Machine for stacking panels

In a machine for stacking rectangular panels of building material or the like,

• (a) an input conveyor for receiving panels at its rear end and conveying them forwardly therealong,
• (b) an elongated elevator conveyor the top run of which is of variable length pivoted to the forward end of the input conveyor for receiving and further conveying panels from said end of the input conveyor,
• (c) leveling means for confining the extended end of the elevator conveyor to a substantially vertical path during the pivoting movement thereof,
• (d) an elongated discharge conveyor pivoted to the extended end of the elevator conveyor for further conveying panels beyond the end of the elevator conveyor and onto a stack,
• (e) the elevator conveyor pivot and the discharge conveyor pivot lying on parallel axes,
• (f) a first power means for driving all these conveyors to convey panels successively and forwardly therealong until they are discharged from the discharge conveyor, and
• (g) a second power means for elevating the elevator conveyor about its pivotal connection with the input conveyor, wherein said leveling means further includes a plurality of pivot arms pivoted at one end to a base frame and at the other end to the elevator conveyor frame, the lengths and pivot points of the pivot arms determining the travel of the elevator conveyor frame and wherein a pivot arm extends beyond the elevator conveyor frame to a third pivot point so that the elevator conveyor frame pivot is medial to the arm and pulleys mounted at each of the end pivots to support a continuous conveyor belt in conjunction with a third pulley at the end of the elevator conveyor frame pivot so that the conveyor belt path is close to a constant length regardless of the angle of the arm relative to the elevator conveyor frame.