US487519A - Thermostat - Google Patents

Description

UNITED STATES PATENT OFFICE.

FRANKLIN O. ELLIOTT, OF OATAWBA, NORTH CAROLINA.

THERMOSTAT.

SPECIFICATION forming part of Letters Patent No. 487,519, dated December 6, 1892.

Application led August 20, 1892. Serial No. 443,644. (No model.)

To all whom zit may concern.'

Be it known that I, FRANKLIN O. ELLIOTT, acitizen of the United States, residing at Catawba, in the county of Catawba and State of North Carolina, have invented certain new and useful Improvements in Thermostats, of which the following is a specification, reference being had therein to the accompanying drawings.

My invention relates to electrically-operated tire-alarms of the class employing a circuit-closer that is maintained in circuit-breaking position by a fusible plug. Upon the melting of the plug when the surrounding temperature reaches a predetermined degree the circuit is closed and an alarm sounded.

My object is to provide a simple, efficient, and inexpensive automatic circuit-closer of this description; and to this end my invention consists in the device having the con-- struction and combination of parts hereinafter specified.

In the drawings, Figure l is a longitudinal section of my circuit-closer; Fig. 2, a transverse section, and Fig. 3 a detail perspective view of the terminal-carrying piece detached.

Referring to the drawings by letter, A designates a box or casing, oblong in shape and closed on all sides. One end B has attached to its inner face two separated plates, of copper or other good conductor of electricity b and b, to each of which is connected a wire c, that forms part of a circuit, which includesa battery and an alarm mechanism, such as an electric bell. For hotel use I contemplate attaching the wires c c to the ordinary pushbutton terminals to enable the usual annunciatortobe utilized-an expedient notonly rendering a separate alarm mechanism unnecessary, but being, also, of great value in indicating by the annunciator the locality of the fire. Such an arrangement, obviously, will not interfere with the use of the button. The plates b thus form the terminals of a circuit that normally is open. To close the circuit and so sound an alarm on the outbreak of a tire, a sliding contact-carrying rod I) is employed, which is supported and guided by the other end B of the casing and a partition a at the longitudinal center thereof. The inner end of the rod carries a copper or other suitable contact-disk d, that by the inward movement ot` the rod is adapted to engage both of the terminal plates B B and so close the circuit, and such inward movement is imparted by a lcoiled spring E, that encircles the rod in the space between the portion a and the casing end B', one end of said spring bearing against the inner side of the latter and the other end engaging a pin that projects beyond the sides of the rod. To hold the rod away from the terminals B B against the stress of the spring, so as to normally keep the circuit open, an opening cl is provided near the outer end of the rod D to receive a pin F to abut against the outside of the casing end B. This pin is made of some alloy that will melt at a degree of heat not very much higher than the normal temperature of the room orlocality where the device is to be used. Thel outer end of the rod is furnished with a head or knob cl2 to enable the rod to be readily drawn out the proper extent to permit the putting in place of the fusible plug.

To insure good contact between the contactdisk d and the terminals, the latter are provided with numerous teats or projections for the face of the disk to impinge against, and said disk is insulated from the rod by a disk g, of rubber or other non-conductor, interposed between it and the end of the rod.

The casing end B is detachably connected with the sides of the casing A by means of ribs b b on its opposite edges, which slidein grooves formed in the inner sides, but is rigidly attached tothe cover-section a of the casing that extends from the partition a, to itself. This construction is adapted to enable the terminals to be rst and permanently fixed at the place determined on-say the center ot the ceiling of aroom-and then the placing in position of the remainder of the device. At any time the remainder of the device may thus be removed without disturbing the termimals and the wires leading therefrom.

The cover-section o. is provided with holes for the passage of screws to secure it in place, and like holes are also provided in the other section ot' the casing-cover for a like purpose.

It will be seen thatthose portions of my device which might be injured or impaired by being exposed are perfectly housed by the IOO ently securing it to a support, a casing A,

carrying an automatic spring-actuated rod provided With a contact-plate, and means for independently securing it to a support, the

inner sides of one end of said easing being provided with grooves in which Work the edges of end piece B, as and for the purpose described.

2. In a circuit-closer, in combination, the casing made in two separable parts, one of which carries the fixed and the other the movable contact, substantially as described.V

In testimony whereof I atlx my signature in presence of two Witnesses.

FRANKLIN O. ELLIOTT.

Vitnesses:

WM. C. WHITNER, W. A. MARLER.

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