Showing papers on "Coupling published in 1977"

Substructure coupling for dynamic analysis and testing

Abstract: Fixed interface and free interface methods of substructure coupling for dynamic analysis are discussed. Three methods for reducing the number of coordinates required by fixed interface methods are introduced. Matrix ordinary differential equations are employed to improve accuracy in free interface substructure coupling methods.

Parallel end-butt coupling for optical integrated circuits.

Abstract: The method of parallel end-butt coupling has been used to couple GaAs laser diodes to Ta 2O5 thin film waveguides. Theoretical caluclations predict that a coupling efficiency into the lowest order waveguide mode of 90% is achievable if the thicknesses of the waveguide (tg) and the laser light emitting layer (tL) are equal. Experimentally, efficiencies as high as 45.1% have been measured for laser and waveguide combinations with t/tL = 0.34. The tolerance to misalignment of the laser and waveguide has been theoretically and experimentally evaluated.

Radiation coupling of a disk to a plane and back or a disk to a disk: An exact solution

Abstract: The radiation coupling or coupling by propagating waves is solved for a disk in an infinite baffle to a plane and back or equivalently a disk to a disk both in infinite baffles. The radiation coupling is defined as a linear filter operating between lumped mechanical components which may be incorporated into transducer models. The impulse response of the radiation‐coupling filter and the Fourier transfer function for the radiation‐coupling filter are solved in closed form. The radiation‐coupling gain (loss) is applicable to the correction of experimental data and to the absolute calibration of circular transducers by self‐reciprocity measurements.

Quick disconnect coupling

Abstract: A quick disconnect coupling for coaction with a checkvalve equipped male coupling is provided with a lockable spool and a lockable valve actuator. A first locking pin on the spool locks the spool when the male coupling is not coupled with the female coupling and is engageable with the male coupling for unlocking the spool when the male coupling is inserted into the female coupling. The locking mechanism for the actuator permits the actuator to move when a pressurized male coupling is inserted and locks the actuator when the actuator opens the check valve.

The singular coupling and weak coupling limits

Abstract: We show that the analysis of the motion of a system coupled to an infinite reservoir in the singular coupling limit and the weak coupling limit can be performed in the same mathematical framework. This enables us to clarify the way in which the motion of the system in the singular coupling limit depends on the temperature of the reservoir.

Simplified theory of the multimode fiber coupler

Abstract: We simplify the coupling theory between two contiguous, parallel, multimode step-index fibers, describe the coupling concept, and derive an upper estimate for the overall coupling efficiency between the two fibers. The maximum coupling obtainable, according to this estimate, is less than 72 percent (−1.5 dB). The coupling efficiency derived for short coupling lengths shows good agreement with experimental results.

Quick disconnect rotary valve coupling

Abstract: A coupling having two valved sections. The valves of each section are open when the sections are joined together and the valves close whenever the sections separate.

Pulsating hair dryer

Abstract: A pulsating attachment for use with an electric hair dryer that has a tubular end through which air is expelled is described comprising a coupling section with an asymmetrical and unbalanced single impeller supported in the coupling for rotation therein and mounting structure connecting the coupling and the tubular end whereby the expelled air rotates the impeller and, due to its unbalanced mounting, creates a pulsating flow of air at a constant flow rate from the coupling. This results in a rotating path of pulsating air on the head of the user to create a fluffing action.

Plasma-wave coupling and propagation using phased waveguide arrays

Abstract: A study of the coupling and propagation of electron plasma waves excited by waveguide arrays is presented. The waves are generated in a low-temperature, linear plasma column in a homogeneous magnetic field. As predicted from a theoretical model, under appropriate conditions efficient coupling to plasma waves can be obtained. These studies are of relevance to plasma heating in that the modes are identical with those that must be generated in any lower hybrid heating experiment. We discuss the implications of these results with respect to future heating experiments on large devices.

Unifying approach to the static torque of stepping-motor structures

Abstract: Important stepping-motor structures are compared and their logical relationship to a basic doubly-salient machine is demonstrated. This leads to a single expression for holding torque, applicable to the majority of motors, comprising a product of the following terms: (a) a theoretical limiting mean torque, (b) a factor allowing for finite excitation, (c) the fraction of rotor volume effectively utilised on any one step, (d) a shape factor for the torque/angle curve. The analysis is cast in dimensionless form, both in respect of component terms in the torque expression and of motor variables. In particular, a critical value of m.m.f., calculable from gap geometry, is shown to be the significant unit of applied excitation. Advantages offered by this approach are quick calculation, a ready means of comparing different motors and insight into physical behaviour. Sample calculations are presented for a variety of motors and several individual problems discussed. Support for the theory is also provided by a range of experimental work and an appraisal of commercial data.

Lever-type quick disconnect coupling

Abstract: A lever-type quick disconnect female coupling for coaction with a check-valve equipped male coupling is provided with a movable valve member which functions both as a sealing valve for the female coupling and a push member for opening the check valve of the male coupling.

Carrier for skis and ski poles

Abstract: A carrier for releasably engaging and supporting a pair of skis and a pair of ski poles in horizontal hand-carrying spaced relationship with the poles above the skis, whereby the poles function as a carrying handle. The carrier comprises a pair of flexible coupling straps, each of which includes a lower adjustable ski-engaging loop, on upper adjustable ski-pole-engaging loop, and a vertical intermediate hand-clearing web therebetween.

Parametric-Excitation of Kinetic Alfven Waves by Whistler Waves

Abstract: It is shown that a whistler wave can parametrically decay into another whistler wave plus a kinetic Alfven wave. The parametric coupling occurs due to the electrostatic properties of the kinetic Alfven wave. Corresponding growth rate and threshold condition are obtained.

On the use of active coupling networks with electrically small receiving antennas

Abstract: An analysis of the noise performance of an active receiving antenna system consisting of an antenna, active coupling network, and high-gain preamplifier is described. It is shown how this noise performance can be described by circular loci in the output-impedance plane of the coupling network. These loci are not restricted to the right-half plane. A coupling network having an output impedance in the left-half plane was built using a negative-impedance converter (NIC), and experimental results obtained by using this circuit in conjunction with a short monopole are presented.

Parking brake assembly

Abstract: A braking assembly includes a carrier for a hydraulically actuated braking piston; a shaft movable axially to also displace the piston, a rotary actuator member, and a coupling responsive to rotation of the rotary member to effect advancement of the shaft toward the piston, accompanied by gripping of the shaft.

Pickup truck loading ramp

Abstract: Loading ramps for a truck having stake rack pockets are dimensioned to extend between adapters registerable with the pockets for non-use storage in a position where they function as side racks or vertical extensions thereof. The ramps are provided with a unique coupling means for engagement with the truck tail gate when in use.

Couplings having sliding splines

Abstract: At least one of the splined members of the splined coupling has its splines modified so that they have maximum thickness in an intermediate part of the splines and progressively decrease to the ends of the splines. The resulting profile is such that, upon application of a given torque, the pressure produced in the zones of contact between the interengaged splines is substantially constant throughout the interengaged length of the splines.

Tapered fit coupling method and apparatus

Abstract: This is a unique tapered fit coupling arrangement for coupling a load to a power means, such as a trailer to a self propelled vehicle, wherein movement is allowed in all directions for coupling to allow for ease of hook-up, and wherein the device is characterized by a tapered female member with a corresponding tapered male member which can be inserted and drawn into firm and complete tapered fit to completely engage the power means and the load in a safe and compact relationship.

Transducer coupling apparatus

Abstract: Apparatus for coupling an ultrasonic energy transducer to a target object, such as a human patient, through an energy transmitting liquid. The coupling apparatus comprises an open top container for holding the energy transmitting liquid. The transducer extends through the open container top for immersion below the surface of the liquid and for selective movement relative to the container. A support member is provided for holding the container in contact with the patient. The support member has a ring for rotatably receiving and supporting the container. The ultrasonic wave output from the transducer may be directed to different portions of the patient by selective rotation of the container and/or by repositioning the transducer within the container.

High strength, non-metallic coupling

Abstract: A torque coupling comprising two non-metallic inserts linked together by alip-fitted shaft having a multi-sided cross-section. One of the inserts is press-fitted into the internal involute shaft of a driving mechanism, such as a gear box, while the other is similarly fitted into the internal involute shaft of a driven mechanism, such as a pump. The multi-sided configuration of the slip fitted shaft permits the torque load to be distributed compressively on the inserts. Consequently, greater torque loads can be transmitted by the coupling with the benefit of the low-wear, self-lubricating characteristics of certain non-metallic insert materials.

Torque exchange coupling

Abstract: A novel torque exchange coupling for transmitting rotational mechanical power is described. The coupling includes a torque receiving member, a torque transmitting member and means for conveying rotational mechanical power between the torque transmitting and receiving members. Typically, the torque receiving member is a housing, a cam or other suitable structure which has a surface comprising a circuitous track. The linear circumference of the track is undulant with respect to its axis of rotation. The torque transmitting member is any suitable rotatable mounting means such as a rotor which is positioned in a rotational power conveying relationship with the undulant track of the torque receiving member. Alternatively, the function of the torque receiving and torque transmitting members can be reversed. In this regard, the torque transmitting member is a housing, a cam or other suitable structure having a surface comprising a circuitous track, the linear circumference of which is undulant with respect to its axis of rotation. The torque receiving member is any rotatable mounting means such as a rotor which is positioned in a rotational power conveying relationship with the undulant track of the torque transmitting member. Where a rotor is employed as the rotatable mounting means, a preferred means for conveying power between the rotor and the undulant track is a variably extendible member attached to the rotor and typically comprises an arm which is pivotally attached to the rotor in a manner such that it is capable of making contact with the undulant track at any point in its linear course. This member is made variably extendible either by centrifugal force, centripetal force, or mechanical, electrical or hydraulic means. The novel coupling of this invention is highly efficient, is easily maintained, is not significantly affected in operation by the presence of heat, and is capable of operation without its components being in close alignment. It contains few moving parts and is strong, durable, and comparatively inexpensive to manufacture. It can be utilized as a clutch, as a transmission, in a braking application, or in practically any other application where a rotational coupling is indicated.

Theory of multidither adaptive optical systems operating with zonal control of deformable mirrors

Abstract: A theory is developed for multidither adaptive optical systems that employ N discrete actuators driving a deformable control and dither mirror with the same shape of influence function. The major emphasis is on mirrors with a Gaussian influence function. It is shown, as a special case, that single-actuator displacements or errors of such systems yield error signals that can be described in closed form, via sine integral functions of the actuator displacement. Closed-form expressions for both the first- and second-harmonic content in the dither signal outputs are developed. Expressions for servo cross coupling (from adjacent actuator deformations) are developed and it is shown how the coupling is typically larger than the mechanical (actuator center) coupling. Effective modulation index comparisons are established between Gaussian and piston mirrors, for piston and Gaussian phasing error components. It is shown how a potential secondary maxima lock-up condition (the 2nπ problem) can occur when operating hill-climbing adaptive optical systems with deformable mirrors. In some cases a major loss in system Strehl ratio may result.

Hybrid laser-to-fiber coupler with a cylindrical lens.

Abstract: Several laser-to-fiber coupling schemes have been compared with regard to coupling efficiency. A coupling scheme with a cylindrical lens is simple and effective for enhancing coupling efficiency. As a mounting and aligning structure for the laser-to-fiber coupling with a cylindrical lens, a hybrid structure has been proposed using a copper mount on which two vee grooves are produced for aligning all optical elements without adjustment. Even though the mounting structures have been produced by machining, the average coupling efficiency of about 50% has been achieved when using a multimode optical fiber with a half acceptance angle of 3–4°. The couplers have been successfully mounted in hermetically sealed laser packages, indicating feasibility and usefulness for practical applications.

Coupled Transmission Lines

Abstract: An analysis of coupling between a stripline and a rectangular waveguide is presented. Coupling is through small apertures in the form of a circular hole or a narrow rectangular slot. A closed form expression for the normalized field distribution in the stripline, required for the purpose of analysis, is also derived. The theoretical results show good agreement with the experimental results.

Shaft dynamics in closely coupled identical generators

Abstract: Previous analyses of shaft dynamic effects have been based on the practice of 'lumping' identical generators feeding into the same transmission line. This paper investigates the effect on shaft dynamics of the electrical cross coupling between identical generators operating in parallel. It is concluded that the natural frequencies and mode shapes of an arbitrary number of units can be determined from two equivalents. Also the extent to which the shaft modes may be stimulated in feasible on line experiments is predicted.