US986023A - Thermostat. - Google Patents

Description

H. Y. NORWOOD. THERMOSTAT.

APPLICATION FILED NOV.29,1909.

986,023. Patented M317, 1911.

UNITED STATES PATENT OFFICE.

HARRY Y. NORWOOD, OF ROCHESTER, NEW YORK, ASSIGNOR TO TAYLOR INSTRUMENT COMPANIES, OF ROCHESTER, YORK, A CORPORATION OF NEW YORK.

THERMOSTAT.

Specification of Letters Patent.

Patented Mar. '7, 1911.

Application filed November 29, 1909. Serial No. 530,412.

To all 'wlwm it may concern:

Be it known that I, HARRY Y. Nonwoon, of Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Thermostats; and I do hereby declare the following .to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the reference-numerals marked thereon.

The present invention relates to thermostats of the typeinwhich one or more contacts are arranged to be engaged by an expansible conducting body such as mercury in order to establish an electrical circuit of which the expansible body forms a part, and the object of this invention is l9 provide for securing the contacts to the casing contain- .ing the expansible body in 'such a manner that greater life to the instrument is insured.

To these and other ends theinvention relates to certain improvements and combinations of parts all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings: Figure 1 is a view showing the instrument and the means supporting the same; Fig. 2 is a detail and enlarged sectional view of the instrument, and Fig. 3 is a section on the line (z-a of Fig. 1.

An electric contacting thermostat is usually a regular mercury and glass thermometer having platinum wires fused into the glass with one end of each wire rojecting into the bore and into the path of the mercury to complete the electric circuit while the other end projects from the exterior of the stem and has a suitable conductor secured thereto. These platinum wires at the point where they enter the glass are very brittle and are easily broken, thus requiring the exercise of great care in handling them both during" the process of manufacturing as well as in use, for once they are broken they cannot be repaired, and an instrument thereafter has no.utility for the purpose, for

which it was designed.

In this invention a suitable casing 1, preferably made of glass, with a bulb and a bored stem-as in an ordinary thermometer, has fused therein one or more conductors 2,

' end embedded therein.

preferably in the form of platinum wires extending transversely through the stem of the casing, and each projecting at its inner end into the bore 3 thereof and at its outer end from the outer surface of the stem.

At the outer end of each conductor wire is electrically connected an enlarged contact 4 which preferably is in the form of a copper sleeve surrounding the stem in proximity to the conductor 2, and having the wire In order that this contact will lie in most intimate engagement with the glass and the conductor 2, the contact is preferably deposited thereon electrolytically in accordance with any electroband of copper and this band cannot be shifted without breaking the glass so that the platinum wire cannot break away where it enters the glass. The thin film of silver or other material deposited by chemical action is in the most intimate contact possible with the surface of the glass, conforms to the most minute inequalities in its surface, and is with difliculty stripped from it, and the copper bandwhen deposited by electrolysis thereon forms a solid contact which is practically iridestructible- Every part of the band may serve as apoint of contact so that the conductor wire may be easily connected thereto in order to complete a circuit.

As a simple means for supporting the there may be rovided sleeves 6 each having a. stem 7 pro ecting therefrom and passing ,through an insulating bushing 8 in a suitable'wall -or support 9', said stem being secured in the bushings in any suitable manner as, by anut 10, and the circuit wires 11 being'held in engagement with the nuts 10 bynuts 12 also fitting on the stems 7. Two or more of the supporting sleeves 6 are axially aline'd and the thermostat stem is fitted into them so that its contacts 4 lie within the sleeves 6. In this position, the screws 13 or other suitable devices maybe caused to frictionally engage the contacts 4 to maintain the thermometer against movement in the sleeve.

A thermostat constructed in accordance with this invention has the conductors or platinum wires supported in such a manner that the breaking thereof is prevented and thus the life of the thermostat is greatly increased. lhe size of the thermostat contacts are also greatly increased thus permitting a quicker connection of the instrument to the signaling circuit.

I claim as my invention:

1. An electrical alarm thermostat embodying a stem of insulating material having a bore therein, an expansible conductor in the bore, a stationary conductor extending through the Wall of the stem into the bore, and a contact plate or body on the exterior of the stem, consisting of metal deposited upon the stem by electrolysis and having the outer end of the stationary contact embedded therein.

9.. An electrical alarm thermostat embodying a tubular stem of insulating material having a bore therein, an expansib e conductor in the bore, a stationary conductor extending through the Wall of the stem into the bore, and an annular contact plate or body encircling the stem consisting of metal HARRY Y. NORWOOD.

\Vitnesses VVALTER B. PAYNE, HENRY W. HALL.

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