US282294A - field - Google Patents

Description

(No Model.) 2 Sheets- Sheet 1.

S. D. FIELD.

DYNAMO TELBGRAPHY.

No. 282,294. q Patented July 31. 1883.

)In l By his Afforney @.2 mm2/M (No Model.) 2 sheets-shea 2.

s. DQFIBLD.

DYNAMO TELEGRAPHY. I v No. 282,294. Patented July 31. 1883.`

UNITED STATES- PATENT OFFICE.

t STEPHEN D. FIELD, oF NEw venir, N. Y., As'sreNoE To THE WESTERN 4UNION TELEeEAPH COMPANY, oF SAME PLACE.

DYNAMO-TELEGRAPHY.

SPIE()IFlCATllONl forming part of Letters Patent No, 282,294, dated July 31, 1883.

' Application filed August 5,1882. (No model.)

lo all whom t may concern:

Beit known that I, STEPHEN D. FIELD, of the city, county, and State of New York, and a citizen of the United States, have 'invented a new and useful improvement relating tothe application of dynamo-electric machines for actuating stock-quotation instruments upon a 4 single main line, whose type-wheels are moved step by step by to-and-fro currents of short duration, said type-wheelsbeing held or locked in. a position for printing by prolonging into a continuous current the pulsation, whether of positive or negative polarity, last Sent to line7 while at the same time the prolonged pulsation or continuous current of either polarity Serves to raise or actuate the printing-pad to printthe desired character. j

To the end of procuring a series of electrical pulsations of alternately positive and negative polarity, and of obtaining a continuous current of the same polarity as the pulsation last generated, l employ what is commonly known as a continuous-current dynamo7 or magneto electric7 7 machine-such, for example, as is described in United States patent of dlvernois and Gramme, N oi 120,057, of 1871, or the machine set forth in Siemens English Patent No. 2,006 of `1873. Alnthese forms of dynamo-electric machines it is customary, for the purpose of procuring continuous currents in one direction, to wind the armature with an even number of coils of insulated conducting-wire, which are all electrically connected together, and to employ a commutator having a series of metallic strips insulated from one another of a number equal to the numberof coil-Sections upon the armature. From each wire connecting the. terminal of one coil-section of the armature to the beginning of the succeeding coil-section an electric conductor iscarried to acorrespondin g commutator-strip.

Thus the commutator-strips, respectively, are all Separately conne'otedwith the coils of the armature at points between adjacent coils or sections. `ln connection with this commutator two conducting-brushes are employed, which simultaneously connect with diametrically-opposite commutator-strips and those strips which `are connected, respectively, `with those coils or sections of coils upon the armature that, in their course of rotation, happen tobe in a plane or line at right angles to the line or plane joining the poles of the eldmagnetsof the dynamo-machine. By means of such an arrangement a continuous. current only will be produced. However, if from any two diametrically-opposite strips of the commutator conducting-wires be carried to two insulated and independent metallic rings upon the same shaft, and such metallic rings be rotated in contact with electrical conducting brushes or strips forming the extremities of an exterior electrical conductor, it is obvious that as the armature is rotated a maximum current of one polarity will be set up when the coil-sections of the armature immediately joining the commutator-strips which are connectedV with said metallic rings are in the plane at right angles to that joining the magnetic poles ofthe field-magnets; `and that upon a further rotation of the armature of ninety degrees such maximum current will fall to zero, and from that point of rotation the polarity of current will be reversed, and will increase in strength to a maximum of opposite polarity after a further rotation of ninety degrees, from which point the current will de= crease to zero upon rotating ninety degrees farther, and fromthis point the current will be re-reversed and will attain a maximunr at the end of a complete rotation of the armature. Thus `the current generated will beof one polarity during one half of a rotation of thearmature, and of the opposite polar` conditions, as the armature of the dynamo-electric machine rotates short pulsations of positive and negative electricity will be establshed throughout the main-line circuit. The armature-shaft of the dynamo-electric machine is l `printing-telegraph transmitter.

prolonged and provided with cam projections, which serve to actuate respective main-line electrical switches. Normally, when a iinger-key is not depressed, these two electrical switches complete the main-line circuit through the armature devices for giving only reverse currents. However,ifaf1ngerkeyis depressed, one of the two electrical switches will be moved from its normal position, thereby diverting the main line from a path through the two metallic rings through a second set of electrical brushes, and thereby connecting said main line from earth through the generating-coils of the armature by way ofthe commutator-bru shes for giving a current in one direction. Alternate keys upon the key-board of the transmitter invariably actuate one of the electrical switches, which so connects the main line to the conimutator-brushes for giving continuous currents as to always cause a continuous current of, say, positive polarity, to flow to the line. By depressing any one of the other set of alternate keys of the transmitter the other of the two electrical switches will be actuated, and will cause a continuous current of negative polarityto iiow through the main line. The .respective keys of the transmitter are connected with corresponding strips of what is technically known as the sunfiower77 of a In combination with the suniiower, a rotating arm having a conducting-spring attached to a rotating shaft is employed, which is actuated step by step by a pallet-yoke. The pallet-yoke is given a reciprocating movement by reverse pulsations of electricity passing through a main-line polarized electro-magnet. Branch conductors, joining the transmitting-keys and the sections of the suniiower, form a part, successively, of a local circuit. rlhe anvils of alternate keys forming one set are all electrically connected, and by means of one electrical conductor are connected with one pole of a local battery. The anvils of the second alternate set of transmitting-keys are also electrically connected together by means of a single conductor, and are likewise connected with the same pole of the Alocal battery. The opposite pole of the local battery is connected with the shaft of the sunflower-arm. Normally, therefore, the local circuit is broken both at the transmitting-keys and at the sunflower.

1While no one of the transmitting-keys is depressed reverse currents are traversing the main line, thereby actuating the poiarized electro-magnet and causing a step-by-step rotation 'of the sunfiower-arm. However,- if any one ofthe transmitting-keys is depressed the sunflower-arm will continue rotating until it has arrived at that one of the suniiower sectionselectrically connected with the key depressed. Upon depressing any one of the transmitting-keys, therefore, thelocal -circuit will be closed through either of two branches forming a part of the local circuit, and a current will be set up in one of such branches.

These two local branches are each provided with electro-magnets which attract armatures that, respectively, are mechanically connected with two electrical switches, either of which serves to switch the main line from the reversecurrent devices of the dynamo-machine to the commutator-connections, from which only curl rents of one polarity, either positive or negative, may be directed to line. When the armature of one of the electro-magnets in one branch of the local or sunflower circuit is attracted, a sliding-arm is depressed, which is provided with two stops, one above and the other below the shaft .of the dynamo-electric machine. Vhen the armature is depressed a lug upon the shaft of the dynamo-machine strikes a projection connected with the switch-` arm, thereby moving the switch so as to prevent reverse currents from being sent to line, and into position to cause a continuous current-say of positive polarity-to be sent. If the transmitting-key is released and the armature of the electro-magnet in this local branch is retracted, the same stop upon the armatureshaft of the dynamo-machine will, in its rotation, strike a lug which will throw the electrical switch back to its original position-that is, in a position to cause reverse currents to be sent over the line. On the other hand, if any one of the other set of alternate transmitting-keys be depressed, the electro-magnetin the other of the two local branches of the transmitter will cause the second electrical switch to be thrown so as to prevent reverse currents from being sent to line, and to cause only a continuous current of negative polarity to be sent. Primarily, therefore, a reverse andv re-reverse current causes arotating arm of a sunflower to move two steps during one ro tation of the armature of the dynamo-machine. The depression of a nger-key brings apparatus into such a position that the rotation of the armature of .the dynamo-machine mechanically moves either of two electrical switches, whereby reverse currents upon the line are suspended and a continuous current, either of positive or negative polarity, accordingto the switch moved, is placed to line. The act of depressing a transmitting-key, accordingly, in the first place, causes a suspension of reverse currents upon the main line, which in turn causes the armature of the polarized electro-magnet to be held in one position, thereby locking the rotating armof the sunfiower in a Xed position during the depression of the transmitting-key. While the suniiower-arm is arrested and a corresponding key is depressed the local magnet of the-switch will render a return movement ofthe switch impossible, and only a continuous current can be be sent to line,

To fully explain my invention, I will now refer to the accompanying drawings.

Figure l represents a complete diagram ofthe transmitting apparatus. Fig. 2 is a diagrammatic view of a Gramme armature having a commutato'r from which currents of one po- IOO laritymaybe obtained, and also metallic rings,

which are respectivelyieonneeted with diametrically opposite Lsections of the commu tator, whereby reverse currents may be procured,which Iterm "reverse-current devices.

In Fig. 1 F F` represent the poles of fieldmagnets ofthe dynamamachine mounted upon base B. is a cylindrical or` ring armature, as will be more fully hereinafter described, and armature A isrigidly iixed to a shaft, Q. Upon shaft Q is placed commutator C, consisting of a series of metallic strips parallel to the axis of shaft Q, which are insulated from one i another, and which are connected, respectively,

` in a plane at right `angles to the plane joining with wires of the armature joining adjacent coil-sectionsthereof.` Electrical brushes a and b are pressed in contact with commutator C, and are so` positioned that` they are in electrical `contact with those `strips of the commu tator which are electrically connected with those coils of the armature which occur to be the poles ofthe field-magnets. Thusas the .i armature A is given a continuous rotation a continuous current oi' electricity will be set up from the brush b through the `wire 6 and the common external conductor, back to wirel() through `brush a, and through the coils ofthe armature. Upon the saine shaft Q are placed two metallic rings, w and z, which are insulated from one another, and which are electrically connected, respectively, with two diametrically-opposite metallic strips or" the commutator C. Conducting strips or brushes and y are employed, whereby alternating currents of electricity may be passed from the armature,

through brush x, line 4, and any external con-` .ductor, back to line 3, and brush y] to the armature. i i

For convenience of illustration, I haveshown in Fig. 2 a Gramme ar1nati1re7'wliose sectional bobbins 60 to 67 are connected by wires to 47. These wires, which join the secj tional coils of the armature, are connected, re-

spectively, with thcinsulated strips of the commutator 50 to 57 by separate wires, and the .stationary brushes a and b are set in a line at right angles to the line joining the ie1d-poles F and F. From point 46-that is, from commutator-strip 56-a wire, 70, iscarried tothe electrical conducting-ring w, and from the dia- Vmetrically oppsite comlnutator-strip 52, or from point 42, awire, 71, is carried to conducting-ring c.. Uponrotating the shaft Q from the` position shown in Fig. 2, the ringarmature A being rigidly iixed therewith, a maximum current of one polarity will be set up through the wires70and 71, their'respective contact-brushes x and y, and through an external conductor, 3 4, when the points 46 and 42 have been brought into a line at right anglesto the line joining the `field-magnets. When the armature has been moved to such a position that wires 42 and 46 are in the line or plane joining the field-poles, the current will ,have diminished to zero, where its polarity will change; and the current `will increase to a maximum of opposite polarity after a further rotation of ninety degrees, or after three-fourths of a rotation. i Upon `a still further quarterrotation the current will have diminished untion, at which point the current will re-reverse its polarity. It is thus seen that upon one rotation of the armature a pulsation of one polarity will be produced, that the polarity oi' this current will be reversed, and that a rereversal will occur.

A single main telegraph-line in which a series of printing-instruments is placed, said single line embracing the `magnetizing-coils both of the type-wheel and printing-magnets, is so arranged by means of suitable electric switches that normally said line is connected through the armature of the dynamo-machine and through brushes x and y, whereby reverse currents are produced. However, by means of proper automatic switches, whenever it is desired `to print a character, the main line is removed from the wires 3 and 4, connecting with the reverse-current brushes x and y, and is connected with the wires 6 and 1l),` whereby straight currents may be sent to line. The means for switching the main line from one set of brushes and y to the commutator-brushes b and a is effected by means of thefapparatus -now to be described.

X and Y represent two electrical main-line switches, one of which-say X-will disconnect the main line from the brushes and y, and so connect it with the-commutator-brushes b and a that a straight current-sayof positive polarity-will be" passed over the line, and of the same polarity as that onejof the reverse `pulsations last sent, whileY'is an electrical switch whereby the main line is disconnected from the brushes andy and is so connected with the commutator-brushes band a that a continuous current of negative polarity willbe sent over the main line, the polarity of the last pulsation sent to line having been of negative polarity. The switches X and Y, respectively, will be called into action according to which of the two sets of keys the one depressed belongs. For instance, if any one of the keys A C E, 825e., is dewill be suspended and a continuons negative current will be transmitted. lf B, D, or F be depressed, the alternate currents will be suspended and only a continuous positive current will be transmitted.` j

L B is a local battery whose circuit iscompleted from point 14 through either of two branch wires,` 15 or 17, according as a key of one alternate set or of the other is depressed, to points 16 and 18, and thence to one of the anvils 19 and 21, &c., or to one of the anvils 2() and 22, 85e. The transmitting-keys A B C D, Ste., are connected separately by means of branch conductors 30 31 32 33, 8vo., asshown, with the sections 8() 81 82 83, `ne., of the sunflower G; thence through the revolving-` til the armature has received a complete rotal pressed, reverse currents upon the mainline 4 esegua spring K, arm J, and the shaft S to the opposite pole ofthe local battery. It will be seen that vthe local circuit may be closed through either the branches 15 or 17 upon depressing any vone of either of the two sets of transmitting-keys, providing the revolving spring K is upon that one of the sunflower-sections corresponding to the key depressed. The spring K is given a step-by-step movement upon each reversal of the main-line current-that is, upon a reversal from positive to negative of the main-line current. The polarized magnets M M move the pallets N N in one direction, thereby rotating the ratchet-wheel R one step, and thereby carrying the spring K from one section of the sunflower to an adjoining one, and upon a re-reversal of the main-line current the springK will be moved the further distance of one sunflower-section. The main line proceeding from the distant station passes through coils M M of the polarized magnet; thence by L to spring j, metallic block z', wire 5, spring h, conducting-block g, wire 4, brush x, metallic ring w, through coils of the armature of the dynamo-machine to metallic ring z, brush '1, conductor 3, metallic block f, spring e, wire 2, metallic block d, spring c, and wire 1 to earth. As shown in the drawings, if key B or D be depressed, the sunflower-arm will rotate until spring K reaches either section 80 or 82, in which event the local circuit of L B will be closed through the electro-magnet M, when armature b', attached to lever a, which is pivoted at c', will be attracted, thereby depressing a sliding bar, H, which, between points r and s, consists of two parts, t and t', between which passes the shaft of the dynamo-electric machine.

Thelink-bar H is pivoted at point g to h. Armature-lever a is provided with an elbow, a', having an opening through which slides the stem qof bar H. Armature-lever a is also provided with a retracting-spring, s. Upon the lever h is mounted a horizontal bar, of insulating material, t, upon which is mounted conducting-springs e and h, which normally rest upon conducting blocks f and g, but which, 'upon a backward movement of the arm h', will be carried to rest separately upon the conducting-blocks k and Z. The part t of the link-bar H is provided upon its under side with a tooth, d, while the part t is provided with a tooth, f', and in the same plane the shaft Q of the dynamo -machine has affixed thereto a tooth, e. The two limbs of the linkbar t and t', with their respective projections d and f, are so arranged in respect to the tooth e that when the armature of M is attracted the projection cZ will be so far depressed that in thel rotation of c it will strike d', driving the spindle g through the opening in d', thereby moving the lower end of arnrjt toward shaft Q, and thereby moving the spii'ngs c and h from blocks f and g over to blocks k and Z. However, if either a key B or D be released after being depressed, the armature of M will be retracted by its spring.s,-when thetooth d will be kraisedoutfof the path of rotation of tooth c', and the link-bar' H will be given a backward movement, thus returning the spring h and c from the blocks Z and 7c to g and f, and projections eZ and f are so'arranged that when either is moved into the path of c it will be driven to a point just without the arc of revolution of point e, so that the rotation of the shaft Q may continue, and the link-bar H will be held in the same position until the armature-bar a is again attracted or retracted, as the case may be. In the same manner, if either of the alternate keys A or C be depressed, the sun flower-arm will continue to rotate until spring K arrives at sections 83 or 81, when the local circuit will be closed through branch 15. Electro-magnet M, in the branch 15, serves, in the same manner as electro-magnet M, to actuate an armature-lever, thereby raising or lowering link-bar I, which is similar to linkbar H, and which is given a to-and-fro longitudinal movement, according as the armature is attracted or retracted, whereby lever h of the switch Y throws the springs c and j from conducting-blocks (Z and i to the conductingblocks m ahd n. Thus if key A or C of the alternate series be depressed the mainline will be disconnected from the brushes x and 1 and will be so connected with commutator-brushes a and b as to direct upon the main line a continuous current of one polarity, but of a polarity opposite to that which would be sent by depressing one of the keys B or D.

For convenience of description I designate electro-magnets M and M and their armatures as switch-controlling devices,77 while bars H and I and shaft Q, having lugs thereon, I term switch-actuating devices.7 The operation of the switch-controlling devices enables the actuating apparatus to be brought into action.

rlhe commutators for affording a continuous current uponthe main line in one`direction or the Iother are connected by wires 6, 8,V 9, 10, 12, and 13 with the metallic blocks k Zand m n, respectively. It will be seen, therefore, that if the conducting-strips e and h of the switch X be moved into contact with blocks 7c and Zthe conducting-brush a will be connected directly to earth through wires 10, 12, 2, and 1, while conducting-brush b will be conducted IOO IIO.

through wires 6, 8, and 5 to the main lines.

Again, if the brushes e and h of the switch X remain in their normal position upon fand g', and the brushes o and j of switch Y be moved upon the conducting-blocks m and n, the brush b will be connected to earth through. wires 6, 9, m, c, and wire 1, while the brush a will be connected to line throughwire l0, 13, n, and j. The revolving arm of the sunflower, as Vit `is carried over the metallic sections thereof, is carried into contact with one half of the sunflower-sections by the transmission over the main line of impulses of one polarity, `and the arm is carried upon the other half of the alternate sunflower-sections by impulses of an opposite. polarity. It is thereforeapparent thatto bring the sunfiower-arm into contact with any particular section a pulsation of prey operation of either one of the electro-magnets MA or M inthe branchesof the local circuit, the sunflower-arm must be arrested upon any one of that series of sunflower-sections through `which the electro-magnet M or M, asthe case may be, is connected. lf a positive impulse has last been sent to line, `the armature of the polarized electro-magnet `M M will be so moved asto throw the sunflower-arm upon some one of its sections, which will connect the y local battery through, say, local electromagnet M", and according as the last impulse sentl is positive or negative either electromagnet Ml or M willbe operated. If, upon depressing any particular finger-key of one series, a positive pulsation is the last one sent to line, and M is operated, the positive pulsation will always be prolonged or continued into a current of positive polarity. Again, if

any particular finger-key of the second alternate set is depressed so that thelast pulsation sent to line is negative, and M is operated,

under all such circumstances will the negative pulsation sent to line be prolonged into a continuous negative current.' The positive and negative pulsations `are normally upon the main line, and they, by the polarized main-line electro-magnet, serve to control or actuate the movement of the sunflower-arm, which is a switch `for the local circuit. By depressing any one of the finger-keys oneof the two mainline switches, X or Y, is placed in a condition to be operated by a continuedrotation `of the shaft Q of the armature of the dynamo-electric machine; and in either event the reverse pulsations upon the main line are suspended and a continuous current is sent to line, whereby the sunflower-arm 1s arrested. The depression of a nger-key first enables the `sunflower-arm `to close a local circuit; and this act, through the` agency of M or M, effects conditions whereby, upon the continued rotation of the armature-shaft, the main-line switch is operated, which in turn, by suspending reversals of current and by developing a continuous current, immediately causes the arrest of the suniower-arm.` Upon releasing the depressed key, and thereby the main-line switch, reverse currents are re-established in the main line,

which causes the suniiower-arm to again be given a continued step-by-step movement.

For convenience of illustration I have herein described a Gramme armature in preference to the cylindrical armature described in Siemens7 English Patent N o. 2,006 of 187 3. However, it is apparent that one canbe substituted for the other, or, in fact, any well-known form of dynamo-electric machine can be used forl the purpose herein speciiied -which is capable of giving a continuous current.

It is also obvious that instead of employing a commutator for taking continuous currents from the machine, and the .reverse-current devices herein shown a commutator maybe employed which, when continuous currents are required, shall be held stationary, while said commutator, when it is desired to produce reverse currents, shall be y permitted to rotate with the shaft of the dynamo-electric machine; but l desire to disclaim such feature from this case,as it is made thesubject-matter of r another application, nor do I desire to claim in this application the combination, in a dynamo-electric machine, of an armature `whose series of coils o'r bobbins are electrically connected together, and which at their junctions are respectively connected with a series of insulated commutator-strips, conductingbrushes for said commutator, means for deriving from said armaturereverse pulsatory currents, consisting of two insulated metallic hubs, which are electrically connected with said armaturecoils or the combination, broadly, of such an arrangement with a switch or switches for connecting a single line either with the straight or reverse-current'brnshes or commutators ofthe machine, as such subject-matter is claimed in another application filed by me.

y 'What I claim, and desire to secure by Letters Patent is- 1. A dynamo-electric machine having an armature substantially as specied, means for deriving fromsaid armature a reverse pulsatory current, meansl for deriving from said machine continuous currents, a series of trans- IOO mitting-keys, a sunflower whose rotating arm V rotates in unison with the armature of the dynamo-electric machine when reverse currents are being sent to line, and two switches, said switches serving, when brought into action, to c IIO flower-arm, switches for connecting the inain .y

line with devices for deriving from the dynamo-machine pulsatory currents, or continuous currents of either polarity, and switchactuating apparatus operated by the shaft of the dynamo-machine to actuate either switches when its correspondingbranch ofthe local current is closed.

3. The combination, substantially as specied, of a switch-controlling device, switch for connecting the main line with devices by which pulsatory or continuous currents may be derived fr'om the machine, and a switchactuating device which is given a to-and-fro movement by the agency of the rotatingarmature of the dynamo-machine when said switch-controlling device is brought into action or released.

4. The combination, substantially as speciiied, of two switch-controlling devices, two main-line switches for deriving from the dynamo-machine either pulsatory or continuous currents, two switch-actuating devices,which are operated through the agency of the rotating armature of the dynamo-machine,whereby the main line may be disconnected from said device for deriving pulsatory currents from the dynamo-machine, and may be so connected with said dynamo machine as to establish thereon a continuous current of the same polarity as the pulsation last sent to line.

5. The combination of an armature of a dynamo-electric machine, substantially as speciiied, conducting brushesx y, brushes a b, main: line switches X Y, electrical connections for joining said brushes through said switches, a mainline, L, and the switch controlling and actuating devices, substantially as described.

6. The combination of a dynamoelectric machine, substantially as specified, devices for deriving therefrom pulsatory currents, a main line, an electro-magnet, a suniiower arrangement, and a rotating sunlower-arm, a'nd an escapement device controlled by said electromagnet for controlling or actuating the move-- ment of the suniiower-arm, whereby said suniiower-arm is given a step-by-step movement when pulsatory currents are transmitted over the main line, and which is held in a fixedposition when a pulsation is prolonged into a continuous current.

7. The combination of alocal circuit, branches 15 and 17, embracing the magnetizing-coils of electro-magnets M M, the circuit-controllin g electro-magnets l\ M, the main-line switches -Y and X, and the switch-actuating links I H,

which are moved to and fro by the rotation of the armature of the dynamo-machine when the circuit-controlling devices are called into action or released.

S. The combination of the switch X, having the four stationary insulated metallic blocks f gl 7c and two movable springs, e h, the switch Y, having the four metallic insulated blocks d i m n and two movable springs, c j, the main line L, brushes b a and x y, and suitable connecting-wires, substantially as described.

9. The combination of the pivoted switcharm 71,', sliding bar H, having lugs clf., armature-lever a', armature-shaft Q, having lug e, whereby, when the armature-lever a is depressed, the rotating lug e will move bar H to the right, and when said armature-lever is retracted said rotating lug e will drive bar H to the left.

10. The combination of local battery L B, whose circuit is completed separately through branches 15 and 17, and any one of the two alternate series of keys, switch-controlling arrangements M M, conductors joining said keys with their respective sunflower-sections, and the sunflower-arm, whereby either switchcontrolling arrangement, M or M is brought into action upon depressing any transmittingkey whose anvil is connected with the branch passing through the electro-magnet of the circuit-controlling device.

11. VThe combination of a sunflower-arm whichis driven or permitted to act step by step by alternating main-.line pulsations, a series of transmitting-keys, alocal circuit and branches, main-line-switch controlling devices, mainline-switch actuating devices, main-line switches, and a dynamo-electric machine for generating pulsatory or continuous currents, the whole being so arranged that up on depressing a transmitting-key the sunflower-arm, when in contact with the suniiower-section corresponding with the key depressed, causes the switch-controlling device t0 bring the switch-actuating device into such a position that the rotation of the armature causes a movement of its respective main-line switch and acessation of pulsatory currents upon the main line, and also the arresting of the sunflower-arm upon that section of the sunflower connected with the key depressed.

Signed by me this 6th day of July, 1882.

STEPHEN D. FIELD. Vitnesses:

WM. B. VANsiZE, WM. ARNOUX.

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