Patent Grant
8782944
In the status quo, heavier weapons or equipment items, e.g., heavy machine guns, are mounted on stands, including portable stands, to assist with the stability and ease of using such items. Stands may be used in a wide variety of end uses including on moving platforms, portable applications, fixed sites, submersible vehicles, moving vehicles, airborne applications, to name a few. Users of these mounted guns also desire the use of accessories with the weapons. For example, a user desires using targeting aids, such as a light, laser, or sight, to help increase the effectiveness of using the equipment item or weapon. Additionally, the user may desire increased protection or armament while using the weapon. For example, a user desires using a ballistic shield. An accessory might be attached directly to an equipment item or weapon or might be attached to a rail system that is connected to the weapon. For example, a laser sighting device is attached to a weapon near the rear of the weapon and a ballistic shield is attached to the weapon in between the laser sighting device and the front of the weapon. The ballistic shield is also in between the front of the weapon and the user of the weapon. A disadvantage to this approach is the possibility of obstruction by the shield, resulting in “splash-back” of laser radiation. Such splash-back may “bloom-out” a weapon user's night vision, effectively blinding the user. It can also be an eye safety concern, depending on the location of personnel in relation to any reflected laser radiation. Another difficulty with attempts to create accessory mounting systems is creating a mounting system which is compatible with more than one shield or shroud design which also meets other needs and satisfies design, manufacturing constraints, a wide variety of real world field events and failure modes, mounting scenarios, equipment/weapon types, equipment interaction limitations, or environmental constraints, such as described in this application.
In the case of some other weapons, especially heavy equipment or weapon systems, rail systems might mount directly to the weapon or to the shroud of the weapon. Such direct or shroud mounted systems place undesired stresses on the weapon itself. Furthermore, weapon shrouds are also typically non-uniform in positioning, often resulting in the rail system, and hence the accessories, being in an undesired and often non-uniform, unusable, and unreliable orientation which creates unpredictable, damaging, or undesired effects in field use. Thus, it would be desirable to have an accessory mounting system that does not mount on the weapon or the shroud of the weapon. Furthermore, it would be desirable to have an accessory mounting system that is uniformly positioned and modular. Additional features such as minimized weight and strength are also desired by users in combination with the various desired features.
Accessory mounting systems have limited capabilities and can be overloaded by the weight and orientation of the accessories connected to its components, e.g., a rail system. An overloaded rail can impact the area connected to the rail system. For example, an overloaded rail system on a weapon or weapon shroud can warp the weapon or the weapon shroud, thereby damaging the weapon or weapon shroud and affecting the performance of the weapon. Therefore, it would be desirable to have a rail system that addresses overloading of the rail system.
With increased use of accessories on a rail system, also comes the increased management of collateral items that accompany the accessories. For example, many accessories have collateral items, e.g., cables, (e.g., electrical, power, control, and other wise) coupled to the accessory that must be located somewhere. The cable can dangle from the weapon, which could significantly affect the user of the weapon and his use of the weapon, or, preferably, it can be managed on the weapon. Therefore, it would be desirable to have an accessory mounting system that also addresses management of collateral items.
a)-2(d) depict the forward module of
a)-3(d) depict the ancillary rail module of
a)-4(f) depict the mounting module of
a) and 5(b) depict the rail system of
a) and 6(b) depict a second rail system of
a)-(c) depict the accessory interface system in application with a weapon and weapon mount; and
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific exemplary embodiments of the invention. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to make and use the invention, and it is to be understood that structural, logical, or other changes may be made to the specific embodiments disclosed without departing from the spirit and scope of the present invention.
The invention discloses an accessory interface system that enables the mounting of weapon accessories to a weapon mount. The invention also discloses an accessory interface system that enables uniform positioning of accessories and modularity. The invention also discloses an accessory interface system that addresses overloading of the rail system. The invention also discloses an accessory interface system that addresses management of collateral items.
An accessory interface system 100 is depicted in
The underside of the forward module 101 is open for the majority of its length, to reduce the likelihood of obstructing a vertical path of a weapon that is mounted in the weapon mount 160, thus increasing the likelihood of enabling the weapon to achieve full depression. Five mounting surfaces 104 for accessories are provided at the free end, e.g., the front end or end away from the weapon mount 160, of the load bearing or traverse portions of the accessory interface system 100. Each mounting surface 104 includes, for example, a rail system 106, is equidistant from a common centerline located within the accessory interface system 100. In a preferred approach, the common centerline is substantially the same as a centerline of a weapon mounted in the weapon mount 160 and accessory interface system 100, e.g., where the centerline is also the centerline of the interior of the barrel of the weapon. Along its length, the accessory interface system 100 contains collateral clamps 107, e.g., cable clamps, allowing management of accessory collaterals, e.g., cables. For example, the accessory collaterals are routed from an accessory mounted on a rail system 106 back to the rear of weapon system for remote operation.
In a preferred approach, an accessory interface system 100 also comprises an upward arching ancillary rail module 102, which is mounted on forward module 101 above a weapon. The ancillary rail module 102 has, on its top side, a mounting surface 108 for accessories. The mounting surface 108 includes, for example, a rail system 105, which is equidistant from the common centerline located within the accessory interface system 100, being the same common centerline that the mounting surface 104 is equidistant from. The ancillary rail module 102 can be mounted at different locations along the top of the forward module 101. Further descriptions of the accessory interface system 100 are provided below.
a)-2(d) depict the forward module 101 in greater detail.
The interface portion 204 is subdivided into further substantially rectangular portions: first portion 210, second portion 212, third portion 214, fourth portion 216 and fifth portion 218 as depicted in
Metal blank 200 is bent along first bend region 220 to form a forty five (45) degree between a plane formed by the face of first portion 210 and a plane formed by the face of second portion 212. Metal blank 200 is further bent along second bend region 222 to form a forty five (45) degree between a plane formed by the face of second portion 212 and a plane formed by the face of third portion 214. Metal blank 200 is further bent along third bend region 224 to form a forty five (45) degree between a plane formed by the face of third portion 214 and a plane formed by the face of fourth portion 216. Metal blank 200 is further bent along fourth bend region 226 to form a forty five (45) degree between a plane formed by the face of fourth portion 216 and a plane formed by the face of fifth portion 218.
b) depicts a front perspective view of forming an intermediate stage of forward module 101 of
c) depicts a side perspective view of forming a later stage of forward module 101 of
A plurality of apertures is applied to mounting surfaces 104 (
Portion 218, and similarly portion 210 (not shown) include a plurality of weight reduction apertures 240 which are used to remove some of the weight of the forward module 101 without impacting the effectiveness of forward module 101. Fourth bend region 226 and third bend region 224, and similarly second bend region 222 (not shown) and first bend region 220 (not shown), also include a plurality of weight reduction apertures—apertures 241 in fourth bend region and apertures 242 in third bend region. Although the apertures are shown to be significantly in the bend regions, the apertures are not limited and can be large enough such that they also encompass part of portion, e.g., fifth portion 218.
Load bearing or traverse portions 202 (although only one is depicted in
The size and orientation of the weight reduction apertures, e.g., apertures 240, 241, 246, etc, are subject to the designer's wishes balanced with the impact on the efficacy of the weapon system including the impact on accessory interface system 100.
d) depicts a portion of the accessory interface system 100 in a perspective view showing more of the bottom of interface portion 204. As depicted in
As noted above, portion 218, portion 216, and portion 214 include a plurality of weight reduction apertures which are used to remove some of the weight of the forward module 101 without impacting the effectiveness of forward module 101. Fourth bend region 226 and third bend region 224, and similarly second bend region 222 (also include a plurality of collinear weight reduction apertures—apertures 241 in fourth bend region 226, apertures 242 in third bend region 224, and apertures 243 in the second bend region 222. Although the apertures are shown to be significantly in the bend regions, the apertures are not limited and can be large enough such that they also encompass part of portion, e.g., fifth portion 218.
a)-3(d) depict the ancillary rail module 102 in greater detail.
The metal blank 300 is subdivided into further substantially rectangular portions: first portion 310, second portion 312, third portion 314, fourth portion 316 and fifth portion 318 as depicted in
Metal blank 300 is bent along first bend region 320 to form a forty five (45) degree between a plane formed by the face of first portion 310 and a plane formed by the face of second portion 312. Metal blank 300 is further bent along second bend region 322 to form a forty five (45) degree between a plane formed by the face of second portion 312 and a plane formed by the face of third portion 314. Metal blank 300 is further bent along third bend region 324 to form a forty five (45) degree between a plane formed by the face of third portion 314 and a plane formed by the face of fourth portion 316. Metal blank 300 is further bent along fourth bend region 326 to form a forty five (45) degree between a plane formed by the face of fourth portion 316 and a plane formed by the face of fifth portion 318.
b) depicts a front perspective view of an intermediate stage of forming an ancillary rail module 102.
c) depicts a top perspective view of a later stage of forming an ancillary rail module 102. As depicted in
Ancillary rail module 102 includes a plurality of weight reduction apertures 340, 342 which are used to remove some of the weight of the ancillary rail module 102 without impacting the effectiveness of forward module 101 and the ancillary rail module 102. Apertures 340 are primarily located in portion 314; apertures 342 are primarily located in regions 312, 316, and apertures are also located in portions 310, 318 (not shown). Although the apertures are shown to be significantly in the bend regions, the apertures are not limited and can be large enough such that they also encompass part of a bend portion, e.g., fifth portion 322.
d) depicts a perspective view of a later stage of forming the ancillary rail module 102.
a)-(d) depict the mounting module 103 (
Support structure 571 includes a structural element section 570 and a coupling bracket section 575. In an exemplary approach, structural element section 570 has a substantially rectangular main body with a lobe 579 being below and dog-leg-right of the main body. Coupling bracket section 575 is substantially rectangular and having a height comparable to the height of the main body of the structural element section 570. Coupling bracket section 575 is placed such that a portion of coupling bracket section 575 has a side mating portion which is laterally offset from the main body of structural element section 570, and in this embodiment is machined as a single component. Coupling bracket section 575 has three (3) apertures 580. Apertures 580 are used to couple the mounting module 103 to the forward module 101 using corresponding apertures 262 (
b) depicts a back view of a support structure 571. As seen in
c) depicts a top view of a support structure 571. As seen in
d) depicts a front view of a backplate 550, which includes two apertures 114 and a two lobes 554 extending slightly upward from the main body of the back plate 550. Apertures 114 are used to couple the backplate 550 to a weapon mount.
e) depicts a side view of a backplate 550 being coupled to a support structure 571. The coupling bracket section 575, having apertures 580, is coupled to structural element section 570. Structural element section 570 is coupled to backplate 550 along section 578. Although only one support structure 571 is shown, this support structure 571 is representative of the other support structure.
f) depicts a front view of a mounting module 103. As seen in
a) and 5(b) and
a) depicts a top view of mounting rail 105. Mounting rail 105 includes a top surface 513 and grooves 512 in the top surface 513. Mounting rail 105 also includes a plurality of apertures 515 used to couple the mounting rail 105 to another structure.
As seen in
In an exemplary embodiment, the forward module 101 provides several locations to mount ancillary rail module 102. Although weapon sights are often placed to the rear of a weapon, some weapon users may opt to mount a sight further away for increased eye relief. Some weapon users may also choose to use two sights, each zeroed for a different distance. Thus, an easily movable ancillary rail module 102 provides flexibility in placement of a sight or other accessory for use with a weapon.
Mounting module 103 is coupled to forward module 101. Apertures 580 in mounting module 103 have been lined up with corresponding apertures 262 (
The fastening system 115 employs the bolts 112 to fasten the mounting module 103 to the weapon mount (not shown), where the bolts 112 may be the bolts previously existing in the weapon mount. Alternatively, bolts 112 are similar to the bolts previously existing in the weapon mount but are slightly longer to account for the mounting of the accessory interface system 100. Using the mounting system previously existing in the weapon mount enables retaining the buffer system of the weapon mount.
In another aspect, a second designed failure point is included to permit ancillary rail module 102 to break from the forward module 101 in the event that a large stress or shear force(s) is applied to the ancillary rail module 102. In the event, for example, that the forward module 101 broke off from the mounting module 103, the ancillary rail module 102, (being coupled to the forward module 101) would be resting on a barrel of a weapon in the interior space of the accessory interface system 100; whereby the ancillary rail module 102 would be supporting the forward module 101 and anything coupled to the forward module 101. Therefore, it could be desirable to have a second engineered failure point in the system that couples the ancillary rail module 102 to the forward module 101. Accordingly, the ancillary rail module 102 would break off from the forward module 101 and reduce the chance that ancillary rail module 102 will damage and/or effect the operation of the weapon. Alternatively, a retrieval system is employed to couple the ancillary rail module 102 to the forward module 101 or the mounting module 103, to permit quick retrieval of the ancillary rail module 102. An example fastening system could include a flexible lanyard (not shown) which couples the ancillary rail module 102 to the forward module 101. The flexible lanyard could also have quick release pins which couple one or both ends of the lanyard to a particular component (e.g., 101, 102). Consequently, retention and implementation of the desired second engineered failure point is considered in the selection and implementation of appropriate fastening mechanisms, e.g., screws or bolts 611. Examples of such fastening mechanisms include shear fasteners or bolts which have a desired shear strength which is more than the force associated with typical use and forces arising from accessories which are coupled to various components such as the forward module 101, ancillary rail module 102, and/or mounting module 103.
a)-(c) depict the accessory interface system 100 in application with a weapon and weapon mount.
As noted above and depicted in
b) depicts a forward-looking, side perspective view of accessory interface system 100 surrounding a weapon 868 which is mounted on a weapon mount 160. As depicted in the figure, the barrel of the weapon 808 is located within the interior space of the forward module 101. The barrel of the weapon 808 is also located within the interior space of the ancillary rail module 102 which has a rail 105 fastened on top of the ancillary rail module 102. Also depicted is a portion of mounting module 103 coupled to forward module 101.
c) depicts a forward-looking, side perspective view of accessory interface system 100 surrounding a weapon 868 which is mounted on a weapon mount 160. As depicted in the figure, the barrel of the weapon 808 is located within the interior space of the forward module 101 which has five (5) rails 106 fastened on it. The barrel of the weapon 808 is also located within the interior space of the ancillary rail module 102. As noted above and depicted with reference to, for example,
Efforts to design accessory mounting systems have run into a wide variety of problems or operating mode limiting design choices. The various problems associated with current art accessory mounting designs are increasing rather than decreasing given an increased desire to have a wider variety of accessories in use under an increasing variety of operating conditions. In the development of the above referenced invention, finite element modeling and analyses were performed for an accessory interface system 100 which maximized the number and variety of accessories, increased the number of ballistic or other type of shield/shrouds which could be used, addressed a variety of shortcomings associated with existing designs (e.g., weight, power management, range of motion, traversal, or elevation associated with equipment/weapon utilization), and reduced risks associated with a number of operating conditions/events. Testing was also accomplished to ensure various embodiments of an equipment/weapon and accessory mounting system was compatible for use with a weapon mount 160 in order to determine the structural integrity of an accessory interface system 100 under shock loading. This analysis was also conducted due to the need to ascertain the reliability of the accessory interface system 100 given it was found that initial selections of various combinations of components did not yield predictable results other than equipment failure or rejections of existing or experimental designs by various user classes. Thus, extensive testing was required in order to ascertain which designs would function as intended under the conditions that the various systems were to be employed. During these analysis efforts, experiments were conducted including ones on weld size and geometry as well as shear fastener sizes and specifications. In the course of the testing, including testing described herein, various design changes had to be made given testing results showed design failure in various component choices and design features for the combination of features, capabilities, and structures associated with various embodiments of the invention in this case. These analyses included finite element analysis modeling a heavy accessory mounted to an exemplary accessory interface system 100 where the accessory was a 10 lb spotlight (not shown).
One analyses consisted of a series of static and dynamic analyses. One static analysis was performed to determine preferred weld sizes and geometry and to also determine various worst case loading scenarios. Once design changes were made, revised models were subjected to a more severe dynamic shock loading analysis as outlined in MIL-STD-810. Separate models were constructed for the side, angle, and bottom mounted accessory configurations.
Various accessory interface system 100 parts were constructed of a fine mesh of three dimensional solid elements. Selected accessory interface system 100 parts were assigned material properties 4340 steel in accordance with AMS 6414. The weapon mount front cross member 161 was given material properties of 17-4PH H900 stainless steel. Pertinent material properties are listed in Table 1. The shear fasteners 613 and bolt 112 were modeled using rigid beam elements. The weapon mount cross member (e.g., 161) was rigidly constrained on its left and right surfaces. Contact interactions were defined between bolted or fastened connection contacting surfaces. An exemplary accessory, e.g., a spotlight mass, was coupled to the appropriate mounting hole surfaces. In one test, it was located four inches from the mounting surface in the middle of the bolt hole pattern. Static 20 g inertial loads were applied to each model in the up, down, lateral, fore, and aft directions. A 20 g static load is one worst case load used to analyze helicopter structures for a potential aviation user.
Static modeling results for a number of embodiments showed worst case loads were in a down direction for the side and angle mount configurations. Additional tests showed a number of embodiments have a worst case load in a lateral direction for a bottom mount configuration
Weld configuration and size for a number of embodiments were determined to be a 0.125 full penetration groove finished on both long sides of the weld joint with 0.06 fillet welds. Table 2 lists worst case stresses/safety margins for each component of certain embodiments for each load. All safety margins are based on ultimate stresses. Safety margins for exemplary bolts 112 were based ½-13 UNC 300 series stainless steel (i.e. ultimate tensile strength=80 ksi, ultimate shear strength=50 ksi). Exemplary safety margins for exemplary shear fasteners are based on #8-36UNF SAE grade 8 fasteners (i.e. ultimate tensile strength=150 ksi, ultimate shear strength=120 ksi). Static analysis for various redesigned embodiments found that the new combinations and components passed the worst case 20 g static loading testing.
Other tests were also completed to include a dynamic model test. The dynamic model set-up is similar to the static model set-up described above with the significant exception that the mesh is coarser and continuum shell elements were used instead of three dimensional solids. A rigid body, which was constrained in all directions, was placed inside the accessory interface system 100 to simulate movement of a heavy equipment item, such as a barrel of the weapon 808. The dynamic loads were applied as 40 g acceleration for a 23 ms duration and 75 g acceleration for a 13 ms duration sawtooth shock pulses in accordance with MIL-STD-810 Method 516.5 page 516.5-14.
Results of dynamic modeling for a number of embodiments focused on a side mount configuration loaded with a 75 g acceleration with a 13 ms duration shock pulse in the down direction which is worst case and most likely direction to be severely loaded in one or more field utilization scenario (e.g., river patrol boat, mobile firefighting, submersible, whaling, ship mounted, dismounted infantry, or other special operations). An exemplary bolt 112 under test fails at a time of 0.110 s. However, selected shear fasteners, e.g., 613, fail before that time (the right and left top shear fastener 613 at t=0.015 s, the left aft shear fastener 613 at 0.02 s, the right bottom shear fastener 613 at 0.035 s, and the right aft and left bottom shear fastener 613 at 0.065 s). Stress plots reveal that stress for the left section (viewed from the muzzle end of a weapon) of backplate 550 exceeds ultimate material strength (i.e. 260 kilograms per square inch (ksi)) at 0.0175 s. At t=0.035 s the exemplary weapon mount cross member 161 exceeds its ultimate stress of 190 ksi but the stress is localized.
Results from different analyses conducted on various embodiments found that redesigned accessory interface system 100 passed static 20 g loading. As discussed in Table 2, shear fasteners 613 likely have the lowest safety margin which was one goal of various embodiments design. Dynamic analyses revealed that two exemplary shear fasteners 613 would likely break before stresses throughout the rail, e.g., 100, exceed ultimate stress levels associated with one set of potential field conditions. One of the exemplary analysis models does not allow all of the shear fasteners 613 to “release” and thereby load the remaining shear fasteners, e.g., 613 at one potential point of failure. One means for determining if a shear fasteners 613 will shear sooner than expected is to insert failure criteria for the shear fasteners 613 or re-run an analysis from a point of failure without the shear fasteners 613 or additional actual shock testing. It may be desirable to increase the size of the fillet welds (e.g., welds coupling sections 570, 550 of mounting module 103) to an exemplary 0.090 inch at least on outer welds. The shear fasteners 613 can remain #8-36UNF SAE grade 8 screws or equivalent (i.e. minimum ultimate tensile strength=150 ksi, minimum ultimate shear strength=120 ksi).
In one exemplary embodiment, an accessory interface system 100 is modular. For example, a same type weapon is employed in different contexts, where the context dictates certain design features, e.g., length of the accessory interface system 100. An embodiment can be constructed by removing two mounting bolts e.g., 112, that fasten the accessory interface system 100 to a weapon mount 160, the accessory interface system 100 can be removed and a different accessory interface system 100 easily mounted in its place. Additionally, different devices or weapons are mountable on a same type of weapon mount 160. As such, it may be desirable to have different design features corresponding to a different device, respectively. As noted above, straightforward design modification can incorporate an exchange of one accessory interface system 100 for another accessory interface system 100, accessories and the ability to include accessories can be tailored to different devices on the weapon mount.
Although the invention may depict one method of fastening an element to another element, the invention is not so limited. Different methods of fastening can be employed as appropriate under the circumstances or as desired by the user or designer in view of a wide variety of design considerations and required testing to verify utility and safety of a particular design.
While the invention has been described and illustrated with reference to specific exemplary embodiments, it should be understood that many modifications and substitutions can be made without departing from the spirit and scope of the invention. For example, the invention describes using a rail system 106 on the forward module 101 and second rail system 105 on the ancillary accessory module 102, the invention is not so limited and any combination of rail systems can be used, preferable such that heights are substantially all the same (to maintain equidistance from common centerline of weapon) and use similar mechanisms to fasten the rail system to the accessory interface system 100. Accordingly, the invention is not to be considered as limited by the foregoing description but is only limited by the scope of the claims.
The present application claims priority to U.S. patent application Ser. No. 13/168,459, filed Jun. 24, 2011, entitled “ACCESSORY INTERFACE SYSTEM,” now U.S. Pat. No. 8,479,434, the disclosure of which is expressly incorporated by reference herein.
The invention described herein includes contributions by one or more employees of the Department of the Navy made in performance of official duties and may be manufactured, used and licensed by or for the United States Government for any governmental purpose without payment of any royalties thereon.
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|---|---|---|---|
| 6779288 | Kim | Aug 2004 | B1 |
| 8316574 | Swan | Nov 2012 | B1 |
| 8336243 | Langevin et al. | Dec 2012 | B2 |
| 20050000142 | Kim et al. | Jan 2005 | A1 |
| 20100154280 | LaFrance et al. | Jun 2010 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20140013643 A1 | Jan 2014 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13168459 | Jun 2011 | US |
| Child | 13865292 | US |
