Method of and apparatus for reversing spring cords

Claim 1

IN COMBINATION WITH A HELIX-REVERSING AND OVERTWISTING APPARATUS OF THE TYPE WHEREIN A PAIR OF CLAMPS SECURE OPPOSITE ENDS OF A SPRING CORD, THE CLAMPS ARE ADVANCED TO CARRY THE CORD TRANSVERSELY OF ITS LENGTH ALONG A DEFINITE PATH, AND RELATIVE ROTATION IS EFFECTED BETWEEN THE ADVANCING CLAMPS ALONG A PORTION OF THE PATH SO AS TO REVERSE THE HELIX OF THE CORD AND OVERTWIST THE SAME; AN IMPROVED MECHANISM FOR STRETCHING THE CORD WHICH COMPRISES A FIRST STRETCHING CONVEYOR HAVING A FINGER PROJECTING THEREFROM DESIGNED FOR ENGAGING A FIRST INTERMEDIATE PORTION ALONG THE CORD BEFORE THE START OF THE HELIXREVERSING OPERATION AND FOR MAINTAINING ENGAGEMENT THEREWITH DURING A FIRST SUBSTANTIAL PORTION OF THE HELIX-REVERSING OPERATION, SAID FIRST CONVEYOR BEING ARRANGED SO THAT THE FINGER CROSSES THE PATH OF THE CORD AND TRAVELS AT AN ACUTE ANGLE WITH RESPECT TO THE DIRECTION OF ADVANCEMENT OF THE CLAMPS SO AS TO PULL THE INTERMEDIATE PORTION OF THE CORD AWAY FROM THE CLAMPED ENDS THEREOF TO STRETCH THE CORD INTO A CURVED PATH OF PROGRESSIVELY INCREASING LENGTH; MEANS FOR DRIVING SAID FIRST CONVEYOR AT SUCH A SPEED THAT THE SPEED COMPONENT OF THE FINGER THEREOF IN THE DIRECTION OF ADVANCEMENT OF THE CLAMPS IS GREATER THAN THE SPEED OF THE CLAMPS, SO THAT THE FIRST INTERMEDIATE PORTION OF THE CORD LEADS THE CLAMPED ENDS THEREOF BY PROGRESSIVELY INCREASING AMOUNTS DURING THE INTERVAL OF ENGAGEMENT WITH SAID FIRST CONVEYOR; A FIRST TRANSFER WHEEL HAVING A PIN PROJECTING THEREFROM DESIGNED FOR ENGAGING A SECOND INTERMEDIATE PORTION ALONG THE CORD SO AS TO PICK THE CORD OFF OF SAID FIRST CONVEYOR AND LATER RELEASE THE CORD AFTER STRETCHING THE CORD ADDITIONALLY TO A MAXIMUM LENGTH DURING THE INTERVAL OF ENGAGEMENT WITH THE CORD; A SECOND STRETCHING CONVEYOR HAVING A FINGER PROJECTING THEREFROM DESIGNED FOR ENGAGING A THIRD INTERMEDIATE PORTION ALONG THE CORD AS THE CORD IS RELEASED BY SAID FIRST TRANSFER WHEEL AND FOR MAINTAINING ENGAGEMENT THEREWITH DURING THE REMAINDER OF THE HELIX-REVERSING OPERATION; MEANS FOR DRIVING SAID SECOND CONVEYOR AT SUCH A SPEED THAT THE FINGER THEREOF TRAVELS AT SUBSTANTIALLY THE SAME SPEED AS THE CLAMPS SO THAT THE CORD IS STRETCHED BY A SUBSTANTIALLY CONSTANT AMOUNT DURING THE INTERVAL OF ENGAGEMENT WITH SAID SECOND CONVEYOR; AND A SECOND TRANSFER WHEEL HAVING A PIN PROJECTING THEREFROM DESIGNED FOR ENGAGING A FOURTH INTERMEDIATE PORTION ALONG THE CORD SO AS TO PICK THE CORD OFF OF SAID SECOND CONVEYOR AT APPROXIMATELY THE POINT WHERE THE OVERTWISTING OPERATION STARTS AND LATER RELEASE THE CORD AFTER THE OVERTWISTING OPERATION WHILE STRETCHING THE CORD ADDITIONALLY DURING THE MAJOR PORTION OF THE OVERTWISTING OPERATION, THE SPEED OF SAID MEANS FOR DRIVING SAID FIRST CONVEYOR BEING SET AT SUCH A VALUE THAT THE CORD REACHES SAID SECOND TRANSFER WHEEL AT APPROXIMATELY THE START OF THE OVERTWISTING OPERATION.