Sign letter constructions

Claim 1

IN AN ILLUMINATED SIGN LETTER STRUCTURE, A GENERALLY FLAT LETTER-FORM THROUGH WHICH LIGHT CAN PASS, A MEMBER MADE OF COMPOSITE STRIP MATERIAL BENT TO CONFORM TO THE PARIPHERY OF SAID LETTER-FORM AND POSITIONED ALONG THE ENTIRE PERMITER OF SAID LETTER-FORM AS A FRAME THEREAROUND; SAID COMPOSITE STRIP MATERIAL CONSITUTING A FLAT METAL PLY SANDWICHED BETWEEN TRANSPARENT PLASTIC PLIES; SAID LETTER-FORM BEING IN CONTACT WITH AT LEAST ONE OF SAID PLASTIC PLIES AND BONDED THERETO; THE WIDTH OF SAID COMPOSITE STRIP MATERIAL BEING SUBSTANTIALLY GREATER THAN THE THICKNESS OF SAID LETTER-FORM; SAID LETTER-FORM BEING RECRESSED IN SAID FRAME FROM THE FRONT EDGE OF SAID FRAME; SAID FRAME INCLUDING A PERIMETRICAL EDGING EXTENDING INWARDLY OF SAID FRAME FROM THE PERIMATRICAL FRONT EDGE OF SAID FRAME TO SAID LETTER-FORM; SAID EDGING CONSITUTING A METAL PLY SANDWICHED BETWEEN TRANSPARENT PLIES; THE FRONT SURFACE OF SAID LETTER-FORM BEING IN CONTACT WITH THE ENTIRE INNER PERIMETRICAL EDGE OF AT LEAST THE EXPOSED PLASTIC PLY OF SAID EDGING; THE EXPOSED PLASTIC PLY OF SAID INWARDLY EXTENDING PERIMETRICAL EDGING WHOSE EDGE IS IN CONTACT WITH SAID LETTER-FORM BEING OF A SUFFICIENT THICKNESS TO PICK UP ILLUMINATION FROM THE LETTER-FORM, TRANSMIT THE LIGHT RAYS THROUGH SAID EDGING AND EMIT SAID RAYS AT THE FRONT PERIMETRICAL EDGE OF THE EDGING WHEN THE LETTERFORM IS ILLUMINATED FROM BEHIND.