operating voltage, through potentiometer B and hence for a low-speed terminal winding portion. When the pre-set count is reached in counter B, the relay KB is deenergized and a re-coil operation is initiated by a limit switch LS2 mounted on the cam-shaft. The amount of re-coil is controlled by the counter D which passes a signal voltage to the control unit 348, the reversing switch and the second spindle clutch. Forming operations and cut-off then occur at the ends of the spring and then a limit switch LS3 is closed which through relay KE1 rotates the spindle to a start position. Finally, alimit switch LS4 actuates the solenoidcontrolled cylinder assembly 262 to return the spindle axially to its start position. Slow speed operation for winding short springs.-A single slow speed method of operation is selected by moving the switch CS4, following the relay contacts KA1, from the switch position 330 which it occupies for normal operation to the position 332, in which the signals from both counters A and B transmit signals through the potentiometer B.