Abstract: A sensing system for measuring the angle of aim of an adjustable remote lighting fixture comprising a pendulum adapted to be mounted on the remote fixture, a potentiometer coupled to the pendulum, and a battery-powered measuring circuit connectable by means of a cable to the potentiometer to thereby form a resistance bridge circuit. During operation, a microammeter connected in the bridge circuit provides a read out proportional to the angle formed between the suspended pendulum and a predetermined reference surface of the remote fixture.

Abstract: The angular deflection or tilt angle from vertical is determined by an inclinometer wherein a weight is offset and hung from a rotatable shaft to which a needle pointer is affixed. When the inclinometer is oriented such that the shaft is vertically aligned, the gravitational force on the weight is in a direction parallel to the shaft's axis and no torque results. When so oriented, a magnetic spring system holds the shaft in a reference position and the needle points to the center of a graduated scale, thereby indicating a zero tilt angle. If the inclinometer, and consequently the shaft, are tilted in a tilt plane, defined by the shaft and the center of the scale, the weight exerts a torque on the shaft and causes pivoting of the needle away from the center of the scale to indicate the direction of tilt and the magnitude of the tilt angle.

Abstract: A tightening wrench with an angle indicator for the final tightening operation on threaded fasteners, the angle indicator having a pointer or other angle indicating element which assumes a given angular orientation under the influence of an ambient force field of gravity or magnetism and maintains this orientation while the wrench is rotated, thereby giving an angular reading of the tightening angle. Gravity is used with a weighted pointer, magnetism with a needle compass or liquid compass. Also usable is a gyro, or a freely rotatable mass of high inertia. The wrench may be a torque wrench.

Abstract: A level indicator which features a pendulum-style magnified dial and a versatile magnetic swing plate or base. The swing plate is pivotally and laterally moveable with respect to the main casing of the level indicator to provide a more stable and accurate adherence to the surface whose alignment is being checked. The magnetic surface of the swing plate cooperates with a coplanar magnetic face of a fixed-position heel plate to add further stability and accuracy. The level indicator features a hairline-bearing suspended mass in the form of a magnifying lens, the hairline being preferably scribed along its outer convex surface to eliminate parallax errors. The indicia-bearing dial plate may be edgewise illuminated by one or two light sources internally positioned and powered. Two substantially identical viewing faces are preferably provided to increase versatility.

Abstract: The instrument includes a shaft or tube which is inserted into the end of a gun barrel and includes at least one balanced module having an index pointer disposed a few inches in front of the free end of the barrel and extending vertically upwardly into the field of vision of the line of sighting. The index pointers are centered directly over the center line of the gun bore and mark its vertical plane. By sighting through the scope of the gun verification of the vertical collimation of the line of sighting can be made since one can readily see if the reticle cross hairs coincide precisely with the index pointers or not. If not, adjustments can be made to correct the line of sighting.

Abstract: A method of adjustment, by use of a gravity-operated angle measuring device, of the azimuth and/or elevation of the major axis of a light fixture having a normal operating position located at an inaccessible height, as on a tower holding runway approach lights. The method includes lowering the tower by rotating it about its base to a position wherein the light fixtures are accessible; measuring the vertical angle of the tower axis in the lowered position; adjusting the fixture to the desired angle relative to the tower axis by attaching the measuring device directly to the fixture; elevating the tower with the device still attached to the fixture; locking the angle shown on the device in the elevated position of the tower; again lowering the tower to read the angle locked on the device; and making any necessary adjustment of the light fixture axis relative to the tower axis so that the axis of a beam emanating from the fixture is directed at a predetermined azimuth and elevation.

Abstract: An aperture control mechanism particularly for use in planetarium projectors, including a weight lever for controlling the horizontal position of the edge of an aperture, said weight lever is seated for rotation on a plate, the rotations being limited to two stops mounted on said plate, at which stops a projection of the weight lever is arrested.

Abstract: A normal pendulum is coupled to an inverted pendulum to provide a composite conjugate pendulum having an effective length much longer than the actual physical lengths. The motion of the pendulum is sensed by a capacitive transducer and pivot friction is minimized by a two-bar two-strap suspension system.

Abstract: A gauge for measuring the angle of attack, or incidence of a wing or horizontal stabilizer-elevator on a model aircraft is described. The gauge comprises an L-shaped angle beam having a gravity-type angular indicator mounted on its shorter arm. Slidably mounted on the longer arm is a trailing edge reference block having a notch facing inwardly toward a similar notch in the shorter arm of the angle beam. In measuring the angle of incidence the model aircraft is stabilized in one position and the notch in the shorter arm of the angle beam is placed against the leading edge of the wing and the trailing edge reference block is slid forward along the longer arm of the angle beam until the notch in the reference block is secured against the trailing edge of the wing. The relative incidence of the wing may then be read from the indicator.

Abstract: A hydraulic fluidic level sensor for detecting an angular deviation from vity vertical comprising an inverted pendulum in conjunction with two fluidic proximity sensors to provide an output signal proportional to the angular deviation. Opposing fluid jets from the fluidic proximity sensors impinge on the inverted pendulum shaft to produce a net jet force which counterbalances the pendulum moment due to gravity. The pressure signal output from the proximity sensors is proportional to the angular deviation from the vertical and provides the input signal to a level control system. A secondary pendulum damping system is used to provide necessary viscous damping.

Abstract: This invention relates to an attitude meter which measures the orientation of a plane surface with respect to the magnetic North direction and a horizontal plane. The meter includes a hollow transparent sphere containing liquid for supporting a compass and a vertical indicator, combined with a rotatable arcuate scale for facilitating visual reading of the compass and relative position of the vertical indicator. More particularly, the arcuate scale includes vertical orientation indicia and is mounted for rotational displacement to a position immediately adjacent the vertical indicator. By this arrangement the vertical angle of the surface being measured may be read directly from the arcuate scale and the direction of inclination relative to the magnetic North may be determined from the point of intersection of the arcuate scale and the liquid supported compass.

Abstract: A wall hanger device includes a wall mountable first member having a pair of laterally spaced forwardly projecting support arms terminating in upwardly directed fingers and a forwardly directed intermediate bearing arm. A plumb defining elongated plate has a longitudinal opening in its upper part provided at its top with a depending fulcrum which separably rests on the bearing arm. Vertical lines are medially formed on the plumb and mounting plate and are in vertical longitudinal alignment when the support arms are at the same level. A bracket is mounted on a picture frame and includes a pair of laterally spaced, apertured arms for engaging the support arm fingers.

Abstract: A dynamic vertical angle sensor operable on a vehicle that isolates the output device from the vehicle movement in that the rotor of the output data device is not directly coupled to the sensor mounting frame. The output rotor is driven by a low pass servo that is slaved to a level sensor, which in itself is driven by the same servo until it is nulled. The level sensor which may be a pendulum, is mounted free from the output device so as to rotate independently therefrom, thus allowing the error signal to be picked off of the pendulum mounting and applied to the low pass servo system. Because a low pass filter is in series with the servo drive, high frequency disturbances are greatly attenuated in the output device, to effectively provide a DC average angle signal that is required, for example, in a tank system, rather than instantaneous values.

Abstract: An instrument for indicating or checking the angular position of an object. A movable part is mounted on a stationary part; said parts have a pattern of equally wide parallel lines separated by interspaces. When the parts overlap in use of the instrument the line patterns form a moire pattern to indicate the angular position of the object.

Abstract: First and second inclinometers are mounted above the deck of a ship at different distances from the ship's center of gravity. Each inclinometer generates a signal in response to the angular movement of said ship with respect to the true vertical. The difference between the signals is multiplied by a factor which is proportional to the ratio of the distance from the higher inclinometer to the center of gravity to the distance between the inclinometers. This product is then subtracted from the electrical signal generated by the higher inclinometer resulting in a signal which is proportional to the roll or pitch angle of the ship.