Coat vent construction

Claim 1

A COAT VENT CONSTRUCTION COMPRISING TWO COAT PIECES, EACH PROVIDED WITH A BOTTOM HEM AND A SIDE EDGE PORTION, A LATERAL CUT FORMED IN THE ADJACENT SIDE EDGE PORTION OF ONE BACK PIECE IN SPACED RELATION TO SAID BOTTOM HEM, A VERTICAL SEAM JOINING TOGETHER ADJACENT SIDE EDGE PORTIONS OF THE TWO PIECES DOWN TO THE LATERAL CUT AND PROVIDING A BOOK SEAM ON THE ONE PIECE TERMINATING AT THE LATERAL CUT AND A BOOK SEAM ON THE OTHER PIECE EXTENDING INTO THE BOTTOM HEM OF SAID OTHER PIECE, A FLAP FORMED ON THE ONE SAID PIECE BELOW THE LATERAL CUT AND UNDERLYING THE BOOK SEAM ON THE OTHER SAID PIECE, SAID FLAP HAVING AN OBLIQUE FOLD LINE EXTENDING DOWNWARDLY AND OUTWARDLY ACROSS THE FLAP FROM A POINT NEAR THE INSIDE END OF THE LATERAL CUT TO A POINT ADJACENT ITS LOWER OUTER EDGE, A RECTANGULARLY-SHAPED VENT LINING ON THE INSIDE OF THE FLAP, SAID VENT LINING HAVING AN OBLIQUE FOLD LINE EXTENDING FROM A POINT CENTRALLY OF THE TOP EDGE ANGULARLY DOWNWARDLY TO THE BOTTOM HEM ADJACENT A SIDE EDGE THEREOF, MEANS SECURING TOGETHER THE OBLIQUE FOLD LINES OF THE FLAP AND VENT LINING, MEANS SECURING THE TOP END PORTION OF THE VENT LINING TO THE INTERIOR FACES OF THE BOOK SEAMS, AND MEANS SECURING THE BOTTOIM OF THE VENT LINING TO THE BOTTOM HEM OF THE ONE SAID PIECE.