U.S. patent application number 14/518620 was filed with the patent office on 2015-09-24 for sear trip bar for a firearm.
This patent application is currently assigned to Sig Sauer, Inc.. The applicant listed for this patent is Sig Sauer, Inc.. Invention is credited to Robert Hirt, Christopher Sirois.
Application Number | 20150267985 14/518620 |
Document ID | / |
Family ID | 54141769 |
Filed Date | 2015-09-24 |
United States Patent
Application |
20150267985 |
Kind Code |
A1 |
Hirt; Robert ; et
al. |
September 24, 2015 |
SEAR TRIP BAR FOR A FIREARM
Abstract
A sear trip bar for use in an automatic firearm is disclosed. In
accordance with some embodiments, the sear trip bar can be
operatively interfaced with the bolt carrier and the automatic sear
of the host firearm. The disclosed sear trip bar can be configured
such that, upon sufficient displacement thereof (e.g., exhaustion
of its stroke length) by the bolt carrier, the automatic sear may
be caused to trip. Thus, the disclosed sear trip bar can be
utilized, for example, to transfer the force of the moving bolt
carrier during a given firing cycle to automatically trip the sear
so as to initiate one or more subsequent firing cycles without
having to release and again operate the trigger of the host
firearm. The disclosed sear trip bar can be utilized, for example,
in pistol-caliber and/or rifle-caliber automatic firearms.
Inventors: |
Hirt; Robert; (Exeter,
NH) ; Sirois; Christopher; (Newfields, NH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sig Sauer, Inc. |
Newington |
NH |
US |
|
|
Assignee: |
Sig Sauer, Inc.
Newington
NH
|
Family ID: |
54141769 |
Appl. No.: |
14/518620 |
Filed: |
October 20, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13679966 |
Nov 16, 2012 |
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14518620 |
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61560435 |
Nov 16, 2011 |
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61893563 |
Oct 21, 2013 |
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Current U.S.
Class: |
42/69.02 |
Current CPC
Class: |
F41A 19/44 20130101;
F41A 19/46 20130101 |
International
Class: |
F41A 19/44 20060101
F41A019/44 |
Claims
1. A sear trip bar for a firearm, the sear trip bar comprising: an
elongate body portion having a forward end and an opposing rearward
end; a first hooked portion extending upwardly away from the
forward end of the body portion and configured to be operatively
interfaced with a bolt carrier of the firearm; and a second hooked
portion extending laterally away from the rearward end of the body
portion and configured to be operatively interfaced with an
automatic sear of the firearm.
2. The sear trip bar of claim 1, wherein the body portion, the
first hooked portion, and the second hooked portion are formed as a
unitary component.
3. The sear trip bar of claim 1, wherein the first hooked portion
and the second hooked portion are orthogonal to one another.
4. The sear trip bar of claim 1, wherein the first hooked portion
extends upwardly away from the forward end of the body portion by a
distance in the range of about 0.1-0.5 inches.
5. The sear trip bar of claim 1, wherein the second hooked portion
extends laterally away from the rearward end of the body portion by
a distance in the range of about 0.1-0.4 inches.
6. The sear trip bar of claim 1, wherein the body portion includes
a first slot and a second slot formed therein, the first slot
proximal to the forward end of the body portion, and the second
slot proximal to the rearward end of the body portion, and wherein
the first and second slots are configured to provide the sear trip
bar with a stroke length in the range of about 0.1-0.5 inches.
7. The sear trip bar of claim 6, wherein at least one of the first
slot and the second slot has a length in the range of about 0.1-0.5
inches.
8. The sear trip bar of claim 6, wherein the first slot and the
second slot are of different lengths.
9. The sear trip bar of claim 1, wherein at least a portion of the
second hooked portion is offset in elevation with respect to the
body portion by a distance in the range of about 0.01-0.1
inches.
10. A firearm comprising: a lower receiver having an automatic sear
disposed therein; and an upper receiver having a groove formed in
an interior sidewall portion thereof, the upper receiver having
disposed therein: a bolt carrier; and a sear trip bar comprising: a
first hooked portion configured to operatively interface with the
bolt carrier; and a second hooked portion configured to operatively
interface with the automatic sear; wherein the sear trip bar
resides, at least in part, within the groove of the upper receiver
and is configured such that, upon sufficient forward displacement
of the bolt carrier within the firearm, the sear trip bar trips the
automatic sear to automatically initiate a firing cycle.
11. The firearm of claim 10, wherein the sear trip bar further
comprises: a first slot defined therein proximal to the first
hooked portion; and a second slot defined therein proximal to the
second hooked portion.
12. The firearm of claim 11, wherein the first slot and the second
slot each have a rounded rectangular geometry and each have a
length in the range of about 0.1-0.5 inches.
13. The firearm of claim 11 further comprising: a first retention
pin disposed within the upper receiver and slidably inserted within
the first slot of the sear trip bar; and a second retention pin
disposed within the upper receiver and slidably inserted within the
second slot of the sear trip bar.
14. The firearm of claim 10, wherein the sear trip bar has a stroke
length within the groove in the range of about 0.1-0.5 inches.
15. The firearm of claim 10, wherein the sear trip bar resides, at
least in part, adjacent to a hammer slot formed in the bolt
carrier.
16. The firearm of claim 10, wherein the firearm is chambered for
pistol-caliber ammunition.
17. The firearm of claim 10, wherein the firearm is chambered for
rifle-caliber ammunition.
18. A firearm comprising: a bolt carrier having a notched portion
formed in a bottom surface thereof, the notched portion adjacent to
a hammer slot formed in the bolt carrier; an automatic sear having
an actuating portion including a rear surface; and a sear trip bar
comprising: an elongate body portion having a forward end and an
opposing rearward end; a first hooked portion extending upwardly
away from the forward end of the elongate body portion, the first
hooked portion configured to physically contact the notched portion
of the bolt carrier; and a second hooked portion extending
laterally away from the rearward end of the elongate body portion,
the second hooked portion orthogonal to the first hooked portion
and configured to physically contact the rear surface of the
actuating portion of the automatic sear; wherein the sear trip bar
has a total length in the range of about 2-3 inches, and at least a
portion of the sear trip bar has a thickness in the range of about
0.01-0.1 inches; wherein upon exhausting a stroke length of the
sear trip bar, the automatic sear is tripped.
19. The firearm of claim 18, wherein the stroke length is in the
range of about 0.1-0.5 inches.
20. The firearm of claim 18, wherein the firearm comprises a
submachine gun.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a Continuation-in-Part of U.S.
patent application Ser. No. 13/679,966, titled "Firearm Actuation
System," filed on Nov. 16, 2012, which claims the benefit of U.S.
Provisional Patent Application No. 61/560,435, titled "Barrel
Suppressor," filed on Nov. 16, 2011. This patent application also
claims the benefit of U.S. Provisional Patent Application No.
61/893,563, titled "Sear Trip Bar for a Firearm," filed on Oct. 21,
2013. Each of these patent applications is herein incorporated by
reference in its entirety.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates to firearms and more
particularly to firearms configurable for automatic-fire
capabilities.
BACKGROUND
[0003] Firearm design involves a number of non-trivial challenges,
and compact firearms platforms have faced particular complications,
such as those with respect to achieving automatic firing
capabilities. Continued platform scaling will make these challenges
even greater.
SUMMARY
[0004] One example embodiment provides a sear trip bar for a
firearm, the sear trip bar including: an elongate body portion
having a forward end and an opposing rearward end; a first hooked
portion extending upwardly away from the forward end of the body
portion and configured to be operatively interfaced with a bolt
carrier of the firearm; and a second hooked portion extending
laterally away from the rearward end of the body portion and
configured to be operatively interfaced with an automatic sear of
the firearm. In some cases, the body portion, the first hooked
portion, and the second hooked portion are formed as a unitary
component. In some cases, the first hooked portion and the second
hooked portion are orthogonal to one another. In some instances,
the first hooked portion extends upwardly away from the forward end
of the body portion by a distance in the range of about 0.1-0.5
inches. In some instances, the second hooked portion extends
laterally away from the rearward end of the body portion by a
distance in the range of about 0.1-0.4 inches. In some cases, the
body portion includes a first slot and a second slot formed
therein, the first slot proximal to the forward end of the body
portion, and the second slot proximal to the rearward end of the
body portion, and the first and second slots are configured to
provide the sear trip bar with a stroke length in the range of
about 0.1-0.5 inches. In some cases, at least one of the first slot
and the second slot has a length in the range of about 0.1-0.5
inches. In some instances, the first slot and the second slot are
of different lengths. In some cases, at least a portion of the
second hooked portion is offset in elevation with respect to the
body portion by a distance in the range of about 0.01-0.1
inches.
[0005] Another example embodiment provides a firearm including: a
lower receiver having an automatic sear disposed therein; and an
upper receiver having a groove formed in an interior sidewall
portion thereof, the upper receiver having disposed therein: a bolt
carrier; and a sear trip bar including: a first portion configured
to operatively interface with the bolt carrier; and a second
portion configured to operatively interface with the automatic
sear; wherein the sear trip bar resides, at least in part, within
the groove of the upper receiver and is configured such that, upon
sufficient forward displacement of the bolt carrier within the
firearm, the sear trip bar trips the automatic sear to
automatically initiate a firing cycle. In some cases, the sear trip
bar further includes: a first slot defined therein proximal to the
first portion; and a second slot defined therein proximal to the
second portion. In some cases, the first slot and the second slot
each have a rounded rectangular geometry and each have a length in
the range of about 0.1-0.5 inches. In some instances, the sear trip
bar further includes: a first retention pin disposed within the
upper receiver and slidably inserted within the first slot of the
sear trip bar; and a second retention pin disposed within the upper
receiver and slidably inserted within the second slot of the sear
trip bar. In some cases, the sear trip bar has a stroke length
within the groove in the range of about 0.1-0.5 inches. In some
instances, the sear trip bar resides, at least in part, adjacent to
a hammer slot formed in the bolt carrier. In some cases, the
firearm is chambered for pistol-caliber ammunition. In some other
cases, the firearm is chambered for rifle-caliber ammunition.
[0006] Another example embodiment provides a firearm including: a
bolt carrier having a notched portion formed in a bottom surface
thereof, the notched portion adjacent to a hammer slot formed in
the bolt carrier; an automatic sear having an actuating portion
including a rear surface; and a sear trip bar including: an
elongate body portion; a first hooked portion extending upwardly
away from a forward end of the body portion, the first hooked
portion configured to physically contact the notched portion of the
bolt carrier; and a second hooked portion extending laterally away
from a rearward end of the body portion, the second hooked portion
orthogonal to the first hooked portion and configured to physically
contact the rear surface of the actuating portion of the automatic
sear; wherein the sear trip bar has a total length in the range of
about 2-3 inches, and at least a portion of the sear trip bar has a
thickness in the range of about 0.01-0.1 inches; wherein upon
exhausting a stroke length of the sear trip bar, the automatic sear
is tripped. In some cases, the stroke length is in the range of
about 0.1-0.5 inches. In some instances, the firearm is a
submachine gun.
[0007] 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 inventive subject
matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1A is a perspective view of a sear trip bar configured
in accordance with an embodiment of the present disclosure.
[0009] FIG. 1B is a side view of the sear trip bar of FIG. 1A.
[0010] FIG. 1C is a top view of the sear trip bar of FIG. 1A.
[0011] FIGS. 1D and 1E are forward and rearward end views,
respectively, of the sear trip bar of FIG. 1A.
[0012] FIGS. 2A and 2B are partial cross-sectional views of an
upper receiver of a firearm including a sear trip bar, in
accordance with an embodiment of the present disclosure.
[0013] FIG. 3 is a cutaway side view of a firearm including a sear
trip bar, in accordance with an embodiment of the present
disclosure.
[0014] FIG. 3' is a partial magnified view of FIG. 3 showing
operative interfacing between the sear trip bar and the bolt
carrier.
[0015] FIG. 3'' is a partial magnified view of FIG. 3 showing
operative interfacing between the sear trip bar and the automatic
sear.
[0016] FIG. 4 is a cutaway perspective view of the firearm of FIG.
3 after discharge of a chambered round, in accordance with an
embodiment of the present disclosure.
[0017] FIG. 5 is a side cutaway view of the firearm of FIG. 3 in
the full recoil position, in accordance with an embodiment of the
present disclosure.
[0018] FIG. 6A is a side cutaway view of the firearm of FIG. 3
momentarily before tripping of the automatic sear by sear trip bar,
in accordance with an embodiment of the present disclosure.
[0019] FIG. 6B is a cutaway perspective view of the firearm of FIG.
6A.
[0020] These and other features of the present embodiments will be
understood better by reading the following detailed description,
taken together with the figures herein described. In the drawings,
each identical or nearly identical component that is illustrated in
various figures may be represented by a like numeral. 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.
DETAILED DESCRIPTION
[0021] A sear trip bar for use in an automatic firearm is
disclosed. In accordance with some embodiments, the disclosed sear
trip bar can be operatively interfaced with the bolt carrier and
the automatic sear of the host firearm. The disclosed sear trip bar
can be configured such that, upon sufficient displacement thereof
(e.g., exhaustion of its stroke length) by the bolt carrier, the
automatic sear may be caused to trip, in accordance with some
embodiments. Thus, the disclosed sear trip bar can be utilized, for
example, to transfer the force of the moving bolt carrier during a
given firing cycle to automatically trip the sear so as to initiate
one or more subsequent firing cycles without having to release and
again operate the trigger of the host firearm. The disclosed sear
trip bar can be used, for example, in pistol-caliber and/or
rifle-caliber automatic firearms. Numerous configurations and
variations will be apparent in light of this disclosure.
General Overview
[0022] As previously indicated, there are a number of non-trivial
issues that can complicate automatic firearms design. For example,
as automatic firearms scale down in size, their internal
componentry can require a similar reduction in size. For instance,
as the bolt carrier of a given automatic firearm is reduced in
length, the distance between the bolt carrier and the automatic
sear of the firearm increases. Also, some existing approaches to
tripping the automatic sear of an automatic firearm add mass to the
moving bolt carrier and can render it prone to mechanical
failure.
[0023] Thus, a sear trip bar for use in an automatic firearm is
disclosed. In accordance with some embodiments, the disclosed sear
trip bar can be operatively interfaced with the bolt carrier and
the automatic sear of the host firearm. The disclosed sear trip bar
can be configured such that, upon sufficient displacement thereof
(e.g., exhaustion of its stroke length) by the bolt carrier, the
automatic sear may be caused to trip, in accordance with some
embodiments. Thus, the disclosed sear trip bar can be utilized, for
example, to transfer the force of the moving bolt carrier during a
given firing cycle to automatically trip the sear so as to initiate
one or more subsequent firing cycles without having to release and
again operate the trigger of the host firearm.
[0024] A sear trip bar configured as described herein can be
utilized in any of a wide range of pistol-caliber and/or
rifle-caliber automatic firearms, in accordance with some
embodiments. For instance, some embodiments may be configured for
use in a submachine gun or other pistol-caliber automatic firearm,
such as the SIG MPX machine pistol produced by Sig Sauer, Inc. Some
other embodiments may be configured for use in a rifle-caliber
automatic firearm, such as the SIG MCX rifle produced by Sig Sauer,
Inc. In some cases, a sear trip bar configured as described herein
may be used, for example, in a firearm having a shortened bolt
carrier. Other suitable host firearm platforms will be apparent in
light of this disclosure.
[0025] In some embodiments, the disclosed sear trip bar may serve
as a damper which can help to realize a reduction in bolt bounce
exhibited by a host firearm, for example, during automatic firing
thereof. In some embodiments, the disclosed sear trip bar may be a
small form factor component constructed from materials that are
lightweight, resilient, and/or inexpensive. In some such instances,
minimal (or otherwise negligible) mass and/or bulk may be added to
the host firearm, thereby helping to maintain a reliable,
lightweight, compact automatic firearm. Also, in some instances, a
reduction in cost (e.g., of production, repair, and/or replacement)
may be realized.
[0026] By toggling the host firearm's safe/fire selector switch,
the firearm's automatic sear can be rotated into and out of index
with the firearm's hammer, and thus by virtue of how the sear trip
bar and automatic sear are operatively interfaced, in accordance
with some embodiments, the sear trip bar can be permitted and
prevented, respectively, from operating to trip the automatic sear.
That is, the disclosed sear trip bar can be configured, in some
embodiments, such that it is allowed to move rearward and forward
in a given firing cycle, but prevented from functioning to trip the
automatic sear, for example, when the host firearm is put in a
semi-automatic firing mode or safe mode. In turn, this can obviate
the need to include additional componentry for purposes of
preventing unwanted tripping of the automatic sear, which can help
to reduce mechanical complexity and/or improve mechanical
reliability of the host firearm, in some instances.
Structure
[0027] FIGS. 1A-1E illustrate several views of a sear trip bar 100
configured in accordance with an embodiment of the present
disclosure. As described herein, sear trip bar 100 includes a body
portion 110, a forward hooked portion 120, and a rearward hooked
portion 130, and may have one or more slots 112, 114, etc., formed
therein, in accordance with some embodiments. In some embodiments,
sear trip bar 100 may be formed as a unitary component; that is,
body portion 110, forward hooked portion 120, and rearward hooked
portion 130 are formed from a single piece of material to provide a
single, continuous element. In some other embodiments, however,
sear trip bar 100 may be several separate elements that are
operatively coupled with one another; that is, forward hooked
portion 120 and/or rearward hooked portion 130 are attached to or
otherwise assembled with body portion 110 (e.g., such as by
welding, riveting, or other suitable technique for joining portions
of sear trip bar 100).
[0028] The dimensions (e.g., length, width, thickness, etc.) of
sear trip bar 100 can be customized for a given target application
or end-use. For instance, in some embodiments, sear trip bar 100
may have a length D.sub.1, for example, in the range of about
2.0-3.0 inches (e.g., about 2.0-2.25 inches, about 2.25-2.5 inches,
about 2.5-2.75 inches, about 2.75-3.0 inches, or any other
sub-range in the range of about 2.0-3.0 inches). It should be
noted, however, that the present disclosure is not so limited, as
sear trip bar 100 may be provided in longer or shorter lengths
D.sub.1, as desired.
[0029] Sear trip bar 100 can be constructed from any suitable
material(s). For example, in some embodiments, sear trip bar 100
can be constructed from a stainless steel, such as AISI 1074 steel
or AISI 1095 steel. As will be appreciated in light of this
disclosure, it may be desirable in some instances to ensure that
sear trip bar 100 is comprised of a material (or combination of
materials), for example, which is corrosion-resistant, reliable
over a wide temperature range (e.g., -50.degree. F. to 170.degree.
F.), and/or resistant to deformation, fracture, and/or cyclic
fatigue. In a more general sense, sear trip bar 100 can be
constructed from any suitable material which is compliant, for
example, with United States Defense Standard MIL-W-13855 (Weapons:
Small Arms and Aircraft Armament Subsystems, General Specification
For). Other suitable configurations, dimensions, and materials for
sear trip bar 100 will depend on a given application and will be
apparent in light of this disclosure.
[0030] In accordance with some embodiments, body portion 110 can be
an elongate member having a substantially planar geometry. The
dimensions (e.g., length, width, thickness, etc.) of body portion
110 can be customized for a given target application or end-use. In
some embodiments, body portion 110 may have a thickness D.sub.2,
for example, in the range of about 0.01-0.1 inches (e.g., about
0.01-0.03 inches, about 0.03-0.06 inches, about 0.06-0.09 inches,
or any other sub-range in the range of about 0.01-0.1 inches). In
some cases, sear trip bar 100 may be substantially uniform in
thickness along its length. In some other cases, however, a first
portion of sear trip bar 100 may have a thickness within a first
range, whereas a second portion thereof has a thickness within a
second, different range.
[0031] Also, as can be seen from the figures, the forward end of
body portion 110 includes hooked portion 120. In some cases, body
portion 110 may transition to forward hooked portion 120, while in
some other cases, forward hooked portion 120 may be attached to or
otherwise assembled with body portion 110 at its forward end. In
accordance with some embodiments, surface 122 of forward hooked
portion 120 can be configured to operatively interface, for
example, with a bolt carrier 200 (FIG. 2A), as discussed herein.
That is, during a given firing cycle, surface 122 may come into
physical contact with a notched portion 222 located on the
underside of bolt carrier 200, in accordance with some
embodiments.
[0032] The dimensions (e.g., length, width, height, curvature,
etc.) of forward hooked portion 120 can be customized for a given
target application or end-use. In some embodiments, forward hooked
portion 120 may extend upwardly from body portion 110 by a distance
D.sub.3, for example, in the range of about 0.1-0.5 inches (e.g.,
about 0.1-0.2 inches, about 0.2-0.3 inches, about 0.3-0.4 inches,
about 0.4-0.5 inches, or any other sub-range in the range of about
0.1-0.5 inches). In some embodiments, forward hooked portion 120
may have a width D.sub.4, for example, in the range of about
0.1-0.4 inches (e.g., about 0.1-0.2 inches, about 0.2-0.3 inches,
about 0.3-0.4 inches, or any other sub-range in the range of about
0.1-0.4 inches). In some embodiments, forward hooked portion 120
may have a thickness that is equal to the thickness D.sub.2 of body
portion 110. Other suitable configurations for the forward hooked
portion 120 of sear trip bar 100 will depend on a given application
and will be apparent in light of this disclosure.
[0033] Furthermore, as can be seen from the figures, the rearward
end of body portion 110 includes hooked portion 130. In some cases,
body portion 110 may transition to rearward hooked portion 130,
while in some other cases, rearward hooked portion 130 may be
attached to or otherwise assembled with body portion 110 at its
rearward end. In accordance with some embodiments, surface 132 of
rearward hooked portion 130 can be configured to operatively
interface, for example, with an automatic sear 300 (discussed
herein). That is, during a given firing cycle, surface 132 may come
into physical contact with the rear surface 332 of the actuating
portion 330 of automatic sear 300, in accordance with some
embodiments.
[0034] The dimensions (e.g., length, width, height, curvature,
etc.) of rearward hooked portion 130 can be customized for a given
target application or end-use. In some embodiments, rearward hooked
portion 130 may extend laterally from body portion 110 by a
distance D.sub.5, for example, in the range of about 0.1-0.4 inches
(e.g., about 0.1-0.2 inches, about 0.2-0.3 inches, about 0.3-0.4
inches, or any other sub-range in the range of about 0.1-0.4
inches). In some embodiments, rearward hooked portion 130 also may
be offset in elevation (e.g., downwardly offset) from body portion
110 by a distance D.sub.6, for example, in the range of about
0.01-0.1 inches (e.g., about 0.1-0.3 inches, about 0.3-0.6 inches,
about 0.6-0.9 inches, or any other sub-range in the range of about
0.01-0.1 inches). In some embodiments, surface 132 of rearward
hooked portion 130 may have a width D.sub.7, for example, in the
range of about 0.1-0.4 inches (e.g., about 0.1-0.2 inches, about
0.2-0.3 inches, about 0.3-0.4 inches, or any other sub-range in the
range of about 0.1-0.4 inches). In some embodiments, rearward
hooked portion 130 may have a thickness that is equal to the
thickness D.sub.2 of body portion 110. Also, as can be seen from
the figures, rearward hooked portion 130 may be substantially
orthogonal to (e.g., at about 90.degree. offset from) forward
hooked portion 120, in accordance with some embodiments. Other
suitable configurations for rearward hooked portion 130 of sear
trip bar 100 will depend on a given application and will be
apparent in light of this disclosure.
[0035] As previously noted, body portion 110 of sear trip bar 100
may have one or more slots formed therein. For instance, in some
embodiments, body portion 110 of sear trip bar 100 may have a
forward slot 112 and a rearward slot 114 formed therein. Each of
forward slot 112 and rearward slot 114 may be formed in body
portion 110 so as to traverse the full thickness D.sub.2 of body
portion 110 (i.e., pass completely through body portion 110 from
one side thereof to the opposing side thereof), in accordance with
some embodiments. Also, in accordance with some embodiments,
forward slot 112 and rearward slot 114 may be substantially aligned
(e.g., precisely or otherwise within an acceptable tolerance) with
one another along the length of body portion 110, for example, so
as not to inhibit the stroke length of sear trip bar 100, as
discussed herein. Furthermore, in accordance with some embodiments,
each of forward slot 112 and rearward slot 114 may be provided with
a rounded rectangular geometry (e.g., a box-like shape having
radiused or otherwise rounded ends). In some other embodiments,
however, slots 112, 114, etc., may have a rectangular geometry
(e.g., a box-like shape having right-angled or otherwise angled
ends).
[0036] The dimensions (e.g., length and width) of a given slot 112,
114, etc., can be customized for a given target application or
end-use. In some embodiments, forward slot 112 may have a length
D.sub.8, for example, in the range of about 0.1-0.5 inches (e.g.,
about 0.1-0.2 inches, about 0.2-0.3 inches, about 0.3-0.4 inches,
about 0.4-0.5 inches, or any other sub-range in the range of about
0.1-0.5 inches). In some embodiments, rearward slot 114 may have a
length D.sub.9, for example, which is in the same example
measurement range noted with respect to length D.sub.8 of forward
slot 112. In some cases, lengths D.sub.8 and D.sub.9 may be
substantially equal, while in other cases, lengths D.sub.8 and
D.sub.9 may be different from one another (e.g., the length D.sub.9
of rearward slot 114 may be greater than the length D.sub.8 of
forward slot 112; the length D.sub.8 of forward slot 112 may be
greater than the length D.sub.9 of rearward slot 114). Other
suitable configurations for the one or more slots 112, 114, etc.,
will depend on a given application and will be apparent in light of
this disclosure.
[0037] FIGS. 2A and 2B are partial cross-sectional views of an
upper receiver 500 of a firearm 10 including a sear trip bar 100,
in accordance with an embodiment of the present disclosure. As can
be seen, each of the one or more slots 112, 114, etc., of sear trip
bar 100 may be configured to receive therein a retention pin 510.
The retention pin(s) 510 may be disposed, for example, within the
upper receiver 500 of a host firearm 10 (e.g., such as is generally
depicted in FIG. 2A). A given retention pin 510 may be configured
to reside, in part, within a given slot 112, 114, etc., of sear
trip bar 100. The dimensions (e.g., length, width/diameter, etc.)
and geometry (e.g., rounded cross-section, angled cross-section,
etc.) of a given retention pin 510 can be customized as desired for
a given target application or end-use. In some embodiments, a given
retention pin 510 may have a width/diameter which is less than the
width/diameter of a corresponding slot 112, 114, etc.
[0038] As can be seen further, sear trip bar 100 may be configured
to reside, at least in part, within a groove 502 formed in the
upper receiver 500 of the host firearm 10. Groove 502 may be
formed, for example, within an interior sidewall portion of upper
receiver 500, in accordance with some embodiments. The dimensions
(e.g., length, width, depth, etc.) of groove 502 can be customized
for a given target application or end-use. As will be appreciated
in light of this disclosure, it may be desirable to ensure that the
dimensions of groove 502 are sufficient to accommodate sear trip
bar 100. Other suitable arrangements for sear trip bar 100 within a
given host firearm 10 will depend on a given application and will
be apparent in light of this disclosure.
[0039] By virtue of how retention pins 510 are slidably inserted
within the one or more slots 112, 114, etc., sear trip bar 100 may
be permitted to slide in the forward and rearward directions, while
being substantially prevented from moving from side to side (e.g.,
in the lateral directions), in accordance with some embodiments.
Also, by virtue of how sear trip bar 100 is slidably inserted
within groove 502, sear trip bar 100 may be permitted to slide in
the forward and rearward directions, while being substantially
prevented from moving upward and downward (e.g., in the vertical
directions), in accordance with some embodiments. The range of
forward and rearward motion (i.e., the stroke length) of sear trip
bar 100 can be customized for a given target application or
end-use. As will be appreciated in light of this disclosure, the
stroke length of sear trip bar 100 may depend, at least in part, on
the length D.sub.8 of forward slot 112 and/or the length D.sub.9 of
rearward slot 114 (and/or the lengths of any other slots, if
optionally provided). In some example cases, sear trip bar 100 may
be configured to have a stroke length in the range of about 0.1-0.5
inches (e.g., about 0.1-0.2 inches, about 0.2-0.3 inches, about
0.3-0.4 inches, about 0.4-0.5 inches, or any other sub-range in the
range of about 0.1-0.5 inches). As will be further appreciated, the
stroke length of sear trip bar 100 may depend, at least in part, on
the dimensions and/or geometry of retention pin(s) 510. For
instance, if a given retention pin 510 is provided with a size that
is similar to the size of a given slot 112, 114, etc., then the
stroke length of sear trip bar 100 may be reduced as compared to a
scenario in which the retention pin 510 is provided with a size
which is dissimilar to the size of a given slot 112, 114, etc. If a
given retention pin 510 is provided with a geometry that is not
commensurate with the geometry of a given slot 112, 114, etc.
(e.g., a square or angled retention pin 510 within a slot 112, 114,
etc., having radiused ends), then the stroke length of sear trip
bar 100 may be reduced as compared to a scenario in which the
retention pin 510 is provided with a geometry which is commensurate
with the geometry of a given slot 112, 114, etc. (e.g., a rounded
or curved retention pin 510 within a slot 112, 114, etc., having
radiused ends). Other suitable stroke lengths for sear trip bar 100
will depend on a given application and will be apparent in light of
this disclosure.
[0040] As previously noted, sear trip bar 100 can be configured to
operatively interface with the bolt carrier 200 of a host firearm
10, in accordance with some embodiments. In some cases, bolt
carrier 200 can be a bolt carrier that is configured as
traditionally done, as will be apparent in light of this
disclosure. However, the present disclosure is not so limited, as
in some other cases, bolt carrier 200 may be configured as a
non-traditional and/or custom bolt carrier, as desired for a given
target application or end-use.
[0041] In any such case, bolt carrier 200 may have a notched
portion 222 formed on its underside, adjacent to its hammer slot
210. In accordance with some embodiments, forward hooked portion
120 of sear trip bar 100 may physically interface with notched
portion 222 of bolt carrier 200. As discussed herein, physical
interfacing of sear trip bar 100 with bolt carrier 200 can provide
for transferring the force of the forward movement of bolt carrier
200 during a given firing cycle to automatic sear 300 (FIG. 3) for
purposes of tripping the sear 300, in accordance with some
embodiments. Also, the offset (e.g., laterally adjacent) location
of notched portion 222 with respect to hammer slot 210 may help to
ensure that sear trip bar 100 does not impede the operation of the
hammer 410 and other firing mechanisms of the host firearm 10 while
physically interfacing with notched portion 222. Other suitable
configurations for bolt carrier 200 and its notched portion 222
will depend on a given application and will be apparent in light of
this disclosure.
[0042] Also, as previously noted, sear trip bar 100 can be
configured to operatively interface with the automatic sear 300
(FIG. 3) of a host firearm 10, in accordance with some embodiments.
In some cases, automatic sear 300 can be an automatic sear assembly
that is configured as traditionally done, as will be apparent in
light of this disclosure. However, the present disclosure is not so
limited, as in some other cases, automatic sear 300 may be
configured as a non-traditional and/or custom automatic sear
assembly, as desired for a given target application or end-use. In
accordance with some embodiments, automatic sear 300 may be
disposed, for example, in a lower receiver of host firearm 10.
[0043] In any such case, the automatic sear 300 may include an
actuating portion 330 configured to sear with the hammer 410 of the
host firearm 10. In accordance with some embodiments, rearward
hooked portion 130 of sear trip bar 100 may physically interface
with the rear surface 332 of actuating portion 330 of automatic
sear 300. As discussed herein, physical interfacing of sear trip
bar 100 with automatic sear 300 can provide for transferring the
force of the forward movement of bolt carrier 200 during a given
firing cycle to automatic sear 300 for purposes of tripping the
sear 300.
[0044] Also, the arm portion 320 of automatic sear 300 and sear
spring 340 may operate in conjunction with one another to
operatively interface automatic sear 300 with a safe/fire selector
switch 600 of the host firearm 10. As will be appreciated in light
of this disclosure, toggling of that switch 600 (e.g., such as by
rotation thereof) serves to change the angle of automatic sear 300
about its rotational axis, thus bringing actuating portion 330 into
and out of index with hammer 410 of host firearm 10, consequently
changing the firing mode thereof. Thus, in a sense, the operative
interfacing between automatic sear 300 and safe/fire selector
switch 600 contributes to enabling/disabling functional interaction
between sear trip bar 100 and automatic sear 300, in accordance
with some embodiments. Other suitable configurations for automatic
sear 300 will depend on a given application and will be apparent in
light of this disclosure.
Operation
[0045] As described herein, and in accordance with some
embodiments, sear trip bar 100 may be utilized to transfer the
force of a moving bolt carrier 200 during a given firing cycle to
initiate a subsequent firing cycle without need to release and once
again operate the trigger 405 of the host firearm 10. To illustrate
this, consider FIG. 3, which is a cutaway side view of a firearm 10
including a sear trip bar 100, in accordance with an embodiment of
the present disclosure. At this depicted moment in the firing
cycle, the hammer 410 of firearm 10 has been released and is
traveling towards hammer slot 210 in bolt carrier 200. Also, as can
be seen, sear trip bar 100 is simultaneously in physical contact
with both of bolt carrier 200 and automatic sear 300 (i.e., there
are two points of contact for sear trip bar 100). That is, as can
be seen from FIG. 3', which is a partial magnified view of FIG. 3
showing operative interfacing between sear trip bar 100 and bolt
carrier 200, surface 122 of forward hooked portion 120 and notched
portion 222 are in physical contact with one another. Furthermore,
as can be seen from FIG. 3'', which is a partial magnified view of
FIG. 3 showing operative interfacing between sear trip bar 100 and
automatic sear 300, surface 132 of rearward hooked portion 130 and
rear surface 332 of actuating portion 330 of sear 300 are in
physical contact with one another.
[0046] FIG. 4 is a cutaway perspective view of the firearm 10 of
FIG. 3 after discharge of a chambered round, in accordance with an
embodiment of the present disclosure. At this depicted moment in
the firing cycle, bolt carrier 200 is moving rearward, taking
notched portion 222 out of physical contact with forward hooked
portion 120 of sear trip bar 100. As bolt carrier 200 moves away
from forward hooked portion 120, the restoring force of sear spring
340 is momentarily unopposed by the restoring force of the recoil
spring(s) 230 operatively coupled with bolt carrier 200. Thus,
because rearward hooked portion 130 is still in physical contact
with back surface 332 of actuating portion 330 of automatic sear
300, the restoring force of sear spring 340 causes automatic sear
300 to rotate rearward, forcing sear trip bar 100 rearward. Sear
trip bar 100 continues to travel rearward until its rearward stroke
length is exhausted (e.g., until it is arrested by retention pins
510 within slots 112, 114, etc.).
[0047] FIG. 5 is a side cutaway view of the firearm 10 of FIG. 3 in
the full recoil position, in accordance with an embodiment of the
present disclosure. As bolt carrier 200 disengages sear trip bar
100 and moves rearward to the full recoil position, sear trip bar
100, automatic sear 300, and hammer 410 are allowed to reset for
the next firing cycle. After reaching the full recoil position, the
restoring force of the recoil spring(s) 230 moves bolt carrier 200
forward, toward the firing position. As bolt carrier 200 moves
forward, physical contact between notched portion 222 of bolt
carrier 200 and forward hooked portion 120 of sear trip bar 100 is
reestablished. Thus, sear trip bar 100 is once again simultaneously
in physical contact with both of bolt carrier 200 and automatic
sear 300 (i.e., again, there are two points of contact for sear
trip bar 100).
[0048] FIG. 6A is a side cutaway view of the firearm 10 of FIG. 3
momentarily before tripping of the automatic sear 300 by sear trip
bar 100, in accordance with an embodiment of the present
disclosure. At this depicted moment in the firing cycle, bolt
carrier 200 is pulling sear trip bar 100 forward, which in turn
causes rearward hooked portion 130 to pull on actuating portion 330
of automatic sear 300, rotating sear 300 forward about its axis of
rotation. Also, as can be seen from FIG. 6B, which is a cutaway
perspective view of the firearm 10 of FIG. 6A, sear trip bar 100 is
in an intermediate position along its stroke length. That is, at
this instant, sear trip bar 100 is neither fully forward, nor fully
rearward. Thus, from a given intermediate position, sear trip bar
100 may have some amount of stroke length remaining before it is in
its fully forward position (i.e., before its forward stroke length
is exhausted). Therefore, if sear trip bar 100 were to be forced
forward that remaining distance, thereby exhausting the stroke
length of sear trip bar 100, automatic sear 300 would be caused to
trip, as discussed herein. In some embodiments, sear trip bar 100
may have a remaining stroke length (e.g., from an intermediate
position), for example, in the range of about 0.001-0.010 inches
(e.g., about 0.001-0.003 inches, about 0.003-0.006 inches, about
0.006-0.009 inches, or any other sub-range in the range of about
0.001-0.010 inches). Other suitable remaining stroke lengths will
depend on a given application and will be apparent in light of this
disclosure.
[0049] If the operator has not released trigger 405, then as the
bolt carrier 200 moves forward into the firing position, sear trip
bar 100 travels forward in tandem with bolt carrier 200 until its
stroke length is exhausted, causing automatic sear 300 to rotate
and trip, releasing hammer 410 again and initiating the next firing
cycle. If instead the operator has previously released trigger 405,
then the current firing cycle will be completed, and the bolt
carrier 200 will be returned to its firing position, thereby
returning the firearm 10 to its ready-to-fire state.
[0050] 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.
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