Abstract:
A chuck including a body having a tail section defining an annular shoulder and a nose section having an axial bore and angularly disposed passageways intersecting the axial bore. An O-ring is disposed in the annular shoulder and a plurality of jaws is slidably positioned in the passageways. A nut is rotatably mounted on the body in engagement with threads on the jaws. A first sleeve and a second sleeve each define a gripping surface thereon and one of the first and second sleeves is axially reciprocal on the body. The one of the first and second sleeves defines an annular groove on an inner surface thereof having a first shoulder and a second shoulder. The O-ring is received in the groove such that axial motion of the one of the first and the second sleeve is limited by abutment of the O-ring with said first and second shoulders.

Description:
CLAIM OF PRIORITY 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 13/179,880 filed Jul. 11, 2011 (now U.S. Pat. No. 8,371,779), which is a continuation of U.S. patent application Ser. No. 12/753,219 filed Apr. 2, 2010 (now U.S. Pat. No. 7,976,253), which is a continuation of U.S. patent application Ser. No. 11/811,683 filed Jun. 12, 2007 (now U.S. Pat. No. 7,690,871), which is a continuation of U.S. patent application Ser. No. 11/371,798 filed Mar. 9, 2006 (now abandoned U.S. Pat. No. 7,237,988), which is a continuation of U.S. patent application Ser. No. 10/988,045 filed on Nov. 12, 2004 (now U.S. Pat. No. 7,128,503), which is a continuation of U.S. patent application Ser. No. 10/167,708 filed Jun. 11, 2002 (now U.S. Pat. No. 6,832,764), which is a continuation of U.S. patent application Ser. No. 09/736,762 filed Dec. 12, 2000 (now abandoned U.S. Pat. No. 6,435,521), which is a continuation of U.S. patent application Ser. No. 09/593,726 filed Jun. 13, 2000 (now abandoned U.S. Pat. No. 6,179,301), which is a continuation of U.S. patent application Ser. No. 09/092,552 filed Jun. 5, 1998 (now U.S. Pat. No. 6,073,939), the entire disclosure which is incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    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 which may be tightened or loosened by hand. 
         [0003]    Both hand and electrical or pneumatic tool drivers are well known. Although twist drills are the most common tools on such drivers, the tools may also comprise screw drivers, nut drivers, burrs, mounted grinding stones, and other cutting or abrading tools. Since the tool shank 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 or any other suitable means. 
         [0004]    A variety of chuck types have been developed that are actuated by relative rotation between a chuck body and an annular nut. In a typical oblique jawed chuck, for example, a body member 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 body. Three jaws are constrained by and movable in the passageways to grip a cylindrical tool shank disposed approximately along the chuck center axis. The nut rotates about the chuck&#39;s center and engages threads on the jaws so that rotation of the nut moves the jaws in either direction in the passageways. The body and nut are configured so that rotation of the nut in one direction (the closing direction) with respect to the body forces the jaws into gripping relationship with the tool shank, while rotation in the opposite direction (the opening direction) releases the gripping relationship. Such a 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, commonly assigned to the present assignee and the entire disclosure of each of which is incorporated by reference herein. Various configurations of keyless chucks are known in the art and are desirable for a variety of applications. 
         [0005]    Keyless chucks actuated by relative rotation between a nut and a chuck body include means to control the rotational position of the nut and the body. For example, a first sleeve may be provided in communication with the nut while a second sleeve, which is independent of the first sleeve, may be attached to the body. Thus, a user may rotate the first sleeve with one hand while gripping the second sleeve with the other hand, thereby holding the body still. Alternatively, in some devices in which only a single sleeve is provided, a user may grip the single sleeve and actuate the tool driver to rotate the spindle, thereby rotating the chuck body with respect to the sleeve. In addition, a mechanism may be located in a driver to lock the spindle of the driver when the driver is not actuated, thus enabling use of a single sleeve chuck. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention recognizes and addresses the foregoing considerations, and others, of prior art constructions and methods. 
         [0007]    Accordingly, it is an object of the present invention to provide an improved chuck. 
         [0008]    It is a further object of the present invention to provide an improved drill. 
         [0009]    It is a still further object of the present invention to provide a chuck having an improved mechanism for loosening and tightening the chuck. 
         [0010]    One embodiment provides a chuck for use with a manual or powered driver having a housing and a rotatable drive shaft extending therefrom, the chuck including a generally cylindrical body having a nose section and a tail section, the tail section defining an annular shoulder and configured to mate with the drive shaft so that the body rotates with the drive shaft and the nose section having an axial bore formed therein and a plurality of angularly disposed passageways formed therethrough and intersecting the axial bore. An O-ring is disposed in the annular shoulder of the tail section and a plurality of jaws is slidably positioned in each of the angularly disposed passageways, each of the jaws having a jaw face formed on one side thereof and threads formed on the opposite side thereof. A nut is rotatably mounted on the body in engagement with the threads on the jaws so that rotation of the nut moves the jaws axially within the passageways. Each of a first sleeve and a second sleeve defines a gripping surface thereon, wherein, in a first state, the first sleeve is rotationally held to the body and the second sleeve is rotationally held to the nut and is rotatable with respect to the housing and with respect to the body. One of the first sleeve and the second sleeve is axially reciprocal between the first state and a second state in which the one of the first sleeve and the second sleeve is rotationally held to the nut and the housing and is rotatable with respect to the body. One of the first sleeve and the second sleeve defines an annular groove on an inner surface thereof, an axial length of the annular groove being defined by a first shoulder and a second shoulder. The O-ring is received in the groove such that axial motion of the one of the first sleeve and the second sleeve is limited by abutment of the O-ring with the first and the second shoulders of the axial groove. 
         [0011]    Other objects, features and aspects of the present invention are discussed in greater detail below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    A full an enabling disclosure of the present invention, including the best mode thereof to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, which makes reference to the accompanying figures, in which; 
           [0013]      FIG. 1  is a longitudinal view, partly in section, of a chuck in accordance with an embodiment of the present invention; 
           [0014]      FIG. 2  is a longitudinal view, partly in section, of the chuck as in  FIG. 1 ; 
           [0015]      FIG. 3  is a longitudinal view, partly in section, of the chuck as in  FIG. 1 ; 
           [0016]      FIG. 4  is an exploded view of the chuck as in  FIG. 1 ; 
           [0017]      FIG. 5  is a partial exploded view of a chuck in accordance with an embodiment of the present invention; 
           [0018]      FIG. 6A  is a longitudinal view, in cross section, of a chuck in accordance with an embodiment of the present invention; 
           [0019]      FIG. 6B  is a longitudinal view, in cross section, of the chuck as in  FIG. 6A ; 
           [0020]      FIG. 7A  is a longitudinal view, in cross section, of a chuck in accordance with an embodiment of the present invention; 
           [0021]      FIG. 7B  is a longitudinal view, in cross section of the chuck as in  FIG. 7A ; 
           [0022]      FIG. 8A  is a longitudinal view, in cross section, of a chuck in accordance with an embodiment of the present invention; 
           [0023]      FIG. 8B  is a longitudinal view, in cross section, of the chuck as in  FIG. 8A ; and 
           [0024]      FIG. 9  is an exploded view of the chuck as in  FIGS. 6A and 6B . 
       
    
    
       [0025]    Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the invention. 
       DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0026]    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 or 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 appended claims and their equivalents. 
         [0027]    In the embodiments illustrated in the figures, a drill chuck has a body configured for attachment to a drill spindle and having passages in which jaws are held. The jaws reciprocally move (in either an opening or closing direction) by a threadedly engaged nut. In these embodiments, a locking member in the form of a generally cylindrical sleeve is axially moveable to either of two positions. In the first position, the sleeve rotates with respect to the drill housing. In the second position, it is rotationally held to the housing and to the nut. That is, the locking sleeve does not rotate with respect to the housing or to the nut in the embodiment shown in  FIGS. 1-4 , the locking sleeve remains in the second position throughout opening and closing of the chuck once the operator moves the locking sleeve into the appropriate position. In the embodiments shown in  FIGS. 6A-9 , however, the locking sleeve is held to the nut through a clutch mechanism that rotationally locks the sleeve and housing to the nut as long the clutch mechanism or nut does not substantially resist the rotational torque applied by the other component, as is described in more detail below. When the resistance does overcome this torque, the nut teeth and clutch teeth slip over each other, allowing the nut to rotate with the body with respect to the locking sleeve, thereby preventing over tightening. It should be understood, however, that the present invention is not limited to such embodiments. 
         [0028]    Referring to  FIGS. 1-4 , a chuck  10  includes a front sleeve  12 , a body  14 , jaws  16  and a nut  18 . Body  14  is generally cylindrical in shape and comprises a nose or forward section  20  and a tail or rearward section  22 . An axial bore  24  is formed in nose section  20 . Axial bore  24  is dimensioned somewhat larger than the largest tool shank that the chuck is designed to accommodate. A threaded bore  26  is formed in tail section  22  and is of a standard size to mate with a drive shaft  28  of a powered or hand driver indicated in part at  30 . The bores  24  and  26  may communicate at a central region of body  14 . While a threaded bore  26  is illustrated, such bore could be replaced with a tapered bore of a standard size to mate with a tapered drive shaft or with any other suitable connection mechanism. 
         [0029]    Passageways  32  are formed in body  14  to accommodate each jaw  16 . Three jaws  16  are employed, and each jaw is separated from the adjacent jaw by an arc of approximately 120°. The axes of the passageways  32  and the jaws  16  are angled with respect to the chuck axis and intersect the chuck axis at a common point ahead of chuck body  14 . Each jaw  16  has a tool engaging portion  34 , which is generally parallel to the axis of chuck body  14 , and threads  36  on its opposite or outer surface. Threads  36  may be constructed in any suitable type and pitch. 
         [0030]    Body  14  includes a thrust ring member  38  which, in a preferred embodiment, may be integral with the body. In an alternate embodiment, thrust ring  38  may be a separate component from the body member. Thrust ring  38  may also include a ledge portion to receive a bearing assembly  40 . Thrust ring  38  includes a plurality of jaw guideways  42  formed around its circumference to permit retraction of the jaws  16  therethrough. 
         [0031]    Nut  18  is a one piece nut which includes threads  44  for mating with threads  36  on jaws  16 . Nut  18  is positioned about the body in engagement with the jaw threads so that when the nut is rotated with respect to body  14 , the jaws will be advanced or retracted. A nut retainer  46  is pressed to nose section  20  of body  14  and engages nut  18  at a forward ledge  48  thereof. Thus, retainer  46  secures nut  18  in the axial direction with respect to the body. 
         [0032]    Nut  18  also includes a plurality of notches  50  receiving drive dogs  52  of front sleeve  12  by which front sleeve  12  and nut  18  are rotationally held to each other. A nose piece  54  is pressed to forward section  20  of body  14  and retains front sleeve  12  in the axially forward direction by an annular lip  56  of sleeve  12 . 
         [0033]    The outer circumferential surface of sleeve  12  may be knurled or may be provided with longitudinal ribs or any other configuration to enable a user to grip it securely. The sleeve may be fabricated from a structural plastic such as polycarbonate, a filled polypropylene, for example glass filled plypropylene, or a blend of structural plastic materials. Other composite materials such as, for example, graphite filled polymerics may also be suitable in a given environment. In one embodiment, the sleeve is constructed from a 30% glass filled nylon 66 material. As would be appreciated by one skilled in the art, the materials for which the chuck of the present invention is fabricated will depend on the end use of the chuck, and the above are provided by way of example only. 
         [0034]    A pair of rear body flanges  58  and  60  are pressed to rear portion  22  of body  14  at knurled portion  62 . An O-ring  64  sits in an annular shoulder  66  of rear body flange  60  to limit axial movement of a rear sleeve  68  in both the forward and rearward directions as is discussed below. Although rear body flanges  58  and  60  are illustrated in this embodiment as separate members from body  14 , it should be understood that they may be constructed integrally therewith. 
         [0035]    Rear sleeve  68  is axially reciprocal with respect to body  14 . In the position of rear sleeve  68  shown in  FIG. 1 , axially aligned teeth  70  extending radially inward from an inner circumferential surface  72  of rear sleeve  68  engage axially aligned teeth  74  (referring also to  FIG. 4 ) extending radially outward from outer circumferential surface  76  of rear body flange  58 . Thus, rear sleeve  68  is rotationally held to body  14  through rear body flange  58 . O-ring  64  and rear body flange  60  prevent further rearward axial movement of rear sleeve  68 . Using this axial rear sleeve position, an operator may operate chuck  10  as a two-sleeve keyless chuck. By gripping rear sleeve  68  and front sleeve  12 , the operator holds body  14  and nut  18 , respectively. Rotating the sleeves with respect to each other rotates the body and nut with respect to each other, thereby opening or closing the chuck depending upon the direction of relative rotation. 
         [0036]    As shown in  FIG. 2 , however, forward axial movement of rear sleeve  68  disengages teeth  70  from teeth  74 , and teeth  70  move toward axially aligned teeth  78  extending radially outward from an outer S circumferential surface  80  of front sleeve  12 . Teeth  78  are disposed far enough forward of teeth  74  so that teeth  70  clear teeth  74  before engaging teeth  78 . This allows for any slight rotation of sleeve  68  necessary to align teeth  70  with the gaps between teeth  78 . It should be understood, however, that teeth  78  may be disposed more closely to teeth  74  so that teeth  70  engage teeth  78  before entirely disengaging teeth  74 . 
         [0037]    As teeth  70  engage teeth  78 , axially aligned teeth  82 , which extend radially inward from inner circumferential surface  84  of rear sleeve  68 , engage axially aligned teeth  86 , which extend radially outward from an outer circumferential surface  88  of drill housing  90 . Referring to  FIGS. 3 and 4 , in the rear sleeve&#39;s axially forward position, rear sleeve teeth  82  and  70  engage teeth  86  and teeth  78  of drill housing  90  and front sleeve  12 , respectively. Further forward axial movement of rear sleeve  68  is prevented by O-ring  64 , upon which bears shoulder  92  of rear sleeve  68 . In this position, teeth  70  have completely disengaged teeth  74  of rear body flange  58 . 
         [0038]    Accordingly, in the rear sleeve axial position shown in  FIG. 3 , nut  18  is rotationally held to housing  90  by front sleeve  12  and rear sleeve  68 . At the same time, nut  18 , front sleeve  12  and rear sleeve  68  are rotatable with respect to body  14 , which rotates with spindle  28 . Accordingly, activation of drill  30  to rotate spindle  28  rotates body  14  with respect to nut  18 , thereby opening or closing chuck  10  depending upon the spindle&#39;s rotational direction. Because opening and closing of the chuck with sleeve  68  in this position requires only one of the operator&#39;s hands (to operate the drill), the operator may use his other hand to hold a drill bit or other tool being locked into or released from the chuck. 
         [0039]    Rear sleeve  68  may have the same or similar construction as front sleeve  12 . 
         [0040]    It should be understood that various suitable locking mechanisms may be used to rotationally hold the rear sleeve to the body, the front sleeve, the housing and/or any other chuck component as appropriate in a given embodiment of the present invention. For example, the teeth  86  as illustrated in  FIG. 5  are wider and more spaced apart than the teeth  86  illustrated in  FIG. 4 . Correspondingly, teeth  82  at the rear of rear sleeve  68  are wider to fill the gaps between teeth  86 . In further embodiments, discussed in more detail below, radially extending teeth may be replaced by axially extending teeth. Moreover, it should be understood that any suitable locking mechanism construction and configuration is within the scope and spirit of the present invention. 
         [0041]    In the embodiment illustrated in  FIGS. 6A ,  6 B and  9 , front sleeve  12  is pressed onto a nose piece  100  at  102 . Nose piece  100  is, in turn, pressed onto forward section  20  of body  14 . Accordingly, unlike the embodiment illustrated in  FIGS. 1-4 , front sleeve  12  is rotationally held to body  14  rather than nut  18 . 
         [0042]    Rear sleeve  68  is rotationally held to nut  18  during normal operation through a clutch mechanism including an annular clutch plate  104 . Axially aligned teeth  106  extend radially outward from an outer circumferential surface  108  of clutch plate  104  and are received by grooves  110  between axially aligned teeth  112  extending radially inward from an inner circumferential surface of a forward section  114  of rear sleeve  68 . Rear sleeve  68  is axially reciprocal with respect to clutch plate  104  by the interaction between teeth  106  and grooves  110 . 
         [0043]    Clutch plate  104  is held in position between body  14  and nut  18  by a wave spring  116 . Wave spring  116  bears on one side on body  14  through nose piece  100  and on the other side directly on clutch plate  104 . Wave spring  116 , which may include one or more individual springs, biases clutch plate  104  axially toward nut  18 . A lubricant may be provided on one or both sides of wave spring  116  and/or one or both surfaces of clutch ring  104  and nose piece  100  to facilitate relative rotation between the clutch plate and the nose piece. 
         [0044]    An engaging surface of clutch plate  104  includes a pair of lugs  117  extending axially forward from annular surface  118  of the engaging surface. Sides  120  of each lug  117  are disposed at an oblique angle with respect to a plane  122  including the chuck axis  124 . 
         [0045]    One side  120  of each lug  117  abuts an opposing side  126  of a lug  128  extending axially from an annular surface  130  of an engaging surface of nut  18  as nut  18  is rotated with respect to body  14 . As with sides  120 , sides  126  are disposed at an oblique angle with respect to plane  122 . 
         [0046]    Rear sleeve  68  is biased forwardly by a wave spring  132 , here formed by a plurality of wave springs, bearing on one side on body  14  through a rear body plate  134  pressed onto body  14  at  136  and on the other side on rear sleeve  68  through a rear sleeve flange  138 . Although not illustrated in  FIG. 9 , it should be understood that surface  136  may be knurled to facilitate the press fit between it and rear body plate  134 . Furthermore, while rear sleeve flange  138  is illustrated as being attached to rear sleeve  68  by dowels  140 , it should be understood that any suitable attachment mechanism may be employed. For example, the rear sleeve flange may be integral with the rear sleeve or may be a separate piece integrally molded with the rear sleeve. One or both sides of spring  132  and/or one or both of the sides of rear body plate  134  and rear sleeve flange  138  on which it directly bears may include a suitable lubricant to facilitate relative rotation between sleeve  68  and body  14 . 
         [0047]    In its axial position illustrated in  FIG. 6A , rear sleeve  68  is rotatable with respect to body  14  and chuck  10  may be operated as a two-sleeve keyless chuck. For example, an operator may grip front sleeve  12  to rotationally secure body  14  and may grip rear sleeve  68  to rotationally secure nut  18 , which is rotationally held to sleeve  68  through clutch ring  104  and the interface between lugs  117  and  128 . Thus, relative rotation between front sleeve  12  and rear sleeve  68  opens or closes chuck  10  depending upon the direction of relative rotation. 
         [0048]    When chuck  10  reaches a fully opened or a fully closed position, further movement of jaws  16  is prevented by the abutment of face  142  of jaws  16  against nut  18  or by the abutment of jaw faces  34  against each other or a tool. Nut  18  then tightens onto threads  36  of jaws  16  and resists further rotation. 
         [0049]    Because of the angled interface between sides  126  and  120  of lugs  128  and  117 , respectively, part of the rotational force applied by sleeve  68  to nut  18  through clutch ring  104  is translated to an axial force tending to separate the clutch ring and the nut. During normal operation, this force is resisted by the bias of spring  116 . Because nut  18  is tightened onto the jaw threads as chuck  10  reaches a fully opened or closed position, however, nut  18  resists the rotational force applied by the clutch plate, and additional rotational force is required to further rotate the nut. When the force applied between sides  126  and  120  creates a separation force exceeding the counter force provided by biasing spring  116 , clutch plate  104  is moved axially forward, compressing spring  116 . Lugs  117  and  128  thus ride over one another, thereby allowing sleeve  68  to rotate with respect to nut  18  and preventing over tightening of the nut. 
         [0050]    The force necessary to cause clutch plate  104  to ride over nut  18  is primarily determined by the strength of spring  116  and the angle of the sides  126  and  120 . In one preferred embodiment, spring  116  includes two 22 lb. wave springs, and sides  120  and  126  are disposed at an angle of approximately 60° from surfaces  118  and  130 , respectively. It should be understood, however, that the construction and dimensions of these components may be varied as suitable for a given chuck construction. 
         [0051]    The chuck illustrated in  FIGS. 6A ,  6 B and  9  may also be opened and closed through operation of the drill spindle. Accordingly, referring to  FIGS. 6B and 9 , rear sleeve  68  may be pushed axially rearward against the bias of spring  132  so that axially aligned teeth  144  extending radially inward from inner circumferential surface  146  of rear sleeve  68  engage Axially aligned teeth  148  extending radially outward from an outer circumferential surface of drill housing  90 . Rear sleeve  68  slides axially rearward with respect to clutch plate  104  but remains rotationally held thereto through the cooperation of grooves  110  and teeth  106 . Thus, nut  18  is rotationally held to housing  90  through clutch plate  104  and rear sleeve  68 . While holding sleeve  68  in the axially rearward position illustrated in  FIG. 6B , an operator may activate the drill to rotate spindle  28 , thereby rotating body  14  with respect to nut  18  to open or close chuck  10  depending on the spindle&#39;s rotational direction. The clutch mechanism operates as discussed above with respect to  FIG. 6A  to prevent over tightening, except that rotational force is applied through nut  18  rather than through clutch plate  104 . 
         [0052]    The embodiment illustrated in  FIGS. 7A and 7B  operate similarly to the embodiment illustrated in  FIG. 6A  and  FIG. 6B , primarily except for the rotational engagement between rear sleeve  68  and housing  90 . For purposes of clarity, wave spring  132  ( FIGS. 6A and 6B ) is not illustrated in  FIGS. 7A and 7B . It should be understood, however, that this spring is present in the embodiment illustrated in  FIGS. 7A and 7B  to perform a function similar to that discussed above. For example, the spring biases rear sleeve  68  forward to the axial position shown in  FIG. 7A . 
         [0053]    Rather than employing radially extending teeth, rear sleeve flange  138  includes radially aligned teeth  150  extending axially rearward from rear sleeve flange  138 . A housing plate  152  includes radially aligned teeth  154  extending axially forward therefrom and opposing teeth  150 . In the axial position illustrated in  FIG. 7A , rear sleeve  68  is rotatable with respect to body  14  and housing  90 , and chuck  10  may be operated as a two-sleeve keyless chuck as described above with respect to  FIG. 6A . 
         [0054]    As shown in  FIG. 7B , rear sleeve  68  may be pulled rearwardly against the biasing spring to engage teeth  150  and  154 , thereby rotationally holding sleeve  68  to housing  90 . Sleeve  68  slides rearwardly with respect to, but remains rationally held to, clutch plate  104 . Thus, nut  18  is rotationally held to housing  90  through clutch plate  104  and rear sleeve  68 . Activation of the drill to rotate spindle  28  thus rotates body  14  with respect to nut  18 , thereby opening or closing chuck  10  depending upon the spindle&#39;s rotational direction. 
         [0055]    The embodiment of chuck  10  illustrated in  FIGS. 8A and 8B  is constructed and operates similarly to the embodiment illustrated in  FIGS. 7A and 7B , primarily except that the rear biasing spring  132  ( FIGS. 6A and 6B ) and rear body plate are replaced by a detent mechanism including a coil spring  156  and a ball  158 . In one preferred embodiment, the detent mechanism is a self-contained mechanism that threads into body  14 . A collar or other suitable stop is provided to prevent ball  158  from being pushed entirely out of the mechanism by spring  156 . 
         [0056]    Referring to  FIG. 8A , rear sleeve  68  is held in the forward axial position by ball  158  bearing against rear sleeve flange  138 . With rear sleeve  68  in this position, chuck  10  may be operated as a two-sleeve keyless chuck as described above with respect to  FIGS. 6A and 7A . 
         [0057]    When rear sleeve  68  is pulled rearwardly, rear sleeve flange  138  presses ball  158  downward, compressing spring  156 . If sufficient rearward axial force is applied, rear sleeve  68  passes over ball  158  so that teeth  154  engage teeth  150  to rotationally hold rear sleeve  68  to housing  90 , thereby rotationally holding nut  18  to housing  90  through clutch plate  104  and rear sleeve  68 . Chuck  10  may then be opened or closed through activation of the drill as discussed above with respect to  FIGS. 6B and 7B , except that it is not necessary for the operator to grip rear sleeve  68  during this operation. The rear sleeve is retained in the rearward axial position as shown in  FIG. 8B  by ball  158  bearing upon rear sleeve flange  138 . Spring  156  is strong enough to hold rear sleeve  68  in the rearward axial position as shown in  FIG. 8B  during opening and closing of chuck  10  but yet compressible enough so that an operator may move rear sleeve  68  between the forward and rearward axial positions. 
         [0058]    While one or more preferred embodiments of the present invention are described above, it should be appreciated that various suitable embodiments are encompassed by the present invention. For instance, in another preferred embodiment, the reciprocal locking sleeve is mounted about the chuck body and is axially movable to either of two operative positions. In the first, the locking sleeve is rotationally held to the body by opposing teeth on the sleeve and the body as at  70  and  74  in  FIGS. 1 and 4  above. With the locking sleeve in this axial position, the chuck may be operated as a two-sleeve keyless chuck by relative rotation between the locking sleeve and a second sleeve rotationally held to the nut. The second sleeve may be forward of the locking sleeve. A suitable biasing mechanism may be provided to bias the locking sleeve to the first axial position. 
         [0059]    In this axial position, the locking sleeve does not rotatably engage the nut and is therefore rotatable with respect to the nut. Opposing lugs, such as lugs  117  and  128  on clutch plate  104  and nut  18  in  FIG. 9 , are provided on the nut and the locking sleeve so that when the locking sleeve is moved axially into engagement with the nut, the locking sleeve is rotationally held to the nut. While an operator grips the locking sleeve, activation of the drill to rotate the drill spindle opens or closes the chuck depending upon the rotational direction of the spindle. The lugs on the locking sleeve and nut have angled sides as described above with respect to the lugs on the clutch plate and nut in  FIGS. 6A and 6B , creating a clutch to prevent over tightening of the nut. 
         [0060]    The clutching action causes the locking sleeve to move axially away from the nut. Thus, enough space is provided so that the locking mechanism between the locking sleeve and the body in the first axial position does not reengage during the clutching action. A clutch spring may be provided between the nut and the body so that the nut moves away from the locking sleeve, with respect to the body, when the nut and locking sleeve are pushed apart. 
         [0061]    In a still further embodiment, the locking sleeve as described with respect to the previous embodiment is always rotationally held to the drill housing during the chuck&#39;s operation. The sleeve may be held in any suitable manner, for example by an axially toothed interface, so that the locking sleeve may move axially, but not rotationally, with respect to the drill housing. A spring bears on one end on the chuck body and on its other end against the locking sleeve to bias the locking sleeve away from the nut. Thus, during normal operation, the locking sleeve does not engage the nut. To open or close the chuck, an operator axially moves the locking sleeve against the spring bias to engage the nut. As above, opposing angled teeth are provided on the nut and the locking sleeve to rotationally hold them to each other. When the drill is thereafter activated to rotate the spindle, the body rotates with respect to the nut, thereby opening or closing the chuck depending on the spindle&#39;s rotational direction. When the chuck is fully opened or closed, the nut and locking sleeve are pushed apart with respect to each other, allowing the nut to again rotate with the body and thereby preventing over tightening. A clutch spring is provided between the nut and the body so that the nut moves away from the locking sleeve, with respect to the chuck body, when the nut and locking sleeve are pushed apart, thereby reducing the axial force applied to the locking sleeve opposing the operator&#39;s grip. 
         [0062]    Furthermore, it should be understood that the identification of a “rear” sleeve in the embodiments in the figures is for illustrative purposes only. Moreover, it should be understood by those skilled in this art that the chuck components described above Ray be arranged and configured in various suitable manners within the present invention. For example, the locking and biasing mechanisms may be arranged so that the locking sleeve is pushed forward, rather than rearward to hold the nut to the drill housing. Thus, various modifications and variations to the present invention may be practiced by those of ordinary skill in the art without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is provided by way of example only, and is not intended to be limitative of the invention so further described in such appended claims.