US1875369A

US1875369A - Thermostat

Info

Publication number: US1875369A
Authority: US
Publication date: 1932-09-06
Anticipated expiration: 1949-09-06

Description

Sept. 1932- H. D. COLMAN 1,875,369

T HERMO S TAT Filed May 12. 1930 'NVENTOR 4 l fowar'd D- Colman v ATTORNEYS Patented sept. 6, 1932 umjrso STATES HPI'ATEN'II? oFFica HOWARD D. COLIAN, Oil? ROCKFORD, ILLINOIS THERMOSTAT Application filed. Kay 12, 1930. Serial no. 451L579.

This invention relates to thermostats and more particularly to those ofthe open switch type.

R Thermostats of the above character gen-" free circulation of air about the element.

With the contacts thus exposed, dust and other'foreign particles "carried by the circu- U *tlOIl 1n the drawing includes an elongated lating air accumulate on the contact surfaces and prevent proper engagement thereof which causes undue sparking and burning oil of the contact points. The sensitivity of the instrument is thereby materially impaired.-

The primaryobject of the present invention is to overcome the above objection through the provision of a new and improved casing construction which efl'ectually encloses the thermostat sw itches without decreasing the required circulation of air around the thermo-sensitive element.

In carrying out this object, the control v V switches are enclosed efiectually through the provision'of-a partition separating'the thermostat easing into a lower compartment through which air may circulate freely and anupper compartment WhiCh "iS completely closed except for a narrow opening in the partition through which the thermostatic tongue rojects. 7

Another object secure the partition above mentioned on the removable cover as distinguished from the supporting 'base of the thermostat,'preferably forming the'partition inte a1 with the walls of the cover; Other 0 jects and advantages of the invention will become apparent from thefollowing detailed description, in which Figure 1 of the-drawing is a front elevational view'partially in section of a thermostat embodying the features of the present invention.

Fig.,2 is a right side view of Fig. 1 with the cover shown in substantially central section.

detail in the preferred form and in connection with a particular type of thermostat, it is to be understood'that modifications and alternative constructions made by those skilled in the art to adapt the same to different conditions will lie within the scope of the invention as defined by appended claims.

The thermostat shown by way of illustrabase 5 adapted to be secured in vertical position against a flat wall surface and supporting at its lower extremity one end of a coiled strip 6 of bimetallic metal which constitutes the thermo-responsive element. Secured to the other end of the strip. and projecting upwardly along the center of the base is an elongated fiat tongue 7 whose upper end carries a contact which cooperates with twofixed terminals 8 to form control switches which alternately open and close with reversals in the temperature to which the thermal element is exposed. The ends of the terminals 8 are, according to the usual practice, spaced close together and confine the lateral movement of the tongue to a narrow range.

\ The operating parts above described are protected against mechanical injury by a removable cover having a front wall 9 and a strip 6,.the lowers-portion of the side wall 10 is formed with a series of'perforations 12.

Thatportion of the cover enclosing the control switches is unp'erforated and this end of the compartment is substantially. closed 'througlf the provision of apartition 13 extending between the two opposite sides of the cover somewhat below the contacts 8 and defining the bottom wall of aseparate switch compartment. To form a more rugged construction, the partition is mounted on the cover and to this end the latter is preferably made of molded bakelite so that the partition wall may be readily formed integral with the side and front walls of the cover as is clearly shown in Fig. 4.

At its center the partition is formed with a slot 1A of a width slightly greater than the range of movement of the thermostat tongue. This slot opens at the inner edge of the partition so as to receive the tongue 7 as the cover is fitted onto the base and guided into proper position by the shoulder portion 11. With the cover thus positioned, the inner edge of the partition abuts against the face of the base as shown in Fig. 3.

With this simple construction, the control switches are housed in a substantially closed compartment from which dust and foreign particles are eifectually excluded by reason of the fact that the only opening into the switch compartment is through the lower defining wall thereof, which opening may be made small because of the relatively narrow range of motion of the thermostat tongue which projects into the switch compartment. Casting the partition integral with the cover affords an inexpensive method of forming the partition and avoids the danger of dislocating the partition and thereby impair ing the thermostat in the act of placing the cover onto the base. Inasmuch as the partition is carried by the cover, it is removed with the cover and therefore does not interfere with the adjustment of the thermostat or cleaning of its contacts.

I claim as my invention:

1. A thermostat comprising, in combination, an elongated substantially flat base, a removable cover composed of molded insulating material and having a substantially flat front wall and -aperipheral side wall, said cover being adapted to fit onto said base and cooperating therewith to form an elongated compartment, a coiled bimetallic strip supported on said base at one end of said compartment, an elongated substantially fiat tongue supported by said strip and project-- ing longitudinally of said compartment, :1. contact mounted on said base at the end thereof opposite said strip and cooperating with the free end of said tongue toform a control switch, and a partition molded integral with the cover walls and extending transversely across the cover to divide said compartment into a perforated portion containing said thermostatic strip and an unperforated portion substantially closed by said partition and containing said switch, said partition-having a slot therein open at its inner edge so as to receive said tongue when said cover is fitted onto said base.

2. A thermostat comprising, in combination, an elongated base, athermo-sensitive element mounted on one end of said base,

a circuit terminal mounted at the other end of said base, an elongated tongue extending longitudinally of the base and having one end associated with said element and the other end cooperatingwith said terminal to form a switch, a casing enclosing the device and having the portion thereof adjacent said bimetallic element perforated to permit free circulation of air therethrough, the remainder having solid walls, and a partition cast in tegrally with said casing dividing said perforated from said unperforated portions to form a substantially dust-proof compartment for said switch, said partition having a narrow slot receiving said tongue when said casing is placed on said base.

3. A thermostat comprising, in combination, an elongated base, a cover adapted to fit on and cooperating with said base to form an elongated compartment, a partition formed integral with said cover and dividing said compartment into a substantially closed portion at one end, the walls defining the compartment being perforated to permit the circulation of air through the other end portion ofthe compartment, a thermo-sensitive element mounted on said base in said open end portion, an elongated member arranged to be actuated by said element and extending longitudinally of said compartment through said partition into said closed portion, and a contact within the closed portion of said compartment cooperating with said tongue to form a control switch.

4. A thermostat comprising, in combination, an elongated base adapted to be mounted in an upright position, a bimetallic strip responsive to temperature variation and mounted at the lower end of said base, a circuit terminal mounted at the upper end of said base, an elongated tongue extending longitudinally of the base and having one end rigid with said bimetallic strip and the other end cooperating with said terminal to form a switch, a casing formin a cover for the device, the lower portion of said casing enclosing the bimetallic element having perforations to permit free circulation of air therethrough, the remaining lower portion being unperforated, and a partition within said casing dividing said perforated from said unperforated portion to form a substantially closed chamber for said switch, said partition having a narrow slot through which said tongue projects.

5. A thermostat comprising, in combination, a casing defining an elongated c0mpartment, a partition extending transversely of said compartment and dividing the same into a substantially closed portion at one end, said casing having at its other end portion a perforated wall permitting the circulation of air therethrough, an elongated switch actuating member projecting longii tudinally of said compartment through an 0 Jening in said artition, a thermo-sensitive eiement mounte in the open end portion of said compartment and arranged to actuate said memJer, and acontact mounted in the closed end portion of said compartment and cooperating with said control'sw1tch.

6. An automatic control device for air conditioning systems comprising, in combination, an elongated casing having perforated walls at one end thereof so as to permit the free circulation of air therethrough, a, partition extending across said casing near the other end thereof and cooperating wit-h member to form I a such end to form asubstantially closed compartment, a contactswitch disposed in said closed compartment, an element responsive to changes in the condition of the circulating air and mounted 1n the end of said casing opposite said compartment, and an elongated member extending longitudinally of,

the casing through said partition having one end associated with said element and the other end arranged to actuate said switch in response to said element.

7, A thermostat comprising, in combination, acasing comprising two separable parts adapted when assembled to define a chamber having one section defined by closed walls and another section defined by walls perforated to permit air circulation therethrough, thermostatic means insaid last mentioned section including an elongated member laterally movable as an incident to temperature changes, a. contact in said closed section cooperating with said member to form a control switch, said contact and thermostatic means being mounted on the same one of said parts to permit adjustment of the thermostat prior-to assembly of the parts. and a.

partition between the sections of saidchamber' havmg an aperture therein adapted to receive said member as an incident to assembly of Silld parts andof a size permit-- ting of the necessarv lateral movementof said member.

In testimony whereof, I have hereunto affixed my signature.

HOWARD D. comma.