Patent Publication Number: US-2023150097-A1

Title: Ratcheting tool

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 17/513,642 filed on Oct. 28, 2021, now U.S. Pat. No. 11,565,386, which claims priority to U.S. Provisional Patent Application No. 63/126,033 filed on Dec. 16, 2020, and U.S. Provisional Patent Application No. 63/106,690 filed on Oct. 28, 2020, the entire contents of all of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to ratchet tools, and more particularly to powered ratcheting tools. 
     BACKGROUND OF THE INVENTION 
     Powered ratchet tools sometimes allow an operator to drive an output member in a forward direction or an opposite reverse direction to apply torque to a fastener for tightening or loosening the fastener. Powered ratchet tools are typically powered by an electrical source, such as a DC battery, a conventional AC source, or pressurized air. Powered ratchet tools are constructed of components such as a drive mechanism including a motor and an output member for applying torque to the fastener. 
     SUMMARY OF THE INVENTION 
     The present invention provides, in one aspect, a powered ratchet tool comprising a housing and an output member having an inner opening, an outer toothed surface, and an output member aperture extending through the outer toothed surface to the inner opening. The powered ratchet tool further comprises a drive mechanism for driving the output member. The drive mechanism includes a yoke in which the output member is arranged. The yoke has a yoke aperture. The powered ratchet tool further comprises a first selective pawl in the yoke that is biased toward the outer toothed surface of the output member, a second selective pawl in the yoke that is biased toward the outer toothed surface of the output member, a non-selective pawl in the yoke that is biased toward the outer toothed surface of the output member, and a blocking member configured to move between an operating position, in which the non-selective pawl is engaged with the outer toothed surface of the output member, and a home position, in which the blocking member inhibits the non-selective pawl from engaging with the outer toothed surface of the output member. The outer toothed surface includes a first selectively-toothed section and a second selectively toothed section. When the first selectively-toothed section is rotationally aligned with the first selective pawl, the first selective pawl is incapable of transferring torque to the output member. When the second selectively-toothed section is rotationally aligned with the second selective pawl, the second selective pawl is incapable of transferring torque to the output member. When the output member is in a home position, the first selectively-toothed section is rotationally aligned with the first selective pawl, the second selectively-toothed section is rotationally aligned with the second selective pawl, and the output member aperture is aligned with the yoke aperture. 
     The present invention provides, in another aspect, a powered ratchet tool comprising a housing and an output member having an inner opening, an outer toothed surface, and an output member aperture extending through the outer toothed surface to the inner opening. The powered ratchet tool further comprises a drive mechanism for driving the output member. The drive mechanism includes a yoke in which the output member is arranged. The yoke has a yoke aperture. The powered ratchet tool further comprises a first selective pawl in the yoke that is biased toward the outer toothed surface of the output member, a second selective pawl in the yoke that is biased toward the outer toothed surface of the output member, a first non-selective pawl in the yoke that is biased toward the outer toothed surface of the output member, and a second non-selective pawl in the yoke that is biased toward the outer toothed surface of the output member. The powered ratchet tool further comprises a collar configured to move between an operating position, in which the first and second non-selective pawls are engaged with the outer toothed surface of the output member and the collar inhibits the first and second selective pawls from engaging with the outer toothed surface of the output member, and a home position, in which the first and second selective pawls are engaged with the outer toothed surface of the output member and the collar inhibits the first and second non-selective pawl from engaging with the outer toothed surface of the output member. The outer toothed surface includes a first selectively-toothed section and a second selectively-toothed section. When the first selectively-toothed section is rotationally aligned with the first selective pawl, the first selective pawl is incapable of transferring torque to the output member. When the second selectively-toothed section is rotationally aligned with the second selective pawl, the second selective pawl is incapable of transferring torque to the output member. When the output member is in a home position, the first selectively-toothed section is rotationally aligned with the first selective pawl, the second selectively-toothed section is rotationally aligned with the second selective pawl, and the output member aperture is aligned with the yoke aperture. 
     Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of a ratchet tool in accordance with an embodiment of the invention. 
         FIG.  2    is a cross-sectional view of the ratchet tool of  FIG.  1   . 
         FIG.  3    is a perspective view of a yoke of the ratchet tool of  FIG.  1   , with portions removed. 
         FIG.  4    is a perspective view of a yoke of the ratchet tool of  FIG.  1   , with portions removed. 
         FIG.  5    is a perspective view of an output member of the ratchet tool of  FIG.  1   . 
         FIG.  6    is a plan view of a ratchet tool of  FIG.  1   , with portions removed. 
         FIG.  7    is a perspective view of the ratchet tool of  FIG.  1   , with portions removed and a collar in an operating position. 
         FIG.  8    is a perspective view of the ratchet tool of  FIG.  1   , with portions removed and a collar in a home position. 
         FIG.  9    is a perspective view of the ratchet tool of  FIG.  1   , with portions removed and a collar in an operating position. 
         FIG.  10    is an enlarged, cross-sectional view of the ratchet tool of  FIG.  1   . 
         FIG.  11    is an enlarged, perspective view of the ratchet tool of  FIG.  1   . 
         FIG.  12    is an enlarged, cross-sectional view of a ratchet tool according to another embodiment of the invention. 
         FIG.  13    is a perspective view of a yoke of the ratchet tool of  FIG.  1   , with portions removed, according to another embodiment of the invention. 
         FIG.  14    is a perspective view of a collar of the ratchet tool of  FIG.  1   , according to the embodiment of  FIG.  13   . 
     
    
    
     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 is for the purpose of description and should not be regarded as limiting. 
     DETAILED DESCRIPTION 
     A shown in  FIG.  1   , a powered ratchet tool  10  includes a housing  14  and a drive mechanism  18  for driving an output member  22 , such as a socket driver used to tighten or loosen fasteners (e.g., nuts or bolts). As shown in  FIG.  1   , the drive mechanism  18  includes a motor  26  and a transmission  30  terminating in a crankshaft  34  (all shown schematically in  FIG.  1   ). As shown in  FIG.  2   , the crankshaft  34  has a drive bushing  36  arranged eccentrically on an end  38  of the crankshaft  34 . The motor  26  is powered by a removable and rechargeable battery pack  40 . The drive mechanism  18  also includes a yoke  42  through which the output member  22  extends. The yoke  42  has a recess  46  ( FIG.  2   ) in which the drive bushing  36  is arranged and a yoke aperture  48  giving the yoke  42  a C-shape. As explained in further detail below, when the crankshaft  34  rotates, the drive bushing  36  pivots the yoke  42  in a reciprocating manner, relative to the housing  14 , to drive the output member  22 . 
     With reference to  FIGS.  2 - 4   , the ratchet tool  10  also includes a first selective pawl  50 , a second selective pawl  54 , and a non-selective pawl  58  in the yoke  42 . Thus, in the illustrated embodiment, there are three total pawls, but in other embodiments, there may be more than three pawls. The non-selective pawl  58  is arranged in the yoke  42  between the first and second selective pawls  50 ,  54 . The first and second selective pawls  50 ,  54 , as well as the non-selective pawl  58 , are each biased by springs  62 , respectively, toward an outer toothed surface  66  of the output member  22 . The output member  22  also has an inner opening  70  defining a longitudinal axis  74 . The non-selective pawl  58  has a width W NSP  ( FIGS.  3  and  4   ) that substantially spans a width W TS  of the toothed surface  66  ( FIG.  5   ) in a direction parallel to the longitudinal axis  74 , whereas the first and second selective pawls  50 ,  54  each have a width W SP  that spans less than the width W TS  of the toothed surface  66  in a direction parallel to the longitudinal axis  74 . The inner opening  70  includes a first end section  78  ( FIG.  1   ) with a first size and a first shape, such as a 12-point double hexagon shape, and a second end section  82  with a second size and a second shape. However, in other embodiments, the first shape can be something other than a 12-point double hexagon shape. 
     In the illustrated embodiment, the second size is smaller than the first size and the second shape is also a 12-point double hexagon shape, but in other embodiments, the second size can be smaller and the second shape can be different than the first shape. The first end section  78  is configured to receive a fastener or an insert having a corresponding shape and size. Likewise, the second end section  82  is configured to receive a fastener or an insert having a corresponding shape and size. In some embodiments, the first size is the same as the second size and the first shape is the same as the second shape. 
     The output member  22  also includes an output member aperture  86  extending through the outer toothed surface  66  to the inner opening  70 . As shown in  FIGS.  1  and  6   , when the output member  22  is in a “home” position, the output member aperture  86  is aligned with the yoke aperture  48 , creating a passage allowing a fastener or nut to be moved horizontally (i.e., transverse to the axis  74 ) through the apertures  48 ,  86  and into the inner opening  70  of the output member  22 . 
     As shown in  FIG.  5   , the outer toothed surface  66  includes a first selectively-toothed section  90  along a first outer arc length Al of output member  22  and a second selectively-toothed section  94  along a second outer arc length A 2  of output member  22 . The first selectively-toothed section  90  includes a first non-toothed section  98  that is longitudinally aligned with the first selective pawl  50 , with respect to the longitudinal axis  74 . The first selectively-toothed section  90  also includes a first toothed section  102  that is not longitudinally aligned with the first selective pawl  50 , with respect to the longitudinal axis  74 . Thus, when the first selectively-toothed section  90  is rotationally aligned with the first selective pawl  50 , the first selective pawl  50  is unable to transfer torque to the output member  22  via the outer toothed surface  66  (as described in further detail below), because the first selective pawl  50  is arranged in the first non-toothed section  98  and does not engage the first toothed section  102 . However, when the first selectively-toothed section  90  is rotationally aligned with either of the second selective pawl  54  and the non-selective pawl  58 , the second selective pawl  54  and the non-selective pawl  58  can transfer torque to the output member  22  via the outer toothed surface  66  (as described in further detail below), because the second selective pawl  54  and the non-selective pawl  58  engage with the first toothed section  102 , which is longitudinally aligned with both of the second selective pawl  54  and the non-selective pawl  58 , with respect to the longitudinal axis  74 . 
     With continued reference to  FIG.  5   , the second selectively-toothed section  94  includes a second non-toothed section  106  that is longitudinally aligned with the second selective pawl  54 , with respect to the longitudinal axis  74 . The second selectively-toothed section  94  also includes a second toothed section  110  that is not longitudinally aligned with the second selective pawl  54 , with respect to the longitudinal axis  74 . Thus, when the second selectively-toothed section  94  is rotationally aligned with the second selective pawl  54 , the second selective pawl  54  is unable to transfer torque to the output member  22  via the outer toothed surface  66  (as described in further detail below), because the second selective pawl  54  is arranged in the second non-toothed section  106  and does not engage the second toothed section  110 . However, when the second selectively-toothed section  94  is rotationally aligned with either of the first selective pawl  50  and the non-selective pawl  58 , the first selective pawl  50  and the non-selective pawl  58  can transfer torque to the output member  22  via the outer toothed surface  66  (as described in further detail below), because the first selective pawl  50  and the non-selective pawl  58  engage with the second toothed section  110 , which is longitudinally aligned with both of the first selective pawl  50  and the non-selective pawl  58 , with respect to the longitudinal axis  74 . 
     As shown in  FIGS.  1  and  6   , the ratchet tool  10  includes a home actuator  114  that is coupled, via a linkage  118 , to a collar  122  that is arranged in the housing  14  and rotatable relative thereto, as explained in further detail below. In the illustrated embodiment, the home actuator  114  is a slide actuator that is movable between an operating position and a home position. When the home actuator  114  is in the operating position, the linkage  118  and collar  122  are in operating positions shown in  FIG.  6   , in which a blocking member  126  of the collar  122  is not rotationally aligned with the non-selective pawl  58  ( FIG.  7   ). 
     However, when the home actuator  114  is moved to the home position, the linkage  118  is pulled by the home actuator  114  such that the collar  122  is rotated (as indicated by arrow  130 ) to a home position shown in  FIG.  8   . In the home position of the collar  122 , the blocking member  126  is rotationally aligned with non-selective pawl  58 , thus pushing the non-selective pawl  58  away (as indicated by arrow  134 ) from the outer toothed surface  66  of the output member  22 , such that the non-selective pawl  58  is inhibited from engaging with the outer toothed surface  66  of the output member  22 . As shown in  FIG.  9   , when the home actuator  114  is moved back to the operating position, the linkage  118  is pushed (as indicated by arrow  138 ) back to its operating position, and the collar  122  is rotated (as indicated by arrow  142 ) back to its operating position. Once the blocking member  126  is no longer rotationally aligned with the non-selective pawl  58 , the non-selective pawl  58  is biased back into engagement with the outer toothed surface  66  of the output member, as indicated by arrow  146 . In some embodiments, the home actuator  114  may be biased to its operating position. 
     As shown in  FIG.  10   , a plurality of compression springs  150  (only one shown) are arranged within the housing  14  and configured to bias a friction ring  154  against a ledge  158  of the output member  22 . However, a retaining ring  162  ( FIG.  11   ) arranged within a circumferential groove  166  of the output member  22  and abutted against a side  170  of the housing  14  inhibits the output member  22  from being ejected from the housing  14 . Thus, the ledge  158  of the output member  22  experiences continuous friction by virtue of the friction ring  154  being in constant contact with the ledge  158 . As shown in  FIG.  12   , in a different embodiment, instead of a plurality of compression springs  150  as in the embodiment of  FIGS.  1 - 11   , a wave spring  174  is arranged between the housing  14  and the friction ring  154  to bias the friction ring  154  against the ledge  158  of the output member  22 . 
     In operation, the ratchet tool  10  may be used for adjusting a nut on an intermediate portion of a threaded rod, in a first direction along the rod. Specifically, while the output member  22  is in the home position, the ratchet tool  10  can be inserted onto the rod by inserting the rod through the yoke aperture  48  and output member aperture  86 , until the rod is received in the inner opening  70  of the output member  22 . Once the rod is received in the inner opening  70  and aligned with the longitudinal axis  74 , the output member  22  is moved along the longitudinal axis  74  and the rod until, for example, the second end section  82  engages the nut. After ensuring that the home actuator  114  is in the operating position, the motor  26  of the drive mechanism  18  is activated. Activation of the motor  26  causes the crankshaft  34  to rotate the drive bushing  36 , which causes the yoke  42  to pivot in a reciprocating manner relative to the housing  14 . 
     Initially, as the yoke  42  is undergoing a “driving” pivot motion (pivoting counterclockwise as viewed in  FIG.  2    about the longitudinal axis  74 ), at least one of the three pawls, i.e., the first and second selective pawls  50 ,  54  and the non-selective pawl  58 , engage the toothed surface  66  of the output member  22 . As noted above, if at a certain moment during the “driving” pivot motion, the first selectively-toothed section  90  of the outer toothed section  66  is rotationally aligned with the first selective pawl  50 , the first selective pawl  50  is not capable of transferring torque to the output member  22  via the toothed surface  66 . As also noted above, if at a certain moment during the “driving” pivot motion, the second selectively-toothed section  94  of the outer toothed section  66  is rotationally aligned with the second selective pawl  54 , the second selective pawl  54  is not capable of transferring torque to the output member  22  via the toothed surface  66 . 
     However, if at a certain moment during the “driving” pivot motion, the first selectively-toothed section  90  is rotationally aligned with either of the second selective pawl  54  and the non-selective pawl  58 , the second selective pawl  54  and the non-selective pawl  58  can transfer torque to the output member  22 , because the second selective pawl  54  and the non-selective pawl  58  engage with the first toothed section  102 , which is longitudinally aligned with both of the second selective pawl  54  and the non-selective pawl  58 , with respect to the longitudinal axis  74 . Likewise, if at a certain moment during the “driving” pivot motion, the second selectively-toothed section  94  is rotationally aligned with either of the first selective pawl  50  and the non-selective pawl  58 , the first selective pawl  50  and the non-selective pawl  58  can transfer torque to the output member  22 , because the first selective pawl  50  and the non-selective pawl  58  engage with the second toothed section  110 , which is longitudinally aligned with both of the first selective pawl  50  and the non-selective pawl  58 , with respect to the longitudinal axis  74 . 
     If at a certain moment during the “driving” pivot motion, the output member  22  reaches the “home” position, the first selectively-toothed section  90  is rotationally aligned with the first selective pawl  50  and the second selectively-toothed section  94  is simultaneously rotationally aligned with the second selective pawl  54 , such that only the non-selective pawl  58  will transfer torque to the output member  22  via the toothed section  66 . If at a certain moment during the “driving” pivot motion of the yoke  42 , the output member aperture  86  is rotationally aligned with the non-selective pawl  58  (and thus not engaged with the outer toothed surface  66 ), neither of the first or second selectively-toothed sections  90 ,  94  of the toothed surface  66  will be respectively rotationally aligned with the first or second selective pawls  50 ,  54 , such that the first or second selective pawls  50 ,  54  can continue transferring torque to output member  22  via the outer toothed surface  66 . Thus, during the “driving” pivot motion, torque is transferred from the yoke  42  to the output member  22  by at least one of the three pawls, i.e. the first and second selective pawls  50 ,  54 , and the non-selective pawl  58 , causing the output member  22  to rotate counterclockwise about the longitudinal axis  74 , as viewed in  FIG.  2   . 
     As the crankshaft  34  continues to rotate the drive bushing  36 , the yoke  42  undergoes a “ratcheting” pivot motion (pivoting clockwise as viewed in  FIG.  2    about the longitudinal axis  74 ), causing all three pawls, i.e., the first and second selective pawls  50 ,  54 , and the non-selective pawl  58 , to ratchet back across the toothed surface  66  of the output member  22 , thus not transferring any torque to the output member  22 . It is worth noting that when the first selectively-toothed section  90  is rotationally aligned with the first selective pawl  50  during the “ratcheting” motion of the yoke  42 , the first selective pawl  50  does not “ratchet” back across the toothed surface  66 ; rather the first selective pawl  50  merely slides against the first non-toothed section  98 . It is also worth noting that when the second selectively-toothed section  94  is rotationally aligned with the second selective pawl  54  during the “ratcheting” motion of the yoke  42 , the second selective pawl  54  does not “ratchet” back across the toothed surface  66 ; rather the second selective pawl  54  merely slides against the second non-toothed section  106 . In addition to the pawls  50 ,  54 ,  58  not transferring torque to the output member  22  during the “ratcheting” pivot motion of the yoke  42 , the output member  22  is also inhibited from rotating via the friction ring  154  creating friction against the ledge  158  of the output member  22 . 
     After completing the “ratcheting” pivot motion, the yoke  42  continues to perform a series of subsequent “driving” and “ratcheting” pivot motions to move the nut along the threaded rod in the first direction via the output member  22 . Once the nut has been moved along a sufficient distance in the first direction, the motor  26  is deactivated and the output member  22  is moved along the longitudinal axis  74  and the rod until the nut is removed from the output member  22 . At this point, the output member  22  may need to be removed from the threaded rod, but may be blocked if the output member  22  is not in the “home” position, and thus, the output member aperture  86  is not aligned with the yoke aperture  48 , such that there is no passage allowing for the output member  22  to be removed from the rod. 
     Thus, the home actuator  114  must be moved to the home position, thereby moving the collar  122  to its home position, such that the non-selective pawl  58  is blocked from engaging the outer toothed surface  66  of the output member  22  by the blocking member  126 . The motor  26  is then reactivated, causing the yoke  42  to perform a series of subsequent “driving” and “ratcheting” pivot motions, until the output member  22  is rotated to the “home” position. As noted above, when the output member  22  is in the “home” position, the first selectively-toothed section  90  is rotationally aligned with first selective pawl  50  and the second selectively-toothed section  94  is rotationally aligned with the second selective pawl  54 . Thus, neither of the first or second selective pawls  50 ,  54  is capable of transferring torque to the output member  22 . And, because the non-selective pawl  58  is inhibited from engaging with and transferring torque to the output member  22  by the blocking member  126 , the output member  22  stops rotating even while the yoke  42  continues to reciprocate. The motor  26  is then subsequently deactivated, leaving the output member  22  in the home position. Because the output member aperture  86  is re-aligned with the yoke aperture  48 , a passage is opened for the rod to be laterally removed from the output member  22 , thus removing the ratcheting power tool  10  from the rod. 
     In operation, when an operator wishes to move the nut in a second direction along the rod that is opposite the first direction, the ratchet tool  10  may be vertically flipped and nut may be arranged in the output member  22  as discussed above. Then, the motor  26  may be activated and the “driving” and “ratcheting” motions of the yoke  42  above may be repeated until the nut has been moved a sufficient amount along the rod in the second direction. 
       FIGS.  13  and  14    illustrate a different embodiment of a ratchet tool  10   a.  The ratchet tool  10   a  is the same as the ratchet tool  10  of  FIGS.  1 - 11   , with like parts having the same annotation with the suffix “a” added, except for the three differences noted below. 
     The first difference is that the non-selective pawl  58   a  is a first non-selective pawl  58   a,  and the orientation of the first non-selective pawl  58   a  is opposite that of the orientation of the non-selective pawl  58 , such that when the yoke  42   a  is undergoing a second pivot motion (pivoting clockwise as viewed in  FIG.  13    about the longitudinal axis  74   a ) and the first non-selective pawl  58   a  is engaged against the toothed surface  66   a,  the first non-selective pawl  58   a  transfers torque to the output member  22   a  via the toothed surface  66   a,  causing the output member  22   a  to rotate in the second (clockwise) direction about the longitudinal axis  74   a.    
     The second difference is that the ratchet tool  10   a  includes a second non-selective pawl  178  having the same orientation as the first non-selective pawl  58   a,  Thus, when the yoke  42   a  is undergoing the second pivot motion (pivoting clockwise as viewed in  FIG.  13    about the longitudinal axis  74   a ) and the second non-selective pawl  178  is engaged against the toothed surface  66   a,  the second non-selective pawl  178  transfers torque to the output member  22   a  via the toothed surface  66   a,  causing the output member  22   a  to rotate in the second (clockwise) direction about the longitudinal axis  74   a.    
     The third difference is that that the collar  122   a  includes first and second blocking portions  182 ,  186  and an opening  190  therebetween. When the collar  122   a  is in the operating position, the first blocking portion  182  is positioned between the first selective pawl  50   a  and the toothed surface  66   a,  the second blocking portion  186  is positioned between the second selective pawl  54   a  and the toothed surface  66   a,  the opening  190  is positioned adjacent the first non-selective pawl  58   a,  and no portion of the collar  122   a  is arranged in front of the second non-selective pawl  178 , such that the first and second selective pawls  50   a,    54   a  are inhibited from engaging against and transferring torque to the output member  22   a  via the toothed surface  66   a,  and the first and second non-selective pawls  58   a,    178  are engaged against and capable of transferring torque to the output member  22   a  via the toothed surface  66   a.  When the collar  122   a  is in the home position, the first blocking portion  182  is positioned between the second non-selective pawl  178  and the toothed surface  66   a,  the second blocking portion  186  is positioned between the first non-selective pawl  58   a  and the toothed surface  66   a,  the opening  190  is positioned adjacent the first selective pawl  50   a,  and no portion of the collar  122   a  is arranged in front of the second selective pawl  54   a,  such that the first and second non-selective pawls  58   a,    178  are inhibited from engaging against and transferring torque to the output member  22   a  via the toothed surface  66   a,  and the first and second selective pawls  50   a,    54   a  are engaged against and capable of transferring torque to the toothed surface  66   a.    
     These three differences result in the ratchet tool  10   a  functioning slightly differently than the ratchet tool  10 , as explained below. 
     In operation of the ratchet tool  10   a,  the ratchet tool  10   a  may be used for adjusting a nut on an intermediate portion of a threaded rod, in a first direction along the rod. Specifically, while the output member  22   a  is in the home position, the ratchet tool  10   a  can be inserted onto the rod by inserting the rod through the yoke aperture  48   a  and output member aperture  86   a,  until the rod is received in the inner opening  70   a  of the output member  22   a.  Once the rod is received in the inner opening  70   a  and aligned with the longitudinal axis  74   a,  the output member  22   a  is moved along the longitudinal axis  74   a  and the rod until, for example, the second end section  82   a  engages the nut. After ensuring that the home actuator  114   a  is in the operating position, the motor  26   a  of the drive mechanism  18   a  is activated. Activation of the motor  26   a  causes the crankshaft  34   a  to rotate the drive bushing  36   a,  which causes the yoke  42   a  to pivot in a reciprocating manner relative to the housing  14   a.    
     Initially, as the yoke  42   a  is undergoing a first pivot motion (pivoting counterclockwise as viewed in  FIG.  13    about the longitudinal axis  74 ), because the first and second selective pawls  50   a,    54   a  are respectively blocked by the first and second blocking portions  182 ,  186 , neither of the first and second selective pawls  50   a,    54   a  engage against the toothed surface  66   a.  Also, although the first and second non-selective pawls  58   a,    178  are engaged against the toothed surface  66   a,  because of their respective orientations, both of the first and second non-selective pawls  58   a,    178  simply ratchet across the toothed surface  66   a  as the yoke  42   a  is undergoing the first pivot motion. Thus, during the first pivot motion, no torque is transferred to the toothed surface  66   a  and the output member  22   a  remains in place. 
     As the crankshaft  34   a  continues to rotate the drive bushing  36   a,  the yoke  42   a  undergoes a second pivot motion (pivoting clockwise as viewed in  FIG.  13    about the longitudinal axis  74   a ). Because the first and second selective pawls  50   a,    54   a  are respectively blocked by the first and second blocking portions  182 ,  186 , neither of the first and second selective pawls  50   a,    54   a  engage against the toothed surface  66   a.  Also, because the yoke  42   a  is undergoing the second pivot motion, because of their respective orientations, both of the first and second non-selective pawls  58   a,    178  transfer torque to the output member  22   a  via the toothed surface  66   a.  Thus, during the second pivot motion while the home actuator  114   a  and the collar  122   a  are in their respective operating positions, the output member  22   a  is caused to rotate in the second (clockwise) direction about the longitudinal axis  74   a,  thus moving the nut along the threaded rod in the first direction. 
     After completing the second pivot motion, the yoke  42   a  continues to perform a series of subsequent first and second pivot motions to move the nut along the threaded rod in the first direction via the output member  22   a.  Once the nut has been moved along a sufficient distance in the first direction, the motor  26   a  is deactivated and the output member  22   a  is moved along the longitudinal axis  74   a  and the rod until the nut is removed from the output member  22   a.  At this point, the output member  22   a  may need to be removed from the threaded rod, but may be blocked if the output member  22   a  is not in the home position, and thus, the output member aperture  86   a  is not aligned with the yoke aperture  48   a,  such that there is no passage allowing for the output member  22   a  to be removed from the rod. 
     Thus, the home actuator  114   a  must be moved to the home position, thereby moving the collar  122   a  to its home position, such that the first blocking portion  182  is positioned between the second non-selective pawl  178  and the toothed surface  66   a,  the second blocking portion  186  is positioned between the first non-selective pawl  58   a  and the toothed surface  66   a,  the opening  190  is positioned adjacent the first selective pawl  50   a,  and no portion of the collar  122   a  is arranged in front of the second selective pawl  54   a,  such that the first and second non-selective pawls  58   a,    178  are inhibited from engaging against and transferring torque to the output member  22   a  via the toothed surface  66   a,  and the first and second selective pawls  50   a,    54   a  are engaged against and capable of transferring torque to the toothed surface  66   a.  The motor  26   a  is then reactivated, causing the yoke  42   a  to perform a series of subsequent first and second pivot motions, until the output member  22   a  is rotated to the home position, as described below. 
     Specifically, as the yoke  42   a  is undergoing the first pivot motion (pivoting counterclockwise as viewed in  FIG.  13    about the longitudinal axis  74 ), because the first and second non-selective pawls  58   a,    178  are respectively blocked by the second and first blocking portions  186 ,  182  of the collar  122   a,  neither of the first and second non-selective pawls  58   a,    178  engage against the toothed surface  66   a.  However, because the first and second selective pawls  50   a,    54   a  are engaged against the toothed surface  66   a,  and because of their respective orientations, the first and second selective pawls  50   a,    54   a  transfer torque to the output member  22   a  via the toothed surface  66   a.  Thus, during the first pivot motion while the home actuator  114   a  and the collar  122   a  are in their respective home positions, the output member  22   a  is caused to rotate in the first (counterclockwise) direction about the longitudinal axis  74   a.    
     As the crankshaft  34   a  continues to rotate the drive bushing  36   a,  the yoke  42   a  undergoes the second pivot motion (pivoting clockwise as viewed in  FIG.  13    about the longitudinal axis  74   a ). Although the first and second selective pawls  50   a,    54   a  are engaged against the toothed surface  66   a,  because of their respective orientations, both of the first and second selective pawls  50   a,    54   a  simply ratchet across the toothed surface  66   a  as the yoke  42   a  is undergoing the second pivot motion. Thus, during the second pivot motion, no torque is transferred to the toothed surface  66   a,  and the output member  22   a  remains in place. 
     After completing the second pivot motion, the yoke  42   a  continues to perform a series of subsequent first and second pivot motions until the output member  22   a  is rotated to the home position. Once the output member  22   a  is in the home position, neither of the first or second selective pawls  50   a,    54   a  is capable of transferring torque to the output member  22   a  even when the yoke  42   a  is undergoing the first pivot motion. Thus, the output member  22   a  stops rotating even while the yoke  42  continues to reciprocate. The motor  26   a  is then subsequently deactivated, leaving the output member  22   a  in the home position. Because the output member aperture  86  is re-aligned with the yoke aperture  48   a,  a passage is opened for the rod to be laterally removed from the output member  22   a,  thus removing the ratcheting power tool  10   a  from the rod. 
     In operation, when an operator wishes to move the nut in a second direction along the rod that is opposite the first direction, the ratchet tool  10   a  may be vertically flipped and nut may be arranged in the output member  22   a  as discussed above. Then, the motor  26   a  may be activated and the first and second pivot motions of the yoke  42   a  described above may be repeated until the nut has been moved a sufficient distance along the rod in the second direction. 
     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. 
     Various features of the invention are set forth in the following claims.