GB2113723A

GB2113723A - Steam iron

Info

Publication number: GB2113723A
Application number: GB08300697A
Authority: GB
Inventors: Antonius Franciscus Pe Groenen; Vries Henderikus Fokke Will De
Original assignee: Philips Gloeilampenfabrieken NV
Current assignee: Koninklijke Philips NV
Priority date: 1982-01-15
Filing date: 1983-01-12
Publication date: 1983-08-10
Also published as: DE3300294A1; GB8300697D0; KR880001914Y1; FR2520019B1; GB2113723B; JPS58117300U; FR2520019A1; KR840003974U; NL8200146A

Abstract

In an electric steam iron, steam produced in a steam chamber (4) in the sole plate (2) of the iron flows through a steam riser pipe (12) to a steam dome (11) in the upper part of the water tank (8) of the iron. From the steam dome the steam flows through a steam delivery pipe (13) to outlet ports (7) in the sole plate. To permit continuously variable steam production at constant temperature, a valve member (28) is provided which is operable by means of an actuating knob (18) on the housing of the iron to control the rate at which steam can flow through the steam riser pipe. <IMAGE>

Description

SPECIFICATION Steam iron The invention relates to a steam iron comprising a housing which is closed at the underside by a sole plate comprising an electric heating element, a steam chamber and steam outlet ports, a water tank in the housing, means providing a passage for water between the water tank and the steam chamber, a steam dome disposed in upper part of the water tank, a steam riser pipe which extends from the steam chamber into the steam dome and a steam delivery pipe which connects the steam dome to the steam outlet ports.

U.S. Patent Specification 3,896,572 discloses a steam iron in which the water is metered into the steam chamber by means of a valve construction at the location of a metering orifice which provides a passage for water between the water tank and the steam chamber. When the metering rate is excessive, i.e. when the amount of water which drips into the steam chamber per unit of time is greater than the amount that can be evaporated, the steam output of this known iron depends on the sole plate temperature.

It is an object of the invention to provide an iron whose steam output can be controlled continuously at a constant temperature.

According to the invention there is provided a steam iron comprising a housing which is closed at the underside by a sole plate comprising an electric heating element, a steam chamber and steam outlet ports, a water tank in the housing, means providing a passage for water between the water tank and the steam chamber, a steam dome disposed in the upper part of the water tank, a steam riser pipe which extends from the steam chamber into the steam dome, and a steam delivery pipe which connects the steam dome to the steam outlet ports, wherein means are provided for controlling the rate at which steam can flow through the steam riser pipe, which means are controllable by means of an actuating knob on the housing.

These means preferably comprise a valve member which is operable to form in cooperation with an end of the steam riser pipe a variable restriction for controlling the flow rate through the riser pipe.

In the steam iron according to the invention, steam output is not controlled by metering the water entering the steam chamber. As a result of this the water passage between the water tank and the steam chamber may be larger than in steam irons in which the water is metered by means of a valve construction in front of a metering orifice. This reduces the risk of the steam output being hampered by soiling as a result of scale particles becoming detached in the steam chamber and blocking the water passage. An additional advantage is that when the flow of steam through the steam riser pipe is cut off altogether, the steam present in the steam chamber is blown back into the water tank through the water passage. This has a cleaning effect on the water passage.

In a preferred embodiment of the steam iron according to the invention the steam delivery pipe passes centrally through the steam riser pipe and extends beyond the upper end thereof so that at this end of the riser pipe an annular passage is formed between the two pipes for the egress of steam from the riser pipe, and the aforesaid valve member is mounted on the lower end of a sleeve which is slidable in an opening in a wall of the water tank and is slidable on the upper end portion of the steam delivery pipe and which is closed at its upper end and has a steam inlet port intermediate its ends, the valve member comprising a tapered body which is movable by means of said sleeve into said annular passage to vary the size thereof for variably restricting the rate at which steam can flow through the riser pipe.

An embodiment of the invention will now be described in more detail, by way of example, with reference to the accompanying drawings, in which Fig. 1 is a part-sectional elevation of an embodiment of the steam iron according to the invention, and Fig. 2 is a similar view to Fig. 1 showing modification for facilitating the change to dry ironing.

The iron shown in Figure 1 comprises a housing 1 and a sole plate 2. The sole plate contains an electric heating element 3 and a steam chamber 4. The steam chamber is closed by an inspection cover 5, which is secured to the sole plate by means of a screw. Over the inspection cover 5 a steam outlet plate 6 is arranged, which is flush with the underside of the sole plate. In the steam outlet plate steam outlet ports 7 are formed. The housing 1 accommodates a water tank 8.

Between the sole plate 2 and the water tank 8 is an insulation plate 9 which protects the water tank against excessive heating. A duct 10 connects the water tank 8 to the steam chamber.

The duct has a narrow passage through which the water drips into the steam chamber. The water tank has a raised portion forming a steam dome 1 A steam riser pipe 12 forms a connection between the steam chamber 4 and the steam dome 1 1. A steam delivery pipe 13 passes centrally through the steam riser pipe 12 and extends beyond the upper end thereof so that at this end of the steam riser pipe an annular passage 14 is formed between the two pipes for the egress of steam from the riser pipe. The lower end of the steam delivery pipe 13 is connected to the inspection cover 5. A sleeve 15 is slidable in an opening 1 6 in the upper wall 1 7 of the water tank 8.

In the top of the housing is mounted an actuating knob 18 comprising a bush 19, which is rotatable in the housing and which is formed with a radially extending finger-grip 20, and a plunger 21 which is slidable in the bush. The plunger 21 is formed with a radial projection 22 which is slidable in a vertical slot 23 in the housing 1. The lower end of the bush 19 extends helically or obliquely relative to the bush axis to form a cam surface 24 for co-operation with the radial projection 22 on the plunger 21. In this way a rotary movement of the bush 19, imparted to it by means of the finger-grip 20, is converted into a vertical movement of the plunger 21.

A push-rod 25 is connected to the closed upper end of the sleeve 15. A compression spring 26 acting between the upper wall 1 7 of the water tank 8 and a ring 27 on the push-rod 25 urges the push-rod upwards against the lower end of the plunger 21 of the actuating knob 18.

Consequently, when the finger-grip 20 is turned the sleeve 15 is moved downwards or upwards.

An annular valve member 28 is connected to the open lower end of the sleeve 1 5. The valve member 28 consists of an annular body of elastic material, the outer diameter of which decreases towards the steam riser pipe 12 to form an external taper, either curved or straight on the valve member. The sleeve 15 is slidable on the upper end portion of the steam delivery pipe 13 so that the tapered valve member 28 can be moved into the upper end of the steam riser pipe 12 to form in cooperation therewith a variable restriction for controlling the rate at which steam can flow through the riser pipe. A steam inlet port 29 is formed in the sleeve 1 5 intermediate the ends thereof.

The operation of the steam iron is as follows: via the duct 10 water drips into the steam chamber where it is heated. The steam thus formed passes through the steam riser pipe 12 and the annular passage 14 to the steam dome 11 and thence through orifices 30 in the wall of the water tank 8 and through the steam inlet port 29, the interior of the sleeve 1 5, the steam delivery pipe 13 and the steam outlet ports 7 to the fabric to be ironed. The steam output can be varied by varying the size of the annular passage 14, and therefore the rate at which steam can flow through the riser pipe 12, by means of the valve member 28.If the sleeve 1 5 is lowered by turning the finger-grip 20, the valve member 28 is moved into the upper end of the steam riser pipe 12 to reduce the size of the annular passage 14, so that per unit of time less steam flows to the steam dome and consequently less steam is ejected from the iron. Upon further restriction of the flow of steam through the annular passage 14 by means of the valve member 28, the pressure in the steam riser pipe 12 and the steam chamber 4 will rise, so that less water will drop into the steam chamber. When the annular passage 14 is closed completely by the valve member 28 the steam present in the steam chamber will be blown back into the water tank 8 via the duct 10 and immediately condense in the tank. The steam blown back into the tank may clear the narrow duct 10 should this be clogged by scale particles from the steam chamber. However, if necessary the duct may also be scraped clean by means of a calibrated pin. To do this the steam outlet plate 6 and the inspection cover 5 have to be removed.

If the iron shown in Figure 1 is to be used for dry-ironing, that is ironing without steam, the water tank 8 must be emptied first. In the modified iron shown in Figure 2 the duct 10 can be closed by means of a valve member 31 which is coupled to an actuating button 33 by a valve stem 32. When the button 33 is depressed the valve 31 completely closes the upper end of the duct 10. Then dry-ironing is possible while the tank 8 contains water. Any convenient known means may be provided for latching the button 33 in the depressed position.

Claims

1. A steam iron comprising a housing which is closed at the underside by a sole plate comprising an electric heating element, a steam chamber and steam outlet ports, a water tank in the housing, means providing a passage for water between the water tank and the steam chamber, a steam dome disposed in the upper part of the water tank, a steam riser pipe which extends from the steam chamber into the steam dome and a steam delivery pipe which connects the steam dome to the steam outlet ports, wherein means are provided for controlling the rate at which steam can flow through the steam riser pipe, which means are controllable by means of an actuating knob on the housing.

2. A steam iron as claimed in Claim 1 ,wherein the means for controlling the rate at which steam can flow through the steam riser pipe comprise a valve member which is operable to form in cooperation with an end of the steam riser pipe a variable restriction for controlling the flow rate through the riser pipe.

3. A steam iron as claimed in Claim 2, wherein the steam delivery pipe passes centrally through the steam riser pipe and extends beyond the upper end thereof so that at this end of the riser pipe an annular passage is formed between the two pipes for the egress of steam from the riser pipe, and wherein the valve member is mounted on the lower end of a sleeve which is slidable in an opening in a wall of the water tank and is slidable on the upper end portion of the steam delivery pipe and which is closed at its upper end and has a steam inlet port intermediate its ends, the valve member comprising a tapered body which is movable by means of said sleeve into said annular passage to vary the size thereof for variably restricting the rate at which steam can flow through the riser pipe.

4. A steam iron as claimed in Claim 1, 2 or 3, wherein a valve member is provided for closing the water passage between the water tank and the steam chamber.

5. A steam iron substantially as herein described with reference to Figure 1 or 2 of the accompanying drawings.