Patent GB-742923-A (GB)
Title: Improvements relating to the production of permanently assembled washers and nuts
IPC: B23P19/08
Filed: 1951-11-05
Abstract: 742,923. Assembling nuts and washers; tapping nuts. ILLINOIS TOOL WORKS. Nov. 5, 1951 [Nov. 4, 1950], No. 25888/51. Classes 83 (2), 83 (3) and 83 (4). [Also in Group XXX] Washers are permanently assembled with nuts by feeding the washers in succession along a path, and feeding nuts from a random mass successively into axial alignment with the washers and telescoping or force-fitting the aligned members. When the parts assemble merely by fitting, then after assembly one of the members is deformed to prevent axial separation whilst permitting relative rotation. The assembly may be carried out in a machine that taps the nut blanks. Nuts are supplied in random order to a hopper 50, Figs. 1 and 3, having a non-rotary bottom plate 100 supported by a fixed shaft 96 about which the rest of the hopper rotates, being driven by a motor 106 through a gear-box. Radial slots 94 in the annulus 86 each receive a row of nuts that are carried to the top of the hopper and discharged into a guide channel 54. A guard ring prevents premature discharge. The channel 54 leads to a selector-56 that passes nuts that are right-way - up to a continuation channel 60 and rejects those that are the wrong way to a shoot 62. delivering to a receptacle 64 from which they may be returned to the hoppers. Selection is effected by intergeared driven toothed wheels 128, 130 (Fig. 7), shaped to fit the nuts. Keyed above the wheel 130 is a disc 194 carrying a series of spring-plungers 200, Fig. 12. A cam 224 raises these plungers by engaging under 'a shoulder 214 on the head to permit the plungers to pass over the nut blanks but releases the plunger on the line of wheel centres so that it drops on to the nut 108. If this be the wrong way up it enters the countersunk end as shown in Fig. 12 and carries the nut past a blade-spring 230. The plunger is then raised by a cam 214 and the nut is discharged at 190 to the shoot 62. Nuts the correct way up pass from under the plunger to the channel 60. Loose washers 262, Fig. 15, in a rotating hopper 256, when correctly presented, pass through slots 260 to slide over a plate 280 with a spaced transparent plastic guard-plate 282, that enables jams to be located and dealt with, to a dial feed-plate 344 composed of upper and lower toothed plates 346, 348 separated by a flange 354 integral with the top plate and provided with holes of a size to pass the nuts. The hopper is rotated at a speed sufficient to ensure an excess of washers passing across the plate 280 and those that do not enter the notches in the bottom plate are carried on to a discharge shoot 364 that delivers at 76, Fig. 1, to a receptacle 78 for return to the hopper. The nut guide 60 ends at a transverse guide 440, Fig. 17, closed by a plug 442 shaped to fit the nuts and locate one above the plate 346 in position to pass through the next hole that is presented. The leading nut from the guide 60 is fed against the plug 442 by a plunger 446 shaped to turn the nut, if necessary, to the position shown in Fig. 17 and operated through a spring 462 by a lever 456 pivoted at 458 and operated through a spring 470 by a plunger 384 and lever 378 from a cam 334. A spring 388 maintains the follower roll 366 against the cam. The dial plate is mounted together with a ratchet-wheel 342 and spacing washer 349 that affords adjustment according to the washer size, on a flanged sleeve 340 turning on a sleeve 336, forming the hub of the cam 334 and itself turning on a fixed pin 316 that has a central bore with lateral passages serving to lubricate the parts. The cam is worm-driven at 416 and an arm 390 connected to the lever 378 carries a pawl that engages the ratchet wheel 342 that is also provided with a detent. Both the pawl lever and the detent have adjustable eccentric pivots. The hub of the cam drives a sleeve 526 carrying a bevel wheel that drives a cam 492 that acts on a pivoted-plate 484 to press the nut down on to the washer so that a number of inwardly-directed projections 546, Fig. 22, are forced over the wide end of a flanged boss on the washer. In a modification the assembly is effected by passage under a spring-pressed roller. Tube-expanders.-In a further modification the bevel wheel is replaced by a cam that acts oii a lever forcing a guided plunger 582, Fig. 29, on to the nut which is thus forced with the washer over the end 620 of a tube-expander having a conical surface 618 that expands a flange 622, Fig. 30, on the nut, thus preventing separation from the washer. A spring-pressed sleeve 612 returns the assembly to pass over the plate 280 and beneath a spring finger 548, Fig. 15, that presses the assembly through a cut-away part of the plate to a funnel 552, Fig. 1, leading to a shoot 72 and receptacle 74. The ratchet drive for the dial plate provides indexed periods of rest during which a nut is fed at one station and the assembly with the washers completed at a subsequent one. To prevent the feeding of a nut to a recess from which the washer is absent an arm 474, Fig. 15, pivoted on a bracket 476 carries two plates 480, one engaging the upper notched member and the other the lower. A spring 478 urges the plates towards the disc. When a washer is absent the lower plate enters the empty notch and the upper plate 480 enters the notch in the upper dial-plate and prevents the dropping of a nut. A bevelled edge 482 causes the arm 474 to be cammed outwards as the dial-plate turns. In a modification the nuts rejected pass through an inverting channel leading to a second, guideway that delivers them to the dial plate. A further form is described for use when the nuts are required the opposite way up to that effected by the means shown in Fig. 7. Tapping; taps.-The nuts may be supplied to the hopper 50 untapped, and in this case the guide channel 60a, Fig. 32, delivers the nuts to a hollow-spindle 652 carrying a spur wheel 646 driven through further gears from a motor. A plunger 658, hollow for the supply of oil from a flexible pipe, is reciprocated by a cam to advance the leading nut past spring aligning- pins 656 to other driving arms 654, constructed as described in U.S.A. Specification 2,090,698, and on to a tap having a long shank bent to guide the tapped nuts down a channel leading to the device for assembling with the washers. The shank extends almost to the end of the channel and a micro-switch, in the lower part of the channel, stops the assembly part of the machine should the supply of nuts fail. A front distributing ring 650 supplies further oil during tapping. The shank is knurled at 666 to assist in the removal of cuttings from the nuts. The removal is completed by an air and oil spray delivered at 718 and this also lubricates the nuts sufficiently to facilitate their passage through the rest of the machine. The shank is gripped alternately by two sets of lever-jaws 676, 678 connected by toggle links actuated by levers arranged on opposite sides of a common cam, .through a two-part spring plunger. A slide 672, cam and lever operated, carries fingers pivoted at 722 and spring-urged towards the tap shank as limited by pins 726, and as the slide is.moved to the left, Fig. 32, bevelled edges 728 cause the fingers to ride over one or more nuts and start them travelling along the shank when the slide returns to the right. The slide also carries stripper fingers 742, 744, which co-operate with bevel-edged spring detents 730, 732, 734 and 736 in maintaining the travel of the nuts towards the washer-assembly mechanism. An air jet 838 further cleans the nuts and-assists the travel. The. down-bent tubular channel delivers the nuts to the assembly mechanism that is similar to that first described except that the nuts are supplied by gravity feed only and the telescoping is effected by passing under a spring- pressed roller.