US385943A - Commutator for dynamo-electric machines - Google Patents

Description

(No Model.)

F. B..MITCHEL-L. GOMMUTATOE FOR DYNAMO ELECTRIC MACHINES. N0. 385,943.

Patented July 10, 1888.

UNITED STATES PATENT- (demote.

FRANK B. MITCHELL, OF COLUMBUS, OHI O.

COMMU l'ATOR FOR DYNAMO-ELECTRlC MACHlNES.

SPECIFICATION forming part of Letters Patent No. 385,943, dated July 10, 1888.

- Application filed July 15, 1897. Serial No. 244.373. (X model.)

Dynamo-Machines, of which the following is a specification.

My invention relates particularly to that of electrical connections with the remainder of the circuit duringa portion of each revolution.

- shaft of an electrical machine n any wellkind of commutator in which. the segments are so arranged that'thc several bobbins of the an I mature to which they are connected are cut out JEhe object of my invention is to greatly reduceflie weightandscost of the commutator and increase its insulating and its circuit making and breaking efficiencymnd provide means which greatly facilitate mounting all or any of ture-wires. 1

The improvement .consists, mainly, in constructing the hub of thecom utator of hard wood with insulatiuglsegincn'ts and conductin -segmcnts secured thereto, in making the in mating-segments of glass, in, covering the conducting'wires'with a nou-conducting tubing and securing them in grooves or pockets formed in the hub, and in providing the conductin -u' i res with an enlarged head and clamp, and connecting the inner endef said conduit ing-wire ti'ith a conducting plate oi! the armature, and clamping the outer end hf the said c'ondudlinguvire with the armature-wire, as will hrlreinalter appear. 3

In tie accompanying drawings, Figure 1 is a side elcnation of my improved commutator; Fig. 2, an elevation of the commutator broken away to show one of the o imecting-wires in elevation; Fig. 8, a scctional'clevation of the the parts and conncctinglthe m to the armaparts shown in Fig. 2; l, an end elevation of the commutator; Fig.5, an elevation, partly in section, of the conducting-wires; and Fig. (5 a perspective of one of the filling strips.

The'conunutator-core A is. fitted upon the known or preferred manner, and consists of a cylindrical block of hard wood having itspcriphery longitudinally grooved at a to receive the conducting-wires B, which, are preferably of copper with an enlarged head, Z), screw threaded at b and split in four quarters at b to receive the armature-wire C. A nut, 5*, is fitted 'upon the screw-threadedportions bof the conducting-wire and serves toelanilp; the jaws of the conducting-wire upon the wire. insulating-jacket, If, of suitable noncondueting material, and has an elbow, bi atits inner end,which passesthr'ough an innerring, D,'and

is securely united to or terminates against an The conducting-wire is covered with an outer segment, E, of copper, over which the brushes of the electrical machine pass to complete the circuit through the said conductingwires and armature-wires.- Filling-strips F, that may be dovetailethare fitted over the conducting-wires B and grooves a in the core A, and are held in place by the inner rings, D, which surround the core.

The cutting-out or insulating segments G of the commutator are made of glass secured to the core'A, and are diagonally grooved in a well k nown-,manner, or have small cavities (Z to receive oil to prevent cutting between the contact-brushes and the insulating segments and for the dispersion of heat.

The commutator (jOilStllilCtCll, as above .described,with a wooden core, is found in practice to work better than a commutator made mainly of metal, theprincipal advantages pos- So sessed by wood being its insulating properties and its lightness.

The insulating-segments G of the commutator being made of glass are light and extremely hard and are not liable to be grooved by the commutatorbrushes, and as glass is a non-conrial are not liable to burn out or carry off the 5 currents through irregular channels,

The co m inutator may be constructed atsmall cost, and being light is easily handled, and should any of its connections become impaired or severed they may-be quickly andrea'dily re Y paired and its insulations examined and'kept the core A, having groovesa and the conductperfect. 3 ing and insulating plates, of the conducting- 20 Although the core A above mentioned is derods B, fitted within saidgrooves, and fillingscribed as formed of wo0d,'the entirecore may strips F, adapted tocover said grooves and 5 be formed of glass, in which case the glass may rods,'substantially as described. be blown about the wires and the glass seg 3. In a commutator, the eombinatiom; with ments above referred to formed with the core..- the core A, grooved at a, of the conducting-rod 2 5- I claim as my inventionand desire to secure B, having a clamping outer end and an elbow by Letters Patentupon its inner end and a conducting-plate se- IO 1. In a commutator for electrical machines, cured to said-elbow, and a cylindrical insulatthe combination of the wooden core A, having ing-jacket inclosing said elbow and rod,vsnbsegments removed therefroxmth'e conductors stantially as described, for the purpose speoio 1% and the filling-strips F, the inner ring, D; fied. t econdncting-segmentsEupon said rings,and s y :5 theinsulating-segmentshavingcavitiesdthele B LL in,'substantiall-y as .and for the purpose d'e- Attest: i f scribed. G. R. GILMORE,

2 In acommutator, the combination, with g \V. S. SHEPHERD.

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