Abstract: A magnetic compass has an instrument body adapted to be held level by a gimbal mechanism and having a vertical cylinder member, a spherical or semi-spherical float body on the upper end of the cylinder member and having a spherical surface facing downwardly into the upper end of the cylinder member, a magnet at a bottom center of the float body for making the center of gravity of the float body near the bottom center of the float body, a graduated azimuth scale on the float body, a lubber's line indicator on the surface of the instrument body surrounding the float body, and an air blowing device operatively associated with the cylinder member for blowing rectified air upward through the inside of the cylinder member with a force sufficient for making the float body float stably on the upper end of the cylinder member and out of contact therewith for enabling the float body to freely turn in response to geomagnetic force.

Abstract: A magnetic compass in which a conventional compass card provides an analog readout of compass heading and a binary coded digital disk together with fiber optic sensing technology provides a digital readout of compass heading contained within a single housing, together with a gravity driven inclinometer providing a measurement of the inclination of the ground. The compass magnet is shielded by Faraday type shielding from the electronics that processes the digital reading. An analog electronic readout of both compass heading or inclination, capable of remote display, is provided by a tapered iris disk and fiber optic reader combination. A magnetic compass employing a compass disk with a reflecting tapered iris on one side of the disk sensed by a reflecting fiber optic reader and a standard compass card on the other side which can be read visually provides an improved magnetic compass being very compact and providing both analog and digital readouts.

Abstract: A navigation device is disclosed, having a lens across an opening at one end of a case, and a compass across an opening at the opposite end of the case. A transparency holder is positioned between the lens and the compass, adapted to receive a map transparency with magnetic north thereon aligning with a north marking on the body of the compass, at a distance from the lens approximating the focal length of the lens. A grid wheel is provided between the transparency holder and the compass, having a transparent or translucent central area inscribed with parallel grid lines and at least one first directional arrow aligned parallel to the grid lines, the grid wheel being in close proximity to the transparency holder such that it is also at a distance from the lens approximating the focal length of the lens.

Abstract: A magnetic heading sensor alignment device for an acoustic towed line array s described. It includes a generally cylindrical non-magnetic piece having a longitudinal opening along its central axis to accommodate the heading sensor. A plurality of longitudinal non-magnetic strips or springs are provided around the cylindrical piece by securing them at the ends of the cylindrical piece to form a cage. This provides a spring-like action when the alignment device including the heading sensor is inserted inside the hose of the towed line array and thus keep the heading sensor aligned during the deployment of the acoustic towed array.

Abstract: A roll-independent magnetometer which may be used for example in a towed array magnetometer system comprises a first magnetic field sensor having iso-angular flux sensitivity about a roll axis and a second magnetic field sensor having sensitivity along the roll axis, the arrangement being such that a component of a magnetic field along the roll axis is measured by the second unidirectional sensor and the component of the field lateral to the roll axis is measured by the first sensor. Corrections may be applied for the inclination of the sensor and the angle of dip of the Earth's field. The angle of dip may be measured either in the towing vessel, in the towed body, or provided in look-up tabulated form.

Abstract: An earthquake predicting magnetometer having a compass assembly with a graduated dial and an adjustbly positionable magnet assembly having magnetic poles oriented opposite the direction markings on the compass dial. The device is oriented to the cardinal points using the compass. Then the magnet is adjusted in proximity to the compass assembly until the magnet counterbalances the magnetosphere of the earth. This leaves the compass needle facing east or west. When the magnetosphere of earth weakens prior to a major seismic event, the compass needle will point to the south on a graduated scale on the dial, indicating an imminent quake of large magnitude.

Abstract: The instant invention is a magnetic field sensor intermittently shielded by a controllable, saturable, magnetic shield. The magnetic shield is periodically driven into saturation by means of an excitation coil. The magnetic field to be measured is not disturbed by the shield during those time intervals when the shield is saturated. Intermittent sensing of the magnetic field to be measured, by the intermittently shielded magnetic field sensor, yields a magnetic field measurement unaffected by l/f noise and offset errors.

Abstract: The invention relates to a mask compass comprising a case attached to the outer surface of glass of goggles. The compass box is placed inside the casing. Thus the checking of the compass does not interfere with regular diving movements and e.g. cause deviations from the right direction.

Abstract: A device and process for measuring cervical range of motion about three axes comprises a frame which is supported on the nose of a subject and which has side temple pieces for locating the frame on the wearer's head. Cervical range of motion of a wearer's head can be measured through the use of gravity type angle meters and a magnetic type angle meter which are mounted on the frames and easily referenced back to the frame. The magnetic type angle meter is mounted above the head on a removable arm, which is supported on the frame. A magnetic field is created using magnets mounted on the subject to obtain reliable head rotation readings. The magnetic type angle meter can be removed, and an arm which is mounted on the frame and extends above the head of a wearer and which when coupled with a locator arm can determine a forward head position measurement.

Abstract: A compass assembly comprising a base, a dial member received in a recessed portion of the base and rotatable relative the base about a dial member central longitudinal axis, and a compass housing received in a recessed portion of the dial member and fixedly secured to the base by a connecting disk. The disk has a first surface attached to the housing and a second surface attached to the base and a peripheral edge surface positioned in frictionally engaging contact with the dial member. The dial member is biased against rotation relative the base and the compass housing by the disk.

Abstract: A portable device for communication is useable during movement by a person. Individual portable receivers (2), the size of a credit card, display and/or broadcast to a user, automatically or by selection, data coming via waves (3) coming from microwave or laser transmitters (1) and FM transmitters (4). The transmitters (1) can cover nerve zones such as population centers, and sequentially send a flow of data transmitted by a digital signal with for instance 900,000 bits/second. At the same time, the transmitters (4) are used to cover 95% of a territory in audio. This provides a service of public interest, allows changing the descriptive speech, provides a choice of messages, offers a presale service, and makes possible selective identification.

Abstract: A three winding induction compass mounted in a host vehicle has each winding output coupled to an analog to digital converter. Each winding output is weighted and accumulated by a push down stack circuit to obtain a time filtered output; the filtered outputs are mapped into equivalent two winding outputs as the vehicle is turned in a 360.degree. circle to form sensitivity values from the windings readings and using these values to obtain measurement parameters which are incorporated into a least squares matrix which is solved for calibration coefficients to obtain the calibration parameters representing the distortions due to the permanent and inducted magnetism of the host vehicle and due to winding imbalance between the three windings and misorientation of the three windings. The calibration parameters are applied to the outputs of the three windings to obtain an equivalent two winding output which is normalized for determining the corrected compass heading.

Abstract: The orientation of a moving platform with respect to a magnetic field is determined by rotating a 3-component vector magnetometer mounted on the platform about at least two axes in the magnetic field. Changes in the signals from the magnetometer are monitored, and the direction of the magnetic field relative to the platform is computed from the signal changes. It is not necessary to know the DC bias of each magnetometer channel or the component of the background magnetic field along each axis of the magnetometer.

Abstract: A one-man field survey instrument for conducting small scale engineering surveys. The instrument automatically measures relative vertical and horizontal angles as it is moved over the terrain. The measurements are thereafter processed to prepare a topographical survey. Alternative configurations are disclosed as are methods for using the instrument.

Abstract: A quick ranging technique controlled by a microcomputer, makes predetermined stepped adjustments to the charge times in a ranging circuit to bring the charge time into a required range, thusly minimizing calibration time for an electronic compass; a digital filter also controlled by the microcomputer smooths out the magnetic field component signals.

Abstract: An ornamental compass comprises an ornament such as a doll or car. The ornament is attached to a direction-adjustable means which makes the ornament easy to be adjusted and pointed in right direction. The direction-adjustable means is connected to a magnet. The magnet is powerful enough to make the ornament, direction-adjustable means, and magnet point in a direction. A rotatable means for supporting the ornament, direction-adjustable means, and magnet fluctuate in any direction, which fluctuation gives the ornament an interesting movement.

Abstract: The compass is composed of a glass plate constituting a transparent outer component and of a thin plate constituting an inner transparent component. Two bearings are fixed in holes in these plates, one bearing being situated near the upper face and covered by a disk. An arbor can thus be machined with a maximum length and can support the compass needle with the greatest possible precision. The compass unit, comprising a setting ring which holds the two plates in place, may be driven with a gasket into the radial wall of the case body in lieu of the usual watch glass.

Abstract: A system is provided for detecting wind shifts on a floating vessel which is anchored. The system has particular applicability to commercial gill net fishing where a net is set for the night and a fishing boat is tied to the downwind end of the net. The system employs a modified compass which has a compass rose freely rotatable relative to and in electrical isolation from a housing. An electrical contact is mounted on the compass rose and is electrically connected to a power supply and to an alarm. The power supply is also connected to limit contacts on the housing. The limit contacts are initially oriented to locations on opposite sides of the electrical contact on the compact rose when the vessel is anchored to the downwind end of the net to define allowable variations in wind direction. A significant wind shift will reorient the vessel relative to the net to maintain the vessel at a location downwind from its anchoring point on the net.

Abstract: A compass assembly including a compass mechanism mounted in supported relation on a base and covered by a transparent material shield wherein the assembly is specifically structured to be mounted on a handle element itself being a part of a support structure on the interior of an automobile type vehicle. The compass assembly is also structured so as to be movable with the handle element or like element on which it is mounted and at the same time viewable by an occupant of the vehicle to inform such occupant of the direction of travel of the vehicle.

Abstract: A housing defines a chamber having a spherical inside surface, and a spherical float is supported within the chamber by a liquid so that the outside surface of the float is equidistantly spaced from the top and bottom of the inside surface of the chamber. The float incorporates a permanent magnet defining diametrically-opposed opposite poles which serve to orient the float with respect to the earth's magnetic field. The liquid is magnetizable, and the float is laterally centered within the chamber by magnetic interaction between the magnet poles and the magnetizable liquid. A differential fluxgate sensing head serves to sense the relative orientation of the housing and the float in a horizontal plane and to supply an electrical output signal indicative of that orientation. A highly accurate direction-finding device is thereby produced at modest cost.

Abstract: A compass having a color coded compass card for enhanced reading of the compass. The compass card is divided into four quadrants each of which is further subdivided into equal sectors differently colored within each quadrant; the color sequence of the sectors within each quadrant is repeated in each quadrant. The color sequencing enables an efficient method of navigating a sailing dinghy around an olympic course.

Abstract: A three winding induction compass mounted in a host vehicle has each winding output coupled to an analog to digital converter. Each winding output is weighted and accumulated by a push down stack circuit to obtain a time filtered output and the maximum and minimum values of each filtered output are determined and stored as the vehicle is turned in a 360.degree. circle. The distortions due to the permanent and induced magnetism of the host vehicle and due to winding imbalance between the three windings and misorientation of the three windings are obtained from the maximum and minimum values to obtain calibration parameters. The calibration parameters for the windings are applied to the outputs of the three windings to obtain an equivalent two winding output which is normalized for determining the corrected compass heading.

Abstract: A vibrator attenuator, especially for a compass. The vibration attenuator is situated to prevent transfer of vibrations from the fastening base of a compass, e.g. from the framework of a boat, to the compass rose, to prevent revolving of the compass rose that results from such vibrations, and to prevent transfer of external impacts to the compass rose itself. The vibration attenuator is disposed between a supporting rod of a bearing of the compass rose, and a frame of the compass, so as to resiliently interconnect the supporting rod and frame. The vibration attenuator is preferably attached to a supporting bridge in turn affixed to the compass frame. The vibration attenuator may be an elastic member or a spring, which is attached to the supporting rod and to the supporting bridge, so that the vibration attenuator is resilient in both a vertical or longitudinal direction, and in a lateral or horizontal direction.

Abstract: A compass attached to a car door mirror is disclosed which provides protection for the compass and improved readability, while avoiding the reliability problems of compasses mounted inside the car. The compass is embedded in the frame of the car door mirror which makes it both less obtrusive and physically more secure.

Abstract: A device for preventing error or misreading in a marine compass fastened to a sloping plane, the compass being provided with a pendulum (9) mounted for limited pivoting movement inside its spherical casing (1), the pendulum having rotatably and pivotably mounted on it a compass disk (16) with a scale (18), which is intended to be read against a co-called steering line (12) on the pendulum (9) at an angle of 0.degree. to about 45.degree. relative the horizontal plane. The pendulum is pivotably mounted in a cradle (5) pivotably mounted inside the compass casing (1) for movement relative the casing in two planes substantially at right angles to each other so that its steering line (12) and the mounting point (c) of the compass disk (16) are continuously maintained by the action of gravity in the same vertical plane relative the fore-and-aft line of the boat independent of heeling of the boat.

Abstract: A pocket sized portable information device provides an alarm indicating Moslem prayer times. Means are provided for entering information identifying geograpical location, from which the hours of sunrise and sunset are calculated and then the prayer times. The device includes an oscillator driving a clock calendar and an interrupt time both of which are linked to a microprocessor. Codes identifying geographical locations are input via suitable key pads, resulting in geographical co-ordinate information being supplied to the microprocessor from a location ROM. By means of suitable algorithms the microprocessor calculates sunrise, sunset and the prayer times, and at the appropriate times provides an audible alarm through an amplifier and a transducer (T). The device is also provided with a compass identifying the direction towards magnetic north. Using the information from the location ROM the microprocessor calculates the deviation from magnetic north to the direction towards Mecca for the location concerned.

Abstract: A cylindrical compass gimballing and data readout system permitting 360.degree. rotation about both yaw and roll axes includes a cylindrical compass housing flooded with semiconductive fluid to permit transmission of a digitally multiplexed signal from a remote reading compass to a processing unit in which the fluid is interposed between spaced-apart plates located along and perpendicular to the roll axis of the compass. This permits electrical connection to and from the compass, and permits not only 360.degree. rotation about the yaw axis for compass heading readout, but also 360.degree. rotation of the compass about the roll axis to permit use in seismic streamers.

Abstract: An orienteering compass comprises a compass housing (3) with a movable north indicator (4) and a base plate (1) having a fixed course line (5). To enable directions to be extracted and checked in a simple fashion, and to enable a map to be read more positively when orienteering, the compass housing (3) is non-rotatably connected to the base plate (1) and the base plate together with the compass housing is arranged so that it can be pressed against and readily held on a map with the course line (5) in the desired direction. Preferably, the course line (5) extends in front of the compass housing (3) and coincides with a longitudinally extending edge (6) of the base plate (1).

Abstract: A three axis orientation sensor for sensing the orientation of an attached object such as an aircraft with respect to the earth's magnetic field. The sensor can be aligned and used in the presence of ferrous materials and magnetic fields which are inherent in the surrounding environment of the aircraft.

Abstract: A recreational or sportman's compass is comprised of an inner vial including a compass needle which together with an azimuth ring is resiliently mounted within a housing so as to be rotatable together or independently of one another. The vial is assembled together with the outer azimuth ring and retainer in such a way as to permit assembly of the parts into snug-fitting concentric relation to the housing without the necessity of positively fastening or affixing the vial to the housing.

Abstract: The present invention incorporates a flux-gate sensor for a vehicle compass. The sensor is mounted in association with the mounting system for a rearview mirror mounted to the vehicle windshield. In one embodiment of the present invention, the flux-gate sensor is contained in the mounting bracket for the rearview mirror. This location isolates the sensor from the undesired effects of the metallic mass of the vehicle as well as the dashboard, typically housing the vehicle's wiring.

Abstract: A remote-reading compass in which a compass assembly is buoyantly supported within a housing to accommodate a large range of tilt. Buoyancy is provided by a float surrounding the compass assembly and a liquid within the housing chamber. A pivot pin extends from either side of the float along a first normally horizontal axis to permit rotation of the float and compass assembly about the axis. The ends of the pivot pin ride in a circumferentially extending track which is disposed on the interior of the housing. The track permits rotation of the compass assembly and float about a second normally horizontal axis orthogonal to the first axis of the pivot pin. In this manner, the compass assembly is permitted to remain in a normally horizontal orientation during movement of the compass housing without need of gimbals, and rotation about a normally vertical axis is prevented. In addition, the track and the pivot pin together maintain a desired spacing between the float and the interior of the housing.

Abstract: The angular position of a compass card or like rotary encoder disk includes the utilization of an optical pickoff system in which the accuracy associated with a digitally encoded disk is enhanced through the utilization of a secondary analog optical pickoff system in which the outer periphery or border of the disk carrying the digital code is provided with a series of skewed lines running at an angle to the radius of the disk. A mask having a narrow slot is located to one side of the disk along the radius of the disk. A light source is positioned on the other side of the disk, and a linear array of detectors is positioned above the slot. The use of the skewed lines and slot amplifies the motion of the rotary encoder disk such that fine angular orientation may be detected by virtue of the position along the length of the slot of a line within the slot aperture.

Abstract: The invention is in the field of compass course following and comprises a means and method of mounting a compass directly on a map with a North-South reference line and following a course on the map directly once the compass needle is aligned with North. In all references to the direction "North" throughout this document magnetic North only shall apply.

Abstract: A direction indicating device has an azimuth card which is positioned upon a compass. The card is provided with a number of indicia marks corresponding to specific geographic locations. An adjustable straight-line cursor is positioned to be aligned with an indicia marking corresponding to the geographic location at which the device is being used and with the pivot point of the compass magnetic needle such that when the compass magnetic needle is pointing to magnetic North, the straight-line cursor will indicate the true direction of the predetermined locale from that specific geographic location.

Abstract: A spherical compass having a gravity operated support for automatically positioning its double axis gimbal system into a horizontal plane for selective mounting of the compass with its outer athwartships gimbal system axis mounted horizontally and its fore and aft compass mounting plane oriented at any angle between the horizontal and vertical. The support comprises a gimbal support unit mounted within the pair of hemispherical compass bowls for limited vertical movement from a normal lowered position in frictional damping contact with the inner surface of the lower of the hemispherical bowls to a raised position of reduced frictional contact to permit gravity adjustment of the gimbal system fore and aft axis and the fore and aft lubber lines and compass card into a horizontal plane.

Abstract: A magnetic compass comprises a case having a transparent cover and a magnetic compass card having a hub, which is rotatably supported on a central shaft projecting up from the base of the case by bearings comprising a thrust bearing between the hub and the upper end of the shaft and a radial bearing between the hub and a portion of the shaft spaced downwardly from the upper end. The radial bearing comprises a bearing ring set in a central recess in the hub and a full circle of small balls between the bearing ring and the shaft. In one embodiment there are two such radial bearings located one below the other. The bearings rotatably support the compass card on the shaft and retain it approximately perpendicular to the shaft even if the case is tilted.

Abstract: This invention is directed to a method of determining and recording an indeterminate sequence of distance/direction coordinates in a manner that permits the user or some other person to subsequently retrace the coordinates. Apparatus is disclosed to enable the user to record and retrace the coordinates with a high degree of precision.

Abstract: A device for attaching a compass assembly to a vehicle body comprising a support rod provided with a ball member on its end, said rod being disposed vertically on the upper surface of the housing of said magnetic needle assembly.

Abstract: A terrestrial magnetism responsive device adapted to be worked using a north or south seeking magnet in both north and south headings, the device including a housing having a north or south seeking magnet therein. The magnet is suspended adjacent one pole by a sensitive spring to permit the magnet to be movable horizontally, when released, from a north pointing position or a south pointing position. Secured and balanced on the seeking or free end of the magnet is a soft iron rod, generally at ninety degrees to the magnet and having substantially the same diameter as the magnet. The rod is balanced along with the magnet so that the magnet and rod together will move horizontally. The housing is rotatable on a plate by which it is held and during operation is fixed on the plate to be moved horizontally in the direction of an area to be explored.

Abstract: A toy including a housing having a front panel, a compass having a magnetic needle mounted on the panel, a pair of LED's on opposite sides of the compass, a sound alarm on the panel, and an electronic circuit, having a pair of contacts, which energizes one of the LED's and the sound alarm in response to the needle being pivoted in one direction to close one of the contacts, and which energizes the other LED and the sound alarm in response to the needle being pivoted in the other direction to close the other contact. The needle is pivoted by strategically positioned bar magnets external of the toy. The electronic circuit can be manually reset or automatically reset after a predetermined period.

Abstract: Set out herein is an electronic compass suitable for public use having a conventional pin supported magnetic needle which is placed over a set of magneto diodes or Hall devices arranged in quadrature. The magneto diodes or Hall devices are thus exposed to the highly enhanced magnetic field around the needle and will thus provide a direct readout, in electrical form, of the deviation from magnetic North. In this manner a relatively conventional arrangement of a magnetic needle may be utilized to provide the necessary signal source for electronic pick-off with the same accuracy obtained by a conventionally suspended arrangement practiced in the past.

Abstract: A compass includes a chamber, a card, needle or the like together with suspension means which suspend the card, needle or the like within the chamber. Magnet mounting means are engaged with the card, needle or the like and a magnet is engaged with the magnet mounting means in such a manner that in use the magnet may rotate at least in a plane normal to the plane containing the card, needle or the like, and such movement does not cause any substantial movement of the card, needle or the like.

Abstract: A terrestrial magnetism responsive device adapted to use a north or south seeking magnet in both north and south headings, the device including a housing having a north or south seeking magnet therein, the magnet being suspended adjacent one pole by a sensitive spring to permit the magnet to be movable horizontally, when released, from a north pointing position or a south pointing position. The method includes the releasing of a north or south seeking magnet in the housing so that it is free to move easterly or westerly on the spring, moving the housing over the areas to be explored, and recording the east/west diversions of the magnet and the exact locations of the diversions.

Abstract: A magnetic compass has been devised which is of the type having a pivot point displaced above the plane of the permanent magnets so that the distance of displacement of the pivot point with respect to the center of force will reduce the tilt angle or tipping otherwise caused by changes in latitude when the compass is to be operated in different parts of the world and a spherical needle bearing can be employed at the pivot point as a result of the increased pendular effect achieved by displacing the pivot point above the magnets. The need for a lift assembly to cushion the pivot point is eliminated while providing for an extremely rugged and versatile magnetic compass which will serve as a light, portable pocket transit capable of measuring horizontal and vertical angles as well as being used as a prismatic compass, level, clinometer, plumb or alidade.

Abstract: A compass with means attached thereto for presenting a visual indication of the direction of the true wind. Such compass includes a compass dial divided into a plurality of equal parts, and it can be arranged to suit different viewing angles. To suit different types of boats, sailing conditions, etcetera, the indicating means may be adjustable. The device computes mechanically the direction of the true wind from the knowledge of the boat's course and the angle between such course and the direction of the true wind.

Abstract: A small, light magnetic compass, in which the magnetic moment of the compass card is large relative to its weight, is adjustably mounted upon a member firmly coupled to the human head so that accurate compass bearings may be obtained, or a vessel steered, through an optical system presenting a magnified image of the compass card to the eye of the wearer.

Abstract: A compass having a magnetic element pivotally mounted in a housing, the housing including a light source and one end of an array of fiber optic bundles and the element carrying a reflector and/or an aperture to selectively permit light from the source to reach a selected one or more of the fiber optic bundle ends within the housing in dependence upon the orientation of the element relative to the housing about the pivot axis of the pivotal mounting.

Abstract: A course indicator including a marker which is normally movable following a compass and which may be automatically set to a reference position in alignment with a lubber line upon command. Thereafter, the marker will indicate any deviation from the course upon which it was set.

Abstract: A device for taking and plotting magnetic bearings which includes an elongated straight edge device having numerical graduated indicia along one edge thereof, and a housing receiving said straight edge. A magnetic compass is mounted on the straight edge, and the housing includes folding portions adapted to enclose and protect the magnetic compass. A pair of sight pins are removably attachable to the compass and straight edge to provide a line of sight extending through the pivot point of the magnetized needle of the compass.