U.S. patent application number 13/451203 was filed with the patent office on 2012-11-29 for pendulum crosshair for weapon sight.
Invention is credited to Carl L. Lattimer.
Application Number | 20120297659 13/451203 |
Document ID | / |
Family ID | 47218234 |
Filed Date | 2012-11-29 |
United States Patent
Application |
20120297659 |
Kind Code |
A1 |
Lattimer; Carl L. |
November 29, 2012 |
PENDULUM CROSSHAIR FOR WEAPON SIGHT
Abstract
The pendulum crosshair for a weapon sight incorporates a thin,
rigid wire pivotally suspended at its upper end to a point at or
immediately above the peripheral end point of the fixed vertical
crosshair in the reticle of a weapon sight. If the weapon, and thus
the sight, is tilted or canted from the vertical when aiming, the
pendulum crosshair will misalign with the fixed vertical crosshair
in the sight to indicate to the shooter that the weapon is canted.
This allows the shooter to correct the cant or tilt of the weapon
to avoid the lateral displacement of the shot that would otherwise
occur due to lateral displacement of the elevation correction for
the sight line.
Inventors: |
Lattimer; Carl L.;
(Boonsboro, MD) |
Family ID: |
47218234 |
Appl. No.: |
13/451203 |
Filed: |
April 19, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61489905 |
May 25, 2011 |
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Current U.S.
Class: |
42/122 ; 124/87;
42/130 |
Current CPC
Class: |
F41G 1/38 20130101 |
Class at
Publication: |
42/122 ; 42/130;
124/87 |
International
Class: |
F41G 1/38 20060101
F41G001/38; F41G 1/00 20060101 F41G001/00 |
Claims
1. A pendulum crosshair for a weapon sight, comprising: a sight
reticle support defining a periphery; a fixed vertical crosshair
disposed diametrically across the sight reticle support, the fixed
vertical crosshair having an upper end adjacent the periphery of
the sight reticle support; a pendulum crosshair mount disposed at
the periphery of the sight reticle support adjacent the upper end
of the fixed vertical crosshair; and a movable crosshair pivotally
suspended from the crosshair mount.
2. The pendulum crosshair for a weapon sight according to claim 1,
further comprising a weapon sight, the sight reticle support being
mounted in the weapon sight.
3. The pendulum crosshair for a weapon sight according to claim 2,
wherein the weapon sight is a firearm telescopic sight.
4. The pendulum crosshair for a weapon sight according to claim 2,
wherein the weapon sight is an archery bowsight.
5. The pendulum crosshair for a weapon sight according to claim 1,
wherein the sight reticle support has a vertical span, the movable
crosshair having a length substantially one-half the vertical span
of the sight reticle support.
6. The pendulum crosshair for a weapon sight according to claim 1,
wherein the pendulum crosshair attachment is a pin, the pendulum
crosshair being suspended from the pin, the pendulum crosshair
further comprising a spacer disposed on the pin between the
pendulum crosshair and the periphery of the sight reticle
support.
7. The pendulum crosshair for a weapon sight according to claim 1,
wherein the pendulum crosshair is a thin metal wire.
8. A sight, comprising a weapon sight having a pendulum crosshair
assembly, the assembly having: a sight reticle support mounted in
the weapon sight, the sight reticle support defining a periphery; a
fixed vertical crosshair disposed diametrically across the sight
reticle support, the fixed vertical crosshair having an upper end
adjacent the periphery of the sight reticle support; a pendulum
crosshair pivot disposed adjacent the upper end of the fixed
vertical crosshair and axially aligned therewith; and a movable
crosshair pivotally suspended from the crosshair pivot.
9. The sight according to claim 8, wherein the weapon sight is a
firearm telescopic sight.
10. The sight according to claim 8, wherein the weapon sight is an
archery bowsight.
11. The sight according to claim 8, wherein the sight reticle
support has a vertical span, the movable crosshair having a length
substantially one half the vertical span of the sight reticle
support.
12. The sight according to claim 8, wherein the pendulum crosshair
attachment is a pin, the pendulum crosshair being suspended from
the pin, the sight further comprising a spacer disposed on the pin
between the pendulum crosshair and the periphery of the sight
reticle support.
13. The sight according to claim 8, wherein the pendulum crosshair
is a thin metal wire.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application Ser. No. 61/489,905, filed May 25, 2011.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to sighting devices
for firearms and archery bows, and particularly to a pendulum
crosshair for a weapon sight to alert the marksman of an out of
plumb orientation of the weapon.
[0004] 2. Description of the Related Art
[0005] Virtually all weapons intended for serious hunting and/or
target use include sights that are adjustable for elevation, i.e.,
to compensate for the drop or fall of the projectile (bullet,
arrow, etc.) between the time it is fired and the time it reaches
the target. As an example of the above, a bullet or round traveling
at an average velocity of 2,000 feet per second to a target that is
2,000 feet away from the shooter will be accelerated downward by
the force of gravity at a rate of about 32 feet per second per
second, for a drop or fall of about sixteen feet over the 2,000
foot distance. Of course, arrows travel at a considerably slower
speed and over shorter distances, but the principle remains the
same. Accordingly, weapon sights universally have some means to
compensate for this factor by angling the sight slightly downward
so that the weapon is aimed slightly high when the sight is
precisely on the target. Ideally, the line of sight of the scope or
other sights and the parabolic arc traveled by the projectile will
meet at the range of the target, or very close to that range. At
relatively longer ranges, the bullet will actually tend to rise
somewhat above the line of sight of the scope before dropping back
below the sight line as its energy is expended.
[0006] A problem with the above is that such an elevation
correction will only be absolutely accurate when the weapon is
aligned vertically relative to gravity, i.e., the weapon is held in
a plumb orientation. If the weapon is canted or tilted relative to
the vertical, the elevation correction will be canted from the
vertical accordingly. The lateral error induced will depend upon
the angle of the cant of the weapon, as well as the angle subtended
between the sight line and the alignment of the projectile when it
is fired from the weapon (i.e., the bore of the firearm or the
alignment of the arrow when released) and, of course, the distance
to the target. All other things being equal, the greater the cant
or tilt angle of the weapon from the vertical, the greater will be
the resulting lateral error between the sight line to the target
and the impact point of the projectile at the target distance.
[0007] Thus a pendulum crosshair for a weapon sight solving the
aforementioned problems is desired.
SUMMARY OF THE INVENTION
[0008] The pendulum crosshair for a weapon sight comprises a sight
reticle having a pivotally movable crosshair therein, formed of a
thin, rigid wire or the like. The pivoting crosshair is suspended
at its upper end at or immediately above the peripheral end point
for the upper end of the fixed vertical crosshair in the reticle,
the pivoting crosshair being free to pivot about its attachment
point. The movable pivoting crosshair acts as a pendulum, always
hanging vertically within the reticle, regardless of the lateral
tilt or cant of the reticle. The shooter need only orient the
weapon so that the pivotally attached crosshair is directly aligned
with the fixed vertical crosshair of the sight reticle to assure
that the weapon is being held vertically or plumb with no lateral
tilt or cant. This assures the shooter that the elevation
correction is entirely in the vertical plane, and will not throw
off the aim laterally due to an undesired lateral component as a
result of the cant or tilt of the weapon. The device may be applied
at the focal plane of a telescopic sight for a firearm, e.g., a
rifle, or may be applied to the sighting mechanism of an archery
bow sight or other weapon sighting system.
[0009] These and other features of the present invention will
become readily apparent upon further review of the following
specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1A is a diagrammatic view of a rifle with telescopic
sight having a pendulum crosshair and sight reticle, shown enlarged
separately, showing the general path of a bullet fired from the
rifle when the rifle is canted, i.e., not plumb.
[0011] FIG. 1B is a diagrammatic view of a rifle with telescopic
sight having a pendulum crosshair and sight reticle, shown enlarged
separately, showing the general path of a bullet fired from the
rifle when the rifle is plumb.
[0012] FIG. 2 is an exploded environmental perspective view of a
firearm scope and reticle incorporating a pendulum crosshair for a
weapon sight according to the present invention, showing
installation of the crosshair in the second or rear focal plane of
the scope, the scope being shown in broken lines.
[0013] FIG. 3 is an exploded detailed rear perspective view of a
pendulum crosshair for a weapon sight according to the present
invention, showing installation of the pendulum crosshair in the
reticle.
[0014] FIG. 4A is a rear elevation view of an archery how sight
having a pendulum crosshair for a weapon sight according to the
present invention, showing the alignment of the crosshair with the
vertical crosshair of the reticle to indicate that the weapon is
plumb.
[0015] FIG. 4B is a rear elevation view of the archery bow sight of
FIG. 4A, showing misalignment of the crosshair with the vertical
crosshair of the reticle to indicate that the weapon is not
plumb.
[0016] Similar reference characters denote corresponding features
consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The pendulum crosshair for a weapon sight provides the
shooter with information regarding the vertical alignment of his or
her weapon, thereby allowing the shooter to maintain true vertical
alignment of the weapon and corresponding elevation adjustment
between the sight system and the initial projectile path as defined
by the firearm bore or arrow release. This is desirable in order to
prevent the introduction of a lateral component to the plane
defined by the sight line of the weapon sights and the parabolic
path of the projectile after it has been fired. If the weapon is
tilted or canted from the vertical, i.e., out of plumb, the
resulting lateral offset of the sight line and projectile path will
result in lateral displacement of the impact point of the
projectile on the target, even when the sight line is aligned
precisely with the center of the target. The pendulum crosshair is
adaptable to any practicable weapon sight, including telescopic
sights for firearms (rifles, etc.) and archery bow sights.
[0018] FIGS. 1A and 1B illustrate the vertical or plumb alignment
of a firearm F1 and the vertically tilted or out of plumb alignment
of a firearm F2, respectively. In the case of FIG. 1A the firearm
F1 is plumb or vertically oriented, as noted. This places the plane
defined by the sight line L1 of the sight S1 (e.g., telescopic
sight, as shown in FIGS. 1A and 1B) and the vertical parabolic path
P1 of the bullet or projectile in flight in the vertical, i.e.,
with no lateral offset. Thus, the flight path of the bullet or
projectile remains coplanar with the plane of the sight line L1 and
the projectile path P1, so that the projectile strikes the target
T1 in vertical alignment with the point of intersection of the
sight line L1 with the target T1. If the elevation correction has
been set properly and all other factors (e.g., windage, etc.)
properly accounted for, the projectile will strike the target T1 at
precisely the point of intersection of the sight line L1 with the
target T1 with no lateral or vertical error. The vertical alignment
of the firearm F1 is clearly indicated by the weapon sight 10,
which has a pendulum crosshair 12 aligned vertically with the
vertical crosshair 14 of the reticle of the sight 10.
[0019] FIG. 1B provides an illustration of the error introduced
when the firearm is tilted out of the vertical, or out of plumb. In
FIG. 1B, the firearm F2 is tilted to the right, out of plumb with
the vertical. The sight line L2 of the sight S2 is still aligned
with the aiming point of the target T2, just as in the case of FIG.
1A. However, the lateral tilt of the firearm F2 has resulted in a
corresponding lateral tilt of the plane defined by the sight line
L2 and the parabolic path of the projectile P2. This lateral tilt
results in a horizontal offset of the impact point of the
projectile with the target T2, as shown in FIG. 1B of the drawings.
The lateral tilt or out of plumb orientation of the firearm F2 is
clearly indicated by the tilted weapon sight 10 in FIG. 1B, the
vertical crosshair 14 being tilted at an angle from the vertical
corresponding to the tilt or cant of the firearm F2, the pendulum
crosshair 12 remaining in the vertical to show the angular
difference between the vertical crosshair 14 and pendulum crosshair
12.
[0020] FIG. 2 is an illustration of an exemplary installation of
the weapon sight 10 with a telescopic sight S, with the sight S
being shown in broken lines, The weapon sight 10 comprises a
periphery or frame 16 surrounding a sight reticle 18, the reticle
18 including the fixed vertical crosshair 14 described further
above and a fixed horizontal crosshair 20, which may be etched onto
a lens, or onto a thin, transparent plastic disc, or onto any other
crosshair support (a sight reticle support) known in the art, or
which may be formed by fibers embedded into a lens, plastic disk,
or other sight reticle support, or which may be formed on a sight
reticle support in any other manner known in the art. The two fixed
crosshairs 14 and 20 extend diametrically across the reticle 18 and
periphery 16. Each crosshair 14 and 20 has opposite ends
terminating at the periphery 16 of the sight 10, e.g., the upper
end 22 of the vertical crosshair 14 terminating at the uppermost
point of the periphery 16 of the sight 10. The movable pendulum
crosshair 12 is aligned with the fixed vertical crosshair 14 of the
weapon sight 10 shown in FIG. 2, and is thus not visible
separately. The weapon sight 10 may be installed at the rearward or
second focal plane of the telescopic sight S by removing the
eyepiece E of the sight and reinstalling the eyepiece E when the
sight 10 has been installed, generally as shown in FIG. 2.
Alternatively, the weapon sight 10 may be installed farther forward
in the telescopic sight S in the forward or first focal plane (not
shown), if desired.
[0021] FIG. 3 of the drawings provides a detailed exploded
perspective view of the weapon sight 10, illustrating the
installation of the pendulum crosshair 12 therewith. A small pin
passage 24 is formed at the top of the frame or periphery 16 of the
sight, adjacent the upper end 22 of the fixed vertical crosshair 14
and in vertical and axial alignment therewith. The pendulum
crosshair 12 has a small eye 26 at its upper end. A pendulum
crosshair attachment pin 28 is installed through the eye 26 of the
pendulum crosshair 12, the pin having a head with a diameter larger
than the diameter of the eye 26. A small spacer or washer 30 is
placed over the shaft of the pin 28 after the shaft of the pin is
passed through the eye 26 of the pendulum crosshair 12, before
installing the pin 28 in the passage 24 of the sight periphery
16.
[0022] The movable pendulum crosshair 12 is of very lightweight,
preferably being formed of a very thin strand of metal wire or
other suitable material. The pendulum crosshair 12 preferably has a
length 32 of only about half the vertical span of the sight reticle
18 as subtended by the fixed vertical crosshair 14, i.e., the
pendulum crosshair 12 extends from its attachment pin 28 only to
the center of the reticle 18, as defined by the intersection of the
fixed vertical and horizontal crosshairs 14 and 20 and as shown in
FIG. 1B of the drawings. The spacer or washer 30 precludes binding
of the movable pendulum crosshair 12 on the periphery or frame 16
and/or the reticle 18 of the sight 10, thus permitting smooth
arcuate motion of the pivotally suspended, lightweight pendulum
crosshair 12 as the sight 10 is tilted or canted laterally.
[0023] FIGS. 4A and 4B of the drawings show the incorporation of a
weapon sight having a pendulum crosshair, the sight being
vertically oriented in FIG. 4A, and having a cant or tilt in FIG.
4B. FIGS. 4A and 4B are thus somewhat analogous to FIGS. 1A and 1B,
but the weapon sight of FIGS. 4A and 4B is adapted for use with an
archery bow rather than a firearm. Accordingly, the archery sight
of FIGS. 4A and 4B is designated as weapon sight 110, and extends
from an archery bow attachment bracket B1 (FIG. 4A) and B2 (FIG.
4B). The only difference between the brackets B1 and B2 is their
orientation relative to the vertical.
[0024] The two archery bow sights 110 of FIGS. 4A and 4B are
configured identically to the weapon sights 10 of FIGS. 1A through
3, with the exception of their attachment means. Each of the
archery bow sights 110 has a pivotally moving pendulum crosshair 12
aligned with the fixed vertical crosshair 14 of the sight 110 when
the sight is oriented vertically, the pendulum crosshair 12 being
pivotally attached to the upper center of the peripheral frame 16
of the sight, substantially as shown in FIG. 3 for the sight 10 and
described further above. A fixed horizontal crosshair 20 extends
diametrically across the periphery 16, the vertical and horizontal
crosshairs 14 and 20 forming the sight reticle 18.
[0025] In the case of FIG. 4A the archery bow is plumb or
vertically oriented, as evidenced by the orientation of its sight
mounting bracket B1. This places the plane of the arrow or
projectile path and the elevation sight line in the vertical, or
parallel to the sight plane referenced by the vertical crosshair 14
of the sight 110, with no lateral offset. Thus, the flight path of
the arrow or projectile remains coplanar with the plane of the
sight line and the arcuate projectile path, similar in principle to
the scenario described further above, as shown with the firearm in
FIG. 1A.
[0026] FIG. 4B provides an illustration of the error introduced
when the archery bow is tilted out of the vertical, or out of
plumb. In FIG. 4B, the archery bow is tilted or canted to the left,
out of plumb with the vertical, as evidenced by the orientation of
the sight mounting bracket B2. The lateral tilt or out-of-plumb
orientation of the archery bow and its sight bracket B2 is clearly
indicated by the tilted weapon sight 110 in FIG. 4B, the vertical
crosshair 14 being tilted at an angle from the vertical
corresponding to the tilt or cant of the bow and sight bracket B2,
and the pendulum crosshair 12 remaining in the vertical to show the
angular difference between the vertical crosshair 14 and pendulum
crosshair 12.
[0027] It is to be understood that the present invention is not
limited to the embodiments described above, but encompasses any and
all embodiments within the scope of the following claims.
* * * * *