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.