US1716041A - Safety switch plug - Google Patents

Description

June 4, 1929.

J. GOERGL 1,716,041

SAFETY SWITCH PLUG Original Filed July 30, 1926 IIIIIIII INVENTOR ATTORNEYS '25 peratures.

plug, looking along thelinc 44' Patented June 4,1929.

UNITED STATES v PATENT OFFICE.

eomi' sonnet, or cnrcAGa-nnmom, ASSIGNOR or ommnr ro a. m. nvm, or

CHICAGO,

ILLINOIS.

SAFETY SWITCH PLUG.

Application filed July 80, 1926, Serial No. 125,997/ Renewed August 31, 1928.

My invention relates to improvements in safety switch plugs, and it consists in the combinations, constructions, and arrangements herein described and claimed.

An objectof my invention is to provide a plug which may be used in connection with electric irons or other appliances of the type, and which contains switching mechanism by means of which the current may be cut oil? or turned on at a predetermined temperature.

A further object of my invention is to provide a device of the type described in which the temperature at which the current is automatically cut off or turned on maybe varied so that in the case of an electric iron the heat may be regulated as desired and automatically maintained at a substantially given temperature.

' A further object of my invention is to pro-' vide a plug, containing a thermostatic element whichautomatically moves to cut off or turn on the current with means for controlling the movement of the thermostatic element, so that-it will operate at difierent tem- A further object is to provide a plug having the size of the ordinary plug, and which may be used with the ordinary electric iron or other electrical device that makes use of plugs. a

Other objects and advantages will-appear in the following specification, and the novel features of the invention will be particularly pointed out in the appended claims. 7 My invention is illustrated in the accom 'panying drawings, forming part of this ap plication, in which F Figure 1 is a side view of a plug, constructed according to my invention, j. V Figure.2 is aface view of one side of the plug, i s. Figure 3 is a seetlonal v ew along the line 33 of Figure 2,

Figure 4 is a face view of one half of the of Figure 1 in the direction of the arrows, Figure 5 is an enlarged sectional" view -,showing the thermostatic element and the- 4 spring for controlling the same.

Figure 6 is an enlarged sectional view through a portion of the spring contacts, 1

plan view of the spring conviews of opening being of such size as to receive the ad-; justing knob later to be described; this enables the part B which serves as a cover to be removed and replaced without interfering with the internal parts; As will be observed from FignreB, the section A is recessed to provide for a condenser 10, Whose opposite ends have connected therewith conducting pins 11 and 12, respectively. The portion B is also recessed, and between the portions A and Bare the three conducting- plates 13, 14

' and 15, shown in Figures 9, 10and 11. vThe plate 13 lies next to the wall of the portion vB, (see Figures 3 and 5). This plate has one corner bent up to form a hOOkr 13, by means of which one of the sets of spring contacts is secured. The form .of these spring contacts is shown in Figures 6 and 7; It will material, and which are held to-, y means of screw bolts 9. The secbe observed that thereis a strip 16 which has a semi-circular portion 16 stamped thereon vand that to this strip is another strip 17, hav-,

ing a spring portion '17 bent in the manner shown in Figure 6, so that when a conducting terminal pin enters from the bottom, the spring 17 will be moved aside and will form a close contact with the pin, whichis pressed. upon the conducting side 16. As will be seen from Figure 3, this spring contact is secured to the up-turn'ed' pogtion 13 by means of ascrew. The lower en of the contact 16' fits'intoarecess in the assembled plug sections and is, therefore, held securely;

Referring now again to Figures 3, 5 and 8, it will be seen-that the plates 13, 14 and 15 are separated by suitable insulation. The

central plate'l has a conducting terminal 18, whiclf extends through an opening 19 in the plate 13; the latter is provided with a thermostatic rod or arm Q0, which 'is' made of "metal and which, when heated, tends to spring. away from the terminal 18 and when cooled tendsto contact with it. This strip maybe of any suitable material, such as a compound-metal strip, and it is pressed upon inormally by/a spring 21, which is secured at- 22-to the plate 13. The upperend of the Spring is arranged to be engaged by the end of a screw 23, whiclr is carried by a milled insulating knob 24. The latter is pressed on subsequent operation of. the

pass through the conducting by a spring 25, which tends to push the head outwardly thus exerting 'friction on the threads of the screw so as to hold'the latter in adjusted position. In Figure 5 the ther mostatic element 20 is shown away from the terminal. When the spring 21 is forced by the screw23 toward the thermostatic element,

it will require a greater amount of heat for the latter to leave the terminal. 23 engages with a threaded aperture in a bridge 13, the ends of which are secured by screws 13, to the plate 13.; a'boss 13 on the bridge surrounds the'threaded aperture and serves to center'and hold the spring 25. The

outer end of the spring is held beneath the skirt 24 at the margin of the knob 24. e

The three plates 13, 14 and 15, as stated, are insulatedfrom each other and are held in spaced relation by means of screws 26, which plates, but do not electrically connect them, as shown in Figure8.

:A spring socket contact 16*, similar to the spring contact 16 is secured to plate 15 in substantial alignment with the contact 16.

The condenser is connected with the plate 14 on one side and the plate 13 on the other. From the foregoing description of the vari ous parts of the device, the operation thereof may be readily understood. When the parts are assembled, the plates 15 and l are connected to the' wires leading from the source of current. As has been stated, the'sock ets, WhlCh receive the terminal pins of the electrical device such as electric iron, are carried by the plates "15 and 13 respectively. Normally, the thermostatic element 20 is in engagement with the terminal18, thereby closing1 the circuit through the plates 13 and 1 an When, now, theithermostati element reaches a certain temperatu're,-i w ll move away from the terminal 18, and

this will cause the breaking-of the circuit. In order to condenser 10,

prevent arcing, I provide the which will permit the break to be made without. arcing and destroying the contacts; When itis desired to make the automatic" circuit opener operate at a higher I temperature, then the milled thumb knob 24 is turned to the 'right,forcing the spring 21 againstfthe thermostatic arm, so that'in the device greater The screw,

hence closing the circuit through the elece t tric'al device.

force must be; exerted by the thermostatic arm to move away from the contact 18. In

other words, the arm which is reinforced by the spring may be made to operate at yarious desired temperatures.

It will thus be seen that my improved plug not only embodies an automatic switch'for. operating at a predetermined temperature, but it also provides for the regulation of the temperature, or the adjustment to various temperatures so as to give more or less heat where, an iron is being used.-

I claim:

1. A switch p lug, comprising a pair of insulating sections, one of said sections having a boss provided with an opening, a stationary co tact carriedflwithin said plug, a thermo-- statically actuated arm hav ng one end nor-4 mally in engagement with said adapted to move away from said contact, at a predetermined temperature, a spring for opposing said movement, a screw in engagement with said spring, surrounding the header the screw and secured thereto for voperating the screw, said receivable in the opening in said spring for exerting pressureon for frictionally maintaining the screw in its adjusted position.

3: A switch plug, tion, a pair of insulating sections, one of, said sections having a. lateral opening, a station ary contact carried within the said thermostatically actuated arm having one end normally in engagementwith said tact andadapted to move away from said con- 115 -f "oppos ng said movement, a bridge overly-I act at a pre-determined temperature, a spring P ug a contact and- 7 an insulating knob maintainthe screw in its adjusted ob sun comprising incombina gsaid contact, a screw engaging said bridge, 7

f'and. adapted to contact said spring, a knob;.-,

'for actuating said screw, and means for maintaining saidknob and screw in'adjusted posi-' tions, the openingthroughsaid section being of a -size to permit said knob to pass. therethroughi 4 A plug comprising,

;section having an. opening, a stationary cons in combination, an main section and a eover section, saidcover tact, a movablecontact, said movable contact being in theform of a 'bimetal arm, said contacts being normally in engagement and said movable contact being adapted to move away from said stationary contact at a predetermined temperature, a spring for opposi-ng said movement, a bridge overlying said contacts, a screw engaging said bridge and contacting said spring, a knob for actuating said screw, all of said parts being fixed to said main section, said cover section overt;

ing said parts, and the opening therein serving to accommodate said adjusting screw whereby said cover section may be removed without interfering with the operatin parts,

- JOHN GOEL GL,

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