Inflation valve with bulb having a bisymmetric cavity for passage of a tubular core

1. An inflation valve to be positioned in an orifice of a wheel rim of a motor vehicle, the valve being of the elastic deformation type, the inflation valve comprising:

a tubular core adapted to form an internal air passage from an external longitudinal end of the valve toward an internal longitudinal end, extending around a longitudinal central axis,

the tubular core being at least partially surrounded by a sleeve of elastically deformable material from a longitudinal central portion toward the internal longitudinal end of the valve,

the sleeve having the shape of a bulb widening toward the internal longitudinal end of the valve and ending in an internal longitudinal end of the bulb,

the bulb having a sealing groove extending at least partially around the bulb on an outer contour thereof and having internal and external edges oriented toward the internal and external longitudinal ends of the valve respectively,

the groove being adapted for receiving an edge of the orifice of the rim in an interior portion of the groove,

a cavity being present between the bulb and the tubular core,

wherein the cavity has an external periphery of bisymmetric shape with a first spacing between each first point of two opposed first points on a periphery of the cavity taken in a first direction radial to the tubular core, and each first point of a periphery of the tubular core aligned with the first radial direction and facing the first point of the periphery of the cavity, the first spacing being greater than a second spacing between each second point of two opposed second points on the periphery of the cavity taken in a second direction radial to the tubular core and perpendicular to the first direction, and each point of the periphery of the tubular core aligned with the second direction and facing the second point of the periphery of the cavity, a cross section of the inflation valve taken at the position of the cavity exhibiting symmetry with respect to the first and second directions.

2. The inflation valve as claimed in claim 1 , wherein the cavity is of oval shape.

3. The inflation valve as claimed in claim 1 , wherein the cavity is continuous around the whole of the tubular core.

4. The inflation valve as claimed in claim 1 , wherein said first spacing is at least 1.4 millimeters and said second spacing is not more than 0.7 millimeters.

5. The inflation valve as claimed in claim 1 , wherein the cavity extends axially in the bulb between a first plane, perpendicular to the tubular core, passing through the external edge of the groove and a second plane, perpendicular to the tubular core, which is nearer to the internal longitudinal end of the bulb than is the internal edge of the groove.

6. The valve as claimed in claim 5 , wherein the internal longitudinal end of the bulb is positioned axially between the groove and the internal longitudinal end of the valve.

7. The valve as claimed in claim 1 , wherein the tubular core comprises, on an innermost longitudinal end portion, two opposed flats, each of the flats extending in a plane perpendicular to the first direction facing a respective portion of cavity of greater width, each of the flats defining, with a portion of the external periphery of the cavity, a first hollow space, each of the two first hollow spaces being associated with two second hollow spaces defined by the periphery of the tubular core, the first hollow spaces being larger in area than the second hollow spaces.

8. An assembly of a motor vehicle wheel rim and an inflation valve, the inflation valve being placed in position through an orifice of the rim with one part outside the rim and one part inside the rim, wherein the valve is as claimed in claim 1 , the second direction extending radially with respect to a center of the rim.