HRP920403A2 - Process for closing the evaporation chamber of an electric steam iron - Google Patents

Description

The technical field to which the invention belongs

The invention relates to a process for closing the evaporation chamber on electrically heated steam irons, and according to the International Classification of Inventions, the invention is classified and marked with the classification symbol F16B 5/04 and F16B 4/00.

Technical problem

The technical problem that is solved by the invention consists in the following: how to realize a procedure by which the lid of the steam iron's evaporation chamber will be hermetically and permanently connected to the base plate, without the appearance of known defects.

State of the art

In electric steam irons that work on the principle of dripping, the evaporation chamber from which the liquid is converted into the vapor phase, as well as the associated steam channels, are placed in an electrically heated base plate. Water drips from the water reservoir into the evaporation chamber. The saturated steam created here is overheated in the steam channels and comes out on the ironing surface of the base plate. The base plate consists of die-cast aluminum. The evaporation chamber and the steam channels are closed with a lid in the base plate. Evaporation of water and associated physical processes create pressure in the evaporation chamber that acts on all sides of the chamber wall. The weakest point of the steam chamber is the connection of the steam chamber cover with the base plate, which is achieved by riveting in the case of known steam irons. In addition to this, on the upper part of the surface of the vertical wall of the steam chamber, rivets are cast with an approximately conical shape of the base of the rivets. After placing the cover on the upper surface of the wall of the steam chamber, the cover is firmly connected to the base plate by breaking the rivets. This known process has the disadvantage that the cover can be connected to the base plate only via molded heads. Since the rivets are cast on the wall of the steam chamber, from the casting point of view, it is necessary that each rivet base be made in the form of a truncated cone. In addition, due to the hermetic connection between the lid and the vapor chamber, before riveting the lid to the vapor chamber, the lid must lie smoothly on the upper surface of the wall of the vapor chamber. This requires that the cross-section of the opening belonging to each rivet in the cover is equal to or greater than the maximum cross-section of the base of the rivet. Due to the shape of the base of the rivet in the form of a truncated cone, after the completion of the riveting process, the volume of the rivet hole is not completely filled with the split rivet and the cross-section of the rivet head is only slightly larger than the cross-section of the rivet hole. The side of the rivet does not exert chest pressure of the opening on the cover. Through the pressure from the evaporation chamber on the lid, each individual rivet will not be subjected to stretching due to the lack of chest pressure. Chamber pressure alone acts as a shearing force on the rivet head. The lid will be lifted due to the pressure of the chamber and the rivet head will be tensioned due to shearing forces. Due to the non-sealing between the cover and the wall of the chamber, steam passes, and thus moisture, into the interior of the iron. With known steam irons, there is a very high risk of a short circuit due to eddy currents or the user coming into contact with the voltage on the device, which causes health damage.

Description of the solution to the technical problem

This problem will be solved by a characteristic feature of the patent claims.

With the method according to the invention, it was achieved that the limit of stretching of the cover material is exceeded by the high pressure of the ring former and that the cover material in the edge area of the rivet opening is stretched to each rivet. Each rivet will be surrounded in the area of the wall of the rivet hole by the cover material. Any hollow spaces between the rivet and the cover will be filled with fusible cover material. After breaking the rivet shank and shaping the rivet head, the edge area of each rivet hole in the cover will be covered over a large area. After completion of the riveting process, high chest pressure is applied to the lid from each rivet shank. A solid connection is formed between the individual rivets and the cover, so that the rivet heads are not stressed solely in shear. The pressure exerted by the evaporation chamber on the chamber wall and the lid cannot separate the connection riveted between the lid and the wall of the evaporation chamber. As the rivet heads are larger in diameter than the diameter of the rivet hole, the rivet heads cannot be exposed due to stretching forces, thus achieving an absolutely hermetic and more inseparable connection between the cover and the wall of the evaporation chamber.

An example of the implementation of the invention is shown in the drawings and will be described in more detail in the following.

They show:

- Fig. 1 partial area of steam iron vaporization chamber and ring shaper in section,

- figure 2 partial area of the steam iron evaporation chamber according to figure 1 after carrying out the procedure according to the invention.

Figure 1 shows a partial area of the vaporization chamber of the steam iron before closing the vaporization chamber with a lid 1. On the upper surface of the wall 3 of the vaporization chamber, rivets 4 with a foundry technically conditioned base 6 of rivets in the shape of a truncated cone are cast. The cover 1 rests on the upper surface of the vertical wall 3 of the evaporation chamber. The opening 5 for the rivet belonging to each rivet has a cross-section that is equal to or greater than the maximum cross-section of the corresponding base 6 of the rivet. When carrying out the procedure according to the invention, after placing the cover 1 on the upper surface 2 of the wall 3 of the evaporation chamber, the ring shaper 7 is lowered over the rivet 4 onto the cover 1. The edge area 8 of the cover 1 is exposed to the pressure of the ring shaper 7 until the limit is exceeded stretching of the cover material. The material of the cover is stretched in the direction of the rivet 4, so that the handle of the rivet is surrounded on all sides by the material of the cover. After the permanent deformation of the edge area 8, the rivet breaks and the free end 9 of the rivet 4 is formed into the head 10 of the rivet. It is possible to think about closing the vaporization chamber of the base of the steam iron with the lid 1 via multiple ring formers 7 that act on the edge areas 8 of the lid 1, and in one operation according to the method of the invention, the vaporization chamber will be closed. Figure 2 shows a partial view of the vaporization chamber with a fixed cover 1 after carrying out the process according to the invention. From this view, it can be seen that the rivet 4 is tightly surrounded by the material of the cover and the head 10 of the rivet overlaps the edge area 8 of the cover 1 over a large area.

Claims (1)

1. Method for closing the evaporation chamber of an electrically heated steam iron, with a base plate of injection-molded aluminum, with the evaporation chamber firmly connected to the base plate and a closed lid, having a vertical wall of the chamber on the upper surface of which rivets are cast with approximately conical the shape of the base of the rivet, and the cover has a rivet opening opposite each rivet, while the cross-section of the rivet opening is equal to or greater than the cross-section of the rivet base, the opening of the corresponding rivet and where the cover, after placing the upper surface of the chamber wall, is connected to the base plate by the deformation of the rivet , indicated by the fact that the edge area (8) of each rivet hole (5) is exposed to the pressure of the ring former (7) in which the pressure of the ring former (7) increases until the limit of stretching of the material of the cover is exceeded, which is less than the limit of stretching of the material of the base plates, and after permanent deformation of the edge area (8), r the ring shaper (7) is removed, the rivet (4) is pulled apart and the free end (9) of each rivet (4) is shaped.