US2788119A - Spring assembly machine - Google Patents

Description

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SPRING ASSEMBLY MACHINE l2 Sheets-Sheet 8 April 9 1957 H. sTuRM SPRING ASSEMBLY MACHINE Filed June 2, 1951 12 Sheets-Sheet 9 April 9, 1957 H. STURM i SPRING ASSEMBLY MACHINE l2 Sheets-Sheet l0v Filed June 2, 1951 April 9, 1957 H. sTURM SPRING ASSEMBLY MACHINE 12 sheets-sheet 11 Filed'June 2, 1951' /W WQ;

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Apnl 9, 1957 l H. sTuRM 25788119 SPRING ASSEMBLY MACHINE Filed June 2, 1951 l2 Sheets-Sheet l2 f3-ff@ JAW OPERATING CAMS P05/ffl? CAMS nited States Patent O SPRING ASSEMBLY MACHINE Helmut Sturm, Kenosha, Wis., assigner to Simmons Company, Kenosha, Wis., a corporation of Delaware Application June 2, 1951, Serial No. 229,607

4 Claims. (Cl. 203-135) This invention relates to the manufacture of spring assemblies (commonly known as inner constructions or inner construction units) for bed springs, cushions, mattresses, upholstered furniture and the like. These spring assemblies usually comprise a multiplicity of axially vertical spiral springs arranged in rows. The springs of adjacent rows are interconnected by means of helical wires or tie members which extend the length of the rows and are threaded around relatively overlapping or juxtaposed portions of selected coils of the springs, usually around portions of the top and bottom coils.

The apparatus herein disclosed is an improvement of the spring assembly machine shown in Patent No. 2,388,- 106, issued October 30, 1945, to Edward E. Woller.

In general, the object of this invention is to provide means for adapting a spring assembly machine to the production of spring assemblies or inner constructions of a wider range of sizes than has heretofore been possible. A more specific object of the invention is to provide, in a machine for assembling inner constructions of the type described, means for infinitely varying the length of helical tie members by which the rows of springs are united, and still more specifically, to provide infinitely adjustable means for controlling the length of wire supplied to the coiler or helix forming portion of a spring assembly machine of the type, for example, which is shown and described in the Woller patent, above referred to.

Other objects of the invention will also become apparent and be understood by reference to the following specification and to the accompanying drawings (12 sheets) in which there is illustrated a preferred embodiment of the invention.

In the drawings:

Figure l is a diagrammatic front elevation of a spring assembly machine embodying the invention.

Figure 2 is a diagrammatic plan View of the same.

Figure 3 is a front elevational view of the improved helical-forming mechanism.

Figure 4 is a plan view of the main drive of the spring assembly portion of the machine, showing in part the operative relationship ofthe main drive with the drive of the helix-forming mechanism.

Figure 5 is a plan view of the helix-forming mechanism and drive therefor, showing in dotted outline the relationship thereto of the improved helical-length control means of the invention.

Figure 6 is a rear elevational view of the mechanism shown in Figure 5. y

Figure 7 is a side elevational View of the mechanism shown in Figure 5.

Figure 8 is an enlarged side elevational view of a portion of the drive mechanism shown in Figure 7.

Figure 9 is an enlarged rear elevational view corresponding to Figure 8.

Figure 10 is a sectional elevational view of the helixforming mechanism taken along the line 10--10 of Figure 3.

Figures 1l, 12 and 13 are diagrammatic sectional elevational views of the helix-forming mechanism taken respectively along the lines 11-11, 12-12 and 13-13 of Figure 5.

Figure 14 is an enlarged front elevational view of the helix-forming mechanism, showing in detail the means for controlling the length of helix formed.

Figure 15 is a plan View of the mechanism shown in Figure 14.

Figure 16 is a side elevational view of the mechanism shown in Figure 14. v

Figure 17 is a diagrammatic illustration of the electrical circuit by which various operations of the entire machine are coordinated, and

Figure 18 is a timing diagram showing the synchronized action of various elements or portions of the entire spring assembly machine.

General explanation As previously indicated, the invention is concerned with an improvement in one phase of operation of an overall assembly machine designed for the production of inner construction units employed in the manufacture of mattresses, cushions and the like. Such inner construction units employ a multiplicity of axially vertical coil springs S arranged in rows as indicated in Figure 2. The top and bottom coils of the springs S in adjacent rows of springs are tied together by means of helical wires H which are fed endwise and rotated about their own axes so as to be threaded around adjacent portions of the top and bottom coils respectively, as indicated in Figures 1 and 2.

A machine for assembling such constructions is desirably one which is capable of performing a multiplicity of operations in prearranged sequence, each cycle of operation being `such as to unite one pair of rows of springs, the entire inner construction unit being assembled by repetitions of this cycle of operation. Furthermore, v

such machine would also include some means for interrupting its operation after a specied number of cycles so as to define individual inner-construction units.

The individual steps of each cycle of operation, except as they relate speciiically to the invention, are here indicated only diagrammatically and will be explained only to the extent necessary to provide a background of understanding for the present invention.

Reference may be had to the Woller Patent 2,388,106 as illustrative in detail of a complete assembly machine of the type with which the present invention may be employed. The individual operations of such an assembling machine may, for example, comprise the following, occurring in proper sequence under the control of an automatic programming device or controller.

A number of individual pre-formed coil springs are loaded into proper pockets or receptacles in an endless conveyor 1 which is advanced intermittently to present a specified number of springs, sufficient to form a row of the desired length, to an assembly point, where they v are unloaded from the conveyor by means of pusher elements 2 which form a part of the machine. Assuming that this row of springs is the rst row or leading edge of a new construction, the upper and lower coils of the springs are then gripped at their forwardmost portions by jaws which are formed so as to constitute, or have associated therewith, segmental portions of a screwthreaded guideway or channel extending longitudinally of the row of springs, each guideway encompassing the forwardmost portion of the upper or lower coil of each spring of the row. A helical tie wire is then fed into the threaded guideway and rotated so as to be fed longitudinally of a row of springs while simultaneously threading itself around that portion of each spring coil which is disposed within the guideway. When. the helical tie wires reach the end of the row of springs, the feeding of the helices is stopped and the helices are cut olf at their ends.

While the helices are being. threaded, the conveyor is advanced so as to present4 another row of springs to the operating zone of the machine. However, before these springs are unloaded from the conveyor' by thel pushers, the aforementioned jaws are released so that the rst row of springs may be simultaneously displaced forwardly by other advancing `or conveying means when the new row is unloaded from the supply conveyor by the pushers. The guidewaydorming jaws are then repositionedabout the rearwardmost portions of the top and bottom coils of the first row of springs and the juxtaposed forwardmost'portions of the` `corresponding coils of `the second row of springs, so as to encompass both within the screwthreaded -guideway. Another set of helices is then fed in as above described,threading` themselves through the guideways around the juxtaposed portions of the spring coils and uniting the. rows together. The first set of helices are meanwhile crushed andv crimped at their ends to prevent unthreading thereof from the coils of the springs. This sequence of operations is repeated a specied number of times in. order to produce an inner construction having the desiredy number of rows. Automatic indexing means areV preferably provided for causing the conveyor to dwell for one cycle after the desired numbers of rows havebeen united in order to provide for the separation of individual spring assemblies. In such case, the trailing row of each spring assembly is provided with a tying helix in the sam'e manner as was the first or leading row of the construction.

inasmuch as itis the purpose of the present invention to adapt a machine of this type to the assembly of inner construction units which vary in size, i. e., in the length of the individual rows, the invention is concerned primarily with that portion of the machine which forms and feeds the tying helix, and only that portion of the machine and the necessary linking apparatus by which the function of the helix-forming portion is related to other functions of the entire machine, will be subsequently explained in detail. It should also be understood that while the apparatus` embodying the invention is particularly adapted for service in an assembly machine of the type shown n Woller Patent 2,338,106, it is not so limited in application, since, as will presently appear, the operation of the helix forming portion or coiler ofthe assembly machine is self-contained, itA being related only tothe mam assembly portion forthe purpose of' controlling its operation in synchronism with the other operations of the assembly mechanism.

It will also be understood that while the helix-forming portion or coiler of the, adjustable so as to producea helical` tie` wire of any desired length within practicable limits; the degree of utilization of this adjustability; so far as it permits the assembly of inner constructions of different sizes is dependent upon the nature of the assembly machine with which the coiler is employed,because the size of the inner construction units produced will be determined by the size, number and spacing of the individual constituent coil springs of which the inner construction unit is comprised.

Supply and feed of helix wire As shown in Figure 3, coils 4 and 5` of wire for forming the helicals H aresuitably supported on stands. The supports are preferably of a type in whichfthe` coils 4 and 5 of spring wire are carriedby suitable racks or baskets which are rotatably supported about vertical axes on upright stands. Also,` provision is preferably made for effecting rotation of. the baskets supporting coils 4 and 5 present invention is universally in accordance with. the direction in whichl the wire` is withdrawn therefromY for delivery tot-he helical-'forming l mechanism or coiler 3. As shown, the racks for the coils 4 and 5 embody suitable bottom disks 6 which are engaged by friction wheels 7, the latter being journaled on the supporting posts of the stands and driven (from the coiler 3, later to be described) at such a speed as to feed the wire at a slightly slower speed than the speed of travel of the wire through the coiling mechanism. The main feed of the wire comprises cooperating pairs of Wire feed disks which propel the wire at the required rate of speed and pull the wire through suitable straightening rolls indicated at 8 and cleaning devices 9. The friction drive of the wire coil racks permits the latter to advance as may be required by the pull on the wires and the friction drives serve primarily to reduce the resistance of the baskets to the required feed of the wire. The Wire straightening devices S and cleaning devices 9 are known constructions.

The feed wheels for the uppermost wire W comprises the cooperating wheels i0 and 11 forming one pair and cooperating wheels 12 and 13 which constitute the second pair. For feeding the lower-most wire there are pro vided similar pairs of feed wheels, one pair comprising the wheels 14 and 15 and the other pair comprising the wheels 16 and 17. The wheels 1li to 17 inclusive are peripherally grooved as indicated in Figures 5 and 7 and they arc so related that they are operativo to grip between them the wires to be fed with su'icient tightness to insure positive feeding of the wire through the coiling mechanism. The wheels 19 to 17 inclusive are respectively mounted on shafts 18 to 25 inclusive.

Driving power is applied separately to the set of wheels 10 to 13 inclusive for feeding the upper wire W and to the set of wheels 14- to 17 inclusive for feeding the lower wire W.

The shafts 22, 19, 24, and 21 are suitably journaled in the side frames of the coiler mechanism substantially as is shown in respect of the shaft 24 in Figure 10. The shafts 18, 20, 23 and 25 are each journaled in bearings movably mounted' in the side frames of the apparatus substantially as is shown in respect of the shaft 25 in Figure l0. As there shown, the shaft 25 has one end journaled in a bearing block 32 which is pivoted as indicated at 33 in the` side frame of the mechanism for rocking movement about a horizontal axis. The other end of the shaft, i. e., the end which carries the wire feed wheel 17, is journaled in a bearing block 34 which is vertically slidably mounted in a guide-way or slot 35` provided in the adjacent side frame of the apparatus. The bearing block 34 is normally urged to move upwardly by a spring 36 which is interposed between the bearing block 34 and the adjacent end' of a screw 37 which threadedly engages a suitably tapped opening in a bar 38 which extends across the otherwise open end of the frame slot 35. By adjustment of the screw 37, the pressure exerted by the spring 36 to effect upward movement of the adjacent end of the shaftZS and the wire feed wheel 17 may be adjusted. The wire feed wheel 17 is thereby caused to effectively cooperate with 'the feed wheel 16 to grip and feed the wire which is propelled thereby. Similarly the feed wheels 10, 12 and 15 are resiliently urged into cooperative relationship to the feed wheels 11, 13 and 14 respectively.

The gear connections for properly driving the wire feed wheels are shown in Figures 5, 6, 7, and l0 to l3 inclusive. By reference to said figures, it will be sccn that the upper wire feeding rolls 10to 13 inclusive are driven by gear connections to the shaft 21 which may be considered the input-shaft of the drive system for said feed wheels.

Intermediate the supporting side frames of the coiler mechanism, the shaft 21 is equipped withl a gear 40 which meshes withfa gear 41 on the shaft 20 of the feed wheel 12 (Fig. ll). Hence the feed wheels 12 and 13 are properly driven to cooperate in feeding the upper` wire. The shaft 21 also has mounted on it, between the supporting side frames of the mechanism, a gear 42 (Fig. 13) which meshes with an idler gear 43 which is mounted on the shaft 24 for free rotation thereon. Said gear 43 meshes with a gear 44 which is keyed to the shaft 19 so as to thereby drive the shaft 19 incident to the said gear connections to the drive shaft 20. In addition to the gear 44 on the shaft 19, there is also a gear 45 (Fig. 11) which meshes with a gear 46 which is keyed to the shaft 1,8 to thereby rotate the latter incident to the drive of the shaft 19 as already explained. The gear connections described are of course such as to drive the feed wheels 10, 11, 12 and 13 in the proper direction for feeding the upper wire. The amount of lateral vshifting movement which may occur between certain of the above mentioned meshing gears due to the pivoted mounting of the bearing blocks for the ends of certain of the shafts, will of course be understood to be so slight that the eiciency of the driving connections is not materially impaired.

The lower wire feed wheels 14, 15, 16 and 17 are driven from the input shaft 22 which is in turn driven through the agency of a gear (72). Between the supporting side frames of the apparatus, the shaft 22 is provided with a gear 48 (Fig. 11) which is keyed to the shaft to rotate therewith and said gear meshes with a gear 49 which is keyed to the shaft 23 of the wire feed roll 15. The shaft 22 is also provided with a gear 50 (Fig. 12), which meshes with an idler gear 51 which is mounted on the shaft 19 for free rotation thereon. The gear 51 meshes with a gear 52 which is keyed to the shaft 24 of the feed wheel or roll 16 whereby the latter is appropriately driven. In addition to the gears 43 and 52 on the shaft 24 (Figs. 13 and 12), there is also a gear 53 (Fig. 11) keyed to the shaft and meshing with a gear 54 keyed to the shaft 25 of the feed wheel 17 to thereby drive the latter.

Wire feed drive The said shafts 21 and 22 are driven by means of gear connections to clutch shafts 60 and 61 on which are mounted clutch pulleys 62 and 63 respectively. The pulleys 62 and 63 are driven through the agency of multiple driving belts 64 which are in turn driven by engagement with a pulley 65 on the shaft of a motor 66. The motor 66 is mounted on a bracket member 67 (see Fig. 6) which is suitably vertically adjustably mounted on the main framework of the apparatus so as to facilitate vertical adjustment of the motor to thereby adjust the tautness of the belts driven by the said pulley 65. The pulleys 62 and 63 are adapted to be clutched to the shafts 60 and 61 respectively by means of suitable clutch mechanisms indicated generally at 68, the details of which form no part of the present invention and are therefore not described. The gear connection between the clutch shaft 60 and the upper wire feed roll shaft 21 comprises a gear 69 which is mounted on the shaft 60 and a gear 70 mounted on an end extension of the shaft 21. The gear connection between the clutch shaft 61 and the lower wire feed roll shaft 23 comprises a gear 71 mounted on the shaft 61, a gear 72 mounted on an end extension of the shaft 22 and an idler pinion 73, the latter meshing with both the gears 71 and 72 and being employed so as to eect rotation of the gear 72 and shaft 22 in the proper direction. Any suitable clutch mechanism, many of which are well known, may be employed for the purpose of interconnecting the pulleys 62 and 63 and theirrrespective shafts 60 and 61 on which they are journaled.

The clutches 68 are here shown as being of a type which are adapted to be engaged by means such as a collar 75 (one for each clutch) which is movable axially of the shaft on which it is slidably supported to spread apart clutch controlling arms as illustrated and as well understood.

The clutches 68 associated with the respective coiler input shafts 21 and 22 are of the normally-disengaged type and are adapted to be automatically engaged by the automatic programming controller to initiate operation of the coling mechanism. However, provision is also made for manually engaging each of the clutches independently of the other and also for mechanically and automatically effecting disengagement of both clutches upon completion of a predetermined period of operation and for disengaging both clutches for emergency purposes.

The clutches are normally held in disengaged condition by means of a spring 76 (Figs. 7 and 8) which is stretched between a suitable part of the framework of the mechanism and the lower end of a lever or arm 77 which is keyed to or clamped on a shaft 78, the latter being suitably journaled in a bearing opening provided in a frame part or bracket provided for that purpose, as best indicated in Figures 8 and 9. The lever 77 extends upwardly from said shaft 78 and is provided at its upper end with a yoke 79 which embraces the clutch-actuating collar 75 and is equipped with suitable rollers 80 which enter peripheral grooves 81 in the respective clutch collars.

It will be understood that in Figures 8 and 9, there is shown the clutch mechanism associated with the coiler input shaft 22 and that the clutch mechanism employed in connection with the input shaft 21 is identical in form and construction so that the description of the clutch mechanism shown in Figures 8 and 9 is also applicable to the clutch mechanism associated with the shaft 21.

For automatically engaging the respective clutch, each clutch mechanism comprises a bell crank arm 82 rockably mounted on the shaft 78. The upper end of said arm 82 has pivoted to it a dog 83, one end of which is suitably formed to engage a pin 84 carried by the yoke 79. The other end of said dog 83 is connected by a spring S5 to a portion of the arm 82 so as to be thereby normally held in a predetermined operative position, as illustrated in Figure 8, but capable of being rocked about its pivot so as to pass under the pin 84 under certain circumstances. In the disengaged condition of the clutch, the forward end of the dog 83 engages the pin S4 so that clockwise rocking movement of the bell crank arm 82 will effect appropriate movement of the clutch collar 75 for effecting engagement of the clutch. The bell crank arm 82 comprises also an arm portion 86 which is suitably connected to mechanism for rocking the bell crank arms 82 and 861to effect engagement of the clutch in synchronized relation to the operation of the spring assembling mechanism, and particularly with reference to the stopping and starting of the coiling mechanism duringv the feeding of a new row of springs into operative position in the spring assembling mechanism. The operating connections will hereinafter be described.

The bell crank arm 82 is rocked to move the clutch collar 75 for engaging the clutch but said arm is not maintained in an advanced position but is permitted to return to its normal position to which it is restored by a spring S7 stretched between a portion of the arm 82 and a suitable anchorage carried by the supporting frame structure. For holding the clutch engaged, there is provided a latch member 88 pivotally mounted as indicated at 89 on an adjacent frame part or bracket. Said latch is normally urged to move in a counterclockwise direction so as to cause its shouldered front end to lockingly engage the clutch collarrpin 84 to hold said clutch collar in clutch-engaging position. Accordinglyfthe latch 88 is provided with a rearward extension 90 which is connected by means of a spring 91 to a suitably located part of the supporting frame or bracket or a pin extending therefrom, as indicated in Figures 8 and 9.

The latch S8 is automatically disengaged from the pin 84 in properly timed relation to other operations of the apparatus to permit disengagement of the clutch. For such automatic timed disengagement of the clutch latch 88, there is provided a solenoid 92 which, when energized, draws a core 93 into the solenoid. The core is pivotally connected at its upper end as shown at 94 to the latcl1.88,so that when the solenoid is energized, Vthe latch mayberdisengaged whereupon the clutch will automatically disengage itself incident to the force of certain springs constituting part of the clutch structure. These self-contained springs normally tend to pull together the clutch-operating arms which are spread apart by the clutch collar when the clutch is to be engaged. The solenoids92 for operating the respective clutches 68 are arranged in an electrical circuit later to be described in detail, which circuit contains a number of switches arranged in parallel, each adapted when closed, either in response to the improved helical length-controlling mechanism of the invention, or in response to certain emergency conditions, to energize the solenoids, or either of them, to effect disengagement of the coiler clutches.

Electrical `wiring ale-energized when machine not operating For the purpose of safeguarding workmen around the machine during such time as the machine is not in operation, provision is made for ,automatically breaking the electric circuit in the wiring required on the machine for energizing the solenoid 92, `and other controls yet to be described. For that purpose, there is provided a double pole switch mechanism comprising switch units 95 and 96. There is of course one such switch associated mechanically and electrically with each of the clutch mecha nisms for the shafts 60 and 61 and each'switch is controlled by means of an arm 97 which is adjustably secured to the shaft 78. The lower end of the armzis operatively connected to a rod 98 which is slidably mounted in a block 99 which carries the contact elements of the switch units 95 and 96. The front end of the rod 93 is pointed and is adapted to be moved between suitable blocks 100 and 101 of insulation material carried by the innermost contact elements of the switch units to move the same outwardly into electrical contact with the outermost elements. lt will be seen that the arrangement is such that when the clutch is engaged, the arm 97 will be moved to the left from the position shown in Figure 8 sufficiently to close the switches 95 and 96. Thus, when the `machine is in operation Vthe switches 95 `and 96 are closed so that electrical wiring on the apparatus is energized except insofar as other switch means maintain the circuit open. Also, when the clutches are disengaged, the wiring will of course be de-energized by opening of the switches `95 and 96. Hence when the machine is not in operation and an attendant or perhaps a repairman is `working on the machine, he is protected from any live electric wiring.

Wire feed bra/ring mechanism There is associated with each .of the coiler mechanism input shafts 21 vand 22braking mechanismfor quickly stopping the operation of the coilers upon disengagement ofthe controlling clutches. lt will be understood that upon the completion of the feeding of the necessary length of wires for the formation of the necessary lengths of helicals, it is advantageous to quickly` stop the operation of the coiler mechanism so as to avoid the feeding of `a helical more than a short distance beyond the far side of the spring unit being assembled, thereby to prevent waste of helical wire. Also quick stopping is desired to assure complete operation of. the coilers within the time allotted by the masterrcontrol.

The brake for each of the coiler mechanism wire feeds may `comprise a suitable brake drum securely mounted on the respective shafts 60 and 61 and a brake band 106, ione end of which may be anchored as indicated at .107 on a pin rigidly mounted on and secured toa portion ofthe supporting frame structure. The other end of the brake band 105 yis suitably connected to a rod '108 which in turn extends through an opening in the free end ,of anarm 109 whichis rock-ably mounted on a supporting pin or shaft 110 carried vby the support n 2,7ss,1 1on ing framework. Said arm `109 has rigidly connected to it, either directly or through the agency Aof the pin 110, an upwardly extending arm (111, the upper` end portion 112 ofwhich extends upwardly at an angle in such a position as Ato be engageable by a roller 113 carried by a portion of the pin S4. ln the position of the parts shown in Figure 8, the clutch is disengaged and the roller 113 has rocked the arm 111 in a counter-clockwise direction and the arm 109 in a downward direction whereby said arm vhas pulled the brake band 106 `tight on the brake drum 105, whereby rotation of the shaft controlled by the clutch was promptly stopped upon disengagement of the clutch.

Provision for manual operation or control of wire feed and helix-forming mechanism To facilitate manual turning of the shafts 60 `and 61 for any purpose whatever, there is provided on each of these shafts, aliand wheel 115. The hand wheel is preferably so mounted on the shaft as to be normally free of connection therewith and any suitable manually adjustable clutch or interlocking means may be provided. In this instance, locking pins 116 are indicated and these locking pins, upon movement inwardly, are operative to lock `the respective hand wheel to the shafts 60 and 61.

For the purpose of permitting manual engagement and disengagement of the clutches 63, there are provided upwardly extending levers 117, each of which is pivotally mounted at its lower end on the pin 540i the clutch collar locking mechanism. The 4clutch collar yoke 79 is provided with an upward extension 118 near the upper end of which there is secured a bolt 119 which passes through a slot 120 in the lever 117. The lever is capable of limited rocking movement about the axis of the pivot pin 84 relative to the arm extension 11S of the clutch yoke. At the lower end of each lever 117 there is provided a laterally offset extension 121 from which a pin 122 extends into overlying relation to the `latch 80.

As shown in Figure 8, the hand lever is in the position which `it occupies when the clutch is disengaged. It will be apparent that by moving the lever 117 to the right, the clutch yoke 79 will also be moved to the right to thereby adjust `the clutch collar 75 to engage the corresponding clutch. By examination of Figure 8, it will also be apparent that when the clutch is engaged and the lever and yoke moved to the right, the lever may be rocked `to the left about the axis of the pin 84 without correspondingly moving the yoke because of the pin and slot connection 119-120 between the lever 117 and said yoke arm 11S. However, when the lever 117 is so rocked independently of the yoke arm, the pin 122 carried by the lateral extension of the lower cnd of the lever will engage and move Ithe locking latch 88 downwardly to thereby disengage it from the clutch pin 84, whereupon the clutch is permitted to disengage itself. The upper end of each lever 117 has connected to it an operating rod 123 which extends across the coilingmechanism and is provided with a handle 124 on the wire' ceiling side of the mechanism where it is conveniently accessible to an operator or attendant of the machine.

Drive of wire supply reels The supply rolls of wire 4 and 5 may be driven by power derived from the shafts 19 and 22 (Fig. 3) of the upper and lower wire feed roll sets respectively. For this purpose the shaft 22 of the lower `wire feed roll set is provided with a gear 131 which drives a chain 132, which in turn engages a sprocket 133 on a shaft 134 journaled in suitable brackets carried by the yframe structure as best shown in Figures 3 and 7. The shaft 134 is provided with a sprocket 135 which drives a chain ,136 which in turn drives a sprocket 137 which is connected to the friction wheel 7 for driving the wire roll basket 5.

`The wire basket .4 is driven `by a power takeoff :from the shaft 19 for which purpose said shaft is provided with maar 1.9

a sprocket 138 which drives a chain 139 which in turn drives a sprocket 140 which is secured to a shaft 141 suitably journaled in bearing brackets carried by the framework of the apparatus. Said shaft 141 also has secured .to it a sprocket 142 which drives a chain 143 which in turn drives a sprocket 144 rigidly connected to the friction wheel 7 for driving the upper wire roll basket 4.

Helix-forming mechanism The wires W are guided in their passage between the two pairs of said rolls which feed the wires, .in suitable guides 150 which are preferably of such a character that they may be easily :lisrnounted for cleaining and other purposes when desired.

From the last pair of feed rolls for the upper wire, i. e., the rolls 12 and 13, and from the last pair of feed rolls for the lower wire, i. e., the rolls 16 and 17, the wires are delivered to the helixfforming coilers. The coilers proper are indicated generally Vat 151, but, not being essential to an understanding of the present invention are not shown in detail. Reference may be had to the Woller Patent 2,338,106, heretofore mentioned, for one type of coiling device, which comprises two main portions, a helix-forming die and a sizing die. The former may comprise an arbor having formed therein a peripheral helical groove, and a telescoping overlying sleeve, and the latter may consist simply of a collar or sleeve having an inner peripheral helical groove. The greater work of bending the wire is performed by the forming die, the pitch variation between the two dies being only that necessary to control the nal size and pitch of the helix to the desired degree. It will be understood of course that other types of coilers may be used. y

The helical wire upon emerging from the ceiling and sizing device 151 enters a tubular guide 152 which conducts the helix to the spring assembling apparatus, said guide 152 having a side opening 153 of sufficient size to permit the helix to bow outwardly from the guide in the event that its passage through the spring assembly portion of the apparatus (not shown in detail) is obstructed. Disposed at said side opening is the arm 154 of a switch 155 which is connected in the electrical control circuit so as to energize the proper solenoid 92 to effect disengagement of that one of the clutches 68 associated with the feed rolls of the obstructed helix. By the circuit arrangement yet to be described, the same switch is effective to cause the master control to dwell until the interrupted cycle of operation is again manually resumed.

Means is also provided for stopping the operation of the machine in the event of exhaustion of the supply of wire or in the event of a breakin the length of the wire drawn from the supply roll to the coiling apparatus. For that pupose there is provided in connection with each wire an electrical switch 156 which is adapted to be closed by the movement of an arm 157 (Fig. 3). The arm 157 is pivotally mounted on a suitable stationary supporting part and it has a Weighted end portion overlying and resting on the wire W. In the event that the wire is broken or the supply exhausted so that the support of the wire for the weighted end of the arm 157 is removed, the arm will automatically be rocked incident to the weight of one end thereof and will close the switch 156, which will serve to energize appropriate means for halting the master controllers to interrupt the machine cycle until the supply of wire is replenished.

Main drive As was earlier explained, the several functions of the entire machine are coordinated by a master controller which, in the present instance, comprises a motor driven shaft having mounted thereon a multiplicity of cams from which the respective elements -of the machine, with the exception of the coilers, are both powered and controlled. vIt will be readily understood that because of the considerable amount of power required for the operation of the coilers, and also because it is desirable for the purpose of clearing faults to be able to operate the coilers separately without reference to the spring assembly portion of the machine, a separate motor drive, already explained in considerable detail, is provided for powering the coilers. However, the initiation of operation of the coilers in proper synchronism with the other elements of the machine, is effected by the master controller. This control is exercised by means of one of the cams on the aforementioned cam shaft, the cam being effective through a follower and appropriate linkage etc. to clfect simultaneous engagement of the two clutches 68. Control and variation of the period of operation of the coilers so as to produce helices of different length, however, is accomplished in the illustrated embodiment by means within the coiler itself, which means constitutes the important feature of the invention. It will be understood, however that control over the period between the engagement and disengagement of the clutches 68 may also be accomplished within the scope of the invention by the master cam shaft, the drive for which will now be explained.

The main cam shaft is normally driven continuously by an electric motor 161, the shaft of which is equipped with a pulley 162 for receiving a series of belts 163. rThe belts 163 also engage a main clutch pulley 164 which constitutes the free Arunning part of a clutch, of which the other part is indicated at 165. The clutch part 165 has secured to it a gear 166 which meshes with a gear 167 secured to one end of a `countershaft 168 suitably journaled in a supporting bracket 169. The other end of said countershaft 168 has secured to it a gear 17h which meshes with a gear 171 carried by the adjacent and overlying end portion of the main cam shaft 160. The clutch comprising the parts 164 and 165 may be of a type which is adapted to be controlled by an 4axially movable collar 172 which is slidably mounted v on the clutch shaft 173 to which the clutch part 164 and gear 165 are secured. The clutch collar 172 is adapted to spread apart arms such as indicated at 174 (Figure 6) to engage the clutch so as to transmit rotation from the motor 161 to the cam shaft 160. Spring mechanism contained within the clutch normally urges the clutch to a disengaged position. The details of the clutch structure are well known and are therefore not herein described.

In addition to the normal spring structure within the clutch for effecting its disengagement, it is normally urged to a disengaged position by means of a tension spring 175 which is stretched between a fixed portion of the base plate or frame structure of the apparatus and the lower end of an arm 176. The arm 176 is pivoted intemediate its ends as shown at 177 to a suitable supporting bracket and the upper end portion of said lever 176 is forked so as to embrace the clutch collar. The ends of the forked portion of the lever 176 carry pins 178 which enter a suitable circumferential groove in the collar 172 to thereby transmit any rocking movement of the lever 176 to the clutch collar.

The last mentioned clutch is adapted to be manually engaged against the tension of Vthe spring 175 through the agency of an upwardly extending lever 179 which is pivotally mounted on the forked lever 176 in lthe same manner as has already been described in connection with the levers 79 and 117 associated with the clutches 68 of the coiler mechanism. And by means of a substantially identical arrangement, the lever 179 permits manual dis engagement, as .vell as engagement of the clutch 164-165. In addition, a solenoid 150 is also provided for tripping the latch mechanism 181 substantially identical with that already described in connection with the coiler clutches 68, which maintains the engagement of the main drive clutch 164-165. Also, as with the shafts 60 and 61 of the coiler mechanism, suitable braking means 182 is provided for the clutch shaft 173, the braking means being operative upon disengagement of the main drive clutch,` to bring the clutch shaft 173 and the `cam shaft 160 immediately to rest. Means not necessary to be described is also provided for releasing the brake 182 without engaging the clutch. 164--165 to permit turning of the shafts 173 and 160 by means of a handwheeel 183 secured to the shaft 173.

The upwardly extending clutch-engaging lever 179 is connected at its upper end by means of a short link 184 to the rear end of a lever 185 which is pivoted for horizontal movement on thesupporting base of the coiler mechanism. The lever 18S extends forwardly so as to be conveniently accessible at the operators station in front of the coiler.

Automatic starting of wire feed am] helix-forming mechanism For automatically initiating operation of the coiler mechanism when a new row of springs has been delivered and clamped by the jaws of the spring assembly mechanism in position for receiving the helix, there is provided a cam 190 on the camshaft 160 (scc Figure 4). Said cam 190 is provided with a suitable rocker arm follower 191 (not shown in detail) to which there is ccnnected a chain 192.` Said chain 192 is guided around a suitable idler roll 193 and `is connected to a pair of chains 194 and 195. The chain 194 extends around a suitably supported guide roll 196 and then upwardly to have its other end connected to the lever 86 which is pulled downwardly to engage the coiler clutch 68 as` sociated with the coiler clutch shaftt). The other chain 195 is guided around a suitable idler roll 197 andthen upwardly to have its other end connected to the othery clutch-operating arm 86 for engaging the coiler clutch associated with the coiler clutch shaft 61.

Helical lengt/1 control The important feature of the invention is the means provided for adjusting the length of helix which is formed and fed by the coiler 3 and, as may already be appreciated from the foregoing, it contemplates the operation of a switch to energize the solenoids 92 for tripping the latches 88 to permit disengagement of the coiler clutches 68 after a helix of the desired length has been fed. The mechanism for effecting this control is illustrated in Figures 3, 6 14, 15 and 16, substantially identical arrangements being vprovided for the upper and lower coilers.

The length controlling mechanism 200 for the lower coiler comprises a disc sprocket 201 rotatably mounted upon a shaft 202 supported in a bracket 203 secured to the rear side `frame of the coiler mechanism. The hub of the sprocket is preferably made in two parts 204 and 205, having interposed between them compression springs 206 for urging the two parts away from one another. One of the hub parts 204 abuts1thc bracket 203 and serves as a base for resiliently urging the disc sprocket 201 forwardly toward the front side frame of the coiler. The disc sprocket is connected by means of a chain 207 to a sprocket 208 keyed on the shaft 22 so as to be driven thereby at a speed bearing a fixed ratio to the speed of the lower coiler feed rolls 14 to 17 inclusive.

Mounted on the front side frame of the coiler is an i-shaped frame or bracket 209, the upright or column portion 210 of which is slotted to form a guideway for a vertically movable crosshead 211. Between the forwardly extending arms of the I-shaped bracket, there is journalled a vertical adjusting screw 212 which threadedly engages the crosshead 210, said screw having secured thereon a hnndwheel 213 for turning the screw 212 to move the crosshcad up or down inthe guideway. The upper `journal for the screw `212 is split and provided with a locking screw 214, whereby the adjusting screw avenue` 12 may be securely locked in any position for determining the vertical position of the crosshead 211.

Between the rearwardly extending arms of the l-shaped bracket 209, there is journalled a vertically extending shaft 215 having keyed thereon a friction disc 216 provided with a grooved hub 217. The rearwardly extending portion of the crosshead 211 is provided with a fork 213, each branch of which has a pin 219 seated within the groove of the hub. At the upper end of the shaft 21.5 there is secured a crank 220, the offset arm 221 of which is adapted to cngageand depress the plunger of an cicctrical switch `222 mountedon a strap or other suitable bracket 223 secured to the I-shaped bracket 269. The depression of the switch plunger closes the circuit to the associated solenoid 92 to permit disengagement of the affected drivingr clutch 68.

Referring particularly to Figures l5 and 16, it may be seen that the disc sprocket 201 is urged forwardly by the springs 206 into .driving engagement with the friction disc 216 which is driven at a speed determined by the radial distance from the center rotation of the disc sprocket to the point of contact between the sprocket and the friction wheel. This distance may be varied by turning the handwheel 213 to raise or lower the friction wheel, thereby varying the rotational speed of the friction wheel and the switch-operating crank 220 mounted at the upper end thereof. The voffset arm of the crank is of course long enough to assure its engagement with the plunger of the switch 222 regardless of the relative positions of the friction wheel and sprocket.

inasmuch as the switch 222 is closed, and the associated coiler clutch 68 disengaged, once per revolution of the friction disc, it will be appreciated that the number of turns ofthe feed rools 14 to 17 inclusive, and hence the length of the wire fed thereby, is determined by the speed ratio of the disc sprocket `and the friction wheel. Accordingly, the length of wire fed by the feed rolls is capable of infinite variation within the range of speed permitted by axial movement of the friction disc.

The helical length control mechanism 225 for the upper coiler is the same as that described for the lower coiler, with the exception, of course, that the disc sprocket 226 thereof is connected by means of a chain 227 to a drive sprocket 228 keyed to the shaft 20. The disc sprocket for the upper coiler length `control mechanism is, there fore, driven at a speed which bears a fixed relation to the speed of the upper feed rolls 10 to 13 inclusive.

The llexibility of control achieved by means of the innitely variable control Amechanisms herein described, in addition to adapting a spring assembly machine to the assembly of inner constructions of a greater number of sizes than was heretofore possible, has another very important function. It has been found that for any given setting of the coiler declutching control, the length of helix which is formed may vary considerably, due pre sumably to the lack of uniformity of cross-sectional dimension of the spring wire from which the helices are formed, to the variations in temperature from day `to day or hour to hour of operation of the machine and possibly also due to other `undetermined factors. As a result, it is desirable to be able to make, from time to time, the corrections `which are necessary to compensate for these effects in order to avoid the `unnecessary scrapping of wire. This is normally not possible where the length of the helices is limited to one or more fixed sizes, for in those instances, the iixed or semi-variable controls must be adjusted so as to supplysutlicient wire to insure that the shortest helix formed will belong enough to span the entire row. With the present control arrangement, however, the machine operator may keep a constant check on the performance of .the coilers, making minor adjustments from time to time in order to compensate for the variables mentioned without undue wastage of materials.

T he electrical circuit Referring to the circuit diagram of Figure 17, the soleavisar 19.

noids 92, controlling the coiler clutches68, are connected in parallel to a source of power through the single-throw double pole switches 95-96.'and the solenoid 180 controlling'the'main drive clutch 164-165 is similarly connected through a manually-operated single-throw double pole switch 2.30. However, each of the circuit branches is provided with a number of single pole, single throw normally open switches arranged in parallel with one another and in series with their respective solenoids. It will be observed, for example, that each coiler clutch solenoid 92 is adapted to be energized by the switch 222 which is operated by the variable helical length control mechanism, and also by the switch 155 associated with the tubular guideway 152v which conducts the helix from the coiling and sizing dies V151 of the respective coilers to the spring assembly portion of the machine. Furthermore, each switch 155 has mechanically associated with it another switch 231 which is adapted to be closed simultaneously therewith in order to energize the main clutch solenoid 180 to disengage the main driving clutch whenever the helix becomes jammed as it is being threaded along between the spring-holding jaws. It will be appreciated, of course, that it is desirable in that instance to simultaneously halt the cam shaft 160 of the master controller until the fault is cleared in order to prevent damage to the machine.

ln addition to the switches already mentioned, other switches are provided for independent operation of the main clutch solenoid 180 including the wire exhaustion detection switches 156 and a number of manually operated switches 232 strategically located about the machine so as to be readily accessible to the attendants in the event of any emergency. As previously noted, the closing of either of the switches 156 or 232 is ineffective to halt operation of the coilers, should they be in operation when those switches are closed.

Operation Referring only to the helix forming and feeding portion of the entire spring assembly machine, the operation of the coiler 3 is initiated by the cam 190 which is effective through the follower 191, the chains 192, 194 and 19S, to operate the bell crank levers 86 to engage the coiler clutches 68. Assuming no emergency, e. g., one of the helices becoming jammed, the coilers continue in operation until the switches 222 are actuated by the adjustable control mechanisms 200 and 225, thus energizing the solenoids 92 to trip the clutch latches 88, permitting disengagement of the clutches 68.

inasmuch as the coilers are declutched independently of the cam shaft 160, the maximum period of operation of the coilers must be coordinated with the cam shaft 16d in the design of the machine so that feeding of the helices is initiated and completed within the time allotted by the master program controller. It may be seen, however, by reference to the diagram of Figure 18, that in a cycle of 360 there is provided an angular space of about 225 between the engagement of the coiler clutches 68 and the actuation of the helical cut-off mechanism. However, since the coiler and the master cam shaft are separately driven, this space of 225 in the cycle is not a fixed limitation on the maximum length of helix, which may be increased by increasing the speed of the coiler drive relative to the speed of the master cam shaft.

ln the event that either of the helices becomes jammed in the threaded guideways which extend along the rows of springs, one set of switches 155 and 231 will be closed to simultaneously energize the associated solenoid 92 and the solenoid 180 to permit disengagement of the affected coiler clutch, as well as the main drive clutch. This, of course, permits the unaffected coiler to continue in operation to thread a complete helix, but interrupts the main cycle of operation to permit clearing of the fault. The machine operator may then engage the affected coiler manually by means of the handle 124 to thread a new helix to replace the faulty one, and followingthat, may resume operation by throwing the lever to reengage the main drive clutch.

Similarly, when either of the supply rolls 4 and 5 run out, one of the switches 156 effects disengagement of the main drive clutch to interrupt the cycle of operation of the machine, but since both coilers normally operate in unison, each will continue to operate until timed out by the adjustable control mechanisms 200 and 225. However, since the exhaustion of the wire supply can only occur while the coilers are in operation, it will usually result in the formation of an incomplete helix which will have to be withdrawn and replaced by individual manual engagement ofthe clutch of the coiler effected after a new roll of wire has been provided. Again, in order to resume operation of the machine, the operator will have to throw the lever 185 in order to re-engage the main drive clutch 164.-165.

The structure described and the details illustrated in the drawings represent a preferred embodiment of the apparatus whereby inner spring construction units of var. ions sizes may be produced, and in which the changeover from the production of inner construction units of one size to that of another can be effected in a minimum amount of time. Furthermore, by means of the infinitely variable adjustment herein described, substantial savings can be effected by the elimination of waste which otherwise would occur as a result of variation of the length of the helices due to non-uniformity of the wire from the helices are formed and other factors not within the control of the operator.

The features of the invention believed to be new and patentable are set forth in the following claims.

I claim:

1. In apparatus of the class described a pair of wirefeeding rolls, means for driving said rolls, clutch mechanism for controlling the transmission of power from said driving means to said feed rolls, means for effecting the engagement of said clutch mechanism, a disc connected for rotation with said feed rolls, a friction wheel engaging the face of said disc and having connected therewith means disposed to disable said clutch mechanism once per revolution of said friction wheel, said friction wheel being shiftable radially of said disc to vary the speed of said wheel relative to said rolls, whereby to vary the length of wire fed by said rolls.

2. In apparatus of the class described, a pair of wirefeeding rolls, means for driving said rolls, normally disengaged clutch means for connecting said driving means to said feed rolls, means for engaging said clutch means and latch means for maintaining said engagement, a solenoid connected to trip said latch means when energized, thereby to permit said clutch to become disengaged, a normally open switch for connecting said solenoid to a source of power, a rotatable element adapted to momentarily close said switch once per revolution thereof, and a variable speed transmission connecting said rotatable element for rotation with said feed rolls whereby the period of engagement of said clutch may be varied to vary the length of wire fed by said feed rolls.

3. 1n apparatus of the class described, a pair of wirefeeding rolls, means for feeding the wire to be formed into a helix, means for driving said rolls, normally disengaged clutch means for connecting said driving means to said feed rolls, means for engaging said clutch and latch means for maintaining said engagement, a solenoid connected to trip said latch means when energized, thereby to permit said clutch to become disengaged, a normally open switch for connecting said solenoid to a source of power, a disc connected for rotatin with said feed rolls, a friction wheel engaging the face of said disc and having connected therewith means for momentarily closing said switch once per revolution of said friction wheel, said friction wheel being axially shiftable radially of said disc to vary the rotational speed of said disc thereby to 15 vary the period of engagement ofsaid clutch and the length of wire fed by said feed rolls.

4. In apparatus of the class described, a pair of Wirefeeding rolls, means for driving said rolls, clutch mechanism for connecting said Vrolls to said driving means, means for effecting the engagement of said clutch, a rotatable member adopted to disable said clutch mechanism after one revolution of said rotatable member, and variable sped transmission means conecting said rotatable member with said rolls whereby the period of operation of said rolls and the length of wire `fed thereby may be varied.

References Cited in the file of this patent UNITED `STATES PATENTS 629,883 Zielke Aug. 1, 1899 16 Parker Mar. 19, Gail Dec. 17, Schmid Oct. 10, Clarke Nov. 19, Bourn Ian. 25, Noack Jan. 15, Wingren May 21, Dickey Nov. 18, Zimmerman Sept. 1, Saval Sept. 29, Bronstien `une 20, Woller Oct. 30, Ritzert Apr. 22, Gauci May 24,

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