Central tightening system for anti-skid devices and an anti-skid device having the same

A tightening system for use in anti-skid and traction enhancement devices, comprising:

• an anti-skid device comprising at least three, separate u-shaped contact members, each contact member having a pair of triangular shoulder portions situated on opposing surfaces of a vehicle wheel, the triangular shoulder portions being connected by a rectangular gripping portion abutting treads of the wheel;
• a central node (111, 112, 113) which is located on a principle axis of an axle of the wheel, wherein said central node (111, 112, 113) has a plurality of arc shaped recesses (114) defined therein and adapted to fasten and tighten a plurality of radially extending straps around a periphery of said central node and being free of any connection to the wheel;
• and
• a plurality of radially extending flexible straps, which are attached to tips of the triangular portions at their first ends and to said central node (111, 112, 113) at their second ends, wherein said flexible straps are bent and passed through a corresponding buckle (32) located in an arc shaped recess of the central node for tightening said surface contact members in a radial direction,
• wherein said straps are provided with ratchet teeth (30) along at least one of their surfaces, and
• said buckle (32) has a driving thumb (36) which, when pulled in a first direction, adjusts a tightness of each strap and said each strap is prevented from reverse movement by a tooth (38) and a pawl (37) of said buckle (32), wherein said arc shaped recesses provide limited angular movement of said straps or buckles (32) and allows said straps or buckles to match with their corresponding fastening members in cases of uneven distribution of surface contact members around a periphery of the tire.