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Publication numberUS2248531 A
Publication typeGrant
Publication dateJul 8, 1941
Filing dateMar 3, 1939
Priority dateMar 3, 1939
Publication numberUS 2248531 A, US 2248531A, US-A-2248531, US2248531 A, US2248531A
InventorsHarris Gwin C
Original AssigneeRichard J Fitz Maurice
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
US 2248531 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

G. c. HARRIS July 8, 1941.

THERMOSTAT Filed March 3, 1939 gwuwrvfm 50172 C Harris Patented July '8, 1941 assignments, Orange, N. J.

to Richard J.

THERMOSTAT Gwin C. Harris, Orange,- N. 1.,

assignor, by mesne Fits Maurice,

Application March 8, 1939, Serial No. 259,648

1 Claim.

This invention relates to a balanced double blade opposed bimetallic thermostat, enclosed in abnon-metaliic casing and mechanically adjusta le.

The primary object of the present invention is the provision of a thermostat of this character which, while capable of general use, is designed more particularly for use in connection with a heating pad.

The invention is illustrated in the accompanying drawing in which:

Figure 1 is a longitudinal section. partly in elevation, of the improved thermostat.

Figure 2 is a section on line 2-4 of Figure 1.

Figure 3 is. a" section on line 3-3 of Figure l.

The improved thermostat comprises an open loosely through the block I insulating material is arranged between the bimetallic arms 9, which latter converge block I to the contacts ll. nected to a freely rotatable rod-like element I! having threaded connection at I! with the wall and the block adjusted to correspondingly, in-

ended cylindrical insulating casing I within 0 which is arranged a heating coil 2. The coil is preferably supported by winding on a thin phenol fiber tube 2' and may be arranged as closely placed relative to the bimetallic arms, to be'later described, as possible to make the wattage in the coil as eilective in the temperature as possible. The coil is of materially less length than that of the casing and is arranged in contact with the inner surface of the casing. I

An insulating block I is secured within the casing adjacent one end, the block being longitudinally cut away on its peripheral edge in diametrically opposed positions, as at I. Arranged on each cut away portion is a metallic plate Ii, one

end 6 of each of which is bent laterally at 'l on the block to hold the plate in position. The opposite end of each plate I is bent inwardly, as at I, to overlie the end of the block I, thus securing the plate against endwise movement relative to the block. Each plate 5 is projected lon'gitudinally oi the casing and within the coil 2 as a bimetallic, heat-responsive arm I and the terminal: of the arrn remote from the block are provided with-contacts iii. Obviously, the plate I for the entire length may be bimetallic for convenience.

Obviously, if appropriately constructed, the 1 arms 8 respond to the heat condition induced by the coil 2, correspondingly affecting the contacts I... In the particular guse in a heating pad wherein the thermostat is designed to accurately control heat conditions with minimum degrees v of fluctuation, provision is made for adjusting the contact holding tension of the bimetallic arms I. in order that such arms may automatical y respond to heat degrees of the coil in slight variations.

Tb provide for this adjustment. a block lip! cal hollow fluence the bimetallic arms and render the same less or more sensitive to the heat influence oi the coil in positioning the contacts -II.

In the more particular use of the thermostat in connection with a heating pad, 9. service conductor I6 is led into the casing i in strip form and terminally connected to one oi'the plates I and to the coil. The remaining plate 5 is connected to a strip conductor i1 while the. opposite end of the coil is connected to a strip conductor i8. These conductors lead through the respective ends of the casing and are securely clamped in position by end caps i9 and 20 each having an end projection It to fit snugly in the end of the casing and clamp the wires in position. Beyond the casing the caps are rounded to avoid abrasive eflect on the material of the pad. These caps have the additional eiiect of sealing the casing against rapid ingress and egress 01 air, which results in the contacts making and breaking the circuit in devitalized air at atmospheric pressure.

It is, of course, apparent that the block ii, here illustrated as oi cylindrical term, may obviously be or wedge or conical form if desired, such additional formation the purpose designed and not requiring illustration.

what is claimed to be new is:

An adjustable thermostat including a'cylindricasing open at the respective ends. an insulating block conforming to and accurately fitting the interior surface or the casing, said block' being formed with diametrically opposing flattened recess portions extending throughout the full axial length of the block, a plate fitted in each recess, the plate being bent over the opposing ends of the block inwardly of the bottom of thelrecess to hold the plate against movement longitudinally of the block and form thesole securing means 01' the plate relative to the block, said plates being extended beyond the block toirom the The block II is conbeing conventional for specific ward the opposite end of the casing in the form of convergingbimetallic arms, the free ends of the arms remote from the block having contact points, a coil surrounding the arms and in contact with the interior surface of the casing, the block being formed with a central axial opening extending entirely through the block and being interiorly threaded, a rod cooperating with the threaded opening, a terminal on the rod beyond the block contacting with the plates and serving to adjust the contacts on the plates relative to each other in accordance with the adjustment of the rod in the block, a conductor leading into the casing at one end and connected with one plate and the coil, 0, second conductgr leading into the same end of the casing and connected to the other plate, and a conductor leading into the opposite end of the casing and to the coil and caps removably closing the ends of the casing and trictionally holding the conductors in place, the removal of the cap adjacent the block permitting access to the rod in the block for adjustment of the contacts.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2415965 *May 29, 1944Feb 18, 1947Mcgraw Electric CoCreep-type thermal retarder for water heating control systems
US2589614 *Jul 19, 1946Mar 18, 1952Mcgraw Electric CoConstruction for electric heaters for flexing bars
US2743335 *Sep 4, 1953Apr 24, 1956Gen Motors CorpCircuit breaker
US2748222 *Aug 11, 1953May 29, 1956De Lancey Ralph WThermal switches
US2750475 *Jan 10, 1951Jun 12, 1956Gen Motors CorpThermostatic switch
US2762885 *Mar 5, 1953Sep 11, 1956S W Farber IncControl means for electric apparatus
US2793268 *Jul 1, 1954May 21, 1957Gen Mills IncThermal relay with shorting strip
US2801314 *Sep 27, 1955Jul 30, 1957Ford Earl GThermostatic switch
US2944324 *Feb 14, 1956Jul 12, 1960Gen Motors CorpMethod of assembling a circuit breaker
US3474372 *Feb 16, 1967Oct 21, 1969Crowell Designs IncTemperature-responsive switch having self-contained heater
US3670281 *Apr 5, 1971Jun 13, 1972Robertshaw Controls CoThermally responsive switch and method for making the same
US3747208 *Jan 26, 1972Jul 24, 1973Robertshaw Controls CoThermally responsive switch and method for making the same
US3816910 *Jan 15, 1973Jun 18, 1974Jackson WMethod for making thermally responsive switches
US4033029 *Aug 27, 1976Jul 5, 1977Robertshaw Controls CompanyMethod of assembling calibrated switch
US7265652 *Jul 28, 2004Sep 4, 2007Yingco Electronic Inc.Controllable electronic switch
US7324876Dec 14, 2004Jan 29, 2008Yingco Electronic Inc.System for remotely controlling energy distribution at local sites
US7688175Aug 31, 2007Mar 30, 2010I/O Controls CorporationControllable electronic switch
US7693610Sep 6, 2005Apr 6, 2010Yingco Electronic Inc.Remotely controllable wireless energy control unit
US7925388Feb 23, 2010Apr 12, 2011Yingco Electronics, Inc.Remotely controllable wireless energy control unit
US7961073Sep 29, 2009Jun 14, 2011Yingco Electronic Inc.Controllable electronic switch
US20120092122 *May 6, 2011Apr 19, 2012Yingco Electronic Inc.Controllable electronic switch
EP0062082A1 *Apr 3, 1981Oct 13, 1982Pai I. KuoHeat-sensitive safety resistor
U.S. Classification337/95, 374/E05.37, 337/109, 337/112, 337/102
International ClassificationH01H61/00, G01K5/00, G01K5/62, H01H61/02
Cooperative ClassificationG01K5/62, H01H61/02
European ClassificationH01H61/02, G01K5/62