Patent Publication Number: US-6212332-B1

Title: Steam iron station

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to steam irons, and in particular, to stations that cooperate with steam irons. 
     2. Description of Related Art 
     A conventional steam iron has an internal reservoir that feeds water to a steam chamber in an electrically heated soleplate, in order to produce steam from the iron. Typically, water dripped or sprayed into the steam chamber then passes through a channel in the soleplate in order to complete the vaporization and/or to heat the resulting steam. Conventional irons have limits on their steam producing capacity based on the size of the soleplate, which limits the length of the channel from the steam chamber. 
     Also conventional irons rely on gravity to feed water from the reservoir when the iron is horizontal. Such irons cannot apply steam when the iron is upright or vertical. Such a capability is important when the user wants to apply steam to a hanging garment to coax out wrinkles or to prepare a garment for ironing. 
     Another disadvantage with these arrangements is the weight added to the iron by the water reservoir. Moreover, since the reservoir cannot be too large, it must be periodically refilled. Such refilling can be a great inconvenience for long ironing sessions. 
     Another difficulty with conventional irons is the tendency of mineral deposits to clog various passages in the iron that normally conduct water or steam. 
     In U.S. Pat. No. 4,535,556 water from an external reservoir is pressurized by a pump so that a valve can spray water into a steam chamber. In the embodiment of FIG. 3 a pump keeps up pressure to a valve, but the pump and the entire reservoir assembly would need to be carried to a faucet in order to fill the reservoir. In the embodiment of FIG. 1, a pump is switched on and off by a control at the iron, but the pump is a unit separate from the reservoir and the iron, with separate hoses running to each. 
     In U.S. Pat. No. 3,130,507 an iron has an internal water container. Water can be supplied either from this container or from a hose fed from a faucet (the hose can also fill the water container). Cloth can be dampened by depressing a button to open a valve that allows water into a steam generating chamber, so that a spray is emitted from openings 25 and 23. Another valve can be manually adjusted to allow water into a steam generating chamber in order to supply steam to outlets 35. This unit has neither a pump nor an external reservoir and therefore lacks the ability to operate at a distance from a faucet. Also, its internal reservoir will make the iron relatively heavy. 
     In U.S. Pat. No. 5,315,773 an ironing head can be placed in a rest assembly that includes couplings that supply water and electrical power to the ironing head. This rest assembly is part of a larger structure that includes a water tank and an ironing table. A pump in the rest assembly supplies water if a water reservoir inside the ironing head is low. The internal reservoir in the ironing head adds substantially to its weight. Also, no power line or hose is connected to the ironing head. Instead the ironing head must be periodically returned to the rest assembly in order to receive additional water and electrical power. 
     U.S. Pat. No. 5,414,945 shows a base for receiving an iron and a water cassette. The water cassette does not have plumbing to fill the iron when mounted on the base. 
     In U.S. Pat. No. 5,428,910 an iron is supplied with water from an external reservoir having a pump that is controlled by a control at the iron. Water from the external reservoir is supplied through a valve to a steam chamber. Water from an internal reservoir is supplied through another valve. 
     In U.S. Pat. No. 3,599,357 water is either dripped into one chamber for low velocity steam, or pumped into another chamber for high velocity steam. The steam so generated follows a tortuous backward path in a soleplate, and then a distribution path in the soleplate cover to feed steam holes. 
     See also U.S. Pat. Nos. 4,197,664; 4,870,763; 4,920,668; and 5,170,577, as well as design Pat. Nos. D374,322 and D380,068. 
     SUMMARY OF THE INVENTION 
     In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a steam iron station having a removable tank mounted in a case. Also included is a conduit adapted to be coupled to the steam iron. The steam iron station also has a pump mounted in the case and coupled to the tank and the conduit for discharging to the conduit, liquid drawn from the tank. 
     According to another aspect of the invention, a steam iron station includes a case having a tank with an outlet. Also included is a removable filter having an intake. The filter is mounted at the case to communicate with the tank. The steam iron station also has a conduit adapted to be coupled to the steam iron. Also included is a pump mounted in the case and coupled to the filter and the conduit for discharging to the conduit, liquid drawn through the filter from the tank. 
     According to still another aspect of the invention, a steam iron includes an electrical heater mounted in a soleplate. The soleplate has an upper channel and a lower channel. The upper and the lower channels each have a forward flowing and a backward flowing branch. The upper channel serially communicates with the lower channel. The iron also has a duct for delivering liquid to the upper channel. 
     By employing apparatus of the foregoing type, an improved steam iron and steam iron station is achieved. In a preferred embodiment, a steam iron station has a case with a heat resistant upper deck acting as a rest for a steam iron. A removable tank can be attached to the case with a pair of latches. Being removable, the tank can be carried to a tap, where a preferred filling cap can be removed to allow filling of the tank. 
     Preferably, a removable filter is mounted in the tank of the case to eliminate minerals dissolved in the water in the tank. The filter can have an intake that connects to a preferred valve located adjacent a cavity designed to hold the filter. This valve can close when the filter is removed in order to stop water from flooding the vacated filter cavity. 
     An outlet from the filter preferably feeds a pump that is mounted inside the case of the steam iron station. The preferred pump has a solenoid-operated piston controlled by a pump controller inside the case. In one embodiment, the pump controller had a capacitive timing circuit that drove a D-type flip flop to operate a thyristor-controlled pump. 
     In a preferred embodiment, the pump can supply water to a steam iron in either a continuous or enhanced (super steam) mode. In both modes, the pump reciprocates during an active interval, and stops reciprocating during a subsequent, quiescent interval. In the preferred embodiment, the quiescent interval is shortened to increase the pumping volume during the enhanced mode. 
     In either event, the pump enables steam generation, even if the steam iron is held upright, as when coaxing wrinkles from a hanging garment. Unlike steam irons relying on gravity to supply water from a reservoir, the pump provides a positive, reliable supply. 
     The preferred steam iron has a soleplate with a lower channel on its underside and an upper channel on its top side. The lower and the upper channels each have a backward flowing branch and a forward flowing branch. The forming of channels on opposite sides of the soleplate increases the length of the path available for vaporizing water and heating steam. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred but nonetheless illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein: 
     FIG. 1 is a perspective view of a steam iron resting atop a steam iron station, in accordance with principles of the present invention; 
     FIG. 2 is a top view of the steam iron station of FIG. 1; 
     FIG. 3 is a cross-sectional view of the steam iron station, taken along line  3 — 3  of FIG. 2; 
     FIG. 4 is a bottom view of the tank of FIG. 1, removed from the station; 
     FIG. 5 is a cross-sectional view of the filter of FIG. 3; 
     FIG. 6 is a cross-sectional view of the filter taken along line  6 — 6  of FIG. 5; 
     FIG. 7 is a cross-sectional, plan view of the steam iron station of FIG. 2; 
     FIG. 8 is a cross-sectional, elevational view taken along line  8 — 8  of FIG. 7; 
     FIG. 9 is a schematic diagram of the pump controller shown in FIG. 7; 
     FIGS. 10A and 10B are timing diagrams associated with the pump controller of FIG. 9; 
     FIG. 11 is a side view, partly in section, of the steam iron of FIG. 1; 
     FIG. 12 is an exploded view of the soleplate and its associated hardware in the steam iron of FIG. 11; 
     FIG. 13 is a top view of the soleplate of FIG. 12; and 
     FIG. 14 is a bottom view of the soleplate of FIG.  13 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1 and 2, steam iron  10  is shown resting atop a heat resistant upper deck  12  of a steam iron station. Upper deck  12  comprises a platform  14  with heat resistant ribs  16 . The steam iron station includes a case  18  that is preferably made of molded plastic, but in other embodiments, can be made of sheet metal or other materials. 
     One end of case  18  has a recess designed to receive removable tank  20 . Tank  20  can be secured in place by a pair of toggle latches  22 , acting as a latch means. Latches  22  are pivotally mounted on case  18  and each have a catch  24  for engaging lugs  26  on tank  20 . Tank  20  may be a plastic, molded container with an opening stopped by a removable filling cap  28 . Mounted in a cavity in tank  20  is a removable filter  30 . 
     Referring to FIGS. 3-6, filter  30  is shown mounted inside cavity  32  of tank  20 . Filter  30  comprises a cartridge  34  covered by a lid  36 . Cartridge  34  is divided into two compartments  40  and  42 , separated by a baffle or weir  38  to form an upstream path and downstream path, respectively. The compartments  40  and  42  are filled with an appropriate filter material for eliminating dissolved minerals. The filter material  40  is a salt or other substance chosen to remove minerals such as calcium in order to soften the water. Preferably, the filter  30  brings the concentration of calcium carbonate CaCO 3  to less than 50 mg/L. Compartment  40  is shown supplied by an intake  46 , while compartment  42  is drained by an outlet  48 . The opposite ends of compartments  40  and  42  are packed with a foam material  44  to prevent migration of the filter material out of the respective compartments. 
     A vertical chute  50  molded in the underside of tank  20  has a side hole  52  (FIG. 8) communicating with the interior of the tank. Mounted inside chute  50  is a valve means comprising a cylinder  54  and piston  56 . Cylinder  54  has a hole matching previously mentioned hole  52  (FIG.  8 ). Compression spring  58  is mounted between piston  56  and the floor of cylinder  54  to urge piston  56  upwardly. Intake  46  of filter  38  is designed to normally depress piston  56  to open the valve means and allow water from inside tank  20  to flow through filter  30 . A plug  60  is shown pressed into the underside of tank  20  to hold cylinder  54  in place. 
     Referring to FIGS. 4,  7  and  8 , the outlet  48  of filter  30  is shown fitting into an opening in tunnel  62 . Tunnel  62  is a concavely molded depression in the underside of tank  20 , which is closed by a bottom plate  64 . 
     Tank outlet  66  is shown connecting to a female end of fitting  68 , which is screwed in place to bosses on the inside of case  18 . The male end of fitting  68  connects through hose  70  to pump  72 . Pump  72  has an axially reciprocating piston  74  mounted within a pump cavity  73 . A check valve  78  is mounted at the outlet of pump cavity  73 . A solenoid coil  76  mounted around pump cavity  73  can receive pulses of current in order to pull piston  76  towards check valve  78  and perform pumping in a known manner. 
     The outlet of pump  72  is shown connecting through pipe  80  to a conduit  82 , which can be bundled with electrical wires  84  that connect to the previously mentioned steam iron. 
     A pump controller  86  is shown connected to pump  72  for controlling it in a manner to be described presently. Controller  86  receives power from cable  88  for distribution to pump  72 , as well as the steam iron through cable  84 . Power cable  88  can be stored inside case  18  by opening door  90  and stuffing cable  88  inside the externally accessible compartment  92  inside the case. 
     Referring to FIG. 9, the circuitry of the previously mentioned pump controller  86  is shown connecting to pump  72 . Alternating current is supplied to controller  86  through live line  94  and neutral line  96 , which lines are shunted by station pilot light LP 1  and serial resistor R 11 . 
     Serially connected across lines  94 ,  96  are variable thermostat TH 1 , fuse F 1 , and heater H 1 , which are all located in the previously mentioned steam iron. Also located in the steam iron is the serial combination of pilot light LP 2  and resistor R 12 , which is connected in parallel with heater H 1 . 
     A regulated 12 volts is produced by the parallel combination of filter capacitor C 1  and Zener diode D 6 , which receives positive current pulses from the cathode of rectifier D 1 , whose anode connects through resistor R 1  to high line  94 . This 12 volts is supplied through collector resistor R 3  to common emitter transistor Q 2 , whose base connects to the cathode of diode D 2 , whose anode is grounded. The positive switching pulses applied to the base of transistor Q 2  are supplied through resistor R 2 , which connects between the anode of diode D 1  and the cathode of diode D 2 . 
     Switch SW 1 , located in the previously mentioned steam iron, is shown in its enhanced steam (super steam) position. This is a momentary contact position and the user must keep his or her thumb pressed against the switch SW 1  to maintain this enhanced steam mode. The switch SW 1  connects to the output {overscore (Q)} of D-type flip flop U 1 A. Output {overscore (Q)} is initially high because the input D of flip U 1 A remains initially low by virtue of being connected to initially discharged, shunting capacitor C 3 . With the wiper of switch SW 1  pressed to the  1   a  position, current from output {overscore (Q)} flows through switch SW 1 , variable resistor VR 3 , and resistors R 10  and R 9  to charge capacitor C 3  in about 250 milliseconds, in order to convert the D input of flip flop U 1 A. Accordingly, the next trigger applied by transistor Q 2  to the clock input CLK will set flip flop U 1 A. The collector of transistor Q 2  regularly produces such triggering pulses in synchronism with power line  94 , which connects through resistors R 1  and R 3  to the base of transistor Q 2 . 
     With flip flop U 1 A set, output {overscore (Q)} is low and can discharge capacitor C 3  through resistor R 9  in about 10 milliseconds. This discharge path is accomplished by diode D 4 , whose cathode connects to output {overscore (Q)}, and whose anode connects through resistor R 9  to capacitor C 3 . 
     Before capacitor C 3  discharges and while flip flop U 1 A is still set, output Q is high to supply a positive signal through resistor R 7  to the gate of SCR (Silicon Controlled Rectifier) Q 1 , whose cathode is grounded. Pump  72  is connected between power line  94  and the anode of rectifier D 6 , whose cathode connects to the anode of SCR Q 1 . While the gate of SCR Q 1  is high, positive half cycles of current can flow through pump  72  and through rectifier D 6  and SCR Q 1 . This energizes the previously mentioned solenoid coil  76  (FIG. 7) to reciprocate piston  74  at the same frequency as the power line. 
     Eventually however, capacitor C 3  is discharged to apply a low signal to the D input of flip flop U 1 A. Accordingly, flip flop U 1 A will be reset by the next trigger applied to input CLK. Consequently, output Q of flip flop U 1 A will apply a low signal to the gate of SCR Q 1  to stop current flowing through pump  72 . The cycle can repeat by recharging capacitor C 3  as before. If however, the wiper of switch SW 1  is now moved to the opposite contact,  1   b,  charging current flows through variable resistors VR 1  and VR 2  and resistors R 10  and R 92  to charge capacitor C 3 . Variable resistors VR 1  and VR 2  have a much higher resistance value and can be adjusted to increase the charging time of capacitor C 3  by zero to six minutes. 
     Referring to FIG. 10A, this longer charging interval is indicated as interval T 1 . During the enhanced (super steam) mode the charging interval is the shorter interval T 2  as shown in FIG.  10 B. In either mode, the shorter discharging interval is indicated as interval T. Interval T is shown with the duration sufficient to produce three current pulses in synchronism with the power line, although a different number of pulses over a different duration may be employed in alternate embodiments. Similarly, the charging intervals T 1  and T 2  may be made longer or shorter depending upon the specific application. 
     If the wiper of switch SW 1  is placed in the middle (unconnected) position, capacitor C 3  is never recharged. Therefore, the D input of flip flop U 1 A remains low and this flip flop remains reset. Consequently, SCR Q 1  remains switched off and pump  72  remains inactive. 
     Referring to FIGS.  1  and  11 - 14 , mounted at the top edge of the steam iron  10  are the previously mentioned pilot light LP 2 , and two manual controls, namely, the previously mentioned steam selector switch SW 1 , and the variable resistor VR 1  for adjusting the continuous steam setting. A knob  98  is mounted inside the hand hole of iron  10  for adjusting the previously mentioned thermostat (variable thermostat TH 1  of FIG.  9 ). An external power cord  100  is shown routed through sleeve  102  to the interior of steam iron  10 . Also, an external hose  104  is also routed through sleeve  102  to connect to an internal duct  106 . Duct  106  and hose  104  communicate with the outlet of previously mentioned pump  72  (FIG.  7 ). 
     A soleplate  108  is shown with a surrounding wall  110  integral with a plate  112  having a bevelled outer edge. Previously mentioned electrical heater H 1  is shown embedded in soleplate  108  and leading to connection standards  132 . Soleplate  108  also has a steam producing chamber  114 . Soleplate  108  is covered by a top plate  116  having an inlet hole  120  adapted with a fitting  122 , which is coupled to duct  106 . The underside of soleplate  108  is fitted with a bottom plate  124  having a number of steam holes  126 . Soleplate  108  and bottom plate  124  are covered with a metal shroud  128  to provide a continuous ironing surface interrupted by steam holes  130 . 
     Referring to FIG. 13, water dripping into chamber  114  will go around the diverting wall  132  to flow along the backward flowing branch  134 , which is part of an upper channel. Backward flowing branch  134  communicates with a forward flowing branch  136 , which is also part of the upper channel. Forward flowing branch  136  leads to a transfer hole  137  that communicates to a lower channel on the underside of soleplate  108 . 
     The surface at the steam generating chamber  114  has a grid of raised ridges  115 . A similar grid of raised ridges  117  is formed in backward flowing branch  134 . These cross-textural surfaces increase the overall surface area to enhance the steam generating capacity of the chamber. Also, area  115  is covered with a steam generation paint chosen to enhance vaporization. Paint of this type can be obtained from Weilburger (Far East) Ltd. as Hydrotherm Paint 1210. This paint has a combination of fillers and binders to ensure an even formation of steam, while preventing drop formation at the soleplate. 
     Referring to FIG. 14, the lower channel includes a backward flowing branch  138  communicating with a forward flowing branch  140 . Branch  140  terminates in nine stubs  142  that communicate with steam holes (steam holes  126  in bottom plate  124  of FIG.  12 ). 
     To facilitate an understanding of the principles associated with the foregoing apparatus, its operation will be briefly described. Tank  20  can be filled by pulling latches  22  to release catches  24 . Tank  20  is then removed from the recess of case  18 . Next, cap  28  can be removed and the tank  20  can be filled at a water tap, or in some other fashion. When the tank is filled, water does not spontaneously spill from outlet  66 . To flow through outlet  66  under the force of gravity, water must be overfilled to spill over weir  38  (FIG.  8 ). Thus if the tank  20  is not overfilled, water will not spill through outlet  66 . Once filled, cap  28  is replaced on tank  20 , and the tank is installed again in case  18 , using latches  22  to secure the tank. 
     If filter  30  must be replaced or inspected, it is pulled out of filter cavity  32 , which causes spring  58  to drive piston  56  upwardly and close the valve means. Accordingly filter cavity  32  will not be flooded when filter  30  is removed. When the same or a replacement filter is reinstalled, its intake  46  depresses piston  56  to reopen the valve means. 
     Power cord  88  (FIG. 7) can be removed from chamber  92  by opening door  90 . Cord  88  can then be plugged into a power outlet (not shown). This immediately conveys power through cord  84 , which connects through cable  100  (FIG. 11) to the heater H 1  (FIG. 13) of the steam iron. The temperature of the steam iron  10  can be adjusted by turning knob  98  (FIG. 1) to adjust the variable thermostat TH 1  (FIG.  9 ). 
     If switch SW 1  is slid into the position for continuous steam, pump  72  is activated so that piston  74  (FIG. 7) reciprocates during interval T (FIG.  10 A), followed by inactive interval T 1 , whose duration can be adjusted by variable resistor VR 1  (FIGS.  1  and  9 ). Consequently, pump  72  draws water from tank  20  through filter  30 , through its upstream compartment  40  and downstream compartment  42 . Water drawn through filter  30  flows through passage  62  and hose  70  to the outlet side of check valve  78 . Water under pressure then flows through pipe  80  and conduit  82  into hose  104  (FIG. 11) of steam iron  10 . Water then flows through conduit  106  into steam generating chamber  114 . 
     The steam enhancing surface  115  (FIG. 13) is heated by electrical heater H 1  to quickly generate steam. Steam and any residual water leaving chamber  114  flow through backward paths  134  where the special surfaces  117  further enhance steam generation. Steam then flows along forward paths  136 , eventually passing through transfer hole  137  to the underside of soleplate  108  (FIG.  14 ). Steam passing through the hole  137  flows through backward paths  138  and forward paths  140  before reaching stubs  142  and exiting through holes  126  and  130  of elements  124  and  128 , respectively. 
     In some instances, it may be desirable to hold steam iron  10  in an upright or vertical position next to a garment that may be suspended on a hanger. The pump  72  together with the backward and forward paths  134 ,  136 ,  138 , and  140  ensure a strong continuous flow of steam, even when the steam iron  10  is held upright. In fact, in this upright position, the operator may choose to generate an enhanced steam flow by pushing switch SW 1  into the momentary, “super steam” position, which decreases the inactive pump interval (T 2 ) thereby generating additional steam. This additional steam flow can also be initiated when the steam iron  10  is oriented horizontally while pressed on a garment. 
     Alternatively, switch SW 1  can be placed at its neutral position to inactivate pump  72  and stop all steam generation. This latter position may be useful when the operator is no longer ironing and rests steam iron  10  on platform  12 . 
     It is appreciated that various modifications may be implemented with respect to the above described, preferred embodiments. The size and shape of the water tank and the case of the steam station can be altered, depending upon the desired capacity, strength, size, or for aesthetic reasons. In addition, the tank may be secured to the case by different latches, or may not be latched at all. Also, the filter can be placed in a variety of locations at the tank or case, and may use a variety of filter materials of different volumes. Moreover, the pump may employ a different pumping mechanism and may be located in different positions inside or alongside the case. Additionally, the fittings connecting the various hydraulic components may use different seals, connections, or fittings, depending upon the desired sealing properties, integrity etc. Also, the circuit for driving the pump can employ a variety of analog or digital circuits and may in some cases provide a continuous drive, as opposed to a pulsed drive. Furthermore, the soleplate can be composed of a different number of components than that illustrated. Moreover, the forward and backward paths of the soleplate can be modified into a number of serpentine passages, depending upon the desired length, capacity, etc. 
     Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.