Device for shaping a pneumatic tire comprising a conditional assistance system for the rotation of the flanges carrying the beads of the tire
AssigneeCompagnie Generale Des Etablissements Michelin
InventorVincent ROBIN
Life of this patent
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Abstract
The device is a drum brake and allows for the shaping of a tire by axial convergence and relative rotation of a first flange carrying the first bead of the tire and a second flange carrying the second bead of the tire. The device applies a law comprising a conditional assistance mode in which assistance with rotation of the flanges is triggered if and only if the angular difference found between the flanges leaves a pre-established permitted region.
Claims12
A device for shaping a tire, comprising a first flange intended to receive a first bead of a tire;
- a second flange intended to receive a second bead of said tire;
- a translation mechanism allowing movement of at least one of the first flange and the second flange in translation along a common central axis in order to modify the so-called “center distance” which axially separates the first flange from the second flange, so that the flanges can be brought axially closer together and hence the beads closer together, to accompany a radial expansion of the tire;
- a rotation mechanism which allows rotation of at least one of the first flange and the second flange around the central axis so as to allow modification of the relative azimuthal angular position of the first flange relative to the second flange, called the “angular difference”;
- wherein said device comprises a control system configured to apply a control law which comprises a function mode called “conditional assistance mode” in which i) over a first predetermined center distance range called the “first application region”, the control law associates with each center distance value of said first application region a range of permitted angular differences, called the “permitted region”, which has a predetermined amplitude delimited by a low boundary and a high boundary separate from the low boundary;
- and in which ii) when a mutual axial convergence of the flanges is performed and the center distance thus passes through the first application region, the rotation mechanism remains passive if the angular difference lies inside the permitted region, so as to allow the first flange and the second flange to rotate freely relative to one another under the effect of the natural reaction of the tire to the radial expansion of said tire and to the mutual axial convergence of said flanges, and said rotation mechanism selectively triggers an assistance with rotation if the angular difference reaches one of the boundaries of the permitted region or leaves said permitted region, in order to actively manage the relative rotation of the flanges so as to force the angular difference to remain in or return within said permitted region.
A method for shaping a tire, comprising a convergence step during which a first flange carrying a first bead of the tire and a second flange carrying a second bead of said tire are brought axially closer together in order to modify the distance axially separating said flanges, called the “center distance”, so that said tire passes from an initial substantially cylindrical configuration to a final toroidal configuration, wherein during the step of axial convergence, the relative azimuthal angular position of the first flange relative to the second flange, called the “angular difference”, is measured, and the rotation of at least one of the first flange and the second flange around the central axis common to said flanges is controlled by implementing a control law which comprises a conditional assistance mode in which, over a first predetermined center distance range called the “first application region”, the control law associates with each center distance value of said first application region a range of permitted angular differences, called the “permitted region”, which has a predetermined amplitude delimited by a low boundary and a high boundary;
- then in which, if the measured angular difference lies inside the permitted region, the first flange and the second flange are allowed to rotate freely relative to one another under the effect of the natural reaction of the tire to the radial expansion of said tire and to the mutual axial convergence of said flanges, and if the angular difference reaches one of the boundaries of the permitted region or leaves said permitted region, assistance with rotation is selectively triggered in order to actively manage the relative rotation of the flanges so as to force the measured angular difference to remain in or return within said permitted region.
Dependencies are inferred from the claim text.