US3711972A

US3711972A - Steam iron

Info

Publication number: US3711972A
Application number: US00195927A
Authority: US
Inventors: G Risacher
Original assignee: Westinghouse Electric Corp
Current assignee: Hamilton Beach Inc; CBS Corp
Priority date: 1971-11-05
Filing date: 1971-11-05
Publication date: 1973-01-23
Anticipated expiration: 1990-01-23
Also published as: JPS4856989A; AU472996B2; GB1395564A; AU4711172A; CA963376A; AR192819A1

Abstract

The invention discloses a steam iron having a primary steam generating chamber for the generally continuous generation of steam and a separate auxiliary steam generating chamber for a manually controlled intermittent generation of a substantially larger volume of steam. The auxiliary chamber is connected to the primary chamber via a ''''S''''-shaped steam path with the primary chamber also being downstream from the auxiliary chamber so that steam generated in the auxiliary chamber must pass through the ''''S''''-shaped path and into the primary chamber before being distributed for discharge through apertures in the soleplate. The auxiliary chamber and the temp responsive bimetal control regulating the temperature of the iron are in close proximity to each other so the heat loss in the area of the soleplate bounding the auxiliary chamber, in instances when there are successive demands for the larger generation of steam which tend to deplete the heat from the auxiliary chamber, can be rapidly sensed and quickly replenished by actuating the heater.

Description

United States Patent [1 1 Risacher Jan. 23, 1973 STEAM IRON [75] Inventor: Gerard l-l. Risacher,

Ohio

Mansfield,

[73] Assignee: Westinghouse Electric Corporation,

[52] US. Cl ..38/77.83 [51] Int. Cl. ..D06i 75/06 [58] Field of Search ..38/77.5, 77.83, 77.9

[5 6] References Cited UNITED STATES PATENTS 3,165,843 1/1965 Willman ..38/77.83 5,599,357 8/1971 Gronwick ..38/77.83

Primary Examiner-Patrick D. Lawson AttorneyF. l-l. Henson et al.

[57] ABSTRACT The invention discloses a steam iron having a primary steam generating chamber for the generally continuous generation of steam and a separate auxiliary steam generating chamber for a manually controlled intermittent generation of a substantially larger volume of steam. The auxiliary chamber is connected to the primary chamber via a S-shaped steam path with the primary chamber also being downstream from the auxiliary chamber so that steam generated in the auxiliary chamber must pass through the S-shaped path and into the primary chamber before being distributed for discharge through apertures in the soleplate. The auxiliary chamber and the temp responsive bimetal control regulating the temperature of the iron are in close proximity to each other so the heat loss in the area of the soleplate bounding the auxiliary chamber, in instances when there are successive demands for the larger generation of steam which tend to deplete the heat from the auxiliary chamber, can be rapidly sensed and quickly replenished by actuating the heater.

6 Claims, 2 Drawing Figures PATENTEUJAH23 ms 3 711 SHEET 2 UF 2 i .972

FIG. 2

tion being primarily directed to those portions of the internal mechanism of the iron directly related to the invention.

As shown in FIG. 1, the iron of the present invention has a bellows-type pump 12 having an inlet tube 14 disposed in the water reservoir tank 16 and an outlet tube 18 directing the water to a nozzle 20 disposed in an aperture in the soleplate cover 22 (contrary to a forwardly projecting spray nozzle as shown in the incorporated patent). It is to be understood that both inlet 14 and outlet 18 contain one way valving, as is well known in the art, to direct the water from the inlet to the pump bellows, and from the pump bellows to the nozzle, while preventing any reverse flow. A button 24 extends through the iron handle and abuts the bellows pump 12 so that the manual depression of the button actuates the pump and subsequent release permits the pump to refill.

The bottom wall of the water reservoir tank 16 supports a nozzle 68 having an orifice 70 with a tapered throat 72 for seating a needle valve 74. The nozzle provides a water flow path from the tank 16 to the primary steam generating chamber 76 defined generally by a depressed area 78 cast in the soleplate l1 and a cover plate 22 which also defines an aperture through which the nozzle 68 extends.

The position of the needle valve 74 is controlled by a cam follower rod 82 and a cam surface 84 directly connected to a control knob 39 so that when the control knob is set on any steam setting shown by appropriate indicia on the top of the iron handle, the needle valve is in the upper position shown, permitting a metered amount of water to drip from the water tank through the nozzle into the primary steam generating chamber for a generally continuous generation of steam. Setting the control knob 39 at a position other than steam, permits the needle valve to seat on the tapered throat 72 of the orifice and prevents water in the reservoir tank from entering the chamber.

A second or auxiliary steam generating chamber 86, similarly defined by a depression east in the soleplate 11 and also covered by the coverplate 22, is disposed rearwardly of the primary chamber and in fluid flow communication therewith via a substantially 5"- sh'aped duct 104 also cast into the soleplate and covered by the coverplate. The nozzle 20 at the end of the outlet tube 18 is disposed in the coverplate so as to be immediately above the auxiliary chamber 86 so that the water pumped by the bellows pump 12 enters the chamber 86. It is to be noted from this that water enters each steam chamber independently of the other, with the ability of water to enter the primary chamber being dependent upon the setting of the control knob 39 and the ability of a large volume of water to enter the auxiliary chamber being dependent only on depressing but-- ton 24. Thus, even with control knob 39 set for dry ironing, water can be pumped into chamber 86 merely by depressing button 24.

A temperature responsive bimetal element 38 is attached to the soleplate and in intimate contact therewith in the vicinity immediately adjacent the auxiliary chamber 86 and the inlet portion of the S- shaped duct leading therefrom. The free end of the bimetal is disposed between two

contact carrying arms

36 and 37 electrically connected in series with the sheathed heater element 33 cast in the soleplate 11. Contact carrying arm 37 is also attached via appropriate linkage to the control knob 39 so that its position relative to the remaining arm 36 can be varied to control the temperature at which the bimetal makes and breaks the connection between the two contacts. In this manner, the temperature of the soleplate of the iron is controlled generally within a variation of $25F of a setting which itself is generally within a range from 200F. to 400F with proper large volume steam generation permissible at a setting providing a temperature above 250F.

Referring now to FIG. 2 the relative position of the auxiliary steam chambers including their respective 'steam flow paths to the exit ports in the soleplate, and

the temperature responsive bimetal control will be shown.

A coverplate (not shown in this figure) is placed over the soleplate in sealing relationship therewith'which, in cooperation with the soleplate, defines certain passageways so that the steam is confined to the area and paths shown by the arrows to exit the apertures on the ironing surface of the soleplate.

In comparing the soleplate of the present invention with the soleplate of U.S. Pat. No. 3,599,357 as shown in FIG. 2 therein, it is noted that the steam generated in the auxiliary steam chamber of the patent is fed into a path downstream of the primary chamber and that both chambers are used for their respective steam generation each to the exclusion of the other. Also, it is to be noted that the bimetal temperature responsive control (41) is attached to the soleplate generally remote from the vicinity of either generating chamber. However, it is seen that the soleplate ll of the present invention defines a primary chamber 76 and a secondary or auxiliary chamber 86 with the primary chamber being downstream from and common to the path the steam generated in the auxiliary chamber must take for exit to the apertures 100 in the soleplate. Also, the path 104 leading from the auxiliary chamber 86 to the primary chamber 76 is generally maze-shaped and in this instance S-shaped providing a generally longer path and a larger area from which heat can be drawn to fully convert the larger quantity of water deposited in the auxiliary chamber into steam prior. to itsentering the steam flow path to the apertures in the soleplate.

The soleplate 11 of the present invention is further distinguished by supporting the temperature responsive bimetal control 38 in intimate conductive heat exchange relationship with the area immediately surrounding the auxiliary chamber 86 and the initial leg of the steam flow path l04.from the auxiliary chamber by being intimately attached to the raised area of the soleplate which defines one wall of the chamber 86 and the initial leg of the interconnecting flow path 104. It is this area inwhich it is critical to maintain at a sufficient temperature to convert the water pumped into the auxiliary chamber into steam. Thus, as the heat is used for this purpose, the temperature in the immediate vicinity drops accordingly. This drop in temperature is sensed by the bimetal control to actuate the heater 33 to replenish the heat. The closeness of the bimetal 38 to STEAM IRON BACKGROUND OF THE INVENTION l. Field of the Invention The invention relates to a steam iron and more particularly to a steam iron having, in addition to its ability to continuously generate steam at a relatively low volume, the added ability of intermittent controlled generation of steam at a large volume to exit through ports in the soleplate for increased steam penetration.

2. Description Of The Prior Art The ever increasing popularity of the steam iron over the dry iron attests to its greater inherent versatility in that it can satisfactorily iron a wider range of garments and materials than previously permitted with an iron providing only dry heat. However, the ordinary steam iron, which generally generates steam by a continuous metered drip of water from a reservoir tank to a heated chamber cast in the soleplate, has definite limitations in its ability to provide a deeply penetrating steam that is sometimes required to satisfactorily remove wrinkles from a thick or coarse material. In this respect and in order to make the steam iron even more versatile, it is known to provide means for momentarily increasing the water delivered to thesteam generating chamber so as to develop arather large volume of steam which, when exiting from the steam ports in the soleplate, is under considerable pressure so as to provide more steam with deeper penetration. This water was generally added by manual depression of a plunger to pump water to the generating chamber when the user demanded it. Exemplary of such irons is the. one described in U.S. Pat. No. 3,165,843 which shows a single steam generating chamber in which both continuous generation and the intermittent controlled generation for the penetrating steam occur. Another prior art steam iron, shown in U.S. Pat. No. 3,599,357, has two steam generating chambers, one for the generally continuous generation of steam and the other for an intermittent controlled generation of a separate large volume of steam.

In steam irons having the added ability of controlled large volume steam'generation', it is important to have a sufficient source of heat to permit a number of consecutive demands for this steam before the temperature of the generating chamber becomes lowered to a point which does not provide complete conversion of the water into steam. The temperature of the generating chamber is related to the temperature of the soleplate which, in turn, is controlled by a temperature responsive bimetal attached directly to the soleplate and maintains the soleplate at the desired setting within generally +..25F of. a temperature level to' insure complete conversion of the water that enters the steam generating chamber.

In anv electric iron the heat lossof the soleplate is due to conduction from its contacting the cold surfaces being ironed -and fr om conversion of water'to steam. In those instances where an extraordinary numberof consecutive demands are made, this heat loss, in the area surrounding the steam chamber is sufficient to lower the temperature of the immediate area below that required for complete conversion of the water to steam, thereby resulting in undesirable water droplets being exited through the steam apertures in the soleplate.

In the prior art irons, as clearly shown in the U.S. Pat. No. 3,599,357, the temperature sensing bimetal was attached to the soleplate at a generally remote area with respect to the chamber developing the large volume steam. This required the iron to depend on the heat reservoir or thermal mass of the soleplate immediately surrounding this chamber for the ability to supply consecutive demands of penetrating steam, as once this 0 area was cooled to a temperature that would not satisfactorily convert the water to steam, there would be a length of time or time lag for such heat loss to actuate the remote thermostat and energize the heater to replenish the heat loss. During this time lag, no penetrating steam could be developed.

SUMMARY OF THE INVENTION The present invention provides a steam iron having an auxiliary steam generating chamber similar to the known prior art devices as shown in U.S. Pat. No. 3,599,357 but within at least the following two important improvements:

l. The auxiliary chamber is disposed upstream of the primary chamber and connected thereto in fluid flow communication via a maze-like path so that the steam path from the auxiliary chamber include this path plus the primary chamber and thus provides a sufficient area for heat exchange for the larger volume of water to thereby promote complete conversion of this water to steam; and The auxiliary chamber and heat responsive bimetal control are in close proximity for relatively quick response of the bimetal to the temperature of the area surrounding the chamber to actuate the heater to replenish the heat so that a larger number of consecutive demands for the large volume steam can be made without loweringthe temperature of the chamber below the point required for completeconversion.

In providing the above listed improvements the iron of the present invention is able to be made lighter in that it does not depend upon a relatively large mass to provide a sufficient heat source for conversion of water to steam on consecutive demands but, in the alternative, depends on the ability of the bimetal control to quickly respond to the loss of heat and-actuate the heaters to replenish the heat loss thereby requiring less material in-the soleplate. This makes the iron more manageable for the user and less expensive to manufacture while retaining its ability to provide, in addition'to its generally continuous generation of steam, a large volume of penetrating steam for a relatively large number of consecutive demands. i 7 I DRAWING DESCRIPTION -FIG. 1 is an elevational view of a steam iron with parts broken away to more clearly show the present in- DESCRIPTION OF THE PREFERRED I EMBODIMENT The iron of the present invention is similar in most respects to the iron shown and described in U.S. Pat.

this area provides a relatively short reaction time, eliminating delay that would cause the immediate area to decrease to a sufficiently low temperature that would not satisfactorily convert the water to steam. In this respect, as previously explained, it is not necessary for a soleplate of a large mass as a source of sufficient heat to permit generally continuous conversion but, as an alternative, the ability of continuous conversion of relatively large volumes of water is aided by a quick response of the bimetal control to the temperature in the auxiliary generating chamber and flow path for actuation of the heater to replenish the heat loss and additionally permits a lighter, less expensive soleplate that provides a more manageable iron.

I claim as my invention:

1. An electric steam iron selectively operable as either a steam iron or a dry iron including: a soleplate having a heater element imbedded therein, said soleplate defining a plurality of steam exit apertures in fluid communication with steam generating chambers and steam distributing ducts defined between said soleplate and a cover member in sealing engagement therewith, said generating chamber and said distributing ducts further being disposed generally adjacent the heater means and comprising:

a primary steam generating chamber for the generally continuous generation of steam when said iron is on a steam setting;

first duct means directing steam generated in said primary chamber to said plurality of exit apertures;

an auxiliary steam generating chamber for intermittent generation of steam as demanded by the user irrespective of the setting of said iron above a given temperature level; and,

a second duct connecting said auxiliary chamber to said primary chamber in upstream series relation so that steam generated in said auxiliary chamber must initially flow through said second duct to said primary chamber prior to entering said first duct means directing it to said exit apertures.

2. The steam iron of claim 1 including temperature responsive means for controlling said heater, said control means being mounted on and attached to said soleplate in intimate heat conductive relation and disposed closely adjacent said auxiliary chamber.

3. The steam iron of claim 2 wherein:

said temperature responsive means is disposed in a generally rearward direction of said auxiliary chamber; and

said second duct carries said steam generated in said auxiliary chamber generally forwardly and away from said temperature responsive means to said primary chamber.

4. The steam iron of claim 2 wherein:

said soleplate includes means formed thereon defining at least a part of the wall of said auxiliary chamber;

said temperature responsive means being mounted on said formed means, said formed means at said mounting location being uninterrupted by steam passages between said auxiliary chamber and said mounting so that conduction of heat between said auxiliary chamber and said temperature responsive means is promoted.

5. The steam iron of claim 1 wherein: said heater element has a generally elongated U- shape with the bight of said U being located immediately forward of said primary chamber;

said primary chamber has opposite side exits for directing steam into said first duct means, and has a rear side inlet for receiving steam from said second duct.

6. The steam iron of claim 5 wherein:

said first duct means includes opposite side passages directly overlying said heater element and extending to the rearward portion of said soleplate;

said opposite side passages being connected at said rearward portion to the remaining portion of said first duct means having said exit apertures.

Claims

1. An electric steam iron selectively operable as either a steam iron or a dry iron including: a soleplate having a heater element imbedded therein, said soleplate defining a plurality of steam exit apertures in fluid communication with steam generating chambers and steam distributing ducts defined between said soleplate and a cover member in sealing engagement therewith, said generating chamber and said distributing ducts further being disposed generally adjacent the heater means and comprising: a primary steam generating chamber for the generally continuous generation of steam when said iron is on a steam setting; first duct means directing steam generated in said primary chamber to Said plurality of exit apertures; an auxiliary steam generating chamber for intermittent generation of steam as demanded by the user irrespective of the setting of said iron above a given temperature level; and, a second duct connecting said auxiliary chamber to said primary chamber in upstream series relation so that steam generated in said auxiliary chamber must initially flow through said second duct to said primary chamber prior to entering said first duct means directing it to said exit apertures.

3. The steam iron of claim 2 wherein: said temperature responsive means is disposed in a generally rearward direction of said auxiliary chamber; and said second duct carries said steam generated in said auxiliary chamber generally forwardly and away from said temperature responsive means to said primary chamber.

4. The steam iron of claim 2 wherein: said soleplate includes means formed thereon defining at least a part of the wall of said auxiliary chamber; said temperature responsive means being mounted on said formed means, said formed means at said mounting location being uninterrupted by steam passages between said auxiliary chamber and said mounting so that conduction of heat between said auxiliary chamber and said temperature responsive means is promoted.

5. The steam iron of claim 1 wherein: said heater element has a generally elongated U-shape with the bight of said U being located immediately forward of said primary chamber; said primary chamber has opposite side exits for directing steam into said first duct means, and has a rear side inlet for receiving steam from said second duct.

6. The steam iron of claim 5 wherein: said first duct means includes opposite side passages directly overlying said heater element and extending to the rearward portion of said soleplate; said opposite side passages being connected at said rearward portion to the remaining portion of said first duct means having said exit apertures.