The present invention relates to a tyre valve, in particular gas and/or air tyre valve, according to the preamble of the main claim, and a moulded seal which is suitable and provided in particular for use in such a valve.
Various approaches are known from the state of the art for sealing against air loss between an air tyre valve and the valve bore (below also: rim bore) surrounding the air tyre valve in the air tyre rim. Firstly, so-called shoulder or flat seals exist, secondly O-ring seals are used.
However, both solutions, considered in each case in themselves, are disadvantageous technically: A shoulder or flat seal typically consisting of a flat rubber ring and optionally provided with a shoulder section, places relatively small demands on the evenness of the support surface (that is, the outer-lying flat edge section of the rim bore) and on the aperture tolerances of this rim bore, since the large rubber volume of such seals compensates deviations in simple manner. However, it is disadvantageous that during installation of valves using such seals, (low) torque limits may not be exceeded, this would lead to the destruction of the seal. Since in addition the sealing elements are deformed under pressure, very low release moments for the union nut securing the valve are usually produced in disadvantageous manner.
On the other hand, the known O-ring seals facilitate very much higher tightening moments, since the union nut engages directly on the edge section of the rim bore and in this respect a metal-metal contact exists; correspondingly high release moments can advantageously be achieved for the securing union nut. On the other hand, it is disadvantageous that such an O-ring seal places very high requirements on the evenness of the support surface in the rim bore edge region and the bore tolerances themselves, so that here in some cases considerable additional expense is necessary for manufacture and assembly.
The object of the present invention is therefore to provide an improved air seal between a tyre valve and the tyre rim surrounding it, wherein this seal should place firstly, fewer requirements on the surface condition or evenness of the rim surface in the rim bore edge region, but secondly high tightening moments should be ensured for the union nut securing the valve.
The object is achieved by the tyre valve having the features of the main claim and the moulded seal having the features of the independent claim 4; advantageous developments of the invention are described in the sub-claims.
In advantageous manner according to the invention, the favourable properties of both sealing methods described in the introduction are combined by the present solution, while the particular disadvantages may be effectively avoided: Hence, the ring shoulder formed on the lower valve body section ensures that, together with the union nut, a metal-metal connection may be realised in the gripped state with high tightening and release moment. At the same time, the sealing effect of the chamber section of the moulded seal of the invention sitting in sealing manner in the chamber formed by the ring groove in the lower valve body section and the edge section of the rim bore in conjunction with the vertical section sitting integrally on the chamber section, ensures that both the flat edge section in the region of the rim bore and the annular end-face of the bore are effectively surrounded by sealing material and even high bore tolerances and surface unevenness do not disadvantageously impair the sealing capacity facilitated not least by the considerable rubber volume and the large rubber contact surface.
It has thus additionally been proved to be advantageous that such a moulded seal forming a graduated (ring shoulder-like) transition region is suitable, even particularly effective, for sealing rim bores having chamfering; in the assembled and gripped state, this ring chamfer would namely engage on the ring shoulder of the moulded seal or be pressed into the latter, so that, almost independently of a particular chamfer width (or, for variations occurring in practice), effective sealing may take place.
In this context, it is thus also advantageous when on the upper valve body section in the region of the valve bore (rim bore), an annular shallow groove is provided, into which in the gripped state, the rubber material of the vertical section is pressed.
The moulded seal itself is advantageously characterised by an outwardly directed graduation (to form the outer-lying ring shoulder), whereas lying on the inside a homogeneous transition between vertical section and chamber section is realised. The inner or outer region may be suitably designed to be conically tapering, in particular in the region of the vertical section, and it is additionally advantageous when the annular sealing surface formed by the outer-lying ring shoulder, relative to the surface described by the rim bore, does not run parallel (that is purely horizontally), but is slightly tilted with respect to the latter.
Whereas usually within the framework of the invention, the lower valve body section with the ring shoulder formed by it or the chamber for the moulded seal is arranged in a rim interior, it is nevertheless also encompassed by the present invention to reverse the securing principle of the invention: In this case, a lower valve body section would sit outside of the rim (optionally with the further valve elements), form accordingly the annular chamber section for the moulded seal from the outside onto the rim, whereas the union nut then cooperates from the rim interior with the upper valve body section or the rim in the region of the rim bore or valve bore.
As a result of the present invention, favourable tolerance and surface properties of the seal are combined with high tightening and release moments for securing the union nut, so that in particular also areas of application with greater manufacturing tolerances are developed for the present invention.
Further advantages, features and details can be seen from the following description of preferred exemplary embodiments and using the drawings; these show in
The lower valve body section 10 has in the contact region with the valve or rim bore region 12, an annular ring groove 18 such that on the edge side in the lower valve body section, a ring shoulder 20 is formed, which offers a support or abutment for the rim bore region 12. At the same time, between an under surface of the rim bore region and the ring groove, an incompletely closed, annular chamber is formed, in which a correspondingly annular chamber section 22 of a moulded seal 24, shown as a non-deformed cross-section in
As shown in the detailed views of
The present invention is not restricted to the exemplary embodiments described, hence the present invention is suitable not only for vehicle rims and air valves, but is suitable in principle for any gas valves or the like in cooperation with a rim, from the inside or from the outside.
Number | Date | Country | Kind |
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20 2004 020 121.6 | Dec 2004 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2005/014083 | 12/28/2005 | WO | 00 | 8/17/2007 |