Showing papers on "Angular displacement published in 1970"

Optical scanning system

Abstract: An optical scanning system wherein infrared energy radiating from an object is directed to a Porro prism, such Porro prism being rotatable about the boresight axis of the optical scanning system so that the image of the object rotates, in the image plane of such system about its boresight axis, at an angular rate twice that of the Porro prism. A linear array of infrared detector elements is disposed in the image plane radially from the boresight axis of the scanning system. The angular deviation of the object from the boresight axis of the scanning system is measured by determining: (1) the angular position of the Porro prism when one, or more, of the infrared detector elements in the linear array is energized; and (2) which one, or ones, of such elements is energized.

Angular position determining system compensated for doppler

Abstract: Disclosed are systems for determining the true angular position of a target with respect to a reference location. One such system employs a novel array of antenna units at the reference location. The units are uniquely excited by a pulse type signal in two opposite predetermined sequences to produce a pair of radiated pulse trains. A target located in the field of this array is illuminated by these radiated pulse trains each of which has a phase distribution proportional to the angular position of the target with respect to the array and opposite in sense to that of the other. Furthermore, the frequency of each pulse train undergoes a doppler shift due to the radial velocity, if any, of the target with respect to the array and therefore the ambiguity due to such shifts can be compensated for by detecting the phase distribution of each pulse train and processing the information obtained. In this manner an indication of the target's true angular position, free from doppler ambiguities, can be provided either at the reference location alone, the target alone, or at both the reference location and the target.

Material testing device for the continuous measurement of stress relaxation

Abstract: An apparatus in which one end of a material test specimen is affixed to a calibrated plate on a stationary housing and the other end is affixed to a rotatable element within the housing. A calculated stress is applied to the test specimen by rotating the calibrated plate through a specific angular displacement. An electromagnetic spring field applies a torque proportional to rotational displacement of the test specimen. The angular displacement is sensed by an electromagnetic pick-off which controls a torque motor that applies a sufficient torque to the rotatable element to maintain it at a null position. Any stress relaxation within the specimen results in movement of the rotatable element. Such movement is sensed by the electromagnetic pick-off which generates an error signal that is applied to the torque motor which returns the rotatable element to its null position. The error signal is a measure of the stress relaxation within the material and is routed to a recorder.

Rotating-wave rotation detector and method of operating same

Abstract: A bell-like high-Q member having sides capable of being flexed in a radial vibration pattern defining an anti-nodal region that is free to rotate about the sides in proportion to the rotation of the sides about an input axis. A forcer is mounted adjacent and encircling the periphery of the sides and is effective at the instantaneous angular position of the anti-nodal region to parametrically excite and exercise the sides. Sensor means are located adjacent the periphery and along radii fixed with respect to the bell sides to measure the pattern rotation with respect to bell rotation.

Wide-angle two-coil electrical gauge

Abstract: A wide-angle electrical gauge having two coils whose magnetic axes are at right angles. A signal source supplies a signal whose magnitude is proportional to the magnitude of the condition to be indicated. A sine generator is responsive to the output of the signal source and controls the current through one of the coils in a manner such that the magnetic field along its magnetic axis varies in an approximated sinusoidal fashion. A cosine generator is responsive to the output of the signal source and controls the current through the remaining coil in a manner so as to generate a magnetic field along its magnetic axis which is phase shifted from the magnetic field generated by the sine generator so as to take the form of an approximated cosine waveform in relationship thereto. A magnetic armature aligns itself with the resultant of the two magnetic fields whose angular position corresponds to the magnitude of the condition being measured.

Power transmitting system

Abstract: CYCLIC IRREGULARITIES IN THE ANGULAR VELOCITY OF THE DRIVE TO A ROTATIONAL COUPLING ARE COMPENSATED FOR BY PROVIDING ANGULAR PLAY IN THE COUPLING EQUAL TO THE PEAK TO PEAK AMPLITUDE OF THE IRREGULARITIES IN ANGULAR DISPLACEMENT OF THE DRIVE MEMBER OF THE COUPLING. THE COUPLING COMPRISES INNER AND OUTER MEMBERS HAVING COMPLEMENTARY RECESSES OR PROJECTIONS ON THEIR FACING SURFACES, FORMING HOUSING FOR COUPLING MEMBERS DIMENSIONED TO PERMIT THE DESIRED ANGULAR PLAY. THE COUPLING MEMBERS ARE PREFERABLY CYLINDRICAL AND MAY BE OF ELASTIC MATERIAL.

Method of friction welding and apparatus therefor

Abstract: An improved method of friction welding consisting of friction, correction, and upset steps, is disclosed. Said improvement exists in that during said correction step, as soon as the relative rotational speed between the respective bodies to be welded has been reduced to zero, at least one of said bodies to be welded is quickly rotated about the axis of said rotation by the amount falling within 0 DEG to 360 DEG in one direction to make correction of the relative angular position about said axis of rotation. In the preferred embodiment of the disclosure, the quick correction of relative angular position is achieved by means of a pair of positioning members having complementary configurations to mesh with each other, one being fixedly secured to one of the bodies to be welded, while the other being secured fixedly in the rotational direction but slidably in the axial direction relative to the other body to be welded.

Self-timed reaction-mass compass

Abstract: Two horizontal discs of identical mass and dimensions are rotated in opposite directions at identical and fixed speed. Each disc is pierced by a radial slot. Coincidence of said slots provides an index spot on a compass card. Said coincidence is independent of the device support and holds its direction in space despite support movement and rotation. The discs may be rotated by any means. A counter may be employed to read out the slot-coincidence position in degrees relative to any fixed angular position about the axis of said discs.

Mechanisms for converting angular motion to straight line motion

Abstract: A tensioning mechanism for a belt or chain particularly a conveyor belt or chain comprises two eccentric devices mounted one within the other and geared together by an epicycliclike gear train. One eccentric device carries a shaft for a wheel around which the belt or chain passes. A member of the epicycliclike gear train has means whereby it can be rotated manually so as to cause relative angular displacement of the eccentric devices and thereby movement of the shaft in substantially a straight line in a tension-adjusting direction for the belt or chain.

Apparatus for signalling an angular displacement of a body about an axis

Abstract: To provide an indication of the angular displacement phi of the rotor of a synchro transmitter or resolver, two cyclically varying signals having amplitudes representing the sine and cosine respectively of the rotor shaft angle are derived and are used with two further cyclic signals, having a higher frequency n and in phase quadrature, to derive two trains of pulses at the higher frequency in phase quadrature, the two-pulse trains having amplitudes representing respectively the sine and cosine of the shaft angle. These pulse trains are combined and processed to provide a signal which is a function of ( omega nt+ phi ), which is then compared with a reference signal at frequency n to obtain an indication of the rotor shaft angle phi .

Speed reducer and positioning device

Abstract: Two mechanical elements are mounted for independent rotation in the same direction about a common a axis. The difference of the rates of rotation of the two mechanical elements is converted into a resultant mechanical rate of rotation of an output shaft. An electrical element may be mounted on each of the mechanical elements in electrical coactive relationship providing a variable electrical value dependent on the relative angular displacement of the two mechanical elements when the electrical elements are connected into an electrical circuit.

Speed control apparatus

Abstract: A control apparatus for synchronizing the speed of a rotating member with a variable speed input or for producing angular displacement of an output shaft in response to an input signal. The apparatus achieves correlation between the input and output by the use of a mechanical gear arrangement between the input and output shafts which arrangement produces angular displacement of a control member upon receipt of an input pulse or up variation of the speed of the input shaft from the output shaft. This displacement is then utilized to regulate an electrical speed control device, the flow to a hydraulic actuator, or a mechanical variable speed drive which adjusts the speed or displacement of the output shaft accordingly.

Device for detecting the instantaneous speed of rotation of a machine

Abstract: A detector device for detecting the instantaneous speed of rotation of a machine, e.g., a turbomachine, comprising: a disc rotated by the machine; a first signal generator producing a first signal each time said disc occupies a predetermined angular position; a second signal generator receiving the signals coming from the first generator and, each time it receives such a signal, producing a second signal; a timer device inserted between the first and second signal generators and designed to introduce a delay in the transmission of the first signal; and a device for detecting the angular position occupied, at the instant at which the second signal is emitted, by the disc, said angular position being a function of the speed of rotation of the machine.

Simple capacitance transducer for instantaneous angular-velocity measurement

Abstract: To measure accurately the instantaneous angular velocity of a low-inertia stepper motor, a simple noncontact capacitance transducer has been developed. The capacitance has a value linear1 related to angular displacement of the motor shaft. The basic design is discussed, and construction details and practical result are give.

Asymptotic analysis of a nonlinear autonomous vibratory system

Abstract: A system consisting of a spring, dashpot, and mass upon which is mounted an eccentric driven by a motor with a linear torque-speed characteristic, is analyzed by perturbation procedures based on small reciprocal of rotational inertia. Periodic solutions of the third order system, which arises when the angular position of eccentric mass is taken as the new independent variable, are constructed, and their stability is analyzed. An asymptotic solution is also obtained which is more general than a periodic solution, in that the averaged rotational speed is a slowly varying function, rather than a constant. The results are applicable to the determination of the interaction between the rotational motion of a flexibly mounted motor and the translational vibratory motion of its frame.

A New Involute Tooth Profile Measuring System with Special-Purpose Computer

Abstract: In this paper, a new method of tooth profile measurement is proposed. In this measuring method, the involute generating mechanism is not used. The principle of this method is that profile errors can be determined on a point-to-point basis by measuring the linear displacement of the tooth flank along a tangent to the base circle, and the angular displacement of the gear about its axis at the same time. This measuring system consists of two important elements: (1) the electronic digital readout circuit for linear and rotary measurements (using a linear optical grating and a rotary magnetic scale), and (2) the special-purpose digital computer. The computer computes the departure of the measured values from the theoretical values given by the relationship between the linear and rotary displacements. The main advantages of this method are as follows:(1) It is not necessary to carry out calibration with the master involute specimen.(2) For gears of different dimensions, the desired base circle radii can be selected by the preset switch operation on the panel of the computer.(3) The mechanical structure of the measuring system has been simplified. Therefore, if the scales of high accuracy are incorporated with the measuring system, the measuring accuracy will assuredly be enhanced.

Linear motion meter device

Abstract: A meter having a flat linear readout scale and utilizing a rotating input shaft, the shaft being driven by a torque motor and connecting to a two-arm linkage which converts the rotation into straight-line motion. The longer of the two arms in this linkage is divided into two segments, and it is found that for maximum linearity output the relative lengths of the arms should be, for the first arm, the first segment of the second arm, and the second segment of the second arm, in the ratio of about 1.31: 1.58:2.06, respectively. Because there is still a small amount of nonlinearity involved in such a linkage where even this ratio is used, a shaped follow-up potentiometer is connected to the drive shaft of the motor so as to develop a correcting signal in accordance with the angular position of the shaft, which signal is fed back to the motor.

Stability of free rotation of a rigid body

Abstract: The paper shows that a greater excursion of initial conditions, than that previously derived by the author, permits stability of free rotation of a rigid body about either of its stable principal axes. The results are exhibited by means of contour plots, in a new diagram that represents the dynamical properties of any rigid body.