Clothes iron sole

Abstract: The invention refers to a process to manufacture a clothes iron sole, that comprises: a molded aluminum base (1) in which a heating resistor (2) is inlaid, the base (1) including steam outlet holes (3); and a plate that constitutes a sliding surface of the sole and that is connected to the base (1). The process comprises: a first step, in which a laminated iron plate (4, 4') is coated with an enamel coating as of an enamel frit that is vitrified, the vitrification of the enamel being carried out at a temperature between 700ºC and 900ºC; and a second step, in which the plate (4, 4') coated with the enamel is connected to the base (1). The invention also refers to the sole.

Description: OBJECT OF THE INVENTION The invention refers to a clothes iron sole that is especially applicable to steam irons of the type wherein the sole has an exterior enamel layer. The object of the invention is to achieve a greater hardness of the sole, less friction when sliding and greater simplicity in the manufacturing process. The invention also refers to a process for manufacturing said sole. BACKGROUND OF THE INVENTION Various types of soles, basically comprised of a first injected aluminum body, in which some tube-shaped heating resistors are inserted, and a second body, which constitutes the sole of the clothes iron and that is formed by a laminated aluminum sheet, are known in the steam iron sector. This second body is provided with an enamel coating to improve the sliding of the clothes iron. This type of structure of the clothes iron is described in European patent EP-B-0200647. In this case, and as a main characteristic in contrast to previous arrangements, the laminated aluminum sheet that constitutes the sole is connected directly to the molded aluminum body, and this laminated aluminum sheet is coated with an enamel coating, made from an enamel frit vitrified at a temperature between 500ºC and 600ºC. It has been proven that depending on the vitrification or curing of the enamel, the enamel is harder or less hard and it has also been proven that it has more or less sliding resistance. The less hard the enamel coating is, the sole coated with this enamel has a greater sliding resistance and is less resistant to becoming scratched. Therefore, the structure provided for in European patent EP-B-0200647 has, due to the enamel frit coating which is vitrified at a temperature between 500ºC-600ºC, certain limitations to sliding and scratching, which are inherent in the manufacturing process described in the cited patent. On the other hand, in the type of connection of the injected or molded aluminum body to the laminated aluminum sheet base which is generally done by a blast of heat, it is necessary to subject the sheet to rather complex cleaning processes, which constitute an inconvenience as to costs. A particular arrangement that uses the structure described in European patent EP-B-0200647 is described in European patent application EP-A-0378479, in which a clothes iron sole with an enamel coating formed by appreciably parallel enamel strips in relief that extend longitudinally along the sole, is shown. In European patent EP-B-0200647 as well as in European patent application EP-A-0378479, the enameled surface occupies the entire surface of the sole, reaching even the periphery of the base; this may cause, due to possible knocks during transfer or use thereof, the enamel to chip. GB-A-1380415 describes an electric iron with a composite sole plate consisting of a support member to the base of which is secured a detachable facing plate at least the outer surface is smooth and relatively scratch resistant. The facing plate can be a steel plate having a vitreous enamel coating. GB-A-2225345 discloses a sole plate for electrically heated irons that has an aluminium sole plate member which is covered by a stainless steel sheet and the periphery of the sheet is in engagement with a groove on the surface of the sole plate which extends substantially around the plate member periphery. EP-A-0522401 describes a steel sheet member having an aluminium coating and an enamel coating being vitrified at a temperature between 800°C and 850°C. US-A-4493900 describes a steel sheet member with an enamel frit which is capable of firing at temperatures lower than 723°C. DESCRIPTION OF THE INVENTION In order to solve the above mentioned inconveniences, the invention provides for a clothes iron sole for steam irons that is constituted as of a laminated iron sheet or plate that is joined to the base of the iron, said base being made up of the injected aluminum, and prior to this connection the enameling of the iron sheet is carried out. Thanks to the difference of materials used and, above all, thanks to the fact that the enameling is done on the sheet that constitutes the sole before it is connected to the aluminum body, the vitrification or curing may be carried out at higher temperatures than those provided for in European patent EP-B-0200647 and in European patent application EP-A-0378479, since this vitrification is done at temperatures between 700ºC and 850ºC. The fact that the vitrification of this enamel is carried out at between 700ºC and 850ºC implies that the enamel surface has a hardness greater than 30% with regard to the enamel applied to laminated aluminum. Therefore, the enamel surface provided for in the arrangement of the invention, has a greater hardness and, consequently, more resistance to scratching and, as we have mentioned above, this greater hardness determines better sliding of the sole of the clothes iron, which is one of the purposes of the enamel coating. Besides, in the manufacturing process of the sole of the invention, it is necessary to carry out a less complex cleaning process of the iron surface of the sole, which determines a simpler process than those provided for in the background of the invention. However, the greater hardness achieved in the enamel to obtain greater sliding and greater scratching resistance, represents greater brittleness of the enamel, in such a way that the enamel may peel more easily in the case of accidental knocks, and this danger of peeling of the enamel is even higher on the periphery of the sole. So that the sole of the clothes iron has the previously foreseen advantages and to avoid the above mentioned inconvenience, in accordance with the invention, it has been provided for that the base of molded aluminum has a recess or hollow in which the iron plate is located, in such a way that the periphery of this enameled sole remains totally protected. In this sense, it should be indicated that the recess or hollow may be provided for in the most part of the surface of the base, with the exception of a small peripheral section, or on the contrary, it may exclusively consist in a channel provided for close to the edge, which runs along the perimeter of the clothes iron, in such a way that in order to protect the enamel of the laminated iron plate, this plate is thinner than the previous one and has a flange that is introduced in said channel, in such a way that the enamel periphery remains perfectly protected at the same time that this channel represents a means of mechanical connection to the base. The enamel coating consists of depositing several layers of enamel product. Therefore, by means of the invention, with regard to previous solutions, greater hardness of the sole, less friction during sliding and a simpler manufacturing process are obtained. BRIEF DESCRIPTION OF THE FIGURES Figure 1 shows a partial sectioned view of one portion of a sole of a clothes iron in accordance with an embodiment of the invention. Figure 2 shows a partial schematic sectioned view of another embodiment of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENT A description of some preferred embodiments of the invention, based on the above mentioned figures, is made hereinafter. Hence, the sole of the invention is constituted starting from a base (1) made of molded aluminum in which the corresponding heating resistor (2) is inlaid, and besides it includes the steam outlet holes (3). A hollow or recess has been made in the base, in which a laminated iron plate (4) is housed, which may remain assembled to the base (1) by mechanical connection or by chemical connection (for example, with silicone), as well as by a combination of both. In accordance with the invention, prior to the cited connection between the base (1) and the laminated iron plate (4), on the laminated iron plate (4) (at least, on the surface that corresponds to the exterior surface of the plate, in other words, to the sliding surface) is deposited several layers of enamel (5). A first coating of the enamel layer, whose coating may cover all of the surfaces of the plate (4), is vitrified at a temperature between 800ºC and 850ºC. Then the coating of a second layer of enamel, that is applied to the exterior or lower surface of the plate (4) and that reproduces the corresponding pattern of the sole (for example, in the form of alternate rhombi in the form of a chessboard and whose sides have a slant of 37º with regard to the longitudinal axis of the sole), and that is vitrified at a temperature between 700ºC and 800ºC, is carried out. As one can see in figure 1, the hollow or recess remains located in such a way that the enamel does not reach the periphery of the body (1), whereby the entire periphery of the enamel remains protected, preventing it from undergoing peeling by knocks. According to another embodiment provided for in figure 2, the laminated iron plate (4') is assembled on the base (1), as indicated above, with the particularity that close to the edge of the base, a channel (6) has been made in which a flange (7) provided for on the periphery or end of the iron plate (4'), is inserted, in such a way that the periphery of the enamel remains protected, and besides, in this way, a mechanical connection with the base (1) is carried out. Upon forming the aluminum base (1) and the laminated iron plate (4), and upon carrying out the enameled coating of this plate (4) before the connection with the base (1), the vitrification of the layers is done at temperatures between 700ºC and 850ºC, with which the enameled surface is harder than in the known systems; in this way, the plate (4) of the sole slides more easily and has a greater scratching resistance; the inconvenience of the brittleness of the coating is eliminated by means of the system of protection of the periphery of the enameled surface.

Claims: Process to manufacture a clothes iron sole, the sole comprising: a molded aluminum base (1) in which a heating resistor (2) is inlaid, the base (1) including steam outlet holes (3); and a laminated iron plate (4,4') that constitutes a sliding surface of the sole and that is connected to the base (1); characterized in that the process comprises: a first step, in which the laminated iron plate (4,4') is coated with an enamel coating (5) made from an enamel frit that is vitrified, the coating consisting of several layers, the vitrification of a first of the enamel layers being carried out at a temperature between 800°C and 850°C and the vitrification of a second of the enamel layers being carried out at a temperature between 700°C and 800°C; and a second step, in which the iron plate (4,4') coated with the enamel is connected to the base (1). Process according to claim 1, in which the laminated iron plate (4,4') is housed in a hollow or recess made in the base (1), the recess or hollow goes along the surface of the base (1) up to a distance close to its edge, the enameled plate (4,4') remaining housed in said recess, in such a way that the periphery of the enameled surface remains protected by the base (1) itself. Process according to claim 1, in which the base (1) has close to its perimeter a perimetric channel (6), in which a flange (7) made in the plate (4') is introduced, the enamel remaining protected on its periphery, this flange carrying out a mechanical connection between the base (1) and the laminated iron plate (4'). Clothes iron sole, the sole comprising: a molded aluminum base (1) in which a heating resistor (2) is inlaid, the base (1) including steam outlet holes (3); and a laminated iron plate (4,4') that constitutes a sliding surface of the sole and that is connected to the base (1), the plate being coated with a vitrified enamel coating (5); characterized in that the iron plate (4,4') is coated with several enamel layers, a first layer vitrified at a temperature between 800°C and 850°C and a second layer vitrified at a temperature between 700°C and 800°C. Sole according to claim 4, in which the laminated iron plate (4,4') is housed in a hollow or recess made in the base (1), the recess or hollow goes along the surface of the base (1) up to a distance close to its edge, the enamel plate (4,4') remaining housed in said recess, in such a way that the periphery of the enameled surface remains protected by the base (1) itself. Sole according to claim 4, in which the base (1) has close to its perimeter, a perimetric channel (6), in which a flange (7) made in the plate (4') is introduced, the enamel remaining protected on its periphery, this flange carrying out a mechanical connection between the base (1) and the laminated iron plate (4').

Inventors: ALBANDOZ RUIZ DE OCENDA CARMEL, ALBANDOZ RUIZ DE OCENDA, CARMELO
Applicants: BSH BOSCH SIEMENS HAUSGERAETE, BSH BOSCH UND SIEMENS HAUSGERAETE GMBH
Application year: 1998
Main classification: D06F75
IPC codes: D06F75