Abstract:
A chuck that can be operated with or without a key, depending upon the amount of torque desired. The jaws are controlled by rotation of a screw ring about the axis of the chuck body that slides the jaws along jaw passages by engagement with teeth on the jaw surfaces. The screw ring is housed in a tightening knob that has a planar ring gear perpendicular to the chuck body axis. A tail section is rigidly attached to the chuck body below the tightening knob and houses a pinion gear that matingly engages the planar ring gear and rotates in concert with the tightening knob. Insertion of a hex key into a recess in the pinion gear allows the application of additional torque. Alternate embodiments incorporate a idler gear to reverse pinion gear rotation; locate the pinion gear in the tightening knob with the planar ring gear in the tail section; and utilize a planar ring gear on both the tail section and the tightening knob with a floating ring to house the pinion gear between the planar ring gears.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a keyless tool chuck, and more particularly relates to an improvement in construction of a chuck for firmly holding a tool such as a drill bit or a driver bit of electric work devices without assistance by a chuck key. This invention relates to a chuck for use with rotating equipment such as drills. Such rotating equipment is commonly driven manually or in the case of power drivers, electrically, hydraulicly or pneumatically. More particularly, the present invention relates to a keyless style of chuck which may be tightened or loosened by hand and can alternatively be tightened or loosened by rotation of a key after insertion into a recess formed in the chuck body.  
           [0002]    Both hand and powered tool drivers are well known. The general configuration is a rear rotational driver, mechanically coupled to a chuck by threaded engagement or via a tapered sleeve that mates into a corresponding recess in the chuck body. The chuck has any number of circumferentially equally spaced jaws that are advanced concurrently both axially outward and radially inward from a front orifice. It is the advancement of these jaws that grip a tool or bit. The chuck may be used to hold any one of a multitude of tools such as screw or nut drivers and cutting, shaping or grinding bits, although the most common is a twist drill. With such a diverse selection of tool bits, the diameters and configurations of the shanks vary considerably from circular to polygonal in cross section. For this reason the chuck is adjustable over a relatively wide range.  
           [0003]    Numerous chucks have been developed and are well known in the art. The most common type is found on the household hand drill. This is perhaps the most simple configuration with three jaws approximately spaced circumferentially 120 degrees apart from each other. Each jaw is housed in an angularly disposed passageway in the chuck body configured so that rotation of the chuck body in one direction with respect to a constrained nut engaging the jaws forces the jaws into gripping relationship with the tool bit. Counter rotation acts to release the gripping relationship. The rotation is commonly accomplished through the use of a key. If sufficient torque can be developed by hand rotation of the chuck, a key is not necessary. This is a desirable configuration in that bits can be quickly removed or inserted and lost or damaged keys do not hinder the process.  
           [0004]    In the current state of the art, key and keyless chucks both have several disadvantages. First if they require a key, it is made of a specific size as all keys are not interchangeable. Keys are easily lost and the engagement teeth can become stripped. Replacement keys can often be hard to find. Second, this type of tightening is slow as it requires insertion and separate tightening at different axial positions around the chuck. If it is a hand tightening chuck it often does not hold the tool bit secure enough for arduous operations, or conversely it holds the tool bit too firm such that hand release of the bit is extremely difficult. The disadvantages of the keyed and keyless chucks are in direct opposition to their respective advantages. It would be desirable to have a hybrid style of chuck that is keyless with a backup keyed operation to remedy all of these drawbacks in the existing chucks. It would be desirable if the keyed operation was accomplished by a standard and commonly available key. Elimination of the multiple keying operations would serve to maintain the ease and speed of tightening the tool bits in the keyed fashion as would less turns of the key to advance and tighten the jaws. It would also be desirable to have a keyless chuck that requires fewer components or has a lower manufacturing cost.  
         SUMMARY OF THE INVENTION  
         [0005]    In accordance with the invention, a keyless chuck includes a rotatable hand tightening knob with a planar ring gear on the back surface lying perpendicular to the axis of rotation. A pinion gear is housed in an internal cavity between the chuck body and a tail piece and is in mating engagement with the ring gear such that the pinion gear rotates as the tightening knob is rotated when advancing and closing the jaws. The pinion gear has a recess which is accessible through an orifice in the tail piece and is adapted accept a key device such as an hex key, or a screwdriver that when inserted and rotated, can provide additional torque to open or close the jaws. A second embodiment utilizes a substantially similar configuration but incorporates an idler gear to reverse rotation between the pinion gear and the tightening knob.  
           [0006]    In a third embodiment of the keyless chuck, a keyless chuck includes a rotatable hand tightening knob with a pinion gear housed in a void formed in the tightening knob. The tail piece of the chuck has an planar ring gear on the front surface that lies perpendicular to the axis of rotation where the ring gear is in mating engagement with the pinion gear such that the pinion gear rotates as the knob is rotated to advance and close the jaws. The pinion gear has a recess that is accessible through an orifice in the tightening knob and corresponds to a key device such as an hex key, that when inserted and rotated, can provide additional torque to open or close the jaws.  
           [0007]    In a fourth embodiment a keyless chuck includes a rotatable hand tightening knob with an planar ring gear formed on its back surface lying perpendicular to the axis of rotation. A tail piece has a planar ring gear on a front surface lying perpendicular to the axis of rotation and positioned such that its teeth oppose the teeth of the planar ring gear of the tightening knob. A pinion gear is housed in an internal cavity of a floating ring that fits between the knob and tail piece such that the pinion gear is matingly engaged with both the tail piece ring gear and the knob ring gear. The floating ring and pinion gear have corresponding recesses to accept a keyed device such as a hex key, that when inserted and rotated, will rotate the knob and tail piece in opposite directions thereby providing additional torque to open or close the jaws and closing the jaws in less turns as in the first and second embodiments.  
           [0008]    In the final embodiment a keyless chuck includes a rotatable hand tightening knob with a planar ring gear formed on the back surface lying perpendicular to the axis of rotation. A set of two gears, a first pinion gear and a second idler gear are housed in an internal cavity of the tail piece such that the idler gear is in mating engagement with the ring gear. The idler gear rotates as the knob is rotated to advance and close the jaws. This causes the pinion gear to rotate in the opposite direction of the idler gear. The tail piece and pinion gear have corresponding recesses to accept a keyed device such as an hex key, that when inserted and rotated, can provide additional torque to open or close the jaws. This embodiment changes the direction that the pinion gear is rotated in the preferred embodiment to accomplish the same effect.  
           [0009]    Accordingly, it is an object of the present invention to provide an improved keyless chuck with the ability to use a key to gain additional mechanical advantage to tighten or loosen the jaws.  
           [0010]    It is a further object of the present invention to provide an improved chuck that uses a standard fastener tool to tighten or loosen the jaws.  
           [0011]    It is yet another object of the present invention to provide an improved keyless chuck that eliminates the multiple keying operations common to the chuck industry.  
           [0012]    It is still a further object of the present invention to provide an improved keyless chuck capable of an increased tightening torque over conventional chucks.  
           [0013]    It is a final object of the present invention to provide an improved chuck that would require a minimum number of key turns to advance and tighten the jaws thus serving to increase the ease and speed of tightening the tool bits in the keyed fashion.  
           [0014]    The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, both the organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with accompanying drawings wherein like reference characters refer to like elements. Other objects, features and aspects of the present invention are discussed in greater detail below. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 is a perspective view of the keyless chuck with the jaws fully advanced;  
         [0016]    [0016]FIG. 2 is an exploded view of the keyless chuck showing the interconnection between the pinion gear and the tightening knob&#39;s ring gear;  
         [0017]    [0017]FIG. 3 is a cross sectional view of the chuck showing the chuck body, tail piece and tightening knob;  
         [0018]    [0018]FIG. 4 is a cross sectional view of a second embodiment chuck showing the chuck body, a modified tail piece, tightening knob and idler gear;  
         [0019]    [0019]FIG. 5 is a cross sectional view of a third embodiment chuck with a showing the chuck body, tail piece and modified tightening knob;  
         [0020]    [0020]FIG. 6 is a cross sectional view of a fourth embodiment chuck showing the chuck body, tail piece, tightening knob and floating ring; and  
         [0021]    [0021]FIG. 7 is a cross sectional view of the fourth embodiment chuck showing the chuck body, tail piece, tightening knob and an internally housed floating ring. 
     
    
     DETAILED DESCRIPTION  
       [0022]    The chuck apparatus according to a preferred embodiment of the present invention comprises a chuck body, a tightening knob, and a tail piece. Referring to FIG. 1, a perspective view of the keyless chuck with the jaws fully advanced, keyless chuck  2  is comprised of cylindrical chuck body  4  which is housed inside tail piece  6  and tightening knob  8 . Tightening knob  8  and tail piece  6  are arranged in a stacked configuration. Jaws  10  extend axially from chuck body  4 . Dust ring  12  (only illustrated in FIG. 1) is attached to tightening knob  8  and spans across clearance gap  56  (see FIG. 3) onto chuck body  4  so as to prevent debris from fouling the operation of chuck  2 . Tightening knob  8  has a cylindrical configuration terminating in a radiused frusticonical face  16 . Grooves  14  are formed in cylindrical face  18  and extend partially along its longitudinal axis. Pinion gear  20  and key recess  22  can be seen protruding through tail piece bore  24  in tail piece  6 .  
         [0023]    Looking at FIG. 2, an exploded view of the keyless chuck, it can be seen that pinion gear  20  with pinion gear teeth  27 , has shoulder  30  extending perpendicularly from gear face  32 . Shoulder  30  has key recess  22  formed therein that matingly engages with hex key  34 . Tightening knob  8  has rear face  36  with planar ring gear  28  and teeth  38  formed thereon. The interconnective alignment of pinion gear  20  with ring gear  28  and tail piece recess  24  is illustrated.  
         [0024]    [0024]FIG. 3, a cross sectional view of the chuck, illustrates the physical orientation of the internal components of chuck  2 . Tail piece  6  is fixedly attached to chuck body  4 . Shoulder  30  acts as a plain bearing for pinion gear  20  to rotate on within tail piece bore  24  and also acts to retain pinion gear  20  within bore  24 . Pinion gear teeth  27  matingly engage planar ring gear teeth  38 . Recess  40  is bored longitudinally through chuck body  4 . Three jaw passages  42  are bored inclinedly through chuck body  4  and are in communication with recess  40 . Jaw passages  42  are oriented so as to be converging passages and are spaced approximately angularly equidistant about the longitudinal axis of chuck body  4 . Jaws  10  are of a generally cylindrical configuration with rack teeth  52  and tapered faces  58  located on the exterior longitudinal surface of jaw  10  approximately 180 degrees apart. Jaws  10  reside in jaw passage  42  oriented such that rack teeth  52  face into annular groove  50  of chuck body  4  at an acute angle with respect to the longitudinal axis of chuck body  4 . Threaded ring  48  frictionally fits into annular recess  46  in tightening knob  8  such that threads  54  extend into annular groove  50  in chuck body  4  and engage with rack teeth  52  of jaws  10 . There is a clearance gap  56  between chuck body  4  and tightening knob  8 .  
         [0025]    [0025]FIG. 4, a cross sectional view of a second embodiment chuck with a modified tail piece, illustrates first modified tail piece  60  with tail piece idler gear bore  62  and tail piece pinion gear bore  64 . Pinion gear  20  is secured into pinion gear bore  64  by pinion gear shoulder  30 . Tail piece idler gear  66  is secured into tail piece idler gear bore  62  by idler gear shoulder  70 . Idler gear  66  engages planar ring gear  38  and pinion gear  20 .  
         [0026]    [0026]FIG. 5, a cross sectional view of a third embodiment chuck, shows pinion gear  20  housed by shoulder  30  in orifice  82  of first modified tightening knob  80 . Pinion gear  20  resides in void  84 . Recess  40  is bored longitudinally through chuck body  4 . Three jaw passages  42  are bored inclinedly through chuck body  4  and are in communication with recess  40 . Jaw passages  42  are orientated so as to be converging passages and are spaced approximately equidistant about the longitudinal axis of chuck body  4 . Jaw  10  is of a generally cylindrical configuration with rack teeth  52  and tapered face  58  located on the exterior longitudinal surface of jaw  10  180 degrees apart. Jaw  10  resides in jaw passage  42  oriented such that rack teeth  52  face into annular groove  50  at an acute angle with respect to the longitudinal axis of chuck body  4 . Threaded ring  48  frictionally fits into annular recess  92  in first modified tightening knob  80  such that threads  54  extend into annular groove  50  in chuck body  4  and engage with rack teeth  52  of jaw  10 . There is a clearance gap  56  between chuck body  4  and first modified tightening knob  80 . Second modified tail piece  86  has a hollow cylindrical shape with upper flange  88  and lower flange  90 . Upper flange  88  forms planar ring gear  92  having teeth  96  which engages teeth  27  of pinion gear  20 . Lower flange  90  is fixedly attached to chuck body  4 .  
         [0027]    [0027]FIG. 6, a cross sectional view of a fourth embodiment chuck, shows external floating ring  100  housed in a stacked arrangement between third modified tail piece  102  and second modified tightening knob  104 . Second modified tightening knob  104  has planar ring  106  with teeth  108  formed on a surface thereof that is perpendicular to the longitudinal axis of chuck body  4 . Third modified tail piece  102  has planar ring gear  110  with teeth  112  formed on a surface thereof that is perpendicular to the longitudinal axis of chuck body  4  and parallel planar ring gear  106 . Floating ring  100  is of a generally hollow cylindrical shape with recess  118 . Floating ring  100  fits into the space defined by tail piece groove  114  and tightening knob groove  116 . Shoulder  30  on pinion gear  20  resides in floating ring recess  118  and teeth  30  of pinion gear  20  matingly engage teeth  108  and  112  simultaneously. FIG. 7, a cross sectional view of the fifth embodiment chuck, shows internal floating ring  120  housed in a stacked arrangement between fourth modified tail piece  122  and third modified tightening knob  124 . Third modified tightening knob  124  has planar ring  126  with teeth  128  formed on a surface thereof that is perpendicular to the longitudinal axis of chuck body  4 . Fourth modified tail piece  122  has planar ring gear  130  with teeth  132  formed on a surface thereof that is perpendicular to the longitudinal axis of chuck body  4  and parallel planar ring gear  126 . Floating ring  120  is of a generally hollow cylindrical shape with recess  136 . Floating ring  120  resides in groove  134  cut in third modified tightening knob  124 . Chuck key  138  has shoulder  140  and teeth  142  formed thereon. Shoulder  140  can be fit into recess  136  such that chuck key teeth  142  will matingly engage tightening knob planar ring gear teeth  128  and tail piece planar ring gear teeth  132  simultaneously.  
         [0028]    Now referring to FIGS.  1 - 3  it can be seen that in operation, rotating tightening knob  8  with respect to tail piece  6  causes threads  54  of threaded ring  48  to engage rack teeth  52  so as to slidingly advance or retract jaws  10  in jaw passages  42  until tapered faces  58  of jaws  10  contact each other or until bottom face  90  contacts abutment  92  of chuck body  4 . Rotating tightening knob  8  with respect to tail piece  6  also causes pinion gear  20  to rotate on shoulder  30  in tail piece bore  24  by virtue of its engagement with teeth  38  of ring gear  36 . This mating engagement between pinion gear  20  and ring gear  36  can also allow additional torque to be exerted on tightening knob  8  to slidingly advance or retract jaws  10  in jaw passages  42  when hex key  34  is inserted into key recess  22  and rotated. Although jaws  10  can be tightened or loosened by hand manipulation of tightening knob  8  with respect to tail piece  6 , jaws  10  may also be tightened or loosened with additional mechanical advantage provided by a rotating hex key  34 . Although the mechanical advantage is provided through six sided hex key  34 , any key style tool configuration, as commonly known in the industry, would function equally as well provided that key recess  22  was configured to match.  
         [0029]    [0029]FIG. 4 is a second embodiment wherein first modified tail piece  60  houses idler gear  66  in mated engagement with pinion gear  20 . Idler gear  66  is in mated engagement with ring gear  38 . This configuration accomplishes a substantially similar jaw tightening and loosening function as described in the preferred embodiment with a reverse rotation of pinion gear  20 .  
         [0030]    [0030]FIG. 5 is a third embodiment wherein pinion gear  20  is housed in first modified tightening knob  80  and ring gear  92  is located on upper flange  88  of second modified tail piece  86 . Manual operation of this embodiment in the keyless mode is the same as that of the preferred embodiment to the user, however internally, as first modified tightening knob  80  is rotated with respect to second modified tail piece  86 , pinion gear  20  is rotated by mating engagement with tail piece ring gear  92 . When hex key  34  is inserted into pinion gear recess  22  and rotated, teeth  27  will rotate second modified tail piece  86  and chuck body  4  thereby revolving jaws  10  around the longitudinal axis of chuck body  4  such that rack teeth  52 , which are engaged with stationary threads  54  of threaded ring  48 , advance or retract jaws  10  slidingly along jaw passages  42 . In this manner additional torque and mechanical advantage can be added to tighten or loosen the jaws.  
         [0031]    Referring to the fourth embodiment of FIG. 6 the advancement of jaws  10  is still accomplished by rotation of jaw teeth  52  with respect to threads  54  of threaded ring  48  as in all of the embodiments. This alternate embodiment incorporates planar ring gears on both second modified tightening knob  104  and third modified tail piece  102 . With pinion gear  20  engaged with tightening knob planar ring gear  106  and tail piece planar ring gear  110 , both second modified tightening knob  104  and third modified tail piece  102  are rotated simultaneously when hex key  34  is inserted into key recess  22  and rotated for keyed operation. This reduces the number of rotations of key  34  that are required to fully open or close jaws  10  as compared to chuck embodiments incorporating only one planar ring gear, but requires more torque to accomplish each rotation. The floating ring  100  houses pinion gear  20  in a stationary position about the axis of chuck body  4  while second modified tightening knob  104  and third modified tail piece  102  revolve about this axis.  
         [0032]    The fifth embodiment in FIG. 7 functions similarly to the fourth alternate embodiment since both embodiments utilize two planar ring gears for keyed operation, except there is no pinion gear  20  rotated by hex key  34 . Instead shoulder  140  of a conventional chuck key  138 , standardized in the industry, is inserted into recess  136  of internal floating ring  120  such that teeth  142  matingly engage teeth  128  of tightening knob planar ring gear  126  and teeth  132  of tail piece planar ring gear  130 . Floating ring  120  maintains key  138  in a stationary position about the axis of chuck body  4  while third modified tightening knob  124  and fourth modified tail piece  122  revolve about this axis.  
         [0033]    This additional mechanical advantage in the “key mode” allows the jaws in all embodiments to be tightened beyond what could be accomplished by hand manipulation in the “keyless chuck” mode. This is useful in situations where the tool to be gripped is not of uniform diameter or when working on particularly hard surfaces. This additional mechanical advantage also allows for the jaws to be loosened when the tool has stopped rotating in the work material and the driver has input additional torque to tighten the jaws on the tool beyond what could be accomplished by hand manipulation.  
         [0034]    The coupling of the driver mechanism (not part of this invention) to chuck body  4  is accomplished in several ways as is well known in the industry. Commonly, tapered or threaded shafts or sleeves are fixedly engaged in the longitudinal bore  40  of chuck body  4 . Although chuck body  4  is illustrated with a smooth bore  40  this bore can also be threaded or otherwise adapted to receive the driver mechanism&#39;s drive shaft.  
         [0035]    The amount of mechanical advantage or torque available to tighten or loosen the jaws of the various chuck embodiments is determined through the gearing ratios, configurations and designs of the pinion gear, idler gear, planar ring gears and check key as is well known in the industry.  
         [0036]    While a preferred embodiment of the present invention and four alternate embodiments have been shown and described, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from the invention in its broader aspects. The appended claims are therefore intended to cover all such changes and modifications as fall within the true spirit and scope of the invention.