Abstract: A linear actuator includes an electric drive motor which is connected to a drive screw through a gear train. Rotation of the drive screw causes the drive nut to move axially in order to impart axial motion to an extension member. Limit switches function to disengage power to the electric motor upon the extension member reaching the outer or inner limits of its stroke. Also, a thermal sensing element located in the windings of the electric motor interrupts power to the motor upon the heat-up of the motor windings above a predetermined temperature, as when the drive nut jams or locks up. A sealed housing contains the drive screw, drive nut and extension to protect against entry of dust. The housing has reaction surfaces which cooperate with the drive nut to permit linear movement of the nut while holding the nut against rotation.

Abstract: A digital linear actuator includes a plurality of digital actuator cells each connected to the next in sequential fashion. Each of the digital actuator cells contracts or expands a predetermined amount along an expansion/contraction axis when it is actuated by a corresponding digital signal. Each digital actuator cell includes an inner portion containing a medium which expands or contracts in response to a digital signal. The inner portion is disposed within an outer portion that contracts in the direction of the axis in response to expansion of the inner portion, and expands in the direction of the axis in response to contraction of the inner portion. The device is useful in simulating the behavior of a muscle in a prosthetic device. Several embodiments of the invention are disclosed in which an arm can be extended to and retracted from a snake-like configuration. Another embodiment of the invention is disclosed which effectively simulates a shoulder and arm mechanism.

Abstract: A cutting device for plastic pipe for use principally in the aid of plumbing, swimming pool and spa installations. The pipe cutter is designed specifically to be used or attached to a hand held drill motor of the type which tradesmen commonly carry and use for drilling holes and setting screws. The pipe cutter includes a body which is attachable to the front of a drill motor and houses a dual directional linear actuator such as an epicyclic ball screw with bi-directional brake. The epicyclic ball screw linear actuator responds to the chuck or rotating shaft of the drill motor. The housing defines or holds a U shaped recess or cradle for receiving a plastic pipe extending transverse to the length of the housing or more particularly on center or to the axis of the drill motor shaft. A guillotine type of cutter blade is driven by the screw actuator to move through a slot into the cradle to be driven through the side wall of the pipe and therefore sever the pipe within the cradle. Upon completion of travel of the guillotine blade through the U shape holder and severance of the pipe, the guillotine blade is returned to its at rest position outside of the U shaped holder. Both mechanical limits and electrical limit switches on movement of the guillotine blade are disclosed. This invention is disclosed as an attachment to a conventional drill motor, as an integrated pipe cutter, and as a bench top model.

Abstract: An apparatus 10 for positioning a laser mirror 16 secured within mirror mount 14. A centrally disposed linear actuator 20 is positioned to impart a force to the mirror mount 14 which is in line with the net center of percussion of the laser mirror 16 and mirror mount 14, thus providing tip/tilt free single point piston actuation. Three tip/tilt actuator assemblies 18,76 equidistantly disposed about the linear actuator 20 provide coarse adjustments and fine tip/tilt actuation. The mirror mount 14 is resiliently connected to the base 12 by support means 24,54.

Abstract: A remote control mechanism connects the shifting lever of a motor vehicle to the vehicle gearbox or transmission, and has a drive member connected to the shifting lever, and a driven member operatively connected to the transmission shift rail. The drive member is supported for both linear motion for selecting a gear, and rotary motion for shifting into a gear. The driven member is supported for both linear motion and rotary motion. A push-pull cable transmits the linear motion of the drive member to the driven member, and master and slave hydraulic linear actuators transmit the rotary motion of the drive member to the driven member so that the transmission is responsive to the shifting lever being moved along two perpendicular paths of motion in a gear shifting pattern. In another embodiment, master and slave hydraulic linear actuators connect the drive and driven members for transmitting both the linear and the rotary motion of the drive member to the driven member.

Abstract: 1. An arrangement for reinforcing the driving force of a servomotor (1) in a linear actuator with a threaded spindle (5) and a spindle nut (6) which is connected to a hollow cylindrical connecting rod (9) and is constructed as a piston acting at both ends in the external cylinder (7), the connecting rod (9) penetrating a cylinder base (8) as piston rod and wherein there is provided a measuring device which operates as a function of a resilient stop means (27) in order to supply pressure fluid via an electrically controlled valve (13) to said cylinder (7), characterised in that there is provided a gear mechanism (20 - 28) which comprises the resilient stop means (27), measures the torque and is located in a housing (3) between the other base of the cylinder (7) and the motor (1).

Abstract: A governor is disclosed for governing engine and load speed and which is especially adapted for use with motor vehicles It comprises an overriding throttle closing device with a linear actuator for moving the device to a position for limiting the engine speed and load speed to governed values An electronic control circuit comprising a microprocessor operating under program control produces motor control signals for a reversible electric motor which drives the actuator means through a gear train and lead screw An engine speed signal generator provides an electrical speed signal to the control circuit and a road speed signal generator supplies a load speed signal to the control circuit When the speed signal exceeds a predetermined value, the control circuit produces motor control signals for operating the motor at full speed to move the actuator to a reference position causing operation in a reference point governing mode In this mode when the speed signal exceeds the governed value, the control circuit produces motor control circuits for operation of the motor at slow speed in the close throttle direction When the speed signal is less than the governed speed, the control circuit produces motor control signals for operating the motor at slow speed in the wide open throttle direction The slow speed of operation is adapted to provide smooth governing action with small overshoot and minimal droop

Abstract: Conventional piston-cylinder hydraulic actuators require external pressure sources. The hydraulic actuator disclosed utilizes the centrifugal head developed in its chambers. The piston (36) is attached to shaft extension (24) which is splined to the actuator cylinder (20). The cylinder (20) rotates with the shaft (16) to develop a centrifugal fluid head which is selectively directed from the outlet port (40a, 40b) of a contracting chamber through a servo valve (46) to the return passageway (46b, 46a) of an expanding chamber to axially displace piston (36) and shaft (16). An accumulator in the fluid circuit retains fluid displaced from the cylinder (20).

Abstract: A hand held self-contained automated pipette for portable operation having an electrically operated digital linear actuator is disclosed. The digital linear actuator preferably includes a stepper motor driving a rotor. A threaded screw is coaxially positioned within the rotor and is connected to an actuator shaft having elongate grooves slidable in a guide for preventing actuator shaft rotation so that precise linear motion is imparted to the actuator shaft. Provision is made for the removable attachment of pipetting displacement assemblies of various sizes all actuated by a common digital linear actuator including programmed movement of a displacing piston in a displacement cylinder to optimize air interface volume, neutralize variations in vacuum pipette effects, and provide an accommodated stroke and readout for improved accuracy while pipetting and/or titrating different ranges of volumes. A control circuit is provided so that the back EMF of the stepper motor coils is recirculated when power is duty-cycled off for power conservation. Conversely, recirculation is switched off when power is duty-cycled on for minimizing losses. Recirculation is switched off when coils are commutated which produces a rapid magnetic field collapse for assuring high torque. Upon calibration the displacing piston undertakes immediate excursion to an end of travel limit and after motor slippage is retracted to a home position. This home position is chosen for optimum preservation of an air interface volume between drawn liquid and the displacing piston tailored with particularity to the displacement assembly being used. Multiple precision modes are provided for the convenience of the operator, these modes including pipetting, multiple dispensing, titration, and dilution. Other features are also disclosed.

Abstract: A threadless linear actuator apparatus comprising a sealed actuator unit with a sealed housing for a set of spool-shaped roller bearings. The roller bearing set includes at least one variable pitch loading roller and two fixed pitch rollers arranged in a skewed relationship about a cylindrical drive shaft. A variable moment is applied to the apparatus through a moment applied about an axis which is perpendicular to and intersects the drive shaft axis which, when applied, varies the pitch of the pivotable loading roller.

Abstract: PURPOSE:To obtain an actuator capable of stepwisely feeding in small size and high accuracy by forming the operation corresponding to the teeth of a step motor by a sensor and a controller. CONSTITUTION:A coil movable type linear actuator 10 has a permanent magnet 12 and pole pieces 16 on the inner surface of a stator 11, and coils 15 disposed in the intermediate gaps. A movable unit 13 directly coupled with the coils 15 is supported by slide bearings 14 and laterally moved. A sensor 3 is disposed oppositely to the unit 13, the position of the unit 13 is detected, and the detection signal is applied to a signal processor 6. The sensor 3 generates different 2-phase outputs A, B of 90 deg., the processor 6 forms a reverse conversion signal and applies a voltage command signal Vc to a voltage controller 5 on the basis of one of the signal selected by a command generator 7 by the voltage instructing circuit 5. The controller 5 controls the voltage of the coil 15 to stepwisely feed.

Abstract: PURPOSE:To perform high-precision control which has high reliability for a long period by using a positioning bearing, linear actuator, spring, and lock mechanism in combination. CONSTITUTION:An antenna pedestal 1 holds an antenna reflector 9 on the surface and has plural positioning hole parts on the reverse, and the linear actuator 3 is fixed to one terminal of one of plural supporting rods which serve as positioning bearing by having the other tips inserted corresponding to the hole parts and moves in the axial direction of the supporting rod. An elastic member 5 links a fixed part fixed to a satellite body 13 where the other terminal of the supporting rod is fixed to the pedestal 1 with tensile force. Then, the lock mechanism 6 fixes the member 5, pedestal 1, and fixed part when the satellite is launched and allows the actuator 3 to move after the launching to control the direction of an antenna beam.

Abstract: A controlled liner actuator shaft that may be used to open and close hydraulic valves is tapped to control a second valve or the like by an actuator shaft housing selectively lockable to the actuator shaft. An adjustable sleeve on the housing pivotally supports a control handle collar and spaced pivotal connections of the control handle to a stationary member and to the valve to be controlled permits manual control when the shaft housing is released from the shaft, and permits actuator shaft control when the shaft housing is locked to the shaft.

Abstract: PURPOSE:To provide a fluid control valve which can be operated at high speed and has good responsibility by applying a thrust to a movable member of an actutator and intermittently driving the brake to intermettently put the movable member in a stationary state. CONSTITUTION:A valve body 14 disposed in a valve main body 12 of a fluid control valve 10 is coupled to a movable member having a diameter larger than that of the valve body to be united in a body. The movable member 18 is provided with a linear actuator 32 for moving the movable member in a straight line and a brake 34 for limiting the movement of the movable member 18 which are sisposed outside the valve main body 12. The movable member 18 can be displaced by thrust from the actuator only when the braking force of the brake 34 is off and be put in a stationary state when the braking foce is on.