Patents Assigned to Zeto Industries, Inc.
  • Patent number: 4301731
    Abstract: An air shooting system for use in lieu of explosives in the mining of coal employing a set of tubular shooting heads fitted in respective shot holes in a coal seam. Each shooting head is fed with air under high pressure and has a valve mechanism for triggering discharge of the air when it reaches a predetermined pressure. The source of air pressure is connected to a manifold and automatic shut-off valves are interposed between the manifold and the lines feeding the individual shooting heads. Each shut-off valve has a movable valve element biased into a normally open position to permit flow of air from inlet to outlet but which is snapped into closed position and held there by the inlet pressure when there is a sudden drop in pressure at the outlet accompanying discharge at the associated shooting head. The shooting heads are set to trigger in series at incrementally spaced pressures until all of the shut-off valves are in closed condition.
    Type: Grant
    Filed: September 12, 1979
    Date of Patent: November 24, 1981
    Assignee: Zeto Industries, Inc.
    Inventor: John E. Fitzgerald