Side vertical gear shaft automatic releasing unit for trailer

The utility model relates to a trailer cross-stand bumping post automatically casting device for the oil field well repairing work carrying the tubular products. The utility model consists of a short fulcrum 2, a long fulcrum 5, a long block 7 which is fixedly arranged on a supporting base 4 by a three link mechanism which consists of an annul axes 3, an annul axes 6 and an air cylinder 10 which is connected with the annul 3 and an annul axes 9. The utility model has simple structure, convenient operation, is safe and practical, and can be utilized for realizing the automatic discharging and managing during the well repairing work or other constructions carrying the tubular products, thereby ensuring the personal safety, reducing the labor intensity of workers, greatly elevating the work efficiency and is suitable for popularization.