US384117A - Governor for electric motors - Google Patents

Description

(No Model.) l 5 sheets-sheet 1 W. BAXTER, Jr. GOVERNOR EUR ELECTRIC MOTORS.

No. 884,117. Patented June 5, 1888.

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(No Model.) 5 sheets-sheet 2. W. BAXTER, J1". GOVERNOR EOE ELECTRIC MOTORS.

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(No Mode1.) 5 Sheets-Sheet 3. W. BAXTER, Jr,

GOVERNOR EOE ELECTRIC MTORS.

No. 384,117. Patented June 5, 1888.

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(No Model.) 5 Sheets-Sheet 4. W. BAXTER, J1. GOVBRNGR FOR ELECTRIC MOTORS.

No. 384,117. Patented June 5, 1888.

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UNITED STATES PATENT OEEicE.

VILLAM BAXTER, JR., OF EALTHIORE COUNTY, ASSIGNOR TO THE BAXTER ELEOTHO MANUFACTURING AND MOTOR COMPANY, OE BALTMORE,

lli ARY E A ND.

GOVERNOR FOR ELCTRlO MOTORS.

SPECIFICATXON forming part of Letters Patent No. 384,117, dated June 5, 1898.

,inplannen nieu August 2o, teer.

To @ZZ wtont it may Concern-.-

Be it known that LWiLLniM BAXTER, Jr., a citizen ot the United States, residing` in the Ninth election district of the county of Balti more, State ot' Maryland, have invented eertain new and useful Improvements in Electric Motors with Governors, l'ully described and represented in the following speciiication and the accompanying drawings, forming a part ro ofthe saine.

rlhe object of this invention is partly to furnish a more compactand durable construction i'or the shunt-connections freni the field-coils to a shnntlliox, i'or which purpose I place the shunthox upon a bridge connecting` the polepieces of the held-magnet and conduct the shunt-coln1ections l'roin the saine point upon the coils over the pole-piece directly to the shuntbox, Bycxtending,- all the connections 2O freni the nearest point upon the coils to the shunt-l ox in such a location, and wrapping,` the connections lirinly together and securing them to the poleepiece, l forni a very direct conjunction ot'the coils and the contacts in the :e5 shunt-box and protect thc connections in the most effective in an ner frein accidental derangenient or injury.

My invention also consists, partly, in counecting with the ticldcoils an auxiliary coil wound in an oppositedireetion and connected with a contact in the saine shunt-box as the connections troni the various sections ol'l the Viieldvcoils, so that the saine ineans may he enr ployed to iirst close the circuit through the shunt-connections of the niain coils and then through the auxiliary coil to react upon the residual magnetism ot' the field when the niotor is very lightly loaded. By this construction the niotor is prevented l'roni ru nning` away 4o (attaining,1 an excessive velocity) when the inotor is wor-kin` under a very light load.

My improvement also consists in the conibination, with the inotor, ot' a governor lever having,` a tensionspring,` applied to the lever- 45 arm at an acute angle to operate with a diminishing' leveraoe upon the arin as the speed of the rnotor increases, and in the eon'ihination7 with the niotor arniatureshaft having a governor applied thereto and acting upon an arm Serial No. 247,907. (oniodel.)

provided with such an opposing spring, of a 5o revolving tlirustiing connected with the govcrnorweights and provided with antifriction halls fitted to a groove in such ring and to a collar upon the governor-arm, to diminish the frictional resistance iuiposed by the spring,` upon such thrust-ring.

My improvementsare especially adapted to motors which use a constant current such as is employed in arc-light circuits7 and the speed of the motor is regulated hy modifying' the 5o strength of the magnet-ic iield automatically hy the action of the governor.

My invention will be understood hy relci1^ ence to the annexed drawings, in which- Figure l is a side elevation of a inotor provided with myimprovements, certain parts oi" thc governor being shown in section on their central line where hatched. Fig. 2 is an end view ol' the inotor traine and magnet -peles with the coils upon oncinagnet-core cnt away 7o tothe center line of the core and the wires blacked which connect with the strips c c' c, &c. Eig. 3 is a plan7 with coils outside the iirst, in section, ot' one ofthe magnet-cores de tached from the motor-frame and viewed at right angles to its axis, with the elbow-pieces for connecting` the coils to the shunthox. Eig. i is an edge view,A and Eig. 5 a plan, ot the elbow-connections from the coils to the shunt box; and Fig. (i is a transverse section ofthe So clhowconnections on line ,fr m in Fig. 5. Eig, 7 is a side view of the shunt-hox with its connector and 1governor-rod. Fig. 8 is a plan of the same with the elbow connect-ions at one side omitted, as well as the cover to the spring- S5 holder and the connector and governor-rod; and Fig. 9 is a transverse section of the saine on line n; in Fig. 7. Eig. il) is an end view ofthe governor-lever. Fig. il is an end view ofthe governoncollar, Fig. l2, a, side riewof 9o the governor-sleeve; Figs. lil and il, a plan and end view oi" the shuntblocl; connector; Figs. 15 and i6, a plan and side view of the cl1eel-pieces for the shunt-box, l? and 18 are a plan and side view of the spring 95 guide or holder. Figs. 1,9 and 20 are a plan and end view of the cap for the spring-holder; Fig. 2l, an end view of the same, and Figs. 22

and 23 are a plan and end view of the spring abutment. Fig. 24 is a diagram showing the magnet-coils with their shunt-connections. In Fig. 8 the cap 1J, cheek-pieces Z, and shuntblock h are removed, and Fig. 25 shows a plan of such parts with the springs s and abutment 7c.

A is the frame of the motor, forming the bridge between the magnet-cores B and provided with bearings C for the arbor of the armature D. .These parts, as well as the governor-links E and their guard E', are similar to those shown in rny United States Patent, No. 361,116, issued April 12, 1887. The governor is mounted upon a shaft, F, extending from the end of the arbor F. Theinner ends of the links are pivoted to rotate with a collar, I, affixed to the shaft, and the outer ends of the links are pivoted to a sleeve, l', (shown detached in Fig. 12,) and furnished at its inner end with a head, l2, and at its outer end with a nut, I3. A collar, J, is tted tothe sleeve between the head and the nut, and provided with pivots J', which operate in sockets J3 in a governor-lever, J4. The nut l3 and the collar J are each formedv with an angular groove, j, and balls a are inserted in the groove (being shown in Figs. 11 and 12 both) to diminish the friction between the nut and collar when the sleeve is drawn inward by the expansion of the governor-links. The lever is pivoted at j upon the guard E and is furnished with an arm, H, having a tightening-bolt, H', fitted in its outer end and connected with a spring, H2. The bolt is connected with the spring by an eye, H5, and is provided with a wedge-shaped block, H3, having sharp edges fitted to a forked bearing in the end of the arm Hand adj ustablebyanuaH", to vary thetension ofthe spring. The spring is extended from the bolt at an acute angle with the arm H past the pivot j, and is attached to the frameA in such position that an increased speed of the governor-links operates to extend the spring.

The links are shown in Fig. 1 in the position assumed at their greatest velocity, and the spring operates, when the velocity is diminished, to draw the arm H downward and the sleeve I outward, thus drawing the mass of the links nearer to the shaft F.

The movement of the eye H5 around the pivot j, as indicated by dotted line w is not in a line with the spring, and therefore operates, as the spring retracts, to move the axis of the spring gradually away from the pivot j. and to A thus increase the leverage of the arm H. This increase in the force of the spring upon the arm H corresponds with the increased force of the governor when the links lie closer, to the shaft. vIf the resisting force of the spring remained constant while the governor force decreased, (with the changed relation of the links to the shaft at higher velocities,) the governor would not operate as desired; but the decreasing tension of the spring enables the governor to move the lever J through its whole range with a very slight increase of velocity, the

spring being adj usted in practice to just about balance the force of the governor at the beginning of its movement above the normal velocity.

By properly proportioning the weight of the links and the strength of the spring tothe normal velocity for which the-motor is designed the resistance of the spring to the governor may be made nearly uniform throughout its whole range of movement, so that a very slight increase of the centrifugal force will produce a great movement of the lever. The spring is readily adjusted by a nut, H4, and its tension may thus be varied and the governor rendered sensitive to any speed desired.

The velocity of the motor is regulated, as is sometimes done in constant-current motors,

without varying the position of the commutator-brushes, the intensity of the magnetic field being changed when it is necessary ,to vary the power of the motor by cutting out more or less of the magnet-coils which are wound around the magnet-cores B. My invention differs, however, from other constructions for the same purpose in leading the different shuntconnections of the magnet-coils from the same point upon` lthe surface of the coil, and extending the same directly to the shunt-box upon the bridge. By forming a notch in the flange at the inner end of the magnet-core the connections may all be conducted from the coils at the nearest point to the bridge, and may be hunched together and secured upon the pole-piece in a single band, which is thus wholly protected from injury or accidental derangement.

The wrapping of the magnet is formed of a continuons wire with its primary end connected with the circuit in any convenient manner.

o' is the rst coil extending between the flanges B of each magnet-core, and c?, c3, c", and so on are the exterior coils wrapped about the first, the terminal of the final coil being arranged to connect with the terminal ofthe opposite magnet-coil, or with the commutatorbrushes, in the usual manner.

Vhen operating with a full load,the current enters the rst coil upon one side, and after traversing all the other coils passes through the coils upon the other side, and thence through the commutator and armature to line. To diminish theintensity of the magnetic field IOL IIC

IZO

in any desired degree, I extend a shunt conf nection formed of a fiat strip, e e' e,.&c., from each coil (or from any other preferred section of the magnet-helix) toashuntbox,whereashunt block-or connector, d, may operate to unite the similar coils upon the opposite magnetcores, (and thus cut out part of the field-wires on both cores simultaneously,) or to shortcircuit the layers of each coil individually, as may be preferred.

In Fig. 24 is shown by a diagram the operation of these shunt-connections, the lines c', c2, c3, ci, c5, and c representing an equal number of coils upon the opposite magnet-cores.

G represents the positive-current wire, G the negative, G2 the commutator, and e', e?, and so on, the strips or shunt-connections from the several coils, terminating in springs inthe shuntbox.

A shuntbloek, d, is arri nged to move over the ends of the springs to unite electrically any of the similar connections, e ef, die. The shuntdoloclr d is made, in practice, long enough to cover all the springs a7 at once, to prevent its rear end from catching upon their ends when the block is retracted. As the block may thus cover any number of the springs nir der one of its ends, it may operate, it' such springs form the terminals of suitable circuit, to short-circuit either or both ofthe magnetic coils independently of the other. Vhen the bloel; is withdrawn from all the springs, the current passes through all the coils and produces a iield ot' maximum intensity; hntit' the pair of coils farthest from the connection G are united by placing the block d in Contact with the springs rcit is obvious that the coils c would be entirely cutout of the circuit and the intensity of tue magnetic field correspondingly diminished. In like niaiiiiei,it'tlie block be placed in contact with the springs attached to the connections e, two coils would be eut ont of the circuit, and it' the block be placed in contact with the springs attached to the connections c the current would pass directly tothe commutator through such block, and all the magnet-coils would be cut out. The motor would then be destitute of power and motion, but Yt'or the residual magnetism in the metal ot the poles, which in practice is safticient to rotate the armature at a high velocity when propelling` a very light load, or when the belt is suddenly thrown oi't.

To maintain a constantspeed when the work to be done is less than the power which the residual magnetism will develop, I provide means to send an electric current around the magnet-cores in a reverse direction, the new tralizing eli-ect of such current balancing the difference between the force required and that which the residual magnetism can develop. rlhe line-wire is not, therefore, connected with the first turn of the coil c', but to a point, c, several turns distant troniitsbeginning. Such turns are therefore wholly outside ot' the ciu cuit on its passage through the coils c c2c-i", and so on, but aii'ord a means of throwing a reverse current directly around the magnetcores by connecting the first ot`.such turns through the sections e with the shuntbox, where they may be connected by the block d when it is desired to thus reverse the current.

In Fig. ltthe normal movement of the current is shown by the arrows K, while the movement ofthe reverse current is clearlyindicated by the arrows K', applied to that portion oi' the coil c which is connected with the springs c. rEhe connection of such springs by the bloel; d furnishes a short circuit for the current by cutting out the remainder of the coil e and the coils cl c3, dac, and the magnetic field is thus not only deprived of its normal magnetism, but its residual polarity is reduced or reversed in the degree required to maintain a constant armature velocity. The number of turns required upon a given magnet to produce this effect is readily determined in practice, and the practical construction for making the connections e c, hre., is shown in Figs. 2 and 3 applied tothe magnet-cores, and in Figs. 7, S, and tl connected with the shuntbox.

The primary connection G is shown in Fig. 3 applied to the eighth turn c of the coil c', while the [lat connection c is shown applied to the iirst turn, and carried along the magnet core beneath the whole ot" the li rst layer, l'rom which it is extended through a notch, si, in the flange B ol' the pole-piece to an elbow piece, connected with the shunt-box.

The connections e are shown inthe drawings formed of ilat copper strips, which are readily arranged and insulated between the several coils, and are extended along the heads B* of the pole-pieces nearly to thel shuntbox L, which is secured between the ends ofthe polepieces over the top of the armature.

rthe shoutbox is shown formed with a series Ct' llexible springs connected in pairs with the opposed ends of the strips e e2, die., and sustained adjacent to one another in a spring guide or holder, g, over which a shunt-block, Iz., is moved by the governor, as required.

rThe spring guide or holder is shown in Fig. S, as also in the dotted view in Figs. 17 and 18, as a block oi' wood or analogous material, with notches y in its opposite edges to receive elbow-connections from thespringsarml lornied with vertical slits gY in its opposite edges, through which the springs p reject uliward into the path ot'the shunt-block hf. A cap, i', bevA eled at its forward end adjacent to the springs, is fitted over the guide or holder y to support the block iz when retracted from the springs, and is formed with stops j to then arrest the block.

An abutment, It, is inserted in the shunt-bor:- in front of the springs, and caps l (shown only in Figs. lo and lo) would be placed at each side ot' the pieces f/ and i', at the points indicated at Z in Fig. S, to keep the springs in the slits y2.

The parts fj. y1', 7.', and Z would be formed of wood or other insulating material, and would be secured in the springbox by snilaliile fast enings.

The block h insulated and securedby nuts 7l adjustably upon a rod, It?, connected with the govcrnor-leverjt, and moved thereby with the varying velocity ol' the armature.

To press the rod toward the springs to malte a positive electrical contact therewith, a roller, h3, is mounted upon the shunt-box [over a part of the rod 7i?, and is provided with a screwshank, ut, Vfitted to a standard, il, upon the shunt-box and adjustable by means of threaded nuls a'.

The top of the abutment t: is inclined, like ICO the end ofthe cap i, and the springs are bent to a similar angle, so as to yield readily as the block moves over them, and the last spring, which is connected with the strip e, is made longer than the others and laid upon the inclined face of the abutment, so that the shuntblock may press it hard upon the same to form a more perfect connection therewith when the operation of the governor is intended to cut off all the direct field-coils from the electrical circuit and to reacton the polarity of the magnet to reduce the residual magnetism.

The motion of the rod h2 when transmitted from the governor lever is parallel with the armature-arbor, whilc the shunt connections from the magnet-coils are conducted at right angles to the armature to reach the shunt-box by the shortest course. To join the shunt-connections with the springs, I therefore provide the latter with elbow-pieces s. The elbowpiece is formed integral with the spring s', and while the springs extend in the direction of the armature-arbor the elbow-pieces extend at right angles thereto, and thus project directly over the heads of the pole-pieces toward the iange s2, which holds the field-connections upon the pole-pieces in place. A notch, s, is formed in the flange in line with the elbowpieces, and all the strips, e', e2, &c., which extend from the different field-wire coils, are thus brought directlyinto line with the elbowpieces to make the shortest possible connection therewith.

As shown in Figs. 2 and 3, the strips ee'l, Ste., are clamped upon the head B4 alternately with the elbow-pieces s, each strip making an electrical connection with one of the springs, with paper or equivalent insulation inserted between each pair of connections, as is shown in the edge view of a part of such connections in Fig. 4 and the section iu Fig. G.

The clamp s" is merely a plate pressed upon the group of connections by screws S5, and the entire bundle or bunch of connections would be preferably enveloped with a non-conducting and waterproof coating, s, as shown in Fig. 6.

Heretoforc it has heen common in dividing the field-coils into different sections to form shunt-circuits, to extend the electrical connections from the different coils outward between the wires at different points upon the surface ol' the field-coils; but it will be noticed that my arrangemcntdiffers from such construction in the use of the fiat strips e c?, &c., which enable me to extend all my shunt-connections from different points within the coils under or between the same to a single point, as the notch s3 in the fiangc, which holds the coilsin place, and to form the several shunt-connections into a compact bundle which may be thoroughly protected from accident or derangement, while its several conductors may be readily connected with a suitable shunt-box. I thus avoid the liability to damage and derangement which occurs when the various shunt-connections are extended separately from the coils at different points and require to be separately led to binding-posts orto a switch-board to form the desired shunt-connections.

I hereby disclaim the division of the eldcoils into sections to form shunt-circuits and the regulation of the magnetic field by directing the current into more or less of such circuits, as I am aware that such a construction is old, and that the regulation has also been effected by shunting the current as required through reversing-coils,through which the current passesin a direction opposite to thatin the field-coils.

My present invention, so far as it relates to the connection of the shunt-coils with the shunt-box, consists in the mechanical arrangements adopted for protecting the shunt-'connections where they are extended from the coil to the shunt-box, and for uniting such shuntconnections with the contact-pieces in f the shunt-box.

I am not aware that any one has heretofore connected a single auxiliary coil with the cir cuit-wires and wound it upon the cores in the opposite direction from the main coils and operated it when the connection was first shnnted from the main coils to react upon the residual mechanism of the field in the manner described herein.

I am aware that it is common to use a spiral spring upon a governor-lever to oppose the centrifugal force of the governor, and my claim herein is thereforelirnited to the attachment of the spring to a governor-arm at an acute angle, so as to operate with a diminishing leverage upon the governor-arm as the speed of the motor increases.

Having thus set forth my invention, what I claim is#- 1. In an electric motor having the polepieces united by a bridge, the combination, with a series ofcoils wound upon the iield-magnet cores, of the shunt-connections e e e?, the., united with the several coils at intervals and extended from the surface of the magnet-coils (at the same point) to the bridge from opposite sides thereof, a shunt-box upon the bridge between the polepieces, with contacts united to the said shunt-connections, a shunt-block or connector, and a centrifugal governor actuated by the motor for successively closing the circuit through the shunt-connections, as and for the purpose set forth.

2. In an electric motor, the combination, with the series of coils wound upon the magnetcores,of a series of shunt-connections connected with the several coils at intervals, means, as a shifting block or piece, for closing successively the electrical circuit through the several shunt-connections, a centrifugal governor mounted upon the armature arbor or shaft, a lever actuated by such governor to operate the shunt-connector, an arm attached to such lever, and a tension-spring resisting the centrifugal Vforce of the governor and arranged atan acute angle with the said arm to IOO IIO

operate with a diminishing leverage upon the arno as the speed of the motor increases, as and for the purpose set forth.

3. in an electric niotor, the combination, with the niain coils upon the magnet-cores, of an auxiliaryv coil connected with the line or circuit Wires and .vound upon the cores in the opposite direction from the main coils,ashunt connection from the ends of such auxiliaryT coils, shunt-connections attached at intervals to the inaiu coils, contact-pieces attached to such shunt-connections, and a moving contact operating in connection With the saine to first close the circuit through the shunt-connections of the niain coils, and to subsequently close the shunt-connections from the auxiliary` coil to cause a reaction upon the residual niagnetisin oi1 the eld 'when the inotor is very lightly ioaded, substantially as herein set forth.

in an electric inotor, the combination, With the iirst coil of Wire Wound upon the magnet-cores, of the line or circuit connection attached to the coil between its ends, an electrical connection from one end of the coil to the other coils, and a shunt-connection 'from the opposite end of such coil, and means for closing the circuit through such shunt-connection to react on the residual magnetism of the held, as and for the purpose set forth.

5. In an electric motor, the combination, with magnet-cores having poles at opposite sides of tno ar rature, of the magnet-coils Wound upon such cores, a shunt-bos: mounted upon a bridge between the ends of the poles, shunt-eonnections attached at intervals to the inain coils and terminated in electrical connections adjacent to one another in the shuntbox, a governor inounted upon the armatureshaft, and a connector moved therebiT to successively close the several shunt-circuits and thus cutout the successive sections ofthe inain coils ironi the circuit, as and for the purpose set forth 6. In an elect 1ic niotor, the combination, with magnet-cores having poles at opposite sides oi. the armature, of the niain coils Wound upon such poles, shunt-box mounted upon a bridge between the ends of the poles, shuntconnections ibrined of metallic strips attached at intervals to the niain coils, with the latter Wrapped oer the saine, and the said strips terminated in electrical connections adjacent to one another in the shunt-bos', a governor actuated bytheniotor, and a connector nioved thereby to successively close the several sh untcircuits and thus out out the successive sections of the main coils from the circuit, us and for the purpose set forth.

7. In an electric niotor provided with a bridge between the pole-pieces and a shuntbox mounted upon said bridge, the combination, with the cores, of flanges upon the saine, fieldcoils Wound betvfecu said flanges, shuntconnections attached at intervals to the iieldcoils, with the latter Wrapped over the saine, a notch, s, in one of the iiangcs, and the shuntconnect-ions brought together and extended through such notch in a single band to the shunt-bos, as and for the purpose set forth.

8, In an electric motor, the combination, with a bridge between the pole-pieces and a `shunt-bos: mounted upon said bridge, oi" the niagnct-cores, iield-coils Wound upon said cores, shnnteconncctions attached at intervals to the field-coils (with the latter Wrapped over the saine) and extended i`roin the coils toward the shoutbox upon the bridge, elbow-pieces s s', having,` each one arm litted in the shuntbox to forni a contactsnrface and the other arnis extended upon the polepieccs between the several shunt'eonnections, insulating` niaterial between the several slnint-conneotions, and a clamp pressing` such connections and elbow-pieces tog-ether, as and for the purpose set forth 9. in an electric niotor, the combination, with a bridge between the polepicces and a shuntbor; mounted upon said bridge, ofthe magnet-cores, iield coils Wound upon said cornes, and shuntconnections :torined of dat strips of thin sheet metal attached at intervals to the field-coils and ertended beneath the several layers of theiicldcoils to the saine point upon the exterior of the latter and to theshunt-box upon the bridge and connected with contacts therein, as and for the purpose sot forth.

In testimonyT whereof l have hereunto set iny hand in the presence of' two subscribing,` witnesses.

XVM, PAXTll-t, En. iitnesses:

(l R. Cfr-iranienne, HENRY S. Trroiirson.

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