US463608A - brown - Google Patents

Description

(No Model.) 3 SheetsSheet 1. G. W. BROWN.

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3 Sheets--Sheet 2.

(No Model.)

G. W. BROWN. AUTOMATIC FIRE ALARM SYSTEM.

Patented Nov. 17,1891.

Z Fig.6.

(No Model.)

3 Sheets-Sheet 3.

G. W. BROWN.

AUTOMATIC FIRE ALARM SYSTEM.

Patented Nov. 17, 1891.

in: News Incas cm, wmwuma, WASHINGTON o c NlTED STATES PATENT FFICE.

GILMAN W. BROWN, OF VEST NEW'BURY, MASSACHUSETTS, ASSIGN OR OF ONE-HALF TO HAYDEN BROWN, OF SAME PLACE.

l AUTOMATIC FIRE-ALARM. SYSTEM.

SPECIFICATION forming part of Letters Patent No. 463,608, dated November 17, 1891. Application filed August 21, 1891. Serial No. 403,377 (No model.)

To all whom it may concern: will be pointed out in the claims at the end of Be it known that I, GILnAN BROWN, of this specification. West Newbury, in the county of Essex and Figure 1 is an elevation of the receiving- State of Massachusetts, have inventedcertain instrument employed on an automatic the 5 new and useful Improvements in Automatic alarm system embodying my invention. Fig. Fire-Alarm Systems, of which the following is 2 is a sectional detail, on an enlarged scale, of a Specificationthe upper portion of the receiving'instrument,

This invention in automatic fire-alarm systhe section being taken on the line 2 2; Figterns has for its object to provide a novel sys- 3, a top or plan view of a thermostat embody- 1o. tem, as will be described, whereby the sounding my invention, the thermostat being shown ing of false alarms is obviated and the sysin operative condition; Fig. 4, alongitudinal tern rendered more reliable in case of fire. section of the thermostat shown in Fig. 3 on In accordance with my invention one or line 4 4; Fig. 5, an under side view of-the more thermostats constructed as will be dethermostat shown in Fig. 3; Fig. 6, alongio 5 :5 scribed and located in a building or structtudinal section of the thermostat, shown in ure to be protected are included in a nor- Fig. 3 on line t 4, showing the thermostat as inally-closed circuit supplied with current having been operated. Fig. 7 is a diagram from a battery or other suitable source of of circuits showing two thermostats as conelectricity, and provided at amain or-central nected to the receiving-instrument, only a 0 2o station with a receiving-instrument consistportion of the case of which is shown, the in g,essentially,of an audible signal controlled thermostats being in their operative positions by the polarized armature of an electro-magready to send in an alarm of tire; and Fig. 8, net. The thermostat referred to is cona diagram of circuits, showing the thermostrncted, as will be described, so as to prostats connected to the operative parts of the 25 duce reversals of the current over the main receiving-instrument, the thermostats being line and thereby operate the electro-magnet shown as having been operated by a fire. to sound the audible signal in case of a fire. The receiving-instrument of my improved The receiving-instrument, preferably, also automatic fire-alarm system consists, essencomprises a visual indicating-instrument by tially, of an audible signal, (shown as an 30 which the condition of the l ne-circuit may electro-mechanically-operated gong or bell,) be made known to the operator or attendant of any usualor well-knownconstruction,itcon- V at the fire-station or central oflice. The p0 sisting of a striker or an arm a, secured to a larized armature of the electro-rnagnet is shaft Ct, having the crank-arm a joined by preferably adjusted so as to be withdrawn a connecting-rod a to a pivoted arm a pro- 3 5 from its electro-magnet when the strength of vided with a detent a co-operating with a the current flowing over theline falls below detent on a lover or arm a having at its upthe normalas, forinstance,in case of a weakper end a detent 0 (shown in dotted lines in d ening of the battery, a short-circuiting of the Fig. 1,) with which co-operates a detent a on line, ora dead break in the line, the withan armature-carrying lever a pivoted as at 40 drawal of the armature operating the audible a and provided with an armature a for an signal to call the attention of the operator at electro-magnet a, suitably supported within the central office to the factthat a change in the case a of the receiving-instrument. The the condition of the main line has taken pivoted arm a is rotated in the usual man: place. The visualindicating device referred ner, as herein shown, by a system of gears or 5 45 to is preferably provided with a scale suitably clock-work (L15, actuated by a normally-woundmarked to indicate a weakening of the batup spring a, orit may be a weight. The tery, a broken line, or a tire, whereby the atarmature (L of the electro-magnet is prefertendant upon hearing the alarm may see at a ably composed of hardened steel and polarglance under what condition the line-circuit ized or made apermanent magnet, and under o is placed. normal conditions the polarity of the electro- The particular features of my invention magnet a is such as to attract the armature (L and place the detent a 011 the armaturelever a" in the path of movement of the detent a on the arm a, and thereby prevent the movement of the pivoted arm a and consequently hold the striker on the arm a away from the gong or bell A.

In accordance with my invention, the polarized armature a of the electro-magnet is repelled away from the poles of the magnet (L by a reversal in the current flowing over the line in which the electro-magnet a is located. The reversal of the current is effected by means of a polechanging thermostat, preferably constructed as shown in Figs. 3 to 6, inclusive. The thermostat consists, essentially, of a block or supporting-base b of insnlating material-usuallywood, porcelain, or hard rubber-and provided on one face with two springs L 6 (shown as flat strips of 1netal,) constituting the other set of polechanging arms for. the thermostat. These springs are firmly secured to the base I) at one end, they being herein shown as bent down over the rear side of the block b, and the said strips have secured to them binding screws 11 5*, respectively, to which the line-wires are secured, as will be described. of the strips l) b are normally secured by a fusible material or soldersuch as an alloy of lead, tin, cadmium, &c.-to conductingstrips 11 Z). (Shown in Figs. 3 to 63, inclusive, as secured to the front side of the block or su pporting-base b.) The conducting-strips b Z2, as herein shown, have secured to them bindingscrews U 11 by which the line-wires may be connected with the thermostat. The springstrips Z) l) have secured to them on their under side projecting pole-changing arms Z) b one of which is shown in full lines, Figs. 4 and 6, and both of which are indicated by dotted lines in Fig. 5. The pole-changing arms 6 b project into a recess or cavity 11 in the base I) and co-operate with the circuitterminal, herein shown as rods or bars Z1 I), extending across the said recesses. The circuit-terminal Z1 is connected by a conductjug-wire (J to the binding-screw b and the circuit-terminal b is connected by conducting-wire Z1 to the binding-screw b, as clearly shown in Fig. 5. The pole-changing arms b" b as herein shown, are provided with fingers, which extend under the circuit terminals b b when the thermostatic springs Z) b are in their normal condition, (shown in Figs. 3 and 4,) but which are adapted to be brought up into contact with the circuit-terminals Z2 12 when the thermostatic springs are released by the melting of the solder or fusible connection, as in the case of a fire. This position of the thermostatic springs is indicated in Fig. 6. In the normal condition of the system the thermostatic springs b b are secured to the contact-strips B Z) by the fusible connection, and the armature (e is attracted by its magnet a, the current flowing over the line in what may be termed the normal direction, as indicated by the ar- The free en derow 20 in Fig. 7. ll. now the thermostat should be operated, as by the breaking out of a fire in its vicinity, the thermostatic springs 1') b being released by the melting of a fusible connection, would fly upward and thus brihg the pole-changing arms I) Z2 into contact with the circuit-terminals D b, in which case the current. would flow over the line, as indicated in Fig. 8, it passing from the positive pole of the battery Bin the direction indicated by arrow 20 until it came to the spring b and the connection between the spring 11 and its cooperating strip I) being interrupted, the current will flow down the pole-changing arm, as indicated by arrow 21, and by the circuit-terminal b and wire b to the binding-screw I)", from whence it would pass into the receiving-instrument, and through the electro-magnet a, in a reverse direction, and thence out over the line again to the bindingscrew [1 from whence it would pass by the conducting-wire Z1 and terminal I) to the polechanging arm and thence by the spring I) to the negative pole of the batter By the reversal of the current over the main line, as thus described, the polarized armature a is repelled by its magnet (L13 and the armature lever a is turned on its pivot a so as to withdraw the detent a from engagement with the detent a 011 the lever a, and thereby permit the spring or motor a to turn the pivoted arm a and the striker-arm a and sound the gong or bell A, thus giving an alarm at the receiving-instrument that a change in the condition of the circuit has been effected.

In order that the operator at the central oiiice may positively know whether the alarm thus sounded is due to the. operation of the thermostat or to a broken wire or for other cause, an indicating device, preferably visual, is employed, which may be and preferably is located within the case a. The indicating device, as herein shown, consists of a galvanometer-coil 0, having pivotally suspended within it a polarized needle 0, preferably of hardened steel, mounted on a shaft or arbor 0 within the coil 0, said 'arbor having secured to it a pointer 0 which co-operates with the plate or dial 0 secured in a suitable manner to the frame-work of the case. The dial a, as herein shown, (see Fig. 1,) is provided with four graduations or indications marked, respectively,- OK, battery run down, line broken, and fire, the line-broken indication occupying a central or zero position on the scale. It the galvanometer-coil is not being traversed by an electric current, the pointer 0" would stand on the zero position or line-broken indication, and when the current is traversing the coil in its normal direction the pointer 0 will be turned to one side of the zero position-as, for instance, to the left, as shown in Fig. 1-and when the current is reversed, as has been described, the pointer will be deflected to the indication marked fire. The attendant at the main oifice by glancing at the dial might ascertain from the pointer the fact that the battery had been weakened; but in order to render this feature more positive I prefer that the alarm or audible signal a should also be sounded when the battery is thus weakened. This may be accomplished by adjusting the tension of the retractor for the armature a, which retractor is herein shown as a spiral spring d. When the battery has been weakened, the spring (1 will withdraw the armature a from its electromagnet and release the motor mechanism and sound the alarm A. In case of a broken wire the current will cease fiowingover the mainline and the pointer 0 will fall to zero or to the indication marked brokenline. So, also, if the main line should be short-circuited the same effect would be accomplished, and in either case the armature 0/ would be withdrawn by its spring (1 to start the motor and operate the alarm. In the normal condition of the main line the pointer 0 stands at the indication OK; but when the thermostat is operated, as by the breaking out of a fire, the current is reversed and the pointer 0 will pass beyond the zero position to the other side toward the indication marked fire. In this way the operator at the fire or receiving station is enabled to know positively for what cause the alarm has been sounded; or, in other words, the true condition of the line-circuit at all times is made known to him, so that in case of any accidents of the line-circuit the same may be readily repaired without rendering the circuit inoperative for any considerable length of time.

Referring now to Figs. 7 and 8, the current in the normal condition of the circuit, as indicated in Fig. 8 by arrow 20, passes through the galvanometer and electro-magnet back over the line-wires, whereas when the thermostatis operated and the polarity reversed the current passes through the electromagnet and galvanometer back over the line.

In practice it might happen that the current would be reversed by the operation of one thermostat, the alarm sounded,and the pointer c deflected to the indication marked fire, and immediately after a second thermostat might be operated and the current-again reversed and the current restored to its normal direction, thus restoring the parts of the receiving-instrument to their normal condition.

In order that the operator may know positively whether the alarm is due to a fire,- I have provided a detent or catch a (see Figs. 1 and 2) for the pointer 0 the said detent or catch being located near the fire indication and adapted to engage the pointer 0 when the latter has been moved to the fire indication by the reversal of the current. So, also, I prefer that the polarized armature should be withdrawn by its spring (l when repelled from its magnet sufficiently far to remove it from the influence of its magnet, thus requiring that the said armature be replaced in operative position by the operator.

I claim-- 1. In an automatic fire-alarm system, the combination, with a main-line circuit, an elec tro-magnet located therein and provided with a polarized armature, and a receiving-instrument controlled in its operation by the said but adapted to be included inthe said circuit by the melting of the fusible connection to reestablish the main line with reversed polarity after the said line has been opened by the operation of the fusible connection, substantially as described.

2. In an automatic fire-alarm system, the combination, with a main-line circuit, an electro-magnet located therein and provided with a polarized armature, and an audible signal controlled in its operation by the said polarized armature, of a pole-changing thermostat located in the main-line circuit and consisting of two sets of pole-changing arms, one set being normally connected in the main line by a fusible connection and the other set being normally not included in the said circuit, but adapted to be included in the said circuit by the melt-ing of the fusible connection to reestablish the main line with reversed polarity after the said line has been opened by the operation of the fusible connection, substantially as described.

3. In an automatic fire-alarm system, the combination of the following instrumentalities, viz: a main-line circuit, an electro-magnet located in said circuit and provided with a polarized armature, a visual indicating device included in the main-line circuit, and a pole-changing thermostat adapted to be operated by increase in temperature to reverse the polarity of the main line and operate the V18 ual indicator reversely, substantially as described.

t. In an automatic fire-alarm system, the combination of the following instrumentalities, viz: a main-line circuit, an electro-magnet located therein, an audible signal con trolled by the said electro-magnet, a visual indicating device operated by changes in condition of the circuit, and a pole-changing thermostat, substantially as described.

5. A pole-changing thermostat having two sets of pole-changing arms, one set consisting of conducting-springs held in tension by fusible solder and in position to conduct the current in one direction, the other set of polechanging arms being connected to the said springs and normally not included in the linecircuit, but which are included therein by the operation of the said springs to reverse the line-current when said springs are released, substantially as described.

6. The herein-described pole-changingthermostat consisting of a base, conductingsprings secured thereto at one end and pro- IIO vided with poie'changing arms, conductors on In testimony whereof I have signed my I said base, fusible conneet-ionsjoining the said name to this specification, in the presence of conducting-springs to the said conductors, two subscribingwitnesses,thisSth dayof Auand circuit-terminals with which the polegust, A. D. 1891.

5 changing arms co operate vh'en the said T springs are released by Lhe melting'of the fnsi- GILMAN ble connections to reestablish the said circuit \Vitnesses:

and reverse the polarity of the same, snbstan- O. F. BROWN,

tially as described. A. D. HARRISON.

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