US977295A - Electrical thermostatic alarm system. - Google Patents

Description

A. GOLDSTEIN. ELECTRICAL THERMOSTATIG ALARM SYSTEM.

APPLICATION FILED MAY 2, 1910.

Patented Nov. 29, 1910 "UNITED STATES PATENT oFF oE.

ALBERT GOLDSTEIN, OF NEW YORK, N. Y., ASSIGNOR TO INTERNATIONAL ELECTRIC PROTECTION COMPANY, A CORPORATION OF NEW YORK.

ELECTRICAL THERMOSTATIC ALARM SYSTEM;

Application filed May 2, 1910. Serial No. 558,819.

To all whom it may concern:

Be it known that I, ALBERT GOLDSTEIN, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented a certain new and useful Improvement in Electrical Thermostatic Alarm Systems, of which the following is a specification.

The invention relates to anelectrical thermostatic alarm system,..and has forits object the prevention of false alarms, due to accidental troubles on the line.

The invention consists, first, in the combination whereby three changes must be produced in the circuit, such as two breaks and a make, or two makes and a break, before the alarm operates; and also in the construction of the thermostat whereby upon the movement of the diaphragm due to expansion of air within thecase, said changes are caused. In this way, two accidental changes occurring on the line, such as a crossing, and then a separation of the wiresdue, for example, to the wires swinging together and then swinging apart-is prevented from giving a false alarm.

In the accompanying drawings-Figure 1 is a cross section of my thermostat, andFig. 2 is an electrical diagram of an alarm circuitincluding three of said thermostats located at differentstations.

Similar letters and numbers ofreference indicate like parts.

The circular case 1' comprises two. flanged cup-shaped members 2, 3, between which the diaphragm 4 is received and held. Said diaphragm is to be made of thin sheet metal, preferably the thinnest sheet copper procurable, and may be corrugated and provided with a central contact boss 5'. The member 2 is to be preferably made of steel much heavier than the member 3, so as to form the chief support for the device. The member 3 is preferably of a metal that is highly con-' ductlve of heat, such as copper, and as thin as will afford the necessary rigidity The flange of member 3 has a corrugationt which enters a similar corrugation in the flange of member 2. The flange of' diaphra m 4 is clamped between said corru gate members, sothat the diaphragm is thus strained and a close air-tight joint formed between the parts. The member '3: may be secured by bendin its circumferen ftial edge 7 overthe edge 0 member 2.

Specification of Letters Patent.

Patented Nov. 29, 1910.

8 of insulating material, on which are two contact plates 9, 10. In the block is an opening' through which loosely passes a metal r0 11 supported on ascrew 12, which passes through a metal bridge piece 13, which normally rests on the contact plates 9, 10. The bridge piece 13 forms a nut for the screw 12 in which said screw may be adjusted by turning the milled head 14 so as to bring the lower end of rod 11 into desired proxlmity to the boss 5 on diaphragm4. The contact plates 9, .10. are respectively connected to terminals of the circuit wire a, while thediaphragm 4 is connected to terminals of the Centrally disposed in member 2 is a block' the chamber therein on one side of the 'diamunicating with an opening in the wall of said chamber.

The Q eration of the thermostat is as fol- 'lows: T e contact piece 11 is first adjusted in suitable proximity to the diaphragm 4.'

When the surrounding atmosphere" increases in temperature, the heat is rapidly conducted through the thin metal wall of the chamber in member 3 and expands the air therein. This airv can escape only through the tube 16 which is made long,

and of: small cross sectional area as compared with the vents 15, so as to retard the air flow. On the other hand, the air in-the' chamberin member2 on theother side of the diaphragm can escape more freely-through expansion of the air in. the chamber canthe vents 15. The consequence is, that the taming the tube is so quick as to be prac- 'tically an impulse in the confined/ai body which, being communicated to. the diaphragm 4, first moves it into contact with rod. 11-, thus producing a crossin from wire a' to wire 'a,-.and' then the furt er upward movementof the diaphragm raises the rod 11 and bridge-13, first, to break contact be- 1 tween the terminal lates 97.10, and then to close contactwitht e contact piecesfzl).

In Fig. 2 the thermostat is shownin an alarm circuit.

The wires a, a are line conductors connected to opposite poles of the battery A.

In the conductor a is a magnet B which controls the two switch levers b and b.

.The battery current normally energizes magnet B, so that a metallic circuit proceeds from one pole of battery A, by wire a, to magnet B, to contact point 0, switch lever b, and wire a back to battery. In the conductor a and on opposite sides of the battery A are two magnets C, D, which respectively actuate pivoted armatures E, F, which arein bell-crank form. At the end of each vertical arm of the armatures E, F,

are formed Z-shaped slots 6, f, which receive pins G on the ends of the pivoted arms H. Said arms may fall by gravity to meet contact points 2', j, and so close a local circuit which includes a battery I and'electric bell J.

In the circuit conductors a, a at N, N, N are interposed as many of the thermostats, shown in Fig. 1, as there are stations from which it is desired alarms shall be given. v

The operation is as follows: Assume the diaphragm of the thermostat at N, Fig; 2, to

drawing. The

breaking circuit in wire a at 9 and 10. Mag-' nets C and D then fail, and the armatures E, F return to the position shown in the pins G then descend tothe second angle 1 1n slots 6 and f. The diaphragm still continuing its movement car ries the bridge piece now out of'contact for two abnormal changes in the electricalconditions to actuate said alarm. In this way, false alarms from troubles on the line will be largely prevented.

I claim:

1. The combination in circuit of an electrical thermostat comprising a case, a diaphragm in said case and operated by air,

expansion therein, means-controlled by said diaphragm for making successively three changes in the electrical condition of the circuit, and an alarm device operating only after the third change in said condition.

2. The combinationin circuit of an electrical thermostat comprising a case, a diaphragm in said case and operated by air expansion therein, means controlled by said diaphragm for first making, then breaking and then making said circuit, and an alarm device operating only after said second make.

3. The combination in circuit ofa magnet, a circuit closing switch controlled by said magnet to move over three successive portions of its path before closing circuit, and an electrical thermostat comprising a case, a diaphragm in said case and operated by air expansion therein, and means actuated by said diaphragm to control said magnet to cause said movement of said switch.

In testimony whereof I have aflixed my signature in presence of two witnesses.

Y ALBERT GOLDSTEIN.

Witnesses:

GERTRUDE T. PORTER, MAY T. MOGARRY.

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