Center-fire bow
A bow includes a bow frame with a geometric center, and a frame outlining the geometric center. The pivoting center thrust points are disposed within the frame, and a bow handle is pivotally attached to the vertical pivoting center thrust points at a position offset from the geometric center. The bow is configured such that a user can fire an arrow through the geometric center of the bow, and with pivoting center thrust points it allows free pivoting of the bow about two substantially orthogonal axes.
The present application claims priority from U.S. provisional patent application Ser. No. 60/496,836, filed Aug. 21, 2003 and is a CIP of U.S. regular patent application Ser. No. 10/922,213, filed Aug. 18, 2004 entitled “Center-Fire Bow”.
FIELD OF THE INVENTIONThe present invention relates to archery equipment.
BACKGROUNDThe bow is one of the most ancient weapons, and there have been innumerable designs for bows over the centuries. While the development of firearms long ago displaced bows as among the most powerful and accurate weapons, there is still widespread use of bows in sport hunting and target shooting. Because of this continued enthusiasm, there have been a number of significant improvements and changes in bows in relatively recent times. For example, the development of the compound bow and the introduction of lightweight resilient carbon fiber composite materials have greatly improved the ease of use and performance of modem bows.
Despite modem improvements, however, some traditional problems still remain. For example, the traditional straight bow fires the arrow to the side of the bow, causing a slight waver or curve in the trajectory of the arrow. To eliminate this problem, many modem bows include a lateral offset in the bow just above the handle, allowing the arrow to be fired in line with the vertical axis of the bow.
However, this solution to one problem actually introduces another problem. In order to allow the archer to steady the bow, the handle must be located at the geometric center of the bow. Because the handle occupies the center of the bow, the arrow is therefore necessarily fired slightly above center, and the arrow nock must therefore contact the bowstring slightly above the center. This offset causes the bowstring to apply differential forces to the arrow, causing a vertical waver in the trajectory of the arrow.
SUMMARY OF THE INVENTIONIt has been recognized that it would be advantageous to develop a bow that avoids the vertical and horizontal offsets that affect the trajectory of an arrow.
The invention provides a bow, including a bow frame with geometric center, and a frame supporting the geometric center. A bow handle set on an angled bracket that is attached to the bow frame at a position offset from the geometric center such that a user can fire an arrow through the geometric center of the bow.
In accordance with a more detailed aspect of the present invention, a pivoting center thrust points is disposed within the frame, and the bow handle is pivotally attached to the pivoting center thrust points, allowing free pivoting of the bow about two substantially orthogonal axes.
In accordance with another more detailed aspect of the present invention, the bow further includes a stabilizer bar, rearwardly extending from the bow handle, configured to contact with an arm of the user of the bow, to compensate for moment generated by the offset between the geometric center and the position of the handle.
Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Alterations and further modifications of the inventive features illustrated herein, and additional applications of the principles of the inventions as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.
The bow of the present invention is designed so that an arrow can be fired through a geometric center of the bow. The geometric center has previously been occupied by the archer's hand, rather than locating the archer's hand above or to the side of the center. This configuration allows greater accuracy. This re-positioning of the archer's hand is accomplished by providing a riser that includes a C-frame or window frame through which the arrow is fired. This C-frame allows the shooter to effectively hold the bow from both sides of center using a gimbal-mounted handle.
With reference to
The bow string also includes a pair of nock point indicator bushings 42 for indicating the nock point 44, which represent the proper point for aligning an arrow nock with the bow string. It will be apparent to those skilled in the art that the bow also includes other features not specifically mentioned, and can include other features not shown that are well known in the art.
While the embodiment depicted in
In the embodiment of
While the bow of
The C-frame 50, 90 is part of the riser. The C-frame can be integrally formed as part of the riser, or the riser can be assembled from multiple pieces. Nevertheless, those skilled in the art will recognize that the C-frame must have sufficient structural strength to bear the large bending forces experienced by the bow. Ordinarily, the structure at the geometric center of a bow (typically at the location of the handle) is the thickest and most robust portion of the bow structure, because the bending forces are largest at that point. However, with the bow of the present invention, there is no structure at the geometric center. There is only empty space. Consequently, the bending stresses that ordinarily pass through the geometric center of the bow structure are borne on either side of the geometric center, by the C-frame, which creates an open window frame or partial frame around the bow center. This configuration may use a structure for the C-frame (and also of the pivoting center thrust points 52, 92) that is sufficient to withstand these forces.
Shown in dashed lines in the top view of
With this bow configuration, the firing point 68, 116 coincides with the geometric center of the bow 10, 80 inside the firing C-frame 50, 90, above the handle 62, 102. The firing point/bow center coincides with the intersection of the horizontal axis 58, 98 and the vertical axis 64, 104. With reference to
When firing an arrow, an archer normally draws the bow (and the rear extremity of the arrow) back to a position approximately at the lever of his/her chin. A peep hole (not shown) is provided in the bow string several inches above the nock point 44. With the bow drawn, the archer looks through the peep hole and along the cross hairs of a bow sight with the target to fire. To compensate for the arc of the arrow with distance, the height of the peep hole above the nock point is greater than the height of the bow sight above the geometric center 68, so that the line of sight from the peep hole to the cross hairs of the bow sight is slightly downward relative to the firing axis 70. The bow sight includes several horizontal pins, each one at a different height above the geometric center, the lower pins corresponding to greater target distances (by producing a line of sight that is more downward relative to the firing axis), and the higher pins corresponding to closer target distances (by producing a line of sight that is closer to parallel to the firing axis).
While most archers use a bow sight as described above, a few archers prefer to sight along the arrow itself. The present invention makes doing so easier because the line of the arrow (i.e., the firing axis 70) passes through the C-frame 50, 90. The C-frame thus allows a concurrent unobstructed full view through the C-frame of a center target region aligned with the arrow trajectory at the same time as release of the arrow through the geometric center 68.
As most clearly shown in
With reference again to
The pivoting center thrust points configuration also allows the follow-through to be truer, regardless of how the archer holds the wrist. Upon release of an arrow, an archer's wrist. With the present invention, any twist in the wrist (horizontal or vertical) is taken up by the pivoting center thrust points 52, 92, allowing the bow 10, 80 to stay straight.
A variety of materials are suitable for manufacture of the center-fire bow of the present invention. For ease of use, lightweight materials are generally preferred, such as are currently used in the manufacture of sport and hunting bows. For example, the inventor has manufactured a bow in accordance with the invention having an aluminum riser in the configuration shown. Alternatively, the riser could be manufactured of other materials, such a wood, titanium, polymers, fiberglass, carbon fiber composites, etc.
By way of example, and without limitation, the invention can be described as a bow, including a bow frame with a geometric center, and a C-frame outlining the geometric center. The pivoting center thrust points are disposed within the C-frame, and a bow handle is pivotally attached to the pivoting center thrust points at a position offset from the geometric center. The bow is configured such that a user can fire an arrow through the C-frame, through the geometric center of the bow, the gimbal and bow handle allowing free pivoting of the bow about two substantially orthogonal axes.
It is to be understood that the above-referenced arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements can be devised without departing from the spirit and scope of the present invention. While the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiment(s) of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications can be made without departing from the principles and concepts of the invention as set forth herein.
Claims
1. A bow, comprising:
- a bow frame having a geometric center;
- a window frame partially surrounding the geometric center, such that a user of the bow can fire an arrow through the geometric center of the bow;
- a gimbal, pivotally attached to the bow frame; and
- a bow handle, pivotally attached to the gimbal at a position offset from the geometric center of the bow, the gimbal and bow handle being configured to allow free pivoting of the bow about two substantially orthogonal axes.
2. A bow in accordance with claim 1, wherein the gimbal is pivotally attached to the window frame.
3. A bow in accordance with claim 1, wherein the bow handle is disposed at a 45 degree angle.
4. A bow in accordance with claim 1, wherein the window frame includes pivoting center thrust points to connect the window frame to the bow handle.
5. A bow in accordance with claim 1, wherein the window is a C-frame.
6. A bow in accordance with claim 1, further comprising a stabilizer bar, rearwardly extending from the bow, configured to contact an arm of a user of the bow, so as to compensate for moment generated by the offset between the geometric center and the position of the handle.
7. A bow in accordance with claim 6, wherein the stabilizer bar is connected to the bow handle.
8. A bow in accordance with claim 1, further comprising: a bow string, connected between opposing ends of the bow frame, having a center and a nock point at the center, the bow being configured such that a user can fire the arrow through the geometric center of the bow with the arrow nocked at the nock point.
9. A bow in accordance with claim 1, wherein the bow frame further comprises: an upper limb, a lower limb, and a riser interconnecting the upper and lower limbs, the window frame comprising a portion of the riser.
10. A bow in accordance with claim 9, wherein the limbs are selectively removable from the riser.
11. A bow in accordance with claim 9, further comprising: a bow string, connected between the upper limb and the lower limb, having a center and a nock point substantially at the center, the bow being configured such that a user can fire the arrow through the geometric center of the bow with the arrow nocked at the nock point.
12. A bow in accordance with claim 11, further comprising:
- an upper cam mechanism, disposed at an extreme upper end of the upper limb, and operatively connecting the bow string to the upper limb;
- a lower cam mechanism, disposed at an extreme lower end of the lower limb, and operatively connecting the bow string to the lower limb; and
- a tension line, interconnected between the upper cam mechanism and the lower cam mechanism, the cam mechanisms and tension line being configured to reduce tension on the bow string and increase tension on the tension line when the bow string is fully drawn.
13. A bow in accordance with claim 1, wherein the window is configured to allow a concurrent full view of a center target region aligned with an arrow trajectory at the same time as release of the arrow through the geometric center.
14. A bow in accordance with claim 1, further comprising an arrow rest, attached to the window frame and extending thereinto, configured to support an arrow shaft so as to place a center axis of the arrow shaft substantially at the geometric center.
15. A bow, comprising:
- a bow frame, having a geometric center;
- a C-frame, integrally disposed in a center of the bow frame and surrounding a portion of a geometric center;
- a gimbal, pivotally attached to the window frame;
- a bow handle, pivotally attached to the gimbal and offset below the geometric center, the bow handle being configured to pivot about an axis that is substantially perpendicular to a pivoting axis of the gimbal, so as to allow free pivoting of the bow about two substantially orthogonal axes, the bow being configured such that a user can fire an arrow through the geometric center of the bow with the arrow nocked at the nock point.
16. A bow in accordance with claim 15, wherein the gimbal is pivotally attached to the C-frame.
17. A bow in accordance with claim 15, further comprising a stabilizer bar, rearwardly extending from the bow handle, configured to contact an arm of a user of the bow, so as to compensate for moment generated by the offset between the geometric center and the position of the handle.
18. A bow in accordance with claim 15, further comprising an arrow rest, attached to the window frame and extending thereinto, configured to support an arrow shaft so as to place a center axis of the arrow shaft substantially at the geometric center.
19. A bow in accordance with claim 14, wherein the bow frame further comprises:
- an upper limb;
- a lower limb; and
- a riser, interconnecting the upper and lower limbs, the window frame comprising a central portion of the riser.
20. A bow, comprising:
- a bow frame, having a longitudinal axis and a geometric center;
- a bow string, connected between opposing ends of the bow frame, having a center and a nock point at the center, and being oriented substantially parallel to the longitudinal axis;
- a window frame located around a portion of the geometric center of the bow, the window being integrally disposed in a center of the bow frame;
- a gimbal, disposed within the window and configured to pivot about an axis that is substantially perpendicular to the longitudinal axis of the bow frame;
- a bow handle, attached to the gimbal and offset from the geometric center, the handle being configured to pivot about an axis that is substantially parallel to the longitudinal axis of the bow, the gimbal and bow handle being configured to allow free pivoting of the bow about two axes relative to the handle, the pivotal axis of the gimbal and the pivotal axis of the bow handle intersecting substantially at the geometric center of the bow; and a stabilizer bar, extending from the bow, configured to contact an arm of a user of the bow, such that a user can fire an arrow through the geometric center of the bow with the arrow nocked at the nock point, the stabilizer bar compensating for moment generated by the offset between the geometric center and the position of the handle.
Type: Application
Filed: Oct 13, 2005
Publication Date: Apr 19, 2007
Inventor: Kent Perry (Koosharem, UT)
Application Number: 11/167,080
International Classification: F41B 5/00 (20060101);