Ammunition and explosives – Having reaction motor – Having separation means
Reexamination Certificate
1999-09-02
2001-10-09
Jordan, Charles T. (Department: 3644)
Ammunition and explosives
Having reaction motor
Having separation means
C102S377000
Reexamination Certificate
active
06298786
ABSTRACT:
FIELD OF THE INVENTION
The present invention generally relates to providing quick access to a closed area, and, in particular, to a frangible access panel which provides emergency or quick access to a host structure.
BACKGROUND OF THE INVENTION
Various systems have been developed over the years in the aerospace industry to provide access to an interior area of an aircraft or to an interior area of a payload fairing interconnected to a launch vehicle. One such system utilizes a number of traditional threaded fasteners such as NAS series bolts to mount an emergency access door onto a launch vehicle payload fairing or aircraft. The disadvantage of this system lies in the additional complexity and increased weight of the system, which is not desirable in aircraft and launch vehicle application. Use of traditional threaded fasteners also inhibits timely access to the interior area of the host structure due to the time and difficulty associated with de-mating a bolted access door. Another method for allowing access to the interior of a host structure is to simply cut an access hole through the wall of the host structure when such access is required. The disadvantage of this method is that it typically ruins the host structure (e.g., aircraft, payload fairing, etc.), which, in some cases, is worth several thousand or million dollars.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a system for providing an opening to an interior area of a host structure.
It is another object of the present invention to provide a system which allows the interior area of a host structure to be quickly and efficiently accessed, such as in emergency situations.
It is a further object of the present invention to provide a system which provides non-labor intensive access to the interior area of a host structure while minimizing damage to the host structure.
The present invention achieves one or more of these objectives by providing an access panel or door which is readily separable from the host structure (e.g., payload fairing, aircraft, spacecraft, sea vessel skins, bulkheads, barriers, etc.) interconnected thereto. Generally, in one aspect of the present invention, the access panel is initially interconnectable to the host structure via a separation system, the separation system including first and second interconnect members (e.g., doubler plates) and an explosive or detonation assembly position therebetween. The explosive assembly may include a detonation cord extending about at least a portion of the perimeter of the access panel. The system may further include a detonation initiator, which is adapted to supply energy to the detonation cord to thereby detonate the explosive assembly, which results in the separation of the first and second interconnect members, which, in turn, facilitates separation of the access panel from the host structure.
In one aspect, the separation system functions to facilitate lateral separation of the access panel relative to the longitudinally-extending host structure. In one embodiment, the first and second interconnect members include first and second notches or grooves, respectively, the first and second notches defining first and second break planes along which the first and second interconnect or structural members separate or break, respectively. In this embodiment, for purposes of allowing severed portions of the interconnect members to separate without substantial collision therebetween, the first and second notches are displaced or staggered relative to each other. In this regard, the first and second break planes of the first and second interconnect members, respectively, are different and non-coplanar.
In another aspect, the present invention is directed to providing a system for separating at least portions of a noncircular (e.g., three or more sides) access panel from a host structure to allow access to an interior area of the host structure. In one embodiment, where the access panel has first and second laterally spaced side walls and first and second longitudinally spaced end walls, the separation system includes first, second, third and fourth separation assembly sections which extend between and initially interconnect the side walls and end walls of the access panel and the corresponding portions of the host structure. Each separation assembly section includes first and second structural or interconnect members and a detonation cord enclosed in a detonation tube positionable between the first and second interconnect members. In this embodiment, the system further includes a detonation initiator for providing a charge or energy to the detonation cord, which results in detonation of the detonation cord. In instances where the detonation tube and cord enclosed therein do not extend around at least one comer defined by a side wall and an end wall of the access panel, the system may further include an ordnance transfer assembly, which functions to transfer the energy or charge from one portion of the detonation cord (e.g., within the first separation assembly section) to another portion of the detonation cord (e.g., within the second separation assembly section). Such ordnance assemblies are particularly useful in instances where it is technically difficult or cost prohibitive to bend the detonation tube and detonation cord contained therein around such a comer.
More specifically, the separation system may include first and second structural members (e.g., doublers or doubler plates) which at least initially interconnect the first and second structures, the first structural member being displaced from the second structural member, first and second notches or grooves positioned on the first and second structural members, and an explosive assembly, contained between the first and second structural members, for breaking the first and second structural members at first and second break planes defined by the first and second notches on the first and second structural members, respectively. Of importance, the first and second notches are displaced or staggered relative to one another (e.g., nonplanar), such that the first and second break planes of the first and second structural members, respectively, are offset or displaced relative to each other (e.g., nonplanar) to avoid undesirable contact therebetween. In addition, in order to enhance fracture of the first and second structural members, the first and second notches are positionable on the explosive-facing and/or non-explosive facing sides of the first and second structural members, depending upon the particular structural member on which the groove is positioned.
For purposes of facilitating separation of and otherwise avoiding undesirable contact or a substantial collision between the first and second structures upon separation, in one embodiment, the first notch on the first structural member is positionable along a first tangential plane defined by the explosive means, and the second notch on the second structural member is positionable such that the second notch is aligned with at least a portion of the explosive means. For example, the second notch on the second structural member may be aligned with a center portion of the explosive core of the explosive means, such that the second structural member will fracture or break as the explosive means expands to a circular configuration upon firing. In another embodiment, the staggered first and second notches on the first and second structural members, respectively, are both positionable along tangential planes defined by the explosive means. Such tangential planes may be defined by first and second portions of the explosive means (e.g., end portions of explosive means in an unexploded state). In this regard, the first and second displaced break planes defined by the first and second displaced notches on the first and second structural members, respectively, may be substantially coincident with the first and second tangential planes defined by the explosive means. In these embodiments of the separation system of the pre
Grosskrueger Duane D.
Smith John J.
DiCostanzo N.
Jordan Charles T.
Lockheed Martin Corporation
Marsh & Fischmann & Breyfogle LLP
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