US007784453B1
`
`(12) United States Patent
`Yehle
`
`(10) Patent N0.:
`(45) Date of Patent:
`
`US 7,784,453 B1
`Aug. 31, 2010
`
`(54) DRAW MECHANISM FOR A CROSSBOW
`
`(75) Inventor: Craig T. Yehle, Junction City, OR (U S)
`
`(73) Assignee: Extreme Technologies, Inc., Eugene,
`OR (U S)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 450 days.
`
`(21) App1.No.: 11/933,394
`
`(22) Filed:
`
`Oct. 31, 2007
`
`(51) Int. Cl.
`(2006.01)
`F41B 5/12
`(52) US. Cl. ...................................................... .. 124/25
`(58) Field of Classi?cation Search .................. .. 124/25
`See application ?le for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`6/1986 Waiser
`4,593,675 A
`4,697,571 A * 10/1987 Waiser ...................... .. 124/25
`
`5/1992 Farris ........................ .. 124/86
`5,115,795 A *
`5/2002 Bednar
`2002/0059924 A1
`2004/0194771 A1 10/2004 Malucelli
`
`2005/0022799 A1
`2006/0086346 A1
`2006/0169258 A1
`
`2/ 2005 Bednar
`4/ 2006 Middleton
`8/2006 Chang
`
`* cited by examiner
`
`Primary Examinerilohn Ricci
`(74) Attorney, Agent, or FirmiDavid S. Alavi
`
`(57)
`
`ABSTRACT
`
`A draW mechanism for a crossboW comprises a drive gear,
`coupling gear, retaining member, one-Way rotary clutch,
`retainer, rotary drive member, tension member, and catch.
`The drive gear is coupled to the coupling gear. The retaining
`member and coupling gear are coaxially coupled by the one
`Way rotary clutch. The retainer releasably engages the retain
`ing member. The coupling gear is coupled to the rotary drive
`member Which is engaged With the tension member. The
`catch is connected to the tension member and retains a boW
`string as the crossboW is draWn. Rotation of the coupling gear
`in one direction causes the rotary drive member to tension the
`tension member to move the catch to draW the crossboW.
`Engagement of the retainer With the retaining member retards
`rotation of the coupling gear in the other direction thereby
`retarding movement of the catch to “undraW” the crossboW.
`Release by the retainer alloWs movement of the catch to
`undraW the crossboW.
`
`26 Claims, 4 Drawing Sheets
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`120
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`114
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`RAVIN - EXHIBIT R1003
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`US. Patent
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`Aug. 31, 2010
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`US 7,784,453 B1
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`US 7,784,453 B1
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`US. Patent
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`US. Patent
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`US 7,784,453 B1
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`1
`DRAW MECHANISM FORA CROSSBOW
`
`BACKGROUND
`
`The ?eld of the present invention relates to crossbows. In
`particular, a draw mechanism is described herein for a cross
`bow.
`A wide variety of draw mechanisms are available for cross
`bows. Some of these are described in:
`US. Pat. No. 4,593,675 entitled “Crossbows” issued Jun.
`10, 1986 to Waiser;
`U.S. Pub. No. 2002/0059924 A1 entitled “Crossbow bow
`string drawing mechanism” published May 23, 2002 in the
`name of Bednar;
`U.S. Pub. No. 2004/0194771 A1 entitled “Automatic cock
`ing device in a crossbow for hunting and archery” published
`Oct. 7, 2004 in the name of Malucelli;
`U.S. Pub. No. 2005/0022799 A1 entitled “Crossbow rope
`cocking device” published Feb. 3, 2005 in the name of Bed
`nar;
`U.S. Pub. No. 2006/0086346 A1 entitled “Crossbow cock
`ing and stringing device” publishedApr. 27, 2006 in the name
`of Middleton; and
`US. Pub. No. 2006/0169258A1 entitled “Bowstring draw
`ing device for a crossbow” published Aug. 3, 2006 in the
`name of Chang.
`
`SUMMARY
`
`A draw mechanism for a crossbow comprises a drive gear,
`a coupling gear, a retaining member, a one-way rotary clutch,
`a retainer, a rotary drive member, a tension member, and a
`releasable catch. The drive gear is arranged to be rotated by a
`user of the crossbow and is coupled to the coupling gear. The
`retaining member is mounted coaxially with the coupling
`gear, and the one-way rotary clutch is arranged to couple the
`retaining member and the coupling gear to allow their relative
`rotation in a ?rst rotation direction and to substantially pre
`vent their relative rotation in a second rotation direction oppo
`site the ?rst rotation direction. The retainer is arranged to
`releasably engage the retaining member to substantially pre
`vent rotation of the retaining member when engaged and to
`permit substantially unrestricted rotation of the retaining
`member when released. The coupling gear is coupled to the
`rotary drive member which is in turn engaged with the tension
`member. The releasable catch is connected to the tension
`member and arranged to retain a bowstring of the crossbow as
`it is drawn.
`Rotation of the coupling gear in the ?rst rotation direction
`causes the rotary drive member to tension the tension member
`to move the catch in a ?rst direction to draw the crossbow.
`Engagement of the retainer with the retaining member sub
`stantially prevents rotation of the coupling gear in the second
`rotation direction thereby substantially preventing movement
`of the catch in a second direction opposite the ?rst direction.
`Release of the retaining member by the retainer allows rota
`tion of the retaining member and the coupling gear in the
`second rotation direction thereby allowing movement of the
`catch in the second direction.
`Objects and advantages pertaining to crossbow draw
`mechanisms may become apparent upon referring to the
`
`2
`exemplary embodiments illustrated in the drawings and dis
`closed in the following written description or appended
`claims.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIGS. 1 and 2 are top and left side views, respectively, of an
`exemplary crossbow.
`FIG. 3 is a left side view of a barrel and draw mechanism of
`an exemplary crossbow.
`FIG. 4 is a left side cut-away view of a barrel and draw
`mechanism of an exemplary crossbow.
`FIG. 5 is a left side cut-away view of a barrel, draw mecha
`nism, and trigger mechanism of an exemplary crossbow.
`FIGS. 6, 7, and 8 are left, right, and top views, respectively,
`of a gear assembly of an exemplary draw mechanism for a
`crossbow.
`The embodiments shown in the Figures are exemplary, and
`should not be construed as limiting the scope of the present
`disclosure or appended claims.
`
`DETAILED DESCRIPTION OF EMBODIMENTS
`
`FIGS. 1 and 2 show an exemplary crossbow 10 comprising
`a barrel 12, a stock 14 connected to the barrel 12 at the rear of
`the crossbow 10, a bow 16 connected to the barrel 12 at the
`front of the crossbow 10, a bowstring 18 (also referred to as a
`draw cable) connected to the bow 16, and a trigger mecha
`nism 20. The bow 16 comprises a pair ofbow limbs 16a and
`16b. In the example shown each bow limb comprises a pair of
`limb members, however, each limb can instead comprise a
`single limb member. The exemplary crossbow 10 shown in
`the drawings is a compound bow with a pair of pulley mem
`bers and additional cables, however, any type of crossbow
`(simple, recurve, re?ex, single-cam compound, dual-cam
`compound, hybrid-cam compound, and so on) shall fall
`within the scope of the present disclosure or appended claims.
`Numerous details of the construction of the compound bow
`10 can vary considerably while remaining within the scope of
`the present disclosure or appended claims, and all such varia
`tions need not be enumerated herein.
`The crossbow 10 further comprises a draw mechanism (not
`visible in FIGS. 1 and 2. An exemplary draw mechanism is
`shown in FIGS. 3 and 4 with only the barrel 12 of crossbow
`10, and shown in FIG. 5 with barrel 12 and trigger mechanism
`20. FIGS. 6-8 show a gear assembly for the exemplary draw
`mechanism. The exemplary draw mechanism comprises a
`drive gear 102, a coupling gear 104, a retaining gear 106, a
`one-way rotary clutch 108, a pawl 110, a drive sprocket 112,
`a chain 114, and a releasable catch 116.
`The drive gear 102 is arranged to be rotated by a user of the
`crossbow 10 and is coupled to the coupling gear 104. In the
`exemplary embodiment the drive gear 102 is mounted on a
`shaft 103 that can be rotated by a user with a crank handle
`(detachable; not shown). Any suitable mechanism or arrange
`ment for enabling the drive gear 102 to be rotated by a user of
`a crossbow (e. g., shaft, crank, handle, lever, motor, and so on)
`shall fall within the scope of the present disclosure. In the
`exemplary embodiment the drive gear 102 is coupled to the
`coupling gear 104 by direct engagement of the teeth of the
`respective gears. The coupling gear diameter is larger than the
`drive gear diameter in this example, resulting in a mechanical
`advantage for rotating the coupling gear 104. Any suitable
`relative diameters can be employed for the drive and coupling
`gears 102 and 104. The drive gear 102 and coupling gear 104
`can also be coupled indirectly, e.g., by a reduction gear pair
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`US 7,784,453 B1
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`3
`(not shown). Any suitable mechanism or arrangement can be
`employed for coupling the drive and coupling gears 102 and
`104.
`The retaining gear 106 is mounted coaxially With the cou
`pling gear 104. The one-Way rotary clutch 108 is arranged to
`couple the retaining gear 106 and the coupling gear 104 to
`alloW their relative rotation in a ?rst rotation direction (e.g.,
`With the coupling gear 104 rotating counter-clockWise rela
`tive to the retaining gear 106 in FIGS. 3-6, i.e., When vieWed
`from the left side of the exemplary crossbow) and to substan
`tially prevent their relative rotation in the opposite direction
`(e.g., preventing the coupling gear 104 from rotating clock
`Wise relative to the retaining gear 106 in FIGS. 3-6). The
`one-Way rotary clutch 108 can comprise a roller clutch, a
`sprag clutch, or other functionally equivalent mechanism.
`Examples of a roller clutch can be found in, e. g., U.S. Pat. No.
`7,147,091, U.S. Pat. No. 5,819,899, U.S. Pat. No. 5,740,893,
`U.S. Pat. No. 3,104,744, U.S. Pat. No. 2,292,988, orU.S. Pat.
`No. 1,337,634. Examples ofa sprag clutch can be found in,
`e.g., U.S. Pat. No. 6,059,084, U.S. Pat. No. 5,960,917, U.S.
`Pat. No. 4,546,864, U.S. Pat. No. 3,066,779, U.S. Pat. No.
`2,954,855, or U.S. Pat. No. 2,599,793. Each of said patents is
`incorporated by reference as if fully set forth herein. The
`one-Way rotary clutch 108 can comprise any of the cited
`examples or any other suitable functionally equivalent
`mechanism.
`The one-Way rotary clutch 108 can be substantially silent in
`its operation as it alloWs the coupling gear 104 to rotate
`relative to the retaining gear 106. This substantially silent
`operation contrasts the relatively noisy operation of a ratchet
`type mechanism, for example, as the paWl of such a ratchet
`mechanism clicks against each successive tooth of the
`ratchet. Substantially silent operation of the one-Way clutch
`108 can prove advantageous in a hunting situation, for
`example, When any noise produced by the crossboW might
`scare off a potential target animal. A roller clutch or a sprag
`clutch can provide the desired substantially silent operation
`during relative rotation of the coupling gear 104 and the
`retaining gear 106.
`The paWl 11 0 is arranged to releasably engage the retaining
`gear 106 to substantially prevent rotation (in either direction)
`of the retaining gear 106 When engaged and to permit sub
`stantially unrestricted rotation (in either direction) of the
`retaining gear 106 When released. In the exemplary embodi
`ment the paWl 110 is resiliently biased (by a torsion spring
`109) into engagement With the retaining gear 106. A user can
`press the lever portion 111 of the paWl 110 to rotate it against
`its bias to disengage it from the retaining gear 106. Any
`suitable arrangement of the paWl 110 and the retaining gear
`106 can be employed.
`Instead of retaining gear 106, any other suitable retaining
`member can be coupled to the coupling gear 104 by the
`one-Way clutch 108. Instead of paWl 110, any other suitable
`retainer can be arranged to releasably engage such a retaining
`member to retard or prevent its rotation When engaged and to
`permit substantially unrestricted rotation of the retaining
`member When disengaged. In one alternative example (not
`shoWn), the retaining member and retainer can comprise a
`pair of friction disks, With one friction disk acting as the
`retaining member coupled to the coupling gear 104 through
`the one-Way clutch 108 and With the other friction disk acting
`as the retainer arranged to be releasably engaged With the ?rst
`friction disk (by spring loaded engagement or other suitable
`arrangement). Any other suitable mechanism or arrangement
`can be employed for the retaining member and the releasably
`engaged retainer Within the scope of the present disclosure or
`appended claims.
`
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`The coupling gear 104 is coupled to the drive sprocket 112.
`In one example (not shoWn), the coupling gear 104 and the
`drive sprocket 112 can be coupled to rotate together on a
`common shaft (by being integrally formed, by each being
`?xed to the common shaft, or by any other suitable arrange
`ment). In another example (shoWn in the draWings), the cou
`pling gear 104 and the drive sprocket 112 can be coupled
`through a reduction gearpair 118a and 11819. In the illustrated
`example, coupling gear 104 and reduction gear 11811 are
`coupled to rotate together on a common shaft (by being inte
`grally formed, by each being ?xed to the common shaft, or by
`any other suitable arrangement), and drive sprocket 112 and
`reduction gear 118!) are coupled to rotate together on another
`shaft (by being integrally formed, by each being ?xed to the
`common shaft, or by any other suitable arrangement). In the
`exemplary arrangement shoWn in the draWings, the drive
`sprocket 112 and the reduction gear 118!) rotate together on
`shaft 103 independently of the shaft 103 and the drive gear
`102; such an arrangement enables a more compact arrange
`ment of the draW mechanism. Other suitable arrangements
`can be employed. The reduction gear pair 118a and 11819 are
`directly coupled to one another through engagement of their
`gear teeth in the exemplary embodiment, but can instead be
`coupled by additional intervening gears if needed or desired.
`In the illustrated example, the diameter of reduction gear
`11811 is smaller than that of coupling gear 104 and reduction
`gear 118b, and the diameter of reduction gear 118!) is larger
`than that of drive sprocket 112. These relative diameters yield
`a mechanical advantage for driving the drive sprocket 112.
`Any suitable combination of gear diameters can be employed
`as needed or desired. Any suitable mechanism or arrangement
`can be employed for coupling the coupling gear 104 and the
`drive sprocket 112.
`The drive sprocket 112 is engaged With the chain 114. The
`releasable catch 116 moves along the barrel 12 and is con
`nected to the chain 114. The catch 116 is arranged to retain the
`boWstring 18 of the crossboW 10 as it is draWn. The catch 116
`can take any suitable form, including a hook, a claW, a caliper
`as shoWn in the draWings or in co-pending U.S. non-provi
`sional application Ser. No. 11/763,155 (incorporated by ref
`erence as if fully set forth herein), or any other form suitable
`for retaining the boWstring 18 as the crossboW 10 is draWn. In
`one example (not shoWn), the catch 116 can be arranged to
`release the draWn boWstring 18 after it has be positioned to be
`retained by the trigger mechanism of the crossboW and after
`said trigger mechanism has been engaged to retain the draWn
`boWstring 18. In another example (illustrated in the draW
`ings), the catch 116 becomes operatively coupled to the trig
`ger mechanism 20 When the boWstring 18 is draWn. Actuation
`of the trigger mechanism 20 causes the catch 116 to release
`the draWn boWstring 18, thus shooting the crossboW.
`Instead of drive sprocket 112, any other suitable rotary
`drive member can be employed, e.g., a sprocket, a pulley, or
`other suitable rotary drive member. Instead of chain 114, any
`other suitable tension member can be engaged With the rotary
`drive member and connected to the catch 116, e.g., a chain, a
`cable, a belt, a ribbon, or other suitable tension member.
`To draW the crossboW 10, the boWstring is ?rst engaged
`With the catch 116 (initially positioned toWard the front of the
`barrel). With the boWstring retained by the catch 1 1 6, a user of
`the crossboW 10 rotates the drive gear 102 (by a hand crank or
`other mechanism) to rotate the coupling gear 104 in the ?rst
`rotation direction. The draW mechanism is arranged so that
`rotation of the coupling gear 104 in the ?rst rotation direction
`causes the drive sprocket 112 to tension the chain 114 to move
`the catch 116 rearWard along the barrel 12 of the crossboW 10.
`Engagement of the paWl 110 With the retaining gear 106
`
`7
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`

`US 7,784,453 B1
`
`5
`substantially prevents rotation of the coupling gear 104 in the
`second rotation direction (due to the coupling of the one-Way
`clutch 108), thereby substantially preventing movement of
`the catch 116 back toWard the front of the crossboW 10 under
`the tension of the draWn boWstring 18. The user continues to
`rotate the drive gear 102 until the crossboW 10 is fully draWn
`and ready to be loaded and shot. The trigger mechanism 20
`can optionally include a safety feature to prevent shooting the
`draWn crossboW Without a bolt loaded (for example, as taught
`in said application Ser. No. ll/763,l55).
`Release of the retaining gear 106 by the paWl 110 alloWs
`rotation of the retaining gear 106 and the coupling gear 104 in
`the second rotation direction thereby alloWing movement of
`the catch 116 forWard along the barrel 12 of the crossboW 10.
`In the example shoWn, the user presses lever portion 111 of
`the paWl 110 to disengage it from the retaining gear 106. Any
`other suitable disengagement mechanism can be employed.
`The paWl can be thus released and the drive gear 102 rotated
`(in reverse, i.e., in the opposite direction of that used to draW
`the crossboW) to alloW the carrier 116 after shooting the
`crossboW to return toWard the front of the barrel 12 to prepare
`for the next draW. Alternatively, if the user Wishes not to ?re
`the draWn crossboW, the paWl 110 can be released and the
`drive gear 1 02 rotated in reverse to safely alloW the carrier 1 1 6
`to move forWard along the barrel 12 and to release the tension
`on the draWn boWstring 18. This latter capability is often
`lacking in prior crossboWs.
`The crossboW can further comprise an idler sprocket 120
`engaged With the chain 114, and chain 114 can form a closed
`loop (With catch 116 incorporated into the looped chain 114,
`as in the draWings, or With catch 116 attached to the looped
`chain 114). With the paWl 110 released and the drive gear 102
`rotated in reverse, the looped chain 114 is tensioned to move
`the catch 116 forWard along the barrel to prepare for the next
`draW. Such a looped arrangement also eliminates the need for
`a chain take-up mechanism as the catch 116 is draWn back
`Ward along the barrel 12 of the crossboW 10. If an alternative
`tension member is employed (cable, belt, ribbon, and so on),
`then a suitable alternative idler member can be employed as
`Well.
`The draW mechanism can be arranged on or in the cross
`boW 10 in any suitable, needed, or desired con?guration. It
`can be advantageous to enclose a portion of the draW mecha
`nism 10. In the exemplary embodiment shoWn, the drive gear
`102, the coupling gear 104, the one-Way rotary clutch 108, the
`retaining gear 106, the drive sprocket 112, and the chain 114
`are enclosed Within the stock 14 or the barrel 12. Other
`suitable arrangements shall fall Within the scope of the
`present disclosure or appended claims.
`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 equiva
`lents thereof, may be modi?ed While remaining Within the
`scope of the present disclosure or appended claims.
`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,”
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`“having,” and variants thereof shall be construed as open
`ended terminology, With the same meaning as if the phrase “at
`least” Were appended after each instance thereof.
`What is claimed is:
`1. A draW mechanism for a crossboW, the draW mechanism
`comprising:
`a drive gear arranged to be rotated by a user of the cross
`boW;
`a coupling gear coupled to the drive gear;
`a retaining member mounted coaxially With the coupling
`gear;
`a one-Way rotary clutch arranged to couple the retaining
`member and the coupling gear to alloW their relative
`rotation in a ?rst rotation direction and to substantially
`prevent their relative rotation in a second rotation direc
`tion opposite the ?rst rotation direction;
`a retainer arranged to releasably engage the retaining mem
`ber to retard or prevent rotation of the retaining member
`When engaged and to permit substantially unrestricted
`rotation of the retaining member When released;
`a rotary drive member coupled to the coupling gear;
`a tension member engaged With the rotary drive member;
`and
`a releasable catch connected to the tension member and
`arranged to retain a boWstring of the crossboW as it is
`draWn,
`Wherein the draW mechanism is further arranged so that:
`rotation of the coupling gear in the ?rst rotation direction
`causes the rotary drive member to tension the tension
`member to move the catch in a ?rst direction to draW the
`crossboW;
`engagement of the retainer With the retaining member sub
`stantially retards or prevents rotation of the coupling
`gear in the second rotation direction thereby retarding or
`preventing movement of the catch in a second direction
`opposite the ?rst direction; and
`release of the retaining member by the retainer alloWs
`rotation of the retaining member and the coupling gear
`in the second rotation direction thereby alloWing move
`ment of the catch in the second direction.
`2. The draW mechanism of claim 1 Wherein the retaining
`member comprises a retaining gear and the retainer com
`prises a paWl arranged to releasably engage the retaining gear
`to substantially prevent rotation of the retaining gear When
`engaged and to permit substantially unrestricted rotation of
`the retaining gear When released.
`3. The draW mechanism of claim 1 Wherein the rotary drive
`member comprises a drive sprocket and the tension member
`comprises a chain engaged With the drive sprocket.
`4. The draW mechanism of claim 1 Wherein relative rota
`tion of the coupling gear and the retaining member in the ?rst
`rotation direction is substantially silent.
`5. The draW mechanism of claim 1 Wherein the one-Way
`rotary clutch comprises a roller clutch or a sprag clutch.
`6. The draW mechanism of claim 1 further comprising an
`idler member engaged With the tension member, Wherein (i)
`the tension member or (ii) the tension member and the catch
`form a closed loop, so that rotation of the coupling gear in the
`second rotation direction causes the rotary drive member to
`tension the tension member to move the catch in the second
`direction.
`7. The draW mechanism of claim 6 Wherein the rotary drive
`member comprises a drive sprocket, the idler member com
`prises an idler sprocket, and the tension member comprises a
`chain engaged With the drive sprocket and the idler sprocket.
`8. The draW mechanism of claim 1 Wherein the diameter of
`the coupling gear is greater than the diameter of the drive gear.
`
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`US 7,784,453 B1
`
`7
`9. The draw mechanism of claim 1 further comprising at
`least one reduction gear pair coupling (i) the drive gear and
`the coupling gear or (ii) the coupling gear and the rotary drive
`member.
`10. The draW mechanism of claim 1 Wherein the catch is
`arranged to release the draWn boWstring to shoot the crossboW
`in response to actuation of a trigger mechanism of the cross
`how.
`11. The draW mechanism of claim 1 Wherein the catch is
`arranged (i) to position the draWn boWstring to be retained by
`a trigger mechanism of the crossbow, and (ii) to release the
`draWn boWstring retained by the trigger mechanism.
`12. A crossboW incorporating the draW mechanism of
`claim 1, further comprising:
`a barrel;
`a stock connected to the barrel at the rear of the crossboW;
`a boW connected to the barrel at the front of the crossboW
`and comprising tWo boW limbs;
`a boWstring connected to the boW limbs; and
`a trigger mechanism,
`Wherein:
`the draW mechanism is arranged on the crossboW to draW
`the boWstring in the ?rst direction rearWard along the
`barrel.
`13. The crossboW of claim 12 Wherein the drive gear, the
`coupling gear, the one-Way rotary clutch, the retaining mem
`ber, the rotary drive member, and the tension member are
`enclosed Within the stock or the barrel.
`14. A method for making a draW mechanism for a cross
`boW, the method comprising:
`arranging a drive gear to be rotated by a user of the cross
`boW;
`coupling a coupling gear to the drive gear;
`mounting a retaining member coaxially With the coupling
`gear;
`arranging a one-Way rotary clutch to couple the retaining
`member and the coupling gear to alloW their relative
`rotation in a ?rst rotation direction and to substantially
`prevent their relative rotation in a second rotation direc
`tion opposite the ?rst rotation direction;
`arranging a retainer to releasably engage the retaining
`member to retard or prevent rotation of the retaining
`member When engaged and to permit substantially unre
`stricted rotation of the retaining member When released;
`coupling a rotary drive member to the coupling gear;
`engaging a tension member With the rotary drive member;
`connecting a releasable catch to the tension member and
`arranging the releasable catch to retain a boWstring of
`the crossboW as it is draWn;
`arranging the draW mechanism so that rotation of the cou
`pling gear in the ?rst rotation direction causes the rotary
`drive member to tension the tension member to move the
`catch in a ?rst direction to draW the crossboW;
`arranging the draW mechanism so that engagement of the
`retainer With the retaining member retards or prevents
`rotation of the coupling gear in the second rotation direc
`tion thereby retarding or preventing movement of the
`catch in a second direction opposite the ?rst direction;
`and
`
`5
`
`15
`
`20
`
`25
`
`45
`
`8
`arranging the draW mechanism so that release of the retain
`ing member by the retainer alloWs rotation of the retain
`ing member and the coupling gear in the second rotation
`direction thereby alloWing movement of the catch in the
`second direction.
`15. The method of claim 14 Wherein the retaining member
`comprises a retaining gear and the retainer comprises a paWl
`arranged to releasably engage the retaining gear to substan
`tially prevent rotation of the retaining gear When engaged and
`10 to permit substantially unrestricted rotation of the retaining
`gear When released.
`16. The method of claim 14 Wherein the rotary drive mem
`ber comprises a drive sprocket and the tension member com
`prises a chain engaged With the drive sprocket.
`17. The method of claim 14 Wherein relative rotation of the
`coupling gear and the retaining member in the ?rst rotation
`direction is substantially silent.
`18. The method of claim 14 Wherein the one-Way rotary
`clutch comprises a roller clutch or a sprag clutch.
`19. The method of claim 14 further comprising engaging
`an idler member With the tension member, Wherein (i) the
`tension member or (ii) the tension member and the catch form
`a closed loop, so that rotation of the coupling gear in the
`second rotation direction causes the rotary drive member to
`tension the tension member to move the catch in the second
`direction.
`20. The method of claim 19 Wherein the rotary drive mem
`ber comprises a drive sprocket, the idler member comprises
`an idler sprocket, and the tension member comprises a chain
`30 engaged With the drive sprocket and the idler sprocket.
`21. The method of claim 14 Wherein the diameter of the
`coupling gear is greater than the diameter of the drive gear.
`22. The method of claim 14 further comprising coupling,
`using at least one reduction gear pair, (i) the drive gear and the
`5 coupling gear or (ii) the coupling gear and the rotary drive
`member.
`23. The method of claim 14 further comprising arranging
`the catch to release the draWnboWstring to shoot the crossboW
`in response to actuation of a trigger mechanism of the cross
`40 how.
`24. The method of claim 14 further comprising arranging
`the catch (i) to position the draWn boWstring to be retained by
`a trigger mechanism of the crossboW, and (ii) to release the
`draWn boWstring retained by the trigger mechanism.
`25. A method for making a crossboW incorporating the
`method of claim 14 and further comprising:
`providing a barrel for the crossboW;
`connecting a stock to the barrel at the rear of the crossboW;
`connecting a boW to the barrel at the front of the crossboW,
`the boW comprising tWo boW limbs;
`connecting a boWstring to the boW limbs;
`providing a trigger mechanism for the crossboW; and
`arranging the draW mechanism on the crossboW to draW the
`boWstring in the ?rst direction rearWard along the barrel.
`26. The method of claim 25 further comprising enclosing
`the drive gear, the coupling gear, the one-Way rotary clutch,
`the retaining member, the rotary drive member, and the ten
`sion member Within the stock or the barrel.
`
`50
`
`55
`
`*
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`*
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`*
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`*
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`*
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`9
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