Showing papers on "Chamber pressure published in 1976"

Jet-driven helmholtz fluid oscillator

Abstract: A jet-driven Helmholtz fluid oscillator having two openings located coaxially in opposite walls of a chamber. A fluid jet enters through one opening, the inlet, at a constant flow rate and exits through the other opening, the outlet, at a pulsating or oscillating flow rate. The pressure level within the chamber also fluctuates. All critical dimensions of the oscillator are subject to geometrical similarity and scale with the diameter of the inlet. The inlet flow rate is proportional to the Helmholtz frequency of the chamber and the jet length within the chamber. The outlet fluid flow and the chamber pressure oscillate at substantially the same frequency as the Helmholtz frequency.

Fluid dispensing pump assembly

Abstract: An atomizing pump assembly for use with a variety of types of containers is disclosed in which a housing is formed with both an outlet port and an internal fluid chamber that communicates via a passageway with the outlet port. Tubular means provides communication between the fluid chamber in the housing and a reservoir of the material that is to be dispensed by the pump. A flexible frustroconical skirt or diaphragm having a valved opening therethrough is operatively located intermediate the tubular means and both the fluid chamber and the outlet port, with an integral upper portion of the diaphragm initially obstructing the outlet port. When an actuating cap is depressed, material within the fluid chamber is compressed until a minimum predetermined chamber pressure is achieved, whereby under pressure the skirt or diaphragm is flexed from its normal position to a discharge position. The flexing action results in movement of the diaphragm upper portion from its initial obstructing position to a non-obstructing position, whereby fluid contents may be discharged under pressure through the outlet port. Venting means are also provided.

Fluid-tight cold-chamber pressure casting apparatus

Abstract: Apparatus comprising a crucible, a level-determining tank, a vacuum pump, an injection cylinder, a mould and appropriate interconnecting pipes. Molten metal is kept under vacuum throughout except that in a modification a gas may be deliberately introduced into the mould to provide a surface treatment of the casting.

Pressure balancing valve

Abstract: A valve assembly for use in building water systems where a hot and cold water supply line pressures vary, and having separate valve means for regulating the hot and cold water pressures. Independently mounted pressure equalizing means operated by the supply water pressures are connected to operate each of the valve means responsive to any pressure differential caused by changes in the supply pressures, to change the water pressure regulated by each of the valve means, with the magnitude and sense of the change reducing any such differential to zero and equalizing the pressures. The separate valve means and pressure equalizing means are contained in a cartridge having separate supply water chambers and hydraulic fluid chambers associated with each water chamber. A pair of movable walls are mounted in the cartridge each one separating one water chamber from the associated hydraulic fluid chamber, and the cartridge has restricted orifice means interconnecting the hydraulic fluid chambers to equalize the pressures therein while dampening movable wall oscillations due to changes in water chamber pressure. Each movable wall operates one of the valve means, so that the water pressure in one water chamber acts against one side of the movable wall and hydraulic fluid pressurized by the water pressure in the other water chamber acts against the other side of each movable wall.

Method of controlling apparatus and servoactuator therefor

Abstract: A novel electropneumatic servoactuator utilizing a fluid pressure control signal chamber and a duty-cycle control valve alternating between a fluid supply pressure port means and port means venting the chamber to the atmosphere and controlling fluid pressure in the chamber. The control valve is driven by electromagnetic means comprising a coil responsive to an electrical input signal. Pressure responsive actuator means moves in response to the chamber pressure level for providing a mechanical position output. Feedback means senses movement of the actuator means and throttles the fluid flow in one of said port means. In another aspect of the invention, an auxiliary dump release valve armature means is also driven by the coil in preferably magnetic series circuit arrangement with the control valve and coil for rapidly porting the control chamber to the atmosphere for emergency release.

Radiation source shielding and collimating device

Abstract: Especially for use in agricultural machines such as lettuce harvesters having a maturity tester thereon, there is provided a radiation source such as Americium 241 sealed in a capsule at atmospheric pressure. The capsule is disposed in a plunger movable in an evacuated chamber between a first position in alignment with a passage having a window permeable by radiation to the outside and a second position in which the capsule is out of alignment with the passage. A pressure responsive switch monitors the pressure in the chamber and affords an alarm if the chamber pressure rises.

Performance prediction of BPN pyrogen-type igniters for rocket motors

Abstract: Performance prediction of BPN-charge pyrogen-type igniters by two theoretical methods is presented and compared with experimental results. Using the form function technique, the igniter chamber pressure history is calculated by: 1) an approximate isothermal analytical solution of the theoretical model, and 2) a numerical solution of the more general case. Five different grain configurations and two BPN pyrotechnic compositions have been studied. The grains consist of one, two, or four large pellets bonded in a row. Good agreement between experimental pressure-time records and corresponding solutions of the theoretical model has been obtained. A parametric study, conducted to reveal the effects of some parameters on igniter performance and prediction validity, is presented. The results may be used for design purposes.