US2227602A - Automatic coil winding machine - Google Patents

Description

Jan. 7, 1941. 5 PLATT AUTOMATIC COIL WINDING MACHINE Filed Aug. 16, 1959 4 Sheets-Sheet l INVENTOR M4. V6412 BY 1:4 M4

ATTORNEYS.

J 1941. s. A. PLATT AUTOMATIC COIL WINDING MACHINE 4 Sheets-Sheetfi Fi led Aug. 16. 1959 INVENTOR ATTORNEYS Jan. 7, 1941. I s. A. PLATT AUTOMATIC COIL WINDING MACHINE Filed Aug. 16, 19159 4 Sheets-Sheet *1 :NVENTOFQ ATTORNEYS Patented Jan. 7, 1941 UNITED STATES PATENT OFFICE I 2,227,602 AUTOMATIC COIL WINDING MACHINE Stephen A. Platt, Lake Decatur, Ill.

Application August 16, 1939, Serial No. 290,397

23 Claims. (Cl. 153-64) The present invention relates to automatic coil pressure of the rolls, expand slightly so that the winding machinery, and more particularly to coil will slide freely along the major length of automatic machinery for manufacturing electrisaid mandrel and may then be transferred to a cal resistance coils. suitable guide from the mandrel end, and cut off i The automatic production of resistance coils into predetermined lengths intermediate the end on a quantitative basi requires a machine capaof the mandrel and the entrance to the guide. ble of producing coils of uniform physical and It is, therefore, a principal object of the invenelectrical characteristics. The coils produced tion to provide a machine meeting the foregoing should be uniformly wound and with small tolequi ementserances have the same electrical resistance rat- It is another object of this invention to p 10 lugs for a given length and wire size, duce a successfully operating machine depending The importance of uniformity is so great that up n the principles of operation noted above in some instances, where, for example, the re- Which is efilcieht and Which y e p duc d sistance units operate very close to their melting co mercial use at reasonable cost.

W point, the resistance coil units are X-rayed after Another object of t invention o p s e being embedded in magnesium xide, or the like, provision of means for cutting off predetermined to check the spacings of the windings. coil lengths during the winding of the coil with- Unllke spring wire or steel wire, electrical reout interfering with the W n ing operation. This slstance wire is soft or malleable and is not readcut-oif mechanism must operate intermittently m ily pushed or forced into coil form. It must so asto sever, in highly accurate manner, coils be pulled or drawn into the de ir d form, si having substantially uniform predetermined electhe resistance per unit length of the wire detrical and physical characteristics. pends upon its cross-sectional area, the pulling Still another object of the invention is to proor drawing operation in winding of the coil must vide special wear-resistant metering mechanism 2% not stretch the wire, and thereby reduce its crosswhich serves to operate the cut-off mechanism sectional area and resistance. Moreover, the and which does not requir frequent replacee coiling machine must not otherwise deform the ment or resurfacin wire and thus alter its electrical characteristics. A further object is to provide a machine adap The coil winding operation usually winds the able for winding coils of differently sized wi e.

an adjacent turns of the coil in contact with each and for such coils to have desired difierent other. Thereafter, the coil is stretched to seppitches. arate the adjacent turns. It is important to have An additional object is to provide a machine uniform spacing between adjacent turns of th having mechanism for detecting defects in coils coil because lack of uniformity results in a conbeing wound and automatically stopping operacentration of heat in the region of the closest ad tion of the machine when defective coiling occurs. 35 iacent turns. If the coil is. operating close to To the accomplishment of the foregoi and the melting point of its wire, such heat concensuch other objects as y hereinafter pp tration at a hot spot" between two turns which this invention consists in the construction and are too close results either in a quick fusing of arrangement of parts hereinafter described, and

o the coil or quick deterioration thereat. Winding then sought to be defined in the appended claims, of the coil turns uniformly as is accomplished in r f rence e n had to the c mpanying drawthe machine of the present invention, insures s forming a P hereof and which Show. uniform stretching and uniform spacing between merely for the purpose of illustrative disclosure, individual coil turns when stretched. a prefe embodiment of the t on. it be- The operation of the machine depends upon ing expressly understood, however, that various 45 the fact that if coil wire under necessary tension changes may be made in practice within the is led to a rotating polished mandrel having a scope of the claims without digressing from th comparatively low coefficient of friction, and inventive idea.

wound around the latter under pressure from In the drawings, in which similar reference in two freely rotating resilient biased rolls having characters denote Corresponding Da high coefficients of friction, the wire will form a Figure 1 is a front elevational view of my novel continuous coil of uniformly wound and spaced coil-winding machine;

turns having a uniform pitch determined by the Figure 2 is a rear elevation on an enlarged bias of the rolls. The coil turns will move along scale of the left hand portion of the said ma-- M the mandrel and, after passing from the zone of chine shown in Figure 1; 5.5

Figure 3 is a vertical section taken along line 3-3 of Figure 1, viewed in the direction of the arrows, and illustrating the cut-off mechanism and part of the guide mechanism for receiving the wound coil;

Figure 4 is a vertical section taken along line 4--4 of Figure 1, viewed in the direction of the arrows;

Figure 5 is a vertical section taken along line 3-3 of Figure 1, viewed in the direction of the arrows, and illustrating the metering wheel construction as well as the drive connection between said wheel and a part of the cut-off mechanism;

Figure 6 is a fragmentary top plan view of the portion of the machine between the boundaries 3-3 of Figure 1, viewed in the direction of the arrows;

Figure 7 is anjelevational view taken in direction of the arrows between the boundaries 1-1 in Figure 4 and illustrating the safety switch-operating mechanism;

Figure 8 is an enlarged detail view of the clutch control means for operating the cut-oil mechanism;

Figure 9 is a detail view of the yoke and clutch trip mechanism for operating the clutch means viewed in the direction of the arrows 3-3 of Figure 4; and

Figure 10 is an enlarged vertical section taken along line l0l3 of Figure 7, viewed in the direction of the arrows and illustrating a detail of the switch-operating mechanism of Figure 7.

Referring now to the drawings and first to Figure 1, l0 denotes generally a machine frame. This frame is provided with a bearing flange H which rotatably supports on suitable bearings the journal portion of an axle or shaft l2 which protrudes from each end of the flange H. One end of the shaft has keyed to it the pulley wheel l3 and the cone pulley wheel l4. Each pulley wheel being provided with V-shaped grooves to receive V-sectioned driving belts to be presently described. The opposite end of the shaft I2 is constructed to receive any standard form of chuck I3, that illustrated being a well-known key-tightening type. This chuck I3 is adapted to receive and support horizontally by one of its ends a winding mandrel I6 upon which the wire is wound into coil form.

A motor 20 has a swinging base 23' adjustably carried on a support rod 21 extending laterally from the machine frame H). The rotor shaft 22 of the motor has a cone pulley wheel 23 keyed thereto and whose apex extends oppositely to that of cone pulley wheel M. This pulley wheel 23 likewise has V-shaped grooves and a driving belt 24 passed around the two pulley wheels 23 and i4 serves to couple the motor and chuck-bearing axle or shaft l2, so that the motor drives the mandrel I6. Variability of speed is obtained by shifting the belt from step to step of the cone pulley wheels l4 and 23.

The frame I3 forwardly has an upwardly extending vertical arm 30 which has a bore 3i in axial alignment with the shaft I2. A tube 32 is fitted into this bore 3i and the free end of the mandrel extends into, but not through, the entire length of said tube whose diameter is so ametrically opposite points with respect to said mandrel. To this end. a bracket arm 33 (Figs. 6 and 7) is suitably attached to the rear of the flange ll of the frame In by bolts 40, or the like, and extends parallel to the mandrel. This arm 39 has a pair of parallel vertically extending guide rods 4| and 42 attached thereto and projecting from the top and bottom faces of said arm. Midway between these guide rods 4! and 42, the arm is bored to receive a vertically extending rotatable bolt 43. The bolt 43 has two oppositely threaded portions 43' and 43' separated by an unthreaded, smooth portion 43 whose length is in excess of the thickness of the arm 33. The bolt also has a manipulating knob 44 at its upper end and a suitable lock nut 43 threadedly engaging the portion 43' of the bolt. Slidably supported on the guide rods 4| and 42 on opposite sides of the arm 33 are the blocks 43 and 41 having respectively the oppositely threaded openings 43' and 43 in which the respective threaded portions 43 and 43' of the bolt 43 engage. Rotation of the bolt 43 in suitable direction causes the blocks to move toward or away from each other. The lock nut 43 serves to lock the blocks in any desired position relative to each other. A bracket arm 43 suitably attached thereto projects laterally from each block substantially perpendicularly to the axis of the mandrel l3. Each bracket arm at its free end has an arcuate bearing portion 33 for the reception of an arcuate bearing block 3| provided on the end of an axle 32. Each arcuate bearing portion is slotted at 30 and a set screw or bolt 34 movable therein and threadedly engaging the arcuate bearing block 3| serves to permit angular adjustment of each axle 32. Each axle 32 carries one of the rolls 33 or 38. The angular adjustability of the axles 32 permits biasing of the rolls 3'3 and 33 with respect to each other and with respect to the axis of the mandrel IS. The relative biasing determines the pitch of the 0011 being wound, as will be presently described. The bracket arms 49 are so admeasured in length that when the axles 32 are parallel with the axis of the mandrel l3, their center lines all lie in the same vertical plane. Since the blocks 43 and 41 are movable vertically, the rolls 33 and 33, carried by the bracket arms 43- thereon, are movable toward or away from the mandrel by manipulation of the bolt 43 and capable of being fixed in any adjusted position by the lock nut 43.

Wire for forming the coils is fed to the mandrel from a spool 33. This spool is rotatably and removably carried on a spool spindle 33 suitably supported from the machine frame. The wire 31 from said spool is led around a pulley wheel 33, over a second pulley wheel 33, around a third pul-' ley wheel 33, and around substantially the major portion of the peripheral surface of a metering wheel 6|. All of the wheels are rotatably sup ported on the front of the frame Ill. The location of the axis of the metering wheel and the diameter of the latter are so arranged that the wire leaves the surface of the metering wheel on the tangent which is perpendicular to the axis of the mandrel. The pulley wheels 33, 33 and 33, and particularly pulley wheel 60, are so positioned that the wire must pass from the latter around the major portion of the periphery of the meteringwheel 3|.

A worm gear wheel 32 having an annular guide groove 32' in its peripheral surface is rotatably supported from a bracket 33 with its axis horizontal and parallel to the mandrel l3 and so positioned that wire leaves the groove E2 on a tangent substantially inthe horizontal plane of the lower face of said mandrel. The bracket 63 is carried by the frame II and attached there- 5 to as by bolts 64. The groove 82" is centrally located with respect to the widths of the rolls 35 and 35. The wire leaving the metering. wheel surface is passed around a fourth pulley 85 also 1 supported from the bracket 88, around the groove 82', and then past a verticalguide pulley l8; and finally between the bight formed by the mandrel l8 and the lower roll 38.

It is desirable to lubricate only that surface of the wire which comes in direct contact with the surface of the mandrel ii. In the embodiment shown, the wire surface to be lubricated is the top surface of the wire 51 as it passes from the groove 52' to the vertical pulley 85. To this end, a hollow socket 88 is vertically and rotatably carried in a bearing flange Ill provided on the bracket 53. This socket is provided with an external gear 11 meshing with the worm gear 62. The hollow socket has a polygonal section and receives a polygonally shaped stick of lubrieating medium 12, such as parafnn' or other suitable substance. The lubricating stick is pressed against the top of the wire 51 by its own weight or by the use of a slidably supported weight 14 which is suitably carried by the brack- 621; 63. This weight is adapted to press downwardly on the upper end of the lubricating stick. The axis of the lubricating stick is arranged to lie substantially perpendicular to the top face of the wire 51 and in the same plane therewith. 5: Passage of the wire in the groove 52' rotates the worm wheel 52 and consequently causes rotation of the lubricating stick socket iil'through gear 11. As a result, the lubricating stick 12 rotates as the wire passes under itand wears 40 down uniformly while lubricating only the one face of the wire 51 which comes into direct contact with the mandrel i5.

It is necessary to tension the wire 51 as it passes from the spool 55 to the mandrel l5 during the i v winding operation. This tensioning is accomplished herein through the agency of the metering wheel 8|. The latter is slidably keyed at 80 to the rotatable shaft borne in a bearing opening 82 in the front face of the frame 10.

The said front face is provided with a pad surface 88 concentric about the bearing opening 82 and of substantially the same diameter as the metering wheel 6|. A circular friction disc or mat 84 is mounted around the shaft 8i between the inner face of the metering wheel and the pad surface 88 and pressed between the two by the compression spring 85 carried on the shaft 8!. The pressure of spring 85 is adjustable through the agency of the washer 88 and clampuo lug nut 81 which latter threadedly engages the outer threaded end ll of the shaft II. This variability of pressure permits adjustment of the frictional resistance between the metering wheel and the frame and consequently permits varia- 05 tion in tension on the wire 51.

Since the wire passes over the peripheral surface of the metering wheel at high speed during the coil-winding operation a special wearresisting peripheral surface is necessary toelimi- 7 nate the necessity for frequent replacement of the metering wheel and consequent readjustment of the machine, particularly because the metering wheel also serves to drive a special cut-off mechanism whose accuracy must be maintained. it To this end, the peripheral surface of the metering wheel has a portion 88 of reduced diameter.

on the said reduced portion a rubber ring II is mounted which is somewhat less in external diameter than the maximumv external diameter of g the wheel 8|. A clamping ring II. also mounted g on said reduced portion 88, serves to clamp the said ring to the annular flange 58 of said metering wheel. Suitably spaced bolts 84 extending through said clamping ring,and rubber ring, and

into said flange u. serve to effect clamping. The

rubber ring 9| may be replaced by other suitable resilient material having a high coemcient of friction. This ring, if of rubber. is compreuai to about one-third of its original axial thickness 7 by the clamping ring. Its peripheral surface is 15 then slightly below that of theperipheral surfaces of the flange 88 and clamping ring 82 so i that a groove 85 is provided inthe peripheral face of the composite metering wheel in which the wire 51 travels. The friction between the 90 wire 51 and the compressed rubber ring surface in conjunction with the retarding action, of the friction pad 84 on the metering wheel surface affords an adjustable means for tensioning the wire. This specific metering wheel structure has 35 been found to be exceedingly wear-resistant. In actual practice hundreds of thousands of miles of wire run over such metering wheels have not required reiacing thereof.

The rotation of the metering wheel caused by 30 the passage of the wire over it is used to drive automatic cut-off mechanism which serves to cut of! predetermined lengths of wound coil. To this end. the wheel shaft Ii is provided with a pinion M0. The latter meshes with a pinion! of larger diameter attached to a pulley wheel I82, which latter is rotatably supported from the frame In by the spindle I83. The pulley I82 is of the variable speed type, i. e., it has opposed inclined faces Ill and I05 on separate sections [04 and N5 which are adiustably movable toward or away from each other by means of a manipulating nut Hi5 and clamping nut I81.

A second variable speed type pulley III is rotatably borne on the spindle l5! carried by the a frame Hi. This pulley. too, has oppositely inclined faces H0 and ill on separate sections iii! and iii, one of which is movable toward and away from the other by the action of, or against the action of. a compression spring ill 0 on the spindle I08 between one of the sections and' the frame. Thispulley I" is coupled to the pulley I82 by a V-shaped belt H8 operating between the opposed faces of the respective pulley sections. The two pulleys and the belt oonstitute a variable speed drive of the Reeves type in which the rotational speed of the pulley I88 is adjusted by the relative adjustment of the opposing faces of the pulley m. 'Rius. it is possible to vary the lengths of the colts cut 0 off by the mechanism now to be described.

The cut-off mechanism comprises a reciprocally movable knife blade I28 movable versely of the axis of the mandrel i8 and'the c011 wound thereon. This knife blade III is adopted a to move across the outer end of the tube 82 and sever the wound coil whenever so moved. The knife blade is removably attached at III to the connecting rod I23. This connecting rod is pro vided with a longitudinal slot in and a headed f0 guide pin H5, engageable in the vertical arm 88, serves to guide the vertical movement of the connecting rod. The latter at its lower end has a bearing I26. An eccentric ill integrally formed with a clutch member I28 operates in the bearing and serves upon rotation to reciprocate the connecting rod and the blade carried thereby.

The clutch member I28 is rotatably borne and slidable longitudinally on a rotary shaft I23 suitably journalled in bearings I30 in the frame I0. This shaft extends parallelly to shaft I2 and at one end has a driving pulley I3I. Belting I32 connects this driving pulley with the pulley I3 on shaft I2 so that when the latter is driven by the motor 20, the shaft I29 is likewise driven. In the embodiment shown, the pulley ratio of the diameters of pulleys I3 and I3I is such that shaft I29 is driven at a lower speed than shaft I2.

The opposite end of shaft I29 has a collar I35 fixed thereto. This collar has two diametrically arranged, axially extending, engaging pins I36, one or the other of which is adapted to engage an oppositely extending pin I31 on the eccentric I21 when the latter and the clutch member I28 are moved into one position on the shaft I29, thereby serving to drive the eccentric and reciprocate the connecting rod. In another position of the eccentric I21 and clutch member I28 on the shaft, the pins I36 clear the pin I31 without engaging it and do not drive the eccentric.

The intermittent engagement of the pins I36 and I31 is such that a single revolution of the clutch and eccentric, and, consequently, a single reciprocation of the connecting rod, takes place for each single revolution of the pulley I08.

To effect the intermittent engagement, the clutch member I28 has an annular yoke groove I40. A U-shaped yoke I is pivotally supported on a spindle I42 attached to the frame I0 and extending transversely of the shaft I29 so that the yoke I4I swings longitudinally of said shaft. The yoke has oppositely extending lugs I44 which permanently engage in the yoke groove I40. When the yoke is swung about its spindle I42,

the lugs in the groove I serve to shift the so: A cam groove follower I of substantially square cross section is suitably supported in vertical direction at I5I from the frame I0. The lower end I50 of the follower is adapted to engage in the cam groove I45 and normally to abut the shoulder I46 at the exit end of'said groove.

While so positioned, the clutch member is locked against rotation and the pin I31 is clear of the pins I36. In the embodiment shown, a shift of the clutch member I28 to the left will cause the follower I50 to clear the shoulder and enter the starting end of the cam groove, thus freeing the clutch member and permitting it to rotate. This tripping action is effected by a trip lever I60 (Figs. 2, 4 and 9) carried on a face of the 5 section IIO of the pulley wheel I08. Trip lever I60 is pivoted at one end to the face of said section by a pivot pin I6I. Stop pins I62 also projecting from the face of said section serve to limit rotation of the trip lever about its pivot pin and a resilient member I63 serves to urge said lever against the forward stop pin in the direction of rotation of the section IIO.

The yoke I has 9. lug I10 projecting laterally into the path of travel of the trip lever I60. As

the lever moves upon rotation with the section while the follower moves in the groove I45.

groove I84.

IIO, its free end engages the lug I10 causing the said lever to move back against the rear stop pin I62 whereupon said lever rotates the yoke HI and slides the clutch to the left until the cam follower I50 clears the shoulder I46 and enters the start of cam groove I45. At this instant of clearance one of the pins I36 engages the pin I31 of the eccentric and starts to rotate the latter and the clutch member of which it is part In so doing it, of course, follows the helical angle of the said groove and shifts the clutch still further to the left moving with it the yoke I4I into a release position (Fig. 9), where the trip lever I60disengages the lug and is snapped by resilient member I63 to the front stop pin I62 and clear of the lug I10. The follower moving in the cam groove as the clutch rotates then causes the clutch to shift toward the right (Fig. 8) so that after a single revolution when said follower again abuts the shoulder I48, the clutch member has been so shifted that its pin I31 has disengaged the pins I36. Thus, a single rotation only of the clutch member I28 occurs each time the trip lever engages the lug I10. The latter engagement occurs once for each revolution of section IIO of pulley wheel I08. Therefore, the speed of rotation of said wheel determines the frequency of single rotations of the clutch member. In consequence, the frequency of the single reciprocations of the knife blade I20, which is reciprocated once for each revolution of the eccentric I21, is controlled and the lengths of coil cut off can be controlled by changing the speed of the pulley wheel I08.

The clutch-op rated cut-off mechanism driven by rotation of the metering wheel is positive in its action and eliminates any irregularity in coil lengths. There is no danger of double tripping. Simple adjustment of the variable speed pulley I05 permits a change in the length of coil cut-off by changing the relative frequency of cut-off action as compared to the speed of coiling of the wire.

The coil formed on the mandrel and moved off the latter at its forward end passes through the tube 32 and is received by a guide I80. This guide I comprises an arm I8I attached to the frame I0 at I82. The upper portion I83 of this arm is provided with a semi-circular groove I84 extending in the same direction as said mandrel I6 and concentric with respect to the axis of said mandrel. A semi-circular tube I85 having lateral arms I86 is rotatably supported by these arms from a pivot spindle or rod I81 carried by the vertical arm 30 and extending parallel to the The concavity of tube I85 faces that of the groove I84 and the two function when in register as a tubular guide for the coiled wire passing thereto from the mandrel. Resilient means as a torsion spring I89 acting on the rod I81 and an arm I86 tend to maintain the tube I85 in registry with the groove I84.

When a length of coil is cut off from that being wound on the mandrel it is desirable to effect quick removal thereof from the guide I80. To this end a crank lever I90 is pivotally mounted on a pivot pin I9I carried bythe vertical arm 30. One arm I90 of the lever extends into the path of travel of the connecting rod I23. The other arm I90 is connected by a linkage member I92 to a projecting lug I93 on one of the arms I86 supporting the tube I85. Thus, as the connecting rod reaches the top of its stroke, shown in dotted lines in Figure 3, its upper edge engages the and 2M.

arm I 99' of lever199 and rotates the latter to the dotted line position causing the linkage member I92 to rotate the arm I99 and tube I95 to the dotted position shown and permits the severed coil to fall from the groove I99. The impact of the cut-oil stroke of the blade is sufficient to dislodge the severed coil section from said groove. Spring I99 returns the tube I95 to full line position of the figure whenthe connecting rod returns to non-cutting-ofi position.

Occasionally, during coiling, an overlapping of turns will occur at the coiling point. A detector device and safety switch operated by the detector device are provided to stop the machine when this occurs. 1

The detector device comprises a tubular support I95 carried by the arm 39 (Figures 4 and 6). This support extends toward the mandrel from the said arm 39 and carries a longitudinally slidable pointer rod I99 whose forward end is bent to permit the tip I91 to engage the coil surface adjacent therear of entry point of the wire into the bight between the mandrel and roller 39. Tubular support I95 is longitudinally slotted at I95 and a guide pin I93, fastened to the pointer rod I99, is movable in said slot to limit the extent of movement of said rod. The said rod I99 extends from the rear end of the tubular member, through a suitable bore 39' in the arm 39 and projects be-- yond the rear face (Fig. 10) of the latter. Said rod is threaded at its rear end I99.

A switch-operating member I99 extending iongitudinally of the rear face of the arm 39 is provided with two longitudinally extending slots 299 A suitable guide bolt 292 screwed into the arm 39 through the slot 299 serves as one of the guides for said member I99.

The slot 29I in width is slightly in excess of the diameter of the end I99 of the pointer rod I99, and said end projects through said slot. This slot 2! has also an enlargement 29I' at one end defining shoulders with respect to the balance of the slot 29I. An engaging nut 293 having a reduced portion 293' of substantially the same diameter as the enlargement 29I' of the slot is screwed onto the end I99 of the pointer rod I99. When said reduced portion rests in said enlargement 29 I the member I99 is prevented from sliding longitudinally of the arm 39 notwithstanding tension applied to induce such sliding by the tension spring 295 fixed at opposite ends to said arm 99 and to said member I99. of the rod I99, caused by overlapping turns of coil pushing its pointer end rearwardly, moves the reduced portion 293' of the nut out of the slot portion 29l' and permits the spring to snap the switch-operating member longitudinally until the opposite ends of the slots 299 and 29I are reached by the bolt and rod I99. Laterally project'ing lugs 291 on the member I99 engage a toggle switch lever 298 of an electrical swi ch 299. If the latter is connected in electrical series with the main motor switch 2I9 the electrical circuit to the motor is broken by a movement of the toggle switch lever 298 induced as described above. Thus, the motor stops if overlapping is detected by the pointer rod I99, and the attendant can reset the machine for proper coiling. A clamping nut 2 on the end of the rod I99 permits adjustable setting thereof to compensate for different sizes of wire used in winding coils.

Operation of the machine in brief is as follows:

Wire 51 from the spool 55 is led over the various pulleys 58, 59, 69, metering wheel 9|, pulley 95 and around groove 92 of gear 92 and past pulley A longitudinal shift 99 to the bight between the lower rubber roll 39 and the mandrel I9. Then the shaft I2 and, consequently the mandrel I9, are given a few manual rotations to start the wind on the mandrel, The rolls and 39 are given the desired opposing bias with respect to each other and moved toward each other until they both press firmly on the wire-windings on the mandrel. They are clamped in this position by the clamping nut 45. The motor is then started, causing the mandrel I9 to rotate at high speed. The coefficient of friction between the mandrel and the wire, aided by the pressure of the lower roll 36, is sufiicient to draw the wire from the spool and coil it about the mandrel. The bias of the rolls 39 and 39 determin% the pitch of the wind and forces the windings to move along the mandrel and clear of the rolls 35 and 39. Once clear of the rolls, the turns on the mandrel expand slightly and slide freely along the mandrel surface in axial direction toward the guide I99, passing oil the mandrel in the tube 32 on the way to said guide. The lubricant applied by stick I2 to the face of the wire adjacent the face of the mandrel facilitates the sliding of the coil along the mandrel. At intermittentperiods controlled by the trip lever I59,as hereinbefore described, the cut-oil knife sweeps across the exit end of tube 32 cutting off predetermined lengths of coil which fall from the opened guide I89 at the time of severance. The adjustable ratio of speed between the coiling speed of the mandrel and the rotational speed of the trip lever I99 determines the length of coil cut-off. This ratio can be adjusted with a high degree of accuracy to insure highly accurate cutoff of uniform predetermined lengths of coil.

In the embodiment shown, the rolls 35 and 39 have respectively the annular shoulders 35' and 39' atthe mid-points of their surface peripheries. These shoulders produced by slightly reducing the diameter of the respective rolls on one side of the respective shoulders'facilitate the guiding of the wire at the desired pitch angle during the coiling operation. The shoulder height depends upon the wire size and in cases of very small-sized wire can be eliminated. For the' larger wire sizes, however, the shoulder is important.

The adjustability of the speed of drive of various parts, the adjustability of tension by the metering wheel, as well as the adjustability of the pressure and degree of bias of the rolls 35 and 39 makes the machine adaptable for making accurate coils of any desired predetermined length and of desired different wire sizes.

The material of the mandrel is optional as long as it is wear-resistant and has a low coefficient of friction. Nitrided" steel mandrels have been found satisfactory.

The special metering wheel construction, including its specially constructed wear-resisting peripheral surface, eliminates a source of error normally induced by wear and also eiiminatesthe necessity for frequent readjustment of the machine during the preparation of a particular biased with respect to each other and in fric-' tional surface contact with said mandrel, means for driving said mandrel, means for leading coil wire to said mandrel between it and said rolls, and means for cutting off predetermined lengths of coils wound on said mandrel.

3. A coil winding machine comprising a drivable mandrel, a pair of rolls oppositely biased with respect to each other and in surface contact with said mandrel, means for driving said mandrel, means for leading coil wire to said mandrel between it and one of said rolls, rotating means for lubricating only that surface of the coil wire coming into direct contact with the surface of said mandrel, and means for driving said mandrel to wind said wire in coil form thereon.

4. A coil winding machine comprising a drivable mandrel, a pair of stepped rolls oppositely biased with respect to each other and in surface 'vmtact'with said mandrel, means for driving said mandrel. and means for leading wire to said mandrel between it and one of said rolls adjacent the shoulder formed by the step on said ne of said rolls to wind said wire about said mrjrel with a prede ermined pitch.

5. A coil winding machine comprising a drivable mandrel. a pair of oppositely biased rotatahie rolls in surface contact with said mandrel, means for leading coil wire to said mandrelbeween it and one of said rolls, means for drivin d andrel to coil the wire thereabout, said ro l uiding said wire onto said mandrel, regula ing the pitch of the wind thereon by the relative bias of said rolls and pushing the coil wardly along the mandrel as the latter is driven. receiving means adjacent the end of said mandrel for leading the wound coil off the end of said mandrel, and means for cutting oif predetermined lengths of coils formed on said mandrel between the end thereof and said receiving means.

6. A coil winding machine comprising a drivable mandrel, a pair. of adjustable rotatable rolls oppositely biased with respect to each other and in surface contact with said mandrel, means for leading coil wire to said mandrel between it and one of said rolls, and means for driving said mandrel to coil wire thereabout, said rolls serving to guide said wire onto said mandrel, to regulate the pitch of the wind thereon and to push the wound coil forwardly along the mandrel toward the discharge end thereof as the said mandrel is driven.

'7. In a device of the character described, means for winding wire into a coil, means for cutting oil lengths of coil from the wound coil without impeding the winding operation, and infinitely adjustable means for automatically metering the length of each coil cut off, said lastnamed means being controlled by the movement of the wire to said first-named means, and being capable of adjustment while said device is in operation.

8. In a device of the character described, means for continuously winding wire into a coil, means for cutting ofi lengths of coil from the wound coil without impeding the winding operation, and means for automatically metering the length of each coil cut off, said last-named means including a clutch member for operating said cut-off means operated by movement of the wire to said first-named means.

9. In a device of the character described, means for winding wire into a coil, means for cutting off lengths of coil from the wound coil without impeding the winding operation and means for automatically metering the length of each coil cut off, said last-named means including a. clutch member for operating said cut-ofl means, a metering wheel around which said wire passes prior to being wound into coil form to rotate said wheel; and a trip mechanism operable during a prescribed period of the rotation of said metering wheel for moving said clutch member into operative engagement with said cut-oil. means.

10. In a device of the character described, means for winding wire into a uniform coil, means for cutting off lengths of coil from the wound coil without impeding the winding operation and means for automatically metering the length of each coil cut-off, said last-named means including a clutch member for moving said cutoff means into operative relationship with said coil, a metering wheel around which said wire passes prior to being wound into coil form to rotate said wheel, a trip mechanism operable during a. prescribed period of the rotation of said metering wheel for moving said clutch member into position to cause operative movement of said cut-oii means, and variable speed means interposed between said trip mechanism and said metering wheel for varying the frequency of the operation of said trip mechanism and said cut-ofi means. 7

11. In a device of the character described, means for winding wire into a coil on a driven mandrel and moving said coil along and of! said mandrel, guide meansfor receiving said wound coil from said mandrel, and means for cutting ofi lengths of coil from the wound coil between its exit from said mandrel and its entrance into said guide means without impeding the coil winding operation.

12. In a. device of the character described, means for winding wire into a coil, a reciprocally movable cut-off member for severing lengths of coil from the wound coil without impeding the I winding operation, means for reciprocating said cut-oil member, and infinitely adjustable metering means controlled by the passage of wire to the winding means adjustable during operation of said device and for actuating said reciprocatmg means.

13. A metering device for use in a coil winding machine comprising a wheel having a grooved peripheral surface, the bottom of the groove consisting of compressed resilient material, and means for mounting and compressing said material which constitutes the bottom of said groove.

14. A metering device for use in a coil winding machine comprising a wheel having a grooved peripheral surface, the bottom of the groove consisting of highly compressed resilient material.

15. A metering device for use in a coil winding machine comprising a wheel having a peripheral flange, a compressed resilient ring adjacent said flange and having a smaller outside diameter than said flange, a clamping member of the same overall diameter as said flange applied over said ring, and attaching means for compressing said ring between said flange and said clamping member.

16. A metering device for use in a coil winding machine whose elements comprise a solid wheel, a compressed resilient member arranged along the side of said wheel adjacent and somewhat below its peripheral rim and a compression mem- 1 her of the same diameter as said wheel for attaching said resilient member to said wheel and highly compressing said resilient member between said wheel and said compression member so that the composite peripheral surface of said wheel comprises two solid rims adjacent opposite side faces of the wheel separated by a groove whose bottom face constitutes the peripheral face of the highly compressed resilient member.

17. In a device of the character described, means for winding wire into a coil, means arranged adjacent to the mandrel at the coiling point for detecting overlapping turns of coil windings, and means operated by said detecting means for stopping said device when said overlapping occurs.

18. A coil winding machine comprising a drivable mandrel, means for-driving said mandrel, means for directing wire to be coiled to said mandrel to wind the latter uniformly around said mandrel with a predetermined pitch, means arranged adjacent to the mandrel at the coiling point for detecting overlapping windings on said mandrel, and means operated by said detecting means for stopping said machine when said overlapping occurs.

19. A coil-winding machine comprising a drivable mandrel, a pair of resilient rolls oppositely biased with respect to each other and in surface contact with said mandrel, means for driving said mandrel and means for leading coil wire to said mandrel to be wound thereon.

20. A coil winding machine comprising a drivable mandrel, a pair of rolls oppositely biased with respect to each other and in surface contact with opposite sides of said mandrel, means for varying the bias of said rolls relative to each other, means for driving said mandrel, and means for leading coil wire to said mandrel to be wound thereon.

21. In a device of the character" described means for winding wire into a coil, means for cuttingofl lengths of coil from the wound coll without impeding the winding operation, and means for automatically metering the length of each cell cut off, said meanscomprising a metering wheel over which said wire moves in its passage to the winding means, control means for actuating said cut-oi! means and variable speed means connecting said control means and said wheel whereby the lengths of coils cut oil may be varied.

22. A metering device for use in a coil winding machine comprising a wheel having a grooved peripheral surface, resilient material at the bottom of said groove and means for compressing said material highly in the direction of the width of said groove.

23. A coil winding machine comprising a drivable mandrel, a pair of resilient rolls oppositely biased with respect to each other and in surface contact with opposite sides of said mandrel,

means for driving said mandrel, means for leading coil wire to said mandrel between one of said rolls and said mandrel and means for varying the bias between said two rolls to vary the pitch of wire coiled on said mandrel.

STEPHEN A. PLATT.

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