Abstract: A dynamic displacement sensor for detecting an out-of-fluid condition in a liquid delivery system detects an increased amplitude of pump motion of a reciprocating air pump and provides an output signal upon detecting the increased amplitude motion. The detector includes a spring-mass combination supported within a housing such that the mass is movable along a defined axis of the housing, with the spring applying a restoring force to the mass when the mass moves away from its static position. The detector is attached to the pump with its defined axis aligned parallel with the pump axis. A sensor within the housing is triggered to change state when the mass is displaced by pump motion of a predetermined amplitude and frequency, thereby providing an output signal indicating an out-of-fluid condition.

Abstract: A dynamic displacement sensor for detecting an out-of-fluid condition in a liquid delivery system detects an increased amplitude of pump motion of a reciprocating air pump and provides an output signal upon detecting the increased amplitude motion. The detector includes a spring-mass combination supported within a housing such that the mass is movable along a defined axis of the housing, with the spring applying a restoring force to the mass when the mass moves away from its static position. The detector is attached to the pump with its defined axis aligned parallel with the pump axis. A sensor within the housing is triggered to change state when the mass is displaced by pump motion of a predetermined amplitude and frequency, thereby providing is an output signal indicating an out-of-fluid condition.

Abstract: A well apparatus adapted to be disposed in a wellbore includes a perforating apparatus and a packer adapted to set and isolate an annulus above the packer from a rathole annulus below the packer, the perforating apparatus including a new and novel rathole differential pressure balanced firing system where the firing system includes a ball release sleeve holding a firing piston, means for initially opening a top end and a bottom end of the ball release sleeve to the rathole annulus below the packer; and a plurality of sequentially operable hydraulic systems, the top end of the ball release sleeve being initially open to the rathole annulus below the packer but being subsequently closed to the rathole annulus below the packer and then reopened to the annulus above the packer when the packer is set.

Abstract: A perforating gun having no firing head and no primary explosives is attached to a tubing string and the tubing string is run into a borehole. A new pump apparatus, having a firing head, is run into the tubing string until the pump firing head is adjacent the perforating gun. The firing head in the pump apparatus detonates, firing the perforating gun. If the firing head fails to detonate, one need only remove the pump apparatus from the tubing string in order to gain access to the firing head, for repair and replacement thereof. One need not remove the tubing string to gain access to the firing head.

Abstract: A perforating gun having no firing head and no primary explosives is attached to a tubing string and the tubing string is run into a borehole. A new pump apparatus, having a firing head, is run into the tubing string until the pump firing head is adjacent the perforating gun. The firing head in the pump apparatus detonates, firing the perforating gun. If the firing head fails to detonate, one need only remove the pump apparatus from the tubing string in order to gain access to the firing head, for repair and replacement thereof. One need not remove the tubing string to gain access to the firing head.

Abstract: A perforating gun having no firing head and no primary explosives is attached to a tubing string and the tubing string is run into a borehole. A new well apparatus, having a firing head, is run into the tubing string until the firing head is adjacent the perforating gun. The firing head in the well apparatus detonates, firing the perforating gun. If the firing head fails to detonate, one need only remove the well apparatus from the tubing string in order to gain access to the firing head, for repair and replacement thereof. One need not remove the tubing string to gain access to the firing head.

Abstract: A demountable hitch for quickly facilitating the engagement, lift and tow of one end of a vehicle which includes a transverse tow bar pivotally connected to a truck and a mounting rib upstanding thereon. The rib is demountably connected to a central portion of the tow bar and adapted for simple interlocking engagement of the towed vehicle rearwardly of the bumper thereon. The rib is encapsulated in a resilient material for increasing the frictional engagement with the bumper or vehicle frame to facilitate immediate towing while reducing the noise associated with the initial hook-up. In this manner a parked vehicle can be hitched and towed in a minimal amount of time and with a minimum of noise, which is particularly advantageous in times of emergency.