The present disclosure relates generally to firearms and, more specifically, to blowback-type automatic and semi-automatic firearms.
Blowback-type automatic and semi-automatic firearms have a common principle of operation which simply stated is this: a bolt reciprocates with respect to a barrel affixed to a body of the weapon to carry successive cartridges from a magazine into a rearward open breech of the barrel in position to be fired by a firing pin on the bolt. The explosive force of the fired cartridge propels the bolt rearwardly against the force of one or more compression springs. In a semi-automatic firing mode the bolt is caught by detent means in its rearward position and is moved forwardly by the spring for the next firing cycle only by operation of a trigger. In an automatic firing mode the bolt is propelled forwardly by the spring for repeated reciprocation and firing so long as the trigger is depressed.
Representative blowback-type automatic and semi-automatic firearms include the Beretta, the Uzi (see U.S. Pat. No. 4,335,643) and the Mendoza (see U.S. Pat. No. 3,906,833). Other blowback-type firearms include those shown in U.S. Pat. Nos. 4,019,423 and 2,437,548. In these prior designs the bolt reciprocates back-and-forth in sliding engagement with a cylindrical interior surface of the gun body. It is generally the practice in these conventional designs to add the bolt, barrel and spring one-by-one to the gun assembly as all of the parts are put together, not necessarily in immediate sequence and not as a separate independent subassembly. Field assembly and disassembly is relatively complicated. Foreign matter making its way to the slideable interface between the bolt and gun body can seriously impair the operation of the weapon, and cleaning is both necessarily frequent and painstaking.
The compression spring in most of the prior blowback-type firearms is aligned axially rearwardly of the barrel and bolt and relies upon a cap at the end of the gun body to provide a spring abutment in opposition to the bolt. The weapon disclosed in U.S. Pat. No. 3,906,833 is an exception to this but the other prior art designs mentioned above include the rearward spring contained by the gun body. This appreciably lengthens the weapon and increases its weight.
U.S. Pat. No. 4,327,626 discloses to some extent a combination of barrel-spring-bolt which is assembled together and then assembled within the remainder of the gun, though without carrying that concept to its highest advantage. That patent described a barrel having a rearward spring abutment and securing means for affixing the barrel to the gun body. A compression spring parallel to the barrel has a rearward end abutting the rearward spring abutment. Parallel to the spring and barrel is a reciprocable bolt having a forward spring abutment against which the forward end of the spring abuts and a firing pin base axially rearwardly of the barrel with apertures defined between the forward spring abutment and the base permitting entry and ejection of successive cartridges relative to the barrel breech. The bolt and barrel are in longitudinal slideable engagement.
A disadvantage of prior weapons with a rearward spring is that such a design shifts the center of gravity of the weapon rearwardly thus increasing the tendency of the barrel to buck upwardly in an uncontrolled fashion during recoil.
U.S. Pat. No. 4,649,800, the disclosure of which is incorporated herein by reference, discloses a self-contained blowback-type firing unit, the barrel-spring-bolt subassembly of which is able to be inserted as a discrete unit in and of itself in a gun body. Although U.S. Pat. No. 4,649,800 requires few internal mechanics, the design has a slow lock time (the time elapsed from the bolt release to discharge) of the weapon. More importantly, the long travel of the bolt creates a downward thrust of the weapon due to the weight of the bolt, making at least the first shot inaccurate.
While the prior devices are useful to a degree, they still suffer from certain drawbacks, including limitations on accuracy particularly during a fully automatic mode. Therefore, there exists a need in the art for an improved firearm that solves some or all of these problems, and does so in an efficient, reliable, low cost way.
The present disclosure provides an improvement in a self-contained blowback-type firing unit insertable as a discrete subassembly in a gun body. The firing unit may include a barrel with a forward muzzle and a rearward open breech and a rearward spring abutment and securing means for affixing the barrel to the gun body. The firing unit also may include a compression spring parallel to the barrel with a rearward end abutting the rearward spring abutment. Also, the firing unit may include a reciprocable bolt parallel to the spring and barrel having a forward spring abutment against which the forward end of the spring abuts and a firing pin base axially rearwardly of the barrel with apertures defined between the forward spring abutment and the base permitting entry and ejection of successive cartridges relative to the barrel breech. The bolt and barrel may be in longitudinal slideable engagement. The bolt may comprise a firing pin that is moveable independently of the bolt.
In one form, a self-contained blowback-type firing unit insertable as a discrete subassembly in a gun body, comprises a barrel comprising a forward muzzle and a rearward open breech and a rearward spring abutment; a compression spring parallel to the barrel with a rearward end portion abutting the rearward spring abutment; a bolt parallel to the spring and barrel, where the bolt comprises a firing pin that is moveable independently of the bolt; and wherein the blowback-type firing unit insertable as a discrete subassembly in a gun body is self-contained.
In one embodiment, the firing pin may be located in a counter bore of the bolt. The firing pin may be retractable. In some embodiments the firing pin may be spring loaded. The bolt may further comprise a pin retainer. In other embodiments the bolt further comprises a firing pin anvil. The subassembly may comprise a barrel, a bolt, and a compression spring, where the subassembly may be completely removed from the gun body without disassembling the member parts of the subassembly.
In a preferred embodiment, the bolt can move forward against the barrel without discharge of the firing unit. The bolt and barrel may further be in longitudinal slideable engagement. The bolt may comprise a forward spring abutment against which a forward end portion of the spring abuts and a firing pin base axially rearwardly of the barrel with apertures defined between the forward spring abutment and the firing pin base permit entry and ejection of successive cartridges relative to the barrel breech. The barrel may be inserted laterally into the bolt, the compression spring may be telescoped around the barrel so that the rearward end of the compression spring is abutted by a rearward spring abutment on the barrel. The firing unit may further comprise a quick connection of a forward annular element by means of a bayonet attachment.
In one form, a self-contained blowback-type firing unit is insertable as a discrete subassembly in a gun body, which includes a barrel with a forward muzzle and a rearward open breech and a rearward spring abutment, and which includes a compression spring parallel to the barrel with a rearward end portion abutting the rearward spring abutment, and which further includes a reciprocable bolt parallel to the spring and barrel, the bolt comprising a forward spring abutment against which a forward end portion of the spring abuts, the bolt and barrel being in longitudinal slideable engagement, the improvement which comprises where a firing pin is movable within the bolt.
In one form, a firearm is disclosed, comprising a self-contained blowback-type firing unit insertable as a discrete subassembly in a gun body, a barrel comprising a forward muzzle and a rearward open breech and a rearward spring abutment; a compression spring parallel to the barrel with a rearward end portion abutting the rearward spring abutment; a bolt parallel to the spring and barrel, where the bolt comprises a bore containing a spring loaded firing pin.
In one embodiment, the firing unit further comprises matching slideably engaged longitudinal track surfaces on the barrel and bolt respectively which are other than cylindrical and circumferentially complete and which prevent rotation of the bolt on the barrel, the bolt being free of slideable engagement with any surface other than the barrel track surfaces. In one form of the firing unit the securing means on the barrel is the only support for the firing unit. The securing means may be forwardly on the barrel adjacent the muzzle and the firing unit may be cantilevered rearwardly therefrom. The apertures in the firing unit may be longitudinal slot means formed in the bolt with opposed sides defining opposed track surfaces, and radially extending tongue means are formed on the barrel with opposed sides defining opposed barrel track surfaces, the slot means having a length sufficient to permit lateral entry of the barrel into the bolt during assembly. The tongue means may be formed adjacent the breech of the barrel remote from the muzzle.
Another advantage of the present disclosure is that the firing unit is interchangeable within various gun bodies since it may be held in place only at its forward muzzle end in one form. Different firing units of varying caliber can also be inserted into a given style of gun body for a quick change in fire power.
Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description, including disclosed embodiments and drawings, are merely exemplary in nature intended for purposes of illustration only and are not intended to limit the scope of the present disclosure, its application or use. Thus, variations that do not depart from the gist of the present disclosure are intended to be within the scope of the present disclosure.
Referring first to
A forward end 17 of the housing 11 has attached to its underside a palm-held stock 18. Rearward of that is conventional cartridge magazine-receiving means 19. To the rear of the magazine-receiving means 19 is a conventional trigger 20 which cooperates through a suitable linkage (not shown) with a conventional sear 21 which is schematically suggested in each of
The gun body 11 with all of its attendant parts referred to above, in combination with a firing unit 30 described below and with a typical loaded magazine in place in the magazine-receiving means 19, has a center of gravity well forward of the trigger 20 and its accompanying sear 21. An advantage of the forward center of gravity is that it creates a downward turning moment around the shooter's hand grasping the pistol handle 22 and this moment offsets at least some of the upward turning moment generated by recoil during firing. The result is that the weapon may be intentionally front-heavy and has less tendency to buck upwardly in the shooter's hand under the effect of recoil.
In addition, the accuracy of the weapon may be enhanced by the forward palm-held stock 18. Cradling of the front portion of the weapon with an upward palm (for example, the left hand of a right-handed shooter) in the manner of a shotgun is a more natural and easy manner of bringing the weapon quickly and accurately on target as compared to those automatic and semi-automatic weapons such as the Beretta which have a depending fist-held forward stock.
The firing unit 30 is indicated in
The barrel also may include securing means for affixing it to the gun body, namely external threads 37 on the muzzle portion 34 and a shoulder 38 rearwardly thereof. A circular securing flange 39 (see
An upper radially extending tongue 40 extends from the breech portion 35 of the barrel and a downwardly extending tongue 41 extends from the breech portion in the opposite direction. In the embodiment shown in
The compression spring 32 is disposed concentric with and around the barrel 31 as shown in
The reciprocable bolt 33 comprises a plurality of parts, the principal ones being shown in
At the opposite end of the bolt 33 is a firing pin base 51 which is disposed axially rearwardly of the barrel 33 as seen in
The bolt 31 and barrel 33 are in longitudinal slideable engagement. Matching slideably engaged longitudinal track surfaces are provided on the barrel 31 and the bolt 33 which are other than cylindrical and circumferentially complete and which prevent rotation of the bolt on the barrel. The upper slot 53 and lower slot 54 on opposite sides of the bolt each have opposed sides defining opposed track surfaces. The upper tongue 40 and lower tongue 41 on the barrel each define opposed barrel track surfaces. These surfaces are in sliding engagement as seen in
The firing pin base 51 of the bolt 33 further may include conventional extractor means 57 appearing schematically in
A description of the assembly and operation of the device shown in
It will be recognized that this assembly of the firing unit is of the utmost simplicity. It involves simply lateral insertion of the barrel into the bolt, a telescoping of the spring around the barrel so that its rearward end is abutted by the rearward spring abutment on the barrel, and a quick connection of the forward annular element by means of the bayonet attachment to complete the assembly. The firing unit at that point is a discrete subassembly ready for insertion into the gun body.
The assembly of the firing unit 31 with the gun body 10 is done in four simple and quick steps. First the cocking element 27 is connected to the bolt by placing the land 60 in the corresponding slot 59 in the firing pin base 51. Next the firing unit is telescoped forwardly from the position shown in
The movement of the parts of the firing unit during firing is shown sequentially in
Upon squeezing of the trigger 20 the detent 61 is released from the position of
The explosive effect of the fired cartridge causes the bolt 33 to be propelled rearwardly as shown in
If the weapon is on automatic firing mode, the sear 21 does not engage the detent 61 so long as the trigger 20 is squeezed and therefore the bolt 33 reciprocates back to its
Throughout these stages of reciprocation of the parts of the firing unit, the barrel 31 and bolt 33 may be in slideable engagement with one another along the matching longitudinal track surfaces shown in
The two main designs used in auto loading weapons are open bolt and closed bolt types.
Open bolt weapons have a fixed firing pin located within the bolt body itself, with the bolt locked back under spring tension. Once released by a devise, the bolt travels forward within the body of the weapon pushing a cartridge from the magazine into the chamber of the barrel. The rapid forward motion of the bolt strikes the chambered cartridge causing discharge. The bolt also houses an extractor device. Upon discharge of the cartridge, gas blow back occurs, pushing the bolt back. The empty cartridge case is extracted and ejected from the open cartridge port in the housing. This action completes one full cycle of the weapon.
Closed bolt weapons have non-fixed (retractable) firing pins located within the bolt body. With the bolt locked back under spring tension, that once released by a device, travels forward within the body of the weapon, pushing a cartridge from the magazine into the chamber of the barrel. However, the weapon does not yet discharge as it does with an open bolt fixed firing pin design. Located below the bolt, within the frame of the weapon is a hammer, hammer spring, sear, sear spring and trigger. The hammer is under spring tension and is released by pulling the trigger. The hammer then travels forward and strikes the retracted firing pin. The firing pin then strikes the chambered cartridge causing discharge. Finally, the same gas release blow back action takes place as described in the open bolt operation above.
The bolt 833 may further include conventional extractor means appearing schematically in
In a preferred embodiment, the barrel 931, spring 32, and bolt 933 are not fixedly attached to the firing unit. For example, the barrel 931 may not be screwed into the frame of the gun body 10. In some embodiments, the barrel may rest against a structure, such as a barrel flange 836 or barrel retainer 814, to prevent movement of the barrel 931 within the firing unit, while allowing the firing unit to be easily removed from the gun body, and allowing for easy disassembly of the firing unit. In some embodiments, the barrel will be kept from rotating. The upper slot 53 and lower slot 54 on opposite sides of the bolt each may have opposed sides defining opposed track surfaces. The upper tongue 40 and lower tongue 41 on the barrel each may define opposed barrel track surfaces. These surfaces may be in sliding engagement, with matching slideably engaged longitudinal track surfaces on the barrel and bolt respectively defined by radially extending tongue means on one of the barrel and bolt and slot means on the other of the barrel and bolt and which prevent rotation of the bolt on the barrel. The arcuate surface 42 of the upper tongue 40 of the barrel may engage a small segment of the cylindrical interior of the bolt 31 as shown in
One advantage of an embodiment as shown in
The advantages of this closed bolt configuration include a much more accurate first shot capability, a much faster lock time (where time is elapsed from the trigger pull to discharge), a decreased chance for dirt and foreign matter to enter the weapon, a much quieter mechanical function, and allowing for weapon suppression for covert use (since open bolt weapons have difficulty in being suppressed). Shells of any caliber used in law enforcement or military applications may be used in this firing unit including, but not limited to shells within the range of 0.22 LR (Long Rifle) to 0.45 ACP (Automatic Colt Pistol) caliber. In particular, 9 mm, 10 mm, 40 S&W (Smith & Wesson), or 45 ACP calibers are preferred.
The scope of the present disclosure is set forth in the following claims and is not limited to the specific preferred embodiment described above.