Patent GB-724090-A (GB)
IPC: B21D53/20
Abstract: 724,090. Making washers. ILLINOIS TOOL WORKS. July 6, 1951 [Aug. 3, 1950], No. 16117/51. Classes 83 (2) and 83 (4). Relates to machines for producing helicallycoiled strips of lightly attached lock washers and like articles and consists in the means for effecting the coiling in superposed nested arrangement. In the example described strip stock is formed into four separate washer strips 30 and the coiling mandrels 84 are driven by worm gearing through a shaft and universal joints from the press, even tension being maintained by a common tensioning roller carried by a pivoted arm bearing on all the strips. As the strips are laid on their respective mandrels they are flexed about the points of connection of their locking teeth so that when coiled they lie flat and compact in which condition they are held by relatively heavy rings 86 that bear on the coils which are supported on flanges 90 of the mandrels. Each mandrel has a shallow square recess by which it is driven by a square 106, being held by a nut 116, on its supporting shaft 94 running in ball-bearings 112, 124. The strip passes over a guide 147 on the ring 86 that also supports the flexing means consisting of three grooved rollers and associated guide channels. The strip just passes between guide plates 154 that ensure that all the washers lie in one plane and guide them to the groove 180 in a roller that bends the strip to present the washers to the grooves 92 in the mandrel, at an angle as shown in Fig. 11. The guide plates and roller are mounted on a plate 158 pivoted to the ring 86 at 162 and having a slotted flange engaging an adjusting screw 168 carrying a compression spring 170 tending to urge the roller 182 towards the mandrel 84. The washer strip is then engaged by a second roller 208 with a groove in plane perpendicular to the axis, this brings the washers back into such a plane and at the same time bends them to fit the mandrel. Mounted on the pivoted plate 196 that supports the roller 208 is a deflector 222 that bends the washer strip away from the mandrel again but keeps it still in the same plane by guides 224, Fig. 13. A circular member 228 clamped in position by a screw 232 prevents the washer strip from leaving the guides. A third roller 246 carried by a pivoted plate 236 with its end upturned to present the groove in the roller at an angle returns the washers into place in the mandrel grooves, further flexing the metal at the points of connection of the washers. The washers then pass through an inclined groove in the inner surface of the ring 86 to be nested in compact and stable form with the previously coiled part of the strip. The rings 86 are prevented from rotating by arms 258 engaging vertically extending abutments 262. In a modification the abutments are of channel form to prevent rotation in either direction. A modified set of rollers is illustrated for dealing with washers of conical form. Instead of gearing the coiling mandrels to the press actuating mechanism both press and mandrels may be driven by separate synchronous motors and in this case more slack is. allowed in the strips between the two devices and further guide rollers are employed for each mandrel. The arm carrying the common tensioning roller carries a mercury switch to stop the coiling motor should the slack in the strips all be taken up. The coils are claimed broadly in Specification 704,559 which also describes the machine for stamping out the washer strips.