Mechanism for controlling a rotary member by means of a pivoting handle, and a seat fitted with such a mechanism

A control mechanism for driving an outlet member selectively in both opposite directions of rotation, by means of a handle which is pivotally mounted about a pivot axis and which is resiliently urged towards an angular position that is neutral, said handle being displaceable in a first pivot direction over a first angular sector from its neutral position, and in a second pivot direction over a second angular sector from said neutral position, the outlet member being driven by a circular set of teeth disposed in a plane perpendicular to the pivot axis of the handle, and said teeth themselves being driven by first and second drive pawls each pivotally mounted about an axis displaceable with the handle, the first drive pawl being adapted to drive the circular set of teeth solely when the handle is displaced in the first pivot direction over the first angular sector, and the second drive pawl being adapted to drive the circular set of teeth only when the handle is displaced in the second pivot direction over the second angular sector, both drive pawls being displaceable between a respective drive position in which it co-operates with the circular set of teeth and a respective retracted position in which it does not co-operate with the circular set of teeth, and both drive pawls co-operating with a stationary support which holds the first drive pawl in its retracted position when the handle is displaced over the second angular sector and which holds the second drive pawl in its retracted position when the handle is displaced over the second angular sector and which holds the second drive pawl in its retracted position while the handle is displaced over the first angular sector, wherein said mechanism further comprises:

• first and second locking pawls which are respectively pivotally mounted relative to the stationary support to pivot between respective locking positions in which they co-operate with the circular set of teeth and respective retracted positions in which they do not co-operate with said circular set of teeth, the first and second locking pawls being urged resiliently towards their respective locking positions, the first locking pawl being adapted to prevent rotation of the circular set of teeth solely in the first pivot direction and the second locking pawl being adapted to prevent rotation of the circular set of teeth solely in the second pivot direction;
• and
• a camming means actuated by the handle and acting on the first and second locking pawls, said camming means being organized to displace only the first locking pawl into its retracted position when the handle is displaced over the first angular sector in the first pivot direction, and to displace only the second locking pawl into its retracted position when the handle is displaced over the second angular sector in the second pivot direction, with the camming means otherwise allowing the locking paws to remain in their locking positions;
• the circular set of teeth formed inside a rigid ring, where the stationary support is constituted by a stationary cheekplate which extends substantially in a plane perpendicular to the pivot axis of the handle and which is disposed against the ring cooperating therewith to define at least in part a housing that contains at least the two drive pawls and the two locking pawls;
• and wherein both drive pawls are resiliently urged into their respective drive positions, the stationary support including at least one guide ramp which holds the first drive pawl in its retracted position and does not interfere with the second drive pawl while the handle is in the second angular sector and which holds the second drive pawl in its retracted position and does not interfere with the first drive pawl while the handle is in the first angular sector.