Abstract: A linear motor includes an armature having a plurality of side-by-side electrically conductive coils formed on an electrically and magnetically nonconductive substrate with adjacent coils electrically isolated from each other. Each coil includes a plurality of electrically conductive windings positioned coaxially and electrically connected so that in response to an electrical current flowing therethrough each winding produces a magnetic field having the same polarity. Each electrically conductive winding of each coil is preferably formed on a layer and a plurality of layers is laminated together to form the substrate.

Abstract: A small footprint vertical lift and rotary positioning stage comprises a bottom wedge and a top wedge, a linear bearing between the bottom wedge and the top wedge, cam grooves and cam surfaces for constraining the motion of the top wedge in a vertical direction, a brushless linear motor for moving the bottom wedge back and forth along a horizontal path raising and lowering the top wedge, a circular table rotatably mounted on the top wedge and having a first cylindrical flange extending downward from a segment of the circumference of the circular table, a bracket mounted on the side of the top wedge, the bracket supporting an upwardly extending second cylindrical flange coaxial with the circular table and the first cylindrical flange, and a brushless curvilinear motor between the first and second cylindrical flanges.

Abstract: A stage assembly includes a first element and a second element. A coarse and fine adjustment mechanism is attached to the first element and engages the second element. Turning either a coarse or fine range selector produces relative movement of the second element in relation to the first element. An encoder is attached to the first element and the second element. The encoder detects movement of the second element in relation to the first element and determines the position of the second element from a home position. A display electrically connected to the encoder displays the position of the second element. A multiplier may be electrically connected to the encoder to partition a digital signal from the encoder to improve the resolution of the adjustment mechanism.

Abstract: A small footprint mechanical positioning stage capable of operating in two perpendicular orientations comprises a base plate, a carriage plate, linear bearings, a brushless linear motor, and a linear encoder. The linear bearings, the linear motor and the encoder scale are all parallel to the direction of travel of the positioning stage.

Abstract: A small footprint vertical lift and rotary positioning stage comprises a bottom wedge and a top wedge, a linear bearing between the bottom wedge and the top wedge, cam grooves and cam surfaces for constraining the motion of the top wedge in a vertical direction, a brushless linear motor for moving the bottom wedge back and forth along a horizontal path raising and lowering the top wedge, a circular table rotatably mounted on the top wedge and having a first cylindrical flange extending downward from a segment of the circumference of the circular table, a bracket mounted on the side of the top wedge, the bracket supporting an upwardly extending second cylindrical flange coaxial with the circular table and the first cylindrical flange, and a brushless curvilinear motor between the first and second cylindrical flanges.

Abstract: A small footprint mechanical positioning stage capable of operating in two perpendicular orientations comprises a base plate, a carriage plate, linear bearings, a brushless linear motor, and a linear encoder. The linear bearings, the linear motor, and the encoder scale are all parallel to the direction of travel of the positioning stage.

Abstract: A low profile tilt stage comprises a planar base, a cradle defining a cylindrical surface having a cylindrical axis parallel to the base, a table mounted on the cradle by curvilinear bearings, a curvilinear direct drive brushless motor between the cradle and table, and an encoder reader fixed relative to the base and an encoder scale fixed to the table.

Abstract: A ventilation fan assembly (10) having a fan (22) mounted in a housing (12) and a shutter assembly (60). The housing has a square inlet portion (12C), a circular center portion (12E) and a conical outlet portion (12D) having rifling grooves (20). The shoulder (16) formed between the inlet portion and the center portion is radiused to reduce disruption of air flowing from the inlet portion to the center portion. The shape of the blades (32) of the propeller (28) is such that the axial velocity produced as the propeller rotates is essentially constant along the length of the blades. The shutter assembly has a large, radiused entrance and airfoil shaped blades which reduce air disruption. The blades have a flexible flap (68) along the trailing edges (64D) which form a seal between adjacent blades to prevent air from leaking from the housing through the shutter assembly.

Abstract: A device for receiving first and second analog signals consisting of two sinusoidal signals shifted in phase from an encoder and outputting digital pulses corresponding to the approximate number of equal steps the system of which the encoder is a part has advanced or retreated comprising flash memory storing a table relating total value counts to the precise value as previously determined by calibration and that adds or subtracts counts to or from a difference register so that the count in the difference register corresponds to the calibrated value moved by the system.

Abstract: A linear motor driven positioning stage comprises a wedge positioned between a carrier and a base and a linear motor positioned between the wedge and the base for moving the wedge relative to the base along a second axis whereby the carrier moves relative to the base along a first axis.

Abstract: A pyrotechnic valve, igniter and combustion preheater for hybrid rocket motors is described. Particularly, the present invention comprises a ported connection means in which is mounted a solid charge of pyrotechnic material which provides a barrier to and obstructs the flow ports of the connection means to maintain the physical separation of the fluid propellant from the solid propellant. In operation, the solid charge is ignited and burns which burning consumes the charge and thereby removes the barrier to fluid propellant flow. The preferred pyrotechnic charge also ignites the solid propellant and thereby initiates combustion. The ported connection means may also include a preheater chamber in which is disposed a hollow or slotted cylinder of solid fuel which when burned, reacts with and heats the fluid oxidizer as it flows to the main combustion chamber to increase the ignitability and combustion efficiency of the solid fuel grain disposed therewithin.

Abstract: A method of correcting quadrature signal errors comprises the steps for generating an error function signal E by summing the squares of the quadrature signals and subtracting a constant K therefrom, saving the value of the error function E at .theta. equals approximately 0, .pi./2, .pi., and 3.pi./2, using the saved values of the error function to generate signals indicative of the quadrature errors, and generating corrected quadrature signals by processing the quadrature signals to eliminate the errors.

Abstract: A novel and unique rocket ignition system comprising a novel igniter having copper foil laminated plastic substrate having a electro-conductive pyrotechnic coating disposed on one end thereof and ignitable by means of a special power-supplied igniter clip having offset positive and negative terminals for engaging the igniter and transmitting an electrical current therethrough to initiate combustion of the pyrotechnic coating which in turn ignites a rocket propellant disposed in close proximity thereto. Special means are provided to selectively position and secure the rocket ignition system to a rocket motor.

Abstract: Parachute ejection and recovery system for rockets which protects and permits recovery of the entire rocket after launch including means for cooling ejection gases, means for directing the cooler ejection gases for using in ejection, the nose cone and parachute therefrom during flight, and means for controlling descent of the rocket body, its nose cone and a parachute associated therewith.

Abstract: A stable single-frequency laser interferometer comprises a Michelson interferometer having a power stabilized single-frequency laser and a dual light sensor comprising two closely spaced very small sensor surfaces mounted in substantially the same plane. Devices rotate the plane of the dual light sensor and/or elements of the interferometer to adjust the effective convergent angle of the recombining beams to have a sufficiently large effective convergent angle to promote stability and so that the output signals of the two sensors are in phase quadrature.

Abstract: A finlock mechanism for recreational rockets having a pair of finlock ring members disposed in spaced relationship to each other in circumscription about the motor tube in the rocket, each ring member having a plurality of finlock receptors disposed on the perimeter thereof in equispaced relationship to each other for receiving a finlock root extending through the rocket housing in snaplock engagement therewithin.

Abstract: A closed loop motor system having a motor with a plurality of poles and motor windings associated therewith. The poles define full step motor output positions. The system is of the type that assigns intermediated current values to the motor windings for fine step positions of the motor. The system also comprises a motor output position encoder for generating an integral and fixed number of encoder pulses as the motor moves between any two motor poles. The pulses are equally spaced and at least some corresponding to the fine step positions. An initializing current comprising components for applying full step current values to motor windings for a time interval in which the motor output is assumed to align with a full step position, and components for zeroing the count in the counter and assigning the torque angle value, whereby the encoder does not require alignment relative to the motor.

Abstract: A single frequency adapter for a gas laser comprises a jacket for engaging and being secured to the casing surrounding the gas laser. An induction coil is fixed within the jacket and positioned to surround the hollow mirror mount at one end of the laser tube while being outwardly spaced from the hollow mount. A power supply and modulator apply an alternating current to the induction coil.

Abstract: A micro-stepping translator controller for supplying current to a stepping motor having a plurality of windings comprises a power supply for supplying current to all windings and electronic switches for gating current to all windings. Logic means receive inputs comprising a clock input having a frequency being indicative of the micro-stepping rate and a multiplexing pulse. The logic means having digital circuits for outputting over a data bus signals indicative of two quadrants of a stepped periodic function. The signals correspond to different phases of the stepped periodic function during different multiplexing intervals. The logic means has digital circuits for sequentially outputting signals indicative of one of the four quadrants. A digital-to-analog converter is connected to the output data bus for producing an analog signal.

Abstract: A switching amplifier comprises an input terminal connected to a d.c. power supply and an output terminal connected to a load. At least one power transistor is placed in series with the input and output terminals. A PWM circuit outputs a pulse width modulated signal. An isolating driver circuit between the PWM circuit and the control terminal of the power transistor comprises a low voltage power supply; a transformer having primary and secondary windings; an oscillator for outputting a high frequency signal; means for gating the high frequency signal from the oscillator to the primary winding of the transformer in response to the pulse width modulated signal from the PWM circuit; a MOSFET; means for rectifying the voltage in the secondary winding of the transformer and for applying the rectified voltage to the gate of the MOSFET; and switching means for rapidly discharging the gate of the MOSFET when the high frequency signal is no longer gated to the transformer.