Archery bow construction

Unique bow structure formed of three lengths of light weight tubular material and inclusive of a primary beam member, having removably but hingedly secured thereto, two identical lever arms having end extremities connected to the adjacent end extremity of the beam member by a spring-like member, said end extremities of lever arms being spanned by a bow string, maintained in tension in the static position and an even greater tension when the bow string is pulled back together with an associated arrow at the mid region of said bow string.

The present invention relates generally to the sport of archery. More 
particularly, the present invention relates to a bow structure designed to 
provide an extremely economical but extremely efficient operation and 
having an extremely high but uniform spring rate considering its 
relatively small size and cost as well as, and perhaps most importantly, 
simplicity. 
Traditionally, archery bows are formed of a single piece of wood, a 
plurality of pieces of wood in laminated but glued, unitary assembly or 
fiberglass reinforced polyester or the like. The contour or configuration 
of the essentially one-piece unitary structure is designed to possess a 
bending flexibility calculated to yield a desired resistance to bending as 
the associated bow string is pulled rearwardly or, stated another way, in 
a direction opposite to that desired for the projectile arrow. The 
strength, weight or size of bows are thus calibrated, ranging from as 
little as about twenty (20) pounds up to one hundred (100) pounds and even 
higher. The number of pounds, of course, refers to the quantity of pull on 
the bow string which is necessary to cause the bow to yield to the desired 
preselected arrow release point. In turn, of course, the higher pull bows 
will be able to propel either a heavier arrow or a heavier arrow farther 
and with more force as necessary in the hunting of big game. In target 
archery, the higher number corresponds to a longer range or higher speed 
leading to greater accuracy. 
The construction or fabrication of one-piece bows capable of exhibiting the 
flex, stress, spring capabilities, as above described, entails 
considerable expense and, consequently, high performance bows having 
desirable uniform spring characteristics are quite expensive. One-piece 
bows also, especially in the high performance range, are quite heavy and 
cumbersome which factors adversely effect the archer and his consistent 
accuracy. 
Recognizing some of these deficiencies, multi-component bows or bows made 
of several members featuring external spring means and hinge means have 
been developed. See, for example, U.S. Pat. Nos. 586,712 (1897), 428,912 
(1890), 3,957,022, 1,932,195 and 2,116,650. Certain of these patents 
disclose bow structures of more than one piece. A brief comparison of the 
drawings in these patents and those accompanying the present application 
will, however, reveal the obvious differences amongst which are 
complicatedness vs. simplicity, cumbersomeness vs. clarity and others as 
will reveal themselves from a closer comparison of the patent disclosure 
and the explanation and description set forth hereinafter. 
It is, accordingly, a general object of the present invention to provide an 
archery bow structure of extremely simple design and accompanying low cost 
of manufacture and, accordingly, economical availability to the public. 
It is another object of the present invention to provide a bow structure 
which is quite small in overall size yet capable of performance belying 
that size and, in fact, otherwise associated with much larger dimensions. 
It is another object of the present invention to provide such a bow 
structure which additionally embodies uniformity of performance yet being 
capable of enduring handling and treatment which would destroy or 
adversely effect performance or uniformity of performance of bows known 
heretofore. 
It is a significant object of the present invention to provide an archery 
bow design embodied in several principal elements and having 
interdependent cooperative regions of assembly which accommodate marketing 
of the bow in unassembled and/or kit form adding to or contributing to the 
economy of acquisition. 
It is a major object of the present invention to provide a novel archery 
bow construction of interdependent components and which combines 
smallness, simplicity of design, low cost and yet be yieldative of 
operational performance normally expected of much larger conventional 
sized archery bows and possessed of a spring rate or "pull" consistency 
normally associated with extremely expensive and/or exotic archery bows. 
The foregoing, as well as other objects of the present invention, will 
become apparent to those skilled in the art from the following detailed 
description taken in conjunction with the annexed sheet of drawings on 
which there is presented, for purposes of illustration only, a single 
embodiment of the archery bow structure of the present invention.

Returning now specifically to the drawings, the archery bow structure, 
identified by the reference numeral 11, will be described with specific 
and particular reference to preferred components and members employed in 
forming the archery bow. 
Reference numeral 12 identifies an elongate primary beam or anchor member 
consisting of a twenty four and one-half inch (241/2") length of one-half 
inch (178 ") inside diameter conduit normally and frequently employed in 
electrical wiring installation. The terminal cut ends 12a are open but the 
edges are deformed inwardly to avoid sharp edges and provided with 
transverse holes 12b for a purpose to be described. Rather than deforming 
or binding, apertured plastic plugs or caps can be used to cover sharp 
edges. 
Reference numerals 14 and 15 identify identical pivot arms formed of 
one-half inch (1/2") inside diameter electrical conduit. The arms 14 and 
15 are desirably formed of the same one-half inch (1/2") conduit but 
seventeen and one-half inches (171/2") in length and are provided with 
rounded distal ends 14a and transverse holes 14b, as shown. Pivot member 
14 is hingedly secured to primary beam member 12 employing one-half inch 
(1/2") water pipe hanger 16 formed to encircle the principal member 12 and 
with ear portions 16a (FIG. 5), each containing matching holes 16b to 
enclose the end 14a of the pivot arm 14 which likewise contains a 
three-sixteenth inch (3/16") hole 14b registering with the holes 16b in 
the ear portions 16a of the pipe hangers 16 whereby bolt 40 and acorn 41 
permits securement in the manner shown. Pivot arm 15 is similarly secured 
to the primary member 12 at a distance equidistantly from the center and 
ends of member 12. The distal ends of pivot arms 14 and 15 are provided 
with holes 14d. A linear seven inch (7") by one-half inch (7".times.1/2") 
expansion spring 17 having terminal circular hooks 17a is secured by 
appropriate hog ring or squeeze clips 18 to the terminal end 12a of beam 
member 12 and the outer end 14a of pivot arm 14 and, in similar fashion, 
identical spring 17 is secured to the terminal ends of beam member 12 and 
the distal end of pivot arm 15 in the manner shown. A forty two inch (42") 
length of one-eighth inch (1/8") diameter nylon string, identified by the 
reference numeral 20, is secured in tension to the distal ends of the 
pivot arms 14 and 15 to complete the archery bow structure. It has been 
found that a nylon having a tensile strength of four hundred pounds (400 
lbs.) is suitable for the intended purpose. It is important that the bow 
string 20 be secured with sufficient tension or tautness that the pivot 
arms 14 and 15 are sufficiently extended that the springs 17 are in a 
significant state of tension as opposed to a slack or neutral state. 
Reference numeral 30 identifies a combination hand-hold and spacer member 
shown in section in FIG. 1. The combination hand-hold and spacer 30 is 
preferably fabricated of a length of plastic water pipe measuring 
eleven-sixteenth inches (11/16") inside diameter and about seven-eighth 
inches (7/8") outside diameter which dimensions provide a snug fit about 
the primary beam member 12, yet allowing it to be telescopically moved 
from one end of the beam to its central position, as shown. The plastic 
water pipe is formed of rigid polyvinyl chloride which has a surface which 
is comfortable as a hand gripping feature. The size, particularly the 
outside diameter, can be varied by selecting a thicker walled length of 
plastic water pipe to accommodate a larger or smaller hand to provide a 
more comfortable grip. Importantly, the hand grip member 30 is 
multi-functional in serving to provide a necessary function, namely of 
maintaining the water pipe hanger members 16 from sliding toward each 
other. This inward sliding would occur through the operation of the 
archery bow, as hereinafter described, if not for the positioning of the 
hand grip, spacer member 30 in the position as described. Clearly, 
movement of the pipe hanger member 16 would change the pivotal connection 
of one or both of the pivot arms 14 and 15 and, contemporaneously, vary 
the attitude of the springs to adversely effect the operation of the bow. 
From the foregoing description, it can be appreciated that the components 
of which the archery bow of the present invention is composed, are readily 
available at low cost; further, that the number of elements or parts is 
minimal and, additionally, that the assemblement thereof, in the manner 
described herein and illustrated in the drawings, could not be more 
simple. Springs of different size and characteristics can be selected to 
vary the performance of the archery bow structure of the invention. At the 
same time, the diameter and length of the primary beam member and pivot 
arms can be varied either alone or in combination with the choice of 
springs to provide a considerable latitude in bow performance 
characteristics in accordance with the present invention. 
A further and considerable advantage of the archery bow construction, in 
accordance with the present invention, resides in the utter simplicity and 
ease with which the elements can be assembled and disassembled requiring 
only a simple screwdriver and/or pliers to secure the pivot arms in the 
pipe hangers. At the same time, the space occupied by the components in 
disassemblement is minimal. The primary beam member and pivot arms would 
clearly fit into an arrow quiver along with the pipe hangers, bow string 
and springs. The springs, of course, can be completely removed or left 
attached at one end. Similarly, the pivot arms do not have to be 
completely removed but rather the pipe hanger loosened so that the arms 
can be folded alongside the beam member. Even the bow string can be left 
secured to one end of one of the pivot arms to provide a small package of 
parts for storage or travel. 
The bow string 20 is, as shown, secured to the terminal end of the pivot 
arm member 14 in the manner shown in FIG. 4. The end of the bow string 20 
is threaded through a tiny hole (not shown) in a plug-like plastic fitment 
or eyelet 24 whereupon a figure-eight knot (as shown) is tied in the 
terminal end of the bow string which prevents it being withdrawn through 
the hole in the fitment. The opposite end of the bow string is then 
similarly threaded through the fitment and another figure-eight knot is 
tied in that terminal end of the bow string preventing its withdrawal 
through apertured fitment. Most conveniently, the springs, of one of them, 
is disconnected at one end so that the bow string is secured at both ends 
following which the spring can be secured, as described earlier herein, 
using the spring clips. 
In FIG. 4, a distal end of one of the pivot arms is shown, somewhat 
enlarged, from which it can be seen that the end contains an axial 
aperture 14e and a side aperture 14b. The end aperture 14e permits an 
insertion of the plastic eyelet 24 therethrough for placement of the small 
end through aperture 14f, leaving the enlarged flange 24a inside 
preventing displacement. The other end 24b on the outside is deformed to 
secure the fitment preventing removal of the eyelet and, of course, serves 
to secure the bow string safely and without danger of fraying since the 
plastic eyelet has a smooth surface. 
The operation of the novel bow construction of the present invention is 
basically no different than that of other bows. The space generally 
designated by the reference numeral 35, between the pipe hangers 14a and 
14b, defines a hand-hold to the rear of which is situated the taut or 
tensioned bow spring 20 as drawn against the tension of the springs. At 
the same time, an arrow 50 is arranged with the pointed or projectile end 
51 extending over the hand (not shown), usually gloved, or between the 
fingers of the user's hand in the hand-hold grasping position 40 of the 
primary member 12 while the opposite end 52 engages the bow string 20 
which is extended to the degree desired, as indicated in the drawings by 
the dotted line representation of the pivot arms 14 and 15 and the dotted 
arm representation of the bow spring 20. Upon the release of the arrow and 
bow string, the identical spring members 17 will recoil from the extended 
state to the return position, shown in full line, causing the bow string 
to likewise return projecting the arrow in the direction guided by the 
aimed alignment of the arrow past the primary beam member 12 and the 
holding, guiding hand. 
It is an important feature of the present invention that the exterior 
springs 17, in conjunction with the cooperating design and size 
parameters, provide a uniformity of spring recoil as contributes to 
uniformity of bow spring recoil and, contemporaneously, with a more 
uniform propelling force upon the arrow. This leads to increased accuracy 
and, at the same time, reduces the transition of the user from complete 
novice to a reasonable degree of accomplishment and skill. 
Contemporaneously, it is important that the spring be selected in size, 
that is, length and diameter and, of course, spring rate, as to be in 
balanced performing relationship with the size of the other elements or 
components of the bow structure. 
It has been found that a convenient size for the primary frame or beam 
member 12 is twenty four and one-half inches (241/2") in length while the 
pivot arms are desirably seventeen and one-half inches (171/2") in length; 
with both being formed of one-half inch (1/2") diameter galvanized 
electrical conduit. 
With members of the foregoing dimensions, a hand-hold space of 
approximately five inches (5") will find the distal or remote ends of the 
lever arms extending slightly outwardly from the terminal or distal ends 
of the primary beam member 12. With this arrangement, the linear tension 
springs 16 and 17 are at a slight outward or obtuse angle with respect to 
the primary beam member 12, which arrangement is preferred and, in fact, 
essentially necessary in order to have the bow of this invention possess 
optimum performance characteristics. Most desirably, for optimum 
performance coupled with convenient size, the pivot arms are selected to 
have a length such that the springs define an acute angle with respect to 
the primary beam member 12 as measured between the adjacent distal ends of 
each. 
Considering the preferred size of the primary beam member 12 and the pivot 
arms, it has been found most desirable that the associated linear springs 
each be seven inches (7") in length and one-half inch (1/2") in diameter, 
and, otherwise, be standard tension springs available from a variety of 
suppliers. 
With the component parts of the bow structure assembled, as described 
herein, it is found that the springs are in a sufficient state of tension 
that sudden release from maximum extension or greatest "pull" will find 
the springs recoiling to a state still characterized as in tension. 
Properly assembled, the springs never return to a static or neutral 
position since this would be accompanied by considerable reaction 
manifested as a physical or manually felt shock which, while not 
particularly uncomfortable, would more importantly be accompanied by total 
failure of the arrow to receive the moment of recoil force necessary to 
propel the arrow in the desired manner and direction. 
Thus, it is necessary in the selection of the size of the various 
components and the selection of the springs, that the spring or tension 
state always be maintained in order that the archery bow will be capable 
of performing in the desired fashion. 
In accordance with a preferred embodiment of the present invention, the 
primary beam member and the pivot arm members are anodized in order to 
impart a pleasing coloration serving as a cosmetic and/or decorative 
affect while, at the same time, providing a protection against oxidation 
and rust attack of the surface of those members. Alternatively, a suitable 
primer and paint can be applied to the members by spray, brush or dipping 
to achieve the desired pleasing coloration and, at the same time, likewise 
provide protection against oxidation and rust deterioration of the 
members. 
Any modification, changes or substitutions, as would be obvious to those 
skilled in the art, are intended to be included within the scope of the 
present invention unless specifically excluded by the language of the 
appended claims or unless such substitutions, modifications and/or changes 
would do violence to the language and meaning of the appended claims.