GAS BLOCK ALIGNMENT FIXTURE
Provided is a fixture for holding a firearm gas block for mounting or removal of a gas tube. holding fixture. The fixture includes an elongated body having a mounting portion and a holding portion. The mounting portion is sized to correspond to and receive a bore of a gas block and includes at least one attachment feature for temporary securement of a gas block placed thereon against rotational and axial movement relative to the body.
This application claims priority to U.S. Provisional Patent Application No. 62/505,083, filed May 11, 2017, and incorporates the same herein by reference.
TECHNICAL FIELDThis invention relates to a fixture for firmly holding a gas block, such as for an AR-pattern firearm, in a secure and convenient position while attaching a gas tube with a roll pin.
BACKGROUNDGas operated semiautomatic or fully automatic firearms use a portion of the propellant gas diverted from the barrel bore for automatically cycling the action each time a round is fired. Such firearms, including AR-pattern firearms, typically use a gas block that is mounted over a gas port in the barrel. The gas block may be mounted to the barrel and secured in place over the gas port, such as with set screws or pins. In a direct impingement gas system, a gas tube carries a flow of gas pressure from the gas block to the upper receiver where it is directed into a bolt carrier assembly. Connection of the gas tube to the gas block is commonly achieved by pressing a small roll pin through a cross bore in the gas block that aligns with openings adjacent the forward end of the gas tube. This holds a port in the wall of the gas tube in alignment with an internal gas passageway in the gas block.
Holding a gas block securely while holding the gas tube in the proper position and simultaneously driving a roll pin through the cross bore to secure the gas tube can be a challenging task. Gas blocks do not typically have flat sides, making it difficult to lay it on a flat surface during this installation process. Clamping the gas block in a vise can mar the finish or otherwise damage the gas block. Moreover, gas blocks come in a variety of external sizes, styles, and shapes, some being low profile, some including an integral front site, and others including an accessory mounting rail. Accordingly, a wide variety of jigs or fixtures would be needed to adapt to the varies external sizes and shapes.
A “universal” fixture that is simple, versatile, effective, and inexpensive is needed.
SUMMARY OF INVENTIONThe present invention provides a fixture for holding a firearm gas block for mounting or removal of a gas tube. The fixture includes an elongated body having a mounting portion and a holding portion. The mounting portion is sized to correspond to and receive a bore of a gas block and includes at least one attachment feature for temporary securement of a gas block placed thereon against rotational and axial movement relative to the body.
According to one embodiment, the mounting portion can be substantially round in cross section. The attachment feature can be, for example, one or more dimples for receiving a gas block set screw and/or one or more transverse slots for receiving a gas block taper pin or roll pin. According to another feature of one embodiment, the holding potion may include one or more flats for clamping the fixture in a holding device. According to yet another embodiment, the mounting portion can include multiple segments having different diameters to accommodate gas blocks for barrels of different diameters using the same fixture.
Other aspects, features, benefits, and advantages of the present invention will become apparent to a person of skill in the art from the detailed description of various embodiments with reference to the accompanying drawing figures, all of which comprise part of the disclosure.
Like reference numerals are used to indicate like parts throughout the various drawing figures; wherein;
With reference to the drawing figures, this section describes particular embodiments and their detailed construction and operation. Throughout the specification, reference to “one embodiment,” “an embodiment,” or “some embodiments” means that a particular described feature, structure, or characteristic may be included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” or “in some embodiments” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the described features, structures, and characteristics may be combined in any suitable manner in one or more embodiments. In view of the disclosure herein, those skilled in the art will recognize that the various embodiments can be practiced without one or more of the specific details or with other methods, components, materials, or the like. In some instances, well-known structures, materials, or operations are not shown or not described in detail to avoid obscuring aspects of the embodiments.
Referring first to
As shown in
The mounting portion 12 could be made shorter in length than in the illustrated embodiment, if differently spaced pairs of dimples 16 (and/or other attachment features) are positioned around its circumference rather than along its length. Because the fixture indexes only to the interior diameter of the gas block bore 15, a close tolerance dimension of the part with both ends necessarily open, the fixture 10 can be used on any type/style of gas block, including those with unusual shapes, those that include a front sight or accessory rail, and those that are split or clamp onto the barrel.
Another well-known means for securing a gas block to a barrel uses transverse taper pins or roll pins driven into transverse openings in the gas block that partially intersect the barrel through slots drilled or cut in the barrel's surface. Accordingly, the mounting portion 12 of the fixture 10 could be configured with slots (not shown) or features other than dimples 16 to accommodate such other gas block mounting configurations or means.
The fixture 10 also includes a holding portion 22, which allows the fixture 10 and temporarily mounted gas block 14 to be manipulated by hand or clamped in a support or holding device, such as a bench vise (not shown). The holding portion 22 may be substantially round, may be in the form of a blade, or may include a series of flat surfaces to facilitate clamping the fixture 10 in various selected orientations. In the illustrated embodiment, the holding portion 22 is octagonal in cross section, although having as few as a single flat surface at a selected position can aid in clamping the fixture 10 in an orientation selected by the installer. Alternatively, user orientation could be a function of selecting attachment features (e.g., dimples 16) that are positioned around the circumference of the mounting portion 12, instead of changing the position of the holding portion 22 in the holding device.
Referring now also to
Referring now to
While one or more embodiments of the present invention have been described in detail, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. Therefore, the foregoing is intended only to be illustrative of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not intended to limit the invention to the exact construction and operation shown and described. Accordingly, all suitable modifications and equivalents may be included and considered to fall within the scope of the invention, defined by the following claim or claims.
Claims
1. A gas block holding fixture, comprising:
- an elongated body having a mounting portion and a holding portion, the mounting portion sized to correspond to and receive a bore of a gas block, and the mounting portion including at least one attachment feature for temporary securement of a gas block placed thereon against rotational and axial movement relative to the body.
2. The fixture of claim 1, wherein the attachment feature includes at least one dimple for receiving a gas block set screw.
3. The fixture of claim 2, wherein the attachment feature includes a series of dimples axially spaced apart at differing intervals.
4. The fixture of claim 1, wherein the attachment feature includes at least one transverse slot for receiving a gas block pin.
5. The fixture of claim 1, wherein the holding portion includes at least one flat surface for clamping the fixture in a holding device.
6. The fixture of claim 5, wherein the holding potion includes a plurality of corresponding pairs of flat surfaces.
7. The fixture of claim 6, wherein the holding portion is octagonal in cross section.
8. The fixture of claim 1, wherein the mounting portion is substantially round in cross section.
9. The fixture of claim 1, wherein the mounting portion includes a first segment having a first size and a second segment having a different second size.
10. The fixture of claim 9, wherein the first and second segments are substantially round in cross section.
11. The fixture of claim 10, wherein the first segment corresponds to a 0.625″ barrel diameter and the second segment corresponds to a 0.750″ barrel diameter.
12. The fixture of claim 10, wherein the first segment corresponds to a 0.875″ barrel diameter and the second segment corresponds to a 0.936″ barrel diameter.
Type: Application
Filed: Apr 27, 2018
Publication Date: Nov 15, 2018
Inventor: David Glen Brinson (Houston, TX)
Application Number: 15/964,809