초록 ▼

A two-stage, bi-directional valve is provided for controlling gas flow into and out of a storage volume. The solenoid is provided to actuate a first stage piston to seal communication with a pressure source. In doing so, the sources imparted by the solenoid overcome biasing forces applied by a resil

A two-stage, bi-directional valve is provided for controlling gas flow into and out of a storage volume. The solenoid is provided to actuate a first stage piston to seal communication with a pressure source. In doing so, the sources imparted by the solenoid overcome biasing forces applied by a resilient spring on the first stage piston. Simultaneously, actuation of the first stage piston opens the bleed passage to permit the depressurization of space behind the second stage valve. Upon sufficient depressurization, the second stage valve is unseated from the main orifice by fluid pressure forces, thereby creating the flow path for escape of the gaseous fluid through the main orifice.

대표청구항 ▼

A two-stage, bi-directional valve is provided for controlling gas flow into and out of a storage volume. The solenoid is provided to actuate a first stage piston to seal communication with a pressure source. In doing so, the sources imparted by the solenoid overcome biasing forces applied by a resil

A two-stage, bi-directional valve is provided for controlling gas flow into and out of a storage volume. The solenoid is provided to actuate a first stage piston to seal communication with a pressure source. In doing so, the sources imparted by the solenoid overcome biasing forces applied by a resilient spring on the first stage piston. Simultaneously, actuation of the first stage piston opens the bleed passage to permit the depressurization of space behind the second stage valve. Upon sufficient depressurization, the second stage valve is unseated from the main orifice by fluid pressure forces, thereby creating the flow path for escape of the gaseous fluid through the main orifice. limbing and self-lowering concrete wall form hoist of claim 1, wherein said vertical mast comprises a plurality of regular spaced cleats. 3. The self-climbing and self-lowering concrete wall form hoist of claim 2, wherein the dog is pivotable between the platform-raising-position and the platform-lowering-position by manually repositioning a handle. 4. The self-climbing and self-lowering concrete wall form hoist of claim 2, wherein the regular spaced cleats are further defined as having engagement surfaces comprised of corners, or right angles. 5. The self-climbing and self-lowering concrete wall form hoist of claim 2, wherein the lower end portion of the dog is brought into contact engagement with one of the regularly spaced cleats of the mast when the dog is pivoted to the platform-raising-position, and wherein the upper end portion of the dog is brought into contact engagement with the regularly spaced cleats of the mast when the dog is pivoted to the, mast-raising-position. 6. The self-climbing and self-lowering concrete wall form hoist of claim 1, wherein the means for releaseably securing the mast or platform to the wall mounting comprises at least one pivotable support finger which releasably engages the wall mounting. 7. The self-climbing and self-lowering concrete wall form hoist of claim 1, wherein the engagement device comprising a notch.