US2295341A - Pressing iron - Google Patents

Description

Sept, 8, 1942.

F. E. FINLAYSON PRESSING IRON I Filed Jan. 6, 1941 Inventor- Finlayso His Abbot-heg- Patented Sept. 8, 1942' raassmo IRON Frank E. Finlayson, Ontario, Calif., assignor to General Electric Company, a corporation of New York Application January 6, 1941, Serial No. 373,369 11 Claims. (01. 38-17) This invention relates to pressing irons, and it has for its object the provision of an improved pressing iron which is arranged so that it may I be used as a conventional dry iron, and also to generate steam so that it may be used as a steam iron.

More particularly, this invention relates to a steam iron provided with a water reservoir from which the water is fed into a steam generating chamber, and it contemplates the provision of a steam iron of this character having an improved organization of parts; this improved organization includes suitable means for conducting the generated steam to the pressing surface which prevents any water from flowing from the reservoir to the pressing surface, and also suitable means for conducting generated steam to the reservoir to equalize the pressure between the reservoir and generating chamber and thereby insure a steady flow of water to the generating chamber.

In accordance with this invention in one form thereof the iron is provided with a steam generator or boiler which receives its heat from the sole plate. Water is fed to the generator at a regulated rate from a reservoir. The reservoir is placed in communication with the generator, so that substantially the same pressure that exists in the generator also exists in the reservoir. This equalization of pressure insures a uniform steady flow of water from the reservoir into the flash generator, and thereby insures the generation of steam at a substantially uniform rate. The communication means between the steam generator and the reservoir includes a steam dome rising from the reservoir and which is connected with the generator by a suitable pipe rising up into it.

The steam fed into the steam dome from the reservoir is conducted from the dome by suitable conduit means to the pressing surface.

The steam dome functions to supply steam from the generator to the top of the reservoir to equalize the pressure, and the steam dome, together with the arrangement of the conduit means functions to prevent water flowing from the reservoir through the conduit means to the pressing surface when -the iron is in its horizontal operating position.

In one specific form of this invention, the steam dome and the communicating means between the steam dome and the generator and between the steam dome and the pressing surface are located at the forward part of the iron so that water cannot flow through the system to the pressing surface when the iron is tilted on 1 its heel in its position of rest.

For a more complete understanding of this invention, reference should be had to the *accompanying drawing in which Fig. 1 is a central longitudinal vertical sectional view taken through an electrically heated fiatiron embodying this invention; Fig. 2 is a plan view of a portion of the flatiron shown in Fig. 1, parts being broken away so as to illustrate certain details of construction; Fig. 3 is a vertical sectional view taken through the line 3-3 of Fig. 1 and looking in the direction of the arrows; and Figs. 4 and 5 are sectional views taken through the lines l4 and i5 of Fig. 2 and looking in the direction of the arrows.

Referring to the drawing, this invention has been shown in one form as applied to an electrically heated flatiron comprising a sole plate Ill. The sole plate l0 may be formed of any suitable material, such as aluminum, and preferably it will be cast from this material. Embedded in the sole plate I0 is a suitable electrical heating element II, which preferably will be of the sheathed type. Briefly, this heating element comprises a helical resistance conductor l2 mounted within an outer metallic sheath i3 and supported in spaced relation with reference to the sheath by an electrically insulating, heat conducting mass it, such-as highly compressed granulated magnesium oxide. This heating element I l is roughly in the shape of a hairpin with the extremities of its legs located at the rear of the iron, and its nexus at the forward end of the iron. As shown, suitable terminals l5 for the resistance the sheath- Formed within the sole plate I0 is a suitable flash steam boiler or generating chamber it which is located in the forward central part of the sole plate between the legs of the heating element, as shown. Located within the forward end at the point of the sole plate is a suitable steam discharge chamber ii. A series of vertical ports i8 connect this chamber with the pressing surface IQ of the sole plate, as shown. At one side of the sole plate-the lower, as viewed in Fig. 2-is a steam feed passage 20 for the chamber ii. A similar passageway 21 is formed on the other. side of the iron, but this passageway does not communicate with the steam chamber ll. Located between the rear ends of the two passageways 20 and 2| is a chamber 22 fllled with metal wool 22a. v 1

Preferably, the chambers I6 and ii, the pasconductor project from the ends of sageways 23 and 2|, and the chamber 22 all will be formed in the sole plate II when it is cast.

Mounted on the sole plate is a cover plate 23 which is so shaped that it closes the steam chamber H, the chamber 22, and the passageways 20 and 2| at the top. The plate 23 is provided with an aperture 24 registering with the chamber l6 so as to leave this chamber open at the top. Furthermore this plate is provided in its bottom with two relatively large recesses 25 and 28 (Fig. 4) which connect the two channels 28 and 2| with the chamber 22, In addition, the plate is provided in its bottom with another recess 21 which connects the forward end of the passageway 2! with an aperture 28 extending through the cover plate, as shown. It will be observed that in effect the cover plate 23 forms a part 'of the pressing plate, the plate 23 and sole plate housing the chambers and passageways.

The flash steam boiler cavity I6 is covered by means of a closure member 29 which, as shown, is of flat, inverted pan-like form. This member, asshown is defined by a flat plate having a downwardly extending flange 39 at its periphery; this flange in turn terminates in an outwardly extending flange 3| which rests directly upon the upper surface of the sole plate closure plate 23. Preferably, the flanges 38 and 3| will be elliptical in shape. Mounted upon the flange 3| is a clamping ring 32. The clamping ring and the flange 3| are rigidly secured to the sole plate ID by means of a pair of screw-fastening devices 33 and 34 which are directed through apertures provided for them in the clamping ring and flange, and which are threaded in tapped holes provided for them in the sole plate l8, as shown in Fig. 1.

vMounted above the cover 29 in spaced relation with it is a suitable water reservoir 35 extending from a point adjacent the'forward end of the iron rearwardly thereof so that it overhangs the rear edge of the sole plate, as clearly shown in Fig. 1. This reservoir is attached to the cover plate 29 so that the cover plate constitutes the sole means of support for the reservoir. As shown, thereservoir is provided in its bottom wall with a discharge port 36 and with a second opening 31 positioned close to and in front of the opening 36. Below the opening 36 is a suitable bushing 38 rigidly secured to the bottom wall of the reservoir and mounted within the opening 31 is a second bushing 39. These bushings 38 and 39 may be secured to the bottom wall in any suitable fashion, as by welding or brazing. Inserted through an opening in the cover 29 which is aligned with the opening 36 is a suitable member 40 which is received in threaded engagement by the bushing 38, and

I threaded through a second opening in the cover the bushing 38, as shown. Also, the cover 23 is made thin and is formed of a suitable material that will not conduct heat readily as a great many common metals; preferably it will be made of stainless steel. The transfer of heat by radiation from the sole plate It to the reservoir is barred by means of a metallic shield 4| a which extends from the point of the iron to the heel thereof and which is provided with a peripheral down-tumed flange which rests upon the sole plate, as clearly shown in Figs. 1 and 3. As shown, the body of this shield is spaced both from the sole plate and from the reservoir. This shield is provided with an opening 4|b through which the cover 29 and its fastening means pass.

The reservoir is provided at one side with a fill opening 42 in which is mounted a bushing 43. Threaded into this bushing 43 is a closure cap 44;

The member 48 threaded into the bushing 38 is provided with a valve seat 45 which opens into a tube 46 that extends downwardly into the flash steam chamber I6 to a point close to its bottom wall, as shown in Fig. 1. A suitable needle valve 41 cooperates with the valve seat 45 to control the flow ofwater from the reservoir into the flash boiler, and, also to shut off the flow entirely when it is desired to do so. The needle valve is provided with an enlarged threaded section 48 which is threaded in a cylindrical member 49 secured to the member 38, and which is provided with apertures 49a through which the water may flow from the reservoir to the valve seat 45. An operating rod 50 isattached to the needle valve. This rod, as shown, extends upwardy through the top of the reservoir, and attached to the top of the rod is an operating knob 50a. A suitable packing gland 5| seals the operating rod 58 where it passes through the top wall of the reservoir.

Rising from the upper wall of the reservoir at its forward end is a suitable steam dome 52. And rising in this steam dome is a steam riser pipe 53 which at its lower end is rigidly secured to the bushing 38 by a water-tight Joint, which joint may be formed in any suitable manner, as by welding; the top of the riser pipe is closed by a top wall, as shown, but it is provided with an opening 54 adjacent this top wall which connects the riser pipe with the steam dome. Ex-

tending downwardly through the riser pipe 53 is a steam outlet pipe 55. This pipe 55 at its lower end is mounted within the opening 28 in the cover plate 23 for the sole plate and at its upper end is directed through an aperture provided for it in the top wall of the steam riser pipe so that it enters the steam dome and connects the passageway 21 with the steam dome.

The energization of the heating element H is controlled by means of a thermostatically operated switch 56 which preferably will be of the type described and claimed in the copending application of Harold R. Batchelor, Serial No.

354,380, filed August 27, 1940, and which is assigned to the same assignee as this invention. Briefly, this switch comprises a bimetallic temperature responsive element 51 which has one end in thermal contact with the sole plate l0 and its other end free to move in response to temperature changes. The switch further comprises a pair of switch arms 58 and 59 carrying cooperating contacts. These switch arms are mounted upon and electrically insulated from a flexible support 6| which is clamped between a rigid bracket 62 and the thermostatic element, as shown. The members 51, 6| and 62 are rigidly secured to the sole plate by means of a pair of taps 63 (only one shown) received in tapped holes 64 provided for them in the sole plate. The thermostat carries on its movable end an operating member 65 which is adapted to em gage the arm 56 to open and close the contacts 60 as the temperature .of the thermostat and falls. The temperature held is adiusted by' arms 58 and 59 will be connected in the ener-. gizing circuit of the heating element ll so that when the contacts are opened by the thermostat,

-- the heating element will be deenergized, and

when they are permitted to close, the heating element will-be energized.

It will be observed that the walls of the reservoir are formed so as to provide a verticalopening 51 extending completely through the reservoir fromthe top to the bottom, and that the thermostatic switch 56 and its temperature adreservoir and also the top surface of the water,

Y but the major portion is discharged through the ports l8.to the sole plate. The steam that condenses in the reservoir rapidly heats the reservoir and the water therein so thatin a short time condensation ceases, after which the entire and after the condensation ceases is not great justing member 66 extend upwardly through this opening. The iron is covered by means of a suitable shell 7 68. At the rear, the shell extends outwardly over the overhanging end of the reservoir 35, as shown in Fig. l. Preferably and as shown, this shell will be spaced somewhat above the upper wall of the reservoir. The shell is secured to the sole plate through the medium of the screw-fastening device 34, which, as shown, extends upwardly through a vertical circular wall 59 provided for it in the reservoir and which at its upper end is provided with a tapped socket 10 which receives a screw-fastening device'li directed through an aperture provided for it in the shell. The shell is provided with an aperture 12 at its forward en through which the steam dome 52 projects, with an aperture 12a.

for the shaft 50, and with an aperture 13 adjacent its rear through which is inserted gan operating knob 14 for the temperature adjusti shaft 66. The shell is further provided with an opening 15 through which the fill bushing 53 projects.

Mounted upon the shell 68 is a suitable operating handle 16. The handle is provided with a protuberance 16a. which cooperates with the rear edge of the shell 68 to support the iron on its heel in an upright position of rest.

In the operation of the iron thus far described, it will be understood that the reservoir 35 will be supplied with water with the iron standing on its ironing face is and with the needle valve Ml closed. The iron will then be plugged in and heated up to the desired operating temperature, which temperature will be controlled by the thermostatically operated switch 56. If it be desired to generate steam tomoisten the fabrics being ironed, the needle valve-55 will be opened so as to permit the water in'the reservoir to drop into the flash steam cavity l6. The-walls of this cavity will have the high sole plate temperature and will immediately flash the water dropping therein into steam. This steam risesin the, steam riser pipe 53 and flows out through the opening 55 into the steam dome 52. A part of thissteam immediately fills the space above the water in the reservoir, and the remainder enters the steam outlet pipe 55, fiows down this pipe and through the opening 28 into the passageway 21. The steam thence flows through the volume of steam generated passes .out through the discharge ports l8 in the sole plate. The difference in steam flow from the sole plate before enough to be apparent to the user.

It will be observed that the pressure on top of the water in the reservoir is substantially equal to the pressure in the steam generator and, therefore, the water-feed through the tube 48 into the generator is independent of the pressure in the generator. This isa very important feature of this invention because if the pressure were not equalized as in this iron, any back pressure cre ated by the fabric offering resistance to steam flow through the ports l8 would greatly retard the flow of water from the reservoir to the gen-. erator and at times would cause the flow to cease. However, where the pressure above and below the valve 40 is equalized the water will continue to flow into the flash boiler at a uniform rate and generate steam for discharge through the ports l8, irrespective of how great the back pressure maybe. When there is resistance to steam flow through the ports 18 by. the fabric, the pressure in the whole system will increase due to the continuous generation of steam and will overcome the resistance to flow by the fabric. It has been found that the fiow of steam remains substantially constant.

This balance in the pressure above and below the valve also minimizes the efiect of change in water level in the reservoir on the steam fiow since the weight of the water in this iron is not required to overcome the effects of steam pressure under the valve.

Furthermorethe rate of flow'of water into the flash steam boiler is independent of the sole Y the steam trap in the steam dome. This metal passageway 2!, the recess 25, the chamber v22,

the recess 26, the passageway 20 and'into the steam discharge chamber H, from which it flows through the ports I 8 to the pressing surface I9.

I At first a portion of the steam in-the reservoir erated in the boiler must fiow vertically through the riser pipe 53 into the steam dome, and thence down through the discharge pipe 55. This construction functions as a water trap for any water that may be carried up with the steam, the water being trapped-out directly into the reservoir. As a further insurance against the passage of water into the steam discharge'chamber I 8, the chamber 22 with the metal wool 22a therein is provided. This highly heated metal wool effectively prevents the passage of any water through the-chamber 22 that might have escaped wool immediately evaporates any water that might pass into the chamber 22. Furthermore, it is to benoted that any water carried, into "the passageway 2| must pass up the walls of the chamber 2| and through the recess 25 before it can enter the chamber.22; this is a further barrier to the passage of water through the dis-- charge system; and in addition, the passageway through the recess 25 offers resistancev to flow of any freewater from the chamber 22.

It 'will be understood thatthe amount of.

voir from the sole plate to cause thewater in the reservoir to boil. Thepreviously described low thermal conducting cover 25 which supports the reservoir, and the" heat shield a prevent overheating of the water in the reservoir.

To refill the reservoir when empty it is merely necessary to close the valve 40, wait a moment for steaming to stop, and remove the filler cap and refill the tank after which, of course, the filler cap will be replaced.

It will be understood that the iron can be operated as a dry iron merely by shutting the valve 53 so as to prevent any water flowing into the flash boiler.

The simplicity of construction of the iron is to be noted. The reservoir 35, the valve construction, the steam dome 52, the steam riser pipe 53 and the cover 29 for the steam boiler all are formed into one unitary structure. This unitary structure is secured to the sole plate-merely by means of the two screws 33 and 34 so that the entire construction may be removed merely by unscrewing these two members. At the same'time, the cover plate 23 for the sole plate may be removed because the cover plate itself is also secured by the two screws 33 and 34. Thus, should it be desired to clean the steam passages and bolier in the sole plate it is merely necessary to remove the two screws 33 and 34 which permits the removal of the unitary construction referred to above and also the cover plate 23. This at times is desirable in hard water areas where it is likely that the flash steam boiler and steam passageways will lime." Also it will be observed that the shell 58 and the handle attached to it are secured to the screw fastening device 34 by means of the single screw I l.

Another important feature is the location of the steam dome 52 and the pipes 53 and 55 rising in it. These members are located at the very forward end of the reservoir so that when the iron is tilted upwardly on its heel to its upright position of rest, the water in the reservoir cannot flow into the steam dome. If these members were located at a point back of their present location, water could flow directly from-the reservoir into the steam dome when the iron is tilted upwardly.' This would result in water running down the pipe 53 into the steam generator l5, and also in water running down the pipe 55 to the passageways in the sole plate. The steam pressure generated in the chamber It would force the water in the sole plate passages out through the sole plate openings Hi. This, of course, is undesirable, and is effectively prevented by locating the steam dome at the forward end of the reservoir. Also it will be observed that because the pipes 53 and 55 open into the steam dome at levels above the water level in the reservoir, the water in the reservoir cannot flow through the discharge pipe 55 to the pressing surface even if the iron be deenergiz'ed while on its pressing surface and the valve 40 left open.

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'modiilcations 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 A steam iron comprising a sole plate having I 2,295,841 prevent a sufllcient transfer of heat to the resera steam discharge port, a water reservoir above said sole plate having a lower port for discharging water from said reservoir, a valve controlling the. flow of water through said reservoir port, a flash steam generating chamber under said reservoir port, means for heating said generating chamber to flash the water dropped therein into-steam, a steam dome rising from said reservoir, conduit means connecting said generating chamber with I said dome and thereby with said reservoir, an upright steam take-oil pipe in said dome, and

' conduit means connecting the lower end of said pipe with said discharge port.

2. An electric steam iron comprising a sole plate having a flash steam generating chamber (formed therein, steam ports opening on the pressing surface of said sole plate, an electric heating element for heating said sole plate, a water reservoir supported by said sole plate, a valve controlled port connected with said reservoir and discharging into said generating chamber, a steam riser pipe rising from said generating chamber, a steam dome'rising from said reservoir around the upper end of said riser pipe and receiving the steam discharged therefrom, and a steam discharge pipe connected with said steam ports and rising in said riser pipe and said steam dome.

3. A steam iron comprising a sole plate having a flash steam generating chamber formed therein at its'forward end and also steam ports opening into its pressing surface, means for heating said sole plate, a water reservoir supported by said sole plate, a valve controlled port connected with I said reservoir at its forward end and discharging into said generating chamber, a steam riser pipe rising from said generating chamber, a steam dome rising from said reservoir around the upper end of said riser pipe and receiving the steam discharged therefrom, and a steam discharge pipe connected with said ports and rising in saidriser pipe and said steam dome.

4. A steam iron comprising a sole plate formed with a flash steam generating cavity, a heating element for heating said sole plate, a cover for said cavity formed of a poor heat conducting material, a water reservoir spaced above said cover and attached thereto so as to be supported solely thereby, the top wall of said reservoir being provided with a steam dome rising therefrom, a steam riser pipe fastened to said cover so that its lower end opens into said cavity and its upper end into said steam dome, fastening means deitachably securing said cover to said sole plate so that said cover, said reservoir, steam dome and riser pipe can be removed from and applied to said sole plate as a unitary structure, a discharge pipe extending through said riser pipe and opening into the steam dome, and passage means connecting said discharge pipe with the pressing surface of said sole plate.

5.- A steam iron comprising a sole plate, a cover plate over said sole plate, said sole plate and cover plate defining a closed steam outlet chamber and a steam passageway for conducting steam to said chamber, said sole plate being provided with steam outlet ports connecting said outlet chamber with the pressing surface of said sole plate, and also provided with a flash steam cavity opening through said cover plate, a cover for said cavity resting on said cover plate, common screw fastening means detachably securing said cover and cover plate to said sole plate, means for admitting water into said cavity to generate steam therein, and conduit means connecting said cavity with said steam passageway comprising a first conduit extending upwardly through said cover and; a second conduit in communication with said first conduit extending downwardly through said cover plate to' said steam passageway. said first and second conduits forming a trap to prevent the passage 01 water from saidcavity tosaid steam passageway.v

6. A steam iron comprising a sole plate provided with a pressing surface and with a steam generating chamber, a water reservoir on said sole plate for feeding water into said chamber to generate steam, a riser pipe directed upwardly from said generating chamber, a steam dome into which said riser pipe discharges, a discharge pipe having one end opening into said dome, and conduit means connecting the other endoi said discharge pipe with said pressing surface, the ;end of said riser pipe that discharges into said dome and said one end of said discharge pipe that opens into said dome each being located at a level higher than the level of water in said reservoir so that water cannot possibly fiowl from said resto control the fiow of water from said reservoir to said generating chamber, and means for conducting steam from said steam dome through said sole plate to said pressing surface.

9. A steam iron comprising a sole plate formed with a flash steam generating cavity, a heating element for heating said sole plate, a cover for said cavity formed of a poor heat conducting material, a water reservoir spaced above said cover. and attached thereto so as to be supported solely thereby in spaced relation with said sole plate, a duct connected with said reservoir directed through said cover and discharging into, said cavity, a valve in said duct controlling the flow of water from said reservoir to. said cavity,

. the poor but conducting cover retarding the flow of heat from said sole plate to said reservoir by conduction, and a radiant heat intercepting bailie in the space between said reservoir and said sole plate spaced both from said reservoir and said sole plate.

ervoir to said conduit means through said riser and discharge vpipes when said iron is resting on said pressing surface.

'7. A steam iron comprising a sole plate having a flash steam generator cavity therein, a metallic closure plate for said cavity formedoi' a metal having a poor heat conductivity, a water reser- -voir above said closure plate, connection means between said reservoir and closure plate constituting the sole supporting means for said reservoir, said closure plate having an outwardly extending flange, and a clamping ring detachably securing said flange to said sole plate.

8. A steam iron comprising a sole plate having a pressing surface, a reservoir provided with a bottom wall and an upper wall and also having an upright steam dome rising from said upper wall, said reservoir further having in said bottom wall first and second spaced apertures, bushings aligned with said apertures rigidly secured to said bottom wall, a plate having two apertures aligned with said first mentioned apertures, a.

10. A steam iron comprising a sole plate having a steam discharge port, a heel at its rear end, and also a steam generating chamber, means for heating said chamber, a water reservoir having a discharge port for discharging water into said generating chamber, a steam dome rising upwardly from the forward end of said reservoir opposite said heel and in communication with said reservoir, steam conduit means leading from said steam generating chamber to said steam dome to convey the steam generated in said chamber into said dome, and conduit means for conveying steam from said steam domev to said discharge port, the forward location of said steam dome preventing the flow of water from said reservoir into said steam dome and said conduit member having a port therethrough formed with ably securing said plateto said sole plate to cover said chamber, a valve cooperating with said seat means when the iron is tilted upwardly on its heel to. a position oi. rest.

11. A steam iron comprisinga sole plate having a steam discharge port, a water reservoir having a lower port for discharging water, a steam generating chamber for receiving the' water'discharged from said port, means. for heating said chamberto heat the water dropped therein to generate steam, a steam dome rising from said reservoir, a vertically arranged'riser pipe connected at its lower end with said generating chamber and extending upwardly through said reservoir intosaid steam'dome, the upper end or said pipe being closed by a top wall but said pip having a lateral opening under said top wall Y said discharge port.

connecting the pipe with said steam dome, a steam take-oi! pipe extending upwardly through said riser pipe and entering said steam dome through said top wall, and conduit means connecting the lower end of FINLAYSON.

said take- -ofi pipe with a

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