Patent Grant
7750275
1. Field of the Invention
The present invention relates to folding fin assemblies for airborne or waterborne vehicles.
2. Description of Related Art
Control surfaces, such as fins, wings, or the like, are often used to control the trajectory of an airborne or waterborne vehicle, such as a rocket, missile, torpedo, or the like. It is often desirable to fold such control surfaces prior to deploying the vehicle, so that the vehicle occupies a smaller volume in a launch tube or a barrel. Once deployed from the launch tube or barrel, however, the control surfaces are unfolded to operational configurations, so that the vehicle's trajectory may be controlled.
It is very desirable to maximize the amount of propellant and/or payload of such a vehicle. The vehicle's radial diameter, however, is limited to an inner diameter of the launch tube or barrel from which the vehicle is deployed. Conventional folding control surface assemblies typically use torsion springs to bias the control surfaces from folded, stowed configurations to unfolded, operational configurations. Such torsion springs, however, are bulky and, thus, significantly contribute to the radial diameter of the vehicle. Accordingly, torsion springs occupy volumes within the launch tube or barrel that could more beneficially be occupied by increased propellant and/or payload of the vehicle.
There are many designs of folding control surface assemblies well known in the art, however, considerable shortcomings remain.
There is a need for an improved, folding control surface assembly.
Therefore, it is an object of the present invention to provide an improved, folding control surface assembly.
This and other objects are achieved by providing a folding control surface assembly, including a torsion shaft, a base, and a control surface hingedly attached to the base via the torsion shaft, such that the torsion shaft biases the control surface toward an unfolded configuration with respect to the base.
In another aspect of the present invention, a folding control surface assembly is provided. The folding control surface assembly includes a torsion shaft, a base, and a control surface. The folding control surface assembly further includes a first torsion shaft pin attaching a first end of the torsion shaft to the control surface and a second torsion shaft pin slidably attaching a second end of the torsion shaft to the base. The control surface is hingedly attached to the base via the torsion shaft and the torsion shaft biases the control surface toward an unfolded configuration with respect to the base.
In yet another aspect, the present invention provides a vehicle including a body and at least one folding control surface assembly. The at least one folding control surface assembly includes a torsion shaft, a base attached to the body, and a control surface hingedly attached to the base via the torsion shaft, such that the torsion shaft biases the control surface toward an unfolded configuration with respect to the base.
The present invention provides significant advantages, including: (1) providing a folding control surface assembly that occupies a smaller volume than conventional assemblies that employ torsion springs; and (2) providing a vehicle that is smaller in radial diameter than conventional vehicles employing torsion spring control surface folding mechanisms.
Additional objectives, features and advantages will be apparent in the written description which follows.
The novel features believed characteristic of the invention are set forth in the appended claims. However, the invention itself, as well as, a preferred mode of use, and further objectives and advantages thereof, will best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings, in which the leftmost significant digit(s) in the reference numerals denote(s) the first figure in which the respective reference numerals appear, wherein:
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
The present invention represents a folding control surface assembly. The folding control surface assembly comprises a torsion shaft about which a control surface hinges and by which the control surface is biased from a folded, stowed configuration to an unfolded, operational configuration. The torsion shaft occupies much less volume than a torsion spring while providing sufficient motive force to bias the control surface toward the operational configuration.
Still referring to
Torsion shaft 107 also biases control surface 103 from the folded, stowed configuration of
According to the present invention, torsion shaft 107 may comprise any material and have configuration (e.g., diameter, length, etc.) that will allow torsion shaft 107 to elastically twist or torque about central axis 109 sufficiently to bias control surface 103 from the folded, stowed position to the unfolded, operational position. In one embodiment, torsion shaft 107 comprises a super-elastic material (e.g., a super-elastic nickel-titanium alloy, such as Nitinol), exhibits a diameter of about 4.8 mm, and exhibits a length of about 54 cm. Note, however, that the scope of the present invention is not limited by this example. The particular composition and configuration of torsion shaft 107 is implementation specific. For example, torsion shaft 107 may comprise a high-strength steel. Torsion shaft 107 may take on the form of a solid rod or a tube. Torsion shaft 107 preferably exhibits sufficient mechanical properties to only substantially reversibly deform when twisted or torqued about central axis 109 to place control surface 103 in the folded, stowed position.
For example, in embodiments wherein torsion shaft 107 comprises a super-elastic material, torsion shaft 107 deforms reversibly via the creation of a stress-induced metallurgical phase. When the load is removed (i.e., when torsion shaft 107 urges control surface 103 to the unfolded, operational position), the stress-induced phase becomes unstable and torsion shaft 107 regains its original shape. In one embodiment, torsion shaft 107 comprises a substantially austenitic structure when relaxed, i.e., when control surface 103 is in the unfolded, operational configuration. When control surface 103 is moved to the folded, stowed position, at least a portion of torsion shaft 107 is transformed to a martensitic structure. When control surface 103 is released to the unfolded, operational configuration, the martensitic structure becomes unstable, transforming to an austenitic structure.
It should be noted, however, that second torsion shaft pin 115 and slot 117 are but one means for accommodating changes in length of torsion shaft 107. Other means are contemplated by, and thus encompassed by, the present invention. It should also be noted that sliding torsion shaft lock 114 can be operatively associated with torsion shaft 107 proximate first end 111 and that control surface 103 can be affixed to torsion shaft 107 at any suitable location, such as distal from first end 111.
It should be noted, however, that control surface lock 119 is but one means for retaining control surface 103 in the unfolded, operational configuration. Other implementations of the means for retaining control surface 103 in the unfolded, operational configuration are contemplated by, and thus encompassed by, the present invention.
The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below. It is apparent that an invention with significant advantages has been described and illustrated. Although the present invention is shown in a limited number of forms, it is not limited to just these forms, but is amenable to various changes and modifications without departing from the spirit thereof.
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| Number | Date | Country | |
|---|---|---|---|
| 20080078859 A1 | Apr 2008 | US |
