Purposes and features：
MQQSD-G series of automatic braking positioner（hereinafter referred to as brakes）may make a crane that is running away under wind force to be positioned into the concave part after running over through the boss on the tip of the iron shoe, and reliably fixed onto the iron shoe, with independence of tracks. It may effectively overcome the rebounding to the iron shoe after the travel is impacted on the iron shoe. With full pressure of the crane travel applied to the iron shoe, the friction braking resistance is resulted between the iron shoe bottom and track, forcing the running-away crane under the wind force to be slowed down and braked. Each crane needs to be provided with four brakes, which should be distributed on both sides with two unit according to the crane traveling direction, allowing that the crane travels left or right with two brakes simultaneously fixing the crane. It features falling in case of power failure, easy operation, and operating safety and reliability.
Data sheet of installation drawing：