rod bent into a form having three lobes 44 46 and 48 generally congruent with the lobes 30 32 and 34 so as to fit in close contact therewith as shown in fig7 the assembly is started by threading a bilaterally crimped and compacted ribbon 50 produced by the method described above and appearing as in fig1 through the three pairs of legs so as to produce the configuration shown in fig2 the frame 22 is shown in fig1 in exploded relation to fig2 for clarity of illustration the upper selvage has no uncut yarns and forms the free edges 52 54 and 56 of valve leaflets thus a double layer of the fabric is passed through each pair of rod portions forming one of the legs 24 26 and 28 it is necessary to attach the fabric firmly to these legs and also to the connecting lobes 30 32 and 34 to facilitate this attachment the fabric is preferably cut lengthwise externally of each leg as shown in fig6 referrng to fig6 adhesive such as polyurethane dissolved in tetrahydrofuran is applied to attach the fabric to each of the legs as follows flaps such as 58 and 60 are spread apart and the adhesive is applied at the external point of juncture of the flaps where they enter between the rod portions in a continuous line extending between points a and b the adhesive material reaches to the external surfaces of the frame by penetration through the fabric flaps along this line that is the adhesive contacts the rod portions of the frame only on their outer surfaces the leaflets comprise only those portions of the fabric on the inside of the frame and these portions are not.