Oscillating backstop for right angle delivery

Claim 1

EQUIPMENT FOR FORMING STACKS OF SHEET MATERIAL COMPRISING A NORMALLY STATIONARY TRANSFER CONVEYOR, A FEEDING CONVEYOR HAVING A DISCHARGE END, SAID FEEDING CONVEYOR EXTENDING AT RIGHT ANGLES TO SAID TRANSFER CONVEYOR SUCCESSIVELY TO DISCHARGE SAID SHEETS THEREON, MEANS TO INTERRUPT DISCHARGE OF SHEETS FROM SAID FEEDING CONVEYOR ONTO SAID TRANSFER CONVEYOR, A BACKING MEMBER EXTENDING LONGITUDINALLY OF SAID TRANSFER CONVEYOR ADJACENT THE DISCHARGE END OF SAID FEEDING CONVEYOR AND BELOW THE HORIZONTAL PLANE OF THE LATTER, A BACKSTOP EXTENDING LONGITUDINALLY OF SAID TRANSFER CONVEYOR AND TRANSVERSELY SPACED FROM THE BACKING MEMBER SO THAT AT LEAST THE LOWER EDGE THEREOF IS NORMALLY LOCATED AT A DISTANCE FROM SAID BACKING MEMBER SUBSTANTIALLY EQUAL TO THE WIDTH OF THE STACK TO BE FORMED, SAID SHEETS BEING ADAPTED TO ABUT AGAINST SAID BACKSTOP UPON DISCHARGE ONTO SAID TRANSFER CONVEYOR, AND MEANS WHEN THE DISCHARGE OF SHEETS ONTO SAID FIRST CONVEYOR IS INTERRUPTED TO EFFECT PIVOTAL MOVEMENT OF SAID BACKSTOP TO MOVE THE LOWER END THEREOF TO A RETRACTED POSITION AWAY FROM SAID PREDETERMINED POSITION AND TO EFFECT MOVEMENT OF SAID TRANSFER CONVEYOR TO MOVE THE STACK OF SHEETS THEREON AWAY FROM SAID DISCHARGE END IN DIRECTION AT RIGHT ANGLES TO THE DIRECTION OF DISCHARGE ONTO SAID TRANSFER CONVEYOR.