Patent Grant
8739769
The field of the present invention relates to archery bows. In particular, a compound archery bow is described herein wherein a power cable take-up mechanism has an effective lever arm that decreases to a distance less than the axle radius during a latter portion of drawing the bow.
For purposes of the present disclosure and appended claims, the terms “compound archery bow” or “compound bow” shall denote an archery bow that uses a levering system, usually comprising one or more cables and pulleys, to bend the limbs as the bow is drawn. Examples of compound bows include dual-cam bows (including those that employ a Binary Cam System®), hybrid-cam bows, or single-cam bows. Many compound archery bows typically include one or more power cables (sometimes referred to as buss cables or anchor cables). Conventionally, each power cable is engaged at its first end to be taken up by a power cam (or other take-up mechanism) of a pulley member rotatably mounted on one bow limb, and is coupled at its second end to the other bow limb (in some cases a fixed connection, and in other cases including a mechanism for taking-up and/or letting-out the second end of the power cable). Tension developed as the bow is drawn and the power cable is taken up causes deformation of the bow limbs and storage of potential energy therein. A portion of that potential energy is transformed into the kinetic energy of the arrow shot by the bow. A few examples of various compound bow types are disclosed in the following patents and application, all of which are incorporated by reference as if fully set forth herein:
A compound archery bow comprises: a substantially rigid riser; first and second resilient bow limbs extending from respective end portions of the riser; first and second pulley members connected to the respective bow limbs; a draw cable; and a power cable. The first pulley member rotates relative to the first bow limb around a first rotation axis, and includes a first draw cable journal, a power cable take-up mechanism, and first and second axle segments arranged to extend from opposite sides of the first pulley member. The second pulley member rotates relative to the second bow limb around a second rotation axis, and includes a second draw cable journal. The draw cable is engaged with the first and second draw cable journals and is arranged to rotate the first and second pulley members as the bow is drawn and the draw cable is let out from the first draw cable journal. The power cable is engaged to be taken up by the power cable take-up mechanism as the bow is drawn and the first pulley member rotates. The axle segments are substantially coaxial with the first rotation axis and rotatably connect the first pulley member to a corresponding portion of the first bow limb. The first pulley member is arranged so that an effective lever arm of the power cable take-up mechanism decreases, during a latter portion of drawing the bow, from a distance that is greater than a radius of the axle segments to a minimum distance that is less than that radius. The first pulley member is further arranged so that, with the bow fully drawn, at least a portion of the power cable passes through at least a portion of a space between the first and second axle segments.
Objects and advantages pertaining to compound archery bows may become apparent upon referring to the exemplary embodiments illustrated in the drawings and disclosed in the following written description or claims.
The embodiments shown in the Figures are exemplary, and should not be construed as limiting the scope of the present disclosure or appended claims. The Figures may illustrate the exemplary embodiments in a schematic fashion, and various shapes, sizes, angles, curves, proportions, and so forth may be distorted to facilitate illustration. The specific shapes, sizes, angles, curves, proportions, etc should not be construed as limiting the scope of the present disclosure or appended claims.
An exemplary compound archery bow 100 is illustrated schematically in
A power cable 145 is engaged to be taken up by a power cable take-up mechanism of pulley member 150a as the bow 100 is drawn and the pulley member 150a rotates. The power cable 145 is shown in
The power cable take-up mechanism in a compound archery bow is typically arranged to provide a significant “let-off” (i.e., decrease) of the force required to pull back the draw cable 140 when drawing the bow. The smaller the draw force required at full draw, the greater the let-off (generally expressed as a percent reduction of the peak draw force; therefore, a greater percent let-off corresponds to a smaller draw force required at full draw). The pulley member 150a and its corresponding power cable take-up mechanism (e.g., power cable take-up journal 154a) are typically arranged so that the let-off occurs somewhat abruptly at a draw distance suitable for a given user of the bow (usually referred to as “full draw”). A pulley member 150a can in some instances be adjusted to provide differing draw lengths for a given bow.
One way in which the let-off is provided is by a decrease in the effective lever arm of the power cable take-up mechanism. For purposes of the present disclosure and appended claims, the effective lever arm of a journal, cam, or other take-up or let-out mechanism is the perpendicular distance from the rotation axis of the corresponding pulley member to the inside edge of a cable's tangent point. More accurately, a decrease in the effective lever arm of the power cam take-up mechanism relative to the effective lever arm of the draw cable journal determines the let-off of a given bow. In most instances, the effective lever arm of a power cable take-up mechanism decreases during a latter portion of drawing the bow, and that decrease provides a mechanical advantage that reduces the force required to pull the draw cable and rotate the pulley member 150a (i.e., provides the let-off).
In a conventional compound bow, a minimum practicable effective lever arm is about equal to the radius of an axle used to mount the pulley member 150a. Once that minimum is reached, any further let-off can be achieved only by further increasing the effective lever arm of the draw cable journal 152a. However, increasing the draw cable journal effective lever arm has other undesirable effects, including the increased size and mass of the pulley member 150a and a reduction of the energy that can be stored in the bow limbs 111a and 111b by rotation of the pulley member 150a.
The pulley member 150a according to the present disclosure (for the exemplary single-cam compound bow 100) comprises first and second axle segments 158a, a draw cable journal 152a, a power cable take-up mechanism (in this example a power cable take-up journal 154a), and a secondary cable let-out mechanism (in this example a secondary cable let-out journal 156a). The first and second substantially coaxial axle segments 158a are arranged to extend from opposite sides of the pulley member 150a and to rotatably connect the pulley member to the bow limb 111a. The first and second axle segments 158a are substantially coaxial and substantially define the rotation axis of the pulley member 150a relative to the bow limb 111a. The draw cable journal 152a is connected to the axle segments 158a and is arranged to let out the draw cable 140 as the bow 100 is drawn and the pulley member 150a rotates about its rotation axis. The secondary cable let-out journal 156a is arranged to engage a secondary cable (in this instance the other end of the draw cable 140 after it passes over the idler wheel 150b) and to let out the secondary cable as the bow 100 is drawn and the pulley member 150a rotates. The power cable take-up journal 154a is arranged to take up the power cable 145 as the bow 100 is drawn and the pulley member 150a rotates. The other end of the power cable 145 is secured to an axle of the idler wheel 150b, but could alternatively be connected or coupled to bow limb 111b by any suitable let-out and/or take-up mechanism, as disclosed in various of the references cited above.
The pulley member 150a is arranged so that the effective lever arm of the power cable take-up journal 154a decreases during a latter portion of drawing the bow 100, from a distance that is greater than a radius of the axle segments (as in
Any suitable dimensions can be employed for the radius of the axle segments 158a and for the minimum distance between the power cable 145 and the rotation axis at full draw. The forces typically exerted on the axle segments 158a and available or suitable materials may dictate a minimum radius to be employed for the axle segments (to provide sufficient mechanical strength). The axle segments 158a can comprise separate components mounted, assembled, or connected to the pulley member 150a, or can comprise integrally formed parts of the pulley member 150a. In one example, the entire pulley member 150a is machined from a single piece of aluminum, and the axle segments 158a are integrally formed and are about 4 mm in radius (about 8 mm in diameter). In various other examples, the axle segments 158a can be less than about 6 mm in radius, less than about 5 mm, less than about 4 mm, less than about 3 mm, or even less than about 2 mm in radius. In still other various examples, the axle segments can be greater than about 1 mm in radius, greater than about 2 mm, greater than about 3 mm, greater than about 4 mm, greater than about 5 mm, or even greater than about 6 mm in radius.
The minimum distance between the power cable and the rotation axis at full draw (i.e., the minimum effective lever arm at full draw) is less than the radius of the corresponding axle segments 158a. How much less determines in part the let-off that can be achieved with a given draw cable journal 152a. In the integrally formed, aluminum example described above, the minimum effective lever arm is about 0.5 mm at full draw (i.e., about ⅛ the size of the axle segment radius, which would decrease the required draw force by about a factor of 8, all other things being equal). In various other examples, the minimum effective lever arm can be greater than about 0.5 mm, greater than about 1 mm, greater than about 2 mm, greater than about 3 mm, or greater than about 4 mm. In still other various examples, the minimum effective lever arm can be less than about 4 mm, less than about 3 mm, less than about 2 mm, or less than about 1 mm.
The ratio of the axle segment radius to the minimum effective lever arm is greater than 1:1. In the integrally formed, aluminum example described above, that ratio is about 8:1. In various other examples, that ratio can be greater than about 1.5:1, greater than about 2:1 greater than about 3:1, greater than about 4:1, greater than about 5:1, greater than about 6:1, greater than about 8:1, or even greater than about 10:1. In still other examples, the ratio can be less than about 10:1, less than about 8:1, less than about 6:1, less than about 5:1, less than about 4:1, less than about 3:1, or less than about 2:1.
The preceding are exemplary values that yield satisfactory bow performance, however, other values for the axle segment radius, minimum take-up lever arm, or ratio, including values outside the exemplary ranges, can be employed while remaining within the scope of the present disclosure or appended claims. As stated earlier, any suitable combination of dimensions or ratio can be employed to achieve a desired degree of let-off for a given pulley member 150a.
Preferably, the pulley member should be arranged so that the power cable does not pass “over center” (i.e., the minimum effective lever arm should not go through zero and become “negative”). If such an “over center” arrangement were permitted, the bow could exhibit 100% let-off or “cocking,” in which the draw cable goes limp and the bow limbs are stuck in their deformed state. Releasing the draw cable at this point does not shoot the arrow; instead the pulley members must be mechanically forced (preferably using a bow press for safety) back past the 100% let-off position. The first pulley member is preferably arranged so as to avoid 100% let-off of the draw force or so as to prevent cocking of the bow, e.g., by ensuring that material comprising the power cable journal or the axle segments occupies at least a minimal volume between the axle segments 158a that includes the rotation axis. Such an arrangement could prevent the power cable from passing “over center.”
Another arrangement for avoiding the cocked bow, 100% let-off scenario is use of a rotation stop (not shown) on the pulley member 150a, as disclosed in, e.g., U.S. Pat. No. 7,305,979. Such a rotation stop can comprise, for example, a simple peg or other protrusion secured to the pulley member so that, upon rotation, the stop eventually comes into contact with a bow limb, the draw cable, or a power cable to hinder or prevent further rotation of the pulley member. Such a rotation stop can be secured to the respective pulley member at a position chosen to limit its rotation to a desired value. The rotation limit can be chosen for yielding a desired let-off or avoiding 100% let-off, for yielding a desired draw length, or for another purpose. The rotation stop can be integrally formed with or permanently secured to the cam assembly. Alternatively, the rotation stop can be adjustably secured to the pulley member by means of a slot or other suitable adjustable attachment.
In some examples of a single-cam or hybrid-cam compound bow, it may be desirable to decrease the effective lever arm of the let-out journal 156a to a distance smaller than the radius of the axle segments 158a. In that event, a corresponding portion of the space between the axle segments 158a can be adapted in a manner similar to that described above for the power cable journal 154a. That arrangement is most clearly seen in
A second exemplary compound archery bow 200 is illustrated schematically in
A power cable 245a is engaged to be taken up by a power cable take-up mechanism of pulley member 250a as the bow 200 is drawn and the pulley member 250a rotates. A power cable 245b is similarly engaged to be taken up by a power cable take-up mechanism of pulley member 250b. The power cables 245a and 245b are shown in
The pulley members 250a and 250b substantially resemble pulley member 150a with respect to function and arrangement of the draw journals 252a and 252b, the power cable take-up journals 254a and 254b, and the axle segments 258a and 258b. The following description refers only to pulley member 250a, but applies equally to pulley member 250b. The pulley member 250a is arranged so that the effective lever arm of the power cable take-up journal 254a decreases during a latter portion of drawing the bow 200, from a distance that is greater than a radius of the axle segments 258a (as in
The various examples of dimensions and ratios given above for pulley member 150a can be employed for pulley members 250a and 250b as well. Various arrangements described above for avoiding a 100% let-off, cocked-bow scenario for bow 100 can be employed for bow 200 as well.
It is intended that equivalents of the disclosed exemplary embodiments and methods shall fall within the scope of the present disclosure or appended claims. It is intended that the disclosed exemplary embodiments and methods, and equivalents thereof, may be modified while remaining within the scope of the present disclosure or appended claims.
In the foregoing Detailed Description, various features may be grouped together in several exemplary embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that any claimed embodiment requires more features than are expressly recited in the corresponding claim. Rather, as the appended claims reflect, inventive subject matter may lie in less than all features of a single disclosed exemplary embodiment. Thus, the appended claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate disclosed embodiment. However, the present disclosure shall also be construed as implicitly disclosing any embodiment having any suitable combination of disclosed or claimed features (i.e., combinations of features that are not incompatible or mutually exclusive) that appear in the present disclosure or the appended claims, including those combinations of features that may not be explicitly disclosed herein. It should be further noted that the scope of the appended claims does not necessarily encompass the whole of the subject matter disclosed herein.
For purposes of the present disclosure and appended claims, the conjunction “or” is to be construed inclusively (e.g., “a dog or a cat” would be interpreted as “a dog, or a cat, or both”; e.g., “a dog, a cat, or a mouse” would be interpreted as “a dog, or a cat, or a mouse, or any two, or all three”), unless: (i) it is explicitly stated otherwise, e.g., by use of “either . . . or,” “only one of,” or similar language; or (ii) two or more of the listed alternatives are mutually exclusive within the particular context, in which case “or” would encompass only those combinations involving non-mutually-exclusive alternatives. For purposes of the present disclosure or appended claims, the words “comprising,” “including,” “having,” and variants thereof, wherever they appear, shall be construed as open ended terminology, with the same meaning as if the phrase “at least” were appended after each instance thereof.
In the appended claims, if the provisions of 35 USC §112 ¶ 6 are desired to be invoked in an apparatus claim, then the word “means” will appear in that apparatus claim. If those provisions are desired to be invoked in a method claim, the words “a step for” will appear in that method claim. Conversely, if the words “means” or “a step for” do not appear in a claim, then the provisions of 35 USC §112 ¶ 6 are not intended to be invoked for that claim.
This application is a continuation of U.S. non-provisional application Ser. No. 12/985,659 filed Jan. 6, 2011 in the names of Nicholas C. Obteshka and Craig T. Yehle (now U.S. Pat. No. 8,469,013), said application being hereby incorporated by reference as if fully set forth herein.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3990425 | Ketchum | Nov 1976 | A |
| 4300521 | Schmitt | Nov 1981 | A |
| 4440142 | Simonds | Apr 1984 | A |
| 4546754 | Smith | Oct 1985 | A |
| 4686955 | Larson | Aug 1987 | A |
| 4733648 | Martin | Mar 1988 | A |
| 4781167 | Martin | Nov 1988 | A |
| 4909231 | Larson | Mar 1990 | A |
| 4995373 | Mussack | Feb 1991 | A |
| 5368006 | McPherson | Nov 1994 | A |
| 5381777 | Mitchell et al. | Jan 1995 | A |
| 5390655 | Mitchell et al. | Feb 1995 | A |
| 5505185 | Miller | Apr 1996 | A |
| 5623915 | Kudlacek | Apr 1997 | A |
| 5782229 | Evans et al. | Jul 1998 | A |
| 5890480 | McPherson | Apr 1999 | A |
| 5975067 | Strother | Nov 1999 | A |
| 6082347 | Darlington | Jul 2000 | A |
| 6098607 | Strother | Aug 2000 | A |
| 6237582 | McPherson | May 2001 | B1 |
| 6443139 | McPherson | Sep 2002 | B1 |
| 6474324 | Despart et al. | Nov 2002 | B1 |
| 6659096 | Nealy et al. | Dec 2003 | B1 |
| 6688295 | Miller | Feb 2004 | B1 |
| 6691692 | Adkins | Feb 2004 | B1 |
| 6792930 | Kronengold et al. | Sep 2004 | B1 |
| 6871643 | Cooper et al. | Mar 2005 | B2 |
| 6976484 | Gallops | Dec 2005 | B1 |
| 6990970 | Darlington | Jan 2006 | B1 |
| 6994079 | Darlington | Feb 2006 | B1 |
| 7082937 | Land | Aug 2006 | B1 |
| 7143757 | Cooper | Dec 2006 | B1 |
| 7305979 | Yehle | Dec 2007 | B1 |
| 7311098 | Gallops | Dec 2007 | B2 |
| 7441555 | Larson | Oct 2008 | B1 |
| 7770568 | Yehle | Aug 2010 | B1 |
| 8006679 | Strother | Aug 2011 | B2 |
| 8020544 | McPherson et al. | Sep 2011 | B2 |
| 8037876 | Yehle | Oct 2011 | B1 |
| 8181638 | Yehle | May 2012 | B1 |
| 8205607 | Darlington | Jun 2012 | B1 |
| 8220446 | Batdorf | Jul 2012 | B2 |
| 8276574 | Wilson | Oct 2012 | B1 |
| 8281774 | Grace | Oct 2012 | B2 |
| 8281775 | Larson | Oct 2012 | B1 |
| 8360041 | Strother | Jan 2013 | B2 |
| 8469013 | Obteshka et al. | Jun 2013 | B1 |
| 20090288650 | Batdorf | Nov 2009 | A1 |
| Entry |
|---|
| Krenz, Bill: “Mathews McPherson Series Monster”; Inside Archery (Jun. 2009; p. 30); http://mathewsinc.com/data/mathewsinc/file/245—45289—Mathews%20Monster—2.pdf. |
| Silks, Jon E.; “Mathews McPherson Series Monster”; Bowhunting (Aug. 2009; p. 18); http://mathewsinc.com/data/mathewsinc/file/245—45293—BOWP-090800-HGM.pdf. |
| Bell, Joe; “Mathews McPherson Series Monster”; Bow & Arrow Hunting (believed published in 2009); http://mathewsinc.com/data/mathewsinc/file/245—44981—BOW—4.pdf. |
| Hartle, Luke L.; “. . . And Then There Were Two”; North American Hunter (believed published in 2009); http://mathewsinc.com/data/mathewsinc/file/245—44305—NorAmerHunterMathews2009NewProducts.pdf. |
| Murray, Jeff; Mathews is Unbearish for 2009; Bear Hunting Magazine (Jan./Feb. 2009); http://mathewsinc.com/data/mathewsinc/file/245—44237—Mathews-Murray.pdf. |
| Mathews, Inc.; magazine ad copy (believed published in 2009); http://mathewsinc.com/data/mathewsinc/file/245—44993—monster—full-boww-lrz.pdf. |
| Notice of Allowance dated Mar. 22, 2013 in parent U.S. Appl. No. 12/985,659. |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12985659 | Jan 2011 | US |
| Child | 13897374 | US |
