US2201712A - Signaling system - Google Patents

Description

May 21, 1.940. F. R. BRIDGES SIGNALING SYSTEM 2 Sheets-Sheet 1 Filed July 22, 1936 LIME F. R. BRIDGES 2,201,712 SIGNALING SYSTEM Filed July 22, 1936 2 Sheets-Sheet 2 Witness lizxvewior I Patented May 21, 1940 UNITED TES hTENT OFFICE SIGNALING SYSTEM Application July 22, 1936, Serial No. 91,825

12 Claims.

The present invention relates to signaling systems.

The principal object of the present invention is to provide a multiple circuit repeater type system, particularly suitable for fire alarms, which is simple and dependable, which affords full non-interfering operation, and which has reliable protective facilities for automatically maintaining all normal circuits in operative condition after the occurrence of a break in any circuit.

With this and other objects in view, as will hereinafter appear, the present invention comprises the system hereinafter described and particularly defined in the claims.

In the accompanying drawings, Fig. l is a diagram of the preferred system in normal or inactive condition; Fig. 2 is a diagram illustrating the operation during transmission of a code signal; Fig. 3 is a diagram illustrating the operation of the lookout relay of a faulty box circuit; and Figs. 4 and 5 are diagrams of modified systems.

The invention is herein described as embodied in a repeater type fire alarm system having a number of box circuits, but since the principles of the invention may be understood from the description of the system having two box circuits, for simplicity only two circuits are shown in the drawings. The box circuits are indicated at C and C The circuits are normally closed and each is energized by an individual battery B. Each box circuit includes a number of boxes in series, of the non-interfering and succession type. The particular box construction forms no part of the. present invention since various types of non-interfering and succession boxes may be employed, all of which operate on theprinciple that a box is unable to formulate a signal if it looks into an open line when its own contacts are closed.

At the central office each box circuit includes a normally energized main relay, the two relays being indicated at M and M Each main relay is provided with a set of three contacts designated I, 2 and 3 of which the contact 2 is movable and is normally held closed on the fixed contact I.

Associated with each box circuit is a repeater relay which is normally de-energized. The repeater relays for the two circuits are designated at R and R Each repeater relay has contacts for abnormalizing its box circuit and for controlling its corresponding main relay. These contacts are indicated at 4, 5 and '5. The contacts 4 and 6 are in series in the box circuit and are normally closed. Contact 4 is a spring contact which follows contact 6 when the latter is attracted, so that upon energization of the repeater relay its contact 4 first closes on 5 and immediately thereafter contacts 4, 6 open. Contact 5 is connected to a resistance 8 which establishes a shunt circuit around the battery and the main relay coil. Upon energization of any repeater relay, therefore, an independent energizing circuit for the corresponding main relay is established through contacts 4, 5 and the resistance 8, and the corresponding box circuit is opened at 4, 6.

One side of each repeater relay coil is connected by a Wire ID with contact I of the corresponding main relay. The other side of the relay coil is connected to the negative terminal of a local battery l2. To avoid confusion in the diagram this connection and other connections to the battery 12 are not fully shown, but are simply indicated by suitable plus and minus signs, it being understood that a plus sign represents a connection to the positive terminal and a minus sign a connection to the negative terminal of the. local battery.

Also associated with each box circuit is a lockout relay, the several relays being indicated at L and L The lockout relays are normally deenergized. Each lockout relay has a set of contacts I l, l5, l6 and H. The movable contact H5 is normally closed on the contact ll, but is adapted to close on the contact l4 when the relay is energized. The contact I4 is a spring contact which is normally closed on IE, but is moved away therefrom when the contact IE is attracted to close on l4.

Contact 2 of each main relay is connected by a wire l8 with the movable contact N5 of the corresponding lockout relay. The fixed contacts ll of all lockout relays are connected to a repeater bus D.

The main relays and repeater relays and the connections thus far described are suflicient to transmit and repeat code signals from any box in the system. The. lockout relays, as well as other parts of the system to be later described, enter into operation only upon the occurrence of a fault in one of the box circuits. Before proceeding to a further description of the other parts of the system the normal code signaling operation will first be explained.

During a code signaling operation in one of the box circuits, say C the circuit is successively opened and closed under the action of the code Wheel of the active box. This operation results in opening and closing all other box circuits in unison therewith in the following manner: Upon the first opening of the circuit C by the code wheel of the active box, the main relay M is tie-energized and its movable contact 2 falls away from contact I and closes on contact 3. The repeater relay R remains normal or deenergized because its circuit is broken at contacts I, 2 of the main relay M The repeater relay R however, is abnormalized or energized through a circuit traced from the positive terminal through contacts 3, 2 of the main relay M wire [8, contacts I6, I! of the lockout relay L the repeater bus D, contacts ll, 16 of the lookout relay L wire 18, contacts 2, l of the main relay M and the repeater relay coil R to the negative terminal. Energization of the repeater relay R attracts its contact '5 thereby permitting the independent shunt circuit for the relay coil M to be established through the resistance 8. Immediately thereafter the contact 6 breaks away from contact to open the box circuit C This condition of the system is shown in Fig. 2.

Upon closing of the box circuit C by the normal operation of the active box, the relay M is again energized and its contacts are restored to normal. This results in isolating the repeater bus D from the positive side of the battery by the opening of contacts 2, 3 of the relay M Accordingly, the repeater relay R is de-energized to close the box circuit C at contacts 4, 6 and to open the shunt circuit contacts 4, 5. Thus all parts of both circuits are restored to normal, as shown in Fig. 1. This completes a full cycle in the signaling operation. Subsequent opening and closing of the circuit C result in a repetition of the same actions.

It will be observed that the relay M of the inactive box circuit is always held normalized during transmission of a code signal in another circuit either by the box circuit current through the contacts 4, 6 or the shunt circuit current through contacts 4, 5. The result of the foregoing operation is, however, that the inactive box circuit is opened and closed at its repeater relay contacts in unison with the opening and closing of the active circuit. Since all boxes are of the non-interfering type, only the first to gain control of the system is permitted to formulate its signal, and all others are prevented from interfering therewith. It will be understood that any number of box circuits may be connected into the system in the same manner as the circuit C and C and that the formulation of the signal in any active circuit acts to open and close all inactive circuits in the manner described above for the circuit C Any suitable registers and local and public alarms may be associated with the system to operate in the usual manner.

The system also provides protective equipment for automatically isolating a broken box circuit from the remainder of the system, followed by normalization of all other circuits. This is accomplished by a time actuated mechanism which comes into operation only after a box circuit is held open for an abnormal time. The protective equipment comprises the lookout relays L L heretofore described and a single time relay T for the whole system. The time relay has contacts Zil and 21, the movable contact being connected with a timing mechanism indicated diagrammatically at 22 and of any usual or preferred form so arranged that the contacts are not permitted to close unless the relay T remains energized for a predetermined time. The timing mechanism is reset upon each de-energization' of the relay, so that the contacts cannot close until after a period of continuous energization, which is longer than the longest open interval be tween rounds of any box on the system.

One side of the relay T is connected by a wire 24 with the repeater bus D and the other side is connected to the negative battery terminal. The relay is, therefore, energized upon each energization of the repeater bus. The relay contact 20 is connected to the positive battery terminal and the contact 2! is connected to a lockout relay bus E which in turn is connected to the contacts l of all lockout relays. One side of each lockout relay coil is connected to the negative terminal and the other side is connected to its own contact l4.

When the whole system is inactive the time relay T remains de-energized since the repeater bus D is isolated from the positive side of the battery at contacts 2, 3 of all main relays. Under code signaling conditions (in circuit C for example) the repeater bus D is connected as previously described to the positive side of the battery through contacts 2, 3 of the active main relay, upon each opening of the active box circuit. Consequently the time relay coil T is energized during each open interval of the active box circuit and in unison with the repeater relay R of the inactive box circuit. Under such conditions, however, the time relay contacts 20, 2| are never permitted to close because the main relay M is always re-energized before the timing mechanism has run its course. The time relay and the lockout relays, therefore, have no effect on the signaling operation which takes place as heretofore described.

If a break occurs in a box circuit, say C the system is first operated in exactly the same manner as if C had been opened by an active box, and the system then assumes the condition shown in Fig. 2. Under these circumstances, the timing mechanism runs for a suflicient period to permit closure of the contacts 20, 21. All lockout relays are then energized by the following circuits: From the positive terminal through contacts 2!], 2i, bus E, all lockout relay contacts 15, I and relay coils L L to the negative terminal. Each lockout relay is then energized, thus attracting its contact It to close on 14 and simultaneously opening the contacts l4, 15. Also, the contacts Hi, I! are opened. To this point all lockout relays have operated in identical fashion, but subsequent actions are different for the lockout relays of the fault and normal box circuits. For the faulty box circuit C the opening of contacts M, 5 opens the circuit just traced by which the lockout relay L was energized, but a holding circuit for L is established from the positive terminal through the closed contacts 3, 2 of the relay M wire 23, contacts I 6, Id of L and thence through the coil L to the negative terminal. Furthermore, the opening of contacts l6, ll of L breaks the circuit of the repeater bus D. The time relay T and the repeater relay R are, therefore, de-energized and restored to normal. If the time relay is of the quick release type, the holding circuit through contacts 16, 14 should be established before the bus circuit through contacts I6, H is broken; this can be accomplished by using a contact ll of the follow-up type, which, as diagrammatically shown in Fig. 3, will permit the movable contact It to make on 14 before breaking from H.

For the normal circuit C the lockout relay L is initially energized upon the closure of the time relay contacts, as above described, but the circuit to L is immediately broken at its own contacts l4, l5. Since the main relay M is energized and u contacts 2, 3 are open, there is no holding circuit for L and the relay is ole-energized; in other words, the energization of L is the means by which the relay is immediately thereafter restored to normal.

The ultimate consequence of the operation of the time relay is, therefore, that the repeater relay R is de-energized and the normal box circuit C is restored to operative. condition. The same applies to all other normal box circuits in the system, which now stand ready to formulate, transmit and repeat signals among themselves in the usual manner. The faulty box circuit C is, however, ineffective to exercise any control over the remainder of the system since it is now isolated from-the repeater bus at the contacts I6, I! of the lookout relay L This condition of the system, during which C is cut out of commission, is shown in Fig. 3. Ihe time relay T stands in readiness with respect to all but the box circuits C to cut out of commission any other box circuit in which a break may subsequently occur.

Upon repair of the break in the faulty circuit C the main relay M is again energized and the holding circuit of the lookout relay L is broken, after which the relay L is tie-energized and all parts of the system are automatically restored to normal.

It has been stated that the time relay and the lookout relays do not enter into any normal operation of the system. This can be seen from the fact that the protective equipment can influence the repeater circuits only through the contacts l [1 of the lookout relays. If, therefore, any fault occurs in any of the protective relays or in the connections thereto, it has no effect on the ability of the system to formulate and transmit signals in normal manner; in other words, so long as the signaling equipment is normal, failure of the protective equipment cannot prevent any normal operation. Failure of the protective equipment would result in a loss of protective function, but with the customary daily test, the chances of box circuit failure occurring at a time when the protective equipment is out of order are extremely small, and even in that event a warning would be given on the various alarms. v

Modified forms of the invention are shown in Figs. 4 and 5. The repeating action is the same as in the system previously described, but the main relay contacts of an inactive box circuit are held attracted during an open circuit interval in an active circuit by the provision of an auxiliary coil rather than through the shunt circuit energization of Fig. l. The main relays of the modified embodiments are indicated at MR MR each having a main coil in its box circuit and each being provided-with an auxiliary coil 24. The auxiliary coil of the inactive box circuit is adapted to be energized when an active circuit is opened. This energization of the auxiliary coil is carried out in different ways in the systems of Figs. 4. and 5.

In Fig. 4 one side of each auxiliary coil 24 is connected to the negative battery terminal and the other side is connected to its, own contact I by a wire 25, that is, each auxiliary coil is connected in parallel with the repeater relay of its corresponding circuit. Each repeater relay has a single pair of contacts 26, 21 in the box circuit. These correspond to the contacts 4 and 6 of Fig. 1 and are arranged to open the box on,-

cuit when the repeater relay is energized. In all other respects, the connections are as in Fig. 1.

Upon opening of any box circuit, say C at the initiation of a signal, the main coil of relay MR is de-energizedand the repeater bus is energized in the same manner as in the system of Fig. 1. The repeater relay R and the auxiliary coil 24 of the main relay MIR, are both energized; thus the box circuit C is opened at 26, 21 and the main relay contacts are held attracted by the auxiliary coil. Upon closure of the active box circuit 0 the repeater relay R. and the auxiliary coil 24 of the relay MR. are both de-energized; the box circuit C is again closed and the main coil of the relay MR, is again energized. The sequence of operations in normal box signaling is identical with the sequence of operations in the system previously described, with the exception of the manner of controlling the main relay.

It is important that the-main relay contacts of the inactive box circuit C should be main tained attracted by either the main coil or the auxiliary coil at all times during the formulation of the signal in the active circuit. Although it may appear that there might be an interval in which the relay MR could lose control of its contacts, actually this is not the case. The ar-,

rangement is such as merely to shiit'energization from one coil to the other, and since the magnetic field of the relay is already established, the timeconstant of the coil which is being energized is small; in other words, the current always builds up quickly enough in one coil to sustain the magnetic field before the field can decay sufliciently to release the contacts.

The system of Fig. 5 represents an improvement over that of Fig. 4, particularly in providing for positive main relay control during the formulation of a signal in another circuit. Each repeater relay has four contacts, namely, two contacts 28 and 29 in the box circuit and two contacts 30 and 3! to control the auxiliary coil 24 of the corresponding main relay. Contact 30 is connected to the positive terminal of the local battery and contact 3| is connected by a wire 32v with one side of the coil 24, the other side of which is connected to the negative terminal. The box circuit contacts 28, 29 are normally closed and the contacts 30, 3| are normally open. The contacts are so arranged that upon energization of the repeater relay, the auxiliary contacts 30, 3| close before the box circuit contacts 28, 29 open, and conversely so thatupon de-energization of the repeater relay the box circuit contacts. 28, 29 close before the auxiliary,

contacts 30, 31 open. It is thus insured that the magnetic field of the main relay shall be positively established either through its box circuit coil or through its auxiliary coil during the formulation of a signal in another circuit. The se-, quence of operations in box signaling is thesame as in the system of Fig. 4.

In Figs. 4 and 5, the protective equipment, including the time relay and the lookout relays operate in the same manner and give the same. results as in the system of Fig. 1.

Although the invention has been illustrated and described in several embodiments of fire alarm systems it is to be understood that the invention is not thus limited, but may be applied to alarm and signaling systems for other purposes, and that the term box circuit is to be considered as applicable to a circuit containing one or more means for formulation of signals.

Furthermore the invention is not to be considered as limited to the particular details shown and described, but may be modified Within the scope of the appended claims.

The invention having been thus described, what is claimed is:

1. A signaling system having, in combination, a plurality of normally closed box circuits, repeater devices controlled by the box circuits, a normally inactive lockout relay for each box circuit having provision for rendering its corresponding box circuit ineffective to control the repeater devices, a time relay having contacts to operate only after an abnormal box circuit remains open for a predetermined time, and connections including the time relay contacts to energize the lockout relays, and means for establishing a holding circuit for the lookout relay of the abnormal box circuit.

2. A signaling system having, in combination, a

'plurality of normally closed box circuits, each having a normally energized main relay, a repeater relay and a normally inactive lockout relay, repeater connections for actuating the repeater relays of inactive box circuits including contacts of the main relays and contacts of the lockout relays, a time relay having contacts actuated only by the de-energization of the main relay of a faulty box circuit for a predetermined time, connections between the time relay contacts and the lookout relays to actuate the latter to render the faulty box circuit inefiective to control the repeater connections, and means for normalizing the time relay with respect to normal box circuits.

3. A signaling system having, in combination, a plurality of normally closed box circuits each having a normally energized main relay, the main relay having a movable contact and two fixed contacts, a repeater relay for each box circuit having a winding connected with one of the fixed contacts of the main relay, repeater relay contacts to open the box circuit and to establish an independent energizing circuit for the main relay, a bus connected with the movable contacts of all main relays, means for energizing the bus upon de-energization of any main relay through the other of the fixed contacts thereof, whereby the repeater relays of inactive circuits are abnormalized, and time actuated means for isolating the main relay contacts of an abnormal circuit from the bus.

4. A signaling system having, in combination, a plurality of normally closed box circuits each having a normally energized main relay, the main relay having a movable contact and two fixed contacts, a repeater relay for each box circuit having a winding connected with one of the fixed contacts of the main relay, repeater relay contacts to open the box circuit, a bus connected with the movable contacts of all main relays, means for energizing the bus upon de-energization of any main relay through the other of the fixed contacts thereof, whereby the repeater relays of inactive circuits are energized, means operated through energization of the bus for maintaining the main relays of inactive box circuits energized, and time actuated means for isolating the main relay contacts of an abnormal circuit from the bus.

5. A signaling system having, in combination, a plurality of normally closed box circuits each having a normally energized main relay, the main relay having a movable contact and two fixed contacts, a repeater relay for each box circuit having a winding connected with one of the fixed contacts of the main relay, repeater relay con-'- tacts to open the box circuit, a lockout relay for each box circuit having normally closed contacts in series with the movable contact of the corresponding main relay, a repeater bus connecting corresponding contacts of the several lockout relays, means for energizing the bus upon deenergization of any main relay through the other of the fixed contacts thereof, whereby the repeater relays of inactive box circuits are energized, time actuated means to energize the lockout relays and thereby to open the contacts thereof, and means for establishing a holding circuit for the lockout relay'of any box circuit for which the main relay remains ole-energized.

6. A signaling system having, in combination, a plurality of normally closed box circuits each having a normally energized main relay, the main relay having a movable contact and two fixed contacts, a repeater relay for each box circuit having a winding connected with one of the fixed contacts of the main relay, repeater relay contacts to open the box circuit, a lockout relay for each box circuit having normally closed contacts in series with the movable contact of the corresponding main relay, a repeater bus connecting corresponding contacts of the several lockout relays, means for energizing the bus upon deenergization of any main relay through the other of the fixed contacts thereof, whereby the repeater relays of inactive box circuits are energized, a normally de-energized time relay connected to the bus and having contacts adapted to close only after the bus remains energized for a predetermined time, means operated by the time relay contacts to energize the lockout relays and thereby to open the contacts thereof, and means for establishing a holding circuit for any lockout relay for which the corresponding main relay remains de-energized, whereby the contacts of the tie-energized main relay are isolated from the bus.

7. A signaling system having, in combination, a plurality of normally closed signaling circuits each having a normally energized main relay, a repeater bus, the several main relays having contacts connected with the repeater bus, repeater devices controlled by the repeater bus and having provision for opening inactive signaling circuits upon opening of an active signaling circult and for establishing an independent energizing circuit for the main relay of each inactive signaling circuit, and time controlled means operable upon de-energization of the main relay of a signaling circuit for greater than a predetermined time for isolating the contacts of said relay from the bus during continued de-energization of said relay.

8. A signaling system having, in combination, a plurality of normally closed signaling circuits each having a plurality of signal transmitting devices and a normally energized main relay, each main relay having contacts, a repeater bus connected with the contacts of the several main relays to be energized by said contacts upon deenergization of any main relay, a repeater relay for each signaling circuit controlled by the repeater bus and having contacts to open the signaling circuit and to establish an independent energizing circuit for the main relay thereof, timing means operable upon de-energization of the main relay of a signaling circuit for greater than a predetermined time, and means controlled by the timing means to isolate the main relay contacts of said circuit irom the repeater bus during continued de-energization of said main relay.

9. A signaling system having, in combination,

a plurality of normally closed signaling circuits each having a normally energized main relay, a repeater bus, the several main relays having contacts connected with the repeater bus, repeater devices controlled by the repeater bus and having provision for opening inactive signaling circuits upon opening of an active signaling circuit and for establishing an independent energizing circuit for'the main relay of each inactive signaling circuit, and a single timing means for the system operable upon de-energization of the main relay of any signaling circuit for greater than a prdetermined time to isolate the contacts of said relay from the bus during continued de-energization of said relay.

10. A signaling system having, in combination, a plurality of normally closed signaling circuits each having a normally energized main relay, a repeater bus, the several main relays having contacts connected with the repeater bus, repeater devices controlled by the repeater bus and having provision for opening inactive signaling circuits upon opening of an active signaling circuit and for establishing an independent energizing circuit for the main relay of each inactive signaling circuit, time controlled means including a time relay connected to the repeater bus and operable upon de-energization of the main relay of any signaling circuit for greater than a predetermined time, and means actuated by operation of the time relay for isolating the contacts of said main relay from the bus during continued de-energization of said main relay.

11. A signaling system having, in combination, a plurality of normally closed signaling circuits each having a normally energized main relay, a repeater bus, the several main relays having contacts connected with the repeater bus, repeater devices controlled by the repeater bus and having provision for opening inactive signaling circuits upon opening of an active signaling circuit and for establishing an independent energizing circuit for the main relay of each inactive signaling circuit, time controlled means including a time relay connected to the repeater bus and operable upon de-energization of the main relay of any signaling circuit'for greater than a predetermined time, lockout contacts between each main relay and the repeater bus, and means operated by the time relay for opening the lookout contacts for any main relay which remains deenergized for greater than said predetermined time.

12. A signaling system having, in combination, a plurality of normally closed signaling circuits each having a normally-energized main relay, a repeater bus, the several main relays having contacts connected with the repeater bus, repeater devices controlled by the repeater bus and having provision for opening inactive signaling circuits upon opening of an active signaling circuit and for establishing an independent energizing circuit for the main relay of each inactive signaling circuit, a single time relay connected to the repeater bus and having contacts operable upon de-energization of the main relay of any signaling circuit for greater than a predetermined time, and means controlled by the time relay contacts to isolate the contacts of said main relay from the bus during continued de-energization of said main relay.

FRANK R. BRIDGES.

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