Single gripper conveyor system

Abstract

A chain conveyor moves gripper assemblies to pass a pickup station. A signature stream moves at a faster velocity beneath the gripper assemblies whereby the leading edge of each signature enters the open jaws of a gripper assembly. A closing cam closes the jaws which firmly grip the leading end. The gripper assemblies enter a curve abruptly accelerating the gripped signature and the upstream signature resting thereon to facilitate its entry into the next set of jaws. A conveyor delivers the signature stream to the pickup station. A vacuum is provided to retain signatures in alignment on the conveyor, the vacuum condition terminating before a signature is gripped by the jaws. Each gripper assembly includes a wrap spring normally holding the jaws closed. When a release ring engages an opening cam, the wrap spring opens the jaws. A closing lever roller engages a closing cam to close the jaws to firmly grip a signature. Otherwise, the jaws are maintained open by the clutch, enabling selective release of the jaws. Signatures are dropped when the release ring engages an opening cam releasing the clutch and thus the jaws. The chain links are unitary bodies with guide rollers to guide the chain through a track which may traverse a small diameter curve due to a pivot ball embedded in each link by molding which ball swivels the roller shaft and joins adjacent link and supports vertical guide rollers. Each link positively mounts a gripper assembly.