1. An electromechanical valve assembly for regulating and shutting off the flow of a oxygen from a compressed oxygen source in an aircraft, said valve assembly comprising:
a valve housing comprising an inlet, an outlet, and a connecting passageway for enabling the flow of oxygen from said inlet to said outlet, said inlet comprising a fitting for sealable connection with said compressed oxygen source;
a spring-biased conical poppet disposed in and movable within said passageway;
a spring-biased pressure regulating piston engagable with said conical poppet to maintain said poppet in an open position;
a push rod engagable with said conical poppet to maintain said poppet in a closed position; and
a movable seat disposed in said passageway, and engagable with said conical poppet to regulate gas flow through said passageway, said movable seat being actuated by an electric motor assembly that is effective to move said seat either towards said conical poppet, or away from said poppet and towards said pressure regulating piston;
wherein actuation of said electric motor assembly to cause said movable seat to move towards said conical poppet, enabling said poppet to engage said push rod, resulting in closing of said valve assembly and shutting off of said oxygen flow from said compressed oxygen source; and
wherein actuation of said electric motor assembly to cause said movable seat to move towards said regulating piston, enabling said poppet to contact said pressure regulating piston, resulting in opening of said valve assembly and regulation of said oxygen flow from said compressed oxygen source by said pressure regulating piston.
2. The electromechanical valve assembly of claim 1 wherein said electric motor assembly is actuated from a position remote from said compressed oxygen source.
3. The electromechanical valve assembly of claim 2 wherein said compressed oxygen source is located in the tail section of said aircraft, and said electric motor assembly is actuated from the cockpit of said aircraft.
4. The electromechanical valve assembly of claim 3 wherein said electric motor assembly is actuated by a toggle switch whose operation causes said movable seat to move either towards said conical poppet or away from said poppet and towards said pressure regulating piston, resulting in, respectively, closing or opening of said valve assembly.
5. The electromechanical valve assembly of claim 4 further comprising means for indicating whether said conical poppet is in an open or closed position.
6. The electromechanical valve assembly of claim 5 wherein said indicating means comprises a position indicating switch that actuates an indicator light.
7. The electromechanical valve assembly of claim 1 wherein said electric motor assembly comprises a motor whose rotational movement engages a worm gear set coupled to a power screw, wherein said worm gear set comprises a worm gear and a worm, and wherein said power screw engages said movable seat, thereby effecting its movement.
8. The electromechanical valve assembly of claim 1 wherein said regulating piston further comprises a low pressure relief seat that is engagable with said conical poppet;
whereby, when said poppet is in an open position, said low pressure relief seat is disposed in a closed position; and, when said poppet is in a closed position, said low pressure relief seat is in an open position, allowing low pressure oxygen trapped between said closed poppet and said regulating piston to escape to the surrounding environment or be routed to the exterior of said aircraft.
9. The electromechanical valve assembly of claim 1 further comprising a gauge for measuring the oxygen pressure in said compressed oxygen source.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A guidewire comprising:
a core shaft;
a coil body that covers the core shaft; and
a tip portion where a distal end of the coil body and a distal end of the core shaft are coupled by a metal solder, wherein
the tip portion includes: i) an outside diameter decreasing portion where an outside diameter of the tip portion decreases in a direction toward a distal end of the tip portion, and ii) a hemisphere-shaped portion provided at a distal end of the outside diameter decreasing portion, and
an outside diameter of a proximal end of the hemisphere-shaped portion is substantially the same as an outside diameter of the distal end of the outside diameter decreasing portion.
2. The guidewire according to claim 1, wherein
the outside diameter decreasing portion and the hemisphere-shaped portion are connected to each other at a boundary portion, so as to form a curve.
3. The guidewire according to claim 1, wherein
the coil body has a tapered portion where an outside diameter of the coil body decreases in a direction toward the distal end of the coil body, and
a degree of tapering of the outside diameter of the outside diameter decreasing portion is greater than a degree of tapering of the outside diameter of the tapered portion.
4. The guidewire according to claim 1, wherein
the tip portion is coated with a lubricant coating.
5. The guidewire according to claim 4, wherein
the lubricant coating is applied to a portion other than the hemisphere-shaped portion of the tip portion.
6. The guidewire according to claim 4, wherein
in a wet state, a friction resistance of the hemisphere-shaped portion with respect to biological tissue is higher than a friction resistance of the outside diameter decreasing portion with respect to the biological tissue.
7. The guidewire according to claim 1, further comprising
a multi-thread coil body disposed at an inner side of the coil body, the multi-thread coil body covering the core shaft, wherein
a proximal end of the multi-thread coil body is coupled to the core shaft, and
a distal end of the multi-thread coil body is disposed closer to a distal end side than the distal end of the coil body, and is joined to the core shaft in the outside diameter decreasing portion through the tip portion.
8. The guidewire according to claim 2, wherein
a diameter of the hemisphere-shaped portion is greater than a diameter of the boundary portion.
9. The guidewire according to claim 1, wherein
the metal solder has a melting point that is lower than a melting point of the coil body and a melting point of the core shaft.
10. The guidewire according to claim 1, wherein
the core shaft is disposed within at least part of the outside diameter decreasing portion.
11. The guidewire according to claim 1, wherein
the core shaft is disposed within at least part of the hemisphere-shaped portion.