FIRE VAPOR VALVE SEAL FIELD OF THE INVENTION This invention relates to a steam valve seal for a steam iron or the like, and more particularly, in a preferred embodiment, to an improved seal that contracts against, instead of away from, the cover of the steam box and the steam valve in such a way that the useful life of the seal is increased. BACKGROUND OF THE INVENTION Normal steam valve seals, for steam irons, contract when exposed to high temperatures generated in steam irons for long periods of time.
In addition, the design of the known steam valve seals is such that when shrinkage occurs, the seals actually contract away from the cover plate of the steam box and the steam valve, causing the seal to fail, thus allowing steam to escape from the steam box. As a result, the useful life of the steam irons in which said known steam valve seals are used decreases. Therefore, there is a need for an improved steam valve seal, which eliminates the known undesirable shrinkage effects associated with steam valve seals. It is also desirable, therefore, to provide improved steam valve seals that contract against, rather than away from, the steam box cover plate and the steam valve.
It is also desirable to provide an improved valve seal that has a longer life than known steam valve seals. SUMMARY OF THE INVENTION The present invention provides a novel steam valve seal for a steam iron comprising: a hollow cylindrical base disposed within an opening defined by a cover plate of the steam box of the iron, the base receiving a cylindrical valve seat of the steam valve of the iron; a middle annular portion disposed between the base and an outer annular wall having an annular shoulder extending downwardly; the annular shoulder arranged in an annular channel defined by the cover plate of the steam box; and an annular groove defined by, and disposed between, the middle annular portion and the outer annular wall, the annular groove receiving an annular pin disposed within the plate, which holds the seal against the cover plate of the steam box. Any shrinkage of the steam valve seal causes the indian cylindrical base to be tensioned against the valve seat and causes the middle portion and the annular shoulder to be tensioned against the cover plate of the steam box. A better understanding of the present invention, its uses and other advantages can be obtained from the consideration of the following detailed description of the preferred embodiments and the appended claims thereto, particularly when read together with the accompanying drawings, A brief description of which is the following. BRIEF DESCRIPTION OF THE DRAWINGS In the attached drawings, the preferred embodiments of the invention, and preferred methods for practicing the invention, are illustrated, in which: Figure 1 is a bottom perspective view of a steam valve seal of the present invention. Figure 2 is a front elevational view of the steam valve seal of the present invention. Figure 3 is a cross-sectional view of the steam valve seal of the present invention. Figure 4 is a cross-sectional view of a plate incorporating the steam valve seal of the present invention. Figure 5 is a partial cross-sectional view of the plate of Figure 4, which illustrates in more detail the steam valve seal of the present invention. Figure 6 is a partial cross-sectional view, partially broken away, of the plate of Figure 4, illustrating the position of the steam valve seal of the present invention. DETAILED DESCRIPTION OF THE PREFERRED MODALITIES This invention is described with respect to the preferred physical embodiments constructed in accordance therewith. It will be evident to those with ordinary experience in the technique, that various modifications and improvements can be made without departing from the scope and spirit of the invention. Accordingly, the invention is not limited by the specific embodiments illustrated and described, but only by the scope of the appended claims, including all equivalents thereof. The steam valve seal 10 of the present invention is shown in Figures 1-6. As shown herein, the steam valve seal 10, comprises a hollow cylindrical base 1 1. The upper part of the base 1 1 opens radially outward to form an annular mid portion 12 of the valve seal 10. As shown in Figures 3 and 5, the middle portion 12 is curved in a convex manner. Formed integrally with the middle portion 12, there is an outer annular wall 13 and an annular shoulder 14 extending downwardly. Preferably, the steam valve seal 10 of the present invention is made of a silicone rubber compound at high temperatures. As shown in Figure 3, the outer annular face 15 of the middle portion 12 and the inner annular face 16 of the outer annular wall 13 define an annular groove 17. The annular groove 17 completely circumscribes the middle portion 12. Preferably , the angle, x °, between the outer annular face 15 of the middle portion 12 and the inner annular face 16 of the wall 13, is approximately 40 °.
As shown in Figures 4 and 5, the steam valve seat 24 of the plate 20, preferably is molded integrally with the lower part of the water tank 23. The steam 26 of the steam valve 25, sits on the steam valve seat 24. Referring to Figures 4-6, the steam valve seal 10 is disposed within the plate 20 between the cover plate 22 of the steam box and the steam valve seat 24. as shown in Figure 6, the cover plate 22 of the steam box, defines an opening 30 through which the steam valve seat 24 and the rod 26, extend in communication with the steam box 40 The cylindrical base 11 of the steam valve seal 10, also extends through the opening 30 and receives the cylindrical valve seat 24 of the steam valve 25. The cover plate of the steam box 22, further defines an annular channel 32 disposed concentrically with respect to the opening 30. As shown in Figures 4-6, the annular shoulder 14 extending downstream of the steam valve seal 10, is preferably disposed within the annular channel 32 in the cover plate 22 of the housing steam. The steam valve seal 10 is held firmly in place against the cover plate 22 of the steam box, by an annular pin 29, disposed on the lower part of the jacket of the plate 28. The annular pin 29 is receives and is disposed in the annular groove 17 of the steam valve seal 10. Unlike the known steam valve seals, which tend to fail due to shrinkage, the integrity of the steam valve seal 10 of the present invention, remains in contact because the seal 10 actually contracts against the cover plate 22 of the steam box, and the steam valve seat 24. When the contraction of the seal 10 occurs, the diameter of the seal is reduced. cylindrical opening 18 defined by the base 11. Therefore, the base 11 contracts against the cylindrical valve seat 24 disposed therein. In addition, the dimensions of the middle portion 12 and the annular shoulder 14 also decrease when the seal 10 is contracted, thus pulling the middle portion 12 and the annular shoulder 14 against the cover plate 22 of the steam box, to maintain the Seal integrity 10. As a result, the life of the steam valve seat 10 is lengthened, compared to known steam valve seals. Although the invention has been described in detail in the foregoing for the purpose of illustration, it should be understood that said detail is only for that purpose and those of ordinary skill in the art can make variations therein, without departing from the spirit and scope of the invention. the invention as defined by the following claims, including all equivalents thereof.