The inventive concepts disclosed herein relate to trigger assemblies for initiating the firing sequence in firearms such as bolt action rifles.
Firearms such a rifles and handguns typically include a trigger assembly by which the user initiates the firing sequence that results in the discharge of the firearm. A trigger assembly configured for use with a bolt-action rifle commonly includes a mechanism for restraining a spring-loaded firing pin that, when released, strikes a primer of an unfired cartridge located in a chamber of the rifle. The impact ignites the primer, which in turn ignites a propellant within the cartridge. The expanding propellant drives a projectile from a casing of the cartridge and through a barrel of the firearm so that the projectile exits the rifle via the muzzle of the barrel.
The trigger assembly restrains the firing pin until the user actuates the trigger assembly by pulling or otherwise exerting pressure on a rotating or linear-motion trigger. Pulling the trigger initiates a series of mechanical interactions within the trigger assembly that result in the release of the firing pin.
The trigger assembly is critical to the safe, reliable, and accurate operation of the rifle. For example, the trigger assembly needs to securely restrain the firing pin so as to minimize the potential for an accidental discharge of the rifle. Configuring the trigger assembly to avoid an accidental discharge, however, can give the trigger assembly undesirable characteristics. The degree of restraint on the firing pin can be increased, and the potential for an accidental discharge decreased, by increasing the friction and the overlap between the various components within the trigger assembly that interact to restrain the firing pin. Increasing the friction and overlap between components, however, can increase the trigger pull weight, i.e., the amount of force that needs to be applied to the trigger; can make the trigger pull rough and uneven; and can increase the distance through which the trigger must be pulled to initiate the firing sequence. These factors can diminish the accuracy and reliability of the rifle; can result in premature wear of the trigger assembly; and can cause fatigue, discomfort, and injury to the user.
Trigger assemblies typically include some type of safety mechanism that further reduces the potential for an accidental discharge when the rifle is not in use. Safety mechanisms usually function by blocking or otherwise interfering with the movement of a single component within the trigger assembly, so that the trigger assembly cannot be actuated. Blocking a single component, however, may be not be sufficient to prevent an accidental discharge, especially when the rifle is dropped or otherwise subjected to some type of impact. On the other hand, a safety mechanism that interferes with the movement of multiple components may be too large, and may require the user to manipulate more than one lever or button to fully engage and disengage the mechanism.
The space allocated for the trigger assembly within a rifle typically is limited, which in turn limits the overall dimensions of the trigger assembly. Also, trigger assemblies are exposed to dirt, carbon, and other contaminants during normal use, and thus need to be cleaned and lubricated on a periodic basis. Trigger assemblies that require significant disassembly to clean and lubricate, or that otherwise are difficult to maintain, often do not receive a proper degree of maintenance.
The present disclosure relates generally to trigger assemblies for initiating the discharge of a firearm.
In one aspect, the disclosed technology relates to a trigger assembly for restraining a firing pin of a firearm on a selective basis, the trigger assembly including: a housing; a first lever mounted for rotation on the housing and movable between a first and a second angular position of the first lever; a second lever mounted for rotation on the housing and movable between a first and a second angular position of the second lever, wherein the first lever is configured to move the second lever from the first to the second angular position of the second lever when the first lever moves from the first to the second angular position of the first lever; and a safety mechanism including: a first interfering member configured to be positioned in proximity to the first and the second levers on a selective basis so that the first interfering member simultaneously interferes with movement of the first lever from the first to the second angular position of the first lever, and movement of the second lever from the first to the second angular position of the second lever.
In one embodiment, the safety mechanism further includes a safety lever mounted for rotation in relation to the housing and movable between a first and a second angular position of the safety lever; the safety lever includes the first interfering member; and the safety lever is configured so that the first interfering member is positioned in proximity to the first and the second levers when the safety lever is in the second angular position of the safety lever. In another embodiment, the trigger assembly further includes a third lever mounted for rotation on the housing and movable between a first and a second angular position of the third lever; wherein: the second lever is configured to move the third lever from the first to the second angular position of the third lever when the second lever moves from the first to the second angular position of the second lever; the safety lever further includes a second interfering member configured to be positioned in proximity to the third lever when the safety lever is in the second angular position of the safety lever, so that the second interfering member interferes with movement of the third lever from the first to the second angular position of the third lever. In another embodiment, the trigger assembly further includes a cover plate mounted on the housing, wherein the safety lever is mounted for rotation on an exterior of the cover plate. In another embodiment, the second interfering member is configured to extend through an aperture in the cover plate and into an interior of the housing. In another embodiment, the trigger assembly further includes a guide located on the cover plate and configured to engage the safety lever as the safety lever moves between the first and the second angular positions of the safety lever. In another embodiment, the first and the second interfering members include tabs.
In another embodiment, the first interfering member is configured to not interfere with movement of the first lever from the first to the second angular position of the first lever, and movement of the second lever from the first to the second angular position of the second lever when the safety lever is in the first angular portion of the safety lever; and the second interfering member is configured to not interfere with movement of the third lever from the first to the second position of the third lever when the safety lever is in the first angular portion of the safety lever. In another embodiment, the first interfering member is configured to be positioned between the first and the second levers when the safety lever is in the second angular position of the safety lever. In another embodiment, the housing includes a first and a second alignment post each configured to engage the cover plate and to maintain the housing and the cover plate in a state of alignment. In another embodiment, the housing has a port formed in an exterior surface of the housing, and a passage formed within the housing; and the passage is in fluid communication with the port and at least one of the first and second levers.
In another embodiment, the housing and the cover plate each have a plurality of raised surface portions formed thereon, and the housing and the cover plate contact at least one of the first, second, and third levers by way of the raised surface portions. In another embodiment, at least one of the first, second, and third levers has a plurality of raised surface portions formed thereon, and the least one of the first, second, and third levers contacts the housing and the cover plate by way of the raised surface portions. In another embodiment, the cover plate has a threaded aperture formed therein and positioned adjacent a solid surface of the housing. In another embodiment, the trigger assembly further includes a spring configured to bias the first lever toward the first angular position of the first lever; and a ball positioned between the spring and the first lever. In another embodiment, the first lever has a beveled surface; and the first lever is configured so that the ball is captured between the beveled surface and the housing. In another embodiment, the trigger assembly further includes a spring plunger configured to bias the second lever toward the first angular position of the second lever; wherein the spring plunger includes a casing, and a spring positioned at least in part within the casing. In another embodiment, an end of the casing faces a surface of the second lever; a first portion of the end contacts the surface; a second portion of the end is spaced from the surface; and the first and the second portions are located on opposite sides of a centerline of the spring plunger. In another embodiment, the second interfering member is configured to interfere with movement of the casing when the safety lever is in the second angular position of the safety lever. In another embodiment, the third lever is configured to restrain the firing pin when the third lever is in the first position of the third lever.
Embodiments will be described with reference to the following drawing figures, in which like reference numerals represent like parts and assemblies throughout the several views.
The inventive concepts are described with reference to the attached figures. The figures are not drawn to scale and are provided merely to illustrate the instant inventive concepts. The figures do not limit the scope of the present disclosure. Several aspects of the inventive concepts are described below with reference to example applications for illustration. It should be understood that numerous specific details, relationships, and methods are set forth to provide a full understanding of the inventive concepts. One having ordinary skill in the relevant art, however, will readily recognize that the inventive concepts can be practiced without one or more of the specific details or with other methods. In other instances, well-known structures or operation are not shown in detail to avoid obscuring the inventive concepts.
Referring to
The striker 105 includes a firing pin 106, a spring (not shown), a bolt shroud 110, and a cocking piece 112. The bolt shroud 110 is secured to a rearward end of the bolt body 113. The firing pin 106 extends through the bolt shroud 110; and moves linearly, in the forward and rearward, or “x” directions, in relation to the bolt shroud 110. The spring is positioned around the firing pin 106, and biases the firing pin 106 in the forward direction. The cocking piece 112 is secured to a rearward end of the firing pin 106, and is biased in the forward direction due to its attachment to the forwardly-biased firing pin 106.
Following discharge of the rifle 10, an unfired cartridge is introduced into the action 101 by moving the bolt assembly 102 from its closed to its open position. As the empty casing of the fired cartridge is carried rearward with the bolt assembly 102, an ejector (not shown) on the bolt head strips the empty casing from the bolt assembly 102 and ejects the casing through a loading ejection port 125 in the receiver 103. An unfired cartridge is then introduced into the receiver 103, forward of the bolt head.
Once the unfired cartridge has been fed into the receiver 103, the user pushes the bolt assembly 102 forward, toward its cocked position. The bolt head pushes the unfired cartridge forward as the bolt assembly 102 moves toward its closed position. As the bolt assembly 102 and the attached striker 105 move forward, a lip 127 on the cocking piece 112 catches on a sear lever 20 of the trigger assembly 10, as shown in
Subsequent actuation of the trigger assembly 10 causes the sear lever 20 to release the cocking piece 112, which in turn allows the firing pin 106 to move forward under the bias of the spring of the striker 105, as can be seen in
The trigger assembly 10 comprises a housing 12, and a cover plate 14 that mates with the housing 12. The trigger assembly 10 is attached to the receiver 103 by two press fit pins that extend through apertures 176 in the housing 12. The assembly 10 also comprises a first lever in the form of a trigger lever 16; a second lever in the form of a re-cocking lever 18; and a third lever in the form of the sear lever 20, each of which is pivotally mounted on the housing 12 and the cover plate 14. The trigger lever 16, re-cocking lever 18, and sear lever 20 interact mechanically in a manner that causes the firing pin 106 of the striker 105 to be restrained in its cocked position until the trigger assembly 10 is actuated by the user.
a. Trigger Lever
Referring to
The trigger lever 16 is mounted for rotation on a pin 50, as shown in
The pin 50 extends through a bore formed in the third portion 34 of the trigger lever 16. The pin 50 and the bore are sized so that minimal clearance is present between the outer surface of the pin 50 and the periphery of the bore. This feature permits the trigger lever 16 to rotate freely on the pin 50, with minimal non-rotational motion.
The trigger lever 16 is biased in a counter-clockwise direction, from the perspective of
The non-planar spherical surface of the ball 88 permits the spring 86 to change its orientation to conform to the rotational movement of the trigger lever 16, while maintaining its linear configuration. More specifically, the spherical surface permits the spring 86 to tilt, rather than bend in relation to its axis as the trigger lever 16 rotates. Because the spring 86 does not bend, i.e., because the spring 86 remains square with respect to its axis, the load being applied to the spring 86 by the trigger lever 16 remains a compressive load applied along the axis of the spring 86. As a result, the relationship between deflection and applied force for the spring 86 remains substantially linear as the spring 86 is compressed by the rotating trigger lever 16, and the spring 86 deflects in a smooth and predictable manner. Also, the spring 86 is not susceptible to the buckling that can result from the off-axis loading of a compression spring; such buckling, in extreme cases, can result in drag, binding, and damage to the spring. The upper end of the spring 86 can be positioned against other types of non-planar surfaces, such a curved or conical surface, instead of the spherical surface of the ball 88 in alternative embodiments.
The housing 12 has a rearward-facing interior surface 89, as can be seen in
Contact between the lower surface 170 of the third portion 34 of the trigger lever 16 and an underlying interior surface 85 of the housing 12 limits the extent to which the trigger lever 16 can rotate in the clockwise direction, as shown in
b. Re-cocking Lever
Referring to
The re-cocking lever 18 also has an upper surface 64. The upper surface 64 includes a generally flat first portion 65; a generally flat second portion 66 that adjoins the first portion 65, and is oriented generally perpendicular to the first portion 65; and a curved third portion 67 that adjoins the second portion 66. The first, second, and third portions 65, 66, 67 define a detent 63 in the re-cocking lever 18, the purpose of which is discussed below.
The upper surface 64 also includes a fourth portion 68 that adjoins the third portion 67; a fifth portion 69 that adjoins the fourth portion 68; and a sixth portion 70 that adjoins the fifth portion 69. The sixth portion 70 has a bend 77 formed therein, the purpose of which is discussed below.
The re-cocking lever 18 is mounted for rotation on another pin 50, as shown in
The re-cocking lever 18 is biased in a clockwise direction, from the perspective of
The second end 187 of the casing 185 is biased against the sixth portion 70 of upper surface 64. The second end 187 is rounded, as can be seen in
c. Sear Lever
Referring to
Due to the need for the second portion 66 of the upper surface 64 of the re-cocking lever 18 to separate cleanly and reliably from the contact surface 74 of the sear lever 20, the detent 63 in the re-cocking lever 18 includes a channel portion 99, visible in
As can be seen in
The sear lever 20 is mounted for rotation on another pin 50, as can be seen in
The pin 50 extends through a bore formed in the sear lever 20. The pin 50 and the bore are sized so that minimal clearance is present between the outer surface of the pin 50 and the periphery of the bore. This feature permits the sear lever 20 to rotate freely on the pin 50, with minimal non-rotational motion.
The sear lever 20 is biased in a counter-clockwise direction, from the perspective of
The second end 187 of the casing 185 of the second spring plunger 189 is biased against a lower surface 22 of the body 71. As can be seen in
The body 71 of the sear lever 20 has a contact surface 23. The contact surface 23 engages a contact surface 134 on the lip 127 on the cocking piece 112 when the bolt assembly 102 is in its closed position. The contact surface 134 is angled by, for example, approximately 27 degrees in relation to the horizontal, i.e., the “x” direction; and the contact surface 23 of the sear lever 20 is similarly oriented, so that the overlapping portions of the contact surface 134 and the contact surface 23 lie substantially flat against each other.
The contact surface 134 of the cocking piece 112 comes into contact with the contact surface 23 of the sear lever 20 as the bolt assembly 102 is moved forward, toward its closed position. The engagement of the contact surface 134 by the contact surface 23 restrains the cocking piece 112 and the attached firing pin 106 from further forward movement. The contact surface 134 and the contact surface 23 remain engaged until the trigger assembly 10 is actuated, at which point the cocking piece 112 and the firing pin 106 are free to move forward under the bias of the spring of the striker 105, toward the unfired cartridge in the barrel chamber 128.
Due to the angled orientations of the contact surface 134 and the contact surface 23, the cocking piece 112 exerts a force on the sear lever 20 that acts in the forward (“+x”) and downward (“−z”) directions. The cocking piece 112 thereby biases the sear lever 20 in a clockwise direction from the perspective of
d. Housing and Cover Plate
The housing 12 has two cylindrical alignment posts 90 integrally formed therein, as shown in
The alignment posts 90 can be formed separately from the housing 12 in alternative embodiments. In other alternative embodiments, the alignment posts 90 can be formed in the cover plate 14, and the apertures 91 can be formed in the housing 12.
The cover plate 14 is secured to the housing 12 by a plurality of fasteners. The cover plate 14 has an aperture 92 formed therein and depicted in
As noted above, the housing 12 and the cover plate 14 have apertures 51, 49 formed therein that receive the pins 50 upon which the trigger lever 16, re-cocking lever 18, and sear lever 20 are mounted. An interior surface 180 of the housing 12 has a raised areas 181 located around the apertures 51 in the housing 12, as shown in
The raised areas 181 on the housing 12 form the contact areas between the housing 12, and one of the respective sides of the trigger lever 16, re-cocking lever 18, and sear lever 20. The raised areas 181 on the cover plate 14 likewise form the contact areas between the cover plate 14, and the other respective sides of the trigger lever 16 and the re-cocking lever 18. The raised areas 181 on the housing 12 minimize the contact area between the housing 12, and the trigger lever 16, re-cocking lever 18, and sear lever 20. The raised areas 181 on the cover plate 14 likewise minimize the contact area between the cover plate 14, and the trigger lever 16 and the re-cocking lever 18. The raised areas 181 thereby can reduce friction resulting from the rotation of the trigger lever 16, re-cocking lever 18, and sear lever 20 in relation to the housing 12 and cover plate 14; and can lower the potential for binding of the trigger lever 16, re-cocking lever 18, and sear lever 20. In alternative embodiments, the raised areas 181 can be formed on the sides of the trigger lever 16, re-cocking lever 18, and sear lever 20 instead of, or in addition to the interior surface 180 the housing 12 and the interior surface 182 of the cover plate 14.
Referring to
The ability to introduce cleaning fluid and compressed air to various locations within the trigger assembly 10 without the need to disassemble the trigger assembly 10 can reduce the time and effort needed to clean the trigger assembly 10; can lead to more frequent cleaning of the trigger assembly 10; and can make it possible to clean the trigger assembly 10 under field conditions in which cleaning otherwise would not be feasible.
e. Actuation of the Trigger Mechanism
Actuation of the trigger assembly 10 initiates the firing sequence for the rifle 100.
The user actuates the trigger assembly 10 by exerting a rearward force on the surface 36 of the first portion 30 of the trigger lever 16, causing the trigger lever 16 to rotate in a clockwise direction from the perspective of
Continued clockwise rotation of the trigger lever 16 causes the second timing element 62 to rotate in relation to the upper surface 47 of the second portion 32 of the trigger lever 16, imparting further rotation to the re-cocking lever 18. Because the second timing element 62 is located farther from the axis of rotation of the trigger lever 16 than the first timing element 61, the clockwise rotation of the trigger lever 16 eventually brings the first timing element 61 into contact with the upper surface 47, as shown in
Because the first timing element 61 is located closer to the axis of rotation of the re-cocking lever 18 than the second timing element 62, the moment arm through which the trigger lever 16 applies force to the first timing element 61 is shorter than the moment arm through which the trigger lever 16 applies force to the second timing element 62. The user, therefore, feels an abrupt increase in the trigger pull weight at the transition from the first to the second phase of the trigger pull; and the increased trigger pull weight continues to be present throughout the second phase of the trigger pull.
Continued clockwise rotation of the trigger lever 16 through the second stage of the trigger pull causes the re-cocking lever 18 to rotate further in the counter-clockwise direction, which in turn decreases the degree of overlap between the second portion 66 of the upper surface 64 of the re-cocking lever 18, and the contact surface 74 of the sear lever 20. As discussed above and as shown in
The counter-clockwise rotation of the re-cocking lever 18 eventually eliminates the overlap between the second portion 66 of the upper surface 64, and the contact surface 74. At this point, depicted in
The first and second timing elements 61, 62 of the re-cocking lever 18 have substantially identical dimensions. The dimensions and locations of one or both of the first and second timing elements 61, 62 can be varied in other embodiments of the re-cocking lever 18, to change the point in the trigger pull at which the transition between the first and second stages occurs, and/or to change the trigger pull weight during the first and second stages.
Alternative embodiments of the trigger assembly 10 can be configured to produce a single-stage trigger pull, i.e., a trigger pull in which the trigger pull weight remains substantially constant throughout the trigger pull. This can be accomplished by configuring the re-cocking lever 20 with one timing element instead of two. In other alternative embodiments, the first and second timing elements 61, 62 can be located on the upper surface 47 of the second portion 32 of the trigger lever 16. In still other alternative embodiments, one of the first and second timing element 61, 62 can be located on the re-cocking lever 18, and the other timing element 61, 62 can be located on the trigger lever 16.
Following discharge of the cartridge, the user can decrease or remove finger pressure on the surface 36 of the trigger lever 16. This will allow the trigger assembly 10 to reset to the state shown in
f. Safety Mechanism
The trigger assembly 10 also comprises a safety mechanism 200 comprising a safety lever 201 mounted on the exterior of the housing 12. A substantial entirety of the safety mechanism 200 is located external to the housing 12 and the cover plate 14, giving the trigger assembly 10 a more compact overall footprint that a comparable trigger mechanism having a safety mechanism located partly or entirely within the trigger mechanism.
Referring to
The safety mechanism 200 also includes a tab 217. As can be seen in
The cover plate 14 includes a curvilinear retaining element or guide 218. The guide 218 is integrally formed with the remainder of the cover plate 14. The guide 218 can be formed separately from the rest of cover plate 14, and can be fastened to cover plate 14 in alternative embodiments.
The guide 218 includes an inner surface 220, and a lip 221 that extends from the surface 220. As can be seen
The safety mechanism 200, when in its locked position, interferes with the movement of three different components of the trigger assembly 10, each which must move to effectuate the firing sequence. The safely lever 201 thus provides three independent points of interference with the firing sequence.
Referring to
The tab 222 thus interferes both with clockwise rotation of the trigger lever 16, and counter-clockwise rotation of the re-cocking lever 18, from the perspective of
The middle portion 204 of the safety lever 201 has an interfering member in the form of a tab 224 formed thereon. The tab 224 provides a third point of interference that inhibits the trigger assembly 10 from initiating the firing sequence when the safety lever 201 is in its locked position. The tab 224 extends through a slot (not shown) in the cover plate 14. The safety lever 201 is configured so that the tab 224 becomes positioned directly below, and in close proximity to an edge of the first end 186 of the casing 185 of the second spring plunger 189 when the safety lever 201 is moved to its locked position, as shown in
As discussed above, the sear lever 20 must rotate in the clockwise direction, from the perspective of
The safety mechanism 200, with one movement of the safety lever 201, thus provides a three point interlock that, when engaged, prevents the trigger assembly 10 from being actuated. The safety mechanism 200 thereby can provide an enhanced level of safety against an accidental discharge of the rifle 100 in comparison to a conventional safety having one, or even two points of interfering contact. Also, the safety mechanism 200 provides this three-point safety interlock without consuming any appreciable amount of space within the housing 12.