Snow chains
Link-type, diamond pattern snow chains on a front-wheel drive automobile. Snow chains at the front wheel of a grader at the Pikes Peak Highway. Automatic tire chains are permanently mounted near the drive tires and engage by turning a switch, then move into position to fling the pieces of chain under the tires automatically. Automatic chains were invented in 1941 in the United States [1] . The Onspot Automatic Tire Chain System was invented in Sweden in 1977. Snow chains , or tire chains , are devices fitted to the tires of vehicles to provide maximum traction when driving through snow and ice. Snow chains attach to the drive wheels of a vehicle or special systems deploy chains which swing under the tires automatically. Although named after steel chain, snow chains may be made of other materials and in a variety of patterns and strengths. Chains are usually sold in pairs and often must be purchased to match a particular tire size (tire diameter and tread width), althou...