The present disclosure generally relates to apparatus and methods for tuning an archery bow by adjusting the position of limbs of the bow and relates specifically to apparatus and methods for non-permanently adjusting a tilt angle of a limb relative to a riser.
In archery bows, customization and adjustability are highly prized features. Skilled archers take advantage of even small adjustments to the weight, size, and position of various elements of the bow to improve their accuracy and precision. One part of the bow that is greatly affected by fine adjustments is the bow's limbs. The limbs are the flexible members that are usually attached to the upper and lower ends of the handle riser of the bow in limb pockets. The limbs are usually secured to the bow by bolts such as dovetail bolts and tiller bolts.
A tiller bolt extends through an opening in the proximal end of the limb to retain the limb in the limb pocket. When a tiller bolt is adjusted, the limb moves forward or backward relative to the riser. A bow's “tiller” is defined as the difference in the perpendicular distance from the upper limb to the string and the lower limb to the string, as measured at the base of the limbs where they attach to the riser. Controlling the tiller may allow the archer to more easily and comfortably aim during the draw and release of the shot. The tiller also affects the angle at which the arrow is launched from the bow when the arrow is released.
Dovetail bolts extend toward the riser from the proximal end of the limb to mate with dovetail openings in the end structure of the limb pocket and/or a dowel that is attached to the riser. The dovetail bolt is used to keep the limb from falling out of the limb pocket and, in bows using dowels, to fix the limb's position relative to the dowel's main cylinder. In bows with dowels, the lateral position of the limb may be adjusted to the left and right relative to the riser by adjusting the dowel. When adjusted, the main cylinder of the dowel moves left and right within the riser, thus causing the dovetail bolt and the limb to which it is connected to move left and right as well. The limb's motion may be lateral translation or may be a rotation of the vertical axis of the limb to the left or right, depending on whether the limb is pivotally connected proximal to the dowel in the limb pocket. By adjusting the lateral position of the limb, the bowstring may be moved left and right at the distal end of the limb, so the archer may adjust the alignment of the bowstring relative to the riser and the arrow plane.
Conventional methods of adjusting the position of the limb relative to a riser only control the left-right lateral position of the limb or the front-back lateral position of the limb. This limits the amount of control the archer has over the tuning of his or her bow limbs. Therefore, there exists a need for improvements in archery bow limb tuning, particularly in positioning a riser relative to a limb.
According to one aspect of the present disclosure, an archery bow assembly having adjustable limb placement is provided. The bow assembly may comprise a riser having a limb attachment portion and a limb that has a distal end extending away from the riser and a proximal end retained at the limb attachment portion of the riser. The limb may have a riser-facing surface and an outer surface. The bow assembly may also include an anchor retaining the proximal end of the limb in the limb attachment portion, the anchor having a limb-facing surface and at least one adjustable separator configured to spread apart the limb-facing surface of the anchor and the outer surface of the limb.
In the archery bow assembly, the proximal end of the limb may be a limb pivot surface and the anchor may be a weight-tiller adjustment bolt. A weight-tiller adjustment bolt may be referred to as a limb bolt configured to adjust the weight and/or tiller of the limb. Thus, the anchor may be a limb bolt, and the outer surface of the limb may comprise an adjacent surface positioned adjacent to the limb bolt, wherein the adjustable separator separates the adjacent surface from the limb-facing surface of the anchor. The adjacent surface may, for example, be lateral to the limb bolt on an outward-facing surface of the limb.
The adjustable separator may be adjustably retained in the limb, and it may spread apart the limb-facing surface of the anchor and the outer surface of the limb by adjustably extending from the outer surface of the limb. The adjustable separator may be adjustably retained in the anchor, and it may spread apart the limb-facing surface of the anchor and the outer surface of the limb by adjustably extending from the limb-facing surface of the anchor. The adjustable separator may be adjustable by driving a threaded surface of the adjustable separator.
The limb may comprise a central longitudinal axis, wherein the at least one adjustable separator separates the anchor and the limb along an axis perpendicular to the central longitudinal axis of the limb.
In some embodiments, the at least one adjustable separator may comprise at least two adjustable separators, wherein each of the at least two adjustable separators are positioned on opposing sides of the anchor. The at least one adjustable separator may comprise a shim removably attachable between the limb-facing surface of the anchor and the outer surface of the limb. A shim may be retained by a shaft, such as a shaft of a fastener.
The at least one adjustable separator may also be partially insertable into at least one opening in the outer surface or riser-facing surface of the limb.
In another aspect of the present disclosure, a method of adjusting the position of a limb of an archery bow is set forth. This method may comprise providing an archery bow assembly which includes: a riser having a limb attachment portion, a limb having a distal end extending away from the riser and a proximal end retained at the limb attachment portion of the riser, the limb having a riser-facing surface and an outer surface, an anchor retaining the proximal end of the limb in the limb attachment portion, the anchor having a limb-facing surface, and at least one adjustable separator configured to spread apart the limb-facing surface of the anchor and the outer surface of the limb. The method may further comprise adjusting an angle between the limb-facing surface of the anchor and the outer surface of the limb by adjusting the at least one adjustable separator to at least partially separate the limb-facing surface from the outer surface. The angle may be adjusted continuously or incrementally.
In another embodiment, an archery bow assembly having adjustable limb placement is provided. The bow assembly may include a riser having a limb attachment portion, wherein the limb attachment portion may have a limb-facing surface. The assembly may also have a limb having a distal end extending away from the riser and a proximal end retained at the limb attachment portion of the riser. This limb may have a riser-facing surface and an outer surface. A dovetail bolt may also be included that at least partially extends through the limb-facing surface of the limb attachment portion and the riser-facing surface of the limb, with the dovetail bolt retaining the limb to the riser. The assembly may further include at least one adjustable separator positioned lateral to the dovetail bolt between the limb-facing surface of the limb attachment portion and the riser-facing surface of the limb, the at least one adjustable separator being configured to spread apart the limb-facing surface of the limb attachment portion and the riser-facing surface of the limb. In these assemblies, the adjustable separator may comprise a threaded bolt. The adjustable separator may also comprise a removable shim.
In another embodiment, an archery bow assembly having adjustable limb placement is provided which may comprise a riser having a limb attachment portion. The limb attachment portion may have a limb-facing surface. The bow assembly may also include a limb having a distal end extending away from the riser and a proximal end retained at the limb attachment portion of the riser by an anchor, wherein the limb may have a riser-facing surface and an outer surface. In the bow assembly, a dowel may be positioned between the limb-facing surface of the limb attachment portion and the riser-facing surface of the limb, the dowel being positioned between the anchor and the distal end of the limb and the dowel comprising a limb-facing surface and at least one adjustable separator extending from the limb-facing surface. Herein, the adjustable separator may contact the riser-facing surface of the limb, wherein the adjustable separator may be configured to adjustably separate the limb-facing surface of the limb attachment portion from the riser-facing surface of the limb.
In the archery bow assembly, the adjustable separator may comprise a threading, wherein turning the adjustable separator drives the threading to extend or retract the adjustable separator from the limb-facing surface of the dowel.
In another configuration, the adjustable separator may comprise at least one shim positioned between the limb-facing surface of the dowel and the riser-facing surface of the limb. This shim may be removably attached to the dowel. The adjustable separator may also further comprise at least one cover plate positioned between the shim and the riser-facing surface of the limb. In some cases, the cover plate may have a curved surface facing the limb.
The adjustable separator may be removably attached to the dowel. The dowel may comprise at least two adjustable separators each being configured to contact the riser-facing surface of the limb.
In yet another embodiment, an adjustable dowel for an archery bow is provided, wherein the dowel may comprise a body portion having a first end and a second end, the body portion having a limb-facing surface and a riser-facing surface extending between the first end and the second end, wherein the body portion is configured to be laterally movable upon attachment to a bow riser. The dowel may also include an adjustable separator positioned on the limb-facing surface of the body portion, the adjustable separator extending from the limb-facing surface to a height, the adjustable separator being configured to change the height upon adjustment.
The height of the adjustable separator may be continuously adjustable, such as by the adjustable separator comprising a threaded post that may be adjustable by turning the threaded post relative to the body portion, thereby changing the height of the adjustable separator. The adjustable dowel may also comprise at least one set screw, the set screw preventing adjustment of the height upon tightening of the set screw against the threaded post.
In some arrangements the height of the adjustable separator may be incrementally adjustable, and the adjustable separator may comprise at least one shim removably attached to the limb-facing surface of the body portion.
In yet another aspect of the disclosure, a method of tuning an archery bow limb is provided, wherein the method comprises providing an archery bow comprising: a riser having a limb retaining portion, the limb retaining portion having a limb-facing surface, and a limb retained in the limb retaining portion of the riser, the limb having a riser-facing surface. The limb-facing surface may have a separator extending to a separation distance from the limb-facing surface toward the riser-facing surface of the limb. The method may further comprise adjusting the straightness of the limb relative to the riser by altering the separation distance of the separator.
The straightness of the limb may be adjustable relative to the riser while the limb is retained by the riser. Altering the separation distance may comprise inserting a removable shim between the separator and the limb-facing surface. The separator may comprise a threading, and altering the separation distance may comprise turning the separator.
The separation distance of the separator may be altered incrementally or continuously, and the straightness of the limb may be adjusted by tilting the limb-facing surface relative to the riser-facing surface.
In some embodiments, the limb-facing surface may be positioned on a dowel positioned between the limb retaining portion and the riser-facing surface of the limb. Thus, the dowel may be considered a component of the riser.
The above summary of the present invention is not intended to describe each embodiment or every implementation of the present invention. The Figures and the detailed description that follow more particularly exemplify a preferred embodiment.
The present disclosure generally relates to systems, apparatuses, and methods that allow a user to pivot, turn, or rock a bow limb, such as a recurve bow limb, relative to a riser. This may allow the distal tip of the limb to be tuned so that it is pulled in a straight line throughout a draw cycle. This may improve the comfort, accuracy, and precision of a bow by giving archers more customization and control over the forces acting on an arrow.
In one aspect of the disclosure, a bow may have a riser configured to receive and retain a limb. The limb may be secured to the riser at a proximal end of the limb by a limb bolt and/or dovetail bolt, and a distal end of the limb may extend away from the riser. The limb bolt may be referred to as an anchor. An anchor may also be a post, bolt, clamp, or another device used to keep the limb attached to the riser. In some embodiments, the limb is permanently attached to the riser at its proximal end. The riser and limb may be part of a bow, such as, for example, a recurve bow, traditional bow, or compound bow. The riser may comprise a limb attachment portion, such as, for example, a limb pocket configured to receive the proximal end of the limb. The limb pocket may have a surface facing the limb (i.e., a limb-facing surface), and the limb may have a surface facing the riser (i.e., a riser-facing surface).
In one embodiment, the limb may comprise openings or apertures in the riser-facing surface of the limb at a portion of the riser-facing surface that contacts the riser or a dowel positioned in the limb pocket. For example, the portion of the riser-facing surface may be laterally adjacent to (i.e., to the left or right of) the dovetail bolt. This area may also be defined as being lateral from a longitudinal axis running along the limb. The openings may be configured to receive one or more removably attachable shims. The shims may separate the limb-facing surface of the riser from the riser-facing surface of the limb. By inserting an uneven number or size of shims into the openings on each side of a dovetail bolt or on opposite sides of the riser-facing surface and then seating the limb in the limb pocket, the limb may be turned to an angle around the limb's longitudinal axis, which angle is provided by the offset of the shims. Thus, the distal tip of the limb may be pivoted and turned relative to the riser, causing the bowstring to also be repositioned relative to the riser. In some cases, the shims may be used to evenly space apart the limb-facing surface and riser-facing surface on each side of the limb's longitudinal axis. This may allow the archer to adjust the tiller of the bow by moving the limb forward relative to the riser.
In another example embodiment, the limb may comprise adjustable posts positioned at its proximal end that are adjacent to a limb bolt extending through the limb. The posts may separate the outer or frontal surface (i.e., a bolt-head-facing surface) of the limb from a limb-facing surface of the limb bolt. The posts may be positioned laterally from the longitudinal axis of the limb. Thus, when the posts are adjusted to extend from the outer surface of the limb or to retract into the outer surface of the limb, the limb-facing surface of the bolt and the outer surface of the limb may be separated to a desired angle, thereby pivoting the limb around its longitudinal axis. In another embodiment, the posts may be mounted in the head of the bolt and extend toward the outer surface of the limb. These posts may also have their height adjusted relative to the limb-facing surface of the bolt to change the angle between the limb-facing surface of the bolt and the outer surface of the limb.
In yet another example, the angle of the limb relative to the riser may be adjusted by adjusting a post or shim portion of a limb dowel. For instance, the dowel may have an adjustable post that extends between the riser-facing surface of the limb and the limb-facing surface of the dowel. As the post is adjusted, the limb may rotate relative to the riser around the limb's longitudinal axis due to contact with the post. In some embodiments, additional posts may be used, such as one post on each side of the longitudinal axis, so that the tiller of the bow may be changed by increasing the distance between the dowel and the limb on each side of the longitudinal axis and so that the angle of the limb may be adjusted in either direction around its longitudinal axis. Similarly, the dowel may have a portion configured to retain shims that fit between the dowel and the limb. These shims may also space the limb from the riser to adjust the tiller of the bow.
The present disclosure sets forth a detailed description of specific embodiments of the invention, but it will be understood that various combinations of elements of the individual embodiments may be made to obtain related embodiments. The disclosure is therefore not meant to define every embodiment, but is to provide illustrative examples of how certain embodiments operate while incorporating related embodiments in the spirit and scope of a more general disclosure. For example, a limb angle may be adjustable by posts extending from a limb bolt and also by shims attached to the limb adjacent to a dovetail bolt. Other such embodiments will be apparent to those having skill in the art and the benefit of the present disclosure.
Turning now to the figures in detail,
The limb 104 may be retained in a limb pocket 112 of the riser 102 by a limb bolt 114 and a dowel 116 having a dovetail bolt 118 (see
The limb 104 may form a riser contact plane 126 along the riser-facing side 128 of the limb 104. The riser-facing side 128 may also be referred to as the rear surface or pocket-facing surface of the limb 104. The outward-facing side 130 of the limb 104 forms a bolt contact plane 132 where the outward-facing side 130 contacts the underside of the head of the limb bolt 114. See also
The tiller measurement of the limb 104 may be measured perpendicular to the bowstring where the limb 104 contacts the riser 102, as shown by tiller distance T in
The posts 136, 138 may be retained in the bolt head 134 by a non-permanent or semi-permanent attachment mechanism, such as a threading (see
The limb bolt 114 may have single-piece, unitary construction, or may have a bolt head 134 that is attachable or removably attachable to the shaft 142 of the bolt 114. If the bolt head 134 is a separate part of the bolt 114, the head 134 may be pivotable or rotatable relative to the shaft 142.
The limb opening 143 may be defined as an aperture through the limb 104 through which the bolt 114 extends. The limb opening 143 may be a hole through the limb, a slot in the proximal end 120 of the limb 104, or another comparable space through which the bolt 114 may fit. In some embodiments, the proximal end 120 of the limb 104 may flex laterally and/or longitudinally in order to open and receive the shaft 142 of the limb bolt 114 when the limb 104 is installed in the pocket 112. In the embodiments pictured, a slot is formed at the end of the limb 104 within which the limb bolt 114 is seated when the limb 104 is completely inserted into the pocket 112.
In
As shown in
At the same time, if the bow 100 includes a dowel 116 (as shown in these figures), the limb 104 may be laterally adjusted at the dovetail bolt 118. Adjustment of the dowel 116 may move the limb 104 laterally with respect to the limb pocket 112 at the dovetail bolt 118, such as along the X1-axis shown in
In post 900, the head 906 and shaft 908 may be smooth and uninterrupted by openings, apertures, depressions, and other shapes. This post 900 may beneficially be press-fit or interference-fit into a bow. Alternatively, this post 900 may be interchangeable with other posts having a different length of shaft 908 or thickness of head 906 so that each interchangeable post extends from the limb or limb bolt at a different length or height.
Post 902 comprises a threaded shaft 908 that allows the post 902 to be adjusted when inserted into a threaded opening in the limb or limb bolt. For example, the post adjustment openings 148, 150, 260, 262 may be threaded to receive threads of the shaft 908 of the post 902 so that turning the shaft 908 reversibly adjusts the position of the post 902 in the bow. Thus, the post head 906 may comprise a driver feature 910 such as, for example, an opening or depression in the post head 906 that allows the post 902 to be turned by insertion of a tool. In the embodiment of
The lateral adjustment portions 1208, 1210 may be threadably engaged with the first and second ends 1204, 1206 of the body portion 1202, respectively. Thus, with the dowel 1016 installed in the riser (e.g., in the manner shown in
The adjustable posts 1212, 1214 may be installed in bores 1224, 1226 extending through the body portion 1202 of the dowel 1016. The bores 1224, 1226 may be threaded to engage threading on shafts 1228, 1230 of the adjustable posts 1212, 1214. The bores 1224, 1226 may extend entirely through the body portion 1202 as shown or may extend partially through the body portion 1202. In some embodiments, the shafts 1228, 1230 may not be threaded, but may be retained in the bores 1224, 1226 by the set fasteners 1218, 1220 without being threaded to the bores 1224, 1226. The ends of the shafts 1228, 1230 may be configured to receive a tool to allow the posts 1212, 1214 to be turned and moved relative to the body portion 1202. For example, in
The adjustable posts 1212, 1214 may have head portions 1232, 1234 that are broadened relative to the shaft portions 1228, 1230. The surfaces of the head portions 1232, 1234 extending away from the body portion 1202 may be configured to contact the limb adjacent to the dowel (see
The dovetail bolt retaining recess 1216 may be shaped to receive the inside end of a dovetail bolt. See also
The set fasteners 1218, 1220 may extend through the body portion 1202 into contact with the shafts 1228, 1230 of the posts 1212, 1214. In some embodiments, the set fasteners 1218, 1220 may be screws or bolts that may be tightened against the shafts 1228, 1230 to keep the shafts 1228, 1230 from shifting or turning while the bow is in use. The set fasteners 1218, 1220 may be loosened when desired in order to allow the posts 1212, 1214 to be adjusted. Some embodiments may omit set fasteners 1218, 1220, such as where the posts 1212, 1214 are removable, but do not have adjustable height while installed in the body portion 1202.
As discussed with reference to dowel 1016, dowel 1716 may be configured to translate the dovetail bolt 1718 and, therefore, the limb 1704, along the D4 axis.
Shim plates 1912, 1914 are positioned at the first and second ends 1904, 1906, respectively, one on each side of the dovetail bolt retaining recess. The shim plates 1912, 1914 may be shaped to mimic the cylindrical shape of the body portion 1902. For example, the outward-facing surfaces of the shim plates 1912, 1914 may be curved where they contact a limb, as shown in
Shims 1922 may be configured to be inserted between the shim plates 1912, 1914 and the body portion 1902. The shims 1922 may be thin plates held in position by pressure applied by the fasteners 1918, 1920 against the shim plates 1912, 1914. Shims 1922 may also be held in position by the fasteners 1918, 1920 extending through an opening or slot in each shim 1922. See
The dowel 1716 may also include an end bolt 1924 to secure the adjustment portion 1908 to the body portion 1902. The distance between the adjustment portion 1908 and body portion 1902 may be controlled by dowel shims 1926 placed between them.
As shown in
The shims 2412, 2414 may have the same or different thicknesses, surface shapes, and profiles. Shims 2412, 2414 are shown in the section view of
In another aspect of the present disclosure, methods may be provided for assembling and adjusting an archery bow. In one example embodiment, a method may be provided of adjusting the position of a limb of an archery bow that comprises providing a bow assembly. The bow assembly may have a riser having a limb attachment portion or limb pocket, a limb having a distal end extending away from the riser and a proximal end retained at the limb attachment portion of the riser, with the limb having a riser-facing surface an and outer surface, an anchor retaining the proximal end of the limb in the limb attachment portion that has a limb-facing surface, and at least one adjustable separator configured to spread apart the limb-facing surface of the anchor and the outer surface of the limb. The method may further comprise adjusting an angle between the limb-facing surface of the anchor and the outer surface of the limb by adjusting the at least one adjustable separator to at least partially separate the limb-facing surface from the outer surface.
The angle between these surfaces may be adjusted continuously, such as by the adjustment of a threaded post that acts as the adjustable separator, or the angle may be adjusted incrementally, such as by the changing of the number or thickness of shims inserted between the surfaces.
The angle between the surfaces may be defined as the angle between two axes; one running laterally across the limb perpendicular to the longitudinal axis of the limb, and one running laterally across the riser and also perpendicular to the longitudinal axis of the limb (at least before the limb is rotated). Thus, adjusting the adjustable separator (e.g., a shim, shim plus shim plate, adjustable post, or other similar feature) may include changing the height of the adjustable separator relative to the surface to which it is attached.
Adjusting the angle between the limb-facing surface of the anchor and the outer surface of the limb may comprise adjusting the adjustable separators so that the angle between the surfaces changes, such as by adjusting one adjustable separator more than the other or adjusting them so that at least one has a different height than another on the other side of the surfaces being separated. As used herein, the anchor may be a fastener for a bow limb, such as, for example, a limb bolt or a dovetail bolt that anchors the limb to the riser.
In another method, an archery bow limb may be tuned. The method may comprise providing an archery bow having a riser with a limb retaining portion, wherein the limb retaining portion may have a limb-facing surface. The bow may also have a limb retained in the limb retaining portion of the riser, the limb having a riser-facing surface. The bow may have a dowel positioned between the limb-facing surface of the limb retaining portion and the riser-facing surface of the limb, the dowel having a separator extending to a separation distance from the dowel toward the limb. The method may further include adjusting the straightness of the limb relative to the riser by altering the separation distance of the separator. The straightness of the limb may be defined as the difference in angle between a longitudinal vertical axis of the riser and a longitudinal vertical axis of the limb when installed in the riser. Thus, the straightness of the limb may be changed by increasing or decreasing the included angle between these two axes.
The straightness of the limb relative to the riser may be adjustable while the limb is retained by the riser. For example, the separator may be adjusted through an opening in the riser or through the limb. In another example, the separator may be adjusted by access between the limb and the riser.
Altering the separation distance may comprise inserting a removable shim between the separator and the dowel. The separator may alternatively be turned to have its separation distance adjusted. Thus, the separation distance may be altered incrementally or continuously. The limb-facing surface of the riser may be tilted relative to the riser-facing surface of the limb due to altering the separation distance of the separator.
Various inventions have been described herein with reference to certain specific embodiments and examples. However, they will be recognized by those skilled in the art that many variations are possible without departing from the scope and spirit of the inventions disclosed herein, in that those inventions set forth in the claims below are intended to cover all variations and modifications of the inventions disclosed without departing from the spirit of the inventions. The terms “including:” and “having” come as used in the specification and claims shall have the same meaning as the term “comprising.”