US700800A - Multiplex-telegraph circuit. - Google Patents

Description

UNITED STATES LAVRENOE A. MCCARTHY,

P T NT OFFICE.

OF BROOKLYN, NElV YORK.

MULTIPLEX-TELEGRAP H CIRCUIT.

SPECIFICATION forming part of Letters Patent No. 700,800, dated May 27, 1902. Application filed November 18, 1901. Serial No. 82,712. (No model.)

To all whom it may concern:

Be it known that I, LAWRENCE A. MCCAR- THY,a citizen of the United States of America, residing at 1059 Bedford avenue, Brooklyn, New York, have inventednew and useful Improvements in Multiplex-Telegraph Circuits, of which the following is a specification.

The objectof this invention is to combine with the receiving instruments and controlling device at the one end of a quadruplextelegraph circuit, as shown in Patent No. 693,530, allowed me February 18, 1902, shunting-magnets, so arranged that the incoming current from the distant end of the circuit will not be able to interfere with or change the resistance of the artificial line, and thereby throw the receiving instruments out of balance and cause them to record false or mutilated signals.

I attain the object of my invention by the combining with the controlling and receiving instruments in the main and artificial line at the home station of a non-polarized electromagnet having a single winding the separated coils of which are inserted one in the main and the other in the artificial line and are arranged to act in an opposite directionon an armature common to both, drawing said armature to either the one side or to the other side,pr'essing one or the other of the contact-arms away from the central contact-stop, thereby breaking and keeping open the local circuit on the controlling instrument as long as one of the magnets of the shunting -'relay is enough stronger than the other magnet to overcome the retractile springs, which are adjusted to a prearranged strength,as hereinafter set forth.

Referring to the accompanying drawings, which are made a part of this specification, Figure 1 gives a general outline of the arrangement and connections of the receiving and controlling instruments in the main and artificial line and the local circuit of the con trolling instrument at the one end of a cir cuit and shows a dynamo or source of power at the other or distant end of the circuit. Fig. 2 gives a side view of a modified form of the controlling instrument, a top view of the rheostat, a battery or source of power, and an electromagnet in the rheostat-circuit arranged to'polarize or reverse the polarity of the needle as the polarity ofthe coils of the controlling instrument is changed by a reversal of current through them from the home battery, and thus compelling the needle to be always drawn toward the stronger coil'irrespective of the changes in the polarity of the current passing through them from the home battery. Fig. 2 also shows local contact-stops ,to the needle, a local circuit between said needle and contact-stops, and a local battery and magnets in said local circuit.

Again referring to Fig. 1 and starting atM B, the main battery N R is a neutral relay, P R a polarized relay.

S R S R are the magnets of a shunting-relay having a single winding, magnet S R loeing connected in the main-lineside of the circuit and magnet S R connected in the rheostat or artificial-line side.

S is a non-polarized armature pivoted to' swing between and common to both magnets S R and S R, the free end of said armature extending between the free ends of contactarms h h.

h and h are contact-arms trunnioned at i.

l is a limit or contact post, against. which contact-arms hand h rest.

j and jareadjustable springs arranged to draw or press contact-arms hand h toward each. other and against the limit or contact stopl, and thuscomplete the local circuit shown from needle or through contact-arm h, stop Z, and contact-arm h to and through local battery L B and local magnet m or m to stop 3 or s. v

W represents condensers attached to the artificial linethrough the adjustable resistance v,-and R represents an automatic rheostaf. (Covered by patent previously referred to.

In Fig. 2 the current is shown as passing from one pole of the main batteryMB through coil 0 to the main line and through coil 0, magnet K, and rheostat R to ground at G. The needle 01 is shown pivoted to one end of the core of magnet K at t and'is thereby magnetized by said magnet. Therefore if opposite magnetic poles are'presented to each other and to needle n' by coils O and C by reversing the poles ofmagnet K and needle at every time the current is reversed through the coils by the home battery needle 'n' will be compelledto pull always toward the shorter and thereby the stronger side instead of swinging from sideto side on each reversal of the current through said coils, as would be the case were the needle permanently magnetized. Now assuming that retractile springs j and j (shown in Fig. l) have been adjusted so that contact-arms h and h cannot be drawn away from post Z by less than an excess of one-fourth of the full strength of the main battery passing through one side more than through the other side of the circuit the action of different currents passing through the magnets S R and S R of the shunting-relay and through coils O and O" of the controlling instrument and their action with or on each other and on the rheostat or artificial line is substantiallyasfollows: Withthedistantend of the main line to ground the current from the home battery would divide, going to the line on the one side and to the ground through the rheostat on the other side, and if the resistance in the rheostat equaled the resistance of the main line the current from the battery would divide equally through each side and have equal effect on armature so or needle N; but if the line had, say, a resistance of three thousand five hundred ohms and the rheostat a resistance of four thousand ohms there would more current go through the main line than through the artificial line, and while this difference in strengthof current would not be great enough to enable shunting- -inagnet S R to attract armature S with suffi- ,;the' local circuit.

cient strength to cause it to overcome spring j and press contact-arm h. away from post Z it would be great enough to cause mutilated signals by the receiving instruments and would also be great enough to cause coil 0 of the controlling instru ment to attract the lower end of needlen and causing its upper end to swing against stops, closing the local circuit through m and cause rheostat R to act and its resistance to be changed until it equaled the resistance of the line, when coils C and 0, having regained equal strength, would have an equal attractive power over needle 11 and draw it again to a central position and break Now with both branches of the circuit of equal resistance if a positive current of a certain strength be sent to line from the home battery and a negative current of equal strength be sent to line from the distant station the effect would be to double the attractive power of magnet S R and coil C, causing armature S to be strongly drawn against arm 71, pressing it away from stop Z and open the local circuit shown from needle n through arm h, stop Z, arm it, local battery L B, and magnet m to stop sand preventing needle 01 from closing said circuit by being drawn against stop 8, and thus preventing rheostat R from being actuated and the resistance in the artificial line from being changed or with the positive current from the home battery remaining to line and the current at the distant end being reversed, sending a current of positive polarity to line,

the result would be to neutralize the magnetizing effect of each other on magnet S R and allow magnet S R to attract armature sa and,

as long as a current is sent from the distant station the effect will be to cause magnet S R or S R to act on armature sot, causing it in turn to act against contact-arms h or h and prevent coils G O and needle n from being able to have any eitect on or control over magnets m or m and through them on automatic rheostat R; but as soon as the battery is taken off at theudistant end and the'wire put to ground the home battery splits through magnets S R and S R andcoils C and O, causing coil C or C to act on needle 11 and through it on magnets m or m up to a dif ference of resistance in the main and art1ficial line equal to the strength at which retractile springs j andj' have been set, which would normally be one-fourth of the strength of the main battery, as that is the lowest division of battery made in quadruplex circuits, and as the difference of resistance at which mutilated signals are caused is much less than this equivalent there is quite a wide margin between the resistance at which coils O O would be able to act on rheostat R and the resistance at which magnets S R S R would prevent them from acting by causing armature set to break the local circuit controlled by needle 91. It can therefore be seen that it is possible for a person at one end of a circuit to balance the instruments at the other end of the circuit by merely cutting off his own battery and putting the wire to ground, thus saving much valuable time and preventing annoying delays.

Now, having described the action of the different parts on or with each other, what I claim as new, and desire to secure by Letters Patent, is

1. In a multiplex-telegraph circuit,the combination of a shunting instrument, consisting of electromagnets, an armature, common to said magnets, contact-arms, a contact-post, separating the latter, and the adjustable springs, cooperating with said contact-arms,

with the controlling instrument and its local circuit, and means actuated by said local circuit, for varying the resistance of the artificial line, substantially as set forth.,

2. In a multiplex-telegraph circuit,the combination of ashunting instrument, consisting of electromagnets, an armature, common to said magnets, the contact-arms, a contactpost, separating the latter, and the adjustable springs, cooperating with said contactarms, with the controlling instrument and its local circuit,'and the main and artificial line, and means actuated by said controlling instrument, for varying the resistance of the artificial line.

3. In a multiplex-telegraph circuit,the comof electromagnets, an armature, common to said magnets, contact-arms, contact-post, and adjustable springs, with the controlling instrument, its local circuit, the local magnets, in said local circuit, and the automatic rheostat, all substantially as and for the purpose set forth.

4. In a multiplex-telegraph circuit,the combination of a shunting instrument, consisting of electromagnets, an armature, common to said magnets, the contact-arms, a post, separating the latter, and the adjustable springs, cooperating with said contact-arms, with the controlling instrument and its local circuit, the main battery, the receiving instruments, the main and artificial line and condensers, and means in said artificial line, operated by said controlling instrument for varying the resistance of the artificial line, substantially asset forth.

5. In a multiplex-telegraph circuit,the com bination of a controlling instrument, having coils of wire, a needle, common tosaid coils and pivoted to an electromagnet, local contact-stops, for said needle; and said magnet, connected in the artificial line, with the local circuit, the local magnets, in said circuit, the main battery, the main and artificial line, and means in said artificial line for so adjusting the resistance of the latter, that the resistance of the main line and artificial line are always equal, all substantially as and for the purpose set forth.

LAWRENCE A. MCCARTHY.

Witnesses:

O. R. DANFORTH, M. MCCARTHY.

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