標準號：IS 12351-1988
發布日期：1988/9/1 12:00:00
實施日期：1999/12/31 12:00:00
適用范圍：1.Lays down the dimensional characteristics necessary for the compatibility of mechanical coupling devices between light trailers, caravans and towing vehicles when the latter are fitted with a coupling ball.1.1 This standard applies to a coupling ball designed for caravans and light trailers, the maximum total weight of which is less than or equal to 3.5 tonnes. It does not necessarily apply to special trailers drawn by special vehicles.Note — The value 3.5 tonnes is chosen to include categories T1and T2 of trailers according to the classification of vehicles given in IS: 11852 (Part2)-1987 'Recommendations for brakes and braking systems for automotive vehicles : Part 2 General functions and features'.