The present disclosure relates generally to components for firearms magazines, and more particularly to a spring for a firearms magazine and a magazine including the spring.
Firearms design involves many non-trivial challenges. Traditionally, semiautomatic handguns have been made with a metal frame having a grip portion that defines a magazine well configured to retain a magazine. Autoloading rifles similarly have a receiver that defines a magazine well configured to receive a magazine. Whether for use in a handgun or a long gun, an ammunition magazine can retain cartridges in a single vertical stack, in an offset double stack, or a combination of single and double stacks. A magazine includes a magazine tube generally of rectangular cross-sectional shape that extends from a bottom end to an open upper end that defines feed lips. The bottom end of the tube can be closed by a removable baseplate. A magazine spring is retained in the magazine tube in a compressed state between the baseplate and a follower, where the spring biases the follower, and any ammunition in the magazine, towards the feed lips at the upper end of the magazine tube. When installed in the magazine well, the top-most round is positioned to be stripped from the magazine and loaded into the chamber during the reloading cycle.
The present disclosure is directed to a spring for an ammunition magazine, a components kit including the spring, and a magazine assembly including the spring. In one example embodiment, the spring is configured for a handgun magazine and includes upper coils of a smaller size that can nest within larger coils of a rectangular coil shape. In another example, the components kit includes a spring, a spring plate, and a magazine base plate, and is configured to replace components of an existing magazine for the purpose of increasing the magazine capacity or simply replacing parts. A magazine spring is discussed with reference to a handgun magazine, but the present disclosure is not so limited, and the concepts disclosed herein apply to magazine springs for rifles and other long guns. Numerous variations and embodiments will be apparent in light of the present disclosure.
The features and advantages described herein are not all-inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims. Moreover, it should be noted that the language used in the specification has been selected principally for readability and instructional purposes and not to limit the scope of the disclosed subject matter.
The Figures depict various embodiments of the present disclosure for purposes of illustration only. For purposes of clarity, not every component may be labeled in every drawing. Furthermore, as will be appreciated, the figures are not necessarily drawn to scale or intended to limit the present disclosure to the specific configurations shown. Numerous variations, configurations, and other embodiments will be apparent from the following detailed discussion.
Disclosed is a spring for an ammunition magazine, a components kit including the spring, and a magazine assembly including the spring. In accordance with one embodiment, a spring for a handgun magazine includes a top attachment leg, upper coils below the top attachment leg, intermediate coils below the upper coils, and a bottom attachment leg below the intermediate coils, where the upper coils are sized and shaped to nest within the plurality of intermediate coils when the spring is fully compressed. In some such embodiments, the spring includes one or more lower coils between the bottom attachment leg and the intermediate coils. In some embodiments, at least two upper coils and/or at least two lower coils can nest within the intermediate coils. The spring can have coils of oval or square shape, or a combination of oval and square coils, in accordance with some embodiments.
In some embodiments, the magazine spring has unique rectangular coils in addition to nesting features that reduce the solid height of the spring. Rectangular coil shapes tend to stack more neatly and tend to nest easier since the rectangular coil has a greater area than an oval coil of the same length and width. Also, rectangular spring coils can be designed to increase the effective length of each coil, resulting in increased deflection and pitch. Such rectangular coil design also can reduce the peak stresses along the spring by distributing the stress along a greater coil length. Attachment coils at the top and bottom of the spring can nest into the adjacent working coils when the spring is compressed so that the attachment legs do not add to the solid height of the spring. Also, the smaller upper coils can nest within the larger intermediate coils, and smaller lower coils (when present) can nest at least partially within the intermediate coils when the spring is compressed. For example, front portions of the lower coils nest within the intermediate coils, but rear portions of the lower coils need not nest in all embodiments since the floorplate may not be oriented perpendicularly with the magazine tube axis and therefore allows additional space for non-nesting rear portions of the spring. Some or all of these features can be combined to result in a spring having a reduced coil count, an increased coil pitch, and/or improved efficiency. In some embodiments, the solid height of the magazine spring provides a stop between the follower and the floorplate.
In addition to nesting features of the spring, a magazine assembly can include one or both of a spring plate that is recessed into the magazine base plate and a follower that is shaped to reduce vertical height of the assembly. The follower can be constructed to overlap the spring when the spring is compressed, reducing vertical height of the spring and follower.
Advantageously, a magazine spring and magazine assembly of the present disclosure can include combinations of features to increase magazine capacity by 1-2 rounds for a handgun magazine of a given tube length. For example, the capacity of a magazine originally configured to hold 15 rounds can be increased to hold 16 or 17 rounds by retrofitting with a magazine components kit. Examples of handgun magazines that can benefit from components disclosed herein include the 9 mm P320 and P365 magazines made by Sig Sauer Inc. Magazines for rifle ammunition can also benefit from the concepts disclosed herein. Numerous variations and embodiments will be apparent in light of the present disclosure.
Depending on the intended use, ammunition capacity can be an important factor when selecting a handgun. Semiautomatic handguns use a removable box magazine that is received in the magazine well defined in the gun's handgrip. Handgun magazines traditionally have been available in two main configurations, namely, single stack and double stack. In single-stack magazines, all cartridges are aligned in a single column with each cartridge arranged on top of the cartridge below it. Single-stack box magazines enable the grip of the handgun to have a lateral thickness of about one inch (˜2.5 cm), sometimes slightly less, depending on chambering and the particular grips installed on the frame. A single-stack magazine is often found in handguns with a smaller thickness. Another approach to increasing magazine capacity is to structure the magazine tube to hold two offset columns of cartridges, referred to as a “double stack” magazine. Many full-size handguns include a double stack magazine and can have a capacity of 10, 12, 15, or 17 rounds, for example. The capacity can be increased slightly by adding some length to the magazine baseplate, also referred to as an extended baseplate. However, increasing the grip's lateral thickness or adding length to the grip are approaches that increase the overall size and mass of the handgun. This increased size makes it more difficult to effectively conceal the handgun.
It would be desirable to increase magazine capacity without adding to the overall size of a magazine. The present disclosure addresses this need and others by providing a magazine spring with a reduced solid height. Increased magazine capacity can further be realized with features of other magazine components that save space in the magazine tube. In accordance with some embodiments, features of the spring and other magazine components reduce the vertical size of those components and increase the ammunition capacity compared to existing magazines using the same magazine tube. Numerous configurations and variations will be apparent in light of this disclosure.
As will be appreciated in light of the present disclosure, and in accordance with some embodiments, ammunition magazines configured as described herein are not limited to semiautomatic handguns and can be utilized with any of a wide range of firearms. In accordance with some example embodiments, a magazine configured as described herein can be utilized with a semiautomatic handgun chambered in .380 Auto, 9 mm Luger, .357 SIG, 10 mm Auto, .40 S&W, .45 ACP ammunition, or other suitable ammunition. Other suitable host firearms and ammunition will be apparent in light of this disclosure.
As discussed herein, terms referencing direction, such as upward, downward, vertical, horizontal, left, right, front, back, etc., are used for convenience to describe embodiments of a magazine in an upright orientation. Embodiments according to the present disclosure are not limited by these directional references and it is contemplated that magazines of the present disclosure could be used in any orientation. Also note that the spring plate and base plate as disclosed herein can alternately be referred to as an inner base plate and outer base plate, respectively.
Spring 100 includes a top end portion 102 that includes straight segments 104a, 104b and turn 106. Straight segment 104b is part of one of the upper spring coils 110 of a first size. Intermediate spring coils 120 of a second, larger size are below the upper spring coils 110 and connect to lower spring coils 130. The lower spring coils 130 connect to straight segments 142a, 142b. Straight segment 142a is part of the lowermost lower spring coil 130 in some embodiments. Straight segment 142b can be an attachment leg that engages the magazine's spring plate.
Some or all of the upper spring coils 110 can nest within the intermediate spring coils 120 when the spring 100 is compressed. In some embodiments, at least two complete coils of the upper spring coils 110 nest (or can nest) within the intermediate spring coils 120. In some embodiments, at least three complete upper spring coils 110 can nest within the intermediate coils 120. Similarly, some or all of the lower spring coils 130 can nest within the intermediate spring coils 120 when the spring 100 is compressed. In some embodiments, at least two complete coils of the lower spring coils 130 nest (or can nest) within intermediate coils 120. In some embodiments, at least three coils of the lower spring coils 130 can nest within intermediate coils 120. For example, in a fully compressed state, portions of the lower spring coils 130 are nested within the intermediate coils 120 below the upper spring coils 110, which are nested within the intermediate coils, such as shown in
In the example shown, part of top end portion 102 (e.g., straight segment 104b and part of turn 106) and part of bottom end portion 140 (e.g., straight segment 142a and part of turn 144) are part of working coils. Straight segments 104a, 104b are connected by a turn 106 of about 180°, where the straight segments 104a, 104b are oriented generally parallel to one another (e.g., ±10° from true parallel). The bottom end portion 140 includes straight segments 142a, 142b connected by a turn 144 of about 180°. Straight segment 142b connects to a terminal transverse leg 146 that extends towards straight segment 142a. Straight segment 142b is generally parallel to straight segment 142a (e.g., ±10° from true parallel) in this example.
In accordance with one embodiment, upper coils 110, intermediate coils 120, and lower coils 130 have a rectangular coil shape that includes straight side segments and straight end segments connected by curved corners. For example, upper coils 110 include straight side segments 111 and straight end segments 112 connected by curved segments 113. In some embodiments, the straight side segments 111 of upper coils 110 have a length from 10-15 mm, such as about 14 mm; straight end segments 112 of upper coils 110 have a length from 1-5 mm, such as about 3 mm. Similarly, intermediate coils 120 include straight side segments 121 and straight end segments 122 connected by curved segments 123. In some embodiments, straight side segments 131 of the intermediate coils 120 have a length from 12-17 mm, such as about 15.5 mm; straight end segments 132 of the intermediate coils 120 have a length from 4-8 mm, such as about 6 mm. Also, lower coils 130 include straight side segments 131 and straight end segments 132 connected by curved segments 133. In some embodiments, straight side segments 131 of lower coils 130 have a length from 11-15 mm, such as about 14 mm; straight end segments 132 of lower coils 130 have a length from 2-5 mm, such as about 4 mm. In accordance with some embodiments, a straight spring coil segment is defined as having a linear path of at least 1 mm, include at least 1.5 mm, at least 2 mm, or at least 3 mm. Curved segments 113, 123, 133 span an arc of about 90°±5°.
In other embodiments, some or all of the spring coils have an oval shape, an elliptical shape, or a “racetrack” shape (e.g., straight sides with semicircular ends). In some such embodiments, intermediate coils 120 have a rectangular coil shape and upper coils 110 have an oval shape that is sized to nest within the intermediate coils 120. In some embodiments, the lower coils 130 can also have an oval shape that nests partially or completely within the intermediate coils 120. For example, a front portion of each lower coil 130 can nest within intermediate coils 120 while a rear portion of lower coils 130 stacks with intermediate coils 120. In yet other embodiments, all of the upper coils 110, intermediate coils 120, and lower coils 130 have an oval shape.
In the top view of
Referring now to
In its fully compressed state, the spring 100 has a solid height H that is less than the product of the number of coils and the wire diameter. That is, the different sizes of spring coils along the height of the spring 100 allow for nesting of upper coils 110 and/or lower coils 130 within intermediate coils 120. Note in this example that the solid height H at the front 150 of the spring 100 is less than the solid height H at the rear 152 of the spring 100. This difference is due to the size and shape of the lower coils 130, which allows some or all of the front 150 of lower coils 130 to nest within the intermediate coils 120 and at least some of the rear 152 of lower coils 130 to stack with intermediate coils 120. Accordingly, in the compressed state, the rear 152 of spring 100 has a greater number of stacked coils and greater solid height H compared to the front 150 of the spring 100, in some embodiments. In other embodiments, the lower coils 130 nest completely within the intermediate coils in both the front 150 and rear 152 of the spring 100. In some embodiments, the maximum solid height Hmax is less than 60% of the product of number of coils and wire diameter. In one example, such as the spring 100 shown in
In the perspective view of
A wall 186 protrudes up above the top surface 180b and extends along the sides and front of the base plate body 181. The wall 186 has a contour that is configured to mate with the outside surface of the magazine tube when assembled. Typically, the inside surface 186c of the wall 186 contacts the magazine tube when assembled therewith, however, a gap between the tube and the inside surface 186c is permissible, although not preferred. The outside surface 186d of the wall 186 can be continuous with the outside surface of the base plate body 181, but it does not necessarily have to be. In an assembled state, the bottom of the magazine tube is received within the bounds of the wall 186 and in contact with the top surface 181b of the base plate body 181. In this example, lateral portions 186a, 186b of the wall 186 each includes a vertical protrusion 188.
The wall 186 defines an undercut 189 along each lateral portion 186a, 186b, positioned between the top surface 181b of the base plate body 181 and the wall 186, and extending forward from a rear end 180a of the base plate 180. The undercut 189 is open at the rear end 180a to enable laterally-extending lips or flange at the bottom of the magazine tube to be slidably received in the undercut 189 as the base plate 180 is slid onto the end of the magazine tube.
Ammunition 202 on top of the follower in an offset, double-stack arrangement. The follower 210 overlaps the spring 100 at the front and back, and the follower 210 is cut away on its sides to accommodate the coils of the spring 100. The spring protrusion 212 on the underside of the follower 210 extends into the nested coils of the spring 100. Note that a central axis 202a of the ammunition 202 is inclined downward with respect to the bottom surface 181a of the base plate 180.
The top end portion 102 that includes straight segments 104a, 104b and turn 106. Straight segment 104b is part of one of the upper spring coils 110 which include larger upper coils 110a of a larger size and smaller upper coils 110b of a smaller size. Intermediate spring coils 120 of the larger size are below the smaller upper coils 110b and connect to lower spring coils 130, which include larger lower coils 130b of the larger size and smaller lower coils 130a of the smaller size. The larger lower coils 130b connect to straight segments 142a, 142b that are part of the lower-most coil.
Some or all of the upper spring coils 110 can nest within the intermediate spring coils 120 when the spring 100 is compressed. In some embodiments, at least two complete coils of the upper spring coils 110 nest (or can nest) within the intermediate spring coils 120. In some embodiments, at least three complete upper spring coils 110 can nest within the intermediate coils 120. Similarly, some or all of the lower spring coils 130 can nest within the intermediate spring coils 120 when the spring 100 is compressed. In some embodiments, at least two complete coils of the lower spring coils 130 nest (or can nest) within intermediate coils 120. In some embodiments, at least three coils of the lower spring coils 130 can nest within intermediate coils 120.
In the side view of
The following examples pertain to further embodiments, from which numerous permutations and configurations will be apparent.
Example 1 is a spring for a firearm magazine, the spring comprising a top attachment leg; a plurality of upper coils below the top attachment leg; a plurality of intermediate coils below the upper coils; and a bottom attachment leg below the plurality of intermediate coils, wherein individual coils of the plurality of intermediate coils have a rectangular coil shape, and wherein the upper coils are sized and shaped to nest within the plurality of intermediate coils when the spring is fully compressed.
Example 2 includes the subject matter of Example 1, wherein the upper coils have an oval coil shape.
Example 3 includes the subject matter of Example 1, wherein the upper coils have a rectangular coil shape.
Example 4 includes the subject matter of any one of Examples 1-3, further comprising a plurality of lower coils between the plurality of intermediate coils and the bottom attachment leg.
Example 5 includes the subject matter of Example 4, wherein the lower coils have a rectangular coil shape.
Example 6 includes the subject matter of Example 4, wherein the upper coils and/or the lower coils have an oval shape.
Example 7 includes the subject matter of any one of Examples 4-6, wherein the lower coils are sized and shaped to nest at least partially within the plurality of intermediate coils when the spring is fully compressed.
Example 8 includes the subject matter of Example 7, wherein when the spring is fully compressed, the top attachment leg is sized and shaped to nest within the plurality of upper coils, and the bottom attachment leg is sized and shaped to nest within the plurality of lower coils.
Example 9 includes the subject matter of any one of Examples 1-8, wherein the spring has from 9 to 11 coils.
Example 10 includes the subject matter of any one of Examples 1-9, wherein the spring has a maximum solid height of not more than 6 wire diameters.
Example 11 includes the subject matter of any one of Examples 1-10, wherein a front portion of the spring has a solid height of not more than 4 wire diameters.
Example 12 includes the subject matter of any one of Examples 1-11, wherein the wire diameter is from 1.1 to 1.45 mm, preferably 1.2-1.3 mm.
Example 14 includes the subject matter of any one of Examples 1-12, wherein the spring is configured for the firearm magazine sized for handgun ammunition.
Example 15 includes the subject matter of any one of Examples 1-12, wherein the spring is configured for the firearm magazine sized for rifle ammunition.
Example 16 is a magazine parts kit comprising the spring of any one of Examples 1-12, a magazine base plate, a follower, and a spring plate configured to nest with the magazine base plate.
Example 17 includes the subject matter of Example 15, wherein the base plate has a base plate body with a top surface that defines a recess sized and shaped to receive the spring plate such that the spring plate is recessed into the base plate body.
Example 18 includes the subject matter of any one of Examples 16 or 17, wherein the follower is configured such that a front portion and a rear portion of the follower overlap the intermediate coils when the spring is fully compressed.
Example 19 includes the subject matter of any one of Examples 16-18, wherein one or both sides of the follower are cut away to accommodate the intermediate coils when the spring is fully compressed.
Example 20 includes the subject matter of any one of Examples 16-19, wherein a lower rear margin of the follower is inclined with respect to a horizontal.
Example 21 includes the subject matter of any one of Examples 16-20, wherein an underside of the follower defines a protrusion configured to engage the top end portion of the spring, wherein the protrusion is laterally offset from a center of the follower.
Example 22 is a handgun magazine comprising a magazine tube extending along a central axis from a bottom end to a top end having feed lips; a follower retained in the magazine tube; a base plate on the bottom end of the magazine tube; a spring plate with a plate body; and a spring retained within the magazine tube between the spring plate and the follower, the spring including a top attachment leg, a bottom attachment leg, a plurality of upper coils, and a plurality of intermediate coils below the plurality of upper coils, wherein when the spring is compressed, at least two of the plurality of upper coils nest within the plurality of intermediate coils. In other examples, at least three of the upper coils nest within the intermediate coils.
Example 23 includes the subject matter of Example 22, wherein individual coils of the plurality of intermediate coils have a rectangular coil shape.
Example 24 includes the subject matter of any one of Examples 22-23, where the base plate has a base plate body with a top surface that defines a recess sized and shaped to receive the plate body of the spring plate such that the plate body is recessed into the base plate body.
Example 25 includes the subject matter of any one of Examples 22-24, wherein a rear end of the spring plate is between the magazine tube and the base plate.
Example 26 includes the subject matter of any one of Examples 22-25, wherein a height of the magazine tube, measured along a front wall of the magazine tube from a front bottom margin to an imaginary line through a central axis of a cartridge retained by the feed lips, is not greater than 120 mm.
Example 27 includes the subject matter of Example 26, wherein the height is not greater than 118 mm.
Example 28 includes the subject matter of any one of Examples 22-27, wherein an underside of the follower defines a protrusion configured to engage the top attachment leg of the spring, wherein the protrusion is laterally offset from a center of the follower.
Example 29 includes the subject matter of any one of Examples 22-28, wherein the follower is configured such that a front end portion and a rear end portion of the follower overlap at least some of the plurality of intermediate coils when the spring is fully compressed.
Example 30 includes the subject matter of Example 29, wherein sides of the follower are cut away to accommodate the plurality of intermediate coils when the spring is fully compressed.
Example 31 includes the subject matter of any one of Examples 22-30, wherein a lower rear margin of the follower is inclined with respect to a horizontal.
Example 32 includes the subject matter of any one of Examples 22-31, wherein the magazine has a capacity of 17 cartridges of 9 mm Luger ammunition.
The foregoing description of example embodiments has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the present disclosure to the precise forms disclosed. Many modifications and variations are possible in light of this disclosure. It is intended that the scope of the present disclosure be limited not by this detailed description, but rather by the claims appended hereto. Future-filed applications claiming priority to this application may claim the disclosed subject matter in a different manner and generally may include any set of one or more limitations as variously disclosed or otherwise demonstrated herein.
Number | Date | Country | |
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63312443 | Feb 2022 | US |