Vibration-insulating stability improving torque force device
OwnerHugh G. Evans, Stephen Speer +1inventors
InventorsHugh G. Evans, Stephen Speer, James S. Christy
Life of this patent
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Abstract
A conventional aircraft having horizontal stabilizers and hinged elevators, which is controlled, preferably, through push-pull rods, is provided with a dynamic torque (bob) weight connected to a rotating member, in the direct line of control to the elevator surfaces. The torque member is located in the nose portion of the aircraft with its center of gravity angled up from 20.degree. to 50.degree. when the elevator surfaces are in the neutral position. The torque member is also mounted in a flexible manner to isolate it from horizontal tail vibrations, or flutter.
Claims18
In a conventional aircraft comprising wing surfaces mounted on a fuselage, a tail having a separate vertical rudder and horizontal stabilizer surfaces, with elevators pivotally mounted on the trailing edges of the horizontal stabilizers;
- and a control system for manually pivoting the elevators, the control system comprising a manually controlled, laterally extending, rotating control member and direct motion-transmitting means comprising relatively rigid, vibration-carrying members, between the rotating member and the elevators, designed to pivotally move the elevators in response to rotation of the rotating control member, the improvement which comprises a constant mass torque member fixedly connected to the rotating member such that the torque member is at a substantially constant radial distance from the axis of rotation of the rotating member, the center of gravity of the torque member being at least about two inches radially distant from the axis of the rotating control member, along a radial line defining the effective torque arm, and a resilient vibration insulating connecting joint between the torque member and the rotating member being located relatively radially inwardly towards the axis of the rotating member from the center of gravity of the torque member, whereby the fundamental natural frequency of the torque member and the rotating member is less than the fundamental natural frequency of the horizontal stabilizer and greater than the pitch stability oscillation frequency.
In a conventional aircraft comprising wing surfaces mounted on a fuselage, a tail having a separate vertical rudder and horizontal stabilizer surfaces, with elevators pivotally mounted on the trailing edges of the horizontal stabilizers;
- and a control system for manually pivoting the elevators, the control system comprising a manually controlled, laterally extending, rotating control member and direct motion-transmitting means comprisng relatively rigid, vibration-carrying members, between the rotating member and the elevators, designed to pivotally move the elevators in response to rotation of the rotating control member, the improvement which comprises a constant mass torque member comprising at least one rigid longitudinal member extending transversely outwardly from the rotating member and a torque weight connected adjacent one end thereof, the torque member being fixedly connected to the rotating member such that the torque member is at a substantially constant radial distance from the axis of rotation of the rotating member, the center of gravity of the torque member being at least about two inches radially distant from the axis of the rotating control member, along a radial line defining the effective torque arm, and a resilient, vibration-insulating, connecting joint between the second end of the longitudinal member and the rotating member, and being located relatively radially inwardly towards the axis of the rotating member from the center of gravity of the torque member, the connecting joint comprising a first plate secured to the rotating member and extending transversely outwardly from the rotating member;
- a vibration-insulating member;
- and a second plate secured to the vibration-insulating member and extending transversely outwardly from the rotating member, the second plate being secured to the longitudinal member;
- whereby the fundamental natural frequency of the torque member and the rotating member is less than the fundamental natural frequency of the horizontal stabilizer and greater than the pitch stability oscillation frequency.
Dependencies are inferred from the claim text.