Abstract:
A chuck for use with a driver having a rotatable drive shaft, the chuck including a body having a nose section and a tail section, the tail section being configured to rotate with the drive shaft and the nose section having an axial bore. A plurality of jaws is movably disposed with respect to the body and in communication with the axial bore. A first sleeve is rotatably mounted to the body in operative communication with the jaws so that rotation of the sleeve moves the jaws either toward a longitudinal center axis of the axial bore or away from the longitudinal center axis. A second sleeve is rotatably mounted to the body and is movable between a first position in which the second sleeve is rotatably fixed to the body and a second position in which the second sleeve is rotatable about the body. The second sleeve moves in a direction transverse to the longitudinal center axis of the axial bore when moving between the first position and the second position.

Description:
CLAIM OF PRIORITY 
     This application is a continuation of U.S. patent application Ser. No. 13/251,747, filed Oct. 3, 2011, now U.S. Pat. No. 8,387,995, which is a continuation of U.S. patent application Ser. No. 12/951,154, filed Nov. 22, 2010, now U.S. Pat. No. 8,029,000, which is a continuation of U.S. patent application Ser. No. 11/476,379, filed Jun. 28, 2006, now U.S. Pat. No. 7,837,200, which claims priority to U.S. Provisional Patent Application No. 60/696,009 filed Jul. 1, 2005, the entire disclosures of which are incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to chucks for use with drills or with electric or pneumatic power drivers. More particularly, the present invention relates to a chuck of the keyless type that may be tightened or loosened by hand or actuation of the driver motor. 
     BACKGROUND OF THE INVENTION 
     Hand, electric, and pneumatic tool drivers are well known. Although twist drills are the most common tools on such drivers, the tools may also comprise screwdrivers, nut drivers, burrs, mounted grinding stones and other cutting or abraiding tools. Since the tool shanks may be of varying diameter or of polygonal cross section, the device is usually provided with a chuck that is adjustable over a relatively wide range. The chuck may be attached to the driver by a threaded or tapered bore. 
     A variety of chucks have been developed in the art. In an oblique jawed chuck, a chuck body includes three passageways disposed approximately 120° apart from each other. The passageways are configured so that their center lines meet at a point along the chuck axis forward of the chuck. The passageways constrain three jaws that are movable in the passageways to grip a cylindrical or polygonal tool shank disposed approximately along the chuck center axis. The chuck includes a nut that rotates about the chuck center and that engages threads on the jaws so that rotation of the nut moves the jaws in either direction within the passageways. The body is attached to the driveshaft of the driver and is configured so that rotation of the body in one direction with respect to the nut forces the jaws into gripping relationship with the tool shank, while rotation in the opposite direction releases the gripping relationship. The chuck may be keyless if it is rotated by hand. Examples of such chucks are disclosed in U.S. Pat. Nos. 5,125,673 and 5,193,824, the entire disclosures of which are incorporated by reference herein. Various configurations of keyless chucks are known in the art and are desirable for a variety of applications. 
     SUMMARY OF THE INVENTION 
     An embodiment of the present invention provides a chuck for use with a manual or powered driver having a rotatable drive shaft. The chuck includes a generally cylindrical body having a nose section and a tail section, the tail section is configured to rotate with the drive shaft and the nose section has an axial bore formed therein. A plurality of jaws is movably disposed with respect to the body and in communication with the axial bore. A first sleeve is rotatably mounted to the body in operative communication with the jaws so that rotation of the sleeve in a closing direction moves the jaws toward a longitudinal center axis of the axial bore and rotation of the sleeve in an opening direction moves the jaws away from the longitudinal center axis. A second sleeve is rotatably mounted to the body, the second sleeve being selectively movable between a first position in which the second sleeve is rotatably fixed to the body and a second position in which the second sleeve is rotatable about the body. The second sleeve moves in a direction transverse to the longitudinal center axis of the axial bore when moving between the first position and the second position. 
     Another embodiment of the present invention provides a chuck for use with a manual or powered driver having a rotatable drive shaft. The chuck includes a generally cylindrical body having a nose section and a tail section, the tail section is configured to rotate with the drive shaft, and the nose section has an axial bore formed therein. A first set of locking teeth is disposed on the body. A plurality of jaws is movably disposed with respect to the body and in communication with the axial bore. A nut is rotatably mounted about the body and in operative communication with the jaws so that rotation of the nut in a closing direction moves the jaws toward a longitudinal center axis of the axial bore and rotation of the nut in an opening direction moves the jaws away from the longitudinal center axis. A first sleeve is rotatably mounted to the body in operative communication with the nut and is rotatable over a limited angular distance between a first angular position and a second angular position with respect to the nut. A second sleeve includes a second set of locking teeth and the second sleeve is rotatably mounted to the body and selectively movable between a first position in which the second sleeve is rotatably fixed to the body by the first and second locking teeth and a second position in which the second sleeve is rotatable about the body. The second sleeve moves in a direction transverse to the longitudinal center axis of the axial bore when moving between the first position and the second position. When the first sleeve is in the first angular position the second sleeve is in the first position and when the first sleeve is in the second angular position the second sleeve is in the second position. 
     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended drawings, in which: 
         FIG. 1  is an exploded perspective view of a chuck in accordance with an embodiment of the present invention; 
         FIG. 2  is a longitudinal view, in cross-section, of the chuck shown in  FIG. 1 ; 
         FIG. 3A  is a cross-sectional view of the chuck shown in  FIG. 2  along line  3 - 3 ; 
         FIG. 3B  is a sectional view of the chuck shown in  FIG. 2  along line  3 - 3 ; 
         FIG. 4  is an exploded perspective view of a chuck in accordance with an embodiment of the present invention; 
         FIG. 5  is a longitudinal view, in cross-section, of the chuck shown in  FIG. 4 ; 
         FIG. 6A  is a cross-sectional view of the chuck shown in  FIG. 5  along line  6 - 6 ; and 
         FIG. 6B  is a cross-sectional view of the chuck shown in  FIG. 5  along line  6 - 6 . 
     
    
    
     Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention. 
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Reference will now be made in detail to presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope and spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the present disclosure. 
     Referring to  FIGS. 1 and 2 , a chuck  10  in accordance with the present invention includes a body  12 , a gripping mechanism, generally  14 , a sleeve  18 , and a nose piece  20 . In the embodiment illustrated in  FIGS. 1 and 2 , gripping mechanism  14  includes a nut  28  and a plurality of jaws  26 . Body  12  is generally cylindrical in shape and comprises a nose or forward section  30  and a tail or rearward section  32 . An axial bore  34  formed in forward section  30  is dimensioned somewhat larger than the largest tool shank that chuck  10  is designed to accommodate. A threaded bore  36  is formed in tail section  32  and is of a standard size to mate with a drive shaft of a powered or hand driver, for example a power drill having a spindle. The bores  34  and  36  may communicate at a central region of body  12 . While a threaded bore  36  is illustrated, such bore is interchangeable with a tapered bore of a standard size to mate with a tapered drive shaft. Furthermore, body  12  may be formed integrally with the drive shaft. 
     Body  12  defines three passageways  38  that accommodate jaws  26 . Each jaw is separated from each adjacent jaw by an arc of approximately 120°. The axes of passageways  38  and jaws  26  are angled with respect to the chuck center axis  40  and meet at a common point. Each jaw  26  has a tool engaging face  42  generally parallel to chuck axis  40  and threads  44  formed on the jaw&#39;s opposite or outer surface that may be constructed in any suitable type and pitch. 
     Body  12  includes a thrust ring  46  that, in a preferred embodiment, may be integral with body  12 . In an alternate embodiment, thrust ring  46  may be a separate component from body  12  that is axially and rotationally fixed to the chuck body by interlocking tabs, press fitting or other suitable connection means. Thrust ring  46  includes a plurality of jaw guideways  48  formed around its circumference to permit retraction of jaws  26  therethrough and also includes a ledge portion  50  to receive a bearing assembly as described below. 
     Body tail section includes a knurled surface  52  that receives a dust cover  24  in a press fit fashion. Dust cover  24  could also be retained through a press fit without knurling, by use of a key or by crimping, staking, riveting, threading or any other suitable method of securing the dust cover to the body. The chuck as described in the present embodiment may be used with a power driver that includes a spindle lock feature to enable actuation of the chuck by sleeve  18  when the spindle is rotationally fixed by the spindle lock. Alternatively, dust cover  24  may be replaced by a rear sleeve rotationally secured to body tail section  32  in a similar manner by which an operator may grip and rotationally secure the body while turning sleeve  18  to drive nut  28  as described below. 
     Nut  28 , which in the illustrated embodiment is a unitary nut, defines female threads  54  located on an inner circumference of the nut and is received over the central part of body  12  proximate thrust ring  46 . A bearing washer  62  and an annular bearing cage  58  are received between thrust ring  46  and nut  28 . Bearing cage  58  holds a plurality of balls  60  that facilitate the nut&#39;s rotation relative to the chuck body. 
     Preferably, sleeve  18  is molded or otherwise fabricated from a structural plastic such as a polycarbonate, a filled polypropylene, e.g. a glass-filled polypropylene, or a blend of structural plastic materials. Other composite materials such as graphite-filled polymerics may also be suitable in certain environments. It should be appreciated by one skilled in the art that the materials from which the chuck of the present invention are fabricated will depend on the end use of the chuck, and the above materials are provided by way of example only. 
     The outer circumferential surface of sleeve  18  may be knurled or may be provided with longitudinal ribs or other protrusions to enable the operator to grip it securely. In like manner, the circumferential surface of a rear sleeve (if provided) may be knurled or ribbed if desired. Nose piece  20  is press fit to body nose section  30  and retains sleeve  18  against forward axial movement. Sleeve  18  is secured in the rearward axial direction by a lock ring  80  and nut  28 . Nose piece  20  may be coated with a non-ferrous metallic coating to prevent rust and to enhance its appearance. Examples of suitable coatings include zinc or nickel, although it should be appreciated that any suitable coating could be utilized. 
     As described in more detail below, sleeve  18  rotationally drives nut  28  with respect to the body, thereby moving jaws  26  axially within passageways  38  due to the engagement of jaw threads  44  and nut threads  54 . The direction of axial movement of jaws  26  depends on the rotational direction of sleeve  18  and nut  28  with respect to body  12 . If a tool, such as a drill bit, is inserted into bore  34 , the sleeve and nut may be rotated about chuck axis  40  in a closing direction  116  ( FIG. 3A ) so that jaws  26  move to a closed position at which the jaws&#39; tool engaging surfaces  42  grippingly engage the tool. Rotation of sleeve  18  and nut  28  about axis  40  in the opposite or opening direction  117  ( FIG. 3B ) moves the jaws axially rearward out of the closed position to an open position. 
     Chuck  10  also includes a tightening torque indicator comprising an annular ring  74  and ratchet teeth  81 . Annular ring  74  defines an inwardly extending flange  76  seated on a shoulder  88  extending rearwardly from nut  28  and flush against a rearward face of a flange  86  that extends radially outward from the nut&#39;s primary outer circumferential surface. Four retaining tabs  82  are spaced evenly about the periphery of flange  76  and extend forward into corresponding notches  84  in flange  86  so that ring  74  is rotationally fixed to nut  28 . A plurality of pawls  78  extend from flange  76  over flange  86  and are biased radially outward so that the pawls&#39; distal ends  90  engage ratchet teeth  81 . 
     The engagement between pawls  78  and ratchet teeth  81  rotationally couples sleeve  18  to ring  74 . The engagement between annular ring  74  and nut  28  at tabs  82  and notches  84  thus rotationally couples sleeve  18  to nut  28  during normal operation. That is, when opening and closing the chuck, torque applied by the user&#39;s hand at sleeve  18  transfers to ring  74  through teeth  81  and pawls  78  and then to nut  28  through the engagement of tabs  82  and notches  84 . 
     A toothed ring  92  is pressed onto body  12  forward of nut  28 . Lock ring  80  is disposed about body  12  and toothed ring  92  so that a plurality of locking teeth  94  radially oppose a series of teeth  96  disposed about the outer circumference of ring  92 . A rearward face  97  of ring  80  abuts a front face  98  of nut  28 , and two tabs  100   a  and  100   b  that extend rearwardly from lock ring  80  are received in corresponding grooves  102  in the outer surface of nut  28  so that lock ring  80  is rotationally fixed to the nut. 
     Lock ring  80  is slightly elliptical in shape so that the width of its inner diameter between tabs  100   a  and  100   b  is slightly greater than the outer diameter of ring  92  at the outer edges of teeth  96 . Flats  104  on opposite sides of the inner diameter of lock ring  80  (90° offset from tabs  100   a  and  100   b ) abut the outer diameter of teeth  96 . Flats  104  ride on ring  92  as the lock ring is moved in the radial direction with respect to axis  40  between a first position ( FIG. 3A ), in which teeth  94  engage teeth  96 , and a second position ( FIG. 3B ), in which teeth  94  are disengaged from teeth  96 . 
     Referring also to  FIGS. 3A and 3B , an annular area  106  between ratchet teeth  81  and a radially inward extending lip  108  in the inner diameter of sleeve  18  defines opposing cam surfaces  107  and  109  that engage tabs  100   a  and  100   b , respectively. Sleeve  18  is rotatable with respect to lock ring  80  between two positions at which the cam surfaces drive lock ring  80  via tabs  100   a  and  100   b  to its first and second (engaged and disengaged) positions, respectively. That is, in one rotational position of sleeve  18  with respect to lock ring  80 , cam surface  107  pushes lock ring  80  via tab  100   a  to the lock ring&#39;s first position, in which teeth  94  engage teeth  96 . In the other rotational position of sleeve  18  with respect to lock ring  80 , cam surface  109  pushes lock ring  80  to its second position, in which teeth  94  disengage from teeth  96 . 
     The degree of relative rotation between sleeve  18  and lock ring  80  is defined by the difference in angular width between each of a pair of drive dogs  110  extending rearwardly from lip  108  and each of a pair of grooves  112  in the forward face of lock ring  80  that receives a respective dog  110 . 
     During normal operation, when jaws  26  are in a retracted position so that they do not grip a tool shank, dogs  110  are received in respective grooves  112  so that each dog abuts an edge  114  of its respective groove  112 , as shown in  FIG. 3B . Thus, assuming the user turns sleeve  18  in the chuck&#39;s closing direction  116 , dogs  110  abut the trailing edges  114  of their respective grooves  112 . In this condition, cam surface  109  pushes lock ring  80  to its second position, so that teeth  94  are disengaged from teeth  96  ( FIG. 3B ). This permits lock ring  80 , and therefore nut  28 , to rotate with respect to the body so that the rotating nut drives jaws  26  in their respective passageways as described above. That is, rotation of sleeve  18  in direction  116  rotationally drives nut  28  through ring  74  to close the jaws. 
     The engagement of jaws  26  with a tool shank blocks the jaws&#39; further forward movement in the jaw passageways, and nut  28  therefore resists further rotation. Lock ring  80  also stops rotating due to the rotational connection between the lock ring and the nut via tabs  100  and grooves  102 . Application of sufficient torque to sleeve  18  in closing direction  116  to overcome the engagement of pawls  78  with ratchet teeth  81  causes the ratchet teeth to pass over the pawls. The pawls&#39; radially inward movement over teeth  81  and into successive gaps between adjacent teeth produces a click sound notifying the user that the jaws have gripped the tool shank and that sufficient torque has been applied to nut  28  to overcome the engagement between pawls  78  and teeth  81 . 
     As sleeve  18  rotates with respect to lock ring  80 , dogs  110  move in grooves  112  from edges  114  to opposing edges  118 . The length of this travel corresponds to the movement of sleeve  18  from its second position ( FIG. 3B ) with respect to lock ring  80  to its first position ( FIG. 3A ). As this transition occurs, cam surface  107  pushes lock ring  80  to its first position so that teeth  94  engage teeth  96 . The radial distance of this movement is insufficient to disengage tabs  100   a  and  100   b  from grooves  102 , and lock ring  80  remains rotationally fixed to the nut. Alternatively, each tab  100   a ,  100   b  may move out of its groove  102  at one of the first and second positions, but remains in the groove in the other position, such that at least one of the tabs  100   a  and  100   b  remains in its groove at all times and the lock ring remains rotationally fixed to the nut. Because lock ring  80  is now also rotationally fixed to ring  92  and the body through the engagement of teeth  94  with teeth  96 , nut  28  is rotationally fixed to the body, thereby inhibiting the nut&#39;s undesired rotation during the power driver&#39;s operation. Teeth  94  and  96  may be angled such that they oppose each other in more direct opposition to the nut&#39;s rotation in the opening direction. 
     To open the chuck, the user grips and rotates sleeve  18  in the direction opposite direction  116  (opening direction  117 ). In the chuck&#39;s closed and tightened condition the engagement between nut threads  54  and jaw threads  44  is generally stronger than the engagement between pawls  78  and ratchet teeth  81 . Thus, sleeve  18  again rotates with respect to annular ring  74  such that ratchet teeth  81  ride over pawls  78  and dogs  110  travel in their respective grooves  112  from edges  118  to edges  114  ( FIG. 3B ). This also moves cam surfaces  107  and  109  relative to lock ring  80  so that the cam surface  109  drives lock ring  80  back to the lock ring&#39;s second position. Teeth  94  are now disengaged from teeth  96 , and further rotation of sleeve  18  in opening direction  117  carries lock ring  80  and nut  28  with the sleeve, thereby retracting jaws  26  in their passageways. 
     In an alternate embodiment, sleeve  18  and lock ring  80   a  of chuck  10   a  rotate together, and lock ring  80   a  is actuated manually rather than by relative rotation between the lock ring and the sleeve. The sleeve and nut  28  also rotate together, and ring  74 , flange  86 , ratchet teeth  81 , dogs  110 , grooves  112 , and cam surfaces  107  and  109  are omitted. Sleeve  18  is preferably pressed onto the outer surface of nut  28  so that the sleeve is rotationally fixed to the nut. A self-contained bearing assembly is disposed between nut  28  and ledge portion  50  of body  14 . A plurality of bearing balls  68  are positioned between an outer race  64  and an inner race  66 , and a shroud  69  secures the two races together. 
     Flats  104  remain on lock ring  80   a  and ride on the outer surface of teeth  96  as the lock ring moves radially between its first and second positions with respect to chuck axis  40 . Tabs  100   a  and  100   b  extend slightly further radially outward and through respective apertures  17  in sleeve  18  so that lock ring  80   a  may be selectively actuated to either the first “locked” ( FIG. 6A ) or second “unlocked” ( FIG. 6B ) position through pressing of tabs  100   a  and  100   b  by the user&#39;s thumb. 
     Lock ring  80   a  is not rotationally keyed to nut  28  through tabs  100   a  and  100   b . Thus, grooves  102  are omitted from the outer surface of nut  28 , and tabs  100   a  and  100   b  do not extend rearward of lock ring face  97 . An annular lip  19  extends radially inward from the inner circumference of sleeve  18  between opposing faces  97  and  98  of lock ring  80  and the nut  28 , respectively, so that the lock ring&#39;s rear face  97  is flush against lip  19 . A blind bore  120  extends into rear face  97  above one of flats  104  parallel to chuck axis  40  and receives a first ball and spring detent  122 . The ball extends partially out of the blind bore and engages either of two grooves  124   a ,  124   b  in the opposing forward face of annular lip  19 , depending on whether the lock ring is in its first ( FIG. 3A ) or second ( FIG. 3B ) position. That is, the ball engages a first  124   a  of the two grooves when the lock ring is in its first position. When the user pushes the lock ring to its second position, the ring&#39;s radial movement causes the ball to move over a ridge separating the two grooves and into second groove  124   b  when the lock ring reaches its second position. Thus, first ball detent  122  retains the lock ring in one of its two radial positions. 
     Lock ring  80   a  is rotationally fixed to sleeve  18  through a second spring and ball detent  126  ( FIGS. 6A and 6B ) in annular lip  19 . A blind bore  128  extends into the forward face of annular lip  19  parallel to chuck axis  40  and receives second spring and ball detent  126  so that the spring biases the ball forward from the mouth of the bore and toward rear face  97  of lock ring  80   a  at a point radially outward of the opposite flat  104 . A blind slot  130  extends into rear face  97  at this point. Slot  130  has a width in the radial direction with respect to chuck axis  40  so that the ball, which is biased outward from the front face of annular lip  19 , is received partially in slot  130  and partially in the blind bore in the lip. The blind slot in rear face  97  has a width perpendicular to chuck axis  40  to accommodate the lock ring&#39;s radial travel between its two positions. 
     In alternate embodiments, slot  130  and second ball detent  126  may be omitted. In those embodiments, tabs  100   a  and  100   b  can be extended beyond rear face  97  of lock ring  80   a  so that they are received in corresponding grooves formed in the sleeve. Interaction of tabs  100   a  and  100   b  with the grooves prevents rotation of lock ring  80  relative to sleeve  18 . In yet another embodiment, tabs  100   a  and  100   b  can be extended radially outward so that they both extend through their respective apertures  17  in sleeve when in both the first and second positions. As such, lock ring  80   a  is rotationally fixed to sleeve  18 . 
     During normal operation, when jaws  26  are in a retracted position so that they do not grip a tool shank, the user can press the tab  100   b  opposite teeth  94  so that lock ring  80   a  moves to the second position ( FIG. 3B ) and teeth  94  are disengaged from teeth  96 . As noted above, first ball detent  122  engages second groove  124   b  and retains the lock ring in this position. 
     Because teeth  94  are disengaged from teeth  96 , lock ring  80   a  and, therefore, sleeve  18  and nut  28  may rotate with respect to the body so that the rotating nut drives jaws  26  in their respective passageways as described above. That is, rotation of sleeve  18  in direction  116  rotationally drives nut  28  to close the jaws. 
     The engagement of jaws  26  with a tool shank blocks the jaws&#39; further forward movement in the jaw passageways, and nut  28  therefore resists further rotation. Because sleeve  18  is pressed to the nut, the sleeve also stops rotating when the user has applied as much tightening torque to the nut through the sleeve as desired. The user may then apply thumb pressure to tab  100   a  at which teeth  94  are disposed so that lock ring  80   a  shifts to its first position ( FIG. 3A ), whereby teeth  94  engage teeth  96 . Again, first ball detent  122  engages first groove  124   a  and retains lock ring  80   a  in this position until the user again actuates the ring. 
     Since second ball detent  126  rotationally fixes the lock ring to the sleeve, and since sleeve  18  is rotationally fixed to nut  28  by press fit, the engagement between teeth  94  and teeth  96  rotationally locks the nut to the body, thereby inhibiting the nut&#39;s undesired rotation during the power driver&#39;s operation. Teeth  94  and  96  may be angled such that they oppose each other in more direct opposition to the nut&#39;s rotation in the opening direction. 
     To open the chuck, the user actuates lock ring  80  at the tab  100   b  opposite teeth  94  so that the lock ring returns to its second position ( FIG. 3B ). Teeth  94  are now disengaged from teeth  96 , and rotation of sleeve  18  in opening direction  117  carries nut  28  with the sleeve, thereby retracting jaws  26  in their passageways. 
     While one or more preferred embodiments of the present invention have been described above, it should be understood that any and all equivalent realizations of the present invention are included within the scope and spirit thereof. Thus, the depicted embodiment(s) are presented by way of example only and are not intended as limitations on the present invention. It should be understood that aspects of the various one or more embodiments may be interchanged in whole or in part. Therefore, it is contemplated that any and all such embodiments are included in the present invention as may fall within the scope of the present disclosure.