US2903804A - Steam iron - Google Patents

Description

2 Shgae'esf-Sheec. 1

Spt. 15, .1959V 'Mg M. KlsTNlv-:R l STEAM IRON Filed oct. 23,1956,

A itin! FLY Sept. 1.5, 1959 M. KISTER STEAM IRON Filed Oct. 23. 1956 2 Sheets-Sheerl 2 BY /wull Lum/,

M/truA )La fl/ ATTO R N EYS theftlas type and the boiler type.

STEAM IRON Merrill M. Kistner, St. Petersburg, Fla. Application'october z3, 1956, serial No. 617,777 z claims. (ci. .ss- 77) rThis invention relates to steam irons, and more particularly to a domestic steam iron of the flash type.

Heretofore steam irons have been made of two types, In flash type irons, as disclosed in my prior Patents No. 2,313,382, granted March 9, 1943, and No. 2,384,839, granted September 18, 1945, a quantity of water is contained in a reservoir mounted over the sole-plate and the water is delivered-v through a valve-controlled outlet to a steam generating chamber in the sole-plate. The steam may ow fromthe steam generating chamber through chaunels in the sole-plate to outlet or discharge openings iu the sole-plate to properly condition .the steam, as disclosed and claimed in PatentrNo. 2,384,839.

In commercial steam irons at present available it is the usual practice to provide valve-controlled means for 'the delivery of water tothe .steam 4generating chamber that is incapable of regulation, i.e., the valve has only an .on -position and an -o position. To obtain the full advantages of an iron of this type, the water control should be. capable of regulation. When pressing heavier fabrics requiring higher temperatures, larger quantities of steam should be supplied.

` In addition, as the temperature fof the sole-plate is increased, the amount of steam generated should be proportionately increased to, assure production of -a uniform type of steam' at all temperatures. For best operation, a steam iron should produce steam that is not too wet, that is, does not contain any appreciable quantity of water droplets in liquid form. Such steam causes spotting of various fabrics. On the other hand, the steam should not be super-heated to an appreciable amount. If it is,

no condensation will take place in the fabric and the fabric will not be conditioned in the pressing operation in the manner that a properly constructed and properly used steam iron is capable of conditioning fabric.

. AIt. Will `be apparent that a certain portion of the heat supplied by the heating-element of an iron is used for heating -the sole-plate `and a .certain proportion is used to vaporize the water supplied to the steam generating chamberI and condition thesteam before it is delivered to thedischaige ports.I This proportion is roughly the same at any setting of .the thermostat. It will thus be apparent that in an ironhavingonly one rate of water delivery to the steamgeneratingA chamber, the type of steam delivered will vary with diierent thermostat setl-tings. If a properly conditioned steam is delivered with alow thermostat setting, a higher setting requiring 'a greater heat input to maintain-the sole-plate at the higher temperature, will result in superheating the steam 'to an extentthatthe iron does not properly condition .the fabric, because insuicient steam` is condensed in lthe fabric. Likewise, if the steam delivered is in proper condition with a high setting, a lower setting will result in thedeliveryof steam that is too wet. and which will spot delicate, colored fabrics.

-. In @the present invention I provide afconstuction` in I ing 38 over the steam generating chamber.

'which the water delivery is correlated to the temperal ture, and in which a single control member regulates the setting of the thermostat and the valve. The control is also capable of cutting oi the iiow of water, and permitting regulation of the thermostat. Thus the iron may be used as a dry iron, and the thermostat adjusted to permit temperature variations of the sole-plate.

Correlated regulation of the temperature setting and the water supply is, thus, an important feature of the present invention. By properly calibrating the iron at the time of manufacture, steam may be supplied of uniform character regardless of the temperature setting. As stated, that should be a steam which will not deposit water on the surface of tbe fabric, and is of such temperature that some condensation occurs in the fabric to properly condition the fabric.

lIn the accompanying drawing, I have shown one embodiment of the invention. In this showing:

Fig. l is a vertical, longitudinal, sectional view of the iron;

Fig. 2 is a detailed, horizontal, sectional view on line 2-2 of Fig. 1;

Fig. 3 is a bottom plan view of the control cam;

Fig. 4 is a detailed, vertical, sectional view on line 4-4 of Fig. 3;

Fig. 5 is a similar view on line 5-5 of Fig. 3; and

Fig. 6 is a side elevation of the cam.

Certain parts of .the illustrated iron are of more or less conventional construction and are included for the purpose of illustrating an operative iron in which the parts forming the present invention have their environment. Thus, the iron includes a sole-plate 2, with a heating element 4 embedded in it. Water reservoir 6 is .arranged over the sole plate, preferably covered by a shell 8. A handle 10 is mounted over the shell. The rear leg 12 of the handle may be provided with a recess for electric terminals (not shown) to be connected -to a cord connector (not shown). A lead 16 extends from the recess to one terminal of thermostat 18. A second lead from recess 14 (not shown) and a lead from the thermostat (not shown) are connected to the terminals of heating element 4.

The sole-plate maybe of the construction shown in my prior Patent No. 2,384,839. As shown in that patent, fthe'heating element 4 generally follows the contour of the sole-plate, being in the form of a U. A steam generating chamber 20 is arranged in the sole-plate in the loop of the heating element, and channels 22 are connected to the steam generating chamber. These channels convey the steam from the steam generating chamber-to discharge ports (not shown) in the sole-plate. The thermostat 18 is mounted in a well 24 in the soleplate in -the rear of a transverse lrib 26 which is arranged at the rear of the steam channels or passages 22.

The front lelg 28 of the handle is provided with a bore 30. This bore communicates with an opening 32 extendf ing through the'front face of the leg. At its lower end, it

communicates with an opening 34 in the top of reservoir 6. The portion of the sole-plate in 'which steam generator 20 and channels 22- are arranged is provided with a cover plate 36. The cover plate is provided with an open- A domeshaped member 40 of low heat conductive metal is secured to the cover and mounted in opening 38. An internally threaded nut 42 is brazed, or otherwise mounted in a central opening in the member 40. An externally threaded valve seat member 44 is received in nut 42. `As

shown, the valve seat member extends through an opening in the bottom of the reservoir. It is provided with a head 46 of larger diameter than this opening. The head engages the inside surface of -the bottom of the reservoir vand clamps the reservoir between the head 46 and. nut 42. Suitable 'gaskets may be arranged on the nut 42 and beneath head 46 to prevent leakage of water. At lthe rear of the iron, the reservoir is supported above the sole-plate by bracket 48.

Valve member 44 is provided with a central bore 50. At the bottom of bore 50, I providea conical section 2, which forms the valve seat.l A bore 54 of smaller dameter than bore 50 is formed `beneath the valve seat. yThe v alve is formed on a valve stem 56, and consists of a conical section`58 adjacent the lower end ofthe stern. The en d 60 of the stem is a second conical section at a lesser angle to the axis of the valve stem than the angle of section 58. The valve seat 5'2 and valve 5,8 are of -the same -angle and are in engagement with each other when the valve is closed. But when the valve stem is raised, the space between the lower bore 54, which is cylindrical, and the tapered end portion 60 of the valve stern increases as vthe stem is raised to `increase the amount of Water delivered to the steam generating chamber.

Valve stem 56 extends upwardly through the reservoir and bore 30 in the front leg of the handle. Adjacent its upper end it passes through a smaller bore 62 which communicates with the top of bore 30. The upper end of the valve stem is received 4in a recess 64 in the top of the handle. This recess is normally closed by a plate 66. The plate is removable to permit access to the upper Vend of the valve stem. It may be retained in place in any suitable manner. The upper end of the valve stem is threaded and receives a nut 68 and lock nut'70. Nut 68 carries a plate 72 adapted to be engaged by a valve opening member 74 to raise the-valve stem and open the valve.

The valve is biased toward a lower o r closed position. As shown, a pair of metal washers 76 and a Vfeltvvasher 78 surround the valve stem at the juncture of bores 30 and 62. A recess of suitable size for the reception yof the washers is preferably formed at the upper end of bore 30. A metal tube 80 surrounds the stem beneath the lower washer 76. Washer 82 is arranged on the stern in contact with the lower end of tube 80. A spring 84 surrounds the stem beneath the washer 82. The lower end ofthe spring engages a washer 86 which is secured to the valve stem. The Washer 86 may be secured to the stem in any suitable manner. It may be in the form of a split ring received in a groove in the valve stem. l

In the operation of the valve, spring 84 engaging washer 86 normally moves the valve stem downwardly to retain the valve in Ithe closed position. When valve operating lmember 74 raises the valve stem to open the valve, as illustrated in Fig. 1, spring 84 is placed under compression. When member 74 moves Ato a position which permits downward movement of the valve stem, spring 84 moves it downwardly to close, or partially close, the valve.

The combined valve and thermostat operating mechanism includes a king bolt 88 which extends through a sleeve 89 in the reservoir and is received in a threaded opening in the transverse wall 26 of the sole-plate. A Supporting plate 90 which extends over the thermostat (see Fig. l) is mounted on the king bolt. The king bolt has a head 92 just above its threaded end. This head passes through an opening in the supporting plate 90 and clamps the plate on the upper surface of wall 26. At its rear end, plate 90 may be provided with ears 94, one of which is shown in dotted lines in Fig. 1. These ears extend downwardly on each side of the thermostat and are provided with at portions having openings for the reception of bolts 96. The bolts are received in openings in the sole-plate and give the plate 90 a three-point, anchorage, or support.

The upper end of king bolt 88 extends above the reservoir and is positioned adjacent a portion 98 of the top of the shell 8. The end of the king bolt is provided with a threaded, axial opening. A threaded member 100 is received in the threaded opening in the end of the king bolt. This member has a head 102 intermediate itsends which engages the outer face of Shell portion i98 to clamp the shell in place. It may be provided with a notch 104 in its upper end for the reception of a screw driver or other tool. The handle, which is generally molded from a suitable plastic, includes a lower horizontal portion 106 which covers the top of the shell. The portion 106 is provided with a suitable opening for access to the king bolt. This opening is normally covered by a plate 108, which may be formed of metal and which may be designed to snap into place.

Supporting plate is provided with an opening positioned over the thermostat and the lower, enlarged end 109 of a tube 110 is mountedin this opening. Tube 110 extends upwardly through a sleeve 112 in the reservoir to an opening in top 98 of the shell. Tube 110 is provided with an enlargement 114 adjacent its upper end. Beyond the enlargement, it is threaded for the reception of a nut 116. A plate 118 is clamped in place between nut 116 and the enlargement 1 14. A thermostat operating rod 120 extends through tube'1'10. In `the 'drawing the rod is shown as two members. The 'bottom member s preferably ceramic to reduce heat flow' and avoid metal contact with vthe thermostat element. At its -lower end the thermostat rod yengages one of the movable elements'vj122 of lthe thermostat 'in the usual manner. At 'its upper end, it is engaged by one of several cams formed on a cam disc 124.

Cam disc 1,24 is arranged beneath an opening inthe lower, horizontal portion 106 of the handlev and is mounted on a' pin or shaft A126 vcarried b y plate '118. The portion `106 of the handle is generally arranged at an angle to the horizontall as shown. To arrange the disc 124 substantially parallel to it', with the shaft 1,26 Vperpendicular to them, the portion of supporting plate 118 rearwardly of tube 110 is arranged at the proper angle to dispose the shaft perpendicular Vto surface' 106, as shown.

A threaded bushing 128 is mounted on shaft 126. Disc 1124* vis rotatably mounted .onA the shaft being clamped in place by nuts 130 and 132 which are mounted on the bushing 128. A dial member 134 is secured to nut 130 by a set screw, and projects through the opening in portion 106 of the handle for manipulation by the user of the iron.

Disev 124 is provided with two sets of cams to be described in greater detail in connection with Figs. 2 to -5 of the drawings. One set of cams is concentrically ar.- ranged in alignment with thermostat rod 120 to either lower the rod or to permit it to be raised 'by the inherent resiliency of thermostat member 122. The second vvset of cams on the periphery of the disc engage a rocker arm `136 to depress the adjacent end of thearrn. As shown (see 2) the end 138 of arm `136 which 'is engaged by the cams may be Arounded to facilitate its movement over the cams. The mid-portion of the rocker arm is provided with an opening 140 to receive the threaded member 100. In alignment with the opening, the arm is provided with curved portions 142i, substantially semicircular, which rest upon head 102 of the threaded member'and form the .pivot of the rocker arm. Beyond the pivot the rocker arm engages the valve actuating rod 74. As shown, this rod extends through abore l29 in the front leg of the handle. Thus, as Ythe 'end P138 of the rocker arm is Adepressed by .one of the cams on disc 124, `the other end is raised to move Ythe actuating member 74 and raise valve stem 56. When' the end 13,8 ,is in engagement Vwith a at portion `of the surface of disc 124, spring 84 will close the valve, as heretofore described.

` Referring to Figs. 3 and 4 ofthe drawings, cams ,144, 146 and 148 on the `periphery of the disc 1,24 provide for three valve settings to deliver regulated amounts of water to the steam `generating chamber.. It will 'be noted that the cams may vary in size, 144. being the largest and 148 the smallest. Thus, When cam 144 engages rocker arm 136, it depresses 'it the maximum 301911,@ .and opens the valve to its limit, As Ieither-,of

the other cams engages the rocker arm, the valve is opened a lesser amount. Throughout the remainder of the peripheral edge 150 of the disc, it is of uniform height (see Figs. 3 and 6) and is of such height that rocker arm 136 assumes a position that permits spring 84 to close the valve.

In radial alignment with the cams 144-148 and over the thermostat rod 12 is a second series of cams 152, 154 (see Figs. 3 and 4). These cams depress the rod 120 varying amounts, depending on the size of the cam, to set the thermostat 18 for various cut-o temperatures as is the conventional practice. The cams 152, 154 and 156 are radially aligned with cams 144, 146 and 148, respectively, so that the thermostat setting for highest temperature is coupled with the valve control for the delivery of maximum quantity of water and each lower setting is coupled to a valve control for delivery of a lesser quantity of water.

It will be noted from Fig. 3 that the cams 144, 146, 148, 152, 154 and 156 are arranged on one-half of disc 124, the left half as seen in this g'ure. I also provide for temperature regulation or control by dial 134 when the iron is used as a dry iron with valve 58 closed. On the right side of the disc 124 and concentric with cams 152, 154 and 156, I provide a cam 158 (see Figs. 3 and 5). 'This cam extends approximately 180 and is a continuously sloping cam. As it is radially aligned with the portion 150 of the periphery of the disc on which no cams are provided, the spring 84 retains valve 58 closed during any setting in which cam 158 is in contact with the thermostat rod 120. Thus, the iron can be set at any desired temperature by proper positioning of cam 158 and used as a dry iron.

The dial 134 may be provided with suitable indicia (not shown) to permit the user of the iron to set it for a desired temperature, either for use as a dry or steam iron. The edge of disc 124 may be provided with a series of notches 160 corresponding to the pairs of cams 144-152, 146-154 and 148-156, respectively. These notches receive a spring nger 162 (see Figs. l and 2) which is secured to supporting plate 118. When the thermostat is set for the highest temperature and delivery of the greatest amount of water with thermostat rod 120 in engagement with cam 152 yand rocker arm 136 in engagement with cam 144, the finger 162 is in the lower notch 160, at 4 oclock in Fig. 3. As the dial is turned to move the thermostat and valve controls to other settings, there is a click each time the finger 162 enters one of the notches, notifying the user of the iron that the parts are now arranged in the next setting.

While interconnected controls for the thermostat and valve of a steam iron have hertofore been proposed, such devices have not had means for cutting ol the water supply and permitting setting of the thermostat at a. selected temperature. Of greater importance perhaps is the provision of an interconnected control whereby 6 l the delivery of Water is correlated to the temperature setting in such manner that the amount of water supplied for each temperature setting is such that steam in a uniform condition is produced, regardless of the variation of total input heat units and of heat units available for producing and heating steam. As the total heat units available for production and heating of steam is increased, the amount of steam produced and heated is proportionately increased so that any given unit of water or steam receives the same amount of heat. This permits production of steam of uniform condition at all times and by properly Calibrating the parts of the iron, steam that is best suited for ironing may be produced.

The illustration of three inter-related thermostat settings and three valve settings and means for setting the thermostat throughout a temperature range with the valve closed is merely one example of the innumerable combinations that may be made by use of diierent cams. The invention is, therefore, not to be considered as limited to the illustrated arrangement.

I claim:

l. In an electric steam iron comprising a sole-plate having a steam generating chamber, steam delivery channels in the sole-plate and outlet openings in its lower face, a water reservoir over the sole-plate, a handle over the reservoir, the sole-plate, reservoir and handle being operatively connected to each other to form a unitary structure, a valve controlling delivery of Water from the reservoir to the steam generating chamber, a valve stem connected to the valve, a thermostat to control the temperature of the sole-plate, a thermostat control rod associated with the thermostat, the improvement which comprises a single control member consisting of a disc mounted on the exterior of the iron, two sets of concentric cams on the lower face of the disc, and means for connecting one of said sets of cams to the valve stem and the other set of cams to the thermostat control rod to vary the valve setting and the ow of water to the steam generating chamber when the thermostat setting is changed.

2. Apparatus in accordance with claim 1 in which said two sets of cams occupy a portion of the disc, the remainder of the disc being provided with a cam concentric with the iirst set of cams for regulation of the thermostat, and being without cams, in the circle of the second set of cams whereby the valve 'will remain closed to permit use of the iron as a dry iron.

References Cited in the tile of this patent UNITED STATES PATENTS 2,411,199 Felver Nov. 19, 1946 2,441,586 Morton May 18, 1948 2,655,746 McFarland et al Oct. 20, 1953 2,749,633 Seck June 12, 1956

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