FIREARMS LOCK

Abstract: A firearm lock comprises a substantially cylindrical body of three annular sections (12, 14, 16). First and third sections (12, 14) are of rigid construction and first section (12) is provided with a locking device (18) attached to a connecting bar (20) which passes through all three sections. The connecting bar (20) has a threaded part which engages with a nut (22) fixedly attached to the third section (14). The second section (16) located between the first section (12) and third section (14) is of a flexible and relatively incompressible material such as rubber. The lock is placed in the barrel of a firearm preferably at the breech end and the locking device (18) is operated to rotate the bar (20). The rotation of the bar causes axial displacement of the third section (14) which is prevented from rotating itself by frictional engagement with the barrel walls of the firearm. This displacement compresses the second section (16) causing a radial expansion thereof and a corresponding frictional engagement with the barrel inner wall preventing removal of the lock therefrom.

Description: FIREARMS LOCK The present invention is licensed exclusively to Royal Ordnance pic of Euxton Lane, Euxton, Chorley, Lanes. PR7 6AD, England. The present invention relates to a firearms lock for securing and preventing firing of a firearm, especially a shotgun or similar breech loading firearm. It has always been desirable to secure firearms, for example shotguns, rifles, pistols, etc. such that they cannot be used by unauthorised persons. Commonly this has been achieved by arranging for the firearm to be securely locked to a relatively immovable object. Such methods are effective although relatively expensive requiring, at least for rifles or shotguns, a relatively large enclosure or surface to which the firearm can be secured. A further disadvantage of these known methods is the relative immobility of the security in that the firearms may not be secured whilst being transported or between periods of actual use at, for example, a firing range. Thus, it would be an advantage if a locking device could be provided which would actually be secured to or within a firearm such that unauthorised firing would be prevented. It is an object of the present invention to provide a firearms lock which is lockably securable within a chamber, eg. the barrel, of a firearm thereby preventing its unauthorised use. Firearm locks having the same object as the present invention are known but none is ideal or has yet become a commercial success. For example, prior patent specification GB2215822A (equivalent to International Application No.WO8910528A) describes a device insertable in a firearm barrel and having a high security key operated locking SUB TI device. The locking device operates a mechanism which causes a split ring collar on a tapered head to be forced outward and to engage the inner wall of the barrel. The present invention provides a simpler device for achieving a similar result more efficiently. According to the present invention in a first aspect there is provided a firearms lock of a kind insertable and securable within a substantially cylindrical chamber of a firearm and incorporating a key operated security locking device having a rotatable member which is rotated when the device is operated, the locking device being insertable as part of the lock inside the firearm chamber, a rod having a screw threaded portion and which is rotatable by rotation of the rotatable member of the locking device and a mechanism, which includes an axially displaceable member having a screw thread engaged with the screw thread of the rod, operated by rotation of the rod, for gripping the inner wall of the firearm chamber and characterised in that the firearms lock includes three substantially cylindrical sections, an inner section between two outer sections, of substantially annular configuration and providing a common axially located passage through the inner section and at least part of the two outer sections, the rod passing through the passage in the inner section and at least part of the two outer sections and being arranged so that rotation of the rod draws together the two outer sections against the inner section, the inner section being of a tough, flexible resilient material which expands radially when compressed between the two outer sections. According to the present invention in a second aspect there is provided a firearm having in a cylindrical chamber thereof, for example in the barrel, a firearms lock according to the first aspect of the invention described hereinbefore. The firearms lock may, for example, be intended to be placed within the barrel of a breech loading firearm of small arms calibre at or near the breech assembly and then locked in place such that its removal cannot be attained without authorised access to the locking mechanism. In the case of a double or multiple barrel firearm, for example a shotgun a plurality of such firearms locks would be provided, one for each barrel. The material of the inner section may be neoprene rubber or a similar tough rubber. Preferably the arrangement of the firearms lock is such that when the key operated locking device attached to one of the said sections is operated the threaded rod is rotated, thereby causing an axial displacement of the cylindrical section distant from the locking device and engaged therewith through a suitable internal thread provided in that section or in a member attached thereto. As the two outer body sections of the three move toward one another the inner or intermediate flexible cylindrical section is compressed axially and expanded radially outwards thereby engaging with interior barrel walls of a firearm in which the firearms lock is placed. Thus the firearms lock is securely engaged within the barrel and cannot be removed without reverse operation of the locking device to release the pressure on the flexible section. Desirably, the said three sections of the firearms lock are dimensioned to provide a slideable push-fit into the chamber to be protected whereby the lock may be positioned in the chamber by light friction between the flexible section and the chamber inner wall. Preferably, the said three sections of the firearms lock have substantially the same outer diameter prior to operation of the locking device such that there is no gap between the outer surfaces of the sections and the chamber inner wall. Rotation of the axially displaceable section having the internally threaded member in the same sense as the rod may be prevented by ensuring that that section has an outer curved surface which in use provides a light frictional rubbing against the inner wall of the firearm chamber. The section may have a suitable non-metallic friction promoting coating to achieve this. The firearms lock according to the present invention may have an outer shape like that of a cartridge case whereby the lock serves the SUBSTITUTE SHEET additional function of providing a dummy cartridge. Such dummy cartridges are employed in shotguns, for example, to practise use of the striking mechanism of the breech. Desirably, the said three sections are secured together as a single undetachable unit, eg. by provision of a burr or head at or adjacent to the end of the rod distant from the locking device and by a suitable attachment at the locking device. This ensures that when the firearms lock is removed by an authorised user one of the sections cannot accidentally remain in the chamber thereby causing a safety hazard when the firearm is used. The end of the rod distant from the locking device which in use is innermost in the chamber to be protected may conveniently carry a rubber cap which provides protection of the firearms lock if its end is subject to a blow from an object pushed down the chamber by an unauthorised user. The locking device employed in the firearms lock according to the present invention is preferably housed inside a recess provided in one of the said outer sections (i.e. that which faces outward when the lock is inserted in a chamber to be protected). This enables the firearms lock to have an overall shape or envelope which is substantially cylindrical. The recess may extend inward from the outer surface of the said outer section and the locking device may be secured in the recess of the said outer section by a fastening device, eg. screw accessible only at the inner end wall of the section. Alternatively, the locking device may be held in position in the recess by one or more flanges on its outer surface which fit in a corresponding slot or slots in the recess or by one or more slots in the device body into which a flange protruding from the wall of the recess fits. Such flange and slot attachments may be made by a twisting action of the locking device in its housing recess in a known way. Alternatively, the recess may extend outwardly from the inner surface of said outer section the outer surface of the section being in the form of an annular flange which holds the locking device in position in the recess between the outer section and the adjacent inner flexible section. The rod may be secured in the cylinder of the locking device in one of a number of known ways, eg. by complementary screw threads on the rod and in the lockmg device, by welding, by a flange and slot connection or by a pin and socket connection. The locking device and its key preferably have a plurality of pins and slots such that the locking device may be operated only when the correct combination of pins and slots is obtained by use of the correct 5 key. Preferably, the lock and key design is such that more than 10 5 desirably more than 10 pin and slot combinations are possible thereby reducing the risk of the lock being opened other than by the correct key. The locking device may for example be a proprietary constant rotation cylinder lock eg. having 7 to 10 radial pin tumblers. The locking device may have a substantially annular recess into which a generally cylindrical key of annular cross-section may be inserted. The annular recess may have one or more notches or locating recesses at its entrance into which one or more locating pins on the key may be inserted so that the key can be inserted with the correct initial angular rotational alignment relative to the locking mechanism. A plurality of pins or tumblers inside the cylinder of the locking device may then engage with a plurality of slots in correct positions in the circular outer surface of the key to push aside the pins and thereby provide operation of the key to rotate the lock cylinder. The locking device may for example be a lock of the HS or SB Ranges manufactured by Camlock Ltd. Desirably, the two outer sections of the firearms lock between which the flexible section is located are made of a hard wearing inflexible material, eg. a metal such as stainless steel or brass. In order to provide a suitable contact between these outer sections and the inner flexible section all three sections desirably have mating surfaces which are substantially plane and perpendicular to the lock axis and which occupy at least half of the area bounded by the outer surface of SUBSTITUTE SHEET the flexible section (the other part of that bounded area providing the axial passage for the threaded rod). The ratio of the length (measured parallel to the axis of the section) of the outer surface of the inner flexible section of the firearms lock to the outer diameter of that section (prior to compression) is desirably greater than 0.25 and desirably less than 2.0. This optimum working range provides a gripping outer surface which is suitably large but not excessive and therefore wasteful of material. Desirably, the flexible material when gripping the inner surface of the chamber of the firearm can withstand blows providing a pressure of greater than 50 pounds per square inch (3.45 x 10 5 Nm -2 ) desirably greater than 100 pounds per square inch (6.9 x 10 5 Nm -2 ). The firearms lock according to the present invention provides an improvement over the prior art in that it can be provided as a simpler and cheaper constructional form than known locks. For example, it is a simpler mechanism and gives at least similar if not better performance than the lock described in GB2215822A. The lock of the said prior specification provides gripping of the inner wall of the chamber by a sliding annular locking collar having an axial split and a wedge shape in a cross-sectional plane containing the axis of the collar. The collar is made of metal and therefore the frictional force between itself and the chamber is not designed to be maximised. No frictional force exists where the axial split is provided; the split grows, of course, when the collar expands. The collar slides along a frusto-conically inclined surface of a member drawn along the lock axis by a screw threaded rod and the radial displacement of the collar therefore requires a greater axial displacement of the threaded member than is required to provide a comparable radial expansion of the flexible section in the lock according to the present invention. US Patent No. 3,768,189 describes a firearms lock in which a flexible sleeve is compressed by operation of a locking device to grip the inner surface of a firearm barrel. In this case the locking device is much larger than the diameter of the barrel and is provided externally to the end of the barrel. It would be quite possible for a would-be thief to remove the lock by a blow from a hammer or similar tool. Further, compression of the sleeve is achieved against a resilient C-ring which is carried on the threaded rod or shaft and which itself could be easily deformed and removed by a blow applied down the barrel. Such a C-ring does not provide sufficient strength or surface area for compressive action against the flexible sleeve. Furthermore, the firearms lock according to the present invention gives a simpler and more efficient operation because the flexible section is located between the portion of the threaded rod where it engages the security locking device and the portion where it engages the co-operating internally threaded member. Such member may for example be a nut welded or adhered to an outer surface of that of the said sections which is distant from the security locking device. In contrast, in the lock described in the said US specification the flexible sleeve is, relative to the position of the locking device, located beyond a cylinder which has a threaded portion which engages the thread of the rod or shaft. Devices having a mechanism similar to the firearms lock of the present invention have been proposed in the prior art but for quite different purposes. In particular, prior patent specification no. GB2125141A describes a plug assembly for use in thermal-medium passages in air conditioning systems. The assembly comprises an annular elastomeric gasket placed on a gasket seat having an internally threaded circular projection and a sleeve which fits over the projection against the gasket. After the assembly has been located in position in a passage or pipe the gasket may be compressed between the sleeve and the gasket seat by a threaded fastener. The published assembly is designed to act as a fluid sealing device rather than a firearms security and safety device and because these two applications require different properties the known assembly shows the following features which would make it unsuitable for use with a firearm. The fastener device is operated by a simple Allen key or hexagonal headed screwdriver and is not therefore secure. The assembly is not self locatable in position in SUBSTITUTE SHEET a passage; it has to be brought into a position adjacent to a grub screw projecting laterally through the passage wall which is tightened to hold the assembly in position prior to operation of the fastener device to compress the elastomeric seal. It would, of course, be quite impracticable to use a similar grub screw arrangement to locate the position of a device in a firearm. The elastomeric ring of the known assembly will be a soft, deformable sealing material in contrast to the relatively tough, resilient material used in the inner section of the firearms lock according to the present invention. The sleeve of the known assembly has adjacent to the elastomeric gasket a portion where its outer surface has a smaller diameter than that of the elastomeric gasket (before compression) to enable the grub screw to be more easily received. The gasket will be extruded into the gap between the sleeve outer surface and the inner wall of the passage. The gasket is thus intended to be used only once in contrast to the inner section of the firearms lock of the present invention which is intended to be reused many times and its mechanical properties are selected accordingly. The elastomeric gasket in the known assembly is illustrated in GB 2125141 A as having a ratio of outer surface length to outer diameter of less than one tenth which according to the desired ratio specified above is unduly small. The effect is that the elastomeric gasket is unlikely to withstand pressures greater than, 5 -2 say 3.45 x 10 Nm , which could be applied by say a blow from a hard object. The gasket is not therefore suitable for providing the high security required in a firearms lock. In order that a firearms lock according to a preferred form of the present invention may be used for securing a revolver or a semi-automatic pistol, rifle or shotgun it is preferable to provide a projection near the locking device which will project into or engage a breech or cylinder area of a firearm thus preventing chambering of a cartridge whilst a firearms lock is locked within the barrel. In the absence of any such precaution it would be possible to place such a firearms lock in the barrel of, for example, a revolver, load and close its cylinder and then fire the firearm causing an explosion when the bullet thus fired strikes the firearm's lock. By providing a projection extending from the firearms lock into the cylinder area the cylinder is prevented from closing and the bullet cannot be fired. In the case of a semi-automatic pistol, rifle or shotgun the projection would extend into the space normally occupied by a cartridge during the feeding cycle of the automatic mechanism thus preventing a cartridge from being placed in line with the barrel. Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a part cross-sectional side elevation of a firearms lock according to an embodiment of the present invention in an open position; and Figure 2 is a part cross-sectional side elevation showing the firearms lock of Figure 1 in a closed or activated position in which it is suitable for engaging with a firearms barrel. Figure 3 is a diagrammatic side elevation of a firearm containing a firearms lock embodying the present invention. Referring firstly to Figure 1, an embodiment of a firearms lock according to an aspect of the invention comprises a substantially cylindrical body 10 comprising two rigid annular body parts or sections 12, 14. The two body parts 12, 14 are connected by an annular flexible expansible section 16 preferably made of hard rubber or a similar flexible and relatively incompressible material. First body part 12 is attached to a key operated locking device or mechanism 18. As such mechanisms are well known per se the mechanism 18 will not be further described herein. It may, for example, be a mechanism of the kind employed in the firearms lock of prior art specification GB2215141A. The locking mechanism 18 is connected to a partially threaded connecting bar 20 (acting as the threaded rod described hereinbefore) which passes through the annular passageways in body parts 12, 14 and expansible section 16. Thus the bar 20 is free to rotate by activation of the locking mechanism within SUBSTITUTE SHEET the section 16 and parts 12, 14. The bar 20 is inseparably attached to the mechanism 18, eg by welding to the inside of the cylinder of the mechanism 18. A nut 22 having an internal thread engaging with the threaded part of the bar 20 is attached for example by welding or adhesive to body part 14. Rotation of the bar 20 about its axis will cause a displacement of the nut 22 relative to the bar 20 along its axis and therefore the body part 14 may be move towards or away from the first body part 12 by rotation of the bar 20. This displacement will cause a radial expansion of the expansible section 16 when the movement is toward the part 12. This is illustrated in an exaggerated way in Figure 2. In practice the expansion is likely to be a small fraction (eg. less than one hundredth) of the diameter of the section 16. In use the firearms lock embodying the present invention is placed in the barrel of a firearm near the breech area. This is illustrated in Figure 3 where the lock 10 is inserted inside the barrel 31 of the firearm near its opening next to the breech 32 of the firearm. Although it is possible to place the firearms lock in the muzzle end of the gun barrel this is unsafe since a bullet could still be loaded in the breech assembly and fired causing an explosion at the muzzle end. Furthermore in the case of a shotgun the actual barrels are often cut down and this would effectively remove the firearms lock from the gun. Thus it will be appreciated that a firearms lock embodying the present invention can be inserted into the barrels of most models of firearms except revolvers having a fixed cylinder and a side opening loading gate, for example Ruger Blackhawk or Colt 1873 pattern revolvers. In such weapons the lock could be inserted in the one chamber of the cylinder provided that the lock had a projection member which would prevent rotation of the cylinder and hence render loading thereof impossible. With the firearms lock placed in the barrel of the firearm the threaded bar 20 is rotated causing expansion of the expansible element 16 which locks firmly against the interior wall of the barrel. Rotation of the body part 10 is prevented by frictional engagement of the element 16 with the barrel inner walls. The key activated locking mechanism 18 is engaged thus preventing further rotation in either direction of the threaded bar and effectively preventing removal of the firearms lock without engagement of the correct key. The end of the bar 20 has an enlarged head 20a to prevent separation of the part 14 and nut 22 from the bar 20 and a rubber cap 21 is provided over the end of the bar 20 and head 20a to protect the lock against blows made by an object pushed down the barrel. It will be understood that with a double barrel firearm, for example a double barrel shotgun, two such locking devices are required in order that the firearm be effectively secured against unauthorised firing. The invention is not confined to the foregoing details which are illustrative and not restrictive to the scope of the invention. For example, any suitable material may be used for the expansion element providing a necessary characteristic of flexibility and relative incompressibility and resilience thus ensuring that an axial compression will cause radial expansion and release of axial compression will return the element to its original shape and size. If desired the locking mechanism could be permanent such that operation thereof causes breaking of the connecting bar between the lockmg mechanism and the threaded part of the bar. This will result in a permanent locking of the firearm and its effective disablement. In an alternative embodiment the locking mechanism is lockably retained in the first body part and rotation of the threaded bar is only possible by removal of the mechanism. It will be appreciated that this simplifies construction of the firearms lock and does not require any connection between the locking mechanism and the bar. Other variations are also possible. SUBSTITUTE SHEET

Claims: CLAIMS 1. A firearms lock of a kind insertable and securable within a substantially cylindrical chamber of a firearm and incorporating a key operated security locking device having a rotatable member which is rotated when the device is operated, the locking device being insertable as part of the lock inside the firearm chamber, a rod having a screw threaded portion and which is rotatable by rotation of the rotatable member of the locking device and a mechanism, which includes an axially displaceable member having a screw thread engaged with the screw thread of the rod, operated by rotation of the rod, for gripping the inner wall of the firearm chamber and characterised in that the firearms lock includes three substantially cylindrical sections, an inner section between two outer sections, of substantially annular configuration and providing a common axially located passage through the inner section and at least part of the two outer sections, the rod passing through the passage in the inner section and at least part of the two outer sections and being arranged so that rotation of the rod draws together the two outer sections against the inner section, the inner section being of a tough, flexible resilient material which expands radially when compressed between the two other sections. 2. A lock as claimed in Claim 1 and wherein the overall envelope of the said three sections and the locking device is substantially cylindrical. 3. A lock as claimed in Claim 2 and wherein the lock has an outer shape like that of a cartridge case whereby the lock serves the additional function of providing a dummy cartridge. 4. A lock as claimed in Claim 1, Claim 2 or Claim 3 and wherein the said three sections are secured together as a single undetachable unit. 5. A lock as claimed in any one of the preceding Claims and wherein the end of the threaded rod which is distant from the locking device carries a protective rubber cap. 6. A lock as claimed in any of the preceding Claims and wherein the said three sections have substantially the same outer diameter prior to operation of the locking device. 7. A lock as claimed in any one of the preceding Claims and wherein the mating surfaces between the said inner flexible section and the two adjacent outer sections are substantially plane and perpendicular to the lock axis and occupy at least one half of the area bounded by the outer surface of the flexible section. 8. A lock as claimed in any of the preceding Claims and wherein the ratio of the length of the outer surface of the flexible section prior to compression and the outer diameter of that section is in the inclusive range 0.25 to 2.0. 9. A firearm having in a cylindrical chamber thereof a firearms lock according to any one of the preceding Claims. 10. A firearm as claimed in Claim 9 and wherein the lock therein prior to being secured is self-locatable by a slideable push-fit in the chamber by light friction between the flexible section of the lock and the inner wall of the chamber. SUBSTITUTE SHEET

Inventors: BALL STEPHEN, BALL, STEPHEN
Applicants: BALL STEPHEN, BALL, STEPHEN
Application year: 1991
Main classification: F41A17
IPC codes: F41A17