What is the structure and working principle of telescopic pin type mine car latch？

The telescopic pin type mine car latch is composed of 14 parts. The round pull rod passes through the pin body made of 45 # steel. The lower part of the pull rod is hinged with two short pin plates. The short pin plate and the long pin plate are also riveted with pins. The long pin passes through two long plates and is riveted on the pin body. A cylindrical pressure spiral spring is installed at the upper end of the pull rod, and the spring force is adjusted by the adjusting nut. The handle and sleeve are welded together, and then the cotter pin is used to connect with the pull. The flat steel bent bracelet is welded on the upper end of the pin body. In order to save materials and reduce processing, the retainer ring is used to spot weld the pin body. To protect the lower end from deformation, spot weld a retainer ring. During installation, it shall be noted that the spring force is appropriate and the long and short pin plates can rotate flexibly. Its strength is the bending stress calculated according to the simply supported beam with concentrated load, which is 6 times higher than the safety factor of the bolt material strength specified in the specification.

When the hand ring is held by hand, the finger pulls the lever of the handle and moves upward about 10mm, the spring is compressed, the pin plate is pulled, and the long pin plate is folded into the pin body. Therefore, it can be inserted or taken out of the pin hole of the mining car. When the handle of the pin is pulled by an external force, the long pin plate is always open.