US 3263350 A
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Description (OCR text may contain errors)
Aug. 2, 1966 c. s. ABRAHAM ELECTRIC STEAM IRON 4 Sheets-Sheet 1 Filed Dec. 15 1959 Q @ww 1966 c. s. ABRAHAM 3,263,350
ELECTRIC STEAM IRON Filed Dec. 15, 1959 4 Sheets$heet Fla g 2, 19 6 c. s. ABRAHAM 3,263,350
ELECTRIC STEAM IRON Filed Dec. 15. 1959 3 4 Sheets-Sheet :5
Aug. 2, 1966 4 Sheets-Sheet 4 Filed Dec. 15, 1959 IN VEN TOR.
United States Patent 1 Claim. or. 3877) The present invention relates to electric irons in general, and more particularly to improvements in electric steam irons.
An object of the invention is to provide an electric steam iron in which the water reservoir and the steam generating means constitute a self-supporting unit which is readily attachable to and separable from the sole plate.
Another object of the invention is to provide an electric steam iron in which the sole plate and the steam generating means embody separate, individually controllable heating elements whereby the user of the steam iron may control the generation of steam without in any Way affecting the heating of the sole plate.
A further object of the invention is to provide a steam iron of the just outlined characteristics wherein the heating action of the sole plate may be varied as desired without in any way affecting the generation of steam, i.e. in which the raised temperature of the sole plate need not cause increased generation of steam.
An additional object of the instant invention is to provide a steam iron of the above outlined type whose current consumption is comparatively low despite the fact that it utilizes separate electric heating elements for the sole plate and the steam generating means; which is capable of automatically shutting off the supply of electric current when the steam generating means reaches a given maximum temperature; in which the amount of steam to be generated may be controlled with very great accuracy; and in which the generation, quantities and discharge of steam may be controlled independently of the heating action of the sole plate.
A concomitant object of the present invention is to provide a steam iron of the above described characteristics which is equally practical for use in households as well as in commercial ironing and tailoring establishments.
A further object of the invention is to provide an improved steam iron which can be readily taken apart for inspection, cleaning or repair of its component parts; wherein the steam must cover a very short distance on its way into contact with a fabric to be ironed; wherein the distribution of steam is such that it may reach all or nearly all zones of the sole plate by utilizing comparatively few connections with the steam generating means; and which is so constructed as to render the obstruction of steam discharging tubes less likely.
An ancillary object of my invention is to provide an improved valve for controlled discharge of water into the steam generating unit of the steam iron.
With the above objects in view, the invention resides in the provision of an electric steam iron comprising a one-piece attachment which is connected to the sole plate and contains a partition separating its interior into a water tank and a steam generating chamber beneath the water tank. Independently controllable electric heating elements are mounted in the sole plate and in the base of the attachment below the steam generating chamber, i.e., the temperature of the sole plate is adjustable independently of the extent to which the attachment base is heated. The steam iron also comprises one or more preferably straight and comparatively short vertical or nearly vertical tubular elements which extend through the sole plate and the attachment base to convey the steam from the aforementioned chamber to the underside of the sole plate.
3,263,350 Patented August 2, 1966 The attachment comprises a readily removable cover plate and a special valve which extends through the cover plate and also through the partition to permit controlled gravity flow of water from the tank into the steam generating chamber. The valve is operable by a trigger or the like which is located above the cover plate within reach of a users fingers so as to be adjustable by a finger of that hand which holds the handle of the steam iron when the latter is in actual use.
Means is provided for permitting continuous or intermittent delivery of water into the tank which latter is completely sealed save for a bore located in its lowermost zone for conveying water to the valve means.
In the preferred form of my improved steam iron, the heating elements in the sole plate and in the base of the attachment are controllable by separate thermostats which may be connected to a common source of electric current. The thermostat which controls the supply of current to the heating element of the sole plate may be adjusted by hand, while the setting of the other thermostat may be effected in the manufacturing plant by full consideration of maximum heat requirements for satisfactory generation of steam. The base plate is preferably located at a short distance above the sole plate to receive heat radiated by the latter and to thus reduce the current consumption insuring more economical operation of the appliance.
The novel features which are considered as charac teristic for the invention are set forth in particular in the appended claim. Theinvention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of a specific embodiment when read in connection with .the accompanying drawings, in which:
FIG. 1 is a central vertical section through the improved electric steam iron;
FIG. 2 is a transverse section taken substantially along the line 22 of FIG. 1, as seen in the direction of arrows;
FIG. 3 is an enlarged detail sectional. view of valve means for discharging water into the steam generating compartment of the steam iron;
FIG. 4 is a perspective view of the combined watercontaining and steam-generating unit with the cover plate of the water reservoir and the lid of the steam container removed;
FIG. 5 is a perspective view of the sealing member or lid for the steam compartment of the unit shown in FIG. 4;
FIG. 6 is a top plan view of the cover plate for the water reservoir of the unit shown in FIG. 4; and
FIG. 7 is a bottom plan view of the sole plate.
Referring now in greater detail to the drawings, and first to FIGS. 1 and 2, there is shown an electric steam iron which comprises a combined water reservoir and steam generating attachment or unit I, also shown in FIG. 4, which preferably consists of a single piece of suitable metallic material and whose base 2 contains a heating or thermal element 3. The latter serves as a means for heating the base and for thereby transforming into steam any water which is discharged into the lower compartment 4 formed between the comparatively thick base 2 and a substantially horizontal intermediate wall or partition 1a of the attachment 1. The space 8 above the partition 1a and below the removable metallic cover plate 9 (best shown in FIG. 6) constitutes a water reservoir or tank which may be periodically or continuously refilled in the manner to be described in greater detail hereinafter.
The rear end of the steam generating compartment or evaporation chamber 4 is scalable by a removable metallic lid 5 (shown in FIG. 5) which is secured to the body &
of attachment 1 by a number of screws 6 and fits over a rectangular sealing member 7. The lid may be removed whenever it is desired to evacuate water from the evaporation chamber 4. The cover plate 9 fits over a packing member 10 and is fixed to the upper end of the upstanding wall of the attachment by a number of screws 11.
The communicating passage in and close to the forward end of the partition 1a which separates the tank 8 from the evaporation chamber 4 is controlled by a special valve 12 which permits controlled amounts of water to enter the chamber 4 by gravity flow, preferably in the form of droplets, the amounts of water released by the valve 12 depending upon the desired quantities of steam to be generated owing in part to the heating action of thermal element 3 and in part to heat radiation from the sole plate of the steam iron as will be described in greater detail hereinafter. The cylindrical body 12a of the valve 12 is formed with external threads 13, 14 which mesh with internal threads provided in aligned bores at the forward end of the cover plate 9 and partition 1a, respectively. In order to avoid leakage of water from the tank 8 along the threads 13, the boss 12b of the valve body 12a which is located above the cover Plate 9 defines a circumferential shoulder bearing against a sealing ring 15 and pressing the latter against the upper side of the member 9. The externally threaded somewhat reduced lower end of the valve body 12a is surrounded by a sealing ring 16 and meshes with a nut 17 which presses the ring 16 against the underside of the partition 1a. Thus, the sealing means 10, 15 and 16 completely seal the water tank 8 save for a tapped inlet orifice or filler opening 9a in the plate 9 which receives the externally threaded lower end of a funnel-shaped coupling member 43 whose outwardly diverging upper portion defines a circumferential shoulder to press a sealing ring 44 against the upper side of the cover plate 9. The lower part of the coupling member 43 is internally threaded and meshes with external threads on a respirator tube 45 which also serves as a water inlet nipple by being insertable into a rubber or like hose 47. When the tank 8 needs refilling, water is introduced through the hose 47 in the direction of arrow A to flow through the bore 46 of tube 45 and thence through the lower part of the coupling member 43 into the receptacle 8. When the hose 47 is removed, the bore 46 in the respirator tube 45 permits entry of air into the tank 8 whenever the valve 12 is actuated to allow gravity flow of water into the evaporation chamber 4.
The valve 12 is formed with a vertical through bore 18 and with a preferably radial inclined bore 25, the
latter communicating with the bore 18 and also with the bottom of the water tank 8. The upper part of the bore 18 in the boss 12b is enlarged, as at 18a, whereby the valve body 12a defines an upwardly facing shoulder to support a sealing ring 29 and a washer 30, the purpose of parts 29, 30 being to prevent escape of water from the bore 18 into the bore 18a when the tank 8 is being refilled. The bore 18 slidably receives a vertically reciprocable one-piece valve stem or rod 19 whose upper end extends into the larger-diameter bore 18a :and is connected with the upper end of a helical expan sion spring 21. The lower end of the resilient member 21 bears against the washer 30 and urges the valve stem 19 in upward direction. The lower end of the stem 19 carries a discoid head 20 which is constantly biased into sealing contact with the underside of the valve body 12a, i.e. the parts 19, 20 and 21 normally seal the bore 18 from the evaporation chamber 4. The means for reciprocating the valve stem 19 against the bias of spring 21 comprises a trigger in the form of a two-armed lever 22 whose rear end defines an eye 23 and whose forward end extends into a vertical guide slot 120 formed in the boss 12b. The trigger is pivotally mounted on a horizontal pivot axle or pin 24. The nose 22:: at the foremost end of the trigger 22 abuts against the upper end of the valve stem 19 and, whenever the trigger is pivoted about its pin 24, the nose 22a compresses the spring 21 and moves the valve head 20 away from the valve body 12a so as to permit controlled gravity flow of water from the tank 8 through the inclined bore 25, into the vertical bore 18, and thence into the evaporation chamber 4. The trigger 22 is operable by the users finger introduced into the eye 23 while the users hand grasps the handle 42 fixed to the upper part of a hollow casing or housing 40. It will be noted that the upper side of the intermediate wall 1a is inclined in forward direction and may be of slightly conical configuration so that the bore 25 communicates with the lowermost zone or bottom point at the forward end of the water tank 8. In this manner, the latter may be completely evacuated before a refilling with water becomes necessary. It is also preferred to form the base plate 2 with an at least slightly inclined upper surface so that water discharged through the bore 18 of valve 12 will be caused to flow by gravity along the base 2 and toward the lid 5 in order to insure more rapid evaporation. Thus the inclination of the base plate is preferably contrary to that of the partition 1a so that water may flow in the tank 8 toward the bore 25 but away from the valve head 20 in the lower compartment 4.
As is best shown in FIG. 3, the lower end portion of the valve stem 19 above the head 20 is formed with cylindrical zones 26, 27, 28 of progressively diminishing diameter which constitute means for controlling and varying the amounts of water entering the evaporation chamber 4. Thus, when the trigger 22 is only slightly pivoted about its pin 24 to bring about a short downward displacement of the valve stem 19, the difference in diameters of the bore 18 and cylindrical zone 26 will determine the amount of water flowing into the chamber 4. The flow of water may be increased if the valve stem 19 descends sufiiciently to expel the zone 26 from the bore 18, and so forth. It will be seen that the magnitude of the angle described by the trigger 22 about its pivot axle 24 is proportional with the quantities of water (i.e., with the number of droplets) flowing from the water tank 8 into the evaporation chamber 4 per unit of time.
The attachment 1 is removably fixed to a sole plate 31 which latter contains a second electric heating or thermal unit 32. The means for releasably connecting the attachment 1 with the sole plate 31 comprises two or more angular brackets or spacers 33 fixed to the upper side of member 31 by a series of screws 34a and to the underside of the base 2 by a number of screws 34b.
When the assemblies 1 and 31 are connected with each other in the just described manner, a series of steam conducting tubes 35 may be inserted :through the bores 31a formed in the sole plate to be thereupon sealingly screwed into tapped bores 36 of the base member 2. To that end, the tubes 35 are externally threaded, as at 35a. It will be noted that, owing to the provision of comparatively large bores 31a in the sole plate 31, the tubes 35 may be withdrawn and reinserted without requiring separation of attachment 1 from the sole plate. The upper ends of tubes 35 extend close to the underside of the partition 1a, i.e., unless the evaporation chamber is completely filled with water, only steam can be discharged through the tubular members 35. FIG. 1 also shows that the tubes 35 need not be vertical but may be inclined through different angles with respect to each other in order to insure better distribution of steam along the underside of the sole plate. As may be observed in FIG. 7 which shows the underside of the sole plate, the latter is formed with a series of preferably V-shaped channels or grooves 37 whose outwardly and rearwardly diverging legs meet in the central plane common to the steam conveying tubes 35. Thus, the steam discharged through the lower end of a tube 35 will pass through the outwardly diverging legs of the respective channel 37 to insure an even more uniform distribution of steam over the fabric when the steam iron is put to actual use.
Referring again to FIG. 1, the thermal unit 32 in the sole plate 31 is connected to a thermostat 38 by means of insulated electric conductors 32a. A similar thermostat 39 is connected to the thermal unit 3 in the base of attachment 1 by means of insulated electric conductors 3a. Thus, the base 2 may be heated to the desired temperature independently of the sole plate 31, and the thermostat 39, depending upon its setting, will disconnect the unit 3 from the supply of electric current at a predetermined maximum temperature. Both thermostats are connected to a common plug 48 which may be inserted into a non represented outlet to deliver current to thermal elements 3 and 32. The exact construction of elements 3, 32 and of thermostats 38, 39 forms no part of my present invention. It will be noted that the thermostat 38 is provided with an adjusting member or manual control setting means 38a which is readily accessible so as to allow for adjustments in the temperature of the sole plate 31. The adjustment of the thermostat 39 is preferably etfected in the manufacturing plant and is calculated in a way to take into consideration the amounts of heat required for rapidly transforming into steam maximum quantities of water discharged by the valve 12 per unit of time. Thus, the user need not adjust the thermostat 39 which controls the generation of steam but may readily vary the temperature of the sole plate 31 merely by turning the adjusting member 38a.
The underside of the handle 42 is formed with a recess or cutout 42a to accommodate the boss 12b. The lower end of the casing 40 is removably connected with the sole plate 31, e.g., by means of screws 49 or the like. It will be noted that the casing is provided with a passage for the boss 12b of valve means 12.
Since the base plate 2 is heated by its own thermal element 3, the production of steam is instantaneous whenever the trigger 22 is operated to permit gravity flow of water into the evaporation chamber 4. The advantage of the valve 12 is in that the flow of water is induced by gravity alone, i.e., the steam iron may operate without pumping devices which normally contain rubber hoses and like rapidly deteriorating parts characteristic of many presently known steam irons.
Though the improved appliance embodies two independently controllable thermal units 3 and 32, the consumption of electric current is comparatively low because the thermostat 39 which controls the thermal unit 3 in the base plate 2 often shuts off the supply of current for comparatively long periods of time. By way of example, the temperature of the base plate 2 may be set to a maximum of 170 C., i.e., at this temperature the thermostat 39 will automatically shut otf the supply of electric current to the thermal unit 3. Thenceforth, the temperature of the base 2 is normally maintained at the desired level merely by such heat as is radiated upwardly from the sole plate 31. As is clearly shown in FIG. 1, the sole plate 31 is rather close to but does not contact the underside of the base plate 2. Only when the steam iron should produce comparatively large quantities of steam for extended periods of time without any interruption in the steam supply, the thermostat 39 will again complete the circuit of the thermal unit 3 in order to raise or maintain the temperature of the base plate at the required level. In normal use, however, the thermostat 39 will rarely allow the current to pass because it has been found that the base plate is cooled only after about -12 minutes of incessant dripping which is not expected under normal operating conditions because the person using a steam iron is not likely to operate the trigger for such extended periods of time. During each interruption in the actual use of my improved appliance, the base plate 2 receives its heat by radiation from the sole plate 31 and the thermostat 39 need not permit the current to pass into the thermal unit 3.
On the other hand, if the base plate 2 reaches an excessively high temperature, the production of steam is again interrupted because the drops of water discharged onto the upper side of the plate 2 merely roll therealong and do not evaporate until several seconds or even minutes have elapsed. In order to avoid such overheating, the thermostat 39 is usually set at C. or thereabouts.
The specific construction of the valve 12 renders it possible to control the flow of water into the evaporation chamber 4 within the desired range necessary for proper operation of the steam iron. The provision of stepped zones 26 to 28 on the valve stem 19 insures that the water descends in the form of drops rather than in a continuous stream.
Because the user is free to control not only the temperature of the sole plate 31 independently of the temperature of the base plate 2, but also the supply of steam independently of such temperatures, the improved steam iron may be put to use under greatly varying conditions such as are best suited for a particular type of fabric which requires ironing. For example, large quantities of steam may be produced and discharged at comparatively low temperatures of the sole plate, or vice versa. The presently known steam irons, particularly those intended for household use, cannot be adjusted in the just described manner. As regards the industrial steam irons of known design, i.e., those used in tailoring and like establishments, steam is often generated in a separate boiler and is introduced into the steam iron through a flexible conduit or the like. Thus, the steam iron of my invention is equally practical for domestic and also for industrial use, particularly if the respiration tube 45 is connected with a large outside water tank or with a faucet so that the receptacle 8 may be refilled while the steam iron is in actual use.
It is preferred to utilize steam conveying tubes with comparatively large diameters because each of these tubes must supply steam to a rather large area of the sole plate. The tubes 35 are comparatively short because they pass directly from the underside of the sole plate 31 and into the chamber 4; thus, the steam need not travel through long and winding channels as in many steam irons of presently known design. Also, it is very unlikely that the bores of steam conducting tubes 35 would become obstructed, but, should one or more of these tubes require cleaning, inspection or replacement, such operation may be carried out without taking apart the appliance.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claim.
What is claimed as new and desired to be secured by Letters Patent is:
A steam iron comprising: a sole plate having a pressing surface, a steam generating vessel, means mounting said steam generating vessel in poor heat transfer relationship with said sole plate, steam passage means leading from said steam generating vessel to said pressing surface, a water reservoir disposed above said steam generating vessel and having a port therein communicating with said steam generating vessel, a valve disposed in said port, said valve being continuously variable from a fully closed position to a fully opened position to vary the amount of water admitted to said steam generating vessel, first electric heating means embedded in said sole plate, second electric heating means embedded in said steam generator, a first thermostatic switch having its heat sensing element in good heat conducting relationship with said sole plate and having its contacts arranged to control energization of said first electric heating means, a second thermostatic switch having its heat sensing element in good heat conducting relationship With said steam generating vessel and having its contacts arranged to control the energization of said second heating means.
References Cited by the Examiner UNITED STATES PATENTS Hull 3877 Leprestre 38-77 Klaren 3877 Smith 3877 Dowinsky 3877 Kistner 3877 Morton 3877 Waage 3889 X FOREIGN PATENTS 1/ 1952 Germany.
FRANK I. COHEN, Primary Examiner.
THOMAS HICKEY, DAVID J. WILLIAMOWSKY,
15 R. s. BRAMSON, J. FRANKLIN, s. G. LAYTON, M.
J. COLITZ, P. D. LAWSON, Assistant Examiners.