Abstract: The instrument comprises two rigid yokes 1 and 2 capable of sliding one with respect to the other in the direction of the clearances to be measured between two components (R, 5) and 8. First of all, using an operating member 3, enough force to bring the ball R against the stop b1 of its socket is exerted on the component 5 by means of a spring 10. The comparator 9 is zeroed. Enough force is then exerted on the component 5 to bring the ball R to rest on the opposite stop b2 of its socket, this being done using an operating member 4 that acts in the opposite sense, the clevis mount 8 still being held between two resting faces 6, 7 of the yokes 1, 2. The clearance of the ball R in its socket is then read directly off the comparator 9. Application to measuring clearances in ball joints.

Abstract: A hingeless rotor including a rotor mast driven in rotation about an axis of the rotor, a hub secured in terms of rotation to the mast, and at least two blades, each of which is, firstly, joined to the hub by a root attachment part comprising at least one arm which can twist about a longitudinal pitch-change axis of the blade and, secondly, equipped with a cuff which is rigid in torsion, surrounding the at least one twistable arm, and the radially external part of the cuff, with respect to the rotor axis is secured in terms of torsion to the blade and to the twistable arm about the pitch-change axis, while the radially internal part of the cuff surrounds, without contact, the at least one twistable arm and exhibits a pitch lever projecting towards the outside of the cuff and joined to a pitch-control rod, wherein, for each blade, an intermediate pitch-control ring which is rigid in terms of torsion about the corresponding pitch-change axis, and which surrounds the corresponding at least one twistable arm is a