This invention relates generally to vehicles with canopies and, more specifically, to closing mechanisms for injection-molded canopies.
Modern aircraft canopies contain many parts. A transparent portion of the canopy may be replaced several times during the life of an aircraft due to scratches and general deterioration. Replacement of the transparent portion entails frame disassembly and reassembly. This is time-consuming, labor intensive, and costly.
Attempts have been made to produce frameless aircraft canopies in order to simplify replacement of the transparent portion, among other reasons. However, a frame provides structural stiffness and strong, secure, attachment points for hinges and latches. As is known, the viable frameless canopy system must include a method for latching. Prior latching methods include a male hook or pin located on the aircraft structure or canopy frame and a female receiver on the canopy frame structure or aircraft structure respectively. Such discrete latching methods produce concentrated loads, which cause bearing stress in the transparency in the region of the latch.
Stress causes problems for transparencies. Glassy polymers craze at low stress levels. The effect of crazing on crack growth and localized failure is not well understood. Polymer transparencies yield at low stress levels and creep occurs after a fraction of service life. Cyclic, long-term loading, such as cockpit pressurization, induces creep and/or craze and reduces service life. Elevated temperatures, such as those experienced by high-speed aircraft, further increase the rate of creep and amplify the effect of crazing.
Therefore, there exists an unmet need to produce a latching system for an injection-molded canopy which avoids plastic creep or crazing due to concentrated loads yet securely holds the canopy in place.
The present invention provides an apparatus and method for latching a canopy to a vehicle, such as an aircraft, that avoids plastic creep or crazing due to concentrated loads. The apparatus includes first attachment components that are at least partially embedded within an injection-molded canopy and second attachment components that are connected to the canopy rail for attaching to the one or more first attachment components and thereby attaching the canopy to the canopy rail.
In another aspect of the invention, the first component includes a shaft with two ends and one or more knobs attached to the ends of the shaft. The knobs are molded into the canopy, and the shaft is exposed within a cavity formed by the canopy. The cavity is opened at a base of the canopy.
In still another aspect of the invention, the first component includes a hook at least partially embedded within the canopy. A portion of the hook protrudes from a base edge of the canopy.
The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings.
The present invention is an injection-molded canopy with canopy attachment devices that are inserted into the canopy during an injection molding process. As shown in
A canopy rail 50 includes a canopy-receiving channel 52 that receives the canopy 30 and the mounted hook 32. The canopy rail 50 is attached around a cockpit in a conventional manner. One of the walls of the channel 52 suitably includes an inflatable seal 58 that is attached to a pneumatic or hydraulic system (not shown) that is included within the vehicle. The inflatable seal 58 inflates when the canopy 30 is inserted into the channel 52 and locked in place in the canopy rail 50. The inflatable seal 58 provides a moisture and air pressure seal between the vehicle cockpit and the environment outside of the cockpit.
In one embodiment, the canopy 30 is first inserted into the rail 50. The canopy 30 is moved by a support structure (not shown), thereby making contact between the U-shaped cutout of the hook 32 and a locking mechanism (not shown) that is included as part of the canopy rail 50. Co-pending patent application Ser. No. 10/367,062, Attorney Docket No. BOEI-1-1142, hereby incorporated by reference, illustrates a mechanism for receiving the hook 32 without requiring fore and aft motion of the canopy 30 when the canopy 30 is inserted into the channel 52.
The end holders 106 are then inserted in a mold for the injection-molded canopy 100 such that when the molding of the canopy 100 is complete, the pairs of end holders 106 are surrounded by the molded canopy 100 and only the handles 104 protrude out of the base of the canopy 100. In this embodiment the parts 106a,b are trapezoidal in shape with a first length at the side that includes the cavity 110 that is smaller than a second length of the side that is opposite the side that includes the cavity 110. Therefore, because the parts 106a,b are wider at a point that will be further embedded into the canopy 100 after the molding process, the canopy material that surrounds the parts 106a,b holds the parts 106a,b securely in place.
In one embodiment, the exterior wall 134 of the canopy rail 130 includes an inflatable seal 150 along a wall of the channel 132. The seal 150 inflates by a pneumatic or hydraulic system (not shown) that is included within the vehicle once the canopy 100 is fully seated within the channel 132. The seal 150 provides a moisture and air pressure lock between the environment within the cockpit and outside of the cockpit.
Referring to
It can be appreciated that various other types of attachment mechanisms can be imbedded within an injection-molded canopy during canopy creation.
While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.
This invention is a Divisional Application of U.S. patent application Ser. No. 10/367,064, filed Feb. 13, 2003, which is hereby incorporated by reference.
This invention was made with Government support under U.S. Government contract F33615-97-2-3407 awarded by the U.S. Air Force. The Government has certain rights in this invention.
Number | Date | Country | |
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Parent | 10367064 | Feb 2003 | US |
Child | 10960144 | Oct 2004 | US |