Abstract:
A steam iron including a soleplate, a steam chamber having an upper surface portion with a water inlet opening, a water reservoir having a bottom surface portion with a water outlet opening and a valve assembly for directing controlled amounts of water from the reservoir into the steam chamber. The valve assembly including a valve port member having a body formed of a matrix of material with a bore and hollow bypass conduit. The upwardly-facing surface of the valving portion including an opening for the hollow bypass conduit. The hollow bypass conduit having a lower end open along an inside wall portion of the valving portion of the bore, a valve element extending into the bore, rotatable about an axis for controlling the flow of water through the valving portion. The valving portion including first and second barriers such that rotation of the valving element allows the user to allow or prevent water from flowing to the steam chamber.

Description:
FIELD OF THE INVENTION 
     This invention relates to a steam iron with a variable steam control assembly primarily intended for domestic use, although the invention is not necessarily so limited. 
     BACKGROUND OF THE INVENTION 
     Steam irons often are provided with mechanisms for changing the rates at which steam exits from steam outlet ports in the sole plates. There are occasions during which steam irons are used when no steam is desired and other occasions during which a specific rate of steam production is desired. The rate varies with the fabric being ironed and with the preferences of the person using a steam iron. 
     Steam is usually produced in steam irons by dispensing small quantities of water from a water reservoir through a restricted orifice into a steam chamber formed by the top surface of the sole plate and a cover plate which covers and is sealed to a portion of the sole plate. In a domestic iron, typical steam production rates are on the order of 1 to 15 grams of steam per minute. Since small quantities of water are used to produce steam within the typical range of flow rates, small differences in the size of the orifice can make substantial differences in the steam flow rates. A substantial number of cooperating parts is typically required to achieve reliable adjustments to the steam production rates in prior iron constructions. The cost of the steam production control mechanism adds significantly to the overall cost of a steam iron. 
     SUMMARY OF THE INVENTION 
     A primary object of the present invention is to provide a steam iron having a variable steam control which is inexpensive yet rugged and reliable. A steam iron in accordance with this invention comprises a sole plate, a steam chamber having an upper surface portion with a water inlet opening, a water reservoir having a bottom surface portion with a water outlet opening, and a valve assembly for directing controlled quantities of water from the reservoir into the steam chamber. The valve assembly includes a valve port member at the bottom of the water reservoir. The valve port member, which preferably comprises matrix of flexible, resilient material, such as silicon rubber, has a bore through which water from the reservoir is dispensed into the steam chamber. In addition, the valve port member has a hollow bypass conduit including an upper open end that opens to one side of the bore and a lower open end that opens along an inside wall of the bore. 
     The valve assembly further includes a valve element extending into the bore, and rotatable about the axis of the bore, that prevents water from flowing through the bore except for water that passes through the bypass conduit into the bore. The valve element includes a first barrier that can, by rotation of the valve element, confront and cover the open lower end of the bypass conduit to prevent water from exiting from the bypass conduit into the bore. To provide varying amounts of water passing through the bore, the valve element can be rotated to position a second, variable barrier in confronting relation to the lower end of the bypass conduit. The second barrier partly uncovers the open lower end of the bypass conduit to permit a controlled dispensing of water from the water reservoir into the steam chamber. The second barrier terminates in a third barrier which, when confronting the bypass conduit, substantially reduces the amount of water exiting from the water reservoir. A cavity is formed between the first and the third barrier which opens the bypass conduit to the extent that the steam chamber can be flooded for purging the valve assembly. 
     Other objects, advantages and features of this invention will become apparent from the following description and the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partly exploded, fragmentary, isometric view of a steam iron in accordance with this invention, with parts broken away to better illustrate other parts. 
     FIG. 2 is a fragmentary, longitudinal cross-sectional view of parts of the steam iron of FIG.  1  and particularly the steam control assembly of this invention. 
     FIG. 3 is an exploded, fragmentary, isometric view of the assembly of a steam control knob, a steam control shaft and a coil spring associated therewith. 
     FIG. 4 is an isometric view of a valve port member of the iron of FIG.  1 . 
     FIG. 5 is an exploded, fragmentary isometric view of the steam control shaft and the valve port, showing the valve port member in cross section. 
     FIG. 6 is a cross-sectional view taken along line  6 — 6  of FIG. 2, showing the steam control shaft rotated to one end position thereof. 
     FIG. 7 is a fragmentary elevational view, with parts in cross section, taken along line  7 — 7  of FIG. 2, showing the position of a valve element at the bottom of the steam control relative to the valve port member at the end position illustrated in FIG.  6 . 
     FIG. 8 is a fragmentary elevational taken along line  8 — 8  of FIG. 7 of the inside wall of a bore in the valve port member and showing, by phantom lines, the position of a valve element barrier relative to the valve port member at the end position illustrated in FIG.  6 . 
     FIG. 9 is a fragmentary cross-sectional view, taken on line  9 — 9  of FIG. 8, which also shows the position of the valve element barrier relative to the valve port member at the end position of the parts illustrated in FIG.  6 . 
     FIG. 10 is a cross-sectional view similar to FIG. 6 but showing the steam control shaft rotated to an intermediate position to permit a relatively small quantity of water to drain from the water reservoir through a bypass conduit into the steam chamber. 
     FIG. 11 is a fragmentary elevational view, with parts in cross section, similar to FIG. 7, showing the position of the valve element at the bottom of the steam control relative to the valve port member at the intermediate position of the parts illustrated in FIG.  10 . 
     FIG. 12 is a fragmentary elevational taken along line  12 — 12  of FIG. 11 of the inside wall of the bore in the valve port member and showing, by phantom lines, the position of a valve element barrier relative to the valve port member at the intermediate position illustrated in FIG.  10 . 
     FIG. 13 is a fragmentary cross-sectional view, taken on line  13 — 13  of FIG. 12, which also shows the position of the valve element barrier relative to the valve port member at the intermediate position of the parts illustrated in FIG.  10 . 
     FIG. 14 is a cross-sectional view similar to FIGS. 6 and 10 but showing the steam control shaft rotated to a second intermediate position to permit a larger quantity of water to drain from the water reservoir through the bypass conduit into the steam chamber. 
     FIG. 15 is a fragmentary elevational view, with parts in cross section, similar to FIGS. 7 and 11, showing the position of the valve element at the bottom of the steam control relative to the valve port member at the second intermediate position of the parts illustrated in FIG.  14 . 
     FIG. 16 is a fragmentary elevational taken along line  16 — 16  of FIG. 15 of the inside wall of the bore in the valve port member and showing, by phantom lines, the position of the valve element barrier relative to the valve port member at the second intermediate position illustrated in FIG.  14 . 
     FIG. 17 is a fragmentary cross-sectional view, taken on line  17 — 17  of FIG. 16, which also shows the position of the valve element barrier relative to the valve port member at the second intermediate position of the parts illustrated in FIG.  14 . 
     FIG. 18 is a cross-sectional view similar to FIGS. 6,  10  and  14 , but showing the steam control shaft rotated to a second end position thereof. 
     FIG. 19 is a fragmentary elevational view, with parts in cross section, similar to FIGS. 7,  11  and  15 , showing the position of the valve element at the bottom of the steam control relative to the valve port member at the second end position of the parts illustrated in FIG.  18 . 
     FIG. 20 is a fragmentary elevational taken along line  20 — 20  of FIG. 19 of the inside wall of the bore in the valve port member and showing, by phantom lines, the position of the valve element barrier relative to the valve port member at the second end position illustrated in FIG.  18 . 
     FIG. 21 is a fragmentary cross-sectional view, taken on line  21 — 21  of FIG. 20, which also shows the position of the valve element barrier relative to the valve port member at the second end position of the parts illustrated in FIG.  14 . 
     FIG. 22 is a greatly enlarged top plan view of the valve port member. 
     FIG. 23 is a cross-sectional view of the valve port member taken on line  23 — 23  of FIG.  22 . 
    
    
     DETAILED DESCRIPTION 
     Referring to FIGS. 1 and 2, this invention is directed to a steam iron, generally designated  30 , having a sole plate  32 , a steam chamber  34  formed by the top surface of the sole plate  32  and a top wall  36  sealed to the sole plate  32 . The steam chamber top wall  36  has a water inlet opening  38 . The iron  30  additionally includes a housing  40  formed by a base cover  42 , a handle  44  and a top cover  46  that can be snapped onto the handle  44 . Here it may be noted that, as used in this description and the claims that follow, relative terms such “upwardly” and “downwardly”, “vertical” and “horizontal” are with reference to a steam iron oriented such that its sole plate lies flat against a horizontal surface. 
     In the embodiment illustrated in the drawings, the base cover  42  and the handle  44  have mutually joined surfaces, such as at  48  in FIG. 1, sealed to one another to form a cold water reservoir  50 . As is well understood in the art, the sole plate  32  has a heater (not shown). Water from the water reservoir  50  drips onto the top of the heated sole plate  32  to form steam in the steam chamber  34 . The steam travels through labyrinths to steam exit openings (not shown) in the sole plate  32 . Here it should be noted that the details of construction of the cold water reservoir are mostly unimportant for the purposes of this invention. Many other constructions are possible. As one example, this invention could be used with a cold water reservoir (not shown) that is separate from and mounted between the base cover  42  and the handle  44 . 
     In FIG. 1, the iron  30  is shown also to include a water spray pump assembly  52 , a water inlet spout  54  that leads to the water reservoir  50 , and a thermostat adjusting knob  56 , the details of which may be conventional and are unimportant for purposes of this invention. 
     In accordance with this invention, a novel, inexpensive and reliable steam control valve assembly  60  shown assembled in FIG. 2 is provided for directing differing quantities of water from the water reservoir  50  to the steam chamber  34 . Referring to FIGS. 1,  2  and  3 , the valve assembly  60  includes a valve port member  62 , a steam control shaft  64 , a steam control knob  66 , and a compression spring  68 . A valve element  70  is located at the bottom of the control shaft  64  and integral therewith. The control shaft  64  is preferably molded from a heat resistant plastic material, such as polyester, of which many are commercially available. 
     With reference to FIGS. 2,  4 ,  22  and  23 , the valve port member  62  is made in one-piece from a matrix of flexible and resilient material, such as silicon rubber, and comprises a cylindrical body  72  having a central, downwardly extending, cylindrical projection  74  that extends through the steam chamber opening  38  into the steam chamber  34 . The body  72  has a through bore  76  with a larger diameter counterbore  78  that creates an upwardly facing shoulder  80  inside the valve body  72  which shoulder  80  surrounds the lower, smaller diameter end, designated  76 A, of the through bore  76 . The top of the valve body  72  is countersunk to form a beveled inside margin  82 . A narrow, ring-shaped band  84  encircles the valve body  72  and is connected to the valve body  72  by an annular web  86 . An upper annular groove  88  and a lower annular groove  90  separate the upper and lower margins, respectively, of the valve body  72  from the band  84 . A locating boss  92  projects forwardly from the upper part of the band  84  to enable the valve port member  62  to be oriented for reasons which will become apparent. 
     The lower, uniform and smaller diameter portion  76 A of the through bore  76  functions as a cylindrical valving portion which is centered on its longitudinal axis which is coincident with the axis of the steam chamber inlet opening  38 . The edge formed by the upper end of the valving portion  76 A and the shoulder  80  has a notch  94  effective to provide a hollow bypass conduit having an upper end  96  (FIG. 23) open to the shoulder  80  and a lower end  98  open along the inside wall of the valving portion  76 A. The employment of the notch  94  to provide the bypass conduit is preferred, but other constructions could be used, such as a conduit extending from the shoulder  80  to the inside wall of the valving portion  76 A spaced outwardly from the edge joining the shoulder  80  to the valving portion  76 A. 
     The valve port member  62  is held centered with respect to the steam chamber inlet opening  38  by a circular flange  100  that extends downwardly from the bottom of the base cover  42 . The forward portion of the flange has a gap which receives the locating boss  92  to so orient the valve port member  62  that the conduit notch  94  is aligned along the centerline of the iron. 
     During manufacture of the steam iron  30 , the valve port member  62  is compressed between the water reservoir  50  and the steam chamber  34 . The relatively narrow band  84  is squeezed to form a watertight seal surrounding the valve port body  72 . A funnel shaped opening  102  is formed in the base cover  42  in alignment with the steam chamber inlet  38 . The margins of the opening  102  enter into the counterbore  78 . As can be seen in FIG. 2, the entire valve port member  62  is securely clamped in a fixed position and forms a good, watertight seal between the water reservoir  50  and the steam chamber  34 . 
     With reference to FIGS. 2 and 3, the upper end of the steam control shaft  64  has four equally-spaced ribs  110  projecting outwardly from a central core around which the spring  68  is coiled. The knob  68  has a hollow stem  112  with sections interfitting with the ribs  110  such that the ribs  110  can only fit in one orientation on the control shaft  64  and so that rotation of the knob  68  in either direction will cause rotation of the control shaft  64 . The hollow stem  112  also houses the spring  68 , which biases the knob  68  upwardly so that an outer flange  114  at the bottom of the knob&#39;s outer skirt  116  is held against stops  118  provided on the bottom of the top cover  46 . The spring  68  also biases the control shaft  64  downwardly so that a lower stop member  120  on the control shaft  64  engages the top surface of the base cover  42  to ensure a proper vertical alignment between the valve element  70  and the valve port member  62 . 
     An o-ring  122  is mounted. in a groove in the control shaft  64  to provide a seal between the top wall of the water reservoir  50  and the control shaft  64 . The frictional engagement of the o-ring  122  with the water reservoir top wall, the lower stop  42  with the base cover  42  and the valve element  70  with the valve port member  62  ensures that the control shaft will remain in any manually selected position and provides a tactile feel to resist rotation of the control knob  68 . 
     With reference to FIGS. 5 through 9, the valve element  70  comprises a disk-like body  124  and a first barrier  126  extending downwardly from the body  124  that is adapted by its size and shape to be positioned by rotation of the control shaft  64  in confronting relation to the lower bypass opening  98 . When so positioned, the first barrier  126  closes the bypass lower end  98  to prevent liquid from exiting from the water reservoir  50  to the lower end of the through bore  76 . In this position of the control shaft  64 , an upper stop plate  128  carried by the control shaft  64  engages a first stop surface  130  of a stop member  132  molded integrally with the handle  44 . 
     The section of the disk-like body extending circumferentially, in a counterclockwise direction, as viewed in FIG. 5, forms a second barrier  134 , which only partly closes the open lower end  98  of the bypass notch  94 . The bottom surface of the second barrier  134  is formed to provide a circumferentially-extending peripheral ramp  136  which slopes upwardly in the counterclockwise direction, again as shown in FIG. 5, so that increasing amounts of water can be permitted to be dispensed from the water reservoir  50  into the steam chamber  34  as the control knob  68  is rotated in a clockwise direction, as viewed in FIG. 10, for example. FIGS. 10 through 13 diagrammatically reveal the opening of the lower end  98  of the notch  94  after the control shaft  64  has been rotated through 90 degrees from the first stop position. FIGS. 14 through 17 reveal the greater opening of the lower end  98  after 180 degrees of rotation of the control shaft  64  from the first stop position. With further rotation of the control shaft  64 , even greater amounts of water will be dispensed up to a maximum at the end of the peripheral ramp  136 , at which a third barrier  138 , which may be vertically coextensive with the first barrier  126 , substantially limits the flow of water through the lower window  98 . 
     With reference to FIGS. 18 through 21, the control shaft  64  may be rotated through an additional several degrees past the maximum water delivery position to position a cavity  140  between the first barrier  126  and the third barrier  138  into confronting relationship with the lower notch end  98 . At this point, the upper stop plate  128  engages a second stop surface  142  on the stop member  132 , as illustrated in FIG.  18 . This provides maximal exposure of the open lower end  98  of the notch  94 , and is used to flood the steam chamber  34  for cleaning out the lower end of the valve assembly, the steam chamber  34 , and the steam vent holes (not shown) in the sole plate  32 . 
     The top surface of the control knob  68  is provided with artwork  144 , which is preferable molded into the knob  68 , to indicate to the user the results that will be achieved at various rotary positions of the control knob  68 . 
     Although criteria may differ, the valve assembly of this invention can be constructed to produce steam from a lower limit of zero grams per minute to a maximum of about 13 grams per minute. A water flow rate of 20 grams per minute can be used to flood the steam chamber, with the control shaft  64  at the second stop position illustrated in FIGS. 18 through 21. 
     Although the presently preferred embodiment of this invention has been described, it will be understood that within the purview of the invention various changes may be made within the scope of the following claims.