US20070271834A1

US20070271834A1 - Firearm accessory mount adapted for use with rifles having tangent or ladder-style read sights

Info

Publication number: US20070271834A1
Application number: US11/703,824
Authority: US
Inventors: Da Keng
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-02-08
Filing date: 2007-02-08
Publication date: 2007-11-29

Abstract

An accessory mount is removably affixed in place of a pre-existing tangent rear sight lever arm or leaf. The accessory mount is adapted for installation by a user without gunsmithing and includes an elongated body with a distal protuberance carrying opposing transverse trunnions or pins adapted to engage the tangent sight's base. In a preferred embodiment of the present invention, the elongated body has an upper surface configured to accept accessories designed to clamp on a Picatinny-style rail, or a Weaver™ style rail and so provides a universal mounting surface for optical sights, scope rings or other accessories.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority, under 35 U.S.C. 119(e), to U.S. Provisional Application No. 60/771,019 filed Feb. 8, 2006, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to firearms and accessory mounts for securing accessories, such as optical sights, to firearms.
2. Description of Related Art
Soviet and Eastern-Bloc firearm designs have become widely available to the public, and purchasers of rifles often want to use optical sights or other firearm accessories that are not readily mounted on rifles patterned after those designs.
To name one example, the AK-47 (Avtomat Kalashnikova 1947) is a gas-operated assault rifle designed by Mikhail Kalashnikov, produced by Russian manufacturers, and used in many Eastern bloc nations during the Cold War. It was adopted and standardized in 1947. It was one of the first and surely the most prolific assault rifle. The AK-47 and numerous variants, was produced in greater numbers than any other assault rifle in the 20th century and continues in production to this day.
The AK's notched rear tangent iron sight has a pivoting lever arm that is pinned at its forward or distal end. As issued, the sight's lever arm is calibrated with each numeral denoting hundreds of meters. The front sight is a post adjustable for elevation in the field. Windage adjustment is done by the armory prior to issue. The battle setting places the round within a few centimeters above or below the point of aim out to approximately 250 meters. This “point-blank range” setting allows the shooter to fire the gun at any close target without adjusting the sights. Longer settings are intended for area suppression. The AK's sights were fashioned to emulate the Mosin-Nagant and SKS rifles which the AK-47 replaced in order to ease transition and simplify training.
The AK-47 is in the AK family of weapons, including the Chinese Norinco, or Poly Tech™, AKS, type 56, AK-47 S, the Hungarian AKM variations, the Romanian AKM variations, the AK-74, the Polish Tan Tal and the Russian AK 74 versions and the 545. Most often, three variations are discussed, including the AKS, AKM, and AK-74 and the pre-existing rear sight supports differ only in minute details. Each has a rear sight that includes an adjustable tangent sight with a hinged member that is hinged at the distal or barrel end of the sight and is aligned along the bore. Typically a tangent sight has a sliding member that bears on left and right walls having curved surfaces.
The tangent sights on all of these rifles, while crudely effective, do not provide the precision now sought by many sportsmen who have recently acquired these rifles, and many users now seek a simple and effective way to mount telescopic sights and other types of optical sighting aids. Modern optical sights include the AimPoint™ and the EO-Tech™ red dot sights, and such sights do not work well when mounted upon an assault style rifle's receiver.
Others have attempted to make aftermarket mounts available, but with limited success. In general, the releasable mounts or replacement receivers with attached scope mounts (e.g., a Weaver or picatinny rail) are not very stable and are not precise enough to guarantee that a the point of aim or “zero” will be restored once the user disassembles the firearm for cleaning. At the end of the shooter's day, to clean the gun one must take the gun apart and there is no way to do that without removing the receiver cover first, at which point the zero is lost, since upon re-installation, the point of aim will have changed. The problem with mounting either dovetails or mounting plates on the left side of the AK receiver is that it alters the weapon permanently and technical issues often foil unskilled people trying to mount these types of plates. One can mount the plate in the wrong place and actually block internal moving parts, interfering with the insertion of the magazine. Such changes also permanently destroy a rifle's collector value. Others use picatinny rails manufactured right into forearms to replace the standard forearms and when mounting an optic there, the optic is too far forward to see a correct sight picture. The more serious problem, though, is that it gets very hot near the forearm very quickly, since the forearm is directly over the gas tube on an AK, and an unwary user can overheat and damage an optical sight.
Another problem confronting the shooter on a limited budget is that the AK and its variants often were manufactured using stamped steel receivers, and so were not suited to conventional scope rail mounts, which are usually affixed by threaded fasteners after drilling and tapping a rifle's receiver.
There is a need, therefore, for a method and apparatus for mounting telescopic sights and other types of optical sighting aids and accessories onto inexpensive surplus rifles such as the AK-47.

BRIEF SUMMARY OF THE INVENTION

Accordingly, the present invention overcomes the above mentioned difficulties by providing an easily installed accessory mount for use with rifles carrying tangent or ladder-style sights. Preferably, the present invention provides an accessory mount which permits attachment of Picatinny rail compatible accessories onto older rifles having stamped steel receivers or other impediments to use of conventional mounts. These advantages may be achieved individually and in combination, and it is not intended that the present invention be construed as requiring two or more of these advantages to be combined.
The accessory mount of the present invention removably engages to mounts upon a rifle in a safe place located at a pre-existing tangent sight base. In accordance with a preferred embodiment of the present invention, the accessory mount is adapted for installation by a user without requiring tools, alteration or gunsmithing and includes an elongated body with an upper surface configured to accept accessories designed to clamp on a Picatinny-style Rail, and so provides a universal mounting surface for optical sights. The accessory mount of the present invention has an elongated body with a distally projecting protuberance carrying laterally opposing transverse pin members. In a preferred embodiment of the present invention, the overall length of the accessory mount is 105 mm or 4.134 inches and terminates proximally in a tapered end. In this preferred embodiment, for most of its length, the width of the accessory mount is 16.155 mm, and the mount has V-shaped opposing lateral edges adapted to receive clamping attachments used with either picatinny or Weaver™ style mounts. It should be understood that the exact dimensions of the accessory mount may vary.
This removable accessory mount doesn't interfere with the function of the rifle in any way. The place on the rifle where the accessory mount is attached does not get too hot and it is easy to disassemble since all that one must do is fold or raise it slightly upward. The accessory mount may be locked by tilting it up and forward where it can also be freed and stripped from the receiver's tangent sight base sidewalls. Since the accessory mount is removably attached, it may be cleaned with various solvents without worrying about damaging the optic.
The preferred embodiment of the present invention has an upper surface defining a standard picatinny configuration including an elongate body carrying transverse block segments having the appropriate mil-spec height and grooves between the blocks or raised segments.
In a preferred embodiment, the side edges and bottom of the elongate body are contoured. The bottom is specifically designed to match the contour of the tangent-style sight base, preferably the AK rear sight's contoured sidewalls which are pre-calculated to correspond to the trajectory of the ammunition the rifle happens to be chambered for. So the sight sidewalls will differ for each rifle variation and the contour on the accessory mount of the present invention is going to basically match the contour on the rear sight housing.
An important advantage of the present invention is that the accessory mount does not permanently alter the firearm in any way. It is just a simple matter of exchanging the standard rear sight lever arm for the protuberance portion of the accessory mount. If a user has second thoughts, he or she can go back and change it out the other way, since installation doesn't harm the firearm in any way.
The preferred material for making the accessory mount is steel, preferably 41 40 which is traditionally used because it is suitable for use on a firearm. The accessory mount will preferably be finished using a process called melonite which creates extremely hard surface in a black finish, to allow for rough use, e.g., by professionals. The melonite finish is made by a heat treating process that doesn't distort the steel. Preferably, the method of making the Picatinny-style rails of the preferred embodiment uses wire EDM cutting to ensure absolute trueness in conventional accuracy.
Laterally projected distally carried opposing pins engage the body of the sight and are spaced from the leading edge of the elongated body, and the forward or distal edge of the protuberance is shaped to engage and be bias against the rifle's powerful leaf spring. The accessory mount does not substantially move even in sustained automatic fire and so stays stable, doesn't get hot, doesn't change “zero” and won't require modification of the firearm.
The selected overall length of the picatinny style support surface for the illustrated embodiment is 85 millimeters or approximately 3.346 inches. Shorter lengths are possible, but longer lengths would probably present a slight concern, since the only attachment point to the firearm is in the front and the user relies upon a very powerful, very robust leaf spring to keep the accessory mount from wobbling, shaking or bouncing around. If an accessory mount of greater length were required, one can use a more forceful spring (with a higher spring coefficient K for the leaf spring) or, optionally, some set screws could be added, to tighten and bear against the rifle's receiver as a rest against a perfectly stable surface.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

The above and still further features and advantages of the present invention will become apparent upon consideration of the following detailed description of a specific embodiment thereof, particularly when taken in conjunction with the accompanying drawings, in which:
FIG. 1 a shows, in elevation, the left side of an AK-47 rifle.
FIG. 1 b shows, in elevation, the right side of the AK-47 rifle of FIG. 1 a.
FIG. 1 c shows, in perspective, the tangent rear sight the AK-47 rifle of FIGS. 1 a and 1 b.
FIG. 1 d shows, in perspective, the sight base of the tangent rear sight of FIG. 1 c, with the sight's leaf and slide removed from the base, in accordance with the method of the present invention.
FIG. 2 shows a top view including the upper surface 16 of the accessory mount 10 in accordance with a preferred embodiment of the present invention;
FIG. 3 shows a right side view of the accessory mount 10 in accordance with a preferred embodiment of the present invention;
FIG. 4 shows the distal or front end of the accessory mount 10 in accordance with a preferred embodiment of the present invention;
FIG. 5 shows the tapered end 32 of the accessory mount 10 in accordance with a preferred embodiment of the present invention;
FIG. 6 shows a top, angled view of the accessory mount 10 in accordance with a preferred embodiment of the present invention;
FIG. 7 shows a bottom angled view of the accessory mount 10 in accordance with a preferred embodiment of the present invention; and
FIG. 8 shows a bottom view including the lower surface 16 of the accessory mount 10 in accordance with a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIGS. 1-8, FIGS. 1 a and 1 b show a standard AK-47 rifle 100, and illustrate the position of the standard tangent rear sight assembly 102 including a pivoting elongated leaf member 104 carrying a slide 106. As shown in FIG. 1 c, Tangent rear sight assembly 102 includes a sight base 108 solidly mounted over the distal end of the rifle's receiver 110, above the barrel 112. As best seen in FIG. 1 d, the standard sight base 108 has left and right spaced apart side walls 113, 114 terminating distally in left and right opposing trunnion or pin receiving segments 116 and 118. The open central portion 111 of sight base 108 includes a powerful biasing leaf spring 120 which biases upwardly to stabilize and retain the opposing pins or trunnions of elongate rear sight leaf member 104, when installed. All of the forgoing is well known to gunsmiths and armorers around the world who build, repair and maintain the millions of AK-47 style rifles in use today.
FIGS. 2-8 illustrate different perspectives of a preferred embodiment of the accessory mount 10 of present invention, a unitary, one-piece elongate support adapted to removably mount in place of pre-existing tangent or ladder-style sight slide or lever arm 104. Accessory mount 10 is preferably fabricated or machined from a single piece of steel and is adapted for installation by a user without tools and without modifying the rifle or gunsmithing.
In accordance with the present invention, the accessory mount 10 has an elongated body 12 with a distally projecting protuberance 14 provided at a distal end of the elongated body 12. The elongated body 12 has an upper surface 16, lower surface 18, a right edge 20, and a left edge 22. The upper surface 12 is configured to accept accessories such as scope rings and preferably comprises a plurality of transverse raised segments 24 alternately spaced with a plurality of transverse grooves 26 configured to accept equipment or supports designed to clamp on a Picatinny-style rail providing a universal mounting surface for optical sights. The distally projecting protuberance 14 has a right side 27 carrying a right transversely projecting trunnion or pin 28 and a left side 29 carrying a left transversely projecting trunnion or pin 30 on opposing sides of the distal protuberance 14. The right edge 20 and the left edge 22 of the elongated body 12 are dimensioned to receive clamping attachments and preferably have a V-shaped profile such that the center of the V-shape projects outwardly. Although a wide variety of clamping attachments may be used in connection with the present invention, the reinforced firearm sight support ring disclosed in U.S. Pat. No. 6,629,381 can be affixed to the elongated body 12 including a Picatinny-style rail on its upper surface 16 as provided in a preferred embodiment of the present invention. Therefore, U.S. Pat. No. 6,629,381 is expressly incorporated herein by reference.
The protuberance 14 is dimensioned to include a distal or forward end that substantially fits within a pre-existing tangent-style sight housing or base 108 and hinges within the sight housing's left and right opposing trunnion or pin receiving segments 116 and 118 by releasably engaging the mount's right and left pins 29, 30 leaving the elongated body 12 to project proximally from the sight housing's left and right opposing trunnion or pin receiving segments 116 and 118. The elongated body 12 is not physically attached to the sight housing or rifle at any other location other than the protuberance 14 via the right and left pins 28, 30 and so mount 10 is hingedly engaged and supported in sight housing or base 108.
Unlike other standard or mil-spec Picatinny-style rails that have a substantial portion of the length of the rail physically attached to the rifle (usually at two or more points along the rail's length), the present invention is attached to the rifle at a single point only, at the mount's distal end, within the sight housing's at the protuberance 14 via right and left pins 28, 30. This allows the accessory mount 10 of the present invention to be easily installed and removed from the rifle without damaging or physically altering the rifle.
In a preferred embodiment of the present invention, the accessory mount 10 has an overall length of about 105 mm or 4.134 inches and terminates proximally in a tapered proximal or rear end 32. For most of its length, the mount's upper surface 16 has a preferred width of about 16.155 mm and the accessory mount preferably has opposing V-shaped lateral edges 20, 22 that may extend about 2 mm each and are adapted to receive clamping attachments used with either the preferred Picatinny or Weaver™ style scope or accessory mounts. The distally projecting protuberance 14 extends from a tapered segment (as seen in FIGS. 2, and 6-8) and has a protuberance width that is preferably less than the width of the elongated body 12. In a preferred embodiment of the present invention, the protuberance width is 8 mm and the right pin 28 and left pin 30 each extend laterally by 2 mm. The total height of the elongated body 12 is preferably greater than the total height of the protuberance 14. The total height of the elongated body 12 is preferably 9.32 mm and the total height of the protuberance 14 is preferably 3 mm. The exact dimensions of the accessory mount 10 may vary and the present invention should not be limited to the dimensions listed for the preferred embodiment. One of ordinary skill in the art will understand that the dimensions of the accessory mount 10 may vary without departing from the scope of the present invention.
A preferred embodiment of the present invention has an upper surface 16 defining a standard mil-spec Picatinny configuration carrying transverse raised segments 24 having the appropriate mil-spec height alternately spaced with a plurality of transverse grooves 26 located between the raised segments 24. However, the present invention is not limited to an upper surface including a picatinny configuration. One of ordinary skill in the art will understand that the upper surface 16 may be configured to include a variety of designs adapted for the accessory desired by the user.
The lower surface 18, right side 20, and left side 22 of the elongate body are contoured. The lower surface 18 is preferably designed to match the contour on the sidewalls of the pre-existing tangent-style sight. In a preferred embodiment, the lower surface 18 is designed to match the contour of an AK rear sight's contoured sidewalls which are pre-calculated to correspond to the trajectory of the ammunition the rifle happens to be chambered for. Since the sight sidewalls will differ for each rifle variation, the contour on the lower surface 18 of the accessory mount 10 of the present invention is going to preferably match the contour on the rear sight housing.
The accessory mount 10 is preferably made from a steel material, most preferably 4140 which is traditionally used in firearms. Accessory mount 10 will preferably be finished using a process called melonite which creates extremely hard surface in a black finish, to allow for rough use, e.g., by professionals. The melonite finish is made by a heat treating process that doesn't distort the steel. Preferably, the method of making the upper surface 16 of the accessory mount 10 including the raised segments 24 and grooves 26 uses wire EDM cutting to ensure absolute trueness and accuracy. However, the upper surface may be machined using other appropriate methods known to those having skill in the art.
The right pin 28 and left pin 30 located on the distal protuberance 14 of the accessory mount 10 engage the sight base's left and right opposing trunnion or pin receiving segments 116 and 118 and are spaced from the distal end of the elongated body 12. The distal protuberance 14 is shaped to engage and be bias against the rifle's powerful sight leaf spring 120. The applicant has discovered that accessory mount 10 will not move significantly even during sustained automatic fire and so stays stable, doesn't get hot, doesn't change “zero” and won't require modification of the firearm.
The upper surface 16 of the elongated body 12 is preferably configured as a Picatinny-style support surface having an overall length of about 85 millimeters or approximately 3.346 inches. Shorter lengths are possible, but longer lengths would probably present a slight concern, since the only attachment point to the firearm is distally, in the front, and the user relies on the powerful, robust leaf spring 120 to keep the accessory mount from wobbling, shaking or bouncing around. If an elongated body 12 of greater length were required, one can use a more forceful spring (with a higher spring coefficient K for leaf spring 120) or, optionally, set screws could be added to tighten and bear against the rifle's receiver as a rest against a stable surface.
The accessory mount 10 is attached to the rifle at the pre-existing tangent-style sight housing or base 108. In a preferred method, the rear sight lever arm or leaf 104 is removed from the rear sight housing or base 108. The accessory mount 10 is secured to the rifle by placing the protuberance 14 within the rear sight housing such that the right pin 28 and left pin 30 are positioned against the inner sidewalls 113, 114 of the sight housing. Since the protuberance 14 is biased against the rear sight leaf spring 120, the accessory mount 10 is stable and secured to the rifle (e.g., 100). The present invention is intended to be used with any tangent-style or ladder-style sight (e.g., such as 102).
Although the accessory mount 10 may be adapted for attachment to any rifle having a pre-existing tangent or ladder-style sight (e.g., such as a K98 Mauser, a Mosin-Nagant variant or one of the SKS family of rifles), the AK family of rifles is of particular interest. As noted above, the AK family includes the AK-47, the Chinese Norinco, or Poly Tech, AKS, type 56, AK-47 S, the Hungarian AKM variations, the Romanian AKM variations, the AK-74, the Polish Tan-Tal and the Russian AK 74 versions and the 545. Most often, three variations are discussed, including the AKS, AKM, and AK-74 and the pre-existing rear sight supports differ only in minute details. Any reference herein to the AK family of weapons or the AK-47 is an express reference to the AK family of weapons generally.
While this invention is well suited for retrofitting existing military surplus or service rifles (e.g., 100), it can also be incorporated as an OEM feature in rifles configured for sale or delivery with optical sights.
Having described preferred embodiments of a new and improved method, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in view of the teachings set forth herein. It is therefore to be understood that all such variations, modifications and changes are believed to fall within the scope of the present invention.

Claims

1. An accessory mount adapted for retrofitting on rifles using tangent-style sights comprising:

an elongated body having a distal end carrying a distally projecting protuberance having a left side and an opposing right side;

said left side of said protuberance carrying a left transversely projecting pin, and said opposing right side of said protuberance carrying a right transversely projecting pin;

said elongated body having a left edge and a right edge each dimensioned to receive clamping attachments for firearm accessories; and

said elongated body having an upper surface adapted to accept firearm accessories.

2. The accessory mount of claim 1, wherein said upper surface comprises a plurality of transverse raised segments alternately spaced with a plurality of transverse grooves.

3. The accessory mount of claim 2, wherein said upper surface is Picatinny-style rail.

4. The accessory mount of claim 1, wherein said right edge and said left edge of said elongate body are dimensioned to have a V-shaped profile such that the center of the V-shape profile projects outwardly.

5. The accessory mount of claim 1, wherein mount is a unitary, one-piece elongate member and said protuberance has a distal end dimensioned to engage the rifle sight's left and right opposing pin receiving segments.

6. The accessory mount of claim 1, wherein said elongated body has a width that is greater than a width of said protuberance

7. The accessory mount of claim 1, wherein said elongated body has a height that is greater than a height of said protuberance.

8. A method for retrofitting rifles having tangent-style sights comprising:

a) providing an accessory mount comprising an elongated body having a distal end carrying a distally projecting protuberance having a left side and an opposing right side; said left side of said protuberance carrying a left transversely projecting pin, and said opposing right side of said protuberance carrying a right transversely projecting pin; said elongated body having a left edge and a right edge each dimensioned to receive clamping attachments; and said elongated body having an upper surface adapted to accept accessories;

b) providing a rifle including a sight housing comprising opposing sidewalls and fitted with a leaf spring; and

c) inserting said protuberance within the sight housing such that said left pin and said right pin are secured against said opposing sidewalls of the sight housing and said protuberance is biased against the leaf spring.

9. The method of claim 8, wherein said elongated body remains outside of said sight housing.

10. The method of claim 8, wherein said accessory mount is attached to said rifle only at said protuberance via said left and right pins.

11. The method of claim 8, further comprising

d) attaching an accessory to said accessory mount.

12. The method of claim 11, wherein said accessory is a scope attached to said accessory mount using a sight support ring.

13. A rifle carrying a releasably affixed mounting rail, comprising:

a) a tangent-style sight base sight base with left and right spaced apart side walls terminating distally in left and right opposing pin receiving segments and fitted with a biasing spring;

b) an accessory mount comprising an elongated body having a distal end carrying a distally projecting protuberance having a left side and an opposing right side; said left side of said protuberance carrying a left transversely projecting pin, and said opposing right side of said protuberance carrying a right transversely projecting pin; said elongated body having a left edge and a right edge each dimensioned to receive clamping attachments; and said elongated body having an upper surface adapted to accept accessories;

wherein said left pin and said right pin of said protuberance are releasably secured in said sight base's left and right opposing pin receiving segments and said protuberance is held against said spring.

14. The rifle of claim 13, wherein said elongated body extends proximally beyond the proximal end of said sight base.

15. The retrofitted rifle of claim 13, wherein said accessory mount is attached to said rifle only at said distally projecting protuberance via said left and right pins.