Top rushing prevention device for lifting hook of overhead and portal crane

The utility model relates to an anti-top-rushing device for a lifting hook of a portal crane, which solves the safety problem of use in an extremely cold working site. The sections of the upper fixing support and the lower fixing support are U-shaped in opposite directions, the upper ends of two vertical walls of the U-shaped upper fixing support are connected with the lower portion of the winch, a round plate is arranged on the bottom face of the U-shaped upper fixing support, a safety pin linkage device is fixedly installed on the round plate, and symmetrical grooves are formed in the two sides of a cylindrical hole of the round plate and located in a shaft of a rectangular plate. The inclined surface of the safety pin is matched with a top block; the top block is matched with a hole in a shaft of the rectangular plate; the large end of the top block is matched with the inclined surface of the safety pin; the small end of the top block is matched with the large edge of a safety pin linkage device; and the s