US1114939A - Selective signal system. - Google Patents

Description

W. R. TOMLIN.

SELECTIVE SIGNAL SYSTEM.

APPLIOATION rum) IEB.27, 1914.

Patented Oct. 27, 1914.

r Invemor: y/z'fnes-sesr Wesley Randavb 75mlz'n. aw w'zwf 5 Attor- THE NORRIS PETERS CO" PHOTU'LITHO" WASNINGFON. D, C.

WESLEY RANDOLPH TOMLIN, OFFORT COLLINS, COLORADO.

SELECTIVE SIGNAL SYSTEM.

Specification of Letters Patent.

Application filed February 27, 1914. Serial No. 821,425.

To all whom it may concern Be it known that I, WESLEY RANDOLPH ToMLIN, a citizen of the United States, residing at Fort Collins, in the county of Lari'mer and State of Colorado, have invented new and useful Improvements in Selective Signal Systems, of which the following is a specification.

My invention relates to improvements in electrical signal systems, and the object of the improvement is to provide a system of electrical signals wherein any number of signals may be arranged in parallel at any distance apart along a two-wire line and any one of those signals may be selected and operated from a centralstation without operating the others.

The invention is especially adapted to use in ringing the telephone bells on a telephone system, although the same apparatus may be used in the control and operation of any other kind of signals or apparatus where it is desired to operate any one along a two-wire line without operating any of the others along the same line. and adaptation in a telephone system, as more especially referred to in this specification, it makes it possible to have any number of party telephones on a two-wire line and to ring any one of the parties without ringing any of the other parties along the same line.

In the drawing the figure indicates apparatus that may be installed and used at each local party station on a four party line. In the right handportion of the drawing the insulations in the apparatus are shown in section andlin the left hand portion of the drawing the .insulations are shown in elevation.

Having reference to the letters and numerals of reference, C represents the central station with batteries or other suitable electrical power P and keys or press-buttons R and S.

A and B are the two main wires leading from the central station and represent a two-wire telephone line. tons Rand S are so connected as to constitute a pole changer so that when S is pressed the current passes in the opposite direction In its use i The keys or but- 1 out on wire B and returns on wire A... The

remainder of the figure shown on the drawa ing, exclusive of the portion C,represents m diagram the signal apparatus at any one local telephone station on a four-party line. i

a and b are the points of connection of Patented Oct.27, 1914.

the local signal apparatus to the main wires A and B, respectively. p

M and M are stationary and permanent horseshoe magnets with positive and negaw tive poles as marked.

1 is an electromagnet armatureof horseshoe magnet M and in normal positionis held away from the magnet by spring 2 carrying the armature and fastened to stationary insulation 3. a The winding on armature 1 is electrically connected directly to a. at one end and to the iron armature itself at the other.

"l; is a strip metal tongue electrically con:- nected to and carried by the armature 1. In normal position tongue 4: is held incontact with an adjustable metal screw plug 5.

(i is an adjustable metal screw plug adapted to contact with a metal block 6 carried on insulation fastened to armature 1 when 1 and 5 are in contact. a

6 is electrically connected to the wire leading from a to the winding on .armature 1.. v

7 is an iron armature of a stationary electromagnet 11. and in normal position is held away from the electromagnet by spring 8 fastened to stationary insulation 9.

10 is a bent arm carried by armature 7 and carries a knob adapted to striketongue lwhen actuated by spring 8. v

12 is an adjustable metal screw plug electrically connected with the winding onelectromagnet 11 and adapted to contact with shoe magnet M ill'llll'l normal position is.

held away from the magnet :by spring 25 carrying the armature and fastened to stationary lnsulatlon 3.

The winding on armature 1 is electrically connected directly to b by metal wire at one end and to the armature itself at the other end; 1 y r i 4 is a strip metal tongue electrically connected to and carried by the armature 1 In normal position tongue 4 is held by the spring 2 in electrical contact with an adjustable screw plug 5.

7 is an iron-armature of a stationary electromagnet 11 and is normally held away from the electromagnet by spring 8 fastened to stationary insulation 9.

10 is a bent arm carried by armature 7 and carries a knob adapted to strike tongue 4 when actuated by spring 8.

12 is an adjustable metal screw plug electrically connected with the winding on electromagnet 11 and adapted to contact with tongue 4 when the armature 1 is drawn toward the horseshoe magnet M, tongue 4 being arranged to extend in between plugs 5 and 12.

The port-ions of the local station apparatus thus far described constitute two polarized electric switches of similar construction except that the one has the extra contact 66. I

13 indicates a stationary electromagnet with iron armature 14. The armature 14 is carried by metal spring 15 fastened to stationary insulation 16. Armature 14 is electrically connected with plug 5. The spring 15 tends to hold armature 14 away from the electromagnet 13; 17 is a stationary electro magnet with iron armature 18v held away from the magnet in normal position by metal spring 21 fastened to stationary insulation 22. The armature 18 carries a block of insulation 19 which has a cut or notch in which is fastened a metal block 20 electrically connected to screw plug 5. Spring 21 is electrically connected both to the armature it carries, 18, and to screw plug 6. 23 is a metal spring strip fastened to stationary insulation 24 and is adapted to contact with armature 18 when that armature is drawn toward the electromagnet 17 and be disconnected from that armature when the armature is held away from the electromagnet in normal position as shown. Strip 23 is made adjustable by suitable means as by an adjusting screw 25'. These parts constitute a double electric release switch, it being a double switch and provides for the releasing of the cut-out apparatus after a signal has been operated, as explained below.

Armatures 14 and 18 are so arranged in the apparatus that in normal position 14 is caught and held in the cut or notch in insulation 19 and held in electrical contact with metal block 20. Then the armature 18 is drawn toward its electromagnet 17 armature 14 is released'from the notch in 19 and spring 15 carries 14 along the face of 19 disconnecting 14 from 20 and the armature 14 then acts as a brace to hold armature 18 in contact with the strip 23.

H is, a high resistance shunt electrically connecting the screw plug 5' with the end of the winding on electromagnet 11 opposite the end connected to screw plug 12, and as will be seen constitutes a shunt across a bell when a bell is ringing. Electromagnets 11 and 17 are wound in series by the same wire leading from screw plug 12.

The portion of the apparatus thus far described pertaining to a local station is a controlling unit, consisting of the two polarized electric switches and the double release switch and connections, and this unit is to be used at each local station regardless of the number of local stations on the line or the number of multiple switch cut-out units (described below) in each station. This controlling unit is of a uniform and permanent construction and may be installed on one block of insulation with six posts for connections to the cut-out units.

The portion of the apparatus next to be described, numbered from 26 to 50, inclusive, is a multiple switch cut-out or eliminating unit of a uniform and permanent construction and may be installed on a block of insulation by itself. As will be explained below, the number of these cut-out or eliminating units to be used at any local station is dependent upon the number of parties on the telephone line and thenumber of the particular station where the apparatus is installed. The drawing shows three of these units as used at a party station on a fourparty line. The units described by numbers 26 to 50, inclusive, and 26 to 50, inclusive, are in all respects constructed similar to the first unit (numbers 26 to 50).

26 is a movable U shaped block of insulation carried by a strip spring 27 fastened to stationary insulation 28. Through the body of block 26 a metal conductor 29 is. fastened with its ends extending beyond the opposite faces of the block and adapted to contact either with a metal spring contact 36 at one end or a metal spring contact 39 at the opposite end.

30 and 31 are adjustable metal screw plugs set opposite each other through the arms of the U shaped block 26.

32 is an iron electromagnet armature extending in between plugs 30 and 31 and is carried by a metal strip spring 33 fastened to stationary insulation 34.

50 is a stationary electromagnet to oper ate the armature 32. Spring 33 tends to hold armature 32 awavfrom its electromagnet 50, and 35 is an adjusting screw to liniit the movement of this armature. The iron armature 32 is placed so as to extend as a tongue in between the points of plugs 30 and 31 and is so arranged as to contact with 30 in normal position and with 31 in the set position, as explained below.

36 is a metal spring contact fastened to stationary insulation 37 and is placed with its contact end in alinement with conductor 29 and adjustedso as to contact with 29 in normal position. 38 is ascrew provided for:

between spring 36 and conductor 29 is broken.

42 is a stationary electromagnet havingan iron armature 43 carried on spring 48 fastened to stationary insulation 49. Armature 43 is arranged to rest against the end of block 26 innormal position and when the block 26 is raised or moved to a set position spring 48 carries armature 43 away from its electromagnet and past the end of block 26 thus acting as a brace holding the block in othe set position so contact 29-36 is broken and contact 29-39 is made; also contact 30-32 wouldthen be: brokenand contact 3132 made. When armature 43 is allowed to move away from its electromagnet by block 26 being lifted or moved from normal position it isarranged to strike and bear against the bent arm of a metal spring tongue 44 which is supported on stationary insulation 47. In normal position spring tongue 44 is held by its spring in contact with an adjustable metalscrew plug 45 and when pressed away from that contact by armature 43 it is pressed and held in contact with another adjustable metal screw plug 46, opposite the plug 45. In therapparatus shown on the drawing this first multiple switch cut-out unit is electrically connected with the controlling unit as follows: Screw plug 30 is connected through the winding on electromagnet 50 with screw plug 5 and armature 14 in the controlling unit; armature 32 is connected with screw plug 12 through the windingon electromagnet 11; and spring contact 39 is connected with spring contact 36 through electromagnet 42 1n the cut-out unit and electromagnet 13 in the controlling unit; a

G is an electric bell or any other electric signal or device desired connected in circuit between screw plugo and screw plug 45. G is a similar electric bell or signal in circuit between screw plug 5 and screw plug 46. Gr and G are similar bells or signals in circuit between screw 5 and screws 46 and 46 in the second and third cut-out units, respectively. As explained below, only one of these bells or signals is installed in "any one local station, the others beingreplaced by resistance coils of approximately the same resistance asa bell or signal, such resistance coils being silent signals in a local station.

Reference numerals 26 to 50, inclusive, show parts in a second cutting-out unit in all respects constructed and arranged as the respective parts inthe first unit shown by numerals '26 to 50, inclusive. And in the same manner reference numerals from 26" to 50", inclusive, show parts of a third cutout unit identical in construction and arrangement as the respective parts 26 to 50, inclusive, in the first unit and the parts 26', to 50, inclusive, in the second unit.

The electrical connections between the several cut-out units and between the controlling unit and cut-out units other than the first are as follows: Adjustablelscrew plug 30 is connected through the winding :on electromagnet 50 with screw plug 5 in the controlling unit; screw 30" is connected to the same plug in like manner through the winding on clectromagnet 50"; tongue armatures 32 and 32 areconnected with screws 31 and 31, respectively; spring con: tacts 39 and 39 are connected throughthe winding on electrolnagnets 42 and 42, respectively, and the winding on electromagnet 13 in the controlling unit with spring contact 36 in the first cut-out unit; metal conductor 29" in the last cut-out unit, regardless of the number of such units in the local station, is connectedto the connection I) on the controlling unit and tliusto the,

main line wire B; conductors 29 and 29 are connected to spring contacts 36 and 36", respectively; spring tongue 44 in the last setting unit in a local station is connected through the windings on electromagnets 17 and 11 to screw 12 in the controlling unit; spring tongues 44 and 44 are connected to 0nd and third cut-out units; and screws 46 and 46" are connected through the respective bells or signals G and G with screw 5 inithe controlling unit. Screw 31" on the last cut-out unit in a local station is connected through a resistance K approximately equal to that of the winding on an electromagnet 50, to screw plug 5 of the control ling unit.

In operation when the operator at the central station presses key or push button R the first bell G is rung when the appascrews 45 and 45", respectively, in the sec- 4 S will set the apparatus so key R will ring a,

the fourth bell G"'. And in each case only the one hell will be affected, In like manner, as will be seen, any number of additional bells might be used by installing an additional cut-out unit in the series at each local station, and the particular bell rung depends upon the number of times the operator first presses keyS. Of course, in

order to obtain the desired result it is necessary to disconnect or remove all but one bell or signal at each local station, and in such case a silent signal or resistance equal to the resistance of a bell is inserted in place of the hell or signal removed. The particular bell to be connectedat any one station depends upon the number of the station on the line in which the apparatus is being installed. I

in order that the operation may be more readily understood, assume that the apparatus at a local station on a four-party line is in normal position as shown on the drawing. If it is desired to ring bell G, which would be in the first local station along the line, the operator would merely press ringing key R. The current passes out from central on wire B, into the local apparatus at Z), through the armature winding on armature 1 through strip 4 andscrew plug 5 to armature lt and metal block 20 to screw plug 5, then through strip 1 and the winding on armature 1 back to connection a and main wire A. In the circuit thus made the armatures 1 and 1 are electrically magnetized, 1 in a manner to be attracted toward horseshoe magnet M and 1 in manner to be repelled from horseshoe magnet M. Thus armature 1 isheld in its normal position as shown in the drawing; but armature 1, magnetized by the current, overcomes the resistance of its spring and is drawn against horseshoe magnet M breaking the contact between screw plug5 and stripaand making contact between screw plug 12 and strip 4 also break ing the contact between screw plug 6 and block 6. At the instant these contacts are thus changed the current instead of passing from screw plug 5 to and through armature 1%, passes through bell or signal G, ringing the bell, through contact &511, thence through 4E51: l and 13 14, thence through the winding, on electromagnet 17, exciting that magnet and drawing its armature 18 breaking contact between 1 1 and 20. and making the contact between 18 and 23, thence through the winding on electromagnet 11, exciting this magnet and drawing armature 7 to it, thence to screw plug 12 through strip @1- and the winding. on armature 1 to connection a and back to the central station on wire A. The current being in the same direction through the winding on armature 1, this armature is still held down to horseshoe magnet M, during the ringing of the bell. To prevent armatures 1 and 7 from vibrating or fluttering when the current is being broken and made by the ringing bell, the high resistance H allows a shunt current to flow around the bell through the windings on these arniatures. Resistance H is made large enough not to interfere with the ringing of the bell and at the time small enough to allow current to pass suflicient to hold the armatures in place while the bell is ringing. When the ring key R is released by the operator and the circuit is broken, the electromagnet 1-1 releases its armature 7 and it is carried back in normal position by spring 8 and the bent arm 10 strikes strip 1 knocking the armature 1 away from permanent magnet M, and allowing it to be held back in normal condition by spring Armature 18 is still held in contact with strip spring 23 by the bracing armature L1, which has been released from the notch in insulation 19 and carried upward (in the drawing) by spring 15, bracing against the face of'insulation 19. Other than this last particular the ap paratus is then back in normal position. It will be seen,however, that the next impulse of electricity along the main line,

whether it be ringing current or setting current, excites electromagnet 13 drawing armature 11 downward (in the drawing) allowing contact 1S--23 to be broken and contact 1 120 made, bringing the entire apparatus back to normal position. The same impulse on the line that causes this latter change in armature 18 will immediately ring the bell Gr or set the apparatus, as explained below, as the case may be.

If it is desired to ring bell G the operator first presses set key S once. When this key is pressed the current passes out from the central. station on wire A. through connection a into the local station apparatus, through the winding on armature 1, through 4, 5, 20, 1-1, 15, 5, 4L, the winding on armature 1, and out at connection I) towire Bon main line. With the current in this direction, armature 1 remains stationary, but armature 1 is magnetized so as to overcome the resistance oi'i spring 2 and is drawn against horseshoe magnet M, breaking contact 4t5, and'inaking contactl'12. At the instant these contacts are changed, the current is made froniarmature 14-. and spring 15 through the winding on electromagnet 50 of the first cut-out unit to screwplug 30, thence through 32, 33, and through winding on electromagnet 11 to screw plug 12 to 41 and through winding on armature 1 to connection 7) and main wire B. With the circuit thus made the electromagnet 50 draws its armature 32 upward (in the drawing) lifting the block 26 by the contact: be tween 30 and At the same time armature 7 is drawn to its electromagnet 11, and, the currentbeing in the same direction, armature 1 is held down to horseshoe magnet M until the circuit is broken. lVhen the block 26 is raised armature 13 is allowed to slip past the end of the block and spring under and act as a brace holding the block 26 in the set position. In this position contact 29-89is made andcontact 29.-36

is broken. And by armature 43 springing away from its normal position the spring tongue 44 is pressed into contact with screw 46, and the contact 44-45 is broken. lVhen the set key S is released and the circuit broken, armature 32 is released and springs away from plug 30 into contact with screw 31; and armature 7 is released and allowed to spring away from its electromagnet and its bent arm 10 strikes strip 4 knocking armature 1 loose from horseshoe magnet M. Thus, after the set key S is pressed once and released, the entire apparatus is in normal position except that the block 26 is held in the set or raised (in the drawing) position and that cut-out unit, the first, is set, and the corresponding first signal G is cut out of circuit. Then upon the operators pressing the ring key R the second bell G is rung without affecting any of the other bells. When the first cut-out unit is thus set the corresponding first signal is cut out and when the ring key is pressed the circuit is as follows: The current passes out along wire B through connection I) through winding on armature 1, 4, 5, 14, 20, 5, 4, winding on armature 1 to connection a and back on wire A. This circuit causes the armature 1 to be drawn to magent M breaking contact 54, and the current then passes from 5 through bell G to plug. 46, thence through 44, 45,44,45,44,through winding on electromagnet l7 and winding on electromagnet 11 to plug 12, thence through 4 and windingon armature 1 and to connection a and back on main wire A. This circuit rings the bell G and operates the denble release switch in the controlling unit identically the same as the ringing current did when the first cut-out unit was not set.

and the first signal was operated, as explained above. And when the ringing current is stopped by release of the key R the cut-out unit remains set and in the release switch armature 18 is held in contact with strip spring23, by armature 14 bracing against the insulation 19, and the other portions of the apparatus automatically come back to normal position.

If it is desired to ring bell G" the operator presses the set key Stwice before pressing thering key R. Upon the first pressing of the set key the first cut-out unit is set and the first signal thrown out of circuit, as explained above, and upon the key beingreleased the remainder of the apparatus is in normal position. Then when the setting key S is again pressed the second cut-out unit is set in the same manner as was the first Then the operator presses key and bell G 1 12, thence through 4, the winding on armature 1, and to connection a. and main wire A. This ringing current affects the release switch in the controlling unit the same as explained above in connection with the ringing of bells G and G, the contact between armature 18 and spring 23 being left made and the contact between armature 14 and a block 20 being broken. In like manner if it desired to ring bell G' the setting key S is pressed three times, setting the first, second and third cut-out units successively,

cutting out of circuit the corresponding bells. Then upon the ringing key being pressed bell G is rung, the ringing current passing from the bell. directly to screw plug 464 to 44 and backon the same circuit as when any of the other signals were sounded.

After any bell has been rung the armature 18 in the release switch is held in contact with strip spring 23 and the contact between armature l4 and metal block 20 is broken. a

to normal position and also re-set armature 18 in its normal position in {the release switch as shown inthe drawing.

Assuming that all of the setting units are set and that the bell G," has beenrung, When the operator next presses a key assume that key S is pressed; the circuit is made through main wire A, connection a, block l to (5, 21, 18, 23, through the winding on 42", to 39", 29", and backto connection b and main wire B. This current excites electromagnet 42 drawing the armature 43 away from block 26 and allowing the block 26 to becarried back to normal position, thus breaking contact 3929. Then the circuit is made through the winding on electromagnet 42 and the second cut-outunit is brought to all of the cut-out units and bring them back a normal position. Then the circuit is made through the winding on electromagnet ;42,

29, etc, back to connection 6 and main switch of the controlling unit, to 36, 29, 36,

wire B. This current excites electromagnet 13 and draws its armature 14 away from the face of insulation 19 into the notch in contact with metal block 20, and spring 21 carries the armature 18 away from spring 23, releasing the entire apparatus and bringing it to normal position- Of course, as indicated above, the key S being held down at the time the apparatus is thus brought back to normal position, the first cut-out unit will be again instantly set; and if it be the key R that was pressed to bring the apparatus back to normal position, and this key being held down, the first bell G will be instantly rung. It will be seen that the pressing of the ring key R, when any or all. of the cut-out units are set and a bell has been rung, will have the same efiect in first bringing the entire apparatus back to normal position. The circuits are the, same and the direction of the current in this operation makes no difference.

From the description and explanation given above, it will be apparent that any number of cut-out units with corresponding bells or signals maybe installed and operated and controlled in a local station, the connections between any additional units and the third unit shown being made the same as between the first and second and second and third units, and the conductor 29 in the last unit being connected to 7).

In the installation of this signal system on a party line only one active bell or signal is placed in each local station, the others be-" mg removed and silent signals or resist 'ances approximately equal to that of a bell connected in their stead. The first station will have but one hell G, the second one bell G and so on. And further, by connecting the screw plug 31 in the U block of the last cut-out unit, in a station through a resistance K with the screw plug 5 of the controlling unit, it is necessary to have cutout units in any local station only in number equal to the number of the active bell or signal in that station. Thus, in the sta-' tion having the first bell G only the first cut-out unit is required to cut that signal out; and in the station having the second.

bell G only the two cut-out units, the first and second are required, and so on. In such case, where the setting key is pressed by the operator more times than there are cut-out units in a station, the setting current, after, all units are set, passes through resistance K without affecting the set units. This] not only enables the apparatus to be in- 1 stalled economically, but makes possible the; addition of any number of stations on a twowire line without the necessity of readjusting those already installed on that line. The resistance K 1s placed in each station so when a statlon of higher number is being called the armature 1 will not vibrate or' flutter because of the contact 4"5' being broken.

The shunt resistance H is required only when the signal used is a bell or other sounder where its operation makes and breaks the circuit. If the signal used allows a continuous current to flow through it the shunt H is unnecessary.

In the use of this signal system in connection with telephones the usual way of throwing the signal out of circuit when the telephone receiver is down may be employed.

I claim:

1. In a signal system a series of electric signal stations connected in parallel on a main two-wire line, each station having a controlling unit and a series of electric signals and a series of cut-out units corresponding with said series of signals, each of said cut-out units adapted whenoperated to cut out of circuit a corresponding signal, said controlling unit adapted when operated by one direction electric current through said main line to make an electric circuit through one of said signals, and said controlling unit adapted when operated by an opposite direction'current through said. main line to make an electric circuit to operate one of said cut-out units, substantially as described.

2. In a signal system the combination at a signal station of an electrically operated controlling unit, a series of electric signals, a series of electrically operated cut-out units corresponding to said series of signals, said controlling unit adapted when operated by a one direct-ion electric current to make a circuit'through one of said signals, and said controlling unit adapted whenoperated by an opposite direction electric current to make an electric circuit to operate one of said cut-out units, substantially as described. a 8. In an electric signal system the combination of a series of electric signals, a cor responding series of cut-out means, each of said cut-out means having a switch in the circuit of the corresponding signal, an electromagnct adapted to operate said switch, controlling means having polarized elect-romagnet switches adapted when operated by one direction current tomake an electric circuit through one of said signals and when operated by the opposite direction current to make an electric circuit through one of said cut-out operating electromagnets, substantially as described.

4. In a device of the character described the combination of an electric signal and a cut-out switch having electroma'gnet operating means and a polarized controlling unit in electric circuit, said controlling .unit adapted to make the circuit through said signal when an electric current passes'through said circuit in one direction and adapted to make the circuit through the operating means of said cut-out switch when an elsetric current passes through said. circuit in the oppositedirection, substantially as described.

5. In an electric signal system the combination at a signal station of an electric signal, a cut-out switch in the circuit of said signal having an electromagnet adapted to open said cut-out switch when excited by an electric current, a polarized electromagnet switch adapted when operated to make an electric circuit through said first said electromagnet, substantially as described.

6. In an electric signal system the combination at a signal station of a series of electric signals each signal having a cut-out switch in its circuit and each cut-out switch having an electromagnet adapted to open said switch when said electromagnet is excited by electric current, a polarized electromagnet switch adapted when successively operated to make successive electric circuits through the electromagnets of said cut-out switches, substantially as described.

7 In an electric signal system an electric signal, means consisting of electromagnet controlled switches in electric circuit with said signal adapted to out said signal out of circuit when an electric current passes through said circuit in one direction and to make the electric circuit through said signal when an electric current passes through said circuit in the opposite direction.

8. The combination in signaling apparatus of a controllingunit having two polarized electric switches connected in series and having opposite polarity, an electric signal, a cut-out unit having an electric switch adapted to break the signal circuit when operated and an electromagnet adapted to operate said switch, one of said polarized switches adapted when operated to make a circuit through said signal and the other polarized switch adapted when operated to make a circuit through the electromagnet of said cut-out unit, substantially as described.

9. In apparatus of the character described a controlling unit having two permanent magnets, each of said magnets having a spring supported electromagnet armature, a metal tongue carried by each of said armatures, stationary contacts adapted to contact with said metal tongues when said armatures are held away from their magnets and other stationary contacts adapted to contact with said tongues when said armatures are drawn toward their magnets, a stationary electromagnet having a spring supported armature corresponding with each of said permanent magnets, said last said armatures carrying nent magnets being oppositely wound and having their windings connected in series through said metal tongues and said contacts, substantially as described.

10. In apparatus of the character described, a multiple switch cut-out unit having a movable block of insulation, a conductor carried by said block two metal contacts in alinement with said conductor adapted to contact with said conductor when said block is moved to its extreme positions, two metal plugs carried by said block adjacent and opposite each other, a stationary electromagnet having a spring supported armature extending between said plugs and adapted to contact with said plugs when said block is moved to its extreme positions, said armature adapted to move said block when said armature is drawn toward its elcctromagnet. a second stationary electromagnet having a spring supported armature, the last said armature adapted to rest against the end of said block when said block is in one extreme position and adapted to sprin past the end and rest against the side of sald block when said block is moved to the opposite extreme position, a tongue switch adapted to be operated by the movement of said last said armaturc, substantially as described.

11. In ap aaratus of the character described a double re lease switch havinga stationary electromagnet, a sprin supported armature adapted to be operated net, said armature carrying an insulation block, a metal block carried in a notch in sald insulation block, a metal contact against, which said armature is adapted to contact when said armature is drawn toward its electromagnet, a second stationary electromagnet having an armature adapted to contact with said metal block when said first said armature is held. away from its electromagnet and adapted to race against the face of said insulation when said first said Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G.

by said olectromags

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