ES381950A1 - Apparatus for forming retaining members - Google Patents

Abstract

Apparatus for bending shanks of helical springs into loops wherein tangentially projecting shanks of the helical spring are bent over to extend axially parallel with the axis of the spring body and then loops are formed therein comprises two mechanically drivable and spacedapart bending units which are adjustable relative to each other and each have a device for bending a spring shank and a device for forming loops and a holder mounted between said units for clamping the coiled part of the spring. The two end loops of the spring are formed simultaneously. Two tail stocks 2 are arranged on a frame 1 and each carry rotatable coaxial rods 3 axially adjustable in the tailstock. Each rod carries two adjustable clamping grips 4 in which hydraulic rotaty pistons 5, 6 and 7, 8 are adjustably mounted by means of links 4 and 11. The rotary pistons have driven shafts 9 carrying interchangeable bending tool heads 10. The holder 12 has jaws 14 actuated by a hand lever 13 for gripping a spring. The holder also has an hydraulic impulse generator 16 for actuating rotary pistons when the jaws are closed. In operation, firstly each tangentially projecting spring shank 17 (Fig. 2, not shown) is bent-over about an abutment 19 (Fig. 3) by a finger 18 projecting from the tool head 10. The axially extending shanks now extend between an axially projecting mandrel 20 and an axially parallel projecting finger 18 of the tool heads 10 and rotation of the heads form loops 21. The angle of rotation of the tool heads is controlled by time switches in an automatically timed sequence. Springs 18 are fed to the holder 12 from a magazine.