| 摘要 |
<p>A machine for clipping strip material including a blade operated in a cyclic manner having a cutting stroke and a return stroke. A toggle linkage includes a toggle bar which moves in a longthwise direction to reciprocate the blade by toggle linkages. The toggle bar is coupled to an actuating piston rod of a pneumatic cylinder. End caps of the cylinder are recessed to receive piston extensions during final stages of piston travel for cushioning purposes. Seal means engage each piston extension during the later stage of piston travel to trap air between the advancing piston and the end cap to dissipate blade and linkage inertia. Exhaust ports within each of said end caps a?e valve controlled to release cylinder pressure at a desired pressure prior to completion of piston travel. A modified cylinder includes exhaust poppet valves each subject to a valve regulated, poppet closing pressure as in the first form of cylinder and additionally having a surface area thereon against which a secondary supplementary source of air may act to hold the poppet closed against extremely high piston actuating pressures. The modified cylinder further includes end caps each having a port served by an end cap mounted valve to admit a piston impinging charge and a remaining port admitting a secondary flow into the cylinder and controlled by an end cap mounted valve.</p> |
