US1282051A - Manufacture of commutators. - Google Patents

Description

` A. E. DOMAN. MANUFACTURE 0F COM'MUTATORS. APPLICATION'HLED Dc.26'. i916.

Patented Oct. 22, 1918.

UNITED sTATEs PATENT oEiaIoE.

ALBERT E. DOMAN, OE ELBRIDGE, NEW YORK, AssIGNoR, BY MEsNE ASSIGNMENTS, TO DYNETO ELECTRIC CORPORATION, OE sYRACUsE, NEW YORK, A CORPORATION 0F NEW YORK.

MANUFACTURE OF COMMUTATORS.

To all whom t may concern:

Be it known that I, ALBERT E. DOMAN, a citizen of the United States of America, and resident of Elbridge, in the county of Onondaga, in the State of New York, havey which the bars or segments thereof are made. I The primary object of the invention is to' reduce the expense of raw materials, as copper, and the cost of manufacture b forming the raw materials preferably in ong, cold drawn strips tapered laterally from a central portion or formed with a double bevel so that the bars, with suitable integral tangs,

may be punched from the strips with butslight waste of material, the angle or bevel of the strip being of such degree as to correspond with a required angle when a predetermined 'number of bars or segments are to be nested together to form a complete cylinder. y

Other objects and advantages will appear from the following description taken in connection with the accompanying drawings, in which* Figure l is a view of the blank of this invention from which the commutator bars or segments may be punched.

Fig. 2' is a top plan view ofthe blank, the shape of the bars and the method of punchin` being indicated.

ig. 3 is a view of a complete bar or seg ment.

Fig. 4 is a cross section of a commutator as constructed from such segments.

The invention, as shown, comprises the blank -1- which inay preferably be a relatively long, cold drawn strip of suitable material, as copper, having a central substan-- tially plane horizontal portion -2- with side portions -3- and -4- tapered or beveled in opposite directions therefrom. Both sides of the blank are symmetricalV and of'the same conformation. f

The side portions -3- and -4- are disposed at the same angle relatively to the portion -1- and are of equal width, the angle of disposition of the outwardly converging Specification of Letters Patent.

Application illed December 26, 1916. Serial No. 138,971.

Patented Oct. 22, 1918.

portion -3 or the outwardly converging portion -4- being of such a degree as is required in the manufacture of a complete cylinder from a predetermined number of similarly shaped nested bars or segments. With a commutator constructed of thirtythree bars or segments as here illustrated, the angle of disposition of the outwardly converging side portions -4- or the ou'twardly converging side portions -3- is approximately 10, 51', 32, the angle of dispositionof each beveled portion -4- or each beveled portion 3- and the central the angle last described. The angular disposition will, of course, vary in accordance with the number of segments to be used in forming a complete cylinder.

The strip -1- is of a width equal to the complete width of the commutator bar 5-- including the tang -G for electrical con- -7- of the commutator bar adapted to form the cylindrical portion of the commutator.

From the strip -lw commutator bars -5- can be punched or cut with a minimum Waste of material and with a minimum cost of production in the manner shown in Fig. 2. The bar is punched along lines 8, 9 and 10, the line 8 extending from one side of the bar to the central portion of the bar, said line being spaced from the adjacent end of the strip -1- a distance equal to the desired wldth of tang The line 9 extends from the inner terminationV of line 8 longitudinally and centrally of the strip.

'shaped member 1l-'adapted to receive suitable, usual and well known means, as ring members, for holding the segments in nested position in the completed commutator. These portions -13- and 14- which are cut out to form the wedge-shaped member -11- are Athe only waste material in constructing the commutator bars.

In order to form the second commutator ,.'portio'n fbeing approximately one-half ,nections and is twice theA width of the body equal in wid-th to the radial length of a com' mutator bar and equal in length to the complete Width of a commutator bar plus the width of one tang.

The bars, as shown, may be mounted upon a suitable sleeve or core l5- and may be held in assembled position upon the sleeve in any suitable and usual manner.

Although I have shown and described one particular construction and exact method as constituting a preferred embodiment of this invention, 1t will be apparent that changes and alterations may be made in the exact form of the commutatorvbar and the exact method of punching the same Without departing from the spirit ot this invention as set forth in the appended claims.

Whatl claim isz- 1. The method of manufacturing commutator bars consisting in forming suitable material into a relatively thin Wide strip tapering from a central portion toward opposite edges, cutting the bar at substantial right angles to its length from a .predetermined edge to substantially the central portion of the bar and along a line located at a distance from the end of the bar substantially equal to the Width of the tang of the commutator bar to be produced, cutting the bar longitudinally along its central portion a distance equal to the Width of the commutator bar to be produced less the width of the said tang, cutting the bar at right angles to its length from the termination of the said central longitudinal cut Ito the ed e opposite the predetermined edge first re. erred' to, cuttin the bar at right angles to its length an throughout Its entlre Wldth at a distance from the last-named cut substanfirst referred to, cutting the bar at rig tially equal to the width of the tang of the commutator bar to be produced, removing spaced wedge-shaped portions from the opposite edges of said strip at corners adjacent the respective cuts described to form keystone shaped parts at the opposite edges, said parts tapering in thickness toward their longitudinally Wider portions.

2. The method of manufacturing commutator bars consisting in forming suitable material into a relatively thin wide strip havin .a central lane portion with opposite si es substantia ly parallel and opposite side portions having tieir opposite walls convergin outwardly, cutting the bar at substantia ly right angles to its length from a predetermined edge to substantially the central portion of the bar and along a line located at a distance from the end of the bar substantially equal to the Width of the tang of the commutator bar to be produced, cut- `ting the bar longitudinally along its central portion a distance equal to the width of the commutator bar to be produced less thc width of the said tang, cutting the bar at right anglesto its length from the termination of the said centrallongitudinal cut to the edge opposite the predetermined edge it angles to its length and throughout its cntire width at a distance from the last named cut substantially equal to the Width of the.

tang of the commutator bar to be produced, removing Ispaced wedge-shaped portions from the opposite edges of said strip at corners adjacent the respective vcuts dcscribed to form keystone shaped parts at thel opposite ed es, said parts tapering in thickness towar their longitudinally Wider portions.

In witness whereof I have hereunto se: my hand this 20th day of December, 1916.

ALBERT E. DOMAN.

Witnesses:

WILLIAM Mm'rzaorH, AUSTIN M. CATELY.

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