172 extends inwardly but does not engage a plate 60 because walking beam 70 is below the plates however as walking beam 72 is raised cam follower wheel 180 engages cam plate upper portion 196 pivots the upper end of lever 172 outwardly against spring pressure so as to allow a plate 60 to be properly positioned longitudinally between opposing lands 90 after a plate 60 has been received on ledges 102 of beam members 72 and 74 cam follower wheel 180 clears cam plate 182 as walking beam 70 is lifted further whereupon the spring forces the upper end of lever 172 into engagement with plate 60 in this manner plate 60 is removably rigidly held between lever 172 and the opposing vertical member 98 of beam member 74 after walking beam 70 has been positioned to its forwardmost position and as it is being lowered cam follower wheel 180 strikes cam plate 184 pivoting lever 172 against spring pressure out of engagement with the plate 60 thus a plate 60 can be deposited onto rail 80 as walking beam 70 continues to travel downwardly working in cooperation with walking beam clamping assembly 170 is a further assembly 198 depicted in fig2 and 6 for permitting a pitching motion of plate 60 when in engagement with a laminate on drum 38 plate motion permitting assembly 198 is comprised of two spaced apart cylindrical rods 200 mounted.