This invention relates to an improved trigger mechanism for firearm fire control.
Trigger sensation (i.e., trigger pull weight, creep and feel) and safety are important issues in the operation of a firearm's fire control. Too often in the design of firearm fire control mechanisms, these two factors are seen as being in opposition to one another in that an increase in safety of operation comes at the expense of a decrease in trigger sensation and vice versa. However, it is both desirable and possible to improve both the safety and trigger sensation of firearms, using an improved trigger mechanism according to the invention disclosed in this specification that does not require a two-stage trigger feel found objectionable by many shooters.
One aspect of the invention relates to a trigger assembly for a firearm. The firearm has a reciprocating component. In one example embodiment, the trigger assembly comprises a sear movably mounted within the assembly. The sear has a stop surface engageable with the reciprocating component for holding the reciprocating component in a cocked configuration. The sear further comprises a sear cam. A lever is movably mounted within the assembly. The lever has a contact surface. The sear cam engages the lever. A trigger is movably mounted within the assembly. The trigger has an action surface movable into and out of engagement with the contact surface upon motion of the trigger. A lever return spring acts on the lever and biases the contact surface out of engagement with the action surface. A trigger return pendulum is movably mounted within the assembly. The trigger return pendulum has a trigger cam engageable with the trigger. A lever cam is engageable with the lever. A head cam follower is engageable with the reciprocating component. In this example embodiment, motion of the reciprocating component acts through the head cam follower of the trigger return pendulum and forces the lever cam into engagement with the lever, and the trigger cam into engagement with the trigger, to return the lever and the trigger to a configuration of engagement between the action surface and the contact surface.
In a particular example embodiment, the sear is pivotably mounted on a sear fulcrum. By way of example, the stop surface is angularly oriented relatively to a line of motion of the reciprocating component to permit the reciprocating component to pivot the sear about the sear fulcrum upon motion of the reciprocating component along the line of motion against the stop surface.
In another example embodiment, the lever is pivotably mounted on a lever fulcrum. In a further example embodiment, the sear cam engages the lever on one side of the lever fulcrum and the contact surface is positioned on the one side of the lever fulcrum.
In a specific example embodiment, the trigger is pivotably mounted on a trigger fulcrum. By way of example, the trigger comprises an actuation arm and a projection extending transversely thereto. The projection is engageable with the trigger cam. By way of example, the trigger may be balanced about the trigger fulcrum.
In another example embodiment, the trigger return pendulum is pivotably mounted on a trigger return pendulum fulcrum. By way of a further example, the lever cam engages the lever on an opposite side of the lever fulcrum from the contact surface. In another example, the trigger return pendulum fulcrum is positioned at one end of the trigger return pendulum, and the lever cam is positioned at an opposite end of the trigger return pendulum. In this example the trigger cam is positioned between the ends of the trigger return pendulum.
A particular example embodiment further comprises first and second plates attached to one another in spaced apart relation. In this example, the sear, the lever, the trigger and the trigger return pendulum are mounted between the sideplates. By way of further example, the sear fulcrum, the lever fulcrum, the trigger fulcrum and the trigger return pendulum fulcrum each comprises a respective pin extending between the sideplates.
The invention further encompasses a trigger assembly for a firearm having a reciprocating component wherein the trigger assembly comprises first and second sideplates arranged in parallel, spaced apart relation. In this example, a sear pin extends between the first and second sideplates. A sear is pivotally mounted on the sear pin. The sear has a stop surface engageable with the reciprocating component for holding the reciprocating component in a cocked configuration. The sear further comprises a sear cam. A lever pivot pin extends between the first and second sideplates. A lever is pivotally mounted on the lever pivot pin. The lever has a contact surface. The sear cam engages the lever. A trigger pivot pin extends between the first and second sideplates. A trigger is pivotally mounted on the trigger pivot pin. The trigger has an action surface movable into and out of engagement with the contact surface upon motion of the trigger. A lever return spring acts on the lever and biases the contact surface out of engagement with the action surface. A trigger return pendulum pin extends between the first and second sideplates. A trigger return pendulum is pivotally mounted on the trigger return pendulum pin. The trigger return pendulum has a trigger cam engageable with the trigger. A lever cam is engageable with the lever. A head cam follower is engageable with the reciprocating component. In this example embodiment, motion of the reciprocating component acting through the head cam follower of the trigger return pendulum forces the lever cam into engagement with the lever and the trigger cam into engagement with the trigger to return the lever and the trigger to a configuration of engagement between the action surface and the contact surface.
In a particular example embodiment, the stop surface is angularly oriented relatively to a line of motion of the reciprocating component to permit the reciprocating component to pivot the sear about the sear pin upon motion of the reciprocating component along the line of motion against the stop surface. By way of example, the sear cam engages the lever on one side of the lever pivot pin and the contact surface is positioned on the one side of the lever pivot pin. In a particular example embodiment, the trigger comprises an actuation arm and a projection extending transversely thereto. In this example embodiment, the projection is engageable with the trigger cam. Further by way of example, the trigger may be balanced about the trigger pivot pin. In an example embodiment, the lever cam engages the lever on an opposite side of the lever pivot pin from the contact surface. Further by way of example, the trigger return pendulum pin may be positioned at one end of the trigger return pendulum, the lever cam may be positioned at an opposite end of the trigger return pendulum, and the trigger cam may be positioned between the ends of the trigger return pendulum.
The invention further encompasses a firearm. In a particular example embodiment, the firearm comprises a reciprocating component and a trigger assembly comprising a sear movably mounted within the assembly. The sear has a stop surface engageable with the reciprocating component for holding the reciprocating component in a cocked configuration. The sear further comprises a sear cam in this example embodiment. A lever is movably mounted within the assembly. The lever has a contact surface. The sear cam engages the lever. A trigger is movably mounted within the assembly. The trigger has an action surface movable into and out of engagement with the contact surface upon motion of the trigger. A lever return spring acts on the lever and biases the contact surface out of engagement with the action surface. A trigger return pendulum is movably mounted within the assembly. The trigger return pendulum has a trigger cam engageable with the trigger. A lever cam is engageable with the lever, and a head cam follower is engageable with the reciprocating component. In this example embodiment, motion of the reciprocating component acting through the head cam follower of the trigger return pendulum forces the lever cam into engagement with the lever, and the trigger cam into engagement with the trigger to return the lever and the trigger to a configuration of engagement between the action surface and the contact surface.
By way of example, the sear is pivotably mounted on a sear fulcrum. In an example embodiment, the stop surface is angularly oriented relatively to a line of motion of the reciprocating component to permit the reciprocating component to pivot the sear about the sear fulcrum upon motion of the reciprocating component along the line of motion against the stop surface. By way of example, the lever may be pivotably mounted on a lever fulcrum.
In an example embodiment, the sear cam engages the lever on one side of the lever fulcrum and the contact surface is positioned on the one side of the lever fulcrum. By way of further example, the trigger may be pivotably mounted on a trigger fulcrum. In a particular example embodiment the trigger comprises an actuation arm and a projection extending transversely thereto, the projection being engageable with the trigger cam. In this example embodiment, the trigger may be balanced about the trigger fulcrum and the lever may be balanced about the lever fulcrum. By way of example, the trigger return pendulum may be pivotably mounted on a trigger return pendulum fulcrum. In an example embodiment, the lever cam engages the lever on an opposite side of the lever fulcrum from the contact surface.
In a particular example embodiment, the trigger return pendulum fulcrum is positioned at one end of the trigger return pendulum, the lever cam is positioned at an opposite end of the trigger return pendulum, and the trigger cam is positioned between the ends of the trigger return pendulum.
By way of further example, the firearm may comprise first and second sideplates attached to one another in spaced apart relation. The sear, the lever, the trigger and the trigger return pendulum are mounted between the sideplates in this example. By way of example, the sear fulcrum, the lever fulcrum, the trigger fulcrum and the trigger return pendulum fulcrum each may comprise a respective pin extending between the sideplates. In a particular example embodiment, the firearm comprises a bolt action rifle and the reciprocating component comprises a firing pin head. In another example embodiment, the firearm comprises a semi-automatic rifle and the reciprocating member comprises a bolt carrier. By way of further example, the firearm may comprise an automatic rifle and the reciprocating member may comprise a bolt carrier. In another example embodiment, the firearm comprises a pistol and the reciprocating member comprises a slide.
As shown in
Trigger 48 comprises an actuation arm 56 (the curved portion that receives a finger of a shooter) and a projection 58 that extends transversely to the actuation arm 56. It is advantageous to balance the trigger 48 about the trigger pivot pin 50 so that there is no net torque from the part's mass about the trigger fulcrum; i.e., the trigger will not tend to rotate under the influence of gravity or inertial forces. Balancing the trigger helps prevent unintended discharge of the firearm when dropped. It is also advantageous to balance lever 42 about its fulcrum pin 44 so that there is no net torque from the part's mass about the lever fulcrum. Balancing the lever also helps prevent unintended discharge of the firearm when dropped. A safety 51 having a safety/trigger detent screw 53 is mounted on sideplate 12.
A trigger return pendulum 60 is movably mounted within the assembly 10 between sideplates 12 and 14. Trigger return pendulum 60 is mounted on a trigger return pendulum pin 18 that extends between the sideplates and provides a fulcrum permitting pivoting motion of the trigger return pendulum 60. (In this example embodiment the trigger return pendulum 60 shares the same pin as the sear 16.) Trigger return pendulum 60 comprises a trigger cam 62, a lever cam 64, and a head cam follower 66. In the example embodiment disclosed herein, the trigger return pendulum fulcrum (pin 18) is positioned at one end 68 of the trigger return pendulum 60. Lever cam 64 and the head cam follower 66 are positioned at an opposite end 70 of the trigger return pendulum from the fulcrum, and the trigger cam 62 is positioned between ends 68 and 70 of the trigger return pendulum 60. With this configuration of trigger return pendulum 60 the lever cam 64 can engage the lever 42 on an opposite side of the lever pivot pin 44 from the lever's contact surface 46, and the trigger cam 62 can engage the trigger projection 58 upon pivoting motion of the trigger return pendulum about pin 18. As shown in FIGS. 2 and 6-8, the head cam follower 66 is engageable with a cam 72 on the reciprocating component 24 when the action of the firearm is worked as described below.
Operation of the trigger assembly 10 is described with reference to
As shown in
As shown in
Trigger return pendulum 60 also acts as a “drop pendulum” to prevent inadvertent discharge of the firearm if dropped. As shown in
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