US695293A - Oven-thermometer. - Google Patents

Description

No. 695,293. Patented Mar. n, I902.

c. E. EVANS.

(No Model.)

iharTnn STATns PATENT Trice.

CHARLES EVERETT EVANS, OF TAUNTON, MASSACHUSETTS.

OVEN-*TI-IERWIOWI ETER.

SPECIFICATION forming part of Letters Patent No. 695,293, dated March 11, 19021.

Application filed December 2, 1901. Serial l\T0 84,299. (No model.)

1"0 CY/ZZ whom it may concern.-

Be it known that I, CHARLES EVERETT EVANS, a citizen of the United States, residing in Taunton, in the county of Bristol and State of Massachusetts, have invented a new and useful Improvement in f)ven-Thermometers, of which the following is a specification.

This invention relates to that class of thermometers which are particularly adapted for use in ovens of stoves, and the nature of the secured to the inside of the oven in the ordinary manner by means of suitable cars A. Secured to this plate is the case formed with the two rings B and B and provided with a dial 0, suitablyinscribed at O to indicate degrees of heat, and with a transparent window D. To the rear side of the plate is secured the operative portion of the thermometer, such portion comprising the shank or stationary portion E, secured at c in any suitable manner to the back plate, the oppositelyprojecting steps E and the oppositely-extending arms F, preferably spreading, as shown, bent back upon themselves at E into the por tion F, and thence inward into the free ends F. The parts E, E, F, F, F, and F are in one integral piece, preferably of cast-iron, and the end of one of the arms F underlaps the other, as indicated in Fig. 2. Rods II, of brass or other relatively expansive metahhave their opposite ends socketed in the steps E and bends F, so that they cannot slip out of position. Eachoftheinwardly-projecting portions F is bifurcated, as indicated at f. A pointer or indicator consists of the shank portion or spindle K and indicating portion mediate position by said portions F', which spring against it and are held apart thereby. This portion K extends from such position through a suitable opening A" in the back plate and a corresponding opening in the dial and at K bends at right angles upward and points normally at zero on the scale C. A disk L is fixed on the portion K of the indicator and extends into the slots or bifurcations in the two parts F and operates as a guide to keep the portion K of the indicator in the proper position andat right angles with the portions F.

In operation asheat is applied to the oven the brass rods II expand, and thereby operate to push on the portions F of the cast-iron frame and draw apart the ends F. This rolls the portion K of the indicator between the surfaces of the portions F.in contact therewith, and hence moves said indicator and causes it to point to the degree of heat reached in the oven. Of course the movement of the parts F is slight, and said portions do not draw actually apart, but move oppositely and from each other, so as to impart a partial rotation to the spindle K, and said spindle being held in place by the disk L in the slots or bifurcationsf causes its indicating end to move fora portion of a circle along the scale.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is

1. In an oven-thermometerof the character described in which the principle of the unequal expansion of metal is employed to indicate changes in temperature, a plate and dial; a frame provided with two oppositely and inwardly extending arms overlapping each other; rods of relatively expansible metal engaging and operating said frame to move said arms oppositely with relation to each other; a spindle held by and between the inner surfaces of said arms; and an indicator extending from said spindle over the dial, whereby the rise of temperature causes said arms to move with relation to each other and roll said spindle between them, substantially as described.

2. In an oveirtllermometer of the character described in which the principle of the un equal expansion of metals is employed to ini overlapping ends F, substantially as set dicate changes in temperature, a plate and forth.

dial; the frame E provided with the steps E In testimony whereof I have signed my and arms F, F, F, F, the portions F overname to this specification in the presence of 5 lapping each other and said portions being two subscribing witnesses.

bifurcated at their endsthe s indle K held i by and between said overlapping portions and CHARLES EVEBE P1 EVANS bent into the indicator K which extends over \Vitnesses: the dial; and the disk L on said spindle and FREDERICK S. HALL, 10 extending into the bifurcations in'tbe two LILLA E. SNOW.

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