US1994877A - Cordless electric iron - Google Patents

Description

March 19, 1935 F. H. sHooP El AL CORDLESS ELECTRIC IRON Filed March 20, 1931 INVENTO R 00 0 Cow/71:1,

ATTO RNE Patented Mar. 19, 1935 CORDLESS ELECTRIC IRON Francis 11. Shoop, Winfield s. Grant, and Thomas I J. McCormick, Detroit, Mich assignors, by mesne assignments, to Therm-O-Lectric Corporation, Michigan Application March 20,

4 Claims.

Our invention relates to electrically heated articles, and has particular reference to means for controlling the electric current to electric irons.

The main object of our invention is the-provision of means for heating an electric iron, which 'will permit the iron to be readily attached and detached to the switch without the necessity of manually connecting and disconnecting the customary plug, thus permitting the iron to be used without the cord attached thereto and without the inconvenience which would be occasioned if the previously well known types of electric iron were to be connected to and disconnected from the plug and cord respectively each time the iron was raised and lowered.

Another object of the invention is the provision of very simple and eilicient safety lock-out means for automatically cutting oif the electric circuit of the heater, and a further object is the provision of simple adjustable means by which the last mentioned means may be regulated. 4

With the above and other ends in' view, the invention consists in the matters hereinafter set forth and more particularly pointed out in the appended claims, reference being had to the accompanying drawing in which Figure 1 is aplan view of the iron illustrative of an embodiment of our invention, the same being partly broken away and partly in section;

Fig. 2 is a side elevation of the same, partly in longitudinal section, and

Fig. 3 is a sectional detail view of control mechanism in an off position.

In the drawing the reference numeral 1 designates a stand upon the rearward end of which there is fastened an insulating block 2 within which are located the parts of a switch whose contact points 3 are brought together by the weight of the iron indicated as a whole by the numeral 4,

and whose terminals 5 make electrical contact with the switch arms 6 which are pivotally supported in the block 2, intermediate their ends, as at 6a, and actuated in one direction by means of springs 7 to normally inoperative position, the contacts 3 then being separated thereby when the iron 4 is lifted from the stand 1, to remove its terminals 5 from engagement with the forward ends of said switch arms.

It will be noticed that only the forward part or point of theiron 4 contacts with the stand 1, there being upturned lips 8 at opposite sides of thestand, serving to guide the iron when placing it on the stand and to hold it so that -it will be supported when in place on the stand, solely at its forward end or point and by resting upon the forward ends of the switching arms 6, the contact points 3 being thus held firmly together to close the external electrical circuit by the weight of the iron resting upon the forward ends of said Detroit, Mich., .a corporation of 1931, Serial No. 524,096

switch arms. The insulating block 2 is formed with suitable guide slots 24 in the forward part thereof to receive and guide the terminals 5 into engagement with the switch arms 6,'whe n the iron is placed upon the stand 1. These terminals 5 as shown, comprise rectangular extension ends on the bolts 9 which pass through the rear wall of the iron and through suitable insulators 10a in said wall, said bolts being threaded on their inner ends and each having an enlargement or collar 10 to engage the outer endsof the insulators, the bolts 9 being secured by nuts as hereinafter set forth.

We secure one of these bolts in place by a common washer 10b and nut 100 on the inner extension of said bolt, and a resistance connector or terminal 11 is electrically connected to said bolt by means of another nut 10d. The other bolt 9 is secured within its insulator 10a by a washer and a nut 90. having an extension forming a contact terminal 12 which is adapted to contact with an arm 13 forming the other resistance connector or terminal of the resistance winding 14 mounted in the usual manner within the body of the iron to form the usual insulated heating element, all arranged in a well known manner. The body of the iron 4 is provided with the usual handle 4a for manipulating the iron in use.

The weight member 15 within the body of the iron and which is common to electric irons, is cut away at its rear end as shown at 16 in Fig. 1, to permit a transverse spring member 17 to be secured at one end to said weight member, as by means of the screw 18 or other suitable means, and this spring 17 is provided with a connecting bracket member 19 which is also secured at its free end to the resistance connecter or arm 13, and suitable insulation 20 is provided to insulate said bracket 19 from said spring 17.

Within a slot or recess in the side of the weight member 15 opposite that at which the spring 17 is secured thereto, is provided a slidable plunger 21 with which the free end of the spring 17 is adapted to contact, thereby causing the bracket 19 to press the resistance connecter 13 into elec-- trical contact with the contact member 12, and thus close the electrical circuit of the resistance winding.

This plunger 21 is provided with an upwardly extending handle 22 passing through a slot 23 in the upper shell or wall of the iron, and this plunger 21 is also provided with a groove or notch 24 adapted to receive the downtumed end 25a of a thermostatic latch 25 to hold said plunger in closed circuit position. This thermostatic latch 25 comprises a strip or strips of bi-metal which are suitably secured above the plunger 21, this bi-metal being of such'anature that it will curl upward when heated, thus-releasing its downtumed free end 25a from engagement with the in the plunger 21 and open the circuit. The fixed contact arms 3a engaged by the contacts 3 are suitably connected byleading in wires 27a to a conductor 2'; in any well known manner. The operation of the device is as follows: the stand 1 being placed in a suitable position relative to the leading-in conductor 27 which is suitably connected to a source of electrical current, the iron is placed on the stand, preferably by is pointing the nose or point downward and forwardly between the upturned lips 8 with the terminals 5 guided in the slots 2a in the insulating block 2, into engagement with the switch arms 6 to rest thereon, whereupon said arms are rocked, causing the contact points 3 and 3a to be brought together and the electric circuit between conductor 27 and resistance winding 14 of the iron, closed, and as the iron now has a three-point suspension the greater part of its weight neces- 5 sarily is transferred through the terminals '5 on the switch arms 6. The plunger 22 is then actu-.- ated to slide the plunger 21 from the position shown in Fig. 3 until the flange of the latch 22 drops into the groove 24 which action causes 39 said plunger 21 to push the spring 17 rearwardly and bring. the arm 19 into contact with the resistance connecter 13 and force it into contact with the terminal 12 and thus close the electrical circuit of the resistance winding 14 and cause the iron to become heated by the energization of said winding.

The iron may be made to heat quickly by simply using high grade materials and a large resistance winding so that the iron becomes very 4o practical for ironing purposes even though it will be disconnected from the source of electrical energy'whenever it is lifted from the stand for the purpose of ironing.

The thermostatic latch 25, by a series of tests,

' may be formed by the manufacturer so that if it is desired that the safety lock-out mechanism should look out the circuit at say 550 F., said latch or switch 25 will curl suficiently to disengage itself from the groove 24 whenever that degree of heat is attained, this adjustment being regulated by simply adjusting the screw 26. Any operator may thereafter adjust the same by merely removing the shell and adjusting the screw 26 as desired, tightening it if a higher temperature is desired before the plunger is to be released. When the latch 25 curls up out of the groove 24, the spring 17 pushes the plunger into open circuit position as shown in Figs. 1 and 2 and the bi-metal will again sufliciently cool to cause the end 25a to ride on said plunger and be in a position to again snap into. said notch 24 when .said plunger is moved by its handle 22 to hold said plunger in closed circuit position. I

Having thus described gour invention so as to 5 be understood by those skilled in the, art, we do not wish to be limited to the precise form or means shown in the drawing and described in the specification nor to the use of our invention solely for electric irons.

What we claim is:

s l. A stand'for an electric sad-iron provided with a pair of rigid terminal members projecting from the rearend thereof, said stand being formed at its forward end with a support for the point of the iron and with an insulating block at its rear end formed with a. pair of guide slots for said terminals of said iron, said slots opening through the top and front end of said block, fixed contacts in said block, switch arms pivotally sup- 5 ported intermediate their ends upon said block, said arms extending longitudinally of said slots with an end portion of each arm projecting into and longitudinally of the bottom of each slot and each with its opposite end positioned to engage one of said fixed contacts in said block upon rocking of said arms by the weight of said iron when said iron is placed on said stand with its terminals resting uponthe forward ends of said arms in the bottoms of said slots, and means for rocking said arms out of contact with said fixed contacts, when said iron is removed from said stand.-

2. A stand for an electric sad-iron provided with a pair of rigid terminal members projecting from the rear end thereof, said stand including a casing of insulating material positioned at the rear of the stand, said casing comprising a rear compartment opening into a pair of spaced slots extending forwardly to the forwardedge of said casing and downwardly from the top thereof to a'point intermediate theheight of the casing, said slots being adapted to receive said terminalmembers, a pair offixed contacts insaid rear compartment, and switch blades engageable with said fixed contacts at one end extending from said compartment into the respective slots and adapted to engage the fixed terminals of the sad-iron, said blades being pivoted intermediatetheir respective ends, and means normally urging the blades out of contact with said fixed contacts but yieldable upon engagement of said sad-. iron terminals with the forward ends thereof to permit establishment of such contact.

3. A stand for anelectric sad-iron provided with a rearwardly projecting contact terminal, said stand including a cooperating contact member fixed to the rear of said stand and comprising an insulation casing provided with a rear compartment, saidcompartment opening into a longitudinal slot extending forwardly to the end of the casing, a fixed contact in said compartment, and a contact blade pivotally supported within the compartment intermediate its ends, said blade adapted to engage the contact in the compartment on one side of its pivotal mounting and extending along said slot on the other side thereof, and means cooperable with the exposed end of said blade yieldably urging the opposite end out of engagement with said contact.

4. A stand for an electric sad-iron provided with a rearwardly projecting contact terminal, said stand including a cooperating contact member fixed to the rear of said stand and comprising an insulation casing provided with-a rear compartment, said compartment opening into a 30 longitudinal slot extending forwardly to the end of the casing, a fixed contact in said compartment, and a contact blade pivotally supported within the compartment intermediate its ends, said blade adapted to engage the contact in the compartment on one side of its pivotal mounting and extending along said slot on the other side thereof, the exposed end of said blade being provided with a downturned flange cooperable with the bottom of said slot to limit con- 7 tact engaging movement thereof.

- FRANCIS H. SHOOP.

WINFIELD S. GRANT. THOMAS J. MCCORMICK.

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