A LOCKING DEVICE FOR FIREARMS

Abstract: A locking device for locking into the bolt cavity of a firearm for making it non-functional, comprises a housing (1) which contains a lock cylinder (3) operable by means of a key which is introducible through a drilling protection (4) in the housing. The cylinder arm (8) of the lock cylinder (3) is non-rotatably connected to a follower (7), which has a flattening (9) which upon rotation of the follower pushes a wedge member (15) in the form of a steel ball between two blocking members (14), also in the form of steel balls, so that they are brought to extend partly from opposite sides of the housing (1). The locking device may be introduced into the magazine well of the firearm and located such that the extending blocking elements (14) will cooperate with e.g. the locking piece or receiver rails of the firearm in order to prevent the extraction of the locking device in its locked condition.

Description: A LOCKING DEVICE FOR FIREARMS The present invention relates to a locking device to be locked in the bolt cavity of a firearm in order to make it non-functional, comprising a housing which contains a lock cylinder which is operable by means of a key which is introducible through an opening in the housing, said lock cylinder at its inner end being provided with a follower which, when turned via the key in the locking direction, causes at least one locking member, which is received movably in a guide in the housing extending transversally of the longitudinal direction of the firearm, to be moved between a position in which it is withdrawn into the housing and a position in which it extends partly from the housing. Such a locking device is known for instance from US 4.266.356. In this case the housing containing the lock cylinder is provided with a cylindrical portion to be introduced into the cartridge chamber of the firearm. Through its follower, which is shaped like a toothed wheel, the lock cylinder acts on a transverse, partly toothed pin, the free end of which may be pushed out of the housing by turning the lock cylinder by means of a key, for coope- ration with a recess arranged in the rear extension of the barrel, thus locking the locking device securely in the barrel. The locking device is introduced through the casing ejection port of the firearm, a fact that limits the dimensions and strength of the locking device. The part of the housing of the device containing the locking cylinder will furthermore be accessible through the casing ejection port, e.g. for attacks by means of a burglary tool or the like. Since it has only one relatively slender locking pin, the locking device can hardly provide the security one desires in assuring that stolen military weapons are not made functional. The purpose of the present invention is to provide a locking device of the type mentioned in the introductory paragraph, the locking device providing high security against unauthorized removal from the firearm and, in addition, being well suited for use in military firearms. This is obtained according to the invention in that in said guide, two blocking members are present and are arranged to extend on either side of the housing, and in that the housing further has a wedge member, which by means of said follower is movable in a direction transversally of said guide and which by pivoting of the follower in the locking direction pushes said blocking members to the extending position. Since the locking device utilizes blocking members on both sides of the housing, a firm and secure attachment of the locking device in the firearm is obtained, and the wedge member is representing a simple and secure activating device for the blocking members. In a particularly advantageous embodiment of the invention, both the wedge member and the blocking members are steel balls, preferably ball bearing balls, which with their smooth and hard surface, high strength, low cost and small production tolerances facilitate a simple, inexpensive, robust and functional locking device. Further advantageous features are recited in the dependent claims. For better understanding of the invention it will be described more closely with reference to the exemplifying embodiments shown, in part schematically, in the appended drawings, wherein: Figure 1 is a side view, partly in section, of a locking device according to the invention in the locked position, Figure 2 is a section along the line II-II in Figure 1 , Figure 3 is a section similar to Figure 2, but shows the locking device in the unlocked position. Figure 4 is a side view of a portion of a firearm having the locking device in Figure 1 installed, Figure 5 is a simplified section along the line V-V in figure 4, Figure 6 is a side view, partly in section, through a second embodiment of the locking device according to the invention, Figure 7 is a simplified section similar to Figure 5 and shows the locking device in Figure 6 installed in the magazine well of a firearm, Figure 8 is a section along the line VIII-VIII in Figure 6, i.e. with the locking device in the locked position, Figure 9 is a section similar to Figure 8, but with the locking device in the unlocked position, Figure 10 is a section similar to Figures 2 and 8 through a third embodiment of the locking device according to the invention in the locked position, and Figure 11 is a section similar to Figure 10, but with the locking device in the unlocked position. The locking device illustrated in Figures 1 - 5 comprises a housing generally designated by 1 , which further com¬ prises a block 2 of hardened steel. The block 2 contains a lock cylinder 3, which is operable by means of a key, not shown, which is introducible through an opening in the block provided with a hardened drilling protection 4. The cavity of the lock cylinder 3 is formed by two parallel, partly overlapping bores, such that the cross sectional contour of the cavity becomes almost like a figure eight. Above the lock cylinder 4 in the cavity of the block a cover 5 is inserted, the cover being held in place by a hardened pin 6 driven into a pre-drilled hole in the block 2 and cover 5. The cover 5 has a bore which rotatably receives a follower 7, which is non-rotatably connected to the cylinder arm 8 of the lock cylinder. As best seen from Figure 2, the follower 7 has a flattening 9 and a longitudinal groove 10 opposite to the flattening, said groove having a larger radial depth than the flattening 9. A pin or screw 11 is placed into the rotational space of the follower through the cover 5 in order to limit the rotational angle of the follower to approximately 90°. Present in the block 2 and cover 5 are two crossing bores 12 and 13. The bore 12 forms a guide for two blocking members 14 in the form of ball bearing balls. The other bore 13 receives a wedge member 15, also in the form of a ball bearing ball. The wedge member 15 is acted upon by the follower 7 and may abut against its flattening 9, as shown in Figure 3. The locking device will then be in the unlocked position so that the blocking members 14 can assume a withdrawn position in the guide 12. By turning the key/follower 7 to the locked position, as shown in Figure 2, the flattening 9 of the follower will push the wedge ball 15 to the right so that the blocking balls 14 are pushed to their extending position, where they will be blocked by the ball 15. The blocking balls 14 are pre¬ vented from falling out of the guide 12 because the outer openings of the guide are provided with an inwardly extend¬ ing edge deformation 16, as best may be seen from Figure 3. When producing the locking device, the balls 14 and 15 must be positioned after the cover 5 has been installed in the block 2. In order to do this, the follower 7, before the pin 11 is installed, is pivoted so that its deeper groove 10 faces the opening of the bore 13, i.e. 180° with respect to the position shown in Figure 3. Next, the wedge ball 15 is introduced through the bore 13 and into the groove 10. The wedge ball 15 will therefore be positioned so deeply that the blocking balls 14 may be introduced via the opening of the bore 13 into their guide 12, whereupon the follower 7 is pivoted to the position shown in Figure 2 before the installation of the pivot restricting pin or screw 11. As shown in Figures 4 and 5, the locking device in this exemplifying embodiment is intended for the introduction into the magazine well 17 of a submachine gun 18 in such a manner that its upper part extends into the bolt cavity of the firearm. In the locked position of the locking device the blocking balls 14 extend into the locking piece 19 of the firearm in front of the receiver rails 20, as schemati- cally suggested in Figures 4 and 5. In order to permit the introduction of the locking device into the firearm in this manner, the block 2 is at the top provided with a tapering 21 (Figure 3). In the exemplifying embodiment in Figures 6 - 9, like or corresponding parts are given the same reference numerals as in the preceding examples. The block 2 shown in Figure 6 has a larger horizontal dimension in order to fill the magazine well 17 of a military rifle 22, which will have a larger cartridge length than the submachine gun in the preceding example. The cover 5 is attached to the block 2 by means of screws 23, preferably having one-way slots in order to prevent them from being unscrewed after installa¬ tion. This locking device has two pairs of blocking balls 14, one on either side of the follower 7, which has diametrally opposed flattenings 9, each serving a separate wedge ball 15. In this example there is enough space to make the blocking balls 14 and the wedge balls 15 of the same size, a fact that simplifies the manufacture of the locking device. In this case the balls are brought in place in the cover 5 before the follower 7 is installed. As will be apparent from Figure 7, the blocking balls 14 lock against the top side of the receiver rails 20 of the firearm. Alternatively, it may be envisioned that e.g. the right side set of balls 14, 15 is situated at a lower level than the left side set of balls, thus making the right side set of balls lock in front of the receiver rails, similar to the first example described. Figures 10 and 11 show a third alternative, where the blocking members 24 and the wedge member 25 are oblong in stead of spherical. Also in this case one has envisioned the housing 1 without a cover, i.e. with a large enough opening at the top for the introduction of the locking cylinder and the follower. The wedge member 25 contributes to holding both the lock cylinder and the follower in place. Thus, the follower has in its periphery a semi¬ circular groove 26, with which the inner end of the wedge member 25 cooperates when the follower is pivoted. A screw 27 is introduced into the groove in order to limit the pivot angle of the follower. The follower is also provided with a longitudinal groove 28 in order to facilitate the installation of the follower in the housing 1 from above. It will be seen that the oblong form of the blocking elements 24 in the example shown will make it necessary to introduce at least one of these into the guide from the outside before the edge deformation 16 is made. It may therefore be more expedient to use balls also for these blocking elements if considerations regarding space or other conditions will so permit. It will be seen that all the blocking members 14, 24 have rounded extending portions in the locked position. When an attempt is made to pull the locking device out of the firearm upon unlocking it, the blocking members, due to their rounded form, will automatically be forced into their respective guides, concurrently with the wedge member 15, 25 being pushed back, without any fixed connection between these members or other means for moving them being present. This not only simplifies the design, but also minimizes the possibility for the locking device being jammed in the firearm in the unlocked position. It will be understood that the invention is not limited to the exemplifying embodiments described above, but that it may be varied and modified in a number of ways within the scope of the following claims. Thus, the housing does not need to have a generally parallel-epipedic form, but may have a forwardly extending portion at the top to be intro- duced into the locking piece or cartridge chamber of the firearm. Furthermore, the wedge members may each consist of several parts, e.g. two or more balls, if the dimensions of the locking device should so indicate. Hardened steel will be a natural choice of materials for the exposed parts of the locking device, but it will be understood that variations are also possible in this respect. If reduced weight is important, the housing may be cast in titanium in accordance with the so-called "lost wax" method, and this method may also be used for casting stellite, which will provide a sufficiently hard product to make any subsequent heat treatment unnecessary. Sintering of a sufficiently hard material may also be an alternative in some cases. The drawings suggest a lock cylinder of the pin tumbler type, but also cylinders of the rotary disc tumbler type may be used.

Claims: C L A I M S 1. A locking device to be locked in the bolt cavity of a firearm (18,22) in order to make it non-functional, com- prising a housing (1) which contains a lock cylinder (3) which is operable by means of a key which is introducible through an opening in the housing (1), said lock cylinder (3) at its inner end being provided with a follower (7) which, when turned via the key in the locking direction, causes at least one locking member (14,24), which is received movably in a guide (12) in the housing extending transversally of the longitudinal direction of the firearm (18,22), to be moved between a position in which it is withdrawn into the housing (1) and a position in which it extends partly from the housing, characterized in that in said guide (12), two blocking members (14,24) are present and are arranged to extend on either side of the housing ( 1 ) , and in that the housing ( 1 ) further has a wedge member (15,25), which by means of said follower (7) is movable in a direction transversally of said guide (12) and which by pivoting of the follower (7) in the locking direction pushes said blocking members (14,24) to the extending position. 2. A locking device according to claim 1, characterized in that said blocking members (14,24) have rounded outer and inner ends. 3. A locking device according to claim 1 or 2, characterized in that each blocking member is constituted by a steel ball (14) . 4. A locking device according to a preceding claim, characterized in that the wedge member comprises a steel ball (15). 5. A locking device according to one of claims 1 - 3, characterized in that the wedge member is constituted by a cylindrical bolt (25) which is pointed at the end being in contact with the blocking members (24) and is rounded at the opposite end being in contact with the follower (7). 6. A locking device according to a preceding claim, characterized in that the follower (7), which has a gene¬ rally cylindrical form, has a flattening (9) for cooperat¬ ing with the wedge member (15) upon rotation of the fol- lower. 7. A locking device according to claim 6, characterized in that the follower (7), on the opposite side with respect to the flattening (9), has a longitudinal groove (10), preferably with a semi-circular cross-section, which has a larger depth than the flattening (9). 8. A locking device according to claim 7, characterized by a pin, screw (11) or the like which limits the rotation of the follower (7) so that its longitudinal groove (10) cannot be brought to face the wedge member (15). 9. A locking device according to one of claims 1 - 6, characterized in that it comprises two pairs of blocking members (14), each having a separate wedge member (15) acted upon by a common follower (7) . 10. A locking device according to a preceding claim, characterized in that its housing (1) is shaped to fit into a magazine well (17) in said firearm (18,22).

Inventors: ANDREASSEN OEYVIND, ANDREASSEN, OEYVIND
Applicants: ANDREASSEN OEYVIND, TRIOVING AS, ANDREASSEN, OEYVIND, TRIOVING A.S
Application year: 1997
Main classification: F41A17
IPC codes: F41A17