Patent Application
20150059222
The present invention relates to followers used in a firearm magazines and, more particularly, a low profile follower that allows maximum space for bullets and accommodates the largest possible magazine spring while also improving slide lock reliability and eliminating existing limitations.
Automatic and semi-automatic firearms usually contain a cartridge magazine in which bullets are stored, wherein magazines are generally comprised of a magazine tube, a magazine spring, and a follower. The magazine is designed to automatically load the bullets into position to be stripped and chambered following each time the firearm cycles and, in many instances, to activate the slide lock lever after the last bullet in the magazine is fired. The magazine tube contains the bullets and the magazine spring forces the follower up to keep the next bullet located at the top of the magazine where it can effectively be stripped and chambered.
To get the most compact profile that allows for maximum bullet storage and maximum spring space, followers are commonly made out of steel or spring steel. These stamped steel followers are generally shaped in a slightly obtuse L-shape. The top side is located between the first bullet loaded in the magazine and the magazine spring. The rear flange is located between the back of the magazine spring and the inside back of the magazine tube. On some stamped steel follower designs, the top length remains flat and a second flange is extended from the approximate intersection of the L-bend extending under the top length at an angle to act as a slide lock step. This follower design allows for a low profile as the top length of the part springs down closing the angle between the top length and the slide lock step when the magazine is full. Because of the low profile when loaded, space for bullets and the spring is maximized. Also, since the rear flange is the only edge that protrudes downward, the magazine spring size can be maximized to the width of the magazine tube and the length of the magazine tube minus only the thickness of the rear flange. In some applications, after the last round is chambered, the follower pivots over the front edge of the magazine tube when the slide lock step on the follower contacts the slide lock lever inside the firearm. This pivot can reduce the spring force transferred to the slide lock lever which may reduce the slide lock reliability.
Slide lock reliability is also affected with this type of follower as the follower can “jump” the slide lock lever. Since the bullets must clear the slide lock lever on the way up and out of the magazine, the slide lock lever is typically shaped as a right triangle when viewed from the top because of a bullet clearance cut. Since the flat steel follower can pivot, and the slide lock shelf is flat, the flat edge of the slide lock step on the follower rides on the hypotenuse edge instead of the bottom side of the slide lock lever in some applications. The angle of contact between the two can force the follower around and over the slide lock lever. Since the follower slide lock shelf is now above the slide lock lever, it cannot act to lock the slide.
Another problem that occurs in applications when the follower pivots over the top edge of the magazine tube is the magazine is prevented from full insertion into the firearm when empty. Full insertion is prevented because as the empty magazine is inserted, the slide lock step of the follower contacts the slide lock lever as the follower pivots over the top edge of the magazine tube. When the slide lock lever pivots upward to its end of travel, the follower begins to travel downward against the magazine spring pressure but will stop when it contacts the top edge of the magazine tube as it has pivoted over it. In some applications this may happen before the magazine reaches its fully inserted and locked position. In applications where this is possible, a different, higher profile follower must be used that takes up valuable space inside the magazine tube.
Given the preexisting problem described above, there is a need for a low profile follower that maximizes space for bullets and accommodates the largest possible magazine spring while also improving slide lock reliability and eliminating existing limitations.
For a fuller understanding of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings in which:
The present invention is directed to a firearm cartridge magazine follower designed to allow the lowest possible profile in order to accommodate maximum storage capacity for bullets, containing the ability to reliably activate the slide lock, and allowing empty magazine insertion into the firearms in a broad range of applications not previously accomplished with this style of follower. The follower is comprised of a thin and strong spring-like material, such as steel or stainless steel. The follower uses the length of a lower flange (slide lock step) of the follower to determine the angle within the magazine tube resulting from follower contact with the front and the rear of the inside wall of the magazine tube. An upper flange that changes angle as the magazine spring pressure increases in response to added ammunition rounds provides more space for the magazine spring when the magazine is fully loaded. The lower follower flange that is split into two surface members lengthwise, one containing a bend or end shape as necessary for proper slide lock activation and the opposite surface being either flat or containing a downward bend that will flatten as necessary when magazine is loaded, and together allowing empty insertion into a broad range of firearms. A raised flange bent in the upward direction at the distal end of the second surface member is disposed for raising the forward contact point between the follower and the inside of the magazine tube, which reduces binding and downward pivot of the front of the follower. A split rear flange allows for a larger spring to be used, smoother spring compression, and avoidance of follower contact with the weld, which is typically located in the center of the rear flat wall of the magazine tube. Spacer flanges along the length of the upper flange may be included for spacing the top surface of the follower down from the slide rail when the magazine is empty.
Referring to the several views of the drawings, the firearm magazine follower of the present invention is shown in accordance with a preferred embodiment and is generally indicated as 10.
The firearm magazine follower 10 is made of a thin, strong and spring-like material, such as steel or stainless steel, and includes a lower follower flange 12 and an upper follower flange 26. The lower flange 12 (i.e., slide lock step) has a length selected to form an adequate angle of the follower 10 within the magazine tube 14 of the magazine. The front end 16 of the lower flange 12 contacts an inner facing side of the magazine tube 14, thereby keeping the front end 16 from diving while the rear flange 18 of the follower 10 is approximately in parallel connection with the opposite inner facing side of the magazine tube 14 and preventing the rear end 20 of the follower 10 from rising. The follower 10 remains at an explicit angle once the lower flange 12 enters the magazine tube 14 as additional bullets 42 are loaded in the magazine.
Referring to
The two surface members 13 and 15 in the lower flange 12 are capable of moving independently. The front end 16 of lower flange 12 that contacts the slide lock lever 24 allows adjacent surface member 15 to spring downward into the magazine tube 14, thereby allowing the magazine to travel to its fully inserted position without hard-stopping, even as surface member 13 remains stopped above the magazine tube 14. The upper follower flange 26 has a relief cut 27 that clears the bend in the lower flange 12 when the magazine is fully loaded and the angle between the lower and upper flanges 12 and 26 is closed. The bend 22 in the slide lock step 12 is offset to avoid interfering with the bullet as the angle between the lower and upper flanges 12 and 26 closes.
Referring to
The opening in the split rear flange 32 prevents the magazine spring 28 from catching on the split rear flange 32 as the spring 28 is compressed when bullets 42 are loaded into the magazine tube 14. Additionally, the split rear flange 32 keeps the follower 10 from contacting the center rear surface of the inside of the magazine tube 14 where the weld is commonly located, thereby maintaining smooth movement during operation of the firearm.
The rear flange 18 (and split rear flange 32) consists of two layers of material formed against one another. The outer layer 34 is less wide than the inner layer 36 in order to provide clearance when the follower 10 rides inside the magazine tube 14. The inside rear bends on the magazine tube typically contain a small radius 38 that would prevent the rear flange 18 of the follower 10 from riding directly on the rear surface of the magazine tube 14. When the outer layer 34 is relieved to provide clearance from the radius in the magazine tube 14, the rear flange 18 can ride against the inside rear of the magazine tube 14 while the inner layer 36 of the rear flange 18 can be designed to a width for a precision side-to-side fit within the magazine.
Referring to
In a preferred embodiment, the upper flange 26, rear flange 18 and lower flange 12 are formed from a single, flexible piece of material, such as steel. In other embodiments of the follower 10, two or more pieces of material formed from one or more types of material may be welded together or otherwise affixed to form the upper flange 26, rear flange 18 and lower flange 12.
While the present invention has been shown and described in accordance with preferred and practical embodiments thereof, it is recognized that departures from the instant disclosure are contemplated within the spirit and scope of the present invention.
This patent application is based on provisional patent application Ser. No. 61/873,631 filed on Sep. 4, 2013.
| Number | Date | Country | |
|---|---|---|---|
| 61873631 | Sep 2013 | US |
