US2655746A

US2655746A - Unitary steam and temperature control for steam irons

Info

Publication number: US2655746A
Application number: US222806A
Authority: US
Inventors: Donald L Mcfarland; Walter E Moore
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1951-04-25
Filing date: 1951-04-25
Publication date: 1953-10-20
Anticipated expiration: 1970-10-20
Also published as: GB694296A; FR1059983A

Description

Oct. 20, 1953 D. L. MOFARLAND ET AL 2,655,746

UNITARY STEAM AND TEMPERATURE CONTROL FOR STEAM IRONS Filed April 25, 1951 Inventors: Donald L.Mc Farland,

Walter" EMoore,

by Their Attorney.

Patented Oct. 20, 1953 UNITARY STEAM AN D- TEMPERATURE CONTRQ-L FOR IRONS Donal'dL. McFarlandand Walter E. Moore, Stratford, Conn, assi'gnors to General Electric Com.- pany, a corporation of New York Application April 25, 1951,. Seriat No..222',-8fl6 4 Claims. 1

This invention relates to pressing irons of the irons of this sort, the most practical way of con trolling the quality of the steam is to supply feed.

water to the steam generating chamber at a constant rate and then control the temperature. of the generating chamber. Since these chambers are customarily heated from the soleplate of the.

iron, the quality of the steam then. actually de pends on the soleplate temperature. This,. however, leads to difficulty in that steam. of the correct quality can be produced only in a limited range of soleplate temperatures, whereas the irons must supply a wide range of solep'late temperatures in. order to be used as dry fiatiro'ns'.

It is a. general. object of. this-invention, therefore, to provide-a new andimproved iron. so constructed that water can be: supplied to the steam generating chamber. in only a limited portion. of.

the soleplate temperature range; and in the fulfillment thereof, it is a more specific object of this invention to provide such an iron in which the steam generating means and the tempera-- tureregulating means areoperated from thes-ame unitary control member.

In accomplishment of the foregoing objectives, anew and improved steam iron. is constructed so that its. soleplate temperature is controlled by the angular position of a rotatable shaft and so that its steam generating means are controlled by a valve positioned between a liquid reservoir and a steam generating chamber; The operating means for the temperature control shaft-and the valve are combined in a single unitary operating lever which is pivotally mounted: on the rotatable shaft to have motion in two discrete planes. Arcuate movement of this lever in apl'ane transverse to the shaft axis causes rotation of the 2 shaft to operate the temperature control device, while pivoting of thelever in: a plane extending across the above transverse plane: actuatesv mechanical connections which open and close the.

valve. In order to: insure that steam is gen.- erated only at the correct.soleplatetemperature, acamsurface. is providedwhich allows pivotalmotion of the operating lever to the steamactuating positionat only one angular position of the-shaft.

The features of. this invention which are be.- lieved-to be novel are-set forth with particularity in the appended claims. The invention itself, however, both as. toorganization and mode of operation, together with further objects and advantagesthereof, may be best understood by reference to the following description to. be taken in conjunction with the accompanying. drawing. in which:

Fig. 1- is-a side elevationview of. a pressing. iron embodying. this invention, aportionof the iron. being shown in vertical section taken. along. its.

longitudinal axis; Fig. 2 isa sectional. view taken along the line 2-2 of Fig. 1; and Fig.3 is afragmentary sectional. view taken on the line 3-3 of Fig. 2.

Referring. to the drawing. thereinv is illustratedan. electrically heated steam. iron of. the type generally described. in the copending application-of Frank E. Finlayson, Serial No. 696,298, filed-September 1 1, 1946 (now Patent 2,557,732),- and. the application of Frank. E. Fi-n1ayson,. Serial No. 69,756, filed January 7,. 1949 (now Patent 2,587,,- 608 both of. which patents. are owned by the General Electric Company the assignee of the instant application. In such an iron the pressing surface is formed by the bottom of a soleplate. I-.- Embedded in the. solepl'ate is anelectrical heating element. w-hichpre-ferably is of the sheathedtype, and here comprises-a helical resistance conductor 2' mounted within. an outer metallic sheath. 3 and held in spaced relation to the sheath by an electrically insulating. heatconducting mass 45,. such: as highly compressed:

The temperature controlling mechanism and. the steam generating system of the iron are" mounted on soleplate I and are covered by a shell which is also mounted on the soleplate. The shell is attached to the soleplate by a pair of transversely spaced bolts 6 which are screwed into the tapped bosses 1 formed integrally with the soleplate, and it extends rearwardly from the soleplate to provide a heel rest member for the iron. Closing the space lying between the rear extremities of the soleplate and the shell is a plate 8 which is secured to the soleplate by means of screws 9 and extends outwardly therefrom to engage the inner surface of the shell.

Mounted on top of shell 5 is a handle I!) which is preferably formed of a heat insulating material such as a phenolic condensation product. In order that it may be somewhat thermally insulated from shell 5, the handle is supported in spaced relation to the shell, the front support being provided by a portion of the steam generating system, as will be more fully explained hereinafter, and the rear support being provided by a pair of upright bosses formed integrally with shell 5. The handle is secured in place by screws (not shown) which extend upwardly through bosses ll.

In effect, the handle includes three distinct portions, a hand grip portion l2, a front support portion I3 and a rear support portion Hi. The rear support portion is provided with a protuberance it? which together with the rear extremity of shell 5 forms a heel rest or support whereon the iron may be upended when not in use; and the front support portion is provided with a vertically extending recess IS in which is positioned a portion of the steam generating system.

Thus, extending into recess V6 through an aperture H in shell 5 is a reservoir member |6. Means for filling this reservoir is supplied by an open end tube l9 which extends through a recess 26 in handle portion I3, and an outlet for emptying the reservoir into a steam-producing chamber is supplied by an orifice member 2| which is threaded into a hole in the base of the reservoir. Beside being the water storage member for the steam-producing system, reservoir l8 also serves as the front support for handle l0 through its contact with tube Hi. The support for reservoir l8" itself is provided by aperture I! and orifice member 2|. In order to secure a watertight seal at the lower end of the reservoir, a bushing 22 is threaded to orifice member 2| below the reservoir and gasket material 23 is positioned to be compressed between the bushing and the reservoir.

Bushing 22, which actually supports orifice 2| and thus the front end of handle I0, is in turn mounted on a hood 24 and a cover plate 25 and is attached thereto by any suitable means. The lower extremity of orifice member 2|, however, extends through an aperture between the hood and the cover plate. Hood 26 and cover plate 25 are secured to soleplate by any suitable means such as screws 25 and together with a recess 21 formed in the upper surface of the soleplate define a steam-generating chamber 28. In order to prevent the escape of steam from the chamber, a gasket 29 is positioned between the soleplate and the edges of the hood and the cover plate.

Mounted below orifice member 2| is a trough 38 which carries any water flowing through the orifice 3| in member 2| over into recess 21. The recess is, of course, heated by the soleplate during operation of the iron, and if the soleplate is at the right temperature, any water. flowing into the recess will be immediately flashed into steam of the correct quality. From recess 27 a circuitous passage (not shown) conducts the steam to the steam discharge ports 32.

In accordance with this invention, the flow of water into the steam generating chamber 28 is controlled by a valve member or plunger 33 on whose lower end is mounted a needle 34. When plunger 33 is in its lower position, as viewed in Fig. 1, its lower end engages orifice member 2| and prevents any water flow from the reservoir into the steam chamber. However, when plunger 33 is moved upwardly to the position indicated by the dotted lines, its lower end is pulled clear of the orifice member 2| and a flow of water into the steam chamber may occur. Orifice 3|, of course, regulate the rate of water flow into the steam generating chamber to the correct value when the valve is'open. The needle or cleanout pin 34 is forced through the orifice 3| when the valve is closed and thereby cleans out any scale or deposit which may have formed in the orifice. A spring 35 disposed around plunger 33 and compressed between the upper surface of reservoir H3 and a flange es mounted on the plunger serves to bias the plunger downwardly and thereby keep the valve closed unless an external force is applied to the plunger.

In order to provide means for applying such a force, the upper end portion of plunger 33 is extended out of reservoir l3 through an aperture 3? provided in the reservoir roof, and an L-shaped member 38 is secured to the portion of the plunger lying outside the reservoir. Member 38 is mounted so that its base portion 38a, to which plunger 33 is attached, extends transversely to the plunger while its shaft portion 381) extends downwardly toward shell 5. to engage the end of shaft portion 38b is an operating lever 39 which is pivotally mounted by a pin an on a rotatable shaft 4|. Lever 39 is biased by spring means 42 so that ordinarily it does not engage member 38. However, upon a sufficient force being applied to the knob 43, which is mounted on the end of the lever opposite from member 38, the lever is pivoted against the spring bias to move shaft portion 33b upwardly and thereby open the needle valve.

Besides being the actuating member for the steam system, lever 39 also serves as the operatmay be produced at only one soleplate temperature, a cover plate 34 is positioned beneath the path of arcuate motion of shaft '33 so as..to form a cam surface preventingdownward movement of the knob, i. e., pivotal movement of lever 39, except at one angular position of shaft s Thus, knob 53 may be depressed sufiiciently to operate the needle valve only when it is over the recess it provided in cover plate. ea. 7

One wall iEia of recess as is sloped inwardly,

while an aperture 45 is cut in the opposite wall. Wall 45a and aperture 6 cooperate with a shoulder formed on the side of knob 43 to supply means to automatically latch the knob down in the steaming position. As knob i3 is depressed, it slides down and arcuately along sloped wall so that when the knob reaches the bot- Positioned tom of the recess, shoulder W has moved under the upper lip of aperture 46-. Then, as the knob is released, shoulder 4!- catches upon the upper lipof aperture and holds theknob' in the steamingposition. Thus, thelatch-down is automatic, the operator needing only to depress the knobto lock the knob in the steaming position.

The temperature regulating device controlled by the angular position of shaft it may be any of those well-known to the art; since it does not constitute part of this invention. A preferred device, however, is illustrated in the diagram, and is fully disclosed and claimed in the copending application of Frank E. Finiayson' for Thermostatic Switch for Automatic Flatirons', Serial No. 165,216, filed May 31', 1 956; Patent 2,602g8'73, issued July 8, 1952, and assigned to the same assignee as the present invention. In the diagram, shaft 4| is rotatably supported by a recess 4-8 in handle It and by a support member 49 which is secured to the top surfaceof sol'eplate I by a pair of screws 50-. Member 69 also serves as the bearing for a rotatable cam plate 51, and for that purpose is provided with a plurality of upright bosses (not shown) which engage the under surface of the cam plate.

Cam plate 5| is held on member 4.9 by means of a spring 52 which is formed integrally with the cam plate. Spring 52' extends outwardly from one edge of the cam plate, and, thence, is folded underneath member 49. In the end of spring 52 extending under member 49 is positioned an aperture which fits onto an extrusion 53 formed on member 49-. The action of spring 52- thus holds cam plate 51' against the upright bosses formed on the top surface of member 49 but permits the cam plate to be rotated by shaft 4| to which it is attached for that purpose.

Mounted on top of cam plate 51' is a cam member 54 having a cam surface 55- on its outer periphery,

and disposed to cooperate with this cam surface is Lever 56 is pivotally mounted by a lever 56. means of a pair of down-turned ears 51 on a shaft 58, the shaft itself being supported by the side walls 59 of a U-shaped base plate 60. The aforementioned support member 49 is actually a part of base plate 50, so that screws 50-also serve as'the means for securing. base plate 60 to sole-plate I. It is the bight of base plate 50- through which screws 50 are disposed, the legs of the base plate extending rearwardly therefrom and side.

portion fixed to the transverse section 64 that joins together the rear ends of upright Walls 59' of the base plate. The switch arm is, however, insulated from the plate by some. insulating material, such as sheet mica. Mounted on the free end of switch arm 63 is a contact and disposed. to cooperate with contact 65 is a second contact. 66 mounted on an electrically conducting spring. switch arm 67. Switch arm 61. is secured to the other side of section 64 from switch arm 63 and is insulated from the section by a sheet of mica or other insulation.

Spring switch arm 63 is biased to move contact 65 upwardly while spring switch arm- 61' is biased to move contact 66 downwardly. The bias of arm 63 is, however, greater than that of arm 6T sothat thepositien of stop '6? determines the'position of bothsw-itch arms by limiting the movement of arm 63% As is disclosed in" the aforementioned Fi-nla-yson Patent 2,602;8-7:3, the cooperating contacts 65 and B6 are connected in' series withresistance conductor 2 and the power supply terminals of the iron so that heating" of the iron is controlled by the opem ng' and clos ihg of the contacts. Thus, for example, switch arm 63 and one terminal 68 of conductor 2 are connected together while switcharm 61 and the other terminal of conductor 2 (not shown) are connected to oppositesupply terminals.

The opening of the contacts is accomplished by ahimetall'ic temperature-responsive bar 69- formed of two metals having dissimilar temperature' coiri'cients of expansion rig-idly secured to gether' lengthwise in any suitable way, as welding. Preferably; and as shown, the bar will be formed of two reversed sections in order to minimize temperature overshoot in thefashion described and claimed in the U. S. patent to R. A. Winborne, No; 2,128,869 dated August 3-0, 193-8. The one end of bimetallic bar 69 is firmly secured between base plate 60' and a heat-conducting clamping block 10-, being joined toboth of these members by a rivet H and to the base platealone by a rivet 1-2; This assembly allows the thermostat to be calibrated as a unit outside theiron and then later'be assembled within the iron by screws 50. The remainderof bar 69" extends rearwardly over a cavity 13' formed in solep'late I and has an upright switch actuator 14 mounted on its end. Actuator 14' is formed of a refractory electrically insulating material and comprises a tube which is closed at its upper end. This actuator is mounted on bar 69 by means of a right angle bracket 15 to which it is secured by a suitable cement and which, in turn, is secured to the bar by welding or some other suitable means. Bar 59 is so constructed that its free end carrying actuator 14 moves upwardly upon the heating of soleplate I and moves downwardly as the soleplate cools.

The actuatoris' spaced below spring switch arm 6.! and engages the arm as it moves upwardly in response to the heating of soleplate I by current flowing in' conductor- 2. The continuing movement of the actuator then moves the arm upwardly against its downward bias and thereby opens contacts 65- and 66. The opening of the contacts" breaks the circuit to conductor 2- and allows the soleplate' to cool, causing actuator 14 to move downwardly. When the actuator has moved a sufficient distance, it allows switch arm 6.1" to reclose the contacts and re-energizethe heating" circuit. This, of course, makes the solepl'ate heat up once again and causes actuator 14: tomoveupwardly until the contacts are opened. Thus, the action of actuator 14 as mounted on thermostatic bar 69 causes the. soleplate temperature to cycle around. a mean value.

This mean. value of sol-eplate temperature is controlled. by means; of shat-t 4 l-. rotated by lever 39;. earn surface 55- causes lever 56 to pivot on shaft 58 moving stop 62 either upwardly or downwardly. Since stop 62 engages switch arm 63, a downward movement of stop 62 force's switch arm 63 and thus contact 65 to also move downwardly, while an upward. movement-of the stop-allows the switch arm 6-3 also to move upwardly, due to its spring bias. This spring. bias, as previously mentioned, is greater" than the downward bias of switch arm 61. and.v therefore forceslswitcharm 61 to also move up As shaft 4| 7. wardly with arm 63. Moreover, as stop 62 moves switch arm 63 downwardly, switch arm 61 also moves downwardly due to its own bias and keeps the contacts closed, except when it is engaged by actuator 14.

The vertical spacing between switch arm 61 and actuator 14, when the iron is cold, is thus dependent upon the position of stop 62 and thereby is dependent on the angular position of shaft 4!. The position of shaft 4! is, of course, controlled by the arcuate position of operating lever as so that actually the spacing between switch arm 5? and actuator H3 is regulated by lever 39. It is this spacing that determines at what temperature the iron is to operate, for the greater is the spacing, the greater is the soleplate temperature required for thermostatic bar 69 to move actuator 14 suficiently that it may engage switch arm 6'! to open the contacts.

In order to provide means for opening the heating circuit at the discretion of the operator, the device is so constructed that stop 62 at its point of maximum downward excursion moves contact 65 downwardly beyond the lowest point to which the downward bias of switch arm 61 carries contact as, i. e., the contacts do not touch at one extreme arcuate position of lever 39. As is indicated in Fig. 2, the heating circuit of the iron may be ole-energized byrmoving lever 35] to its extreme left-hand arcuate position, while various soleplate temperatures ranging consecutively from the lowest to the highest may be obtained by moving the lever from that point to its extreme right-hand arcuate position. The terms left-hand and right-hand refer to the lever as viewed from the pointed end or" the iron. For the convenience of the housewife, the various arcuate positions of the lever are marked with the respective fabrics for which the temperatures produced thereat are the most suitable. Similarly, the lever setting for steam is plainly marked. Of course, even though the operator might disregard the steam marking, she still could not apply steam except at the correct temperature, due to the cam surface provided by the cover plate.

As previously mentioned, this invention is not limited to the particular temperature control device described above, since the new and improved unitary temperature and steam control can be used with any thermostatic device whose setting is controllable by the angular position of a rotatable member. Moreover, various details of the steam generating system could be changed and still permit its actuation by a control formed according to this invention. Thus, while there has been described what at present is considered to be the preferred embodiment of this invention, it will be obvious to those skilled in'the art that numerous modifications and alterations may be made therein without departing from the invention, and it is, therefore, intended in the appended claims to cover all such modifications and alterations as fall within the true spirit and scope of this invention.

What we claim as new and desire tosecure by Letters Patent of the United States is:

1'. In an iron, a water reservoir, a steam gen-' erator, a valve providing liquid flow control from said reservoir to said generator, electrical means for heating said reservoir, a rotatable control member for regulating the heatingfrom said: electrical means upon'rotation of said member, a lever pivotally mounted on said control mem-' ber transversely of said member to pivot inna' plane including the axis of rotation of said memher and adapted to turn said member by arcuate movement thereabout and therewith in a plane transverse to said axis, a cam surface positioned under the path of said arcuate movement, said surface limiting pivotal movement of said lever to a predetermined angular position of said rotatable member, and mechanical connections for operating said valve in response to pivotal movement of said lever.

2. In an iron, a water reservoir, a steam generating chamber, a valve providing liquid flow control between said reservoir and said chamber, an electrical circuit for heating said chamber, a rotatable member for controlling the current in said heating circuit, a lever pivotally mounted on said member to have limited pivotal motion in a plane including the axis of rotation of said member and adapted to turn said member by arcuate movement in a plane substantially at right angles to said axis, a plate disposed under the path of said arcuate movement and having a recess adapted to receive said lever extending through a limited portion of said arcuate path, said plate limiting pivotal movement of said lever to said limited portion, and a mechanical connection between said lever and said valve to operate said valve upon pivotal movement of said lever.

3. In an iron, a water reservoir, a steam generating chamber, a valve providing liquid flow control between said reservoir and said chamber, an electrical circuit for heating said chamber, a rotatable member for controlling the current in said heating circuit, a lever pivotally mounted on said member to be pivotally movable between a pair of positions in a plane including the axis of rotation of said member and adapted to turn said member by arcuate movement in a plane substantially at right angles to said axis, a spring biasing said lever to one of said pivotal positions, a mechanical connection between said lever and said valve tooperate said valve upon pivotal movement of said lever to the other of said pivotal positions, a knob mounted on said lever and provided with a shoulder, a plate disposed under the path of said arcuate movement and limiting movement or said lever to said other pivotal position to a limited portion of said arcuate path, said plate having a recess in said limited portion for receiving said lever and said knob, one wall of said recess being sloped inwardly and the wall opposite to said one wall being provided with an aperture, said knob moving along said sloped wall upon pivotal movement of said lever to cause said shoulder to move into said aperture to latch said lever in said other pivotal position.

4. In an iron, a water reservoir, a steam generating chamber, a valve between said reservoir.

and said chamber having a closed position and having an open position to permit water to flow into said chamber, an electrical circuit for heating said chamber, a rotatable member for controlling the current in said chamber, a lever pivotally 'mounted on said member to be pivotally movable between a pair of positions in a first plane and adapted to turn said member by arcuate movelever to the other. of said pivotal positions, aknob mounted on said leverand provided with a shoulder, a plate disposed under the path of said arcuate movement and limiting movement of said lever to said other pivotal position to a limited portion of said arcuate path, said plate having a recess in said limited portion for receiving said lever and said knob, one wall of said recess being sloped inwardly and the wall opposite to said one wall being provided with an aperture, said knob moving along said sloped wall upon pivotal movement of said lever to cause said shoulder to move into said aperture to latch said valve in said other pivotal position whereby said valve is held in said open position.

DONALD L. MCFARLAND.

WALTER E. MOORE.

References Cited in the file of this patent UNITED STATES PATENTS Number