US1878663A - Electric iron - Google Patents

Description

sept. 2o, 1932. R. B.- a-ENJAWN 1,878,663

f LEc'rRIc 4111011 Filed March so. 1928 2 sheets-sheet 1 Sept. 20, 1932. fR. s. BENJAMIN ELEQTRIC 'IRON Filedfarcr; so. 1928 2 sheets-sheet 2 .w\ Kw. www NMW kN m. UNM, ,l//Wu EB @IW Mm q NNN mg .w M www s nL xwwwvww um t Nw Mw ,Nx Qm, Q www, mn XN fnw N WN Patented Sept. 20, 1932 IJJNITED STATES PATENT OFFICE y RIIUBIIN afanNJAMIN, or CHICAGO, ILLINoIs, AssIGNon 'I'O BENJAMIN ELECTRIC `MA,NuI'AogrImINer COMPANY, OF cIIIcAGO, ILLINOIS, A CORPORATION OF ILLINOIS ELEc'rnIc IRON Application led March 30, 1928. Serial. No. 265,886.

My present invention relates to electric irons, and particularly, to thermally controlled. switches to shut oil the electric heatprovide improved means for automatically opening the circuit, thus preventing undesirable results in case the iron is allowed to stand connected up with the source of current supply.

A further object of my invention is to provide a construction which will be sim le, cheap to` manufacture` durable and efiicient in use.

Another object of mv invention is to provide means wherebythe user of the iron may regulate, either while the iron is in use, or before using the same, the temperature at which the circuit Will be opened by the automatic means.

In the use of this iron, the operator may set the automatic means to open either at a comparatively low temperature, such as would be employed for light goods and work which can not be done rapidly, or at a higher temperature, such as is required when the goods which are being ironed are heavy or of 'such nature that the wfork must proceed rapidly.

A further 4object ofmy invention is to provide an improved thermally controlled switch located within the handle ofthe flat iron and which switch is actuated by thermal kmeans located within or upon the body vOI the iron and connected to the switch releasing means 15 by a metallic or other suitably formed actu- Another object of my Ainvention is to providea form of toggle construction connected to an electric Switch so that when the said thermally Operated connection exerts a lat# eral force upon the toggle, the same will be sprung out of its normal position and will thereby actuate the switch; all of which will be more clearly set forth hereinbelow.

Further objects will appear from the description, the claims and the drawings which form part of the present invention, 1n which drawings:

Figurel 1 is a side elevation of a Hat iron embodying the improvements which are the objects of my present invention;

Fig. 2 is a rear elevation of the iron shown in Fig. 1;

Fi 3 is a partial front elevation of the hand e and means whereby the same is attached to the iron;

Fig. 4 is a cross-sectional view of the handle along the line 4 4 in Fig. 1;

Fig. 5 is a sectional view along the line 5-5 in Fig. 7; v 70 Fig. 6 is a horizontal cross-section, on an enlargied scale, of the handle shown in Fig. 1' an Fig 7 is a vertical cross-section of the same handle on the same scale as Fi 6.

In order to give a general idea o? my in` vent-ion, I will outline briefly some of the main features of the construction before describing the parts in detail. The electric iron shown comprises a body portion l0 of the iron, as shown in dotted lines in Fig. 1, which body contains an electrical resistance forming a heating element. The said body portion is surrounded by a metallic housing 11. .A handle 12 is secured to the body portion of the iron for manipulating the same, there being also provided the usual type of connector device 13 for connecting up the' iron with the feed wires that are connected to the source of electric current supply. Contained within the handle 12 there is a thermostatically controlled switch mechanism 15 for controlling a circuit comprising the feed' wires 14 and 14a and the heating element. A" thermostatic element 16 is actuated by the heat of the iron. The said thermostatic'element 16 controls the switch mechanism 15 through the intermediary of the dat curved metallic actuating member 17 for automatically releasing the switch mechanism 15 to 10c allow it to move to the on position in case the heat becomes excessive. Manual means are also provided for returning the switch to the on osition.

In the or inary use of the iron, the heat is 'conducted laway from the face of the same by reason of the moving contact between the face of the iron and the goods which are to be ironed. This conduction of the heat away from the face of the iron keeps the temperature of the same down to what may be termed the normal operating temperature. If, however, the iron is allowed to stand, and, particularly, if it is allowed to stand with the face of the iron in contact with the goods, the heat is not conducted away very rapidly and the temperature of the body portion of the iron rises and becomes excessive and results in damage to the goods and to the iron and possibly evenin fire unless means are provided to prevent this excessive rise in temperature. For the purpose of preventing this excessive rise in temperature, the connection between the thermostatic element 16 and the switch mechanism 15 is made so that when the temperature of the iron exceeds a predetermined degree, which has been determined as'the critical temperature, the thermostatic element will cause the switch element to be moved to the off position, thus disconnecting the heating element 15. Thus, even though the iron be left on after the operator gets through with it, the continual rise in temperature will very soon serve -to operate the switch release, whereby the flow of current through the heating element in the iron will be permanently interrupted so that the iron will gradually cool down and no harm-will result. If the operator at any time again wishes to continue to use the iron, it suiicies to place the switch release mechanism into the position in which the switch is closed and the iron will ag'ain heat up and the operation will continue.`

Another advantage residing in my present invention, lies in the fact that the switch operating mechanism may also be operated manually so that the operator may use the same to turn the iron off and on, as may be desired. Provisions are also made for setting the .mechanism so that the results will be effected at adeiinite temperature.

I will now describe the construction of my improved mechanism in connection with an electric iron in detail.

Inasmuch as my present invention does not concern itself with the particular constructionof the heating element or with the body` portion of the iron, I will not describe the same in detail. The thermostatic element 16 may consist of'two different strips of metal having a different .co-efficient of expansion, the co-eiiicient of expansion of the lower strip being greater than the co-eiiicient of expansion of the upper strip, s o that under the inuence of heat the composite element will tend to bend. As one end of the element is securely held to the body 10 of the iron whereas the other end 16a is free, the net result of this expansive force will be to curl the end 16a upwardly away from the body of the iron as the heat increases. Such bi-metallic thermostatic elements are known in the art and in my present modification may consist of an upper strip of steel and a lower strip of zinc, zinc having a higher co-efiicient of expansion.

In order to prevent possible injury to the thermostatic element due to excessively high temperature, a sheet of heat insulating material may be placed between the thermostatic element 16 and the main body 10 of the iron. The end 16a of the thermostatic element is in contact with'the upwardly extending fiat metallic actuating element 17 which passes inwardly of the metallic handle supports 18 and extends upwardly into the handle as vshown inFigs. 1, 3, 5, 6 and 7. The upper end of this actuating element 17 is in contact with the longer member 20 of the toggle element that actuates the switch mechanism 15.

The point of contact of the element 17 with the toggle element 20 may be varied by means.

ofthe screw 19 which passes through the forward handle support 18. By moving said screw inwardly against the member 17, the point of contact of the said member 17 with the toggle member 2O will be v gradually raised, thereby causing its release at a lower temperature than when said point of contact is further from the said pivotal connection. A spring 19a serves normally to bias the metallic actuating member 17 against the said screw 19, as most plainly seen in Figs. 1 and 7.

The switch mechanism 15 consists of two knife blades and 31, which constitute metallic conducting bus bars which are attached to or molded in the lower portions 12a of the handle 12. This is accomplished by making the handle 12 of a molded resinoid material, such as is commonly used for electric insulating material and is of such nature that metallic inserts 'may be molded into the same during the molding operation. Metallic conducting wires 14 and 14 serve to connect the bus bars 30a and 31a, respectively, with the source of electric current and with the heatingelement in-the iron, as is well understood in the art, and, furthermore, is described in my Patent No. 1,391,296. The knife blades 30 and 31, when the switchis in the on position, are bridged by a metallic` conducting member 32. The said member 32 is pivoted against the sides of a recess in the lower portion 12a of the molded handle, being pivoted thereto by the pivots 33. When inv the closed position, as shown in Figs. 4 and 6 and in solid lines in Fig. .7, current will ilow -from the knife blade 30 nio to the knife blade 31` and hence through the heatingelement in the body of the iron.

Means are provided for rapidly moving the bridging member 32 from between the . knife blades 30 and 31. In order to eiect understood, however, that no moving parts in Fig. 7. This will cause the roller 27 to gled are in any way attached to the upper part 12. The reason for this will be explained hereinbelow.

The means lemployed for throwing the switch into the pif position will now be described. They consist of a long member and a short member 22 of a toggle, both members 2O and 22 being ivotally connected to each other by means o a rivet 23. The short member 22 of the toggle is, in turn, pivoted to a short upright metallic holding memberV -24 which extends for a short distance into the upper part of the handle 12 (see Figs. 6 and 7). Surrounding the long actuating toggle member 20 for a portion of its length is the compression spring 25 which bears with its forward end, as shown in Fig. 6, against a retaining plate 26 held on the member 20 by the pin 26a. This retaining plate 26 is provided with flanges 266 to prevent the spring from lateral displacement. On the toggle member 20, at the point 21, there is pivoted a roller 27 which bears upwardly against a hairpin-shaped track 28. This track consists of a strip of steel, bent into the shape shown, and rovided at its termini with right-annds 29 which serve as the rearward abutment of the aforesaid spring 25. This construction, by reason of the compression of the spring 25, normally will urge the toggle member 20 in a forward direction and out of the handle 12. However, when the toggle member 20 is in the position shown in solid lines in Fig. 7, so that the member 22 is below the dead center with respect to the member 20,' the spring will not be able to push the member 20 out of the handle unless the said member 20 is slightly pushed 11D- wardly out of alignment with the member 22 whereupon the spring will exert its expansive force and will cause the members 20 and 22 to assume the positions shown in dotted lines move forward under the track 28 and will, therefore, throw the spring into the position shown in dotted lines in Fig. 7 thereby causing the disengagement of the bridging member 32 from between the knife blades 30 and 31, thus interrupting the electric circuit.

As it is possible that the member 32 mayv same, additional means are provided to insure the operation as above described. These means comprise an upwardly projecting hooklike end 29-on the'member 20, which, on the forward movement of the said toggle member 20,.wil1 contact with the spring 35 and will kick the same out of its normal position thus insuring the immediate movement of the switch bridging member 32 from between the knife blades so that the Contact will be broken with a minimum of arcing.

The forward end of the toggle member 20 is provided with an insulating button consisting of molded material, so that any accidental contact with the electric live portions of the switch will not cause a shock to the operator, although, as will be seen from vthe construction, even this danger is remote as long as all the parts remain properly in place.

As the iron cools down, after the current has been disconnected by the switch operating vmechanism 15, the thermostatic element 16 will gradually assume a horizontal position, whereupon it will be possible to push the toggle members 20 and 22 back'into the positions shown in solid lines Iin Fig.V 7, so that the opera-tion of the switch may continue.

One of the characteristic features of myv present invention lies in the extremely simple method of assembly made possible by the handle construction. -The handle consists of two portions 12 and 12a, each molded by itself and containing all necessary metallic inserts required for the rapid assembly of the mechanism. The two portions of the handle when superimposed upon each other, form a complete housing for the entire switch and switch tripping mechanism. The two portions are held together by means of the upwardly extending metallic elements 18 and 18a, which at the same time serve as the sup` ports connecting the handle to the iro proper.

The handle part-s 12 and 12a are secured to the rear support 18a by means of a pair of screws 40 and 41 extending through the support 18a and threaded into a V-shaped plate 41a. This plate 41a may be secured to the lower handle part 12a in any suitable manner,

as by having a portion thereof molded therethrough openings in the front support and are threaded into the U-shaped plate 24 which4 has its lower part molded into the lower handle portion 12a.

The forward handle support 18 is slotted at 44 to allow the' toggle member 20 to project forwardly out of the handle, as is best seen in Fig. 3. The button 50 is held on the end of the member 20 by meansv ofa small rivet being attached after the assembly of the handle and its contained mechanism. In resetting the switch, it sulices to push upon the button 50 in a general downward and inward direction whereupon the spring 35 will snap the metallic brid 'ng member 32 back between the two knife lades 30 and 31.

In Fig. 5, the details of the upper end of the actuating member 17 are shown. This figure, which is a cross-sectional view taken along the line -5 of Fig. 7, also shows the plate 24 to which the shorter toggle member 22 israttached. This plate is provided with a slot.24 a. in which the lmember 20 operates.

In order to prevent any possi le interference betweenthe short member 22 of the toggle and the push member 17, the latter is cut awa at its upper end, asindicated at 51 (Fig. 5 the other side of the member 17 having an extension 52 a inst which the side of the longer toggle mem r 20 ma rest, and the bottom ed e of the longer tog e member ybeing engage by the narrow le ge or shoulder 53. v

From the foregoing description, it will be evident that I have provided an extremely simple and highly eilicient thermo-control means for use in `connection with electric irons. I wish it to be understood however, thatthe particular type of switc opening mechanism need not confine itself exclusively to electric irons, but may likewise be used on other electric heating devices, such as toasters, wallie irons, electric griddles, percolators,

and the like, in which excess temperatures are liable to cause trouble, and whichare-to be provided with automatic means for interrupting the current when a predeterminable critical temperature is substantially exceeded. Modifications that are within the skill of the mechanic, which are merely variations in form upon the device shown by me in the present application, are to be considered within the scope of the invention, for which I claim:

. the heating element of an e ectric iron comprising a pair of members pivotally connected 1 together to form a toggle construction, movable from one position to another for causing the switch to move from open to closedposition, and vice versa, a sprin acting on said toggle construction and ten ing to move the switch to open position, the pivotal connection between the toggle members bein movable past a dead-center to hold the switch in on position, and thermostatically controlled means for breaking said toggle to allow said spring to act to cause said switch to move to open position.

2. A. thermally controlled electric switch construction for controlling the circuit for the heating element of an electric iron comprising a pair of members pivotally connected together to form a toggle construction, a spring connecting one of said toggle members with said switch, said toggle construction being movable from one position to another to shift said spring for causing the switch to move from opened to closed sition, and vice versa, a spring acting on sai toggle construction and tending to move the switch to open position, the pivotal connection between the toggle members being movable past a deadcenter to hold the switch in on position, and thermostatically,controlled means for breaking said toggle to allow said spring to act to cause said switch to moveto open position.

3. A thermally controlled electric switch construction for controlling the circuit for the heating element of an electric iron comprising a pair of members pivotally connected together to form a to gle construction, a spring connecting one o said toggle members with said switch, said toggle construction bein movable from one positionto another to shift said spring for causing the switch to move from opened to closed osition, and viceversa, a spring acting on said toggle construction and tending to move the switch to open' position, the pivotal connectionbetween the toggle members being movable past a dead-center to hold the switch in on position, and thermostatically controlled means for breaking said toggle to allow said spring to act to cause said switch to move to open position, one of said toggle members havin provisions for positively acting on the switc mechanism to actuate it is case the spring tension is insuiiicient to release the switch quickly.

4. A thermally controlled switch construction for use with an electric iron having a heating element and a handle comprising a switch in said handle for controlling the circuit of the heating element, a member movable 'back and forth for causing the switch to move from closed to open position, and vice versa, means for retaining said member in position to hold the switch in on position, and means for releasing said member from said retaining means comprising a push member extending upwardly from the body portion of the iron toward the handle, and adjustable guide means for varying the direction of travel of said releasable member to vary the degree of temperature at which said member will be released from said retainingmeans.

5. A thermally controlled switch construction for use with an electric iron having a heating element and la handle comprising a switch in said handle for controlling the circuit of the heating element, a member movable back 'Y and forth for causing the switch to move from closed to open position,

.and vice versa, means for retaining said member position to hold the switch in on position, and means for releasing said member from said retaining means comprisingy a push member extending upwardly from the body portion of the iron toward the handle, and ad]ustable guide means for varying the direction o travel of said member to vary the degree of temperature at which said member will be released from said retaining means comprising a screw engaging push member.

- 6. A thermally controlled switch construction for use with an electric iron having a heating element,v comprising a switch for controlling the circuit to the heating' element, a pair of members pivotally connected together to form a toggle construction, movable from one position. to another for causing the switch to move from open to closed position, and vice versa, a spring acting on said toggle construction and tending to move the switch to open position, the pivotal connection between the toggle lmembers being movable past a dead-center to hold the switch in on position, and thermostatically controlled means for breaking said toggle to allow said spring to lact to cause said switch to move to openposition, one of said toggle members being provided with a follower memberand a track for guiding said follower member. l

7 A thermally controlled switch construction for use with anv electric iron having a heating element, comprising a switch for controlling the circuit to the heating element, a pair of members pivotally connected toether to form a toggle construction, movable from one position to another for causing the switch to move from o en to closed position, and vice versa, a spring acting on sai toggle construction and tending to move the switch to open position, the pivotal connection between the toggle members being movable past a dead-center to hold the switch in on'position, and thermostatically controlled means for breakingsaid toggle to allow said spring to act to cause said switch to move to open position, one of said toggle members being provided with a roller and a track member engaged by said roller.

8. A thermally controlled electric iron switch construction comprising a handle, and a switchl in the handler forv controlling the circuit for the heating element, said handle being split longitudinally on a horizontal plane, a member shiftable back and forth for controlling the switch, a sprin connectin said member and switch, sai member ybein provided with a follower, a track mem r engaged by said follower a'ndlyi'ng above it, the lower part of the handle having a recess in which said track member is seated, and having a portion engaged by the upper part of the handle for holding the track 1n position whereby the track and member are held in assembled position between the 05 two parte of the handle.

said A 9. A thermally controlled switch construction for use with an electric iro'n having a heating element and a handle comprising a switch blade, a blade-shifting member mounted for general longitudinal movement with respect to said handle, an actuating Vspring acting on said' blade-shifting member, means for holding said blade-shifting member against movement and thermostatic means for releasing it for movement, and rotatable means having a pivotal engagement with said blade-shifting member for guiding said blade-shifting member in its movement, said point of pivotal engagement being movable at least up to the dead center linebetween the center about which said rotatable means rotates and the center of pressure of the actuating spring.

In witness whereof, I have hereunto subscribed my name;

' REUBEN B. BENJAMIN.

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