Abstract: A replaceable sealing member is disclosed which includes a body, lip seal and bonded reinforcement section having a skirt portion and a lip support surface. The skirt portion and lip support restrict elastomeric flow of the body and lip seal portion of the sealing member to prevent extrusion damage. A radially extending flange, from which the skirt portion axially projects, is bonded to the body and has an abutment surface on one side for abutment against a shoulder in a metallic support, such as in a mud pump piston hub, for limiting axial movement of the replaceable sealing member.

Abstract: A lightweight mud pump piston assembly for reciprocating inside of a cylinder. The piston has decreased weight because light weight materials are used to form the majority of the hub which is the heaviest part of the piston. The piston maintains its compressive strength because the critical stress portions of the hub are made with high strength material having higher tensile strength and density than the light weight material.

Abstract: A valve element is disclosed comprised of a body section, upper guide, lower guide, sealing section and reinforcement section. The reinforcement section is made of materials having a hardness greater than the lower guide and sealing section. The reinforcement section, as well as the sealing section, have a frustoconical outer surface to increase support of the sealing section due to bracing from a mating valve seat annular sealing surface. The frustoconical outer surfaces of the valve element combine to form a uniform frustoconical surface. Two sealing sections may be disposed above and below the reinforcement section. These two sealing sections have frustoconical outer surfaces that cooperate with the frustoconical surface of the reinforcement section to form a continuous, co-extensive frustoconical outer surface.

Abstract: A device for preventing aircraft wing flutter causes the port and starboard wings of the aircraft to oscillate at different frequencies. In an exemplary embodiment, engine nacelles are suspended from the port and starboard wings by strut assemblies in a manner that the port and starboard engine nacelles have different oscillation frequencies when subjected to a displacing force. The port and starboard strut assemblies each include a pair of flexible beams whose dimensions and composition may be adjusted to change its stiffness. In this manner, the oscillation frequency of the attached engine nacelle is adjusted in a known manner.

Abstract: A device for preventing aircraft wing flutter causes the port and starboard wings of the aircraft to oscillate at different frequencies. In an exemplary embodiment, engine nacelles are suspended from the port and starboard wings by strut assemblies in a manner that the port and starboard engine nacelles have different oscillation frequencies when subjected to a displacing force. The port and starboard strut assemblies each include a pair of flexible beams whose dimensions and composition may be adjusted to change its stiffness. In this manner, the oscillation frequency of the attached engine nacelle is adjusted in a known manner.

Abstract: A valve element for use in a high pressure pump, the valve element having a body portion with a top side and a bottom side, a guide means attached to and projecting away from the bottom side of the body portion and an insert secured to the top side of the body portion, the insert having a second guide which projects away from the top side of the body portion and an annularly extending flange which defines an annularly extending sealing surface, the insert being formed of a generally non-metallic material having a specific gravity less than the specific gravity of the material forming the body portion and the guide means projecting from the bottom side of the body portion.

Abstract: A wing load alleviation system for redistributing aircraft loads encountered during flight by symmetrically deflecting the outboard ailerons of the aircraft includes a trailing edge tab pivotally supported on each outboard aileron. As each outboard aileron is deflected by the wing load alleviation system to reduce wing bending moments, the corresponding tab is deflected in aerodynamic opposition thereto so as to reduce wing torsional loads caused by the deflection of its associated outboard aileron. The span of each tab is equal to or less than that of its associated outboard aileron, and the chord of each tab is a predetermined fraction of that of its associated outboard aileron. Each tab may be mechanically linked to its associated outboard aileron so that deflection of the outboard aileron causes a proportional but opposite deflection of the tab.