Abstract: Groundbreaking equipment utilizes a gang of discs and a road grader to provide a consistent depth of tilling without skipping areas of ground. In one embodiment, the road grader weighs ten to twenty tons, has articulating tandem rear wheels, front steering wheels, and hydraulic vertical and horizontal angle blade adjusters, whereby the disc tillers may be oriented in a manner for tilling at a desired depth and orientation, and the road grader features can be adjusted to counteract forces produced by the gang of discs. Mud scrapers are preferably provided for individual discs on an opposite side of the gang of discs with respect to the grader blade. In one embodiment, a hitch mechanism with stop surfaces is provided behind the grader blade for mounting and/or removal of the gang of discs to the grader blade within minutes without need of special tools.

Abstract: A digital motor control system utilizes time duration electric pulses generated by digital logic to control the motor speed and direction of rotation of a D.C. or A.C. motor. The digital logic produces width modulated pulses that can be connected to large or small electric motors by mechanical or electrical relays or switches to provide efficient motor control with little control circuit power loss. The mechanical or electrical switches are responsive to the digital logic to change motor direction or remove power from the motor windings. A variable control element such as a computer joystick can be utilized to control both direction and speed of the motor. The system can be configured as an open loop system or as a closed loop servo with a feed back element to control the rotational position of the motor.

Abstract: Aggregate mixtures such as dirt, sand, rock, concrete, etc. are separated into piles according to size by continuous agitation of the mixture and by gravitational and centrifugal forces exerted thereon. A container for the material, such as the bucket of a backhoe, has the bottom thereof at least partially open. An adjustable, hydraulically-driven rotating disk attaches to and covers the open portion of the bottom of the container, the combination having a gap, or a selected spaced-apart relationship, between the stationary container and the rotating disk. The mixture is agitated by the rotating disk and by contact with the other particles in the container. Particles smaller than the selected gap distance are thrown out through the gap between the disk and the open portion of the container by centrifugal force. Material larger than the selected gap size remains in the container.

Abstract: Aggregate mixtures such as dirt, sand, rock, concrete, etc. are separated into piles according to size by continuous agitation of the mixture and by gravitational and centrifugal forces exerted thereon. A container for the material, such as the bucket of a backhoe, has the bottom thereof at least partially open. An adjustable, hydraulically-driven rotating disk attaches to and covers the open portion of the bottom of the container, the combination having a gap, or a selected spaced-apart relationship, between the stationary container and the rotating disk. The mixture is agitated by the rotating disk and by contact with the other particles in the container. Particles smaller than the selected gap distance are thrown out through the gap between the disk and the open portion of the container by centrifugal force. Material larger than the selected gap size remains in the container.

Abstract: A reinforced concrete slab 10 comprising concrete 11 reinforced by parallel, spaced planar truss members 12 fabricated of rebar rod materials, each comprising a sinusoidal wave-like strut 23 with an upper chord member 21 welded thereto at the maxima apexes 24 thereof and a lower chord member 22 welded thereto at the minima apexes 25 thereof, a plurality of spaced rebar braces 14 extending the width of the slab and welded to the truss members 12 in perpendicular relation thereto, a plurality of plastic pipes 16 extending through the concrete 11, each with its ends opening at the edges of the slab 10 for reducing its weight and/or accommodating utilitarian articles, such as electrical wiring and the like therethrough, and a plurality of steel adapters 30A, 30B fixed at the edges of the slab by welding to the rebar components thereof and serving to facilitate lifting of the slab when necessary and for connecting the slab to other slabs or structures.

Abstract: A microwave radar signal is generated (16) and split by a circular (20). A phase shifter (24) introduces a plurality of phase shifts into a first part of the split signal which is then transmitted (36) by antenna (34). A like plurality of phase shifts are introduced by the phase shifter into the return signal (40) from the target. The circulator delivers the phase shifted return signal and the leakage signal from the circulator to a mixer (44) which generates an i.f. signal output at the doppler frequency. The i.f. signal is amplified (46l ), filtered (54), counted (58) per unit of time and the result displayed (62) to provide indications of target sense and range rate. An oscillator (50) controls rate of phase shift in the transmitted and received signals and provides a time base for the counter. The phase shift magnitude increases may be continuous and linear or discrete functions of time.

Abstract: A system for deriving direct digital indications of frequency and phase difference between two incoming pulse trains adaptable for collision avoidance systems or the like.A pair of radar beams 152 and 152A are directed toward a target 153 and corresponding beams 154 and 154A returning therefrom are detected. A digital difference circuit 110 forms a pulse train 66 from the Doppler shift frequencies of each beam pair having a repetition rate functionally related to the difference in magnitude of the shift frequencies. Pulses from the pulse train are counted as a function of time. Visual indications thereof on display 144 are correlative to target position relative to beams 152 and 152A.

Abstract: A signal is transmitted from a first location to a remote second location where a target carrying a transponder is positioned. The transponder re-radiates the signal to the first location where it is received. A phase comparator generates from the transmitted and received signals a measurement of their phase difference which is functionally related to the distance between the first and second locations. In one embodiment, the transponder is a passive parametric oscillator, being powered by energy received from the transmitted signal, which generates and transmits a subharmonic of the transmitted signal.

Abstract: A receiver for tracking and demodulating several types of phase modulated communications, either analog or digital data, for either residual carrier or suppressed carrier signal and for phase modulation or keying of two, four or higher phase angles, from 0.degree. through 360.degree.. A carrier component signal and a converted series sideband component signal are obtained from the incoming signal and summed to produce a carrier tracking signal, permitting more accurate tracking of the above types of phase modulated data.

Abstract: A microwave radar signal is generated (12) for transmission through an antenna (20). Before transmission, the signal is phase modulated (18) by 0.degree. or 90.degree. amounts during each alternate half-cycles of an intermediate frequency (IF) clock signal (26). After transmission and return, the signal is again phase modulated (18) the same amounts during each alternate half-cycles. The return phase modulated signal is mixed (24) with a leakage signal component of the microwave signal, leaving an IF doppler. The IF doppler signal may then be amplified (30), removing any requirement that direct current level signals be amplified and also removing the effect of detector noise from the doppler signal.

Abstract: Bit error rate is measured by sending a pseudo-random noise (PRN) code test signal simulating digital data through digital equipment to be tested. An incoming signal representing the response of the equipment being tested, together with any added noise, is received and tracked by being compared with a locally generated PRN code. Once the locally generated PRN code matches the incoming signal a tracking lock is obtained. The incoming signal is then integrated and compared bit-by-bit against the locally generated PRN code and differences between bits being compared are counted as bit errors.

Abstract: A new and improved apparatus and method for demodulation of quaternary phase shift keyed (QPSK) data, particularly unbalanced QPSK, with phase adjustment of the output of a phase-locked loop local oscillator to reduce sensitivity to amplitude variations internal to the demodulator.