Patent GB-736779-A (GB)
Title: Improvements in machines for assembling fasteners with washers
IPC: B23P19/08
Filed: 1951-07-05
Abstract: 736,779. Assembling screws and washers. ILLINOIS TOOL WORKS. July 5, 1951 [Aug. 3, 1950], No. 16002/51. Classes 83 (2) and 83 (4). Screws are fed from a hopper 43 and pass by gravity down guide rails 64 provided with a guard rail 72 above the heads. A vertically movable yoke 80 engages the screw heads by a spring 84. If the supply of screws fail the spring no longer supports the yoke which descends actuating a switch 86 to stop the driving motor. The rails end in a curved extension that delivers the screws through a gap in a guard rail adjacent a toothed wheel 48. Smooth passage from the rails 64 to the spaces between the teeth is ensured by light fingers engaging under opposite sides of the heads. A continuous strip of washers 46, Fig. 23, in which adjacent washers are connected by opposed twisted teeth 45 already weakened at 47 by the twisting, is in coiled form as described in Specification 704,559, and the coil so placed on a drum 42 being supported by a flange 94. The drum is supported from below in such manner that it can be swung aside from under the wheel 48 to facilitate the loading of a fresh coil of washers. The end of the strip is led up the drum in the form of an open helix and it passes over a supporting roller 102, Figs. 1 and 3, and under a detector roller 106 on an arm 108. If the strip breaks or runs out the arm 108 ceases to be supported and actuates a switch 110 controlling the motor similarly to the switch 86. Beyond the roller 106 the strip enters a guide channel 124 that brings the washers along a path conforming to that of the screws and convergent therewith so that the shanks gradually enter the washers being finally fully engaged by a spring 128. Further guides 54 with a spring holddown 162 conduct the assemblies to indenting rolls 156 that raise burrs on each side of indentations, as described in Specification 736,788, and render the washers captive during subsequent handling prior to the rolling of the screw-threads which renders the washers finally captive and removes all traces of the burrs and indentations. Guides 58 transfer the assemblies from the indenting rolls to a feed wheel 166 which delivers to a device that breaks up the strip into individual washered screws. This device consists of a rotating slotted disc 204 with a central hole to pass the screw-head. One side of each slot is bevelled to facilitate the entry of a shank and the rotation of the disc twists off the washer from the strip and the screw then falls into a storage container or is fed directly to any of a number of thread rolling devices. The drum 42 is a light friction fit on its shaft so that it can adapt itself to the slight change of phase required, as the coil unwinds, due to the changing angle of the strip as it approaches the supply of screw blanks. The machine is driven by a belt transmitting to a main shaft 246 wormgeared at 252 to the indenting rolls and spurgeared at 254 to an axially adjustable shaft driving the wheel 48 by a worm 314, the axial movement providing phase adjustment. Spur gears 270 drive the breaking wheel and the further spur, bevel and worm gearing shown in Fig. 2, transmits to the feed wheel 166. The drum shaft has a disconnectible coupling at 352 to the driven shaft of the wheel 48 to permit disconnection when the drum is to be swung aside.