Abstract: 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.

Abstract: 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.

Abstract: A system for copying images onto a long sheet of paper or vinyl while. A flow of constant-pressure air is pulse-width modulated in accordance with the control signals and passed over an ink meniscus maintained on the end of a small nozzle. The pulse-modulated air flowing across the meniscus causes the ink to be sprayed onto the recording medium. The dot size on the image remains constant and the pulse width within each pixel is varied to produce the desired density of color. Pressure surges in the ink supply system, produced for example by vibration or acceleration of the ink, are suppressed by a second meniscus in the ink-supply system, formed by a gas bubble or interface near the nozzle meniscus. The second meniscus should have a surface area at least as large as that of the jet meniscus. At the end of each pixel, the ink flow is interrupted for a period of about 100 microseconds to restore system equilibrium.

Abstract: 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.

Abstract: 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.

Abstract: A tunable helical antenna consists of a central support of dielectric material having a helical channel in the outer surface of the support. This channel, which may be square, rectangular or of other shape in cross-section, is plated with a conductive material such as copper. Biasing coaxial cables for controlling the tuning of the antenna are then placed within the channel and the channel sealed by a conductive cover. The plated surface becomes the helical radiating element of the antenna while the leads enclosed in the channel are isolated from r-f currents which are confined to the outer surface of the helix coating and conductive cover. The helical channel in the support may be formed by machining or the support may be molded with the helical channel as an integral part. Either way, precision control over the channel dimensions is readily attained. Pairs of oppositely-poled diodes are connected to spaced points on the radiating element.

Abstract: A digital recording medium formed of a thermoplastic substrate having rows of equally-spaced microscopic optically-alterable mirrors each supported by a mesa projecting from one surface. The medium can be formed from a single transparent thermoplastic substrate with an array of indentations in a first surface. The bottom of each indentation is coated with a reflective material. When viewed from the opposite surface of the substrate, the indentations become mesas. The mirrors serve as timing and tracking markers during pretesting, recording, and read-out. The area and location of each information bit is determined prior to recording: not as a result of the recording process. The medium is pretested for defects prior to recording by scanning with a laser beam of sufficiently low energy that the reflectivity of the storage areas is not significantly reduced. Storage areas having lower than the predetermined reflectivity are "fenced off" prior to recording.

Abstract: A digital recording medium formed of a thermoplastic substrate having a regular array of microscopic optically-alterable mirrors each supported by a mesa projecting from one surface of the substrate. The parallel rows of the mirrors are the same distance apart as the mirrors in each row. The medium can be formed from a single transparent thermoplastic substrate with an array of indentations in a first surface. The bottom of each indentation is coated with a reflective material. When viewed from the opposite surface of the substrate, the indentations become mesas. The reflective coating is sputtered onto the first surface thereby coating the first surface and the bottoms of the mesas. The reflective coating is then removed by abrasion from the first surface.Recording is by exposure through a second surface of the substrate to a laser beam that reduces the reflectivity of selected mirrors.

Abstract: A method of recording digital information on a thermoplastic substrate having an array of equally-spaced microscopic optically-alterable mirrors each supported by a mesa projecting from one surface of the substrate. The mirrors may be formed of a composite of gold and SiO.sub.2. Recording is by laser beam that reduces the reflectivity of selected mirrors. Each mirror is capable of recording one or more bits of digital information. After exposure, the mirrors retain enough reflectivity to be distinguishable from the intervening valleys. The mirrors serve as timing and tracking markers prior to and during recording, and during read-out. The area and location of each information bit is determined prior to recording: not as a result of the recording process. The mirrors may be scanned along parallel rows or diagonally across the rows.

Abstract: A digital recording medium formed of a thermoplastic substrate having an array of parallel rows of equally-spaced microscopic optically-alterable mirrors each supported by a mesa projecting from one surface. A layer of transparent plastic over the mirrors provides dust protection. The medium can be formed also from a single transparent thermoplastic substrate with an array of indentations in a first surface. The bottom of each indentation is coated with a reflective material. When viewed from the opposite surface of the substrate, the indentations become mesas. The micromirrors are formed of a composite of gold and silicon dioxide. Recording is by exposure to a laser beam that reduces the reflectivity of selected mirrors. After exposure to the recording laser beam, the mirrors retain enough reflectivity to be distinguishable from the intervening valleys. The mirrors serve as timing and tracking markers prior to and during recording, and during read-out.

Abstract: A digital recording medium formed of a thermoplastic substrate having a regular array of microscopic optically-alterable mirrors each by a mesa projecting from one surface. The parallel rows of the mirrors are the same distance apart as the mirrors in each row. A layer of transparent plastic over the mirrors provides dust protection. The medium can be formed from a single transparent thermoplastic substrate with an array of indentations in a first surface. The bottom of each indentation is coated with a reflective material. When viewed from the opposite surface of the substrate, the indentations become mesas.Recording is by exposure to a laser beam that reduces the reflectivity of selected mirrors. After exposure to the recording laser beam, the mirrors retain enough reflectivity to be distinguishable from the intervening valleys. The mirrors serve as timing and tracking markers prior to and during recording, and during read-out.

Abstract: An ink jet printer with a continuous supply of sheet material from a spool contained within an imaging drum. The sheet material is withdrawn from the interior of the drum by a pair of rollers carried by the drum and removably connected to an external drive system. The sheet material travels around the drum and is held by the rollers in that position. The external drive system is then disconnected allowing the drum to rotate while a printing head scans the surface of the sheet material to produce the desired image. After the imaging process, the drum is stopped in a predetermined position and the rollers connected to the external drive. The rollers are then driven to eject the imaged sheet material while a fresh supply is withdrawn from the interior of the drum and wrapped around its outer surface.

Abstract: For requirements where constant velocity is important and positional error must be small and non-cumulative, a bipolar or unipolar, two-phase, permanent magnet stepper motor is driven by sawtooth currents in such manner as to produce a rotating magnetic field that exerts a substantially constant torque on the rotor. When using a bipolar stepper motor with windings electrically offset by 90.degree., two drive currents are generated that increase and decrease in amplitude linearly between predetermined maximum and minimum values. With a unipolar motor, four sawtooth waveforms, of single polarity, are provided. In either case, the currents are displaced by 90.degree. to produce a rotating magnetic field of uniform amplitude.A microprocessor controls the generation of a number of voltage ramps that control current generators for either the bipolar or unipolar stepper motor.

Abstract: A voice evacuation system using pulse width modulation of square waves at a frequency substantially higher than the voice signals. A number of amplifiers are connected in parallel to the distribution circuit. The signal from each amplifier is examined for the presence of the square waves. If no square waves are present, the amplifier is automatically disconnected from the distribution circuit. The remaining amplifiers are of sufficient capacity to carry the required load. The high frequency components are flitered from the signal before it is applied to the distribution circuit, leaving only the audio signals.Because of the nature of the coupling to the distribution circuit, a monitoring voltage and signals to operate auxiliary devices may be applied to the distribution circuit for supervision and operation of the auxiliary devices during actual operating conditions.

Abstract: An ink jet printer with a roll of paper stored within an imaging drum. The paper through a longitudinal opening in the drum to the outside, passes around the drum, where it is held in place during the imaging process, and then ejected from the drum to the desired length and cut off by a cutter that extends the full width of the paper. While the imaged sheet is being ejected from the drum, the next length of paper is drawn from the interior of the drum and around the outside of the drum in position for the next imaging operation. The length of paper that remains projecting from the drum after the imaged paper has been cut off is then withdrawn into the interior of the drum through the longitudinal opening in the drum surface until only a short stub, which will not interfere with the subsequent imaging operation, remains protruding from the drum. Precise movement of the paper is under the control of a counter that is responsive to the paper movement.

Abstract: An ink jet printer in which a roll of paper is stored within an imaging drum and feeds through a longitudinal opening in the drum to the outside, passes around the drum, where it is held in place during the imaging process, and then ejected from the drum and cut off. While the imaged sheet is being ejected from the drum, the next length of paper is drawn from the interior of the drum and around the outside of the drum in position for the next imaging operation. The paper is withdrawn from the drum by a traction roller that engages only the center portion of the paper to prevent the paper from skewing because of unequal forces applied to the edge portions of the paper. The same traction roller is also used in a reverse mode to tension the paper around the drum.

Abstract: An ink jet printer having an imaging drum with a supply of paper within the drum. The paper is transported by rollers mounted on the imaging drum that are controlled by the transverse position of a cutter mechanism that cuts off the imaged paper. The paper passes from the supply spool in the imaging drum through a longitudinal slot in the drum to the outside, around the exterior of the drum, where it is held in place during the imaging process, and then ejected from the drum to the desired length and cut off. While the imaged sheet is being ejected from the drum, the next length of paper is drawn from the drum and around the outside of the drum in position for the next imaging operation. The length of paper that remains projecting from the drum after the imaged paper has been cut off is then withdrawn into the interior of the drum through the longitudinal opening in the drum surface until only a short stub, which will not interfere with the subsequent imaging operation, remains protruding from the drum.