Abstract: This invention relates to a door closer and holder having a longitudinally movable rod containing a niche which rests against a stop plate to hold the door in an open position. A rotating cam is positioned adjacent the niche in the rod so that further movement of the rod in a longitudinal matter rotates the cam causing the rod to ride over and bypass the stop plate allowing the door to close.

Abstract: This abstract describes a system for acquisition of analog signals at a plurality of sensors, carrying these signals in groups of M channels to each of N spaced-apart array terminals, processing each signal in the array terminals by separately amplifying, digitizing to 1 bit and storing as single bit pulses, one for each channel, in a parallel to serial convertor. Each of the convertors in each of the array terminals are operatively connected in series and to an array controller, which also controls a disc magnetic recorder. On command, the convertors are read out in series as sequential trains of M bits into core memories and then stored on the disc. Successive, bit samples at subsequent digitizing intervals are stored on the disc, to form a first record. Subsequent records are processed, stored in core memory and composited with previous records stored on the disc.

Abstract: A system for the field recording of seismic data in which a large plurality of geophones are arrayed on the earth and divided into groups, and each group is connected to an array terminal. All of the array terminals are connected in series, by cables, with the last terminal connected to a recording unit. In each of the terminals there are means to process the geophone analog signals by amplifying at constant gain and digitizing to 1 bit to provide a plurality of 1 bit pulses, which are stored in parallel in a parallel to serial convertor.

Abstract: This abstract describes a system for acquisition of analog signals at one or more sensors, carrying these signals in groups of M channels to each of N spaced-apart array terminals, processing each signal in the array terminals by separately amplifying, adding to a shifting signal of selected amplitude, axis-crossing-coding these sum signals and storing as single bit pulses, one for each channel, in a parallel to serial converter. Each of the converters in each of the array terminals are operatively connected in series and to an array controller, which also controls a disc magnetic recorder to run at constant speed. The disc generates a disc clock, and responsive to the disc clock the converters are read out in series as a sequential train of MN bits and stored on the disc. Successive samples at subsequent digitizing intervals are stored on the disc, to form a first record.Subsequent records can be processed, coded and recorded, and composited with previous records on the disc.

Abstract: This abstract describes a system for the field recording of seismic data in which a large plurality of geophones are divided into groups and each group is connected to an array terminal. All of the array terminals are connected in series, by cables, with the last terminal connected to a recording unit. In each of the terminals there are means to process the geophone analog signals by amplifying and adding them to a selected shifting function, and axis-crossing-coding (AXC) the resulting sum signals to provide a plurality of pulses which are stored in a prallel-to-serial converter. In addition, each of the terminals contains a buffer register.