Showing papers on "Angular displacement published in 1972"

Dual mode angle encoder

Abstract: An angle encoder for selectively providing from a single rotatable code element an output indication of the angular position of the rotatable element and of angular deviation and sense with respect to a reference position. A Gray coded code element is employed and from which a Gray code is sensed to provide digital signals which are processed by associated logic circuitry operative in two modes. In one mode an output indication is provided of the angular position of the code element, while in a second mode an output indication is provided of the extent and sense of angular deviation of the code element.

Angular orientation measuring apparatus

Abstract: An optical device using a wedge deviation technique for the measurement of the angular orientation about the axis of rotation of one body relative to another. The device employs a passive target, which may be a linear reticle, on one body and optical measuring means on the second body. The measuring means has an optical element such as a prism assembly to split the image of spaced apart portions of the linear target into two transposed halves which are viewed by suitable means such as a telescope. An optical wedge assembly centered in the line of sight on the axis of rotation between the telescope and the target can be used as the optical element. When the target reticle lies in the plane described by the optically deviated split field of view of the telescope, an unbroken line is perceived through the telescope. When rotation about the line of sight occurs in one body with respect to the other, a linear displacement of one half of the split image of the target with respect to the other occurs. The amount of rotation of the optical measuring means required to bring the split image back into coincidence is correlated against a calibrated scale to give an indication of the amount of angular displacement about the axis of rotation that had occured. In a further embodiment, an arrangement of mirrors rather than a wedge assembly is used to produce the split image in the optical measuring means.

Self-organizing control system

Abstract: This disclosure relates to improvements in self-organizing control logic configurations having particular application to automatically or remotely piloted vehicles The improvements include the use of multiple-point (time-distributed) functions for control system performance assessment, the use of performance assessment value-signal magnitude information to govern parameter step sizes, and means for controlling an object that is rotating with a determinable angular rate but unknown phase angle relative to a fiducial angular position of the object

Torsion damping device

Abstract: A torsion-damping device, especially for a clutch friction-disc, for coupling together two parts for rotation with a relative elastically-braked angular displacement, one of the said parts comprising a central plate provided with passage means, while the other part comprises side plates disposed on each side of the central plate and interconnected by spacing members passing through the passage means with an angular clearance defining said displacement in both directions, windows being formed facing each other in the said plates and being intended to receive torsiondamping springs for coupling the plates together in rotation, while offering an elastic resistance to the said displacement, some of the windows facing each other in the central plate and in the lateral plates having different angular lengths in order to cause the corresponding spring to act only after part of the displacement, so as to obtain a progressive variation of the torque as a function of the displacement. High transmissible torque and good progressivity are obtained by increasing the number of windows and arranging the spacing members and/or their passage means closer to the axis of rotation than the windows. In an alternative form, the said passage means are constituted by radial extensions of certain windows in the central plate towards the axis of rotation.

Optical device for position location

Abstract: An optical positioning device providing range and relative positional alignment between two bodies utilizing an autocollimation technique One body carries the illumination source and detector while the second body carries a retroreflector Range information is determined by timing a pulse-modulated beam Angular displacement is determined as a function of the difference between the measured off-axis beam intensity variation and the calculated intensity for the given range

Shift lever device for speed change gear transmission train of a bicycle

Abstract: A shift lever is mounted on the bicycle frame for pivoting about a first axis and for angular displacement about a second axis perpendicular to the first axis. A first speed changing cable connects the shift lever to the first train, and a second speed changing cable is connected to a member displaceable by angular displacement of the shift lever. The first cable is connected to an end of the shift lever so that it is displaced linearly upon pivoting of the shift lever about the first axis. Angular displacement of the shift lever effects rotation of a drum or gear which, in turn, effects linear displacement of the second cable. Conjoint pivoting of the shift lever and angular displacement thereof effects simultaneous linear displacement of both speed changing cables.

Electronic level instrument

Abstract: An improved, highly sensitive, electronic level and protractor instrument is provided which is intended to replace the prior art bubble type level, as well as the prior art electric levels, and which is capable of indicating not only horizontal or vertical axes, but also axes which lie at any inclination thereto. The improved electronic level of the invention includes a pendulum which may be rotated to any desired angular position and which selectively engages a pair of contacts to activate an electronic circuit. Visual and/or aural electrical indicators are activated by the electronic circuits to indicate when the instrument is on a predetermined axis, and to indicate when the instrument is angularly displaced from the predetermined axis. Calibrated dials are provided from which the inclination of unknown axes may be determined, and which also may indicate the extent of the displacement of any particular axis from a particular inclination.

Hindered Molecular Rotation in Liquids

Abstract: Expressions for the angular velocity autocorrelation function of a classical spherical top rigid rotator and the NMR correlation time τ2 are derived. A general relationship of the product of the spin—rotational correlation time (τ1) and τ2 is presented which is proportional to the mean square angular displacement in a diffusive rotational step. The present expression for τ2 is compared with that based on the quasilattice random flight (QLRF) model. The most characteristic difference between the two expressions for τ2 is that present expression depends on the square root of the moment of inertia while the QLRF relationship depends on the square root of molecular mass. In favorable situations this difference can be used to ascertain the mechanism of molecular reorientation such as for NH3 and ND3. Root mean square angular displacement in a diffusive step are computed from observed values of τ2 and compared with the results of infrared measurements. A value for the time τ1 for liquid water at 34°C is calcula...

Method and means for measuring the refractive properties of an optical system

Abstract: Method and means for measuring the refractive properties of an optical system utilizing a rotatable ruling disposed to intercept a refracted light beam passing from the optical system under test. The refracted beam is chopped as a result of relative motion between the refracted light beam and the ruling to produce a series of electrical signal pulses after photo detection of the chopped refracted beam. The train of signal pulses thus produced is analyzed to provide selected quantitative measures of spherical power, cylindrical power, cylindrical axis, prism power and prism axis of the optical system under test. The light beam incident upon the optical system under test is rotated to trace out a cylindrical surface for measuring the cylindrical power, spherical power and cylinder axis. The resulting refracted light beam will describe an ellipse on the grating in the most general case when all three of these refractive properties are present. The rate at which the incident beam is rotated is much greater than the rate at which the ruling is rotated and the signal pulses produced from the photo detector output are counted during each revolution of the incident light beam. The maximum number resulting from such a counting process is proportional to the major axis of the ellipse and therefore proportional to the spherical power of the lens, while the minimum number thus derived is proportional to the minor axis of the ellipse. The difference between these two numbers is proportional to the cylindrical power of the lens while the angular position of the ruling at the instant when the minimum number is detected is indicative of the relative orientation of the cylinder axis. The prism power and axis is measured by using a static incident beam of light and then counting the number of signal pulses produced during one complete revolution of the ruling. The number of such pulses is directly proportional to the prism power while the angular position of the ruling at the time the inter-pulse time interval is at a maximum is a measurement of the prism axis.

Meridian seeking instrument

Abstract: A gyroscope unit having a horizontal spin axis hangs from a suspension band within a container. The container is rotatably supported about a vertical axis. A transducer generates a control signal representative of the angular displacement between the gyroscope unit and the container about the vertical axis from a reference position. The container is rotated about the vertical axis responsive to the control signal to reduce the angular displacement from the reference position. A torque about the vertical axis that opposes the angular displacement is directly applied to the gyroscope unit responsive to the control signal. The directly applied torque is a nonlinear function of the angular displacement, being zero below a threshold value of angular displacement and having a predetermined gradient above the threshold value.

Motion cue effects on pilot tracking

Abstract: The results of two successive experimental investigations of the effects of motion cues on manual control tracking tasks are reported. The first of these was an IFR single-axis VTOL roll attitude control task. Describing function data show the dominant motion feedback quantity to be angular velocity. The second experimental task was multiaxis, that of precision hovering of a VTOL using separated instrument displays with reduced motion amplitude scaling. Performance data and pilot opinion show angular position to be the dominant cue when simulator linear motion is absent.

Adjustment means for the tooling or machining angle in tooling or machining operations

Abstract: Adjustment means is provided for adjusting the tooling or machining angle, especially the boring angle of tooling devices. Said adjustment means is secured to the device proper and comprises a level carried by a lever which is pivoted between two discs having angular graduations on their rim portions for setting the angular position of the lever about a first axis. Also, the level is rotatably adjustable on the lever about a second axis extending perpendicular to the first axis, whereby the tooling angle can be accurately set relative to vertical and horizontal axes, that is, three-dimensionally.

Apparatus for measuring the angular displacement and the angular velocity of a rotation member

Abstract: Apparatus for measuring the angular displacement and the angular velocity of a rotating member. Mechanical energy causing angular motion of the rotating member is transformed into electrical energy in the form of a plurality of electrical pulses which are counted during a preselected time interval. Variations in the magnitude of the cycle do not alter the accuracy of the apparatus. Thus, the angular displacement and the angular velocity of the rotating member can be economically measured with greater accuracy than has previously been possible with voltage dependent apparatus.

Array transducer angular tracking system

Abstract: A system for measuring the angular displacement of a signal source relativeo the center line of an array type transducer. The sum and difference signals of the array are applied to the system which phase shifts the incoming signals, provides a summation of selected phase shifted signals and applies the summed signals to a phase detector. A normalized signal is derived that is an amplitude measurement indicative of the angle between the signal source, and a line incident normal to the array, wherein the sum is a maximum and the difference is zero.

Non-contacting angular position detector

Abstract: The angle between a small radio frequency coil and a spatially uniform magnetic field is measured and a signal commensurate with the measured angle is employed in a computation of angular position. The apparatus employed in the angle measurement is characterized by a DC frequency response whereby an output signal is produced in the absence of motion between the coil and field.

Stress sensor with digital output

Abstract: The sensor is based on the rotation of the easy axis of a thin magnetostrictive film under the stress to be measured. The sensor comprises a plurality of elementary cells located on the same substrate to which said stress is applied. Each cell comprises interrogating means and reading means associated with an elementary spot of magnetostrictive film. The angular position of the easy axis is determined through sequential interrogation of each elementary cell by means of pulsed magnetic fields as a change in the polarity of the sense pulse signal of a given elementary cell. The interrogating means is a set of lines printed according to a preset pattern which controls the coding of the binary output signal. The pulsed voltages induced in the sense circuit reverses it polarity when the interrogating field crosses the normal to the easy axis as rotated under the stress applied to the cell. The output signal conveys as a polarity reversal, the angular position information for further use. An example of use in instrumentation (pressure sensor) is described.

Method and apparatus for optically monitoring the angular position of a rotating mirror

Abstract: An optical system monitors the angular position of a rotating scanning mirror to indicate the effective start and end of each scan. At a certain angular position, a ray of energy transmitted to the mirror is reflected a plurality of times between the reflectors associated with the optical system and the line on the mirror parallel to the axis thereof, and then to a detector to sense that angular position. A single optical system may be arranged to sense a plurality of different angular positions for each revolution of the mirror.

Six-bar linkage having symmetrical displacement curve

Abstract: A six-bar linkage which has an angular displacement curve between theta and phi where theta is the angle of rotation of a driving link and phi is the angle of rotation of a driven link for producing a rectilinear motion of one point of the six-bar linkage without guide means when the driving link rotates.

A note on the angular dispersion of a fluid line element in isotropic turbulence

Abstract: The mean-square angular displacement of a fluid material line element is expressed as an integral of the corresponding angular velocity in material coordinates, with forms like those in Taylor's (1921) linear displacement analysis. Measurements using a hydrogen-bubble tracer in isotropic turbulence show that the mean-square angular velocity of a line is of the same order of magnitude as the mean-square vorticity, and that its ‘Lagrangian’ integral time scale is of the order of the inverse of the r.m.s. vorticity. The angular velocity of a line element is also formulated in spatial co-ordinates. Finally, the connexion between angular dispersion and the approach toward isotropy is pointed out.

Laser beam attitude control device

Abstract: A mirror operatively connected between a frame and a plumb mechanism so that any angular displacement, through an angle of 2 theta , of the frame relative to the plumb effects a corresponding angular displacement, through an angle of theta , of the mirror relative to the plumb. A laser is mounted to the frame and emits along an axis toward the mirror. The mirror will reflect light from the laser at a constant angle relative to the vertical. The laser is adjustably mounted so as to preset the orientation of the reflected beam.

Position indicating apparatus and digital circuitry for it

Abstract: Indicating apparatus includes an incremental shaft position encoder having a shaft whose angular position is to be indicated. A multi-phase electrical signal developed by the encoder in response to rotation of the shaft is processed by digital circuitry to provide pulses suitable for counting by an up/down counter. The counter accumulates a count that represents the net rotation of the shaft.

Fluid actuated control system

Abstract: A rotatable shaft restrained from axial displacement is maintained at a pre-selected angular position by a fluid actuated control system comprising a sensing device disposed for sensing angular displacement of the shaft from the pre-selected position. The sensing device generates signals proportional to the displacement sensed and transmits them to a proportional fluidic amplifier which divides a controlled fluid flow proportional to the signals and directs the proportionally divided flows to opposite ends of a cylinder thereby actuating a piston for linear displacement therein proportional to the angular displacement of the shaft. A motion converting device converts linear displacement of the piston to angular displacement of the shaft.

Ice drill with adjustable cutting edges

Abstract: An ice drill mounts a pair of cutters on a pair of sockets rotatably supported on a bar connected transversely to the end of a drill shaft. The angular orientation of the sockets, and hence the cutters, on the bar may be adjusted by rotating an adjustment member which engages a notch on each socket. Rotation of the adjustment member causes rotation of the sockets in opposite directions but with equal angular displacement thereby maintaining equal cutting angles for the two cutters.

Sector scanning control system

Abstract: A control system for a motor which angularly positions a mirror at a predetermined rate. The initial angular position for the mirror is applied in digital form to a digital analog converter (DAC). The rate of angular rotation is coded in digital form and the digital signals representing a particular rate are applied to a rate of change DAC. The output of the rate of change DAC is connected to an integrator which provides a voltage changing at a constant rate with time. A control signal starts the integrator and resets the integrator after the mirror has been rotated at the predetermined angular rate for a predetermined period of time. The output of the integrator is combined with the output of the position DAC so as to provide a reference position signal which is summed with a negative feedback signal obtained by sensing the position of the mirror. This results in a voltage difference signal which is amplified and applied to a high torque low inertia DC motor.

Fluidic angular displacement sensor

Abstract: Fluidic sensor arrangement for monitoring amount of and incremental frequency of angular displacement includes fluidic interruptable output signals and a corresponding pair of fluidic barrier sets arranged to move in unison in interruptable relation with the fluidic elements in response to angular displacement of the monitored body.

Improvements relating to angular accelerometers

Abstract: 1279223 Measuring angular acceleration electrically FERRANTI Ltd 19 April 1971 [6 Feb 1970] 5810/70 Heading G1N An angular accelerometer comprises an insulating disc 11, Fig1, elastically supported in an electrically conducting liquid fed with an A C potential between top and bottom electrodes 18, 19, and two pairs of pick-up electrodes arranged along mutually perpendicular horizontal axes, whereby displacement of the housing 10 about one of the horizontal axes due to angular acceleration produces a potential difference between the pick-up electrodes on the other axis The disc 11, strengthened by corrugations, is supported on a flexible strip 12 attached to the housing by post 13, cross-member 14 and post 15, angular displacement of disc 11 relative to the housing 10 occurring by bending and/or twisting of strip 12 about axes 22, 25, Fig 2 The measured potential difference is directly proportional to steady angular acceleration, or the double integral of transient acceleration Other embodiments show: (a) different electric support for disc 11, (b) modifications to the shape of disc 11 particularly for measurement of angular acceleration about one axis only, (c) an arrangement of three mutually perpendicular discs 11 for measuring displacement and acceleration about three mutually perpendicular axes, Figs7, 8, 9 (not shown) The discs 11 may be made of electrically conducting material for use with a dielectric liquid and capacitive pick-ups

Hydraulic free-jet servo-valves

Abstract: In this free fluid jet servo-valve comprising a bored body, and a swivel nozzle for emitting a fluid jet, a device is provided for rotatably driving said nozzle and resilient means constantly urge this nozzle against rotation. At least one receiving nozzle has its inlet orifice registering with the outlet orifice of said emitter nozzle; the output in the receiving nozzle depending on the angular position of the emitter nozzle rigid with a cylindrical drum rotatably mounted in a bore formed in the valve body, a guide device provided with hydrostatic bearings of known type preventing any mechanical contact between said drum and the valve body bore.

Transmission Error Measurements In Large Gear Hobbing Machines

Abstract: A seismic instrument for measuring the hob-to-table cyclic error of large gear hobbing machine is described in which a large and heavy torsional vibration pickup, currently in use for detecting the non-uniformity of rotation of the machine table, is replaced by a pair of small and light rectilinear vibration pickups mounted tangentially on a periphery of the machine table, 180 apart. Two differential-transformer seismic pickups of 1.6 s natural period are connected so as to be additive for the rotational vibration and null each other for the rectilinear vibration of the machine table. The sensitivity for rotational vibration increases in proportion to the table diameter, the minimum measurable angular displacement being 0.0025 sec of arc for the table diameter of 6 m.From theoretical analysis of the motion of the seismic system under working condition, it is shown that the equality of the sensitivities and frequency responses and the parallelism of the sensitive axes of both pickups, and the accuracy of the machine alignment are important factors in determining the measurement error; and these factors are examined in detail. The operating principle of the instrument and the adjustment and calibration of pickups, together with the test results on the bobbing machines of 2 m and 6 m in table diameter, are outlined.

Differential-motion timer

Abstract: A differential-motion timer. Reciprocating motion of a predetermined frequency and angular displacement is converted into unidirectional rotary motion by means of at least two ratchet wheels coaxially aligned and independently free-wheeling and each having a different number of notches. Each of the ratchet wheels is driven by a ratchet drive which is connected to the reciprocating element. Accordingly, each ratchet wheel can convert reciprocating motion to unidirectional rotary motion, the speed of the rotary motion being, on the average, proportional to the driver frequency. Since each of the ratchet wheels has a different number of notches, it follows that each of the wheels will be driven at a slightly different speed by the single ratchet driver. This difference speed is the timing motion and the relative angular positions of the wheels correspond to the elapsed time. A switch is actuated whenever certain preselected corresponding points on each of the ratchet wheels arrive at predetermined positions.