Crossbar switching network

Claim 1

A crossbar-type switching arrangement comprising a block of insulating material provided with a first set of holes extending in a first common direction and arranged at intervals in a plurality of parallel planes, a second set of holes extending in a second common direction perpendicular to said first direction and arranged in said plurality of parallel planes so that each hole of said second set of holes intersects a plurality of holes pertaining to said first set of holes, a third set of holes extending in a third direction perpendicular to said first and second directions and each intersecting at least one hole in said first set and one hole in said second set of holes, liquid conducting medium contained in each one of said holes of said first and second sets of holes, a piston of insulating material slidably movable in each hole pertaining to said third set of holes, said piston being provided with at least a notch portion, whereby, when said piston is so positioned that its notch portion overlaps a first and second hole respectively pertaining to said first and second sets at their mutual intersection, an electrically conducting connection exists between the medium in latter said first and second holes through the medium located in said notch portion, and, when said piston is so positioned that said notch portion does not overlap latter said first and second holes at their mutual intersection, no electrically conducting connection exists between the medium in latter said first and second holes by virtue of the presence in said intersection of the insulating material of the piston; said arrangement further comprising mechanical control means controlled by electric control means and including a set of connection-deconnection bars parallel to and in number equal to said first set of holes, a set of selection bars parallel to and in number equal to said second set of holes, a means for selectively locking and unlocking each piston in a working position by the motion of one of said connection-deconnection bars, means for selectively causing each piston to slidably move in said third direction between a rest and said working position by the motion of one of said selection bars, and a return spring for returning latter said piston to its rest position.