US2922932A - Magnetic coils - Google Patents

Description

Jan. 26, 1960 .1.J. GLowAcKl ETAL 2,922,932

MAGNETIC COILS 3 Sheets-Sheet 1 Filed June 25, 1956 5 n zro n wim., 5 fr V759 o 7. 3 4 5 5 Sii N /NA 0 xbmsm OANH T WUG www he .B N n nu WMA J E Jan. 26, 1960 J, J, GLOWACK. ETAL 2,922,932

MAGNETIC COILS Filed June 25, 1956 3 Sheets-Sheet 2 afk /23 60 62 INVENTORS oH/v .Si @Low/ecn 35 f4/ALM? l?. MUA/50N EAK/ D. BR/GHTMAA/ ATTORNEYS' Jan. 26, 1960 Filed June 25, 1956 J. J. GLowAcKl ET AL 2,922,932

MAGNETIC coILs 3 Sheets-Sheet 3 BEI/25,1242 aL/tage ATTORNEYS United States Patent O 2,922,932 MAGNETIC coILs Application June 25, 1956, Serial No. 593,707 9 Claims. (Cl. 317-158) This invention relates to magnetic coils and methods of manufacturing same, and it relates more particularly control mechanisms Such coils are generally bobbin-wound, the conventional bobbin normally consisting of a core portion and a pair of flanges at either end of the core, the coil being wound in the space between the flanges. The ends of the wire are ordinarily then soldered to the ends of short lengths of lead wire which are connected by suitable means to a power supply cord when the coil is installed in the motor. In coils of this type, the solder insulating tape. Moreover, the lead wires must be carefully secured mechanically to the coil so that the delicate solder connections to the extremely fine coil wire will be adequately protected.

because there is not enough room between the flanges of the bobbin for the operators fingers. Furthermore, the washer must necessarily t rather closely around the fcore of the bobbin leaving very little space through which to thread the end of the Wire. On the other hand, if the end of the wire is led out through an aperture at through such aperture.

The finishing operations in the manufacture of prior coils, that is, the operations subsequent to the winding operation, likewise require highly skilled operators to solder the fine coil wire to power terminals or leads and to carefully wrap and insulate the solder connection and coil in order to comply with strict underwriters requirements. Since the soldering and taping operations required in such prior designs are not capable of being done by machine, ithas been necessary in most instances to employ highly skilled personnel to do this work by hand, not to mention the considerable time and great pains which must be taken to train workers to do these finishing operations properly in order to prevent loss through a high percentage of rejected coils. 'I'his necessarily has kept the cost of the coils high.

Since the coil in small synchronous electric motors represents about 40% of the total manufacturing cost of the motor, any reduction in the cost of the coil means a large savings in the motor as a whole. It is an important object, therefore, of this invention to reduce the manufacturing costs of electric coils by providing and methods of manufacturing it not only eliminate the methods of assembly which eliminate the ditlicult hand operations heretofore required and by designing a novel coil construction which is readily adaptable to fabrication by machine, and in fact to complete automation, if desired.

A coil in accordance with the invention consists in general of a bobbin, onto which is wound magnetic wire, a cover being provided for the bobbin and a pair of terminals supported by the cover and the bobbin. The ends of the wire coil are fixed to the terminals which are held firmly between the bobbin and cover. Portions of the terminals project from the coil assembly so that a power cord from an electric power supply can Abe connected directly to the terminals at the coil by means of a simple solderless connection.

Heretofore, due to the necessity for insulating either the outer surface of the coil itself or the wire leads to which the ends of the coil wire are soldered, it has been found necessary to wrap the coil and/or the connections between the lead wires and the ends of -the coil with an insulating tape after the bobbin is wound. The labor and material required in such finishing opmore apparent hereinafter, the present coil construction diicult manufacturing operations and therefore reduce cost, but also provide a completely sealed and insulated coil which is superior to prior coils in many Ways.

An important advantage of the present coil is that it eliminates the wire leads which have usually been provided heretofore in small magnetic coils and Which dangle uncontrolled from lthe side of the coil. In place of these leads, has beenprovided a terminal block, which renders the coil more compact and more readily adaptable for use in machines which assemble them in the motors and other electrical devices in which they are ultimately to be used.

Another object of the invention is to provide a coil, especially one in which a Very fine wire is used, wherein the delicate terminal-ends of the coil are fixed to amore rugged connecting means so that the coil may be reliably connected to a suitable source of electric current in a simple expeditious manner.

These and other objects of the invention, as well as novel features and advantages, will become further apparent from the following description.

In the accompanying drawings in which specific illustrative examples of the invention are shown:

Fig. 1 is a view in top plan of a coil assembly embodying the present invention;

Fig. 2 is a view in side elevation of the coil assembly;

Fig. 3 is a View in end elevation of the coil assembly;

Fig. 4 is a View in section taken along lineV 4 4 of Fig. l;

Fig.v 5 is a view in section taken along line 5-5 of Fig. 1;

Fig. 6 is a view in section taken along line 6-6 of Fig. l;

lFig.' 7 is a view in plan of the coil, terminals, and bobbin with the cover removed;

Fig. 8 is an exploded view in perspective illustrating the manner in which the terminals are fixed in the assembly;

Fig. 9 is a view in section through a coil Winding arbor showing a preliminary step in winding the coil, according to the novel winding method of the invention;

Fig. 10 is a view similar to Fig. 9 showing another preliminary step in winding the coil;

Fig. 11 is another view like Fig. 9 but showing two 2,922,932 6 76 at the outer end of the terminal, then to make several projecting in spaced relation from the flange of sleeve turns around the contact section 72 in notches 74 and 85 so as to fit into slot 31 of the Ibobbin and to rest against 75 until the wire is secure. When the cover 21 is placed opposite ends thereof as shown in Fig. 12. At this point, in position, the Wire thus Wrapped around section 72 of the bobibin d oes not include the outer ilange 34.

bobbin, and this will work its way through the openin 10 Winding apparatus. With the Wire thus looped through neetion. Or, if desired, instead of using the cement, a outwardly between the ange 23 0f the bobbin and the in order to bind the wire and terminal in integral contact tl Plastic Washer 34, applies e liquid Cement t0 tS ange with each other. 34', ts this over the shank 81 of the winding arbor in Both the bobbin and cover can conveniently be made the manner SlloWn in Fig 10 and Places it on the lip of a resmous plastic material, and thus these elements 24 at the outer marginal edge 0f Cere 22 0f the bobbin, can be economically molded in large quantities. 'Ihe on Which it beoofnesd Permanently cemented Wllle the and cover are varied; however, the preferred materials 25 A Second `bobl'nn 20 SnPPolted on another flanged It will be appreciated that whereas specific materials are Place, the Slotted Washer 83 iS Sld onto threaded shank material is within the purview of the present invention tVYo 'bobbins in Place on the Winding arbor aS Shown in at least in its broadest aspects. The material of which F1g- 11 smh as copper, brass, or aluminum, shown) being provided for the wire as it comes from It will be noted from the foregoing description of one the s UPPlY 1n o fdel to lay 1t in eVen layers on the particular construction of a coil embodying the invenbobbins. The winding apparatus is set to automatically tion that the ilange 34 is not molded integrally with the 4.0 Wind eXaCtlY the desired rest of the bobbin 20. One reas less expensive to mold the core 22 and flange 23 in one free to Stelt one 01" mOre Similar sets of piece and the ilange 34 as a second piece than it is to in operation- When the bobbins are Wound mold' a one-piece bobbin having two integral anges. Portion of the Wire t0 each bObbIi is Wra This is due to the fact that the two-flange bobbin must the other Staking lng or Post 35 and Cnt 0r br bemadein asplt mold, the source of supply. The nut 84 is Another and more important advantage 0f providing and split washer 83 slid off the threaded end of the the bobbi'n with only one flange is to facilitate, and thus nbor- The Wound bobbins may then be reduce the cost of, winding the bobbin. Accordingly, from the Winding arbor, d' an important aspect of the present invention is found in 85 and then Placed on e tra 102, as made by the Universal Winding Company of Wire is fastened rmly in place so th om any part of to accommodate the device of the present invention the winding apparatus as has been the case heretofore Reference 1s now had more particularly to Figs 9 to 12, Provision of the staking posts 35 on the bobbin greatly which show the steps in starting the novel Winding operafacilitates handling the coil during the initial assembling tion As will be evident the winding arbor is desigoperations thereof and is, therefore,an important feature nated by the numeral and includes a shank or spindle of the novel construction of the present coil 81 which terminates in a threaded section 82 Received It will also be readily apparent from the foregoing on the threaded section 82 is a slotted washer 83 (Fig Lhat where a wire is used which is provided with a 12) and nut 84 which Abears against it. A anged sleeve 65 coating that will adhere to two bobbins simultaneously. Consequently, the first such as clock motors. Nevertheless, the sleeve 85 is positioned with its flange against the shoulder 70 struction which includes the flanged co 6 formed by the shank 81, which is of smaller diameter entirely possible to omit o than the rest of the arbor 80, and is keyed thereto as bobbi'n in certain instances,

arbor, a bobbin 20 is placed on the sleeve and is fixed the bobbin. against rotation relative thereto by a pair of pins 87 75 In finishing the coil, the following operations are 7. carried out; First the two terminals 70 are pressed into the slots 33 with their terminal sections extending away from the port-,ion 27 of; they bobbin. The enamel insulation on the ends 61g, 6.4;, of the coil is'then removed in order to ensure proper electrical contact with the terminals 70, and they wirres are led through notches '79 at the rear ends ,of terminals 70, along the outer sides of the terminals, through notches 76 at the front end, as shown in Fig. 7, and then wrapped around the up,- standing section 72` of each terminal; If thek wire is to be welded to the terminals 70, as has been found to be desirable, this is done next, and th'ef cover 21 is then secured in place over the bobbin Ztl. This may be accomplished by applying an acetone cement to. the cellulose acetate cover along the edge, of ange 44. before the cover g1 is pressed onto'the bobbin. However, if Ythe coi-l is to be used in a motor or'other'device in such a way that the cover 21 and bobbin 20 are held together by the assembly in which'it is ultimately used, it is only necessary to cement the terminal portions together to ensure that the connection between the ends of the coil and` the terminals 70 are not disturbed. Thus, cement may be applied only to dowel pin 58 on the cover 21 so that this will become fixed in the hole 32 in the bobbin20. In order to ensure that the wire ends 61 and 64- are not disconnected from the terminals '70 when the cover Zlis mounted, the slots 52 are cut away ad jacent the points 63 where the connection is made. As shown in Fig. 4, this prevents the edge of slots 52 from scraping the wire olf the terminal as the cover is pressed into place. After the cover is applied, the coil is tested in the usual way.

It will be readily observed from the foregoing that each finishing operation can be carried out by machine. For example, the terminals 70 may be pressed into the slots 3,3 in the wound bobbin by means of Va press, to which the terminals and bobbins are fed either by hand or automatically. While it has not been found feasible to remove the insulation from the wire ends entirely by machine, this operation can be wholly eliminated by mechanically staking the wire to the terminals as suggested hereinbefore. It is also possible to test the coil at thesame time that the cover furnishing the cover assembling press with suitable contacts, which engage the terminals 70 while the cover is being cemented to the bobbin, these contacts being connected to,l anohm meter or other test instrument so cesarean` 351 held tautly inv contact with the sides of the terminal, as

Vshown in Fig.

is being applied by simply that an operator attending the cover assembling press can also record the results of the tests on each coil. The foregoing illustrates the adaptability of the present coil to massV production methods and the substantial reduction in, or virtual elimination of, the need for skilled personnel to perform the finishing operations on the coil.

One of the finishing operations which requires great skill and which has therefore been felt to be almost indispensable, is the solder connection between the very line wire of the coil and the more rugged contact, such as a power lead. The presentcoil construction makes possible the elimination of this soldering operation, which is difficult, if not impossible, to do by machine. Thus, as has been brought out hereinbefore, the method now being used for making this extremely delicate connection in the present coil is to weld the wire to the terminals by using apparatus shown more or less diagrammatically in Fig. 13.

The welding apparatus consistsof a coil locating fix-` ture 90 in which the Wound bobbin Ztl is held with the terminal sections 72 projecting upwardly. A central contact and hold-down member 91 is movable vertically as viewed in Fig. 13 by conventional power means (not shown) into position between terminals 70. The lower portion of contact 9.1 fitting between terminals 70 is of such a size as to just engage the inner surfaces of' both the terminals. Op both sides. of the. coil locating fixture 90 are guidemembers `92 lhaving tracks 93 in their upper surfaces,'within which terminal blocks 914 may slide'laterally with" respect'to. thecentral contact 91. Each'terminal block 94. hasa plunger 95 connected to a' suitable power'deyice,"`s1cl as'man air cylinder k(not shown), for lmovingtheV blocks 94 toward and away from the central contact. 91'. Blocks 94 are also pro vided with welding points 96 projecting inwardly toward the central contact 91 where they may be "moved into engagement with the ends 61'and 64,v respectively, Yof the wire coil 60 which lay along the Voutersurfaces of terminals `on the wound bobbin 20. Welding points or lateral contacts 96V are furnished electrical power through high tension cables 97 which are connected thereto in'any suitable manner indicated generally at 98, the points 96'and connectionsV 98 being of course properly electrically insulated to prevent s h'ortY circuit. H igh tension cables 97 are connected to suitable Welding equipment (not shown) such as, for example, Raytheon Model 225 Weldpower Unit No. 1537, Equipment No. AL 101, 110 volt, 1() amperes, 60 cycle, single phase, manufactured by Raytheon Manufacturing Company.' The central contact 91 is likewise connected'to thewelding 'equipmentV through asuitable connection'which is not shown in the drawing.

In order to weld the'ends 61, 64 of Vthecoil wire to the respective terminals 70, the wound bobbin A20 is placed in the fixture which holds it againstV movement laterally, the central contact 91 being in its raised position. The ends 61, 64V o f the wire are Vat this point in the assembly Wrapped around the vterminal sections'72 and have had the enamel insulation removed therefrom asby sanding. With the bobbin in place, the ends of the wires are unwrapped from the sections 72 of terminalsp70 andare 13, with each wire engagedin` both the rear notch 79 and theV front notch 76 in'order v,to accurately locate it ata point where it may be engaged by the weldirigpoint 96.l The Vcentral contact 91 is then lowered between the terminals 70 and presses against the portion Z7 Vof the bobbin holding it down and at the same time making contact with the terminals 7 0. The welding points 96 are then moved laterally inwardly until they engage the terminals 70 and wires 614 and 64, respectively, in order to weld the wires to their terminals. A

VyWhen the weld has been made and while'the'bobbin isy being held securely in place'by the central contact 9'1, the ends 61 and 64 of'thewire are broken off ladjacent the forward end of terminals 70 as yshown in Fig. 5. The central contact91 isthen retracted and lateral contacts or welding points 96 moved outwardly in opposite directions so that the bobbin 20 can be removed --and another placed in `the fixture 90. After the ends of thecoil have been welded to the terminals as described above, it is thereafter only necessary to place the cover on the coil in the manner hereinbefore'described.

Coils of the construction disclosed herein using semiautomatic assembling apparatus have been madein production for at least 25% less than it is possible to `make a conventional double anged coil having leads soldered to the ends of the coil and wrapped ininsulating tape with reinforcing strips for-thewire leads to protect the solder connection. The reduction in cost is evenV greater of course when compared with the cost to obtain such conventional coils on the market. `Moreover, it is felt that, due to the particular design of theY present coil, even greater reductions in cost can be'effected by using automatic equipment for assembling thev coil which would be impossibleto use in manufacturing coils ofprior de- Signs.-

1. In an electric coil, the combination comprising a bobbin of electrical nsulating material including a cylindrical core, portion, 'a flange formed integral with one marginal edge of said core. portion and a .terminal plate portion formed integral with said flange, a cover of electrical insulating space completely enclosed thereby, terminal plate portion arranged in overlylng registry with the terminal plate portion of said with the free blades.

4. The combination defined in claim 3, which includes an insulating washer adjacent one side of said coil of flange, and a second flange at the other end of a cover of material similar cover, said terminal portions extendmg radially' of said bobbin adjacent the said first flange thereof.

9. The combination defined in claim 8, wherein the ends of said wire are welded to said terminal blades.

References Cited in the file of this patent i UNITED STATES PATENTS

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