US3238935A

US3238935A - Reversible archery bow

Info

Publication number: US3238935A
Application number: US64143A
Authority: US
Inventors: Warren Y Stanaland
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-10-21
Filing date: 1960-10-21
Publication date: 1966-03-08
Anticipated expiration: 1983-03-08

Description

United States Patent 3,238,935 REVERSIBLE ARCHERY BOW Warren Y. Stanaland, 2818 Twin Brooks Road NE., Atlanta, Ga. Filed Oct. 21, 1960, Ser. No. 64,143 7 Claims. (Cl. 12423) This invention relates to archery bows and arrows and more particularly to a bow in which the plane of bowstring motion does not intersect the hand of the archer and which may have unique limb motion and to arrows which are pulled by the bowstring and whose length and other characteristics may be selected without regard to the relationships which are normally maintained among arrow characteristics, archers arm span, and bow characteristics.

Although the bow and arrow is historically one of the worlds oldest weapons, improvements in its use and construction have continued to receive the attention of both archers and bowyers. Not only have improvements in bows related to bow configuration, but improvements have also related to the actual construction or materials used in construction. Thus, bows have been developed which have improved properties which are inherent solely in the material or manner of construction.

For example, it is known that when a bow is drawn, the belly of the bow is placed in compression and the back of the bow is placed in tension and that useful bows must be constructed to withstand such forces. Moreover, it is known that when the bowstring of a bow snaps or breaks, the forces in the belly and back of the how are reversed and the belly placed in tension and the back placed in compression and that, if the bow cannot with stand this force reversal, it will break. Thus, bows in which both the belly and back are capable of withstanding both compression and tension have been sought by archers and bowyers. As a result, there are methods of constructing a bow so that both the back and belly of the bow are capable of withstanding both compression and tension. Such a method of bow construction is disclosed in the United States patent to E. B. Pierson et al., No. 2,894,503.

The bow described herein requires, with respect to one of its features, that both its belly and back be capable of withstanding both compression and tension. The necessity for both the belly and back of the bow being able to withstand both compression and tension is related to bow limb action and will become apparent when the limb action of the bow is understood. In gainingan understanding of the limb action of the how, it must be realized that the limbs of a bow possess considerable momentum as they move from the fully drawn position to the braced position where motion is normally abruptly stopped by the effect of the bowstring. However, in the bow described herein, the limbs of the bow move freely from their drawn position to a position in which the limbs are reversed or curved in the opposite direction. Thus, there is no abrupt checking of limb motion, and all the energy stored in the bow during the draw and possessed by the moving limbs is utilized during the propelling of the arrow. It is, however, this reversal of limb motion which makes it necessary that both the belly and back of the how be able to withstand both tension and compression.

In obtaining the benefits of the foregoing bow limb motion, it is necessary to restrict the eifect on limb motion of the bowstring. This is accomplished by permitting the bowstring to pass freely and unobstructively from one side of the bow to the other and is structurally provided for by using pins located at the tip ends of the bow and between which the bowstring is attached.

3,238,935 Patented Mar. 8, 1966 This means of construction permits the bowstring, when drawn and released, to travel in a plane which is parallel to the plane in which the bow tip ends move, but which does not intersect any part of the bow, except the pins.

It should be noted that, when the bow described herein is braced with curvature forced into the limbs, the bowstring will be slightly less in length than the length required to stretch between how nocks when the bow is unbraced. Since, in reversing its curvature upon release, the bow will pass through a position which is substantially similar to that in its unbraced position, a feature of the bow is a bowstring having the proper degree of resiliency necessary for it to stretch and permit the passage of the bow limbs through the position at which the bow tip ends are furthest apart.

The pins mentioned above and other features of the bow described herein will either independently or in com bination provide a plane of bowstring motion which does not intersect the hand of the archer. Thus, it is not necessary to rest the point of the arrow near the hand of the archer to ensure that it will safely pass the hand. This permits the use of arrows which do not rest upon any part of the bow and which are .pulled by the bowstring, rather than pushed. Since these arrows do not rest upon any portion of the how, their length and other features are not related in the usual manner to the length of the bow or of the bows draw. Thus, bow characteristics and arrow characteristics are substantially independent of each other and may each be selected to obtain desired optimum characteristics. The tendency of the bow to twist in the hand of archer because of the displacement of the plane of bowstring motion from the archers hand is overcome by the use of a torque bar.

These and other features of the invention will be more clearly understood from the following detailed description and the accompanying drawings in which like characters designate corresponding parts in all figures and in which:

FIGURE 1 is a plan view of the bow in unbraced condition and with the torque bar in the carrying or storage position, but with pins omitted.

FIGURE 2 is a plan view of the bow in which the solid lines show the bow, bowstring, and arrow in drawn bow position and the torque bar in the using position, and in which the dashed lines show the bow limb and bowstring positions at the end of the arrow propelling motion of the bow.

FIGURE 3 is a plan view of the bow in which the solid lines show the bow in braced position with the torque bar removed for clarity and in which the dashed lines show the bow limbs in unbraced position.

FIGURE 4 is an elevational view of the bow as viewed from the belly or archers side of the bow and which shows the bow in braced position with the torque bar removed for clarity.

FIGURE 5 is a detail perspective view of the pin and of the tabs with which it is attached to the tip end of the bow.

FIGURE 6 is a perspective view of the center portion of the bowstring into which a leather pad has been inserted to enable the bow to be used to propel metal balls.

FIGURE 7 is a section view of the torque bar taken in line 99 in FIGURE 2.

FIGURE 8 is a plan view of the arrow as it would be seen if viewed in same position as shown in FIGURE 2.

FIGURE 9 is an elevational view of the arrow as it would be seen if rotated about its lengthwise axis from its position in FIGURE 8.

These drawings and the following detailed description disclose a preferred specific embodiment of this invention, but the invention is not limited to the details disclosed since it may be embodied in other equivalent forms.

The general bow configuration or type shown clearly in FIGURES 1 and 3 is generally referred to and known as deflexed with recurved ends. Moreover, it should be noted that the recurved ends shown in the embodiment of the invention disclosed herein are of the working type since they unbend when the bow is drawn, as shown by the solid lines in FIGURE 2. It is with this general configuration or type of bow and other known bow configurations or types that additional features are incorporated to obtain the invention herein. The nature of some of these additional features is most clearly seen in FIGURE 4, where the structural feature utilized to obtain adequate clearance between the bow and the plane of motion of the bowstring to permit bow limb reversal is shown.

This structural feature is the two metal pins 11, one mounted at each tip end 12 of the bow. Each of these pins 11 is Welded to a strip of metal 13 which is bent to partially surround the pin 11 and to form two tabs 14 which project from the pin in directions generally perpendicular to the pin 11. One tab 14 at each pin 11 is shaped to coincide with the surface and edge contour of the bow belly 15 at the tip end 12, and the other tab 14 at each pin 11 is shaped to coincide with the surface and edge contour of the bow back 16 at the tip end 12. In addition, the space between the two tabs associated with each pin 11 is just sutficient for the insertion of the bow tip end 12 between and flush with the tabs 14 and with the extreme end 17 of the bow flush against the pin 11. When the bow tip ends 12 are inserted in these spaces, the tabs 14 are secured to them by screws placed through holes 18 in the tabs 14. Thus, with proper initial positioning of the pin 11 with reference to the tabs 14, a pin 11 is securely fastened to each tip end 12 of the bow in a position which is perpendicular to the plane in which the bow tip ends 12 move when the bow is used. An addi tional feature of each pin 11 is the groove 19 which receives the bowstring 20 when the bow is braced.

From the foregoing it can be seen that the pins 11 enable the bow to be braced with the bowstring 20 in a plane which is parallel to the plane in which the bow tip ends 12 move when the bow is used, but which is separated from any part of the how, except the pins 11, by a distance equal to the distance along the pin 11 from the bow tip end 12 to which the pin 11 is attached to the groove 19 in the pin 11.

Although the pins 11 described above enable the bowstring 20 to clear the body of the bow, additional structural features have been incorporated into the bow, which in combination with the pins 11, insure that the hand of the archer does not come in contact with either the bowstring 20 or with the arrow 21 as it is being pulled forward by the bowstring 20. Among these features is the taper shown in FIGURE 4 of the bow limbs 22 away from the bowstring 20 as the limb 22 progress from the tip ends 12 to the bow handle 23. Thus, the handle 23 of the bow is further away from the bowstring 20 than the tip ends 12 of the bow.

Another feature providing the same effect is the cutout 24 in the handle 23 of the how. This cutout 24 is similar to those cutouts found in bows having center shot sighting windows and which are well known to the art. The structural integrity of the bow is maintained by building up the opposite side 25 of the bow in the area of the handle 23 and by increasing the depth of the riser 26. Not only is riser 26 depth desirable from a structural integrity standpoint, but it is also utilized to form a saddle type grip having a thumb recess 27 both on the belly 15 of the bow and on the side 25 of the bow, and having width sufficient to insure that the average archers hand is flat against the side 28 of the handle 23 when the bow is gripped by the thumb and by the fingers bent at the first joint beyond the knuckles. The thumb recesses 27 described herein permit the bowstring 20 to be drawn with the left hand and the bow to be held in the right hand with the motion of the bowstring 20 parallel to the ground. The bow may be used in other how positions by placing the thumb recesses 27 and other features in other related locations on the how.

The foregoing features, in combination with the displacement of the bowstring resulting from the use of pins 11, enable the bow to be used in safety without danger of the hand coming in contact with either the bowstring 20 or the arrow 21 as it is pulled by the bowstring 20. However, the displacement of the plane of motion of the bowstring 20 from the axis of the handle 23 tends to introduce a torque about the handle 23 and twisting of the bow in the archers hand when the bow is drawn. This tendency of the bow to twist in the hand is overcome by the addition of a torque bar 29 to the how. The torque bar 29 is attached to the bow with a peg 30, one end of which is securely and fixedly inserted into the side 28 of the bow in the area of the handle 23, and the other end of which is passed through a hole 31 in the bow end of the torque bar 29.

The end of the peg passing through the torque bar 29 is threaded, and a threaded nut is placed on the peg 30 after the torque bar 29 in order to hold the torque bar 29 on the peg 30 while permitting the torque bar to rotate about the axis of the peg 30. The end of the torque bar 29 opposite the peg end is formed into a rectangle 32 which has two sides 33 bent in planes which are generally perpendicular to the lengthwise axis of the torque bar 29 in order to give the rectangle 32 a curvature similar to that of an archers arm as shown in FIGURE 7. When the torque bar 29 is rotated to the using position as shown in FIGURE 2, the rectangle 32 is against the archers arm and the motion of the torque bar 29 is restricted in any plane which is generally perpendicular to the bowstring 20 when it is in braced position. The peg end of the torque bar 29 similarly restricts the motion of the peg 30, which in turn prevents the bow itself from turning about an axis parallel to a line passing through the tip ends 12 of the bow. Thus, the twisting of the bow in the archers hand is prevented.

Since the torque bar 29 rotates about the axis of the peg 30, it is rotated to the position shown in FIGURE 1 when it is not in use. This feature facilitates storage and carrying of the bow. The torque bar 29 may also be rigidly attached to the bow riser 26 in the position shown in FIGURE 2, and regardless of the manner of attachment to the bow riser 26, the torque bar 29 has a slight curvature in its lever portion 34, so that the rectangle 32 will be in proper contact with the archers arm when the peg end is secured to the bow riser 26, the torque bar 29 is in using position, and the bow is being held in using position by the archer.

As has already been mentioned, the bow limbs 22, in moving from their position when the bow is drawn, as shown by the solid lines in FIGURE 2, to their reverse position, as shown by the dashed lines in FIGURE 2, will pass through a position, shown by dashed lines in FIG- URE 3, in which the bowstring 20 must be longer than its length when the bow is braced with curvature forced into the limbs 22, as shown by the solid lines in FIGURE 3.

Therefore, it is apparent that, without sutficient ability to stretch the bowstring 20 would resist the movement of the limbs 22 through this transition position and the bowstring 20 would either break or prevent the limbs 22 from making the transition from drawn to reverse position. In order to provide for sufficient controlled resiliency for this limb transition while at the same time maintaining bowstring strength and responsiveness, the bowstring 20 is constructed in three segments. The two end segments 35 of the bowstring 20 are identical and serve to join the middle segment 36 and the pins 11 when the bow is braced.

The middle segment 36 of the bowstring 20 is the major portion of the bowstring and is constructed of materials commonly used in making good bowstrings. The short end segments 35 are constructed of materials, such as nylon, having slightly greater resiliency or tendency to stretch than that used in the center segment 36. The careful selection of the length and material of the bowstring end segments 35 will result in a bowstring which provides for limb transition, but retains the properties desired by the archer.

Not only does the increased resiliency of these relatively short end segments 35 of the bowstring 20 enable the bowstring 20 to stretch as the bow limbs 22 change their curvature from their drawn position to revense position, but this resiliency also enables the bow limbs 22 to pass easily through the transition position as they return to the braced position shown in FIGURE 3 from their reverse position after each use.

At this point it should be noted that, when the bow limbs 22 are braced with forced curvature in them, there is a snap or quickening of their motion as they reverse curature while propel-ling an arrow. This snap has the desirable effect of increasing the acceleration of the arrow. Although forced curvature of the braced bow limbs 22 improves the propelling properties of the bow, it should be further noted that one reason for bracing a normal bow wit-h forced curvature in the limbs is to insure that the bowstring will check limb motion in braced position when an arrow is propelled and that the limb curvature will not reverse. Since this bow utilizes the reversing of the bow limbs 22, this consideration in regard to bracing other bows is not present, and the bow may be braced with little or no curvature forced into the limbs. Under these conditions, a completely conventional bowstring 211 may be used since maximum bowstring length is approached or used when the bowstring 20 is attached to the bow. Regardless of the type of bowstring used, the bowstring 20 is provided with a conventional nocking point 37 in order to position the arrow 21 on the bowstring 20.

The operation of the bow is characterized by freedom of the bow limbs 22 to move from their position when the bow is fully drawn to a position in which the limbs 22 have dissipated their momentum by assuming a reverse curvature. This complete use of the energy stored in the how when it is in drawn position and of the momentum of the bow limbs 22 provides a bow having arrow 21 propelling properties superior to those possessed by bows whose limb motion is restricted. This characteristic of the bow is, of course, achieved by the structural separation of the planes of motion of the bow and bowstring 20 which permits the momentum of the bow limbs 22, when drawn and released, to carry the bow limbs 22 and the bowstring 20 from positions on the belly side of the bow to positions on the back side 16 of the bow.

In addition, the torque bar 29 permits the bow described herein and other bows having a tendency to twist in the archers hand when drawn to be used without undue strain or annoyance to the archer because of the tendency to twist. Moreover, the three-segment bow string 26 described herein permits a defiexed bow with recurved ends 10 and other conventional bow configurations to be braced with curvature forced into their limbs without having the transition of the bow limbs 22 from drawn to reverse position impeded.

Not only does the separation of the planes of motion of the bow and bowstring permit bow limb 22 curvature reversal, but it also enables the point of an arrow or bolt to move freely from one side of the bow to the other without striking the bow or the archers hand if the motion of the arrow or bolt point is controlled by the motion of the bowstring 20. To obtain this control, the arrow 21 is pulled from the archers hand by the bowstring 20, rather than pushed, when the bowstring 20 is released. This pulling effect is achieved by mocking the arrow 21 to the bowstring 20 by a hook 39 located at a point along the shaft 51 of the arrow 21 and then drawing the bowstring 20 by pulling the feathered end of the arrow 21 rather than by pulling the bowstring 20. Thus, when the bowstring 2!? is drawn and the arrow 21 released, the arrow 21 is pulled from the archers hand by the bowstring 20 and follows the bowstring 20 to clear the bow and the hand of the archer for the same reasons that the bowstring 2t clears these obstructions.

It should be noted at this point that safe arrow clearance of the bow handle 23 and the archers hand is dependent upon sufficient separation of the plane of motion of the bowstring 2t) and the handle 23 of the bow and not upon the separation of the planes of motion of the bowstring 20 and every part of the bow except the pins 11. For example, the necessary separation can be structurally obtained by using no more than the limb taper and handle area cutout 24 features described herein, and yet these structural features alone will not permit the bow limb 22 reversal associated with separating the planes of motion of the bowstring 20 and every part of the bow, except the pins 11.

Whether the plane of motion of the bowstring 20 is separated from the bow handle 23 and the archers hand by taper of the bow limbs 22, by how handle area cutout 24, by pins 11 mounted at the tip ends 12 of the bow, or by the combination of these features described herein, arrow 21 clearance is further insured by placing the arrow 21 on the side of the bowstring 2t) furthest from the bow handle 23 and the archers hand so that, as the arrow 21 is propelled, the hook 39 and the bowstring 20 are between the arrow shaft '51 and the archers hand.

The hook 39 used to nock the arrow 21 to the bowstring 26 is formed by wrapping heavy wire 41 about a length of the arrow 21, looping a short length of the wire 41 away from the arrow 21 which is bent to curve in a concave fashion toward the feathered end 40 of the arrow 21, and then continuing to wrap the wire 41 about an additional length of the arrow 21. Regardless of how it is formed, the hook 39, of course, always opens towards the feathered end of the arrow 21. Moreover, it is preferable that the hook 39 be located along the length of the arrow shaft 51 at a point generally near or in front of the center of gravity of the arrow 21 since if the hook 39 is located too near the feathered end 40 of the arrow 21, the arrow 21 will tend to assume properties of a pushed arrow rather than those of a pulled arrow.

In addition, it should be noted that two hooks 39 symmetrically shaped are used on the arrow 21 shown in FIGURE 9 to enable a hook 39 to be brought into position to engage the bowstring 20 without ever making a full revolution of the arrow 21 and to increase the balance and aerodynamic properties of the arrow 21.

Since the motion of the arrow 21 is determined by the motion of the bowstring 20, it is not necessary for the point 38 of the arrow 21 to rest, in the usual manner, upon the riser 26 or handle 23 of the bow in order that its flight be properly controlled or to assure that it is not driven into the belly 15 of the bow or the hand of the archer. Thus, the length of the arrow 21 is not limited or dictated by the length of the bow or of the draw associated with the how, a fact that often introduces undesirable limitations into pushed arrows when consideration must be given to spine, weight and other structural features related to the response of an arrow to the push of a bowstring. Instead, arrows 21 of relatively short length are used as shown in FIGURE 2, and may be constructed to obtain the weight, aerodynamic and other desired features dictated by arrow use alone with only the restriction that the arrow 21 have sutficient tensile strength to withstand the pull of the bowstring 20 when the bow is drawn.

The arrow 21 shown herein has a weighted metal head 42 and fletching 43 attached in the normal fashion. However, since the arrow 21 is actually used to draw the bow,

it also possesses an additional feature not previously described and which is not normally found in other arrows or bolts. This feature is the thumb grip 44 at its feathered end 40, by which it is readily and firmly gripped between the thumb and finger of the archer as it is being used to draw the bowstring 20. The bow is, of course, released from the drawn position by allowing the arrows feathered end 40 to slip from between the archers thumb and finger. This enables a smoother release of the arrow 21 than can usually be accomplished when the bowstring 20 is held by the archers bent fingers.

In FIGURE 6 a device is shown which, when used on the bowstring 20, enables the bow to propel metal balls rather than an arrow or bolt. This device is a leather pad 45 which is inserted at the center of the bowstring 20 by cutting the bowstring at its midpoint and tying the free ends 46 of the bowstring 20 through the holes 47 in the leather pad 45. The leather pad 45 may have a small circular recess 48 in its center suited for receiving a metal ball. Thus, when a ball is placed in the leather pad 45, with or without a recess 48, and the bowstring 20 is drawn by gripping the ball through the leather pad 45 with the thumb and finger and then the bowstring 20 released, the metal ball is propelled by the bowstring 20. When propelled by the bowstring 20, the metal ball clears the area of the bow handle 23 and the hand of the archer for the same reasons as those described above in regard to the movement of the arrow point 38.

In order to use a single bow to propel both arrows 21 and metal balls with the same degree of safety to the hand of the archer and at the same time keep the plane of motion of the bowstring 20 near the archers hand so that the twisting tendency of the how, when it is drawn, is minimized, the pins 11 mounted at the tip ends 12 of the bow are provided with a groove 49 in addition to the groove 19 already described. This additional groove 49 is for use when the bow is used to propel metal balls and is located on the pin 11 more distant from the bow tip ends 12 than the groove 19 used when the bow is propelling arrows 21. The separation between

grooves

19 and 49 on the pin 11 is equal to approximately one-half the diameter of the ball which it is desired to propel. This separation ensures that the edge of the metal ball nearest the archers hand as the metal ball is propelled with its center in the line of a bowstring 20 which is attached to the metal ball grooves 49 will pass no closer to the archers hand than the nearest edge of the arrow 21, excluding the hook 39, as the arrow 21 is propelled with its entire structure, except for the hook 39, on the away-from-hand side of a bow-string 20 which is attached to the arrow grooves 19.

What is claimed is:

1. A reversible bow comprising, in combination, a handle; two limbs, each having a tip end and the other end attached to the handle; a bowstring of a length substantially equal to the length of said bow to permit reversing of bow curvature; and means for attaching the bowstring between the tip ends of the two limbs so that the plane of motion of the bowstring does not intersect the handle and limbs.

2. A bow comprising, in combination, a handle; two limbs, each having a tip end and the other end attached to the handle; and a bowstring having one end associated with the tip end of one limb and the other end associated with the tip end of the other limb and having means for holding the bow tips in braced position with curvature forced into both limbs and for permitting the distance between the tip ends of the limbs to exceed that when the bow is braced to the extent necessary for the limbs to pass through their braced position into a position where their curvature is opposite to said braced position.

3. A bow comprising, in combination, a handle; two limbs, each having a tip end and the other end attached to the handle and both constructed to withstand both tension and compression in both the belly and back; a bowstring; and means for attaching the bowstring to the tip ends so that the bow limbs will reverse curvature during each drawing and shooting of the bow without restriction of such motion by the bowstring.

4. A bow having a bowstring and reversible curvature limbs constructed and arranged to reverse their curvature during each use of the bow, said bow and bowstring being constructed and arranged in such a manner that said reversal of curvature of said bow is uninhibited by said bowstring.

5. A bow for propelling a ball comprising, in combination, a handle; two limbs, each having a tip end and the other end attached to the handle; two pins, one extending from the tip end of one limb, the other extending from the tip end of the other limb and both extending in the same direction generally perpendicular to the plane of motion of the two tip ends when the bow is drawn and released, said pins being formed with two string-receiving grooves at different distances from the tip end of each limb; a bowstring with one of its ends selectively received in one of said string receiving grooves of one of said pins and the other of its ends selectively received in one of said string receiving grooves of the other of said pins and having a plane of motion which does not intersect the handle and the two limbs; and means associated with the bowstring for receiving and controlling the ball as it is propelled.

6. The combination with a bow having tip ends and a bowstring of pins having a plurality of grooves therearound and extending from the tip ends in a direction generally perpendicular to the plane of motion of the bowstring, said bowstring being selectively attached at its ends to said pins in any of said grooves.

7. A bow having a handle and curved limbs constructed in a single plane, a bowstring extending between the ends of said bow, means to offset the plane of motion of said bowstring a distance from the plane of the bow whereby the plane of motion of said bowstring is parallel to the plane of said how, and means for adjusting said offset distance.

References Cited by the Examiner UNITED STATES PATENTS 322,984 7/1885 Shears 12422 995,053 6/1911 Bradfield 12422 1,853,294 4/1932 Barnhart -12423 2,344,799 3/1944 Brown et al. 12422 2,508,521 5/1950 Lay 12430 2,532,798 12/1950 Wright 124-20 2,625,926 -1/1953 Foster 12420 2,645,217 7/1953 Fisher 124-22 2,769,439 11/1956 Layer 12430 2,815,016 12/1957 Kellogg 12423 2,816,537 12/1957 Irwin 124-24 2,854,965 10/1958 Eberbach 12423 2,882,055 4/1959 Meyer 273-1065 2,891,794 6/1959 Meyer 273- 1065 2,894,503 7/1959 Pierson et al. 12423 FOREIGN PATENTS 241,085 11/1911 Germany. 177,627 8/1935 Switzerland.

DELBERT B. LOWE, Primary Examiner.

ELLIS E. FULLER, JAMES W. LOVE, RICHARD C,

PINKHAM, Examiners,

Claims

7. A BOW HAVING A HANDLE AND CURVED LIMBS CONSTRUCTED IN A SINGLE PLANE, A BOWSTRING EXTENDING BETWEEN THE ENDS OF SAID BOW, MEANS TO OFFSET THE PLANE OF MOTION OF SAID BOWSTRING A DISTANCE FROM THE PLANE OF THE BOW WHEREBY THE PLANE OF MOTION OF SAID BOWSTRING IS PARALLEL TO THE PLANE OF SAID BOW, AND MEANS FOR ADJUSTING SAID OFFSET DISTANCE.