| 摘要 |
Transporting apparatus for stacks of sheets in bookbinding or like machines has an endless chain coupled to equidistant holders which can transport stacks past one or more processing stations. Each holder has a first jaw which is coupled to the chain and is confined to movement in a stationary guide member to prevent tilting or other stray movements of the holder with reference to the chain, and a second jaw which is movable toward and away from the first jaw and carries a set of parallel toothed racks meshing with pinions which are mounted on a shaft rotatable in a bore of the first jaw. A torsion spring biases the second jaw toward the first jaw, and a helical spring serves to normally hold the second jaw against movement toward the first jaw but to permit movement of the second jaw away from the first jaw under the action of cams which can be engaged by a follower provided on the second jaw. The means for disengaging the helical spring from the shaft for the pinions in order to permit movements of the second jaw toward the first jaw under the action of the torsion spring comprises a rod which engages one end of the helical spring and has a follower which can engage one or more stationary cams adjacent to the path of the holders to thereby enlarge the internal diameters of convolutions of the helical spring and to thus cause its disengagement from the shaft. |
