Abstract: A measuring apparatus is provided with a stylus (30), including a column (12), a carriage (14) slidably mounted on the column (12) and a stylus carrier (32). The stylus carrier (32) carries the stylus (30) and is secured to the carriage (14). The stylus carrier (32) is provided with a bar (42) and a support (44). The support (44) is secured to one of the ends of the bar (42). The stylus (30) is secured to the support (44). The carriage (14) is provided with two supports (54, 56) arranged longitudinally on one of the sides of the slide (52), one at each of its ends. The two supports (54, 56) are in contact with one of the faces of the bar (42). A locking member (58) is formed of a lock (74) and cooperates with the other face of the bar (42). A spring (78) generates a blocking force (F) which applies the lock (74) against the bar (42). The force (F) is oriented along an axis passing between the two supports (54, 56).

Abstract: An instrument for measuring the dimensions of a rigid object (10) comprises a fixed member (1), a mobile member (2) slidably mounted on the fixed member, means for indicating the resulting measurement, and a locking device (3) allowing the mobile member (2) to be moved on the fixed member (1) to hold two bearing points (X, X') on the members in contact with the object (10) being measured with a substantially constant bearing force. The locking device comprises a first sleeve (20) slidably mounted on the mobile member (2) under the action of springs (24), and a second sleeve (30) slidably mounted on the fixed member (1) and inside which is a tipping ring (36) connected by a rod (40) to the first sleeve. The second sleeve (30), by acting on the first sleeve (20), enables loading the springs (24) to produce the bearing force when the instrument is in contact with the object (10) being measured.