U.S. patent application number 12/321800 was filed with the patent office on 2013-03-14 for adjustable mechanical sighting mechanism for firearms.
The applicant listed for this patent is Sandy L. Strayer. Invention is credited to Sandy L. Strayer.
Application Number | 20130061511 12/321800 |
Document ID | / |
Family ID | 47828569 |
Filed Date | 2013-03-14 |
United States Patent
Application |
20130061511 |
Kind Code |
A1 |
Strayer; Sandy L. |
March 14, 2013 |
Adjustable mechanical sighting mechanism for firearms
Abstract
An adjustable mechanical sighing mechanism for firearms has a
sight blade mount defining an internal passage having first and
second outwardly flaring passage end surfaces. An adjustment screw
having an external tapered surface is in engagement with the first
of the outwardly flaring passage end surfaces. A sight blade
structure defines a sight adjustment member having an internally
threaded screw passage that receives the adjustment screw. A lock
nut is threaded onto the adjustment screw and has an external
tapered surface in engagement with the second outwardly flaring
passage end surface. The sight blade mount defines a slot through
which a support for the sight adjustment member is movable,
providing for windage adjustment of the sight blade structure by
rotation of the adjustment screw. The tapered surfaces of the
adjustment screw and lock nut provide for locking of the sight
blade at any desired position.
Inventors: |
Strayer; Sandy L.; (North
Richland Hills, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Strayer; Sandy L. |
North Richland Hills |
TX |
US |
|
|
Family ID: |
47828569 |
Appl. No.: |
12/321800 |
Filed: |
January 26, 2009 |
Current U.S.
Class: |
42/136 ;
42/135 |
Current CPC
Class: |
F41G 1/26 20130101; F41G
1/10 20130101 |
Class at
Publication: |
42/136 ;
42/135 |
International
Class: |
F41G 1/00 20060101
F41G001/00 |
Claims
1. An adjustable mechanical sighting mechanism for firearms,
comprising: a sight blade mount defining an internal passage having
first and second outwardly flaring passage end surfaces; an
adjustment screw having an external tapered surface disposed in
engagement with said first of said outwardly flaring passage end
surfaces; a sight blade member defining an internally threaded
screw passage being received in operative blade moving engagement
with said adjustment screw; and a lock nut being threaded to said
adjustment screw and having an external tapered surface disposed in
engagement with said second of said outwardly flaring passage end
surfaces.
2. The adjustable mechanical sighting mechanism of claim 1,
comprising: tightening of said lock nut onto said adjustment screw
causing increase of engagement force of said external tapered
surfaces of said adjustment screw and said lock nut with said first
and second outwardly flaring passage end surfaces.
3. The adjustable mechanical sighting mechanism of claim 1,
comprising: tightening of said lock nut onto said adjustment screw
causing application of tensile forces to said adjustment screw.
4. The adjustable mechanical sighting mechanism of claim 1,
comprising: said sight blade mount defining an elongate slot having
communication with said internal passage; a support member being
defined by said sight blade structure and being movable within said
elongate slot; and an adjustment member being supported within said
internal passage by said support member and being moved to selected
positions within said internal passage by said adjustment
screw.
5. The adjustable mechanical sighting mechanism of claim 4,
comprising: said elongate slot defining spaced elongate nose
sections on said sight blade mount; and said adjustment member
defining an internally threaded screw passage receiving said
adjustment screw therein and being moved within said internal
passage upon rotational movement of said adjustment screw.
6. The adjustable mechanical sighting mechanism of claim 5,
comprising: forcible reaction of said tapered surfaces of said
adjustment screw and lock nut with said first and second outwardly
flaring passage end surfaces upon tightening rotation of said lock
nut causing friction induced locking of said sight blade member
against inadvertent movement thereof from any adjusted position
relative to said sight blade mount.
7. The adjustable mechanical sighting mechanism of claim 5,
comprising: said spaced elongate nose sections being flexible; and
said forcible reaction of said tapered surfaces of said adjustment
screw and lock nut with said first and second outwardly flaring
passage end surfaces causing flexing of said spaced elongate nose
sections and subjecting said adjustment screw to tensile
forces.
8. The adjustable mechanical sighting mechanism of claim 5,
comprising: a sight mount base having a dove-tail mount projection
for mounting engagement within a dove-tail mounting slot of a
firearm; said sight blade mount being pivotally mounted to said
sight mount base; and at least one spring member being interposed
between said sight mount base and said sight blade mount and urging
said sight blade mount in one pivotal direction; and a retainer and
elevation adjustment screw securing said sight blade mount and
being rotatably adjusted for overcoming the force of said spring
member and establishing a selective adjusted elevation position of
said sight blade mount and said sight blade member.
9. An adjustable mechanical sighting mechanism for firearms,
comprising: a sight blade mount defining an internal passage and
defining an elongate slot in communication with said internal
passage, said sight blade mount defining locking surfaces; a sight
blade member defining a sighting slot and having a support moveable
within said elongate slot and having an adjustment member movable
within said internal passage by said support and defining an
internally threaded adjustment screw passage; an adjustment screw
having an external tapered surface disposed in engagement with said
first outwardly flaring passage end surface and being threaded
within said internally threaded adjustment screw passage, selective
rotation of said adjustment screw moving said adjustment member
within said internal passage, moving said support within said
elongate slot and moving said sight blade member with respect to
said sight blade mount; a lock nut being threaded to said
adjustment screw; and said adjustment screw and said lock nut being
disposed for locking engagement with said locking surfaces upon
tightening of said lock nut on said adjustment screw.
10. The adjustable mechanical sighting mechanism of claim 9,
comprising: said internal passage being defined in part by first
and second outwardly flaring passage end surfaces; said adjustment
screw defining a tapered external surface disposed for engagement
with said first outwardly flaring passage end surface; said lock
nut defining a tapered external surface disposed for, engagement
with said second outwardly flaring passage end surface; and
tightening of said lock nut on said adjustment screw developing
forcible engagement of said tapered external surfaces of said
adjustment screw and said lock nut with said first and second
outwardly flaring passage end surfaces and locking said sight blade
member against inadvertent movement.
11. The adjustable mechanical sighting mechanism of claim 9,
comprising: said spaced elongate nose sections being flexible; and
forcible reaction of said tapered surfaces of said adjustment screw
and lock nut with said first and second outwardly flaring passage
end surfaces responsive to tightening of said lock nut causing
flexing of said spaced elongate nose sections and subjecting
said-adjustment screw to tensile forces.
12. The adjustable mechanical sighting mechanism of claim 8,
comprising: said tapered external surfaces of said adjustment screw
and lock nut having different angles of taper as compared with the
angles of taper of said first and second outwardly flaring passage
end surfaces resulting in contact of outer edges of said tapered
external surfaces of said adjustment screw and lock nut with said
first and second outwardly flaring passage end surfaces providing
metal to metal engagement therebetween at said outer edges.
13. The adjustable mechanical sighting mechanism of claim 8,
comprising: a sight mount base having a dove-tail mount projection
for mounting engagement within a dove-tail mounting slot of a
firearm; said sight blade mount being pivotally mounted to said
sight mount base; and at least one spring member being interposed
between said sight mount base and said sight blade mount and urging
said sight blade mount in one pivotal direction; and a retainer and
elevation adjustment screw securing said sight blade mount and
being rotatably adjusted for overcoming the force of said spring
member and establishing a selective adjusted elevation position of
said sight blade mount and said sight blade member.
Description
BACKGROUND OF THE INVENTION
[0001] Field of the Invention
[0002] The present invention relates generally to sighting
mechanisms for firearms and more particularly concerns an
adjustable mechanical sighting mechanism for handguns and other
firearms. Even more particularly the present invention concerns a
mechanical sighting mechanism having a sighting blade member that
is adjustable for elevation and windage to control the strike point
of a bullet fired by the firearm and is provided with a novel
adjustment and locking mechanism to ensure against inadvertent
movement of the sight blade member even when the firearm is
subjected to the impacts and jarring of prolonged firing, such as
during a shooting match or during tactical shooting and firearm
handling activities.
[0003] Description of the Prior Art
[0004] Though it is to be understood that the mechanical sighting
mechanism of the present invention is applicable for use with a
number of different types of firearms, for purposes of simplicity,
to facilitate a ready understanding of the spirit and scope of the
present invention. However, for purposes of simplicity the
mechanical sighting mechanism is discussed particularly as to its
application for handguns, particularly the 1911 A1 semi-automatic
pistol and handguns of similar nature and any handgun having a rear
sight mechanism that is adjustable for elevation and windage.
[0005] An adjustable pistol sight mechanism has been manufactured
and sold for many years by BoMar. The BoMar rear sight mechanism
has both elevation and windage adjustment capability which have the
conventional form of adjustment screws. The rear blade of the sight
mechanism is positioned by the adjustment screws, but cannot be
locked against inadvertent movement. The heads of the adjustment
screws have circular edges defining closely spaced notches that are
engaged by pin members to provide for incremental adjustment of the
position, elevation and windage, of the sighting mechanism.
SUMMARY OF THE INVENTION
[0006] It is a principal feature of the present invention to
provide a novel adjustable mechanical rear sight mechanism for
handguns and other firearms having the capability for being
selectively adjusted for windage and elevation;
[0007] It is another feature of the present invention to provide a
novel adjustable mechanical sighting mechanism having a laterally
moveable sight blade adjustment and locking mechanism that has the
capability for being moved to any selected position of windage
adjustment and locked against inadvertent movement, such as by
vibration, shock forces or impacts;
[0008] Briefly, the various objects and features of the present
invention are realized through the provision of an adjustable
mechanical rear sight mechanism having a sight mount base defining
a dive-tail projection enabling the base to be mounted to a
corresponding dove-tail slot of the firearm. In the case of a 1911
A1 type of firearm, the dove-tail slot is defined in the
reciprocating slide member.
[0009] A pivotally moveable top plate member is mounted to the
sight mount base by a hinge pin and defines a sight blade mount
having a laterally oriented internal passage that is defined in
part by oppositely tapered outwardly flared internal surfaces. The
sight blade mount defines an elongate slot that receives a central
support structure of a sight blade member and defines a tubular
receptacle within which is received a tubular internally threaded
sight adjustment member that is an integral component of the
one-piece sight blade member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] So that the manner in which the above recited features,
advantages and objects of the present invention are attained and
can be understood in detail, a more particular description of the
invention, briefly summarized above, may be had by reference to the
preferred embodiment thereof which is illustrated in the appended
drawings, which drawings are incorporated as a part hereof.
[0011] It is to be noted however, that the appended drawings
illustrate only a typical embodiment of this invention and are
therefore not to be considered limiting of its scope, for the
invention may admit to other equally effective embodiments.
[0012] In the Drawings:
[0013] FIG. 1 is an isometric illustration of a firearm sighting
mechanism that is constructed according to the principles of the
present invention and represents the preferred embodiment;
[0014] FIG. 2 is a side elevational view of the firearm sighting
mechanism of FIG. 1;
[0015] FIG. 3 is a plan view of the firearm sighting mechanism of
FIGS. 1 and 2;
[0016] FIG. 4 is a sectional view taken along the line 4-4 of FIG.
2;
[0017] FIG. 5 is an exploded isometric illustration showing the
various components of the firearm sighting mechanism of FIGS.
1-4;
[0018] FIG. 5a is a fragmentary sectional view of the mounting base
and pivotally movable top plate of the sighting mechanism; and
[0019] FIG. 5b is a side elevational view of the front sight blade
member showing the tubular internally threaded sight adjustment
member thereof.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
[0020] Referring now to the drawings and first to FIG. 1, an
adjustable sighting mechanism constructed according to the
principles of the present invention is shown generally at 10. The
adjustable sighting mechanism 10 incorporates a sight mounting base
12 having a depending dove-tail projection 14 defining undercut
angulated dove-tail surfaces 16 and 18. The dove-tail projection 14
is adapted to be received within a sight mounting slot of a firearm
component having a corresponding dove-tail configuration (not
shown). As an example, the reciprocating slide of the well known
1911-A1 handgun defines a dove-tail sight mounting slot within
which the dove-tail mounting projection of a mechanical sighting
device is received in tight fitting relation. Sight mounting crews
extend through the reciprocating slide structure and are threaded
into the dove-tail mounting projection to secure the sight base in
immovable relation with respect to the reciprocating firearm slide.
Though the adjustable firearm sighting mechanism of the present
invention is particularly adapted for use as a handgun sighting
device, it is to be understood that it is well adapted for use on
shoulder fired arms, such as rifles, shotguns, machine guns and the
like without departing from the spirit and scope of the present
invention.
[0021] The upper portion of the sight mounting base 12 is machined
or otherwise formed to define a pair of spaced, upwardly projecting
elongate parallel bosses 20 and 22 with a slot 24 defined
therebetween. The slot 24 is defined by spaced parallel edge
surfaces 26 and 28 of the pair of spaced, upwardly projecting
elongate parallel bosses 20 and 22. The slot 24 between the bosses
20 and 22 is defined in part by a relatively thin bottom wall 30
which is an integral part of the sight mounting base 12. Internally
threaded set screw holes 32 and 34 extend through the sight
mounting base 12 at the elongate parallel bosses 20 and 22 and
receive set screws 36 and 38 which engage an internal surface of
the dove-tail slot of the firearm to secure the mounting base
immovably within the dove-tail slot.
[0022] A pivotally moveable top plate member 40 is pivotally
mounted to the sight mounting base 12 and provides the sighting
mechanism with the capability for elevation adjustment. At its rear
end portion the top plate member 40 defines a hinge pin bore 42
within which the central portion of a hinge pin 44 is movably
received. The elongate parallel bosses 20 and 22 define aligned
hinge pin bores 46 and 48 within which are received respective end
portions of the hinge pin 44. One of the hinge pin openings 46 or
48 may be internally threaded and thus adapted to receive an
externally threaded portion 50 of the hinge pin. Alternatively, the
hinge pin may be frictionally retained within one or both of the
hinge pin openings 46 or 48 or may be secured in immovable relation
with the mounting base in any other suitable manner.
[0023] It is desirable to provide the moveable top plate member 40
with resistance to upwardly directed pivotal movement and to
provide the moveable top plate member 40 with a force tending to
move it pivotally upwardly and to prevent it from inadvertently
moving downwardly. This feature is accomplished by providing the
bottom wall 30 of the mounting base with an upwardly facing spring
recess 52 within which is received the lower end of one or more
compression springs 54. The upper end of the compression spring or
springs is received within a corresponding downwardly facing spring
recess 56 of the pivotally moveable top plate member 40. The
compression spring or springs 54 continuously urge the top plate 40
pivotally upwardly about the hinge pin 44, tending to raise the
sighting mechanism for elevation. The force of the compression
spring or springs 54 is overcome by the downwardly directed force
of an elevation adjustment member 58, such as an adjustment screw,
that is moveable within an adjustment member receptacle 60 of the
top plate 40 and is rotatably adjustable to permit controlled
upward and downward movement of the top plate.
[0024] The top plate member 40 is provided with a front sight blade
62 having spaced upwardly extending projections 64 and 66 defining
a sighting slot 68 therebetween. The front sight blade defines a
generally planar surface 67 facing the eye of the user of the
firearm. The surface 67 is roughened by the presence of closely
spaced knurling ridges and grooves 69 or any other roughened or
non-reflective surface to minimize the potential for any light or
image reflection being directed to the eye of the user. Also, when
the sighting mechanism is in assembly with the dove-tail mounting
slot of a firearm, the planar surface 67 will typically be disposed
slightly inclined from the vertical, with its spaced upwardly
extending projections 64 and 66 slightly closer to the user as
compared with the position of the lower edge portion of the planar
surface. This feature also minimizes the potential for the
reflection of light toward the eye of the user. If desired,
however, the planar surface 67 may be vertically oriented or
oriented with its upper portion further away from the user than its
lower edge portion. Side edge portions of the spaced upwardly
extending projections 64 and 66 are cut away, so as to define
concavely curved or inclined side edge surfaces 71 and 73 to
minimize the potential for the sight blade catching on clothing or
adjacent objects as the firearm is handled.
[0025] It is appropriate to mount the front sight blade so that it
is movable upwardly and downwardly along with the pivotally
moveable top plate member 40 for sighting elevation and is moveable
laterally for windage adjustment. It is also desirable to provide
the facility for positively locking or securing the front sight
blade at any desired laterally adjusted position so that the front
sight blade will remain in position even during the impact and
vibration forces that occur as the firearm is subjected to repeated
and prolonged firing activities. This feature is accomplished by
providing at the forward end of the pivotally moveable top plate
member 40 a laterally extending sight blade mount 70 having a width
that may essentially correspond with the width of the sight
mounting base 12 as defined by the exterior surfaces 72 and 74
thereof. The laterally extending sight blade mount 70 is machined
to define a laterally oriented passage 76 having oppositely tapered
outwardly flaring passage end surfaces 78 and 80 and has spaced
elongate nose surfaces 82 and 84 having elongate rounded nose edges
86 and 88 and defining an elongate slot 90.
[0026] The front sight blade member 62, shown in the exploded
isometric illustration of FIG. 5 and also shown in the side
elevational view of FIG. 5b and other FIGS., defines a nose
receiving profile having a central support structure 92 and concave
curved surfaces 94 and 96 corresponding to the configurations of
the spaced elongate nose surfaces 82 and 84. From the front sight
blade member 62 extends a tubular sight adjustment member 98 which
is fixed to the central support structure 92 and has a length less
than the width of the front sight blade structure. The tubular
sight adjustment member 98 defines an internally threaded section
100 having threaded engagement with an externally threaded section
of an adjustment and lock screw 102 having a tapered screw head 104
and having a threaded screw shaft 103.
[0027] The tapered screw head 104 defines a frusto-conical external
surface 106 having a greater angle of taper as compared with the
tapered internal outwardly flaring surface 78 so that contact
between the tapered surfaces 78 and 106 occurs at the outward
extent of the tapered internal surface 78 as is evident from FIG.
4. The outer extent of the adjustment and lock screw 102 is defined
by a circular portion of the tapered screw head 104 which defines
evenly spaced windage adjustment slots 105. Within the laterally
oriented passage 76 the laterally extending sight blade mount 70
defines an elongate longitudinal slot 107, within which is located
a small diameter windage adjustment control element 107, which is
shown in the side elevational view of FIG. 2. The small diameter
windage adjustment control element 107 is positioned to engage
within the evenly spaced windage adjustment slots 105, thus
providing the adjustment and lock screw 102 with increments of
adjustment. This feature is typically known as "clicks" of
adjustment, with each click or increment of windage adjustment to
change the strike of a bullet by a selected distance. For example,
one click of adjustment for shooting a known distance may change
the strike of the bullet one inch left or right, for example,
depending on the direction of rotation of the adjustment and lock
screw.
[0028] A lock nut 108 having an internally threaded opening 110 is
disposed in threaded assembly with an end 112 of the threaded shaft
of the lock screw 102. The lock nut 98 defines an externally
tapered or frusto-conical surface 114 having a greater angle of
taper as compared with the angle of taper of the tapered outwardly
flaring passage end surface 80. As the lock nut 108 is threaded
onto the shaft of the adjustment and lock screw 102, such as by
means of a blade type screw-driver engaging with a blade slot 116
of the lock screw, contact between the tapered surfaces 80 and 114
will occur at the outer extent of the tapered frusto-conical
surface 114. This feature minimizes any potential for incursion of
dirt, excess oil, water or any other debris into the laterally
oriented passage 76 of the laterally extending sight blade mount
70. Rotation of the adjustment and lock screw 102 is achieved by
means of a simple Allen wrench that engages within a wrench drive
receptacle 118 of the screw head 104.
[0029] As mentioned above, the laterally extending sight blade
mount 70 defines an elongate slot 90. This feature provides the
essentially tubular blade mount structure with a degree of
flexibility though it is of rather rigid construction. As the
tapered surfaces 106 and 114 are drawn toward one another by
rotating and tightening of the lock nut 108 on the shaft of the
adjustment and locking screw these tapered surfaces will have
forcible reaction with the internally tapered outwardly flaring
passage end surfaces 78 and 80 within the lateral passage 76 of the
laterally extending sight blade mount 70. This forcible activity
enhances the frictional resistance between the respective tapered
surfaces, thus minimizing the potential for rotational movement of
either the adjustment screw or the lock nut from an adjusted
position. The forcible activity also tends to flex and expand the
spacing of the elongate nose surfaces 82 and 84, enhancing the
resistance of the adjustment screw and lock nut from inadvertent
rotation even when the sighing mechanism is subjected to the
repeated impacts and jarring of prolonged rapid fire of the
firearm. Also, forcing the tapered surfaces of the adjustment screw
and lock nut against the respective internal tapered surfaces 78
and 80 causes the adjustment screw 102 to be subjected to tension
so that the threads of the adjustment screw and lock nut will be
maintained in positive engagement even during component expansion
or contraction due to significant temperature changes, ensuring
against any undesired movement of the adjustment mechanism within
the laterally extending sight blade mount 70.
[0030] The sight mounting base 12 is installed to the dove-tail
slot or receptacle of the firearm by inserting the depending
dove-tail projection 14 into the dove-tail slot and extending an
Allen wrench through the internally threaded set screw holes 32 and
34 of the sight mounting base 12 and actuating set screws to apply
downward set screw force to the bottom surface of the dove-tail
slot, thus driving the inclined surfaces 16 and 18 of the dove-tail
projection 14 upwardly for retaining frictional engagement to
maintain the mount 12 against movement relative to the firearm.
When the sight mounting base 12 is installed, the pivotally
moveable top plate member 40 may be mounted to the sight mounting
base by the hinge pin 44 or may be mounted to the sight mounting
base at a later time. At the time the top plate member is mounted,
the compression spring or springs 54 will be positioned with the
ends there disposed within the respective spring recesses 52 and
56. The top plate member will then be manipulated so that the top
plate member will pivot into the slot 24 of the sight mounting base
12 and the elevation adjustment screw member 58 will be rotated
sufficiently to engage within a screw hole of the reciprocating
slide or other component of the firearm and retain the top plate
member against free rotation about the hinge pin 44.
[0031] When the top plate member 40 is installed the front sight
blade member 62 may already be in place, with the central support
structure 92 disposed within the elongate slot 90 of the laterally
extending sight blade mount 70 and the tubular internally threaded
sight adjustment member 98 located within the laterally oriented
passage 76. For its installation, the front sight blade member 62
is moved laterally for insertion of the central support structure
92 into the elongate slot 90, thus positioning the tubular
internally threaded sight adjustment member 98 within the tubular
or cylindrical receptacle section that is defined by the laterally
oriented passage 76. The adjustment and lock screw 102 is threaded
into the internally threaded section 100 of the tubular internally
threaded sight adjustment member 98. Rotation of the adjustment and
lock screw 102 causes lateral movement of the sight blade structure
relative to the laterally extending sight blade mount 70. This
relative movement is accomplished by rotation of the threaded
section of the adjustment and lock screw 102 within the internally
threaded section 100 of the tubular internally threaded sight
adjustment member 98. Axial movement of the adjustment and lock
screw 102 is limited by engagement of the frusto-conical external
surface 106 with the tapered outwardly flaring passage end surface
78. At this point the lock nut 108 is threaded onto the threaded
end of the adjustment and lock screw 102 and is tightened onto the
screw by rotating the lock nut with a blade type screw driver.
Simultaneously, the adjustment and lock screw 102 is prevented from
rotation or intentionally rotated by rotating the screw 102 with a
simple Allen wrench which engages within the wrench drive
receptacle 118. By controllably rotating the adjustment and lock
screw 102 and the lock nut 108 the sight blade member 62 is moved
laterally to its desired position relative to the laterally
extending sight blade mount 70 and is locked in place by tightening
the lock nut on the screw 102.
[0032] Though the laterally extending sight blade mount 70 is
rather rigidly constructed to ensure the durability and operative
character of the adjustable sighing mechanism, the presence of the
elongate slot 90 through which the central support structure 92 is
movable provides the sight blade mount 70 with a degree of
flexibility. When the lock nut is tightened onto the adjustment and
lock screw 102 the surfaces 106 and 114 will react with the tapered
outwardly flaring passage end surfaces 78 and 80, thus subjecting
the spaced elongate nose surfaces 82 and 84 to expansion forces.
These forces also cause the outer extremities of the differently
tapered surfaces 106 and 114 to establish tight engagement at the
outer portions of the tapered outwardly flaring passage end
surfaces 78 and 80, providing metal to metal seals that minimizes
the potential for dust, oil, water and other debris entering the
laterally oriented passage 76. The metal to metal seals further
enhance the retention of lubricating oil within the passage 76 and
on the mechanical components that are present within the passage.
This sealing feature ensures the resistance of the mechanical
sighting mechanism to unusual wear or damage even when the firearm
is utilized in rather hazardous conditions.
[0033] Since firearms are often subjected to wide temperature
fluctuation during use, it is possible that the mechanical
components of a sight mechanism can change to the point that
expansion or contraction of sight components can result in
inadvertent movement of the sight mechanism, resulting in
conditions of firearm inaccuracy. The forces of tightening the lock
nut 108 on the threaded shaft of the adjustment and lock screw 102
subject the screw 102 to tensile forces, tending to stretch and
elongate the screw. With the screw maintained under tension,
expansion or contraction of sight components by changes in
temperature will simply result in changes in the amount of tensile
forces on the screw 102 and will not cause other components to be
tightened or loosened to the extent that the sighting mechanism
might lose its condition of precision aiming.
[0034] In view of the foregoing it is evident that the present
invention is one well adapted to attain all of the objects and
features hereinabove set forth, together with other objects and
features which are inherent in the apparatus disclosed herein.
[0035] As will be readily apparent to those skilled in the art, the
present invention may easily be produced in other specific forms
without departing from its spirit or essential characteristics. The
present embodiment is, therefore, to be considered as merely
illustrative and not restrictive, the scope of the invention being
indicated by the claims rather than the foregoing description, and
all changes which come within the meaning and range of equivalence
of the claims are therefore intended to be embraced therein.
* * * * *