Portable reticle alingment device for firearms

A device for aiding in the cross-hair alignment of the reticle of a gun-mounted telescopic sight wherein the gun includes at least one mounting boss for securing the telescopic sight. The device includes a card having a viewing surface and a contact edge and at least one reference line located on the viewing surface and also aligned "true" with the contact edge. The contact edge of the card is adapted to be positioned in an abutting relationship with the mounting boss of the gun, independent of the telescopic sight so that the reference line on the card automatically aligns with the barrel axis and so that the viewing surface of the card lies adjacent to the reticle. The relative position of the card abutted onto the mounting boss allows the sighting hairline of the reticle to be compared with the reference line and properly adjusted.

FIELD OF THE INVENTION 
This invention generally relates to alignment devices for aligning the 
reticle of a telescopic sight, and more particularly, to alignment devices 
used to true the cross-hairs of the reticle with respect to the barrel 
axis of a firearm to eliminate any "canting" of the mounted telescopic 
sight. 
BACKGROUND OF THE INVENTION 
A typical telescopic sight for use with a firearm includes a reticle having 
centrally located cross hairs, i.e., a vertical centerline and a 
horizontal centerline. For the most part, telescopic sights include 
adjustment controls enabling the operator of the firearm to make several 
main adjustments to the telescopic sight relative to the firearm. Three of 
these adjustments are an elevation adjustment of the horizontal hairline, 
i.e., movement of the horizontal hairline up or down, a lateral adjustment 
of the vertical hairline, i.e., left or right, and a rotational adjustment 
of the entire telescopic sight about the central axis of the telescopic 
sight. 
The elevation adjustment is used to compensate for the arched path a fired 
projectile (bullet) will inherently follow from the muzzle of the firearm 
to the target. Once the elevation of a sight is properly adjusted for a 
given range, the intersection of the cross-hairs of the reticle will 
indicate a theoretical point of impact of the bullet at that range, even 
though the line of fire to the target, that is the actual path of the 
bullet, will not align with the line of sight (the straight line extension 
of the central axis of the telescopic sight to the target). 
The lateral adjustment is used primarily for initial sighting, and also to 
compensate for any expected drift (left or right) by the bullet from the 
line of fire caused by cross winds between the firearm and the target. 
The process of making elevation and windage adjustments to the sight of a 
firearm is called "sighting in". Typically, both adjustments never remain 
consistent and are often difficult to adjust accurately prior to 
test-firing the firearm. 
Apart from collimating the sight with the firearm, the mounted telescopic 
sight is rotatable about its central axis to adjust the relative position 
of the cross hairs of the sight with respect to the longitudinal and 
vertical axis of the barrel of the firearm (i.e., the bore axis). The 
adjustment is made to ensure that the vertical cross hair of the sight 
coincides with the vertical axis of the firearm. This adjustment can be 
made using a padded vice or cradle and a machinist's level and a known 
vertical reference line. However, in the field, this adjustment has been 
proven to be quite difficult to execute accurately due to the lack of a 
known vertical reference line with respect to the bore axis of the barrel 
of the firearm. 
One common method used to attempt to align the vertical cross hair of the 
sight with respect to the bore axis of the firearm includes holding the 
firearm perfectly level with respect to the ground and then "sighting in" 
on a reference line, such as the edge of a building which is known 
vertical with respect to the ground. With this method, the telescopic 
sight is simply rotated until the reference line and the vertical cross 
hair align. Unfortunately, however, this method is rarely successful 
because without the previously mentioned machinist's level and padded vise 
there is no indication of when the firearm is being held truly level with 
respect to the ground. Since it is common to hold a firearm, such as a 
rifle, at a slight tilt or cant, any adjustment to the reticle will 
reflect the angle of the cant and will invariably fail to be truly aligned 
with the bore axis of the barrel of the firearm. 
The problem with aligning the vertical hairline with respect to the bore 
axis of the firearm is that there is no fixed reference line against which 
such an adjustment may be accurately and easily made. Conventional mounts 
for mounting a sight to a firearm do not restrict or otherwise provide 
"self-alignment" of the mounted sight with respect to the bore axis of the 
firearm. Any reference line located on the sight will not remain (or may 
never be) consistently aligned with respect to the bore axis of the 
firearm, and therefore may not be used to properly adjust the hairlines of 
the reticle with respect to the bore axis of the firearm. 
U.S. Pat. No. 2,336,107 issued to Litschert discloses a mounting assembly 
for a telescopic sight for firearms which includes a frame having attached 
vertical and horizontal micro-adjustment screws. These screws have knobs 
which may be turned accurately to align the mounted telescopic sight 
within the frame against the action of a spring-biased member. Each screw 
adjustment includes a reference line which is fixed with respect to the 
frame of the mount. These reference lines are intended only as 
zero-indicators for use with the calibration markings located on each 
adjustment screw knobs. These reference lines cannot be used to align the 
reticle of the telescopic sight because the bell portion of a typical 
telescopic sight would obscure the reference lines. Furthermore, since the 
entire telescopic sight is essentially floating within the frame of the 
mounting assembly and is adjustable within that frame both vertically and 
horizontally, the cross hairs of the reticle will rarely align with both 
reference marks, even if they Could be seen while viewing through the 
telescopic sight.. 
Devices are commercially available to enable the user of a firearm to 
collimate the mounted sight of the firearm for a given target range and 
windage, prior to the firing of any bullets. U.S. Pat. Nos.: 3,908,282, 
3,744,133, 3,112,567, and 4,095,347 disclose collimators for aiding in 
the proper adjustment of a telescopic sight mounted to a firearm, and 
include an alignment reticle and a weight which are together pivotally 
connected to a bore mount. During collimation, the devices of the 
above-listed prior art references are attached to the firearm within the 
bore of the barrel allowing gravity to draw the weight downward and the 
opposing alignment reticle upward, above the barrel of the firearm and 
into the line of sight. All the necessary adjustments to the sight may be 
made by visually "sighting in" the cross-hairs of the sight against the 
alignment reticle. Unfortunately, the rotation adjustment of the reticle 
of the sight may not be accurately made using the prior art devices of the 
above-listed references because the alignment reticle is aligned only with 
respect to gravity and not the bore axis of the firearm. During 
collimation, the firearm may be easily held in a canted position, in which 
case the cross-hairs of the reticle of the sight would be misaligned with 
respect to the bore axis of the firearm. This misalignment between the 
cross-hairs of the reticle and the bore-axis of the firearm may easily 
result in inaccurate firing and difficult re-adjustment of the scope after 
a test firing. 
A reticle alignment device is available from the B-Square Company of Fort 
Worth, Tex., which comprises a bent piece of clear plastic which is 
approximately rectangular in cross section and includes a horizontal 
portion which is sized to roughly fit into the receiver of bolt-action 
rifles. Once inserted within the receiver of the rifle, the horizontal 
portion of the device aligns on the bolt-way flats. A vertical portion of 
the device, which includes a reference line, projects upward from the 
receiver just in front of the eyepiece of the sight. The user may align 
the vertical cross hair of the sight with the reference line provided by 
the B-Square device. 
The B-Square alignment device may only be used with bolt-action type rifles 
having a particular arrangement of bolt-way flats and not with any other 
type of action (pump, auto, single shot, etc.). Even in those situations 
where the B-Square device may be used, it is often difficult to accurately 
align the fine cross hairs of the sight with the overlapping reference 
line of the B-Square device because the reference line interferes with the 
line of sight, being positioned exactly where the reference line should 
be. In adjusting the sight using the B-Square, the user loses sight of the 
vertical cross hair behind the interfering reference line when the cross 
hair nears the correct position but is not necessarily at the correct 
position. 
It is, therefore, an object of the present invention to provide an 
easy-to-use reticle alignment device which overcomes the problems of the 
prior art. 
Another object of the invention is to provide an easy to use device for 
quickly aligning the cross-hairs of the reticle of a firearm-mounted 
telescopic sight with respect to the bore axis of the firearm. 
A still further object of the invention to provide a reticle alignment 
device which has non-interfering unobscured reference lines for aligning 
the cross-hairs of the reticle of a firearm-mounted telescopic sight with 
respect to the bore axis of the firearm. 
A still further object of the invention is to provide a reticle alignment 
device which may be easily attached to the telescopic mounting boss of 
most types of firearms. 
SUMMARY OF THE INVENTION 
A device for aiding in the cross-hair alignment of the reticle of a 
telescopic sight mounted on a gun wherein the gun has at least one 
mounting boss for securing the telescopic sight. The device comprises a 
flat card having a viewing surface and a contact edge and at least one 
reference line located on the viewing surface and also aligned "true" with 
the contact edge. The contact edge of the card is positionable in an 
abutting relationship with the mounting boss of the gun, independent of 
the telescopic sight so that the reference line on the card automatically 
aligns with the barrel axis and so that the viewing surface of the card 
lies adjacent to the reticle. The relative position of the card abutted 
onto the mounting boss allows the sighting hairline of the reticle to be 
compared with the reference line and properly adjusted.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, a telescopic sight 10 is mounted to a rifle 12. The 
scope-sight 10 is secured to the barrel 14 of the rifle 12 by a rear mount 
16 and a front mount 18. The front mount 18 is closest to the muzzle 19 of 
the barrel 14. The rifle 12 includes a rear scope base 20 and a front 
scope base 22. The scope bases 20, 22 are machined into or are otherwise 
attached to the top portion of the barrel 14 to be aligned with a bore 
axis 24 of the barrel 14. The rear and front scope bases 20, 22 are 
adapted to receive their respective rear and front mounts 16 and 18. 
The invention indirectly or directly uses the machined and "true" scope 
bases 20, 22 on the barrel 14 to provide an accessible reference line for 
aligning the cross hairs (28, 30) of a reticle 26 of the scope-sight 10 
with respect to the bore axis 24 of the barrel 14. The invention is easily 
mounted to most telescopic sight mount bases on any type of firearm 
including pistols, rifles and shotguns. 
FIG. 2 illustrates typical canted cross-hairs (28, 30) of the reticle 26 of 
a scope-sight 10. The cross hairs are canted or tilted from an accepted 
"true vertical" reference line by an angle "A". The cross-hairs include a 
horizontal cross hair 28 and a vertical cross hair 30. The front scope 
base 20 is shown as a reference of "true vertical" with respect to the 
bore axis 24 of the barrel 14. 
An alignment device 32, in accordance with a first embodiment of the 
invention is shown in FIG. 3. The device 32 includes preferably two 
opposing reference cards 34 connected to each other within a common plane 
by a connecting bar 36. The reference cards 34 both include aligned 
parallel reference lines 38. The connecting bar 36 is preferably made from 
a bar stock having a square or rectangular cross section which provides a 
flat surface 39. The connecting bar 36 is parallel to the reference lines 
38 of the reference cards 34. A hook 42 is connected to a lower portion of 
each reference card 34 for receiving each respective end of a rubber band 
40. The rubber band 40 is used to provided quick and easy securement to 
the rifle 12, as described below. 
The alignment device 32 is attached to the front or rear scope base 20, as 
shown in FIGS. 1 and 4, so that the two opposing reference cards 34 appear 
on either side of the reticle 26. The connecting bar 36 is positioned on 
the one of the scope bases and held there by the rubber band 40, which is 
looped from a first hook 42, around the barrel 14 (and stock section) of 
the rifle 12 to the other hook 42. The elastic contracting force generated 
by the rubber band 40 looped around the rifle, as described, draws the 
flat surface 39 of the connecting bar 36 into flush contact with the flat 
surface of the front scope base 20. Since the scope base 20 is "true" with 
the bore axis 24, then both the mounted connecting bar 36 and each of the 
reference lines 38 will likewise be "true" with the bore axis 24. The flat 
surface 39 of the connecting bar 36 maintains the entire alignment device 
32 in an upright position. 
Once the alignment device 32 shown in FIG. 3 is properly attached to the 
either scope base 20, 22 of the rifle 12, as shown in FIG. 4, the reticle 
26 may be easily aligned with the bore axis 24 by rotating the telescopic 
sight 10 until the horizontal cross hair 28 is parallel with any 
corresponding pair of reference lines 38. This is easily accomplished 
while sighting through the scope-sight 10 and simultaneously comparing the 
horizontal cross hair 28 of the reticle 26 with the exposed reference 
lines 38 displayed on either side of the eyepiece of the scope-sight 10. 
Since the distance between the bore axis of the firearm and the bore axis 
of the telescopic sight will vary depending on the type of telescopic 
sight and the mount used (typically this distance is between 1.5 and 2 
inches), several parallel reference lines 38 are provided. At least one 
pair of reference lines will lie relatively close to the cross hairs of 
the reticle. 
Referring to FIG. 5, another alignment device 50 is shown, in accordance 
with a second embodiment of the invention. As in the above described 
alignment device 32, the alignment device 50 is mounted to one of the 
scope bases, and therefore automatically aligns with the bore axis 24 of 
the barrel 14. The alignment device 50 provides reference lines which are 
entirely viewed through the sight 10. 
The alignment device 50 includes an optical assembly 54 and a mounting 
assembly 56. The mounting assembly 56 is used to secure the optical 
assembly 54 to the rifle 12 in an aligned orientation with respect to the 
bore axis 24 of the barrel 14. The alignment device 50 is shown in a 
mounted position on the rifle 12 in FIG. 1. 
The mounting assembly 56 includes two parallelogram assemblies 58, a 
mounting bracket 60, a contact bar 62 and a tightening screw 64. The 
mounting bracket 60 is preferably "U" shaped defining two vertical 
sections 66 connected to each other by a bottom section 68 and open at 
upper ends. 
Each parallelogram assembly 58 includes a pair of parallel connecting bars 
70 and a pivot block 72. One end of each connecting bar 70 of each 
parallelogram assembly 58 are pivotally connected to a respective pivot 
block 72. The remaining two ends of the two connecting bars 70 of each 
parallelogram assembly 58 are pivotally connected to a portion of the 
optical assembly 54 (either directly as shown in FIG. 5, or indirectly 
using a collar 71, as shown in FIG. 10 and further described below) so 
that each connecting bar 70 is parallel to the remaining three. 
Each pivot block 72 includes a bore 69 which aligns with similar bores 69 
located in both vertical sections 66 of the mounting bracket 60. These 
aligned bores 69 define an axis "B" along which the contact bar 62 may be 
inserted. Once inserted, the contact bar 62 directly connects each pivot 
block 72 to the mounting bracket 60, as further described below. 
With the mounted assembly 56 in its mounted position on the rifle 12, as 
shown in FIG. 1, the contact bar 62 is positioned along the axis "B" and 
is parallel to and slightly longer than the lower section 68 of the 
mounting bracket 60 and thereby extends past either side of the vertical 
sections 66. 
The contact bar 62 includes two vertical flat surfaces 74 and a central 
horizontal flat surface 76. The horizontal flat surface 76 engages with 
the front scope base 22 and extends the "true" orientation of the scope 
base 22 to the entire mounting bracket 60 so that the mounting bracket 60 
becomes an aligned reference to the central bore axis 24 of the firearm. 
The vertical flat surfaces 74 align with each respective pivot block 72. 
Each pivot block 72 are securely fastened to each respective vertical 
surface 74 of the contact bar 62 and thereby become mechanically aligned 
with each other and the central bore axis 24 of the firearm. In this 
preferred embodiment, securing screws 78 are used to engage threaded bores 
79 located in the pivot block 72 so that each pivot block 72 may be 
selectively secured to each respective vertical flat surface 74 of the 
contact bar 62. 
The parallelogram assemblies 58, each being mechanically restricted to 
pivotal movement within a vertical plane controlled by each respective 
pivot block 72, will also be mechanically aligned with the bore axis 24 of 
the rifle 12. 
Being mechanically connected to the parallelogram assemblies 58 and the 
mounting bracket 60, the entire optical assembly 54 becomes automatically 
aligned with the bore axis 24 of the rifle when the contact bar 62 is 
positioned on the "true" surface of the front (or rear) scope base 22. The 
purpose of the parallelogram assemblies 58 is to give the optical assembly 
54 freedom of movement along the vertical plane extending through the bore 
axis 24 while remaining aligned with the bore axis 24 of the rifle 12 and 
maintaining automatic alignment with the bore axis of the scope. This 
freedom of movement of the mounted optical assembly 54 allows for 
automatic alignment between the bore axis of the mounted scope and the 
front opening 82 of the optical assembly 54, regardless of the distance 
between the bore axis of the mounted scope 10 and the barrel 14 of the 
rifle 12. 
As shown in FIG. 5 and 8, a contact foot 80 is preferably provided below 
the optical assembly 54 (or the collar 71 of FIG. 10) to assist in 
supporting the aligned optical assembly 54 while mounted to the rifle. The 
contact foot 80 includes an inverted "V" shaped groove which automatically 
engages and centers the rifle barrel 14. 
Referring to FIGS. 5 and 6, the optical assembly 54 includes an elongated 
housing 81 having a front opening 82 and a rear opening 84, a lens 86, a 
translucent reticle screen 88 and a translucent frosted screen 90. The 
lens 86 is mounted within the housing across the front opening 82. The 
frosted screen 90 is mounted within the housing 81 across the rear opening 
84. The reticle screen 88 is mounted within the housing 81 between the 
lens 86 and the frosted screen 90 within the focal plane of the lens 86. 
Once properly positioned on the rifle, as described below, the optical 
assembly 54 of the alignment device 50 illuminates an aligned reticle 
pattern 92 which may be viewed through the telescopic sight 10. The 
reticle pattern 92 is located on the translucent reticle screen 88. 
Ambient light enters the housing 81 from the rear opening 84 and is 
diffused by the frosted translucent screen 90. The diffused light 
illuminates the reticle pattern 92. The image of the reticle pattern 92 
passes through the lens 86 to be viewed by the user through the telescopic 
sight 10. 
The user may easily align either the horizontal or the vertical cross hair 
of the mounted telescopic sight 10 with the superimposed "true" reticle 
pattern 92 so that the cross hairs of the telescopic sight become "true" 
with respect to the bore axis 24 of the rifle 12.