Window frame structure

Claim 1

A WOODEN FRAME MEMBER FOR WINDOW CONSTRUCTION, COMPRISING: TOP, BOTTOM AND SIDE FRAME MEMBERS ARRANGED AND CONNECTED IN A GENERALLY RECTANGULAR FASHION TO FORM A FRAME FOR A WINDOW, EACH FRAME MEMBER HAVING THE SAME ASYMMETRICAL CROSS-SECTIONAL SHAPE INCLUDING INNER STEPPED SURFACES FORMING RABBETS, ALTERNATE MEMBERS IN SAID FRAME HAVING TONGUES AT EACH END AND THE OTHER MEMBERS IN SAID FRAME HAVING MATING GROOVES TO RECEIVE SAID TONGUES, SAID TONGUES ON SAID ALTERNATE MEMBERS BEING CENTERED ON SAID FRAME MEMBER AND HAVING AN END SURFACE SQUARE WITH THE LENGTH OF THE FRAME MEMBER, SAID TONGUES HAVING AN OUTWARDLY EXTENDING SHOULDER ON EACH SIDE GENERALLY PARALLEL WITH SAID END SURFACE, SAID SHOULDERS BEING SPACED FROM SAID END SURFACE DISTANCES GENERALLY EQUAL TO THE SHORTEST AND LONGEST DISTANCES RESPECTIVELY ACROSS THE FRAME MEMBER TO SAID RABBETS, SAID SHOULDERS BEING ARRANGED OPPOSITELY IN RELATION TO SAID TONGUES AT OPPOSITE ENDS OF THE FRAME MEMBER PROVIDING FOR ASSEMBLY OF THE FRAME MEMBERS WITH THE RABBETS FACING INWARDLY OR OUTWARDLY OF THE FRAME AS DESIRED.