Breaching ram

Abstract

The breaching ram can have : a ram body being elongated and having a head disposed at a front end of its length; a first handle mounted to a rear portion of the ram body; a second handle mounted to an intermediary location of the ram body; and a first resilient element longitudinally biasing the first handle to a first equilibrium position defined longitudinally relative the ram body, a second resilient element longitudinally biasing the second handle to a second equilibrium position defined longitudinally relative the ram body.

Description

BREACHING RAMBACKGROUND

[0001] Door breaching is a process used by military, police or emergency services to force open closed or locked doors, and can be performed by a variety of methods. In North America and in Europe, it is common for police and firefighter forces, for instance, to have a specialized door breaching tool referred to as a ram (also known as a battering ram or police ram). A typical ram at the time of filing this specification operated somewhat similarly to battering rams of the middle ages except that it is configured in a manner to be handled by a single person rather than more than one person. A ram has an elongated body having a substantial mass and which is swung against the door to be breached by the user. The momentum and the sudden impact caused by its movement against the door is used as a source of energy to break the door open.

[0002] While existing door breaching rams are relatively widespread and satisfactory to a certain degree, there remains room for improvement. In particular, there have been reports of users of the door breaching rams injuring themselves while using the tool.SUMMARY

[0003] A door ram may be relatively heavy, such as in the 20-35 lb range, and have handles spaced apart from an elongated central mass to manipulate the device. It was found that simply handling and moving such a device, namely given the weight, could lead to some injuries. It was also found that energy from the impact could recoil to the arms of the users via the handles, and lead to some injuries, particularly in the form of wrist injuries, but other areas of the human body could be affected as well.

[0004] It was found that the worst case in terms of impact is the case where the ram is swung against a door, but the door does not open or break, fully resisting the impact. The force of this impact was measured, and it was found to cause the greatest levels of sudden deceleration of the elongated ram body, which could be in the 100 to 250 g range for instance (where g is the gravitational acceleration of about 9.8m / s2). When the structural connection between the ram body and the handles is stiff, this sudden deceleration essentially entirely transfers over to the handles, leading to sudden deceleration of the wrist in the 100 to 250 grange. Norm ISO 5349 addresses impacts to the wrists. Impacts above 50 g are considered to be high impacts which are likely to generate injuries. Impacts in the range of 10 to 50 g are considered moderate and less likely to generate injuries in a robust subject, whereas impacts below 10 g considered harmless to robust subjects.

[0005] There was thus a need for reducing the impacts the wrists, ideally to below 50 g or even lower, without significantly affecting the efficiency of the ram.

[0006] It was found that, at least in some embodiments, this could be achieved by introducing resilient elements which bias the handles to an equilibrium position by default, but which can elastically deform to allow relative longitudinal motion between the handles and the ram body, forward of the equilibrium positions, when the ram body is subjected to a deceleration, prior to returning to the equilibrium positions. In this context, the expression “longitudinal” is used in the sense of “in the orientation of the length of the ram body” and in this frame of reference, the expression “transversal” will be used below to refer to an orientation transversal to the length of the ram body.

[0007] In accordance with one aspect, there is provided : a breaching ram comprising : a ram body being elongated and having a head disposed at a front end of its length; a first handle mounted to a rear portion of the ram body; a second handle mounted to an intermediary location of the ram body; and a first resilient element longitudinally biasing the first handle to a first equilibrium position defined longitudinally relative the ram body, a second resilient element longitudinally biasing the second handle to a second equilibrium position defined longitudinally relative the ram body.

[0008] In accordance with another aspect, there is provided a method of operating a breaching ram having a ram body, the ram body having a head disposed at a front end of a length, the ram further having a first handle mounted to a rear portion of the ram body, and a second handle mounted to an intermediary portion of the ram body, the method comprising : a user manually holding the breaching ram including hands of the user grasping corresponding ones of the first handle and of the second handle, and swinging the breaching ram longitudinally, thereby causing an impact between the head of the breaching ram and an obstacle, the obstacle imparting a deceleration of between 100 and 250 g to the ram bodyduring the impact; and a first resilient element and a second resilient element elastically yielding during the impact and thereby allowing relative longitudinal movement between the first handle and the ram body as well as between the second handle and the ram body, the elastic yielding limiting the deceleration at the first handle and at the second handle to below 50 g during the impact.

[0009] All technical implementation details and advantages described with respect to a particular aspect of the present invention are self-evidently mutatis mutandis applicable for all other aspects of the present invention.

[0010] Many further features and combinations thereof concerning the present improvements will appear to those skilled in the art following a reading of the instant disclosure.DESCRIPTION OF THE FIGURES

[0011] Figs. 1A and 1 B are side elevation views of a user manipulating a breaching ram in a process of breaching a door, with Fig. 1A showing the user taking the swing and Fig. 1 B showing the instant of impact;

[0012] Fig. 2 is an oblique view of an example of a breaching ram;

[0013] Fig. 3 is a fragmented oblique view of an example handle assembly of a breaching ram;

[0014] Fig. 4A and 4B are cross-sectional views taken along cross-section lines 4A-4A and 4B-4B of Fig. 2, respectively;

[0015] Fig. 4C are schematic views of electrical circuits including Wheatstone bridges;

[0016] Fig. 5A and 5B are oblique views of compartments of the breaching ram of Fig. 2, shown exploded.DETAILED DESCRIPTION

[0017] Fig. 1A and 1 B show an example method of operating a breaching ram 10. In this example, the breaching ram 10, better seen in Fig. 2, has two handle assemblies 12, 14, each bearing a corresponding handle 16, 18 and mounted to a corresponding portion of a rambody 20. The ram body 20 is elongated and has a head 22 at a front end of its length. The breaching ram 10 has a first handle 16 mounted to a rear portion of the ram body 20 and a second handle 18 mounted to an intermediary location of the ram body 20. The rear portion can be a rear half of the ram body 20 for instance, taken along its length, whereas the intermediary location can be between the point of attachment of the first handle 16 and the head 22.

[0018] Referring to Figs. 1A and 1 B, the user holds the breaching ram 10. More specifically, the user holds the handles 16, 18 of the breaching ram 10 with his / her hands. The user begins the operation of the breaching ram by positioning his / her feet firmly on the ground in front of the door to be breached. The user then proceeds to pull the breaching ram 10 backward and upward, folding the front elbow, into the position shown in Fig. 1A. At that point, the user releases the pull and begins his / her swing, driving the head 22 of the breaching ram 10 against the door and causing an impact between the head 22 of the breaching ram 10 and the door, as shown in Fig. 1 B. The impact causes a sudden deceleration of the breaching ram 10, and the sharpness and amplitude of this deceleration may vary depending on the circumstances.

[0019] In this example, the door yields to the breaching ram and breaks open, which is the intended conclusion of the method of operation. The yielding of the door limits the amplitude of the impact.

[0020] In some scenarios, however, the breaching attempt will fail or otherwise not succeed at the first try. In such cases, the impact against the door may have a significantly higher amplitude than when the door yields. This higher amplitude was measured, in some cases, to reach or exceed 200 g of sudden deceleration of the ram body, for instance.

[0021] It was found that at least in some embodiments, it could be preferred for the breaching ram 10 to have resilient elements disposed in the load path extending between the handles 16, 18 and the ram body 20. More specifically, such resilient elements can bias the handles 16, 18 to an equilibrium position, but elastically deform when significant decelerations occur, to allow a certain degree of longitudinal motion of the handles 16, 18 relative the ram body 20. It was found that in some embodiments, such resilient elements can reduce the deceleration at the handles 16, 18. For instance, in the case where a longitudinally-orienteddeceleration of 200 g is applied to the head 22 of the ram body 20 exposed above, the resiliently limited relative motion of the handles 16, 18 relative the ram body 20 could allow to limit the longitudinally-oriented deceleration to below 50 g, below 40 g, below 30 g, and even lower.

[0022] The example of a breaching ram 10 presented in Fig. 2 has resilient elements. More specifically, this breaching ram 10 can be seen to generally have a ram body 20 being elongated and having a head 22 disposed at a front end of its length. The breaching ram 10 further has a first handle 16 and a second handle 18. The first handle 16 is mounted to a rear portion of the ram body 20, whereas the second handle 18 is mounted to an intermediary location of the ram body 20, between the rear portion and the head 22.

[0023] The handles 16, 18 are mounted to the ram body 20 by a corresponding pair of braces 24, 26. As shown more clearly in Fig. 3, showing pair of braces 24, pivoting joints 28, 30 are provided between the pairs of braces 24 and the ram body 20. Pair of braces 26 can be constructed in a similar manner, with pivoting joints provided between pair of braces 26 and the ram body 20. In this example, the resilient elements are embodied in the form of spider couplers integrated to the pivoting joints 28, 30. In this example, the front handle assembly 14 is identical to the rear handle assembly 12 and only the rear handle assembly 12 is thus shown in Fig. 3.

[0024] More specifically, each brace 32, 34 is connected at one end to the handle 16, and at the other end to the ram body via the pivoting connection 28, and the pivoting connection bears a pair of spider couplers 36, one of which is shown via fragmentation. Spider couplers 36 include a resilient member which is referred to as a “spider” 38. The spider 38 is, roughly, star shaped, and has a number circumferentially interspaced radial protrusions 40, relative the transversally-oriented axis of the pivoting joint 28. Spider couplers 36 also have two elements referred to as hubs 42, 44, extending from axially opposite sides of the spider 38. Each hub 42, 44 has a number of circumferentially interspaced prongs which penetrate in the gaps between pairs of adjacent radial protrusions 40 of the spider 38. The first hub 42 is made integral and structurally connected to the handle 16, whereas the second hub 44 is made integral and structurally connected to the ram body 20. In this specific example, the first hub 42 is morespecifically integrated to the other end of each brace 32, 34. Each radial protrusion 40 is trapped circumferentially between a prong of the first hub 42 and a prong of the second hub 44.

[0025] The prongs are thus engaged circumferentially between alternating pairs of radial protrusions 40 of the spider 38. More specifically, the gaps between adjacent radial protrusions 40 are engaged alternatingly by a prong of the first hub 42, a prong of the second hub 44, a prong of the first hub 42, and so forth, when taken in a circumferential direction around the pivoting axis. Accordingly, when a longitudinal force is applied to the ram body, the resistance from the user’s hands on the handles will act to pivot the handle 16 around the transversally-oriented pivoting joint 28 within which the spider coupler 28 is integrated. This causes namely circumferential / tangential compression of the radial protrusions 40 of the spider 38 between prongs of both hubs 42, 44. The spider 38 being made of an elastic material, such as a rubber for instance, it can elastically deform due to the compression, in a limited manner. While the elastic deformation may be limited, such as not being visible or just barely visible to the naked eye, the radial length of the braces 32, 34 act as a lever arm for the handle 16 which can pivot, within the elastic domain of the spider 38, just enough to allow a longitudinal relative motion of the handle 16 relative the ram body 20, which decreases the longitudinally-oriented deceleration of the handles 16, 18.

[0026] In this example, the first handle 16 is mounted to the rear portion of the ram body 20 by a first pair of braces 24, and the second handle 18 is mounted to the intermediary location along the ram body 20 by a second pair of braces 26. The braces of each pair 24, 26 are transversally interspaced from one another, and their end which is remote from the handle bears a corresponding hub and prongs. In this example, for instance, the braces extend transversally from the ram body, at 90 degrees, and the pivoting of the handles 16 around the axis of the spider couplers 28 forms a circumferential motion which is almost perfectly longitudinal. In some other embodiments, the motion of the handles 16 relative the ram body 20 may be much farther from being perfectly longitudinal, and still be partially longitudinal and satisfactory. For instance, in one embodiment, a rear one of the pairs of braces may extend at 45 degrees relative the length of the ram body, and the movement of the handle upon impact may be partially longitudinal and partially upward, for instance.

[0027] Various alternate mechanisms can embody the resilient elements in alternate embodiments. For instance, in some embodiments, the braces themselves may be designed (e.g., shaped and configured, and made of a correspondingly elastic material) to bend to allow a forward motion of the handles relative the ram body upon impact, in a manner to limit the longitudinally-oriented deceleration to below 50 g at the handles even when the longitudinally- oriented deceleration is of, say, 200 g at the head. In yet other embodiments, the base of the braces can be slidingly mounted to the ram body via longitudinal guides, for instance, and the sliding movement may be limited only by resilient elements such as coil springs integrated to the longitudinal guides, on both a forward and backward side of the base of the braces, and used to bias the longitudinal position of the braces, and hence the handles, to the equilibrium position while elastically yielding and allowing longitudinal motion of the braces and of the handles upon impact. Many other possible embodiments are possible.

[0028] Referring back to Fig. 2, it can, in certain embodiments, be convenient to make the breaching ram 10 adjustable in one or more way. In the example presented in Fig. 2, the braces and pivoting connections associated to the handles are adjustable in two ways. Firstly, the angle at which each pair of brace 24, 26 extends relative to the ram body 20 is adjustable by loosening and retightening the pivotal connections. Secondly, the longitudinal position at which each pair of brace 24, 26 connects to the ram body 20 is adjustable by way of longitudinally oriented guide rails 46, 48, and either one of the pair of braces 24, 26, or both, can be adjusted by loosening the connection to the corresponding guide rail 46, 48, displacing the pair of braces 24, 26 along the guide rail 46, 48, and tightening the connection to the guide rail 46, 48 in the desired position. Such adjustability features are optional.

[0029] Moreover, configuration of mass of the breaching ram 10 can be adjustable. In this example, a plurality of weight supports 50 are provided along the ram body 20, onto which weights can be selectively attached or removed in a manner to adjust the overall weight, and the relative position of the center of gravity, of the ram body 20. A rear end plate support 52 is also provided onto which different end plates bearing different masses may be selectively attached or removed. Such adjustability features are optional.

[0030] One or more, such as any combination, of such adjustability elements can be convenient to test different configurations in an effort to optimize the configuration of thebreaching ram either overall, and / or optimize the configuration specifically to the morphologic features of a given user.

[0031] Fig. 4 presents a cross-sectional view of the forward end of the ram body 20, namely the head 22. As shown in this embodiment, the head 22 is provided with a rounded (spherical cap shaped) forward face and is fastened at the forward end of the ram body 20. The fastening, rather than say, soldering, is optional but can be configured to conveniently allow to interchange the head 22 with a head of another geometry in some embodiments, or simply to easily replace a damaged head.

[0032] In the illustrated embodiment, the breaching ram 10 is configured in a manner to allow measuring the deceleration. More specifically, in this embodiment, the head 22 is received by a support fixture 24. Even more specifically, the support fixture 24 has a central, forwardly- oriented conical support 60 forming a male member, and the head 22 has a mating, centrally disposed, forwardly-oriented conical cavity 62 forming a female member which engages with the male member. The male member is structurally connected to an annular structural ring 66 made integral to a main portion of the ram body 20 via an elastically deformable annular web 68. Indeed, the annular web 68 can be configured such that it may very slightly deform, allowing the central conical member 60 to move very slightly, in the longitudinal orientation, relative the annular structural ring 66, when the head 22 is subjected to the impact. In one embodiment, this deformation ability can be harnessed to measure the forces of the impact. More specifically, one or more strain gauges 70, 72 may be disposed against the annular web 68. A reading from the strain gauges 70, 72 can be used as a measurement of the force of the impact. In one embodiment, one or more pair of strain gauges 70, 72 each including two diametrically interspaced strain gauges 70, 72 electrically connected in a Whetstone bridge configuration may be used. An example configuration having two such pairs of strain gauges 70, 72, disposed at 90 degrees from one another relative a longitudinal axis coinciding with the length of the ram body 20, is shown in Fig. 4B, and the corresponding Whetstone bridge connections are presented in Fig. 4C. Such a configuration may allow obtaining information not only about the force of the impact (e.g., by averaging the measurements obtained from the two Wheatstone bridges), but also about the orientation of the impact (e.g.,by comparing the measurements obtained by different ones of the strain gauges or different pairs of strain gauges).

[0033] In the embodiment presented in Fig. 2, the breaching ram 10 can include two compartments 76, 78, presented in greater detail at Fig. 5A and 5B. Referring to Fig. 5A, a first compartment 76 can be an electronics compartment. The electronics compartment may include a housing 80 made integral to a face plate 82, and an electronics card 84, such as a printed circuit board (PCB), disposed within the housing. The electronics card 84 can have a computer formed by one or more electronic chips and electrical connections. The computer can have a processing unit communicatively coupled to non-transitory memory. In this embodiment, the PCB is secured to a wall of the housing via flexible supports 86 which can elastically deform in a manner to yield upon the impact of the breaching ram 10 against an obstacle.

[0034] Referring to Fig. 5B, a second compartment 78 can be a battery compartment. The battery compartment 78 may include a housing 88 made integral to a face plate 90, and batteries 92 can be disposed within the housing 88. Resilient elements 94, such as foam padding for instance, may be disposed between the batteries 92 and a front wall and a rear wall of the housing in a manner to absorb the shock from the impacts.

[0035] As can be understood, the examples described above and illustrated are intended to be exemplary only. More particularly, it will be noted that the concept of integrating mechanical links having an elastic effect between the handles and the element of impact, or the more specific concept of integrating a spider coupler, can be embodied in different contexts than the one specifically described above. For instance, one or two spring elements can be integrated into the mechanical link between handles and an impact body of other tools which can be affected by impacts of comparable magnitude, such as a demolition mass or a jackhammer to name two examples. The scope is indicated by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A breaching ram comprising : a ram body being elongated and having a head disposed at a front end of its length; a first handle mounted to a rear portion of the ram body; a second handle mounted to an intermediary location of the ram body; a first resilient element longitudinally biasing the first handle to a first equilibrium position defined longitudinally relative the ram body; and a second resilient element longitudinally biasing the second handle to a second equilibrium position defined longitudinally relative the ram body.

2. The breaching ram of claim 1 wherein the first resilient element and the second resilient element are operable to elastically deform when a longitudinally-oriented deceleration of 200 g is applied at the head, thereby allowing relative movement of the first handle and of the second handle at least partially longitudinally away from the first and second equilibrium positions, in a manner to limit the longitudinally-oriented deceleration to below 50 g at the first handle and at the second handle.

3. The breaching ram of claim 2 wherein the first resilient element and the second resilient element are operable to limit the longitudinally-oriented deceleration to below 30 g at the first handle and at the second handle.

4. The breaching ram of any one of claims 1 to 3 wherein the first resilient element and the second resilient element each include at least one spider coupler.

5. The breaching ram of claim 4 wherein each at least one spider coupler includes a pair of transversally interspaced spider couplers, each one of the spider couplers having a spider being star-shaped and made of resilient material, the spider having annularly interspaced protrusions extending radially from a corresponding, transversally-orientedpivot axis, each radial protrusion trapped circumferentially between a first prong made integral to the ram body and a second prong made integral to the corresponding handle.

6. The breaching ram of any one of claims 1 to 5 wherein the first handle is mounted to the rear portion of the ram body by a first pair of braces, and the second handle is mounted to the intermediary location by a second pair of braces.

7. The breaching ram of claim 6 wherein the first pair of braces form the first resilient element, and the second pair of braces form the second resilient element.

8. The breaching ram of claim 6 or 7 wherein an angle of at least one of the first pair of braces and of the second pair of braces relative the ram body is adjustable.

9. The breaching ram of any one of claims 6 to 8 wherein a location of attachment of at least one of the first pair of braces and of the second pair of braces relative the length of the ram body is longitudinally adjustable.

10. The breaching ram of any one of claims 1 to 9 wherein the head is fastened to a support fixture, the support fixture made integral to a main portion of the ram body.

11. The breaching ram of claim 10 wherein the support fixture has a forwardly-oriented conical support connected to the main portion of the ram body by an annular web bearing at least one strain gauge, and the head has a forwardly-oriented conical cavity matingly engaged with the forwardly-oriented conical support of the support fixture.

12. The breaching ram of claim 11 wherein the at least one strain gauge includes at least one pair of diametrically interspaced strain gauges connected in a Wheatstone bridge configuration.

13. The breaching ram of claim 11 or 12 wherein the main portion of the ram body has a cavity slidingly receiving a compartment, the compartment housing a printed circuit board connected to the strain gauges, the printed circuit board supported, within the compartment, via resilient, flexible supports which are configured to elastically deform when subject to a sudden deceleration.

14. The breaching ram of any one of claims 1 to 13 further comprising a plurality of weight supports configured for selective attachment, or removal, of weights allowing to change the mass of the ram body and to change the position of the center of mass of the ram body.

15. A method of operating a breaching ram having a ram body, the ram body having a head disposed at a front end of a length, the ram further having a first handle mounted to a rear portion of the ram body, and a second handle mounted to an intermediary portion of the ram body, the method comprising : a user manually holding the breaching ram including hands of the user grasping corresponding ones of the first handle and of the second handle, and swinging the breaching ram longitudinally, leading to an impact between the head of the breaching ram and an obstacle, the obstacle imparting a deceleration of between 100 and 250 g to the ram body during the impact; and a first resilient element and a second resilient element elastically yielding during the impact and thereby allowing relative longitudinal movement between the first handle and the ram body as well as between the second handle and the ram body, the elastic yielding limiting the deceleration at the first handle and at the second handle to below 50 g during the impact.

16. The method of claim 15 wherein the first handle and the second handle are secured to the ram body via corresponding braces, further comprising adjusting the angle of at least one of the corresponding braces prior to said steps of holding and swinging.

17. The method of claim 16 further comprising adjusting a point of attachment of at least one of the corresponding braces along the length of the ram body prior to said steps of holding and swinging.

18. The method of claim 15 further comprising mounting at least one weight or removing the at least one weight to the ram body prior to said steps of holding and swinging.

19. The method of claim 15 further comprising measuring the deceleration of the ram body during the impact, and storing the measurement in a non-transitory memory housed within the ram body.

20. The method of claim 19 further comprising extracting a compartment housing the non-transitory memory from the ram body subsequently to said storing.

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