Patent Application
20180245893
The technical field of the present invention relates generally to broadheads, a well known type of arrowhead, and more particularly to an expanding broadhead, a type of broadhead with an in-flight configuration in which the blades are retracted, and upon striking a target converts to a deployed, or target penetrating position in which the blades are expanded outward.
In the accompanying drawings:
The instant invention is described more fully hereinafter with reference to the accompanying drawings and/or photographs, in which one or more exemplary embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be operative, enabling, and complete. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention. Moreover, many embodiments, such as adaptations, variations, modifications, and equivalent arrangements, will be implicitly disclosed by the embodiments described herein and fall within the scope of the present invention.
Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. Unless otherwise expressly defined herein, such terms are intended to be given their broad ordinary and customary meaning not inconsistent with that applicable in the relevant industry and without restriction to any specific embodiment hereinafter described. As used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one”, “single”, or similar language is used. When used herein to join a list of items, the term “or” denotes at least one of the items, but does not exclude a plurality of items of the list.
For exemplary methods or processes of the invention, the sequence and/or arrangement of steps described herein are illustrative and not restrictive. Accordingly, it should be understood that, although steps of various processes or methods may be shown and described as being in a sequence or temporal arrangement, the steps of any such processes or methods are not limited to being carried out in any particular sequence or arrangement, absent an indication otherwise. Indeed, the steps in such processes or methods generally may be carried out in various different sequences and arrangements while still falling within the scope of the present invention.
Additionally, any references to advantages, benefits, unexpected results, or operability of the present invention are not intended as an affirmation that the invention has been previously reduced to practice or that any testing has been performed. Likewise, unless stated otherwise, use of verbs in the past tense (present perfect or preterit) is not intended to indicate or imply that the invention has been previously reduced to practice or that any testing has been performed.
Referring now specifically to the drawings, a broadhead and self-locking broadhead blade in accordance with one exemplary embodiment of the present disclosure are illustrated in
The broadhead body 22 may be similar in certain respects to prior art designs, including a target penetrating end or tip 23 at the front, an arrow shaft attachment end 24 at the back, and a longitudinal passage or slot 26 for receiving one or more blades. A blade retaining lug 28 and a blade locking lug 30 traverse the slot 26 substantially perpendicular to a longitudinal axis of the broadhead body. The blade retaining lug 28 is positioned forward of the locking lug 30 in slot 26, or in other words closer to the penetrating end 23 of broadhead body. The lugs 28, 30 may be any type of cylindrical member or bar, such as press-fit metal dowel pins, screws, rivets, or the like that are installed in holes or recesses formed in the broadhead body. Alternatively the lugs may be fabricated as integrally formed portions of the broadhead body. In one particular embodiment the lugs are steel rivets (see
The broadhead blade 10 has a perimeter defined by a front end 11, a distal end 12, an outward facing, sharpened leading edge 13 between the front end and distal end, and a trailing edge 14 opposite the leading edge. In the retracted blade position of
The broadhead blade further includes an aperture 18 that captures the blade retaining lug 28 as shown, thereby functioning cooperatively with lug 28 to effectively retain the blade to the broadhead body. The aperture 18 has a contour that includes a deployed blade retaining surface 20 in a forward portion of the contour proximate the front end 11 of the blade, and a blade locating pocket 34 in an aft portion of the aperture contour substantially opposite the forward portion. The blade locating pocket 34 is configured to substantially restrict lateral movement of the blade 10 relative to the blade retaining lug 28 with the blade retracted.
Referring now also to
The depicted locking system embodiment is intended to represent a spring member integrally formed from the blade material by forming or cutting a pair of adjacent grooves 41 through the blade. The grooves 41 essentially cooperate to define a spring in the form of an elongated, cantilevered, flexible bar that extends into the aperture 18, or more specifically into the pocket 34 portion of aperture 18, from a cantilevered end 45 to a free end 43. The grooves may be parallel and arcuate in shape to produce the curved spring shape depicted, although other shapes such as straight, angled, or a zig-zag pattern are also feasible. In any case, a contact surface 15 at the free end is configured to bear against the blade retaining lug 28 when the blade is in the retracted position.
The spring member 16 works in conjunction with the locking surface 19 in the blade trailing edge to restrain the blade in the retracted position. To that end, spring member 16 is configured to create an interference fit so that in order for the locking surface 19 in the blade trailing edge to be forced over the blade locking lug 30, the spring member must be deflected toward the distal end 12 of the blade. This elastic deflection of the spring member results in a forwardly directed force being exerted against the blade retaining lug 28 by the spring member, and an equal and opposite force being exerted by locking surface 19 against the blade locking lug 30.
Referring to
Although in the depicted embodiments the spring member 16 engages the blade retaining lug 28 in the aperture 18, other configurations are possible. For example, the spring member may instead be located on the blade trailing edge, and configured to bear against (from above or below) the blade locking lug 30. In such a configuration the spring member could incorporate a ramp angle or a detent feature to double as a blade locking surface.
It should be further appreciated that still other configurations and orientations of the spring member and/or locking surface may be beneficially utilized, any of which would be well within the spirit and scope of the invention. Generally stated, the blade retention system may be arranged in any manner that provides a first contact surface on an integral spring configured to bear against a first lug or blade locating feature of a broadhead body, and a second contact surface on the blade configured to bear against a second lug or blade locating feature of the broadhead body, such that the spring must be deflected or compressed for the blade to be placed in the retracted position in which the first and second contact surfaces are bearing against the respective first and second blade locating features.
The process of placing the blades in the retracted or in-flight position is illustrated by the sequence of
The blade may be moved toward the locked position by applying a lateral force “F1” to the forward outer corner 47 of the blade forward end 11. In a fully assembled broadhead with two blades, the lateral force may be conveniently applied by pinching the two corners 47 together. The applied force F1 is reacted at lug 28 against one side of the blade locating pocket 34, creating a couple tending to rotate the blade. For the single depicted blade, the reaction force is against the right side of the locating pocket 34, and the direction of the applied couple is counterclockwise, tending to drive outer corner 50 of the locking surface 19 against lug 30.
By applying enough force, the corner 50 of the locking surface will begin to ride up on lug 30, pushing the blade in a forward direction toward the broadhead tip 23, and causing the spring member 16 to deflect in a rearward direction as it bears against lug 28. With sufficient continued force the blade rotation will continue, overcoming the resisting force of the spring member, while the locking surface 19 moves forward and laterally onto lug 30.
At the same time the forward end of the blade is laterally restrained and stabilized by the blade locating pocket 34. As best seen in
The above described blade locking sequence is essentially reversed when the broadhead strikes a target and the blades deploy. Referring initially still to
As the broadhead continues to penetrate further into the target, the blade leading edge 13 eventually contacts the target, pushing the blade rearward and causing it to rotate counterclockwise, back toward the broadhead body. The rotation will continue until the blade again comes into contact with lug 30 at a blade bracing surface or notch 21 in the blade trailing edge 14, as depicted in the deployed configuration of
In the depicted embodiment, the spring 16 coplanar with the blade, and made of a flat material having substantially the same thickness. The spring may include a cantilevered, or fixed end 45 that is enlarged in the manner of a flange and configured to fit securely inside a corresponding pocket 61 within aperture 18. The remaining portion of spring member 16 from the fixed end 45 to the free end 43 is spaced away from the adjacent edges of aperture 18 to allow the spring to elastically deflect under load in the manner previously described.
The fit of the fixed end 45 in pocket 61 is configured to prevent the spring from falling out, and to prevent any slipping or rotation of the fixed end relative to the pocket when the free end of the spring is deflected, such as occurs when the blade 10 is forced into the retracted position. The means for ensuring a secure arrangement may comprise simply friction, or more positive measures such as creating an interference fit or bonding the spring to the blade with a braze or adhesive material. In addition, the profile shape of a contacting interface between fixed end 45 and the pocket 61 may be non-circular, or elongated, such that rotation of fixed end 45 cannot occur without permanently deforming either the pocket 61 or the spring, or both.
The spring member 16 and aperture 18 may be further configured with one or more features designed to facilitate an interference fit. Referring to
For the purposes of describing and defining the present invention it is noted that the use of relative terms, such as “substantially”, “generally”, “approximately”, and the like, are utilized herein to represent an inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. These terms are also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.
Exemplary embodiments of the present invention are described above. No element, act, or instruction used in this description should be construed as important, necessary, critical, or essential to the invention unless explicitly described as such. Although only a few of the exemplary embodiments have been described in detail herein, those skilled in the art will readily appreciate that many modifications are possible in these exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the appended claims.
In the claims, any means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. Unless the exact language “means for” (performing a particular function or step) is recited in the claims, a construction under § 112, 6th paragraph is not intended. Additionally, it is not intended that the scope of patent protection afforded the present invention be defined by reading into any claim a limitation found herein that does not explicitly appear in the claim itself.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15187777 | Jun 2016 | US |
| Child | 15954593 | US |
