A control system can be used with a single control line to a subsurface safety valve. The operating piston is exposed to the flow tube between two blocks with near identical seals to make the piston insensitive to tubing pressure. A control system seal is carried by the piston in the upper block and a passage between the control system seal and the tubing pressure seal in the upper block communicates to a compressible fluid reservoir in the lower block that is also isolated from tubing pressure ...

An evaluation method for an output signal of a sensing device for scanning a cyclic movement, consisting of a rotatable pole wheel provided with equidistant teeth and an inductive sensor, permits recognition and display of damage to the pole wheel, in particular defective or missing teeth. Contrary to known evaluation processes, where error monitoring of the output signal is carried out for a relatively short time period comprising few signal cycles of the output signal, an observation of the ou...

A tachometer circuit for an outboard motor wherein battery voltage is switched from a signal generated in the capacitor discharge ignition system for providing a pulsating signal to drive the tachometer of a low voltage so as to reduce the sensitivity to noise.

A method of treating depression by administering several active compounds throughout the day to a patient in need of such treatment. Also included are pharmaceutical composition claims incorporating these compounds.

A single line surface controlled, subsurface safety valve, adapted for connection in a well tubing string. The safety valve has a closure means disposed in the bore of the safety valve housing and is operable by action of control pressure fluid causing a longitudinal operator to move the closure means to an open to flow position. The control pressure fluid chamber in the safety valve is protected from well pressure by providing annular areas, between the longitudinal operator and the housing, po...

A surface controlled subsurface safety valve having a main valve and an equalizing valve. The equalizing valve is opened prior to the opening of the main valve. An extra control pressure force is provided to open the equalizing valve against the resistive force present due to high shut-in formation pressures. On the other hand, the safety valve can close when low subsurface pressure conditions exist at the valve. This abstract is neither intended to define the scope of the invention, which, of c...

A device for the production of a tachometry signal of infinite resolution and without ripple from an inductive position sensor. The sensor is fed by a sinusoidal reference signal and supplies two phase signals. A resistance-capacitance circuit tuned to the frequency of the reference signal is fed by the two phase signals of the sensor and supplies a sinusoidal signal whose phase angle is proportional to the rotation of the sensor. This signal is then digitized and processed by digital phase comp...

In combination with a subsurface safety valve for controlling fluid flow through a well tubing of an equalizing system for reducing the pressure differential across the first valve. A housing includes an equalizing line in communication with the bore between points above and below the first valve. An equalizing valve is positioned in the line, operated from hydraulic pressure and opens prior to the opening of the first valve. A labyrinth passageway is provided in the equalizing line upstream of ...

Inducing sleep using acetaminophen, phenylephrine, phenylpropanolamine phenyltoloxamine dihydrogen citrate and ammonium chloride.

Pharmaceutical compositions designed for the relief of premenstrual syndrome are disclosed which comprise acetaminophen, caffeine, a diuretic ammonium salt and an antihistamine.