Abstract: The present invention relates to a rotary spreader where material is deposited on a rotary disc and is broadcast upon rotation of the disc as the spreader is moved. The present invention is directed to a jet action deflector which is used with the rotatable disc. The jet action deflector functions to intercept the material which is broadcast by the rotatable disc, which material would normally be directed to one side of the spreader, and redirect that material across the front of the spreader and to the other side of the spreader. The intercepted material is effectively shot at high velocity by the jet action deflector across the front of the spreader to the opposite side of the spreader. As a result, this material is spread over a wide area of the turf and is not concentrated in any particular area. The deflector may be used to prevent spreading of material on a driveway or sidewalk when the rotary spreader is being used adjacent the driveway or sidewalk.

Abstract: The seismic system includes a seismic sensor cable assembly having 50 cable sections and much of the seismic data processing electronics decentralized into the cable structure itself. The cable assembly is coupled to a central station mounted in a recording vehicle. The central station includes recording circuitry and apparatus to receive, process and record digital data words from a data link in the cable assembly and circuitry for transmitting control signals into an interrogation link in the cable assembly. The electrical output of each sensor unit constitutes a separate input channel. The cable sections are spaced apart and interconnected by small-diameter, cylindrical connector modules which contain a transceiver unit for processing the signals from ten sensor units in an associated cable section. Contained within each transceiver unit is a multiplexer having a plurality of filtered input channels coupled respectively to the elemental sensor units, and an output.

Abstract: It is a purpose of this invention to dispose a large number, such as 500, of elemental seismic sensor units over the earth's surface in a desired pattern. The sensors are arranged preferably in a linear pattern, at increasing distances, remotely with respect to a central station. Each elemental seismic sensor unit comprises a short subarray consisting of three seismic detectors, electrically interconnected. Each elemental sensor unit is a separate source of seismic signals. At regular intervals the analog seismic signals from the elemental sensor units are sampled in sequence and are digitized as a 20-bit binary number. The binary numbers are representative of the analog signal levels. The binary numbers are encoded in a self-clocking, return-to-zero pulse code as digital data words. The data words from the respective elemental sensor units are time-delay multiplexed into a wide band transmission channel for transmission to the central station in a constant current mode.

Abstract: A plurality of data acquisition and transceiver units are connected in series to a central signal processor through a common telemeter link. The telemeter link includes a data channel, an interrogation channel and a control channel. The signal propagation velocity through the control channel may, for example, be greater than the signal propagation velocity through the interrogation channel. The central signal processor sends an interrogation signal through the interrogation channel to the data acquisition units. After a selected delay, a control pulse is transmitted. The delay between transmissions of the two signals is proportional to the differential travel time of the signals in the two channels. Accordingly the signal through the control channel will overtake and intercept the signal propagating through the interrogation channel, at a selected data acquisition unit.

Abstract: A plurality of data acquisition units are connected to a central signal processor through a common telemeter link. The telemeter link includes a data channel, an interrogation channel and a control channel. The central signal processor sends an interrogation signal through the interrogation channel to the data acquisition units. As each data acquisition unit recognizes the interrogation signal, it transmits its acquired data back to the central signal processor through the data channel. Any selected data acquisition unit, when it receives a control signal through the control channel at the same time that it receives an interrogation signal through the interrogation channel, can be caused to perform a function different from all other units. The signal propagation velocity through the control channel is different from the signal propagation velocity through the interrogation channel.