C-type fastener

Claim 1

IN A ONE-PIECE C-TYPE SPRING SHEET METAL FASTENER, A LOWER ARM PORTION IN THE FORM OF A FLAT PLATE, AN UPPER ARM PORTION SPACED ABOVE THE LOWER ARM PORTION, MEANS INTEGRAL WITH SAID UPPER AND LOWER ARM PORTIONS DISPOSED AT ABOUT RIGHT ANGLES TO SAID LOWER ARM PORTION AND CONNECTING CORRESPONDING EDGES OF SAID UPPER AND LOWER ARM PORTIONS, SAID UPPER ARM PORTION COMPRISING A PAIR OF LATERALLY SPACED SPRING STRIPS INCLINING FROM SAID CONNECTING PORTION TOWARD AND INTO JUXTAPOSED RELATION WITH SAID LOWER ARM PORTION, A PANEL INTEGRAL WITH THE ENDS OF SAID SPRING STRIPS, SAID PANEL BEING INCLINED AWAY FROM THE LOWER ARM PORTION AND CONNECTING WITH THE ENDS OF THE SPRING STRIPS ALONG A LINE OF BEND, AND A MAIN PLATE BETWEEN THE SPRING STRIPS HAVING ONE END INTEGRAL WITH SAID INCLINED PANEL, AND A FREE END TOWARD SAID CONNECTING MEANS, SAID MAIN PLATE BEING NORMALLY DISPOSED AT ANGLES WITH RESPECT TO BOTH SAID SPRING STRIPS AND INCLINED PLATE AND JOINING THE LATTER ALONG A LINE OF BEND CONSTITUTING A SUBSTANTIAL CONTINUATION OF THE FIRST-MENTIONED LINE OF BEND AND A NUT IMPRESSION, SAID MAIN PLATE BEING SEPARATE FROM SAID SPRING STRIPS FROM THE FREE END THEREOF AT LEAST TO APPROXIMATELY THE LINE OF BEND ALONG WHICH SAID SPRING STRIPS CONNECT WITH THE PANEL, SAID MAIN PLATE, IN THE UNSTRESSED CONDITION OF SAID FASTENER, BEING DISPOSED IN A PLANE PARALLEL TO SAID LOWER ARM AND WITH THE FREE END SPACED NORMALLY BELOW THE JOINTURE BETWEEN SAID SPRING STRIPS AND SAID CONNECTING MEANS, WHEREBY SAID MAIN PLATE AND SAID LOWER ARM MAINTAIN SUBSTANTIAL PARALLELISM WHEN GRIPPING PANELS OF DIFFERENT THICKNESS.