Telescopic device for crawler-type self-moving tail system

The utility model discloses a telescopic device for a crawler-type self-moving tail system, which is positioned between a first crawler and a second crawler, the left end of the telescopic device is fixedly connected with a second transportation mechanism, and the right end of the telescopic device is fixedly connected with a first transportation mechanism. The installation device is used for unfolding when the first crawler moves towards the working face and is further used for contracting when the second crawler moves towards the working face when the first crawler is static, so that a gap is formed in the left side of the installation device, and a middle belt frame is additionally arranged in the gap. The middle belt frame and the middle belt frame installed on the left side are in butt joint with each other and are matched to continuously convey coal; the telescopic device comprises a motion track and at least two motion units. According to the utility model, the gap can be greatly prolonged and can reac