SIPE BLADE ASSEMBLY

Abstract

The present invention relates to a set of mould elements comprising main blades and secondary blades, intended to be added to a mould for vulcanizing a tread of a tyre, said mould elements being capable of moulding cuts in the tread, characterized in that a main blade comprises at least one assembly means for assembling a secondary blade, said assembly means comprising two series of at least one protrusion arranged facing one another. It is thus possible to ensure a relative positioning and an assembly that can withstand mechanical stresses over the entire height of the blade during moulding/demoulding, while minimizing the volume of material added. This assembly is barely visible on the tyre.

Claims

1. Set of mould elements, comprising main blades and secondary blades, intended to be added to a mould for vulcanizing a tread of a tyre, said mould elements being capable of moulding cuts in the tread, characterized in that a main blade comprises at least one assembly means for assembling a secondary blade, said assembly means comprising two series of at least one protrusion arranged facing one another.

2. Set of mould elements according to claim 1, characterized in that the protrusions facing one another are offset.

3. Set of mould elements according to claim 1, characterized in that the protrusions of a series are spaced apart by a variable pitch.

4. Set of mould elements according to claim 1, characterized in that the protrusions are bevelled.

5. Set of mould elements according to claim 1, characterized in that the series of protrusions are inclined.

6. Set of mould elements according to claim 1, characterized in that the protrusions are cubic, pyramidal, spherical, hemispherical or U-shaped.

7. Mould comprising a set of mould elements according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Further features and advantages of the invention will emerge from the following description, provided by way of example, without intended limitation, with reference to the appended drawings in which:

[0028] FIG. 1 is a view of a set of blades of the prior art,

[0029] FIG. 2 is a view of a set of blades according to the invention,

[0030] FIG. 3 shows an example of protrusions on a primary blade according to the invention;

[0031] FIGS. 4, 4a and 4b depict other examples of protrusions on a primary blade according to the invention;

[0032] FIG. 5 shows in detail the mounting of a secondary blade on a primary blade according to the example of FIG. 4b;

[0033] FIGS. 6, 7 and 8 are an alternative to FIG. 5;

[0034] FIG. 9 shows a blade with its anchoring zone;

[0035] FIGS. 10 and 11 are sectional views of the protrusions according to two embodiments.

[0036] In the description below, substantially identical or similar elements will be designated by identical references.

[0037] The set 1 of mould elements according to the prior art, depicted in FIG. 1, comprises a main blade 2 and a secondary blade 3 interconnected in reception slots arranged in a portion 4 in relief on the main blade 2. As the portion 4 is split, it has a relatively large volume.

[0038] In the set 1 according to the invention, shown in FIG. 2, the portion 4 has been replaced by several protrusions 5 arranged facing one another. These protrusions 5 are of small size. In a non-limiting embodiment, the protrusions represent only 5 to 20% of the main blade 2. In another alternative non-limiting embodiment, the protrusions represent at least 1% of the weight of the set 1.

[0039] The main blade 2 may have an anchoring zone 20.

[0040] The protrusions 5 may have various shapes: circular 53 (FIG. 3), pyramidal 51 (FIGS. 4, 4a and 4b), conical, cubic 50, semi-circular, U-shaped 52 (FIG. 6), etc. It is possible to combine different shapes on the same main blade 2 (FIG. 7). The shape of the protrusion may be complementary to another shape of the object to be assembled, for additional blocking.

[0041] The protrusions may be offset laterally from one another in pairs if the blade is not straight in order to follow the profile of the blade 3, as depicted in FIG. 4a.

[0042] The protrusions 5 are aligned vertically on the main blade 2 and may possibly overlap (FIGS. 5 and 7) in order to insert a secondary blade 3 which is undulated or zig-zag. They may be arranged over the entire height of the main blade 2 or over part of said height. The higher the height of the series of protrusions 4, the better the retention of the secondary blade 3. The protrusions 4 may have a constant pitch or a variable pitch.

[0043] The protrusions 5 facing one another may have vertical edges 500 (FIG. 10) or inclined edges 540, 550 (FIG. 11). In the latter case, the edges 540 and 550 of each protrusion 54 and 55 are inclined on the same side in order to have a constant spacing between the two edges and to guarantee retention of the secondary blade 3. The inclination of the edge will define the angle between the main blade 2 and the secondary blade 3.

[0044] The number of protrusions 5 over the height of the main blade 2 is at least one protrusion per series of protrusions, that is to say at least one protrusion on one side and at least one protrusion on the other side. In this case, it is preferable to place these protrusions 4 as far as possible from the anchoring zone 20 of the main blade 2. In a non-limiting embodiment, a series of protrusions comprises at least two protrusions. In another non-limiting embodiment, the two series of protrusions comprise at least two protrusions.

[0045] In the case where the secondary blade 3 is undulated, it is possible to block the undulations in hollows of the protrusions 5 (U-shaped) or on points (pyramidal or circular shapes).

[0046] The undulated blades generally have a minimum thickness of 0.2 mm, and a maximum thickness of 10 mm. Preferably, the blades have a thickness <2 mm, because for thicker blades, the assembly means may be included in the thickness of the blade.

[0047] The protrusions 5 will preferably have dimensions of at least 1.5 mm per side. The protrusions 5 may be produced by welding on the main blade 2, by laser sintering, or by stamping.

[0048] The invention is not limited to the examples described and shown, and various modifications may be made thereto without departing from the scope of the invention.