Abstract:
In a system that compares the rate of descent of an aircraft with its altitude above ground and generates a warning signal when the sink rate exceeds a predetermined limit for a particular altitude, the maximum warning time is limited to a specified value in order to minimize nuisance warnings at higher altitudes. At a descent rate above a certain value, the excessive sink rate warning signal is inhibited for combinations of descent rates and aircraft altitudes which would provide a warning greater than a selected time to impact, such as 30 seconds.
Abstract:
In a terrain warning system wherein the rate of the aircraft's closure to the terrain is compared to the aircraft's altitude above the terrain in order to generate a warning signal for excessive closure rates, a circuit is provided to inhibit the warning signal when the aircraft begins to climb in response to the warning signal and to measure the altitude gained by the aircraft resulting in the reactivation of the warning signal if the aircraft has leveled off before gaining a predetermined amount of altitude. The circuit includes: a memory element to indicate that a warning signal has been generated; a circuit to generate a climb signal in response to a barometric rate of change signal indicating the aircraft is climbing; and an integrating circuit responsive to the barometric rate signal to determine the amount of altitude the aircraft has gained while climbing. If the aircraft has not gained the predetermined amount of altitude before leveling off, as indicated by the climb signal, the memory element will reactivate the warning signal.
Abstract:
A lightweight, substantially corrosion-proof, conductive wire and terminal assembly (10) comprising a wire (12) laid on and welded to a terminal pad (18) at or near the end (16) of the wire. The wire (12) has an electrically conductive core (24) having a cylindrical surface. The cylindrical surface is substantially completely enveloped in a sheath of noble metal plating (26, 28). The terminal pad (18) has a noble metal surface where it is welded to the cylindrical surface of the wire (12), so the joint (22) formed by the weld is substantially sheathed in a noble metal, and thus is substantially as corrosion-proof as the noble metal sheath (26, 28) and terminal pad (18). The wire (12) is preferably covered with insulation (30) except at its end (16), which may be stripped. This invention has the advantage that the joint (22) does not require a post-plating operation after the wire and terminal pad (18) are welded together, yet the joint (22) is stronger than a joint between dissimilar metals such as copper wire (12) and a gold terminal pad (18) and substantially as corrosion-proof as the plating (26, 28). A method for forming the assembly (10) is also disclosed.
Abstract:
An improved preload system for an accelerometer in which an acceleration sensitive structure is clamped between first and second clamping members. The acceleration sensitive structure includes a paddle supported such that the paddle has a degree of freedom along a sensing axis. The accelerometer further includes a case within which the acceleration sensitive structure and clamping members are mounted. The preload system comprises an internal mounting surface in the case that faces in a first direction along the sensing axis, and that contacts the second clamping member and prevents it from moving in a second direction opposite to the first direction. The preload system also includes a spring washer extending between the first clamping member and the case, such that the spring washer exerts a force on the first clamping member in the second direction. A positioning ring may also be provided between the first clamping member and spring washer, to laterally locate the first clamping member within the case.
Abstract:
A racquet handle with an ellipsoidal cross-section, the long axis of which increases toward its distal end. Attached to the distal end of the handle is a metal weight, which extends the center of percussion, increases racquet head control, increases the power of heavily wristed shots, and neutralizes impact forces that may cause damage to a player's joints. The long ellipsoidal axis may be made radially adjustable about the longitudinal axis of the handle to suit the grip styles of individuals.
Abstract:
A push-pull accelerometer in which both force transducers lie in a common plane. Thus, when implemented in silicon micromachined device, both transducers can be fabricated from a single crystal layer, thereby producing transducers with closely matched common mode responses.
Abstract:
A snap action thermal actuator utilizes a pair of mechanically coupled bimetallic members having different temperature characteristics to provide a fast and positive snap action thermal actuator even when a low temperature differential is required. The actuator is particularly useful for controlling the operation of electrical contacts in a thermal switch.
Abstract:
A ground proximity warning system is disclosed which can recognize when an aircraft is on a final approach to an airport without utilizing a landing flap signal input. Airports together with the surrounding terrain topography are modeled by a simple geometric shape, such as, an inverted truncated cone, and stored on-board the aircraft. The system uses navigational data to determine the distance of the aircraft from the geometric model. Once the aircraft is determined to be within the area defined by the geometric model, the system provides an enabling envelope indicative that the aircraft is on a final approach for enabling various ground proximity warning systems. Also disclosed is a system for altering the enabling envelope as a function of the aircraft's alignment with a particular runway.
Abstract:
An instrument (10) is disclosed for an aircraft having a windshear warning system to vary the threshold alarm setting as a function of a thermodynamic property of the air and as a function of local geographic and seasonal conditions. Specifically, a function generator 16 and other circuitry is disclosed. The output from the function generator 16 and other circuitry is then added to a fixed threshold acceleration signal to produce a threshold alarm signal which has a value that is a function of the temperature of the air, in a basic embodiment.
Abstract:
A dual vibrating beam force transducer having an electrostatic drive system. The transducer comprises a body having first and second generally parallel beams, coupled together at their ends. First and second electrodes are positioned adjacent to but not in contact with the respective beams. A drive circuit causes an oscillating voltage to be applied to the electrodes. The beams are thus subjected to electrostatic forces that cause the beams to oscillate in a vibration plane containing both beams. The mechanical resonance of the beams controls the oscillation frequency, such that the frequency is a function of a force exerted along the beams. An embodiment is also described in which the drive means is coupled directly to one of the beams.