Patent ID: 7363952

Claim:
A non-return block ( 5 ) for locking a terminal tensioning portion ( 7 ) of snow chains ( 2 ), comprising a body ( 51 ) which defines a channel ( 12 ) within which the terminal portion ( 7 ) passes and a ratchet or pawl ( 13 ) pivoted to the body ( 51 ) to lock said terminal portion ( 7 ), characterised in that it comprises at least one insert ( 62 , 63 ) of soft material on at least one side surface of the body ( 51 ) of the non-return block so as to protrude laterally therefrom to come into contact with the rim ( 8 ) of the wheel of the vehicle preventing deterioration thereof through rubbing, the insert of soft material ( 62 , 63 ) being fixed to said body ( 51 ) of the non-return block by press fitting, wherein that the body ( 51 ) of said non-return block has a through hole ( 154 ) that puts two drawn seats ( 55 ) into communication and in that a first insert ( 62 ) comprises a tang ( 64 ) having a tapered end ( 65 ) defining an annular abutment surface ( 66 ) to allow a press fitting in a seat ( 265 ) provided with a narrowing ( 266 ) formed inside a tang ( 264 ) of a second insert ( 262 ), said communication hole ( 154 ) in the two drawn seats being able to receive the tang ( 264 ) of said second insert ( 262 ).