US945018A - Electromagnet. - Google Patents

Description

L. CONN-ELL, JR.

ELEOTROMAGNET.

APPLICATION FILED JULY 2, 1906. RENEWED MAYIZO, 1909.-

Patented Jan.4,1910.

$1 III why/(59);

Z L/MJ i5,018. g Application filed July. 2, 1906, Serial- No. 324,305.

LAWRENCE CORNELL, 13., or PORTLAND, OREGOI\T.

ELECTROMAGNET.

Specification of Letters Patent.

Patented Jan. 4, 1910. Renewed May 20, 1909. Serial No. 497,326.

To all whomet may concern:-

Be it known that I, LAWRENCE CONNELL,

J12, acitizen of the United States, residing at Portland, in the county of Multnomah and State of Oregon, have invented certain new and useful Improvements inElectromagnetsf of which the following is a specification"; t

This invention relates to improvements in electromagnets and it has for its general obv ject to provide a magnet by means of which an armature may be operated to.vibrate in either of'two directions by simply increasing or decreasing the current strength, Without changing current direction andwithout depending upon springs or gravity to act in opposition -to the magnetic force.

The invention is adapted for use in variouseonnections but. finds a special application when employed in quadruple): or multiplex tele raphy.v When thus employed, the sa'lient o'ject of the invention iswto overcome or obviate false signals in the neutral relay incident to thewvorking of the ole changers onthe polar side of the goat rup'lex, such signals being due to what are technicall termed moments of no magnetism in t e line. I accomplish this end by so constructing my improved relay that it depends for itsoperation on no force other than the magnetizing forces developed in it. That is to say, I so construct the magnet that it is unnecessary to employ a spring, gravity or other outside force to pull the armature back from the front stop, ashas heretofore been common.

It is well understood that in quadruplex telegraphy, the eommonside is subject to false signals and that the system is quite sensitive to unfavorable weather conditions,

so that nothingbut an extremely perfect adjustment of instruments and conditions th'coinmon and polar sides will permitof itssuccessful operation,

The chief and most frequent-fault inher-- ent to the instruments of the common side is the false signals induced by momentsof 'no' magnetism. These moments of no magnetisin are caused-by the operation of 'the pole changersywhich in placing first one,

and then the other, pole of, the battery to the line. inevitably produce intervals'wheneither both poles are placed to line at once, or

neither pole is to line. These momentsal though exceedingly brief are nevertheless sufiicient to causefalse signals, and this is I i n I q I 1 particularly true 111 operating long lines, in which ,ease the flow of current in the line does not reach lts maximum and minimum strength instantly but the current assumes a wave-like aspect which magnifies the moments of no magnetism. I s

It will be obvious that a relay so constructed that its armature is free from' the action of external force, such as a spring or gravity and which responds only to variationsin the strength of the magnetism in-' duced therein, will be free from the fault of giving :false signals, since its armature will remain passive during the moments of nomagnetism. The underlying principle which I employ in constructing such a relay is the disproportionate magnetization of a mass of ironunder inductive" currents of varied strengths. To explain more specifically, it 7 is found that in magnetizing soft'airon the increase or decrease of magnetism induced in the iron is not at all proportional to the increase or decreaseof current used. If,

commencing with an extremely small mag- 8 net'izing force, this force is gradually increased, the corresponding increase in mag- 'netic density would be as follows: At first the magnetic. density would. increase more slowly than the magnetizing force until the latter had risen very considerably, but presen'tly the magnetic density would increase faster than proportional to the increase of current and so continue through-a considerable period of increase until the iron approached magnetic saturation, whereupon the increase of density would again fall off and holes than proportionate to the increase of. current, and as the point of saturation was more and more nearly reached the density would fall off correspondingly more and more rapidly until presently increase of current would be unaccompanied by any increase of magnetic density whatever. Ap-

plying this" principle, if one magnet be 10% Woundso comparatively low as toinduce only 10,000 lines of force per square inch when magnetized by a twenty milli-amp'ere vcurrent (the smallen d of the battery commonly used in quadruplex telegraphy) and thisqzurrent were then increased to sixty milli-amperes (representing the'large' end of the battery) the magnetic density would be found to have increased to 55,000 lines of force per square inch, or five and one-half times its former strength while the current strength had been increased only three times,

I If another magnet be wound so highthat when GXQIlZBCl by the small end of the same battery it would induce 100,000 lines of force per square inch, it would be found that when the large end of the battery was applied, the magnetic density had increased to only about 120,000 lines of force per square inch, or an increase of about one-fifth while the current strength had been trebled. If, now, these two magnets were opposed to each other and excited by the same current it will be obvious that a soft iron armature placed between them would be vibrated 1 toward the, one or the other depending upon the increase or decrease of current strength, and this in fact is what occurs in a relay embodying a preferred form of my invention. It will be obvious that the details of construction of a magnet embodying this principle may be varied. I In the accompanying drawings I have illustrated (partly diagrammatically) a practical and what I deem a preferred embodiment of the invention as applied to a system of quadruplex telegraphy, of which one end or station only of the line is shown.

Referring to'the diagram, A and A designate a pair of low voltage generators having their negative and positive poles connected to line, respectively; B and B similar pair of high voltage generators likewise having their negative and positive poles connected to line, each of the series of generators having one pole connected to ground, as indicated at l.

C and'O deslgnate a pair of pole changers (these two instruments are usually made as a a single instrument having one armature which controls twopairs of contacts), the armature, as 2, 3, of each of which operates between a pair of front and back contact screws, as indicated at 4; and 5, and 6 and 7. Contacts 4 and 5 are connected with gener- 'at'ors A and A through resistances D, and contacts 6 and 7 are similarly connected with generators B and B, respectively, through other resistances D. The coils of the pole changer magnets C, C are'inclined in series in" a'local circuit comprising a' conductor 8, battery 9 and a key 10, so that the arinatures 2 and 3 move together and in tlie same di: rection. i

I E designates as a whole the common transmitter, the armature 11 of which operates between the usual pair of, contacts 12 and 13, which are respectively connected with the pole changers. "he .coil of transmitter E is included m a local circuit comprising Tcbhdhctor 14, battery 15.'and key 16.

The parts thus far described are all constructed and arranged in a usual manner. I

F designates as a whole a relay embody- .a comparativelylar ing my invention and connected in the system shown in a manner corresponding to the connections of the usual neutral relay, and accordingly hereinafter designated as the neutral relay. This relay comprises two main magnet spools 17 and 18, each difi'erentially wound as indicated at 19, 19, and 20, 20, an armature 21 interposed and pivoted to vibrate between the poles of the two spools, and a pair of steadying ma 'ets, 22 and 22 connected in series in a loca circuit comprising the conductor 23 and battery 24:. Armature 21 vibrates between contacts 25\ and 25; the former of which is included'in La local sounder circuit comprising a conductor 26, battery 27 and sounder G.

H designates as a whole the -polarized 136- go lay comprising the usual opposed magnet spools 28 and 29, armature 30, and back and front .contacts 31 and 32, respectively. Contact 31 is included in a local sounder circuit comprising end'conn'ected with a contact 34 carried by the armature and its opposite end connected with the contact 31 and including a battery 34 and sounder I. v

M designates the main line which is con- 0 ne'cted with armature 11 of the transmitter E, extends thence to and includes the windings l9 and 20 of the neutral relay (both wound in the same direction), thence extends to and includes the windings of the magnet 29 of the polarized relay and thence to the distant station. 1

N desi nates the artificial line which branches rom the main line at a point between transmitter E and the neutralre- 10o lay, includes the windings 19 andf20 of the'neutral relay, extends thence to and includes the winding of the magnet 28 of the polarized relay and thence passes to ground at 35 through the usual rheostat 36'; a con- 1 5 denser being arranged in shunt with the rlieostat, as usual.

The differentially wound spool 17 of the neutral relay F is constructed with a core ':conta1nmg a relatively large amount of ,iron

and is wound low' as to both windings 19 and-19 so that a small current will have comparatively small magnetizing efiect upon this spool while it is capable of taking 'e current and becomin magnetized to a re atively hi h degree 0 density. Accordingly this s 00% is shown as made relatively long and the turns of the windings comparatively few in'number, as

indicated by the small diameter' ofth spool heads 17. The spool 18, on, the contrary, is i so constructed as to have a';relativelysmall amount of ironin its corefland the core is wound hi h as to both windings; this construction eing indicated by the short core and the spool heads 18 of relatively large V diameter. The steadying' magnets 22 and 22 of this relay simply serve the purpose of holding the armature steady against vibration during moments of no magnetism in-the a conductor 33 having one 35 viz: because the artificial line includes the "natelvto line without changing the polarity.

main spools. To this end these magnets are of equal strength, symmetrically disposed with reference to the vibrating end of the I armature so wound that they oppose each other and included in a. closed circuit so, that they are constantly energized. i I I The operation of the apparatusconstructed and arranged as described should be entirely obvious from the foregoing description but may be briefly recapitulated as :tollows: Assuming a message is to be sent over the polarized side from the statiomshown. the pole changingl It) is operated. l'Vhen this key is open. armatures 2 and 3 engage contacts 4 and respectively, and. arinature 11 of tiansniitter E being at this time in eugagen'ieut with contact 12, the negative I generator of low voltage A is placed to line. I

\Vhen key 10 closed, armatures and 3 close. thus p.acing the positive generator of low voltage A to line. Inasmuch as the circuit from the two high voltage generators is at this time open at contact 13, the latter generators are not concerned in the transmission over the polarized side. If a mes-- .sage is to be transmitted over. the vcommon .side from the station shown, key lti'is op erai'ed. In the normal or open positionof this key th e'i'iegative low voltage generator A is placed to line through contact 4, armature 2. contact 12 and armature 11. \Vhen key 16 is closed the negative generator of high voltage B is placed to linethrough contact 6, armature 3, contact- .13 and armaturc 11. In other WOICIS, current of 130 volts and current of 375 volts is placed alter- Neuti'al relay F being difi'erentially wound as to both ofits spools and half of the current going to ground at 35 over the artificial line and the other half over the main line, it: follows that the neutral relay is unetfected bycurrent sent from the home station whether it be increased or decreased, or r versed in polarity. For the same reason,

windings 28 and 29 of the polarized relay, H which are opposed to each other, the latter instrument is unatl'ecte'd by signals of either strength or polarity sent from the home station. When the pole changing key at the distant stations is operated, the polarized relay H will respond in the usual and well understood manner. I n transn'iitting a message over the common side, the low voltage ger'ierator is normally closed toline as hereinbefore described, and accordingly the low voltage current flowing through the coils of the neutral relay will'magnetizo the high wound coil to a greater degree than it does the low wound cbil, with the. result that the armature 21 willnormally be closed with front contact 25 and the sounder (1} held in open position. When the distant transmittei' key 16 is closed, and the, generator of higher voltage placed to line, the increase of current flowing through the two coils of the neutral relay will bring up the magnetic .d ensity oi. the low'wound coil to such ex- 7 tent that it overpowers the opposing high wound magnet and the arn'iature 21 will be drawn awayfrom contact 25, thus closing the sounder circuit and causing thesignal. The manner in which the current of higher voltage causes the low wound coil to overpower the high wound coil has been hereinlitfOl'E fully explained. Ina word, the low voltage current which is normally flowing throughthe coils of the neutral relay energizes the high wound coil to a degree ap-' 'n'oaching saturation, and when the high voltage generator is placed to line, the high wound coil being already nearly saturated, increases in strength but little, while the op: posed coil. owing to its larger size, increases in strength approximately proportionately with the increase of current, and thus overpowers the smaller coil. At the moments of no magnetism during the ope 'ation of the pole changer key, the armature of the neutral relay obviously remains passive or without. movement becausethere is no exterior force'actingupon and tending to move it.

.\s hereinbefore stated, the inductivelyopposed windings, and the iron or. fields magnetized thereby, may be variousl.y arranged to secure-the result of vibrating an armature or movable member under the inductive force generated in two windings opposed to each other in accordance with the principle of this invention. -For instance, it'will be obvious that, polarization of the armature may be affected by including it in a field subject to the inductive action of opposed high and low windings, in accordance with this invention. Accordingly the appended claims are to be interpreted broadly except in 'so far as they are made specific in terms,

I claim as my invention:

1. In an electromagnet the combination. of two magnet members,-one having a relatively" small core and high winding and the other a relatively larger, core and low winding, anarmature associated with said mag- 11$:

net meu'ibers and arranged to be acted upon by the latter in opposition to each other, andv a source of electric energy connected With and common to both magnet members, whereby they are simultaneously energized and act in opposition to each other and the magnetic strength of 'on'cor the other preponderates as the amplitude of the current varies.

with a movably mounted armature of two-r inductive windings arranged.tgwact -upori said armature inductively and in opposition toeach other, one of said windings being maderelatively high to magnetizeits core to 2. In an electromagn et the coinbi-nation a degree approaching saturation under the action of a relatively small flow of current and the other of said windings beingmade relatively low to energize its core to a relatively low degree of magnetization under said relatively smallflow of current and to overpower the opposedmagnet-under a relatively large to both of said windings.

3. In an electromagnet the combination of a high wound smaller magnet member and a low wound larger-magnet member= connected in series and inductively opposed to each other, a member opei'atively associated with and acted upon by both said posed high windings and the other a relav magnet members, and means for supplying variable current to said magnet members.

4. In an electromagnet, two opposed inductive windings, an armature member subject to the inductive action of each winding, a source of variablecurrent and conductors connecting said windings in series with each other, one of said windings being wound to move the armature against the opposed inductive force under a relatively small curl rent flow and the other wound to move the armature against the opposed inductive force under a relatively larger current flow.

5.'In an electromagnet, the combination of two magnet members, one having a relatively small core and two difierentially disthe other a relaposed high windings and. tively larger core and two differentially disposed low windings, an armature associated with said magnet members and arranged to be acted. upon by the latter in opposition to each other, and two conductors, respectively connecting the pair of high and low windings of the same direction in series with each other and themselveselectrically connected at one side of the relay..

6. In an electromagnet, the combination of two magnet members, one having a relatively small core and two differentially disi i i l l flow of current, and a source of variable current connected with and common tively larger core and two difie'rentially disposed low windings, with said magnetmembers and arranged to be acted upon by the latter in opposition to each other, two conductors, respectively connecting the pair of high and low windings of the same direction in series with each other and themselves electrically connected at one side of the relay, and a pair, of electrically opposed steadying magnets arranged to act upon said armature in opposition to each other and adapted to be vinclined in a.

ber in series, said two c'onductors being electrically connected'with each other at one side of the relay.

8. A relay comprising two magnets .con .nected in series, one wound high to approach magnetic saturation under moderate current excitation and the other wound low and arranged to inductively overpower the first under current of relatively largecamplitude, and an armature-controlled contact device associated with said magnets and shittable thereby in either of two positions, dependent upon which of said magnets at the time 'pree dominates inductively.

LAWRENCE GONNELn-Ja Witnesses:

W. R. LITZENBERG,- L. F. STEEL.

an armature associated so i

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