Device to increase the grip of the tyres

A device to increase the grip of the tread of the wheel of a vehicle comprising:

• a base reversibly secured to the outside face of the rim of a wheel of a vehicle, wherein the wheel comprises a tire that contacts a roadbed;
• a plurality of adjacent moving spokes each comprising an inner segment and an outer segment, wherein each outer segment is connected to a claw, wherein each claw is elastically connected to an adjacent claw to form a belt having a diameter that increases and decreases upon movement of the moving spokes, wherein further said moving spokes cause, upon command, said belt to switch from a retracted rest configuration having the shape of an annulus in which each moving spoke and claw connected to each respective moving spoke are substantially arranged inside the perimeter of the base and the inner segment and outer segment of each moving spoke are aligned in a radial direction, to an extracted work configuration wherein the outer segment of each moving spoke and the claw connected to each respective moving spoke extend beyond the perimeter of the base such that the outer segment of each moving spoke and the claw connected to each respective moving spoke are perpendicular to the inner segment of each respective moving spoke, wherein the diameter of the belt progressively increases to allow positioning of the belt around the tread of the tire, wherein each of the claws contact the roadbed;
• and
• means for positioning the moving spokes between the rest configuration and the work configuration, wherein the means for positioning said moving spokes comprise a plate grooved to form a spiral wherein the plate is rotationally connected to said base, wherein the spiral features an initial and terminal development according to an arc of circle, wherein the inner segment of each moving spoke further comprises a corresponding projecting pin that is inserted in the groove of said spiral so as to radially move each moving spoke in correspondence with rotation of said plate with respect to said base causing each moving spoke to radially translate towards the outer part of the rim of the tire to the extent that each outer segment rotates around said tangential axis until it is positioned on the tread of the tire, thus putting each of the claws in contact with the roadbed,
• wherein the initial and terminal development arcs of the circle formed by rotation of the spiral cover all but one sector of the circle defined by said moving spokes,
• wherein the inner segment of each moving spoke is rotationally coupled to the outer segment according to a tangential axis such that the moving spokes bend as the moving spokes radially translate toward the outer part of the rim of the tire.