Magazine-well Adapter and Magazine Upward-Release Lever
A magazine-well adapter is disclosed for use in a conversion stock of an SKS type rifle which permits a standard AK-style detachable magazine (with fore and aft upper locking lugs) to be attached and detached. The adapter is configured such that it may be added to a conversion kit stock without reshaping said stock, incorporates the rigidity of a conversion kit stock to provide rigidity, and may be positioned accurately using the interior configuration of a conversion stock kit. Additionally, an upward-force release lever is disclosed by which a standard detachable box magazine may be released using less complex movements than current magazine release levers.
This application claims the benefit of Provisional Application No. 62/148,143, titled “SKS Self-Positioning Magazine-Well Adapter with Upward Release Lever”, filed on Apr. 15, 2015, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTIONThe SKS rifle is a rifle that was manufactured in the decades after WWII for use by Soviet and Soviet-bloc soldiers. Millions of SKS's were manufactured. Four of the major varieties, substantially the same but with slight variations, were made for Russian, Romanian, Yugoslavian, and Chinese/Vietnamese use The SKS's characteristics of being inexpensive, robust, and accurate have caused it, since manufacturing ceased, to be acquired in large numbers by gun enthusiasts all over the world.
The original SKS, however, was manufactured with a fixed magazine; that is, a non-detachable magazine which conventionally holds unfired cartridges and feeds them semi-automatically for rapid firing. When empty, the SKS fixed magazine must be reloaded with cartridges to be re-used, which is cumbersome and can be dangerous in emergency conditions.
It was therefore desirous to develop a system by which a standard detachable box magazine could be used in place of the SKS standard fixed magazine, allowing more rapid field reloading of the SKS rifle by simply removing an empty magazine and quickly replacing it with another full magazine. Because of the configuration of the SKS rifle, it would be advantageous to be able to use an AK-style detachable magazine to replace the original SKS fixed magazine. An AK-style detachable magazine, commonly used in AK rifle configurations, is a magazine with two short locking lugs in its upper section, one fore and one aft, used for securely attaching and detaching the magazine to an AK-style rifle.
However, the original SKS fixed magazine is considerably longer in the fore-aft dimension than a standard detachable box magazine such as a typical AK-style magazine, and consequently the magazine-well in the SKS stock and the mechanism in the SKS rifle that holds an SKS magazine is much longer fore-aft than a typical magazine-well used for holding removable magazines. This makes it impossible to attach a standard detachable box magazine to an SKS rifle magazine-well without first making modifications either to the standard box magazine or to the SKS magazine holding mechanism in the SKS rifle. Various such modifications are described below.
An early means was developed to modify a standard box magazine so that it would fit in an SKS magazine-well by adding to it a non-standard fore extension (aptly named a “duck-bill”). The “duck-bill” extension filled the extra fore-aft length of the original SKS magazine-well and provided a forward attachment prong, shaped to removably attach to the original forward attachment point of the original SKS fixed magazine.
Means to avoids the need of a “duck-bill” box magazine extension and allow an AK-style detachable magazine to be used have also been developed, providing an adapter piece that fits within the fore-end of the magazine-well of the SKS stock, attaches to the original attachment point on the SKS rifle of the original SKS magazine, and provides a new attachment point rearward of the original attachment point.
A number of designs for an SKS magazine-well adapter are provided in the prior art. An early design, described in U.S. Pat. No. 5,416,998 and manufactured by DC Engineering, teaches an adapter with a pair of prongs on the forward end, shaped to connect to the same attachment point on the SKS metal barrel as the original fixed magazine, and a rearward projection shaped to seat on the shoulders of an original wooden SKS stock, with a rearward cutaway to engage a proprietary box magazine on each side. Another prior art magazine-well adapter, manufactured by TheSKSMagAdapter, comprises at the front end a notch to connect to the same attachment point on the SKS metal barrel as the original fixed magazine and at least one attachment pin through the SKS stock. A variation on said prior art magazine-well adapter manufactured by TheSKSMagAdapter replaces said attachment pin with a locking plate added to the front end to attach rigidly to said same original metal barrel attachment point. Said prior magazine-well adapters manufactured by TheSKSMagAdapter additionally comprise at their aft end a conventional latching means—either fixed or spring-loaded—by which a standard AK-style box magazine may be detachably held. A spring-loaded latch includes a lever conventionally pulled in an aft-ward direction to retract the latch and release the magazine. Another prior art magazine-well adapter, manufactured by Center Balance Rifle Positioning System, similarly uses a notch to connect to the same attachment point on the SKS metal barrel as the original fixed magazine, a locking plate at the front end to attach rigidly to said same original metal barrel attachment point, a pin through the stock, and a separate spring-loaded lever conventionally pulled in an aft-ward direction to retract the latch and release the magazine.
It is clear that for safety and functional reasons, said SKS magazine-well adapter must provide a precise and rigid aft latching means—fixed or spring-loaded, so that an AK-style magazine will be held rigidly in precise position to repeatedly feed cartridges correctly until removed. An out-of-alignment magazine will not feed cartridges correctly or safely.
The magazine-well adapters of the prior art, as described above, provide such rigid and precise positioning by first attaching rigidly at their fore end to a rigid metal barrel trunnion of the SKS rifle, sometimes augmented by a pin or bolt into the stock, and second providing an adapter body of strong and rigid material that is sized large enough to rigidly hold its position even under repeated use. In addition to costing more to manufacture, the resulting large size generally requires reshaping modifications to the original SKS wooden stock as part of the installation process. Such reshaping presents few safety or functional problems in a wooden stock.
However, it is common to modernize SKS rifles by replacing original wooden SKS stocks with stocks made of newer materials. One reason is weight; the newer stocks are much lighter. A second reason is an increasingly common conversion of the standard SKS long-gun configuration into a shorter “bullpup” configuration. The term “bullpup” refers to a firearm configuration in which the action of the firearm is situated at the rear of the gun, the trigger is moved forward, and the conventional buttstock of the gun is eliminated. The elimination of the buttstock provides a gun that is typically 20% (20-30 cm) shorter than a conventional long-gun, lighter than a conventional long-gun, and easier to handle and manipulate in close quarters, while maintaining the standard longer barrel of a long-gun for increased range and impact energy.
For these and other reasons, owners of SKS rifles commonly replace the SKS original wooden stock with a modern stock made of newer, lighter construction and materials, and the aforementioned prior art magazine-well adapters may not always fit such new stocks safely or conveniently.
Because modern stocks use different materials than the original wooden stock, they generally have different interior configurations than the original wooden stock. In order to save weight or cost, SKS stock conversion kits are generally not made of solid material as the SKS wooden stock is, but instead generally utilize thin interior walls with interior bracing provided for strength in necessary locations. These new interior bracing pieces are important structural elements, but their location in some modern stocks may prevent adding a prior art magazine-well adapter piece without re-shaping modifications to the interior bracing of the new stock. Such re-shaping can be inconvenient and unsafe.
One popular SKS bullpup conversion kit utilizing new materials in its stock is manufactured by Shernic Gun Works (Shernic). The Shernic SKS bullpup conversion kit is discussed hereinafter as exemplar of an SKS stock made of modern materials other than wood that is not able to be used with existing magazine-well adapters without first performing re-shaping modifications, as noted above. For example, to permanently install a prior art magazine-well adapter from TheSKSMagAdapter in the Shernic stock, owners are instructed to use a Dremel, hacksaw, or other such imprecise cutting tool to reshape interior bracing parts of the Shernic stock, including parts that may provide strength and precise alignment. This is undesirable both for reasons of convenience and safety. Modifying a modern gun stock may change the safety and performance characteristics of the stock.
It would be desirable therefore to be able to provide a magazine-well adapter for an SKS rifle, wherein said rifle has been modified by replacing its original wooden stock with a modern stock made of modern materials and construction, which can be installed without the need to reshape or remove pieces from the modern stock as in prior art adapters.
It would also be desirable for cost and other reasons to take advantage of the strength of a modern stock by appropriating the rigidity and strength of the modern stock to provide rigidity and strength to the magazine-well adapter rather than having to depend on only the adapter body itself or the rifle mechanism for rigidity and strength as in the prior art.
Additionally, it would be desirable to take advantage of the precise machining of a modern stock by using the stock, rather than the rifle barrel attachment lug as in the prior art, to precisely place the magazine-well adapter in correct fore-aft, side-to-side, and vertical position.
Additionally, the SKS carbine or rifle was manufactured in many locations over many years in many different conditions. The result is that different instances of the SKS rifle have unpredictable but significant differences in their tooling and consequently in their dimensions, including dimensions that can affect the effectiveness and safety of latching of a standard box magazine to an SKS rifle. It would therefore be advantageous to provide a means by which a magazine-well adapter may be adjusted to fit slight variations in SKS rifle mechanisms.
Finally, the spring-loaded latches used not only in prior art magazine-well adapters but also in all prior art magazine release mechanisms conventionally include a lever to retract the spring-loaded latch. Said lever is conventionally actuated in the prior art by pulling in an aftward direction. When it is desired to remove a magazine, a user lifts his or her hand upward to grasp the magazine with 3 fingers. Simultaneously the user must position one finger correctly on a relatively small lever a distance forward from the magazine, and move that finger in an aftward direction to release the magazine. To pull the magazine away, the user must then remove the finger from the lever while grasping the magazine and pulling in a downward pulling direction. These motions may become automatic and rapid eventually, but practice is needed to automatically locate the small lever and pull it backward while the rest of the hand is going upward, then release the finger while pulling downward. By contrast, it would be desirable and advantageous to replace a conventional aft-direction lever with one that retracts the magazine latch by being pushed upward. In this way, a single upward hand motion may be used to grasp the magazine with all fingers while simultaneously bumping an upward-direction lever to retract the latch and release the magazine. Although this upward-force latch is shown in reference to a magazine adapter, it's scope goes beyond adapters to all release mechanisms of detachable magazines.
SUMMARY OF THE INVENTIONThe current invention claimed herein provides a design of a magazine-well adapter that may be inserted into a modern conversion stock without reshaping modifications of said stock. Further, the current invention provides a magazine-well adapter that is installed entirely in a conversion stock without using attachment points on the rifle mechanism. Additionally, the current invention provides means by which a magazine-well adapter may utilize the rigidity and strength of a modern conversion stock into which it is being inserted to provide at least part of its own rigidity and strength, rather than depending solely on the rigidity and strength of its own construction and of the SKS barrel as in the prior art. In addition, the current invention provides means to use the precise machining of a modern conversion stock to position itself accurately, by utilizing configurations of the stock to provide precise fore-aft, side-to-side, and vertical positioning. Further, the current invention provides means by which the final position of the adapter latch face, used to latch a standard box magazine, may be adjusted vertically so as to accommodate variations in dimensions of an SKS rifle and box magazine. Finally, the current invention provides a novel spring-loaded latch that is released by pushing a lever in an upward-direction in order to remove a magazine.
Clearly, a magazine-well adapter of the present invention as described above, fitting closely as described into a modern conversion stock so as to utilize the precise machining of a modern stock to provide said adapter with rigidity, strength, and accurate three dimensional positioning, will vary in its specific configuration from stock to stock. Although its specific configuration will be shaped by the inner configurations of the modern stock into which it is being designed to be inserted, the fundamental novelties of the present invention described herein are not changed.
An exemplar preferred embodiment of the magazine-well adapter described hereinafter is constructed to be inserted within a bullpup conversion stock manufactured by Shernic Gun Works (Shernic). As will be described in detail hereinafter, the exemplar preferred embodiment of the present invention has a T-shape configured to precisely fit within the T-shaped magazine-well opening of the Shernic bullpup stock so that the arms of the “T” of the present invention rests on the shoulders of the Shernic interior T-shaped opening to provide accurate vertical positioning and the leg of the “T” fits closely into the lower portion of the opening in the Shernic stock to provide accurate side-to-side positioning, and the fit is very tight so as to allow the described exemplar adapter to incorporate the strength and rigidity of the Shernic stock as part of its own rigidity. In addition, the exemplar adapter of the present invention is configured such that when slid forward to butt against the forward wall of the Shernic bullpup conversion stock magazine-well, it will be accurately positioned fore-aft. In this manner, the present adapter is positioned by the Shernic stock within which it is inserted to be substantially in precise alignment to safely, correctly, and repeatedly latch a standard AK-style magazine into cartridge feeding position. Other adapters may differ in specific configuration without violating the spirit of the present invention.
However, as mentioned above, variations in SKS carbine manufacture cause subtle but important variations in the position that a standard box magazine would take when inserted into the SKS rifle provided with the present adapter. For this reason, the present invention also provides a means by which small adjustments may be made to the upper face of the adapter latch, which is the part of the adapter which engages with the fore-lug of a removable AK-style box magazine. In the preferred embodiment described hereinafter, this is accomplished by means of providing for the attachment of one of a variety of adjustment pads to the upper face of the present magazine-well adapter latch so as to precisely place the resultant upper face of the latch.
Following insertion and correct positioning, the preferred magazine-well adapter of the present invention is secured to the Shernic bullpup stock, without reshaping modifications, by bolts or pins.
The aft end of a magazine-well adapter of the present invention may provide either a conventional fixed or a spring-loaded latch point for attachment of a standard box magazine. The exemplar preferred embodiment shown herein provides a spring-loaded latch with a novel upward-release lever in contrast to a conventional aftward-release lever. The upward-release lever retracts said spring-loaded latch to release a magazine when it is pushed upward by a hand that is moving upward to grasp said magazine. In this way, a detachable standard magazine may be easily and rapidly released with one single upward movement of a hand, simultaneously grasping and releasing said magazine. Although this upward-force release mechanism is shown within the current invention adapter, this upward-force release mechanism is novel not just within magazine adapter prior art, but within all magazine release mechansims in the prior art.
In the following detailed description, like numerals used in multiple figures refer to the same element of the invention.
An exemplar preferred embodiment of the present invention is described herein whereby a magazine-well adapter is shown which closely fits the configuration of a Shernic bullpup conversion stock for an SKS rifle, without prior reshaping modification to said stock. Said magazine-well adapter is affixed with bolts or pins only to the Shernic stock, without utilizing, as in the prior art, the metal attachment point of the SKS original fixed magazine for attachment, rigidity, or positioning. Said preferred embodiment adapter additionally provides at its aft end a spring-loaded latch used to attach a standard AK-style magazine. Said spring-loaded latch may be adjusted by adding latch pads to its upper face to provide a higher upper face as needed for different versions of SKS rifles. Said spring-loaded latch may additionally be retracted to release said standard magazine with a user-accessible lever that retracts said latch when pushed in an upward direction rather than an aftward direction as in the prior art.
Referring to
While original fixed magazine 12 provides a working configuration of rifle 10, it is often desirable to provide for more rapid or convenient reloading of rifle 10. This is accomplished conventionally by permanently removing fixed magazine 12 and replacing it with a standard box magazine inserted into magazine-well 14, so that a reload consists only of rapidly replacing an empty magazine with a full one.
However, because SKS magazine-well 14 has a considerably longer fore-aft dimension than a standard box magazine, a standard AK-style box magazine will not engage in a standard SKS magazine-well. It is necessary to use a device such as a magazine-well adapter to fill the extra length and to provide a conventional latch point in the appropriate position to removably hold a standard box magazine.
As aforementioned, for safety and functional reasons, aft latch 34 must be arranged to be precisely and rigidly held in order to secure fore lug 36 of standard AK-style magazine 31 in correct and unmoving alignment for repeatable safe cartridge feeds. Hence, in the construction of adapter 30, front attachment means 32, as the sole attachment means, and adapter body 33, as the sole transmitter of support for aft latch 34, must each be bulky enough and made of rigid materials to provide sufficient rigidity for safety. The necessity to install a bulky magazine-well adapter 30, and the necessity to attach it to trunnion 22 on barrel 11 requires enlarging magazine-well 14 in order to make sufficient room.
Enlarging magazine-well 14 by removing material from original wooden stock 13, shown in
However, for various reasons it is common for owners of an SKS rifle to replace original wooden stock 13 with a modern stock made of modern construction and materials. One reason is to reduce weight, as original wooden stock 13 is heavier than modern stocks. Additionally, because the original SKS has a long barrel, it is a long gun. It therefore may be desirable to reconfigure an original SKS into a shorter, more balanced, and more easily maneuverable configuration such as a conventional bullpup configuration, in which the buttstock of the gun is removed and the trigger control is moved forward for overall length and weight reduction. For these and other reasons including cosmetics, original SKS wooden stock 13 is commonly replaced with a newer, lighter stock made of modern construction and materials.
As will be explained presently, enlarging magazine-well 14 to make room to install prior art magazine-well adapter 30 when original stock 13 has been replaced by a newer, lighter, modern stock, may present functional or safety concerns.
The interior construction of Shernic stock 40 may be understood to be considerably different from original wooden stock 13. Original stock 13 is composed of solid wood, with cut-outs as needed for action, trigger-group, barrel, and magazine. By contrast, Shernic stock 40 is composed of a modern material such as plastic, polymer, composite, or metal in a precisely molded or machined shape. The overall shape is defined by thin outer skin 41. Additionally, brace 42, used both to strengthen stock 40 and to accurately position barrel 11 of the SKS rifle, and bracing network 43, used to strengthen interior shoulder 44 are shown as exemplar braces added where needed to provide strength, rigidity, and precise positioning to an otherwise non-rigid stock. The overall result is lightweight yet strong and rigid, as required by a rifle stock for safety and functional reasons. It should be noted as well that interior dimensions of Shernic stock 40 and similar modern stocks are considerably more precise than interior dimensions of older wooden stocks such as original stock 13, which vary by wood quality, machining, age, manufacturer, temperature, and humidity.
However, unlike a solid wooden stock such as original stock 13, it may be readily understood that the removal or reshaping of brace 42 or similar, which as mentioned previously provides positioning and rigidity, may adversely affect safety or performance characteristics of replacement stock 40 or other similar modern stocks made of modern materials and construction whose interior is constructed of a combination of precisely placed and sized thin skin and braces.
By way of example, according to instructions from TheSKSMagAdapter, the manufacturers of prior art magazine-well adapter 30 shown in
Spring-latch 53 is retracted by exerting upward pressure on lever 55 rotating on pin 56, in contrast with the prior art system shown in
In
It may be seen that, in contrast to prior art adapters as shown by example in
In this manner, magazine-well adapter 50, a preferred embodiment example of the current invention, performs the functions of an adapter which allows use of standard AK-style magazines while exhibiting a number of significant advantages over the prior art of cost, safety, functionality, and ease of use as described in detail above.
The present invention has been described with reference to certain exemplar embodiments thereof. Doubtless, changes may occur to one skilled in the art having had the benefit of the teaching of the present invention without departing from the scope thereof.
Claims
1. An adapter attachable entirely to a conversion stock intended to replace an original wooden stock of a carbine or rifle that is originally equipped with a non-detachable magazine, said adapter permitting the ready attachment and detachment of a removable box magazine.
2. The adapter of claim 1 wherein said adapter is configured such that modifications need not be made to said conversion stock to enable installation of said adapter.
3. The adapter of claim 1 wherein said adapter is configured to closely fit within said conversion stock such that said conversion stock adds rigidity and strength to said adapter when installed in said conversion stock.
4. The adapter of claim 1 wherein said adapter is configured to closely fit at least a first configuration in said conversion stock such that said conversion stock provides accurate fore-aft positioning of said adapter when installed in said conversion stock.
5. The adapter of claim 1 wherein said adapter is configured to closely fit at least a second configuration in said conversion stock such that said conversion stock provides accurate vertical positioning of said adapter when installed in said conversion stock.
6. The adapter of claim 1 wherein said adapter is configured to closely fit at least a third configuration in said conversion stock such that said conversion stock provides accurate lateral positioning of said adapter when installed in said conversion stock.
7. The adapter of claim 1 comprising a latch with at least one latch pad attachable to the top of said latch to adjust the height of the top of said latch.
8. The adapter of claim 7 wherein said adapter additionally comprises at least one latch spacer attachable between said latch and said latch pad to further adjust the height of the top of said latch.
9. In a rifle or carbine which uses a detachable magazine released by the motion of a latch, a springloaded latch configured such that upward force may be used to move said latch in the appropriate direction to release said removable magazine.
Type: Application
Filed: Apr 16, 2016
Publication Date: Oct 19, 2017
Inventor: Nicholas L. Glaros (South Pasadena, CA)
Application Number: 15/130,931