US1808750A - Commutator - Google Patents

Description

June 9, 1931. v. G. APPLE ET AL 1,808,750

' COMMUTATOR Filed Oct. 16. 1929 3 Sheets-Sheet 1 I II Il. Il I Il. Il. Il. IIII Il. Il. Il...

20 5 m I. 25 a June 9, 1931. v. G. APPLE ETAL COMMUTATOR 3 Sheets-Sheet 2 Fil ed Oct. 16. 1929 Patented June 9, 1931 UNITED STATES PATENT OFFICE VINCENT G. APPLE AND WALTER M. DOEHRING, OF DAYTON, H10; SAID DOEHRENG ASSIGNOR TO SAID APPLE COMMUTAIOR Application flled October 16, 1929. Seral No. 400,121.

This invention relates to that class of commutators wherein a plurality of spaced apart segments of conductive material are held in place by a core of insulation molded in s1tu about them.

An object of the invention is to decrease the labor involved in the making of such a commutator.

Another object is to make suoh a commutator from a minimum of material.

Another object is of the commutator. V

Another object is to provide a structure of increased adaptability to the purpose for which it is intended.

These objects are attained by the procedure and the resulting structure which is described in the following specification and shown in the accompanying drawings where- 1n- Fig. 1 is a plan view of a sheet metal stamping which has been divided into a number of commutator segments, integral parts of the stamping serving as tics t0 still hold the segments together for the ti me being.

Fig. 2 is an edge view of Fig. 1.

Fig. 3 is an enlarged fragment cf Fig. 2 taken at 33 of Fig. 1 adapted to more clearly show the integral tics which temporarily hold the segments together.

Fig. 4 is a perspective view of the commutator structure after the first bending operation has been performed on the blank Fig. 1.

Fig. 5 is a perspective view of the commutator ring made by bending the structure Fig. 4 to cylindrical form.

to improve the quality Fig. 6 shows the commutator ring after the prongs at the end of the ring are bent radially inward and downward to form anchors for holding the segments in a cors of insulation.

Fig. 7 shows an end protecting plate for the commutator.

Fig. 8 is an axial section through a mold Within which the plate Fig. 7 and the ring Fig. 6 are held While a core of plastic moldable insulation are pressed' between and about them.

formed when the Fig. 9 (Sheet 3) is a partial transverse section taken at 9-9 of Fig. 8.

Fig. 10 is a partial transverse section through the commutator after removal from the mold.

Fig. 11 is a perspective view of the completed commutator after the tics which held the segments together have been removed.

Fig. 12 is an axial section through the finished .commutator showing the manner of its connection to that type of armature to which it is particularly adapted.

Fig. 13 is a transverse section taken at 1313 of Fig. 12.

Fig. 14 shows the commutator after it is connected to the armature and the risers have been bent down against the Winding.

Fig. 15 shows a mold for forming a jacket of insulation about the commutator risers and the armature winding t0 tic the tWo togethei.

Fig. 16 shows the commutator embodied in an armature.

Similar numerals refer to similar parts throughout the several views.

The toothed metal blank 20, shown in Figs. 1, 2, and 3, is preferably stamped at a single operation from sheet stock, although it may be advantageously produced by continuous operation from a roll of ribbon stock on an automatic press or similar machine, one tooth at a time. The number of divisions in the blank is the number of segments in the commutator, the prongs 21 at the one end being adapted to be formed into hooks or anchors to hold the segments to the core, the separated parts 22 at the other end being destined t0 compose the segment risers and the middle parts 23 being intended eventuafly to be entirely separated into the commutator segments. The lead wire notches 24, common to segment risers, are out in the ends as.

shown.

But in order to hold all of the segments of a commutator together in a single stamping, so that they may be readily handled and quickly o erated on, the middle parts 23 are not comp etely separated one from another, but are held together by bridges 25, which are integral parts of the original sheet metal,

grooves 26, which are inthe risers 22 extending radially therefrom,

after which ithas the prongs 21 formed radially inward and downward to compose the anchors 28 as shown in the sectional view Fig. 6. The integral bridges 25, at this stage,

still connect all of the segments 23 together,

except of course at 29, where the ends of the blank came together when it was-formed into a cylinder. The finished commutator cylinder is broadly designated by the numeral 30.

The end protecting plate 31, Fig. 7 is preferably made of sheet metal, and perf0rated as at 32 and 33. The perforation 32 is intended t0 admit the armature shaft, while the perforations 33 one of larger diameter on one side of the.plate than on the other, this adapting them to serve as tie holes into which the core of insulation may entend as it is being mOlded, to bind the core and the plate together.

A commutator cylinder 30 and a plate 31 being now available, they are placed. together in the mold as in Fig. 8, the plate 31 on the bottom of the mold With its tie holes 33 having their large side down, and the cylinder 30 held against axial movement in the mold by the risers 22.

The mold 35 has a base 36 centrally perforated for the stud 37 and counterbored at 38 t0 concentrically support the mold body. The body 40 has an annular rib 41 extending into the counterbored portion 38, and a central aperture 42 to receive a commutator ring 30. This central aperture 42 is not bored smooth but is grooved lengthwise as at 44 on its inner diameter to receive the bridges 25 of the ring. A stock ring 43 is secured to body 40 by bolts 45 and nuts 46. The underside of this stock ring is radially grooved at 34 to admit and clamp the risers 22, each in its proper place. A plunger 47, slidable fit? ted to stock ring 43 completes the mold.

With the base 36, the stud 37 and the body 40 together, a plate 31 is laid in the bottom and a cylinder 30 inserted, then the stock ring 43 is put on and secured by nuts 46. The mold, the plate and the cylinder together With the plunger 47, which is preferably not yet inserted, are now heated to a relatively high temperature, whereupon a quantity of unmolded insulation is placed into the stock ring 43, the plunger 47 is inserted and the insulation is compressedaround the stud 37, into the plate holes 33, about the anchors 28, outwardly into the grooves 26 between the segments to form the core 48 which binds the entire structure together.

After the core 48 becomes sufliciently hard the structure is removed from the mold.

The sectional view Fig. 10 shows how the integral bridges 25 still span the grooves 26 into which the core 48 has extended to join the segments 42 one to another.

The structure is now placed on an arbor, or is otherwise' concentrically supported, and a out of such depth is taken o of the outside diameter as will bring it to a smooth round surface and remove the bridges 25 thereby separating the segments one from another. The completed eommutator 49 is shown in Fig. 11 with the several segments 42 imbedded in the core 48 and the plate 31 secured to the end.

From Fig. 11 it Will be seen that the risers 22 are of greater height than generally employed in conventional commutators, and it is this increased height that adapte this commutator to the particular armature herein shown, and at the same time acilitates making the electrical connection between the risers and the armature coil leads.

Fig. 12 is a sectional view through an armature ocre 50 which together With a commutator 49 has been placed upon a mandrel 51. and secured by the nut 52. The leads 53 from the coils 54 are brought out along the risers on the side adjacent the coils, entered into the notches 24, and soldered or otherwise electrically connected. Fig. l 3 shows how these leads all lie along the risers 22, and since the leads and risers may be electrically conneted at points which lie radially beyond the armature diameter, soldering them together is facilitated because the outer ends may be dipped into molten solder withot danger of damage to the coils.

When all of the leads are laid along the sides of the risers and electrically joined thereto a layer of tape 55 may'be laid over coils 54 and the risers 22 bent down upon the coils to completely cover the leads With the tape therebetween, thus forming the structure 56, Fig. 14. The coils and the tape may now be impregnated With liquid insulation, or, if desired, the wire composing the coils and the tape may be saturated With liquid insulation before they are placed on the structure 56, but in either event the impregnated structure is baked or the liquid insulation therein otherwise hardened to make it thoroughly rigid, and, since the leads are all completely covered With the risers the structure is adequately prepared to Withstand the subsequent molding operation.

The structure 56 is now placed in the mold 57, Fig. 15 where the jacket 58 of plastic insulation is to be pressed about it. Mold 57 comprises the base 60, the body 61 and the hollow plunger 62. Base is bored at 63 to clear the nut 52 and counterbored at 65 to receive the comxnutator 49 and is held concentric with the body 61 by annular rib 66. Body 61 is bored smoothly at the lower end as at 67 t0 a diameter adapted to receive the commutator 49, next above this at 68 to a diameter sufliciently larger than the coils 54 to admit a layer of plastic insulation which is to form the jacket 58 around it, next above this to a smooth diameter Which Will admit the core 50 to the shoulder 70, and at the uper part to a smooth diameter 71 capable 0 receiving the plunger 62. Plan er 62 is boied at its lower end at 72 to orm the jacket around coils 54, and for the remainder of its length as at 73 to fit the mandrel 51.

In operation the Structure 56 is placed in the mold 57 with the core 50 reSt-ing on the shoulder 70. The assembled mold with structure 56 within it and the plunger 62 are then brought to a relatively high temperature until the temperature is uniformly distributed throughout the mass. A measured quantity of loose molding compound is then put in the opening 71 around the coil 54 and the Inandrel 51 and the plunger 62 is entered above the compound. Pressure from any suitable source is now applied to the top of the plunger 62 and maintained until the com ound absorbs sufiicient heat from the mol and its contents to render it fluid, whereupcn the applied pressure forces the plunger downward pressing the now fluid insulation downward around the upper end of the coil 54 downward through the outer parts of the winding slots 75 left vacant by the coils (sec Fig. 14), around the lower and of coil 54 surrounding and covering the bent over risers 22, forming the jacket 58 entirely around the winding, and providing in efiect a sleeve cf insulation which covers the the 4. The method of making a commutator comprising a cylinder of circumfsrentiaily spaced apart sheet metal segments and a core of insulation extending outwardiy between the segments, which consists of cutting a sheet metal blank as long as the commutator circumference, partly separating it into segments by pressing the material between the segments into a plane parallel to but beyond plane of the sheet without severing the displaced materiai from thesegments, bending the sheet into a cyiinder with the displaced material on the outside, molding a core o insulatin into the ciinder and into the spaces between the segments from which the metal was displaced, then cutting off the displaced material connecting the segments.

In testimon whereoi we afix our signaturcs. V

VINCENT G. APPLE. WALIER M. 'DOEHRIN risers, secures the inner ends of the seg ments against outwardmovement from centrifugal force and tics the commutator 49 to the structure 56. When the mold has been held -closed as in Fig. 15 for a suificient time to. permit ,the heat ofthe mold to harden the jacket 58 of insulation, the completed armature is removed and the mandrel 51 withdrawn whereupon the armature appears as at 76, Fi 16.

While we have herembef0re describe certain methods and tools which we may employ in placing the core of insulation 48 in the commutatcr, and the jacket of insulation 58 around the coils, it is not intended that the invention be confined to these methods of moldng these insulation masses, and where it is desred to use insulation of a different nature, which requires a difierent process in its application, such process may be employed within the spirit of the invention as defined in the following claims.

" W6 claim:

1. A commutator cylinder comprising a plurality of circumferentially spaoed apart segments connected by integral-bridges each bndge extending radmlly outward from one segment then circumferentially acros one

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