Patent Application
20190316863
The technical field of this disclosure concerns recoil management, and more particularly concerns lightweight systems and methods that facilitate recoil management.
Certain types of systems are known to produce recoil. These systems can include projectile weapons and also projected water disruptors. Systems that produce recoil can potentially damage support components that are used to carry, position or transport such systems. For example, unmanned ground vehicles (UGVs) used for explosive ordinance disposal (EOD) are often equipped with a projected water disruptor. As is known, conventional projected water disruptors make use of a water-projectile shaped charge to disable explosive devices. The water projectile shaped charge disables the explosive device by separating the trigger mechanism (e.g., timer, battery, fuse) from the main charge faster than the time it takes for these devices to trigger an explosion. Recoil forces produced by a projected water disruptor typically exceed 4000 lbf.
Various systems have been proposed to prevent recoil producing devices from potentially damaging the underlying support systems that are used to carry, position and/or transport the recoil producing device. But many of these systems are not well suited for UGVs or other robotic systems, in part due to the excessive weight and/or bulk that they add to such systems. It is challenging to provide recoil management system that is both light weight and capable of absorbing very large shock impulses.
A system for managing an impulse force produced by a recoil producing device includes an impulse force coupler. The impulse force coupler is configured to be securely attached to a recoil producing device (RPD) to facilitate indirect transfer of at least a portion of an impulse force produced by the RPD. The system includes a rigid structure which is configured to indirectly receive the portion of the impulse force, and a constraining structure which is configured to removably receive a deformable recoil absorber (DRA) structure having a predetermined size and geometry. At least one air vent can be provided to facilitate the passage of air from an interior portion of the constraining structure which receives the DRA structure.
According to one aspect, the rigid structure can be comprised of a housing which is configured to be interposed between the RPD and a positioning system which supports the RPD. Further, the impulse force coupler can be configured to be fixed to a barrel part of the RPD. The constraining structure is arranged to constrain a deformation of the DRA structure under a condition where the impulse force is indirectly transferred to the rigid structure through the DRA structure.
According to a further aspect, the DRA structure is comprised of a semi-rigid material. The material is permanently deformable so that it will remain in a deformed state after being acted upon by the impulse force. For example, the DRA structure can be comprised of a metal foil. In some scenarios, the DRA structure is comprised of a multiplicity of hollow cells formed of a semi-rigid material. The multiplicity of hollow cells can each comprise a hexagonal shape to define a honeycomb structure.
In some scenarios the housing defines a tubular cavity, and the tubular cavity is configured to facilitate travel therein of the impulse force coupler along at least a portion of an elongated length of the tubular cavity to facilitate the deformation. In such a scenario, the constraining structure can be at least partially defined by at least one interior wall of the tubular cavity. The constraining structure can be further at least partially defined by an exterior surface of the barrel part.
According to one aspect, a barrel part of the RPD can extends though the tubular cavity. In such a scenario, the DRA structure, when received in the constraining structure, at least partially surrounds a part of the RPD. Further, the DRA structure will have an elongated tubular shape which includes a central bore so that a barrel portion of the RPD extends through the central bore when the DRA structure is received in the constraining structure.
The solution also concerns a recoil managed disruptor. The recoil managed disruptor is comprised of a disruptor device having a barrel from which a slug of material is fired. A piston is mechanically coupled to the disruptor device. A housing configured to support the disruptor includes a deformable recoil absorber (DRA) constraint structure. The DRA constraint structure is configured to removably receive therein a sacrificial DRA structure comprised of a semi-rigid material. The piston is responsive to a recoil force produced when the disruptor device is fired to travel along an axial length of the housing and thereby cause a permanent deformation of the DRA structure within the DRA constraint.
The solution also concerns a method for managing recoil of a disruptor device. The method involves securing an impulse force coupler directly or indirectly to a first portion of the disruptor device. A deformable recoil absorber (DRA) structure having a predetermined size and geometry, is removably constrained in a position between a portion of the impulse force coupler and a rigid structure. The rigid structure is secured directly or indirectly to a support structure to facilitate a firing position of the disruptor device. The method continues with a firing operation which involves firing the disruptor to produce an impulse force. Thereafter, at least a portion of the impulse force is transferred to the rigid structure through the DRA structure. This operation produces a permanent deformation of the DRA structure, whereby a portion of the impulse force is absorbed by the DRA structure. The impulse force that is transferred to the rigid structure is modified by the DRA structure with respect to at least one of magnitude and duration.
This disclosure is facilitated by reference to the following drawing figures, in which like numerals represent like items throughout the figures, and in which:
It will be readily understood that the components of the systems and/or methods as generally described herein and illustrated in the appended figures could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description, as represented in the figures, is not intended to limit the scope of the present disclosure, but is merely representative of certain implementations in various different scenarios. While the various aspects are presented in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
This disclosure concerns systems and methods for managing an impulse force produced by a recoil producing device. According to one aspect, the systems and methods can involve a recoil managed disruptor device.
A system for managing an impulse force produced by a recoil producing device (RPD) 102 is shown in
A rigid structure 108 is provided to indirectly receive the portion of the impulse force which is transferred by the impulse force coupler 106. According to one aspect, the rigid structure 108 can comprise a housing 109. A system as disclosed herein for managing an impulse force will also include a constraining structure. In some scenarios, a constraining structure can comprise part of the rigid structure 108. For example, in the system which is shown in
A DRA structure 112 will advantageously have a predetermined size and geometry so that it can be received snugly within the constraining structure. When the RPD produces an impulse force 114 the DRA structure 112 serves as an intermediary to at least partially transfer the force to the rigid structure. However, the materials and construction of the DRA structure are advantageous arranged such that it will be at least partially deformed or crushed while serving to facilitate the force transference operation described herein. This deformation or crushing action can be observed by comparing
In
The deformation or crushing of the DRA structure 112 as disclosed herein will absorb as heat a portion of the energy associated with the impulse force 114 that is produced by the RPD recoil action. The deformation of the DRA structure 112 will also serve to convert the high-force short duration impulse force 114 from the RPD 102 to a lesser magnitude force 116 having a longer duration. Accordingly, the peak magnitude of force 116 that is actually transmitted to the rigid structure is reduced as compared to a scenario where the impulse force 114 is communicated directly to the rigid structure. Changing the force characteristics in this way can prevent potential damage to a supporting structure that is used to position the RPD.
Many RPDs, such as a disruptor device, can be comprised of an elongated tubular barrel 104 which is used to explosively eject a slug of some type of material, such as water. Accordingly a recoil management system disclosed herein can in some scenarios be fitted directly on the barrel 104 of such devices. Such an arrangement is illustrated in
The elongated length of the tubular construct can be configured to extend at least partially over the length of the barrel 104 as shown in
In
In some scenarios, the internal surface 120 which defines the elongated internal bore 118 can also define at least a portion of the constraining structure. The internal bore 118 of the tubular construct can have a cylindrical configuration as shown. According to one aspect, the housing 109 which comprises the rigid structure 108 can be configured as a hollow tubular canister formed of a cylindrically shaped wall 120. However, it should be appreciated that the solution is not so limited and other bore configurations are also possible. For example, rather than have a circular cross-section to define a cylinder as shown, the internal bore could have a square, rectangle or polygon shaped internal bore.
In the scenario shown in
In some scenarios, the toroidal-shaped piston ring type of impulse force coupler 106 can be permanently fixed to the barrel. In other scenarios, the impulse force coupler is configured so that it can be removably secured to the barrel 104. For example, in some scenarios, an impulse force coupler 106 as described herein can be attached to the barrel 104 by means of a clamping action with the help of a suitable fastener (e.g., a threaded screw) 130. Such a configuration can be advantageous to allow the impulse force coupler 106 to be retrofitted to an existing barrel 104.
In an exemplary arrangement, the housing 109 can include a removable cap plate 107, which is removably secured to the housing by suitable means. For example, in some scenarios, the cap plate can be threaded onto an end of the housing 109 as is shown in
The housing 109 also has a lip 132 disposed at an end of internal bore 118 opposed from the cap plate 107. In some scenarios, the lip can extend circumferentially around the internal bore 118. The purposes of the lip 132 is to limit the travel barrel 104 with respect to the housing 109 along the axial direction 122, so that the impulse force coupler 106 and attached barrel cannot slide past the lip. Consequently, with the DRA structure 112 removably captured between the cap plate 107 and the lip 132, the housing is securely fixed to the barrel 104. The DRA structure 112 is a semi-rigid structure so that relative travel of the barrel with respect housing 109 is prevented, except when the disrupter is fired. Further, the DRA structure, when received in the constraining structure, at least partially surrounds a part of the RPD (in this case, the barrel 104).
With the foregoing arrangement, it can be observed in
The DRA is retained by a retention lip 136 defined by the cap plate 107 and a crush face 134 of the impulse force coupler 106. The DRA structure 112 is snugly fitted in the cylindrically-shaped interstitial space provided between the barrel and the interior wall 120. As such, when the disruptor 102 is fired, the DRA structure 112 will be crushed or deformed in the axial direction 122 between the crush face 134 and the retention lip 136. But the DRA structure 112 will be constrained with respect to such deformation by interior wall 120 and by the barrel exterior surface 128. Accordingly, deformation of the DRA structure will be prevented in directions not aligned with the axial direction. These constraining structures ensure consistent and controlled deformation of the DRA structure in response to known recoil forces.
After the disruptor is fired and the DRA structure has been deformed, the DRA structure can be removed from the housing 108. This process can be facilitated by removing the cap plate 107, and sliding the housing off the barrel 104 so that the DRA structure 112 is at least partially exposed as shown in
In an alternative scenario, the impulse force coupler 106 can be temporarily unclamped or removed from the barrel 104, after which the DRA structure 112 can be slid off the end 138 of the barrel 104 in a direction opposite to that which is shown in
In some scenarios, it may be desirable to remove the DRA structure 112 without removing disruptor end portion 103 and/or impulse force coupler 106. In such scenarios, the removal process can be facilitated by forming the DRA structure with at least one slit or a gap extending along its elongated length so that the DRA structure can be more easily stripped from the barrel.
In other scenarios, the DRA structure can be comprised of two or more parts 112a, 112b, as shown in
The rigid structure 108 is configured so that it can be mounted to a positioning system which is designed to support the RPD. For example, rigid structure 108 can include a mounting face 302 as shown in
It will be appreciated that a positioning system that is used to support an RPD 102 can be any of a wide variety of systems and structures. For example, the supporting structure can be relatively simple mechanical system comprising a base be arranged so that it forms a stable platform when placed on the ground. The base can have mounted thereto a jointed mechanical arm. The arm can include one or more movable joints which are manually reconfigurable to allow the mechanical arm to be set to a particular pose which is desired by a user to facilitate use of an RPD. In other scenarios, the supporting structure can comprise a robotic arm which includes a plurality of actuated joints that allow one or more segments of the arm to be positioned using a control system. In some scenarios, a robotic arm as described can be disposed on an unmanned ground vehicle (UGV).
Such a scenario is illustrated in
It will be appreciated that with the arrangement as shown and described with respect to
The DRA structure 112 is advantageously comprised of a semi-rigid material which is configured to remain in a deformed state after being acted upon by the impulse force. In some scenarios, the DRA structure is comprised of a metal foil material which is configured to crush or deform in response to the firing of the disruptor. The exact configuration of the DRA structure is not critical provided that it achieves a desired level of energy absorption and adequately transitions the recoil force from a short duration large magnitude force, to a longer duration, lesser magnitude force. However, it has been determined that certain structures can be particularly well suited for carrying out this purpose. For example, in some scenarios the DRA structure is comprised of a multiplicity of hollow cells formed of a semi-rigid material (such as metal foil). According to one aspect, the multiplicity of hollow cells can be formed so that each cell comprises a hexagonal shape to define a honeycomb structure. An advantage of these types of structures are that they are relatively strong and lightweight. The alignment direction of each cell can be along the direction of the axis 122. Of course, other DRA structure types are also possible and the solution disclosed herein is not intended to be limited in this regard.
From the foregoing it will be understood that the solution can in some scenarios concern a recoil managed disruptor, where the disruptor device includes a barrel from which a slug of material is fired. In such scenarios, an impulse force coupler 106 can be thought of as functioning in the manner of a piston. In this context, the piston is responsive to a recoil force produced when the disruptor device is fired. This recoil force causes the piston to travel along a length of a canister or housing 109 where it crushes the DRA structure within the constraining structure (e.g., inner housing wall 120 and outer barrel wall 128). The housing 109 is configured to facilitate relative travel of the disruptor barrel 104 through the housing along a recoil axis 122 when the disruptor device 102 is fired. For example, such travel can be facilitated by a bushing 137 which guides the barrel as it travels through the housing. In a scenario described herein, the barrel is also guided along the length of the housing by the outer peripheral face 126 of the force coupler 106.
A recoil management system as described herein can be particularly compact and lightweight because the constraining structure is simple, and the DRA structure extends snugly around at least a portion of the barrel 104 when received in the DRA constraining structure. In an exemplary arrangement, an impulse force coupler serves multiple functions. For example, it guides the barrel as it travels along the length of the housing 109, it helps secure the housing to the barrel, it couples the impulse or recoil forces to the DRA structure, and it provides the crush face which is used to actually deform the DRA structure. Similarly, the disruptor barrel is used as a part of the constraining structure, aided by the cylindrical canister housing 109
The solution disclosed herein also concerns a method for managing recoil of a disruptor device 102. In this regard, the method can involve securing an impulse force coupler 106 directly or indirectly to a first portion of the disruptor device 102 (e.g., a first portion of the barrel). The method can further involve removably constraining a DRA structure as described herein, where the DRA has a predetermined size and geometry. The DRA structure is retained during a disruptor firing operation in a position between a portion of the impulse force coupler (e.g., impulse force coupler 106) and a rigid structure (e.g., housing 109, cap plate 107).
The method can further involve securing the rigid structure directly or indirectly to a support structure (e.g. a robotic arm 802) to facilitate a firing position of the disruptor device. The disruptor is then fired to produce an impulse or recoil force, and at least a portion of the impulse force is transferred to the rigid structure (e.g., housing 109) through the DRA structure 112. This operation can involve the barrel 104 traveling through a portion of the housing during the force transference process. This travel causes an impulse coupling device 106 to crush the DRA structure, thereby producing a permanent deformation of the DRA structure. Consequently, a portion of the impulse force is absorbed by the DRA structure and the characteristics of the impulse force are modified before they are transferred to the rigid structure.
In the method disclosed herein the DRA structure 112 is at least partially constrained by the rigid structure of housing 109. Further, it will be appreciated that the DRA structure 112 is at least partially constrained during the deformation process by a second portion of the disruptor device (e.g., a second part of the barrel 104). As will be understood from the foregoing discussion the first and second portion of the disruptor device referenced herein can be both selected to be a portion of a barrel of a disruptor device from which a slug of material is ejected.
The solution disclosed herein is advantageous because it is simple, lightweight, inexpensive and effective. The housing 109 can be a simple cylindrical canister with a threaded end for receiving the cap plate 107. The cylindrical canister can be formed of a strong, lightweight material such as a metal or fiber reinforced polymer. The system has no moving parts to fail or wear out. The sacrificial element (i.e., the DRA structure) can be quickly replaced after each firing operation. Moreover, the system can be retrofitted to existing disruptors with minimal effort. It can be used with any type of RPD, and different types of DRA structures having different deformation characteristics can be used in different circumstances.
In some scenarios, the housing 109 can be comprised of a canister or other type of structure which is configured to enclose all or part of the DRA structure. When the piston or impulse force coupler 106 travels along a length of the housing to crush the DRA structure, it can potentially result in compression of air within the housing in the space where the DRA structure is constrained. If not addressed, this pressure build-up can adversely affect the force modification function facilitated by the DRA structure. In such scenarios, an excessive amount of force can be transmitted from the housing to the supporting or positioning structure. Accordingly, vent holes are advantageously provided in portions of the constraining structure. In the example shown in
As is known, a projected water disruptor mounted to a robotic arm of a UGV can be well suited for allowing EOD personnel to disable an explosive device while remaining a safe distance from a potentially dangerous explosive device. Projected water disruptors make use of a water-projectile shaped charge to disable explosive devices. The water projectile shaped charge disables the fuse and/or anti-tampering device of the explosive device faster than the time it takes for these devices to trigger an explosion. Recoil forces produced by a projected water disruptor typically exceed 4000 lbf. Accordingly, the recoil management system disclosed herein can be advantageously used or combined with a conventional projected water disruptor. In such a scenario, the barrel 104 would be one that is configured to explosively eject a slug of water. However, it should be appreciated that a disruptor 102 as referenced herein is not limited to a projected water disruptor. Instead, a disruptor include devices which are capable of ejecting projectile a wide variety of slugs comprised of various different material types. Further it should be understood that a disruptor device is merely one example of an RPD which is contemplated for use with the solution presented herein.
Furthermore, the described features, advantages and characteristics disclosed herein may be combined in any suitable manner. One skilled in the relevant art will recognize, in light of the description herein, that the disclosed systems and/or methods can be practiced without one or more of the specific features. In other instances, additional features and advantages may be recognized in certain scenarios that may not be present in all instances.
As used in this document, the singular form “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. As used in this document, the term “comprising” means “including, but not limited to”.
Although the systems and methods have been illustrated and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In addition, while a particular feature may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. Thus, the breadth and scope of the disclosure herein should not be limited by any of the above descriptions. Rather, the scope of the invention should be defined in accordance with the following claims and their equivalents.
