US461464A - Frank b - Google Patents

Frank b Download PDF

Info

Publication number
US461464A
US461464A US461464DA US461464A US 461464 A US461464 A US 461464A US 461464D A US461464D A US 461464DA US 461464 A US461464 A US 461464A
Authority
US
United States
Prior art keywords
circuit
line
magnet
armature
contact
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Publication date
Application granted granted Critical
Publication of US461464A publication Critical patent/US461464A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B25/00Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems
    • G08B25/12Manually actuated calamity alarm transmitting arrangements emergency non-personal manually actuated alarm, activators, e.g. details of alarm push buttons mounted on an infrastructure

Definitions

  • This invention relates more particularly to fire and police signaling systems, and to that class of systems wherein a call or signal can be sent from the central oflice to any box or station on a policemans beat or elsewhere, and wherein, also, a signal can be sent from said station to the central office, as a fire-alari'n,
  • One object of the invention is to utilize a normally-closed circuit to send the various calls in either direction to or from any box or station in circuit with the central office.
  • Another object is to utilize a normally-open circuit in connection with said normally-closed circuit to prevent more than one call or signal from passing over the main line at one time and to hold in check any signal mechanism that may be pulled simultaneously with the one nearest the central office, or while one call or message is being delivered, and to then permitthe call from the nearest of said pulled mechanisms to pass along the line, and so on consecutively till all the pulled boxes have sent their calls, whilealso preventing the central oflice from sending a call to a station or box while a call is passing from the box to the central office, and also preventing the call from passing from a box to the central office while the central office is sending a call to a box,whereby after the call is recorded in the central-oftice register the circuit will be restored automatically and the central office will be free to send its call to a box or station, while the call-boxes at the several stations will also then be free to send their messages.
  • Figure l is an elevation of my improved system and mechanism used therewith, part of the mechanism being in section.
  • Fig. 2 is an enlarged detail view, partly in section, on the line 2 2, Fig. 3, showing part of the signaloperating mechanism in the police-call box.
  • Fig. 3 is an edge view, partly in section, of the mechanism shown in Fig. 2.
  • Fig. 4 is a horizontal section of the register at the central oflice, showing the means for controlling the mechanism for sending a police call from the central office and for restoring the normally-open circuit; and
  • Fig. 5 is a section on the line 5 5 of Fig. 4.
  • Fig. 1 the mechanism on the left is that situated at the central office.
  • the mechanism on the right is that contained in the box from which police and fire alarms are sent to the central office, and the series of boxes in the center of the drawing are the call-boxes, simi- 7o lar to that on the right, in circuit in the main line.
  • the letter a: in the drawings indicates the main line for sending messages, calls, or signals to and from the centralotiice.
  • Said main line is a normally-closed line provided with a suitable battery B are police and tire signaling boxes in circuit in the main line and containing mechanism for sending and receiving calls or sig- 8o nals. There may be any desired number of said boxes in the main line at, in the example shown there being nine.
  • a police-signal-receiving mechanism D In each boxBthere is a police-signal-receiving mechanism D, a police-call-sending mechanism E, and a fire- 85 alarm-sending mechanism F.
  • In themain line w is also the mechanism G'for sending a police-signal to any box B.
  • This mechanism as shown, consists of two circuit-breaking wheels G G which have a notch a. for each 0 box B.
  • In the line a: are two contacts I) b to engage the circuit-wheels G G respectively, as shown.
  • the shaft (1 also carries a starnal D which is to be operated in a box B wheel 9 which is adapted to be engaged by 7c from the central station only when the hana pin or lug g or a projection g carried by 5 die 5 is placed over a number on the dial H the lever K. (See Figs.
  • A is always in electrical connection with the is a battery connected with the main line x 100 shaft d as shown.
  • the shaft (1 also carries say between A and G.
  • the battery A also 3 5 a circuit-breaker 6 which has a notch or de leads by a wire 00 to a contact i, preferably pression 6 about in line with the projection situated in the dial H.
  • the handle b carries a circuitcircuit-breaker e closer or contact-strip i which is adapted to J is a magnet in the mam line as and conclose the circuit between 00' and 00 through i nected with the contact 6.
  • the above parts are shown in their normal
  • the circuit-wheels G G3 each have a long 110 positions, and the circuit is normally closed break i in such a position that when the strip 5 throughf, 6 (:1 e, and J; but when the shaft 1' is moved to engage the contacts i 2' the cird is turned sufficiently far to cause the procuit will be broken through I) b and closed jeetion d to engage the contact (1 the circuit through 2' 2' thereby throwing the battery A will be broken throughf, e 6 d c, and J, into the main line m, in addition to the bat- 115 and closed through 01,61 ,61 and e,thus throwtery A, whereby a current of increased ing the magnet I in the line so, so that its arstrength passes over the line 00.
  • Thisinmature I can be operated; but the armature creased current energizes the magnet J, so as I is polarized with a pole opposite to the pole to draw the armature JZ'thereby causing the from whence the current in the line w norpawl g to turn the ratchet g and shaft d one 120 mally flows, so that the armature I will not tooth or space, at the same time moving the be actuated until a reverse current is passed pin g out of the space 71 and within the cirthrough the line, as hereinafter specified.
  • the operator at the central office desires to operate the signal D in one of the boxes B-say box 9.
  • the parts in all the boxes being in their normal positions, the pins 9* will be in their respective spaces 713 in the wheels h.
  • the operator now turns the handle b which first makes contact through i 1' 2' therebyincreasin g the' current through 00, as before stated, whereupon the shaft d will be moved one space.
  • the shafts d in all the boxes B will be turned step by step, causing the magnet 1 to be cut into and then out of the line in the boxes 1 2 3, &c., consecutively until the handle b is brought to rest over 9 on the dial, when theline willbe closed through (Z d (1 &c., and broken through f, 6 e and diwhereby the signal D will be brought into circuit in the box desired.
  • the projections d in the other boxes B do not at this ti me engage the contacts 5?,they having passed that point, the signals in the other boxes B will not be in circuit.
  • the handle b will be brought over the space 10 on the dial, whereby the projections d in all the boxes B will be in contact with their respective contacts (1 to close the circuit in all the boxes B through the magnets 1
  • the following is one means for sending a current through the line a: to operate the signal D
  • the current passing from the battery A through the line 00 in the direction of the arrows is preferably a positive current, and the armature I of the magnet l is polarized with a positive pole, so that it will not be actuated by the normal positive current pass ing through the magnet 1 In order that the armature 1 may be attracted, a negative current must be sent through the line 00 in the direction of the arrow.
  • I insert two contacts 1t and 12 in the line as. l-t, 15, 16, and 17 are circuit-breakers carried by a shaft 18, insulated from each other and from said shaft.
  • the strip 11 is adapted to contact the cir-.
  • a contact strip 19 which leads through the line in to the negative pole of the battery A.
  • the negative .pole of the battery A connects by a wire 20 with a contact-strip 21, adapted to engage the circuit-breaker 15. engaging the circuit breaker 15, connects with the line 00.
  • the current passes from the positive pole of the battery through 11 14 19, through theline 00, to 22 15 21 20, to the negative pole of the battery.
  • the positive pole of the battery connects with the contact-strip 12, adapted to engage the circuit-breaker 16 (as isalso the strip 23) on the same side of the line as 22; but 12 and 23 are normally out of contact with 16.
  • the negative pole of the battery also con- Another contact-strip 22,
  • the armature I may be made to vibrate while the circuit remains closed in manner well known, or the circuit-breakers.
  • circuitbreakers 14, 15,16, and 17 may be rotated by handor by suitable mechanism to make and break the circuit continuously.
  • the circuitbreakers 14, 15, 16, and 17 should be turned back to the position shown in the drawings.
  • M is the register at the central office in circuit with the main line or, as shown.
  • Thepolice-call mechanism E and the firealarin mechanism F in each box B are each in circuit with the main line 00, but will only operate when a normal current from the battery A is passing over the line.
  • the call or signal-sending mechanisms proper E and F maybe of suitable construction, in the example shown E F 'being the call or signal writing wheels of said mechanisms, respectively,
  • E F beingcontacts to engage the wheels E F respectively.
  • the breaks in the wheel. E are preferably short, while in the fire-call F the breaks on the long, for the purpose wheel F are preferably hereinafter set forth.
  • each mechanism E and F is a magnet N in circuit with the line 1 or a branch thereof, one terminal of said magnet leading to a contactN N is another contact adapted to engage N but normally out of contact therewith, which contact N leads by a wire y to zero or ground.
  • the normally-open circuit y will be closed.
  • the line or circuit y is a magnet 0, one terminal of which leads through the battery 0 to ground, while the other terminal leads to a contact 0 normally in contact with a circuit-breaker P.
  • the breaker P has a pro jection j, normally in contact with a contactstrip P in circuit in the line 'y.
  • the circuit breaker P is held in the position shown by a catch or lever Q engaging a pin 7' on the breaker P.
  • the catch or lever Q also carries the armature Q of the magnet 0, so that when said armature is attracted the breaker P will be released, which will then be moved to break the circuit through j P by means of a spring Z, connected to an arm Z rigidly connected with the breaker P, which spring moves the breaker P to cause the projection j to pass from under the contact P
  • the motion of the arm Z or the breaker P is limited by stop I l R is a rod shown resting on the arm Z and adapted to slide in bearings m and to be raised by the action of the spring 1.
  • the rod R is adapted to prevent the handle 19 from being moved when .the circuit is closed through N N and for this purpose I have shown an arm R connected with the handle L -say by being secured to the shaft b This arm R is in such a position that when the parts are in their normal positions the rod or stop R will not engage the arm R but when the circuit is closed through N N the armature Q will be attracted, thus releasing the breaker P, whereupon the spring Z will act to pass the rod R in front of the arm R as shown in dotted lines, and thus prevent the handle 19 from being turned.
  • the operator at the central office is prevented from turning the handle 19 to send a call or interrupt the call from E or F.
  • the armature n of each magnet N is carried by a lever M, which has a projection or arm j "n which is adapted to hold in check the escapement n of the call or signal-writi ng mechanism E and F-say by coming against an arm n, connected with 71 as shown.
  • the end of the lever or catch 0 is adapted to pass in front of the lever n when the armature n is attracted by the magnet N.
  • the lever 0 is also engaged by an arm 19, connected with the handle q of the call mechanism E and F.
  • the arm 19 is adapted to engage the contact N and to close the circuit between N and N hen this is done the armature n will be attracted, which will raise arm n and release the escapement n to permit a message to be sent along the line at.
  • the armature 0 will attract its armature O whereupon the circuit breaker P will be moved by its spring land break the line through jP while the rod R will be I moved to prevent the handle b from being turned.
  • the call or signal will be received by the register M or otherwise.
  • the magnet f the bell V is in circuit in the main line as and its armature V or thearmature-support is normally held against the magnet V by the closed circuit through
  • One terminal ofthe bell mechanism V leads to a contact that is adapted to be engaged by the armature V or its support. Said armature or its support forms part of the circuit of the bell V, as shown.
  • the other terminal of the bell mechanism V leads by a Wire t to a battery A
  • the spring u for the armature V is of such a weak tension that when short breaks pass through the mag net V from the writing-wheel E the spring '11, will not have strength to draw the armature V away from its magnet V and therefore the circuit will not be closed through V 13 and therefore the bell V will not be rung by the current from E but when long breaks from the wheel F of the fire-alarm pass over the line x the spring it will have sufficient time to draw the armature c and thus close the circuit through V 29, whereupon the bell V will be sounded to notify the attendant that a fire-alarm is being received by the register or recorder M.
  • the strip 2' will contact to and 10 and thus the line y will be closed through 10 i 10 If now the operator turns the handle b the circuit will be broken through 1 at w 10 1 as then disconnects from w 20 and if any mechanism E or F should be pulled While the line y is broken at w 10 the call will be held back, as the mag 'net N- (not then'being energized) cannot attract its armature n, and therefore the esy through P, and releasing the handle iVhen the handle b is at capementn will not be released to permit the call to pass from E or F.
  • a signaling system comprising a normally-closed main line, a series of transmitters in said line, a signal-sending mechanism in said line located at the central otfice, a normally-open ground-circuit y, connecting with said transmitters, and circuit-breakers connecting the line y with said signal-sending mechanism, so that when said signal-sending mechanism is actuated the line y will be broken by it, substantially as described.
  • a normally-closed main line a series of transmitters in said line, signal-sending mechanism also in said line and located at the central office, a handle, as b for said signal-sending mechanism, and-a separate normally-open ground-line y, connecting said transmitters, said handle carrying a contact to make and break the line y when said signal-sending mechanism is actuated, substantially as described.
  • a signaling system comprising a normally-closed main line, a signal-sending mechanism in said line located at the central office, a series of transmitters also in said line, a normally-open grou nd-circuit connecting said transmitters, and mechanismin said open circuit to preventthe signal-sending mechanism in the main line from being'operatedwhen a transmitter is using the main line, substantially as described. 5.
  • a normally-closed main line asignal-sendin g mechanism in said line located at the central office, a series of transmitters also in said line, a normallyopen ground-circuit y, connecting saidtransmitters, circuit-breaking mechanism conn ectingthelineg/ with said signal-sending mechanism to break said line y when the signal-send 1mg mechanism is actuated, and mechanism in said open circuit to prevent the signal-sending mechanism from being operated when a transmitter is using the main line, substantially as described.
  • a normally-closed main line a series of transmitters in said main line, and a signal-receiving mechanism, as M, also in said main line, a normally-open ground-circuit y, connecting with said transmitters a circuit-breaking mechanism, as O P, in said line y, and a magnet connected with said signal-receiving mechanism for restoring the circuit in y automatically after the signal is recorded, substantially'as de scribed.
  • a signaling mechanism a normallyclosed main line, a signal-sendin g mechanism in said line, a series of transmitters in said main line, and a signal-recording mechanism also in said main line, anormally-open groundcircuit y, connecting with said transmitters, circuit-breaking mechanism, as O P, in said line y, a magnet, as S, connected .with the signal-recording mechanism for restoring the circuit in 3 after the signal is recorded, and
  • a normally-closed main line a signal-sending mechanism in said line, a series of transmitters in said main line, and asignal-recording mechanism also in said main line, a normally-open ground-circuit y, connecting with said transmitters, circuitbreaking mechanism connecting said line.
  • a normally-closed main line, circuitbreakers G b in said line, a handle, as 19 for said breakers, and an arm or the like R a series of transmitters in said line, a signalrecording mechanism M in said line, a normally-open,ground-circuit y, connecting with said transmitters, terminals 40 40 in said circuit, contact i on the handle b to close and breakthe circuit in y through to 40 magnet 0, contacts 0 P circuit-breaker P, having projection j, catch Q, armature Q arm Z spring Z, rod R, magnet S, armature S a linecircuit connecting the magnet S with the mechanism M, and mechanism in M to close the circuit through magnet S after the signal is recorded in M, substantially as described.
  • a normally-closed main line a transmitter Whose call-writing wheel has short breaks, another transmitter whose call-writing wheel has long breaks, a normally-open ground-circuit y for controlling said transmitters, a magnet, as V in' said main line, a bell, as V, in a separate circuit, the armature of the magnet V being included in the circuit of the bell V, and the armature-sprin g u, of such a weak tension as to actuate said armature when long breaks pass through the magnet V but to not actuate said armature when short breaks pass through the magnet V substantially as described.
  • a normallyclosed main line containing a battery, a circuit-breaker, as G b, in said line, a magnet J in the line, the armature J for said magnet being normally out of the magnetic field of said magnet, .
  • a normally-open short circuit as w x containing a battery, as A and extending from one part of the main line to another between the main battery and the magnet J, a contact-maker connected with the circuit-breaker G b for automatically closing the circuit through :20 00 to throw the battery A into the main line to increase the magnetic field in magnet J, so as to attractits armature, substantially as described.
  • a normally-closed main line and asigrial-sending mechanism located at the central ofiice, combined with a magnet J, whose armature J is normally out of the magnetic .field,'lever K. carrying said armature, and
  • pin or projection 9 carried by said lever, and with a wheel having a hollow or depression on one side to receive the pin g to hold the armature within the magnetic field of J, and
  • a normally-closed. main line a magnet 1 having a polarized armature and a semaphore connected thereto, and a catch, as Z, for holding said semaphore after the current leaves themagnet, combined with a door, a connection on the door for releasing the catch when the door opensto release the semaphore, and with a current-reverser in said line for actuating said semaphore when a reverse current passes through the main line, substantially as described.

Description

(No Model.) 2 Sheets-Sheet 1.
F. B. WOOD. NON-INTERFEBING SUGGESSIVE SIGNALING SYSTEM AND APPARATUS.
Patented Oct. 20, 1891.
wwmwoeo (No Model.) 2 Sheets-Sheet 2.
F. B. WOOD.
NON-INTERFERING SUGGESSIVE SIGNALING SYSTEM AND APPARATUS;
N01 461,464. Patented Oct. 20,1891.
' wve/nboz wimaooeo J (W I m Mona/cue me wows vzrzas cm, moro-u'mo., wasnmcron, :14 c.
UNITED- STATES PATENT OFFICE;
FRANK B. IVOOD, OF NEIV YORK, N. Y., ASSIGNOR TO'THEODORE W. BAYAUD,
' OF SAME PLACE.
NON-INTERFERING SUCCESSIVE SJGNALI NG SYSIEM AND APPARATUS.
SPECIFICATION forming part of Letters Patent No. 461,464, dated October 20, 1891. Application filed October 24,1890. Serial No. 369,205. (No model) T at whom it may concern:
Be itknown that I, FRANK B. VOOD, a resident of New York city, county and State-of New York, have invented certain Improvements in Successive Non-lntertering Electric Signaling Systems and Apparatus, of which the following is a specification.
This invention relates more particularly to fire and police signaling systems, and to that class of systems wherein a call or signal can be sent from the central oflice to any box or station on a policemans beat or elsewhere, and wherein, also, a signal can be sent from said station to the central office, as a fire-alari'n,
or another signal, as a police message.
One object of the inventionis to utilize a normally-closed circuit to send the various calls in either direction to or from any box or station in circuit with the central office.
Another object is to utilize a normally-open circuit in connection with said normally-closed circuit to prevent more than one call or signal from passing over the main line at one time and to hold in check any signal mechanism that may be pulled simultaneously with the one nearest the central office, or while one call or message is being delivered, and to then permitthe call from the nearest of said pulled mechanisms to pass along the line, and so on consecutively till all the pulled boxes have sent their calls, whilealso preventing the central oflice from sending a call to a station or box while a call is passing from the box to the central office, and also preventing the call from passing from a box to the central office while the central office is sending a call to a box,whereby after the call is recorded in the central-oftice register the circuit will be restored automatically and the central office will be free to send its call to a box or station, while the call-boxes at the several stations will also then be free to send their messages.
The invention consists in the novel details of improvement that will be more fully hereinafter set forth, and then pointed out in the claims.
Reference is to be had to the accompanying drawings, forming part of this specification,
wherein Figure l is an elevation of my improved system and mechanism used therewith, part of the mechanism being in section. Fig. 2 is an enlarged detail view, partly in section, on the line 2 2, Fig. 3, showing part of the signaloperating mechanism in the police-call box. Fig. 3 is an edge view, partly in section, of the mechanism shown in Fig. 2. Fig. 4 is a horizontal section of the register at the central oflice, showing the means for controlling the mechanism for sending a police call from the central office and for restoring the normally-open circuit; and Fig. 5 is a section on the line 5 5 of Fig. 4.
In Fig. 1 the mechanism on the left is that situated at the central office. The mechanism on the right is that contained in the box from which police and fire alarms are sent to the central office, and the series of boxes in the center of the drawing are the call-boxes, simi- 7o lar to that on the right, in circuit in the main line.
The letter a: in the drawings indicates the main line for sending messages, calls, or signals to and from the centralotiice. Said main line is a normally-closed line provided with a suitable battery B are police and tire signaling boxes in circuit in the main line and containing mechanism for sending and receiving calls or sig- 8o nals. There may be any desired number of said boxes in the main line at, in the example shown there being nine. In each boxBthere is a police-signal-receiving mechanism D, a police-call-sending mechanism E, and a fire- 85 alarm-sending mechanism F. In themain line w is also the mechanism G'for sending a police-signal to any box B. This mechanism, as shown, consists of two circuit-breaking wheels G G which have a notch a. for each 0 box B. In the line a: are two contacts I) b to engage the circuit-wheels G G respectively, as shown.
b is a handle on the shaft 11 of the circuitwheels G G whereby said wheels will be turned simultaneously to break thecircuit through b 12 Of course this mechanism G (l b b can be altered as desired.
H is a dial or the like carrying graduations 1 2 3 4,850.,130 indicate the different boxes B, I03 and the handle I) will first be placed over any number on the dial in order to operate the mechanism D in the desired box 13. In the thereby the circuit-breakers d e the same mechanism D,I have shown asemaphore-sigdistance. The shaft (1 also carries a starnal D which is to be operated in a box B wheel 9 which is adapted to be engaged by 7c from the central station only when the hana pin or lug g or a projection g carried by 5 die 5 is placed over a number on the dial H the lever K. (See Figs. 2 and 3.) Said starcorresponding to the box B desired; but an wheel and lug act to prevent the Wheel 9 audible or flash signal can be used in place from being turned too far by the pawl g or of the semaphore D if desired. The semaby any momentum said wheel may acquire. 75 phore D is shown connected with an arma- On the shaft (Z is also a wheel or disk 71,
[O ture I of the magnet 1 in the main line a: or that has an annular flange or projection 71 a branch 00 thereof. One terminal of the on one side, wherebya hollow spaceis formed magnet I is connected by a wire 00 with a on one side of the wheel h. (See Figs. 2 and contact-strip d, that is adapted to engage a The pin g passes into said hollow space 80 circuit-breaker d on a shaft d journaled in and is adapted to ride along the inner side the box B. The contact d is normally out of of the flange 72?. One part of the flange h engagement with the circuit-breaker 61 but is cut away, as at 71 so that the pin g can the latter has a projecting part d which will enter the space 7t to move the armature J engage the contact (1 when the circuit-breaker farther away from its magnet J than when 85 d is turned sufficiently far. The projections the pin g is on the inner side of the flange d are so arranged in the several boxes Bthat 77. The pin g is in the space h when the only one projection d in all the boxes B will other parts are in their normal position, as engage its respective contact cl at one time; in Fig. 1. Pins h limit the movement of the but there is also on each breaker (1 another lever K. o projection d adapted to engage the breaker The strength of the current from the batd. These projections d in all the boxes B- tery A, which normally works the main line,
are all in the same relative positions with rewill not be sufficient to cause the magnet J lation to the contact (I, so that when the hanto attract its armature J when the ping is die I) is turned to, say, 10 all the projections in the space h ,(the armature then being out 5 d will engage all the contacts d, whereby all of the magnetic field,) so thata stronger ourthe signals D can be operated simultaneously. rent must be used to draw the armature J 10 e is a contact-strip in circuit in the main its magnet, and thus move the pin g out of the line w, (or a branch thereof,) which contact 6 space 71 This I accomplish as follows: A is always in electrical connection with the is a battery connected with the main line x 100 shaft d as shown. The shaft (1 also carries say between A and G. The battery A also 3 5 a circuit-breaker 6 which has a notch or de leads by a wire 00 to a contact i, preferably pression 6 about in line with the projection situated in the dial H. i is another contact (1 on the circuit-breaker (1 adjacent to but insulated from the contact fis a contact-strip in the main line as (or 11, which contact 1' leads by a wire 00 to the r05 a branch thereof) and adapted to engage the main line 00, The handle b carries a circuitcircuit-breaker e closer or contact-strip i which is adapted to J is a magnet in the mam line as and conclose the circuit between 00' and 00 through i nected with the contact 6. and 1 The above parts are shown in their normal The circuit-wheels G G3 each have a long 110 positions, and the circuit is normally closed break i in such a position that when the strip 5 throughf, 6 (:1 e, and J; but when the shaft 1' is moved to engage the contacts i 2' the cird is turned sufficiently far to cause the procuit will be broken through I) b and closed jeetion d to engage the contact (1 the circuit through 2' 2' thereby throwing the battery A will be broken throughf, e 6 d c, and J, into the main line m, in addition to the bat- 115 and closed through 01,61 ,61 and e,thus throwtery A, whereby a current of increased ing the magnet I in the line so, so that its arstrength passes over the line 00. Thisinmature I can be operated; but the armature creased current energizes the magnet J, so as I is polarized with a pole opposite to the pole to draw the armature JZ'thereby causing the from whence the current in the line w norpawl g to turn the ratchet g and shaft d one 120 mally flows, so that the armature I will not tooth or space, at the same time moving the be actuated until a reverse current is passed pin g out of the space 71 and within the cirthrough the line, as hereinafter specified. cle of the flange h The space h is now The circuit-breakers d and e are to be moved out of line with the pin g and the" actuated from the central office by means of flange 7L brought in line with the pin 9 125 the circuit-breakers G G The breakers d which thereby prevents thearmature J from e are moved as follows: To the shaft d is semoving out of the normal magnetic field of cured a ratchet or toothed wheel g, that is the magnet J when the circuit is next broken adapted to be engaged by a pawl 9 carried through 00 1) 19 When the handle 19 is next by a lever K, which carries the armature J moved farther to the right, the circuit will be 1 0 of the magnet J. The parts are so adjusted broken through i 1' thus cutting out the that each time the armature J is attracted extra battery A and restored through I) b by its magnet (through G G 1:) b the wheel G2 G thus restoring the normal current from g will be turned the space of one tooth, and A to the line 00. Each time the handle 19 is moved over a space 1 2 3, 650., on the dial H the circuit will be made and broken through Z) b G G a, whereby the shaft 61 will be turned step by step as the handle sweeps over 1 2 3, 850., until the shaft d makes a complete revolution as the handle 17 makes a revolution over the dial H.
Suppose now the operator at the central office desires to operate the signal D in one of the boxes B-say box 9. The parts in all the boxes being in their normal positions, the pins 9* will be in their respective spaces 713 in the wheels h. The operator now turns the handle b which first makes contact through i 1' 2' therebyincreasin g the' current through 00, as before stated, whereupon the shaft d will be moved one space. As the handle 17 passes over the spaces 1 2 3, &c., the shafts d in all the boxes B will be turned step by step, causing the magnet 1 to be cut into and then out of the line in the boxes 1 2 3, &c., consecutively until the handle b is brought to rest over 9 on the dial, when theline willbe closed through (Z d (1 &c., and broken through f, 6 e and diwhereby the signal D will be brought into circuit in the box desired. As the projections d in the other boxes B do not at this ti me engage the contacts 5?,they having passed that point, the signals in the other boxes B will not be in circuit. WVhen a current is now sent along the line to attract the armature I, the signal D will be operated only in the desired box. hen the handle 6 is next returned to zero, the space 71, on the wheel h will be brought in line with the pin 9 which latter will then enter said space, as before stated, ready to be again drawn out by an increased current.
If it is desired to actuate the signals D in all the boxes B at the same time, the handle b will be brought over the space 10 on the dial, whereby the projections d in all the boxes B will be in contact with their respective contacts (1 to close the circuit in all the boxes B through the magnets 1 The following is one means for sending a current through the line a: to operate the signal D The current passing from the battery A through the line 00 in the direction of the arrows is preferably a positive current, and the armature I of the magnet l is polarized with a positive pole, so that it will not be actuated by the normal positive current pass ing through the magnet 1 In order that the armature 1 may be attracted, a negative current must be sent through the line 00 in the direction of the arrow. To reverse the current for said purpose and still permit the positive current to pass in the direction of the arrow when the signal D isnot to be actuated, I insert two contacts 1t and 12 in the line as. l-t, 15, 16, and 17 are circuit-breakers carried by a shaft 18, insulated from each other and from said shaft.
The strip 11 is adapted to contact the cir-.
cuit-breaker 14, as is-also and simultaneously therewith, a contact strip 19, which leads through the line in to the negative pole of the battery A. The negative .pole of the battery A connects by a wire 20 with a contact-strip 21, adapted to engage the circuit-breaker 15. engaging the circuit breaker 15, connects with the line 00. When thus arranged ',the current passes from the positive pole of the battery through 11 14 19, through theline 00, to 22 15 21 20, to the negative pole of the battery. The positive pole of the battery connects with the contact-strip 12, adapted to engage the circuit-breaker 16 (as isalso the strip 23) on the same side of the line as 22; but 12 and 23 are normally out of contact with 16. The negative pole of the battery also con- Another contact-strip 22,
nects by a wire 24 with a contact-strip 25,
that is adapted to engage the breaker 17, (but normally out of contact therewith,) as is also a contact-strip 26, that connects by a wire 27 i with the line-wire ac. When nowitis desired to actuate the signal D the circuit-breakers are given a partial turn, which breaks connection between ll and 19' with 14 and between 21 and 22 with 15 and makes connection between 12 and 23 with 16 and between 25 and 26 with 17. The current now passes from the negative side of the battery, through 24E 25 17 26 27 I) G G b :0 m, to the magnet 1 which will i-mmediatelyattraot the positivelypolarized armature I, and thus attractthe signal D 00 d d d c J an 23 16 12 to the positivepole of the battery. The armature I may be made to vibrate while the circuit remains closed in manner well known, or the circuit-breakers.
14, 15,16, and 17 may be rotated by handor by suitable mechanism to make and break the circuit continuously. When the line is to be again used for messages, the circuitbreakers 14, 15, 16, and 17 should be turned back to the position shown in the drawings.
The above-described means for sending a reverse current through the line to actuate The current passes thence through IIO the signal D is substantially the same as that described in myapplication, Serial No. 360,779, filed August 2, 1890, and need not be here further described. M is the register at the central office in circuit with the main line or, as shown.
Thepolice-call mechanism E and the firealarin mechanism F in each box B are each in circuit with the main line 00, but will only operate when a normal current from the battery A is passing over the line. The call or signal-sending mechanisms proper E and F maybe of suitable construction, in the example shown E F 'being the call or signal writing wheels of said mechanisms, respectively,
E F beingcontacts to engage the wheels E F respectively. On the police-call E the breaks in the wheel. E are preferably short, while in the fire-call F the breaks on the long, for the purpose wheel F are preferably hereinafter set forth.
It is designed that only one call from one mechanism E or F in any box B in the line or can be sent in at once, and if more than one of such mechanisms be pulled at once or while a call is going in each will have -to wait until the one nearest the register has finished, the calls being then allowed to pass in consecutively; also, if a call is passing in from E or F, to prevent the central-oflice operator from moving the handle b to send a signal, and also, if the central officeisusing the line, to prevent a call passing alongtheline from E or F until the central office is through. This I accomplish by connecting the mechanisms E F and 1-Ib with a normally-open circuit 3 as follows: In each mechanism E and F is a magnet N in circuit with the line 1 or a branch thereof, one terminal of said magnet leading to a contactN N is another contact adapted to engage N but normally out of contact therewith, which contact N leads by a wire y to zero or ground. When contacts N N engage, the normally-open circuit y will be closed. In the line or circuit y is a magnet 0, one terminal of which leads through the battery 0 to ground, while the other terminal leads to a contact 0 normally in contact with a circuit-breaker P. The breaker P has a pro jection j, normally in contact with a contactstrip P in circuit in the line 'y. The circuit breaker P is held in the position shown by a catch or lever Q engaging a pin 7' on the breaker P. The catch or lever Q also carries the armature Q of the magnet 0, so that when said armature is attracted the breaker P will be released, which will then be moved to break the circuit through j P by means of a spring Z, connected to an arm Z rigidly connected with the breaker P, which spring moves the breaker P to cause the projection j to pass from under the contact P The motion of the arm Z or the breaker P is limited by stop I l R is a rod shown resting on the arm Z and adapted to slide in bearings m and to be raised by the action of the spring 1. The rod R is adapted to prevent the handle 19 from being moved when .the circuit is closed through N N and for this purpose I have shown an arm R connected with the handle L -say by being secured to the shaft b This arm R is in such a position that when the parts are in their normal positions the rod or stop R will not engage the arm R but when the circuit is closed through N N the armature Q will be attracted, thus releasing the breaker P, whereupon the spring Z will act to pass the rod R in front of the arm R as shown in dotted lines, and thus prevent the handle 19 from being turned. By the above arrangement when -a call or signal is being sent from E or F the operator at the central office is prevented from turning the handle 19 to send a call or interrupt the call from E or F.
To prevent more than one call or signal from any mechanism E or F in any one or more boxes B to pass over the line 00 at one time and to hold back any call or signal whose,
mechanism may be started simultaneously with another or while another is passing over the line, the following mechanism is used in connection with the normally-open circuit y: Y
The armature n of each magnet N, is carried by a lever M, which has a projection or arm j "n which is adapted to hold in check the escapement n of the call or signal-writi ng mechanism E and F-say by coming against an arm n, connected with 71 as shown. The end of the lever or catch 0 is adapted to pass in front of the lever n when the armature n is attracted by the magnet N. The lever 0 is also engaged by an arm 19, connected with the handle q of the call mechanism E and F.
The above parts are constructed and oper ate substantially similarly to the corresponding parts shown in my application, Serial No. 360,779. before mentioned, where a more detailed description is given.
The arm 19 is adapted to engage the contact N and to close the circuit between N and N hen this is done the armature n will be attracted, which will raise arm n and release the escapement n to permit a message to be sent along the line at. When the circuit is thus closed, the armature 0 will attract its armature O whereupon the circuit breaker P will be moved by its spring land break the line through jP while the rod R will be I moved to prevent the handle b from being turned. The call or signal will be received by the register M or otherwise. If more than one mechanism E or F be pulled at the same time, the armature n in the one nearest the register will be attracted and the line y broken, while all the other pulled mechanisms will be held back until said call or signal is recorded and the circuit in y restored through P, when the armature a in the next nearest mechanism will be attracted to permit that mechanism to operate, and so on through all the pulled boxes. If a mechanism E or F be pulled while a call is passing from another mechanism, said first-mentioned mechanism will not operate to send the call until the other is through,as the line y is then broken through P, and thus is not restored till after the signal is recorded; but as soon as P is restored the call from said pulled box will be recorded.
It will be seen that only one main line y is I ITO The terminals of said magnet lead by wires S S to binding.
posts 0 r on the register M, a suitable battery A being in the circuit. One of the postssay r -leads by a wire r to an insulated contactstrip 7", that is adapted to be engaged by a contact-strip T (see Figs. 4 and 5) after, the call or drawing down the arm Z lifts the contact T intermittently out of the worm s by means of the armature U and le-' Ver U whereupon, in connection with the spring .9 the contact T is prevented from engaging contact 1; but after the signal is recorded the armature U no longer lifts the contact T, whereupon the worm s will move the contact T to engage the contact r which closes the circuit through magnet S, thereby restoring the circuit in D The call-writing wheel E has short breaks, while the wheel F has long breaks. This is for the purpose of causing the bell V to be rung only when a fire-alarm is sent from F. The magnet f the bell V is in circuit in the main line as and its armature V or thearmature-support is normally held against the magnet V by the closed circuit through One terminal ofthe bell mechanism V leads to a contact that is adapted to be engaged by the armature V or its support. Said armature or its support forms part of the circuit of the bell V, as shown. The other terminal of the bell mechanism V leads by a Wire t to a battery A The spring u for the armature V is of such a weak tension that when short breaks pass through the mag net V from the writing-wheel E the spring '11, will not have strength to draw the armature V away from its magnet V and therefore the circuit will not be closed through V 13 and therefore the bell V will not be rung by the current from E but when long breaks from the wheel F of the fire-alarm pass over the line x the spring it will have sufficient time to draw the armature c and thus close the circuit through V 29, whereupon the bell V will be sounded to notify the attendant that a fire-alarm is being received by the register or recorder M.
When the operator atthe central oflice is sending a signal to D, no call or signal can be sent from E or F. This is efiected by the central oflice breaking the line 3 which is done as follows: The line 3/ leads to the dial H and is connected to the'contact strips or plates to 10 which are insulated fromea'ch other, as shown. zero or in the normal position, the strip 2' will contact to and 10 and thus the line y will be closed through 10 i 10 If now the operator turns the handle b the circuit will be broken through 1 at w 10 1 as then disconnects from w 20 and if any mechanism E or F should be pulled While the line y is broken at w 10 the call will be held back, as the mag 'net N- (not then'being energized) cannot attract its armature n, and therefore the esy through P, and releasing the handle iVhen the handle b is at capementn will not be released to permit the call to pass from E or F. As soon as the handle 6 is next returned to zero the circuit will be again closed through 20 2' 10 The magnet N in any mechanism E or F that may have beeirpulled (and the nearest one to the central ofiice that was pulled, if more than one was pulled) will immediately become energized, which will release said mechanism E or F to send the call or message, while the circuit 9 will then immediately be broken at P, thus moving .up rod R to prevent the handle '5 from being turned until after the message is recorded in M, whereupon the circuit will be restored through P, as the magnet S then draws down Z and R, releasing the. handle b Z is a catch to hold the semaphore-arm D after the magnet I actuates it. A pin or the like Z carried by the door of the box B, (not shown,) will release the arm D from the catch Z when the door is opened."
Having now described my invention, What I claim is 1. A signaling system comprising a normally-closed main line, a series of transmitters in said line, a signal-sending mechanism in said line located at the central otfice, a normally-open ground-circuit y, connecting with said transmitters, and circuit-breakers connecting the line y with said signal-sending mechanism, so that when said signal-sending mechanism is actuated the line y will be broken by it, substantially as described.
2. A normally-closed main line, a series of transmitters in said line, signal-sending mechanism also in said line and located at the central office, a handle, as b for said signal-sending mechanism, and-a separate normally-open ground-line y, connecting said transmitters, said handle carrying a contact to make and break the line y when said signal-sending mechanism is actuated, substantially as described.
3. A normally-closed main line, a series of transmittersin said line, signal-sending mechanism also in said line and located at the central oflice, a handle, as Z), for saidsignal-sending mechanism, a separate normally open ground-line y, connecting said transmitters, terminals to w in said line y and insulated from each other, and contact 2' on the handle 11 for making contact from w to 10 to close the line 3 at that point, whereby when said signal-sending mechanism is actuated the line y will be broken, substantially as described.
4. A signaling system comprising a normally-closed main line, a signal-sending mechanism in said line located at the central office, a series of transmitters also in said line, a normally-open grou nd-circuit connecting said transmitters, and mechanismin said open circuit to preventthe signal-sending mechanism in the main line from being'operatedwhen a transmitter is using the main line, substantially as described. 5. A normally-closed main line, a signal- IIO sending mechanism, as G, in said line and an arm or the like R connected therewith,a series of transmitters in said main line, a normally-open ground line 3 connecting said transmitters, a magnet, as O, in the line y, and intermediate mechanism actuated by said magnet to engage the arm B when the circuit is closed through y to prevent the signalsending mechanism in the main line from being actuated when the transmitters are being used, substantially as described.
6. A normally-closed main line, a signalsending mechanism, as G, in said line and an arm or the like R connected therewith, a series of transmitters in said main line, a normally-open ground-line y, connecting with said transmitters, a magnet O in said line y, a rod R to engage the arm R an arm Z to actuate the rod R, a catch, as Q, to hold the arm Z in the normal position, the magnet -O, actuating said catch, and a spring to move the arm Z when it is released by the magnet O, substantially as described.
7. In a signaling system,a normally-closed main line, asignal-sendin g mechanism in said line located at the central office, a series of transmitters also in said line, a normallyopen ground-circuit y, connecting saidtransmitters, circuit-breaking mechanism conn ectingthelineg/ with said signal-sending mechanism to break said line y when the signal-send 1mg mechanism is actuated, and mechanism in said open circuit to prevent the signal-sending mechanism from being operated when a transmitter is using the main line, substantially as described.
8. In a signaling system,a normally-closed main line, a series of transmitters in said main line, and a signal-receiving mechanism, as M, also in said main line, a normally-open ground-circuit y, connecting with said transmitters a circuit-breaking mechanism, as O P, in said line y, and a magnet connected with said signal-receiving mechanism for restoring the circuit in y automatically after the signal is recorded, substantially'as de scribed. l
9. In a signaling mechanism, a normallyclosed main line, a signal-sendin g mechanism in said line, a series of transmitters in said main line, and a signal-recording mechanism also in said main line, anormally-open groundcircuit y, connecting with said transmitters, circuit-breaking mechanism, as O P, in said line y, a magnet, as S, connected .with the signal-recording mechanism for restoring the circuit in 3 after the signal is recorded, and
' mechanism in said line y to prevent the signal-sending mechanismin the main line from being operated when a transmitter is being used, substantially as described.
10. In a signaling system, a normally-closed main line, a signal-sending mechanism in said line, a series of transmitters in said main line, and asignal-recording mechanism also in said main line, a normally-open ground-circuit y, connecting with said transmitters, circuitbreaking mechanism connecting said line. 11
with said signal-sending mechanism to break' said line y when the signal-sending mechanism is actuated,circuit-breaking mechanism, as O P, in said line y, a magnet, as S, connected with the signal-recording mechanism for restoring the circuit in after the signal is recorded, and mechanism in said line y to prevent the signal-sending mechanism in the main line from being operated when a transmitter is being used, substantially as described.
ll. A normally-closed main line, a series of transmitters in said main line, a signal-receiving mechanism, as M, also in said line, a normally-open ground-circuit y, connecting with said transmitters, a magnet O in said circuit y, contacts P circuit-breaker P, projection j thereon, catch Q, armature Q arm Z to actuate P, spring Z, armature S magnet S in circuit with M, and mechanism in M to close the circuit through magnet S after the signal has been received in M, substantially as described.
12. A normally-closed main line, circuitbreakers G b in said line, a handle, as 19 for said breakers, and an arm or the like R a series of transmitters in said line, a signalrecording mechanism M in said line, a normally-open,ground-circuit y, connecting with said transmitters, terminals 40 40 in said circuit, contact i on the handle b to close and breakthe circuit in y through to 40 magnet 0, contacts 0 P circuit-breaker P, having projection j, catch Q, armature Q arm Z spring Z, rod R, magnet S, armature S a linecircuit connecting the magnet S with the mechanism M, and mechanism in M to close the circuit through magnet S after the signal is recorded in M, substantially as described.
13. In a signaling system, a normally-closed main line, a transmitter Whose call-writing wheel has short breaks, another transmitter whose call-writing wheel has long breaks, a normally-open ground-circuit y for controlling said transmitters, a magnet, as V in' said main line, a bell, as V, in a separate circuit, the armature of the magnet V being included in the circuit of the bell V, and the armature-sprin g u, of such a weak tension as to actuate said armature when long breaks pass through the magnet V but to not actuate said armature when short breaks pass through the magnet V substantially as described. f
14. A normally-closed main line, a trans mitter whose call-writing wheel has short.
breaks, a transmitter whose call-writin g wheel has long breaks, a normally-open ground-circuit y for controlling said transmitters, a magnet V in said main line, abell mechanism V in a separate circuit, a terminal t in said circuit, the armature V for the magnet V adapted to close the circuit in V through the terminal t and the armaturespring u, of such a Weak tension as to actuate said armature when long breaks pass through the magnet V but to not actuate said armature when short breaks pass through the magnet V substantially as described.
15. In a signaling system, a normallyclosed main line containing a battery, a circuit-breaker, as G b, in said line, a magnet J in the line, the armature J for said magnet being normally out of the magnetic field of said magnet, .a normally-open short circuit, as w x containing a battery, as A and extending from one part of the main line to another between the main battery and the magnet J, a contact-maker connected with the circuit-breaker G b for automatically closing the circuit through :20 00 to throw the battery A into the main line to increase the magnetic field in magnet J, so as to attractits armature, substantially as described.
16. A normally-closed main line, circuitbreakers, as G b, in said line, a handle, as 19 for said breakers, contact i magnet J in said line, the armature J for said magnet being normally out of the magnetic field of said magnet, a line x 00 looped in the main line between its battery and magnet J, terminals 2' i in the line 00 00 and insulated from each other, a battery, as A in the line 00 00 the contact 2' being adapted to engage z'and i to close the circuit in Mac while the circuit is broken through G Z) to throw the battery A into the main line toincrease the magnetic field in magnet- J, so as to attract its armature, and means, substantially as described, for holding said armature within the normal magnetic field of Jafter the circuit through so 00 is broken, substantially as described.
17. A normally-closed main line and asigrial-sending mechanism located at the central ofiice, combined with a magnet J, whose armature J is normally out of the magnetic .field,'lever K. carrying said armature, and
pin or projection 9 carried by said lever, and with a wheel having a hollow or depression on one side to receive the pin g to hold the armature within the magnetic field of J, and
also having a space, as k to receive'the pin to hold the armature out of the magnetic field of the magnet J, substantially as de: scribed. i
18. Magnet J, armature J lever K, projection or pin 9 carried bysaid lever,wheel h, and flange h on said wheel, against theinner side of which the pin 9 can run to hold the ar-' mature J within the magnetic field of J, said flange having a space h to receive the pin g when the armature J is out of the magnetic field of J combined with the shaft (1 carrying the wheelh, toothed wheel and pawl g on the lever K, substantially as described.
19. Magnet'J, armature J lever K, pin g on said handle, a
wheel 9 against which said pin g is adapted to abut, whereby as the magnet J attractsits armature the shaft d will be turned step by step and over-rotation prevented by the pin g engaging the star-wheel 9 substantially as described.
20. A main line containing a magnetJ,shaft d and intermediate mechanism between magvnet J and said shaft for turning said shaft, circuit-breakers d e on said shaft, contacts cl f for said breakers, respectively, a contact 6, leading from the magnet J to the shaft d the contact d leading to one terminal of a magnet 1 whose other terminal leads to the main line, the contactf leading to the main line, whereby when 6 andfare in contact the magnet I will be out of circuit, but when d and d contact the magnet 1 will be in ci'rcuit in the main line, substantially as described.
21. A main line, a series of magnets J and I in said line, a series of shafts 61 a circuitbreaker d on each shaft (1 each circuitbreaker having a projection or circuit-closer d arran ed in the same relative position, and
a projection or circuit-closer (1*, arranged in different relative positions, contact d, leading to a terminal of the magnet 1 circuit-breaker e on the shaft (i contact f toengage the same, and contact 6, leading from the magnet J to the shaft (i substantially as described.
22. Amain line containing circuitbreakers G Z), magnets J and 1 shaft d carrying circuit-breakers e 01 contact e, leading from the shaft 61 to the magnet J, contactf, leading from the main line to circuit-breaker (2 contact d, leading from breaker d to the magnet l and a step-by-step mechanism, substantially as described, for turning the shaft d to cause 6 andfand dand d to contact each other, respectively, but alternately, substantially as described.
23. A normally-closed. main line, a magnet 1 having a polarized armature and a semaphore connected thereto, and a catch, as Z, for holding said semaphore after the current leaves themagnet, combined with a door, a connection on the door for releasing the catch when the door opensto release the semaphore, and with a current-reverser in said line for actuating said semaphore when a reverse current passes through the main line, substantially as described.
FRANK B. WOOD. l/Vitnesses:
THEO.- W. BAYARD, T. F. BOURNE.
ICC
US461464D Frank b Expired - Lifetime US461464A (en)

Publications (1)

Publication Number Publication Date
US461464A true US461464A (en) 1891-10-20

Family

ID=2530336

Family Applications (1)

Application Number Title Priority Date Filing Date
US461464D Expired - Lifetime US461464A (en) Frank b

Country Status (1)

Country Link
US (1) US461464A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050045171A1 (en) * 2003-08-26 2005-03-03 Wright Doug S. Snap-in and lock baffle
US20050072891A1 (en) * 2003-08-26 2005-04-07 Wright Doug S. Tool-less frame fastening system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050045171A1 (en) * 2003-08-26 2005-03-03 Wright Doug S. Snap-in and lock baffle
US20050072891A1 (en) * 2003-08-26 2005-04-07 Wright Doug S. Tool-less frame fastening system

Similar Documents

Publication Publication Date Title
US461464A (en) Frank b
US465989A (en) chase
US454924A (en) Frank b
US651325A (en) Electric burglar-alarm system.
US523123A (en) hibbard
USRE8891E (en) Improvement in non-interfering fire-alarm apparatus
US275005A (en) Ments
US944003A (en) Electric signal system.
US559087A (en) smith
US1218682A (en) Police signaling system.
US280707A (en) anders
US424725A (en) Electric indicator
US529986A (en) Electric signaling apparatus
US397364A (en) holcombe
US573924A (en) Fire-alarm system
US563832A (en) young
US574327A (en) Electrical annunciator
US365726A (en) Electric circuit-testing apparatus
US1225937A (en) Factory-fire-drill system.
US329468A (en) Automatic fire-alarm telegraph
US254611A (en) Egbert carter
US472359A (en) Electric indicator for railroad-blocks
US667434A (en) Signaling system.
US329188A (en) Testing apparatus for fire and police telegraph systems
US594382A (en) Signaling system