Abstract: A device for locking and unlocking the position of a moving part of a seat such as a seat on an airplane or other vehicle is disclosed. The device includes a screw and nut assembly with a clamping element. The clamping element allows movement of the moving part of the seat when the clamping element is released and holds the moving part of the seat in position when engaged.

Abstract: The invention concerns a device for locking the configuration of an equipment such as a vehicle seat comprising a support and a mobile part. It comprises: at least three mutually mobile elements (42, 48) linked respectively to a support and to the mobile part in spatial succession; means (54) for clamping the elements (42, 48) to prevent a displacement of the mobile part relative to the support; and an unlocking member (58) for allowing movement, the unlocking member being controllable independently of the mobile part. The unlocking member (58) is designed to cancel the clamping exerted by the clamping means (54).