Abstract: Each pack has a pair of opposite edges and a pair of locating pins, and is also provided with pairs of holes separated by a distance equal to that between the pins to enable the packs to be stacked in offset manner, with the pins inserted inside the holes of the underlying pack. The loading and unloading device has a loading station and an unloading station located on either side of the worktable; and a transfer device movable between the stations and a fixture on the worktable for clamping the pack for machining. An unpinning mechanism for unpinning the pack has punches which are activated to remove the pins from the pack before the pack is deposited at the unloading station.

Abstract: The workpiece or pack of printed circuit boards is fitted to a clamping fixture carried by the table and is machined by a machining head; the head and the table being movable with respect to each other along two coordinate X, Y axes. The aligning method includes the steps of providing the pack with two locating holes; fitting the pack to the fixture; determining the distances between the real positions of the holes and two reference positions; and moving the pack on the fixture to eliminate the distances. The aligning device has an optoelectronic sensor carried by the head to determine the real position of each hole; and a number of motors controlled on the basis of the real position of each hole to move a locating member for locating a first pin on the pack, and to move one bar of a pair of bars for clamping the other pin on the pack.