Abstract: Engine timing fluctuations and intermittent loss of synchronization between the distributor and the timing gear are eliminated by this distributor drive system in which the distributor is mounted on a timing gear cover at the front of the engine. The distributor is driven from the timing gear via a drive disc and an adaptor shaft that are relatively axially moveable so as to isolate the distributor from axial cam shaft movement.

Abstract: A power supply for an ac metal halide lamp employs a dc regulator in conjunction with a commutator for supplying the regulated dc power to the lamp with alternating polarity. A feedback circuit senses the dc voltage and current fed to the commutator and cooperates with the regulator to provide substantially constant power to the lamp. The commutator switching times are sufficiently rapid so that flickerless light output is obtained.

Abstract: This hydraulic engine utilizes two sets of hydraulic cylinders connected to a shaft so as to be alternately pressurized as the shaft is reciprocally driven by a pair of conventional internal combustion chambers. The outlets of all hydraulic cylinders are connected to a common output line via valves. During each power stroke certain of the hydraulic cylinders being pressurized are selectively disconnected (depressurized) from the output line. This effectively decreases the load on the driving chamber, and insures a relatively constant, high pressure hydraulic fluid output level despite changes in supplied force during each power stroke. The selective cylinder disconnection may be implemented programmatically in response to changes in engine parameters such as combustion chamber pressure. The engine also includes a pump for supplying input hydraulic fluid to each set of cylinders while that set is not being pressurized. The input fluid force is additive to the power supplied by the operative combustion chamber.

Abstract: A transcription adaptor for a miniature tape recorder provides foot-operated selection of playback or rewind, and permits adjustment of the playback volume at the earphones. The adaptor includes a housing which holds the recorder, and a foot pedal assembly having a foot pedal and means for operatively, releaseably connecting the pedal to the forward/reverse switch of the recorder. The recorder has an automatic level control circuit for playback which cooperates with a volume control attached to the earphones.

Abstract: A terpolymer material for the formation of soft contact lenses includes a major amount of hydroxy alkyl acrylate or methacrylate, between 0.01 and 0.25% of a diester cross-linking agent containing acrylic or methacrylic groups and having no free hydrophilic groups, and between about 0.5 and 10% of a free acid (typically acrylic or methacrylic acid) having an unsaturated double bond. The material is polymerized in the non-aqueous state to form a rigid terpolymer having physical characteristics established by the diester concentration. The non-hydrated terpolymer can be formed into a contact lens using conventional lens grinding techniques. Upon subsequent hydration, the water concentration of the terpolymer is determined by the free acid concentration in the starting composition.

Abstract: In this key switch scanning and encoding system, open (OFF) switches may be scanned at a faster rate than closed (ON) switches, and a coded signal is produced indicative of each closed switch. The switches are arranged in a matrix of M groups each connected to N common output lines. The switch groups are enabled sequentially, one at a time. As each group of switches is enabled, the N output lines sequentially are gated to a coding matrix. If the gated line is associated with a closed switch in the enabled group, an output code is produced by the code matrix, which, together with a signal designating the enabled group, uniquely identifies the closed switch. Scanning is delayed briefly to permit utilization of the encoded output. If an open (OFF) switch is scanned, no code is produced by the code matrix. This no-code condition immediately causes the next switch matrix output line to be gated to the code matrix. In this way, open switches are "skipped over" or scanned at a rapid rate.

Abstract: In a computor organ, musical tones are generated by separately evaluating the constituent Fourier components of a musical waveshape and summing these to obtain the waveshape sample point amplitudes. The relative amplitude contribution of each Fourier component is established by a harmonic coefficient. In accordance with the present invention, pulse-type tone generation is simulated by using harmonic coefficient values associated with the frequency spectrum of a pulse train of particular pulse shape. For example, the coefficients may be given by the Fourier transform associated with repetitive pulses.To simulate pulse width modulation effects, a set of such coefficients is stored in a memory, the set having more coefficients than the maximum number of Fourier components included in each amplitude computation. Pulse trains of different pulse width are simulated by utilizing different subsets of the stored coefficients in the amplitude computation.

Abstract: A regulated power supply for a laser or gas discharge lamp employs a variable duty cycle oscillator to control the output voltage level. Output current to the laser or lamp load is maintained at a constant value by a feedback loop that controls the oscillator duty cycle. The output current is sensed by a novel circuit which employs a voltage regulator in series with the current return path. A change in output current causes a concomitant change in voltage across a resistor divider that shunts the voltage regulator. The voltage from this divider is a feedback signal that is supplied to a duty cycle modulator which controls the oscillator duty cycle.Another feedback signal is derived in delayed response to voltage output in excess of a certain high value. This feedback signal, which occurs, e.g.

Abstract: Formant filtering is implemented in a computor organ of the type disclosed in U.S. Pat. No. 3,809,786 by eliminating, attenuating or accentuating certain Fourier components included in each waveshape amplitude computation. A set of formant filter factors define the formant filter passband as a function of frequency, logarithmic frequency or Fourier component order. As each constituent Fourier component is independently evaluated, the component amplitude is scaled by the appropriate formant filter factor. The resultant synthesized musical tone includes only Fourier components within the defined passband, so that formant filtering effectively is implemented without the use of an actual filter.

Abstract: Timing signals of adjustable rate are estabilished digitally in an electronic musical instrument through the use of digital timing numbers. A selected one of such numbers is repetitively added to the contents of an accumulating adder at a fixed rate. A train of timing pulses is obtained from one bit output of the adder; the rate of these pulses is directly related to the value of the selected timing number. Alternatively, consecutively updated parallel bit timing codes can be obtained from plural bit outputs of the accumulating adder. These timing codes, which are incremented or decremented in value by amounts established by the selected timing number, are useful for directly addressing a memory containing a set of musical instrument factors that are to be utilized on a time dependent basis.

Abstract: Delayed vibrato is implemented in an electronic musical instrument of the type wherein the fundamental frequency of the generated tone is proportional to a frequency number R supplied to the instrument. At the beginning of note production, the frequency number R itself is supplied to the instrument for a preselected delay time, so that no vibrato is introduced during this initial delay time. Subsequently a periodically varying fractional frequency number R.sub.v is added to the frequency number R and the sum supplied to the instrument. This causes the generated tone to exhibit vibrato at a rate corresponding to the periodicity of the value R.sub.v. The depth of vibrato is established by the maximum value of R.sub.v and may be varied by scaling R.sub.v. Advantageously such scaling is done when the vibrato begins, so that the vibrato depth will increase gradually to the maximum value.

Abstract: Trim marks of equilateral triangular shape are used to define a trim line for sheets containing machine-readable indicia. Each trim mark consists of an equilateral triangle with one corner situated along the trim line, an adjacent side extending perpendicular to that trim line, and an opposite side parallel to but spaced from the trim line. The length of the adjacent side corresponds to the acceptable severance tolerance for the trim line, so that if the sheet is cut away from the desired trim line, the visable width of the truncated triangular trim mark will equal the amount of offset. Advantageously, differently spaced pairs of such trim marks are employed on opposite sides of the desired trim line so that the separation distance between the truncated triangles provides a visual indication of the direction and possible skew of severance offset.