Patent Publication Number: US-2009224491-A1

Title: Chuck wrench for a drill

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 61/034,806, titled “CHUCK WRENCH FOR A DRILL,” and filed Mar. 7, 2008 by Steven. F. Thiel, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND 
     The present invention relates to a chuck wrench for applying a clamp force to a chuck of a drill. 
     Rotary power tools, such as drills, typically include chucks for receiving and clamping an accessory (e.g., a drill bit, an adapter, a pin, etc.). Such chucks are usually rotated by hand to tighten around the accessory. However, some users may not have enough hand strength to rotate the chucks and apply a sufficient clamping force to the accessory. In addition, a user&#39;s hand may become scraped or raw when the user tries to tightly grip and rotate a chuck. 
     SUMMARY 
     In one embodiment, the invention provides a chuck wrench for use with a drill. The drill includes a keyless chuck defining a rotational axis. The chuck wrench includes a body having an interior surface defining an opening. The opening is configured to receive a portion of the keyless chuck such that the body substantially surrounds the keyless chuck. The interior surface includes a projection configured to mate with an exterior surface of the keyless chuck. The chuck wrench also includes a lever coupled to and extending from the body. The lever is operable to rotate the body about the rotational axis such that the projection engages the exterior surface of the keyless chuck to apply a clamp force to the keyless chuck. 
     In another embodiment, the invention provides a power tool assembly including a power tool having a chuck defining a rotational axis. The chuck includes a first projection. The power tool assembly also includes a chuck wrench. The chuck wrench includes a body having an interior surface defining an opening. The opening receives a portion of the chuck such that the body substantially surrounds the chuck. The interior surface has a second projection that mates with the first projection of the chuck. The chuck wrench also includes a lever coupled to and extending from the body. The lever is operable to rotate the body about the rotational axis such that the second projection engages the first projection to apply a clamp force to the chuck. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a chuck wrench according to an embodiment of the invention and a chuck of an exemplary drill. 
         FIG. 2  is an enlarged perspective view of the chuck wrench and the chuck of the drill shown in  FIG. 1 . 
         FIG. 3  is another perspective view of the chuck wrench shown in  FIG. 1 . 
     
    
    
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. 
     DETAILED DESCRIPTION 
       FIG. 1  illustrates an exemplary drill  10 . The drill  10  is a hand-held drill that includes a keyless chuck  14  for clamping a drill accessory  18  (e.g., a drill bit, an adapter, a pin, etc.) to the drill  10 . Referring to  FIG. 2 , the chuck  14  includes a generally cylindrical exterior, or outer, surface  22  and ribs  26  that extend radially from the exterior surface  22 . The ribs  26  are spaced apart from one another about a rotational axis  30  of the chuck  14  and define recesses  32  between adjacent ribs  26 . In other embodiments, the chuck  14  may include splines, keyways, or other types and shapes of projections extending from the exterior surface  22 . In still other embodiments, the drill  10  may include a keyed chuck. 
       FIGS. 1-3  illustrate a chuck wrench  34  according to one embodiment of the invention. The chuck wrench  34  includes a wrench body  38  and a wrench lever  42 , or handle, coupled to the wrench body  38 . The wrench body  38  is generally cylindrically-shaped and defines an opening  46  ( FIG. 3 ) that is generally circular-shaped. As shown in  FIG. 3 , the opening  46  is defined by an interior, or inner, surface  50  of the wrench body  38 . Ribs  54  project radially inward from the interior surface  50  of the wrench body  38  toward a central axis  58  of the wrench body  38 . Similar to the ribs  26  of the chuck  14 , the ribs  54  of the wrench body  38  are spaced apart from one another about the central axis  58  of the wrench body  38  and define recesses  60  between adjacent ribs  54 . In other embodiments, the wrench body  38  may include splines, keyways, or other types and shapes of projections extending from the interior surface  50 . 
     As shown in  FIG. 2 , the shape and features (e.g., ribs  54 ) of the interior surface  50  of the wrench body  38  generally complement the shape and features (e.g., ribs  26 ) of the exterior surface  22  of the chuck  14 . In particular, the ribs  54  of the chuck wrench  34  fit within the recesses  32  in the chuck  14  and the ribs  26  of the chuck  14  fit within the recesses  60  in the chuck wrench  34  such that the interior surface  50  of the chuck wrench  34  mates with the exterior surface  22  of the chuck  14 . In other embodiments, the interior surface  50  of the wrench body  38  may include different patterns or designs of projections to complement and mate with the exterior surface  22  of the chuck  14 . The mating of the chuck wrench  34  to the exterior surface  22  of the chuck  14  allows the chuck wrench  34  to tighten or loosen the chuck  14 , and thereby clamp or release the drill accessory  18 . 
     The wrench lever  42  of the chuck wrench  34  is a bar-like structure that is coupled to and extends from an exterior surface  62  of the wrench body  38 . The wrench lever  42  provides an enlarged grip that facilitates grasping and holding the chuck wrench  34 . In the illustrated embodiment, the chuck wrench  34  is made of metal, such as steel, and the wrench body  38  and the wrench lever  42  are formed as a single piece. In some embodiments, the chuck wrench  34  may be formed of other materials, such as plastic, or combinations of materials. In other embodiments, the wrench body  38  and the wrench lever  42  may be two separate pieces such that a variety of wrench levers may be removably coupled to the wrench body  38 . 
     The chuck wrench  34  acts like a key for the chuck  14  in that it allows a user to apply a clamp force (i.e., torque) to the chuck  14  shown in  FIGS. 1 and 2 . The clamp force is used to either tighten or loosen the chuck  14  around the drill accessory  18 . In operation, the chuck wrench  34  is slid onto the exterior surface  22  of the chuck  14  such that the interior surface  50  of the wrench body  38  frictionally couples to or mates with the exterior surface  22  of the chuck  14 . A user then rotates the wrench lever  42  about the rotational axis  30  of the chuck  14 , and therein the central axis  58  of the wrench body  38 . Referring to  FIG. 2 , as the chuck wrench  34  is rotated, the ribs  54  on the interior surface  50  of the wrench body  38  engage the ribs  26  on the exterior surface  22  of the chuck  14 , thereby rotating the chuck  14  directly with the chuck wrench  34 . By rotating the chuck wrench  34  and therein the chuck  14 , the user may either increase or decrease the clamp force (e.g., torque) presently applied to the drill accessory  18  by the chuck  14 . 
     The wrench lever  42  acts as a mechanical lever arm by allowing a user to apply a load to the wrench lever  42 , which is transmitted as torque to the chuck  14 . This same load could alternatively be applied directly, by the user&#39;s hand, to the exterior surface  22  of chuck  14 . However, when using the wrench lever  42 , the load, or force, is applied a further distance away from the rotational axis  30 , thereby increasing the torque applied to the chuck  14 . When comparing the resulting clamp forces (i.e., torques) on the drill accessory  18  for the same applied load, using the chuck wrench  34  will achieve a greater clamp force (i.e., torque) than rotating the exterior surface  22  of the chuck  14  by hand. 
     In other embodiments, the wrench lever  42  may be actuated by mechanical machinery as opposed to a user, as described above. 
     In some embodiments, when the chuck wrench  34  is not in use, the chuck wrench  34  may be tethered to the tool (e.g., the drill  10 ) via a key holder, a chain, or a wrench holder formed of, for example, rubber. In such embodiments, the chuck wrench  34  will always be located with the tool, reducing the possibility of misplacing or losing the wrench  34 . In other embodiments, the chuck wrench  34  may be stored separately from the tool. 
     Thus, the invention provides, among other things, a chuck wrench for applying a clamp force to a chuck of a rotary tool. Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described. For example, in further embodiments, the chuck wrench  34  may be designed for use with other types of rotary tools, such as rotary hammers, hammer drills, or the like. 
     Various features and advantages of the invention are set forth in the following claims.