Abstract: A real-time machining control system is provided which includes a conventional computer numerical control and a dimensional measurement system which continually measures the actual diameter of the rotating workpiece and provides an error signal representing the difference between the actual diameter of the workpiece and that of the part program. The error signal is used to directly control the movement of the cutting tool to assure that the final actual machined profile and dimensions of the workpiece conform to the part program.

Abstract: The invention relates to an apparatus for mean pressure control of a Stirling engine without the need for a compressor. The invention includes a multi-tank system in which there is at least one high pressure level tank and one low pressure level tank wherein gas flows through a maximum pressure and supply line from the engine to the high pressure tank when a first valve is opened until the maximum pressure of the engine drops below that of the high pressure tank opening an inlet regulator to permit gas flow from the engine to the low pressure tank. When gas flows toward the engine it flows through the minimum pressure supply line 2 when a second valve is opened from the low pressure tank until the tank reaches the engine's minimum pressure level at which time the outlet regulator opens permitting gas to be supplied from the high pressure tank to the engine. Check valves between the two tanks prevent any backflow of gas from occurring.

Abstract: A linear reciprocating electromagnetic machine has an outer stator member having axially spaced apart pole pieces, an open-slot coil cavity housing a coil, and an inner stator member spaced from the outer stator member and providing means for completing a path for magnetic flux. The machine also includes a permanent magnet plunger arranged for reciprocation with respect to the stator members and within the space between such stator members. The plunger is provided with three permanent magnet segments arranged axially along the plunger such that the interface zones between the magnet segments are substantially within the region defined by the stator pole pieces for all operating axial positions of the plunger. The two outer magnet segments are of equal axial length while the center magnet segment is axially longer than an outer magnet segment by an amount equal to the axial length of the open slot of the coil cavity.

Abstract: The present invention relates to a control scheme for power modulation of a free-piston Stirling engine-linear alternator power generator system. The present invention includes connecting an autotransformer in series with a tuning capacitance between a linear alternator and a utility grid to maintain a constant displacement to piston stroke ratio and their relative phase angle over a wide range of operating conditions.

Abstract: "Velocity Observer" and "Imbalance Observer" circuits are used to control the journals in the magnetic field of an attractive type active magnetic bearing and/or damper. The circuits are characterized by the use of integrators rather than differential components. The velocity observer circuit uses a position feedback loop and a velocity observer feedback loop, both with variable gain, to control the levitation of the journal in the magnetic field. The imbalance observer circuit recreates the journal acceleration directly from the displacement measurement and can be used optionally on-line and off-line to suppress vibrations.

Abstract: The present invention relates to a resonant piston compressor in which a double-sided piston reciprocates within a cylinder and defines a valved compression space on one side of the piston and a balance chamber on its other side. The invention further includes a movable head adjustable between first and second positions to effect a large change in the total volume of the balance chamber between the two positions. In one position, of the movable head an extended balance chamber volume is coupled to the balanced chamber while in the other position of the movable head, the extended balance chamber volume is decoupled from the balance chamber.

Abstract: A linear reciprocating machine has a tubular outer stator housing a coil, a plunger and an inner stator. The plunger has four axially spaced rings of radially magnetized permanent magnets which cooperate two at a time with the stator to complete first or second opposite magnetic paths. The four rings of magnets and the stators are arranged so that the stroke of the plunger is independent of the axial length of the coil.

Abstract: An electrodynamic motor having a flat plunger core arrangement formed out of alternating layers of magnetic and insulating strips clamped together and maintained on respective bearing sleeves which reciprocate on guide members with the gap between stator members.

Abstract: A free-piston reciprocating compressor includes a reciprocating piston disposed within a cylinder such that one end of the piston-cylinder provides for a compression space and the other end of the piston-cylinder provides for a balancing space. The piston is coupled to and reciprocatingly driven by the armature of a linear electrodynamic motor, which armature reciprocates on guide means. The compressor also includes porting means operative to establish a stabilizing gradient sufficient to keep the piston operating at a related fixed mid-stroke position. The motor armature is also coupled to a centering-resonance spring.

Abstract: A system for balancing rotating members comprising a laser head which emits a laser shot in response to a laser control signal to remove material from the rotating member. The laser control signal is produced by a computer which is responsive to a plurality of signals representing vibration of the rotating member and influence coefficients from a memory device. The computer applies less than a calculated number of laser shots at each targeted location of the rotating member and then applies this reduced number sequentially to all targeted locations while calculating whether the vibration signals fall below targeted levels and, if so, discontinuing removal of material by the laser.

Abstract: A two piston Stirling engine wherein the pistons are coupled to a common crankshaft via bearing means, the pistons include pad means to minimize friction between the pistons and the cylinders during reciprocation of the pistons, means for pressurizing the engine crankcase, and means for cooling the crankshaft and the bearing means eliminating the need for oil in the crankcase.

Abstract: A tachometer signal conditioner circuit functions to accept a wide range of input signals and produces a digital pulse signal which indicates a gear shaft phase reference position. Tachometer input signals of either a true 1/revolution or an N/revolution signal with a single pulse or N pulses of different amplitude than the other pulses during the same shaft revolution can be used. The circuit comprises tachometer signal conditioner circuitry for amplifying and filtering the input from the tachometer, tachometer signal detector circuitry to produce digital pulses synchronous with the tachometer signal cycles and to detect the occurrence of a tachometer signal with a different amplitude during each 1/revolution or N/revolution period, a blanking signal generator which prevents tachometer signal noise from generating spurious 1/rev pulses during operation in the N/rev mode, and an output driver which produces signals to the remaining signal circuitry and to a front panel indicator lamp.

Abstract: A fiber optic sensor probe system comprises an electromechanical arrangement system which enables a fiber optic probe to lock onto a null point relative to a target which null point represents an in focus condition for the probe relative to the target. A servomechanism feedback circuit maintains the probe in an in focus condition relative to the target if the target moves. A dithering motion is provided to the probe such that, when the electrical output of the probe has a frequency component which is the same frequency as that of the dither, an out of focus condition of the probe relative to the target exists and the servomechanism feedback system operates to correct it. A monochromatic light source is used to eliminate the problem of different spectral components of light having slightly different focal lengths.

Abstract: A resonant reciprocating compressor wherein a reciprocating assembly comprising the movable armature of an electric reciprocating motor and a piston means coupled to the armature is driven cyclically when the electric motor is energized from an alternating current source to compress a working fluid, and including means operatively associated with the reciprocating assembly for producing a stabilizing force gradient in a direction to maintain or restore the reciprocating assembly to a centered operating position.

Abstract: This invention relates to a detection circuit for use in a servo controlled fiber optic sensor. A low noise signal with an amplitude proportional to the magnitude of the synchronous detection output is produced without the use of filter by a calculation of the average vale of the synchronous detector output signal driving one complete cycle of the dither signal cycle. This value is fed into sample and hold circuitry, which in turn controls the series motor.

Abstract: In a resonant piston compressor utilizing a balance chamber to provide a gas spring effect for use in a heat pump arrangement and the like, an adjustable balance cylinder head which adjusts so as to increase or decrease the balance chamber volume so as to increase or decrease the stiffness of the balance chamber, depending upon the mode of operation desired.

Abstract: A system for locating a feature of an object disposed in a frame includes a spot projector for projecting a spot in the general vicinity of the feature and an imaging device with a limited field of view. The spot projector is a precision device which projects the spot towards a preselected location on the frame. When the spot and the feature are in the field of view of the imaging device, the absolute location of the feature is determined from its selective distance to the spot. Provisions are also made for determining depth or relief information about the object.

Abstract: A linear air compressor having a linear electrodynamic motor which is air cooled and has an increased stroke and accordingly increased output. The working piston is provided with and stroke parting on a push-pull spring provides for centering of the plunger of the motor.

Abstract: A new variable impedance type system is described for measuring a preselected physical parameter such as spacing, displacement, pressure, vibration, etc. A sensor/transducer is positioned to provide the variable impedance. The sensor/transducer is part of a self-oscillatory circuit which produces pulses having a pulse rate proportional to the physical parameter being measured.

Abstract: A method of determining the displacement of a fiber optic sensor from a target in which a first lens is spaced from the target at a first distance an a second lens is spaced from said target at a second distance which provides the greatest intensity response at said first distance and thereafter spacing said first lens from said second lens to provide symmetrical slope values of response.