Abstract: An air gun for releasing compressed air into the environment. Two opposing shuttle valves selectively open ports to release compressed air more quickly from the air gun. A centering mechanism returns the first and second shuttle valves to the initial position. The centering mechanism can comprise a pressure compensation system or mechanical stop for positioning the first and second shuttles at the selected position.

Abstract: A method and apparatus in marine seismic surveying for towing an optical-electrical towing cable (leadin) and seismic array (streamer cable) at a perpendicular distance from the centerline of the towing vessel using a short, flexible adapter cable section which optically and electrically connects the leadin to the streamer cable and which attaches to pivoting arms of a removable towing bracket which carries the bending loads.

Abstract: A seismic energy source for producing pressure pulses is disclosed. The source contains a substantially symmetrical main chamber for storing compressed fluid. Two shuttles adapted to abut against each other are slideably placed around the housing to sealingly enclose the chamber. A separate control chamber for each shuttle is formed to urge its associated shuttle against the other shuttle when pressurized fluid is supplied to the control chamber. A separate firing chamber is formed for each shuttle between the shuttle and the housing. The firing chambers are activated by the fluid from the main chamber to simultaneously move both the shuttles away from each other to allow the compressed fluid to discharge from the main chamber into the surrounding medium.

Abstract: A control valve for use in geophysical surveying is disclosed. The valve contains a housing having a through bore intersecting with a fluid path. The fluid passes from an input port to an output port. A seat having recess thereof is placed in the fluid path in the through bore. A poppet assembly is attached to the through bore at the end opposite to the seat. The poppet assembly contains a poppet one end of which is adapted to match the recess and moveable in opposite directions by a motor. A decoder is coupled to the motor for causing the motor to turn in the desired direction. When the motor is turned in one direction, the poppet moves toward the seat and completely closes off the fluid path between the input and output ports. To open the valve, the motor is moved in the opposite directions to move the poppet away from the seat until the fluid path is open.

Abstract: A new and distinct spur-type Red Delicious apple variety is provided which originated as a limb mutation of the apple tree of U.S. Plant Pat. No. 2,816. The fruit of the new variety is conic shaped and highly attractive since at maturity it is fully covered with conspicuous dark red stripes over a bright red ground color. Unlike fruit formed on the parent, the fruit of the new variety colors approximately 15 days earlier, and colors more fully in years when environmental conditions do not favour the coloring of Red Delicious apples.

Abstract: An acoustic source is provided where a high pressure fluid is used to positively control the period an exhaust valve is open. High pressure fluid is introduced to the control chamber at a predetermined instant after the exhaust valve or shuttle has been opened. This results in conservation of air used to fire the acoustic source and also to achieve a desired signature.