Showing papers on "Actuator published in 1978"

On a Three-Link Model of the Dynamics of Standing up and Sitting down

Abstract: Motion of a biped in the sagittal plane is represented by a three-link planar model with torque actuators at every joint. With this model a method is proposed by which postural stability and four motions of the biped can be realized: sitting down, standing up, bending, and squatting. The method is used to derive open loop and feedback torques. Open loop torques are derived from the records of a man performing each of these four motions. The feedback torques are derived as linear sums of the sensed angles and angular rates. This work is relevant to estimating internal feedback gains in the human body solely from remote and external measurements.

Removable trainer handle and brake for skateboard

Abstract: A trainer handle and brake for removable attachment to a skateboard comprises a handle strut, a handle bar fastened to one end of the strut, a clamp secured at the other end of the strut for clamping the strut to the front end of a skateboard in upstanding relation thereto, the clamp having an upper jaw extending substantially perpendicular to the strut, a lower jaw underlying the upper jaw, and an actuator for moving the jaws together and apart for securing and releasing the jaws relative to the front end of the skateboard, a pair of brake shoes pivotally supported beneath the lower clamp jaw having ends adapted to overlie the front wheels of the skateboard, a lever arm connected to the brake shoes, a brake handle pivotally supported to the handle strut adjacent the handle bar, and brake operating linkage connecting the brake handle with the lever arm for pivoting the brake shoes against the top of the front wheels when the brake handle is actuated.

Two stage starter drive system

Abstract: A two stage positive shift starter drive system for an internal combustion engine is disclosed. A pair of electrical switches are sequentially actuated by an actuator solenoid engaging the starter drive's pinion gear with the engine's ring gear. The first switch actuated after a predetermined displacement of the solenoid's armature applies electrical power to the cranking motor through a resistance connected in series with the cranking motor and connected in parallel with the solenoid's pull in coil. The resistance reduces the electrical power applied to the cranking motor and the potential across the solenoid pull-in coil thereby reducing the rotational speed and the engagement force applied to the pinion gear. The end of the armature travel closes the second switch applying full power to the cranking motor permitting normal cranking of the engine with the pinion gear fully engaged with the ring gear.

Actuator disk theory

Abstract: Keywords: modelisation ; viscosite Reference Record created on 2005-11-18, modified on 2016-08-08

Broadband seismic energy source

Abstract: A vibratory seismic energy source capable of generating significant energy over a broad frequency band. The vibrating baseplate and associated structure are designed to have minimum weight while still retaining sufficient structural integrity to permit the use of high actuator forces. This, coupled with a large reaction mass results in the generation of significant energy levels in the earth at high frequencies.

On reliable control system designs with and without feedback reconfigurations

Abstract: This paper contains an overview of a theoretical framework for the design of reliable multivariable control systems, with special emphasis on actuator failures and necessary actuator redundancy levels. Using a linear model of the system, with Markovian failure probabilities and quadratic performance index, an optimal stochastic control problem is posed and solved. The solution requires the iteration of a set of highly coupled Riccati-like matrix difference equations; if these converge one has a reliable design; if they diverge, the design is unreliable, and the system design cannot be stabilized. In addition, it is shown that the existence of a stabilizing constant feedback gain and the reliability of its implementation is equivalent to the convergence properties of a set of coupled Riccati-like matrix difference equations. In summary, these results can be used for off-line studies relating the open loop dynamics, required performance, actuator mean time to failure, and functional or identical actuator redundancy, with and without feedback gain reconfiguration strategies.

Vehicle safety braking system

Abstract: This invention provides a safety arrangement for a dumping vehicle which may include a bumper movable to energize a brake actuator, the bumper being retractable upon tilting of the dumping bed. Modified bumper mounting arrangements are provided for various kinds of vehicles. A latching relay may be included to cause the brake actuator to hold the brakes locked, irrespective of disengagement of the obstruction. The bumper may include a pneumatic chamber with a flexible wall, with a pressure-operated switch for operating the brake actuator. Also, an exteriorly actuated switch may be used in a two-man operation in lieu of a bumper.

Fluid control valve and method

Abstract: A redundantly operating fluid control valve and method particularly suitable for controlling flow of dangerous fluid, utilizing concentric poppets which are sequentially engaged with corresponding seats through movement of a single actuator.

Valve actuator system

Abstract: A pneumatic-hydraulic proportional valve actuator system is provided having a relatively simple and adjustable means of achieving two stroking speeds by the hydraulic actuator, high speed in normal operation and low speed for small position adjustments and for the final part of any large position adjustments. This prevents overshoot and instability of the actuator.

Handle apparatus for a power-assist device

Abstract: A handle apparatus is for use with a device which has a movable component and a variable speed motor system which is responsive to an error signal for driving the movable component to desired positions corresponding to the error signal. The handle apparatus includes a central stationary support member which can be mounted to the movable component. The support member is adapted to receive a miniature force sensor which includes a linear variable differential transformer having an operative axis. The member receives one force sensor for each axis in which power-assist is desired; with the axis of each force sensor positioned corresponding to each axis of power-assist. Each force sensor is electrically connected to an input signal and has an actuator translatable along the operative axis connected to a central core and has a base containing the transformer wherein movement of the actuator translates the core within the transformer to produce the error signal corresponding to the magnitude and direction of the translation of the core. A generally hollow, cylindrical sleeve encloses the support member and the force sensors to form a manually engageable surface. The sleeve is adapted to independently engage each actuator of the force sensors. Each actuator of the force sensors operates through a spring diaphragm which positions and returns the sleeve to a stable position and provides elastic resistance to force in any direction. Any manual force applied to the sleeve translates the corresponding actuator to thus produce the error signal which is proportional to the magnitude and direction of the force.

Active suspensions for vehicles

Abstract: An active suspension for a vehicle, in particular an active tilting suspension for a railway vehicle, has a first main control loop in which a deficiency signal indicative of the difference actuator response and demand is fed through a low-pass filter to control operation of the actuator. A second control loop derives a restraining signal from actuator operation and this restraining signal is fed through a high-pass filter, which is substantially complementary to the aforesaid low-pass filter, to provide a restraining control on the actuator.

Wavefront Error Compensation Capabilities Of Multi-Actuator Deformable Mirrors

Abstract: The concept of a multi-actuator deformable mirror as a high-pass spatial frequency filter which operates upon the spatial frequency spectrum of the incident wavefront error allows us to apply the well-known techniques of linear systems theory to the wavefront error compensation process. The deformable mirror filter function, given by the ratio of the spatial frequency spectrum of the residual wavefront error after compensation to the spatial frequency spectrum of the uncorrected wavefront error, can be considered to be a transfer function characterizing the wavefront error compensation capabilities of the mirror. This concept has been implemented by constructing a realistic transfer function from measured actuator influence function data and incorporating the effects of several different types of wavefront sensors and control algorithms. For the special case of random wavefront errors with Gaussian statistics this transfer function can be used to predict the variance of the residual wavefront error as a function of the autocovariance length of the uncorrected wavefront error for any desired actuator density. The resulting design curves provide a simple method of determining the actuator density and stroke requirements of a deformable mirror capable of achieving a specified degree of wavefront error compensation. The actuator influence function is also explored as a variable in the design of deformable mirrors. The simple analytic model developed here is a valuable tool in the design and evaluation of wavefront error compensation systems.© (1978) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Aircraft servoactuator apparatus

Abstract: A single actuator unit is installed in an aircraft, for example, a helicopter, and is coupled to the control linkage from the pilot's stick to perform the functions of series actuation, trim actuation, artificial feel, control position sensing, control limits and, if needed, force boost. Although the device performs as a series actuator, it is installed in and connected to the vehicle surface control linkages in the conventional parallel actuator manner and therefore greatly simplifies control system installation and reduces problems associated with control rod vibration resonances normally encountered with series actuator installations.

Air conditioning display system for vehicles

Abstract: An air conditioning display system for a vehicle comprising a vehicle's air conditioner proper including a plurality of air intake ducts, a plurality of air discharge ducts, a plurality of dampers, and a fan unit, an air conditioner actuator actuating the dampers and the fan unit thereby regulating a temperature of air discharged out of the discharge duct, and a display device including a display panel carrying the picture of the vehicle body portions including the front seat, front glass and bonnet for displaying the flowing patterns of air into and out of the air conditioner proper. Lamps emitting light of warm color and cold color are disposed behind the display panel and are selectively energized by a plurality of switch means so that the occupant can readily visually confirm the flow of warm air or cold air from the duct outlets and also the flowing directions of air.

Motor starting switch

Abstract: A motor starting switch mountable on an electric motor and actuatable by a centrifugal actuator for energizing the starting winding of the motor during start up of the motor and for deenergizing the starting winding or other circuits upon the motor attaining a desired operating speed. A toggle linkage for operatively connecting the motor starting switch to the centrifugal actuator is included as a part of this motor starting switch, and it includes a slider for opening and closing one or more sets of contacts within the starting switch housing movable in the same direction as the actuator member of the centrifugal actuator, and a lever pivoted to the switch housing and engageable by the centrifugal actuator. The slider is privotally connected to the lever so that upon the centrifugal actuator pivoting the lever, the slider is moved to open or close the contacts.

Dispenser unit with lockable actuating lever

Abstract: A dispenser unit preferably adjustable for either single dose or multiple dose dispensing of fluids; primarily for the precision dispensing of small volumes (e.g. volumes measured in microliters). The unit includes an elongate actuator rod axially moveable in one direction to dispense the fluid, and a hand-engageable dispensing lever including a passageway through which the actuator rod extends. A measured, or predetermined quantity of the fluid is dispensed by manually applying a force to the lever in the one axial direction to maintain a canted relationship between the lever and actuator rod. This canted relationship causes surfaces of the passageway to lock against the actuator rod, and the axially directed manual force on the lever will move the rod to dispense the fluid. Most preferably a separate securing mechanism also is provided to cause the lever and actuator rod to lock together so that they will move as a single unit in either axial direction when it is desired to convert the unit from a multiple dose dispenser to a single dose dispenser. Most preferably the dispensing lever extends through an elongate slot in a side wall of a body section of the unit, and this slot is interrupted by upper and lower surfaces that define the length of the dispensing stroke of the lever. Most preferably the upper and lower surfaces interrupting the slot are axially adjustable to vary the length of the dispensing stroke.

Hydraulic cartridge for improved motion control

Abstract: An improved type of hydraulic control cartridge with mounting structure and accessorial safety device for installation within both ends of reciprocative pneumatic actuators to permit a safe increase in their speed of operation. The safety device automatically stops the actuator if the hydraulic cartridge malfunctions.

Independent biasing means for automatic flue damper

Abstract: For a vent or flue damper of the type in which the damper is closed by an electrically energized actuator when the furnace is off and the actuator has first biasing means to open the damper when the actuator is deenergized, a second biasing means such as a torsion spring, independent of the first biasing means, is associated directly with the damper shaft and is adapted to always move the damper to an open position in the absence of the actuator.

Flutter prevention means for aircraft primary flight control surfaces

Abstract: An apparatus attached to the flight control surface designed to lock the surface in a fixed and generally neutral position when a hydraulic pressure failure occurs. A spring loaded hydraulic actuator is mounted in the fixed wing structure but has an arm with a locking roller extending into a wedge shaped recess in the adjacent movable control surface. When hydraulic pressure is present the actuator spring is compressed and the locking roller on the actuator arm is moved to the wide end of the wedge, effectively avoiding any contact between the roller and the flight control surface surrounding it irrespective of the control surface orientation. Upon the occurrence of a hydraulic pressure drop, the compressed spring translates the actuator arm drawing the locking roller into a detent in the narrow end of the wedge, thereby inhibiting control surface rotation and flutter.

Lift-turn valve and actuator assembly

Abstract: A lift-turn valve and actuator mechanism incorporating a valve plug and slip assembly that is movable with both axial and rotatable components of movement during opening and closing. Rotational movement is accomplished during lifting by cooperative relationship between opposed cam grooves defined in valve stem means and a pair of opposed rotatable cam follower elements that are supported by an actuator housing. The actuator housing is a fabricated structure incorporating threaded structure for receiving replaceable cam follower bearing mechanisms. The cam follower elements cooperate with the opposed cam grooves to provide efficient balanced force transfer through the valve actuator mechanism.

Shift actuator for a multi-speed transmission

Abstract: A shift actuator for a multi-speed transmission includes a valve body and a spool movably positioned in a bore defined in the valve body. Fluid pressure acts on one end of the valve spool while a rotary cam is manually positionable to move the spool to various operating positions. Porting communicating with the valve bore is selectively blocked by the spool in its various positions.

Aircraft horizontal stabilizer drive

Abstract: A mechanical power transmission apparatus, of the differential gear type, for actuating an airplane control surface requiring two independent actuator inputs to a single control surface. Predetermined, proportionately variable, asymmetric loads between the two actuators are accomodated by a load sensitive brake in conjunction with a fuse link which fails in the event of single actuator or drive means failure. The fuse link is provided by employing a shear pin to attach the pinion gear in the differential to the pinion shaft. The shear pin failure strength in conjunction with the load variable brake determines the allowable differential torque between the two driven bevel gears.

Optical image stabilizing system

Abstract: Apparatus for stabilizing the image of an electro-optical sensor system. The stabilizing apparatus includes a mounting structure subjected to various rotational and translational vibrations of various sorts. The mounting structure supports a platform on which the electro-optical system is mounted. The platform system comprises a platform structure isolated from the mounting structure either as a passive system, that is, one which supports the platform through a soft isolator, or as an active system, that is, one in which an actuator is mounted in parallel with the isolator in series with a bearing or flexure or other rotational decoupling. The reflective apparatus of the electro-optical system is driven by an actuator mounted on the mounting structure, i.e., in parallel with the series combination of the reflector and platform, in response to tracking signals derived from line of sight sensors mounted on the platform. This allows the shunting of reaction torques directly to the mounting structure, thereby eliminating the excitation of platform resonances.

Selective fire perforating gun switch

Abstract: A multiple shot selective fire perforating gun for piercing oil field tubular goods, typically during the process of completing an oil or gas well. The perforating gun includes a multiplicity of shaped charges which are fired individually by an associated blasting cap and switch. The switch of all but the lowermost shaped charge is configured to disarm its associated blasting cap until the next lower shaped charge has detonated. The generation of the pressure pulse from detonation of the next lower shaped charge causes a piston in the switch to move to express a stream of flowable material onto a switch actuator which manipulates the switch to place it in an armed condition ready to fire.

Bulldozer blade mounting assembly

Abstract: A mounting assembly for supporting a scraping tool (e.g. a bulldozer blade) forward of a vehicle (e.g. a bulldozer) and enabling independent angling and tilting of the tool is disclosed. The assembly includes a U-shaped mainframe, a swingframe, means for pivotally connecting the swingframe to the mainframe, means for pivotally connecting the tool to the swingframe, tilt actuator means interconnecting the mainframe and the scraping tool for rotating the scraping tool in relation to the swingframe about a tilting axis of rotation, and angle actuator means interconnecting the mainframe and the swingframe for rotating the swingframe and scraping tool in relation to the mainframe about an angling axis of rotation.

Print wire actuator mechanism

Abstract: This invention relates to a wire matrix printer system using a plurality of unique print wire actuator mechanisms operable to print dots on a printing medium. The novelty is in each print wire actuator mechanism using an electro-mechanical combination including (1) a print wire actuator; (2) a permanent magnet collector; (3) a solenoid collector; and (4) a connector assembly holding the aforementioned together as a unit. The print wire actuator includes a print wire assembly having a wire member moved through a printing stroke under the unique combined force of (1) a torsion rod, and (2) a solenoid member. Additionally, the wire member is returned to the rest or starting position under the force of the torsion rod and a permanent magnet collector member.

Clutch for valve actuator

Abstract: A valve actuator utilizing a drive motor and a stored energy device to operate valves primarily in safety related applications is disclosed. The actuator operates on signal or loss of power to return a driven valve to a predetermined position. The actuator in particular utilizes unidirectional coupling between a driven shaft and an output shaft that is coupled to the driven valve. Specifically, the coupling utilizes a coiled spring having a unique diametral relationship with the driven shaft in order to insure reliable actuation and control of shaft wear. A fluid dampened device or dashpot is also utilized to provide controlled operation during the return cycle that is powered by the stored energy device.

Impact print head

Abstract: An impact print head for a matrix printer employs the usual set of wires slidably mounted in the head which are selectively extended from the working end of the head toward a platen by energizing solenoid actuators. However, in lieu of the usual solenoid strikers, return springs therefor and print wire return springs, a single set of unitary ferromagnetic spring arms connected directly to the print wires and positioned opposite the solenoids mounted in a unitary solenoid frame assembly. Also a shunt plate is mounted in the head and positioned on the opposite sides of the spring arms from the solenoids. The shunt disk and frame assembly shape the magnetic flux pattern from each energized solenoid so that a maximum number of flux lines from each solenoid intercept the associated spring arm to attain maximum dynamic print range and efficiency. Higher print speed may be attained by preloading each spring arm toward its associated solenoid and substituting for the shunt disk, a set of permanent magnets positioned on the opposite sides of the spring arms from their solenoids. Their magnetic field strengths are such as to overcome the self-biases of the associated spring arms so that each spring arm, when quiescent, is spaced from its solenoid and contains appreciable potential energy. When energized, each solenoid produces a field which is opposite to and at least equal in strength to that produced by the corresponding permanent magnet so that the potential energy stored in the associated spring arm is released as kinetic energy which helps to rapidly move the spring arm to promptly extend the associated print wire.

Moving permanent magnet limited motion actuator

Abstract: A limited motion actuator which utilizes a moving permanent magnet as an armature. The drive is provided by the simultaneous repulsion and attraction of the movable permanent magnet within stationary coils. The magnetic circuit is formed to allow one pole of the armature to be simultaneously repelled from the coil of like polarity and attracted to the pole of opposite polarity. The preferred magnetic circuit configuration consists of two poles and a magnetic return path, which forms two additional poles. The movable permanent magnetic armature is always located within the regions of the coil poles thus allowing accurate control of the driving forces in both forward and reverse directions over the complete armature cycle.