Patent Publication Number: US-2020276650-A1

Title: Power tool chuck

Description:
RELATED APPLICATIONS 
     This application claims priority, under 35 U.S.C. § 119(e), to U.S. Provisional Patent Application No. 62/812,431, filed Mar. 1, 2019, titled “Chuck for Power Tool,” which is incorporated by reference. 
    
    
     TECHNICAL FIELD 
     This application relates to a chuck for a power tool, such as a drill, a driver, a screwdriver, or a hammer drill. 
     BACKGROUND 
     A chuck may be non-rotationally coupled to an output shaft of a power tool (such as a drill, a driver, a screwdriver, or a hammer drill) in a variety of ways. In one embodiment, e.g., as disclosed in U.S. Pat. No. 5,193,824 (which is incorporated by reference), a chuck body may be provided with a female threaded axial bore so that the chuck may be mounted onto a male threaded end portion of the shaft. However, the threaded connection can loosen during operation of the power tool and has limited torque transmission ability based on the size and pitch of the threads. In another embodiment, e.g., as disclosed in U.S. Pat. No. 2,874,985 (which is incorporated by reference), a chuck body may be provided with a diametrically oriented rear slot that is engaged by a diametrically oriented projection on the output shaft. However, this design requires an axially lengthened chuck body so that the body has sufficient axial length for the slot and the chuck jaw passages. 
     SUMMARY 
     In an aspect, a chuck for a power tool includes a body extending along a longitudinal axis and having a nose portion and a tail portion. A central bore is defined in the body and is open to the nose portion. The central bore extends along a longitudinal axis and is configured to receive a tool bit. A plurality of angled passageways is defined in the body in communication with the central bore, with each passageway disposed at an angle to the longitudinal axis. A plurality of jaws each are at least partially received in one of the passageways. At least one of the jaws has a rear end lying in a first plane transverse to the longitudinal axis. The jaws are moveable in the passageways between an axially forward and radially inward clamping position to clamp a tool bit received in the central bore, and an axially rearward and radially outward retracted position. A first key drive member is coupled to the tail portion of the body and configured to be engaged by a second key drive member on an output shaft of a power tool to non-rotationally couple the body to the output shaft. The first key drive member extends axially from a rearward end to a forward end that lies in a second plane transverse to the longitudinal axis. The second plane is axially forward of the first plane when the jaws are in the retracted position. 
     Implementations of this aspect may include one or more of the following features. The first key drive member may include a recess defined in the tail portion of the body. The recess may be angularly spaced from each of the passageways. The recess may include a radial slot that extends radially outward from the longitudinal axis. The radial slot may have side walls and a base wall extending transverse to the longitudinal axis and lying in the second plane. The radial slot may be configured to be engaged by a radial projection on the output shaft of the power tool. The radial slot may include a plurality of the radial slots, such as three radial slots arranged in a Y-shaped configuration. 
     The recess may include an axial slot having a front end that lies in the second plane. The first key drive member may further include a pin received in the axial slot and that is received in a second slot in the output shaft of the power tool. The axial slot may include a bore that receives a projection on the output shaft of the power tool. The axial slot may include a plurality of axial slots, such as two or three axial slots equal angularly spaced about the longitudinal axis. The first key drive member may include a projection coupled to the tail portion of the body configured to engage a recess on the output shaft of the power tool. The projection may extend from a base wall that lies in the second plane. The passageways may be angularly spaced about the longitudinal axis and the first key drive member may include a plurality of first key drive members angularly spaced about the longitudinal axis and each spaced from the passageways. 
     An outer sleeve may be rotatably received over the body and configured to be rotated in a clamping direction to cause the jaws to move toward the clamping position and to be rotated in an opposite release position to cause the jaws to move toward the retracted position. A fixation device may be configured to couple the body to the output shaft to inhibit axial movement of the body relative to the output shaft. The fixation device may include a screw configured to be received through the central bore and to be threaded into a threaded opening in the output shaft of the power tool. Each passageway may be open to the tail portion of the body. Each jaw may be retracted axially rearwardly beyond the tail portion of the body. 
     In another aspect, a power tool includes a housing, a motor received in the housing, a switch configured to selectively actuate the motor, and an output shaft having a front end, extending along a longitudinal axis, and configured to be rotationally driven by the motor. A chuck is configured to be coupled to the output shaft. The chuck includes a body extending along a longitudinal axis and having a nose portion and a tail portion. A central bore is defined in the body and open to the nose portion. The central bore extends along a longitudinal axis and is configured to receive a tool bit. A plurality of angled passageways is defined in the body in communication with the central bore. Each passageway is disposed at an acute angle to the longitudinal axis. A plurality of jaws each are at least partially received in one of the passageways. A rear end of at least one of the jaws lies in a first plane transverse to the longitudinal axis. The jaws are moveable in the passageways between an axially forward and radially inward clamping position to clamp a tool bit received in the central bore, and an axially rearward and radially outward retracted position. A first key drive member is coupled to the tail portion of the body and a second key drive member is coupled to the output shaft. The first and second key drive members are configured to engage each other to non-rotationally couple the body to the output shaft so that rotation of the output shaft causes rotation of the body. The first key drive member extends from a rearward end to a forward end that lies in a second transverse plane transverse to the longitudinal axis. The second plane is axially forward of the first plane when the jaws are in the retracted position. 
     Implementations of this aspect may include one or more of the following. The first key drive member may include a recess defined in the tail portion of the body. The recess may be angularly spaced from each of the passageways. The recess may include a radial slot that extends radially outward from the longitudinal axis. The radial slot may have side walls and a base wall extending transverse to the longitudinal axis and lying in the second plane. The second key drive member may include a radial projection configured to engage the radial slot. The radial slot may include a plurality of the radial slots, such as three radial slots arranged in a Y-shaped configuration. 
     The recess may include an axial slot that lies in the second plane. The first key drive member may include a pin that is received in the axial slot and the second key drive member may include a second slot in the output shaft that receives the pin. The axial slot may include a bore, and the second key drive member may include a projection on the output shaft that is received in the bore. The axial slot may include a plurality of axial slots, such as two or three axial slots equal angularly spaced about the longitudinal axis. The first key drive member may include a projection coupled to the tail portion of the body and the second key drive member may include a recess on the output shaft configured to be engaged by the projection. The projection may extend from a base wall that lies in the second plane. The passageways may be angularly spaced about the longitudinal axis and the first key drive member may include a plurality of first key drive members angularly spaced about the longitudinal axis and each angularly spaced from the passageways. 
     An outer sleeve may be rotatably received over the body and configured to be rotated in a clamping direction to cause the jaws to move toward the clamping position and to be rotated in an opposite release position to cause the jaws to move toward the retracted position. A fixation device may be configured to couple the body to the output shaft to inhibit axial movement of the body relative to the output shaft. The fixation device may include a threaded opening in the output shaft and a screw configured to be received through the central bore and to be threaded into the threaded opening. Each passageway may be open to the tail portion of the body. Each jaw may be retracted rearwardly beyond the tail portion of the body. 
     Advantages may include one or more of the following. The first key drive member on the chuck and the second key drive member on the output shaft provide more reliable torque transmission than a threaded connection, which improves torque transmission from the output shaft to the chuck. Also, the rear ends of the jaws lying in a first plane and the second key drive member having a front end lying in a second plane that is axially forward of the first plane when the jaws are in the retracted position reduces the axial length of the chuck body. These and other advantages and features will be apparent from the description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of an embodiment of a power tool and a chuck. 
         FIG. 2  is an exploded view of the power tool and chuck of  FIG. 1 . 
         FIG. 3  is a side view, partially in cross-section, of the chuck of  FIG. 1 . 
         FIG. 4  is a rear perspective view of the chuck of  FIG. 1 . 
         FIG. 5  is a rear perspective view of the chuck of  FIG. 1  with its rear cover removed. 
         FIG. 6  is a perspective view of the output shaft of the power tool of  FIG. 1 . 
         FIG. 7  is a perspective view of the output shaft coupled to the chuck of  FIG. 1 . 
         FIG. 8  is a cross-sectional view of the output shaft coupled to the chuck of  FIG. 1 . 
         FIG. 9  is an exploded view of another embodiment of an output shaft of a power tool and a chuck. 
         FIG. 10  is a rear perspective view of the chuck of  FIG. 9 . 
         FIG. 11  is a front view of the output shaft of the power tool of  FIG. 9 . 
         FIG. 12  is a cross-sectional view of the output shaft and chuck of  FIG. 9 . 
         FIG. 13  is a perspective view, partially in cross-section, of another embodiment of an output shaft of a power tool and a chuck. 
         FIG. 14  is a front perspective view of the output shaft of  FIG. 13 . 
         FIG. 15  is a rear perspective view of the chuck of  FIG. 13 . 
         FIG. 16  is a cross-sectional view of another embodiment of an output shaft of a power tool and a chuck. 
         FIG. 17  is a front perspective view of the output shaft of  FIG. 16 . 
         FIG. 18  is a rear perspective view of the chuck of  FIG. 16 . 
         FIG. 19  is a perspective view of another embodiment of an output shaft of a power tool and a chuck. 
         FIGS. 20 and 21  are exploded perspective views of the output shaft and chuck of  FIG. 19 . 
         FIG. 22  is a front perspective view of the output shaft of  FIG. 19 . 
         FIG. 23  is a rear perspective view of the chuck of  FIG. 19 . 
         FIG. 24  is a cross-sectional view of the chuck of  FIG. 19 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 and 2 , a power tool  10  (such as a drill, a driver, a screwdriver, or a hammer drill) has a housing  12 , a motor  14 , a transmission  16 , a clutch  18 , an output shaft  20 , a chuck  22 , a trigger  24  and a battery pack  26 . Rotational power is transmitted from the motor  14  to the chuck  22  via the transmission  16 , the clutch  18 , and the output shaft  20 . The motor  14 , the transmission  16 , the clutch  18 , the trigger  24 , and the battery pack  26  are of known designs and need not be described in significant detail in this application. Reference may be made to a variety of publications for a more complete understanding of the operation of these features, such as U.S. Pat. Nos. 5,897,454 and 7,220,211, which are incorporated by reference. 
     Referring also to  FIGS. 3-8 , the chuck  22  has a chuck body  30  with a central bore  32  centered on a longitudinal axis X. The body  30  has a front nose portion  53  and a rear tail portion  54 . The central bore  32  has a front portion  34  configured to receive a tool bit therein, and a rear portion  36  configured to be fitted on the output shaft  20  (as described in more detail below). The body defines a plurality of (e.g., three) angled passageways  38  in communication with the central bore  32 . Each passageway  38  is disposed at an acute angle α to the longitudinal axis X. The passageways  38  are equal angularly spaced about the longitudinal axis X (e.g., spaced at 120° intervals). 
     A plurality of (e.g., three) jaws  40  are each at least partially received in one of the passageways  38 . Each jaw  40  has a rear end  41  with a threaded portion  42  and a front end  43  with a clamping surface  44  configured to clamp a tool bit received in the central bore  32 . The rear end  41  of at least one of the jaws  40  lies in a first plane P 1  that is transverse to the longitudinal axis X. In an embodiment, the rear ends  41  of all the jaws  40  are co-planar and lie in the first plane P 1 . In another embodiment, the rear ends of the jaws  40  are not co-planar and the first plane P 1  is defined by the rearmost rear end  41  of the jaws  40 . A tightening ring or nut  46  is rotatably received about the body  30  and has an internal screwthread  48  that meshes with the threaded portion  42  of each of the jaws  40 . An outer sleeve  50  is rotatably received over the body  30  and is engaged with the nut  46  so that rotation of the outer sleeve  50  at least selectively causes rotation of the nut  46 . A rear cover  52  is coupled to a rear end  54  of the body  30 . 
     When the sleeve  50  is rotated in a tightening direction, it causes the nut  46  to rotate in the tightening direction. The threaded coupling of the nut  46  with the jaws  40  cause the jaws to move axially forward and radially inward toward one another to a clamping position to clamp a tool bit between their clamping surfaces  44 . When the sleeve  50  is rotated in the opposite loosening direction, it causes rotation of the nut  46  in the same direction, which causes the jaws  40  to move axially rearward and radially outward to a retracted position to release a tool bit clamped between their clamping surfaces  44 . Further details about the operation of the chuck  22  to clamp and unclamp a tool bit can be found, e.g., in U.S. Pat. No. 5,765,839, which is incorporated by reference. 
     The tail portion  54  of the body  30  defines a first key drive member  55  and the front end  58  of the output shaft  20  defines a second key drive member  63 . The first and second key drive members  55 ,  63  are configured to engage each other to non-rotationally couple the body  30  to the output shaft  20  so that rotation of the output shaft  20  causes rotation of the body  30 . The first key drive member  55  extends axially from a rear end  49  to a front end  51 . The front end  51  of the first key drive member  55  lies in a second plane P 2  that is transverse to the longitudinal axis X. As shown in  FIG. 8 , when the jaws  40  are in the retracted position the second plane P 2  is axially forward of the first plane P 1 . 
     In the embodiment of  FIGS. 3-8 , the first key drive member  55  comprises a one or more (e.g., three) radial slots  56  that extend radially outward from the central bore  32 . Each slot  56  is defined by side walls  57  that are parallel to the longitudinal axis X and a base wall  59  that is transverse to the longitudinal axis X and that lies in the second plane P 2 . In another embodiment, the side walls  57  may be non-parallel to the longitudinal axis (e.g., so that they taper toward one another). The slots  56  each are angularly spaced about the longitudinal axis from each other and from each of the angled passageways  38  that receive the jaws  40 . For example, the radial slots  56  may be equal angularly spaced about the longitudinal axis X (e.g., spaced at 120° intervals) with each slot spaced equal angularly from each of the passageways  38  (e.g., by 60°) so that the slots  56  are arranged in a Y-shaped configuration. Angularly spacing the slots  56  from the passageways  38  enables the rear ends  41  of the jaws  40  to be retracted axially rearward of the second plane P 2  without the jaws  40  extending into the slots  56 . In addition, as shown in  FIG. 5 , in an embodiment, each passageway  38  may be open to the rear end  54  of body  30  and the jaws  40  may be retracted beyond the rear end  54  of the body  30  into the sleeve. These features enable better torque transmission from the output shaft  20  to the body  30 , while also reducing the axial length of the body  30  and of the chuck  22 . 
     The second key drive member  63  includes at least one (e.g., three) radial projections  64  disposed on a front face of an optional flange  60  on the front end  58  of the output shaft  20 . Each radial projection  64  extends radially outward from an optional central protrusion  62 , which extends axially forward of the flange  60  along the longitudinal axis X. The projections  64  may be equal angularly spaced about the longitudinal axis by the same angular distance as the radial slots  56  of the first key drive member  55  (e.g., spaced at 120° intervals), so that the projections  64  may engage the slots  56  to non-rotationally couple the chuck  22  to the output shaft  20 . 
     The chuck body  30  and the output shaft  20  may further include an axial fixation device  61  device configured to axially couple the chuck body  30  to the output shaft  20  to inhibit axial movement of the chuck  22  relative to the output shaft  20 . In the embodiment of  FIGS. 3-8 , the axial fixation device  61  includes a threaded opening  66  defined in the central protrusion  62  and extending along the longitudinal axis X, and a threaded screw  68  that is received through the central bore  32  in the body  30  and is threaded into the threaded opening  66  in the shaft  20 . 
     To couple the chuck  22  to the output shaft  20 , the central protrusion  62  and the radial projections  64  on the shaft are received in the central bore  32  and the radial slots  56  in the chuck body  30 . The radial projections  64  and radial slots  56  cause the chuck  22  to be non-rotationally coupled to the shaft  20  so that rotation of the shaft  20  causes rotation of the chuck  22 . The chuck screw  68  is received through the central bore  32  in the body  30  and is threaded into the threaded opening  66  in the shaft  20  to prevent axial movement of the chuck  22  relative to the shaft  20 . 
     Referring to  FIGS. 9-12 , in another embodiment, an output shaft  120  of a power tool and a chuck  122  have a similar design to the output shaft  20  and chuck  22  of  FIGS. 3-8 . The chuck  122  has a chuck body  130  with jaws  140  moveable in angled passageways  138  between a front clamping position and a rear retracted position (similar to the body  30  and jaws  40  of the chuck  22  of  FIGS. 3-8 ). Each jaw  140  has a rear end  141  with a threaded portion  142  and a front end  143  with a clamping surface  144  configured to clamp a tool bit received in the central bore  132 . The rear end  141  of at least one of the jaws  140  lies in a first plane P 1  that is transverse to the longitudinal axis X. In an embodiment, the rear ends  141  of all the jaws  140  are co-planar and lie in the first plane P 1 . In another embodiment, the rear ends of the jaws  140  are not co-planar and the first plane P 1  is defined by the rearmost rear end  141  of the jaws  140 . The output shaft  120  has a front end  158  with a radial flange  160  and a central protrusion  166  (similar to the front end  58  with a radial flange  60  and central protrusion  66  of the output shaft  20  of  FIGS. 3-8 ). The chuck body  130  includes a first key drive member  155  and the output shaft  130  includes a second key drive member  163  that differ from the first key drive member  55  and second key drive member  163  of  FIGS. 3-8  as follows. 
     The first key drive member  155  includes one or more (e.g., three) axial slots  156  in the body  130  and one or more (e.g., three) axial pins  170  that extend parallel to the longitudinal axis X. In another embodiment, the pins are at an angle or tapered relative to the longitudinal axis X. The axial slots  156  and the axial pins  170  each extend axially from a rear end  157  to a front end  159 . The front ends  159  lie in a second plane P 2  that is axially forward of the first plane P 1  (in which at least one of the rear ends  141  of the jaws  140  lie) when the jaws  140  are in their retracted position. The slots  156  and pins  170  each are angularly spaced from each other (e.g., equal angularly spaced by 120°) and from each of the angled passageways  138  (e.g., by 60°). Angularly spacing the slots  156  and pins  170  from the passageways  138  enables the rear ends  141  of the jaws  140  to be retracted axially rearward of the second plane P 2  without the jaws  140  extending into the slots  156 . This reduces the overall axial length of the body  130  and the chuck  122 . 
     The second key drive member  163  includes at least one (e.g., three) axial recesses  164  disposed on the central protrusion  164  of the output shaft  120 . The axial recesses  164  are angularly spaced about the longitudinal axis X (e.g., equal angularly spaced at 120° intervals). The recesses  165  are each configured to receive one of the pins  170  of the first key drive member  155  to non-rotationally couple the body  130  to the output shaft  120 . The output shaft  120  may be axially coupled to the chuck body  130  by a chuck screw, similar to the embodiment of  FIGS. 3-8 . 
     Referring to  FIGS. 13-15 , in another embodiment, an output shaft  220  of a power tool and a chuck  222  have a similar design to the output shaft  20  and chuck  22  of  FIGS. 3-8 . The chuck  222  has a chuck body  230  with jaws  240  moveable in angled passageways  238  between a front clamping position and a rear retracted position (similar to the body  30  and jaws  40  of the chuck  22  of  FIGS. 3-8 ). Each jaw  240  has a rear end  241  with a threaded portion  242  and a front end  243  with a clamping surface  244  configured to clamp a tool bit received in the central bore  232 . The rear end  241  of at least one of the jaws  240  lies in a first plane P 1  that is transverse to the longitudinal axis X. In an embodiment, the rear ends  241  of all of the jaws  240  are co-planar and lie in the first plane P 1 . In another embodiment, the rear ends of the jaws  240  are not co-planar and the first plane P 1  is defined by the rearmost rear end  241  of the jaws  240 . The output shaft  220  has a front end  258  with a radial flange  260  and an optional central protrusion  266  (similar to the front end  58  with a radial flange  60  and central protrusion  66  of the output shaft  20  of  FIGS. 3-8 ). The chuck body  230  includes a first key drive member  255  and the output shaft  230  includes a second key drive member  263  that differ from the first key drive member  55  and second key drive member  163  of  FIGS. 3-8  as follows. 
     The first key drive member  255  comprises one or more (e.g., three) axial bores  256  in the body  230  that extend parallel to the longitudinal axis X from a rear end  257  to a front end  259  that lies in a second plane P 2 . In another embodiment, the bores  256  may be tapered or angled relative to the longitudinal axis. The second plane P 2  is axially forward of the first plane P 1  when the jaws  240  are in their retracted position. The bores  256  each are angularly spaced from each other (e.g., equal angularly spaced at 120° intervals) and from each of the angled passageways  238  (e.g., by 60°). Angularly spacing the bores  256  from the passageways  238  enables the rear ends  241  of the jaws  240  to be retracted axially rearward of the second plane P 2  without the jaws  240  extending into the bores  256 . This reduces the overall axial length of the body  230  and the chuck  222 . 
     The second key drive member  263  comprises at least one (e.g., three) axial pins  264  disposed on the radial flange  260  of the output shaft  220 . The axial pins  264  are each configured to be received in one of the axial bores  256  of the first key drive member  255  to non-rotationally couple the body  230  to the output shaft  220 . The pins  264  may be equal angularly spaced about the longitudinal axis by the same angular distance as the bores  256  (e.g., spaced at 120° intervals). 
     Referring to  FIGS. 16-18 , in another embodiment, an output shaft  320  of a power tool and a chuck  322  have a similar design to the output shaft  220  and chuck  222  of  FIGS. 13-15 , except for the following differences in the first and second key drive members. In the embodiment of  FIGS. 16-18 , the first key drive member  355  comprises two axial bores  356  in the body  330  and the second key drive member  363  comprises two axial pins  364  disposed on a radial flange  360  on the output shaft  320 . In another embodiment, the bores and the pins may be tapered or angled relative to the longitudinal axis. The bores  356  receive the pins  364  to non-rotationally couple the body  330  to the output shaft  320 . The bores  356  and the pins  364  are angularly spaced about the longitudinal axis (e.g., equally angularly spaced at 180° intervals) and are each angularly spaced from each of the angled passageways  338  that receive the jaws  340 , enabling the jaws  340  to be further retracted into the body and reducing the axial length of the body. For example, in the illustrated embodiment, there are three passageways  338  spaced at equal 120° intervals, and two bores  356  spaced at equal 180° and spaced from two of the passageways by 30° and from the third passageway by 90°. 
     Referring to  FIGS. 19-24 , in another embodiment, an output shaft  420  of a power tool and a chuck  422  have a similar design to the output shaft  20  and chuck  22  of  FIGS. 3-8 . The chuck  422  has a chuck body  430  with jaws  440  moveable in angled passageways  438  between a front clamping position and a rear retracted position (similar to the body  30  and jaws  40  of the chuck  22  of  FIGS. 3-8 ). Each jaw  440  has a rear end  445  and a front end  443  with a clamping surface  444  configured to clamp a tool bit received in a central bore  431 . The rear end of at least one of the jaws  440  lies in a first plane P 1  that is transverse to the longitudinal axis X. In an embodiment, the rear ends of all the jaws are co-planar and lie in the first plane P 1 . In another embodiment, the rear ends of the jaws are not co-planar and the first plane is defined by the rearmost rear end of the jaws. The output shaft  420  has a front end  458  with a radial flange  460  and a central protrusion  462  (similar to the front end  58  with a radial flange  60  and central protrusion  62  of the output shaft  20  of  FIGS. 3-8 ). The chuck body  430  includes a first key drive member  455  and the output shaft  430  includes a second key drive member  463  that differ from the first key drive member  55  and second key drive member  63  of  FIGS. 3-8  as follows. 
     The first key drive member  455  comprises a two diametrically opposed radial slots  456  that extend radially outward from the central bore  432 . Each slot  456  is defined by side walls  457  that are parallel to the longitudinal axis X and a base wall  459  that is transverse to the longitudinal axis X and that lies in the second plane P 2 . In another embodiment, the side walls  457  may be non-parallel to the longitudinal axis (e.g., so that they taper toward one another). The slots  456  each are angularly spaced from each other and about the longitudinal axis from each of the angled passageways  438  that receive the jaws  40 . For example, the radial slots  456  are equal angularly spaced about the longitudinal axis X by 180° with each slot spaced equal angularly from one of the passageways  438  (e.g., by 15° to 45°). Angularly spacing the slots  456  from the passageways  438  enables the rear ends of the jaws  440  to be retracted axially rearward of the second plane P 2  without the jaws  440  extending into the slots  456 . In addition, as shown in  FIG. 23 , in an embodiment, each passageway  438  may be open to the rear end  454  of body  430  and the jaws  440  may be retracted beyond the rear end  454  of the body  430  into the sleeve. These features enable better torque transmission from the output shaft  420  to the body  430 , while also reducing the axial length of the body  430  and of the chuck  422 . 
     The second key drive member  463  includes two diametrically opposed radial projections  464  disposed on a front face of an optional flange  460  on the front end  458  of the output shaft  420 . Each radial projection  464  extends radially outward from an optional central protrusion  462 , which extends axially forward of the flange  460  along the longitudinal axis X. The projections  464  may be equal angularly spaced about the longitudinal axis from each other by the same angular distance as the radial slots  456  of the first key drive member  455  (e.g., spaced apart by 180°), so that the projections  464  may engage the slots  456  to non-rotationally couple the chuck  422  to the output shaft  420 . 
     The chuck body  430  and the output shaft  420  may further include an axial fixation device  461  device configured to axially couple the chuck body  430  to the output shaft  420  to inhibit axial movement of the chuck  422  relative to the output shaft  420 . In the illustrated embodiment, the axial fixation device  461  includes a threaded opening  466  defined in the central protrusion  462  and extending along the longitudinal axis X, and a threaded screw  468  that is received through the central bore  432  in the body  430  and is threaded into the threaded opening  466  in the shaft  420 . 
     To couple the chuck  422  to the output shaft  420 , the central protrusion  462  and the radial projections  464  on the shaft are received in the central bore  432  and the radial slots  456  in the chuck body  430 . The radial projections  464  and radial slots  456  cause the chuck  422  to be non-rotationally coupled to the shaft  420  so that rotation of the shaft  420  causes rotation of the chuck  422 . The chuck screw  468  is received through the central bore  432  in the body  430  and is threaded into the threaded opening  466  in the shaft  420  to prevent axial movement of the chuck  422  relative to the shaft  420 . 
     In alternative embodiments, the output shaft and the chuck body may have a different number of radial projections and recesses, and the chuck may have a different number of jaws. In other alternative embodiments, radial projections may be provided on a rear end of the chuck body, and radial slots may be provided on a front end of the shaft. In yet other embodiments, a rear end of the chuck body may have at least one radial slot and at least one radial projection, and the front end of the shaft may have at least one radial projection and at least one radial slot. In another embodiment, the pins could be roll pins, self-collapsing pins, tapered pins, keys, or projections. 
     Example embodiments have been provided so that this disclosure will be thorough, and to fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
     When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
     Terms of degree such as “generally,” “substantially,” “approximately,” and “about” may be used herein when describing the relative positions, sizes, dimensions, or values of various elements, components, regions, layers and/or sections. These terms mean that such relative positions, sizes, dimensions, or values are within the defined range or comparison (e.g., equal or close to equal) with sufficient precision as would be understood by one of ordinary skill in the art in the context of the various elements, components, regions, layers and/or sections being described. 
     Numerous modifications may be made to the exemplary implementations described above. These and other implementations are within the scope of this application.