Transmission joint

1. A transmission joint ( 1 , 1 ′, 1 ″, 1 ′″) for angularly connecting a first member ( 2 , 2 ′, 2 ″) and a second member ( 4 , 4 ′, 4 ″, 4 ′″), and comprising at least one coupling member ( 5 a , 5 b ; 5 a ′, 5 b ′; 5 a ″, 5 b ″; 5 ′″) interposed functionally between said first and second members ( 2 , 2 ′, 2 ″; 4 , 4 ′, 4 ″, 4 ′″) and extending about an axis (A); said coupling member ( 5 a , 5 b ; 5 a ′, 5 b ′; 5 a ″, 5 b ″; 5 ′″) comprising:

a first portion ( 6 , 6 ′, 6 ″, 6 ′″) connectable angularly to said first member ( 2 , 2 ′, 2 ″);

a second portion ( 7 , 7 ′, 7 ″, 7 ′″) connectable angularly to said second member ( 4 , 4 ′, 4 ″, 4 ′″) and located radially outwards of said first portion ( 6 , 6 ′, 6 ″, 6 ′″); and

an intermediate portion ( 8 , 8 ′, 8 ″, 8 ′″) interposed radially between said first and second portions ( 6 , 6 ′, 6 ″, 6 ′″; 7 , 7 ′, 7 ″, 7 ′″) and elongated in a direction (D) crosswise to said axis (A);

said intermediate portion ( 8 , 8 ′, 8 ″, 8 ′″) of said coupling member ( 5 a , 5 b ; 5 a ′, 5 b ′; 5 a ″, 5 b ″; 5 ′″) comprising, from said first portion ( 6 , 6 ′, 6 ″, 6 ′″) to said second portion ( 7 , 7 ′, 7 ″, 7 ′″), a first portion ( 9 , 9 ′, 9 ″, 9 ′″) decreasing in thickness crosswise to said direction (D), and a second portion ( 10 , 10 ′, 10 ″, 10 ′″) of constant thickness;

said intermediate portion ( 8 , 8 ′, 8 ″, 8 ′″) further comprising a flat lateral first face ( 14 , 14 ′, 14 ″, 14 ′″) and a lateral second face ( 15 , 15 ′, 15 ″, 15 ′″) opposite said first face ( 14 , 14 ′, 14 ″, 14 ′″) and connected, at opposite radial ends, to said first and second portion ( 6 , 6 ′, 6 ″, 6 ′″; 7 , 7 ′, 7 ″, 7 ′″);

said first portion ( 6 , 6 ′, 6 ″, 6 ′″) being bounded laterally, at least at a respective outer radial end ( 11 ), by a first surface ( 25 , 25 ′, 25 ″, 25 ′″) contiguous to and coplanar with said first face ( 14 , 14 ′, 14 ″, 14 ′″) of said intermediate portion ( 8 , 8 ′, 8 ″, 8 ′″);

said first portion ( 6 , 6 ′, 6 ″, 6 ′″) being bounded laterally, on the opposite side to said first surface ( 25 , 25 ′, 25 ″, 25 ′″), by a second surface ( 26 ) which, from said outer radial end ( 11 ) towards said axis (A), comprises a first region ( 27 ) connected to said second face ( 15 , 15 ′, 15 ″, 15 ′″) of said intermediate portion ( 8 , 8 ′, 8 ″, 8 ′″), and a flat second region ( 28 ) sloping with respect to said second face ( 15 , 15 ′, 15 ″, 15 ′″);

said second region ( 28 ) sloping away from said first surface ( 25 , 25 ′, 25 ″, 25 ′″) from said outer radial end ( 11 ) towards said axis (A).

2. The transmission joint as claimed in claim 1 , wherein said first region ( 27 ) is shaped so as to be tangent, at a respective radially outer end section ( 11 ), to an analytic curve defining said second face ( 15 , 15 ′, 15 ″, 15 ′″).

3. The transmission joint as claimed in claim 1 , wherein said intermediate portion ( 8 , 8 ′, 8 ″, 8 ′″) is in the form of a membrane.

4. The transmission joint as claimed in claim 1 , comprising at least one pair ( 20 ; 20 ′, 21 ′; 20 ″, 21 ″) of said coupling members ( 5 a , 5 b ; 5 a ′, 5 b ′; 5 a ″, 5 b ″); wherein said second portions ( 7 , 7 ′, 7 ″) of said coupling members ( 5 a , 5 b ; 5 a ′, 5 b ′; 5 a ″, 5 b ″) in said pair ( 20 ; 20 ′, 21 ′; 20 ″, 21 ″) are angularly connected to each other; said first portion ( 6 , 6 ′, 6 ″) of one of said coupling members ( 5 a , 5 b ; 5 a ′, 5 b ′; 5 a ″, 5 b ″) being connectable angularly to said first member ( 2 , 2 ′, 2 ″); and said first portion ( 6 , 6 ′, 6 ″) of the other of said coupling members ( 5 a , 5 b ; 5 a ′, 5 b ′; 5 a ″, 5 b ″) being connectable angularly to said second member ( 4 , 4 ′, 4 ″).

5. The transmission joint as claimed in claim 4 , wherein said coupling members ( 5 a , 5 b ; 5 a ′, 5 b ′; 5 a ″, 5 b ″) are positioned with said first faces ( 14 , 14 ′, 14 ″) facing each other and interposed axially between said second faces ( 15 , 15 ′, 15 ″).