US2307833A - Domestic appliance - Google Patents

Description

Jan. 12, 1943. n. K. FERRIS DOMESTIC APPLIANCE Filed Feb. 14, 1940 INVENTOR. $1M;

ATTORNEYS Patented 12, 1943 DonaldKl-erriaDarto rsOorpor-ati eral Moto notation of Delaware n, Ohio, assignor to Genon, Dayton, Ohio, a cor- Application February 14, 1940, Serial No. 318,913

zclaims.

This invention relates to a domestic appliance and more particularly to an ironing machine.

At the present time the underwriters specifications limit the current input of portable domestic ironing machines so that the wattage available for the shoe is limited to about 1300 to 1500 watts. The shoes of these ironing machines vary in area between 100 and 200 square inches. It will thus be seen that this amount of heating capacity per square inch of area is quite small in comparison to a flatiron, most of which are providedwith a 1000 watt heating capacity and have an area of about square inches.

This lower heat density results in slower temperature recovery of the shoe and in the past it has been necessary to limit the size of the ironing machine shoe or to limit the maximum speed of the roll or both. It is quite obvious that if only a small heating capacity is available that the ironing machine must be run comparatively slow so. that any material being pressed on the ironing machine will be heated sufliciently to be properly ironed.

This limitation of heat recovery is especially noticeable where ironing is done continuously under one portion of the shoe of the ironing machine.-

It is an object of my invention to provide an improved heating circuit arrangement for the shoes of ironing machines which will make a more advantageous disposition of the wattage to heat the shoes available to permit the use of either a larger size ironershoe or greater roll speed in ironing or both.

It is another object of my invention to provide an improved heating circuit arrangement for the shoes of ironing machines for the purpose of concentrating the heating capacity at the point or portion at which it is needed when it is needed.

It is another object of my invention to provide an improved circuit arrangement for the shoe of an ironing machine whereby a much greater proportion of heat may be supplied to one end, preferably the open end of the ironing machine when needed at this point and to provide a suitable thermostatic control for such an arrangement.

It is still another object of my invention to I provide an ironing machine having a plurality of shoes with a plurality of heating circuits each of the maximum 1300 watt capacity controlled in v such a way that they are used alternatively to provide a greater heating capacity in the ironing shoe being used and therefore requiring the most heat. a

Further objects and advantagesof the present invention will be apparent from the following description, reference being had to the-accompanying drawing wherein a preferred form of the present invention is clearly shown.

In the drawing:

Fig. 1 is a wiring diagram for the shoe of an ironing machine embodying one form of my invention;

Fig. 2 is a wiring diagram for a two-shoe type of ironing machine embodying a modified form of my invention;

Fig. 3 is a vertical sectional view of a portion of a two-shoe ironing machine as is shown diagrammatically in Fig. 2; and

Fig. 4 is a simplified two-circuit arrangement for a two-shoe ironing machine.

Briefly, in Fig. 1 I have shown diagrammatically the shoe of an ironing machine which includes two heating circuits each of the maximum permissible 1300 watt capacity. Each circuit is provided with two heating elements, one of 1000 watts concentrated in opposite ends of the shoe and located adjacent the front edge of the shoe together with one of the heating elements of 300 watts located in the .opposite ends of the shoe behind the heating elements of 1000 watts. In the second form of the invention the small shoe is providedv with a single heating element and the large shoe is provided with two heating elements. The two heating elements in' the large shoe are controlled by a thermostat and the heating element in the small shoe is controlled by a second thermostat which either disconnects the heating element in the small shoe or connects it in series with the small heating element in the large shoe. A switch, which is operated when the large shoe is released, is provided for shunting the small heating element in the large shoe and connecting the heating element of the small shoe directly across the supply conductors subject to the control of the small shoe thermostat.

Referring now to the drawing and more particularly to Fig. 1 there is shown diagrammatically the shoe 20 of an ironing machine or electric mangle which is similar to the machine shown in Fig. 3 excepting that only a single shoe is provided. This shoe is adapted to operate upon a roll which is customarily driven from the right end of the machine as viewed in Fig. 1. Thus the left end of the shoe 20 is at the open end of the ironing machine at which the greater portion of the ironing of smaller pieces is performed. In thisleft end portion of the shoe 20 adjacent the front edge I provide the main heating element 22 is provided with a capacity of 300 watts.

having a heating capacity of 1000 watts. Connected in series with the heating element 22 is a heating element 24 of about 300 watts capacity which is provided in the opposite end of the shoe behind a heating element of about 1000 watts capacity made in two sections designated by the reference characters 26 and 28.

A double acting bimetal thermostat 30 is provided in the front edge of the shoe 20 preferably in front of the mid-portion of the heating element 22 at the left or open end of the shoe 20. This bimetal thermostat 30 is adapted to make contact with a contact 32 in order to close the circuit through the heating elements 22 and 24 so as to connect these elements across the supply conductors 34 and 36. When the left end of the shoe 20 is sufiiciently warm the bimetal 30 will be heated sufficiently to move away from the contact 32 thus making contact with the opposite contact 38.

The contact 38 is connected to the heating element portion 26. In the right portion of the ironing machine shoe 20 adjacent the front edge thereof is provided a second bimetal thermostat 40 which when sufliciently cool is adapted to bridge a set of contacts 42 in order to connect the two heating element sections 26 and 28. If the thermostat 30 is in contact with the contact 38 and the thermostat 40 bridges the contacts 42 the heating element sections 26 and 28 will be connected in series with a heating element 44 across the supply conductors 34 and 36. r If the sections 26 and 28 together have a heating capacity of 1000 watts then the heating element 44 This heating element 44 is placed in back of the heating element 22.

Thus by this arrangement two alternative heating circuits are provided each of 1300 watts. The heating capacity is so arranged that whenever desired 1000 watts heating capacity may be concentrated in one end of the shoe at any one time, while the remaining 300 watts is provided for maintaining the other portion of the shoe at an adequate temperature. However, this pr0portion may be varied as desired in order to provide the desired proportioning of heating capacity. Thus if the ironing machine is used for a time only at the open end of the shoe 1000 watts will be available at this end of the shoe instead of about 650 which would otherwise be available for a single heating circuit if uniform distribution were provided.

Where the shoe is used uniformly the heating circuits will alternate in order to provide heat uniformly to the entire shoe.

In Figs. 2 and 3 there is shown an ironing machine of the two-shoe type including a large shoe and a small shoe 62. These shoes are both made so that either or both can be released at any time. This is illustrated in Fig. 3 in which the small shoe 62 is shown as being pressed against the roll 64. The releasing of the small shoe 62 is controlled by the lever 66 while the releasing of the large shoe is controlled by the lever 68. The releasing mechanism for each of these shoes is substantially identical and the releasing mechanism for the large shoe 60 is clearly shown in this figure. The releasing lever the arm I2. A light spring I8 is also provided for engaging the inner wall of the arm I2. The releasing lever 68 is provided with an extension within the arm I2 which is adapted to engage the upper end of the spring I6. When the releasing lever 68 is pulled downwardly the end 16 presses against the end of the spring I6 to move the arm I2 and the shoe 60 in a counter-clockwise direction to press the shoe 60 onto the roll 64. In order to release the shoe 60 the release lever 68 is moved to the position shown in the figure so that the spring I6 will no longer hold the shoe 60 against the roll.

In Fig. 2 I have shown a wiring diagram providing a plurality of circuit arrangements for obtaining better heating of such an ironing machine. In the small shoe I provide a heating element 82 which may extend around the edges of the shoe and preferably has a capacity of about 350 watts when connected in series with the heating element IIO but has a capacity of about 700 watts when connected directly across the supply conductors. The energization of this heating element 82 is controlled by a double acting thermostat 84 which is connected by the conductor 86 to source conductor 88. When the shoe is cool the thermostat 84 will make engagement with the contact 90 to connect the heating element 82 to the source 88. The other end of the heating element is connected by a conductor 92 to a manual switch 94 having two sets of switch contacts, one designated by the reference character 96 and the other by the reference character 98. This switch 94 is operated by the release lever 68 as shown in Fig. 3.

This switch 94 has an operating pin I02 which is adapted to be held inengagement with the adjacent portion of the release lever 68 by a suitable spring. When the large shoe is in operating position the switch 94 will assume the position shown in Fig. 2 whereby the lower contacts 98 will be closed and the upper contact 96 will be in the open position. The contacts 98 connect the conductor 92 to'a conductor I04. This conductor I04 connects to a conductor I06 which is connected to the upper thermostat contacts I08. These contacts I08 control the connection of conductor I06 with a small heating element H0 in the large shoe 60. This small heating element preferably has a heating capacity of 350 watts when connected in series with the heating element 82 and about 700 watts when connected directly across the supply conductors. This heating element H0 is connected by a conductor II2 to the other supply conductor H4.

The thermostat 84 is provided with a second contact II6 which connects to a conductor II8 for the purpose of short-circuiting' the heating element 82 and the switch 94 when the small shoe 62 is heated sufiiciently and does not require any heat at that time. This will allow full voltage to be impressed upon the heating element IIO so that it will then supply twice 350 watts or 700 watts. However, should the large shoe be released by moving its release lever 68 to the position shown in Fig. 3 the switch 94 will be operated to open the contacts 98 and to close the contacts 96 so that the heating element 82, subject only to the control of the thermostat 84, will be connected directly across the conductors 88 and I I4 in a circuit which includes the conductor 86, the contact, 90, theheating element 82, the conductor 92, the switch contacts 96, the conductor I20 and the conductor II2. This will double the heating capacity of the heating element 82 and supply the small shoe with a heating capacity of 700 watts.

The large shoe 68 is also provided with a main heating element I22 of 600 watts. This main heating element is positioned at the front of the shoe 68 and is connected directly across the supply conductors 88 and H4 under the control of the large shoe thermostat I24 and contacts I26. A conductor I28 connects the contacts I26 with the supply conductor 88 while the conductor H2 connects the other end of the heating element I22 with the supply conductor H4. The thermostat I24 also controls the contact I88 so that it controls the energization of both the ,heating elements H8 and I22.

When the thermostat I26 is in its open circuit position, the contact I88 will connect the conductor I86 with a conductor I I l which shunts the heating element II8. This makes it possible for the thermostat 84 to connect the element 82 across the supply conductors 88 and H4 so as to impress the full voltage upon the element 82 I 284 is a diagrammatic form of the switch 84 as shown in Fig. 3 and is intended to be operated in the same manner so as to close the shunt for to give it a heat output of 700 watts whenever the thermostat I24 is in the open position instead of the 350 watt capacity available when the thermostat I24 is in the closed position. When the thermostat I24 is in the closed position the contact I88 connects the element II8 to the conductor I86.

Thus by this circuit arrangement when only the small shoe is being used it is provided with a heating capacity of 700 watts while the idle large shoe is provided with 600 watts to maintain it in a heated condition. When both shoes are being used the small shoe is provided with a heating capacity of 350 watts and the large shoe with the heating capacity of 950 watts. When the small shoe requires no heat the large shoe is provided with a heating capacity of 1300 watts. Although I have specified difierent wattages for the different heating elements it should be understood that these different wattages can be proportioned as desired in order to obtain the desired heat distribution within the maximum permissible limit. Thus by providing a plurality of heating circuits of the maxmum available heating capacity of 1300 watts each I can concentrate the heating capacity wherever it is needed or wherever it is desired, whenever it is desired.

In Fig. 4 there is shown a simplified wiring diagram for the two-shoe arrangement shown in Fig. 2. In this figure the small and large shoes are designated by the reference characters 262 and 268. The large heating unit in the large shoe is designated by the reference character 222 while the small heating element is designated by the reference character 2I8. The heating element in the small shoe is designated by the reference character 282. In this simplified form the main heating element 222 is connected across the supply conductors 288 and 2 under the control of the thermostat 224. The small element 2I8 and the element 282 of the small shoe are conthe small heating element of the large shoe whenever the large shoe is released as shown in Fig. 3. This shunting of the small heating element 2I8 thus connects the small shoe heating element 282 and the small shoe thermostat 284 directly across the supply conductors 288 and 2I4 thereby increasing the voltage' applied to the heating element 282 and greatly increasing the wattage.

The heating elements may be proportioned as suggested in connection with Fig. 2 or they may be varied as desired. Thus in this form the switches and circuits are less complicated and yet means is provided for increasing the heat output of the small shoe 262 whenever the large shoe is released. This wiring circuit is intended to be used with an ironing machine such as is shown in Fig. 3.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. An ironing machine comprising a pair of relatively movable elongated ironing members, at least one of said members being provided with a plurality of heating means arranged to concentrate heat alternately along longitudinally spaced zones, and thermostatic means responsive to heat in a first one of said zones for concentrating the heat in said first zone independently of the temperature of any other zone, and when said first zone is heated to a predetermined limit to render the heating means capable of concentrating heat in another zone, said heating means for concentrating heating in said first zone including a portion having a low wattage heater in another of said zones.

2. In combination, an elongated ironing shoe, a plurality of heating means arranged to concentrate heat alternately along longitudinally spaced zones in said ironing shoe, and thermostatic means responsive to heat in a first one of said zones for concentrating the heat in said first zone independently of the temperature of any other zone, and when said first zone is heated to a predetermined limit to render the heating means capable of concentrating heat in a second one of said zones, said heating means for concentrating heating in said first zone including a portion having a low wattage heater in said second zone, said heating means for concentrating heat in said second zone including a low wattage heater in said first zone.

DONALD K. FERRIS.

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