1. Field of the Invention
A missile launch rail experiences a harsh environment that produces many stresses in the material. This subsequently results in fatigue failures. These stresses can be caused by vibration, bending, and overuse. When failures occur in the form of cracks in the latch pinholes or rail pinholes, catastrophic failures such as a hang fire can occur.
2. Discussion of the Background
The missile launch rail was designed for a finite life measured in missile firings and captive carry vibration hours. The hours and firings needed to be monitored and tracked so that the missile launch rail could be replaced on time. Tracking the life of the rails in combat has proved to be difficult and unfeasible.
When catastrophic failures on a missile launch rail have been discovered, two assumptions have been made about the causes of the cracking: a) there was a coupled vibration between the missile launch rail and the missile, and b) equipment on both the missile and the missile launch rail was stressed.
Several solutions were considered to address the rail pin hole and/or latch pin hole crack. A redesign of the rail would be costly and time consuming. The cracking needs to be addressed quickly because of the missile launch rails currently in use by the Army. Currently, the missile launch rails are being inspected using Non-Destructive Inspection (NDI) methods, but in order for NDI methods to find all of the rail pin hole and/or latch pin hole cracks the rails must be disassembled. The disassembly causes the inspection to be time consuming and costly. A solution for missile launch rail cracking is an immediate issue.
In
Features and advantages of embodiments of the present disclosure will become apparent by reference to the following detailed description and drawings, in which like reference numerals correspond to similar, though perhaps not identical, components. For the sake of brevity, reference numerals or features having a previously described function may or may not be described in connection with other drawings in which they appear.
Referring to
The present application can be used on existing and future missile launchers developed by or for the Army for use in combat.
The present application provides a simple and cost effective solution to the safety and reliability issues of missile launch rail 110 cracking, specifically cracking of the rail pin holes 132 and/or latch pin holes 134. The existing technology is being used longer than expected. When the failures occur, there is a serious safety issue. The present application provides a failsafe in case of a failure of the rail pin holes 132 and/or latch pin holes 134. The present application can be implemented quickly and cost effectively into existing missile launch rails 110.
The present application gives a solution that substantially decreases the problem of missile launch rail 110 cracking.
As shown in
The specific components of the pin retainer 122 are shown in front and back view perspectives, respectively, in
A top view of the missile launch rail 110 with the pin retainer 122 attached is shown in
The present application relates to a missile launch rail device including (but not limited to) the following components.
One of the components is a missile launch rail 110 providing a protected rectangular space in which is secured a latch 114 for attaching and releasing a missile situated on the missile launch rail 110. The latch 114 includes a cam end 136 and a spring end 138. The missile launch rail 110 includes cam shaft holes 130 located one on each side of the missile launch rail 110 on the cam end 136 of the latch 114. The cam end 136 of the latch 114 is situated on top of a latch cam shaft 118. The latch cam shaft 118 has two ends with each end being inserted through one of the two cam shaft holes 130 respectively. The missile launch rail 110 also includes two rail pin holes 132, one located on each side of the missile launch rail 110. The rail pin holes 132 are located approximately halfway between the cam end 136 and the spring end 138. Each of the two rail pin holes 132 is positioned to hold one end of a latch pin 112. Each of the ends of the latch pin 112 is inserted through one of the two rail pin holes 132 respectively.
Another of the components is the latch 114 for attaching and releasing the missile on the missile launch rail 110. The latch 114 includes the cam end 136 under which a latch cam shaft 118 is perpendicularly positioned under the cam end 136 of the latch 114. The latch 114 also includes the spring end 138 opposite the cam end 136. The spring end 138 is positioned on top of a latch compression spring 120. The latch 114 also includes latch pin holes 134 on opposite sides of the latch 114 approximately halfway between the cam end 136 and the spring end 138. Each of the two latch pin holes 134 is lined up with the two rail pin holes 132. Each end of the latch pin 112 is inserted through one of the two latch pin holes 134 and one of the two rail pin holes 132 respectively.
Yet another of the components is the latch cam shaft 118 including at least one flattened side 140 and at least one rounded side 142 extending along the cam shaft length 118. Each end of the latch cam shaft 118 is inserted through one of two cam shaft holes 130 respectively in the missile launch rail 110 and positioned at the cam end 136 of the latch 114. The latch cam shaft 118 is rotatable in the two cam shaft holes 130. Rotation of the latch cam shaft 118 by lifting the latch handle 116 attached to the cam shaft 118 up or down causes the cam end 136 of the latch 114 to alternate between latched or released mode. Alternation between latched or released modes is determined by whether the at least one flattened side 140 or the at least one rounded side 142 of the latch cam shaft 118 is positioned under the cam end 136 of the latch 114.
Still another of the components is the latch compression spring 120 with a bottom end attached to the floor of the missile launch rail 110 and a top end providing tension to the spring end 138 of the latch 114. The tension is provided as the spring end 138 is pushed down on the top end of the latch compression spring 120. Alternatively, the tension is released on the spring end 138 as the spring end 138 is pulled up from the top end of the latch compression spring 120 according to the rotation of the latch cam shaft 118 which causes the latch 114 to latch the missile or release the missile respectively.
Another of the components is the latch pin 112 inserted through both the two latch pin holes 134 and the two rail pin holes 132 which are positioned with relation to the latch 114 approximately halfway between the cam end 136 and the spring end 138. The latch pin 112 functions to pivot the latch 114 as the missile is latched or released with relation to the missile launch rail 110. The latching or releasing functions according to whether the spring end 138 of the latch 114 is pushed down on the latch compression spring 120 because the cam shaft rounded side 142 is directly under the cam end 136, or whether the spring end 138 is pulled up on the latch compression spring 120 because the cam shaft flattened side 140 is directly under the cam end 136.
Yet another of the components is a latch handle 116 to manually control rotation of the latch cam 118. The latch handle 116 is perpendicularly fastened to one end of the latch cam 118 emerging from the missile launch rail 110. The latch handle 116 is operated by either pulling the latch handle 116 up to a vertical position to rotate the rounded side 142 up under the cam end 136 of the latch 114 and latch the missile into the launch rail 110, or pulling the latch handle 116 down to a horizontal position to rotate the flattened side 140 up under the cam end 136 of the latch 114 and unlatch the missile from the missile launch rail 110.
Still another component is a pin retainer 122 attached to the missile launch rail 110. The pin retainer 122 includes a latch pin catch 124 which holds the latch pin 112 in place to restrict radial pressure by the pin 112 on inside surfaces of the two latch pin holes 134 and inside surfaces of the two rail pin holes 132 from pressure created by the missile on the latch 114. By this means, premature disabling of the missile launch rail 110 and the latch 114 by wear on the latch pin holes 134 and the rail pin holes 132 is substantially prevented. The pin retainer 122 also includes a pin retainer body 128 with mounting holes 126 through which the pin retainer 122 is attached to the missile launch rail 110.
In one embodiment of the missile launch rail device, the pin retainer 122 is composed of materials selected from the group consisting of metal material, organic polymer-based synthetic material and combinations thereof.
In another embodiment of the missile launch rail device, the pin retainer 122 is from 1.5 to 3.0 inches in height, from 1.0 to 2.5 inches in width, from 3.0 to 4.5 inches in length.
In yet another embodiment of the missile launch rail device, the pin retainer 122 is mounted securely by driving bolts through the mounting holes 126 in the pin retainer body 128.
The present application relates to a method of preventing damage to a missile launch body 110 including (but not limited to) the following steps.
The first step is providing a missile launch rail 110 and a latch 114 secured to the missile launch rail 110. The latch 114 includes a cam end 136, a spring end 138, a latch pin 112, a latch cam shaft 118 and a latch compression spring 120. The missile launch rail 110 provides a protected rectangular space in which the latch 114 is secured. The latch 114 functions to attach or release a missile situated on the missile launch rail 110. The missile launch rail 110 includes two cam shaft holes 130 located on each side of the missile launch rail 110 at the cam end 136 of the latch 114 situated on top of the latch cam shaft 118. Each end of the cam shaft 118 is inserted through one of the two cam shaft holes 130 respectively. The cam shaft 118 is perpendicularly positioned underneath the cam end 136 of the latch 114. The spring end 138 of the latch 114 is opposite the cam end 136, the spring end 138 being positioned on top of the latch compression spring 120. The missile launch rail 110 also includes two rail pin holes 132 located on each side of the missile launch rail 110 approximately halfway between the cam end 136 and the spring end 138. The latch 114 also includes two latch pin holes 134 on opposite sides of the latch 114 and lined up with the two rail pin holes 132, approximately halfway between the cam end 136 and the spring end 138. Each end of the latch pin 112 is inserted through one of the two latch pin holes 134 and one of the two rail pin holes 132 respectively. The latch pin 112 functions to pivot the latch 114 as the latch cam shaft 118 causes the spring end 138 of the latch 114 to be pushed down or pushed up on the latch compression spring 120 to latch or unlatch the missile from the missile launch rail 110 respectively.
The second step is securely attaching a pin retainer 122 on the missile launch rail 110 to hold the latch pin 112 securely in place as the latch 114 rotates around the latch pin 112. The pin retainer 122 includes a pin retainer body 128 with mounting holes 126 and a latch pin catch 124, whereby the pin retainer 122 is mounted securely into the floor of the missile launch rail 110.
The third step is holding the latch pin 112 in place with the latch pin catch 124 of the latch pin retainer 122. The latch pin catch 124 severely limits movements of the pin 112 that cause pressure on inside surfaces of the two latch pin holes 134 and the two rail pin holes 134. The latch pin catch 124 of the latch pin retainer 122 thereby minimizes forces from the latch pin 112 on the rail pin holes 132 and the latch pin holes 134. These forces are associated with stationary missile vibrations as well as by vibrations and pressures caused by the launching of the missile. The pin retainer 122 thereby substantially minimizes premature disablement of the missile launch rail 110 and the latch 114.
In one embodiment of the method, the pin retainer 122 is composed of materials selected from the group consisting of metal material, organic polymer-based synthetic material, and combinations thereof.
In another embodiment of the method, the pin retainer 122 is from 1.5 to 3.0 inches in height, from 1.0 to 2.5 inches in width, and from 3.0 to 4.5 inches in length.
In yet another embodiment of the method, the pin retainer 122 is mounted securely by driving bolts through the mounting holes 126 in the pin retainer body 128.
To verify these methods and configurations, the following experiments were conducted and described in the Examples below.
Example
The first catastrophic failure on a missile launch rail was discovered in August 2011. After the development of the new prototype pin retainer, Oct. 9, 2012, simulations have been conducted to further prove the solution.
While several embodiments have been described in detail, it will be apparent to those skilled in the art that the disclosed embodiments may be modified. Therefore, the foregoing description is to be considered exemplary rather than limiting.
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