US009255753B2

(12) United States Patent (10) Patent No.: US 9.255,753 B2

Pulkrabek et al. (45) Date of Patent: Feb. 9, 2016

(54) ENERGY STORAGE DEVICE FOR A BOW (56) References Cited

U.S. PATENT DOCUMENTS
(71) Applicant: RAVIN CROSSBOWS, LLC, Superior,
WI (US) 4,030,473 A 6/1977 Puryear
4,192.281 A 3/1980 King
4,287,867 A 9, 1981 Islas
(72) Inventors: Larry Pulkrabek, Osceola, IA (US); 4,479,480 A 10, 1984 Holt
Jay Engstrom, Port Wing, WI (US); 4,545,358 A 10, 1985 Collins
Craig Thomas Yehle, Holmen, WI (US); 4,565, 182 A 1/1986 Barnett
Aaron Pellett, Alborn, MN (US); 4,587,944 A 5/1986 Barnett
4,693,228 A 9, 1987 Simonds et al.
Matthew P. Haas, Duluth, MN (US); 4,719,897 A 1/1988 Gaudreau
Fred H. Hunt, Duluth, MN (US) 4,766,874 A 8, 1988 Nishioka
4,877,008 A 10/1989 Troubridge
(73) Assignee: RAVIN CROSSBOWS, LLC, Superior, 4.942,861 A 7, 1990 BOZek
5,085,200 A 2, 1992 Horton-Corcoran et al.
WI (US) 5,220,906 A 6/1993 Choma
D337,145 S 7/1993 Horton-Corcoran
(*) Notice: Subject to any disclaimer, the term of this 5,243,956 A 9/1993 Luehring
5,265,584 A 11/1993 Judson et al.
patent is extended or adjusted under 35 5,388,564 A 2, 1995 Islas
U.S.C. 154(b) by 265 days. 5,445,139 A 8/1995 Bybee
5,522,373 A 6/1996 Barnett
5,596,976 A 1, 1997 Waiser
(21) Appl. No.: 13/799,518 5,598,829 A 2f1997 Bednar
5,630,405 A 5, 1997 NiZOv
5,649,520 A 7, 1997 Bednar
(22) Filed: Mar 13, 2013 5,884,614 A 3/1999 Darlington et al.
6,073,351 A 6/2000 Barnett
(65) Prior Publication Data 6,095,128 A 8, 2000 Bednar

US 2014/0261358A1 Sep. 18, 2014 (Continued)

Primary Examiner — Melba Bumgarner
Assistant Examiner — Amir Klayman
(51) Int. Cl. (57) ABSTRACT
F4IB5/12 (2006.01)
F4IB5/10 (2006.01) An energy storage portion for a bow and a method of config
F4IB 5/14 (2006.01) uring the same. At least one first limb has both a distal portion
and a proximal portion coupled to the first side of a center
(52) U.S. Cl. Support. At least one second limb has both a distal portion and
CPC ................. F4IB5/105 (2013.01); F4 IB5/123 a proximal portion coupled to the second side of the center
(2013.01); FAIB 5/1469 (2013.01); Y10T support. At least one first pulley is attached to the first limb at
29/49826 (2015.01) a location between the distal and the proximal portions of the
(58) Field of Classification Search first limb and at least one second pulley is attached to the
CPC ........ F41B5/105; F41B5/123; F41B5/0094; second limb at a location between the distal and the proximal
F41B5/12: F41B5/00 portions of the second limb.
See application file for complete search history. 20 Claims, 22 Drawing Sheets
 US 9.255,753 B2
Page 2

(56) References Cited 7,770,567 B1 8, 2010 Yehe

7,810,480 B2 10/2010 Shepley et al.
U.S. PATENT DOCUMENTS 7,836,871 B2 11/2010 Kempf
7.997,258 B2 8/2011 Shepley et al.
6,205,990 B1 3, 2001 Adkins 8,016,703 B1 9/2011 Kronengold et al.
6,286,496 B1 9, 2001 Bednar 8,020,543 B2 9, 2011 Maleski et al.
6.425,386 B1 7/2002 Adkins 8,033,275 B2 10/2011 Bednar et al.
6,571,785 B1 6, 2003 Choma 8,042,530 B2 10/2011 Barnett
6,651,641 B1 1 1/2003 Bower et al. 8,091,540 B2 1/2012 Matasic et al.
6,705.304 B1 3/2004 Pauluhn 8, 104,461 B2 1/2012 Kempf
6,712,057 B2 3, 2004 Andrews 8,240,299 B2 8/2012 Kronengold et al.
6,736,123 B1 5/2004 Summers et al. 8,651,095 B2 2/2014 Islas
6,776, 148 B1 8, 2004 Islas 8,899,217 B2 12/2014 Islas
6,786.214 B2 9, 2004 Andrews 2005/0022799 A1 2/2005 Bednar
6,799,566 B1 10/2004 Malucelli 2007/0028907 A1 2/2007 Bednar et al.
6,901,921 B1 6, 2005 Barnett 2009/0178657 A1 7, 2009 Shaffer
6,913,007 B2 7/2005 Bednar 2009,0194086 A1 8/2009 Kempf
7,174,884 B2 2/2007 Kempfet al. 2009/0223500 A1* 9, 2009 Stanziale ........................ 124/25
7,204.242 B2 4/2007 Dziekan 2010, OO12108 A1 1/2010 Bednar et al.
7,305,979 B1 12/2007 Yehle 2010.0031945 A1 2/2010 Shaffer et al.
7,328,693 B2 2/2008 Kempf 2010, O154768 A1 6, 2010 Bednar et al.
7,363,921 B2 4/2008 Kempf 2010/0170487 A1 7/2010 Kronengold et al.
D589,578 S 3/2009 Choma 2010/0170488 A1 7/2010 Rasor et al.
D590,907 S 4/2009 Barnett 2010, 0186728 A1 7/2010 Bednar et al.
7,624,724 B2 12/2009 Bednar et al. 2010/0269807 A1 10, 2010 Kempf
7,624,725 B1 12/2009 Choma 2011/0203561 A1 8, 2011 Shaffer et al.
T.677,233 B2 3/2010 Bednar 2011/0232619 A1 9, 2011 Bednar et al.
w
7,708,001 B2 5/2010 Kempf 2011/02531 18 A1 10/2011 Kempf
7,743,760 B2 6, 2010 Woodland 2012,0006311 A1 1/2012 Bednar et al.
7,748,370 B1 7, 2010 Choma * cited by examiner
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U.S. Patent US 9.255,753 B2
U.S. Patent Feb. 9, 2016 Sheet 22 of 22 US 9.255,753 B2
 US 9.255,753 B2
1. 2
ENERGY STORAGE DEVICE FOR A BOW and a second end secured to the second pulley. The first and
second pulleys are displaced toward the center Support as the
FIELD OF THE INVENTION draw string is pulled to a drawn configuration. In another
embodiment, the first and second ends of the draw string can
The present disclosure is directed to an energy storage be coupled to the center Support.
portion for a bow with limbs having distal portions and proxi The total displacement of the first pulley axis toward the
mal portions both coupled to a center Support. The present second pulley axis as the draw string is pulled to a drawn
disclosure is also directed to a pulley System in which only the configuration is preferably less than about 3.5 inches, or
draw string crosses over the center Support. about 3.0 inches. In another embodiment, separation between
10 the first and second axes when the draw string is in a drawn
BACKGROUND OF THE INVENTION configuration is less than about 10 inches and less than about
13 inches when the draw string is in the released configura
tion.
Bows have been used for many years as a weapon for In one embodiment, a first power string has a first end
hunting and target shooting. More advanced bows include attached to the center Support and a second end attached to the
cams that increase the mechanical advantage associated with 15
first pulley, and a second power string with a first end attached
the draw of the bowstring. The cams are configured to yield a to the center Support and a second end attached to the second
decrease in draw force near full draw. pulley. The first and second power strings preferably do not
For optimal bow performance, Substantial synchronization cross over the center support from the first side to the second
of rotation of the cams is required, but often problematic to side.
achieve in practice. Synchronization typically requires sec In another embodiment, the first and second limbs each
ondary strings and pulleys that control the rotation of the include a pair of limbs arranged in a spaced apart configura
cams, such as disclosed in U.S. Pat. No. 7,305,979 (Yehle). tion with the first and second pulleys located between the pair
These additional features increase the weight, cost and main of limbs, respectively. The first and second limbs can be
tenance of Such devices, while adding additional friction, arranged in a concave or convex configuration with respect to
further decreasing the potential speed of the projectile. 25 the center support. The first and second pulleys are preferably
cams. The first and second pulleys are preferably coupled to
BRIEF SUMMARY OF THE INVENTION the limbs generally at a midpoint between the distal and
proximal portions.
The present disclosure is directed to an energy storage The present disclosure is also directed to a method of
portion for a bow with limbs having distal portions and proxi 30
configuring an energy storage portion for a bow. A distal
mal portions both coupled to a center Support. The present portion and a proximal portion of at least a first limb are
coupled to the first side of the center support. A distal portion
disclosure is also directed to a pulley system in which only the and a proximal portion of at least a second limb are coupled to
draw string crosses over the center Support. the second side of the center support. At least one first pulley
One embodiment is directed to an energy storage portion is attached to the first limb at a location between the distal and
for a bow including a center Support having a first side and a 35 the proximal portions of the first limb and at least one second
second side. At least one first limb has both a distal portion pulley is attached to the second limb at a location between the
and a proximal portion coupled to the first side of the center distal and the proximal portions of the second limb.
Support. At least one second limb has both a distal portion and The present disclosure is also directed to a pulley System
a proximal portion coupled to the second side of the center for an energy storage portion of a bow. The pulley System
support. At least one first pulley is attached to the first limb at 40 includes a center Support having a first side and a second side.
a location between the distal and the proximal portions of the At least one first limb has at least one of a distal portion and
first limb and at least one second pulley is attached to the a proximal portion coupled to the first side of the center
second limb at a location between the distal and the proximal Support, and at least one second limb has at least one of a
portions of the second limb. distal portion and a proximal portion coupled to the second
The distal portions and the proximal portions of the first 45 side of the center support. At least one first pulley is attached
and second limbs can be dynamically coupled or positively to the first limb and at least one second pulley is attached to
coupled to the center Support. In one embodiment, the distal the second limb. A draw string extends across the center
portions or the proximal portions dynamically coupled to the Support and around portions of the first and second pulleys.
center Support do not contact the center Support until the The draw string includes a first end secured to the first side of
limbs are deformed inward toward the center support. 50
the center Support and a second end secured to the second side
The distal portions and/or the proximal portions of the first of the center Support.
The present disclosure is also directed to a pulley System
and second limbs can be coupled to the center Support by a for an energy storage portion of a bow including a draw string
rigid coupling, a pivoting coupling, a linkage coupling, a extending across the center Support and around portions of the
rotating coupling, a sliding coupling, an elastomeric cou first and second pulleys. The draw string includes a first end
pling, or a combination thereof. At least one of the couplings 55 secured to the first pulley and a second end secured to the
preferably provides limb relief between the proximal portion second pulley. A first power string has a first end attached to
and the distal portion of the limbs. In another embodiment, the center Supportanda second end attached to the first pulley.
the center support provides limb relief between the proximal A second power string has a first end attached to the center
portion and the distal portion of the limbs. Support and a second end attached to the second pulley,
In another embodiment, at least one of the distal portions or 60 whereby the first and second power strings do not cross over
the proximal portions of the first and second limbs are posi the center support from the first side to the second side.
tively coupled to the center Support by rotating translation
arms. The rotation of the rotating translation arms is synchro BRIEF DESCRIPTION OF THE SEVERAL
nized by a synchronization assembly. VIEWS OF THE DRAWING
A draw string extends across the center Support and around 65
portions of the first and second pulleys. In one embodiment, FIG. 1 is a perspective view of an energy storage system in
the draw string includes a first end secured to the first pulley accordance with an embodiment of the present disclosure.
 US 9.255,753 B2
3 4
FIG.2 is an alternate perspective view of the energy storage structed from a light weight metal. Such as high grade alumi
system of FIG. 1. num. As will be discussed below, the center support 52 will
FIG. 3 is a front view of the energy storage system of FIG. include a variety of additional features, such as cut-outs and
1. mounting holes, to accommodate other components such as a
FIG. 4 is a bottom view of the energy storage system of trigger mechanism, cocking mechanism, stock, arrow Stor
FIG 1. age, and the like (see e.g., FIG. 12B).
FIG. 5 is a sectional view showing the draw string of the In the illustrated embodiment, limbs 64A, 66A are located
energy storage system of FIG. 1 in a released configuration. on first side 58A of the centerplane 60 and limbs 64B, 66Bare
FIG. 6 is a sectional view showing the power strings of the located on the second side 58B. Proximal portions 68A, 68B
energy storage system of FIG. 1 in the release configuration. 10 (“68') of the limbs 64A, 66A are coupled to the proximal
FIG. 7 is a top view of the energy storage system of FIG. 1 limb mount 54A in the finger guard 53A, such as by pivot pin
in a released configuration in accordance with the embodi 70 and pivot brackets 72. Proximal portions 74A, 74B (“74)
ment of the present disclosure. of the limbs 64B, 66B are coupled to the proximal limb
FIG. 8 is a top view of the energy storage system of FIG. 1 mounts 56B in the finger guard 53B by pivot pin 70 and pivot
in a drawn configuration in accordance with the embodiment 15 brackets 72. As illustrated in FIG.3, the proximal portions 68,
of the present disclosure. 74 rotate on axes 86A, 86B (“86') relative to the center
FIG. 9 is a sectional view showing the draw string of the Support 52 to provide a pivoting or rotating coupling.
energy storage system of FIG. 1 in a drawn configuration. In the illustrated embodiment, translation arms 62A, 62B
FIG.10 is a sectional view showing the power strings of the (“62) are pivotally attached to the distal limb mounts 54A,
energy storage system of FIG. 1 in the drawn configuration. 54B in the finger guards 53A, 53B, respectively. Distal por
FIG. 11 is a bottom view of the energy storage system of tions 76A, 76B (“76”) of the limbs 64A, 66A are coupled to
FIG. 1 showing a timing belt in accordance with an embodi the translation arm mount 78A, such as by pivot pin 70 and
ment of the present disclosure. pivot brackets 72. Distal portions 80A, 80B (“80') of the
FIG. 12A is a sectional view of a center support with a limbs 64B, 66B are coupled to the translation arm mount 78B
cocking system in accordance with an embodiment of the 25 by pivot pin 70 and pivot brackets 72. The distal portions 76,
present disclosure. 80 rotate on axes 82A, 82B, (“82) relative to the translation
FIG.12B is perspective view of the center support of FIG. arm mounts 78A, 78B, respectively. The translation arms
12A. 62A, 62B rotate on axes 84A, 84B ('84), respectively, rela
FIG. 13 is a sectional view of the cocking mechanism of tive to the center support 52 (see, FIG. 3). The translation
FIG. 12A in a fully open configuration in accordance with an 30 arms 62 to provide a linkage coupling between the limbs 64.
embodiment of the present disclosure. 66 and the center support 52.
FIG.14 is a perspective view of a ratcheting mechanism for As used herein, "coupled’ or "coupling refers to a con
a cocking mechanism in accordance with an embodiment of nection between a limb and a center support. Both positive
the present disclosure. coupling and dynamic coupling are possible. "Positively
FIG. 15 is a sectional view of the ratcheting mechanism of 35 coupled' or “positive coupling refers to a limb continuously
FIG 14. engaged with a center Support. "Dynamically coupled' or
FIG.16 is a plan view of an alternate energy storage device "dynamic coupling refers to a limb engage with a center
for an energy storage system in accordance with an embodi Support only when a certain level of tension is applied to a
ment of the present disclosure. draw string. The coupling can be a rigid coupling, a sliding
FIG. 17 is a bow with the energy storage device of FIG. 16 40 coupling, a pivoting coupling, a linkage coupling, a rotating
in accordance with an embodiment of the present disclosure. coupling, an elastomeric coupling, or a combination thereof.
FIG. 18 illustrates an energy storage portion for a bow with For example, in the embodiment of FIG.1, both ends of the
convex limbs in accordance with an embodiment of the limbs 64, 66 are positively coupled to the center support 52.
present disclosure. The proximal ends 68,74 use a rotating or pivoting coupling
FIGS. 19A and 19B an energy storage portion for a bow 45 and the distal portions 76, 80 use a linkage coupling.
with a center support that provides limb relief in accordance As illustrated in FIG. 8, the inward deformation of the
with an embodiment of the present disclosure. limbs 64, 66 forces the translation arms 62 to rotate in distal
FIGS. 20A and 20B illustrate a conventional energy stor directions 144 around pivotaxes 84 to extended position 146.
age portion of a conventional bow with a pulley System in The translation arms 62 provide limb relief between the distal
accordance with an embodiment of the present disclosure. 50 portions 74 and the proximal portion 68 of the limbs 64, 66.
As used herein, “limb relief means displacement between a
DETAILED DESCRIPTION OF THE INVENTION proximal portion of a limb relative to a distal portion of the
limb when a certain level oftension is applied to a draw string.
FIGS. 1-4 are perspective views of an energy storage The displacement can be translation, rotation, flexure, or a
device 50 for a projectile launching system in accordance 55 combination thereof, occurring at either or both ends of the
with an embodiment of the present disclosure. Center support limbs. The limb relief is typically provided by the couplings
52 includes a first pair of distal and proximal limb mounts and/or the center support 52.
54A, 56A located on a first side 58A of centerplane 60 and a Various structures for providing limb relief are discussed
second pair of distal and proximal limb mounts 54B, 5.6B herein. For example, limb relief can be provided by locating
located on a second side 58B on the second side of the center 60 pivot arms 62 between proximal portions 68,74 of the limbs
plane 60. 64, 66 and the proximal limb mounts 54. In yet another
The center Support 52 can be a single piece or a multi embodiment, limb relief is provided by pivot arms 62 located
component construction. In the illustrated embodiment, the at both the distal portions 76, 80 and the proximal portions 68,
center Support 52 includes a pair of machined center rails 74 of the limbs 64, 66.
52A, 52B coupled together with fasteners, and a pair offinger 65 In an alternate embodiment, the translation arms 62 are
guards 53A, 53B also attached to the center rails 52A, 52B replaced with elastomeric members that are rigidly attached
using fasteners. The components 52, 53 are preferably con to the finger guard 53. Limb relief is achieved by elastic
 US 9.255,753 B2
5 6
deformation of the elastomeric translation arms. In another A more detailed discussion of cams suitable for use inbows is
embodiment, limb relief is provided by a combination of provided in U.S. Pat. No. 7,305,979 (Yehle), which is hereby
deformation and rotation of the elastomeric translation arms incorporated by reference.
62 (see e.g., FIG. 16). FIG. 7 is a top view of the energy storage device 50 in a
In yet another embodiment, one or both of the distal and released configuration 130 with the draw string 100 in its
proximal limb mounts 54, 56 are configured as slots with an forward most position relative to the distal end 132 of the
elastomeric bushing to provide the limb relief. center support 52. Static tension between the draw string 100
In yet another embodiment, limb relief is provided by the and the power strings 106 is opposed by slight flexure of the
center support 52 (see e.g., FIGS. 19A and 19B). limbs 64, 66 to maintain the translation arms 62 in retracted
First pulley assembly 90A is pivotally coupled to the first 10 position 134.
limbs 64A, 66A at a location between the proximal and distal In the retracted position 134 the translation arms 62 are
portions 68, 76. Second pulley assembly 90B is pivotally rotated back toward proximal end 136 of the center support,
with the limbs 64, 66 in a generally concave configuration
coupled to the second limbs 64B, 66B at a location between with respect to the center support 52. In the release configu
the proximal and the distal portions 74, 80. As best illustrated 15 ration 130 distance 128 between the proximal limb mounts 56
in FIG. 3, the first and second pulley assemblies 90A, 90B and the translation arm mounts 78 is at a minimum and width
rotate around axes 94A, 94B. In the illustrated embodiment, 138 of the energy storage device 50 is at its maximum.
the first pulley assembly 90A is located between the limbs FIG. 8 is a top view of the energy storage device 50 with the
64A, 66A and the second pulley assembly 90B is located draw string 100 in a drawn configuration 140. The process of
between the limbs 64B, 66B. drawing the draw string 100 toward the proximal end 136 of
As used herein, the term “pulley” is refers generically to a the center Support 52 simultaneously causes the pulley
member rotating around an axis that is designed to Support assemblies 90 to rotate in directions 142 and the limbs 64, 66
movement of a flexible member, such as a rope, string, belt, to deform inward toward the center support 52.
chain, and the like. Pulleys typically have a groove, channel or In the illustrated embodiment, the limb relief increases the
journal located between two flanges around at least a portion 25 distance 148 between the proximal limb mounts 56 and the
of its circumference that guides the flexible member. Pulleys translation arm mounts 78 to be greater than the distance 128
can be round. Such as a drum or a sheave, or non-round. Such (see FIG. 5). In the drawn configuration 140 distance 148
as a cam. The axis of rotation can be located concentrically or between the proximal limb mounts 56 and the translation arm
eccentrically relative to the pulley. mounts 78 is at a maximum and width 150 of the energy
As best illustrated in FIG. 3, the pulleys 90A,90B include 30 storage device 50 is at a minimum. The distance 148 in the
draw string journals 96A, 96B (“96') configured to receive drawn configuration 140 is greater than the distance 128 in the
draw string 100. The draw string journals 96 are located in released configuration 130. The width 150 in the drawn con
plane 98 that is located above top surface 102 of the center figuration is less than the width 138 in the released configu
ration 130.
support 52. As will be discussed below, the draw string jour 35 Operation of the illustrated embodiment includes locating
nals 96 are arranged so that the string 100 travels close to the an arrow or bolt in groove 162 with knock engaged with the
top surface 102 of the center support 52 between a release draw string 100 in location 164. Release of the draw string
configuration 130 and a drawn configuration 140 (See FIGS. 100 causes the limbs 64, 66 to return to the released configu
7 and 8). The pulleys 90 also include power string journals ration 130, thereby launching the bolt in direction 166.
104A, 104B (“104) configured to receive power strings 40 As best illustrated in FIG. 8, the finger guards 53 is con
106A, 106B that are located below and generally parallel to figured to extend to at least space 101, which corresponds to
the draw string journals 96. As used herein, “string refers the space traversed by the draw string 100 from the drawn
generically to any flexible member, such as woven and non configuration 140 to the released configuration 130. The fin
woven filaments of synthetic or natural materials, cables, ger guard 53 is configured to reduce the chance of a user's
belts, chains, and the like. 45 finger extending up from the bottom of the center support 52
FIG. 5 is a sectional view of the energy storage device 50 and into the path 103 of the drawing string 100 from the drawn
showing the path of the draw string 100 on the pulley assem configuration 140 to the released configuration 130. In the
blies 90 in the released configuration 130. The draw string preferred embodiment, the finger guard 53 completely blocks
100 wraps around distal portions of the draw string journals access from the bottom of the center support 52 to the space
96 in direction 108 and the ends of the draw string 100 are 50 101. In another embodiment, gap 105 between the draw string
attached to anchors 110A, 110B on the pulleys 90A, 90B, 100 and the finger guards 53 is less than about 0.5 cm.
respectively. In the illustrated embodiment, the draw string The energy storage device 50 typically includes a trigger
100 crosses over the center support 52 only once. assembly to retain the draw string 100 in the drawn configu
FIG. 6 is a sectional view of the energy storage device 50 ration 140 and a stock located near the proximal end 136 of
showing the path of the power strings 106A, 106B in the 55 the center support 52. Most trigger assemblies include a dry
release configuration 130. The power strings 106 attach to the fire mechanism that prevents release of the draw string 100
center support 52 by anchors 112A, 112B and wrap around unless a bolt is positioned in the center support 52. Suitable
distal portions of the power string pulleys 105A, 105B, trigger assemblies and stocks are disclosed in U.S. Pat. No.
respectively. The opposite ends of the power strings 106A, 8,240,299 (Kronengold et al.); U.S. Pat. No. 8,104,461
106B are attached to the pulleys 90A, 90B (not shown) by 60 (Kempf): U.S. Pat. No. 8,033,275 (Bendar et al.); U.S. Pat.
anchors 114A, 114B, respectively. In the illustrated embodi No. 8,020,543 (Maleski et al.); U.S. Pat. No. 7,836,871
ment, the power strings 106 do not cross over the center (Kempf): U.S. Pat. No. 7,810,480 (Shepley et al.); U.S. Pat.
support 52. No. 7,770,567 (Yehle); U.S. Pat. No. 7,743,760 (Woodland):
The geometric profiles of the draw string journals 96 and U.S. Pat. No. 7,363,921 (Kempf): U.S. Pat. No. 7,328,693
the power string journals 104 contribute to let-offat full draw. 65 (Kempf): U.S. Pat. No. 7,174,884 (Kempfet al.); U.S. Pat.
The configuration of the limbs 64, 66 and the limb relief of the No. 6,736,123 (Summers et al.); U.S. Pat. No. 6,425,386
limbs 64, 66 to the center support 52 also contribute to let-off. (Adkins); U.S. Pat. No. 6,205,990 (Adkins); U.S. Pat. No.
 US 9.255,753 B2
7 8
5,884,614 (Darlington et al.); U.S. Pat. No. 5,649,520 (Bed elongated tube 206. As the elongated tube 206 is moved to the
nar); U.S. Pat. No. 5,598,829 (Bednar); U.S. Pat. No. 5,596, closed and located configuration 202, the pawl 232 rocks up
976 (Waiser); U.S. Pat. No. 5,085,200 (Horton et al.); U.S. and down around pivot 240 to sequentially engage with teeth
Pat. No. 4,877,008 (Troubridge); U.S. Pat. No. 4,693,228 242. As a result, inadvertent release of the elongated tube 206
(Simonds et al.); U.S. Pat. No. 4,479,480 (Holt); U.S. Pat. No. does not result in the cocking mechanism 200 returning to the
4,192.281 (King); and U.S. Pat. No. 4,030,473 (Puryear), fully open configuration 222.
which are hereby incorporated by reference. Also illustrated in FIGS. 14 and 15 is additional detail for
FIG. 9 is a sectional view of FIG.8 with the center support the latch 226. Spring 244 biases the latch 226 in a locked
52 removed to better illustrate the path of the draw string 100 configuration 246. As the elongated tube 206 is pushed to the
in the drawn configuration 140. The pulley assemblies 90 are 10 closed and locked configuration 222, the latch 226 is pushed
rotated in direction 91 until the draw string is fully drawn. by the pin 228 in direction 248 until the pin 228 clears tip 250,
FIG. 10 is a sectional view of FIG.8 with the draw string at which point the latch 226 returns to the locked configura
pulleys removed to illustrate the path of the power strings 106 tion 246.
in the drawn configuration 140. The power strings 106 wrap As illustrated in FIG. 13, operation of the pawl 232 and the
around the power pulleys 105 in a first direction and around 15 latch 226 is simultaneously controlled by thumb trigger 252
the pivot axes 94 of the pulley assemblies 90 in the opposite located near proximal end 224 of the elongated tube 206. In
direction, terminating at anchors 112, as discussed above. the illustrated embodiment, cable 254 is attached to the thumb
FIG. 11 is a bottom sectional view of the energy storage trigger 252 and both of the pawl 232 and the latch 226.
device 50 with synchronization assembly 158 exposed. In the Depressing the thumb trigger 252 in direction 256 disengages
illustrated embodiment, the synchronization assembly 158 the pawl 232 from the teeth 242 and the latch 226 from the pin
includes timing belt 160 wrapped around pulleys 162 that are 228, respectively. Various alternate cocking mechanisms can
coupled to the rotation of the translation arms 62. The timing be used to pull the draw string 100 to the drawing configura
belt 160 synchronizes the rotation of the translation arms 62 tion 130, such as disclosed in U.S. Pat. No. 7,624,725
(see FIG. 6A) between the retracted position 134 and the (Choma); U.S. Pat. No. 7,204.242 (Dziekan): U.S. Pat. No.
extended position 146. In the illustrated embodiment, the 25 6,913,007 (Bednar); U.S. Pat. No. 4.942,861 (Bozek); U.S.
timing belt 160 is a toothed belt twisted into a figure eight Pat. No. 6,799,566 (Malucelli); U.S. Pat. No. 6,705.304 (Pau
configuration. Alternate synchronization assemblies can luhn): U.S. Pat. No. 6,286,496 (Bednar); U.S. Pat. No. 6,095,
include gears, belts, cables, chains, linkages, and the like. 128 (Bednar); and U.S. Pat. No. 4,719,897 (Gaudreau), which
FIG. 12A is a sectional view of an alternate center support are hereby incorporated by reference.
52 modified to include cocking mechanism 200 shown in a 30 FIG. 16 illustrates an alternate energy storage device 260
closed and locked configuration 202 in accordance with an with alternate limb relief in accordance with an embodiment
embodiment of the present disclosure. FIG.12B is a perspec of the present disclosure. The center support 262, the draw
tive view of the center support 52 with the cocking mecha string 264, and the power stings 266A, 266B are removed for
nism 200 in a partially opened configuration. clarity (see FIG. 17).
The center support 52' is machined to create opening 204 35 Distal portions 270A, 270B (270) of limbs 272A, 272B
that receives the cocking mechanism 200. The cocking (“272) are attached to the device 260 at locations 274A,
mechanism 200 includes an elongated tube 206 pivotally 274B (274"), respectively. The attachment at the locations
attached to the center support 52 at location 208 near the 274 can employ various couplings (e.g., a rigid coupling, a
distal end 132. Arm 210 pivotally couples the elongated tube pivoting coupling, a linkage coupling, a rotating coupling, a
206 to traveler 212 that slides back and forth along axis 216 in 40 sliding coupling, an elastomeric coupling, or a combination
channel 214 formed in the center support 52'. The traveler 212 thereof). Proximal portions 276A, 276B (276”) of the limbs
includes finger 218 that captures the draw string 100 to move 272 are configured to engage with portions 278A, 278B
it from the released configuration 130 to the drawn configu (“278) of the device 260, respectively. It is possible to
ration 140 and into engagement with a trigger assembly (not reverse this configuration by locating the portions 278 at the
shown). In the illustrated embodiment, the elongated tube 206 45 distal end of the device 260.
includes a conventional accessory rail 220, used to attach When the draw string 264 is in the drawn configuration
various accessories to the center Support 52', Such as forward 140, the limbs 272 deform in direction 280 and the proximal
grips, laser sights, and the like. portions 276 translate along portions 278 in direction 282 to
FIG. 13 is a sectional view of the center support 52 in a providelimb relief through a sliding coupling. In one embodi
fully open configuration 222. The arm 210 advances the trav 50 ment, the portions 278 have a curvilinear shape to increase
eler 212 to the distal end 132 of the center support 52 to let-off when the draw string 264 is in the fully drawn configu
capture the draw string 100. In order to cock the energy ration 140.
storage device 50, the user grasps proximal end 224 of the In another embodiment, the proximal portions 276 are
elongated tube 206 and returns it to the closed and locked dynamically coupled to the portions 278 of the device 260.
configuration 202. Latch 226 engaged with pin 228 on the 55 The proximal portions 278 are not attached to the device 260.
center support 52 to lock the cocking mechanism 200 in the For example, space 286 may exist between the proximal
closed and locked configuration 202. portions 276 of the limbs 272 and the portions 278 when the
The limbs 64, 66 resist movement of the elongated tube 206 draw string 264 is in the released configuration 130. As the
back to the closed and locked configuration 202. If the user limbs 272 deformed while the draw string 264 is drawn,
inadvertently releases the elongated tube 206 during this pro 60 however, the proximal portions 276 of the limbs 272 engage
cess, it will snapback to the fully open configuration 222 with with the portions 278 on the device 260 and are displaced in
considerable force. Ratcheting mechanism 230 prevents this the direction 282, in a combination of a dynamic coupling and
OutCOme. a sliding coupling.
As best illustrated in FIGS. 14 and 15, the ratcheting In another embodiment, the proximal portions 276 are
mechanism 230 includes pawl 232 pivotally attached to the 65 positively coupled to the portions 278 by sliding couplings
arm 210. Spring 234 biases distal end 236 of the pawl 232 into 284A, 284B (284). One advantage of the positive couplings
engagement with tooth members 238 that are mounted to the 284 is that when the draw string 264 is released, the proximal
 US 9.255,753 B2
9 10
portions 276 are prevented from lifting off of the portions 278 ment of FIG.20B reverses the wrap of the power strings 390
on the device 260, reducing noise. and draw string 388 around the pulleys 384 in directions 396
In another embodiment, the proximal portions 276 of the to increase the draw length.
limbs 272 are fixedly attached to the portions 278 of the Where a range of values is provided, it is understood that
device 260 as shown. The portions 278 are constructed from each intervening value, to the tenth of the unit of the lower
an elastomeric material configured to deform as the limbs 272 limit unless the context clearly dictates otherwise, between
are deformed in the direction 280 to provide limb relief via an the upper and lower limit of that range and any other stated or
elastomeric coupling. intervening value in that stated range is encompassed within
Any of the limb relief embodiments disclosed herein may this disclosure. The upper and lower limits of these smaller
be used alone or in combination. 10 ranges which may independently be included in the Smaller
FIG. 17 is a perspective view of bow 300 with the energy ranges is also encompassed within the disclosure, Subject to
storage device 260 in accordance with an embodiment of the any specifically excluded limit in the stated range. Where the
present disclosure. Proximal end 302 of the center support stated range includes one or both of the limits, ranges exclud
262 includes stock 304 and trigger assembly 306 configured ing either both of those included limits are also included in the
to releasably retain draw string 264 in the drawing configu 15 disclosure.
ration 140. Cocking assembly 308 is mounted at bottom of Unless defined otherwise, all technical and scientific terms
center Support 262 as discussed herein. used herein have the same meaning as commonly understood
FIG. 18 is a schematic illustration of an alternate energy by one of ordinary skill in the art to which this disclosure
storage device 320 with convex limbs 322A, 322B ("322") belongs. Although any methods and materials similar or
with respect to center Support 324 in accordance with an equivalent to those described herein can also be used in the
embodiment of the present disclosure. The center support 324 practice or testing of the various methods and materials are
includes distal and proximal spacers 326A, 326B (“326’) that now described. All patents and publications mentioned
retain the limbs 322 in a spaced configuration. herein, including those cited in the Background of the appli
The convex limbs 322 deflect inward in directions 330 cation, are hereby incorporated by reference to disclose and
toward the center support 324 as the draw string (not shown) 25 described the methods and/or materials in connection with
is moved to the drawing configuration. In the illustrated which the publications are cited.
embodiment, limb relief is provided by translation arms 328, The publications discussed herein are provided solely for
although any of the limb relief mechanism disclosed herein their disclosure prior to the filing date of the present applica
may be used. tion. Nothing herein is to be construed as an admission that
FIGS. 19A and 19B illustrate an alternate energy storage 30 the present disclosure is not entitled to antedate such publi
device 350 in which limb relief is provided by center support cation by virtue of prior invention. Further, the dates of pub
352 in accordance with an embodiment of the present disclo lication provided may be different from the actual publication
sure. Center support 352 includes a distal portion 354A and a dates which may need to be independently confirmed.
proximal portion 354B connected by displacement mecha Other embodiments are possible. Although the description
nism 356. The displacement mechanism 356 permits the dis 35 above contains much specificity, these should not be con
tal portion 354 to be displaced relative to the proximal portion Strued as limiting the scope of the disclosure, but as merely
354B along axis 358. The displacement mechanism 356 may providing illustrations of some of the presently preferred
be an elastomeric member, a pneumatic or hydraulic cylinder, embodiments. It is also contemplated that various combina
or a variety of other structures configured to bias the distal tions or Sub-combinations of the specific features and aspects
portion 354A toward the proximal portion 354B along the 40 of the embodiments may be made and still fall within the
axis 358. scope of this disclosure. It should be understood that various
Distal ends 360A, 360B (360') of limbs 362A, 362B features and aspects of the disclosed embodiments can be
(362) are attached to the distal portion 354A of the center combined with or substituted for one another in order to form
support 352. Proximal ends 364A,364B (“364) of limbs 362 varying modes disclosed. Thus, it is intended that the Scope of
are attached to the proximal portion 354B of the center Sup 45 at least some of the present disclosure should not be limited
port 352. As the draw string (not shown) is moved to the by the particular disclosed embodiments described above.
drawing configuration 140, the limbs 362 flatten so that dis Thus the scope of this disclosure should be determined by
tance 366 between distal ends 360 and proximal ends 364 of the appended claims and their legal equivalents. Therefore, it
the limbs 362 increases to provide limb relief. As the draw will be appreciated that the scope of the present disclosure
string is released, the displacement mechanism 356 biases the 50 fully encompasses other embodiments which may become
distal portion 354A toward the proximal portion 354B to the obvious to those skilled in the art, and that the scope of the
configuration shown in FIG. 19A. present disclosure is accordingly to be limited by nothing
FIGS. 20A and 20B are top views of an energy storage other than the appended claims, in which reference to an
portion 380 of a conventional bow with a pulley system382 in element in the singular is not intended to mean “one and only
accordance with an embodiment of the present disclosure. 55 one' unless explicitly so stated, but rather “one or more.” All
The pulley system 382 includes pulleys 384A, 384B (“384) structural, chemical, and functional equivalents to the ele
attached to ends of limbs 386A, 386B (“386”). Drawing ments of the above-described preferred embodiment that are
string 388 and power strings 390A, 390B (“390) wrap known to those of ordinary skill in the art are expressly
around the pulleys 384 and attach to the center support 392. incorporated herein by reference and are intended to be
The power strings 390 do not cross-over the center support 60 encompassed by the present claims. Moreover, it is not nec
388. Consequently, only the draw string 384 crosses over the essary for a device or method to address each and every
center support 388. problem sought to be solved by the present disclosure, for it to
In the illustrated embodiment, the power strings 390 and be encompassed by the present claims. Furthermore, no ele
the draw string 388 are a single structure with ends 394 ment, component, or method step in the present disclosure is
attached to the center support 392. In an alternate embodi 65 intended to be dedicated to the public regardless of whether
ment, the power strings 390 and the draw strings 388 can be the element, component, or method step is explicitly recited
discrete structures, such as illustrated in FIG. 3. The embodi in the claims.
 US 9.255,753 B2
11 12
What is claimed is: 11. The energy storage portion for a bow of claim 1 wherein
1. An energy storage portion for a bow comprising: the first and second pulleys, each rotate around first and
a center Support having a first side and a second side; second axes, wherein total displacement of the first axis
at least one first limb having a distal portion pivotally toward the second axis as the draw string is pulled to a drawn
coupled to the first side of the center support at a distal configuration is less than about 3.5 inches.
limb mount and a proximal portion, pivotally coupled to 12. The energy storage portion for a bow of claim 1 wherein
the first side of the center support at a proximal limb the first and second pulleys each rotate around first and sec
mount; ond axes, wherein total displacement of the first axis toward
at least one second limb having a distal portion pivotally the second axis as the draw string is pulled to a drawn con
coupled to the second side of the center Support at a 10 figuration is less than about 3.0 inches.
distal limb mount and a proximal portion pivotally 13. The energy storage portion for a bow of claim 1 wherein
coupled to the second side of the center Support at a the first and second pulleys each rotate around first and sec
proximal limb mount; ond axes, wherein a separation between the first and second
at least one first pulley including a first string journal and a axes when the draw string is in a drawn configuration is less
first power cable journal pulley pivotally attached to the 15 than about 10 inches.
first limb at a fixed position located between the distal 14. The energy storage portion for a bow of claim 1 wherein
portion and the proximal portions; the first and second pulleys each rotate around first and sec
at least one second pulley including a second string journal ond axes, wherein a separation between the first and second
and a second power cable journal pivotally attached to axes when the draw string is in a released configuration is less
the second limb at a fixed position located between the than about 13 inches.
distal portion and the proximal portions; 15. The energy storage portion for a bow of claim 1 com
a draw string extending across the center Support and prising a finger guards on the center Support with a shape
engaged with the first and second string journals, the corresponding to a space traversed by the draw string as it
draw string including a first end secured to the first moves between the drawn configuration and the released
pulley and, a second end secured to the second pulley; 25 configuration.
a first power cable engaged with the first power cable 16. An energy storage portion for a bow comprising:
journal having a first end attached to the center Support a center Support having a first side and a second side;
and a second end attached to the first pulley; at least one first limb having a distal portion pivotally
a second power cable engaged with the second power cable coupled to the first side of the center support at a distal
journal having a first end attached to the center Support 30 limb mount and aproximal portion pivotally coupled to
and a second end attached to the second pulley; and the first side of the center support at a proximal limb
couplings interposed between at least one of the distal mount;
portions or the proximal portions of the first and second at least one second limb having a distal portion pivotally
limbs and the respective limb mounts that provides limb coupled to the second side of the center Support at a
relief as the draw string is pulled to a drawn configura 35 distal limb mount and a proximal portion pivotally
tion. coupled to the second side of the center Support at a
2. The energy storage portion for a bow of claim 1 wherein proximal limb mount;
the first and second limbs each comprise a pair of limbs at least one first pulley including a first string journal and a
arranged in a spaced apart configuration with the first and first power cable journal pulley pivotally attached to the
second pulleys located between the pair of limbs, respec 40 first limb at a fixed position located at about a midpoint
tively. between the distal and proximal portions;
3. The energy storage portion for a bow of claim 1 wherein at least one second pulley including a second string journal
the first and second limbs are arranged in a concave or convex and a second power cable journal pivotally attached to
configuration with respect to the center Support. the second limb at a fixed position located at about a
4. The energy storage portion for a bow of claim 1 wherein 45 midpoint between the distal and proximal portions;
the first and second pulleys comprise cams. a draw string extending across the center Support and
5. The energy storage portion for a bow of claim 1 wherein engaged with the first and second string journals, the
the first and second pulleys are attached to the first and second draw string including a first end secured to the first
limbs, respectively, generally at a midpoint between the distal pulley and a second end secured to the second pulley;
and proximal portions. 50 a first power cable engaged with the first power cable
6. The energy storage portion for a bow of claim 1 wherein journal having a first end attached to the center Support
the first and second power cables do not cross over the center and a second end attached to the first pulley; and
support from the first side to the second side. a second power cable engaged with the second power cable
7. The energy storage portion of a bow of claim 1 wherein journal having a first end attached to the center Support
the couplings comprise rotating translation arms pivotally 55 and a second end attached to the second pulley, wherein
attached to one of the distal portions or the proximal portions the first and second power cables do not cross over the
of the first and second limbs and the respective limb mounts. center support from the first side to the second side.
8. The energy storage portion for a bow of claim 7 wherein 17. The energy storage portion for a bow of claim 16
rotation of the rotating translation arms are synchronized by a comprising couplings interposed between at least one of the
synchronization assembly. 60 distal portions or the proximal portions of the first and second
9. The energy storage portion for a bow of claim 1 wherein limbs and the respective limb mounts that provides limb relief
the couplings comprise pivoting couplings, linkage cou as the draw string is pulled to a drawn configuration.
plings, rotating couplings, sliding couplings, elastomeric 18. The energy storage portion of a bow of claim 16
couplings, or a combination thereof. wherein the couplings comprise rotating translation arms piv
10. The energy storage portion for a bow of claim 1 wherein 65 otally attached to one of the distal portions or the proximal
the center support provides limb relief between the proximal portions of the first and second limbs and the respective limb
portion and the distal portion of the limbs. mountS.
 US 9.255,753 B2
13 14
19. The energy storage portion for a bow of claim 16
wherein the couplings comprise pivoting couplings, linkage
couplings, rotating couplings, sliding couplings, elastomeric
couplings, or a combination thereof.
20. The energy storage portion for a bow of claim 16 5
wherein the center support provides limb relief between the
proximal portion and the distal portion of the limbs.
k k k k k