Abstract: A seal assembly is arranged to contain leakage of hydraulic fluid passing between a wall opening and a penetrant rod portion passing through the opening. The seal assembly includes a sliding-seal member mounted on a portion of the rod for sliding movement toward and away from an abutment surface and a non-sliding flexible-seal member arranged between the body and the sliding-seal member. The body, flexible-seal member, sliding-seal member and rod define a sealed chamber into which such fluid will leak. The chamber communicates with a fluid reservoir through a oneway check valve. The sliding-seal and flexible-seal members are arranged in parallel with one another. In one embodiment, a spring urges the sliding-seal member to move toward an abutment surface provided on the rod. In another embodiment, movement of the sliding-seal member relative to the body is limited by facing abutment steps.

Abstract: An equalizer is arranged to continuously sense the control pressures of two valves. In the event of a differential between the control pressures, the equalizer operates to selectively adjust one valve so that the control pressures of both valves will thereafter be substantially equal.

Abstract: A single-stage servovalve has a movable member operatively arranged to selectively divide a continuously-discharged fluid jet between two receiver passages. The hydraulic output of the valve is the differential between the conditions in the receivers. In the event of a hard-over failure of the control system of which the servovalve is a part, a jet deflector surface becomes operative to create a substantially balanced hydraulic condition in the receiver passages, thus terminating control.

Abstract: An improved electrohydraulic servovalve has first and second valve spools mounted for independent sliding movement relative to a body in response to a common command signal. The valve has a first drive mechanism operatively arranged to cause a desired motion of one valve spool in response to the command signal, and has a second drive mechanism operatively arranged to cause a desired simultaneous similar motion of the other valve spool in response to the command signal. The improvement comprises a differential position sensing mechanism arranged to sense the relative positions of the two valve spools and operative to produce an output related to the difference therebetween, and an indicating device supplied with such output and operative to indicate substantially dissimilar relative positions of the spools.

Abstract: A high response servovalve has an improved valve spool slidably mounted within the bore at a sleeve or body. The bearing surfaces on the spool are formed of a relatively soft material. The balance of the surfaces of the spool and the sleeve or body are relatively hard. The soft bearing material tends to absorb contaminants between the bearing lands and the sleeve, is self-healing, and is not prone to weld to the facing sleeve or body surface.

Abstract: A slide mount is adapted to selectively move a plunger assembly of a ski binding relative to a detent recess component. The slide mount includes a rail mounted on the ski and having a channel aligned with the recess, a slide carrying the plunger assembly and mounted on the rail for sliding movement along the channel both toward and away from the recess, and an actuator arranged to act between the rail and slide to cause the slide to move between a first position closer to the detent recess and a second position farther from the detent recess. The actuator includes a lever pivotally mounted on the rail, and a link pivotally connected to the lever and the slide, so that pivotal movement of the lever will produce corresponding linear motion of the slide.

Abstract: Apparatus is provided for sensing the actual position of an armature in an electromagnetic driver, such as a torque motor, a solenoid, or the like. An oscillator generates a relatively high frequency carrier signal, which is superimposed on a relatively low frequency command signal supplied to a drive coil. Detector coils are positioned in a magnetic circuit, and are arranged to have induced therein, signals identical in frequency to the superimposed signals. The amplitude of the induced signals varies with armature position. The high frequency induced signal is separated and demodulated to provide an output signal indicating the actual position of the armature.

Abstract: Mechanical feedback through an articulated mechanism is provided between the swashplate of a variable displacement hydraulic device and the output stage of an electrohydraulic servovalve for controlling such swashplate.

Abstract: A check valve assembly which when opening has a valve closure which is lifted from its seat before fluid flows past the unseated closure, and which when closing terminates flow in advance of the closure reengaging its seat.

Abstract: The dynamic performance of hydraulic apparatus including a fluid-operated actuator controlled by a servo-controller, is improved by providing phase lead compensation to the controller in response to movement of the movable element of the actuator so that the low frequency response of the apparatus is raised.

Abstract: An improved ski binding has a resiliently-loaded holding device operatively interposed between a boot assembly and a ski to provide points of contact between the boot assembly and ski at each of three mutually-spaced locations arranged at the apices of an imaginary triangle. At each location, a convex member is mounted on the boot assembly to engage a concave surface on the ski. An improved pivot clip is mounted on the ski and provides two of the concave surfaces. The pivot clip has two cam surfaces, each of which is engaged by a convex member mounted on the sole-plate. Each of the cam surfaces is inclined in a direction such that an external moment applied to the boot assembly about the skier's tibial axis will produce a reaction force between one cam surface and its associated convex member, which reaction force will have a longitudinal component not opposing the applied moment.

Abstract: A tool changer is adapted to be mounted on a machine tool having a spindle rotatable about a vertical axis. The tool changer includes a rail adapted to be mounted on the machine tool, a carriage mounted on the rail for movement toward and away from the spindle axis, a carousel-type tool storage magazine mounted on the carriage for movement therewith and also mounted for rotational movement about a vertical axis, a Geneva mechanism selectively operable to rotatably index the carousel, and a mechanism for selectively moving the carousel toward and away from the spindle axis. The carousel includes a plurality of hands spaced thereabout and mounted for independent vertical movement between a lowered position and a raised position. The carousel also includes a mechanism for selectively lifting any one of such hands which is aligned with the sindle. Each of the hands supports a cooperative pair of outwardly extending fingers adapted to embrace and releasably hold a tool holder therebetween.

Abstract: A two-axis positioning servoactuator includes a support, a movable member arranged adjacent the support for independent pivotal movement relative thereto about each of two perpendicular intersecting axes, a pair of differential piston and cylinder actuators operatively interposed between the support and movable member for effecting such angular movement about each of the axes, an electrohydraulic servovalve for each of the actuators and operatively associated therewith to control the same, and means providing a position feedback signal to the corresponding servovalve for effecting controlled movement of the member about each of the axes.

Abstract: A toe clip, adapted to hold the toe portion of a ski boot to a sole plate, is formed of a length of wire bent to have a base portion, two leg portions extending outwardly therefrom, and a loop portion adapted to be received in the toe notch of a ski boot. The ends of the wire are welded together. The toe clip may be operatively positioned in any of a plurality of transversely-extending key-shaped recesses provided in the sole-plate. The toe clip base portion is bowed in each of two perpendicular intersecting planes. One bow impedes insertion and removal of the base portion from a recess. The other bow provides a degree of friction between the base portion and the recess walls.

Abstract: A method of providing a torque motor with air gaps of equal length between an armature interposed between two spaced polepieces, comprises the steps of: assembling the torque motor so that the armature is roughly positioned between the polepieces, positioning an electrode so that two spaced portions thereof of equal width are arranged proximate the air gaps, providing a plurality of repetitious pulses of electrical energy between the electrode and the torque motor assembly, moving the electrode and torque motor assembly relative to one another, and removing proximate material from the armature and polepieces, as necessary, by electrical discharge between the electrode and torque motor assembly, thereby to provide air gaps of equal length between the armature and the polepieces.

Abstract: A rotary power drive is provided for delivering a substantially constant horsepower over a wide speed range in one direction of rotation comprising two or more constant displacement hydraulic motive means operatively associated with a shaft to be driven thereby, an overrunning clutch operatively interposed between at least one of such motive means and said shaft, and means for supplying hydraulic drive fluid to such motive means in different combinations over different shaft speed ranges to provide a multiple displacement hydraulic motor drive apparatus.

Abstract: An electromagneto-mechanical actuator comprising a brushless D.C. torque motor capable of producing a torque proportional to the current fed to coil windings which are arranged as a stator, a permanent magnet being the rotor, these windings being severally arranged opposite the pole end faces of the magnet and being reversely wound so that the magnetomotive forces generated by these windings cancel out each other and thereby eliminate magnetic hysteresis. The pivotal movement of the rotor is converted to translational or rectilinear movement of an output drive element through a substantially frictionless band drive having no backlash. The actuator is preferably arranged in a closed servo loop so that the proportionality of its response can be utilized.

Abstract: Mechanical feedback through an articulated mechanism is provided between the swashplate of a variable displacement hydraulic device and the output stage of an electrohydraulic servovalve for controlling such swashplate.