Abstract:
A torque wrench is provided having body and a handle that is rotatably mounted to the body for adjusting the torque setting, and an axially movable sleeve operable to selectively lock the handle. The sleeve includes a rigid member and an elastomeric member, such as an O-ring, and the sleeve is configured to act against a locking ball held in a bore of the handle. The sleeve is selectively movable between two positions: (a) a locked position wherein the rigid member firmly retains the locking ball seated in one of several detents in the body, thereby preventing rotation of the handle; and (b) an unlocked position wherein the elastomeric member biases the locking ball inwardly, deflecting when the locking ball unseats from the detent to permit handle rotation. When the sleeve is in the unlocked position, the locking ball can incrementally “click” over the detents during handle rotation.

Description:
FIELD OF THE INVENTION 
   This invention generally pertains to torque wrenches and more particularly to torque wrenches having a rotatable handle for adjusting a torque setting. 
   BACKGROUND OF THE INVENTION 
   Adjustable torque wrenches are generally known. One common style of torque wrench has a rotatable handle that is operable to adjust a torque setting. Some conventional handles can have a slidable locking sleeve including an interior coil spring biasing the sleeve toward the locked position. Another conventional locking sleeve is rotatable and includes an interior cam surface acting on a leaf spring. Problems exist with conventional locking mechanisms in known rotatably adjustable handles mounted to these hand tools. For example, conventional handle locking mechanisms have required complicated machining steps during manufacture, and the parts such as the leaf spring can fatigue and fail. 
   Thus, an improved locking sleeve is needed. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention overcomes deficiencies in the prior art and provides an improved torque wrench. For example, in an embodiment, a tool is provided, such as a torque wrench, including a generally tubular body that extends generally along an axis, a handle rotatably mounted to the body, and a locking sleeve mounted to the handle for slidable movement along a direction parallel to the axis relative to the handle. The exterior surface of the tubular body includes at least one detent, such as a groove, recess, or flute, extending along a direction parallel to the axis. The handle includes at least one radial bore, and at least one locking ball positioned in the bore. The locking sleeve includes a rigid member and an elastomeric member, and moves along the direction parallel to the axis between a locked position, wherein the locking sleeve holds the locking ball seated in the detent, and an unlocked position, wherein the locking sleeve permits the locking ball to unseat from the detent when the handle is rotated. 
   In the locked position, the rigid member, having an interior first surface such as a concentric interior first surface, an annular wall, and the like, is positioned to retain the locking ball radially inwardly to seat in the at least one detent of the body so that the handle is prevented from rotating. In the unlocked position, the interior first surface of the rigid member is positioned generally free from the locking ball so that the locking ball contacts the elastomeric member, the elastomeric member biasing the locking ball radially inwardly and being deflectable to permit radial movement of the locking ball to unseat from the at least one detent when the handle is rotated relative to the body. 
   In an embodiment, the torque wrench includes an adjustable signaling mechanism, such as a torque signaling mechanism housed within the body. The torque wrench includes a rotatable handle mounted to the body, the handle being operably linked to a torque signaling mechanism so that rotation of the handle results in adjustment of the predetermined torque setting. 
   In an embodiment, the locking sleeve includes a rigid member having an interior second surface such as an annular recess, an annular groove, and the like. In a related embodiment, the elastomeric member is seated adjacent the annular recess. 
   In an embodiment, the elastomeric member is an O-ring. 
   In an embodiment, the body of the tool has at least two detents positioned along a direction parallel to the axis, and the handle has at least two radial bores and at least two locking balls, one locking ball positioned in each bore. The two radial bores are spaced preferably about 180° apart on the handle. 
   An advantage of the present invention is that it provides a torque wrench having an improved locking mechanism in the handle. The improved locking mechanism avoids a need for complicated machining steps during manufacture, and reduces parts that can fail. 
   In an embodiment, another advantage of the present invention is that the locking sleeve includes an elastomeric member, such as an O-ring, which avoids a need for a metal spring. 
   Yet another advantage of the present invention is that it provides a locking sleeve that can be retained indefinitely in the unlocked position. In an embodiment, the locking sleeve advantageously “clicks” into the unlocked position in which it is held by a slight bias. A related advantage is that in the unlocked position, the handle can be easily rotated to incrementally adjust the torque setting. 
   In an embodiment, a further advantage of the present invention is that it provides a locking ball that can seat in at least one detent or recess while allowing for facile locking and unlocking by slidably moving the locking sleeve that can be biased toward the unlocked position. A related advantage is that when the locking sleeve is in the unlocked position, the locking ball can incrementally “click” over the detents during handle rotation. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an elevational view of a torque wrench having features according to teachings of the present invention, the torque wrench having a body shown partially broken away to reveal internal wrench components. 
       FIG. 2  is a fragmentary, exploded perspective view of a handle of the torque wrench of  FIG. 1 , and a portion of the tubular body of the torque wrench having detents along an exterior surface. 
       FIG. 3  is a sectional view taken generally along line III—III of  FIG. 6 , illustrating the locking sleeve in a locked position, in which the locking balls are retained in the detents by the locking sleeve. 
       FIG. 4  is a sectional view taken generally along line IV—IV of  FIG. 7 , illustrating the locking sleeve in an unlocked position, in which the locking balls are free from the annular wall. 
       FIG. 5  is a sectional view taken generally along line V—V of  FIG. 8 , illustrating the locking sleeve in an unlocked position, wherein the locking balls deflect the O-ring when the locking sleeve has been rotated from the position illustrated in  FIG. 4 . 
       FIG. 6  is a sectional view taken generally along line VI—VI of  FIG. 3 , illustrating the locking sleeve in a locked position, in which the locking balls are retained in the detents by the locking sleeve. 
       FIG. 7  is a sectional view taken generally along line VII—VII of  FIG. 4 , illustrating the locking sleeve in an unlocked position, in which the locking balls are free from the annular wall. 
       FIG. 8  is a sectional view taken generally along line VIII—VIII of  FIG. 5 , illustrating the locking sleeve in an unlocked position, in which the locking balls deflect the O-ring when the locking sleeve has been rotated from the position illustrated in  FIG. 7 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   While the invention will be described in connection with the preferred embodiment, it will be understood that there is no intent to limit the scope of the invention to this embodiment. On the contrary, it is intended that the claims will cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention. 
   Torque wrenches have been developed to attach fasteners of many types to meet varying specifications. Such hand tools can include micrometer adjustable click wrenches and the like, such as that described in U.S. Pat. No. 5,503,042 to Larson et al., herein incorporated by reference in its entirety. The structure for useful torque wrenches is generally disclosed in U.S. Pat. No. 5,503,042, and in the present invention is embodied in an improved locking mechanism in a rotatable handle. 
   Now referring to the drawings, wherein like numerals designate like components,  FIG. 1  illustrates a torque wrench  10  which generally includes an elongate, tubular body  20  that extends generally along an axis A. The body  20  of the torque wrench  10  has a proximal end  24  opposite a distal end  22 . The proximal end  24  includes in its exterior surface at least one detent, such as a flute  28  (as shown in  FIG. 2 ) positioned along a direction parallel to the axis A. The detent can be a groove, recess, or the like, extending along a direction parallel to the axis A. The proximal end  24  of the body  20  can have multiple flutes  28 . For example, the proximal end  24  can have ten flutes  28  evenly spaced. A head  30  such as a tool head for applying torque is mounted to the distal end  22  of the body  20 . A suitable torque signaling mechanism  26 , such as that disclosed in U.S. Pat. No. 5,503,042, for example, is housed within the body  20 . The torque signaling mechanism  26  can indicate or signal when the head  30  is subjected to a torque that matches a predetermined torque setting. For adjusting the predetermined torque setting, a handle  40  is rotatably mounted to the proximal end of the body  20 . The handle  40  is operably linked to the torque signaling mechanism  26  so that rotation of the handle  40  results in an increase or decrease of the predetermined torque setting, depending on whether the handle  40  is rotated clockwise or counterclockwise, respectively, in relation to the body  20 . A locking sleeve  50  is mounted to the handle  40 . The locking sleeve  50  can be mounted for slidable movement relative to the handle  40 , along a direction parallel to the axis A. The locking sleeve  50  is movable along the direction parallel to the axis A between a locked position and an unlocked position and can be retained in the locked position or the unlocked position.  FIG. 1  shows the locking sleeve  50  in the unlocked position. 
     FIG. 2  is a perspective view of the handle  40  of the torque wrench  10 , and a fragmentary perspective view of the proximal end  24  of the body  20 . The handle  40  can be mounted to the body  20 . The tubular body  20  includes in its exterior surface at least one detent, such as a flute  28  positioned along a direction parallel to the axis A. The detent can be a groove, recess, or the like, extending along a direction parallel to the axis A. 
   According to an aspect of the invention, the locking sleeve is mounted for slidable movement along a direction parallel to the axis A relative to a cylindrical portion of the handle. The locking sleeve is movable between a locked position and an unlocked position. The cylindrical portion of the handle has a bore, and includes a locking ball residing in the bore. The locking sleeve includes a generally cylindrical rigid member and an elastomeric member. The rigid member has an interior annular wall and an interior annular recess, the elastomeric member seated adjacent the annular recess. When the locking sleeve is in the locked position, the annular wall of the locking sleeve is positioned to retain the locking ball radially inwardly to seat in the at least one flute of the body so that the handle is prevented from rotating. When the locking sleeve is in the unlocked position, the annular wall of the locking sleeve is positioned generally free from the locking ball so that the locking ball contacts the elastomeric member of the locking sleeve, the elastomeric member biasing the locking ball radially inwardly and being deflectable to permit radial movement of the locking ball to unseat from the at least one flute when the handle is rotated relative to the body. 
   As  FIG. 3  illustrates in greater detail, the rotatable handle  40  includes a locking ball  60 . The rotatable handle  40  includes a cylindrical portion  42  having at least one bore  44 . The bore  44  can have a radial orientation, and is generally circular. A locking ball  60  resides movably in the bore  44  of the handle  40 . The locking ball  60  can be, for example, a steel ball bearing. The handle  40  can have multiple radial bores  44  positioned on its cylindrical portion  42 , the axial position of the multiple bores  44  being the same with respect to the axis A, and the multiple bores  44  being generally evenly spaced on the circumference of the cylindrical portion  42 . Multiple locking balls  60  can be positioned in the multiple bores  44 , one locking ball  60  being positioned in each bore  44 , respectively. For example, as shown in  FIGS. 3–8 , the cylindrical portion  42  of the handle  40  can have two bores  44  and two locking balls  60 , one locking ball  60  positioned in each bore  44 . The two radial bores  44  are spaced preferably about 180° apart on the cylindrical portion  42  of the handle  40 . 
   In order to retain the handle  40  in the locked position, as shown in  FIG. 3 , the locking sleeve  50  is slidably moved along axis A toward the distal end  22 . The locking sleeve  50  is mounted to the cylindrical portion  42  of the handle  40 . The locking sleeve  50  has a generally cylindrical rigid member  52  and an elastomeric member. The elastomeric member can be concentric, for example, an O-ring  58 . The generally cylindrical rigid member  52  can have multiple generally concentric interior surfaces. For example, the generally cylindrical rigid member  52  can have an annular wall  54  (a first interior surface) and an annular recess  56  (a second interior surface) adjacent to the annular wall  54 . The annular recess  56  can include an annular groove, and the like. The annular wall  54  can be positioned radially inwardly relative to the annular recess  56 . In  FIG. 3 , the locking sleeve  50  has been moved to the locked position. In the locked position, the annular wall  54  is positioned to retain the locking balls  60  radially inwardly to simultaneously seat the locking balls  60  in the flutes  28  in the proximal end  24  of the body  20 , so that the handle  40  is prevented from rotating. 
   In order to retain the handle  40  in the unlocked position, as  FIG. 4  illustrates in greater detail, the locking sleeve  50  is slidably moved along axis A toward the proximal end  24 . In  FIG. 4 , the locking sleeve  50  has been moved to the unlocked position. In the unlocked position, the annular wall  54  is positioned generally free from the locking balls  60  so that the locking balls  60  contact the O-ring  58 , while the O-ring  58  biases the locking balls  60  radially inwardly to simultaneously seat in the flutes  28  in the proximal end  24  of the body  20 . The locking balls  60  slightly deflect the O-ring  58  radially outwardly on contact, and the O-ring  58  biases the locking sleeve  50  toward the unlocked position. 
   In order to adjust the torque setting, the handle  40  is rotated while in the unlocked position, as  FIG. 5  illustrates in greater detail. In the unlocked position, rotation of the handle  40  relative to the body  20  permits radial outward movement of the locking balls  60  such that the locking balls  60  simultaneously unseat from the flutes  28  in the proximal end  24  of the body  20 . The locking balls  60  deflect the O-ring  58  radially outwardly to a greater extent when the locking balls  60  are in the unseated position compared to the seated position of  FIG. 4 . Further rotation of the handle  40  permits radial inward movement of the locking balls  60  such that the locking balls seat in the flutes  28  again as in  FIG. 4 . The handle  40  can be rotated in either a clockwise or counterclockwise direction relative to the tubular body  20  for the purpose of adjusting the torque setting when the locking sleeve  50  is in the unlocked position. 
   In  FIG. 6 , which is a sectional view perpendicular to  FIG. 3 , the locking sleeve  50  has been moved to the locked position. In the locked position, the annular wall  54  is positioned to retain the locking balls  60  radially inwardly to simultaneously seat the locking balls  60  in the flutes  28  in the proximal end  24  of the body  20 , so that the cylindrical portion  42  of the handle  40  is prevented from rotating. 
   In  FIG. 7 , which is a sectional view perpendicular to  FIG. 4 , the locking sleeve  50  has been moved to the unlocked position. In the unlocked position, the locking balls  60  contact the O-ring  58 , while the O-ring  58  biases the locking balls  60  radially inwardly to simultaneously seat in the flutes  28  in the proximal end  24  of the body  20 . The locking balls  60  slightly deflect the O-ring  58  radially outwardly on contact, and the O-ring  58  biases the locking sleeve  50  toward the unlocked position. The cylindrical portion  42  of the handle  40  is now able to rotate relative to the proximal end  24  of the body  20 . 
   In  FIG. 8 , which is a sectional view perpendicular to  FIG. 5 , the locking sleeve  50  has been moved to the unlocked position. In the unlocked position, rotation of the cylindrical portion  42  of the handle  40  relative to the proximal end  24  of the body  20  permits radial outward movement of the locking balls  60  such that the locking balls  60  simultaneously unseat from the flutes  28  in the proximal end  24  of the body  20 . The locking balls  60  deflect the O-ring  58  radially outwardly to a greater extent when the locking balls  60  are in the unseated position compared to the seated position of  FIG. 7 . Further rotation of the handle  40  permits radial inward movement of the locking balls  60  such that the locking balls seat in the flutes  28  again as in  FIG. 7 . The handle  40  can be rotated in either a clockwise or counterclockwise direction relative to the tubular body  20  for the purpose of adjusting the torque setting when the locking sleeve  50  is in the unlocked position. 
   O-ring compositions useful in the present invention include fluorinated elastomers such as fluorocarbon elastomers, and the like. One suitable O-ring is VITON®, 75 Durometer, available from Tech-Syn Corp. (Bloomingdale, Ill.). 
   All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
   The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
   Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. It should be understood that the illustrated embodiments are exemplary only, and should not be taken as limiting the scope of the invention. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein.