Erwin Hartel

US Patent:

40476812, Sep 13, 1977

Filed:

Dec 22, 1975

Appl. No.:

5/643030

Inventors:

Erwin H. Hartel - Bellevue WA

Assignee:

The Boeing Company - Seattle WA

International Classification:

B64C 2512

US Classification:

244102SS

Abstract:

In a landing gear of the type that includes a pivotally retractable shock strut, the overall length of the strut is shortened during retraction by a mechanism that is effective to force the shock strut piston to telescope into the shock strut cylinder. The mechanism includes a multiple section, foldable brace which when the landing gear is down functions to rigidify the shock strut and which during retraction folds into a compact, collapsed configuration. One end of the brace is pivotally connected to a collar which in turn is coaxially, rotatably mounted on the strut cylinder, while the other end of the brace is pivotally connected to a support point located on the underside of the wing and offset to one side of the plane of rotation of the strut so that the brace resides at a skewed angle to such plane. As the strut is rotatively retracted, the brace folds toward a collapsed configuration, and because of the brace's skewed mounting location it acts to apply a rotative force to the collar, rotating the collar about the axis of the strut cylinder. A special, reactive linkage is connected between the collar and a modified torque linkage (that interconnects the strut's piston and cylinder), to convert the aforementioned collar rotation into a force moment on one of the links of the torque linkage for telescopically compressing the piston into cylinder and thereby shortening the strut as the gear is retracted.

US Patent:

40078949, Feb 15, 1977

Filed:

Dec 4, 1975

Appl. No.:

5/637576

Inventors:

Erwin H. Hartel - Bellevue WA

Assignee:

The Boeing Company - Seattle WA

International Classification:

B64C 2560

US Classification:

244104FP

Abstract:

The weight and balance of an aircraft is determined by measuring the pressure of a fluid in a variable volume chamber provided in a piston-cylinder shock absorber assembly of the landing gear strut. In order to minimize axial friction forces in the assembly that introduce errors in an otherwise accurate correlation between the measured fluid pressure and the magnitude of the aircraft load, an existing hollow cylindrical bearing structure, coaxially disposed between the piston and cylinder for guiding reciprocation of the former within the latter, is modified so that it can be rotated about the axis of the assembly. An actuator is provided on the strut for rotating the bearing structure with respect to the cylinder and piston. Such rotation minimizes axial friction forces in the assembly, allowing the fluid pressure to assume a value accurately reflecting the axial load.