Convertible billing and reply envelope

Claim 1

A CONVERTIBLE ENVELOPE PROVIDED TO BE MAILED BY AN ORIGINAL SENDER TO AN ADDRESSEE FOR TRANSMITTING A MESSAGE REQUIRING A REPLY, SAID ENVELOPE COMPRISING: A SHEET OF PAPER TRANSVERSELY CREASED TO DIVIDE SAID SHEET INTO THE FOLLOWING ELEMENTS ARRANGED CONSECUTIVELY, A FRONT ENVELOPE POCKET WALL, A BACK ENVELOPE POCKET WALL, A PRIMARY ENVELOPE CLOSING FLAP, AND A SECONDARY ENVELOPE CLOSING FLAP SAID POCKET WALLS BEING CONNECTED TOGETHER ALONG THEIR LATERAL EDGES TO FORM AN ENVELOPE POCKET SAID PRIMARY FLAP ALSO HAVING A TRANSVERSE FOLD BISECTING AREA OF SAID FLAP AND CAUSING SAID PRIMARY FLAP TO BE FOLDED FORWARDLY UPON ITSELF TO INVERT SAID SECONDARY FLAP AND SUPERIMPOSE IT UPON SAID FRONT POCKET WALL, SAID SECONDARY FLAP HAVING A HOLE THROUGH WHICH THE ADDRESS OF THE ADDRESSEE MAY BE WRITTEN WITHIN A CERTAIN AREA ON SAID FRONT POCKET WALL EXPOSED THROUGH SAID HOLE; PRESSURE SENSITIVE COPYING MEANS RESPONSIVE TO PRESSURE APPLIED TO THE UPWARDLY EXPOSED SURFACE OF SAID SECONDARY FLAP IN WRITING OR TYPING A MESSAGE THEREON TO PRODUCE A COPY OF SAID MESSAGE DIRECTLY THEREBENEATH ON SAID FRONT POCKET WALL; MEANS FOR HOLDING SAID SECONDARY FLAP IN CLOSING RELATION WITH SAID POCKET WHEN SAID TWO FLAPS ARE WOUND BACKWARDLY AROUND SAID POCKET FOR THE INITIAL MAILING OF SAID ENVELOPE THEREBY HIDING SAID MESSAGE AND THE COPY THEREOF WHILE EXPOSING SAID ADDRESS TO VIEW THROUGH SAID HOLE; AND MEANS FOR HOLDING SAID PRIMARY FLAP IN CLOSING RELATION WITH SAID POCKET WHEN FOLDED FORWARDLY AGAINST SAID FRONT POCKET WALL AFTER SAID SECONDARY FLAP HAS BEEN SEPARATED FROM SAID PRIMARY FLAP BY THE ADDRESSEE FOR THE RETURN MAILING OF SAID ENVELOPE.