US1867379A - Temperature controlled electric switch - Google Patents

Description

July 12, 1932. Q. A oss 7 1,86%379 TEMPERATURE CONTROLLED ELECTRIC SWITCH Filed Nov. 15, 1927 Patented July 12, 1932 UNIT-ED STATES OSCAR A. ROSS, OF NEW PIATENT-JOFFIKCE FACTURING COMPANY ACORPORATION OF PENNSYLVANIA TEMPERATC'RE CONTROLLED ELECTRIC SWITCH Application filed November 15, 1927; Serial No. 233,483.

'tric flat irons, or similar heat generating ap pliances.

One object of this invention is to produce,

*an automatic. temperature controlled electric switch wherein the normal contact pressure .1 is maintained at maximum until the actual opening of the circuit occurs Another object is to produce a switch wherein the automatic switch actuating member is acted upon by heat and is independently moved for predetermined distance before actuating the contacting mechanism, the actual movement of the contacting mechanism not occurring until after the actuating member has attained a hi h rate of speed and thereby causes a quic break of the contacting mechanism without varying the contact pressure prior to the actual breaking of the\circuit.

Another object is to produce a switch wherein temperature regulation is maintained substantially close whereby as for example, a electric iron will not abnormally cool before the switchis again closed to supply current to the heatingelement forming part of said iron.

Another object isto produce a switch comprising a self contained unit which may be suitably attached to an electric ironv or other heat generating appliance.

Another ob ect is to produce a switch wherein the break is rapid and the make is slow, in this manner preventing fusing of 2) contact on the break andabrasion of said contacts on the make.

' Other objects and advantages will appear as the description of the invention progresses and the features of the invention will be pointed out in the appended claims.

This invention consists in the novel construction and arrangement of parts hereinafter described, delineated in the accompanying drawing, and particularly pointed out 1n that portion of the instrument wherein patentable novelty is claimed for certain and peculiar features of the device, it being understood that, within the scope of what here- "inafter 'is claimed, divers changes in the form, proportions, size and minor details of the structure may be made without departing from the spirit of the invention, or sacrificing any of its details.

In describing the invention in detail, ref- YORK, N. Y., ASSIGNOE '10 WESTINGHOUSE ELECTRIC & mU-.

erence is had to the accompanying drawing; where I have illustrated embodiments of the extension 5 supporting contact disk 6 having contacts 7--7 and thermo metal disk 8, riveted to which are actuating studs 9'9 having circuit closing balls 1 010 and circuit opening balls 1111. Disks 6 and 8 are held in spaced relation by collar 12 and are rigidly securedto stud 3 by collar 13 riveted or welded toextension 5.

ing washers 1'414 and bushings 15-15 are contact posts 16-16 having contact l717 forming one terminus of the circuit to be broken.

Thermo disk 8 comprises two dissimilar Insulatively mounted on base 2 by insulat metals18 and 19 as for example, steel and i brass welded together in sheet form after 'which a flat disk as 8 is stamped therefrom and whereafter said disk is spun or stamped into cup form as shown in Fig. 1, the steel face 18 facing downwardly.

The contact disk 6 is stamped from sheet metal, preferably steel, and its movement is not afiected by variation of temperature. Said disk is'formed cup shaped and of deeper, magnitudethan shown, the position shown being determined by the impin ement of contacts 7-7 against contacts 1 .17, the restraint of said disk determining the contact pressure between said contacts.

As'shown in Fig. 1, the electric iron 18 and its heating element 19 is assumed to have cooled sufliciently to require re -heating of said iron. When said iron is fully heated and whereby switch 2 has opened its contacts, the thermo disk 8 will be substantlally in the position shown as shown in Fig. 2. As the iron 18 and its heating element 19 cool, the outer edge 20 of thermo disk 8 moves substantially slowly upwardly until circuitr closing balls 10-10 impinge on the lowerside of orifices 21-21 in contact disk 6, whereafter the outer edge of contact disk, as 6, or 22, is also moved slowly upward until contacts 77 and 17-17 are substantially close together. As the circuit closing balls 10-10 impinge on orifice 21 the critical H buckling stage ofthermo disk 8 has been reached and without aid of heat, ittends to move upwardly rapidly thereby exerting additional pressure to move contact disk, as

6 or 22 upward more rapidly. However, as

said contact disk has not reached its critical buckling stage it resists the additional upward-action of said thermo disk. As contacts 77 closely approximate contacts 17-717 the critical buckling stage of contact disk, as 6, or 22 is reached and said disk snaps -upwardly rapidly until contacts 77 impinge. on contacts 1717. The outer edge 23 of contact disk, as 6 or 22, is now tendin to move upwardly without the assistance 0 thermo disk 8 and thereby causes contacts 77 to impinge upon, and establish firm contact with contacts 1717. 1

As the iron 18 and its heating element 19 cool, the outer edge 20 of thermo disk 8 moves downwardly slowly until the circuit opening balls 1111 approximate the upper side of orifice 21. As this occurs the buckling stage of said disk is reached and it snaps down- Wardly rapidly independently of temperature control, and as said balls impinge on said orifice the contact disk as 6, or 22, is also.

rapidly moved downwardly in this manner causing a quick break, or separation between contacts 77 and 17-17. As contact disk, as

7 6 or 20 is moved rapidly downwardly by thermo disk 8 it passes through its critical buckling stage and thereafter moves downwardly independently of the restraining action of circuit opening balls 11-11.

By slowly approximating contacts 7 -7 to,

contacts 17 17 and thereafter causing a quick closing of said contact, abrasion from phening, or hammering is reduced to a minimum thus insuring long life of said contact. Furthermore by causing a quick break of said contacts without reducing the contact pressure prior thereto, substantially prevents arcing and fusing of said contacts in this manner further prolonging the life of said con- For certain switches, as 1, the base 2 is formed to include stops, as 24.24 to limit the downward movement of edge 23 of cona d r Referring to the modificated switch 30 shown in Figs. 2 and 3, disk supporting stud 25 has been modified and insulatively supported by insulating washers 1414 .and bushing 15. Also stop lugs 2424 and the reinforcing flange of contact disk 6 have been omitted.

The base 2 of switch 1, is 'insulatively mounted within the electric iron housing 18, whereas the base 2a of switch 30 may be secured thereto Without said insulation, suitable holes 27-27 being purpose.

What I claim .is:

combination; a base member, contacts insulatively supported thereby, a biased disk provided for that 1. A thermo-electric switch comprising in member supported by the base member having a movable circumferential portion, con tacts supported by the movable circumferential ortion arranged to engage the base mem er contacts, a thermostatic member supported by the base member having a heat afcured to the base member, a movable biased circumferential portion surrounding the rigidly secured central portion, contacts supported thereby arranged to engage the base member contacts, a bi-metallic concave disk member having a central portion rigidly secured to the base member, a movable biased circumferential portion surrounding the rigidly secured centralportion arranged to be actuated by variation of temperature, and means supported by the movable biased cir cumferential portion of the thermostatic member for operating the movable biased circumferential portion of the contact sup-. porting disk member from one biased position to the other biased position whereby the contacts may be separated or engaged.

3. A thermally actuable switch includin a base member, contact members insulate 1y supported thereby, an inherently snap-act ing disk member supported on said base, contact members on said disk member arranged D to engage the contacts on the base, an in herently snap-acting bimetal disk member having two limiting positions of stable'equilibrium supported by. said base, and means carried by the bimetal disk member to ensure a predetermined initial movement of a portion thereof independently of the first named disk member and to then operatively engage the same to actuate it.

4. A thermally controlled switch comprising a base, contact members thereon, a singlemetal disk, a bimetal disk, both of said disks being dished to effect operation thereof inherently from one limiting position to anotherwith a snap action, contact members on the single metal disk cooperating with the contact members on the base, a single means for supporting both of said disks in coaxial positions on said base, and lost-motion means carried by the bimetal disk for actuating the single-metal disk when the bimetal disk is subjected to variations of temperature.

5. A thermally controlled switch including a base, contact members thereon, an inherently snap-acting single-metal disk, an inherently snap-acting bimetal disk, each of said disks having two opposed limiting positions, contact members on the single-metal disk cooperating with the contact members on the base. means for supporting said disks in spaced relation on said base, and lostmotion means carried by the bimetal disk for actuating the single-metal disk when the bimetal disk is subjected to variations of temperature.

' Signed at New York city, in the county of New York, and State of New York, this 28th OSCAR A. ROSS.

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