US398740A - Thermostat - Google Patents

Description

(No Model.)

W. E. LEWIS.

THERMOSTAT.

Patent-ed Feb. 26,

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inrTn STATES PATENT Cierres..

WILLIAM E. LEVIS, OF CORRY, PENNSYLVANIA.

TH ERMOSTAT.

SPECIFICATION forming part of Letters Patent No. 398,740, dated February 26, 1889. Application filed February 23, 1888 Serial No. 265,025. (No model.)

mostat, of which the following is a specitication,

This invention has relation to improvements l in apparatus whereby the temperature of an apartment may be maintained at a uniformlydetermined degree by the automatic regulation of the suppl y of the heating medium.

The invention will be full y understood from the fcllowing description and claims, when taken in connection with the accompanying drawing, in which the figure is a vertical longitudinal sectional view of a thermostat embodying my improvements.

Referring by letter to the said drawing, B indicates a metallic reservoir, which is here shown as of a cylindrical form, and which is designed to be illed with any7 suitable liquid having a high degree of expansibility. This reservoir is closed at its upper end by a cap, A, designed to tit tightly therein, so as to torni an air-tight joint with the said reservoir. This cap A is provided with a filling-aperture, C, and which is closed by a screw-plug, D. The cap is furthermore provided with an outletaperture, E, which extends through a lateral horizontal branch, as shown at H', which branch is externally threaded, as shown, to receive a union, F, whereby a connection is had with one end ot a pipe, Z, a packing, G, being interposed at the union before mentioned. The lower end ot' the reservoir has firmly fixed to it a plate, ll, which is recessed annnlarly, as shown at J, and in this recessed portion et the said plate is secured a diaphragm, N, pre'l'eralily ol' metal. This plate i also provided with screw-lunes in its niargin 'for the attachment ot the bottom plate, l, which has similar apertures to receive the conueetiiig-screws l. This bottom plate, l, has a centrally-distended hollow portion, P, for the reception ot' a headed nut, M, which nut is secured to the under side of the diaphragm and is designed to move with it.

S indicates a regulating-screw, which is provided for the greater portion of its length lwith right-hand threads, R, and its upper end is reduced, as shown at o, where it is provided pushed inwardly,

i with left-hand threads, or th reads which run in an opposite direction to the right-hand threads. This screw is seated in a screw-tapped aperture in the lower end of the bottoni plate, l,

and its upper reverscly-threaded portion engages threads in the nut M. By turning the screw to the rightthe diaphragm N will be forced outwardly, slightly increasing the size ot' the reservoir B and diminishing the pressure of the liquid therein, while by turning the said screw to the lett the diaphragm will be which will cause apressure, and by means ol' which the apparatus can be set for diiierent degrees oi heat.

T indicates a valve-chamber having inlet and outlet ports of the usual torni, which ports are internally threaded to receive connectingpipes Jfor the delivery of gas or other combustible iuid.

Screwed in the breast oi the valve case or trame is a plate, D2, having a chamber therein to receive a spiral spring, which surrounds the valve-stem, as shown, and presses against a head on the said stein, so as to normally keep the fuel-passage open. This plate D2 is provided with threaded apertures in its inargin to receive fastening-screws, which pass through an upper plate, D. This plaie D is recessed in its under side, and in the recess is secured a diaphragm, D4, which is designed to be held normally raised by the action of the spring surrounding the valve-stein. This plate D is also provided with a central inlet-aperture, D5, around w iich are formed external threads to receive a packing-gland, C, which latter also serves as a means oi' uniting the said plate with the lower end of the tube Z.

instead of using liquid in the reservoir air may be used.

In operation, after the parts have been properly connected, the screw-plug D is removed until the reservoir has been filled with liquid up to within about one inch of the top. The plug D is then screwed down, and the apparatus is ready for lifted by the action of the spring, so as to allow the gas to iiow for heating purposes. Then the liquid has become sui'cieiiitly warm or hot and begins to expand, it will pass out of the reservoir through the opening E, and thence down the pipe Z upon the diaphragm beneath the same, thereby seating the valve use, and the valve held TOO and checking; the ilow of gas, the diaphragm of the main reservoir bein g regulated by means of the right-and-left-threaded rod S.

Having described my invention, what I claim is l. In a thermostat, the combination, with a reservoir constructed as desoribed and provided with the dia1i)hragm at its lower end, of the threaded nut beneath the diaphragm and the right-an(l-left-threaded regulating-screw tapped in the bottom oi' the said reservoir and engaging the said nut, substantially as speeifled.

2. The Combination, with a reservoir constructed as described, of the oap inV the upper end of the said reservoir having a filling-aperture and the lateral branch provided with an

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