Rubber foot for a heatable metal device The present invention relates to a rubber foot for a heatable or heated metal device, in particular for a cast iron grid of a cooking hob. Further, the present invention relates to a heatable metal device with at least one hole in its bottom. Moreover, the present invention relates to a cast iron grid for a cooking hob. For example, the cast iron grid is provided as a pot support or pan support for a gas cooking hob. Additionally, the present invention relates to the use of a silicone type for a rubber foot. Some kinds of metal grids, in particular a cast iron grid for a gas cooking hob, are used as pot support or pan support. Some rubber feet are attached at the bottom side of the metal grid or cast iron grid in order to avoid the direct contact between the grid and a panel of the cooking hob. The rubber feet separate thermally the grid from the panel and avoid that thermal shocks destroy the panel.

Conventional rubber feet are made of silicone and glued on the grid. However, the gluing of the rubber feet onto the grid is laborious. It is desired to have rubber feet fixable onto the grid by an easy way.

It is an object of the present invention to provide a rubber foot suitable for a heatable or heated metal device, which rub- ber foot is fixable onto the metal device by low complexity.

The object is achieved by the rubber foot according to claim 1. According to the present invention a rubber foot is provided for a heatable or heated metal device, in particular for a cast iron grid of a cooking hob, wherein

- the rubber foot includes a shaft forming an upper part of said rubber foot,

- the shaft includes a cylindrical body and is provided for inserting into a hole in the bottom of the metal device along the symmetry axis of said cylindrical body,

- the rubber foot includes a head forming a lower part of said rubber foot,

- the head is provided for a position below the hole in the bottom of the metal device, when the shaft is inserted in said hole,

- the diameter of the head is bigger than the diameter of the shaft,

- the rubber foot includes at least one wing enclosing at

least partially the cylindrical body of the shaft,

- the at least one wing is formed by at least one ring enclosing the cylindrical body of the shaft and/or the at least one wing is formed by at least one ring enclosing the cylindrical body of the shaft and subdivided by at least one recess, and

- the rubber foot with the shaft, the head and the wings is formed as a single-piece part.

The main idea of the present invention is the shape of the rubber foot. In particular, the at least one wing allows that the shaft is stably inserted into the hole in the bottom of the metal device, wherein no glue is reguired.

Preferably, the recess forms a lateral evacuation channel. The lateral evacuation channel avoids that an isolated chamber is formed upon the shaft, when said shaft is inserted in the hole. In particular, the wings have a triangular cross-section, wherein an upper surface of the wings is inclined more strongly than a lower surface of the wings . For example, the upper surface of the wings is inclined between 30 degrees and 60 degrees, preferable 45 degrees.

Further, the lower surface of the wings may be horizontal or inclined up to 20 degrees.

According to a preferred embodiment the rubber foot includes at least two pairs of wings arranged on top of each other.

Preferably, the recesses of the rings are arranged along common axes parallel to the symmetry axis of the cylindrical body of the shaft, so neighboured recesses of the rings form the lateral evacuation channel.

Furthermore, an upper side of the head is concave.

In this case, the upper side of the head may include an inner curvature and an outer curvature, wherein the inner curvature has a smaller radius of curvature than the outer curvature.

In particular, the rubber foot is made of silicone, preferably of the type BlueStar Silicones Bluesil™ HCR 60 THT or Wacker ELASTOSIL® R 750/50. Alternatively, the rubber foot may be made of general type of silicone. Further, the present invention relates to a heatable metal device with at least one hole in its bottom side, wherein the metal device comprises at least one rubber foot inserted or insert- able into the at least one hole in the bottom side of said metal device . Moreover, the present invention relates to a cast iron grid for a cooking hob, wherein said cast iron grid comprises at least one hole in its bottom side, wherein the cast iron grid comprises at least one rubber foot inserted or insertable into the at least one hole in the bottom side of said cast iron grid.

Additionally, the present invention relates to the use of silicone of the type BlueStar Silicones Bluesil™ HCR 60 THT or Wack- er ELASTOSIL® R 750/50 for a rubber foot for a heatable or heated metal device .

In particular, the silicone of the type BlueStar Silicones

Bluesil™ HCR 60 THT or Wacker ELASTOSIL® R 750/50 is used for a rubber foot mentioned above.

Novel and inventive features of the present invention are set forth in the appended claims .

The present invention will be described in further detail with reference to the drawing, in which

FIG 1 illustrates a perspective view of a rubber foot according to a preferred embodiment of the present invention,

FIG 2 illustrates a bottom view of the rubber foot according to the preferred embodiment of the present invention,

FIG 3 illustrates a sectional view of the rubber foot according to the preferred embodiment of the present invention,

FIG 4 illustrates a side view of the rubber foot according to the preferred embodiment of the present invention, and FIG 5 illustrates a top view of the rubber foot according to the preferred embodiment of the present invention.

FIG 1 illustrates a perspective view of a rubber foot 10 accord- ing to a preferred embodiment of the present invention. In FIG 1 the rubber foot 10 is oriented in the same way, when said rubber foot 10 is in use. Items like "upper" and "lower" relate to this orientation, when the rubber foot 10 is in use. The rubber foot 10 includes a shaft 12 and a head 14. The shaft 12 is substantially cylindrical. The head 14 is arranged at the lower face side of the shaft 12. In this example, the head 14 is formed like a mushroom head, so that the rubber foot 10 is substantially shaped as an upside-down mushroom.

Further, the rubber foot 10 includes two pairs of wings 16. The wings 16 are arranged at the lateral surface of the shaft 12. Each pair of wings 16 is formed as a ring enclosing the lateral surface of the shaft 12, wherein said ring is interrupted by two recesses 18. In this example, the recesses 18 are arranged at opposite sides of the lateral surface of the shaft 12 and the wings 16 of each pair are symmetric. In general, the ring may be interrupted by an arbitrary number of recesses 18, so that said ring is subdivided into a corresponding number of wings 16.

The recesses 18 are positioned in such a way, that two neighboured recesses 18 of different rings form a channel extending parallel to the longitudinal axis of the shaft 12 in each case. In this example, two parallel channels are formed at opposite sides of the shaft 12. The channels are provided as lateral evacuation channels.

The upper side of the head 14 includes an inner curvature 26 and an outer curvature 28. The inner curvature 26 and the outer cur- vature 28 are both concave. The inner curvature 26 is strongly curved, while the outer curvature 28 is weakly curved. The inner curvature 26 forms the intermediate portion between the lateral surface of the shaft 12 and the outer curvature 28.

Furthermore, the shaft 12 includes a bevel 30 between its lateral surface and its upper face side. A central recess 32 is formed in the centre of said upper face side. Moreover, the rubber foot 10 may include an arbitrary number of pairs of wings 16. The shaft 12, the head 14 and the two pairs of wings 16 are formed as a single-piece part. In FIG 1 the rubber foot 10 is aligned such as when said rubber foot 10 is in use, i.e. the shaft 12 forms the upper art, while the head 14 forms the lower part of the rubber foot 10.

FIG 2 illustrates a bottom view of the rubber foot 10 according to the preferred embodiment of the present invention. The lower side of the head 14 of the rubber foot 10 includes a central plane surface 20, an intermediate curved surface 22 and an outer surface 24. In this example, the diameter of the head 14 of the rubber foot is 12 mm.

FIG 3 illustrates a sectional view of the rubber foot 10 accord- ing to the preferred embodiment of the present invention. In FIG 3 the upper part of the rubber foot 10, i.e. the shaft 12, is shown on the left hand side, while the lower part of the rubber foot 10, i.e. the head 14, is shown on the right hand side. The wings 16 have a triangular cross-section enclosing the shaft 12. An upper surface of each wing 16 is inclined by 45 degrees. A lower surface of each wing 16 is horizontal. In this example, the inner curvature 26 on the upper side of the head 14 has a radius of curvature of 0.5 mm, while the outer curvature 28 on the upper side of the head 14 has a radius of curvature of 8 mm.

In this embodiment, the distance between the outer edges of both wings 16 is 2.5 mm. Further, the distance between the outer edge of the upper wing 16 and the upper face side of the shaft 12 is 3.5 mm. Moreover, the distance between the outer edge of the lower wing 16 and the outer edge of the head 14 is 2 mm.

FIG 4 illustrates a side view of the rubber foot 10 according to the preferred embodiment of the present invention. In this embodiment, the shaft 12 has a diameter of 6 mm. Fur ^¬ ther, the head 14 is a height of 3 mm, while the rubber foot 10 has a height of 11 mm.

FIG 5 illustrates a top view of the rubber foot 10 according to the preferred embodiment of the present invention. In this em ^¬ bodiment, the wings 16 have a wing-spread of 9 mm. Further, the recesses 18 have a radius of curvature of 1.5 mm.

The rubber foot 10 is provided as a supporting element for a cast iron grid of a cooking hob, in particular a gas cooking hob. In general, the rubber foot 10 is provided as a supporting element for a heated or heatable metal device . The rubber foot 10 is inserted or insertable into a blind hole at the bottom of the cast iron grid or at the bottom of a foot of said cast iron grid. For example, the cast iron grid is used as a pot holder on a gas cooking hob with a glass panel. The diameter of the blind hole is marginally bigger than the diameter of the shaft 12 of the rubber foot 10. The bevel 30 and the inclined upper surfaces of the wings 16 allow an easy inserting of the rubber foot 10 into the blind hole. Further, the shape of the wings 16 prevents a self-acting disconnection of the rubber foot 10 from the blind hole and guaran- tees the fixation of the rubber foot 10 in said blind hole. Glue is not necessary for fixing the rubber foot 10 in the blind hole .

The lateral evacuation channels formed by the recesses 18 avoid that an isolated chamber is formed within the blind hole. In the isolated chamber high pressure may occur. Said high pressure supports or causes the disconnection of the rubber foot 10 from the blind hole. Preferably, the inner curvature 26 and/or outer curvature 28 at the upper side of the head 14 comprise at least partially a smooth surface. Said smooth surface makes it difficult to disconnect the rubber foot 10 from the blind hole. The rubber foot 10 is formed as a single-piece part and made of silicon or a rubber like material. For example, the silicone of the type BlueStar Silicones Bluesil™ HCR 60 THT or Wacker ELAS- TOSIL® R 750/50 is used for the rubber foot 10.

Although an illustrative embodiment of the present invention has been described herein with reference to the accompanying drawing, it is to be understood that the present invention is not limited to that precise embodiment, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the in- vention. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims . List of reference numerals

10 rubber foot

12 shaft

14 head

16 wing

18 recess

20 plane central surface

22 curved intermediate surface

24 outer surface

26 inner curvature

28 outer curvature

30 bevel

32 central recess