Abstract: Device to feed yarn to machines making use thereof, particularly the weft yarn (T) to gripper or projectile looms, of the type in which the yarn to be feed is unwound from a reserve (R) wound on a drum onto the outlet end of which, where a first yarn deviation takes place, there acts a brake device (FR) which is centered on the drum axis and adjustable along the same, upstream of an outlet yarn guide where a second yarn deviation takes place. The brake device (FR) comprises a frustoconical braking element with continuous surface and differentiated elasticity, carried by a stiff ring support to which it is fixed close to its major circumference, and the stiff ring support is mounted so as to oscillate about two axes (S1, S2) which are perpendicular one in respect of the other and both in respect of the axis of the drum.