Showing papers on "Actuator published in 1976"

Nonlinear feedback in simple locomotion systems

Abstract: The purpose of this short paper is to analyze postural stability and periodic motion of a simple model of a locomotion system. Nonlinear feedback is used to linearize the system. The effects of discretization, quantization and noise are studied via simulation of a compound inverted pendulum with realistic actuator models.

Limit control apparatus

Abstract: An actuator control system includes a ballscrew type actuator for controlling the positioning of a valve device. A processing circuit is responsive to direction and drive signals for driving a synchronous stepper motor which is operatively coupled to the actuator. The processing circuit includes a switching device which applies a DC voltage to the motor windings to hold the valve position when it is not being driven. A limit sensing device provides a limit signal when the movable member of the actuator approaches a limit of travel. A limit control circuit responds to the limit signal to alternately reverse the direction signal applied to the processing circuit so long as that signal is representative of the direction in which the limit is being approached.

Control system for variable displacement compressor

Abstract: A variable capacity wobble plate compressor including a fluid actuator for shifting the centering ball, on which the cam mechanism is supported, to effect a change in the length of stroke by varying the angle of inclination of the wobble plate with respect to the drive shaft axis. A control system automatically responds to suction pressure (or some other predetermined variable to be controlled) to operate the fluid actuator.

Actuator for a syringe

Abstract: An actuator for a syringe is disclosed with which precise liquid quantities can be dispensed in an accurately repeatable manner with single-hand control. The actuator is formed with a main body shaped to support a syringe whose plunger is moved by a plunger actuator. A reciprocating finger actuatable pusher is mounted with the plunger actuator to the main body and a ratchet mechanism operative between the plunger actuator and the pusher provides discrete motions of the plunger actuator. The main components of the syringe actuator are formed of extruded material and shaped in cross section to conveniently fit together. A back motion inhibitor is employed in the form of a fibrous material capable of restraining reverse movement of the plunger actuator while allowing unobstructed operative movement thereof.

Variable pitch mechanism for fan blades

Abstract: In a variable pitch fan assembly having a plurality of fan blades mounted in a rotor for rotation about their longitudinal axes and a drive shaft for rotatively driving the rotor, the pitch varying mechanism has a planetary gear train connected to each fan blade to rotate the latter to change the pitch or angle of attack of the blades, actuator means for effecting bi-directional rotation of the planetary gear train and a no-back, bi-directional brake interposed between the actuator means and the planetary gear train to transmit pitch-changing rotation from the actuator means to the planetary gear train and lock the planetary gear train to the rotor and prevent transmission of blade torque loads to the actuator means during steady state operation when no blade pitch-change is being effected.

Motion amplifier for condition responsive gauge instrument

Abstract: Amplifier apparatus for providing output motion correlated to condition change motion or deflection of a condition responsive element. The amplifier in a preferred embodiment is mounted onto the condition responsive element for floating conjoint movement therewith. A remotely connected actuator, extending into the motion path, defines a pivot axis for a hinged gear sector arm of the amplifier. In pivoting about the actuator axis, the sector arm operably drives a rotatable output shaft supporting a pointer or the like.

Spring return valve actuator

Abstract: A fluid actuator for 90° rotating valves having a return spring coupled to an independent fluid actuated piston to assist in spring compression on the forward stroke.

Hinged flyplate actuator

Abstract: A toggling type of switch actuator is described in which a pivotable coupling plate is caused to snap away from electrical contact members which it couples together. Action is caused by the depression of an actuator which compresses a spring and moves the line of action of compressive force over center to cause a snap-action motion. Pushbutton actuation is achieved in a very low profile apparatus providing good tactile feel and a self-biased, self-returning, snap-action. The device has only three moving parts.

Differential gear mechanism

Abstract: A locking differential mechanism comprises a differential gear means including an input gear and a pair of output gears. A locking mechanism locks up the differential in response to a predetermined amount of differentiating action occurring. The locking mechanism functions to lock one of the output gears to the case of the differential. The actuator for actuating the locking mechanism to effect the lockup comprises an oscillating weight actuator mechanism.

Design of a swinging arm actuator for a disk file

Abstract: An integral disk enclosure that incorporates a novel head-positioning actuator concept is used in the IBM System/32 and in recently announced terminal controllers, such as the Retail Store Controller and the Communication Controller. Based on a swinging arm rather than the conventional linear carriage, the actuator presented the designers with opportunities to create a simplified mechanism and to gain advantages in reliability and cost. This paper describes the geometrical, structural, and electromechanical basis of the design.

Mechanical stored energy positioning actuator

Abstract: A motor driven actuator, providing continuous positioning of an output shaft, and employing energy storage which allows the shaft to return to a predetermined position on failure of the input power source or other predetermined occurrence. Drive motor torque requirements are minimized through sequential application of input torque to the energy storage and actuator load. This arrangement insures that adequate energy storage for return of the output shaft is continuously available during normal actuator operation including alternate output shaft positioning. When utilized to operate a fluid control valve, the valve actuator combination provides a fail-safe valve which under emergency or other prescribed conditions provides return of the valve to a safe condition from any normal operating position throughout the limit of the valve travel. The above functions are provided through the use of a simple highly reliable structure utilizing a reduced number of relatively simple components and a drive motor which can be sized for the output torque alone without additional torque requirements due to the presence of a stored energy device.

Antenna stabilization system

Abstract: An antenna mounting structure is supported and oriented by three linear hydraulic actuators responsive to linear position transducers of a passive stabilization system serving as a vertical reference for keeping an antenna precisely pointed at a geostatically satellite during motion disturbances. The antenna is assembled with each of the linear actuators connected thereto through a gimbaled mount which facilitates accommodation of the requisite angulation thereof necessitated by motion in adjacent actuators. Response in each actuator is derived through an independent linear servo loop directly communicating with a linear position transducer constructed in scaled replication of the respective antenna actuator geometrical configuration and assembled to an inertially stabilized platform. A proportional error signal is thereby generated in the linear position sensors which effectively comprises a mechanical analog computer adapted for integrating pitch, yaw, roll motions and directly converting them into the requisite triaxial linear command signals for the linear actuators. The triaxial control facilitates compensation of pitch, yaw, roll motions while maintaining a preselected polarization configuration.

Variable force actuator

Abstract: An actuator for reciprocating stem control valves having a linkage system affording variable force, reversible action, and adaptability to different valve strokes.

Automatic slack adjuster for vehicle brakes combined with a hydraulic actuator and auxiliary mechanical actuator assembly

Abstract: A hydraulic actuator for a vehicle brake system is provided with an auxiliary mechanical actuator e.g. a handbrake cam which is fitted to a first component (e.g. a first piston) of the hydraulic actuator and acts through an automatic slack adjuster on a second component (e.g. a second piston) of the hydraulic actuator. The adjuster comprises a rotatable push rod and a non-rotatable nut with a screw-thread connection therebetween. The rotatable push rod has a portion which is sealed to the first piston and upon which the mechanical actuator acts. A relatively light spring biasses at least the above mentioned portion of the rotatable push rod away from the mechanical actuator and automatic adjustment comprising rotation of the rotatable push rod is effected when there is at least a tendency for the above mentioned push rod portion to be displaced and the applied hydraulic pressure is at a relatively low value at which the force applied by the hydraulic pressure to the the above mentioned push rod portion is less than the force of the spring. When the applied hydraulic pressure is above this predetermined relatively low value there is no tendency for the rotatable push rod to move away from the mechanical actuator and no adjustment can take place. The adjuster is thereby rendered load insensitive, i.e. it will not overadjust in the event of brake deflection on heavy brake application.

Double piston brake actuator

Abstract: Improved brake actuators of the type having both service chamber and spring emergency-parking chambers utilizing piston in each said chamber (no diaphragms); improved double piston brake actuator wherein the service chamber is inboard of the spring emergency chamber; improved double piston brake actuator having an inboard spring emergency-parking and an outboard service chamber

Modulating failsafe valve actuator using differential gearing

Abstract: A power operated rotary valve actuator utilizing a differential drive and magnetic clutch to provide continuous valve positioning between full open and full closed positions. The valve drive motor operates through a differential drive and in conjunction with a single electric clutch provides sequential application of rotational torque to a stored energy spring and the valve shaft. The sequential torque application minimizes drive system torque requirements and insures that sufficient energy is available to return the valve to a preselected position at any time during normal operation.

Vibration testing system

Abstract: A multi-degree-of-freedom shock and vibration testing system which includes a specimen-holding table having short projections engaged by hydraulic actuator assemblies. Each actuator assembly includes a pair of hydraulic actuators on opposite sides of the projection and a servo valve for connecting the actuators to a source of pressured hydraulic fluid and to a drain, to maintain the pair of actuators pressed firmly against opposite sides of the projection while moving substantially synchronously. A hydrostatic bearing pad bears against a rounded end of each actuator and against opposite sides of the projection, to permit the projection to slide perpendicular to the motion of the actuators and to pivot.

Stepper motor valve actuator control apparatus

Abstract: An actuator control system includes a ballscrew type actuator for controlling the positioning of a valve device. A control circuit is responsive to pulsed drive signals for driving a synchronous stepper motor which is operatively coupled to the actuator. The control circuit includes a switching device which applies a DC voltage to the motor windings to hold the valve position when it is not being driven.

Reduced servo noise control for a hydraulic actuator

Abstract: In a hydraulic actuator such as those used in multiple degree freedom motion bases for aircraft simulators, a secondary force sensitive hydraulic servo loop is added in parallel to the primary position feedback servo loop with the secondary loop having a servo valve possessing substantially greater band pass and less capacity than the main valve used in the first servo loop. Force feedback from the control actuator is applied degeneratively to the smaller servo valve, thereby reducing noise and jitter caused by responses of the system outside the response of the primary servo loop. The response of the main servo loop which control the position of the actuator is low pass and restricts response to the full desired band pass of operational frequencies. The secondary loop is high pass and is shaped to prevent degeneration of operational frequencies while providing optimum gain and phase for the degeneration of the unwanted high frequency portion of the band wherein noise and jitter reside.

Self-contained power subsystem

Abstract: A self-contained power subsystem having at least one actuator module containing at least one actuator, an expulsion tank module connected to the actuator module and a gas generator module connected to the expulsion tank module. A solid propellant within the gas generator module generates a gas, this gas, under pressure, passes into the expulsion tank module where it expels a hydraulic fluid located within the expulsion tank module to a plurality of passageways within the actuator module. Under control of a servo-valve the fluid within the actuator module operates the actuators.

Modelling a Loaded Two-Way Pneumatic Actuator

Abstract: This paper describes experiments on a low-pressure pneumatic actuator and load. An impulse test is described, in which the transient behaviour of a loaded actuator, operating in a particularly simp...

Slot sealing valve for vacuum coating apparatus

Abstract: An elongated gate-type valve is pivotally mounted within vacuum coating apparatus of the multiple-chamber, in-line type, and is operated to vacuum seal an access slot interconnecting vacuum chambers. An actuator for opening and closing the slot valve is connected through transversely spaced thrust links, the actuator ends of which have guide wheels, respectively, that are movable within restraining guide channels for confining the actuator ends to linear, vertical movement. An increasingly large closing and sealing force is applied to the valve, especially during final closure thereof, due to an increasing mechanical advantage of the actuator and thrust link arrangement for valve closing.

Dispensing unit for an aerosol container

Abstract: In a method for the relative orientation of the spray-discharge valve actuator and actuator nozzle of a container with respect to a protective cover which is designed to operate the valve actuator, the cover is brought closer to the actuator in coaxial relation thereto, the cover and actuator are brought into the desired relative orientation with friction between a radial lug carried by the actuator and a helical ramp carried by the cover and inclined at an angle of slope of at least 45° with respect to the axis. The cover is then brought in a movement of axial displacement to a position of operation of the actuator on the container.

Swing valve circuit

Abstract: Control for a swing mechanism having linear actuators such as hydraulic cylinders connected to the swing mechanism in a manner whereby the actuators work in unison with each other over a portion of the swing of the swing mechanism and in opposition to each other over another portion of the swing when imparting arcuate motion to the swing mechanism with the linear motion of the actuators. The control includes a pressure reducing-metering valve and a metering valve in each of two sets of lines which supply and return pressurized fluid to the actuators. The respective valves limit the pressure of fluid to one actuator while requiring a predetermined minimum actuation pressure to provide a more constant speed and torque characteristic for the swing mechanism. A check valve is placed in a line interconnecting the head end of one actuator and the rod end of the other actuator to prevent a regenerative effect occurring from interaction of the actuators, and pilot lines to the metering valves can be provided with orifice sets to damp the signal to the metering valves.

System for preventing collision of vehicles

Abstract: A system for preventing collision wherein a radar system is mounted on a vehicle for generating a relative speed signal and a relative distance signal. There are provided a brake signal generating logical circuit responsive to the relative speed signal and the relative distance signal for actuating a brake actuator, first and second comparators for comparing the relative speed signal and the relative distance signal respectively with reference signals, and an information processing signal responsive to the outputs from the first and second comparators for actuating the brake actuator. There is also provided a braking signal releasing circuit for disenabling the brake actuator after the vehicle has stopped.

Actuator structure for ball-point pens and other writing instruments

Abstract: An exterior actuator structure for the cartridge retracting mechanism of ball-point pens and other writing instruments which use either an axially movable actuator button or a longer actuator cap, the exterior actuator structure having cooperating guide portions on the shell and on the actuator member defining axially extending guide teeth and cooperating guide slots or guide grooves, for a continuous shoulder-free exterior outline of the writing instrument. Extended guide grooves accommodate a clip.

Illumination control apparatus for compensating solar light

Abstract: Illumination control apparatus for supplementing light from solar radiation with light from an artificial light source to compensate for periods of insufficient levels of solar light to maintain a desired illumination level within an interior space comprising an artificial light source connected to an electrical power source with switch means for selectively energizing said light source, actuator means for controlling the on-off operation of the switch means, a light sensor connected to the actuator means for controlling the actuator means in response to the illumination level of the interior space, and a limit switch carried adjacent the actuator for limiting the movement of the actuator within a predetermined range so as to prevent further movement thereof during detection of erroneous illumination conditions.

Ejector retraction mechanism

Abstract: An improved ejector retraction mechanism comprises a fixed actuator, a pair of blocking members positively movable both in and out of the path of the actuator, whereby to positively retract ejector pins on closing of the molds. The actuator and blocking members have flat parallel engaging surfaces for long wear and durability and the actuator also has an enlarged portion which enters a channel and aligns and interlocks the molds.

Disc brake assembly including a self-contained actuator with wear take-up and anti-drag device

Abstract: A disc brake assembly including a self-contained actuator for urging a brake shoe into frictional engagement with a friction disc; the actuator including an actuated piston movably supported within a cylinder for moving the brake shoe into engagement with the friction disc, an actuating piston movably supported within the cylinder which is separated from the actuated piston by a fluid-filled chamber which defines a fluid link therebetween and a rotatable, threaded shaft member connected to the actuating piston for transmitting rotational motion to axial motion whereby rotation movement of the shaft member causes axial movement of the actuating piston which in turn causes axial movement of the actuated piston through the fluid link. In order to compensate for separation between the actuated and actuating pistons as a result of brake wear, the cylinder includes a fluid reservoir for supplying additional fluid to the fluid-filled chamber upon separation of these two members. The assembly also includes a wear take-up and antidrag device.

Low-mass short-stroke voice-coil actuator for integrated disk file module

Abstract: A low-mass low-inductance short-stroke voice-coil actuator used with a positionable transducer and magnetic disk to provide fast memory access in a low cost-per-bit disk file memory system. Enclosed in a sealed disk module, the actuator and transducing system provide access to any disk information track within one disk revolution or less. Integral with said actuator is a total moving mass of less than 50 grams. A short voice-coil, of one inch or less, is always contained within the magnetic flux of the air gap; and the voice-coil, when energized, can provide a full stroke access (across said magnetic disk) within 16 milliseconds. A pair of spider flexures support (for longitudinal movement) a central rod, which is part of a differential velocity transducer and which is integral with the voice-coil. The central rod is also capable of being rotated by a solenoid to turn a cam which will "unload" or remove the transducing heads away from the disk surfaces.