GB1238409A - - Google Patents

Abstract

1,238,409. Making springs; coiling helices. MOOG INDUSTRIES Inc. 10 July, 1969, No. 34816/69. Headings B3A and B3E. [Also in Division G3] A machine for forming a coil spring comprises a cylindrical mandrel 11 means for rotating the mandrel, a guide 22 for directing the rod stock to the mandrel, means for moving the guide along the mandrel and means for changing the rate of travel of the guide at preselected points in its path along the mandrel. The spring winding machine comprises a bed 1 supporting an overhead member 4 mounted on brackets 5 and 6. A tail-stock carrying the mandrel 11 is slidable along the member 4 by means of a fluid pressure motor and the inner end of the tailstock is supported in a chuck 12 rotatable by a gear train within a gear-box 14 driven by a motor 15. Between parallel guide rods mounted in plates 16 and 17 is a lead screw 20 carrying the bar guide 22 having a pair of parallel guide fingers through which the bar stock is fed on to the mandrel. The speed of rotation of the lead screw is controlled by a servo amplifier 34 which actuates a servomotor 30. The mandrel is connected to a sensing transducer or photoelectric encoder 40 which emits electric pulses responsive to the angular displacement of the mandrel for reception by an electronic pulse counter 36 in a console assembly C (Fig. 2). The command voltage circuit 37 which is preadjust. able is connected to the counter 36 and incorporates a number of adjustable voltages obtained by potentiometers which are preset to provide an output which is fed to the servo amplifier 34. The counter is synchronized with the drive system for the mandrel to start the formation of a spring, release the finished spring and reset for the next cycle. The mandrel rotates at a constant speed while the lead screw rotates at a selected rate thus varying the linear velocity of the bar guide which controls the number of coils formed and consequently the pitch. Thus variable pitch coil springs may be produced.