Apparatuses and Methods for Supporting Bow Limbs
The present disclosure generally pertains to apparatuses and methods for supporting bow limbs. In accordance with one exemplary embodiment of the present disclosure, a T-shaped insert is inserted into each prong of a forked limb of an archery bow. An axle on which a cam is mounted passes through each insert in the forked limb. Each such insert helps to redistribute the load exerted by the axle in a manner so that the limb can better withstand the load thereby extending the useful life of the bow.
This application claims priority to U.S. Provisional Patent Application No. 60/834,713, entitled “Apparatuses and Methods for Supporting Bow Limbs,” and filed on Aug. 1, 2006, which is incorporated herein by reference.
RELATED ARTMany conventional archery bows have at least one cam mounted at a respective end of a bow limb. There are generally two types of bow limbs, solid and split. In either case, the end of a bow limb supporting a cam is typically forked such that it has two prongs separated by a gap. An axle passes through each prong, and the cam is mounted on the axle between the prongs. At least one cord is secured to the cam, which rotates when a user pulls the cord. The pulling of the cord also typically deforms the bow limb. The cam can be spring-loaded such that it returns to its original position when the user releases the cord thereby launching a projectile, such as an arrow, that has been positioned against the cord. Releasing of the cord also allows the deformed bow limb to return to its original position as the projectile is being launched, thereby increasing the momentum and velocity of the projectile.
Drawing of the cord by a user to launch projectiles causes significant force to be applied to the bow limb, particularly at the point where the axle passes through the limb. In this regard, forces caused by the drawing of the cord generally pass into the limb through the axle on which the cam is mounted. Repetitive drawing of the cord causes mechanical fatigue at such point eventually resulting in mechanical failure of the bow limb.
Moreover, improved bow designs enabling bows to better handle the forces and stresses caused by repeated use are generally desirable.
The disclosure can be better understood with reference to the following drawings. The elements of the drawings are not necessarily to scale relative to each other, emphasis instead being placed upon clearly illustrating the principles of the disclosure. Furthermore, like reference numerals designate corresponding parts throughout the several views.
The present disclosure generally pertains to apparatuses and methods for supporting bow limbs. In accordance with one exemplary embodiment of the present disclosure, inserts are respectively inserted into prongs of a forked limb of an archery bow. An axle on which a cam is mounted passes through each insert in the forked limb. Each such insert helps to redistribute a load exerted by the axle in a manner so that the limb can better withstand the load thereby extending the useful life of the bow.
A user may abut an arrow (not shown) against the cord 26 and pull the cord 26 thereby rotating each cam 33, 34. The cams 33, 34 are spring loaded such that, when the user releases the cord 26, the cams 33, 34 rapidly return to their original positions projecting the arrow from the bow 20 at a great speed and with great force. Further, the bow limbs 19, 21 typically deform when the cord 26 is drawn by a user and return to their original positions when the cord 26 is released, thereby increasing the arrow's momentum.
During the time that the cord 26 is drawn by the user, great force is exerted on the limbs 19, 21. In this regard, referring to
As shown by
In the exemplary embodiment shown by
The shaft 74 preferably has hole 81 (
The existence of the head 75, however, further enhances the mechanical integrity of the prong 62 by redistributing load exerted by the axle 65 across the prong surface 88 in contact with the head 75. In this regard, a component of the force exerted by the axle 65 tends to pull the insert 70 in the y-direction. Such a force presses the head 75 against the surface 88 of the prong 62. Thus, the head 75 helps to distribute the force across greater surface area relative to the forces exerted by axle 25 of
To better illustrate the foregoing, refer to
In addition, the insert 71 may be identical to the insert 70 described above except that insert 71 is inserted into the prong 63 instead of prong 62. Thus, like insert 70, the insert 71 may have a shaft and a head. Further, the insert 71 may have a similar effect to the mechanical integrity of prong 63 as does insert 70 to prong 62. Indeed, inserting the inserts 70, 71 into the prongs 62, 63, respectively, enhances the mechanical integrity of the limb 52 such that it is better able to withstand forces induced by a user pulling cord 59. Further, inserts may be similarly inserted into the forked limb 53 to enhance the mechanical integrity of this limb 53.
It should be noted that the inserts 70, 71 may be used on various types of bows, including solid limb bows, split limb bows, cross bows, and other types of known or future-developed bows. Further,
If desired, portions of the insert 125 can be beveled or rounded in an effort to remove sharp edges. For example,
The weight of the element 173 provides the arrow or other projectile being launched by the bow with more momentum. In one exemplary embodiment, the weight of the element 173 is about one-quarter of a pound, but the element 173 may have other weights in other embodiments. Further, the shape of the element 173 is immaterial, and the element 173 may have any of a variety of shapes. Further, the element 173 can be attached to the insert 150 via various techniques and configurations.
Each of the components 154, 155, and 163 of insert 150 are integral with respect to each other. In at least one embodiment, the insert 150 is a unitary piece of metal or other material. For example, the insert 150 may be formed by an extrusion or other process that simultaneously forms each of the components 154, 155, 163 by shaping a single piece of metal or other material. In other examples, other techniques could be employed. For example, the tab 163 and/or shaft 154 may be welded to the head 155.
It should be noted that various techniques may be used to manufacture a bow having an insert positioned within a bow limb, as described herein. Exemplary manufacturing techniques will be described in detail below, but it should be emphasized that other manufacturing techniques are possible as well.
During manufacture of a bow, a prong 211 of a bow limb is cut to form a channel 214, as depicted by
In the exemplary embodiment shown by
Note that similar techniques may be employed to retrofit an existing bow with one or more inserts in accordance with the present disclosure. In this regard, the axle on which a cam is mounted may be removed from a bow limb. Then, the process depicted by
Positioning an insert into an end of a bow limb, as described herein, generally increases the mechanically integrity of the bow limb. In particular, the presence of the insert increases the amount of force that the bow limb can withstand and helps to extend the useful life of the bow. Further, in the event that the bow limb does fracture or otherwise fail, the presence of the insert can help reduce the extent to which the limb is damaged thereby helping to prevent or reduce bodily injury.
Claims
1. An archery bow, comprising
- at least one forked limb having a first prong and a second prong separated by a gap;
- an axle passing through the first and second prongs; and
- a first insert having a shaft and a head, the shaft positioned in the first prong, the axle passing through the shaft, and the head extending along a first surface of the first prong.
2. The bow of claim 1, further comprising a second insert having a shaft and a head, the shaft of the second insert positioned in the second prong, the axle passing through the shaft of the second insert, and the head of the second insert extending along a surface of the second prong.
3. The bow of claim 1, wherein the insert has a tab extending from the head, the tab having a hole.
4. The bow of claim 1, wherein the head is external to the first prong.
5. The bow of claim 1, further comprising a cam rotatably mounted on the axle.
6. The bow of claim 5, further comprising a cord attached to the cam and to at least one other point on the bow.
7. The bow of claim 1, wherein the first prong has a channel extending from the first surface to a second surface of the first prong, the second surface opposite of the first surface, and wherein the shaft is positioned in the channel.
8. The bow of claim 7, wherein the head contacts the first surface.
9. The bow of claim 7, wherein the shaft and the channel are dimensioned such that the shaft fits snugly in the first prong.
10. An archery bow, comprising:
- at least one forked limb having a first prong and a second prong separated by a gap, the first prong having a first surface;
- an axle passing through the first and second prongs;
- a cam rotatably mounted on the axle;
- a cord attached to the cam and to at least one other point on the bow; and
- means for transferring a force from the axle to the first surface of the first prong, the force generated by a user pulling on the cord, a portion of the transferring means inserted into the first prong, the portion having a hole through which the axle passes.
11. The bow of claim 10, wherein the first prong has a second surface that is opposite of the first surface, wherein the first prong has a channel extending from the first surface to the second surface, and wherein the portion is positioned in the channel.
12. A forked bow limb having a first prong and a second prong separated by a gap, wherein an insert is positioned in the first prong, the insert having a shaft and a head, the head extending along a surface of the first prong and the shaft positioned in a channel of the first prong, wherein an axle passes through the first prong, the second prong, and the shaft.
13. The forked bow limb of claim 12, wherein a cam is mounted on the axle.
14. A method, comprising the steps of:
- providing a bow, the bow having a forked bow limb and a cam that is rotatably mounted on an axle passing through a first prong and a second prong of the forked bow limb, the cam secured to a cord;
- pulling the cord thereby generating a force passing through the axle; and
- transferring the force from the axle to a surface of the first prong via an insert that is positioned in the first prong, the insert having a hole through which the axle passes, the insert further having a head that is external to the first prong and that extends along the surface.
Type: Application
Filed: Apr 19, 2007
Publication Date: Feb 7, 2008
Inventor: Jon McMurray (Montrose, AL)
Application Number: 11/737,253