Tree stand bow sight

An archery bow sight adapted for tree stand use and of the type which includes a pendulum-like element which is pivotal about a support shaft in response to changes in bow attitude, including angular disposition of the bow. The bow sight is characterized in that there is provided a motion-damping assembly for reducing the time duration of oscillation of the pendulum-like or pendulous element and the sight connected thereto as the pendant body seeks a stable rest position correlated with a given elected and selectable bow orientation. The desired damping may be achieved by any of several types of effective mechanisms and techniques including a damping arm or vane impeded by a fluid medium, magnetic friction forces, and dash pot arrangements.

BACKGROUND OF THE INVENTION 
This invention relates to a sighting device for an archery bow. More 
particularly, the invention is directed to a bow sight having utility for 
use as a tree stand bow sight. The bow sight includes a frame adapted for 
attachment to a bow at the window section of the bow, and, as so attached, 
may be used selectively for tree stand use or, alternatively, while 
hunting on the ground. 
Many types of sighting devices for bows, including bow sights for use in 
tree stands are known in the art. Sighting devices of the type referred to 
include a pendulum-like arm or pendulous element which is pivotal to 
assume a vertically directed disposition irrespective of the angular tilt 
or elevation of the bow. In the structures referred to, the sighting 
element itself is attached to, for movement with, the pivoting arm or 
pendulum. Conventionally, the sighting component includes mechanisms by 
which both elevation and lateral corrections and adjustments may be 
readily made. 
A fundamental requirement of the sight supports utilized in tree stand bow 
sights is that the bead sight element itself be supported on an arm which 
is freely pivotal to assume a vertical direction irrespective of the 
angular shift imposed upon the bow itself. The fact that the pivotally 
supported element is free to swing arcuately on a supporting horizontally 
disposed shaft establishes a situation in which the suspended element 
undergoes oscillatory swinging movement until it finally comes to a rest 
position. The "collapsing" oscillations do take place over a finite time 
period so that there are objectionable delays before a stable sighting 
system has been established. It will be appreciated that such delays may 
often be crucial and may spell the difference between being able to 
release a timely arrow or being delayed to an extent that the 
"opportunity" is lost. 
While it has long been recognized and appreciated that the elimination of 
this delay period would be a highly desirable goal, no tree stand bow 
sights have, heretofore, been devised which provide a solution to this 
vexing problem. It is, therefore, the aim of the present invention to 
provide an efective solution to the problem of the "swinging" bow sight so 
that sighting delays may be eliminated and the efficacy of bowhunting be 
enhanced. 
BRIEF DESCRIPTION OF THE INVENTION 
It is a principal object of this invention to provide an improved tree 
stand bow sight in which prior art shortcomings have been eliminated. 
A related object of the invention is to provide a tree stand bow sight in 
which swinging or oscillatory motion of the sight-carrying arm has been 
minimized and the time of oscillation has been markedly reduced. 
Another object of the invention is to provide a tree stand bow sight having 
a preadjusted sighting element which may be readily calibrated to provide 
a marked degree of accuracy over an extended sighting range. 
It is a feature of the tree stand bow sight of the invention that as the 
target approaches the tree stand, necessitating further depression of the 
arrow trajectory, the sight is moved up, since correction for the 
gravitational force upon the arrow is reduced. 
Another important object of the invention is to provide, in a tree stand 
bow sight, adjustment mechanisms by which the sight settings for both 
elevation and lateral correction may be quickly and conveniently achieved, 
and in which the selected settings are secure and reliably stable. 
It is a feature of the bow sight of the invention that it includes simple 
and effective means by which the bow sight may be conveniently and readily 
attached to any standard bow, and may be easily removed, without the use 
of special tools. 
Yet another object of the invention is to provide, in a tree stand bow 
sight, a structure which will ensure both effective range adjustment and 
lateral deflection or veerage compensation, and in which the archer may 
conveniently preset the ranges to his preferred values. 
Yet another feature of the invention is that the tree stand bow sight may, 
optionally, be locked so as to provide a bow sight which is convenient for 
use for shooting on the ground or on level terrain. 
It is a general feature of the improved bow sights of the invention that 
they include pivotally supported sight-carrying arms, the oscillations of 
which are damped to bring the arm quickly and reliably to a final rest 
position. 
A general object of the invention is to provide a bow sight mechanism which 
is durable in construction, and reliable in use. 
Other and further objects, features and advantages of the invention will 
become apparent from a reading of the following specifications considered 
in conjunction with the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The aims and objects of the invention are accomplished by providing in an 
archery bow sight adapted for tree stand use and which includes a 
pendulum-like sight-carrying element pivotally mounted on a support shaft 
for swinging motion in response to changes in bow attitude or elevation, 
and mechanisms for damping the pivotally supported arm so as markedly to 
reduce the time duration of oscillation of the pendulum and the sight 
connected thereto. It is an important feature of the invention that the 
damping mechanism provided accelerates the assumption, by the swinging 
pendulous element, of a stable rest position correlated with a given 
elected and selectable bow orientation. 
It is a feature of the invention that the desired damping is achieved by 
any of several types of highly effective mechanisms and techniques. In one 
embodiment of the invention there is provided a pivotally supported leg or 
vertical strut which extends downwardly into, to be damped by movement 
through a fluid medium contained in a reservoir of the bow sight. In 
another embodiment of the invention there is provided an outrigger, 
arm-carried wing which contacts to bear upon a fluid contained in the 
reservoir in the bow sight. A baffle within the liquid medium itself 
ensures a certain degree of "stability" to the movement of the fluid 
within the reservoir. 
In yet another damping arrangement, interacting magnetic and/or 
magnet-response elements are disposed to act upon, respectively, the 
pendulous element and the supporting bow sight housing, or between the 
pendulous element and the sight-carrying arm so as to establish magnetic 
friction between the relatively moving components and to damp oscillatory 
motion of the sight bead carrying assembly. It is within the present 
inventive concept to utilize damping mechanisms which include piston and 
cylinder fluid-flow dash pot assemblies as means to achieve damping of 
sighting bead motion derived from the combined action of gravity and 
momentum. 
In accordance with the practice of the invention any swinging movement 
imparted to the pivotally-supported arm which carries the sight mechanism 
is rapidly dissipated and the sight assembly brought to a positive fixed 
orientation. Such prompt stabilization occurs each time the bow is moved 
through a vertical plane in sighting on a target. Objectionable delays in 
establishing a reliable sighting attitude are eliminated, and a more 
reliable and accurate hunting climate is assured. 
Referring now to the drawing, and particularly to FIGS. 1 through 4, there 
is shown, for illustrative purposes and not in any limiting sense, a tree 
stand bow sight embodied as an assembly 20. As illustrated in FIG. 1, the 
bow sight 20 is carried on a flange 24 which is in turn secured by means 
of bolts 26 extending through elongated slots 30 formed in a mounting 
bracket 34 which is, in turn, fastened at a window zone 40 of a bow 44. 
As shown, and as best seen in the exploded view of FIG. 4, the bow sight 
assembly 20, in the embodiment depicted in FIGS. 1 through 8, includes a 
frame including a housing 50 formed by a pair of telescopically 
internesting open-ended dishes including an inner dish or cup 54 and an 
outer dish or cup 56 which, in their assembled configurations, define an 
interior cavity or reservoir 60 (FIG. 5). The inner cup 54 constitutes a 
circular base or end wall 64 integrally formed with a cylindrical, 
circumscribing wall 66. In a center zone the inner cup 54 is formed with 
an internal annular sleeve 70 defining a through bore 74 for rotationally 
supporting a shaft 80 having one end 82 within the cavity or reservoir 60 
and its opposite end 86 extending axially outwardly from the reservoir 60. 
The outer dish or cup 56, dimensioned slidably and contiguously to receive 
therewithin the inner dish 54, includes a base 90 and an integrally-formed 
circumscribing cylindrical wall 94. In the assembled mode of the bow 
sight, the inner dish 54 is nested within the outer dish 56 in 
fluid-sealing engagement therewith to define the fluid reservoir 60. 
As indicated schematically in FIG. 4, and as shown in FIG. 5, the shaft 80 
which is rotationally supported at a central lineal zone thereof 100 in 
the bore 74 of the sleeve 70 is formed at its inwardly-directed end 82 
with spline-like ribs 102 for lockingly engaging within a cooperating bore 
106 formed in a hub 110 connected to, to support a pendulum strut or 
pendulous element 120 within the housing or cavity 60. In the particular 
embodiment of the invention shown in FIGS. 1 through 8, the pendulous 
element 120 carries a bearing-like metal ball 124 which serves as a weight 
confined in a block 126 at a freely-swinging end of the pendulous element 
120. Also, as shown in FIG. 5, a magnetic element 360 may be attached to 
the pendulum, or the metal ball 124 of the pendulum 120, may itself be 
magnetic. In the arrangement described a cooperating magnet 364 is 
conveniently secured to the arm 150. In this embodiment of the invention 
the pendulum 120 and the arm 150 could both be free to rotate on the shaft 
80. At its end 86 extending outwardly of the cavity 60 of the bow sight 
20, the shaft 80 is formed with spline-like ribs 130 for grippingly and 
lockingly engaging within a cooperating bore 140 formed in a hub-like boss 
144 to which is attached to depend therefrom an elongated arm 150 which 
carries a sight bead assembly 154. The arm 150 is feathered to define an 
elongated, integrally formed, coextensive rib 156 for preventing rotation 
of the sight bead assembly 154 on the arm 150. The sight bead assembly 154 
which is slidably positionable, selectively, along the lineal expanse of 
the arm 150 includes a generally U-shaped yoke 158 which defines, at its 
looped end, a through opening 160 through which the arm 150 and the 
arm-carried rib 156 are slidable. The yoke 158 defines a pair of spaced, 
generally parallely disposed legs 166 and 168 formed with aligned through 
bores extending normally of the shaft 150 on which the yoke 158 is 
secured. A pin 172 carrying a sight bead 174 at one end is formed with 
threads 180 extending along its lineal expanse. 
In the specific embodiment of the invention shown, the pin 172 projects 
through the bore in the first arm 166 of the yoke 158 and is threadedly 
engaged in cooperating threads formed in the second arm 168 of the yoke 
158 so that rotation of the pin, manually, by digital force applied at a 
knurled 184 end section of the pin 172 serves to advance or retract the 
pin 172 and the sight bead 174 carried thereby so as to achieve lateral 
adjustment of the sighting mechanism. A locking nut 190 threadedly engaged 
on the threaded pin 172 serves the dual function of urging the opposed 
arms 166 and 168 of the yoke 158 toward one another so as lockingly to 
embrace the sight support shaft 150 and, at the same time, to lock the 
sighting pin in a selectable fixed position. 
In the specific embodiment of the tree stand bow sight depicted, there is 
provided the capability of securing the sighting assembly 154 selectably 
fixed with respect to the bow sight assembly 20 so as to enable the hunter 
to use the bow sight for shooting on the ground or on the level terrain, 
should this option be elected. As shown, and with reference particularly 
to FIGS. 3 and 4, the structure by which this versatility is achieved 
includes a spring band or sheath 200 consisting of a band-like wall 204 
generally cylindrical in form and provided with a slot 206 extending 
transversely, across the band 204 for allowing forced resilient 
deformation or radial enlargement of the band to permit telescoping entry 
of the outer dish 56 therewithin in a mode to establish frictional 
gripping engagement of the band 200 about the cylindrical wall 94 of the 
dish 56 so that the band 200 is rotatable and selectively positionable 
annularly with respect to the embraced outer dish 56 (FIG. 3). As shown in 
FIG. 4, and in FIG. 5, the spring band or sheath 200 is integrally formed 
with a radially inwardly extending annular edge flange 210 which serves as 
a limit stop upon slidably positioning the band 200 over the wall 94 of 
the dish 56. In the particular preferred embodiment of the invention 
illustrated, the resilient band 200 is of an inconstant thickness as 
measured radially transversely of the wall 204 so as to provide improved 
strength and the requisite degree of distortability and resilience. At its 
thickened zone 212 remote from an opposed thinned zone 214, in which the 
slot 206 is cut, the band 200 is integrally formed with a transversely 
extending cross bar 216 to which there is pivotally secured a spring wire 
clip 220, opposed, generally parallel arms 224 and 226 of the clip 220 
being bent at their respective free ends to define probes 230 extending 
into cooperating bores 234 projecting into the bar 216 at opposed sides 
thereof. 
Attached to to extend radially from the hub or boss 144 secured on the 
shaft end 86 is a locking bar 240 terminating at its free end in a finger 
244, the latter being engageable within a spring loop constricted zone 250 
defined by the pivotal clip 220 when the latter is swung on its hinge-like 
pivot probes 230 to extend in a plane generally paralleling the shaft 80 
of the assembly, as shown in FIG. 3. In the arrangement described, the 
sighting assembly 154 is locked against swinging movement and is fixed 
with respect to the clamping band 200 and, accordingly, with respect to 
the mounting bracket 24. In the structure depicted in FIG. 3, the sighting 
assembly 154 may be repositioned, selectively, and in a fixed mode, merely 
by manually gripping the spring band or ring 200 and rotating the latter 
annularly about the outer dish 56. Thus, the tree bow sight of the 
invention may be conveniently used for shooting the bow on the ground or 
on level terrain. By simply disconnecting the spring clip 220 from the 
finger 244 of the locking rod 240, the bow sight is returned to a mode in 
which the sighting assembly is again pivotal, for convenient use as a tree 
stand bow sight. 
Each of the several embodiments of the present invention has in common as a 
definitive feature thereof a mechanism by which the swinging oscillation 
of the sight assembly 154 is damped so as to bring the sight bead 174 to a 
fixed sighting position, without objectionable delay. In the embodiment of 
the invention illustrated in FIGS. 4, 5, and 8, the damping is achieved 
through the intercooperation of the pendulous element 126 coupled to the 
sight assembly supporting an arm 150 and operative in a fluid medium 260 
confined in the housing or reservoir 60 within the internesting dish-like 
cups 54 and 56 (FIG. 8). The fluid 260 which may be any of various 
suitable liquids is a temperature-stable relatively inert, somewhat 
viscous liquid such as a polyhydroxy organic compound, for example, 
glycerol. Other suitable fluids may include mercury, and oils and silicone 
fluids which meet the physical requirements of the system and the ambient 
environment in which the bow sight finds use. It is contemplated that the 
word "fluid" as used herein will encompass within its scope non-liquid 
materials such as fine globules of plastic which may fulfill the 
functional requirements of a damping "fluid" within the concept of the 
present invention. Irrespective of the particular "fluid" selected, the 
aims and objects of the invention are achieved through the use of a fluid 
medium which acts effectively to deter and damp the swinging or 
oscillatory motion of the pendant element 126 within the housing of the 
bow sight. 
A second embodiment of the oscillation damping mechanism of the invention 
is depicted in FIGS. 9 and 10. As there shown, the hub 110a fastened on 
the end 82 of the shaft 80, interiorly of the housing or fluid reservoir 
carries a pair of laterally-outwardly-angled struts or outriggers 300 and 
302 terminating at their respective outwardly directed ends in paddles, 
floats or plates 306 and 308 which contact and tend to float upon the 
fluid 260 confined in the interior of the bow sight. Excessive movement or 
"sloshing" of the fluid within the confining reservoir 60 is minimized by 
providing a baffle 312 which, in the particular embodiment of the 
invention depicted in FIG. 10 is shown as fastened to and extending 
upwardly from the interior of the wall 66 of the inner cup 54a. Through 
ports 316 in the baffle 312 enhance the effectiveness and operation of the 
baffle 312 itself. 
In an alternative structural embodiment of the invention fluid baffles take 
the form of spaced platelets or vanes fastened to and extending radially 
inwardly of the cylindrical wall 66 interiorly of and about the annular 
expanse of the wall 66 in a zone adjacent the base 64 of the inner dish 
54. 
For convenience in introducing the fluid 260 into the bow sight after the 
latter has been assembled, there is provided a fluid inlet port 320 which, 
in the specific embodiment of the invention shown, extends through the 
planar wall 90 of the outer dish 56. The port 320 is threaded so that it 
may be effectively sealed by means of a correspondingly threaded 
cooperating screw 324. While any preferred technique and structure may be 
utilized for attaching the bow sight 20 to the carrying bracket 24, in the 
preferred embodiment of the invention illustrated, the bracket 24 is 
secured to the assembly, at the rear of the end wall 90 of the dish or cup 
56 through the use of a suitable adhesive preparation 330 applied as a 
bonding interface. A pair of diminutive walls 336 and 338 integrally 
formed with and projecting normally of the wall 90 of the cup 56 at the 
rear thereof define physical abutments against which corresponding side 
edges of the bracket 24 bear, further to obviate relative displacement 
between the bracket 24 and the assembly to which it is fastened. 
Yet another technique by which damping of the swinging or oscillatory 
motion of the pendulous element and the sighting assembly attached thereto 
is achieved, in accordance with the present invention, is indicated in 
FIGS. 8 and 11. As shown, the pendulous element 126b attached to the shaft 
82 by the hub 110b carries a magnet 350 at its lower free end presented 
toward the inner face of the cylindrical wall 66 of the inner cup 54. 
Fastened to to extend along an arcuate sector of the wall 66 interiorly of 
the cavity or housing of the assembly is a series of 
longitudinally-spaced, lineally-extending magnetic elements 354. It will 
be appreciated that in the arrangement described and depicted, any 
swinging or oscillatory motion of the pendulous element 126b will be 
effectively damped by the magnetic frictional force established between 
the magnetic element 350 on the pendulous device and the opposed magnets 
354 secured to the arcuate wall 66 of the inner cup 54. 
In an alternative arrangement interacting cooperating magnetic elements may 
be attached one to the body of the bow sight at an outer face thereof and 
the other to the opposed swinging arm 150 which carries the sight pin 180 
and bead 174. 
Referring now briefly to FIG. 12, there is provided a schematic 
representation of a procedure for calibrating the tree stand bow sight of 
the invention for use. In order to ensure the correct bow sight setting 
for a target within the range of 10 yards to 30 yards the archer may shoot 
a group of arrows, from the tree stand, at a 30-yard target and a second 
group at a 10-yard target. The next step is to measure the distance 
between the "center" of the two groups of arrows. If this measured 
distance is greater than 20 yards, the sight pin should be moved upwardly 
on the supporting arm 150. If less than 20 yards, the sight pin supporting 
arm 180 carried on the yoke 158 should be moved downwardly. With the above 
operation completed and the arms setting corrected for a 20-yard distance 
between the two groups, it is necessary merely to reset the assembly up or 
down to bring the pin on the 30-yard target, as described in the initial 
procedure of grouping arrows at a 30-yard and at a 10-yard target. Other 
preferred procedures for "zeroing" or calibrating the tree stand bow sight 
may be used, all as described in the art. 
While the present invention has been described with reference to preferred 
embodiments, it is obvious that numerous changes may be made in the size, 
shape, details and arrangements of the various elements of the invention 
without departing from the scope and spirit thereof. For example, while 
the use of plastics materials for the major components of the bow sight is 
preferred, other materials including light-weight metallic alloys may be 
employed. Additionally, in the light of the present disclosure, 
alternative arrangements for achieving the damping of the sight-carrying 
assembly may occur to those skilled in the art. It is, therefore, intended 
to include within the appended claims all such variations and 
modifications which fall within the spirit and scope of the invention.