Device for positioning and attaching an auxiliary snow-chain device for motor vehicles

A snow-chain device intended to be arranged under a motor vehicle, having an engaged and a retracted position, and comprising a plurality of lengths of chain, a chain-wheel having a circular rim defining a geometric plane, said rim being adapted to press against one wheel of said vehicle in said engaged position, a swivel arm, support means, and motor means held by said support means and arranged for rotating said swivel arm about a first axis of rotation having a predetermined direction with respect to said support means, said chain-wheel being freely-pivotally mounted at a free end of said arm to rotate about a second axis of rotation perpendicular to said plane and having a predetermined direction with respect to said arm, and said plurality of lengths of chain being distributed around said chain-wheel, with one end of each chain secured to said wheel, wherein said support means comprises a cage enclosing said motor means, said cage comprising at least two suspension locations at predetermined positions within said cage, the device further comprising a plurality of locking and attachment components, said components being arranged for cooperating with said suspension locations to allow securing of said cage under said vehicle and adjusting the position of said cage such that said second axis of rotation and said plane have predetermined positions with respect to said one vehicle wheel when said swivel arm extends in said engaged position under the influence of said motor means.