Messier-bugatti Inc.

Messier-hispano-bugatti

Messier-hispano-bugatti (sa)

Pierre Woerner

Jean-Pierre Hainaut

Jacques Veaux

Daniel Robin

Jean-Michel Dubos

Alain Poiret

The invention relates to raisable landing gear having a shortenable leg, including a shock absorber fitted with a plunger rod, and a linkage connecting said plunger rod to the strut of the shock absorber, under the control of a resilient connecting rod having a threshold, serving to pull on the shock absorber when the leg is raised. According to the invention, the linkage includes two arms forming an alignment, with a first arm hinged on the plunger rod and having a lateral appendix whose free end is capable of co-operating with a stationary cam secured to the structure of the airplane, and a second arm which is hinged to the strut. The lateral appendix and the stationary cam are organized to operate in an emergency, in the event of the threshold connecting rod failing, thereby ensuring that the shock absorber is extended and that said lengthened shock absorber is locked in the undercarriage-down position.

Raisable landing gear having a shortenable leg

A retractable landing gear is arranged so as to provide, in use, a highly inclined shock absorber while avoiding high shearing stresses on the shock absorber. The landing gear includes a pivoting panel fixed to an aircraft structure to pivot about a raising axis; a shock absorber including a strut fixed to the pivoting panel so as to pivot relative thereto about a tilt axis, and a sliding rod mounted to slide in the strut and carrying a set of wheels at its bottom end; and a coupling member connected to the pivoting plate and to the bottom end of the sliding rod. Also included is a mechanism for raising and holding the landing gear.

Raisable landing gear

The shock absorber of the invention comprises a struct (1) in which a sliding rod (4) is mounted, with an annular chamber (17) being defined between the strut and the sliding rod. According to the invention, the shock absorber includes at least one support bearing (10) between the strut and the sliding rod in the vicinity of the opening (3) in the strut, and a sealing bearing (12) at a distance from the support bearing (10) and disposed at a level which corresponds to the top portion of the sliding rod when the shock absorber is in its extended position, with the sealing bearing (12) also having a side which is in contact with the annular chamber (17) and spporting at least two sealing rings (14) which are separted by a groove (13) which is connected to the annular chamber via a balance channel (16) capable of being closed by a cock (19).

Shock absorber with improved dynamic sealing

On a shaft (2) which carries a wheel there are mounted: firstly a toothed sector (3) which meshes with a rack (4) on a piston rod (5) which is a part of a double-acting hydraulic actuator (8); and secondly a cam (12) which acts on two rocking levers (13, 14) to apply a bolt (13B, 14B) against a stop face (10A, 10B) of the rod (5) when, by directly swivelling the wheel, the toothed sector (3) is disengaged from the rack (4).

Growing community of inventors

Fontenay-Aux-Roses, France

Pierre Woerner