U.S. patent application number 10/806300 was filed with the patent office on 2007-01-11 for modular trigger group for firearms and trigger group installation method.
Invention is credited to Michael L. McCormick.
Application Number | 20070006510 10/806300 |
Document ID | / |
Family ID | 32067787 |
Filed Date | 2007-01-11 |
United States Patent
Application |
20070006510 |
Kind Code |
A1 |
McCormick; Michael L. |
January 11, 2007 |
MODULAR TRIGGER GROUP FOR FIREARMS AND TRIGGER GROUP INSTALLATION
METHOD
Abstract
A module housing is adapted to be inserted into an operating
position in the trigger group receiving area of a firearm. The
module housing includes at least one pin receiver defined by two
openings formed in the module housing, one on each lateral side of
the housing. A module pin is received in the pin receiver and at
least one trigger group component is mounted or supported for
rotation on the module pin. The pin receiver is located on the
module housing so as to align with a pin receptacle of the firearm
when the module housing is in the operating position. By locating
the pin receiver in the module housing so as to align with a
corresponding pin receptacle of the firearm when the module housing
is in the operating position, the trigger group module and the
trigger group components housed in the module housing may be
readily supported by the OEM pin receptacle. The trigger group
module, pre-assembled with one or more trigger group components,
may be inserted to the operating position and then held in place
using the OEM pin receptacle.
Inventors: |
McCormick; Michael L.;
(Austin, TX) |
Correspondence
Address: |
THE CULBERTSON GROUP, P.C.
1114 LOST CREEK BLVD.
SUITE 420
AUSTIN
TX
78746
US
|
Family ID: |
32067787 |
Appl. No.: |
10/806300 |
Filed: |
March 22, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10152557 |
May 21, 2002 |
6722072 |
|
|
10806300 |
Mar 22, 2004 |
|
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Current U.S.
Class: |
42/75.02 ;
42/69.01; 42/69.03; 42/75.03 |
Current CPC
Class: |
F41A 19/12 20130101;
F41A 19/15 20130101; F41A 19/10 20130101; F41A 19/43 20130101 |
Class at
Publication: |
042/075.02 ;
042/069.01; 042/075.03; 042/069.03 |
International
Class: |
F41A 19/00 20060101
F41A019/00; F41A 21/00 20060101 F41A021/00 |
Claims
1. A method of installing a trigger group in a firearm, the method
including the steps of: (a) assembling a number of trigger group
components in a trigger group module; (b) separating an upper
receiver from the firearm to expose a trigger group receiving
opening in a lower receiver of the firearm; (c) inserting the
trigger group module into the lower receiver through the trigger
group receiving opening so as to place the trigger group module in
an operating position in the lower receiver; and (d) after placing
the trigger group module in the operating position in the lower
receiver, bringing the upper receiver and lower receiver together
while the trigger group module remains in the operating position
and then reattaching the upper receiver to the lower receiver.
2. The method of claim 1 further including the step of retaining
the trigger group module in the lower receiver with one or more
retaining devices prior to reconnecting the upper receiver to the
lower receiver.
3. The method of claim 2 wherein the step of retaining the trigger
group module in the lower receiver includes the step of supporting
the trigger group module from a pin receptacle in the lower
receiver.
4. The method of claim 3 wherein the step of supporting the trigger
group module from the pin receptacle in the lower receiver includes
inserting a pin through the pin receptacle and through a pin
receiver in the trigger group module.
5. The method of claim 3 wherein the step of supporting the trigger
group module from the pin receptacle in the lower receiver includes
inserting a pin through the pin receptacle and through a module pin
opening included in the trigger group module.
6. A method of assembling a firearm having a frame made up of an
upper receiver and a lower receiver which is separable from the
upper receiver, the method including the steps of: (a) assembling a
number of trigger group components in a module housing to produce a
pre-assembled trigger group module; (b) placing the pre-assembled
trigger group module in an operating position in the lower
receiver; and (c) after placing the pre-assembled trigger group
module in the operating position in the lower receiver, bringing
the lower receiver and upper receiver together to enclose the
module housing in the firearm and then securing the upper receiver
to the lower receiver.
7. The method of claim 6 further including the step of securing the
pre-assembled trigger group module in the operating position in the
lower receiver prior to securing the upper receiver to the lower
receiver.
8. The method of claim 7 wherein the step of securing the
pre-assembled trigger group module in the operating position
includes securing the trigger group module in the operating
position through pin receptacle openings formed in opposing side
walls of the lower receiver.
9-22. (canceled)
23. The method of claim 1 further including: (a) prior to inserting
the trigger group module into the lower receiver, removing a first
OEM trigger group pin to release a first OEM trigger group
component with respect to the lower receiver and with respect to a
second trigger group component; (b) prior to inserting the trigger
group module into the lower receiver, removing a second OEM trigger
group pin to release the second trigger group component with
respect to the lower receiver; (c) prior to inserting the trigger
group module into the lower receiver, removing the first OEM
trigger group component and the second trigger group component from
the lower receiver; and (d) securing the trigger group module in
the lower receiver through pin receptacle openings that supported
either the first OEM trigger group pin or the second OEM trigger
group pin.
24. The method of claim 23 wherein the step of securing the trigger
group module in the lower receiver includes securing the trigger
group module through pin receptacle openings that supported the
first OEM trigger group pin and through pin receptacle openings
that supported the second OEM trigger group pin.
25. The method of claim 23 wherein the step of securing the trigger
group module in the lower receiver includes inserting a first pin
through a first pin receiver of a trigger group housing included in
the trigger group module.
26. The method of claim 25 wherein the step of securing the trigger
group module in the lower receiver includes inserting a second pin
through a second pin receiver of the trigger group housing.
27. The method of claim 6 further including: (a) prior to placing
the pre-assembled trigger group module in the operating position in
the lower receiver, removing a first OEM trigger group pin to
release a first OEM trigger group component with respect to the
lower receiver and with respect to a second trigger group
component; (b) prior to placing the pre-assembled trigger group
module in the operating position in the lower receiver, removing a
second OEM trigger group pin to release the second trigger group
component with respect to the lower receiver; (c) prior to placing
the pre-assembled trigger group module in the operating position in
the lower receiver, removing the first OEM trigger group component
and the second OEM trigger group component from the lower receiver;
and (d) securing the pre-assembled trigger group module in the
operating position through pin receptacle openings that supported
either the first OEM trigger group pin or the second OEM trigger
group pin.
28. The method of claim 27 wherein the step of securing the
pre-assembled trigger group module in the operating position
includes securing the pre-assembled trigger group module through
pin receptacle openings that supported the first OEM trigger group
pin and through pin receptacle openings that supported the second
OEM trigger group pin.
29. The method of claim 27 wherein the step of securing the
pre-assembled trigger group module in the operating position
includes inserting a first pin through a first pin receiver of the
module housing.
30. The method of claim 29 wherein the step of securing the
pre-assembled trigger group module in the operating position
includes inserting a second pin through a second pin receiver of
the module housing.
31. A method of installing a trigger group in a firearm, the method
including: (a) separating an upper receiver from the firearm to
expose a trigger group receiving opening in a lower receiver of the
firearm; (b) removing a first OEM trigger group pin to release a
first OEM trigger group component with respect to the lower
receiver and with respect to a second trigger group component; (c)
removing a second OEM trigger group pin to release the second
trigger group component with respect to the lower receiver; (d)
after removing the released first OEM trigger group component and
the released second trigger group component from the lower
receiver, inserting a trigger group module into the lower receiver
through the trigger group receiving opening, the trigger group
module including a number of trigger group components; (e) securing
the trigger group module in an operating position in the lower
receiver through pin receptacle openings in the lower receiver that
supported either the first OEM trigger group pin or the second OEM
trigger group pin; and (f) reconnecting the upper receiver to the
lower receiver while the trigger group module remains in the
operating position in the lower receiver.
32. A method of installing a trigger group in a firearm having a
frame made up of an upper receiver and a lower receiver, the method
including: (a) removing a first OEM trigger group pin to release a
first OEM trigger group component with respect to the lower
receiver and with respect to a second trigger group component; (b)
removing a second OEM trigger group pin to release the second
trigger group component with respect to the lower receiver; (c)
removing the first OEM trigger group component from the lower
receiver and removing the second OEM trigger group component from
the lower receiver; (d) placing a trigger group module in an
operating position in the lower receiver, the trigger group module
including an assembly of trigger group components; and (e) securing
the upper receiver to the lower receiver to enclose the trigger
group module in the firearm.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser.
No. 10/152,557, filed May 21, 2002, and entitled "Trigger Group
Module for Firearms and Method for Installing a Trigger Group in a
Firearm." The Applicant hereby claims the benefit of this prior
application under 35 U.S.C. .sctn.120. The entire content of this
prior application is incorporated herein by this reference.
TECHNICAL FIELD OF THE INVENTION
[0002] The invention relates to firing mechanisms for firearms.
More particularly, the invention relates to a trigger group module
pre-assembled with one or more trigger group components and adapted
to be received in the frame of the firearm. The invention also
relates to a method of installing trigger group components in a
firearm.
BACKGROUND OF THE INVENTION
[0003] Firearm firing mechanisms generally include a number of
components that cooperate to hold a spring-loaded hammer in a
cocked position and then selectively release the hammer. The
firearm is fired or discharged when the force of the released
hammer is applied, directly or through an intermediate device, to
an ammunition cartridge loaded in the firearm. The components for
holding the hammer in a cocked position and then releasing the
hammer as desired may be referred to as a trigger group. In
addition to the hammer itself, a trigger group generally includes a
trigger component having a finger lever or trigger that a user
pulls to release the hammer, and further includes a sear which may
be a separate component or integrally formed with the trigger
component. Some trigger groups also include other components such
as a disconnector for example. The disconnector is used in
semi-automatic firearms to catch the hammer as it rebounds after
firing and to hold the hammer in a cocked position until the
shooter can release the trigger and thereby reset the trigger group
to the "ready to fire position." The disconnector is required for
this function because semi-automatic firearms usually cycle so
quickly that it is physically impossible for the shooter to release
the trigger quickly enough after a discharge to allow the sear to
recapture the hammer in the cocked position.
[0004] Both the hammer component and trigger component are commonly
mounted for rotation in the firearm. The hammer is mounted on a
hammer pin to facilitate the desired rotation, while the trigger
component is mounted on a trigger pin. Each pin is retained in a
respective pin receptacle formed in the firearm. Each such pin
receptacle is defined by a first opening on one side of the firearm
and a second opening on the opposite side of the firearm. A hammer
spring is included in the trigger group to, among other things,
bias the hammer forward to a striking position. The trigger
component is also spring biased to provide resistance against
pulling the trigger and to return the trigger after it has been
pulled.
[0005] It may be desirable to modify or replace trigger group
components in a firearm. This is particularly true for firearms
used in competition. Such competition firearms may be fitted with
special trigger group components designed to improve firearm
performance or operational characteristics, or to suit the
preferences of the particular user. Also, different competitions or
firearm applications may require different trigger group
characteristics. However, due to the relatively small components in
the trigger group, the spring loading of components, the close
tolerances between components, and the small area in the firearm
allotted for trigger group components, a trigger group may commonly
be installed only by a skilled gunsmith using specialized tools in
order to ensure safe, proper, and reliable trigger group
functioning. Due to the difficulty in changing out trigger group
components, it is common for many competition shooters to have
several different complete firearms each with a different trigger
group setup for a particular competition or portion of a
competition. Maintaining several complete firearms greatly
increases the cost of competitive shooting.
[0006] Some prior art original equipment manufacturer (OEM) firearm
designs include a detachable housing that houses trigger group
components. The housing may be attached to the firearm frame with
screws or with pins that extend transversely through the housing
and are supported at either end by receptacles or bearing openings
in the firearm frame. These prior art OEM trigger group housings
attach from the bottom of the firearm and include a trigger guard
and surfaces that actually form part of the exterior of the fully
assembled firearm. Prior art OEM trigger group housings also house
safety components that cooperate with the trigger group components.
These structures and surfaces associated with the prior art OEM
trigger group housings limit their use to firearms specifically
designed for such housings.
SUMMARY OF THE INVENTION
[0007] The present invention provides a trigger group module that
is pre-assembled with the trigger group components and adapted to
be mounted in a trigger group receiving area in place of the OEM
trigger group. The invention includes a special module housing and
also includes the special housing pre-assembled with one or more
trigger group components to form the self-contained trigger group
module. The invention further includes methods for mounting or
installing a trigger group in a firearm.
[0008] A module housing according to the invention is adapted to be
inserted into an operating position in the trigger group receiving
area of a firearm. The module housing includes at least one pin
receiver defined by two openings formed in the module housing, one
on each lateral side of the housing. In one form of the invention a
module pin is received in the pin receiver and at least one trigger
group component is mounted or supported for rotation on the module
pin. In this form of the invention, the module pin includes a pin
receiving opening there through and is located on the module
housing so that this pin receiving opening aligns with a pin
receptacle of the firearm when the module housing is in the
operating position. That is, the two openings defining the pin
receiver on the module housing and the pin receiving opening
through the module pin are adapted to align with the openings on
the firearm that define a pin receptacle for the firearm.
[0009] By locating the pin receiver in the module housing so as to
align with a corresponding pin receptacle of the firearm when the
module housing is in the operating position and by providing a pin
receiving opening in the module pin, the trigger group module and
the trigger group components housed in the module housing may be
readily supported by the OEM pin receptacle. The trigger group
module, pre-assembled with one or more trigger group components,
may be inserted to the operating position and then a pin may be
inserted or extended through the OEM pin receptacle and aligned
trigger group component and module pin to support the trigger group
component in the desired functional position in the firearm. The
module housing and module pin hold the trigger group component in
place while the module housing is being placed in the firearm. No
modification to the frame of the firearm is required and no special
skill or tools are required to install the self-contained,
pre-assembled trigger group module.
[0010] One preferred form of the invention is adapted to be used
with a firearm that includes a hammer pin receptacle and a trigger
pin receptacle. The trigger group module for this firearm includes
a first pin receiver and a second pin receiver. The first pin
receiver aligns with the hammer pin receptacle of the firearm when
the housing is in the operating position and the second pin
receiver aligns with the trigger pin receptacle when the housing is
in the operating position. The first pin receiver is adapted to
receive a first module pin having a pin receiving opening there
through and the second pin receiver is adapted to receive a second
module pin having a separate pin receiving opening there through.
To install this trigger group module, the original trigger group
components are removed from the firearm together with any
interfering components such as safety mechanisms for example, and
then the pre-assembled trigger group module is placed in the
operating position in the firearm. Once in the operating position,
the trigger group module may be held in place by pins inserted
through the openings defining the hammer pin receptacle and trigger
pin receptacle, respectively. Alternatively, caps, screws, or other
elements may be inserted into the OEM pin receptacle openings to
cooperate with a trigger group module or module pin to retain the
trigger group module in the operating position.
[0011] In yet other forms of the invention, the module housing may
include no pin receiver openings located to align with OEM pin
receptacle openings when the trigger group module is in the
operating position in the firearm frame. Rather, the trigger group
component geometry may be completely changed from the OEM trigger
group geometry. In these forms of the invention, the OEM pin
receptacle openings may still be used to receive screws, pins, or
other devices to secure the trigger group module in the operating
position in the firearm frame.
[0012] A module housing according to the invention may also include
a trigger component control feature that defines or sets either the
forward most or rearward most position of the trigger component.
Two different trigger component control features may be used to set
both the forward most and rearward most position of the trigger
component. The trigger component control feature setting the
rearward most position of the trigger component provides overtravel
control to minimize the amount of trigger movement possible after
the hammer release point. The trigger component control feature
setting the forward most position of the trigger component provides
take-up control which minimizes the movement of the trigger
required before reaching the hammer release point. A major
advantage of the present invention is that by incorporating the
overtravel and take-up features in the module housing, trigger
overtravel and take-up may be modified without having to modify the
frame of the firearm itself.
[0013] These and other features and advantages of the invention
will be apparent from the following description of the preferred
embodiments, considered along with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1A is a view in perspective of a trigger group module
embodying the principles of the invention.
[0015] FIG. 1B is a view of the trigger group module shown in FIG.
1A from an opposite perspective to that shown in FIG. 1A.
[0016] FIG. 2 is an exploded view in perspective of the trigger
group module shown in FIGS. 1A and 1B.
[0017] FIG. 3 is a view in section taken a long line 3-3 in FIG.
1B.
[0018] FIG. 4 is a side view showing a portion of a firearm with a
trigger group module embodying the principles of the invention in
position to be inserted to an operating position in the
firearm.
[0019] FIG. 5 is a side view similar to FIG. 4, but showing the
trigger group module inserted to the operating position and showing
an upper receiver in position to be connected over the trigger
group module in the lower portion of the firearm.
[0020] FIG. 6 is an enlarged top view of the trigger group
receiving area of the firearm shown in FIGS. 4 and 5.
[0021] FIG. 7 is a top view of the firearm and trigger group module
shown in FIG. 5, with module securing pins partially inserted.
[0022] FIG. 8 is a top view similar to FIG. 7 but showing the
module securing pins in the fully inserted position.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] A trigger group module 10 and module housing 11 embodying
the principles of the invention may be described with reference to
FIGS. 1A and 1B through FIG. 3. A method embodying the principles
of the invention for installing a trigger group may be described
with reference to FIGS. 4 through 8.
[0024] In the following description and claims, certain elements
may be described as right side elements while others may be
described as left side elements. The terms right side and left side
are used only for purposes of convenience to indicate that a
particular element is located on one lateral side of the respective
structure while another element is located on the opposite lateral
side of the structure. Of course, whether an element is truly
located on a right side or left side depends upon the perspective
of the viewer. For purposes of consistency, the right side elements
described below will be those elements located on the right side of
trigger group module 10 as viewed from the front of the module with
the trigger extending downwardly, while the left side elements will
be those elements on the left side as viewed from the front of the
module. The direction from the rear to the front of the module will
be indicated by the arrow F in each figure showing the module
10.
[0025] Referring first to FIGS. 1A and 1B through FIG. 3, trigger
group module 10 includes module housing or housing 11 for
containing one or more trigger group components. The trigger group
components shown for purposes of example are shown best in FIGS. 2
and 3 and include a hammer 12, hammer spring 14, a trigger
component 15 having a trigger or finger lever 18, a trigger spring
16, and a disconnector 17. It will be appreciated by those skilled
in the art that disconnector 17 is associated with a disconnector
spring, however, the disconnector spring is not necessary or
helpful in describing the invention and is thus omitted from the
drawings. The illustrated trigger group components are held in
place in the module housing with module pins and specifically a
first module pin 21 for hammer 12 and a second module pin 22 for
trigger component 15. Each of the illustrated module pins 21 and 22
include an opening 21a and 22a, respectively, extending there
through. First module pin 21 is received through a pin opening 23
of the hammer while second module pin 22 is received through a pin
opening 24 of trigger component 15 and a pin opening (not shown) of
disconnector 17.
[0026] Housing 11 includes a first pin receiver for receiving first
module pin 21 and supporting the first module pin by its ends. This
first pin receiver is made up of a first right side receiver
opening 26 on a right lateral side or first side wall 31 of housing
11 and a first left side receiver opening 27 on the opposite
lateral side or second side wall 32 of the housing. Similarly,
housing 11 includes a second pin receiver for receiving second
module pin 22 and supporting the second module pin by its ends.
This second pin receiver is made up of a second right side receiver
opening 29 and a second left side receiver opening 30. Module pins
21 and 22 may be held in place in module housing 11 by frictional
engagement with the receiver openings, by "C" retainers, or by any
other suitable means.
[0027] Those familiar with different types of firearms will
recognize that the trigger group components shown for purposes of
example in the embodiment of the invention shown in FIGS. 1A and 1B
through FIG. 3 are the components used in the firing mechanism for
the COLT model AR-15 rifle. However, these trigger group components
are shown only for purposes of example and there are many other
types and arrangements of trigger group components that may be
included in a trigger group module embodying the principles of the
present invention. The invention is in no way limited to the
trigger group arrangement for an AR-15 rifle or the trigger group
components shown in the figures. In particular, some trigger
components are designed to slide along a track rather than pivot on
a pin. Trigger groups having a sliding trigger component may
include only a pin for the hammer.
[0028] As shown best in FIG. 3, the trigger group module 10
according to the invention may include an overtravel feature 41.
Overtravel feature extends from a bottom wall 42 of housing 11 in a
forward or front portion of the housing in position to contact a
forward part of trigger component 15 so that the component cannot
rotate further forwardly or clockwise in FIG. 3. This effectively
defines the rearward most position of trigger 18. As is known in
the art, overtravel control prevents the trigger from excessive
rearward movement after the hammer release point.
[0029] The illustrated module 10 also includes a take-up feature
44. Take-up feature 44 extends from housing bottom wall 42 in a
rear portion of housing 11 in position to contact a rear part of
trigger component 15. Contact between take-up feature 44 and
trigger component 15 prevents the trigger component from rotating
further counterclockwise in FIG. 3, and thus the take-up feature
effectively defines the forward most position of trigger 18. As is
known in the art, take-up control minimizes the amount of trigger
movement or "take-up" before reaching the hammer release point.
[0030] Both overtravel feature 41 and take-up feature 44 represent
trigger component control features that define the limits of
movement of the trigger component. In the preferred embodiment of
the invention where housing 11 is formed from sheet metal, both
features may be formed by pressing out a portion of the bottom wall
of the housing using a suitable stamp or press. The illustrated
overtravel and take-up features are stamped to form an elongated
member that is unsupported at one end. These elongated members may
be bent upward or downward to adjust the overtravel and take-up.
Set screws or other adjustable arrangements in housing 11 may also
be used to form adjustable overtravel and take-up features within
the scope of the present invention. It will be appreciated,
however, that the invention is not limited to modules including
trigger component control features of any type.
[0031] The method of installing a trigger group in a firearm may be
described with reference to FIGS. 4 through 8. The method includes
inserting trigger group module 10 into a trigger group receiving
area of a firearm receiver or frame 50. The trigger group receiving
area in the illustrated firearm frame 50 is shown generally at
reference numeral 51 (distinguishable only in FIG. 6) and comprises
a cavity defined between lateral side walls 53 and 54 of firearm
frame 50 large enough to house all of the trigger group components
and allow each of the components to move as desired to perform
their respective function. As mentioned previously, the model AR-15
rifle is used as a convenient and familiar example in this
disclosure. In the AR-15 example, trigger group receiving area 51
is accessible through a top opening that is exposed by removing a
top component of the firearm referred to as the upper receiver (52
in FIG. 5). Firearm frame 50 comprises the portion of the model
AR-15 rifle known as the lower receiver and is shown in the figures
with upper receiver 52 removed to expose the top opening to trigger
group receiving area 51. Upper receiver 52 may be reattached to the
lower receiver or frame 50 after trigger group module 10 is
installed as described in detail below.
[0032] The OEM trigger group for the AR-15 model rifle includes the
hammer, trigger component, disconnector, and associated springs
similar to that shown in connection with module 10. In order to
support the OEM trigger group components in the trigger group
receiving area 51, firearm frame 50 includes a first pin receptacle
for receiving and supporting a first OEM trigger group pin and a
second pin receptacle for receiving and supporting a second OEM
trigger group pin. In this case the first pin receptacle comprises
a hammer pin receptacle made up of a right side receptacle opening
57 and a left side receptacle opening 58. The second pin receptacle
comprises a trigger component receptacle made up of a right side
receptacle opening 59 and a left side receptacle opening 60.
Openings 57 and 59 are formed through the right lateral side wall
53, while openings 58 and 60 are formed through the left lateral
side wall 54. Each of these openings 57, 58, 59, and 60 provide
bearing surfaces for supporting a respective OEM trigger group pin
extending through frame 50 between left lateral side wall 53 and
right lateral side wall 54. The OEM pins are not shown in the
figures, however, it will be appreciated that the pins fit into the
respective pair of pin openings 57 and 58 or 59 and 60, and through
the pin receiving opening of the respective trigger group component
or components. The OEM hammer and trigger pins for the model AR-15
rifle each include an indent in a mid-section of the pin which
cooperates with a part of the trigger group serving as a detent to
hold the pin in place. In the installed position, the OEM trigger
group pins support the hammer, trigger component, and disconnector
in their respective operational positions and allow the components
to pivot as desired according to the operation of the trigger
group.
[0033] It will be appreciated that the trigger group receiving area
of a firearm is a relatively small area, commonly less than two
inches wide. Considering the small area in which to work, the small
components that fit in the area, the close tolerances between
components, and the spring loading of the components, it is no easy
matter to position the trigger group components in the trigger
group receiving area of a firearm and hold the components in the
proper position under spring pressure and aligned with the pin
receptacle openings while pressing the pins in place. This trigger
group installation according to the prior art method generally
requires special tools, skills, and experience. The prior art
trigger group installation method also requires great hand strength
to hold the various components in position against the pressure of
the springs in the trigger group.
[0034] Trigger group installation according to the present
invention using trigger group module 10 greatly simplifies
installation, and may allow a new trigger group to be installed
without special tools and skills. After the previous or OEM trigger
group components are removed to place the firearm frame in the
condition shown in FIG. 6, the present trigger group installation
method includes first inserting the self-contained, pre-assembled
trigger group module 10 into an operating position in firearm
trigger group receiving area 51. In this operating position, at
least one pin receiver on module housing 11 is aligned with a
corresponding pin receptacle of the firearm. In the illustrated
case, the first pin receiver is positioned with its defining
openings 26 and 27 aligned with the firearm pin receptacle defined
by receptacle openings 57 and 58. This alignment of openings 26 and
27 with receptacle openings 57 and 58 also aligns module pin
opening 21a with these receptacle openings. The illustrated case
also requires positioning module housing 11 with the pin receiver
openings 29 and 30 aligned with firearm pin receptacle openings 59
and 60. This alignment of openings 29 and 30 with pin receptacle
openings 59 and 60 also aligns module pin opening 22a with these
pin receptacle openings. FIG. 4 shows pre-assembled trigger group
module 10 positioned above the firearm and trigger group receiving
area, while FIG. 5 shows the module and its housing 11 inserted to
the operating position with the various openings aligned. It will
be noted that inserting trigger group module 10 from the position
shown in FIG. 4 to the position shown in FIG. 5 may be accomplished
only after removing all of the OEM trigger group components
originally in trigger group receiving area 51 and after removing
the safety mechanism from its receiving opening 61, to place the
firearm frame in the condition shown in FIG. 6. Removing the OEM
trigger group components for a firearm such as the illustrated
AR-15 rifle is accomplished by removing each OEM trigger group pin
to release the respective trigger group component or components
supported by the respective pin as is known in the art. It will
also be appreciated especially from FIG. 5 that the safety
mechanism mounted directly on the firearm frame in openings 61 is
in position to cooperate with the back portion of trigger component
15 to provide the desired safety function when the trigger group
module 10 is in the operating position.
[0035] When module housing 11 is in the operating position shown in
FIG. 5, the lowermost part or lower extremity of the module housing
is located above the lowermost edge of the receiver side walls
which define trigger group receiving area 51. In particular, the
lowermost part of module housing 11 is located above the lowermost
edge of receiver side wall 53 and is also located above the
lowermost edge of opposite receiver side wall 54 (side wall 54
being shown in the top view of FIG. 6). No portion of module
housing 11 extends out of the area defined as trigger group
receiving area 51. The only portion of trigger group module 10 that
is exposed when the module is in the operating position is the pull
portion of trigger component 15. Also, no portion of module housing
11 forms any part of the exterior surface of the assembled
firearm.
[0036] After inserting module 10 to the operating position shown in
FIG. 5 with the various pin openings aligned, the method then
includes inserting a first retainer pin 65 through one of the first
pin receptacle openings and through the corresponding module pin
opening. FIG. 7 shows first retainer pin 65 inserted through first
right side pin receptacle opening 57, through first right side
receiver opening 26 of housing 11, and partially through module pin
opening 21a.
[0037] The trigger group installation method according to the
invention finally includes positioning first retainer pin 65 so
that the pin is supported at one end by first right side pin
receptacle opening 57 and is supported at its opposite end by first
left side pin receptacle opening 58 on the opposite side of firearm
frame 50. This final position of retainer pin 65 is shown in FIG.
8.
[0038] In the embodiment of the invention shown in the figures,
trigger group module 10 includes two module pins, first module pin
21 supporting hammer 12 and second module pin 22 supporting trigger
component 15. Thus, once openings 29 and 30 making up the second
pin receiver is aligned with openings 59 and 60 making up the
second pin receptacle, the method includes inserting a second
retainer pin 66 through one opening of the pin receptacle and into
module pin opening 22a. FIG. 7 shows second retainer pin 66
inserted through the right side receptacle opening 59, right side
receiver opening 29, and partially through module pin opening 22a.
Second retainer pin 66 is pushed further through openings 59, 29,
and 22a until it reaches the position shown in FIG. 8. In this
position, second retainer pin 66 is supported on one end by right
side pin receptacle opening 59 and is supported at its opposite end
by left side pin receptacle opening 60.
[0039] In some forms of the invention, module pins 21 and 22 may
not align with the OEM pin receptacles of the firearm frame.
Because the module pins in the module 10 need not align with the
OEM pin receptacles in some forms of the invention, those modules
may include a completely different trigger group geometry and
structure from the one originally designed for the firearm. Even
where the module pins 21 and 22 do not align with the OEM pin
receptacles the OEM pin receptacles may still be used in retaining
the trigger group module 10 in the operating position in the
firearm frame 50. For example, pins, screws, or other elements may
be mounted in or through OEM pin receptacles and contact the module
10 or some feature on the module to serve as retaining devices or a
retaining arrangement to retain the module in the desired operating
position. The OEM pin receptacles may need to be modified to
provide the desired function. For example, threads may be tapped
into the OEM pin receptacles to accept a retainer or set screw.
[0040] It should also be noted that in the model AR-15 rifle
example described above, the OEM pin receptacles are designed by
the original manufacturer to support trigger group components that
are not pre-assembled in a module according to the present
invention. However, trigger group modules within the scope of the
invention are not limited to use in firearms originally designed to
be used with trigger group components assembled in place in the
firearm Rather, trigger group modules within the scope of the
present invention may be used with firearms specifically designed
to use the trigger group module. An OEM pin receptacle may be a
receptacle designed to cooperate with a trigger group module
according to the invention.
[0041] The above described preferred embodiments are intended to
illustrate the principles of the invention, but not to limit the
scope of the invention. Various other embodiments and modifications
to these preferred embodiments may be made by those skilled in the
art without departing from the scope of the following claims.
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