摘要 |
A drive shaft for transmitting motion to a roll of a tube rolling stand comprising a telescopic body, a slide and a support base. The telescopic body is fixed by one end with a cardan joint to the drive shaft of the gearbox, and on the other end has a fitting for attaching the roll. The slide is hinged to the support base and may rotate under the bias of a jack to either engage or release the telescopic body. A snap-action locking device, contained within the telescopic body, comprises a cylinder, on which two rocker arms are hinged, and a spring which spreads the rocker arms making the two teeth fit into two holes in the wall of the cylinder, when the drive shaft is at its maximum working length. The carriage has two pistons to work on the two rocker arms thus freeing the locking device and allowing the telescopic sliding of the cylinder in the cylinder and the downward rotation of the drive shaft. |