Shearing apparatus having yieldable work-stop means

Claim 1

SHEARING MEANS FOR SHEARING METAL PLATES OR THE LIKE COMPRISING, IN COMBINATION, SUPPORT MEANS; A PAIR OF SHEAR BLADES HAVING EACH A CUTTING EDGE, ONE OF SAID BLADES BEING STATIONARILY AND THE OTHER MOVABLY MOUNTED ON SAID SUPPORT MEANS MOVABLE BETWEEN AN OPEN POSITION IN WHICH SAID CUTTING EDGES ARE SPACED FROM EACH OTHER SO THAT A PLATE TO BE CUT MAY BE FED BETWEEN SAID CUTTING EDGES AND A CUTTING POSITION IN WHICH THE CUTTING EDGE OF THE MOVABLE BLADE CUTS THROUGH THE PLATE; AND STOP MEANS ON SAID SUPPORT MEANS AND COMPRISING A MEMBER FIXED TO SAID SUPPORT MEANS AT A SELECTED DISTANCE FROM SAID CUTTING EDGES OF SAID BLADES, ENGAGING MEANS SPACED FROM SAID MEMBER AND ON THE SIDE OF THE LATTER FACING SAID BLADES AND CONSTRUCTED AND ARRANGE SO AS TO ENGAGE THE FRONT EDGE OF A PLATE FED BETWEEN SAID BLADES IN OPEN POSITION, CONNECTING MEANS CONNECTING SAID ENGAGING MEANS TO SAID MEMBER AND BEING CONSTRUCTED AND ARRANGED TO PREVENT MOVEMENT OF SAID ENGAGING MEANS AWAY FROM SAID MEMBER BEYOND A PREDETERMINED DISTANCE WHILE PERMITTING MOVEMENT OF SAID ENGAGING MEANS TOWARD SAID MEMBER, AND PRESTRESSED SPRING MEANS OPERATIVELY CONNECTED TO SAID ENGAGING MEANS AND SAID MEMBER AND BIASED TO MAINTAIN SAID ENGAGING MEANS SPACED SAID PREDETERMINED DISTANCE FROM SAID MEMBER IN A STOPPING POSITION DETERMINING THE DISTANCE OF THE FRONT EDGE OF THE PLATE FROM SAID CUTTING EDGES OF SAID BLADES WHILE PERMITTING SAID ENGAGING MEANS TO YIELD TOWARD SAID MEMBER WHEN DURING CUTTING OF THE CUTTING EDGE OF SAID MOVABLE BLADE THROUGH SAID PLATE OF FORCE IS EXERTED BY SAID FRONT EDGE OF THE PLATE ON SAID ENGAGING MEANS WHICH IS GREATER THAN THE FORCE DEVELOPED BY SAID PRESTRESSED SPRING MEANS, WHEREBY THE FORCE EXERTED BY THE CUT EDGE OF THE PLATE ON SAID MOVABLE BLADE WILL BE REDUCED SUBSTANTIALLY TO THE FORCE OF THE COMPRESSED SPRING MEANS.