Machines for cutting or shearing sheets or plates

Claim 1

A SHEARING MACHINE COMPRISING A FRAME HAVING A HORIZONTAL TABLE SURFACE UPON WHICH THE WORK TO BE CUT IS PLACED, A TOOL BEAM ABOVE SAID TABLE SURFACE PIVOTALLY CONNECTED AT ONE END TO SAID FRAME ADJACENT ONE SIDE OF SAID HORIZONTAL TABLE SURFACE, A MOVABLE CUTTER BLADE SECURED TO SAID TOOL BEAM AT RIGHT ANGLES TO THE PIVOT AXIS THEREOF, A STATIONARY CUTTER BLADE SECURED TO SAID TABLE SURFACE SUBSTANTIALLY COPLANAR THEREWITH AT RIGHT ANGLES TO THE TOOL BEAM PIVOT AXIS FOR SHEARING COOPERATION WITH SAID MOVABLE CUTTER BLADE, THE CUTTING EDGE OF SAID MOVABLE CUTTER BLADE HAVING A PREDETERMINED DOWNWARD INCLINATION IN A DIRECTION AWAY FROM THE BEAM PIVOT AXIS SO THAT DURING CUTTING OPERATION THE END OF THE MOVABLE CUTTER BLADE REMOTE FROM THE TOOL BEAM PIVOT AXIS WILL COOPERATE WITH SAID STATIONARY BLADE BEFORE THE END OF SAID MOVABLE CUTTER BLADE WHICH IS ADJACENT SAID PIVOT AXIS, AND MEANS CONNECTED TO SAID TOOL BEAM AT THE OTHER END THEREOF REMOTE FROM SAID PIVOT AXIS FOR PIVOTING SAID TOOL BEAM TOWARD SAID TABLE SURFACE, SAID MOVABLE CUTTER BLADE BEING SECURED TO SAID TOOL BEAM IN SUCH MANNER THAT THE CUTTING INTERSECTION BETWEEN SAID STATIONARY CUTTER BLADE AND SAID MOVABLE CUTTER BLADE LIES ALWAYS IN A STRAIGHT LINE WHICH APPROXIMATELY CAN BE DRAWN THROUGH THE TOOL BEAM PIVOT AXIS AND THE POINT OF CONNECTION OF THE MEANS FOR PIVOTING SAID TOOL BEAM ABOUT ITS PIVOT AXIS TOWARD SAID TABLE SURFACE, WHEREBY SAID MOVABLE CUTTER BLADE HAS A SUBSTANTIALLY TRUE ANGLE OF CUT THROUGHOUT ITS LENGTH AND A PROGRESSIVELY INCREASING SHEARING ACTION STARTING FROM ITS END FURTHEST FROM SAID PIVOT AXIS.