US272256A - houston - Google Patents

Description

(Nd-Model.) 2 Sheets-Sheet 1. E. J. HOUSTON.

DYNAMO BLEGTRIG MACHINE. No. 272,266. Patented Feb. 13,1883.

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2 N 0 m S U 0 H J E DYNAMO EILEGTRIG MAOHINE.

Patented Feb. 13, 1883.

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UNITED STATES PATENT Carte EDIVII J. HOUSTON, OE PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE AMERICAN ELECTRIC COMPANY, OF NEW BRITAIN, CONN.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 272,256, dated February 13, 1883.

Application filed December 5, 1881. (No model.)

To all whom it may concern:

Be it known that I, EDWIN J. HOUSTON, ot' the city and county of Philadelphia, State of Pennsylvania, have invented certain new and useful Improvements in Dynamo-Electric Machines, of which the following is such a de scription as will enablethose skilled in the art appertaining thereto to make and use the same, reterence being had to the accompanyi ngdrawings.

The objects of my invention are to secure greater ventilation by certain improvements in the construction of dynamo-electric ma chines, as Well as to so improve the connection of the. coils of the armature and the method of carrying off the currents at the connnutator, so as to greatly increase the electro-motive i'orceof thecnrrents generated in theniachine.

My invention relates especially, so far as the mode of connecting and carrying off the currents by the commutator are concerned, to ma chines of the Gramme and similar types, though it is to be understood that I do not limit myself to machines of this type, since I may, under certain circumstances, apply it as well to other types of machine.

In a practical system of electric lighting by the voltaic are it is desirable, both 011 the score of convenience and economy, that a considerable number of lights be placed at suitable intervals in breaks in one and the same circuit-that is to say, that all the lights, or as many of them as possible, be placed in series. There forty or more of these lights are placed in the same circuit a very high electroinotive force is required. One object of my invention is to readily obtain the requisite electro-motive force. I

It is well known to those skilled in the art that in the Gramme and similar types of machine a dlfficulty is experienced in readily obtaining a high electro-motive force. This is caused by the factthat the mode of connecting the coils placed on the armature and the manner in which such currents are carried off at the commutator are such that the current traverses the coils on the armature in multiple arc. This results, as is well known, in a lowering of the resistance of the armature-coils, and a consequent decrease in the electro-mo tive force of the current generated therein. I propose to socombine the armature-coils with suitable circuit-closing or commutator devices for completing the connection between the suc cessive coils as to cause the current generated in the armature-coils to pass through nearly all of said coils in series or for tension. By this means I obtain with the same length of wire a much higher electro-niotive force than is practicable by the ordinary method of connecting the coils permanently to one another in endless series and joining the points of connection to the cominutator-segments.

I will describe my invention first as it may be applied to a ring-armature wound with successive coils, as in the Gran'n'ne machine, butconnected and carried off in the manner that I will now explain.

In Fig. lis shown a sketch of theGamme ring mounted on a shaft, 8, so as to be capable of rotation between the poles N and S. If X X be taken as the neutral line, then a rotation of the ring in the direction of the large arrows R R will develop currents whose directions will be as indicated by the smaller arrows. Supposing the ring to be composed of separate coils, wrapped and connected in theusual manner,then brushes touching the sectionsofthecommutatorinpositionscorrespondingto B and A would be the positive and negative terminals of the circuit through the arma ture-that is to say, the current would start at A, pass through all the wire on the armature in multiple arc, and emergeat 13. According to my invention, however, the separate coils of the armature, instead of being connected ttb one anotherin series after the manner indicated in Fig. 1, (the outer end of each coil to the inner end of the next coil in succession proceeding in the direction of the arrows R R have their ends separately connected to the contact-points, terminals, or surfaces of suitable circuit-closing devices of such charactor as to complete the connection between the successive coils as they revolve in those portions of the field where current is getterated, but to leave the contiguous ends of successive coils disconnected at the neutral points. As a break is thus caused to existat or near the neutral points between the contignous coils, by suitably connecting those porl tions of the circuit-closing devices that are at the ends of each series ot' coils above and below the line passing through the neutral points, all the coils of the machine may be connected for tension, as will more clearly appear from the detailed description to be presently given. Under such a plan of connection there will obviously be twice as many to pieces, points, or strips in the circuit-closing device or connnutator as there are armaturecoils.

Fig. 2 illustrates diagrammatically the principle of my invention, and also indicates one method of carrying the same into practice. Fig. 3 is a perspective view of a portion of the circuit-closing device or commutator, and illustrates one of the constructions that may be employed.

Referring to Fi 1, a a a, &c., are supposed to representseparate commutator-plates, strips, pieces, segments, or surfaces, which are mounted on a c tinder, and insulated from one another thereupon by any suitable means known in the art. As indicated in Fi 3, they ate blocks of metal let into the edge of a disk or cylinder of insulating material mounted on the armature-shaft s, and separated from one another by the material of said disk.

0 O O (J 0 &c., indicate the twelve separate bobbins of a Gramme ring, the terminals of which are connected separately to the plates at a (L (t, 830., in the manner indicated, while said plates are spaced, as shown, so that those 5 plates to which the inner end of one bobbin and the outer end of the next successive bobbin are connected are nearertogether than the two plates to which the inner and outer ends of any one bobbin are connected. The object of thus spacing the. plates,pieces, or segments will be presently seen. The distances between the plates and the length of said plates is not material, provided the objects to be attained are secured. A series of commutator circuit- 5 closing plates, springs, or brushes, m mm, &c., are applied to bear upon the plates a a a, &c., in such a way as to complete the connection between the inner and outer ends of the successive bobbins, G 0 C 850. These springs, plates, or brushes tnay consist of a series ol plates or springs mounted on any suitable sup- )Ol'l', and insulated from one another in any suitable manner, asindicated in Fig. 3. Each plate or brush in is of suflicient width to completethe connection between each pairof strips a to which the outer end of one bobbin and the inner end of the next contiguous bobbin in succession are connected, proceeding in the direction ot'the arrow T; but no brush m should be sufficiently uide to bridge the longer insulating-spaces between the two plates or strips a a to which the two ends of the same bobbin are connected, excepting at the terminals of the series of brushes or springs, as will be presently described, for the obvious reason that such connection would shortcircuit the curreutgenerated in such bobbin. Two series of brushes on opposite sides of the plates a a, 850., are employed, in order that there shall be no rupture of connection between the pairs of nearer plates at as the edge of a brush passes the insulating-space; and for this purpose the brushes on opposite sides should be made to break joint with one another, as indicated, a brush on one side bridging the joint between two brushes on the opposite side. As will be obvious, the width of each brush should be slightly greater than twice the width of the shorter insulating-space, in order that as a brush on one side is about to break connection between the pair of nearer plates a. a the overlapping brush on the opposite side shall have ad anced suffi iently far to complete the conportion, and thus preserve the continuity oi the connection.

In the above description it is assumed that the brushes move; but the principle is obviously the same as when the brushes are stationary and the plates a a, &c., move. With twelve coils, as indicated, the necessary conditions, as above explained, will be answered it each plate a cover six degrees of the circumference, each longer insulating-space tit'teen degrees, each shorter insulating space three degrees, and each spring at nine degrees. These figures may be varied within the limits above prescribed. If the brushes m were extended around the entire circumference of the cylinder, the twelve bobbins would obviously be connected in endless series at all times during the revolution of the armature. In order, however. to provide for collecting the currents separately from the bobbins on the two halvesot' the armature above and below the neutral line X X, the plates at m are discontinued at and near this line, and provision made for preserving a connection with the same ends of the bobbins in succession as they approach or leave this line, so as to get a continuouscurrentfrom the bobbinson both halves of the armature. This provision consists, in substance, in widening the terminal brushes an of each set above and below the neutral line to a sutiicient extent to preserve a connection between each pair of plates separated by the longer insulating-spaces, and thus in effect, through the shorter brushes m or, contiguous to the widened brush, keep up a constant connection with the same ends of the successive bobbins, so as to pr vent a break in the current collected. The t'ollectingbrush to be thus formed may be made up of a single brush m, sutticiently widened, or of two overlapping brushes m on opposite sides of the commutator-cylinder electrically connect I ed, one of said brushes being sut'ficiently widened to give to the two combined the requisite collecting width. The latter is the plan here indicated. Thus brush P and the overlapping brush m, to which it is electrically connected by a wire, as indicated, or by any other suitable means, cover sufficient space on the cylinder to bridge the longer insulating-spaces. 1f the coils revolve in the direction of the larger arrow and the currents circulate in the coils the line X X are indicated at l m and N m.

in the direction of the dotted arrows Kit is obvious that in order to obtain a continuous current from a collecting-brush. as P m, connection must be preserved by said brush with the outer endsot'thesuccessivebobbinsabovetheneutral line,connectionwithoncbeingmadebeforecounection with theprecedingone is broken. Th s is accomplished by making the brush sufficiently wide t itself be always in connection either with a plate, a, connected to a forward or outerend ot a oobliin ora 'ilateconnected to the rear or inner end of a bobbin. So long as it is in connection with the forward end of one bobbin-say C it is obviously in condition to collectthe current from the whole series of bobbins C C G U 0 G while it it make connection with the plate a connected to inner end of 0 before it breaks connection with the outer end, it is inconditiou to still collect the current from the bobbins above the neutral line, it being then in connection with the outer end of the bobbin through the plate a connected to the inner end of G the contiguous brush or brushes m, which preserve the connection between said plate a and the plate connected to the forward or outer end of C and through said latter plate with C- and the whole series of bobbins between C and the-collecting-brush at the other terminal ot' the series of brushes in above the neutral line. Under the conditions above supposed, in which the longer insulating-spaces are equal to fifteen degiees, it is sutticient to make the combined width of P and on equal to seventeen degrees. This is accomplished by adding three and one-half degrees to the width of a brush, m, to make brush P (which is the proportion indicated in the drawings,) and connecting it with the opposite overlapping brush, which is here supposed to overlap four and one-half degrees, or by simply adding to one brush-as, for instance, to the inner terminal brush-eight degrees in width. In order to allow the current to be taken from the two halves of the armature above and below the neutral line X X independently, it is obvious that at and near that line the bobbins for the time being above and below the same shall not becounected. For this purpose the ends of the two terminal collecting brushes contiguous to one another and above and below tire line should be separated by a space greater than that embraced by any pair of contiguous plates to a connected to the outer and inner endsot' the same coil and the longer insulating-space between the two plates of the pair. As the space thus covered is equal to 6+6+l5=27 degrees, the arc embraced between points (1 (1 should be greaterthan twentyseven degrees when thelengthsof the conductingand non-conducting spaces are those above given. At the opposite end of the series of brushes m,above line X X,a collecting-brush, N m, is indicated, in all substantial respects similar to P m.

The collecting-brushes for the series at below With the directioli of current in the armaturebobhins indicated by the dotted arrows W, brushes P m and P m will both collect current ot'thesamepolarity-saypositive-and thetwo other brushes, N m and N m, current of the opposite polarity. Under such conditions all that is necessary in order to take all the useful current generated in the machine for tension or high electro motive force is to connect brush P m with brush N m, as indicated, and to make the brushes P m and N m respectively the positive and negative terminals of the armature-circuit,and connect them, as usual,one to the field-of-t'orce bobbins and the other to a working circuit, or to utilize the current in any othersuitable manner. Theeircuitot' the armature coils, starting from brush N m, is then, through the series of coils for the time being above the neutral line X X to brush P m to brush N m, through the series of coils for the time being below the neutral line, and out at brush P m.

I have described my invention in connection with armatures of the Gramme type only; but it will be understood that it is also applicable to any form of armature in which all or nearly all the coils on the armature are generating useful current at the same time, and in which the coils on each side of the armature can be connected in separate series. In constructing the armature I may employ a ring or a cylinder and wind it with separatccoilsof insulated wire in any of the ways well known in the art. The ring or cylinder may be continuous, or may be constructed ot'separate piecesinsulated from one another and suitably mounted on a spiderframe, in the manner described in my application for improvements in dynamo-electric ma chines filed October 21, 1881, or in any other suitable manner.

I have described the position of the brushes that effect the connection in one series of the coils on each side of the neutral line as being at the ends of the cylindrical armature; but. it will be understood that this is only one of the means that may be employed for the purpose of carrying out that part of my invention that relates to the connection of the coils on each side of the neutral linein one series. It is uuessential what particular arrangements of parts are employed for this purpose, or what particular mechanical constructions are used for completing the circuit between the ends of contiguous bobbins as the armature revolves. Other means besides those herein shown may be employed without departing from the spirit of the invention, and many other devices will readily suggest themselves to those skilled in the art. 1 therefore wish it to be understood that my invention consists broadly in bringing the contiguous ends of adjoining bobbins to the separateinsulatedplates,contacts,orpoints of a circuit-closing apparatus, and in completing the circuit between the free termiualsor contiguous ends by suitable means as the armature revolves, the construction being such ICC that at or near the neutral points where the circuit-closing apparatus does not act the circuit between the contiguous bobbins is left open.

The armature, constructed and connected as bel'ore described, is mounted on suitable bearings, so as to he capable of rotation between the pole-pieces ot' the field-magnets. I may employ for this purpose pole-pieces of any convenient shape that are suitably arranged for use with this character of armature. When the machine is designed to furnish powerful currents of very high electro-motive force, I sometimes prefer to employ the magnet-frame shown in connection with Fig. et. To the base plate T T, of any suitable material, are attached the heavy uprights D D and D D, of cast-iron. To these uprights are securely fastened, by bolts or otherwise, the field-magnets M M M M M M. The coils of insulated wire on the magnets are wound so as to produce the poles N N N N N N and S S, 8%., as shown-that is to say, the polarity of the magnets that face each other end to end is the same. The magnets are provided with curved pole pieces N N and S S, 850., shaped to conform to the circular outline of the armature that revolves between them. Spaces 0 0 O are left between the Opposite pole-pieces, so as to provide for the proper ventilation of the armature. This end is also secured by the spaces left between the contiguous magnet-coils. Spaces 0, O in the sides D D and D D still further aid ventilation. For the same purpose openings are provided at 0 0 0', extending from the plates D D and D D, through the cores oi the lieldmagnets, to any suitable portion of the inner suriaces ot' the pole-pieces N N and S S. Openings O O,&c.,arealsoprovided,extendingvertic-ally downward completely through the polepieces. These openings are shown cutting the former at right angles. Besides the advantages secured by this construction of the fieldmagnets in thoroughly ventilating the armature, it affords ease in the construction of very large machines from the aid aii'orded in handling and winding the separate coils of the fieldmagnets, and also aids considerably in effecting a more thorough insulation of the coils a thing very necessary in machines developing currents of very high electro-inotivc force.

What 1 claim as my invention is-- 1. The combination, substantially as described, with anarmature provided with a series Oflll(lt1')6ll(i6llt bobbins or helices, each having two free ends, of circuit-closing devices for completing the circuit as the armature revolves between the positive and negative tree ends of contiguous helices, said circuit-closing devices being applied in the manner described, so as to complete the circuit only between these bobbins which are passing from one neutral point to the other, thus leaving the terminals of the bobbins, which are for the time being at the latter points, disconnected.

2. The combination, with the coils orhelices of a ring-armature, ot a commutator provided with independent pairs of insulated strips or pieces, circuit-connections from each pair to the opposite ends of contiguous helices upon the armature, independent insulated circuitclosing plates or springs, arranged, as described, so as close the circuit between each pair ot'insulated cominutator-strips, and an extended terminal collecting plate, brush, or spring, as and for the purpose described.

3. The combination, with the bobbins of a ring-armature, ot' a cominutator-cylinder provided with independent pairs of insulated strips or pieces, arranged as described, circuitconnections from each pair to the opposite ends of contiguous bobbins, two sets of insulated circuitclosing plates or springs upon ear-h side of the neutral line,for closing the circuit between the opposite ends of contiguous bobbins as the armaturerevolves, and terminal collecting plates or brushes, arranged as described, to preserve a connection with the same ends of successivebobbins.

4. The combination, substantially as described, of a series oi" armature helices or bobbins, separate insulated commutator strips or pieces,arrangcd in pairs. as described, with the space between the two strips of any one pair less than that between the contiguous strips of adjoining pairs, independent electrical connections from the. strips of each pair to the opposite ends of contiguous helices, and circuit-closingplates,brushes,orspringsadapted to connect the' strips of each pair, but to leave the connection between the contiguous strips of a joining pairs constantly open.

The combination, substantially as dc scribed, ot' a commutator cylinder provided with separate insulated strips or pieces, arranged in pairs, as described, with the space between the strips of each pair less than the space between independent pairs, and two sets of circuit-closing springs, brushes, or plates for closing the circuit between each pair of strips, said springs orplatcs being arranged, as described, with the plates of one set breaking joint with the plates or springs of the other set.

6. The combinatitm, substantially as described, ot' a connnutator cylinder provided with pairsot'insulated platesorstrips, arranged as, described, a set of insulated circuit-closing springs, brushes, or plates bearing upon the cylinder and adapted to close the circuit between each pair of plates, but to leave the circuit open between contiguous pairs, and an extended terminal connecting plate or spring, as and for the purpose described.

7.,The combination, with a series of armature helices or bobbins, of separate insulated commutator strips or pieces, to which the ends of the helices are separately connected, said strips or pieces being spaced, as described, so that the space occupied by the strips or pieces to which the ends of any one helix are connected is greater than that occupied by the cured, and the series of field-magnets, bolted to the vertical plates and separated from one another by free air-spaces, substantially as and for the purpose described.

10. The combination, substantially as de scribed, of the hollow field-of-force magnetcores and the pole-pieces or extensions, provided with openings extending therethrough at right angles to the hollow cores.

EDWIN J. HOUSTON.

Witnesses:

GEO. I. 1110111 1, GEORGE STUART.

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