Patent Publication Number: US-2022214131-A1

Title: Compact projectile launcher

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Application No. 63/136,451, filed on Jan. 12, 2021, titled COMPACT PROJECTILE LAUNCHER, and to U.S. 63/134,953, filed on Jan. 7, 2021, titled COMPACT PROJECTILE LAUNCHER, the disclosures of which are hereby incorporated by reference in their entireties. 
    
    
     BACKGROUND 
     Projectile launchers, such as crossbows and slingshots, utilize a string that is drawn backward and released to fire a projectile. Flexible limbs are loaded with force by the drawstring being drawn, and limbs are unloaded with force when the crossbow is fired to aggressively power the movement of the drawstring toward the front of the crossbow. 
     To increase the firing speed of a projectile launcher, the power stroke, which is the distance the drawstring travels from the drawn position to a position when it releases the arrow, must be increased and/or the size (and therefore the power) of the limbs must be increased. This increases the size of the crossbow, thereby rendering the crossbow cumbersome to handle, fire, and transport. However, a crossbow must be able to fire projectiles at adequate speeds for a variety of different applications, such as hunting, bow fishing, long-range target shooting, etc. Therefore, improvements are desired. 
     SUMMARY 
     This application generally relates to a compact projectile launcher. Specifically, the disclosure relates to a compact crossbow that includes a movable, compact windable latch mechanism, a drawstring, a pair of power strings, a string hub, and an interface for a modular stock. 
     In one aspect of the present disclosure, a projectile launcher is disclosed. The projectile launcher includes a frame having a vertical grip and the frame defines a horizontal projectile plane at a top side in which a projectile axis is positioned. A projectile moves within the horizontal projectile plane and along the projectile axis during firing and arming of the projectile launcher. The projectile is fired from a front end of the frame. The projectile launcher includes a string hub rotatably mounted to the frame. The string hub is rotatable about a central axis in a first direction and a second direction and the central axis is perpendicular to the projectile axis. The projectile launcher includes a drawstring that is attached to the string hub. The drawstring travels at least partially perpendicular to the projectile axis between first and the second ends of the drawstring. The drawstring is movable within the projectile plane during firing and arming of the projectile launcher. Movement of the drawstring away from the string hub corresponds with rotation of the string hub in the first direction, and movement of the drawstring toward the string hub corresponds with rotation of the string hub in the second direction. The projectile launcher includes a first and a second flexible limb attached to the frame. The first and second limbs are in an unloaded position when the projectile launcher is undrawn and in a loaded position when the projectile launcher is drawn. The projectile launcher includes a first and a second power cable each having a first end and a second end. The first ends of the first and second power cables are attached to the string hub at power cable sections. Upon rotation of the string hub in the first direction, the first and second power cables are configured to draw the first and second flexible limbs closer to the string hub. The projectile launcher includes a latch movable between the rear end of the frame and the front end of the frame and attached to a crank mechanism via a tether. The latch is configured to receive the drawstring and hold the drawstring at the rear end of the frame when the crossbow is drawn. The latch is configured to receive a portion of the projectile and the drawstring therein. The tether travels downward from the latch to wrap around a first gear of the crank mechanism. The crank mechanism has a spring loaded stop in communication with the first gear. The stop is biased against the first gear, and the stop is accessible at an underside of the frame. The projectile launcher includes a trigger assembly in communication with the latch. Upon activation of the trigger assembly when firing, the trigger assembly moves the latch and the drawstring is released from the latch. The projectile launcher includes first and second drawstring guides attached to the frame, each guide guiding the drawstring across the projectile axis between the first and second ends of the drawstring. 
     In another aspect of the present disclosure, a projectile launcher is disclosed. The projectile launcher includes a frame that has a front and rear end. A projectile is configured to be propelled from the front end of the frame and the projectile is movable along a projectile axis during firing and arming of the projectile launcher. The projectile launcher includes a latch movable between the rear end of the frame and the front end of the frame along a travel axis and attached to a crank mechanism via a tether. The latch is configured to receive a portion of the projectile therein. The crank mechanism is configured to pull at least a portion of the tether at least partially in a direction perpendicular to the travel axis. 
     In another aspect of the present disclosure, a projectile launcher is disclosed. The projectile launcher includes a frame that has a front end and a rear end. The projectile launcher includes a string hub rotatably mounted to the frame. The string hub is rotatable about a central axis in a first direction and a second direction. The central axis is perpendicular to the projectile axis. The string hub has a power cable section and a drawstring section. The power cable section has power cable grooves and the drawstring section has drawstring grooves. The projectile launcher includes a drawstring attached to the string hub at the drawstring section and positionable within the drawstring grooves at the drawstring section. The projectile launcher includes at least one flexible limb attached to the frame. The at least one limb is in an unloaded position when the projectile launcher is undrawn and in a loaded position when the projectile launcher is drawn. The projectile launcher includes at least one power cable attached to the at least one flexible limb and the string hub. The at least one power cable is positionable within the power cable grooves at the power cable section of the string hub. The power cable grooves decrease in circumference as the at least one power cable is wound within the power cable grooves as the projectile launcher is moved from undrawn to drawn. 
     In another aspect of the present disclosure, a projectile launcher is disclosed. The projectile launcher includes a frame that has a front end and a rear end. The projectile launcher includes a string hub rotatably mounted to the frame. The string hub is rotatable about a central axis in a first direction and a second direction. The central axis is perpendicular to the projectile axis. The string hub has a power cable section and a drawstring section. The power cable section has power cable grooves and the drawstring section has drawstring grooves. The projectile launcher includes a drawstring attached to the string hub at the drawstring section and positionable within the drawstring grooves at the drawstring section. The drawstring travels at least partially perpendicular to the projectile axis between first and the second ends of the drawstring. Movement of the drawstring away from the string hub corresponds with rotation of the string hub in the first direction, and movement of the string toward the string hub corresponds with rotation of the string hub in the second direction. The projectile launcher includes a first and a second flexible limb attached to the frame. The first and second limbs are in an unloaded position when the projectile launcher is undrawn and in a loaded position when the projectile launcher is drawn. The projectile launcher includes a first and a second power cable each being attached to the first and the second flexible limbs and the string hub at the power cable section, respectively. The first and second power cables are positionable within the power cable grooves at the power cable section of the string hub. The power cable grooves decrease in circumference as the first and second power cables are wound within the power cable grooves as the projectile launcher is moved from undrawn to drawn. The projectile launcher includes a latch movable between the rear end of the frame and the front end of the frame along a travel axis and attached to a crank mechanism via a tether. The latch is configured to receive a portion of the projectile therein and the crank mechanism is configured to pull at least a portion of the tether at least partially in a direction perpendicular to the travel axis. The projectile launcher includes a trigger assembly being in communication with the latch. Upon activation of the trigger assembly when firing, the trigger assembly moves the latch and the drawstring is released from the latch. 
     In another aspect of the present disclosure, a projectile launcher is disclosed. The projectile launcher includes a frame having a vertical grip. The frame defines a horizontal projectile plane at a top side in which a projectile axis is positioned. A projectile moves within the horizontal projectile plane and along the projectile axis during firing and arming of the projectile launcher, and is fired from a front end of the frame. The frame also includes a limb with a distal limb support at first end of the limb and a medial limb support along the length of the limb. 
     In another aspect of the present disclosure, a projectile launcher is disclosed. The projectile launcher includes a frame having a vertical grip. The frame defines a horizontal projectile plane at a top side in which a projectile axis is positioned. A projectile moves within the horizontal projectile plane and along the projectile axis during firing and arming of the projectile launcher, and is fired from a front end of the frame. The frame has a length between a front and a rear end of the frame in a range from about 15 inches to about 23 inches (or from 15 inches to 23 inches) (38 cm to 58 cm). 
     In another aspect of the present disclosure, a projectile launcher is disclosed. The projectile launcher includes a frame having a vertical grip. The frame defines a horizontal projectile plane at a top side in which a projectile axis is positioned. A projectile moves within the horizontal projectile plane and along the projectile axis during firing and arming of the projectile launcher, and is fired from a front end of the frame. The projectile launcher also includes a reinforcement arch that extends over and traverses the projectile axis and connects to the frame on either side of the projectile axis. 
     In another aspect of the present disclosure, a projectile launcher is disclosed. The projectile launcher includes a frame having a vertical grip. The frame defines a horizontal projectile plane at a top side in which a projectile axis is positioned. A projectile moves within the horizontal projectile plane and along the projectile axis during firing and arming of the projectile launcher, and is fired from a front end of the frame. The frame also includes an arrow rest positioned to support a projectile. 
     In another aspect of the present disclosure, a projectile launcher is disclosed. The projectile launcher includes a frame having a vertical grip. The frame defines a horizontal projectile plane at a top side in which a projectile axis is positioned. A projectile moves within the horizontal projectile plane and along the projectile axis during firing and arming of the projectile launcher, and is fired from a front end of the frame. The projectile launcher also includes a string hub that drives the movement of a drawstring. 
     In another aspect of the present disclosure, a projectile launcher is disclosed. The projectile launcher includes a frame. The frame defines a horizontal projectile plane at a top side in which a projectile axis is positioned. The frame also defines a vertical projectile plane perpendicular to the horizontal projectile plane in which the projectile axis is positioned. A projectile moves within the horizontal projectile plane and vertical projectile plane along the projectile axis during firing and arming of the projectile launcher. The projectile is fired from a front end of the frame. The projectile launcher also includes a string hub that drives the movement of a drawstring. 
     A variety of additional aspects will be set forth in the description that follows. The aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings are illustrative of particular embodiments of the present disclosure and therefore do not limit the scope of the present disclosure. The drawings are not to scale and are intended for use in conjunction with the explanations in the following detailed description. Embodiments of the present disclosure will hereinafter be described in conjunction with the appended drawings, wherein like numerals denote like elements. 
         FIG. 1  shows a perspective view of a weapon system, according to one example of the present disclosure. 
         FIG. 2  shows another perspective view of the weapon system of  FIG. 1 . 
         FIG. 3  shows a longitudinal cross-section of a portion of the weapon system of  FIG. 1 . 
         FIG. 4  shows an exploded view of the weapon system of  FIG. 1 . 
         FIG. 5  shows a perspective view of a projectile launcher in the undrawn position, according to one example of the present disclosure. 
         FIG. 6  shows a side view of the projectile launcher of  FIG. 5  in the undrawn position. 
         FIG. 7  shows another side view of the projectile launcher of  FIG. 5  in the undrawn position. 
         FIG. 8  shows a top view of the projectile launcher of  FIG. 5  in the undrawn position. 
         FIG. 9  shows another perspective of the projectile launcher of  FIG. 5  in the drawn position. 
         FIG. 10  shows a side view of the projectile launcher of  FIG. 5  in the drawn position. 
         FIG. 11  shows another side view of the projectile launcher of  FIG. 5  in the drawn position. 
         FIG. 12  shows a top view of the projectile launcher of  FIG. 5  in the drawn position. 
         FIG. 13  shows a front view of the projectile launcher of  FIG. 5  in the drawn position. 
         FIG. 14  shows a rear perspective view of the projectile launcher of  FIG. 5 . 
         FIG. 15  shows a rear view of the projectile launcher of  FIG. 5  in the drawn position. 
         FIG. 16  shows a cross-sectional view along line  16 - 16  in  FIG. 12  of the projectile launcher in the undrawn position. 
         FIG. 17  shows a perspective view of a string hub of a projectile launcher, according to one example of the present disclosure. 
         FIG. 18  shows a side view of the string hub of  FIG. 17 . 
         FIG. 19  shows a side view of a longitudinal cross-section of the projectile launcher of  FIG. 5  with a tether between a front end and a rear end. 
         FIG. 20  shows a side view of a longitudinal cross-section of the projectile launcher of  FIG. 5  with a tether at the rear end. 
         FIG. 21  shows a perspective view of the crank mechanism with part of the frame removed. 
         FIG. 22  shows a bottom perspective view of the projectile launcher of  FIG. 5 . 
         FIG. 23  shows a perspective view of another example weapon system, according to another example of the present disclosure. 
         FIG. 24  shows another perspective view of the weapon system of  FIG. 23 . 
         FIG. 25  shows an exploded view of the weapon system of  FIG. 23 . 
         FIG. 26  shows a perspective view of a projectile launcher in the undrawn position, according to another example of the present disclosure. 
         FIG. 27  shows a left side view of the projectile launcher of  FIG. 26  in the undrawn position. 
         FIG. 28  shows a right side view of the projectile launcher of  FIG. 26  in the undrawn position. 
         FIG. 29  shows a top view of the projectile launcher of  FIG. 26  in the undrawn position. 
         FIG. 30  shows a cross-sectional view along line  16 - 16  in  FIG. 29  of the projectile launcher in the undrawn position. 
         FIG. 31  shows a perspective view of an example string hub of a projectile launcher, according to one example of the present disclosure. 
         FIG. 32  shows a side view of the string hub of  FIG. 31 . 
         FIG. 33  shows a side view of a drawstring wheel of the string hub of  FIG. 31 . 
         FIG. 34  shows a perspective of the projectile launcher of  FIG. 26  in the drawn position. 
         FIG. 35  shows a left side view of the projectile launcher of  FIG. 26  in the drawn position. 
         FIG. 36  shows a top view of the projectile launcher of  FIG. 26  in the drawn position. 
         FIG. 37  shows a side view of the projectile launcher of  FIG. 5  in a misfiring scenario. 
         FIG. 38  shows a perspective view of the drawstring guides and hood of the projectile launcher of  FIG. 26 . 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments will be described in detail with reference to the drawings, wherein like reference to numerals represent like parts and assemblies throughout the several views. Reference to various embodiments does not limit the scope of the claims attached hereto. Additionally, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments for the appended claims. 
     A projectile launcher  100  (e.g., a compact crossbow) is disclosed herein. The projectile launcher  100  can be used in different arrangements to improve efficiency, improve balance, improve safety, shoot different projectiles, and improve accuracy. Further, due to its compact nature and its ability to fire projectiles at high speeds, the projectile launcher  100  can be utilized for hunting, such as for bow hunting. 
     Specifically, the projectile launcher  100  is configured to fire a projectile  101 , such as an arrow. The projectile  101  has a projectile axis P that extends longitudinally along the projectile  101  (shown in  FIGS. 9 and 12 ). The projectile launcher  100  includes a frame  102 , a drawstring  104 , a first limb  106 , a second limb  108 , a string hub  110 , a first drawstring wheel  111 , a second drawstring wheel  113 , a first power wheel  112 , a second power wheel  114 , a first power cable  116 , a second power cable  118 , a first drawstring guide  119 , a second drawstring guide  121 , a latch  120 , a trigger assembly  122 , an arrow rest  124 , an accessory rail  126 , a grip  128 , a trigger guard  130 , and a gripping cutout  132 . 
     The projectile launcher  100  operates by utilizing the movable latch  120  that travels along and between a front  103  and a rear  105  of the frame  102 . The latch  120  travels to the front of the projectile launcher  100  along the frame  102 , attaches to the drawstring  104  and a user draws the latch  120  rearward. As the drawstring  104  is drawn rearward, the limbs  106 ,  108  that are connected thereto are drawn downward and loaded. This is because the drawstring  104  wraps multiple times around the drawstring wheels  111 ,  113  and the movement of the drawstring  104  moves the drawstring wheels  111 ,  113 . The drawstring wheels  111 ,  113  are fixed to string hub  110  and the power wheels  112 ,  114  are also fixed to the string hub  110  and rotate therewith. The power cables  116 ,  118  are each connected to the limbs  106 ,  108  and the power wheels  112 ,  114 , respectively. As the drawstring  104  is moved rearward, the drawstring  104  rotates the drawstring wheels  111 ,  113 , which rotate the string hub  110 , which rotates the power wheels  112 ,  114 , which wind the power cables  116 ,  118  around the power wheels  112 ,  114 , which load (e.g., force downward) the limbs  106 ,  108 . Once fully rearward, the latch  120  is secured and a projectile  101  (i.e., an arrow) can be loaded. The latch  120  is in communication with the trigger assembly  122  and the user can move a trigger pull  123  of the trigger assembly  122  to release the drawstring  104  from the latch  120 , thereby propelling the projectile  101  forward from the projectile launcher  100 . 
       FIGS. 1 and 2  show perspective views of the weapon system  125  that includes a projectile launcher  100  and a stock  134  attached the frame  102  of the projectile launcher  100 . The stock  134  is shown including a quiver  136  removably attached thereto, and a storage area  138  for an arming tool  140 . 
     The frame  102  can be constructed of a composite, wood, metal, or like material. In some examples, the frame  102  is a singular unibody component. In other examples, the frame  102  has a multiple-piece construction. In such an examples, the frame  102  can include multiple portions that mate together along a longitudinal axis of the frame  102 . In such an example, the trigger assembly  122  can be positioned between the multiple portions of the frame  102 . In some examples, the frame  102  is configured to include a variety of different mounting points for various module accessories such as flashlights, sighting accessories, or other attachments. The frame  102  defines a horizontal projectile plane at a top side  155  in which a projectile axis P is positioned. The projectile moves within the horizontal projectile plane and along the projectile axis P during firing and arming of the projectile launcher. 
     The drawstring  104  can be constructed of traditional bowstring material such as, but not limited to, composite and/or natural fibers. 
     The limbs  106  and  108  power the rotation of the string hub  110 . In some examples, the limbs  106 ,  108  are elastic and spring-like in nature. In some examples, a single limb can be utilized. In some examples, the limbs  106 ,  108  extend in an upward direction from a top side of the frame  102  and in a forward direction toward the front end  103  of the frame  102 . It is considered within the scope of the present disclosure that the limbs  106 ,  108  may be positioned in a variety of different ways relative to the frame  102 . 
     The power cables  116 ,  118  can be attached to and/or wound around the first and second limbs  106 ,  108 . In some examples, the power cables  116 ,  118  can be constructed of a variety of different materials such as, but not limited to, composite and/or natural fibers, metal, plastic, etc. 
     As shown in  FIG. 3 , the projectile launcher  100  includes a rear interface  142  that mates with a stock interface  144  of the stock  134 . The rear interface  142  includes an upward facing hook  146  and a post  145 . The stock interface  144  includes a hook recess  147  that mates with the hook  146  and a post recess  148  that mates with the post  145 , as shown in a closer view in  FIGS. 14 and 15 . In some examples, the mating between the stock interface  144  and the rear interface  142  utilizes an interference fit. In some examples, an interference fit is used between the post  145  and the post recess  148 . In some examples, the stock  134  can be removed from the frame  102  without the use of tools. It is considered within the scope of the present disclosure that a variety of different tool-less connections can be used between the stock  134  and the frame  102 . 
       FIG. 4  shows the stock  134 , quiver  136 , and arming tool  140  separated from the frame  102  of the projectile launcher  100 . 
       FIGS. 5-8  show the projectile launcher  100  in the undrawn position.  FIGS. 9-15  show the projectile launcher  100  in the drawn position with the projectile  101  loaded therein. 
       FIG. 16  shows a cross-sectional view along line  16 - 16  in  FIG. 12  of the string hub  110 .  FIGS. 17 and 18  show the string hub  110  removed from the projectile launcher  100 . The string hub  110  includes the drawstring wheels  111 ,  113 , the power wheels  112 ,  114 , and a string hub shaft  152 . In some examples, the rotation of the string hub  110  can be powered by a power source such as, but not limited to, a spring, a motor, a piston, or like device. Movement of the drawstring  104  away from the string hub  110  corresponds with rotation of the string hub  110  in a first direction, and movement of the drawstring  104  toward the string hub corresponds with rotation of the string hub  110  in a second direction. Rotation of the string hub  110  in the second direction is powered. In some examples, the rotation of the string hub  110  is powered by the first and second limbs  106 ,  108 . 
     The drawstring wheels  111 ,  113  are positioned on the outside edges of the string hub  110  and each includes drawstring grooves  150  positioned on the circumferential edge thereof. The drawstring wheels  111 ,  113  define a drawstring section DS of the string hub  110 . In some examples, the drawstring wheels  111 ,  113  include covers  117  positioned therearound. In some examples, the drawstring wheels  111 ,  113  include three drawstring grooves  150  apiece and allow for the drawstring  104  to be wrapped around the drawstring wheels  111 ,  113  three times when the projectile launcher is undrawn. In some examples, the drawstring grooves  150  are connected and spiral to aid in guiding the drawstring  104  around the drawstring wheels  111 ,  113  to ensure reliable wrapping and unwrapping. In some examples, the drawstring  104  rotates the string hub  110 , specifically drawstring wheels  111 ,  113 , approximately 720 degrees about a central axis when the projectile launcher goes from the undrawn position to the drawn position. In some examples, the drawstring grooves  150  are similarly sized. In some examples, the drawstring grooves  150  have similar circumferences. In some examples, the grooves  150  have similar diameters Dd. 
     The power wheels  112 ,  114  are positioned adjacent the drawstring wheels  111   113  at a power cable section PS of the string hub  110 . In some examples, the power wheels  112 ,  114  connect to the drawstring wheels  111 ,  113  at a first side and to the string hub shaft  152  at a second side. The power wheels  112 ,  114  each include power cable grooves  154  positioned on the outside thereof. In some examples, the power cable grooves  154  can have a stepped configuration, having different outer diameters Dp 1 , Dp 2 , Dp 3 . As shown, Dp 1  is greater than Dp 2 , and Dp 2  is greater than Dp 3 . In some examples, diameters Dd of the drawstring grooves are greater than Dp 1 , Dp 2 , and Dp 3 . The power cable grooves  154  can increase in outer dimeter size as they move toward from the drawstring wheels  111 ,  113  and away the center of the frame  102 . In some examples, this increase in outer diameter, and thereby circumference, ensures that the power cables  116 ,  118  are unwound around the power wheels  112 ,  114  at firing at a rate that allows for predictable tension of the drawstring  104 . In some examples, this configuration allows for a consistent force curve on the drawstring  104  when the drawstring is fired. In some examples, the power cable grooves  154  in each power wheel  112 ,  114  decrease in circumference as the respective power cable is wound within the power cable grooves  154  on the respective power wheel  112 ,  114  as the projectile launcher is moved from the undrawn position to drawn position. 
     Because the power wheels  112 ,  114  and drawstring wheels  111 ,  113  are connected to one another via the string hub shaft  152 , they rotate together, thus eliminating timing issues as the projectile launcher  100  is fired. 
       FIG. 19  shows a longitudinal cross-section of the projectile launcher  100  as the latch  120  is between the front  103  and the rear  105  of the frame  102 . 
       FIG. 20  shows the latch  120  attached to the drawstring  104  in the drawn position. 
     The latch  120  is movable between the rear end  105  of the frame  102  and the front end  103  of the frame  102  along a travel axis T. In some examples, the travel axis T is axially aligned with the projectile axis P. The latch  120  is attached to a crank mechanism  156  via a tether  107 . The latch is configured to receive a portion of the projectile  101  therein, as shown in  FIG. 20 . In some examples, the latch  120  is movable parallel to the projectile axis P. In some examples, the crank mechanism  156  is configured to pull at least a portion of the tether at least partially in a direction perpendicular to the travel axis T. In some examples, the crank mechanism  156  is configured to pull at least a portion of the tether  107  at least partially in a direction perpendicular to the projectile axis P. 
       FIG. 21  shows a perspective view of the crank mechanism  156  with part of the frame  102  removed. The crank mechanism  156  is housed in the rear  105  of the frame  102 . As shown in  FIG. 19 , the tether  107  travels downward to, and is wound upon, a first gear  158  that is in communication with a second gear  160 . In some examples, the tether  107  uses a guide  162  before being wound around the first gear  158 . In some examples, the guide  162  is a cylinder. In some examples, the guide  162  is a rotatable shaft. In some examples, the guide  162  includes a bearing. The second gear  160  is rotatable by the arming tool  140  from a post  164 , accessible at an exterior of the frame  102 . Rotation of the second gear  160 , causes rotation of the first gear  158  and wraps the tether  107  therearound. By wrapping the tether  107  around the first gear  158 , the latch  120  is moved rearward. In some examples, a first portion A of the tether  107  extends between the guide  162  and the latch  120  in a direction parallel to the travel axis T, and a second portion B of the tether  107  extends between the guide  162  and the crank mechanism  156  at least partially in the direction perpendicular to the travel axis T. 
     The crank mechanism  156  also includes a movable stop  166  in communication with the first gear  158 . The stop  166  is accessible at the exterior of the frame  102 , specifically, at the bottom of the projectile launcher  100 , shown in  FIG. 22 . In some examples, the stop  166  is spring loaded and biased against the first gear  158 . In some examples, when the stop  166  is depressed, the stop  166  disengages with the first gear  158  thereby allowing the first gear  158  to rotate so that the tether  107  can be unwound therefrom. In some examples, when winding the tether  107  around the first gear  158 , the stop  166  allows the first gear to rotate in a direction where the tether  107  is wound around the first gear  158  but not in a direction where the tether  107  is unwound from the first gear  158 . This prevents the drawstring  104  from inadvertently traveling back to the front  103  of the frame  102  during arming. In some examples, the stop  166  is a pawl. 
     In some examples, the user inverts the projectile launcher  100  to arm. The user can grasp the gripping cutout  132  to stabilize the projectile launcher  100  and the stop  166  is depressed to let out the tether  107 , and the latch  120  can then be moved to the front  103  of the frame  102 . Once at the front  103 , the latch  120  is attached to the drawstring  104  that is positioned against the guides  119 ,  121 . When connected to the drawstring  104 , the latch  120  is moved rearward by winding the tether  107  around the first gear  158  by rotating the second gear via the arming tool  140 . Once rearward, the latch  120  automatically locks rearward by way of the stop  166 . When ready to fire, the user pulls the trigger pull  123  and releases the drawstring  104 , and not the latch  120 , toward the front  103  of the frame  102 . 
     By positioning the crank mechanism  156  under the latch  120 , the projectile launcher  100  is able to utilize a longer drawstring power stroke DPS, shown in  FIG. 20 , while maintaining a compact size. The drawstring  104  is movable along a power stroke DPS distance when arming and firing the projectile launcher  100 . In some examples, the power stroke is in a range from 10 inches to 15 inches. In some examples, the power stroke is 13 inches (33 cm). In some examples, the limbs  106 ,  108  are upward facing and the guides  119 ,  121  hold the drawstring  104  in the undrawn position. Because the guides  119 ,  121  are positioned at the front  103  of the frame  102 , in order to draw the drawstring  104 , the drawstring  104  must be accessed through the limb gap G, shown in  FIG. 13 . The latch  120  is configured to pass through the gap G along the frame and grasp the drawstring  104 . 
       FIGS. 23 and 24  show perspective views of another example weapon system  225 . The example weapon system  225  and projectile launcher  200  of  FIGS. 23 and 24  is capable of being used in a similar manner as described above with reference to the weapon system  125  and projectile launcher  100 . As noted above, the weapon system  225  includes a projectile launcher  200  and a stock  234 . The stock  234  is shown including a quiver  236  removably attached thereto. In some examples, the stock of the projectile launcher also includes an arming tool  240 , and a storage area  238  for an arming tool  240 . In some examples, the component parts of the weapon system  225  are all detachable, as outlined above, and as seen in in  FIG. 25 . 
       FIG. 25  shows an exploded perspective view of the example weapon system  225  of  FIGS. 23 and 24 . As depicted in  FIG. 25 , the component parts of the example weapon system  225  can be taken apart and disassembled for storage or added maneuverability. In some embodiments, the weapon system  225  includes a rear interface and mating stock interface, as previously described above with reference to  FIGS. 6, 14, and 15 . In some examples, each of the hook recess  247 , post recess  248 , hook  246 , and post  245 , described above with reference to  FIG. 6 , may be alternatively located on the projectile launcher  200  or the stock  234  of the example weapon system  225 . 
       FIGS. 26-29  depict the example projectile launcher  200  in an undrawn position.  FIG. 26  is a perspective view of the example projectile launcher  200 .  FIG. 27  is a left view of the example projectile launcher  200 ,  FIG. 28  is a right view of the example projectile launcher  200 , and  FIG. 29  is a top view of the example projectile launcher  200 . As seen in  FIGS. 26-29 , in some embodiments, the left and right sides of the projectile launcher  200  are symmetrical. In some examples, the projectile launcher  200  includes a frame  202  with a front end  203  and a rear end  205 . In some examples, the projectile launcher  200  further includes a drawstring  204 , a first limb  206 , a second limb  208 , a string hub  210 , a first power cable  216 , a second power cable  218 , a first drawstring guide  219 , a second drawstring guide  221 , a latch  220 , a trigger assembly  222 , an arrow rest  224 , an accessory rail  226 , a grip  228 , a trigger guard  230 , and a gripping cutout  232 . 
     In some examples, the limbs  206 ,  208 , include first ends  264 ,  266 , second ends,  268 ,  270 , and limb pulleys  256 ,  258 . The limbs  206 ,  208  power the string hub  210  and the power cables  216 ,  218 , which transmit power through the string hub  210  to the drawstring  204 . In some examples, the limbs  206 ,  208  are elastic and spring-like in nature. In some examples, a single limb can be utilized. In some examples, the limbs  206 ,  208  extend in an upward direction from a top side of the frame  202  and in a forward direction toward the front end  203  of the frame  202 . In some examples, the limbs  206 ,  208 , include the limb pulleys  256 ,  258  at their second ends  268 ,  270 . It is considered within the scope of the present disclosure that the limbs  206 ,  208  may be positioned in a variety of different ways relative to the frame  202 . In some examples, the limbs  206 ,  208  are supported at their first ends  264 ,  266 , by distal limb supports  260  and are supported along their length by medial limb supports  262 . In some examples, the medial limb supports  262  act as a fulcrum upon which the limbs  206 ,  208  bend as the second ends  268 ,  270  of the limbs  206 ,  208  are drawn downward. In some examples, the medial limb supports  262  and distal limb supports  260  are both located rearward of the trigger pull  223  of the trigger assembly  222 . In other examples, the medial limb support  262  is located forward of the trigger pull  223  of the trigger assembly  222  while the distal limb support  260  is located rearward of the trigger pull  223  of the trigger assembly  222 . In other examples, both the medial limb supports  262  and distal limb supports  260  are located forward of the trigger pull  223  of the trigger assembly  222 . 
     An example embodiment of the projectile launcher includes a frame having a vertical grip, the frame defining a horizontal projectile plane at a top side in which a projectile axis is positioned, wherein a projectile moves within the horizontal projectile plane and along the projectile axis during firing and arming of the projectile launcher, wherein the projectile is fired from a front end of the frame, and wherein the frame includes a limb with a distal limb support and a medial limb support. 
     Another example includes, alone or in combination with the above example, the distal and medial limb supports being positioned rearward of a trigger for firing the projectile launcher. 
     Another example includes, alone or in combination with any of the above examples, the distal limb support being positioned rearward of the trigger while the medial limb support is positioned in front of the trigger. 
     The frame  202  may be made of the same materials of the frame  102 . Likewise, the frame  202  may be made of multiple portions. In some examples, the frame  202  includes two symmetrical halves that mate together along the longitudinal axis of the frame  202 . 
     In some examples, the frame  202  is built to minimize the length of the frame  202  between the front end  203  and the rear end  205  of the frame  202 , or minimize the width of the frame  202  between its left side and right side. In some examples, the length FL of the frame  202  is in a range from about 15 inches to about 23 inches (or from 15 inches to 23 inches) (38 cm to 58 cm) between the front end  203  and rear end  205  of the frame  202 . In some examples, the length FL of the frame  202  is in a range from about 18 inches to about 20 inches (or from 18 inches to 20 inches) (45 cm to 51 cm) between the front end  203  and rear end  205 . In other examples, the length FL of the frame  202  is in a range from about 18 inches to about 19 inches (or 18 inches to 19 inches) (45 cm to 49 cm) between the front end  203  and rear end  205 . In other examples, the length FL of the frame  202  is about 18.75 inches (or is 18.75 inches) (47.6 cm) between the front end  203  and rear end  205 . In some examples, the width FW of the frame  202  is in a range from about 1 inch to about 10 inches (or from 1 inch to 10 inches) (2.5 cm to 26 cm) between its left and right sides. In some examples, the width FW of the frame  202  is in a range from about 1 inch to about 6 inches (or from 1 inch to 6 inches) (2.5 cm to 15 cm) between its left and right sides. In some examples, the width FW of the frame  202  is in a range from about 3 inches to about 5 inches (or from 3 inches to 5 inches) (7.5 cm to 13 cm) between its left and right sides. 
     An example embodiment of the projectile launcher includes a frame having a vertical grip, the frame defining a horizontal projectile plane at a top side in which a projectile axis is positioned, wherein a projectile moves within the horizontal projectile plane and along the projectile axis during firing and arming of the projectile launcher, wherein the projectile is fired from a front end of the frame, and wherein the frame has a length between the front end and the rear end of the frame in a range from about 15 inches to about 23 inches (or from 15 inches to 23 inches) (38 cm to 58 cm). 
     Another example includes, alone or in combination with the above example, wherein the frame has a length between front and rear ends of the frame in a range from about 18 inches to about 19 inches (or from 18 inches to 19 inches) (45 cm to 49 cm). 
     Another example includes, alone or in combination with any of the above examples, wherein the frame has a length of about 18.75 inches (or a length of 18.75 inches) (47.6 cm) between the front and rear ends of the frame. 
     Another example includes, alone or in combination with any of the above examples, wherein the frame has a width between the left and right sides of the frame in a range from about 1 to about 10 inches (or from 1 to 10 inches) (2.5 cm to 26 cm). 
     Another example includes, alone or in combination with any of the above examples, wherein the frame has a width between the left and right sides of the frame in a range from about 1 to about 6 inches (or from 1 inch to 6 inches) (2.5 cm to 15 cm). 
     Another example includes, alone or in combination with any of the above examples, wherein the frame has a width between the left and right sides of the frame in a range from about 3 to about 5 inches (or from 3 inches to 5 inches) (7.5 cm to 13 cm). Another example has a frame width of about 4.9 inches (12.4 cm). 
     In some examples, the frame  202  includes a reinforcement arch  272 . the reinforcement arch  272  extends over the projectile axis P between the left and right sides of the projectile launcher  200  and provides reinforcement to the frame  202 . In some examples, the reinforcement arch  272  prevents the left and right sides of the frame  202  from collapsing inward towards the projectile axis P and the middle of the frame  202  when the drawstring  204  is under tension. In some examples, the reinforcement arch  272  serves further functions such as keeping a knocked arrow or other projectile from falling out of place as the projectile launcher  200  is moved in space by a user. The reinforcement arch  272  may also help to keep objects and body parts away from the projectile axis P. 
     An example embodiment of the projectile launcher includes a frame having a vertical grip, the frame defining a horizontal projectile plane at a top side in which a projectile axis is positioned, wherein a projectile moves within the horizontal projectile plane and along the projectile axis during firing and arming of the projectile launcher, wherein the projectile is fired from a front end of the frame, and wherein a reinforcement arch extends over and traverses the projectile axis and connects to the frame on either side of the projectile axis. 
     In some examples, the projectile launcher  200  also includes an arrow rest  224  mounted to the frame  202 . In some examples, as seen in the examples of  FIGS. 26-30 , the arrow rest  224  is positioned forward of the drawstring guides  219 ,  221  and mounted to the front end  203  of the frame  202  of the projectile launcher  200 . In some examples, the distance AL between the arrow rest  224  and the front edge of the drawstring guides  219 ,  221  is in a range from about 0 inches to about 4 inches (or 0 inches to 4 inches) (0 cm to 10 cm). In another example, the distance AL between the arrow rest  224  and the front edge of the drawstring guides  219 ,  221  is in a range from about 0 inches to about 3 inches (or 0 inches to 3 inches) (0 cm to 7.5 cm). In some examples, the distance AL between the arrow rest  224  and the front edge of the drawstring guides  219 ,  221  is about 1.47 inches (or is 1.47 inches) (3.73 cm). In other examples, the arrow rest  224  is positioned rearward of the drawstring guides  219 ,  221  and is retractable. In such examples, the arrow rest  224  is in an upright position and supports the arrow while the drawstring  204  is carried rearward by the latch  220 , and retracts into the projectile plane when the projectile is fired. The arrow rest  224  may be manufactured from a variety of materials including, for example, plastics, metals, and composite materials. 
     In some embodiments, the drawstring guides  219 ,  221  are spaced apart from each other on either side of the projectile axis. The drawstring  204  wraps partially around the drawstring guides  219 ,  221  within a groove around each drawstring guide  219 ,  221 , so that a portion of the drawstring  204  extends between each of the drawstring guides  219 ,  221 . As this portion of the drawstring  204  is pulled rearward during the loading of the projectile launcher  200 , each drawstring guide  219 ,  221  rotates in a first direction, and as the portion is released and propelled forward, each drawstring guide  219 ,  221  rotates in a second direction. 
     The drawstring guides  219 ,  221  may be various sizes and positioned in various ways on the projectile launcher  200 . In some embodiments, the drawstring guides  219 ,  221  have an outer diameter in a range from about 0.5 inches to about 2 inches (or 0.5 inches to 2 inches) (1.25 cm to 5 cm) in diameter. In other embodiments, the drawstring guides  219 ,  221  have an outer diameter of about 1.35 inches (or of 1.35 inches) (3.43 cm). In some embodiments, the drawstring guides  219 ,  221  have an inner diameter, as measured around the inner-most portion of the groove of the drawstring guide  219 ,  221 , that is less than the outer diameter of the drawstring guides  219 ,  221 . In some embodiments, this inner groove diameter is in a range from about 0.5 inches to about 2 inches (or 0.5 inches to 2 inches) (1.25 cm to 5 cm) in diameter. In some embodiments, the inner groove diameter is about 1.05 inches (or is 1.05 inches) (2.67 cm). 
     Likewise, in some examples, the drawstring guides  219 ,  221  are positioned at varying distances from each other. For example, in some embodiments, the distance between the two drawstring guides GD, as measured from a point on the outer diameter of each drawstring guide  219 ,  221 , is in a range from about 1 inch to about 4 inches (or 1 inch to 4 inches) (0 cm to 10 cm). In some examples, the distance between the two drawstring guides GD is in a range from about 1 inch to about 1.5 inches (or from 1 inch to 1.5 inches) (2.5 cm to 3.8 cm). In some examples, the distance between the two drawstring guides GD is about 1.325 inches (or is 1.325 inches) (3.37 cm). 
       FIG. 29  also includes a dashed line, showing the diameter of the drawstring guide  219 , obstructed by the frame  202 . The drawstring guide  221  is shaped equivalently to the drawstring guide  219 . In some examples, the drawstring guides  219 ,  221  are sized small enough, and positioned close enough to one another, so that the outer edge of the diameter of the drawstring guides  219 ,  221  is positioned closer to a central plane of the projectile launcher  200  (defined by a vertical plane positioned along the projectile axis) than the outer edge of the limbs  206 ,  208 . Thus, the outer edges of the limbs  206 ,  208  are positioned distal to the outer edges of the drawstring guides  219 ,  221  and the drawstring guides  219 ,  221  are positioned medial to the outer edges of the limbs  206 . 
     In some examples, the drawstring  204  includes a knocking portion that extends between the first drawstring guide  219  and the second drawstring guide  221 . In some examples, the drawstring guides  219 ,  221  are cams or pulleys, and spin as the knocking portion of the drawstring  204  travels forward or rearward along the projectile axis P. In some examples, the drawstring  204  is routed around the drawstring guides  219 ,  221  into the string hub  210 . 
     In some examples, the frame  202  defines a projectile track  278 . The projectile track  278  includes a left sidewall  280 , a right sidewall  282 , and a bottom  284 . The projectile axis P is positioned within the projectile track  278 . The latch  220  is configured to move forward and rearward within the projectile track  278  during the loading and firing of the projectile launcher  200 . In some examples, the latch  220  must be compact in size as to fit within the projectile track  278  and move in the forward and rearward directions. In some examples, the projectile track  278  is less than about 2 inches wide (or less than two inches (5 cm) wide), as measured between the left sidewall  280  and right sidewall  282 . In such cases, the latch  220  is sized to be less than about 2 inches wide (or less than 2 inches (5 cm) wide) so that it can fit between the left sidewall  280  and the right sidewall  282  and move forward and rearward within the projectile track  278 . In some examples, the latch  220  is sized so that there is about a 0.03 inch (or a 0.03 inch) (0.76 cm) clearance between the sides of the latch  220  and the sidewalls  280 ,  282 . 
     An example embodiment of the projectile launcher includes a frame having a vertical grip, the frame defining a horizontal projectile plane at a top side in which a projectile axis is positioned, wherein a projectile moves within the horizontal projectile plane and along the projectile axis during firing and arming of the projectile launcher, wherein the projectile is fired from a front end of the frame, and wherein the frame includes an arrow rest positioned to support an projectile. 
     Another example includes, alone or in combination with the above example, a plurality of pullies between which a drawstring extends, wherein the arrow rest is positioned in front of the plurality of pullies. 
     Another example includes, alone or in combination with any of the above examples, a plurality of drawstring guides between which a drawstring extends, wherein the arrow rest is positioned behind the plurality of pullies. 
     Another example includes, alone or in combination with any of the above examples, a portion of the drawstring spanning between the drawstring guides in direction perpendicular to the projectile axis, wherein the arrow rest is positioned in a range from about 0 inches to about 4 inches (or 0 inches to 4 inches) (0 cm to 10 cm) in front of the portion of the drawstring. 
     Another example includes, alone or in combination with any of the above examples, a portion of the drawstring spanning between the drawstring guides in direction perpendicular to the projectile axis, wherein the arrow rest is positioned in a range from about 0 inches to about 4 inches (or 0 inches to 4 inches) (0 cm to 10 cm) in front of the portion of the drawstring. 
     Another example includes, alone or in combination with any of the above examples, an arrow rest is positioned in a range from about 0 inches to about 4 inches (or from 0 inches to 4 inches) (0 cm to 10 cm) in front of the portion of the drawstring. 
     Another example includes, alone or in combination with any of the above examples, an arrow rest is positioned about 1.47 inches (or is positioned 1.47 inches) (3.73 cm) in front of the portion of the drawstring. 
     Another example includes, alone or in combination with any of the above examples, the projectile launcher, wherein the frame defines a projectile track with a bottom, a left sidewall, and a right sidewall, wherein the projectile axis is positioned within the projectile track. 
     Another example includes, alone or in combination with any of the above examples, the projectile launcher, wherein a latch is configured to move within the projectile track along the projectile axis, wherein the latch includes a left and a right side, wherein the left and right sides of the latch are spaced about 0.03 inches (or are spaced 0.03 inches) (0.76 cm) from the left and right sidewalls when the latch moves within the projectile track along the projectile axis. 
     The drawstring  204  can be constructed of traditional bowstring material such as, but not limited to, composite and/or natural fibers. Likewise, the power cables  216 ,  218  can be constructed of a variety of different materials such as, but not limited to, composite and/or natural fibers, metal, plastic, etc. In some examples, the power cables  216 ,  218  are attached to and/or wound around the first and second limbs  206 ,  208 . In some examples, a first end of the first power cable  216  is attached to the frame  202  of the projectile launcher  200 . The first power cable  216  is routed around a limb pulley  256  on the second end  268  of the first limb  206  and fed into the string hub  210 . In this example, a first end of the second power cable  218  is also attached to the frame  202  of the projectile launcher  200 . The second power cable  218  is also routed around a limb pulley  258  on the second end  270  of the second limb  208  and fed into the string hub  210 . 
       FIG. 30  shows a cross-sectional view along line  16 - 16  in  FIG. 29  of the string hub  210 . In some examples, the string hub  210  includes bearings  274 , and stationary drawstring wheel covers  217 . The string hub  210  further includes the drawstring wheels  211 ,  213 , the power wheels  212 ,  214 , a shaft  252 . In some examples, the drawstring wheels  211 ,  213 , the power wheels  212 ,  214 , and shaft  252  are connected in such a way that they rotate as a single unit. In some examples, the drawstring wheels  211 ,  213 , the power wheels  212 ,  214 , and shaft  252  are forged from a single piece of material, while in other examples, the drawstring wheels  211 ,  213 , the power wheels  212 ,  214 , and shaft  252  are connected to each other using fasteners. In some examples, as depicted in  FIG. 30 , the drawstring wheels  211 ,  213  are positioned laterally distal from the longitudinal center C of the projectile launcher  200  with respect to the power wheels  212 ,  214 , while the power wheels  212 ,  214  are positioned laterally medial to the longitudinal center C of the projectile launcher  200  with respect to the drawstring wheels  211 ,  213 . In some examples, the shaft  252  extends across the longitudinal center of the projectile launcher  200  between the power wheels  212 ,  214 , and supports the power wheels  212 ,  214  and drawstring wheels  211 ,  213  on each of the left and right sides of the projectile launcher  200 . In this example, the shaft  252  is held in a cantilever-like manner, as it is supported along its length by the bearings, while its ends, which are attached to and support the power wheels  212 ,  214  and drawstring wheels  211 ,  213  are unsupported. 
     In some examples, the large forces, high speeds, and cantilever positioning of the shaft  252  may lead to deterioration in the integrity of the shaft  252  structure. In particular, in some embodiments, the shaft  252  is susceptible to shearing along its length after repeated use. In such cases, it is desirable to manufacture the shaft  252  so that it has a sufficiently large cross-sectional diameter as to withstand such forces. In some examples, the diameter of the shaft  252  is greater than about 0.25 inches (or greater than 0.25 inches) (0.635 cm). In other examples, the diameter of the shaft  252  is greater than ⅜ inches (or greater than ⅜ inches) (0.952 cm). In other examples, the diameter of the shaft  252  is about 0.5 inches (such as, for example, 0.5 inches) (1.27 cm). In some embodiments, it is desirable to manufacture the shaft  252  from a resilient material capable of withstanding large shearing forces. In some examples, the shaft  252  is made from a durable metal material. In some examples, the metal is S7 tool steel heat treated to 48-50 HRC 
     Similarly, due to the high forces experienced within the string hub  210 , in some embodiments, the bearings  274  may be susceptible to wear and deterioration. In some embodiments, needle bearings are used in place of traditional ball bearings to better withstand the forces in the string hub  210 , however, various types of bearings  274  may be employed. In some embodiments, multiple bearings  274  are used to support the shaft  252 . In some embodiments, two bearings  274  are used so that one bearing  274  supports the shaft  252  along its length on each side of the shaft  252 . 
     In some embodiments, the string hub  210  also includes the stationary drawstring wheel covers  217 . In some embodiments, the drawstring wheel covers  217  are mounted to the frame  202  on each side of the projectile launcher  200  and enclose the drawstring wheels  211 ,  213 . In some embodiments, the drawstring wheel covers  217  serve several functions. For example, the drawstring wheel covers  217  may prevent objects from entering the rotational path and interfering with the rotation of the drawstring wheels  211 ,  213  during the arming and firing of the projectile launcher  200 . In some examples, the drawstring wheel covers  217  also help to hold the drawstring  204  in position. As explained in greater detail with reference to  FIGS. 17 and 18 , the drawstring  204  wraps around and fits within grooves of the drawstring wheels  211 ,  213 . When fired, the drawstring wheels  211 ,  213  spin at high speeds. If uncontrolled, the drawstring  204  may become dislodged from the grooves of the drawstring wheels  211 ,  213 . The inner surface of the inner diameter of the covers  217  helps to provide a backstop for the drawstring  204  so that it does not become dislodged from the grooves of the drawstring wheels  211 ,  213 . In some examples, the inner diameter of the covers  217  is only slightly larger than the outer diameter of the drawstring wheels  211 ,  213 . In these examples, only a minimal space exists between the surface of the drawstring  204  routed around the drawstring wheels  211 ,  213  and the surface of the inner diameter of the covers  217 . In some examples, the inner surface of the inner diameter of the covers  217  lightly contacts the surface of the drawstring  204 . In other examples, the space between the surface of the inner diameter of the drawstring wheels  211 ,  213  and the outer surface of the drawstring  204  is in a range from about 0 inches to about 0.125 inches (or 0 inches to 0.125 inches) (0 cm to 0.318 cm). In some examples, the space between the surface of the inner diameter of the drawstring wheels  211 ,  213  and the outer surface of the drawstring  204  is about 0.125 inches (or is 0.125 inches) (0 cm to 0.318 cm). The covers  217  can be made from a variety of materials. In some examples, the covers  217  are made of a rubber, plastic, or aluminum material. Although not shown in  FIG. 30 , in some examples, the covers  217  may also extend around and encircle the power wheels  212 ,  214  to provide similar functionality as noted above with reference to the drawstring wheels  211 ,  213 . 
     An example embodiment of the projectile launcher includes a frame having a vertical grip, the frame defining a horizontal projectile plane at a top side in which a projectile axis is positioned, wherein a projectile moves within the horizontal projectile plane and along the projectile axis during firing and arming of the projectile launcher, wherein the projectile is fired from a front end of the frame, and wherein the projectile launcher further includes a string hub that drives the movement of a drawstring. 
     Another example includes, alone or in combination with the above example, a string hub rotatably mounted to the frame, the string hub being rotatable about a central axis in a first direction and a second direction, the central axis being perpendicular to the projectile axis. 
     Another example includes, alone or in combination with one or more of the above examples, a drawstring being attached to the drawstring hub, the drawstring traveling at least partially perpendicular to the projectile axis between first and the second ends of the drawstring, the drawstring being movable within the projectile plane during firing and arming of the projectile launcher, wherein movement of the drawstring away from the drawstring hub corresponds with rotation of the drawstring hub in the first direction, and wherein movement of the drawstring toward the drawstring hub corresponds with rotation of the drawstring hub in the second direction. 
     Another example includes, alone or in combination with one or more of the above examples, the projectile launcher, wherein the string hub includes a shaft, and wherein the diameter of the shaft is greater than 0.25 inches (0.635 cm). 
     Another example includes, alone or in combination with one or more of the above examples, the shaft, wherein the diameter of the shaft is greater than ⅜ inches (0.952 cm). 
     Another example includes, alone or in combination with one or more of the above examples, the shaft, wherein the diameter of the shaft is greater than 0.5 inches (1.27 cm). 
     Another example includes, alone or in combination with one or more of the above examples, the shaft, wherein the shaft is made from S7 tool steel heat treated to 48-50 HRC. 
     Another example includes, alone or in combination with one or more of the above examples, the projectile launcher, wherein the string hub includes a plurality of bearings, wherein the bearings are needle bearings. 
     Another example includes, alone or in combination with one or more of the above examples, the projectile launcher, wherein the string hub includes a plurality of wheels upon which the drawstring is wound. 
     Another example includes, alone or in combination with one or more of the above examples, the projectile launcher, wherein the string hub includes one or more stationary covers that enclose the one or more of the wheels. 
     Another example includes, alone or in combination with one or more of the above examples, the projectile launcher, wherein the stationary covers include an inner diameter sized approximately equal to the one or more wheels. 
     Another example includes, alone or in combination with one or more of the above examples, the projectile launcher, wherein the stationary covers include an inner diameter that contacts the outer surface of the drawstring when the drawstring is wound onto the one or more wheels. 
     Another example includes, alone or in combination with one or more of the above examples, the projectile launcher, wherein the stationary covers include an inner diameter that is spaced in a range from about 0 inches to about 0.125 inches (or 0 inches to 0.125 inches) (0 cm to 0.318 cm) from the outer surface of the drawstring when the drawstring is wound onto the one or more wheels. 
     Another example includes, alone or in combination with one or more of the above examples, the projectile launcher, wherein the stationary covers include an inner diameter that is spaced about 0.125 inches (0.318 cm) from the outer surface of the drawstring when the drawstring is wound onto the one or more wheels. 
       FIGS. 31 and 32  show the drawstring wheels  211 ,  213 , power wheels  212 ,  214 , and shaft of the string hub  210  removed from the projectile launcher  200 . The string hub  210  of  FIGS. 31-33  functions equivalently to the string hub  110 , described in detail above with reference to  FIGS. 17 and 18  above. 
       FIG. 33  shows a side view of an example drawstring wheel  211  of the string hub  210 . As seen in  FIG. 33 , the drawstring wheel  211  includes a variety of cutouts around the body of the drawstring wheel  211 . In some examples, the cutouts decrease the mass of the drawstring wheel  211  while preserving the strength of the drawstring wheel  211  so that it does not break during repeated operation. Relatedly, the cutouts help to decrease the moment of inertia of the drawstring wheel  211 . In some examples, decreasing the moment of inertia of the drawstring wheels  211 ,  213  decreases the wear on other firing components within the projectile launcher  200 , as back and forth oscillations of the drawstring  204  after firing are minimized. Thus, it is desirable for the drawstring wheels  211 ,  213  to have low moments of inertia so that the movement of the drawstring wheels  211 ,  213  is quickly halted after firing a projectile. In some examples, the rotational moment of inertia of the drawstring wheels  211 ,  213  can be reduced to levels within a range from about 0.025 to about 0.1 (or from 0.025 to 0.1) pound square inches (0.0000731 kg square meters to 0.0000292 kg square meters). In other examples, the rotational moment of inertia of the drawstring wheels  211 ,  213  are about 0.045 (or are 0.045) pound square inches (0.000132 kg square meters). 
       FIG. 34  shows a perspective view of the projectile launcher  200  in the drawn configuration,  FIG. 35  shows a top view of the projectile launcher  200  in a drawn configuration, and  FIG. 36  shows a side view of the projectile launcher  200  in a drawn configuration. With reference to  FIGS. 34-36 , as well as  FIGS. 26-29 , depicting the projectile launcher  200  in an undrawn configuration, the functionality of the limbs  206 ,  208 , string hub  210 , and drawstring  204  is explained. 
     The projectile launcher  200  operates by utilizing the movable latch  220  that travels along and between a front  203  and a rear  205  of the frame  202 . The latch  220  travels to the front  203  of the projectile launcher  200  along the frame  202 , attaches to the drawstring  204  and a user draws the latch  220  rearward along the projectile axis P. The remaining length of the drawstring  204  is routed around the drawstring guides  219 ,  221 , into the string hub  210 , around the drawstring wheels  211 ,  213  and attached to a point on each drawstring wheel at each end of the drawstring  204 . As the drawstring  204  is brought rearward, the portions of the drawstring  204  wrapped around the drawstring wheels  211 ,  213  are gradually unspooled from the drawstring wheels  211 ,  213 . Meanwhile, the power cables  216 ,  218  and drawstring  204  are each connected to the string hub  210  so that as the drawstring  204  is drawn rearward, the power cables  216 ,  218  are gradually drawn into the string hub  210  and around the power wheels  212 ,  214 . The power cables  216 ,  218  are also connected to the limbs  206 ,  208 , so that as the power cables  216 ,  218  are drawn into the string hub  210 , the limbs  206 ,  208  are drawn downward and loaded 
     Thus, as the knocking portion of the drawstring  204  is brought rearward, the drawstring guides  219 ,  221  and drawstring wheels  211 ,  213  spin in a first direction, and unwind a portion of the drawstring  204  from the drawstring wheels  211 ,  213 . Meanwhile, the power cables  216 ,  218  are each attached to their respective power wheels  212 ,  214  at a first end and wrap around the respective power wheels  212 ,  214 . The remaining length of the power cables  216 ,  218  extends out from the string hub  210  and is connected to the limbs  206 ,  208 . The rotation of the drawstring wheels  211 ,  213  in the first direction drives the rotation of the string hub  210  and the power wheels  212 ,  214  in the first direction. As the power wheels  212 ,  214  are rotated in the first direction, a portion of the remaining lengths of the power cables  216 ,  218  is wound around the power wheels  212 ,  214 . As the power cables  216 ,  218  are wound around the power wheels  212 ,  214 , the second ends of the limbs  206 ,  208  are drawn closer to the string hub  210  (compare  FIGS. 26 and 34 ). 
     Once fully rearward, the latch  220  is secured and a projectile  201  (i.e., an arrow) can be loaded. The latch  220  is in communication with the trigger assembly  222  and the user can move a trigger pull  223  of the trigger assembly  222  to release the drawstring  204  from the latch  220 , thereby propelling the projectile  201  forward from the projectile launcher  200 . 
     Once the drawstring  204  is released, it is powered forward along the projectile axis P by the upward movement of the limbs  206 ,  208  and the rotation of the string hub  210  in a second direction. When the knocking length is released, the flexible limbs  206 ,  208  spring upward. This movement of the flexible limbs  206 ,  208  results in the rapid unwinding of the power cables  216 ,  218  from the power wheels  212 ,  214 . The unwinding drives the rotation of the power wheels  212 ,  214  in the second direction, which drives the rotation of the string hub  210  and the drawstring wheels  211 ,  213  in the second direction. The rotation of the drawstring wheels  211 ,  213  in the second direction results in the rapid spooling of the drawstring  204  onto the drawstring wheels  211 ,  213  and the propulsion of the knocking length of the drawstring  204  forward towards the front end  203  of the projectile launcher  200  along the projectile axis. 
       FIG. 37  is a side view of the projectile launcher  100  of  FIG. 5 , depicting a misfiring scenario. In some examples, as depicted by  FIG. 37 , as the projectile launcher  100  is fired and the drawstring  104  is rapidly wound onto the drawstring wheels  111 ,  113 , the drawstring  104  may follow an erratic spooling path and may become dislodged from the grooves of the drawstring guides  119 ,  121 , which results in the misoperation of the projectile launcher  100 . 
     Moving back to  FIG. 36 , in some examples, to ensure the proper spooling of the drawstring  204  onto the drawstring wheel and prevent dislodging of the drawstring  204 , the covers include cutouts  286  that define openings for the drawstring  204  to travel into the string hub  210 . The cutouts  286  may be various shapes and sizes as needed to properly route the drawstring  204  onto the drawstring wheels  211 ,  213 . 
     In some examples, the frame  202  above the drawstring guides  219 ,  221  also provide similar advantages to minimize misfiring.  FIG. 38  is a perspective view, depicting the frame  202  and the drawstring guide  219 . In this example, the portion of the frame  202  directly above the drawstring guides  219 ,  221  is built out to provide a drawstring guide hood  276 . The drawstring guide hood  276  is configured to extend laterally out from the frame  202  and over the edge of the drawstring guides  219 ,  221 . The hood  276  extends around and down over the edge of the drawstring guides  219 ,  221  so that a bottom surface of the hood is flush with an upper edge of the groove of the drawstring guides  219 ,  221 . A recess in the hood  276  in which the drawstring guide  219 ,  221  is positioned is formed have an inner diameter only slightly larger than the outer diameter of the drawstring guides  219 ,  221  so that very little space exists between the outer diameter of the drawstring guide  219 ,  221  and the inner diameter of the recess of the hood  276 . By having a bottom edge that is flush with the upper edge of the groove of the drawstring guides  219 ,  221 , the hood  276  functions to prevent the drawstring  204  from moving out of the groove of the drawstring guides  219 ,  221  in the upward direction as the drawstring  204  is wound onto the drawstring wheel during the firing of the projectile launcher  200 . In some embodiments, the hood  276  is positioned on the bottom side of the drawstring guides  219 ,  221 , with or without the use of the hood  276  on the top side of the drawstring guides  219 ,  221 , to prevent the drawstring  204  from becoming dislodged by falling off a bottom edge of the drawstring guides  219 ,  221 . 
     Additional Example Embodiments 
     An example embodiment of the projectile launcher includes a frame having a vertical grip, the frame defining a horizontal projectile plane at a top side in which a projectile axis is positioned, wherein a projectile moves within the horizontal projectile plane and along the projectile axis during firing and arming of the projectile launcher, wherein the projectile is fired from a front end of the frame. 
     Another example includes, alone or in combination with the above example, a string hub rotatably mounted to the frame, the string hub being rotatable about a central axis in a first direction and a second direction, the central axis being perpendicular to the projectile axis. 
     Another example includes, alone or in combination with one or more of the above examples, a drawstring being attached to the drawstring hub, the drawstring traveling at least partially perpendicular to the projectile axis between first and the second ends of the drawstring, the drawstring being movable within the projectile plane during firing and arming of the projectile launcher, wherein movement of the drawstring away from the drawstring hub corresponds with rotation of the drawstring hub in the first direction, and wherein movement of the drawstring toward the drawstring hub corresponds with rotation of the drawstring hub in the second direction. 
     Another example includes, alone or in combination with one or more of the above examples, a first and a second flexible limb attached to the frame, wherein the first and second limbs a in an unloaded position when the projectile launcher is undrawn and in a loaded position when the projectile launcher is drawn. 
     Another example includes, alone or in combination with one or more of the above examples, a first and a second power cable each having a first end and a second end, wherein the first ends of the first and second power cables are attached to the string hub at power cable sections, wherein upon rotation of the string hub in the first direction, the first and second power cables are configured to draw the first and second flexible limbs closer to the string hub. 
     Another example includes, alone or in combination with one or more of the above examples, a latch movable between the rear end of the frame and the front end of the frame and attached to a crank mechanism via a tether, the latch being configured to receive the drawstring and hold the drawstring at the rear end of the frame when the crossbow is drawn, the latch being configured to receive a portion of the projectile and the drawstring therein, wherein the tether travels downward from the latch to wrap around a first gear of the crank mechanism, the crank mechanism having a spring loaded stop in communication with the first gear, the stop being biased against the first gear, and wherein the stop is accessible at an underside of the frame. 
     Another example includes, alone or in combination with one or more of the above examples, a trigger assembly being in communication with the latch, wherein upon activation of the trigger assembly when firing, the trigger assembly moves the latch and the drawstring is released from the latch. 
     Another example includes, alone or in combination with one or more of the above examples, first and second drawstring guides attached to the frame, each guide guiding the drawstring across the projectile axis between the first and second ends of the drawstring. 
     Another example includes, alone or in combination with one or more of the above examples, a crossbow or projectile launcher that includes a movable, compact windable latch mechanism. 
     Another example includes, alone or in combination with one or more of the above examples, a crossbow or projectile launcher wherein the latch mechanism includes a latch, a tether, and a crank mechanism, wherein the latch is configured to move parallel to a projectile axis and wherein the crank mechanism is configured to pull at least a portion of the tether at least partially in a direction perpendicular to the projectile axis. 
     Another example includes, alone or in combination with one or more of the above examples, a crossbow or projectile launcher wherein the latch mechanism further comprises a guide, and wherein a first portion of the tether extends between the guide and the latch in a direction parallel to the projectile axis, and wherein a second portion of the tether extends between the guide and the crank mechanism at least partially in the direction perpendicular to the projectile axis. 
     Another example includes, alone or in combination with one or more of the above examples, a crossbow or projectile launcher that includes a drawstring, a pair of power strings, a string hub, and an interface for a modular stock. 
     Another example includes, alone or in combination with one or more of the above examples, a crossbow or projectile launcher that includes a string hub that has an increasing size of grooves on the power cable section. 
     Another example includes, alone or in combination with one or more of the above examples, a crossbow or projectile launcher that includes a latch mechanism positioned below a latch. 
     Another example includes, alone or in combination with one or more of the above examples, a crossbow or projectile launcher that includes a frame having a stock interface at a rear end, the stock interface configured to removably secure a stock. 
     Another example includes, alone or in combination with one or more of the above examples, a crossbow or projectile launcher comprising a frame having a multi-piece construction. 
     Another example includes, alone or in combination with one or more of the above examples, a crossbow or projectile launcher comprising a drawstring wheel having a spiral groove, and a drawstring, wherein the drawstring wheel is configured to receive a portion of the drawstring in the spiral groove, wherein the spiral groove passes at least three times around the drawstring wheel. 
     The various embodiments described herein are provided by way of illustration only and should not be construed to limit the claims attached hereto. Those skilled in the art will readily recognize various modifications and changes that may be made without following the example embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the following claims.