This disclosure relates to firearm components and more particularly to a battery safety mechanism for a handgun or rifle utilizing blowback operation.
Firearms design involves many non-trivial challenges. Some semiautomatic handguns use a straight blowback action in which the inertia of firing a round is used to cycle the action. For a handgun chambered in .22 cal. or .380 ACP, for example, the energy to cycle the action comes from expanding propellant gases that push the cartridge case rearward upon firing the gun. As the case moves rearward it also drives the breechblock and slide rearward to cycle the action. In doing so, the breechblock also begins to separate from the barrel as the case begins to move rearward. After the slide moves rearward, a recoil spring returns the breechblock and slide forward while at the same time chambering a round. In a recoil-operated handgun, in contrast, the slide and breechblock are locked with the barrel and move rearward with the barrel for a short distance after firing to ensure the projectile has exited the barrel prior to unlocking and opening the breach. Some small-bore semiautomatic rifles and submachine guns also use blowback system.
One aspect of the present disclosure relates to a mechanism for a firearm that prevents contact between the hammer and firing pin when the slide is out of battery. The mechanism can be used in a handgun or rifle using blowback action, such as one chambered for rimfire ammunition (e.g., 0.22 LR). The safety mechanism can be applied to handguns with hammer-fired or striker-fired actions. 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.
These and other features of the present embodiments will be better understood by reading the following detailed description, taken together with the Figures herein described. 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. In short, the Figures are provided merely to show example structures.
Disclosed is a safety mechanism for a firearm that prevents discharge of the firearm in an out-of-battery condition. In one example, the safety mechanism obstructs the hammer from striking the firing pin when the breechblock is out of battery by more than a predefined distance. For example, when the breechblock is out of battery by more than a predefined distance (e.g., 1 mm), a lever defaults to a blocking position that obstructs the hammer from striking the firing pin. As the breechblock moves into battery, a pin moves the lever to a non-blocking position where the hammer can strike the firing pin. For example, the pin can be oriented vertically with a lower end of the pin positioned to engage a cam surface on the receiver when the breechblock is within the predefined distance of the battery position. As the breechblock continues forward, the pin is displaced upward, which moves the blocking lever to a non-blocking position. However, if the breechblock fails to move sufficiently to the battery position, the lift pin remains in the lowered position and the lever remains in the blocking position. The mechanism can be utilized in firearms utilizing a blowback method of operation, including hammer-fired handguns, striker-fired handguns, and small bore rifles, in accordance with some embodiments.
Safety continues to be an important challenge for firearms designers. Handguns can be made with external safety levers that are activated by the user. Handguns can also have one or more internal safeties that prevent discharge when the firearm is dropped, for example.
One non-trivial issue of firearms design and performance pertains to the possibility of firing the gun when the breech block is slightly out of battery (e.g., more than 1 mm). For example, a breechblock on a blowback handgun may fail to completely close and remain in an out-of-battery position. The out-of-battery condition can result from dirty or damaged parts, bad or improper ammunition, a weak slide return spring, or interference with the slide during blowback (e.g., by contact with the user's hand), for example. Since the breech is not completely closed in an out-of-battery condition, firing the gun in this state means that the pressure of the fired cartridge is not contained within the chamber and can release through the breech or other unintended locations. The result can be damage to the gun and harm to the operator.
In some semiautomatic handguns, such as a handgun chambered for centerfire ammunition, the rear corner of the breechblock is rounded, also referred to as the hammer ramp. As the breechblock moves rearward, the hammer ramp contacts the hammer and returns it to the cocked position. In some handguns, the hammer ramp contacts the hammer at a point that is close to the pivot pin so that the contact point is effective to block the hammer from striking the firing pin unless the breech mechanism is in battery. However, in handguns chambered for rimfire ammunition, lower peak forces of combustion are available to cock the hammer during rearward movement of the slide. For this reason, the radius of the rear corner of the breechblock (e.g., the “hammer ramp”) may be increased so that the breechblock contacts the hammer further away from the hammer pivot pin. The larger radius of the hammer ramp may still block the hammer from striking the firing pin at greater distances from the battery position. However, the increased radius causes the point of contact to be further away from the pivot point, allowing the hammer to rotate further towards the firing position. For this reason, the hammer ramp may fail to effectively prevent the hammer from striking the firing pin when the breechblock is a small distance out-of-battery. Accordingly, a need exists for an improved mechanism to prevent out-of-battery discharge in firearms. In addition to the hammer ramp, it is also desirable to have a redundant safety mechanism that prevents out-of-battery discharge.
To address this need and others, the present disclosure relates to a battery safety mechanism for semiautomatic handguns that utilize a blowback system. The battery safety mechanism can be configured to obstruct a hammer from striking a firing pin or configured to block a striker from impacting a primer when the breechblock is in an out-of-battery position. Accordingly, a safety mechanism as disclosed herein can be used in handguns and rifles having a blowback method of operation. For example, the safety mechanism is particularly useful for firearms configured for rimfire ammunition.
As will be appreciated in light of this disclosure, and in accordance with some embodiments, a battery safety mechanism can be part of a breech block in a semiautomatic handgun. A battery safety mechanism as disclosed herein is particularly useful in a handgun chambered for 0.22 LR, 0.17 HMR, or other rimfire ammunition, and can be implemented in hammer-fired and striker-fired guns. The battery safety mechanism can be utilized in semiautomatic handguns where the breechblock is a distinct component from the slide as well as handguns where the breechblock is formed or machined as part of the slide. A battery safety mechanism as disclosed herein can also be implemented in small caliber rifles that utilize a blowback action. Other suitable host firearms and calibers will be apparent in light of this disclosure.
As used herein, terms referencing direction, such as upward, downward, vertical, horizontal, left, right, front, back, etc., are used for convenience to describe components of a handgun oriented in a traditional shooting position with the barrel extending horizontally in front of the user. Embodiments of the present disclosure are not limited by these directional references and it is contemplated that a firearm and its components in accordance with the present disclosure could be used in any orientation.
Also, it should be noted that, while generally referred to herein as a ‘lift pin’ for consistency and ease of understanding the present disclosure, the disclosed safety mechanism is not limited to that specific terminology and the lift pin alternatively can be referred to simply as a pin, an actuator, or other terms. As will be further appreciated, the particular configuration (e.g., orientation, materials, dimensions, etc.) of a safety mechanism configured as described herein may be varied, for example, depending on the particular firearm in which it is implemented and the intended use. Numerous configurations will be apparent in light of this disclosure
In this example, the breechblock 116 is in the battery position and closes the chamber 105 by abutting the breech 107. As such, the hammer 150 is able to strike the proximal end 152a of the firing pin 152, which extends longitudinally through the breechblock 116 along a central axis 101 and is biased to a rearward position with a firing pin spring 153. Much of the firing pin 152 is shown in broken lines in
The safety mechanism 130 includes a lift pin 132 extending vertically through part of the breechblock 116 as well as a lever 136 that is pivotably attached to the breechblock and actuatable by the lift pin 132. A spring 138 and a cam 134 are also shown. In the battery position, a lower end 132a of the lift pin 132 engages a cam 134 on the receiver 106, causing the lift pin 132 to lift vertically against the force of the spring 138 and actuate (e.g., pivot) a lever 136 to a non-blocking position with respect to the hammer 150. For example, the lift pin 132 is slidably received in a bore or channel extending vertically through a portion of the breechblock 116, where the lower end 132a and upper end 132b of the pin 132 are exposed. The spring 138, such as a torsion spring, biases the lever 136 to the blocking position where it is positioned to contact the hammer 150. In some embodiments, the lever 136 generally extends horizontally in a rearward direction with an end 136a of the lever 136 extending beyond a proximal end or proximal face 116a of the breechblock 116. The end 136a of the lever 136 extends beyond the proximal face 116a by a greater amount than the end 152a of the firing pin 152 extends. Thus, in the blocking position the lever 136 obstructs the hammer 150 from striking the firing pin 152.
In some embodiments, the lever 136 is oriented horizontally when in the blocking position and is elevated slightly from horizontal in the non-blocking position. Preferably, the lever 136 is aligned with the direction of hammer force (e.g., is perpendicular to the face of the hammer) when the lever 136 is in the blocking position so as to reduce or eliminate the possibility that the hammer 150 deflects the lever 136 out of the way and continues on to strike the firing pin 152. When lifted by the lift pin 132 to the non-blocking position, such as shown in
As shown in
In this example, the breechblock 116 is out of battery by about 1.0 mm. The out-of-battery condition is evidenced by the gap 118 between the breech 107 and the distal end of the breechblock 116. Here, the lift pin 132 and breechblock 116 have moved rearward a sufficient distance that the lower end 132a of the lift pin 132 has moved down the ramp 134a of the cam 134, or has otherwise disengaged the cam 134, to the extent that the lift pin 132 is in the lowered position. As a result, spring 138 has returned the lever 136 downward to the blocking position (e.g., horizontal) where it is aligned to block the hammer 150. Accordingly, although the hammer 150 has been released forward, the end 136a of the lever 136 blocks the hammer 150 and prevents it from striking the firing pin 152. Note also that the hammer ramp 154 of the breechblock 116 remains disengaged from the hammer 150 and therefore, in the absence of the safety mechanism 130, may not stop the hammer 150 from striking the firing pin 152.
In use, a safety mechanism 130 in accordance with the present disclosure can prevent a hammer 150 from striking the firing pin 152, or it can prevent a striker from moving forward to strike the primer, when the breechblock 116 is in an out-of-battery position. A safety mechanism 130 as discussed herein can be utilized in a variety of firearms utilizing blowback operation, including semiautomatic handguns, small bore rifles, and other suitable firearms. As applied to semiautomatic handguns, for example, the breechblock can be a component that is distinct from the slide or the breechblock can be machined as part of the slide in a single component. The concepts of the present disclosure can be applied to hammer-fired and striker-fired handguns. For example, when the breechblock 116 is more than a predefined distance from battery, such as more than 1 mm from battery, the lever 136 is positioned to obstruct the hammer from striking the firing pin 152. In some embodiments, the safety mechanism 130 is redundant to the hammer ramp to prevent out-of-battery discharge. In other embodiments, the safety mechanism 130 prevents out-of-battery discharge at smaller distances from the battery position where the hammer ramp 154 may fail by itself to prevent the hammer from striking the firing pin 152.
Although discussed in the context of a lift pin that moves vertically to lift a lever, the safety mechanism 130 is not limited to this movement and similarly can utilize a pin oriented horizontally and that moves laterally to move the lever laterally between blocking and non-blocking positions. Also, the spring 138 disclosed herein is discussed as providing a biasing force toward the blocking position. However, the spring 138 could bias the lever to the non-blocking position, such as where the pin engages the cam in out-of-battery positions and maintains the lever in the blocking position so long as the breechblock is out of battery by more than the predefined distance. Further, the safety mechanism 130 of the present disclosure is not limited to a lever 136 with a pivot movement or limited to a pin with linear movement. For example, the lever can be rotated or displaced between the blocking and non-blocking positions by a pin, toggle, or lever that rotates, pivots, or slides during contact with the lever. Numerous variations and embodiments will be apparent in light of the present disclosure.
The following examples pertain to embodiments of the present disclosure, from which numerous permutations and configurations will be apparent.
Example 1 is a breechblock assembly for a firearm. The breechblock assembly comprises a breechblock extending along a central axis and configured to reciprocate along a top of a receiver between a recoil position and a battery position. An actuator is slidably received through an opening in the breechblock, the actuator having a lower end and an upper end, wherein the actuator is movable between a first vertical position and a second vertical position. A lever on the breechblock contacts the upper end of the actuator and moves between a lowered position and a raised position. When the actuator is in the first vertical position the lever is in the lowered position, and when the actuator is in the second vertical position the lever is in the raised position.
Example 2 includes the subject matter of Example 1, wherein the lever is generally oriented along the central axis and extends rearward beyond a proximal face of the breechblock.
Example 3 includes the subject matter of Example 1 or 2 and further comprises a spring between the breechblock and the lever, the spring biasing the lever to the blocking position.
Example 4 includes the subject matter of Example 3, wherein the spring is a torsion spring.
Example 5 includes the subject matter of any of Examples 1-4, wherein an upper end of the actuator engages the lever.
Example 6 includes the subject matter of any of Examples 1-5 and further comprises a firing pin movable along the central axis of the breechblock from a rearward position to a forward position, the firing pin having a proximal end that extends through the proximal face of the breechblock when in the rearward position. A firing pin spring between the breechblock and the firing pin biases the firing pin towards the rearward position.
Example 7 is a firearm comprising the breechblock assembly of any of Examples 1-6.
Example 8 includes the subject matter of Example 7, where the firearm is a semiautomatic handgun configured for blowback operation.
Example 9 includes the subject matter of Example 8, wherein the semiautomatic handgun is configured for rimfire ammunition.
Example 10 includes the subject matter of Example 9, wherein the ammunition is .22 cal.
Example 11 includes the subject matter of Example 7, wherein the firearm is a rifle configured for blowback operation.
Example 12 is a safety mechanism for a self-loading firearm configured for blowback operation, the safety mechanism comprising a receiver including a cam surface; a hammer or striker coupled to the receiver and movable between a cocked position and a fire position; a breechblock configured to reciprocate along a top of the receiver between a recoil position and a battery position; an actuator on the breechblock, the actuator having an end positioned to engage the cam surface on the receiver when the breechblock is within a predefined distance from the battery position; and a lever actuatable by the actuator and configured to move from a blocking position to a non-blocking position when the actuator engages the cam surface. When the breechblock is out of the battery position by more than the predetermined distance, the actuator is in a first position and the lever is in the blocking position, and when the breechblock is within the predefined distance of the battery position the actuator is in a second position and the lever is in the non-blocking position.
Example 13 includes the subject matter of Example 12, where the actuator is a pin oriented vertically and extending through part of the breechblock.
Example 14 includes the subject matter of Example 13, where the end of the actuator positioned to engage the cam surface is a lower end of the pin.
Example 15 includes the subject matter of any of Examples 12-15, where the cam surface includes a ramp, wherein when the breechblock moves to the battery position, the end of the actuator engages the ramp and moves the actuator, thereby causing the lever to move from the blocking position to the non-blocking position.
Example 16 includes the subject matter of Example 15, where the breechblock moves to the battery position, the actuator moves vertically and lifts the lever from the blocking position to the non-blocking position.
Example 17 includes the subject matter of any of Examples 12-16, where the hammer defines a recess configured and arranged so that an end of the lever is positioned to occupy the recess when the lever is in the non-blocking position and so that the end of the lever is positioned to contact part of the hammer when the lever is in the blocking position.
Example 18 includes the subject matter of any of Examples 12-17 and further comprises a spring between the breechblock and the lever, the spring biasing the lever to the blocking position.
Example 19 includes the subject matter of Example 18, where the spring is a torsion spring having a first leg engaging the breechblock and a second leg engaging the lever.
Example 20 includes the subject matter of any of Examples 12-19, where the predefined distance is not more than 1.0 mm.
Example 21 includes the subject matter of Example 20, where the predefined distance is not more than 0.8 mm.
Example 22 is a handgun comprising the safety mechanism of any of Examples 12-21.
Example 23 includes the subject matter of Example 22, where the handgun is a semiautomatic handgun configured for rimfire ammunition.
Example 24 includes the subject matter of Example 22 or 23, where the receiver defines a chamber and the handgun comprises a barrel fixedly secured to the receiver with a bore of the barrel aligned coaxially with the chamber.
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.