US1929156A - Coil winding die - Google Patents

Description

Oct. 3, 1933- s w s N 1,929,156

COIL WINDING DIE Original Filed Dec. 28, 1929 INVENTOR .5. 14/143,575

ATTORNE Patented Oct. 3, 1933 PATENT oFFicE- COIL WINDING DIE Sten Wadsten, Bloomfield, 'JL, assignor to Westinghouse Lamp Company, a

Pennsylvania corporation of Original application December 28, 1929 Serial No. 417,187.- Divided and this application tober 15, 1931. Serial No. 568,953

2 Claims; (Cl. 1536.5)

The present invention relates to an improvement in machines for helically winding a filamentary'wireas shown and describedin Patent No. 1,670,499, May 22, 1928, to 'John W. Eckstedt and relates more particularly to a coil-winding die for use in'such machines, and is a division of my copending application Serial No. 417,187, filed December 28, 1929. r

I In the above-mentioned patent a machine is shown for coiling a fine hair-like wire to ahelical form in the absence of a mandrel, and particularly for the production of lengths of coiled wire to serve as filaments for incandescent electric lamps. The said machine comprises mechanism for moving a wire'through a given path by tangential engagement with a pair of oppositely disposed driving rollers which propel the wire endwise into arcavity die which is so constructed that the wire issues therefrom in the form of a continuous helix. Means are provided for cutting the helix into sections of proper lengths to constitute filaments for incandescent electric lamps.

The die is so arranged that the cavity is positioned to receive the wire from the driving rolls, the bottom of the cavity being inclined or grooved so that the wire is bent into a succession of coils which pass over a lip or separator member at the edge of the cavity. The successive turns of the coil or helix which issues from-the die are consequently spaced a given distance apart and the helix is, therefore, provided of a certain diameter and pitch depending upon the dimensions of the spacer member and the radius of curvature 'of the effective surface of the cavity as well as the position of the die with respect to the driving rolls.

In the manufacture of coiled filamentary-bodies which serve as electrical resistance elements when used as lamp filaments, it is essential to-exercise extreme accuracy in the formation ofthe coils, since each'filament or coiled section must be made in accordance with specified dimensions so that each coiled section will have a length of wire therein equal to the succeeding coiled sec- 5 tion. Furthermore, the diameter of the coil as well as the spacing or pitch of the turns'of the coil must be uniform. i

The dimensions of the diameter and'the proportions of the coiled sections vary for lamps of different wattage, and the data relating to such dimensions and proportions is known as the rating so that a coiled section ror "a given rating must be made in accordance-with a-predetermined set of dimensions. For example, a filament for a 60 watt 115 volt lamp must conmentioned patent a coil-winding die is shown and disadvantage since when applying a die into posiwill be in accordance with the data supplied for "production of the die is reduced by the time and ercise considerable care as above mentioned. in

tain a length of wire of 517 mm., it must'have a diameter of .0108 inch and the coiled section must-contain 398 turns per-inch. The diameter of the wire also varies in filaments of difierent wattage lamps, and the diameter of the wire of a coiled filament of a watt lamp is preferably .00187 inch.

- It will be obvious that in order to produce a lamp filament and hold the coil formation to the required proportions and dimensions it isnecessaryto accurately form the coil-winding die and toprovide accurately adjustable means for holding the said die in a given relation to the path of movementof the wire thereto- In the abovedescribed as preferably consisting of an extreme- 1y hard material such vas adiamond. A diamond die, although having indefinite life, is difficult to produce and owing to variations in the properties of a diamond, it .is very often brittle to the extent that portions of the coil-winding lip are broken off rendering the die inoperative for the purpose intended.

As set forth in the said patent the coil-winding die may be constructed from hardened steel, but inasmuch as the wire passing over the die results in excessive wear, it is necessary to replacethe steel die at shorter intervals than is necessary with a diamond die. Ordinarily the replacement of one die for another would offer a considerable tion for the winding of a coiled filament, it is necessary to adjust the die in several planes until the cavity is accurately located in such position that the diameterand pitch of'the" coil produced the rating of the particularlamp for which the filament is to be used. 1

When using a diamond die, the die remains in the machinefor: such a long period that the amount of labor and inconvenienceinvolved in a change from one dieto another isnegligible. A

steel die, although easier to produce, must be changed at comparatively short intervals and the advantage given by the facility accompanying the labor involved in replacing the same.

It will further be understood in order to wind fine filamentary wire; to helical form in accordance with given dimensions, it is necessary to exaccurately locating the die cavity. When it is necessary, therefore to change the die owing to wear, dimculty is encountered in replacing a new die in exactly the same position as that previously occupied by the removed die. no

In my copending application Serial No. 242,715, filed December 27, 1927, for adjustable holder for coil-winding dies, apparatus is shown wherein a die may be made of steel while positioned in a holderand so arranged that the die when finished may be inserted into the coil-winding machine in exactly the same position as occupied by a die which was produced by moving a matrix against a soft-metal die blank and compressing the material of the blank to form a die cavity. Although this method is satisfactory it requires a time interval and necessitates considerable care as well as the use of a certain amount of apparatus.

An object of the invention is to provide a coil winding die of vitreous material.

Another object of the invention is to provide a coil-winding die having a hard smooth glassy surface.

Other objects and advantages of the invention will be more fully understood as the description proceeds.

In accordance with the present invention a coilwinding die is produced by moving a matrix into contacting relation with a die blank consisting of a vitreous material such as glass, while the said blank is in a plastic condition. In practicing the invention a coil-winding die is made, for example, for the formation of filaments for 40 watt lamps.

This die may be made of steel or other hard macavity,

terial and adjusted in aholder in the machine until it is inthe exact position to, wind coils for .the rating required. 7

While in its adjusted position in the holder it is moved into contact with the end of a matrix blank and. forced thereagainst untilan-impression of the end of the die is formed in the matrix blank .thus producing a matrix member.

This matrix member is then held in a given position and a die rod having a tip consisting of a -vitreous material is positioned for movement into contact with the matrix. The vitreous material may be heated by a fine pointed flame until its exposed portion is in a plastic state at which time -.Iit.may be moved into contact with the matrix so that the vitreous or die portion of the die blank formed to constitute a cavity die and ready tobe positioned in a coil-winding, machine. 1 By. reason of the present method a die may :be-produced in a rapid and efiicient manner so that if during the winding of a quantity of coiled "filaments it becomes necessary to renew the die, .such operation may be accomplished with a minimum loss of time.v

The invention will be more fully understood by reference to the accompanying drawing in which:

Fig.1 shows a portion of a coil-winding machine partly in section with the coil-winding die in position, 1 Fig. 21s a side elevational view showing apparavtus for moving a die blank in contact with a matrix .for a die-forming operation,

Fig. 3 is an enlarged view of a master die and a matrix member in contact to form the wirea bending cavity in a matrix,

Fig. 4 is a view showing the master die and matrix after the latter has received its wire-bending Fig. .5-is a side elevational view of a portion of a matrix member partly in section,

-showing the die-forming cavity,

Fig.6 is a top'end view of a matrix member Fig. 7 is 'a side elevational view partly. in sec- 'tion showing a die blank'with a diecavity formed jin'a vitreous portion at itsvend,

Fig. 9 is an enlarged fragmentary cross-sectional view showing the formation of a coil-winding die with a portion of a coiled wire.

Although the present invention may be practiced to produce a cavity die, for use in coilwinding machines where adjustment is necessary, it is preferable to practice the invention for producing a die in a predetermined position with respect to a machine element for application to a coil-winding machine.

Fig. 1 shows a portion of a coil-winding machine-comprising a holder 10 hinged at 11 to a spindle 12 which spindle is journaled in a suitable bearing on the body of a coil-winding machine. By reason of the pivot 11 and the spindle 12 it is possible to move the casing 10 in a vertical and-a horizontal plane and adjust a die 13 with relation to wire driving rollers or rolls 14 and 15 which propel a wire 16 against the die 13. .The die may comprise-a die rod 17 and since it is essential to provide a more accurate adjustment of the die than may be accomplished by the above-mentioned vertical and horizontal adjustment, a sleeve 18 is provided to receive the die rod 17 which sleeve is fitted in a suitable bore 19 in the casing 10. v

The sleeve 18 in which the die or die rod is positioned many be termed a die sleeve or collar and a set-screw 21 is provided to engage a notch ordepression 22 in the die rod to hold it in a predetermined relation to the sleeve. An adjustment of the die rod about its longitudinal axis may be obtained by a rotary movement of the sleeve 18. For this purpose the sleeve is provided with a yoke 23 having a split head 24 by means of which a clamping screw25 secures the yoke to the said sleeve 18. Arms 26 and 27 extend downwardly from the yoke and are positioned on opposite sides of a control arm 28 integral with the casing 10, set-screws 29 and 30 passing through threaded apertures in the arms serve to permit an adjustment of the yoke with a consequent adjustment of the sleeve 18 and the die rod 17. I

A further adjustment of the die rod is accomplished by providing a set-screw 31 which extends through a threaded aperture in the yoke 23 and abuts against the casing 10 thus by manipulationof the set-screw 31 the sleeve and consequently the die may be moved toward or away from the wire driving rollers 14 and 15.

For the purpose of clamping the sleeve in its final position the casing 10 is split and clamping screws 32 are provided.

The above tool or die holder constitutes part of a coil-winding machine, and it is thought that the above description is sufiicient for the present purpose in showing the die holder and the means for holding a die in a given relative position in the holder.

It will be appreciated that by reason of the above-mentioned adjusting elements the position of the holder may be changed with an extremely fine degree of accuracy and that the die may be adjusted with relation to the holder.

In producing a die for application to the holder such as that shown in Fig. 1 a die rod 17 may be provided with a tip 33'consisting of a vitreous material such as glass, good results having been obtained from glass .such as pyrex, it being understood, however, that various glass compositions may be employed.

6 a matrix 35 is provided having a die forming lilo r .1 ,929',1"5'e V recess 3'1, thbottom surfaee of which pm 'vided'witharaised portion or fin 38. The matrix is employed-to receive the tip 33" when the same has beenrendered-jplastic so that the saidtip will take the'rverse formof the recess 37 and a die-forming cavity 39 will be produced with a coil-winding lip 41 in thepro'per relative 'posi non. The operation of bringing the matrixand the vitreous tip of the die blank into contact will be more clearly understood by 'reiferencetoFig.v -'2 "which -shows anapparatus comprising a holder 42-to receiyea sleeve l8 which is'substantially a duplicate "of-the "sleeve 18 and in-which may be disposed a die rod 17 having a vitreous die blankatmne'end thereof. A set-screw 21 .en-

gages a seat 22' to hold the die rod in a; given position with respect to thesleevelil' and the said sleeve is positioned in'the holder 42 and secured by a' set screw 43. Adjacent to the holder 42 is positioned a horizontal bearing bracket'44 having a bearing 45 in which a slidable holder 46 is positioned. V i o The holderv 46 is provided with a bore 4'7 in which the matrix35 is positioned. A set-screw 48 is provided to securethe matrix in position and the bearing bracket 44 is provided with a slot 49 to permit the set-screw 48 to travel with the slidable holder 46. V v

The matrix 35 is arranged withits longitudinal axis coincident with the longitudinal axis'of the die rod so .thata movement of the slidableholder will move the recess 37 of the matrix into contacting relation with the vitreous tip'of the die rod.

For the purpose of forming the, vitreous tip to the shape of the matrix, a burner nozzle 51 is provided'to direct a fine needle-point flame 52 against the surface of the vitreous tip 33 to render it sutliciently plastic to take an impression.

The slidable holder 46 is actuated 1w move the.

matrix 35 by means of ahand-lever 53 having a slot 54 to receive-a'pivot pin 55 provided in a.

projection 56 integral with the slidable holder. The lever 53 is pivoted at 5'7 and is provided with a link 58 pivotally attached at 59 to one .end'

of a valve arm 61 of a valve 62 controllingpthe While the arm 53.is in its retracted or initial position the link 58 operates to direct the needle flame 52 against the vitreous die blank. As the arm 53 is moved to advance the matrix the valve 62 is closed to remove the flame and as the matrix advances, to the position shown in dotted lines the softened end'of the die.

blank is impressed with the die formation.

It will be understood that the flame 52 may not be entirely'extinguished but lowered'to a mere pilot light so that when the, lever arm 53 returns "the matrix, the flame may then issue from the nozzle 51 ready to heat another positioned die blank.

The bearing bracket 44 is provided with an.

adjustable stop 63 so arranged as to terminate the advance movement of the slidable holder and thus form the effective die face in a 'predeten mined position as indicated by the arrows X with respectto the set-screw 21'. Thus when a die has been used and has worn or does not give the proper winding, the die rod 17 may be inserted in the sleeve 18 and the end softened and a new die formedimmediately.

It will be understood that although anew die rod mayibe employed having a new tip, it

is, in many cases, only necessary to reheat the end of the vitreous tip having the die formation to renew the die form. Inasmuch as the die is made in exactly the position that it'is used 'removedg 'as-shownin Fig-4 thelrecess' 37 and the new die'may bereadily set up in the machine ,without further "adjustment since it occupies the exact position of -the die-previously employed.

It desirable to make the matrix 35 froma die which is actually used to wind coils to a given rating data as. for example a die; may beimade V of steel or other hard material arid'placed in a machine to wind coils and adjusted and ground,

: amuntil itxis exactly right for the windingof-coiledfilaments for a given wattage. Th s die which in-Figs'. 3 and $4 ,is designated by the numeral 64 is then forced into contact with one end of the matrix rod 35- until an impressionis made as'shown in Fig. 3. When the die 64 is the fin'38 has been formedand the matrix35is ready to be positioned in a slidable holder 46 for movement into contact withthe softenedend of the die blank.

When forming the die by a movement of the matrix toward the die blank it may be preferableto heat the matrix and for this purpose a burner 65 is provided.

It will be understood that the said burner may be operated toclose' off as the slidable holder advances or it may be a continuous flame of rel-.

1 atively low temperature to maintain the matrix heated so as not to chill the die under formation.

It will also be understood that if desirable the flame 52 may, after, the die blank has been formed, operate to'supply only sufficientheat to anneal the formed die.

As hereinbefore set forth, coil-winding diesmu st. obviously be produced of different dimensions for'the manufacture of filaments for lamps no a definite color has beenassigned to a lamp of a given wattage. the selection of the proper die is facilitated and a considerable amount of time is saved. i

By reason of the present invention a mandrelless'coil-winding machine may be operated continuously, and in the event that a new die is required the same may be produced without an appreciable amount of delay.

. Fig. 9 shows a perspective view on anenlarged scale of a coil-winding die such as employed in connection withthe present invention and itwill I be noted that this die includes a lip 41 and a cavity 39. The .wire 16 is driven into the cavity and issues in theform of a series of convolutions in l the form of 1a helix, the :turns of which are separated by the lip 41 which determines the pitch. ,It will be appreciated that inasmuch as the entire action with respect to the wire and the die is a sliding or frictional engagement, it is desirable in order to avoid wear to provide a die with an extremely smooth effective surface.

When employingavitreous materialsuch as glass 40 or enamel composition, it is possible to provide an effective winding surface having an unbroken layer or skin and when using fusible material the skin orsurface layer is extremely hard and wear resistant. Heretofore in the manufacture of a diamond die for example, a reasonably smooth surface was attainable but owing to the grinding operation the. cross-graining of the material becameexposed and ofiered acertain amount of frictional opposition to the passage of the wire ,thereover and caused wear. 1

5, in thee csse. of; a which. is ground,

tiles-same: result would occungiVV-hen formin a metailicdieby pressureit is not possible to get the -glazed smooth layer since the surface of the metal :is comparativelyirrough and remains.- so

whether the, die is formed by pressure orfby' grinding. I When forming a 'die; :for the present purpose of avitreous material a new. article a is produced in that itjprovides a boil-bending; elemerit havingthe desirable continuous glazed or v slippery surface giving the desirable wear-reproperty whioh,;-.in conjunction with the fact-Tttmt the said dies may be madeat a more rapidrrate thandies heretofore produced; makes the present invention -,a decided advance step mthe art of coilwinding'i- I i 1. Adie for helically winding comprising a rod having one 'end tipped with vitreous material having a coiling-winding cavity..

Although a preferred embodiment of the invention is shown and described herefm it is to be understood that; modificationsmay be made therein without -,depa,rting (from the spirit and scope of the invention as set -f orth .in the appended claims. 7 I

What-is claimed is: 7 I Y lamp filaments

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