Thickness adjustable material detector for gripper mechanism

In combination with a mechanism for transferring a single sheet from a magazine to a conveyor during each operational cycle, said mechanism having an oscillatable shaft, a gripper lever fixed to the shaft, a movable jaw, pivot means mounting the movable jaw on the lever, and actuating means connected to the movable jaw for opening and closing thereof to clamp sheets to the gripper lever;

• the improvement comprising sensing means mounted on the gripper lever in spaced relation to the pivot means for displacement in response to movement of the movable jaw to a gripping position on the lever corresponding to the clamping of said single sheet during each of said operational cycles, and means mounted on the shaft remote from the pivot means in engagement with said sensing means for detecting deviation of the movable jaw from said gripping position.

In combination with a mechanism for withdrawing sheets of material from a magazine during operational cycles, said mechanism having an oscillatable shaft, a gripper lever fixed to the shaft, a pivot carried by the lever, a movable jaw mounted on the lever by the pivot, and actuating means connected to the movable jaw for opening and closing thereof to clamp sheets to the gripper lever;

• the improvement comprising sensing means mounted on the lever and engageable with the movable jaw for sensing movement thereof, and limit switch means mounted on the shaft in fixed relation to the lever remote from the pivot for engagement by the sensing means to detect deviation from the thickness of a single sheet of material clamped to the gripper lever by the jaw during withdrawal from the magazine.

In combination with a gripper mechanism comprising a power shaft, a gripper arm having opposite ends, means mounting the gripper arm adjacent one of said ends on the power shaft for rotation in opposite directions to and from an insert pickup position, the other of the ends of the gripper arm forming one portion of a gripper jaw, a pivot rotatably mounted in said gripper arm adjacent to said other of the ends, a gripping jaw affixed to said pivot to form the other portion of said gripper jaw, a movable element displaceable between two extreme positions, a linking lever coacting with and controlling displacement of said movable element, and electrical detection means for detecting the position of said movable element, the improvement comprising housing means for fixedly mounting the movable element and the linking lever on the power shaft adjacent to said one of the ends of the gripper arm and sensing means mounted on the gripper arm in engagement with the gripping jaw and the linking lever for displacement of the movable element relative to the housing means between the two extreme positions causing the detection means to operate.