US2541119A - Electric iron - Google Patents

Description

Feb. 13, 1951 C, H, SPARKLIN 2,541,119

ELECTRIC IRON Original Filed May 4, 1945 3 Sheets-Sheet l Feb. 13, 1951 c. H. SPARKLIN ELECTRIC IRON 3 Sheets-Sheet 2 Original Filed May 4, 1945 Feb. 13, 1951 c. H. sPARKLlN ELECTRIC IRON l5 Sheets-Sheet 3 Original Filed May 4, 1945 Patented Feb. 13, 1951 ELECTRIC IRON Charles H. Sparklin, Chicago, Ill., assignor to Birtman Electric Company, -a corporation of Illinois Original application May 9, 1945, Serial No. 591,911. Divided and this application October 3, 1946, Serial No. 700,957

5 Claims. 1

This -invention relates toa heat regulating iron and more particularly to a sadiron in which .heat indicating means are provided for indicating the setting of the thermostat at a point .remote from the means of adjusting the same.

In my copending application, Serial No. 535,645, led May l5, 1944, now yPatent #2,457,185 `issued Dec, 28.J 1948 a thermostatic adjustment is positioned in a part of the .iron convenient to the fingers with the indicia placed with Van indicator in a position on the iron convenienty to the eye. This application also includes superimposi'ton of the setting indicator and the temperature indicator so that the operator .may ascertain at a single glance how `the actual temperature of the iron corresponds to the pre-determined setting.

In the .present invention .I have perfected a new iron having a thermostatic control member which does not require movement through a non-operating temperature range of the iron. When the off position is reached, the contact points of a switch are forcibly separated and maintained separated. This enables almost the entire range of the thermostatic adjustment to be used for adjusting the iron within the operating range. The abrupt change is preferably accomplished by having the control move from off position to high position and thence to low, but the on position may be at the low end, although this is less desirable.

'I'he invention will be described in considerable detail as related to the embodiment of the same set out in the accompanying drawings. -Of the drawings, Fig. 1 isa side elevation of an iron embodying the feature of this invention; Fig. 2 isa plan view of the iron of Fig. 1; Fig. 3 is a side elevation, partially in section; Fig. 4 is a section taken along line II-4 of Fig. 3; Fig. 5 is a section taken along line 5 5 of Fig. 3; Fig. I6 is a .section taken along -line 6--6 vof Fig. 3; and Fig. 7 is a section taken along line I-l of Fig. 3.

As shown in the drawings, the iron I 0 comprises a sole plate II and a 'hood l2 which together dene the body portion of the iron, a handle ysupport I3, a handle I4 containing openings 48 in either side at the rear for positioning an electric cord, and a control knob I5. The usual form of snap vacting thermostat I-6 is provided in the body y This second himetal element is fastened to another section of spring steel 2l. The second birnetal element 25 provides sharper control for the switch for when it is heated it curls downward in opposite direction to that of the rst bimetal element i5. rihis construction results in a thermostatic switch in which very sharp control is provided.

The thermostatic switch is controlled by rotation of the control knob i5 in the following manner. The knob I5 has a central opening in which an internal sleeve 22 is anchored. Within this sleeve is a square nut 23 which is thus turned by turning of the knob I5. This nut contains a threaded post 2li which is rotatably journaled in the sole plate at its bottom and which has a head 25 fastened within a plate 25 in the handle.

The square nut 23 is provided at its hase with a collar 27 having a groove 2&3. A broken rocker arm 2S is pivotally mounted in a bracket 3.13. This rocker arm is enga-ged at its iront end hy the sides of the groove 2t?. The other end of the rocker arm bears against a post 3l that is fastened to the lower spring steel arm i9 which carries a Contact point l for the make and break switch. Thus the posi Si serves to position the switch relative to the rst bimetal thermostat element I6. The broken rocker arm 23 is constructed so that `it acts as a rocker arm in one direction only. This is provided for by having the `rocker arm in two sections, each mounted on the same pivot, but with the front section '32 terminating around the rocker in a yoke, the ends of which hear upon the top of 'the rear section 33 of the rocker arm. The positioning oi the rocker arm positions the switch relative to `the rst birnetal thermostat element iii which controls the temperature at which the iron operates. This positioning is accompanied by rotation of the knob l5. When the knob I5 is rotated. the square nut "23 is movedup or down on the post 24. This moves the collarvl'! and thus positions the roc'ker'arm 2S which operates as a rocker only when the collar 2 moves upwardly. When the collar is moved in ardownward direction, the rear of the rocker arm is kept .in proper position by means oi the spring steel section` i9 pushing against the vrocker arm through post 3l. Such a construction is provided so that the rear portion 33 of 'the rocher arm may serve as a lever fnlcrumed at kone end around rocker arm pivot. It functions as a lever when the free end of the vrear portion is pushed down. The purpose .of this construction will be explained in greater ldetail hereinafter.

The setting of the thermostat is shown by the indicator 34, the end of which points to the indicia mounted below the handle. The end of the indicator 34 appears through an arcuate opening 3E in the body of the iron. ln the particular form shown, this opening also passes through the handle support i3, the indicator 34 is operated simultaneously with the setting of the thermostat by means of a gear train 31 connected to the square nut 23. A ring gear 33 having a square central opening is slidably mounted on the square nut 23 and meshes with the larger circumference of a iiat ring reducing gear 39. The smaller circumference of the gear meshes with a toothed arcuate member attached to the mounting 4I that bears the indicator 34. This mounting 4| is concentric with the shaft 42 and is designed to turn independently of the shaft.

The temperature indicator preferably comprises a thermostatic coil 43 secured to the sole plate Il of the iron in a central location. This coil may be a conventional bimetal material in spiral shape adapted to expand and contract as it heats and cools. At the inner end of the coil there is located a post 42 that is rotatable under the influence of the biinetal coil. The base of the post 42 is rotatably journaled in the sole plate. As a result when the temperature of the sole plate rises, the coil expands and turns the shaft. The temperature indicating means 44 is secured to the neck of the shaft 42 and rotates therewith. This means comprises a ring 45 having its cir-- cumferential portion underlying the opening 36 and the point of the setting indicator 34. The ring may be painted appropriately, for example, with a red zone, a yellow zone, and a green zone, and is also marked so that whenever the yellow zone underlies the temperature setting the ternperature of the iron is the temperature indicated. On the other hand when the red zone underlies the setting indicator the temperature of the iron will be above that required for a particular operM ating condition, and when the green zone underlies the pointer the temperature of the iron will be below that suitable for the preferred operating conditions. This method of marking and the way in which the setting indicator and the thermometer may be calibrated is explained in detail in my copending application referred to hereinabove.

On the rear section 33 of the broken rocker arm there is mounted an upwardly extending arm 49 projecting through an opening 5i] in the support plate for the reducing gear 39 (Figure '7). The upwardly extending portion is located so that when the control knob I5 is turned to a position corresponding to a high temperature the larger circumference of the ring reducing gear 39 contacts the inclined plate 5D and pushes it down, thereby preventing locking of the parts. This servesJ to push the rear section 33 of the broken rocker arm down and break the contact of the control switch. It can be seen that when the rear portion of the broken rocker arm is used in the above manner it acts as a lever fulcrumed at the point of pivot of the broken rocker arm.

After the new iron has been built and before it has been put in operation it should be syne chronized so that the temperature indicator will coincide with the thermostat setting. This can conveniently be done by means of a headless screw 5| positioned in the hub 52 of the temperature indicating means 44. The screw presses against post 42 that is attached to the bimetal thermostat 43 after the parts have been synchronized.

The knob l5 which is used to control the operating temperature of the iron, has a finger contacting portion 46 extending beyond the main body portion of the knob. This extended portion is separated from the rest of the knob by deep circular grooves 41 on either side which serve to keep the finger contacting portions 46 cool.

This application is a division of my copending application Serial No. 591,911, led May 4, 1945.

The foregoing detailed description has been given for clearness of understanding only, and no necessary limitations should be understood therefrom.

I claim:

1. In an electric iron having a handle and a body portion, a thermostat in the body adjacent the heating element, a switch operated by said thermostat for turning electric current on and oi, and a finger-manipulative rotatable member on said handle for adjusting the switch to any desired setting, a broken rocker arm operable as a rocker arm in one directionl only for positioning said switch, one end of said rocker arm operating on said switch when the other end is adjusted by saidrotatable member, setting-indicating means operated by said rotatable member through a gear train, means operated by said rotatable member also through said gear train for displacing the switch end of said rocker arm to disengage the switch when said rotatable member is turned to a position corresponding to a very high temperature, the broken rocker arm separating when moved in this direction so that the switch end is a lever fulcrumed at one end.

2. The electric iron of claim 1 wherein said means for displacing the switch end of said rocker arm comprises a portion of said gear train.

3. In an electric iron having a handle and a body portion, a thermostat in the body adjacent the heating element, a. switch operated by said thermostat for turning electric current on and ofi", and a finger-manipulative rotatable member on said handle for adjusting the switch to any desired setting relative to said thermostat for regulating the operating temperature in said iron, a broken rocker arm operable as such in one direction only, one end of said rocker arm being positioned by movement of the said rotatable member to position said switch relative to the thermostat, setting-indicating means also operated by said rotatable member through a gear train, and aninclined bearing plate on the end of the switch arm of the broken rocker and adapted to be engaged by a portion of the gear train to disconnect the switch when said rotatable member is turned to a position corresponding to a very high temperature, the broken rocker separating when moved in this direction so that the switch end is a lever fulcrumed at the rocker axis of the rocker.

4. In an electric iron having a handle and a body portion and a heating element, a thermostat in the body portion adjacent the heating element, a switch operated by said thermostat for turning electric current on and off and a ngermanipulative rotatable member for adjusting the switch to a desired setting, lever means for bearing directly against said switch and operated by said rotatable member for said adjusting of the switch, setting-indicating means also operated by said rotatable member and including a gear train, and rigid means operated by said rotatable member through said gear train for displacing the switch end of said lever means to disengage the switch when said rotatable member is turned to a position at one end of its path of movement.

5. The electric iron of claim 1 wherein said rigid means includes an extending portion on the switch end of said lever means normally positioned to be contacted by said gear train when said lever means is displaced to disengage the switch.

CHARLES H. SPARKLIN.

REFERENCES CITED The following references are of record in the i-lle of this patent:

Number 10 Number Great Britain Jan. 18, 1944 Certificate of Correction Patent No. 2,541,119 February 13, 1951 CHARLES H. SPARKLIN It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 5, line 3, for the Claim reference numeral 1 read 4;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the ease in the Patent Oiice.

Signed and sealed this 15th day of May, A. D. 1951 THOMAS F. MURPHY,

Assistant Commissioner of Patents.

Certificate of Correction Patent No. 2,541,119 February 13, 1951 CHARLES H. SPARKLIN It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 5, line 3, for the claim reference numeral 1 read 4;

and that the said Letters Patent `should be read as corrected above, so that the same may conform to the record of the case in the Patent Oce.

Signed and sealed this 15th day of May, A. D. 1951.

THOMAS F. MURPHY,

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