US2162589A - Temperature control device - Google Patents

Description

June 13, 1939. I

I I TEMPERATURE CONTROL DEVICE Filed Oct. 50, 1957 Inventor Theodotfle A. Rich b $4 447 W Y Hi8 AUG or'ney.

Patented June 13, 1939 2,162,589

UNITED STATES PATENT OFFICE TEMPERATURE CONTROL DEVICE Theodore A. Rich, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application October 30, 1937, Serial No. 171,927

3 Claims. (01. 236-7) This invention relates to temperature control machine having an ironing roll i and an irondevices, more particularly to temperature control ing buck I i. The ironing roll and buck are supdevices for ironing appliances, such as a rotary ported on a frame l2. It will be understood that or flat-plate ironer, and it has for its object imthe ironing buck will be pivotally mounted, as on 5 proved temperature control means for ironing an arm 1211, so that it can be swung away from 6 devices of this character. and toward the roll. It will also be understood In ironing machines, such as rotary and flatthat suitable mechanism will be provided for plate ironers there is provided a buck carrying an driving the roll. ironing shoe between the. ironing face of which The ironing buck II is provided with an iron- 10 and a suitable roll or plate, the fabrics are passed ing shoe i3 having an ironing face or surface 10 to be ironed. oftentimes these machines are that faces the ironing roll l0 and between which provided with a thermostat for controlling the face and the roll the fabric is directed to be temperature of the ironing shoe. This thermoironed, the fabric being caused to pass through stat is usually carried by the buck on the side of the machine by the rotation of the roll l0.

the ironing shoe opposite the ironing face. The The ironing shoe I3 is heated by an electrical 5 thermostat is located to respondto the temperaheating element l5, preferably of the sheathed ture of the shoe so as to hold this temperature type, such as described and claimed in the United as nearly constant as possible. Inasmuch as it States patent to Charles C. Abbott, No. 1,367,341, is separated from the ironing face by at least the dated February 1, 1921. Briefly, this element thickness of the shoe, it does not under certain comprises va helical resistance conductor I6 20 conditions of operation follow the temperature of mounted in a metallic sheath I1 and supported in the'ironing face with sufficient rapidity to hold an spaced relation with reference to the sheath and even temperature. Thisis particularly true when electrically insulated from it by a compacted a. cold wet piece of fabric is brought into contact mass of electrically insuatingv material l8, such 1 with the ironing face. When this happens, heat as magnesium oxide. As shown, the heating eleis rapidly drawn from the ironing face and the ment is mounted in channels l9, and is secured moisture in the fabric is converted into steam. the channels by means of barriers 20 positioned This causes a rapid drop in temperature in the over the mouth of the channels. The heating ironing face from the desired ironing temperature. means i5 is provided with terminals 2| positioned This sudden drop is not experienced by the theradjacent each other, as clearly shown in Fig. 1. o

mostat which is remotely positioned'with refer- Mounted onthe buck ii on the .side of the ence to the face. Only after the lapse of some ironing shoe l3 opposite its ironing face is a time is the thermostat cooled so as to operate to temperature control device 22 for controlling the apply heat to the plate to reestablish its ironing energization of the heating means l5. As shown,

temperature. This results in poor regulation. the temperature control device is supported on In accordance with this invention, I provide in the outer casing 23 of the buck, and preferably the ironing shoe a duct, or series of ducts, oppowill be mounted in a recess 24 provided in the site the thermostat and leading from the ironing layer of insulation 25 that usually is provided in face so that when steam is generated by the the ironing buck to prevent heat from traveling pressing operation, itv flows through the duct or through its outer casing. The thermostatic de- 40 ducts to and around the thermostat. The thervice, as shown, comprises a bimetallic thermo mostat is h y p y Cooled as t oni static bar 25 which is formed of two metals havface itself is rapidly cooled. This results in a 'ing dissimilar temperature coeflicients of expanvery even temperature regulation. sion, such as invar and steel, rigidly secured to- For a more p e understanding of his ngether from end to end in any suitable manner, 45

vention, reference should be had to the accomas by welding. pany n d aw i which Fi 1 is a ra ent ry .One end of the bimetallic thermostat bar 26 is elevation o an on machine embodying his fixed and is connected to one of the terminals v i p r being k n w y so as to il- 2| of the heating means l5. Its other end is free lus -rate certain details of construction; and Fig. to move and carries a switch contact which 00- 50 2 is an enlarged fragmentary sectional view operates with a fixed switch contact 21 that is taken through the line 22 of Fig. 1 and looking connected with the opposite terminal 2i of the in the direction of the arrows. heating means. The thermostat 22, it will be ob- Referring to the drawing, this invention has served, is located in the buck to respond to the been shown in one iormas applied to an ironing temperature of the buck, and it controls the temperature in the ironing shoe in accordance with this temperature. The setting of the thermostat can be varied by means of an adjusting screw 28 which bears on the thermostatic bar to vary the tension in the bar, and which, as shown, is accessible on the exterior of the buck for convenience of adjustment,

The ironing shoe is provided with a duct 29 directed through it and positioned opposite the thermostatic member 26, as clearly shown in the drawing. One duct may be used, or a plurality of ducts, as desired. The duct 26 functions to connect the ironing face of the shoe i3 with the bimetal element 26.

In the operation of the ironing apparatus, it will be understood that when the heating element is energized, the thermostatic bar 26 will operate to open the energizing circuit of the heating means l5 when the temperature of the thermostat attains a predetermined maximum, such as 450 F., and will close the switch to reapply the heat when this temperature falls to a predetermined minimum, such as 430 F. It will also be understood that the fabric M will be caused to travel between the roll I0 and the shoe l3 by the rotation of the roll. The roll may either be operated continuously or it may be operated intermittently to successively bring the portions of the fabric into proper ironing position of the buck. The fabric usually is moistened or dampened before it is passed through the machine and when the moistened or wet section of the fabric is brought into ironing position and the ironing shoe contacts it, the hot ironing shoe immediately generates steam of the moisture in the fabric and a portion of this steam is forced or projected through the duct or ducts 29 and into direct contact with the thermal element 26. Thus, when the temperature of the heated ironing shoe l3 rapidly decreases because of its contact with the wet fabric [4 and the absorption of heat from the shoe to generate the steam, the thermostat 26 whichhas approximately the initial temperature of the shoe at the instant it contacts the wet cloth will also be cooled quickly by the impact of the steam on it so that its tmperature will fall substantially at the same rate as that of the shoe. In other words, the thermostat will be caused to respondi rnmediately to the drop in temperature of the shoe to control the heating element to maintain the desired temperature. In this manner, the thermostat will respond to variations in shoe temperature, whether they be slow or sudden, so as to hold a substantially constant temperature in the shoe with good regulation.

It will be observed that the bimetallic thermostatic blade is connected in series in the energizing circuit and that the electric current flows through it. The blade is sufficiently large to afford very little resistance to the passage of this current, and therefore the heat generated by the passage of the current through the blade affects the operation but slightly. However, even if the thermostatic blade did develop an appreciable degree of local heat due to the flow of current through it, this condition would not affect the principle of my invention. In other words, my invention is applicable equally as well to the latter case as to the former where little local heat is developed.

While I have shown a particular embodiment of my invention, it will be understood, of course, that I do not wish to be limited thereto since many modifications may be made, and I, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An ironing device comprising a pressing body having an ironing face, heating means for said pressing body, a temperature responsive element carried by said pressing body at a point remote from said ironing face controlling said heating means responsively to temperature changes in said pressing body, and said pressing body having a duct between said pressing body and said tem perature responsive element for conducting steam generated under said face in the pressing operation into contact with said temperature responsive element when said ironing face is applied to moistened articles so as to cool said temperature responsive element as the pressing body cools when brought into contact with said articles.

2. In an ironing machine provided with a pressing shoe having on one side an ironing face, and a heating element for said shoe, temperature control means comprising a bimetallic thermostatic member located on the side of said shoe opposite said ironing face controlling said heating element responsively to the temperature in said shoe, and said shoe being provided with a duct between said ironing face and said thermo stat to conduct steam generated under said face to said bimetallic member to cool it when the temperature of said ironing face is rapidly reduced by coming into contact with wet fabrics.

3. An ironing machine comprising an ironing roll, a buck having an ironing shoe cooperating with said roll to press a fabric travelling through the machine between the roll and ironing face of said shoe, an electrical heating element carried by said buck for applying heat to said shoe, a thermostatic element carried by said buck back of said ironing face of said shoe controlling said heating element responsively to temperature variations in said shoe, and said shoe having a duct arranged to deliver from said ironing face to said thermostat steam that is generated by the application of said shoe to wet fabrics so as to cool said thermostatat substantially the same rate that said shoe is cooled when applied to said fabrics.

THEODORE A. RICH.

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