Abstract:
An improved design of a two-piece gas block for a semi-automatic rifle barrel. The improvement consisting of integrated attachment features that allow for a smaller overall size and a more reliable fit around a rifle barrel. The integrated attachment features contain minimal hardware for assembly; therefore, easier to assemble and disassemble. These attachment features consist of built-in interlocking protrusions and recesses in each half of the two-piece gas block. When assembled, the interlocking protrusions and recesses radially secure both halves together around a rifle barrel. Once both halves are assembled, fitted pins are then inserted through the interlocking protrusions and recesses to secure both halves axially to each other.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of provisional patent application No. 62/340,466 filed 2016 May 23 by the present inventor. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention pertains to gas blocks for auto-loading firearms and more specifically to gas blocks for the AR-15 rifle. 
       BACKGROUND 
       [0003]    There are many styles of auto-loading rifles with one of the more popular styles of auto-loading rifles being the AR-15, as seen in  FIG. 7 . It is a semi-automatic rifle, meaning it fires one projectile for every one pull of the trigger. It is a rifle that utilizes the expelled gases from the fired cartridge to operate the firearm&#39;s auto-loading action. This action requires the use of a gas block which redirects the expelled gases from inside the firearm&#39;s barrel back into the receiver of the firearm where the auto-loading action takes place. 
         [0004]    When the auto-loading rifle is fired, a small explosion from within the loaded round discharges a projectile from its cartridge. The gases from the explosion of the discharged round propels the projectile through the barrel. Once the projectile passes the gas port hole in the barrel, the built-up gases and pressures then travel through the gas port hole and into the gas block. Once inside the gas block, the pressurized gases is forced into the gas tube. This pressurized gas then travels back towards and in to the receiver where it actuates a device that ejects the fired cartridge and reloads a new round. This auto-loading cycle is completed every time the rifle is fired. See  FIG. 6 . 
         [0005]    The most commonly found gas blocks in the market are of a single whole piece design. The single-piece gas block is designed as a singular unit to be installed over the rifle&#39;s barrel and secured into place. This style of gas block can have a very small profile but requires extra inefficient steps to assemble and disassemble from the firearm. One such step is the removal of the muzzle device on the end of the firearm&#39;s barrel. In some cases this muzzle device is permanently attached to the barrel and removal is impossible without destroying the muzzle device and barrel. 
         [0006]    An alternative to the single piece gas block is the clamp-on gas block. The clamp-on gas block consists of two halves which can be installed around the firearm&#39;s barrel. This design utilizes screws or bolts for attaching each half to the other, thus creating a clamped on effect around the firearm&#39;s barrel. An example of this two-piece gas block can be found in prior art, Patent No. US 2006/0283318 A1, “Clamp On Gas Block Apparatus” by David L. Beaty. 
         [0007]    The use of a clamp-on gas block allows installation and removal from the firearm&#39;s barrel without disassembling any other items on the firearm. Though it may be easily installed or removed from the firearm&#39;s barrel it does inherently have an overly large sized profile, see  FIG. 7A  and  FIG. 7B . Unfortunately this larger sized profile does not allow installation of other popular rifle components. It is also prone to unintentional loosening of the screws or bolts when firing. Thereby, losing the clamping effect and causing the clamp-on gas block to slip out of position, losing its location over the gas port hole in the barrel. Once the clamp-on gas block is out of position the firearm will no longer perform the auto-loading action. This is known as a malfunction with the firearm and is taken very seriously among shooters. 
         [0008]    One of the many issues with the clamp-on gas block is the overall increase in size needed to accommodate the screws or bolts for clamping around the barrel. This increase in size does not allow the installation of the more popular handguards found in the market. 
         [0009]    Typically, the AR-15 handguards are installed around the single-piece gas block and barrel and is securely mounted at the end of the firearm&#39;s receiver. These handguards keep the user&#39;s hands from getting burnt by the hot barrel and the hot gas block when firing the rifle. The more popular handguards found in the market are designed to be as slim and sleek as possible, allowing the user a better control and handling of the firearm. This configuration is continually growing in popularity 
         [0010]    These slimmer handguards, however, will not fit around the bulkier clamp-on gas blocks. This is due to the increase in the clamp-on gas block&#39;s profile size. This profile size increase is necessary for accommodating the bolts or screws. The bolts or screws can be seen in the sectioned view of  FIG. 7B . This additional increase in size will not allow the more popular, slimmer handguards to be installed and used; therefore, the clamp-on gas block is undesirable. 
         [0011]    Another issue found with the clamp-on gas block is that it relies on the use of screws or bolts to attach each half to the other. These screws or bolts do not provide any security against unintentional loosening. As the barrel becomes hotter from firing the projectiles, that heat then transfers to the gas block. The clamp-on gas block then transfers its absorbed heat to the screws and bolts. This heat, along with the vibrations in the barrel created by firing the projectile, will cause unintentional loosening. This loosening will cause the gas block to shift out of position, stopping the firearm&#39;s auto-loading action, causing a malfunction. 
         [0012]    There is a need for an improved separable two-piece gas block that will fit inside the more popular slimmer, sleeker style handguards found in the market. This need will also include a much more secure method of attaching each half to the other. The method to attach each half to the other around the firearm&#39;s barrel must be impervious to heat and vibrations; thereby, negating all chances of a rifle malfunction. The attachment method must allow the total overall profile size of the separable two-piece gas block to be small enough to fit inside the slimmer, sleeker handguards that are popular in the market. 
       SUMMARY 
       [0013]    The improvement of the two-piece gas block can be found in the protrusions and recesses of the two-piece interlocking gas block. The protrusions and recesses allow the overall profile size interlocking gas block to be reduced. This reduction in size will allow the inside diameter of the slimmer, modern handguards to fit around the interlocking gas block without any interferences. As a secondary advantage of the smaller overall profile size is the weight reduction that will follow. The two-piece interlocking gas block will be much lighter than its opposing counter-part due to less material and parts needed to secure it to the barrel. 
         [0014]    The interlocking protrusions and recesses also provide a more secure fit around the firearm&#39;s barrel. This more secure fit eliminates any potential for the assembly to separate radially, or outwardly, from the firearm&#39;s barrel. The connection of the interlocking protrusions and recesses rely completely on the material strength of the two-piece interlocking gas block. 
         [0015]    Pins will then be installed perpendicularly through the assembled connection of the interlocking protrusions and recesses. This will prevent the two-piece interlocking gas block from separating axially, or along the center, of the barrel. The material strength of the pin or pins will determine the strength of the axial connection. 
         [0016]    The upper half of the two-piece interlocking gas block is comprised of a primary bore appropriately sized for a rifle barrel, a secondary bore appropriately sized for a gas tube, and an upwardly extending bore communicating the primary bore to the secondary bore. The outer radial ends of the upper half consists of the interlocking protrusions and recesses. 
         [0017]    The lower half of the two-piece interlocking gas block is comprised of a primary bore shared with upper half and appropriately sized for a firearm&#39;s barrel. The outer radial ends of the lower half consisting of the interlocking protrusions and recesses sized for mating with the upper half&#39;s protrusions and recesses. Multiple screws protruding through the lower half for securing the two-piece interlocking gas block to the barrel. 
         [0018]    The assembled upper and lower half will be radially secured around the firearm&#39;s barrel with protruding pins through the protrusions and recesses for securing axially. 
     
    
     
       DESCRIPTIONS OF THE VIEWS 
       Drawings—Figures 
         [0019]      FIG. 1  is a perspective view of the assembled interlocking gas block. 
           [0020]      FIG. 2A  is a top-left perspective view of the interlocking gas block&#39;s upper half. 
           [0021]      FIG. 2B  is a bottom-right perspective view of the interlocking gas block&#39;s upper half. 
           [0022]      FIG. 3A  is a top-left perspective view of the interlocking gas block&#39;s lower half. 
           [0023]      FIG. 3B  is a bottom-right perspective view of the interlocking gas block&#39;s lower half. 
           [0024]      FIG. 4A to 4C  are perspective views of the assembly steps necessary to install the interlocking gas block onto the firearm&#39;s barrel. 
           [0025]      FIG. 5A  is a representation of a prior art clamp-on gas block. 
           [0026]      FIG. 5B  is a representation of a prior art clamp-on gas block with sectioned view illustrating the bolts or screws. 
           [0027]      FIG. 6  is a section view of the gas block, barrel, and gas tube. It is a representation of the moments immediately following firing of the projectile. 
           [0028]      FIG. 7  is a perspective view of a modern auto-loading rifle. This particular rifle is a representation of the AR-15. 
       
    
    
     DRAWINGS—REFERENCE NUMERALS 
       [0000]    
       
           1 —Barrel 
           2 —Muzzle Device 
           3 —Receiver 
           4 —Barrel Nut 
           5 —Gas Block 
           6 —Gas Tube 
           7 —Handguard 
           8 —Grip 
           9 —Trigger 
           10 —Stock 
           11 —Magazine 
           12 —Charging Handle 
           13 —Accessory Slot 
           14 —Upper Half 
           15 —Radii 
           16 —Top Cylindrical Section 
           17 —Lower Cylindrical Section 
           18 —Primary Bore 
           19 —Secondary Bore 
           20 —Gas Tube Pin Hole 
           21 —Gas Tube Pin 
           22 —Vertical Hole 
           23 —Gas Port 
           24 —Projectile 
           25 —Barrel&#39;s Bore 
           26 —Gases 
           27 —Protrusion (Upper Half) 
           28 —Recess (Upper Half) 
           29 —Axial Locating Pin Hole (Upper Half) 
           30 —Axial Locating Pin 
           31 —Lower Half 
           32 —Half Cylindrical Section 
           33 —Axial Locating Pin Hole (Lower Half) 
           34 —Protrusion (Lower Half) 
           35 —Recess (Lower Half) 
           36 —Threaded Hole 
           37 —Set Screw 
       
     
       DESCRIPTION 
       [0066]      FIG. 7  shows a front/left perspective view, with partial sectioned handguard ( 7 ), of the AR-15 style sporting rifle with updated components typically found in the market. Starting with the barrel ( 1 ); a muzzle device ( 2 ) is attached at the end. The barrel ( 1 ) is attached to the receiver ( 3 ) by a barrel nut ( 4 ). A gas block ( 5 ) is secured to the barrel ( 1 ). Extending from the gas block ( 5 ) and into the receiver ( 3 ) is the gas tube ( 6 ). 
         [0067]    The handguard ( 7 ) then surrounds the gas block ( 5 ) and the gas tube ( 6 ) protecting the shooter&#39;s hand from heat generated by the expelled rounds. The handguard ( 7 ) shown is a representation of the modern style handguards that utilize multiple accessory slots ( 3 ). This style of handguard is a very popular configuration found in the market. These accessory slots allow the user to attach various accessories, such as lights and lasers, to the firearm. 
         [0068]    Continuing is the grip ( 8 ) from which the user&#39;s hand will grip in order to control the firearm. The trigger ( 9 ) extends downward from the receiver ( 3 ) resting in a comfortable area for the user&#39;s finger to press. The stock ( 10 ) connects to the receiver ( 3 ) and is placed in the user&#39;s shoulder pocket when firing. A magazine ( 11 ) which contains multiple rounds is shown inserted into the lower section of the receiver ( 3 ). The firearm can be loaded or “charged” when the user pulls and releases the charging handle ( 12 ). This is a general configuration of the AR-15 sporting rifle that is very popular among shooting enthusiasts. 
         [0069]    Shown in  FIG. 1  is a perspective view of the interlocking gas block in its assembled form without installation on a firearm. It is generally machined or cast out of a metallic material. The preferred material would be a strong carbon steel, an alloy steel, or a stainless steel. Other materials could consist of aluminum, titanium, carbon fiber, or any other material suitable for containing high pressures such as those found in the firearm&#39;s barrel ( 1 ). The finished piece may then be coated or painted to prevent damage or corrosion. 
         [0070]      FIGS. 2A, 2B, 3A, and 3B  are perspective views of the interlocking gas block. In its most complete version, the interlocking gas block is made up of the following components listed below. 
         [0071]    An upper half ( 14 ) of the interlocking gas block containing two cylindrical sections running parallel and stacked vertically on top of each other, blended together by smooth radii ( 15 ). The upper cylindrical section ( 16 ) being smaller than the lower cylindrical section ( 17 ). With the lower cylindrical section ( 17 ) forming a semi-cylindrical shape. The lower cylindrical section ( 17 ) contains a primary bore ( 18 ), semi-circular in shape, running axially and centered in the lower cylindrical section ( 17 ). This primary bore ( 18 ) will be properly sized for the firearm&#39;s barrel ( 1 ). 
         [0072]    The upper cylindrical section ( 16 ) of the upper half ( 14 ) contains the secondary bore ( 19 ). It is a blind hole that runs axially and centered in the upper cylindrical section ( 16 ). This secondary bore ( 19 ) is smaller than the primary bore ( 18 ) and is properly sized for the firearm&#39;s gas tube ( 6 ). Additionally, a fitted pin hole ( 20 ) will be produced through the upper cylindrical section ( 16 ), perpendicular and centered to the secondary bore ( 19 ). This hole will be sized for a fitted pin ( 21 ) and will be used to secure the gas tube ( 6 ) inside the secondary bore ( 19 ). Connecting the primary bore ( 18 ) to the secondary bore ( 19 ) is a vertical hole ( 22 ) that allow gases to flow from the barrel&#39;s gas port ( 23 ) into the gas tube ( 6 ), which then travels into the receiver ( 3 ). 
         [0073]    The upper half ( 14 ) of the interlocking gas block will have multiple protrusions ( 27 ) and a recesses ( 28 ) located at the outer edges of the lower cylindrical section ( 17 ). The protrusions ( 27 ) and recesses ( 28 ) run parallel to the axis of the primary bore ( 18 ). The protrusions ( 27 ) will be rectangular projections traveling the length of the part and will sit below the recesses ( 28 ). The recesses ( 28 ) are rectangular voids that will run the length of the part and will sit above the protrusions ( 27 ) of the upper half ( 14 ). 
         [0074]    Multiple axial locating pin holes ( 29 ) will be produced in the upper half ( 14 ) at the outer edges of the lower cylindrical section ( 17 ). These holes ( 29 ) will be opposite of each other and located mid length of the upper half ( 14 ). The holes ( 29 ) will extrude perpendicularly through the protrusions ( 27 ) and recesses ( 28 ). These holes ( 29 ) will be properly sized for axial locating pins ( 30 ). The pins ( 30 ) will be installed during the assembly of the interlocking gas block. Each of the axial locating pin holes ( 29 ) will have a flat section inset into the round lower cylindrical section ( 17 ) of the upper half ( 14 ). This flat inset is to the ease axial locating pin ( 30 ) installation. 
         [0075]    The upper ( 16 ) and lower ( 17 ) cylindrical sections of the upper half ( 14 ) are sized slightly larger than their corresponding bores ( 18  &amp;  19 ) in the part. This is done to achieve maximum clearance inside a very narrow handguard ( 7 ). 
         [0076]    The lower half ( 31 ) of the interlocking gas block is a half cylindrical section ( 32 ). This section contains the same sized primary bore ( 18 ) which is shared by the upper half ( 14 ). This primary bore is properly sized to the firearm&#39;s barrel ( 1 ). 
         [0077]    At the outer edges of the lower half&#39;s ( 31 ) cylindrical section ( 32 ) are the protrusions ( 34 ) and recesses ( 35 ). These protrusions and recesses are produced inversed of the upper half&#39;s ( 14 ) protrusions ( 27 ) and recesses ( 28 ). The lower half&#39;s ( 31 ) protrusions ( 34 ) and recesses ( 35 ) are located opposite of each other and properly sized to mate with the upper half&#39;s ( 14 ) protrusions ( 27 ) and recesses ( 28 ). The lower half&#39;s ( 31 ) protrusions ( 34 ) and recesses ( 35 ) also run parallel to the axis of the primary bore ( 18 ). 
         [0078]    The lower half&#39;s ( 31 ) protrusions ( 34 ) are rectangular projections that sit above the recesses ( 35 ). The recesses ( 35 ) are rectangular voids that sit below the protrusions ( 34 ). The protrusions ( 34 ) and recesses ( 35 ) of the lower half ( 31 ) are properly sized to mate with the upper half&#39;s ( 14 ) protrusions ( 27 ) and recesses ( 28 ). The proper size will produce a sliding fit between the upper half ( 14 ) and lower half ( 31 ) protrusions ( 27  &amp;  34 ) and recesses ( 28  &amp;  35 ). The sliding fit requires a tight clearance, with minimal play, between both halves when assembling. This fit allows the primary bore ( 18 ), which is shared between the upper half ( 14 ) and lower half ( 31 ), to maintain the correct size when assembling around the firearm&#39;s barrel ( 1 ). 
         [0079]    The lower half ( 31 ) contains multiple axial locating pin holes ( 33 ) located at the outer edges of the half cylindrical section ( 32 ). The holes ( 33 ) extrude perpendicularly through the protrusions ( 34 ) and recesses ( 35 ) of the lower half ( 31 ). These axial locating pin holes ( 33 ) perfectly align to the upper half&#39;s ( 14 ) axial locating pin holes ( 29 ) and are sized for the axial locating pin ( 30 ). 
         [0080]    The lower half ( 31 ) contains multiple threaded holes ( 36 ) extruding through the center of the cylindrical section ( 32 ) and are aligned with each other. These threaded holes are sized for set screws ( 37 ) and are used to secure the interlocking gas block to the firearm&#39;s barrel ( 1 ). 
         [0081]    Refer to  FIGS. 4A, 4B, and 4C  for the assembly of the interlocking gas block. These figures represent the forward section of the firearm containing only the necessary components needed for installation. These figures include the barrel ( 1 ) with gas port ( 23 ), and muzzle device ( 2 ) installed, the upper half ( 14 ) and lower half ( 31 ) of the interlocking gas block, the gas tube ( 6 ), the modern style handguard ( 7 ), the gas tube pin ( 21 ), axial locating pins ( 30 ), and set screws ( 37 ). 
         [0082]    The first step when installing the interlocking gas block can be seen in  FIG. 4A . The upper half ( 14 ) and lower half ( 31 ) are placed around the firearm&#39;s barrel ( 1 ) near the gas port hole ( 23 ). Each half must be located opposite of each other, around the firearm&#39;s barrel, and offset from one another. The protrusions ( 27 ) and recesses ( 28 ) of the upper half ( 14 ) will then be aligned to the lower half&#39;s ( 31 ) protrusions ( 34 ) and recesses ( 35 ). 
         [0083]    Refer to  FIG. 4B  for the second step. In the second step, the upper half ( 14 ) and lower half ( 31 ) will then be slid towards each other along the barrel ( 1 ). Ensure proper mating of the protrusions ( 27  &amp;  34 ) and recesses ( 28  &amp;  35 ) along the axis of the upper half&#39;s ( 14 ) and lower half&#39;s ( 31 ) primary bore ( 18 ). Once each half ( 14  &amp;  31 ) has been assembled together, the gas tube ( 6 ) may then be aligned to the gas tube hole ( 19 ) of the upper half ( 14 ) and then inserted. The gas tube ( 6 ) may then be secured by installing the gas tube pin ( 21 ) through the gas tube pin hole ( 20 ). 
         [0084]    See  FIG. 4C  for the third step. Once both halves ( 14  &amp;  31 ) have been assembled around the barrel, as seen in  FIG. 4C , the upper half ( 14 ) and lower half ( 31 ) axial locating holes ( 29  &amp;  33 ) may then be aligned. Once the axial locating holes ( 29  &amp;  33 ) have been aligned, properly sized axial locating pins ( 30 ) will then be installed to create a solid connection between the upper half ( 14 ) and lower half ( 31 ). This will secure the upper half ( 14 ) and lower half ( 31 ) together; keeping them from separating axially along the axis of the primary bore ( 18 ). At this point both primary bores ( 18 ) will form one complete bore around the rifle&#39;s barrel ( 1 ). 
         [0085]    The final step is to align the rifle barrel&#39;s ( 1 ) gas port hole ( 23 ) to the vertical hole ( 22 ) found in the upper half ( 14 ). Once aligned properly, the set screws ( 37 ) will then be tightened and torqued appropriately to the firearm&#39;s barrel ( 1 ), securing the interlocking gas block in place on the barrel ( 1 ). 
         [0086]      FIG. 6  shows a representation of the fired projectile ( 25 ) inside the barrel bore ( 25 ). The fired cartridge will eject the projectile ( 24 ) from its case and will send the projectile ( 24 ) traveling through the barrel&#39;s bore ( 25 ) toward the muzzle end of the firearm at a very high velocity. The gasses ( 26 ) from the fired cartridge is what propels the projectile ( 24 ). Once the projectile ( 24 ) has passed the barrel port ( 23 ), the gasses will then travel through the barrel port ( 23 ), into the upwardly extending bore ( 22 ) and into the gas tube ( 6 ). Once inside the gas tube ( 6 ), the gasses ( 26 ) will then travel into the receiver ( 3 ) of the rifle; performing the auto-loading action. 
         [0087]    While the present invention has been described above in terms of specific embodiments, it is to be understood that the invention is not limited to these disclosed embodiments. Many modifications and other embodiments of the invention will come to mind of those skilled in the art to which this invention pertains, and which are intended to be and are covered by both this disclosure and the appended claims. It is indeed intended that the scope of the invention should be determined by proper interpretation and construction of the appended claims and their legal equivalents, as understood by those of skill in the art relying upon the disclosure in this specification and the attached drawings.