GB797481A - A control mechanism for spring forming machines - Google Patents

Abstract

797,481. Coiling springs. HACK, K. July 26, 1956, No. 23084/56. Class 83 (4). A spring-forming machine for the manufacture of coiled wire springs with straight arms at the ends disposed at an angle to each other and having a winding tool which is moved so that a length of wire fed thereagainst is coiled thereby is characterized in that a rotating compound cam disc, which moves the tool forward to start the coiling and back to stop the coiling, comprises two coaxially arranged cam discs with different rates of rotation, of which the more rapidly rotating cam disc carries the forward and return cams for advancing and retracting the winding tool and the slower rotating cam disc carries a cam for holding the tool in its advanced position for a selected number of windings of the spring. Spring wire stock 1 is fed by rollers 2 through a guide 3 as far as a leading arm or end 1a of the spring requires. A coiling tool 4 shortly before this length is reached, moves down to engage the wire 1 which coils thereagainst in its continued feed until the desired number of coil turns have been formed. The tool 4 then rapidly retracts and the coiled spring moves forward until a trailing arm or end 1b of the spring has the desired length, whereupon the wire feed is automatically interrupted and a parting knife 5 cuts off the finished spring over an anvil 7 which has been moved into position. Movement of the tool 4 is controlled through adjustable linkages 27, 25, 22 and 21 and camfollower roller 19 by rotating cams. A slowrotating cam comprising two circumferentially adjustable cam elements 30a, 30b is fixed to a rotating shaft 7 and serves to hold the coiling tool 4 in its forward coiling position. A fast rotating cam on a hub 13 (not shown), rotated through gearing at an integral number times the speed of the slow cam, comprises two circumferentially adjustable segments 15, 17 which cause the forward and retraction movements of the tool 4 when the follower roller 19 is off the slow cam elements 30a, 30b. One spring is made for each rotation of the shaft 7.