Other

Compudrive Corporation

Ferrofluidics Corporation

Encynova International, Inc.

Ency Nova Inc.

Michel A Pierrat

Carl J Holt, Jr

A Positive Fluid Displacement Device (PFDD) with single piece double-ended pistons connected to a crankpin for circular motion. Pistons are nested together to maintain all pistons in the same plane perpendicular to the axis of the crankshaft. Cylinders are driven in a reciprocating fashion by the pistons and are held loosely in a cylinder carriage along its axis with radial sealing engagement therebetween. Pliable members mount port plates within a housing such that there is no direct contact therebetween or with a two-layer manifold. A flat surface of the port plate is urged against the cylinder head by a pliable member which exerts a force on the center of the port plate. Grooves in the first layer of the manifold are sealed by the second layer to form fluid passageways. The cylinder head is guided in housing grooves with a pliable member. A sealing lip is integral with a piston head.

Zero leakage valveless positive fluid displacement device

A Positive Fluid Displacement Device (PFDD) with a removable Fluid Displacement Module (FDM) having two opposing pistons connected to a drive block. The drive block slides over a crankpin bearing in assembly to provide orbital piston motion. Opposing cylinders are held within a carriage for reciprocating motion. An opening in the reciprocating cylinder head allows fluid communication to the displacement chamber through inlet and outlet ports in a floating port plate. The flat surfaces of the port plate and cylinder head wipe across each other during cylinder head movement. The piston head carries a protrusion sized to fill the cylinder head opening. Micro-adjustment mechanisms for the position of the cylinder head together with compliant piston and compliant cylinder mechanisms can provide near zero dead volume. Different sized opposing cylinders enable the delivery of pumped fluids in precise ratios. By connecting the outlet of each cylinder to the inlet of the opposing cylinder, the differential displacement of the two cylinders can be pumped, enabling the delivery of very small quantities of fluid. High vacuum may be delivered by series connection of cylinders. The device may incorporate a dual lip piston seal which is wear compensated over the life of the seal. The PFDD is leakage free and can be driven by stepper motors to deliver a precise fluid amount at low speed even to an exact portion of a piston stroke. A sensor is provided for sensing cylinder head position.

In an autoloader having a tape deck for reading and recording on magnetic tape cassettes, such as are used for computer data back-up, a removable magazine for holding a number of cassettes in which a locking and ejection mechanism locks the magazine in position in the autoloader and permits its automatic or manual release and ejection from the tape deck. The magazine has no protrusions on its side, top or bottom surfaces that would interfere with easy insertion into and removal from the autoloader and which would, also, interfere with simple and easy storage of the magazines in a back-up facility. Any size magazine can be inserted in the autoloader without modification of the autoloader. A first latch member engages a receptive space in the magazine when it is partially inserted and stores ejection energy. A second latch member locks the magazine in position when it is fully inserted. The magazine may be released from the autoloader automatically under electronic control or manually by physically releasing the second latch. The stored energy then ejects the magazine a sufficient distance to enable an operator to remove it by hand.

Magazine latching and ejection mechanism for a cassette autoloader

A reversible drive system is provided that is particularly adaptable to low-power drives in which precision mechanical control must be obtained with the lowest possible cost and the highest reliability. The drive is described as incorporated in a lead screw drive in which a control nut reciprocates between two fixed positions. At the end of the movement in one direction, the control nut strikes a fixed abutment that stops the motion thereby increasing the load on the drive motor and causing an increase in the current drawn by the motor. This increase in current is utilized to disconnect the power source from the motor. In such systems, in particular where there is a large reduction in the speed between the motor and the driven object, as with the use of a lead screw drive arrangement, it is desirable to store energy at the end of each stroke that is available to decrease the starting torque required to reverse the direction of motion. To provide additional starting torque, the motor coupling includes a lost-motion coupling by which no significant load is placed on the motor until the output shaft of the motor, or an element driven by the motor, has moved through some fraction of a revolution. For most applications a lost-motion arrangement equivalent to about one hundred eighty degrees of motion is practical.

Motor coupling with angular compliance

A number of data storage cassettes are held in a removeable magazine that forms part of a tape drive by which the magnetic tapes are recorded or played. The magazine holds two parallel vertically-displaced decks of cassettes that are moved under positive driving force along a rectangular pathway formed by the two decks. From a pick-up position in the magazine, a cassette is automatically extracted by a robotic arm and placed in the tape platform for reading or writing by a conventional tape drive mechanism. When the use of the cassette is finished and it is ejected by the tape drive, a sensor activates the robotic arm to return the cassette to the pick-up position. Each deck has one unoccupied cassette space. If during the sequence of operations, the cassettes on the lower deck are moved by the width of one cassette in one direction, the cassettes on the upper deck are moved the same distance in the opposite direction. This movement results in a vacant position at the end of the upper deck farthest away from the pick-up position. The cassette in the pick-up position is either removed and loaded into the tape deck or the cycle is continued. Movement of the cassette is produced by reciprocating drivers along the sides of the magazines. The cassettes are moved in only one direction by the reciprocating drivers and are locked to prevent movement in the opposite direction. Motions of the cassette handling mechanisms are limited by mechanical stops that trigger an electronic circuit to interrupt the driving power eliminating the need for sensitive position switches. Slip clutches prevent mechanical damage from the mechanical stops. The removable magazine does not include any electric motor drives and is automatically disengaged from the cassette driving mechanism by its removal, thus permitting economical use of multiple magazines.

Magnetic tape drive with integral multiple-cassette removable magazine

A storage library with a simplified operating mechanism for computer back-up data cartridges. The cartridge is placed in a tray in an opening in a sealed storage chamber and transported into and removed from a multi-tier storage carrousel by a robotic arm. When a tape is to be retrieved, the arm moves the stored cartridge either to a module or directly to the window tray. A simple transmission operating the carrousel permits any cartridge to be moved to the storage-retrieval station in no more than two revolutions of the multi-carrousel central drive shaft. The use of a carrousel reduces the distance the arm must travel and decreases the time for storage or retrieval of a cartridge. Only two of seven axes have incremental positioning controls: the vertical lift and the carrousel rotation. All other axes have fixed travel distances. A cartridge gripper is compliant, readily adaptable to different cartridge configurations, and materially reduces the need for precision positioning.

Automatic data storage cartridge library with a storage carrousel having

Rectangular pistons are driven in a circular orbit by two spaced eccentrics on a common crankshaft. The displacement chambers reciprocate with a lateral motion parallel with the crankshaft. The radial forces created by the fluid pressure in the displacement chambers are balanced by a connection to the crankshaft through rotatable and slidable antifriction bearings. During the reciprocating lateral motion of the chambers, port openings located in the outer ends of the chambers are connected alternately to matching intake and exhaust port openings in the adjacent surfaces of the casing to provide a reversible valveless control of the fluid to and from the chambers. The apparatus can be used either as a pump or motor without internal modifications. The pistons are secured together as one piece and follow identical orbital paths. Each pair of opposing displacement chambers are secured as one piece and radially connected to the crankshaft. The displacement of the apparatus is continuously variable from zero to its maximum. The apparatus is dynamically balanced by two counterweights, with adjustable eccentricities.

Variable positive fluid displacement apparatus with movable chambers

A method for grinding epitrochoidal, hypotrochoidal, and circular bearing races in one set-up without moving the part and insuring near perfect concentricity between all of the bearing races. A machine blank is mounted on an upper rotary table that is in turn mounted on a lower rotary table. The upper table is driven both by the lower table and by an independent servomotor. The net speed of the upper table is the difference between the two driving speeds of the tables. The axis of rotation of the upper table can be offset from the axis of rotation of the lower table. The tables are rotated in opposite directions while a grinding wheel is moved laterally into contact with the surface of a rough-machined part to form the trochoidal surface. The characteristics are determined by the offset, the diameter of any rollers that are to be positioned between the trochoidal surfaces in the speed change device, and the relative speeds of the two tables. After the trochoidal surface or surfaces are completed, the lower table is stopped in its home position and the upper table is driven to grind the circular bearing race or races. Three independently-driven grinding spindles are laterally adjustable with respect to the tables.

Method for grinding trochoidal and circular bearing races

A trochoidal speed reduction mechanism forms an integral part of the stator and rotor of an electric motor so that a slow-speed high-torque output is produced without having any high speed rotating component in the motor. A rotor has an epitrochoidal contour with a predetermined number of lobes. Positioned around the rotor are two non-rotating orbiting stator-rings, phased 180 degrees apart, each provided with a number of rollers equal to the number of lobes on the rotor plus one. The rollers are rotatably mounted on the inner surface of the stator-ring and are in continuous contact with the epitrochoidal contour of the shaft rotor. The non-rotating orbital movement of the stator-rings is produced by magnetic forces from a series of stator windings arranged as magnetic poles around the stator-rings. This action causes the rotor to rotate at a speed equal to the orbiting speed of the stator-rings divided by the built-in speed reduction ratio. Because the two stator-rings are orbiting 180 degrees apart, the orbiting masses and the torque on the rotor are balanced. The current flow through the stator winding, the sequential timing, the direction of rotation and the speed are all controlled by conventional solid state circuitry.

Low speed brushless electric motor

A fluid pump has two pairs of rectangular oppositely-disposed pistons. The pistons of each pair travel simultaneously in opposite directions at the same speed and over the same distance. Valving is provided by a reciprocating port plate, in face-to-face relation to the piston, driven in a circular path from two spaced crankpins and which in turn drives the associated piston. The sliding movement of the port plate controls the alignment of inlet and exhaust ports in the piston and port plate. The excursion or 'throw' of the pistons can be varied from zero to maximum. A crankpin throw-adjusting mechanism simultaneously adjusts the throw of each crankpin, some in one direction, some in the opposite, so that all chambers are automatically adjusted for varying, but always identical, displacements. Self-lubricated seals between the piston and chamber walls are spring loaded, by an elastomerically sealed structure having non-linear deflection-to-force characteristics.

Variable positive fluid displacement system

A grinding machine for grinding epitrochoidal, hypotrochoidal, and circular bearing races in one set-up without having to move the part and to insure near perfect concentricity between all of the bearing races. A machine blank is mounted on an upper rotary table that is in turn mounted on a lower rotary table. The upper table is driven both by the lower table and by an independent servomotor. The net speed of the upper table is the difference between the two driving speeds of the tables. The axis of rotation of the upper table is capable of being offset from the axis of rotation of the lower table. The two tables are rotated in opposite directions while a grinding wheel is moved laterally into contact with the surface of a rough-machined part to form thr trochoidal surface. The characteristics are determined by the amount of the offset, the diameter of any rollers that are to be positioned between the trochoidal surfaces in the speed change device, and the relative speeds of the two tables. After the trochoidal surface or surfaces are completed, the lower table is stopped in its home position and the upper table is driven in order to grind the circular bearing race or races. Three independently-driven grinding spindles are provided.

Computer controlled universal grinder and method for grinding trochoidal

A speed reducer with an orbital rotor, mounted for free rotation on a rotor drive wheel driven along an orbital path, has a perimeter defined by an epitrochoidal curve that simultaneously engages each of a series of rollers arranged in a circle around the rotor. The rotor drive wheel is driven by a compensation coupler that prevents radial forces of the rotor and the rotor drive wheel. The drive shaft provides only a rotary thrust on the rotor drive wheel and is shielded from reaction movements of the rotor and rotor drive wheel. The rotor drive wheel is driven by a variable-length crank arm that extends into a radial opening in the rotor drive wheel and makes sliding engagement with opposite faces of the radial opening. The driving surfaces that engage the faces of the radial opening form, in a plane perpendicular to the axis of the drive shaft, arcs of a circle equal in diameter to the width of the radial opening. The crank arm includes an expansion slot that divides it into two fingers that embrace opposite sides of the radial opening. For smaller units, the spring quality of the fingers is relied upon to maintain firm engagement between the fingers and the faces of the slot.

Orbital speed reducer with compensation coupling

A speed reduction mechanism having an orbital drive system. A first crank arm drives the orbital system and a second crank arm, offset by 180 degrees, carries a counterweight for counter balancing the off center forces produced by the orbital system. To minimize inertia, the counterweight is symmetrically shaped about its axis and is mounted for free rotation about the second crank arm. Such a counterweight may have a smaller degree of eccentricity and a correspondingly greater mass than a conventional counterweight, but because the inertia is a function of the square of the eccentricity of the counterweight, the inertia may be significantly less.

Counterweight for orbital drive mechanism

A method and apparatus for minimizing backlash and improving the efficiency of speed reduction mechanisms in which a series of rollers are equally spaced in a circle on a disk to perform operationally somewhat like an internal ring gear. Mounted for eccentric movement and simultaneously engaging each of the rollers is an orbital rotor having a perimeter defined by an epitrichoid curve with a number of lobes equal to one less than the number of rollers. The rotor is mounted for free rotation on an eccentric keyed to a drive shaft. Rotation of the drive shaft causes the rotor to move orbitally and to rotate with a speed reduction equal to the reciprocal of the number of lobes on the rotor. Each roller is mounted for controlled omnidirectional compliance and preloaded to provide a controlled pressure between each roller and the adjacent surface of the rotor. The outer surface of each roller is crowned to increase the efficiency and prevent binding that might be caused by angular deflection of the roller. Each roller is mounted on a shaft that is press-fitted into an eccentric bore in a mounting sleeve that is enlarged near the roller to provide for controlled deflection of the shaft as the sleeve is rotated in its mounting. Each roller is individually adjusted to produce a controlled preload pressure between the roller and the rotor.

Speed reducer and method for reducing blacklash

A log splitter having a manually adjustable wedge and a power driven base for supporting the log and forcing it upwardly into the splitting wedge. The wedge is supported by a carriage that is releasably secured to two standards by a pair of quick-release clamps, operable with one hand. The support includes a central projection extending toward and in alignment with the terminus of the wedge to minimize twisting moments generated by the splitting forces.

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Andover, MA, United States of America

Michel A Pierrat