US3302292A

US3302292A - Archery aiming device

Info

Publication number: US3302292A
Application number: US452120A
Authority: US
Inventors: Jr Alfred A Akin
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-04-30
Filing date: 1965-04-30
Publication date: 1967-02-07
Anticipated expiration: 1984-02-07

Description

1957 A. A. AKIN, JR 3,302,292

ARCHERY AIMING DEVICE Filed April 50, 1965 5 Sheets-Sheet l w mmm yum: E

/f7 5467 44 INVENTOR.

Feb. '3, 1%? A. A. AKIN, JR

ARCHERY AIMING DEVICE s Sheets-Shet 2 Filed April 30, 1965 Feb. 7, 1%? A. A. AKIN, JR 3,302,292

ARCHERY AIMING DEVICE I Filed. April 30, 1965 5 Sheets-Sheet 3 United States Patent r 3,302,292 ARCHERY AIMING DEVICE Alfred A. Akin, In, West Coviua, Calif., asslgnor to David P. Bushnell, Altadena, Calif. Filed Apr. 30, 1965, Ser. No. 452,120 3 Claims. (Cl. 33-46) This invention relates to an aiming device for an archery bow, and particularly to mounting apparatus for securing an optical aiming sight to an archery bow.

Archery bows have been used for centuries, but little change has been made in bow-aiming technique up to the present time. The traditional technique involves aligning a specific point on the bow or arrow, typically the head of an arrow mounted on the bow, with the target or some point bearing a fixed relation to the target. For example, the archer might draw an arrow to firing pos1- tion in the bow, visually align the arrowhead directly over the target, and then fire the arrow. Should this arrow fall short, the archer adjusts his aim by aligning the head of the next arrow with a point spaced somewhat above the target.

The weakness of the traditional aiming technique stems from several problems. First, accuracy and repeatability are dependent upon the archers ability to maintain his eye in a fixed position relative to the arrowhead or other reference point on the'bow. This is because two points are required to establish an aiming line which bears a fixed relationship to the bow. This concept is illustrated by analogy to a pistol, where the aiming line is established by one point on a front sight and a second point on a rear sight. The front sight is analogous to the arrowhead, and the rear sight to the archers eye. Once the aiming line is established, it is aligned with the target, or some point spaced from the target it windage or elevation corrections are required.

Unlike the front and rear sights of a pistol, the arrowhead and archers eye, the points defining the aiming line, are not necessarily in a fixed relationship to each other. A fixed relationship is achieved only if the archers eye is maintained in precisely the same position relative to the arrowhead each time the bow is fired. Only the most experienced archers are able to achieve this precise relationship, with the result that the average archer lacks a reliable and accurate aiming system.

A second weakness of the traditional aiming technique is that an aiming point bearing the desired relation to the target may not be available. For example, the archer may find that his first shot falls considerably short of the target. Raising his bow to achieve the desired trajectory may result in the arrowhead being positioned against a background of empty sky, providing no definite aiming point. It then becomes necessary for the archer to select some other point on the bow which can be aligned with an available aiming point adjacent the target.

In recent years, various mechanical sighting devices have become available to aid the archer. These devices typically consist of an adjustable post, the tip of which can serve in place of the arrowhead as one point defining the aiming line. More elaborate systems include a sighting aperture on the bowstring similar to the wellknown peep sight used on rifles. Even these sights, however, are ineffective for truly accurate archery, because the archers eye is constantly forced to shift focus between the post tip and the target. The focal shift causes the archer to hold the bow in a wavering or unsteady manner which is inimical to accurate shooting.

The aiming device of thi invention overcomes the weaknesses of both the traditional aiming technique and the more modern mechanical sights by providing an optical sight, secured to the archery bow by an adjustable 3,302,292 Patented Feb. 7, 1967 mounting apparatus. This type of sight provides an aiming line in known relation to the bow without regard to the position of the archers eye. Windage and elevation adjustments on the aiming device permit the sight to be aimed directly at the target, eliminating the need for aiming points spaced apart from the target.

The optical sight is of a long eye-relief type, but is otherwise similar to optical sights commonly used on rifles. The optical sight comprises a reticle, typically of the adjustable crosshair type, an optical system, typically consisting of objective, ocular, and image-erecting lenses, and a mounting tube to house the reticle and lenses. The optical system may provide magnification of the target, but such magnification is not a necessary part of the invention. Rather, the primary function of the optical system is to place the reticle and an erect image of the target in the same focal plane, eliminating the need for eye-focus change as the archer views the sight and the target.

In use, the sight is pointed at the target, and its position is adjusted until the target image appears at the intersection of the reticle crosshairs. In effect, the target image and the cr-osshair intersection are the two points which define the aiming line of the sight. Eye position of the archer has no effect on this aiming line, the archer being required only to position his eye such that he has a clear view into the sigh-t eyepiece. An optical system having a long eye relief is used as the archers eye is relatively far from the eyepiece.

The purpose of the mounting apparatus is to secure the sight to the bow such that a known adjustable relation is established between the sight aiming line and the bow. The mounting apparatus includes a sight housing which is slidably secured to a curved, elongated bracket, the bracket in turn being attached to the bow by two elongated mounting studs.

The elongated bracket is secured along the midsection of the bow so the length of the bracket is approximately parallel to the length of the bow. The bracket is curved along its length, the curve being concave relative to the archer and having a radius of curvature approximating the draw length (the distance from the bow to the center of the drawn bowstring) of the archer. The sliding sight housing positions the sight transversely to the bracket. As the housing is moved along the curved bracket, the angle between the sight and the bow changes, providing an elevation adjustment for the aiming device.

The bracket is normally mounted on the bow such that the largest angle between the sight and bow is obtained when the sliding housing is at the bottom of the bracket, this angle decreasing as the sight is moved up the bracket. Since the sight is always aimed directly at the target, the eifect of moving the sight along the bracket is to change the elevation correction or angular relation between rthe bow and the target. When the sight is at the top of the bracket, the elevation correction is negligible, resulting in a flat arrow trajectory suitable for close targets. For more distant targets, the sight housing is moved down the bracket, resulting in an increasing elevation correction and a higher arrow trajectory.

The correct technique of elevating the bow to obtain a high arrow trajectory for distant tangets requires the archer to pivot his upper body back from the waist, rather than merely raising his arms while his upper-torso position remains fixed. The geometry of this motion dictates that the radius of curvationof the curved bracket be approximately equal to the draw length of the archer in radius of curvature can also be made by moving one mounting foot of the bracket along its associated mounting stud while the other mounting foot of the bracket is held in a fixed position.

Targets at extreme range may require an elevation correction which exceeds the maximum correction available from the curved bracket unless the position of the entire bracket is shifted. To avoid this repositioning of the bracket and consequent loss of zeroing for close-range targets, a deviating prism is installed in front of the sight. The deviating prism changes the field of view of the sight such that a target image can be centered in the sight even though the axis of the sight is pointed above the target. In the preferred form of the invention, the deviating prism is hingedly or removably mounted on the sight so it may be quickly removed for shooting at close range.

Individual archers may have favored anchor points, this being the point on the archers head or neck adjacent which the arrow nock is positioned when the bow is drawn. To insure that the archer can see comfortably through the sight, regardless of the anchor point selected, the bracket feet can be moved relative to the mounting studs to achieve the desired alignment. Horizontal adjustment is provided by moving the bracket feet, which are slightly curved in cross section, laterally along the mounting studs. Vertical adjustment is made by moving the bracket feet in or out along the mounting studs.

To achieve high accuracy and repeatability, it is important that the archer hold the bow vertically. As an aid to achieving this proper bow position, a small bubble level can be mounted on top of the sight where it is easily viewed by the archer. The axis of the level is transverse to the lengthwise axis of the bow, such that the bubble will be centered only when the bow is held vertically.

These and other aspects of the invention will be more fully understood from the following detailed description and accompanying drawings in which:

FIG. 1 is a side elevation of an archery bow with the aiming device installed on the bow back;

FIG. 2- is a partial enlarged side elevation of the bow and aiming device of FIG. 1;

FIG. 3 .is a side elevation of another style of archery bow with the aiming device installed on the bow front;

FIG. 4 is a sectional view taken on line 44 of FIG. 2;

FIG. 5 is a sectional view taken on line 5-5 of FIG. 2;

FIG. 6 is a sectional view taken on line 6-6 of FIG. 5;

FIG. 7 is a side elevation, partially broken away, of a deviating prism;

FIG. 8 is a perspective view of a modified deviating prism;

FIG. 9 is a side elevation, partially broken away, of a hinged deviating prism; and

FIG. 10 is a front elevation of a bubble level.

Referring to FIGS. 1 and 2, an aiming device 11 is secured to the back of an archery bow 12 having a midsection 13 and bowstring 14. Archers eye 15 is shown in schematic relation to the bow.

'I he aiming device 11 includes an elongated bracket 17 which is concavely curved along its length relative to the archer. Bracket 17 terminates in mounting legs 19 and 20, which in turn terminate in mounting

feet

22 and 23 respectively. Leg is shorter than leg 19, and can be mounted at either the top or the bottom of bow midsection 13 depending upon the midsection shape.

Archery bows are available in a variety of elaborate shapes, but the use of mounting legs of different lengths permits the bracket to be installed on a bow of almost any midsection shape. FIG. 3 illustrates an unusual style of archery bow 26 on which the back 27 of midsection 28 provides a difiicult mounting surface for a bracket as used in this invention. A modified bracket 29 can be used in this situation, the modified bracket being mounted on the front 36 of the bow. Other than bracket 29, the aiming device illustrated in FIG. 3 is identical to the aiming device of FIGS. 1 and 2 and, for brevity, it is not described in detail.

Mounting

feet

22 and 23 are secured to the bow by two elongated threaded mounting studs 32, flat locking nuts 34 and comically-shaped locking nuts 35. Each mounting stud is inserted into a hole 36 in the bow midsection, as suggested in FIG. 4, and cemented or otherwise secured into place. Bracket 17 is positioned to secure proper vertical alignment of the aiming device with the a-r-chers eye by moving mounting

feet

22 and 23 along the mounting studs until the desired position is attained.

Referring to FIG. 4, mounting foot 23 is curved in cross-section presenting a convex face 38 toward flat locking nut 34 and a concave face 39 toward the conical surface 40 of locking nut 35. An elongated hole 43 in the mounting foot allows the foot to be shifted laterally on the stud. When locking nut 35 is tightened against the curved surface of the foot, the foot rotates in an axis parallel to the lengthwise axis of the bow, displacing bracket 17 to provide horizontal alignment of the aiming device wit-h the archers eye. Mounting foot 22 is identical in construction to mounting foot 23 and, for brevity is not described in detail.

Referring to FIGS. 2, 5 and 6, a hollow cylindrical sight housing 46 is slotted on one end transverse to its axis. Slot 47 slidably engages bracket 17 which is secured within the slot by cap 48 which is threaded on one end of the sight housing 46. A screw 49 threaded through the housing forces bracket 17 against

surfaces

50 and 51 of the slotted sight housing, providing a three-point wobblefree suspension for the housing on the bracket.

Optical sight 53, best seen in FIGS. 2 and 5, comprises a mounting tube 54 in which are located ocular lens 55, objective lens 56, crosshair reticle 57, and an erecting lens system (not shown). Windage and elevation adjustments for the reticle crosshairs are located beneath protective caps 60 and 61 respectively.

Mounting tube 54 of the optical sight is installed in the sight housing 46 through close-fitting hole 63 which is bored transverse to the axis of the sight housing and transverse to the axis of slot 47. The mounting tube is locked in place by tubular plastic insert 65 which is slidably disposed within the hollow cylindrical sight housing and forced against the mounting tube by cap 66 which is threaded on the end 67 of the sight housing.

FIG. 7 shows one form of a removable deviating prism assembly 70 used to alter the sight field of view so a target image may be centered in the sight even though the sight is pointed above the target. A prism 71 is secured by cementing or other means within housing ring 72, the ring having an index notch 73. The deviating prism assembly 70 is installed on the aiming device by sliding housing ring 72 over mounting tube 54. Optical alignment is obtained by engaging index notch 73 with index pin 74 which is secured to the mounting tube.

Housing ring 72 is constructed of a slightly elastic material, such as plastic, such that the ring will be secured to the mounting tube by a snug friction fit over the tube. Prism 71 typically provides about four degrees of optical deviation, but prisms providing other ranges of optical deviation can also be used.

FIG. 8 shows a modified deviating prism assembly in which prism 77 is secured within housing ring 78 which fits snugly inside mounting tube 54. Optical alignment is obtained by engaging index notch 79 with index pin 80 which projects slightly into the inner bore of the mounting tube.

FIG. 9 shows a hinge-mounted deviating prism assembly which can be permanently secured to the aiming device and hinged out of the sight field of view when its use is not desired. Prism 83 is secured within housing ring 84 which fits snugly inside mounting tube 54. Flexible plastic hinge 85 is secured at one end to the mounting ring, and at the other end to the mounting tube. When the prism is not needed, housing ring 84 is hinged back over the top of the mounting tube as suggested by the phantom view in FIG. 9. The housing ring is secured in this retracted position by lug 86 which has a snap fit in flexible retainer 87. Optical indexing is provided by the index notch and pin arrangement suggested in FIG. 8.

Referring to FIG. 10, a bubble level 90 is secured by cementing or other means to mounting cap 91 which fits snugly over reticle-adjustment cap 60. This bubble level is in full view of the archer during shooting, and is used as an aid to holding the bow in a precise vertical position.

In use, the aiming device is set to a minimum-distance, flat-trajectory position by sliding the sight housing 46 to the top of bracket 17. The bracket feet are then adjusted along the mounting studs until the sight is comfortably aligned with the archers eye. The initial setting can be checked by firing several trial arrows, and any necessary windage or elevation adjustments are most easily accomplished by moving the reticle cross-hairs.

Once these initial settings are made, the sight is ready for use. As the archer fires at more distant targets, the sight housing is moved down the bracket, introducing an increased elevation correction into the aiming sight and resulting in a higher arrow trajectory. Should a crosswind deflect the arrow laterally away from the target, correction can be made by simply holding off the target by the amount of the deflection encountered. Experience has shown that the eye is capable of judging such a correction with remarkable accuracy. For high-accuracy shooting, very precise windage and elevation corrections can be introduced by the reticle adjustments, leaving the sight mounting unchanged.

I claim:

1. Mounting apparatus for an archery aiming sight, comprising an elongated bracket secured to the midsection of an archery bow, the bracket having a curve along its length which is concave relative to an archer holding the bow, a leg extending toward the bow from each end of the bracket, each leg terminating in a foot, each foot having a mounting hole, two spaced-apart elongated studs, each stud secured to and extending from the bow through a foot mounting hole, and means adjustably securing each foot along the length of a stud, the variable positioning of the two feet permitting adjustment of the radius of curvature of the bracket and positioning of the sight rela tive to the archer, and means slidably securing the aiming sight to the bracket, the elevation setting of the sight being adjustable by sliding said means along the curved bracket.

2. Mounting apparatus for an archery aiming sight, comprising an elongated bracket secured to the midsection of an archery bow, the bracket having a curve along its length which is concave relative to an archer holding the bow, a leg extending toward the bow from each end of the bracket, each leg terminating in a foot having an elongated mounting hole, the feet being shaped convexly toward the bow, the axis of the convexity being generally parallel to the length of the bracket, two spaced-apart elongated studs, each stud secured to and extending from the bow through a foot mounting hole, and means adjustably securing each foot to a stud such that the convexshaped feet can be positioned to adjust the sight position relative to the archer, and means slidably securing the aimin sight to the bracket, the elevation setting of the sight being adjustable by sliding said means along the curved bracket.

3. In an optical aiming sight comprising a reticle, an optical system placing the reticle and an image of a target in the same focal plane, and a mount for the reticle and optical system, a deviating prism hingedly mounted in front of the sight between the sight and the target, the prism altering the sight field of view such that the target image can be centered in the sight even though the sight is not aimed directl at the target, and latching means for securing the deviating prism against the mount out of the sight field of view when use of the deviating prism is not desired.

References Cited by the Examiner UNITED STATES PATENTS LEONARD FORMAN, Primary Examiner. I. M. FREED, Assistant Examiner.

Claims

1. MOUNTING APPARATUS FOR AN ARCHERY AIMING SIGHT, COMPRISING AN ELONGATED BRACKET SECURED TO THE MIDSECTION OF AN ARCHERY BOW, THE BRACKET HAVING A CURVE ALONG ITS LENGTH WHICH IS CONCAVE RELATIVE TO AN ARCHER HOLDING THE BOW, A LEG EXTENDING TOWARD THE BOW FROM EACH END OF THE BRACKET, EACH LEG TERMINATING IN A FOOT, EACH FOOT HAVING A MOUNTING HOLE, TWO SPACED-APART ELONGATED STUDS, EACH STUD SECURED TO AND EXTENDING FROM THE BOW THROUGH A FOOT MOUNTING HOLE, AND MEANS ADJUSTABLY SECURING EACH FOOT ALONG THE LENGTH OF A STUD, THE VARIABLE POSITIONING OF THE TWO FEET PERMITTING ADJUSTMENT OF THE RADIUS OF CURVATURE OF THE BRACKET AND POSITIONING OF THE SIGHT RELATIVE TO THE ARCHER, AND MEANS SLIDABLY SECURING THE AIMING SIGHT TO THE BRACKET, THE ELEVATION SETTING OF THE SIGHT BEING ADJUSTABLE BY SLIDING SAID MEANS ALONG THE CURVED BRACKET.

3. IN AN OPTICAL AIMING SIGHT COMPRISING A RETICLE, AN OPTICAL SYSTEM PLACING THE RETICLE AND AN IMAGE OF A TARGET IN THE SAME FOCAL PLANE, AND A MOUNT FOR THE RETICLE AND OPTICAL SYSTEM, A DEVIATING PRISM HINGEDLY MOUNTED IN FRONT OF THE SIGHT BETWEEN THE SIGHT AND THE TARGET, THE PRISM ALTERING THE SIGHT FIELD OF VIEW SUCH THAT THE TARGET IMAGE CAN BE CENTERED IN THE SIGHT EVEN THOUGH THE SIGHT IS NOT AIMED DIRECTLY AT THE TARGET, AND LATCHING MEANS FOR SECURING THE DEVIATING PRISM AGAINST THE MOUNT OUT OF THE SIGHT FIELD OF VIEW WHEN USE OF THE DEVIATING PRISM IS NOT DESIRED.