GB1260695A - Apparatus and method for winding coil springs - Google Patents

Abstract

1,260,695. Coiling helices; making coil springs. NORTH AMERICAN ROCKWELL CORP. 22 July, 1969 [10 Oct., 1968], No. 36763/69. Headings B3A and B3E. A method of winding coil springs comprises advancing wire 13 by rollers 15, Fig. 1, at a uniform rate to an abutment surface 27, Fig. 3, where it is deflected and bent around a bending surface 23. The abutment surface 27 is movable between first and second end positions whose movement is controlled by a cam 53 having alternate first and second sets of constant radius peripheral portions, the constant radius portions being interconnected by relatively short transition portions. The surface 27 is sequentially maintained in its first end position for a first predetermined period of time, moved to its second end position during a second predetermined period of time, maintained in its second end position for a third predetermined period of time, and moved to its first end position during a fourth predetermined period of time. A single coil formed in this manner will have a first portion of relatively small constant radius formed when the surface 27 is in its first end position, a portion of relatively large constant radius formed when the surface 27 is in its second end position and portions of varying radius formed when the surface 27 is being moved to its end positions. A surface 31 is provided to longitudinally stretch the coils along the coiled axis to produce a desired pitch. In another embodiment, Fig. 7, the cam 53 is replaced by a pressure actuator 102 and valve means 103. The valve means selectively supplies pressurized fluid from a source 110 to a selected one of cylinder regions 112 and 113 so as to move the surface 27<SP>1</SP> between the two end positions. The movement of piston 107 is co-ordinated with the movement of the wire 13<SP>1</SP> by mounting a disc 116 on drive shaft 67 and locating suitable cam lobes 118 on the disc. The lobes 118 indicate formation of the various constant and variable radius portions of the coils and actuate a switch 120 which indicates to a control device 121 the formation of each coil portion. Lobes of a disc 80, Fig. 1, mounted on the same shaft as the cam 58 actuate a switch to indicate to a control device 85 through a circuit 86 that a single coil has been formed. When the required number of coils have been formed the control device 85 actuates a brake mechanism 100 to stop the feed of the wire 13 and the reciprocation of the surface 27. The control device simultaneously actuates a fluid actuator 96 for moving a support 93 along a slide 94 so as to move shears 92 to a cutting position. Actuating mechanism 95 operates the shears to cut the wire after which the support 93 is returned to its original position.