1. An air vehicle comprising:
a bag skirt extendable along a portion of a hull of the air vehicle, the bag skirt being inflatable to provide an air cushion during touchdown and deflatable during flight of the air vehicle;
a cover roller adjacent the bag skirt; and
a cover portion coupled to the cover roller, the cover roller being configured to roll between an exposed position and an unexposed position to expose or hide the bag skirt with the cover portion without generating a separation gap,
wherein the cover roller includes an extensible shaft and a pad securely wrapped around the extensible shaft, the extensible shaft capable of being rotated along a shaft axis, one end of the extensible shaft being pivotally coupled to the hull by an anchor, a circumference of the cover roller being based on a function of a distance between the exposed and the unexposed positions, and
wherein the cover portion has a first end secured to the hull and a second end rollable around the cover roller.
2. The air vehicle of claim 1, wherein an increase in the distance between the exposed and unexposed positions results in a greater portion of the cover portion being rolled around the cover roller compared to the distance between the exposed and unexposed positions being substantially equal to zero.
3. The air vehicle of claim 1, wherein the cover portion conforms to the outer contour of the air vehicle when the bag skirt hidden, thereby reducing drag compared to a drag present when the bag skirt is exposed.
4. The air vehicle of claim 1, wherein evacuation of air from the bag skirt causes the cover portion to retract, thereby decreasing the distance between the exposed and unexposed positions.
5. The air vehicle of claim 1, further comprising a pressurized air source to provide air, the pressurized air source being operable in a suction mode to deflate the bag skirt, the pressurized air source being operable in a blower mode to inflate the bag skirt, and the pressurized air source being operable in a combination mode to inflate the bag skirt and deflate a second bag skirt, the second bag skirt being extendable in a volume enclosed by the bag skirt.
6. The air vehicle of claim 5, wherein the blower mode causes the distance to be increased for takeoff and landing of the air vehicle.
7. The air vehicle of claim 5, wherein the suction mode causes the bag skirt to have a reduced profile compared to the profile in the blower mode.
8. The air vehicle of claim 5, wherein the pressurized air source is selectable to operate in one of the blower mode for takeoff and landing of the air vehicle, the suction mode during the flight of the air vehicle, and the combination mode after the touchdown and before the takeoff of the air vehicle.
9. The air vehicle of claim 5, wherein the suction mode causes the distance to be substantially reduced to zero after a takeoff and during the flight of the air vehicle, the distance being increased to expose the bag skirt in preparation of the touchdown and after completion of the takeoff of the air vehicle.
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 coupling structure for coupling first and second casing halves into a casing, comprising:
a detachment tool storable in a tool retention bore formed in said casing;
an opening formed at an overlapping position of said first and second casing halves of said coupled casing;
a first coupling element projecting inward from an inner surface of the first casing half and formed with a detachment hole, said detachment hole in open communication with said opening to permit extension of said detachment tool therein; and
a second coupling element projecting inward from an inner surface of the second casing half for engaging the first coupling element;
wherein said casing is matingly engaged by aligning said first and second casing halves to engage said first and second coupling elements, and disengaged by inserting said detachment tool into said detachment hole through said opening to abut said second coupling element resulting in inward bending of said second coupling element with respect to said first coupling element, thereby disengaging said second coupling element from said first coupling element.
2. The coupling structure as defined in claim 1, wherein said opening is formed either in the first casing half or the second casing half.
3. The coupling structure as defined in claim 1, wherein the detachment tool is a push rod or a pin rod.
4. The coupling structure as defined in claim 1, wherein said first coupling element is further formed with a hook at an end thereof, said second coupling element being formed with a hooking groove for receiving said hook.
5. The coupling structure as defined in claim 4, wherein said second coupling element has an abutment portion and a hooking portion formed at a distal end, whereby insertion of the detachment tool via the opening and said detachment hole in the casing abuts said abutment portion to disengage said second coupling element from said first coupling element.
6. The coupling structure as defined in claim 1, wherein said first coupling element is further formed with a hooking groove adjacent to said detachment hole, said second coupling element being further formed with a hook for engaging in said hooking groove, thereby coupling the first and second casing halves into the casing.
7. The coupling structure as defined in claim 6, wherein said second coupling element has an abutment portion formed with said hook and a hooking portion located at a distal end thereof, whereby insertion of the detachment tool via the opening and said detachment hole in the casing abuts said abutment portion resulting in inward bending of said second coupling element with respect to said first coupling element, thereby disengaging said second coupling element from said first coupling element.