Patent Publication Number: US-7900662-B2

Title: Power tool with base clamp

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/005,923, filed on Dec. 7, 2007. The entire disclosure of that application is incorporated herein by reference. 
    
    
     FIELD 
     The present disclosure relates to a power tool and, more particularly, relates to a power tool with a base clamp. 
     BACKGROUND 
     The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
     Power tools can include a motor assembly that drives a tool and a base assembly that supports the motor assembly. In some cases, the motor assembly is removably coupled to the base assembly to increase the usefulness of the tool. Typically, these power tools include a clamp assembly that is manipulated by a user to couple and decouple the motor assembly and the base assembly. 
     For instance, some routers include a base assembly with an outer wall that defines a central opening. The outer wall includes a longitudinally extending slit that divides the outer wall into a first and second side. The motor assembly can be positioned in the central opening of the base assembly. The router also includes a clamp assembly that can move between an open position and a closed position. When moving from the open position to the closed position, the clamp assembly pulls the first and second sides of the outer wall together such that the slit becomes narrower and such that the central opening becomes smaller. Thus, the outer wall of the base assembly constricts around the motor assembly to thereby hold the motor assembly to the base assembly. Also, when the clamp assembly moves from the closed position to the open position, the first and second sides of the outer wall move away from each other such that the slit becomes wider and such that the central opening becomes larger. Thus, the outer wall of the base assembly expands to release the motor assembly. 
     These clamp assemblies typically create significant clamping forces and/or require significant input force from the user, especially in cases in which the clamp assembly deflects the base assembly as described above. Thus, some users may have difficulty opening or closing the clamp assembly. 
     Also, in some cases, these clamp assemblies can include ramps or other camming surfaces, and the clamp assembly can actuate on the camming surface when moving from the open position to the closed position to generate sufficient holding forces. These camming surfaces can wear over time due to the significant clamping forces involved. Once these camming surfaces are sufficiently worn, the clamp assembly may not provide enough retention force for holding the motor assembly. 
     Moreover, some clamp assemblies are adjustable for adjusting the amount of clamping force. For instance, some clamp assemblies include an adjustment screw that can be turned to change the position of one or more camming surface to thereby change the amount of clamping force. However, adjustment of the clamp force can be difficult because the base assembly is typically quite stiff relative to the amount of camming throw. As such, the clamp assembly may prematurely wear if the clamping force is adjusted too high, and/or the base assembly can fracture due to excessive clamping force. 
     Furthermore, these clamp assemblies may hang relatively loose from the base assembly when in the open position. As such, it can be difficult to properly orient the clamp assembly before moving the clamp assembly to the closed position. Also, if the clamp assembly is not properly aligned before moving to the closed position, one or more camming surfaces may be subject to excessive force, which can cause additional wear. 
     Still further, conventional clamp assemblies can be bulky. As such, the profile of the overall tool can significantly increase due to the clamp assembly. Thus, the tool may not fit in limited spaces. Also, the power tool may be more difficult to hold due to the bulkiness of the clamp assembly. 
     SUMMARY 
     A power tool is disclosed that includes a motor assembly, a base assembly, and a clamp assembly coupled to the motor assembly or the base assembly to selectively provide a retention force to removably couple the motor assembly and the base assembly. The clamp assembly includes a handle member, a fulcrum member, and a biasing lever member. The biasing lever member includes a first portion and a second portion disposed on opposite sides of the fulcrum member. The handle member is coupled to the first portion of the biasing lever member, and the handle member is movable between an open position and a closed position. The handle member rotates the first and second portions of the biasing lever member about the fulcrum member when moving from the open position to the closed position, causing the second portion of the biasing lever member to provide the retention force to removably couple the motor assembly and the base assembly. Also, the handle member rotates the first and second portions of the biasing lever member about the fulcrum member when moving from the closed position to the open position, causing the second portion of the biasing lever member to reduce the retention force. 
     A router is also disclosed that includes a motor assembly, a base assembly defining an aperture and an axis, and a clamp assembly coupled to the base assembly to selectively provide a retention force to removably couple the motor assembly and the base assembly. The clamp assembly includes a handle member with a pin coupled thereto, a fulcrum member fixed to the base assembly, a biasing lever member with a first portion having a hook coupled to the pin, an adjustment member movably coupled to the base assembly, and a clamp pad coupled to a second portion of the biasing member and being received by the aperture. The first and second portions of the biasing lever member are disposed on opposite sides of the fulcrum member, and the first portion of the biasing lever member is longer than the second portion. The handle member is rotatable about an axis defined by the pin between an open position and a closed position. The handle member cams against the adjustment member when rotating from the open position to the closed position to thereby move the pin away from the axis, pulling the hook away from the axis, and rotating the first and second portions of the biasing lever member about the fulcrum member. This action resiliently deflects the biasing lever member, thereby biasing the clamp pad against the motor assembly to provide the retention force. The adjustment member is movable relative to the motor assembly to change an amount of the retention force provided by the biasing lever member when the handle member is in the closed position. 
     Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
         FIG. 1  is a perspective view of a power tool with a clamp assembly according to the present disclosure; 
         FIG. 2  is a perspective view of the power tool of  FIG. 1  with the handle member of the clamp assembly removed for clarity; 
         FIG. 3  is a section view of the power tool of  FIG. 1  with the clamp assembly shown in an open position; 
         FIG. 4  is a section view of the power tool of  FIG. 1  with the clamp assembly shown in a closed position; and 
         FIG. 5  is a perspective view of a portion of a portion of a clamp assembly according to another embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
     Referring initially to  FIG. 1 , a power tool  10  is illustrated. In the embodiment shown, the power tool  10  is a router; however, the power tool  10  could be of any suitable type without departing from the scope of the present disclosure. It will also be appreciated that certain components (e.g., handles, etc.) of the power tool  10  are not shown for purposes of clarity. 
     As shown, the power tool  10  generally includes a motor assembly  11  and a base assembly  13 . The motor assembly  11  generally includes a motor housing  12 , which is cylindrical in shape. The motor housing  12  encloses and supports a motor (not shown), which can be of any suitable type. A spindle assembly  15  extends out of the motor housing  12 , and a tool (e.g., a routing bit, not shown) can be removably attached to the spindle assembly  15 . The motor assembly  11  also includes an electronics housing  17  mounted atop the motor housing  12  on an end opposite the spindle assembly  15 . The electronics housing  17  encloses and supports necessary electronics equipment (not shown), control switches, buttons, and displays, and other suitable components for operation of the power tool  10 . A power cord  19  extends out of the electronics housing  17  and provides power to the power tool  10 . It will be appreciated that the power tool  10  could be a cordless power tool  10  without departing from the scope of the present disclosure. 
     In the embodiment shown, the motor housing  12  is cylindrical and defines an outer surface  20  having a thread  22  formed thereon. The thread  22  allows the motor assembly  11  to adjust in height relative to the base assembly  13  as will be discussed. 
     Furthermore, in the embodiment shown, the base assembly  13  includes a cylindrical wall  24  defining an outer surface  26 , an inner surface  28 , and a longitudinal axis X. In the embodiment shown, the base assembly  13 , the motor assembly  11 , and the spindle assembly  15  each share the same axis X. 
     In the embodiment shown, the base assembly  13  also includes a support  30  coupled to a lower end of the wall  24 . The support  30  is flat and disc-shaped. In one embodiment, the support  30  is made of a transparent material. The power tool  10  can be supported on a workpiece (not shown) via the support  30 . The support  30  includes a central aperture  32  through which the spindle assembly  15  and/or a tool (e.g., a router bit) extend. 
     The wall  24  includes a plurality of flanges  34  that extend outwardly and horizontally in a direction transverse to the axis X. In the embodiment shown, there are two flanges  34  disposed in a spaced relationship to each other. 
     The wall  24  defines a cavity  36  that is sized to receive the motor assembly  11  therein. The power tool  10  further includes a clamp assembly  38 . The clamp assembly  38  selectively provides a retention force F ( FIG. 4 ) to removably couple the motor assembly  11  and the base assembly  13  as will be described in greater detail below. The clamp assembly  38  can be closed (as shown in  FIGS. 1 and 4 ) to apply the retention force F to the motor assembly  11  and to retain the motor assembly  11  in position relative to the base assembly  13 . The clamp assembly  38  can also be opened ( FIG. 3 ) to change the position of the motor assembly  11  relative to the base assembly  13 . In the embodiment shown, the clamp assembly  38  is operably coupled to the base assembly  13  to apply the retention force F to the motor assembly  11 . It will be appreciated, however, that the clamp assembly  38  could be operably coupled to the motor assembly  11  so as to apply the retention force F to the base assembly  13  without departing from the scope of the present disclosure. 
     The power tool  10  also includes a height adjusting mechanism  40 . In the embodiment shown, the height adjusting mechanism  40  includes a dial  41  provided near a top end of the base assembly  13  so as to encircle the motor assembly  11 . The dial  41  is releasably fixed to the top end of the base assembly  13  via a release member, and is internally threaded so as to threadably engage with the thread  22  provided on the outer surface  20  of the motor assembly  11 . Thus, assuming the clamp assembly  38  is in the open position, rotation of the motor assembly  11  relative to the base assembly  13  threadably advances the motor assembly  11  in either the downward or upward direction parallel to the axis X. 
     Also, the release member  42  can be biased such that the release member  42  disengages from the base assembly  13 . Accordingly, the motor assembly  11  can move out of the base assembly  13 , leaving the dial  41  threadably coupled to the motor assembly  11 . 
     In the embodiment shown, the base assembly  13  is a fixed base, meaning that the base assembly  13  is rigid and the height adjusting mechanism  40  is used to adjust the height of motor assembly  11  relative to the workpiece. However, it will be appreciated that the base assembly  13  could be a plunge base assembly  13  that is collapsible to actuate the motor assembly  11  toward and away from the workpiece without departing from the scope of the present disclosure. 
     Furthermore, the power tool  10  includes a spindle lock assembly  43  that selectively locks the spindle assembly  15  against rotation about the axis X. More specifically, the spindle lock assembly  43  can selectively lock the spindle assembly  15  against rotation to attach and/or remove a tool (e.g., a routing bit) to/from the spindle assembly  15 . 
     The clamp assembly  38  will now be discussed in greater detail with reference to  FIGS. 1-4 . The clamp assembly  38  includes a handle member  44  ( FIGS. 3 and 4 ). (The handle member  44  is not shown in  FIG. 2  for clarity.) The handle member  44  is elongate and rectangular with a slight curvature about the axis X as shown in  FIGS. 3 and 4 . A first end  45  of the handle member  44  includes an indent  46  as shown in  FIG. 4 . The indent  46  provides access for a user to grab an inner surface of the handle member  44  and move the handle member  44  from the closed position ( FIG. 4 ) to the open position ( FIG. 3 ). As shown, the handle member  44  is provided between the flanges  34  and is substantially flush with the flanges  34  when in the closed position such that the clamp assembly  38  has a relatively low profile relative to the base assembly  13 . 
     A second end  47  of the handle member  44  includes a plurality of rounded projections  50  ( FIGS. 3 and 4 ). A pin  48  is coupled to the projections  50  at each end and extends parallel to the axis X between the projections  50 . The projections  50  are rounded so as to be eccentric relative to the axis of the pin  48 . As will be described in greater detail below, the projections  50  define cam surfaces  52  for clamping and unclamping the clamp assembly  38 . As stated, the handle member  44  can move between the closed position ( FIG. 4 ) and the open position ( FIG. 3 ). The handle member  44  rotates about the axis of the pin  48  when moving between the open and closed positions. 
     As will be explained, the clamp assembly  44  provides the retention force F against the motor assembly  11  when the handle member  44  is in the closed position ( FIG. 4 ) to maintain the motor assembly  11  in position relative to the base assembly  13 . When the handle member  44  is in the open position ( FIG. 3 ), the retention force F is reduced or eliminated, and the motor assembly  11  can move parallel to the axis X relative to the base assembly  13 . 
     The clamp assembly  38  also includes a fulcrum member  53  ( FIGS. 2-4 ). In one embodiment, the fulcrum member  53  is a rigid pin that is fixed at both ends to one of the flanges  34 . More specifically, the fulcrum member  53  extends substantially parallel to the axis X between the flanges  34 . As will be described, the fulcrum member  53  provides a surface against which other components of the clamp assembly  38  can abut and rotate. It will be appreciated that the fulcrum member  53  could be of any suitable structure for providing such a surface. 
     The clamp assembly  38  further includes a biasing lever member  54 . In the embodiment shown, the biasing lever member  54  is elongate and thin. The biasing lever member  54  can be made out of a resilient, metallic material. The biasing lever member  54  is provided between the fulcrum member  53  and the outer surface  26  of the base assembly  13 . The biasing lever member  54  includes a first portion  55  and a second portion  57  on opposite sides of the fulcrum member  53 . In the embodiment shown, the first portion  55  of the biasing lever member  54  is longer than the second portion  57 . As such, the biasing lever member  54  provides a mechanical advantage when closing and opening the clamp assembly  38  as described in greater detail below. 
     The first portion  55  of the lever member  54  includes a hook  56  ( FIGS. 3 and 4 ), which partially encircles the pin  48  to thereby couple to the pin  48 . More specifically, the hook  56  partially encircles the pin  48  on an outboard side of the pin  48 . Thus, movement of the pin  48  in a direction radially away from the axis X coincidentally causes movement of the first portion  55  of the lever member  54  radially away from the axis X. The second portion  57  of the biasing lever member  54  is curved slightly toward the axis X and includes an opening  58 . 
     The clamp assembly  38  additionally includes a clamp pad  60  ( FIGS. 2-4 ). The clamp pad  60  can be made out of any suitable material, such as zinc or DELRIN polymer, or other resilient polymer. The clamp pad  60  includes a recess  62  that receives the second portion  57  of the biasing lever member. The clamp pad  60  further includes a post  63  extending outwardly from the recess  62  and away from the axis X. The post  63  is received within the opening  58  of the biasing lever member  54  to couple the clamp pad  60  to the second portion  57  of the biasing lever member  54 . In one embodiment, the clamp pad  60  is fixedly coupled to the biasing lever member  54 . In another embodiment, the clamp pad  60  is movably coupled to the biasing lever member  54 . The clamp pad  60  also defines a retaining surface  64  ( FIGS. 3 and 4 ) on an inner surface thereof. 
     As will be described, the retaining surface  64  of the clamp pad  60  selectively abuts the motor assembly  11  to transfer retention force F from the biasing lever member  54  and to removably couple the base assembly  13  and the motor assembly  11 . More specifically, the clamp pad  60  is received in an aperture  66  formed through the wall  24  of the base assembly  13 . In some embodiments, the aperture  66  is a through hole such that the wall  24  of the base assembly  13  continuously and completely surrounds the clamp pad  60 . Movement of the biasing lever member  54  causes movement of the clamp pad  60  in the aperture  66  of the base assembly  13  such that the clamp pad  60  applies the retention force F to the motor assembly  11 . In other words, the retaining surface  64  moves toward and away from the motor assembly  11  due to movement of the biasing lever member  54 . 
     In the embodiment shown, the clamp pad  60  includes a tapered support surface  67 . The base assembly  13  also includes a corresponding tapered support surface  69  on the periphery of the aperture  66 . The support surfaces  67 ,  69  abut each other so as to limit movement of the clamp pad  60  out of the aperture  66 . In other words, because of the abutment of the support surfaces  67 ,  69 , the clamp pad  60  is unlikely to be pulled out of the aperture  66  by the biasing lever member  54  when the clamp assembly  38  is moved from the open position to the closed position. 
     Furthermore, in the embodiment shown, the clamp pad  60  includes a flange  71 . The flange  71  is located outside the base assembly  13  and at least partially overlaps the periphery of the aperture  66  to ensure proper alignment of the clamp pad  60  and the aperture  66 . 
     In addition, the clamp assembly  38  includes an adjustment member  68  ( FIGS. 3 and 4 ). The adjustment member  68  includes a first end  70 . The first end  70  includes a support surface  72  against which the cam surfaces  52  of the handle member  44  slidingly abut. A second end  74  of the adjustment member  68  includes an aperture  76 . In the embodiment shown, a set screw  78  extends through the aperture  76  and threadably couples to the adjustment member  68  and the wall  24  of the base assembly  13 . The set screw  78  also movably couples the adjustment member  68  to the wall  24  of the base assembly  13 . In other words, rotation of the set screw  78  adjusts the position of the adjustment member  68  in a direction transverse to the axis X toward and away from the outer surface  26  of the wall  24  of the base assembly  13 . As will be described, adjusting the position of the adjustment member  68  changes the amount of retention force F provided by the clamp assembly  38 . 
     Furthermore, the first end  70  of the adjustment member  68  includes an aperture  80  and a rounded pivot surface  82 . In addition, a retaining pin  84  is fixed to the wall  24  of the base assembly  13 , and a pivoting indent  86  is defined in the outer surface  26  of the wall  24 . The retaining pin  84  is received in the aperture  80 , and the pivot surface  82  is received in the pivoting indent  86 . As such, the retaining pin  84  couples the first end  70  of the adjustment member  68  to the wall  24  and positionally retains the adjustment member  68  such that movement of the adjustment member  68  in a tangential direction relative to the wall  24  is limited. Moreover, when the set screw  78  is turned, the adjustment member  68  is able to pivot about the pivot surface  82  due to the sliding abutment of the pivot surface  82  on the pivoting indent  86 . 
     Now, with reference to  FIGS. 3 and 4 , the opening and closing of the clamp assembly  38  will be described in greater detail. When moving from the open position ( FIG. 3 ) to the closed position ( FIG. 4 ), the handle member  44  pivots about the axis of the pin  48  such that the first end  45  of the handle member  44  moves toward the outer surface  26  of the base assembly  13 . Simultaneously, the cam surfaces  52  of the handle member  44  cam against the support surface  72  of the adjustment member  68 . As the cam surfaces  52  slide on the support surface  72 , the pin  48  is moved outward away from the axis X and the outer surface  26  of the base assembly  13 . The pin  48  pulls the hook  56  away from the axis X to actuate the first portion  55  of the biasing lever member  54  away from the axis X and the outer surface  26  of the base assembly  13 . As such, the biasing lever member  54  actuates relative to the fulcrum member  53 . More specifically, in the embodiment shown, the first portion  55  of the biasing lever member  54  rotates about the fulcrum member  53  generally away from the axis X, and the second portion  57  of the biasing lever member  54  rotates about the fulcrum member  53  generally toward the axis X in order to apply the retention force F. In some embodiments, the biasing lever member  54  resiliently deflects (i.e., bends) against the fulcrum member  53  and biases the second portion  57  and clamp pad  60  toward the motor assembly  11  to provide the retention force F against the motor assembly  11 . Accordingly, the biasing lever member  54  deflects to provide the retention force F, and the clamp pad  60  transfers the retention force F to the motor assembly  11  to thereby retain the motor assembly  11  in position relative to the base assembly  13 . 
     In contrast, when the handle member  44  is moved from the closed position ( FIG. 4 ) to the open position ( FIG. 3 ), the cam surfaces  52  slide against the support surface  72 , allowing the biasing lever member  54  to deflect back or recover toward its undeflected shape and rotate about the fulcrum member  53 , and the biasing lever member  54  pulls the pin  48  toward the axis X and toward the outer surface  26  of the base assembly  13 . This movement of the pin  48  reduces the deflection of the biasing lever member  54 , and allows the clamp pad  60  to move away from the axis X and the motor assembly  11 . Accordingly, the retention force F is reduced, and the motor assembly  11  can be moved parallel to the axis X relative to the base assembly  13 . 
     As mentioned above, the adjustment member  68  can be positionally adjusted via the set screw  78  to change the amount of retention force F provided by the clamp assembly  38 . More specifically, rotation of the set screw  78  moves the support surface  72  toward and away from the outer surface  26  of the base assembly  13 . Thus, if the support surface  72  is moved away from the outer surface  26 , the cam surfaces  52  cam the pin  48  further away from the axis X and the outer surface  26  (i.e., there is more throw T of the pin  48 ), thereby causing increased resilient deflection of the biasing lever member  54 . As such, the retention force F provided by the clamp assembly  38  is increased. In contrast, if the support surface  72  is adjusted toward the axis X and the outer surface  26 , the cam surfaces  52  cause less movement of the pin  48  away from the outer surface  26  (i.e., there is less throw T of the pin  48 ) for less resilient deflection of the biasing lever member  54 . Accordingly, less retention force F is provided by the clamp assembly  38 . In one embodiment, the adjustment member  68  is adjusted to provide approximately 2 mm of throw T. 
     It will be appreciated that the set screw  78  can be threadably advanced with a screwdriver (not shown) or other suitable tool. The set screw  78  can be advanced when the handle member  44  is in the closed position and in the open position. For instance, in some embodiments, the handle member  44  includes an opening  90  ( FIG. 1 ) adjacent the second end  47 . The set screw  78  can be accessed and adjusted through the opening  90  when the handle member  44  is in the open position. For instance, when the handle member  44  is in the open position, a screwdriver (not shown) can be inserted through the opening  90  to threadably advance the set screw  78 . The set screw  78  can be adjusted until there is little or no play in the handle member  44  (i.e., the handle member  44  is freely supported approximately orthogonal to the axis X when in the open position) while still allowing the motor assembly  13  to be removed from the base assembly  11 . 
     It will be appreciated that the power tool  10  could be configured such that the cam surfaces  52  cam directly against the outer surface  26  of the base assembly  13 . In other words, the adjustment member  68  is not included in some embodiments. Furthermore, it will be appreciated that the clamp assembly  38  could be coupled to the motor assembly  11  such that the clamp pad  60  abuts against the base assembly  13  without departing from the scope of the present disclosure. Also, in some embodiments, the clamp pad  60  is not included, and the second portion  57  of the biasing lever member  54  abuts directly against the motor assembly  11  to thereby apply the retention force F. Still further, the wall  24  of the base assembly  13  could include a flexible portion, and the biasing lever member  54  can abut against the flexible portion when the handle member  44  is in the closed position to deflect and hold the flexible portion against the motor assembly  13 . 
     It will be appreciated that the necessary input force from the user applied to the handle member  44  is relatively low compared to prior art clamp assemblies. This is because the biasing lever member  54  provides a mechanical advantage and reduces the necessary input force provided by the user and applied to the cam surfaces  52 . Thus, the clamp assembly  38  is easier for the user to operate, and the cam surfaces  52  and the support surface  72  are less likely to wear. 
     Furthermore, the retention force F provided by the clamp assembly  38  can be easily adjusted as described above. The adjustment member  68  can also be adjusted to reduce the amount of sagging (i.e., looseness) of the clamp assembly  38  when in the open position. For instance, the retention force F can be adjusted by the manufacturer and/or the user by simply turning the set screw  78  until the clamp pad  60  abuts slightly against the motor assembly  11  when the clamp assembly  38  is in the open position. As such, the retention force F with be relatively low (e.g., zero) when the clamp assembly  38  is in the open position, but as soon as the clamp assembly  38  begins to move toward the closed position, the retention force F begins to increase. Thus, the clamp assembly  38  is less likely to hang loosely or sag relative to the motor assembly  13  when in the open position. Accordingly, the clamp assembly  38  can be moved to the closed position without having to pre-align the components as is the case with some prior art clamp assemblies. 
     Furthermore, if a user over tightens the clamp assembly  38  while in the closed position, it will be difficult to remove the motor assembly  11  from the base assembly  13  even in the open position. This will discourage users from over tightening the set screw  78 . 
     Moreover, manufacture of the clamp assembly  38  in the power tool  10  is relatively simple. For instance, the base assembly  13  can be cast, and the aperture  66  can be formed during casting operation. Then, a hole for the fulcrum member  53  can be machined to then attach the fulcrum member  53  before attaching the remaining components of the clamp assembly  38 . Thus, tolerancing can be relatively loose, and proper operation of the clamp assembly  38  can be ensured. Furthermore, the power tool  10  can be less expensive to manufacture. 
     Finally, the clamp assembly  38  has a relatively low profile. More specifically, each of the components remains significantly contained between the flanges  34  of the base assembly  13 . As such, the power tool  10  is more compact, and the clamp assembly  38  is less likely to cause interference with surrounding structure. 
     Referring now to  FIG. 5 , another embodiment of the clamp assembly  138  is illustrated. Components that correspond to those discussed above in relation to  FIGS. 1-4  are identified by corresponding reference numerals increased by 100. Only the clamp pad  160  and the wall  124  of the base assembly  113  are shown for purposes of clarity; however, it will be appreciated that the clamp assembly  138  can include other components similar to those discussed above with relation to  FIGS. 1-4 . 
     The tool  110  includes a clamp pad  160  with a post  163 , and flanges  171  similar to the embodiment of  FIGS. 1-4 . The clamp pad  160  also includes extensions  192 . The extensions  192  each extend from opposite sides of the clamp pad  160  in a direction generally parallel to the axis X of the tool  110 . In some embodiments, the extensions  192  are integrally attached to the clamp pad  160 . The extensions  192  can have any suitable shape, such as a cylindrical shape. 
     The extensions  192  are received in corresponding slots  194  of the wall  124  of the base assembly  113 . The extensions  192  are substantially retained in the slots  194 , and hence the clamp pad  160  is substantially coupled to the wall  124 . Thus, the clamp pad  160  can be easier to fit and position on the wall  124  of the base assembly  113 , and the clamp assembly  138  is less sloppy when opened since the clamp pad  160  is more likely to be retained in the wall  124  of the base assembly  113 . 
     The foregoing discussion discloses and describes merely exemplary embodiments of the present disclosure. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations may be made therein without departing from the spirit and scope of the disclosure as defined in the following claims.