Patent Publication Number: US-2023138685-A1

Title: Connector for a firearm accessory

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application claims the priority of Australian Patent Application 2021903497, filed Nov. 2, 2021, which is incorporated by reference as if expressly set forth in its entirety herein. 
     TECHNICAL FIELD 
     The present invention relates to suppressors for guns. In particular, the invention relates to a connector assembly for attaching a firearm accessory such as a suppressor to a muzzle device such as a flash hider attached to the muzzle of a firearm. 
     BACKGROUND ART 
     A gun is a device that uses the expansion of a gas to propel a projectile. The gas can take several forms, such as compressed air stored in a canister attached to the gun. Firearms are a sub-type of gun that use the expansion of a gas created by combustion to propel a projectile. A combustible material such as gun powder is stored within a projectile cartridge. A firing mechanism in the firearm is used to ignite the combustible material. The combustion process creates the gas. The heat of combustion increases the temperature of the gas, which causes it to expand to an area of lower pressure. 
     The primary exit from the firearm is through the open end of the gun barrel. As a result, the gas expands towards the open end of the firearm barrel. That expansion is transferred to the projectile, propelling it out from the firearm barrel. The creation and expansion of the gas is a fast process. Accordingly, the projectile exits the firearm barrel at high speed. The generation and expansion of the gas also creates significant noise in the form of a blast wave. 
     That blast wave is undesirable for a number of reasons. Firstly, the blast wave creates a loud noise, which can damage a person&#39;s ears. Repeated exposure to blast waves will result in hearing loss. Secondly, the noise of the blast wave makes the use of guns unpleasant. That may be relevant where people use guns for recreational purposes such as target shooting. Thirdly, the blast wave can create a safety hazard. For instance, police may use guns around volatile gases such as those present in meth labs, or the flash and noise may attract enemy fire. 
     Devices called suppressors or silencers are used to control the gas expansion and thereby minimise the adverse effects it creates. 
     One common type of suppressor is a device which is configured to be attached to the end of a gun barrel. These devices include an inlet and an outlet, and a connecting passageway. In-use a projectile fired by the gun passes through the inlet, along the passageway, exiting the suppressor via the outlet. 
     These suppressors include a series of internal baffles which define chambers within the suppressor. The gas generated during firing of the projectile is able to expand into the chambers. The chambers are arranged such that a first chamber is comparatively larger than the volume of the gun barrel. Accordingly, the first chamber provides a large volume into which the gas may expand. The gas can subsequently expand into adjacent chambers in the suppressor. Together, the chambers facilitate a gradual expansion of the gas. As a result, the expansion of the gas is slower than were the suppressor not used, which minimises the noise created by the blast wave. As the gas expands from the end of the gun barrel, unburnt fuel mixed with the gas exiting the gun barrel ignites causing a flame or ‘flash’ of fire to be emitted from the end of the barrel after the projectile has exited the firearm. Such a flash can affect the vision of the person firing the firearm, especially when firing the firearm at night. A flash emitted from the barrel of the firearm is therefore undesirable. 
     A flash hider is a muzzle device attached to an end of the gun barrel of a firearm to suppress or reduce the size of the flame or flash emitted from the end of the barrel upon firing. Many different flash hider designs are provided. One particular well known design is an ‘A2’ slotted flash comprising a cylindrical body with five longitudinal slots spaced apart around the body. Often a flash hider remains attached to the muzzle of a firearm. If noise suppression of the firearm is required a suppressor is preferably fitted over the flash hider, to fit the suppressor to the firearm without the need to remove the flash hider from the muzzle of the firearm. Connection arrangements for connecting a suppressor to a flash hider are known. However, these connection arrangements often present connection difficulties, in both connecting a noise suppressor to and removing from a flash hider. Flash hiders such as the A2 flash hider are a cheap commodity type item. The fitment of a noise suppressor to a flash hider can be a ‘loose’ or poor fit due to poor manufacturing tolerances of the flash hider. There also may be a lack of a seal between the suppressor and the flash hider which reduces the effectiveness of the suppressor. Also, with the lack of a seal, carbon deposits created during firing can reach connector components. A suppressor can be difficult to remove from a flash hider due to the build up of carbon deposits binding interfacing surfaces of the suppressor and the flash hider together. 
     Ideally the connection of a noise suppressor to a flash hider is secure and is quick and easy to make and break. Furthermore the connection of other firearm accessories such as blank firing adapters or blast redirectors to a muzzle device attached to the muzzle of a firearm should be secure and easy to make and break. 
     Accordingly, in light of the foregoing it would be advantageous to have an improved connector for connecting a noise suppressor or other firearm accessory to a flash hider or other muzzle device attached to the muzzle of a firearm which addresses any one or more of the foregoing problems. 
     All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country. 
     DISCLOSURE OF THE INVENTION 
     It is an object of the present invention to address one or more of the foregoing problems or at least to provide the public with a useful choice. 
     According to a first aspect of the present invention, there is provided a connector assembly for connecting a firearm accessory to a muzzle device for a firearm, the connector assembly comprising:
         a first connector part, and a second connector part engaged to the first connector part by a threaded engagement, the first connector part presenting a first engagement surface,   at least two clamp members configured to receive the muzzle device therebetween, the clamp members coupled to the second connector part to be axially and rotationally retained thereto, each of the clamp members presenting a second engagement surface to engage the first engagement surface, and   wherein rotation of the first connector part relative to the second connector part in a first direction moves the first connector part from a first relative axial position to a second relative axial position to engage the first engagement surface against the second engagement surfaces to drive the clamp members radially inwards against the muzzle device in an inward radial position to clamp the muzzle device and connect the firearm accessory to the firearm.       

     Rotation of the first connector part relative to the second connector part in an opposite second direction moves the first connector part from the second relative axial position to the first relative axial position to allow the clamp members to move radially outwards from the inward radial position to an outward radial position to allow the connector assembly to be removed from the muzzle device. 
     In some embodiments, at least one said clamp member comprises a radially inwardly facing surface to engage a feature on the muzzle device to prevent relative rotation between the second connector part and the muzzle device when the clamp members are in the inward radial position. 
     In some embodiments, the radially inwardly facing surface is a flat surface to engage a spanner flat on the muzzle device or comprises a protrusion or an indent to engage a corresponding indent or protrusion on the muzzle device. 
     In some embodiments, the first engagement surface of the first connector part is an annular inclined surface, and/or the second engagement surface of each clamp member is a circumferentially extending portion of an annular inclined surface. 
     In some embodiments, the first and/or second engagement surface comprises a conical portion. 
     In some embodiments, each clamp member has a projection or recess engaging a corresponding recess or projection on the second connector part, the projection and/or recess extending perpendicular to the longitudinal axis of the connector assembly, to retain the clamp members axially and rotationally to the second connector part and provide for sliding movement therebetween to allow the clamp members to move radially. 
     In some embodiments, one or more of the clamp members comprises a (second) feature to engage a corresponding axial feature on the muzzle device to axially locate the connector assembly to the muzzle device. 
     In some embodiments, the feature of the clamp member is a radial inward projection to engage a recess on the muzzle device. 
     In some embodiments, each clamp member comprises a said feature such that the features extend substantially around the full circumference of the muzzle device to engage a corresponding annular feature on the muzzle device. 
     In some embodiments, the connector assembly comprises at least one spring between each clamp member and the second connector part to bias the clamp members radially inwards. 
     In some embodiments, the radially inward facing surfaces of the clamp members clamp the respective features on the muzzle device without a clamping force applied between other surfaces of the clamp members and the muzzle device. 
     In some embodiments, clamp members are configured so that there is a circumferential gap between adjacent clamp members when the clamp members are in the radially inward position. 
     In some embodiments, the clamp members are configured to substantially encircle an outer surface of the muzzle device when in the radial inward position and clamped to the muzzle device. 
     In some embodiments, the clamp members are configured to form a substantially continuous ring around the muzzle device when in the inward radial position. 
     In some embodiments, the clamp members are configured to provide a circumferential seal extending substantially around a full circumference of the muzzle device when in the radial inward position and clamped to the muzzle device. 
     In some embodiments, the circumferential seal is between the clamp members and the muzzle device and/or between the first engagement surface and the second engagement surfaces. 
     In some embodiments, the clamp members are configured so that, at an axial location of the muzzle device, a maximum radial gap between the clamp members and a circumference of the muzzle device is less than about 500 microns, or less than about 200 microns, or about 100 microns or less when the clamp members are in the radial inward position and clamped to the muzzle device. 
     In some embodiments, the clamp members are configured so that a circumferential gap between adjacent clamp members is less than about 500 microns, or less than about 200 microns, or about 100 microns or less when in the radial inward position and clamped to the muzzle device. 
     In some embodiments, the connector assembly comprises a mechanism to drive the clamp members from the inward radial position to an outward radial position when the first connector part is in or moved to the first relative axial position to allow a muzzle device to be received in or removed from the connector assembly. 
     In some embodiments, the mechanism is a wedge or cam mechanism comprising one or more wedge members or cam surfaces configured to engage each or a respective clamp member to drive the clamp members radially outwards. 
     In some embodiments, each wedge member comprises a first wedge surface to engage a corresponding surface on a said clamp member and an oppositely arranged second wedge surface to engage a corresponding surface on an adjacent said clamp member, wherein the wedge member is moved relative to the clamp members to drive the clamp members radially apart. 
     In some embodiments, the wedge members move radially. 
     In some embodiments, the clamp members move on a first radial line and the wedge members move on a second radial line perpendicular to the first radial line, and
         the first and second wedge surfaces and/or the corresponding surfaces are inclined to the second radial line so that when the first connector part is in the first relative axial position, movement of the wedge members from a radial outwards position to a radial inwards position drives the clamp members radially outwards.       

     In some embodiments, the wedge members are configured to be pressed inwards by a user to move the clamp members radially outwards when the first connector part is in the first relative axial position. 
     In some embodiments, the wedge members move axially relative to the second connector part and the clamp members,
         wherein the first and second wedge surfaces and/or the corresponding surfaces on the clamp members are inclined to a longitudinal line on which the wedge members move so that axial movement of the wedge members drives the clamp members radially outwards.       

     In some embodiments, the wedge members are rotationally coupled to the first connector part to move axially with the first connector part and allow relative rotation therebetween so that:
         as the first connector part is moved axially towards the second connector part from the first relative axial position to the second relative axial position, the wedge members move axially to allow the clamp members to move radially inwards to the inward radial position to clamp the muzzle device, and   as the first connector part is moved axially away from the second connector part from the second relative axial position to the first relative axial position, the wedge members move axially relative to the clamp members to drive the clamp members to move radially outward.       

     In some embodiments, the wedge members are integrally formed together with a ring in a single wedge component. 
     In some embodiments, the wedge component is rotationally coupled to the first connector part to move axially with the first connector part and allow relative rotation therebetween. 
     In some embodiments, the cam mechanism comprises a cam component rotationally coupled to the second connector part to rotate relative to the second connector part, the cam component comprising a cam surface or cam follower to act on a corresponding cam follower or cam surface on each clamp member,
         wherein rotation of the cam component from a first position to a second position relative to the second connector part causes the cam followers to move along the cam surfaces to move the clamp members radially outwards from the radial inward position to the radial outward position.       

     In some embodiments, the mechanism comprises a lever pivotally coupled to each clamp member to drive the clamp members from the radial inwards (clamped) position to the radial outwards position. 
     In some embodiments, each lever is pivotally coupled at a fulcrum to the second connector part, a coupled end of the lever is pivotally coupled to a clamp member and a free end of the lever extends from the fulcrum to be accessible from an outside of the second connector part, and
         with the clamp members at the radially inward position, each lever is pivoted about the fulcrum to present the free end of each lever at an outward position, and   pressing the free ends of the levers move the free ends to an inwards position, pivoting the levers at the fulcrum to move the coupled end of the levers and the clamp members to the radially outwards position.       

     In some embodiments, the clamp members are captured axially between the first connector part and the second connector part. 
     In some embodiments, the connector comprises two diametrically opposed clamp members. 
     In some embodiments, the first connector part is screwed to or integrally formed with a body of the firearm accessory at an entry end of the body. 
     In some embodiments, the mechanism for driving the clamp members from the inward radial position to the outward radial position comprises a cam component configured to engage an outer surface of the second connector part and to move longitudinally with respect to the first and second connector parts. 
     In some embodiments, the cam component does not rotate relative to the second connector component. 
     In some embodiments, the clamp members are provided inside the second connector component and the second connector component comprises apertures in opposed sides thereof, the apertures configured to allow cam follower portions provided at opposite ends of each clamp member to extend through the apertures, and wherein the cam component comprises a substantially cylindrical outer wall and two pairs of cam races provided to an inner surface of the cylindrical outer wall, each cam race configured to engage a respective cam follower. 
     In some embodiments, the connector comprises biasing means provided between the cam component and the second connector component and configured to bias the cam component towards the first connector component. 
     In some embodiments, the cam component comprises first indexing means configured to engage second indexing means provided to the first connector component, the indexing means configured to resist relative rotation of the cam component and the first connector component when the first indexing means is engaged with the second indexing means. 
     In examples, the first and/or second engagement surfaces comprise conical portions and wherein the second connector part comprises a further conical portion configured to engage the clamp members to drive the clamp members radially inwards against the muzzle device. 
     In examples, each clamp member comprises a tapered projection on a first longitudinal face and a complementary recess on an opposite longitudinal face, such that in use, the tapered projection of one of the clamp members engages the recess of the other clamp member. 
     Throughout this specification, the word “comprise”, or variations thereof such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps. 
     Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further aspects of the present invention will become apparent from the ensuing description which is given by way of example only and with reference to the accompanying drawings in which: 
         FIG.  1    is an isometric view of a connector assembly according to the present invention. 
         FIG.  2    is an exploded isometric view of the connector assembly of  FIG.  1    together with a flash hider. 
         FIG.  3    is a view on an entry end of the connector assembly with flash hider received therein and with the connector assembly in a clamped position. 
         FIG.  4    is a side view of the connector assembly with the connector assembly in an unclamped position and with a wedge mechanism pressing clamp members of the assembly radially outwards. 
         FIG.  5    is a sectional view on section line A-A in  FIG.  3    with the connector assembly in the clamped position and connected to the flash hider. 
         FIG.  6    is an enlarged view showing details in the circle designated E in  FIG.  5   . 
         FIG.  7    is a sectional view on section line B-B in  FIG.  4    with the connector assembly in the unclamped position and clamp members radially outwards. 
         FIG.  8    is a sectional view on section line D-D in  FIG.  4    with the connector assembly in the unclamped position and clamp members radially outwards. 
         FIG.  9    is a sectional view on section line C-C in  FIG.  5    with the connector assembly in the clamped position and connected to the flash hider. 
         FIG.  10    is a sectional view on section line F-F in  FIG.  5    with the connector assembly in the clamped position and connected to the flash hider. 
         FIG.  11    is a sectional view on section line B-B in  FIG.  4    with the connector assembly in the unclamped position but with wedge members in a radial outward position and clamp members in a radial inward position. 
         FIGS.  12 A to  12 C  show a clamp member of the connector assembly.  FIG.  12 A  is an isometric view,  FIG.  12 B  is an end view, and  FIG.  12 C  is a side view showing a radially inward side of the clamp member. 
         FIG.  13    is an isometric view of another connector assembly according to the present invention. 
         FIG.  14    is an exploded isometric view of the connector assembly and flash hider shown in  FIG.  13   . 
         FIG.  15    is a view on an entry end of the connector assembly of  FIG.  13    with flash hider received therein and with the connector assembly in an unclamped position. 
         FIG.  16    is a side view of the connector assembly with the connector assembly in a clamped position and connected to the flash hider. 
         FIG.  17    is a sectional view on section line G-G in  FIG.  15    showing the connector assembly in the unclamped position with the flash hider received therein. 
         FIG.  18    is a sectional view on section line I-I in  FIG.  17    showing the connector assembly in the unclamped position with the flash hider received therein. 
         FIG.  19    is a sectional view on section line K-K in  FIG.  17    showing the connector assembly in the unclamped position with the flash hider received therein. 
         FIG.  20    is a sectional view on section line H-H in  FIG.  16    showing the connector assembly in the clamped position connected to the flash hider. 
         FIG.  21    is a sectional view on section line J-J in  FIG.  16    showing the connector assembly in the clamped position connected to the flash hider. 
         FIGS.  22 A to  22 C  show a wedge component of the connector assembly of  FIGS.  13  to  21   .  FIG.  22 A  is an isometric view,  FIG.  22 B  is an end view, and  FIG.  22 C  is a side view. 
         FIG.  23    is an isometric view of another connector assembly according to the present invention. 
         FIG.  24    is an exploded isometric view of the connector assembly and flash hider shown in  FIG.  23   . 
         FIG.  25    is a view on an entry end of the connector assembly of  FIG.  23    with flash hider received therein and with the connector assembly in an unclamped position. 
         FIG.  26    is a side view of the connector assembly with the connector assembly in a clamped position and connected to the flash hider. 
         FIG.  27    is a sectional view on section line L-L in  FIG.  25    showing the connector assembly in the unclamped position with the flash hider received therein. 
         FIG.  28    is an enlarged view showing details in the circle designated P in  FIG.  27   . 
         FIG.  29    is a sectional view on section line N-N in  FIG.  27    showing the connector assembly in the unclamped position with the flash hider received therein. 
         FIG.  30    is a sectional view on section line Q-Q in  FIG.  27    showing the connector assembly in the unclamped position with the flash hider received therein. 
         FIG.  31    is a sectional view on section line M-M in  FIG.  26    showing the connector assembly in the clamped position connected to the flash hider. 
         FIG.  32    is a sectional view on section line O-O in  FIG.  26    showing the connector assembly in the clamped position connected to the flash hider. 
         FIG.  33    is a sectional view on section line N-N in  FIG.  27    with the connector assembly in the unclamped position but with a cam mechanism positioned so that clamp members are in a radial inward position. 
         FIGS.  34 A to  34 C  show a cam component of the connector assembly of  FIGS.  23  to  33   .  FIG.  34 A  is an isometric view,  FIG.  34 B  is an end view, and  FIG.  34 C  is a side view. 
         FIG.  35    is an isometric view of another connector assembly according to the present invention. 
         FIG.  36    is an exploded isometric view of the connector assembly and flash hider shown in  FIG.  35   . 
         FIG.  37    is a view on an entry end of the connector assembly of  FIG.  35    with flash hider received therein and with the connector assembly in an unclamped position. 
         FIG.  38    is a side view of the connector assembly with the connector assembly in a clamped position and connected to the flash hider. 
         FIG.  39    is a sectional view on section line R-R in  FIG.  37    showing the connector assembly in the unclamped position with the flash hider received therein. 
         FIG.  40    is a sectional view on section line T-T in  FIG.  39    showing the connector assembly in the unclamped position with the flash hider received therein. 
         FIG.  41    is a sectional view on section line V-V in  FIG.  39    showing the connector assembly in the unclamped position with the flash hider received therein. 
         FIG.  42    is a sectional view on section line S-S in  FIG.  38    showing the connector assembly in the clamped position connected to the flash hider. 
         FIG.  43    is a sectional view on section line U-U in  FIG.  38    showing the connector assembly in the clamped position connected to the flash hider. 
         FIG.  44    is a sectional view on section line T-T in  FIG.  39    with the connector assembly in the unclamped position but with a lever mechanism positioned so that clamp members are in a radial inward position. 
         FIGS.  45 A to  45 C  show a cap component of the connector assembly of  FIGS.  35  to  44   .  FIG.  45 A  is an isometric view,  FIG.  45 B  is an end view, and  FIG.  45 C  is a side view. 
         FIG.  46    is an image of prior art flash hiders. 
         FIG.  47    is an exploded isometric view of a flash hider and another connector assembly according to the present invention. 
         FIG.  48    is an alternative exploded isometric view of the flash hider and connector assembly of  FIG.  47   . 
         FIG.  49    is an exploded side view of the connector assembly of  FIG.  47   , excluding the clamp members. 
         FIG.  50    is an isometric view of a clamp member of the connector assembly of  FIG.  47   . 
         FIG.  50   a    is a side view of the clamp member of the connector assembly of  FIG.  47   . 
         FIG.  51    is an inner side view of a clamp member of the connector assembly of  FIG.  47   . 
         FIG.  52    is an exploded cross-section side view of the connector assembly of  FIG.  47   , excluding the clamp members. 
         FIG.  53    shows a side view of the connector assembly of  FIG.  47    in a clamped configuration. 
         FIG.  54    is a sectional view on section line AA-AA in  FIG.  53   . 
         FIG.  55    is a sectional view on section line BB-BB in  FIG.  54   . 
         FIG.  56    is a sectional view on section line CC-CC in  FIG.  55   . 
         FIG.  57    shows a side view of the connector assembly of  FIG.  47    in an unclamped configuration. 
         FIG.  58    is a sectional view on section line DD-DD in  FIG.  57   . 
         FIG.  59    is a sectional view on section line EE-EE in  FIG.  58   . 
         FIG.  60    is a sectional view on section line FF-FF in  FIG.  59   . 
     
    
    
     DETAILED DISCUSSION OF PREFERRED EMBODIMENTS 
     First Embodiment 
     A connector assembly  1  for connecting a suppressor  2  to a flash hider  3  is described with reference to  FIGS.  1  to  12 C . In use the flash hider  3  is connected to a muzzle of a firearm (not shown). The connector assembly  1  connects a suppressor  2  to the flash hider  3 , thus connecting the suppressor to the firearm via the flash hider. 
     The connector  1  has a first connector part  11  and a second connector part  12 . Each of the first and second connector parts are collars or annular members. The first and second connector parts  11 ,  12  are engaged together. The first and second connector parts are engaged by a threaded engagement. The first and second connector parts are threaded together to connect the suppressor to the flash hider. 
     The first connector part  11  may be connected to an entry end of a suppressor  2 , for example by a threaded connection, or may be internally formed with an entry end of the suppressor  2 . In the illustrated embodiment, the first connector part  11  is integrally formed with a suppressor body  2  of the suppressor at an entry end of the suppressor body. Only a portion (i.e. the entry end) of the suppressor body  2  is shown. The second connector part  12  is a nut (a back nut) that is engaged to the first connector part  12 . The second connector part  12  has an aperture  4  to receive the flash hider  3   
     While in the illustrated embodiment the first connector part is connected to the suppressor and the flash hider is received via the aperture in the second connector part, in an alternative embodiment, the second connector part may be connected to or integrally formed with a suppressor and the first connector part may form a back nut with an aperture to receive the flash hider into the connector assembly. 
     In accordance with the present invention, the connector has at least two clamp members  13 ,  14  to be arranged about an outer surface of the flash hider  3 . The clamp members  13 ,  14  are received in the second connector part  12 . The flash hider  3  is inserted into the connector assembly  1  via the aperture  4  to be received between the clamp members  13 ,  14 , and the flash hider  3  is removed from the connector assembly  1  via the aperture  4 . In the illustrated embodiment there are two diametrically opposed clamp members. However, there may be more than two clamp members to surround the flash hider when inserted into the connector assembly. The clamp members extend around a longitudinal axis of the connector assembly  1  to in use extend around and clamp to the flash hider. 
     The first connector part  11  has a first engagement surface  15  and each of the clamp members has a second engagement surface  16 . The first engagement surface  15  and/or the second engagement surfaces  16  are cam surfaces so that engagement between the first engagement surface and the second engagement surfaces by axial relative movement drives the clamp members  13 ,  14  radially inwards. The first engagement surface  15  and/or the second engagement surfaces  16  are tapered or inclined to the longitudinal axis of the connector assembly so that engagement between the first engagement surface and the second engagement surfaces by axial relative movement drives the clamp members  13 ,  14  radially inwards to clamp the outer surface of the flash hider. 
     For example, the first engagement surface  15  comprises an annular inclined surface, and/or each of the second engagement surfaces  16  comprises a circumferential portion of an annular inclined surface. The first engagement surface may be a truncated or part-conical surface and/or each of the second engagement surfaces may be a circumferential portion of a truncated or part-conical surface. The first engagement surface  15  faces radially inwards and the second engagement surfaces face radially outwards  16 , so that axial movement of the first connector part  11  towards the clamp members  13 ,  14  drives the clamp members radially inwards. A truncated/part conical surface and a circumferential portion of a truncated/part conical surface may simply be referred to as a ‘conical surface’, as in a ‘conical’ sealing surface. In the illustrated embodiment, the first engagement surface  15  is a conical surface and each second engagement surface  16  is a conical surface. 
     The clamp members  13 ,  14  are retained relative to the second connector part  12  in an axial direction. Rotation of the first connector part  11  relative to the second connector part  12  moves the first and second connectors parts  11 ,  12  axially together and therefore moves the first connector part  11  axially towards the clamp members  13 ,  14  to engage the first engagement surface  15  against the second engagement surfaces  16  to drive the clamp members  13 ,  14  radially inwards. With the first engagement surface engaging the second engagement surfaces, the clamp members are captured axially between the first and second connector parts, for example between the first engagement surface  15  on the first connector part and a flange  10  on the second connector part. Each clamp member  13 ,  14  has a radially inwardly facing surface  17  to engage a surface or feature on the flash hider  3 . Thus, rotation of the first connector part  11  relative to the second connector part  12  drives the clamp members  13 ,  14  radially inwards so that the radially inwardly facing surfaces  17  of the clamp members engage the flash hider  3  to clamp the connector to the flash hider. 
     The radial inwardly facing surface  17  of at least one of the clamp members engages a feature on the flash hider to prevent rotation of the second connector part relative to the flash hider. In the illustrated embodiment, each clamp member  13 ,  14  comprises a radially inwardly facing surface  17  to clamp to a spanner flat  5  on the flash hider  3 . The surface  17  engages a spanner flat to prevent relative rotation between the second connector part and the flash hider. For example, each clamp member  13 ,  14  has a flat radially inwardly facing surface  5  to clamp to a respective spanner flat  5  on the flash hider  3 . For example, an A2 flash hider (as illustrated in the Figures) has two diametrically opposed spanner flats  5 , and each diametrically opposed clamp member  13 ,  14 , has a corresponding (flat) surface  17  to engage the respective spanner flat. In some embodiments the radially inwardly facing surface  17  may be configured to clamp to more than one flat or spanner flat on the flash hider, for example two adjacent spanner flats (such as on an FN flash hider) or may be configured to clamp to other features on the flash hider. An FN flash hider has a hex and each clamp member may have a surface  17  to engage a respective spanner flat of the hex. A Surefire™ flash hider has a locking protrusion and one clamp member may have a radially inwardly facing surface configured to engage the protrusion to prevent relative rotation therebetween. An SA80 flash hider has a bayonet locking recess or indent and one clamp member  13 ,  14  may have a radially inwardly facing surface configured to engage a respective recess or indent to prevent relative rotation therebetween. 
     With reference to  FIGS.  5 ,  6  and  12 C , to axially retain the clamp members  13 ,  14  to the second connector part  12  and allow for radial movement of the clamp members  13 ,  14 , the second connector part  12  has a rail or projection  18  and/or recess or groove  19  to engage a corresponding rail/projection  20  and/or recess/groove  21  on each clamp member. The projections/rails or recess/grooves extend perpendicular to the longitudinal axis ( 6  in  FIG.  5   ) of the connector assembly. The projections/rails move along the corresponding recesses/grooves so that the clamp members move radially and perpendicular to the longitudinal axis of the connector assembly while preventing axial and rotational movement between the clamp members  13 ,  14  and the second connector part  12 . As shown in  FIGS.  5  and  12 C , each clamp member has a pair of projections or recesses that are radially spaced apart in a radial direction perpendicular to a radial direction in which the clamp member move. The pair of projections or recesses  20 ,  21  are captured by a corresponding pair of projections or recesses on the second connector part  12 , so that the clamp members are only free to move relative to the second member radially inwards and radial outwards on a plane coincident with and perpendicular to the longitudinal axis of the connector assembly. Thus each clamp member is restrained to move with a single degree of freedom only, being in a radial direction of the connector assembly. The clamp members are axially and rotationally fixed or retained to the second connector part. The clamp members are coupled to the second connector part so that relative axial and rotational movement between the clamp members and the second connector part is substantially prevented. Preventing relative rotation between the second connector part and the flash hider allows the first connector part  11  to be rotated relative to the second connector part to clamp the connector assembly to the flash hider without a requirement to hold the second connector part stationary. 
     One or more clamp members  13 ,  14  may further comprise a feature to engage a corresponding axial feature on the flash hider to axially locate the connector assembly to the flash hider. In the illustrated embodiment each clamp member  13 ,  14  includes a radial projection  22  (refer  FIG.  12 A ) to engage an annular recess  7  on the flash hider. The projection  22  extends circumferentially around an inner side of the clamp member  13 ,  14 . Alternatively each clamp member may comprise a circumferential groove to engage a circumferential projection on the flash hider. 
     In use, the connector assembly  1  is fitted over the flash hider  3  with the first and second connector parts  11 ,  12  in a first relative position such that clamp members  13 ,  14  are moveable to an outward radial position. With the clamp members in the radial outward position the flash hider may be inserted into the connector assembly via the aperture  4  so that the flash hider  3  is received in the connector assembly  1  between the clamp members  13 ,  14 , as shown in  FIG.  7   . The connector assembly  1  may be rotated (if necessary) so that the radially inwardly facing surfaces  17  of the clamp members  13 ,  14  locate to the corresponding features (the spanner flats in the illustrated embodiment) on the flash hider. 
     In a preferred embodiment, the connector assembly has at least one spring  23  between each clamp member  13 ,  14  and the second connector part  12 , to bias the clamp member from the outward radial position to an inward radial position. In the inward radial position, the radially inward surface  17  of at least one clamp member  13 ,  14  engages the respective feature on the flash hider to prevent relative rotation between the clamp members and therefore the second connector part. The springs provide a sufficient radial inward force to hold the clamp members in the radially inward position to prevent relative rotation between the clamp members and the flash hider, and therefore prevent relative rotation between the second connector part and the flash hider. Preferably the spring force is sufficient to allow the first connector part to be tightened onto the second connector part without a requirement to hold the second connector part stationary. Ends of springs (e.g. coil compression springs) may be located in a recess in the second connector part and a corresponding recess in the clamp member, as illustrated in  FIGS.  7  to  11   . 
     With the first and second connector parts  11 ,  12  in the first relative axial position ( FIG.  7   ) the connector assembly may be pushed over the flash hider. In some embodiments, an annular tapered/inclined surface or annular bevel  24  on a rear end of the clamp members may contact a front edge of the flash hider  3  to force the clamp members radially outwards against the spring bias as the connector assembly  1  is pushed onto the flash hider. Once the radially inwardly facing surfaces  17  of the clamp members  13 ,  14  align with the corresponding features on the flash hider, the clamp members  13 ,  14  move to the radial inward position under action of the spring bias ( FIG.  11   ). If a user pushes the connector assembly  1  onto the flash hider with the radial inwardly facing surfaces  17  azimuthally misaligned from the respective features on the flash hider, the user may rotate the connector assembly  1  relative to the flash hider to locate the radial inwardly facing surfaces  17  of the clamp members  13 ,  14  to the respective features on the flash hider  3  so that the clamp members move to the radially inward position. 
     With the clamp members in the radially inwards position, the connector assembly is axially aligned to the flash hider. For example, the inward projections  22  of the clamp members  13 ,  14  are received in the annular recess of the flash hider  3 . The connector assembly  1  may be axially aligned to the flash hider and with the radially inwardly facing surfaces  17  of the clamp members engaged with the respective features of the flash hider but unclamped to the flash hider, with the first and second connector parts in the first relative position, as shown in  FIG.  11   . 
     To connect (clamp) the connector assembly  1  to the flash hider the first connector part  11  is rotated relative to the second connector part  12  (and clamp members  13 ,  14 ) in a first direction of rotation to move the first connector part axially towards the second connector part  12  (and therefore the clamp members) to a second relative axial position. The first connector part is rotated relative to the flash hider while the second connector part carrying the clamp members remains stationary relative to the flash hider. As the first connector part  11  is moved axially towards the clamp members  13 ,  14  the first engagement surface  15  moves along or against the second engagement surfaces  16  to drive the clamp members  13 ,  14  radially inwards to clamp the radially inward facing surfaces  17  of the clamp members  13 ,  14  to the flash hider, as described above, and as illustrated in  FIGS.  9  and  10   . 
     To securely clamp the connector assembly to the flash hider, the radially inward facing surfaces  17  of the clamp members  13 ,  14  may clamp the respective features on the flash hider without a clamping force applied between other surfaces of the clamp members  13 ,  14  and the flash hider, so that the clamp members clamp to the respective features on the flash hider only. Features of the flash hider, such as the spanner flats or other features such as protrusions or indents, may be machined and/or have a higher tolerance compared to other surfaces of the flash hider. Clamping to such features may improve repeatability and ensure a tight secure connection between the connector assembly and the flash hider. 
     Other than at the radially inwardly facing surfaces  17  of the clamp member  13 ,  14  that engage the feature on the flash hider, the clamp members may be configured to provide a clearance space between the inside of the clamp members and an outside of the flash hider, so that the clamp members clamp to the respective features on the flash hider only. For example, the clamp members are configured to provide a clearance space between the clamp members and an outside diameter of the flash hider. 
     Furthermore, to ensure the clamp members clamp to the respective features on the flash hider, when in the radially inward position, there may be a gap between adjacent clamp members  13 ,  14 . For example, there is a gap between longitudinal faces  25  ( FIG.  12 A ) of adjacent clamp members  13 ,  14  with the clamp members clamped to the flash hider. 
     In a preferred embodiment, the clamp members  13 ,  14  provide a circumferential seal extending substantially around a full circumference of the flash hider  3 . Preferably the clamp members  13 ,  14  together substantially encircle an outer surface of the flash hider when clamped to the flash hider. The circumferential seal is preferably sufficient to prevent or restrict carbon deposits creating during firing of the firearm passing from the flash hider and rearwardly past the clamp members and/or provides a gas seal to substantially prevent gases escaping rearwardly from the suppressor. The circumferential seal may be provided at an exit side of the radial inwardly facing surfaces of the clamp members, i.e. at a location axially between the radial facing surfaces  17  and an exit end of the clamp members. 
     In some embodiments, a circumferential seal is formed between the clamp members and the flash hider. As described above, other than at the radially inwardly facing surfaces of the clamp member that engage the feature on the flash hider, the clamp members are configured to provide a clearance space between the inside of the clamp members and an outside of the flash hider. To provide a circumferential seal between the clamp members and the flash hider, preferably a clearance space or radial gap at a circumference of the flash hider between the flash hider and the clamp members is very small. For example, with the clamp members clamped to the corresponding features of the flash hider, at an axial location of the flash hider, the clamp members are configured to provide a maximum radial clearance space or gap around the circumference of the flash hider of less than about 500 microns, or less than about 400 microns, or less than about 300 microns, or less than about 200 microns, or about 100 microns or less. 
     As described above, to ensure the clamp members clamp to the respective features of the flash hider, the clamp members are configured so that there is a gap between adjacent clamp members when the clamp members are clamped to the flash hider. To provide a circumferential seal around the flash hider, preferably the gap between adjacent clamp members is very small. For example, with the clamp members clamped to the corresponding features of the flash hider, the clamp members are configured to provide a gap between adjacent clamp members (e.g. a gap between longitudinal faces  25  of adjacent clamp members  13 ,  14 ) of less than about 500 microns, or less than about 400 microns, or less than about 300 microns, or less than about 200 microns, or about 100 microns or less. Therefore, when clamped to the flash hider with the radially inwardly facing surfaces  17  engaging the respective features on the flash hider, the clamp members  13 ,  14  form a substantially continuous ring around the flash hider. 
     As described above, the clearance space or radial gap between the substantially continuous ring and the flash hider may very small to provide a circumferential seal between the clamp members and the flash hider. Alternatively, or additionally, the substantially continuous ring forms a circumferential seal between the first engagement surface  15  of the first (or second) connector part  11  and the engagement surfaces  16  of the clamp members  13 ,  14 . In such an embodiment, the first engagement surface and the second engagement surfaces are first and second sealing surfaces. 
     The substantially continuous ring provided by the clamp members  13 ,  14  encircling the flash hider is intended to reduce or prevent carbon deposits reaching clamped surfaces  17  and associated components of the connector assembly  1  to reduce the chance of the connector assembly binding to the flash hider. Alternatively, or additionally, the continuous ring provided by the clamp members is intended to provide a substantial gas seal to prevent or reduce gases escaping rearwardly from the suppressor, resulting in an improved efficiency in the suppression of noise. Furthermore, the radial inward projections  22  preferably extend substantially around the full circumference of the flash hider and may assist with providing a seal and/or a barrier to carbon deposits passing rearwardly. In an alternative embodiment, the flash hider may comprise an annular projection, and the clamp members may provide an annular groove to extend substantially around the full circumference of the flash hider to receive the annular projection. 
     To remove or disconnect the connector assembly  1  from the flash hider, the first connector part  11  is rotated relative to the second connector part  12  (and clamp members  13 ,  14 ) in a second direction of rotation to move the first connector part axially away from the second connector part from the second relative axial position to the first relative axial position. As the first connector part is moved axially away from the second connector part the first engagement surface  15  moves along or away from the second engagement surfaces  16  to allow the clamp members  13 ,  14  to move radially outwards to unclamp the radially inward facing surfaces  17  of the clamp members from the flash hider. When the clamp members have moved radially outwards to the radial outward position the connector assembly can be removed from the flash hider. 
     In a preferred embodiment, and as shown in the illustrated embodiment, the connector assembly includes a wedge mechanism to drive the clamp members  13 ,  14  from the radial inwards position to the radial outwards position to allow the flash hider to be inserted into and removed from the connector assembly.  FIGS.  7  and  8    show the wedge mechanism operated to drive the clamp members to the radial outwards position. 
     The wedge mechanism comprises one or more wedge members  30  configured to engage each clamp member  13 ,  14  to drive the clamp members radially outwards. In the illustrated embodiment the wedge mechanism comprises two wedge members  30 . Each wedge member comprises a first wedge surface  31  to engage a corresponding surface  33  on one clamp member  13  (a first said clamp member) and an oppositely arranged second wedge surface  32  to engage a corresponding surface  34  on an adjacent clamp member  14  (a second clamp member). The wedge member  30  is moved relative to the clamp members  13 ,  14  to wedge the adjacent clamp members apart. The clamp members  13 ,  14  are restrained to move radially relative to the central axis of the connector assembly, as described above. The wedge members wedge or drive the clamp members radially apart. The wedge members move radially. The wedge members  30  move perpendicular to a radial direction on which the clamp members  13 ,  14  move. Thus, the clamp members  13 ,  14  move on a first radial line and the wedge members  30  move on a second radial line perpendicular to the first radial line. As the wedge members move radially inwards, the clamp members move radially outwards. The first and second wedge surfaces  31 ,  32  and/or the corresponding surfaces  33 ,  34  are inclined to the radial line on which the wedge members move so that movement of the wedge members from a radial outwards position to a radial inwards position drives the clamp members radially outwards. 
     To connect the connector assembly to the flash hider, the wedge members  30  are pressed inwards to move the clamp members to the radial outwards position and the connector assembly is fitted over the flash hider  3 . For example, in the illustrated embodiment, each wedge member extends through an aperture in the second connector part to be accessible from an outside of the connector assembly. Where fitted, the springs drive the clamp members to the radial inward position when the wedge members are released, to engage the flash hider. The biasing of the springs biases the clamp members inwards and the wedge members outwards. The first connector part is then is rotated relative to the second connector part to clamp the clamp members to the flash hider as described above. To remove or disconnect the connector assembly  1  from the flash hider, the first connector part  11  is rotated relative to the second connector part  12  (and clamp members and wedge members) in a second direction of rotation to move the first connector part axially away from the second connector part and therefore the clamp members. As the first connector part is moved axially away from the clamp members the first engagement surface moves along or away from the second engagement surfaces to allow the clamp members to move radially outwards. Where springs are provided, the springs retain the clamp members in the radially inward position ( FIGS.  10  and  11   ). The user moves the wedge members  30  from the radial outwards position to the radial inwards position to move the clamp members  13 ,  14  from the radial inwards position to the radial outwards position ( FIGS.  7  and  8   ). The wedge members may be pressed radially inwards against the spring bias to move the clamp members radially outwards. When the clamp members have moved radially outwards to the radial outward position the connector assembly can be removed from the flash hider. 
     Second Embodiment 
       FIGS.  13  to  22 C  illustrate a second embodiment of a connector assembly  101  according to the present invention. Parts or features that are the same or similar to parts or features of the embodiment 1 described above with reference to  FIGS.  1  to  12    are identified by the same reference numerals or with a prefix of 1. Various parts or features of connector assembly  101  that are the same as parts or features of the above embodiment connector assembly  1  are not described again for brevity. 
     With reference to  FIGS.  13  to  22 C , the connector assembly  101  includes a first connector part  111  and a second connector part  112  and two clamp members  113 ,  114 . The clamp members are retained to the second connector part in an axial direction, for example by rails or grooves (not shown in  FIGS.  13  to  22 C ) as described above with reference to  FIGS.  5  and  6   . Rotation of the first connector part  111  relative to the second connector part  112  moves the first and second connectors parts axially together and therefore moves the first connector part towards the clamp members to engage the first engagement surface  15  against the second engagement surfaces  16  to drive the clamp members  113 ,  114  radially inwards. In a radial inward position, the clamp members  113 ,  114  engage and clamp to the flash hider  3 , by radial inward surfaces  17  engaging and clamping corresponding features on the flash hider  3 , as described for the above earlier embodiment.  FIGS.  20  and  21    show the clamp members in the radial inward or clamped position. 
     The connector assembly further comprises a wedge mechanism to drive the clamp members from the radial inwards (clamped) position to the radial outwards position to allow the flash hider to be inserted into and removed from the connector assembly.  FIGS.  18  and  19    show the wedge mechanism operated to drive the clamp members  113 ,  114  to the radial outwards position. 
     The wedge mechanism comprises one or more wedge members  130  configured to engage each clamp member  113 ,  114  to drive the clamp members radially outwards. In the illustrated embodiment the wedge mechanism comprises two wedge members  130 . Each wedge member comprises a first wedge surface  131  to engage a surface  133  on one clamp member  113  (a first said clamp member) and an oppositely arranged second wedge surface  132  to engage a surface  134  on an adjacent clamp member  114  (a second clamp member). The wedge member  130  is moved relative to the clamp members  113 ,  114  to wedge the adjacent clamp members apart. The clamp members are restrained to move radially relative to the central axis of the connector assembly. The wedge members wedge or drive the clamp members radially apart. 
     Unlike the earlier embodiment, in the embodiment of  FIGS.  13  to  22 C , the wedge members  130  move longitudinally, or axially relative to the second connector part  112  and the clamp members  113 ,  114 . The wedge members  130  are coupled to the first connector part  111  so that as the first connector part  111  is moved axially towards the second connector part  112  and therefore the clamp members  113 ,  114 , the wedge members move axially to allow the clamp members to move radially inwards to the radial inward position to clamp to the flash hider as described above. As the first connector part  111  is moved axially away from the second connector part  112  and therefore the clamp members  113 ,  114 , the wedge members  130  move axially relative to the clamp members to drive the clamp members to move radially outward. The first and second wedge surfaces  131 ,  132  and/or the corresponding surfaces  133 ,  134  on the clamp members are inclined to the longitudinal line on which the wedge members move so that axial movement of the wedge members  130  as the first connector part  111  moves axially away from the second connector part  112  drives the clamp members  113 ,  114  radially outwards. 
     In the illustrated embodiment, the wedge members  130  are integrally formed together with an annular member or ring in a single wedge component  135 . The wedge component  135  comprises the two wedge members  130 . The wedge members are arranged diametrically apart. However, there may be a single wedge member to engage two clamp members, or there may be more than two wedge members where there are more than two clamp members. For example, in one embodiment there may be three clamp members and three wedge members. 
     The wedge component  135  is rotationally coupled to the first connector part  111  to allow relative rotation between the first connector part  111  and the wedge component  135  and wedge members  130 , so that the wedge component moves axially without rotation as the first connector part  111  rotates to move axially. In the illustrated embodiment the wedge component  135  has a circumferentially extending shoulder  136  to engage and slide on circumferentially extending shoulders  137  on the first connector part (e.g. refer  FIGS.  14  and  22 A ). However, the wedge component  135  may be coupled to the first connector part by a circlip or any other known connection to axially retain the wedge component  135  to the first connector part  111  but allow relative rotation therebetween. 
     To connect (clamp) the connector assembly to the flash hider the first connector part is rotated relative to the second connector part (and clamp members and wedge members) in a first direction of rotation to move the first connector part and the wedge members axially towards the second connector part and therefore the first connector part axially towards the clamp members. As the first connector part and wedge members are moved axially towards the first connector part, the wedge surfaces  131 ,  132  of the wedge members  130  move along or away from the surfaces  133 ,  134  on the clamp members  113 ,  114  to allow the clamp members to move radially inwards, and the first engagement surface  15  of the first connector part  111  moves along the second engagement surfaces  16  of the clamp members  113 ,  114  to drive the clamp members radially inwards to clamp the radially inward facing surfaces  17  of the clamp members  113 ,  114  to the respective features on the flash hider, as illustrated in  FIGS.  20  and  21   . 
     To remove or disconnect the connector assembly  101  from the flash hider, the first connector part is rotated relative to the second connector part (and clamp members and wedge members) in a second direction of rotation to move the first connector part axially away from the second connector part and therefore the clamp members. As the first connector part is moved axially away from the clamp members the first engagement surface  15  moves along or away from the second engagement surfaces  16  to allow the clamp members to move radially outwards. Furthermore, the wedge members  130  move axially together with the first connector part  111 , so that the wedge surfaces  131 ,  132  of the wedge members  130  move along the corresponding surfaces  133 ,  134  on the clamp members  113 ,  114  to drive the clamp members  113 ,  114  radially outwards from the radial inwards position to the radial outwards position, as shown in  FIGS.  18  and  19   . Where the connector assembly  101  includes springs  23  to bias the clamp members inwards, axial movement of the wedge members  130  together with the first connector part  111  moves the clamp members  113 ,  114  radially outwards against the spring bias. When the clamp members have moved radially outwards to the radial outward position the connector assembly  101  can be removed from the flash hider. 
     Third Embodiment 
       FIGS.  23  to  34 C  illustrate a third embodiment of a connector assembly  201  according to the present invention. Parts or features that are the same or similar to parts or features of the embodiment 1 described above with reference to  FIGS.  1  to  13    are identified by the same reference numerals or with a prefix of 2. Various parts or features of connector assembly  201  that are the same as parts or features of the above embodiment connector assembly  1  are not described again for brevity. 
     With reference to  FIGS.  23  to  33 C , the connector assembly  201  includes a first connector part  211  and a second connector part  212  and two clamp members  213 ,  214 . The clamp members are retained to the second connector part in an axial direction. For example, the clamp members  213 ,  214  each comprise projections  221  received in corresponding grooves or recesses  218  provided in the second connector part  212  (refer  FIG.  24   ). The recesses extend perpendicular to the longitudinal axis of the connector assembly. The projections move along the corresponding recesses so that the clamp members move radially and perpendicular to the longitudinal axis of the connector assembly while preventing axial and rotational movement between the clamp members  213 ,  214  and the second connector part  212 . Each clamp member has a pair of projections that are radially spaced apart in a radial direction perpendicular to a radial direction in which the clamp member move. The pair of projections are captured by a corresponding pair of recesses on the second connector part  212 , so that the clamp members are only free to move relative to the second member radially inwards and radial outwards in a plane coincident with and perpendicular to the longitudinal axis of the connector assembly, as described for the first embodiment. Rotation of the first connector part  211  relative to the second connector part  212  moves the first and second connectors parts axially together and therefore moves the first connector part towards the clamp members to engage the first engagement surface  15  against the second engagement surfaces  16  to drive the clamp members  213 ,  214  radially inwards. In a radial inward position, the clamp members  213 ,  214  engage and clamp to the flash hider  3 , by radial inward surfaces  17  engaging and clamping corresponding features on the flash hider  3 , as described for the above earlier embodiment.  FIGS.  31  and  32    show the clamp members in the radial inward or clamped position. 
     The connector assembly further comprises a cam mechanism to drive the clamp members from the radial inwards position to the radial outwards position to allow the flash hider to be inserted into and removed from the connector assembly.  FIGS.  29  and  30    show the cam mechanism operated to drive the clamp members  213 ,  214  to the radial outwards position. 
     The cam mechanism comprises one or more cam surfaces configured to engage a cam follower to drive each clamp member radially outwards. In the illustrated embodiment, the cam mechanism comprises an annular cam component  235 . The cam component has an aperture  204 . The flash hider is inserted into and removed from the connector assembly via the aperture  204  of the cam component and the aperture  4  of the second connector part  212 . The cam component is rotationally coupled to the second connector part to rotate relative to the second connector part on the longitudinal axis of the connector assembly. In the illustrated embodiment the cam component  235  has a circumferentially extending shoulder  236  to engage and slide on circumferentially extending shoulders  237  on the second connector part  212  (e.g. refer  FIGS.  24  and  34 A ). However, the cam component  235  may be coupled to the second connector part by a circlip or any other known connection to axially retain the cam component  235  to the second connector part  212  but allow relative rotation therebetween. 
     The cam component has a cam surface to act on a corresponding cam follower on each clamp member. In the illustrated embodiment, the cam component has a first cam surface  231  to act on a cam follower  233  on one (first) clamp member  213 , and a second cam surface  232  to act on a cam follower  234  on the other (second) clamp member. The cam surfaces are provided on an axial wall of the cam component  235 . The cam surfaces  231 ,  233  extend from a radial inward position to a radial outward position ( FIG.  34 C ). Rotation of the cam component from a first position ( FIG.  33   ) to a second position ( FIG.  29   ) relative to the second connector part  212  causes the cam followers  233 ,  234  to move along the cam surfaces  231 ,  232  from the radial inward position to the radial outward position, to move the clamp members radially outwards from the radial inward position to the radial outward position. The illustrated embodiment is arranged so that approximately 45 degree rotation of the cam component moves the clamp members  213 ,  214  from the inward to outward positions. 
     With reference to  FIG.  34 C , in the illustrated embodiment, the cam component has a third cam surface  238  to act on the cam follower  233  on clamp member  213 , and a fourth cam surface  239  to act on the cam follower  234  on the other clamp member  214 . When the cam component is rotated to the second position, the third and fourth cam surfaces  238 ,  239  act on the cam followers  233 ,  234  to press the cam followers and therefore the clamp members  213 ,  214  radially inwards. Thus, the engagement surfaces  15 ,  16  drive the clamp members  213 ,  214  radially inwards at a forward end of the clamp members, and the cam surfaces  238 ,  239  drive the clamp members radially inwards at a rearward end of the clamp members. The cam component further comprises a radial inward projection  240  at a lead-in to each of the third and fourth cam surfaces. The cam followers  233 ,  234  must ride over the radial projections  240  to engage and disengage the third and fourth cam surfaces  238 ,  239 . Each radial projection provides a tactile feedback to the user between the cam mechanism driving the clamp members radially inwards and the cam mechanism driving the clamp members radially outwards. With the cam component positioned so that the cam followers  233 ,  234  are positioned between the radial inward projection  240  and the first and second cam surfaces  231 ,  232 , the clamp members are in a ‘neutral position’ being held against the flash hider by the spring bias only, and without the cam component driving the clamp members in the radial inward or outward directions. 
     In the illustrated embodiment, the cam followers  233 ,  234  are on the clamp members  213 ,  214  and the cam surfaces  231 ,  232  are on the cam component  235 . However, one skilled in the art will appreciate that the cam followers may be provided on the cam component and the cam surfaces on the first and second clamp members. 
     To connect (clamp) the connector assembly  201  to the flash hider  3  the cam component is rotated from the first position to the second position to move the clamp members radially outwards ( FIGS.  29 ,  30   ) and the connector assembly is fitted over the flash hider  3 . Where fitted, the springs drive the clamp members to the radial inward position when the cam component is released. The biasing of the springs biases rotation of the cam component away from the second position with the clamp members in the radial inwards position ( FIG.  33   ). The first connector part is then rotated relative to the second connector part (and clamp members) in a first direction of rotation to move the first connector part axially towards the second connector part and therefore the first connector part axially towards the clamp members. The first engagement surface  15  of the first connector part  211  moves along the second engagement surfaces  16  of the clamp members  213 ,  214  to drive the clamp members radially inwards to clamp the radially inward facing surfaces  17  of the clamp members  213 ,  214  to the respective features on the flash hider, as illustrated in  FIGS.  31  and  32   . Where provided with the third and fourth cam surfaces, the cam component may be rotated to the first position, to also drive the clamp members against the flash hider ( FIGS.  31 ,  32   ). 
     To remove or disconnect the connector assembly  201  from the flash hider, the first connector part is rotated relative to the second connector part (and clamp members) in a second direction of rotation to move the first connector part axially away from the second connector part and therefore the clamp members. As the first connector part is moved axially away from the clamp members the first engagement surface  15  moves along or away from the second engagement surfaces  16  to allow the clamp members to move radially outwards. Where springs are provided, the springs retain the clamp members in the radially inward position, even when the first connector part is in the first position ( FIG.  33   ). The cam component  235  is then rotated from the first position to the second position to drive the clamp members radially outwards from the radial inwards position to the radial outwards position ( FIGS.  29  and  30   ). This drives the clamp members outwards against the spring bias. When the clamp members have moved radially outwards to the radial outward position the connector assembly  201  can be removed from the flash hider. 
     Fourth Embodiment 
       FIGS.  35  to  45 C  illustrate a fourth embodiment of a connector assembly  301  according to the present invention. Parts or features that are the same or similar to parts or features of the embodiment 1 described above with reference to  FIGS.  1  to  12 C  are identified by the same reference numerals or with a prefix of 3. Various parts or features of connector assembly  301  that are the same as parts or features of the above embodiment connector assembly  1  are not described again for brevity. 
     With reference to  FIGS.  35  to  45 C , the connector assembly  301  includes a first connector part  311  and a second connector part  312  and two clamp members  313 ,  314 . The clamp members are retained to the second connector part in an axial direction. The coupling of clamp members  313 ,  314  to the second connector part  312  is as described above for the third embodiment, so that the clamp members  313 ,  314  move radially and perpendicular to the longitudinal axis of the connector assembly to move relative to the second member radially inwards and radial outwards in a plane coincident with and perpendicular to the longitudinal axis of the connector assembly. Rotation of the first connector part  311  relative to the second connector part  312  moves the first and second connectors parts axially together and therefore moves the first connector part towards the clamp members to engage the first engagement surface  15  against the second engagement surfaces  16  to drive the clamp members  313 ,  314  radially inwards. In a radial inward position, the clamp members  313 ,  314  engage and clamp to the flash hider  3 , by radial inward surfaces  17  engaging and clamping corresponding features on the flash hider  3 , as described for the above earlier embodiments.  FIGS.  42  and  43    show the clamp members in the radial inward or clamped position. 
     The connector assembly further comprises a lever mechanism to drive the clamp members from the radial inwards (clamped) position to the radial outwards position to allow the flash hider  3  to be inserted into and removed from the connector assembly  301 . The lever mechanism comprises a lever  341 ,  342  pivotally connected to each clamp member  313 ,  314 .  FIGS.  40  and  41    show the levers  341 ,  342  operated to drive the clamp members  313 ,  314  to the radial outwards position. 
     Each lever  341 ,  342  is pivotally coupled at a fulcrum  343  to the second connector part  312 . In the illustrated embodiment each lever is pivotally coupled to an annular member  346  that is connected to the second connector part, e.g. by welding. The annular member may be considered part of the second connector part  312 . A coupled end  344  of the lever is pivotally attached to a clamp member, and a free end  345  of the lever extends from the fulcrum to be accessible from an outside of the second connector part. With the clamp members at the radially inward position, the levers are pivoted about the fulcrum to present the free end of the levers at an outward position, as shown in  FIGS.  35 ,  38  and  43   . To drive the clamp members radially outwards, a user presses the free ends  345  of the levers  341 ,  342  to move the free ends of the levers to an inwards position, pivoting the levers at the fulcrum  343  to move the coupled end of the levers and the clamp members to the radially outwards position. In the illustrated embodiment the connector assembly comprises two diametrically opposed clamp members and two diametrically opposed levers. 
     To connect (clamp) the connector assembly  301  to the flash hider  3  the free ends of the levers are pressed inwards to move the clamp members to the radial outwards position and the connector assembly is fitted over the flash hider  3 . Where fitted, the springs drive the clamp members to the radial inward position when the levers are released. The biasing of the springs biases the free ends of the levers outwards. The first connector part is then rotated relative to the second connector part (and clamp members) in a first direction of rotation to move the first connector part axially towards the second connector part and therefore the first connector part axially towards the clamp members. The first engagement surface  15  of the first connector part  311  moves along the second engagement surfaces  16  of the clamp members  313 ,  314  to drive the clamp members radially inwards to clamp the radially inward facing surfaces  17  of the clamp members  313 ,  314  to the respective features on the flash hider, as illustrated in  FIGS.  42  and  43   . 
     To remove or disconnect the connector assembly  301  from the flash hider, the first connector part is rotated relative to the second connector part (and clamp members) in a second direction of rotation to move the first connector part axially away from the second connector part and therefore the clamp members. As the first connector part is moved axially away from the clamp members the first engagement surface  15  moves along or away from the second engagement surfaces  16  to allow the clamp members to move radially outwards. Where springs are provided, the springs retain the clamp members in the radially inward position, even when the first connector part is in the first position ( FIG.  44   ). The free ends of the levers are pressed inwards to drive the clamp members radially outwards from the radial inwards position to the radial outwards position ( FIGS.  40  and  41   ). This drives the clamp members outwards against the spring bias. When the clamp members have moved radially outwards to the radial outward position the connector assembly  301  can be removed from the flash hider. 
     Fifth Embodiment 
       FIGS.  47  to  58    illustrate a fifth embodiment of a connector assembly  501  according to the present invention. Parts or features that are the same or similar to parts or features of the embodiment 1 described above with reference to  FIGS.  1  to  12 C  are identified by the same reference numerals or with a prefix of 5. Various parts or features of connector assembly  501  that are the same as parts or features of the above embodiment connector assembly  1  are not described again for brevity. 
     The connector assembly  501  includes a first connector part  511  and a second connector part  512  and two clamp members  513 ,  514 . The clamp members  513 ,  514  are retained to the second connector part  512  in an axial direction, as is described further below. 
     The connector assembly  501  further comprises a cam mechanism to drive the clamp members  513 ,  514  from the radially inward position to the radially outward position, to allow the flash hider  3  to be inserted into and removed from the connector assembly  501 .  FIGS.  57  to  60    show the cam mechanism operated to drive the clamp members  513 ,  514  to the radial outwards position. 
     The cam mechanism comprises one or more cam surfaces configured to engage a cam follower to drive each clamp member radially inwards or radially outwards as required. In the illustrated embodiment, the cam mechanism comprises a cylindrical component  535 . The cylindrical cam component  535  is configured to fit over the second connector part  512  and to engage the second connector part  512  in a sliding fit. 
     The flash hider  3  is inserted into and removed from the connector assembly  501  via an aperture  504  of the second connector part  512 . 
     In the illustrated embodiment the cam component  535  comprises two pairs of cam races  540 ,  541 , each of which define opposing cam surfaces. The cam races  540 ,  541  define divergent paths. In the illustrated example the cam races  540 ,  541  are defined by a group of projecting portions  542  which project radially inward from an inner surface  543  of the cam component. In examples, the cam races  540 ,  541  are open towards a first end  545  of the cam component  535 . 
     The first clamp member  513  comprises cam follower portions  533  at each end of the clamp member  513  and the second claim member  514  comprises cam follower portions  534  at each end of the clamp member  514 . Each cam follower portion  533 ,  534  is configured to extend radially outward from the respective clamp member  513 ,  514 . 
     The clamp members  513 ,  514  are located inside the second connector part  512 . The second connector part comprises apertures  550  in the annular wall  551  through which the cam follower portions  533 ,  534  can extend in order to engage the cam races  540 ,  541 . 
     The cam component  535  is biased towards the first connector component  511  by a spring  552 . The spring  552  may be provided between a shoulder  553  of the second connector component  512  and an internal surface of a radially inwardly extending end wall  554  provided at the first end  545  of the cam component  535 . In examples, the outer surface of the radially extending end wall  554  may be provided with a plurality of indexing features, e.g. axially extending teeth, which engage complementary indexing features  556  provided to a shoulder of the first connector part  512 . In examples the indexing features  555 ,  556  form a Hirth joint. The indexing features  555 ,  556  resist rotation of the cam component  535  relative to the first component  511  when the cam component  535  is urged against the first component  511  by the spring  552 . 
     When the second connector component  512  is tightened onto the first connector  511  the cam component  535  is held against the first component  511  by the compressed spring  552  and the second component  512  moves towards the first component  511 . This movement moves the clamp members  513 ,  514  towards the first component  511  and moves the cam followers  533 ,  534  relative to the cam races  540 ,  541 . This movement of the cam followers  533 ,  534  relative to the cam races  540 ,  541  causes the clamp members  513 ,  514  to be moved radially inward to a position in which they can engage a surface or feature on the flash hider  3 . 
     In examples, final engagement of the clamp members  513 ,  514  with the flash hider  3  may be achieved by engagement of a tapered or inclined (e.g. conical) engagement surface  515  with the clamp members  513 ,  514 , in a similar manner to the example shown in  FIGS.  13 - 22   . In examples, the second connector component  512  may be provided with an opposing tapered or inclined surface  560  to act on the opposite side of each clamp member  513 ,  514 . 
     To release the connector  501  from the flash hider  3 , the cam component  535  is urged away from the first connector portion  511 , against the spring  552 . The first connector component  511  can then be rotated relative to the second connector component  512 , for example by three full turns. Movement of the first connector component  511  away from the second connector component  512  releases the clamp members  513 ,  514  from the action of the engagement surface  515  and opposed surface  560 . 
     When the cam component  535  is released, the spring  552  again urges the cam component  535  towards the first component  511 . This causes relative movement between the second component  512  and the cam component  535 . The consequential movement of the cam races  540 ,  541  relative to the cam followers  533 ,  534  causes the clamp members  513 ,  514  to be moved radially outward to a position in which they disengage a surface or feature on the flash hider  3 . 
     In one form of the technology each clamp member  513 ,  514  may be provided with a tapered projection  570  which extends from one longitudinal face  525   a  of the clamp member  513 ,  514 . The opposite longitudinal face  525   b  may be provided with a complementary recess  580 . In use, each projection  570  engages the recess  580  of the opposing clamping member, to thereby provide a check for the gas, in the event the longitudinal faces  525   a ,  525   b  are not touching when the flash hider is fully engaged. 
     Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims. The invention has been described with reference to the connection of a suppressor to a flash hider by example only. One skilled in the art will appreciate that the invention described herein may be used to connect any firearm accessory to a muzzle device attached to the muzzle of a firearm. For example, a connector according to the invention may be used to connect a suppressor, a blank firing adapter, a blast redirector device or other accessory to a flash hider or other muzzle device such as a muzzle brake or recoil compensator. 
     While the invention has been described in connection with what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments. On the contrary, it is intended that the specification covers various modifications and equivalent arrangements included within the spirit and scope of the invention. Also, the various embodiments described above may be implemented in conjunction with other embodiments, e.g., aspects of one embodiment may be combined with aspects of another embodiment to realize yet other embodiments, Further, each independent feature or member of any given assembly may constitute an additional embodiment.