Tension lockup for thin printing plates

Claim 1

IN COMBINATION, A PRINTING CYLINDER HAVING A LONGITUDINAL SLOT IN THE SURFACE THEREOF, A THIN PRINTING PLATE ADAPTED TO BE CONFORMED TO AND SUPPORTED BY THE SURFACE OF SAID CYLINDER, SAID PLATE HAVING CHANNELS FORMED ALONG ITS OPPOSITE EDGES, AN ELONGATED SPRING OF GENERALLY USHAPED CROSS SECTION HAVING A BIGHT DISPOSED IN THE LOWER PORTION OF SAID SLOT DEFINING ARM PORTIONS AND HAVING NIBS ADJACENT THE SURFACE OF SAID CYLINDER, A PLURALITY OF FASTENING ELEMENTS ENGAGING ONE ARM PORTION OF SAID SPRING SO AS TO ANCHOR THE SPRING IN SAID SLOT WITH THE NIBS ON SAID ONE ARM PORTION BEING FIXED AND THE NIBS ON THE OTHER ARM PORTION BEING FLEXIBLE SUPPORTED BY THE FULL EXTENT OF SAID BIGHT, SAID NIBS BEING FORMED TO ENTER SAID CHANNELS ON THE OPPOSED EDGES OF SAID PLATE AS SUCH NIBS ARE MOVED TOWARD ONE ANOTHER, SAID SPRING BEING FORMED SUCH THAT SAID NIBS ARE NORMALLY CLOSELY SPACED FROM ONE ANOTHER AND WHEN MOVED APART ARE BIASED TOWARD ONE ANOTHER, AND A CAM SHAFT EMBRACED BY SAID ARM PORTIONS OF SAID SPRING AND ROTATABLE TO SPREAD OR RELAX SAID NIBS.