Abstract: Gyroscopic apparatus comprises a gyroscopic device having two mutually perpendicular sensitive axes. The device is suspended in a two-axis gimbal system by means of cross-spring pivots of zero stiffeners. The gimbal system is further supported by a subsidiary suspension about two horizontal axes, and the subsidiary suspension carries damping means to damp movements of the gimbal system.

Abstract: The flexure joint for connecting two members for relative angular displacement comprises a pair of flexure leaves which merge with the members at their ends and cross each other and are rigidly connected with each other at the crossing point. Relative angular displacement of the members results in a flexure of the leaves. The flexure universal joint for connecting a gyroscope to its driving member comprises a Cardan member hinged by a pair of co-axial spaced flexure joints of the kind described hereinabove for relative angular displacement about a first hinge axis to the driving member and hinged by a second pair of co-axial spaced flexure joints of the same type to the gyroscope member for relative angular displacement about a second hinge axis, which intersects the axis of rotation of said gyroscope at right angles, said first hinge axis intersecting said second hinge axis and the axis of rotation of said driving member at right angles.

Abstract: An illustrative embodiment of the invention provides an isolation flexure assembly for the control moment gyroscope of a spacecraft attitude control system for attenuation of vibratory disturbances therein, due to rotor static and dynamic unbalance and spin bearing radial forces. The isolation flexure assembly isolates the rotor, the main generator of the vibratory disturbances, from the spacecraft permitting ultraprecise pointing or precision torquing of the spacecraft.

Abstract: A method of manufacturing a flexure suspension assembly which includes forming four quadrantally and radially disposed single axis flexure joints in a first cylindrical member and four quadrantally and radially disposed single axis flexure joints in a second cylindrical member. The longitudinal axes of the flexure joints in the first cylindrical member are substantially parallel to the longitudinal cylinder axis which is coincident with the spin axis of the suspension assembly and the longitudinal axes of the joints in the second cylindrical member are substantially perpendicular to the longitudinal axis of the second member. The first and second members are integrally joined together in concentric relationship with the bending axes of the four joints in each cylinder in radial alignment to form a composite cylindrical member. The composite cylindrical member is then separated by electro discharge machining into the foregoing components of the flexure suspension assembly.

Abstract: A machine for manufacturing high strength flexure hinges having use in accelerometers. A source of metal material is splat-cooled after it has been heated to a molten state. An induction heater heats the metal material to the molten state and the molten metal is rapidly cooled while being pressed between two water cooled wheels. The wheels are provided with indentations and protuberances on their surfaces to produce flexure hinges and strengthening beams. A chute is provided to catch the flexures as they leave the wheels preventing damage to them.

Abstract: A rotary support device for use with a dial apparatus is disclosed. The rotary support device is formed mainly of a first cylinder having an aperture through which a rotary shaft of the dial apparatus passes, the rotary shaft being then fixed thereto, a second cylinder having an aperture through which the rotary shaft passes with a clearance therebetween, and a coupling member which resiliently couples the first and second cylinders. The second cylinder is coupled to a rotating member of the dial apparatus and they are to be rotated together, so that when the rotating member of the dial apparatus is rotated, the rotary shaft of the dial apparatus is rotated through the second cylinder, the coupling member and the first cylinder even if the axis of the rotary shaft is eccentric to the axes of the support cylinders.

Abstract: A thin plate-like rotor is mounted on a hub which in turn is attached to the shaft of a motor which drives the rotor at a predetermined rotational speed about a spin axes. A framework is provided for mounting the motor. The rotor has a damping face and an opposite signal face. A damping plate is mounted on the hub in close spaced relation with the damping face. A spring member is disposed between the hub and the rotor so that the rotor is free to move in restrained rotational fashion about one diameter of the rotor. Surrounding air is pumped through the space between the damping face and the damping plate to provide damping of the motion of the rotor about the one diameter. Pickoffs are mounted in the framework in close spaced relation to the signal face of the rotor. The pickoffs provide output indicative of the spacing between the signal face and the pickoffs which corresponds to angular velocity inputs about the separate axes disposed orthogonally with the spin axes.

Abstract: A flexure hinge assembly comprising a pair of fixed telescopes inner and outer tubular members separated into at least one driving portion, at least one gimbal portion and at least one driven portion and a plurality of flexure blades all formed by a plurality of slots and apertures through the walls of each tubular member. Flexure blades are formed by pairs of adjacent apertures with the slots interconnecting apertures to separate the tubular members into the driving, gimbal, and driven portions. A pair of diametrically opposed flexure hinges, each comprising two mutually orthogonal flexure blades one in the outer and one in the inner member, connect each gimbal portion to the driving portion. Another such pair of flexure hinges connect each gimbal portion to the driven portion.

Abstract: Apparatus for reducing the twice spin frequency vibration sensitivity of tuned inertial sensors by providing a twice spin frequency rotating filter thereon is disclosed. In accordance with the invention a rotating filter is supported on the shaft assembly of a tuned inertial instrument so as to rotate therewith at the spin speed. By tuning the combination of the filter rotor and the spring support thereof so as to have a natural frequency of twice sin frequency about axes perpendicular to the spin axis, the filter rotor, operating uncaged and substantially undamped, will absorb a large part of the twice spin frequency angular vibration torques imposed on the shaft assembly through bearing noise and other sources.

Abstract: A flexure-pivot for providing resilient restraint that opposes relative angular displacement between two members involves two flat springs, that are held at one end between pairs of pins carried by one member and at the other end between pairs of pins carried by the other member, the flat springs each having two parallel rib portions that are linked at one end and are interlaced with one another. In one form of flexure-pivot the unlinked end of both the rib portions of each spring is secured between a pair of pins carried by one member and the linked end of both the rib portions of each spring is secured between a pair of pins carried by the other member.

Abstract: A flexure hinge assembly comprising a pair of fixed telescopes inner and outer tubular members separated into at least one driving portion, at least one gimbal portion and at least one driven portion and a plurality of flexure blades all formed by a plurality of slots and apertures through the walls of each tubular member. Flexure blades are formed by pairs of adjacent apertures with the slots interconnecting apertures to separate the tubular members into the driving, gimbal, and driven portions. The four slots of each tubular member which divide that member into these three portions are axially coextensive with the slots in the other member and all extend in the same axial direction from the apertures which form the flexure blades. Such axially coextensive slots displace the driving and the driven portions of the tubular members in the same axial direction from the center of suspension, i.e., from the flexure axes of these portions.

Abstract: A flexure suspension assembly is provided for coupling the rotatable spin shaft and flywheel of gyroscopes of the type having relative angular rotation between the shaft and flywheel about two precession axes orthogonally related to the spin axis. A cylindrical central spin shaft mounting member is coupled by a first pair of single axis flexure joints to a first bifurcated gimbal member to permit angular rotation of the gimbal about one precession axis and is coupled by a second pair of single axis flexure joints to a second bifurcated gimbal member to permit angular rotation of the second gimbal about the other precession axis. The gimbal members are interleaved and form segments of an annulus concentrically disposed about the central mounting member.

Abstract: Spin coupled angular rate sensitive inertial sensors of the tuned suspension system type with mounting structure, and method of fabricating and mounting such sensors whereby the twice spin frequency linear and angular vibration sensitivity characteristic of tuned sensors may be eliminated. The twice spin frequency angular vibration sensitivity characteristic of other tuned inertial sensors is reduced by creating an equal and opposite torque component dependent on the same vibrational input by angularly offsetting the rotor suspension system from a plane orthogonal to the spin axis, and by providing the shaft assembly with an effective product of inertia of controlled magnitude and orientation.Compensation for twice spin frequency linear vibration caused primarily by the spin bearings is achieved either by mounting the spin bearings in a relatively soft mounting, or supporting the instrument case (non-rotating portion) on a suspension tuned to twice spin frequency in the translational mode.

Abstract: A universal gyroscope flexure hinge assembly is provided to interconnect the inertial flywheel of a 2-axes free rotor gyroscope to the gyroscope spin shaft, with two symmetrical, axially displaced gimbal elements which allow two axes of angular freedom. Errors which would arise due to axially displaced gimbal elements are compensated for by offsetting the flexure axes of the two gimbal elements. Each pair of flexure blades forming a flexure hinge have a common flexure axis and the flexure hinge assembly has only two orthogonal flexure axes which are axially displaced from one another.

Abstract: Gyroscopic apparatus in which the rotor is elastically-connected to its drive, whereby deflection of the rotor bends the connection and thus sets up a deflection torque which acts upon the rotor. The connection of the rotor to the drive also includes masses carried by springs. When the rotor deflects, these masses oscillate in directions parallel to the driving axis, and when the rotor is spinning at a certain (tuning) speed the sum of the oscillating forces exerted upon the rotor by the individual moving masses will be a steady quantity which may be made equal and opposite to the deflection torque. The apparatus may thus behave like a "free rotor" gyroscope.

Abstract: A dynamically tuned gyroscope having a single gimbal has torsion flexures with torsional stiffnesses such that, at its tuned speed, the gyroscope is insensitive to angular vibration at a frequency of twice the rotor rotational speed. The drive shaft is connected to a first torsion flexure having an effective torsional stiffness K.sub.1 of zero, K.sub.1 being made zero by the use of ball races or pivots, by known mechanical methods such as over-center or toggle spring action, or by the use of magnetic or electrostatic systems. The rotor is connected to a second torsion flexure which is orthogonal to the first flexure. The second torsion flexure has a torsional stiffness K.sub.2 equal to 4w.sup.2 r.sub.3.sup.2 m.sub.3 where w is the tuned rotor speed, m.sub.3 is the component mass of a gimbal, on which the torsion flexures are mounted, on an axis through the center of gravity of the gimbal and normal to the plane of the gimbal, and r.sub.3 is the distance of the component mass m.sub.

Abstract: A taut ribbon rotary suspension system is constructed with ribbons stretched inside a case over a set of ribbon planes intersecting the pivot axis of the suspended member. The ribbons are wrapped over a set of rod segments attached to the suspended member so that the line of departure of the ribbons from the rod coincides with the pivot axis. The ribbons pertaining to each ribbon plane at one side of the pivot axis are rigidly attached to the case to provide positive geometric positioning. The ribbons of the same ribbon plane at the other side of the pivot axis are anchored elastically to minimize effect due to dissimilar coefficient of expansion. Configuration may vary from using single ribbon plane to two orthogonal planes for single axis application and four ribbon planes for two orthogonal axis adaptation.

Abstract: A gyroscopic directional reference system comprising a two-degree-of-freedom gyroscope including a tuned single flexible hinge rotor and capacitance sensors for measuring the torsional displacement of the rotor about its hinge. The sensors are arranged to provide two orthogonal signal output axes and the gyroscope is suspended, for the sake of convenience, with the rotor spin axis parallel with the local earth gravity or, in order to provide maximum signal gradient, perpendicular to the earth rotation axis. A signal summing system produces an output signal which is nulled when the input axes are angularly oriented at 45.degree. with respect to the earth rotation axis and a servo system is provided for rotating the gyroscope about its spin axis to null the output signal. Alternatively, a capacitance sensing transducer system produces an output signal representing the angular orientation of the gyro relative to the earth rotation axis.

Abstract: Spin coupled angular rate sensitive inertial sensors of the tuned suspension system type, and method of fabricating such sensors whereby the twice spin frequency linear and angular vibration sensitivity characteristic of tuned sensors may be eliminated. The twice spin frequency angular vibration sensitivity characteristic of other tuned inertial sensors is eliminated by creating an equal and opposite torque component dependent on the same vibrational input. This is done by angularly offsetting the rotor suspension system from a plane orthogonal to the spin axis, and by providing the shaft assembly with an effective product of inertia of controlled magnitude and orientation. The product of inertia modulates any twice spin frequency angular vibration of the shaft about an axis orthogonal to the spin axis with the spin frequency of the shaft to provide an angular disturbance of the shaft about the spin axis.

Abstract: A universal joint for small angle deflections having a driving element which is rotatable about an axis of rotation wherein the driving element is connected to a driven member by a suspension means which comprises at least two gimbal elements, each gimbal element is connected to the driving element and to the driven element by at least two flexure hinges, each of the longitudinal axes of the flexure hinges forming an angle of the same magnitude with the axes of rotation of the driving and driven elements when the universal joint is in a rest position. A method for fabricating such a multigimbal universal joint for small angle deflections in one-piece wherein integral flexure hinges having such longitudinal axes are provided by forming pairs of adjacent bores in a blank and wherein the driving elements, the driven element and at least two gimbal elements therebetween are formed by electrical discharge machine techniques.

Abstract: A flexure hinge assembly comprising a pair of fixed telescopes inner and outer tubular members separated into at least one driving portion, at least one gimbal portion and at least one driven portion and a plurality of flexure blades all formed by a plurality of slots and apertures through the walls of each tubular member. Flexure blades are formed by pairs of adjacent apertures with the slots interconnecting apertures to separate the tubular members into the driving, gimbal, and driven portions. The four slots of each tubular member which divide that member into these three portions are axially coextensive with the slots in the other member and all extend in the same axial direction from the apertures which form the flexure blades. Such axially coextensive slots displace the driving and the driven portions of the tubular members in the same axial direction from the center of suspension, i.e., from the flexure axes of these portions.