GB1071889A - Method and machine for making non-cumulative force spiral springs - Google Patents

Abstract

1,071,889. Coiling spiral springs; shearing and punching. TENSATOR Ltd. Sept. 30, 1964, No. 39903/64. Headings B3A, B3E and B3W. A close-coiled spiral spring 36 is made by feeding spring strip 4 lengthwise through guides 26, 28, 30 bending the strip sharply around the forward end of the guide 30 to pass over an arcuate surface 66 and then bending the strip to a lesser degree in the opposite direction. Steel strip is fed through a measuring device 6 and the guides 26, 28, 30 by intermittently rotating rollers 18, 20, 22, 24. As it leaves the end of guide 30, the strip is bent upwardly around a freely rotatable roller 66, beneath a shoe 90 which produces the reverse bend, and through further guides 110, 112, Fig. 2 (not shown) to a severing and punching machine 34. Roller 66 and guides 110, 112 are mounted on a horizontal slide 62 which is moved during the bending by linkage 148, 154 and a cam 178, Fig. 6 (not shown), to vary the position of the roller 66 and thus the bending radius. This facilitates the required close coiling of the spring and the reverse bending increases the radius of the coils. The cam may be shaped to move suddenly the roller 66 away from the guide 30 to provide a straight tail on the spring. The latter is severed from the strip and openings are punched in one or both ends by the press 34 having a punch and die set 40, 38 actuated from an eccentric shaft 48. The severing and punching press 34 may alternatively be mounted above or below the bending mechanism 60.