US3693262A

US3693262A - Bowsight

Info

Publication number: US3693262A
Application number: US21353A
Authority: US
Inventors: Brian Wood
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-03-20
Filing date: 1970-03-20
Publication date: 1972-09-26
Anticipated expiration: 1989-09-26

Abstract

A bowsight structure is provided having an L-shaped bracket which is attached at one end to the handle of an archery bow and which supports a plate member on its other end; the bracket is provided with movable adjusting means which engage the plate member to pivot it about a fulcrum pin and hold the plate in a desired position; the plate member supports a pair of rod elements on which is slidably mounted a sighting device; a tightening screw is provided to retain the sighting device in a preselected position on the rod elements.

Description

Unite States Patent Wood [ 51 Se t. 26, 1972 BOWSIGHT [72] Inventor: Brian Wood, 414 E. Harry St.,

Hazel Park, Mich. 48030 [22] Filed: March 20, 1970 [21] Appl. No.: 21,353

[52] US. Cl ..33/265 [51] Int. Cl. ..F41g 1/00, F4lb 5/00 [58] Field of Search ..33/46 A [561 Relerences Cited UNITED STATES PATENTS 2,669,023 2/1954 Pizzuti ..33/46 A 2,742,702 4/1956 Williams ..33/46 A 2,893,124 7/1959 Sundquist ..33/46 A 2,941,296 6/1960 Grandt ..33/46 A 3,455,027 7/1969 Perkins ..33/46 A 3,477,130 11/1969 Egan ..33/46 A Primary Examiner-Leonard Forman Assistant Examiner-Steven L. Stephan Attorney-Cushman, Darby & Cushman [57] ABSTRACT A bowsight structure is provided having an L-shaped bracket which is attached at one end to the handle of an archery bow and which supports a plate member on its other end; the bracket is provided with movable adjusting means which engage the plate member to pivot it about a fulcrum pin and hold the plate in a desired position; the plate member supports a pair of rod elements on which is slidably mounted a sighting device; a tightening screw is provided to retain the sighting device in a preselected position on the rod elements.

8 Claims, 9 Drawing Figures F IGJ.

ztw w PKTENTED I 2 3.893.262

sum

3 or 4 tlslul wg ggm BOWSIGHT The present invention relates to a sighting device for archery bows that will enable the archer to enhance his skill and accuracy and to make compensatory corrections in both the vertical and horizontal directions relative to the spot at which an arrow enters a target.

Prior art bowsights have the disadvantage of either not being sufficiently adjustable or of being of extremely intricate and expensive construction. Further, the majority of prior art bowsights are constructed in such. a manner that they are often difficult to mount on the curving contours of modern archery bow handles.

The present invention overcomes the disadvantages of prior art bowsights by providing for all adjustments required, by being of simple and inexpensive construction, being readily mountable to the one surface which is always flat, on all modern archery bow handles which do not have a sight built into them by the bow manufacturer.

The invention will be described with reference to the accompanying drawings in which:

FIGS. 1 and 2 represent respectively left side and front elevations of a bow showing the sighting device mounted on the bow handle;

FIG. 3 is a side elevation of the bow sight to full scale;

FIG. 4 is a partial plan view of FIG. 3;

FIG. 5 is a view in section on line 5--5 in FIG. 3;

FIG. 6 is a view on line 6-6 in FIG. 3;

FIG. 7 is a front elevation of the sighting deyice looking from the direction of the target; and

FIGS. 8 and 9 are diagrams showing two arrow trajectories.

The sighting device A is adapted to be fitted to any standard bow structure and is secured thereto by means of an L-shaped angular bracket 1 which has a base 2 and an arm 3. A main plate 4 extends the length of the sight structure and is in vertically-slidable and tiltable engagement with the bracket 1 against the inner face of base 2, and securable by means of stabilizing or supporting pin 5, rocker pin or fulcrum 6 and threaded bolt 7 as well as by threaded set screw 8, each of which engages the plate 4 as shown in FIGS. 5 and 6. The pin 5 is rigidly mounted in the arm 3 of bracket 1 and is in stabilizing frictional engagement with the face of plate 4. Bolt 7 and set screw 8 are threadably mounted in the arm 3 and adapted to bear against one edge of the plate 4 and urge the opposite edge of plate 4 against rocker pin or fulcrum 6.

A lock nut 9 is threadably mounted on set screw 8.

It will be noted that the plate 4 will be in the perpendicular position and held rigidly in place when bolt 7 and set crew 8 are advanced by an equal maximum distance, and that by varying the distance that the bolt 7 and set screw 8 are advanced or retracted, the one in relation to the other, it is possible to enable the plate 4 to be rocked or tilted against the pin 6, the maximum tilt being approximately 10 from the vertical in either direction. The entire sight structure tilts with plate 4.

Supporting studs or pins 10 and 11 are mounted endwise of and in sliding engagement with plate 4 in apertures in the plate, and extend horizontally forwardly in A scale plate 14 is mounted on studs' 10 and 11 forwardly of plate 4 and spaced therefrom by spacers 15.

A rod 16 is mounted in apertures in studs 10 and 11 forwardly of plate 14 and spaced therefrom by spacers 17 A threaded adjusting rod 18 is slidingly mounted in apertures in studs 10 and 11 and adjacent to the free ends 19 of the studs.

Knurled nuts

20 and 21 are threaded on the

free ends

22 and 23 of rod 18 and adapted to bear against the studs and restrict vertical movement of rod 18.

A pin 24 is secured in rod 18 toward its lower end 22 and expansion spring 25 is confined between and seated against pin 24 and stud 10 (FIG. 3).

A sight-block 26 is mounted and adapted for vertical movement, on the rods or

bars

16 and 18 in apertures provided in block 26. The block may be locked in position on

bars

16 and 18 by means of bolt 27 threadably mounted in block 26 and adapted to be advanced into engagement with rod 18. Block 26 may be adjusted to any desired vertical position on

rods

16 and 18 between stud I1 and pin 24, the purpose of rod 16 being to stabilize block 26 in position and prevent rotation thereof.

A threaded sight-rod 28 is threadably mounted in a horizontal position in an aperture in block 26 at right angles to the vertical plane of flight of an arrow. One end of rod 28 carries a sight pip or ball 29 and there is a head 30 at the opposite end. A threaded lock-nut 31 is threadably mounted on rod 28 and adapted to bear against block 26, the purpose of the lock-nut being to secure the sight-rod in any desired position.

FIG. 7 is a longitudinal view of the bowsight structure as it faces away from the archer in the direction of the target. The view shows a portion of the front face 32 of the base 2 of bracket 1. A permanent scale 33 is marked on the face 32 and a permanent guide line 34 is marked on one edge of plate 14.

On the opposite edge of plate 14 the archer marks his own arbitrary scale 35, in yards, to represent the position of the sight-block, in relation to plate 14, and corresponding to a specific distance in yards from the shooting line to the target, as will be explained below.

The method of manipulation of the bowsight structure and the operative relationship of the parts in combination may be explained as follows:

Tightening the nuts 13 causes the supporting studs or pins 10 and 11 to be drawn rearwardly causing the bar 16 which passes through the studs to clamp the spacers 17, the plate 14, and the spacers 15, to the supporting plate 4, creating a solid unit of those pieces. As stated above, the bar 18 passes through the studs 10 and 11 fitting loosely enough to slide up and down freely in a vertical direction. The spring 25 thrusts against the pin 24 and the stud l0 forcing the bar 18 upward in a vertical direction. The vertical movement of the bar 18 is restricted by the knurled nut 20. Tightening the knurled nut 21 locks the bar 18 in position, preventing movement in any direction.

The block 26 slides freely up and down on the

bars

16 and 18 when the knurled screw 27 is loosened, and remains fixed in any position when the screw 27 is tightened.

When the sight is on the bow, see FIGS. 1 and 2, the archer lines up the ball 29 on the end of screw 28 with the bullseye, and shoots an arrow. If the arrow strikes the target to the left or right of the bullseye, the archer loosens the knurled nut 31, and rotates the screw 28, moving the screw and the ball in or out to compensate for the error. After the adjustment, the screw 28 is locked in position by tightening the locknut 31.

The pins and 6, the screws 7 and 8, and the lock nut 9, are arranged to allow the following adjustments:

The supporting plate 4 and the whole body of the sight can be tipped from side to side of the vertical by approximately (see FIG. 6) and the plate 4 is slidable in a vertical direction, within the restrictions of the spacers 15.

The pin 5 holds the plate 4 against the face of the bracket 1, (see FIG. 5) loosely enough to permit up and down movement of the plate 4 in a vertical direction.

Loosening the lock nut 9 and knurled screw 7, and rotating the screw 8, creates a change in the angular position of the plate 4, relative to the bracket 1, and thus to the bow.

Tightening the knurled screw 7 causes the plate 4 to rock on the pin 6 until restricted by contact with the end of the screw 8, rotation of the screw 8 causes a linear change in the position of the end of the screw, thereby allowing more or less rotation of the plate 4, causing more of less change in the angular relation of the plate 4 to the bracket 1. After adjustment, the screw 8 is locked in position by tightening the lock-nut 9.

Tightening the screw 7 locks the plate 4 between the end of screw 8 and pin 6 thereby preventing any movement of the plate 4 in a vertical direction.

The function of the sight and the reasons for the adjustments are as follows: When an arrow is shot from a fully drawn bow, it describes an arc relative to the ground, then falls to the ground, (FIGS. 8 and 9). When the archers arm is level the arc of the arrow is small and the arrow travels only a short distance before falling to the earth. However, as the archer raises his arm from the level position, increasing its angle relative to the ground, the length of the are through which the arrow travels increases and the distance relative to the ground (the chord of the arc) increases until the angle of the archers arm reaches 45. As is well understood, should the archer raise his arm higher than 45 the arc through which the arrow travels has a shorter chord than would the arc of an arrow shot from the 45 maximum angle, therefore the arrow would travel a shorter linear distance relative to the ground.

The object of the sighting device is to cause the are which the arrow describes to intersect with the center of the target at distances ranging from 10 to 100 yards.

When the sight is on the bow, and the block 26 is in the uppermost position on the

bars

16 and 18, the archer can hold his bow arm straight and level and line up the ball 29 on screw 28 with the center of the target with the bow fully drawn. That position is for close targets, distance about 10 yards, since when the archers arm is level, the arrow will only travel a short distance before falling to the ground. The further the archer lowers the block 26 on the

bars

16 and 18, the higher he must raise his bow arm to line up the ball with the center of the target, and the further the arrow fill fly. The archer determines, by trial and error, which position of the block 26 will raise his bow arm sufficiently to cause the arrow to describe the correct are through the air and land in thecenter of the target. When the correct position is determined, the archer marks a pen cil line on the surface of plate 14, using the bottom of the block 26 as a guide, thus establishing his own arbitrary scale 35. He then has a permanent record of the position of the block 26 which will allow him to shoot arrows into the target at that particular distance from the target, see FIG. 7. In this way an archer may start at a distance of 10 yards and, using trial and error, obtain sight markings for distances up to 100 yards.

Regardless of the position of block 26, the ball 29 on screw 28 is the archers only reference point to be lined up with the bullseye. Therefore if the ball remains fixed on the bullseye, lowering block 26 requires the archer to raise the bow, while either advancing or retracting sight-rod 28 will require him to move the bow either to left or to right, all in order to hold ball or pip 39 in line with the target center.

When an experienced archer draws and holds his bow, prior to shooting an arrow, he will attempt to hold it consistently at to the ground. Archers often use a spirit level mounted onthe bow as an aid to this kind of consistency. The reason for this is that it is important that the ball 29 on the sight rod 28 travel up and down an exactly vertical line, relative to the ground, as the archer adjusts the block 26 up and down on the

bars

16 and 18 for each different distance to the target. Since, were the ball to be moved downward at an angle from the uppermost position, its linear position at the lowest point would be changed relative to the original position, which would cause movement of the bow either to one side or the other, by the archer, when aligning the ball with the bullseye, which in turn would cause the arrow to strike either to one side or the other of the bullseye.

In spite of the bow being held exactly vertical when fully drawn however, the face of the bow on which the arm 3 of the bracket 1 is mounted is not always parallel to the vertical plane of the fully drawn bow. It can easily be seen, therefore that if the sight were fixed firmly to the how it could be consistently tipped a little to one side or the other, making it impossible for the ball 29 to travel the exact vertical path desired. The adjustment shown in FIG. 6 allows the archer to move the sight body to one side or the other to compensate for a consistent tip, either side of the vertical, and to return the sight to the vertical when the bow is drawn.

Experienced archers know that weather conditions, either of extreme heat or cold, affect the wooden limbs of the bow, causing the bow to loose or gain in power.

Should an archer establish his sight markings on a day when the limbs are in a less powerful condition due to weather, use of the bow under changed weather conditions, when the limbs are more powerful, will cause the arrow to have a flatter trajectory and strike the target above the bullseye since the sighting mark was set when the limbs were weakened and the arrow described a more curving trajectory. Normally the archer must raise the block 26 on the

bars

16 and 18 and lower the bow to compensate for the extra power. Such an adjustment might place the block in a position not marked on the scale which the archer has recorded on plate 14 and require the archer to guess the correct position for the block 26 for each and every distance from which he may shoot on that particular day.

With the present device, the archer leaves the block 26 set in the position for the distance he may be shooting, slackens the screw 7 and raises or lowers supporting plate 4 and with it the whole sight body to compensate for greater or lesser power in the bow. Such an adjustment will carry the whole of the existing scale marked on plate 14 with the sight body, and enable the archer to continue shooting and simply reset block 26 to the existing scale marked on plate 14. Since only one compensation is generally required for greater or lesser power in the bow, on any one day, the adjustment is accomplished in the manner described, thus eliminating the necessity for the archer to readjust his markings on the scale on plate 14.

The amount of adjustment made in the above manner is measured by the relationship of the permanent line 34 on plate 14 to the permanent scale 33 on the bracket.

With respect to archery ranges, when the distances to the targets from the shooting lines are measured, those concerned with the measuring seldom have access to surveyors measuring equipment. Since archery ranges are often found on rough or even hilly land, the distances to the targets vary slightly from range to range. If the archer sets his sight on one range and shoots on another range, he may find that his arrow will strike the target slightly above or below the exact center. Since the archer usually shoots four or more arrows at each separate distance he can adjust his sight, if necessary, after shooting his first arrow in order to bring his next arrows into the exact center of the target. This type of adjustment is usually a very small one, requiring delicate adjustment of block 26. Such an adjustment may be achieved in the following manner: The archer loosens the knurled nut 21, and rotates the knurled nut causing the nut 20 to move up or down on the fine thread on the bar 18 and thereby either draw the bar 18 down against the pressure of the spring 25, or allow the spring to push the bar 18 upward, depending on the direction of rotation of nut 20. Since the block 26 is locked solidly to the bar 18, by tightening the screw 27 the block 26 moves with the bar 18 thus accomplishing the exact amount of adjustment required simply by rotating knurled nut 20. After adjustment, the knurled nut 21 is tightened, tending to draw the bar 18 upward, but upward movement is restricted by contact of the nut 20 with the lowerstud 10. The nut 21 is then firmly tightened against the upper stud ll, locking the bar 18 in position and preventing movement in any direction. As has been pointed out, the main purpose of the rod 16 is to stabilize or prevent rotation of the block 26, since the block 26 fits loosely enough on the

bars

16 and 18 to slide freely, but not so loosely as to permit rotation about the bars.

The embodiments of the invention in which-an exclusive property or privilege is claimed are defined as follows:

l. A bow sight structure for an archery bow comprising in combination: a main plate having spaced apart ends, an L-shaped bracket having one portion adapted to be attached to the handle of an archery bow and another portion having fixed fulcrum means integral therewith, tilt-adjusting and releasing members and a stabilizing pin being mounted in said bracket, said fixed fulcrum means, said members and said pin being engageable with and adapted to bear against said main plate so that said main plate can be secured in predetermined position relative to said bracket and in a predetermined position about said fixed fulcrum means, a sighting means, said main plate having support means for adjustably supporting said sighting means in a predetermined position relative to said main plate, said supporting means including paired supporting studs threadably mounted in each of said ends respectively of said main plate to project perpendicularly therefrom, a scale plate, a stabilizing rod and an adjusting rod mounted in spaced relation on said supporting studs and spaced from said main plate, said sighting means comprising a sight-block mounted on said stabilizing and adjusting rods and releasably fixed on the latter, and an adjustable sighting device mounted in and in threaded engagement with said sight-block.

2. The bowsight structure as claimed in claim 1 wherein said another portion of said bracket is a substantially flat plate and said one portion is adapted to be attached to the handle of an archery bow so that said plate will lie in a plane that extends substantially transverse to the direction of discharge of an arrow from the bow.

3. The combination defined in claim 1, said adjusting rod extending through vertically aligned apertures in said supporting members and being threaded at its ex tremities, securing members threaded on said extremities and being releasably securable against said members, said rod having spring means mounted thereon, said spring means being confined between one of said supporting members and a pin mounted in said rod, said securing members, adjusting rod, spring means and pin being adapted for fine vertical adjustment of said sight block.

4. The combination defined in claim 1 said scale plate including a permanent scale line referable to permanent graduations on a face of said bracket, said plate being arbitrarily scalable in terms of preselected vertical positions of said sight block.

5. The combination defined in claim 1, said sight block having a securing member releasably engageable with said adjusting rod.

6. The combination as claimed in claim 1, said main plate being releasably, slidably and tiltably mounted in an aperture defined by said fulcrum means, said tilt-adjusting and releasing member, said stabilizing pin and said another portion of said L-shaped bracket.

7. The combination claimed in claim 6, said fulcrum means being a pin rigidly mounted in said another portion of said bracket, said members and said stabilizing pin being mounted in said one portion of said bracket, said members being in threaded engagement and said stabilizing pin being in fixed engagement with said bracket.

8. The combination as claimed in claim 7 wherein said main plate has oppositely facing edges and said tiltadjusting and releasing members are adapted to bear against one of said edges to urge the other of said edges of said plate against said fulcrum pin, said main plate having a longitudinal axis which is substantially parallel to the longitudinal dimension of the archery bow when each of said members is advanced by an equal maximum distance relative to said one portion of said bracket and said longitudinal axis of said main plate being in a tilted position relative to the longitudinal axis of the bow when either of said members is advanced a greater distance in relation to the other of said members.

Claims

1. A bow sight structure for an archery bow comprising in combination: a main plate having spaced apart ends, an L-shaped bracket having one portion adapted to be attached to the handle of an archery bow and another portion having fixed fulcrum means integral therewith, tilt-adjusting and releasing members and a stabilizing pin being mounted in said bracket, said fixed fulcrum means, said members and said pin being engageable with and adapted to bear against said main plate so that said main plate can be secured in predetermined position relative to said bracket and in a predetermined position about said fixed fulcrum means, a sighting means, said main plate having support means for adjustably supporting said sighting means in a predetermined position relative to said main plate, said supporting means including paired supporting studs threadably mounted in each of said ends respectively of said main plate to project perpendicularly therefrom, a scale plate, a stabilizing rod and an adjusting rod mounted in spaced relation on said supporting studs and spaced from said main plate, said sighting means comprising a sight-block mounted on said stabilizing and adjusting rods and releasably fixed on the latter, and an adjustable sighting device mounted in and in threaded engagement with said sight-block.

3. The combination defined in claim 1, said adjusting rod extending through vertically aligned apertures in said supporting members and being threaded at its extremities, securing members threaded on said extremities and being releasably securable against said members, said rod having spring means mounted thereon, said spring means being confined between one of said supporting members and a pin mounted in said rod, said securing members, adjusting rod, spring means and pin being adapted for fine vertical adjustment of said sight block.

8. The combination as claimed in claim 7 wherein said main plate has oppositely facing edges and said tilt-adjusting and releasing members are adapted to bear against one of said edges to urge the other of said edges of said plate against said fulcrum pin, said main plate having a longitudinal axis which is substantially parallel to the longitudinal dimension of the archery bow when each of said members is advanced by an equal maximum distance relative to said one portion of said bracket and said longitudinal axis of said main plate being in a tilted position relative to the longitudinal axis of the bow when either of said members is advanced a greater distance in relation to the other of said members.