Abstract:
A ratcheting tool includes a handle and a head in which a gear wheel is rotatably mounted. A pawl is mounted in the head and includes a toothed first side engaged with the gear wheel and a second side facing away from the gear wheel, with the second side of the pawl including two spaced operative sections. A ball is biased to engage with one of the operative sections of the pawl, thereby biasing the pawl teeth to mesh with the gear wheel teeth and biasing the pawl to bear against a wall of the head. A switch member is pivotally mounted to the head and includes a first end engaged with the pawl to move therewith and a second end for manual operation. The switch member is pivotally movable between two positions to optionally cause the ball to engage with one of the operative sections of the pawl, thereby allowing change in ratcheting direction of the ratcheting tool.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an improved gear wheel/pawl engagement for a reversible ratcheting tool. 
     2. Description of the Related Art 
     U.S. Pat. No. 1,957,462 to Kress issued on May 8, 1934 discloses a ratchet wrench including a ratchet wheel  24  housed in a cylindrical recess  23  in the head  22 . A pawl  25  is mounted in a second cylindrical recess  26  in the head  22  for controlling movement of the ratchet wheel  24 . The pawl  25  is retained in place by a spring-biased plunger  41 . Upon rotation of a thumb-piece  58  connected to the pawl  25 , the pawl  25  is movable between two positions and thus provides driving and ratcheting of a socket in opposite directions. The pawl  25  is pivoted through a relatively long distance in the head  22 , i.e., the head  22  must be relatively large to allow pivotal movement of the pawl  25 . Furthermore, the pawl  25  engages with the teeth of the ratchet wheel  24  by only two teeth, i.e., the wrench is not capable of bearing high torque. 
     U.S. Pat. No. 4,328,720 to Shiel issued on May 11, 1982 discloses a socket wrench including a drive ring  30 , a pawl  50  mounted in a recess  52  in the head  21  of the socket wrench and having two toothed portions  56  and  57 , and an external latch handle  53  for controlling position of the pawl  50 , thereby optionally causing a desired one of the toothed portions  56  and  57  to engage with a ratcheted outer peripheral portion  48  of the drive ring  30  and thus changing the ratcheting direction. Nevertheless, there are too many components in this socket wrench, and the head  21  is relatively large, as it has to receive the components. Processing and assembly for the components are both troublesome and time-consuming. In addition, transmission between the elements for changing the ratcheting direction is not reliable, as the latch handle  53  does not directly actuate the pawl  50 . Furthermore, each toothed portion  56 ,  57  has only two teeth, i.e., the socket wrench is not capable of bearing high torque. 
     U.S. Pat. No. 5,626,062 to Colvin issued on May 6, 1997 discloses a ratchet wrench including a drive gear  48  mounted in a head  44  thereof. A reversing pawl  60  is mounted in the head  44  and has teeth  62  for engaging the drive teeth  50  of the drive gear  48  to provide driving and ratcheting of the socket  22  in opposite directions that are reversible by movement of the reversing pawl  60  between two positions under control of a reversing lever  102 . The reversing pawl  60  is pivoted through a relatively long distance in the head  44 , i.e., the head must be large enough to allow pivotal movement of the reversing pawl  60 . Furthermore, the pawl  60  engages with the teeth  50  of the drive gear  48  by only two teeth, i.e., the wrench is not capable of bearing high torque. 
     U.S. Pat. No. 4,762,033 to Chow issued on Aug. 9, 1988 discloses a ratchet wrench including a drive head  30  with inner ratchet teeth  42 . A core assembly  34  is rotatably mounted in the drive head  30  and has a tool-coupling stud  56 . Mounted in the core assembly  34  is a pawl  46  that engages with the teeth  42 . Upon rotation of a control plate  60 , the pawl  46  is movable between two positions and thus provides driving and ratcheting of a socket in opposite directions via transmission of an intercoupling, resilient, spring-like wire  104  that is mounted in the core assembly  34 . The pawl  46  engages with the teeth  42  by about five teeth and thus may bear higher torque. Nevertheless, the user must use both hands to switch the ratcheting direction. In addition, there are too many components in this wrench, and the head must be relatively large for receiving the components and allowing movement of the pawl  46 . Processing and assembly for these components are both troublesome and time-consuming. Furthermore, the wire  104  tends to malfunction as a result of fatigue and thus fails to provide the required switching direction. 
     U.S. Pat. No. 4,520,697 to Moetteli issued on Jun. 4, 1985 discloses a ratchet wrench including a holed head  22 ′ having inner ratchet teeth  30 ′. Mounted in the head  22 ′ is a drive member  32 ′ with a hexagonal drive portion  36 ′. Also mounted in the head  22 ′ is a pawl  54 ′ having a first set of ratchet teeth  58 ′ and a second set of ratchet teeth  60 ′ for selectively engaging with the teeth  30 ′. A reverser plate  70 ′ is mounted on top of the drive member  32 ′ and includes two reverser pins  74 ′ for connection with the pawl  54 ′. The ratcheting action is reversible by merely moving the reverser pins  74 ′. Nevertheless, there are too many components in this wrench, and the head is large, as it has to receive the components. In addition, processing and assembly are both troublesome and time-consuming. Furthermore, the pawl  54 ′ engages with the teeth  30 ′ by only two teeth, i.e., the wrench is not capable of bearing high torque. 
     U.S. Pat. No. 3,337,014 to Sandrick issued on Aug. 22, 1967 discloses a ratchet wrench including a head  10  provided with internal periphery ratchet teeth  15 . Mounted in the head  10  is a double-ended pawl  26  that is pivotable by a spring pressed plunger  38 . Upon rotation of a finger piece  36 , the pawl  26  is movable between two positions and thus provides driving and ratcheting of a socket in opposite directions. Nevertheless, there are too many components in this wrench, and the head is large, as it has to receive the components. In addition, processing and assembly are both troublesome and time-consuming. The pawl  26  engages with the teeth  15  by only three teeth, i.e., the wrench is not capable of bearing high torque. Furthermore, the user must use both hands to switch the ratcheting direction. 
     U.S. Pat. No. 5,144,869 to Chow issued on Sep. 8, 1992 discloses a ratchet wrench including a handle with two box ends each having a ratchet wheel  12  mounted therein. A pawl  20  is engaged with each ratchet wheel  12 . A knob  30  is mounted in a middle of the handle and receives a disc  40  that is connected to each pawl  20  by two resilient members  26 . When the knob  30  and the disc  40  are rotated, the first toothed section  22  and the second toothed section  23  of each pawl  20  are caused to engage with the associated ratchet wheel  12  via transmission by the resilient members  26 , thereby controlling the torque transmission direction of the ratchet wheel  12 . Nevertheless, the resilient members  26  tend to malfunction as a result of fatigue. In addition, position of each pawl  20  cannot be precisely controlled. The handle structure is weak, as it must be machined to provide a space for receiving the knob  30 , the resilient members  26 , and the pawls  20 . Furthermore, each pawl  20  engages with the ratchet wheel  12  by only two teeth, i.e., the wrench is not capable of bearing high torque. 
     FIG. 14 of the drawings illustrates a ratcheting tool including a head  11 ′ having a first compartment  121 ′ for receiving a drive member  20 ′ with a ratchet wheel  21 ′, a second compartment  122 ′ for receiving a pawl  30 ′, and a third compartment  123 ′ for receiving a switch block  40 ′. The pawl  30 ′ includes teeth  31 ′ formed on a first side thereof for engaging with teeth of the ratchet wheel  21 ′. The switch block  40 ′ includes a first side having two operative sections  416 ′ for selectively bearing against a second side of the pawl  30 ′. A second side of the switch block  40 ′ includes two arcuate grooves  414 ′. A thumb piece  42 ′ includes a stem  421 ′ that extends through a hole  13 ′ in the head  11 ′, a vertical hole  413 ′ in the switch block  40 ′, and a hole  71 ′ of a cover  70 ′. A spring  61 ′ is mounted in a cavity  14 ′ in the web area of the tool for urging a ball  62 ′ to engage with one of the grooves  414 ′. An elastic ring  50 ′ is wound around a stub  411 ′ on the switch block  40 ′ and includes an engaging end  51 ′ engaged in a hole  32 ′ of the pawl  30 ′. Upon rotation of the thumb piece  42 ′, the pawl  30 ′ is movable between two positions and thus provides driving and ratcheting of a socket in opposite directions via transmission of the switch block  40 ′ and the elastic ring  50 ′. The pawl  30 ′ engages with the ratchet wheel teeth by more teeth and thus may bear higher torque. Nevertheless, the pawl  30 ′ has a long travel in the head  11 ′, and the head  11 ′ must be relatively large for receiving the ratchet wheel  21 ′, the pawl  30 ′, and the switch block  40 ′ and allowing pivotal movement of the pawl  30 ′ and the switch block  40 ′. In addition, the elastic ring  50 ′ is required for transmitting the force from the switch block  40 ′ to the pawl  30 ′ so as to change the ratcheting direction. More specifically, position of the pawl  30 ′ cannot be precisely controlled. In addition, the elastic ring  50 ′ tends to malfunction as a result of fatigue. 
     In conclusion, the above-mentioned conventional ratcheting tools fail to provide high torque operation, as most of the pawls merely engage with the ratchet wheel by at best three or five teeth. The head of the ratcheting tool has to be relatively large for accommodating those components and thus is difficult to be used in a limited space. Generally, a skilled user uses a combination wrench, a spanner with two open ends, or a ring spanner for tightening or loosening a fastener in a limited space. Yet, it is found that free rotation of the ratcheting tool during ratcheting is too large (larger than the theoretic value of 5°), as the pawl has a long travel. 
     The present invention is intended to provide an improved gear wheel/pawl engagement for a reversible ratcheting tool that mitigates and/or obviates the above problems. 
     SUMMARY OF THE INVENTION 
     It is a primary object of the present invention to provide a reversible ratcheting tool with an improved gear wheel/pawl engagement to thereby provide improved driving torque while keeping the head to a minimum size. 
     A ratcheting tool in accordance with the present invention comprises: 
     a handle; 
     a head extending from the handle and having a first compartment and a second compartment communicating with the first compartment; 
     a gear wheel rotatably mounted in the first compartment, the gear wheel including an outer periphery with a plurality of first teeth; 
     a pawl mounted in the second compartment and including a first side with a plurality of second teeth facing the first teeth of the gear wheel and a second side facing away from the gear wheel, the second side of the pawl including two spaced operative sections; 
     a biasing means mounted in the second compartment and in operative contact with one of the operative sections of the second side of the pawl for biasing the pawl toward the gear wheel such that the second teeth of the pawl mesh with the first teeth of the gear wheel and for biasing the pawl to bear against a wall defining the second compartment; and 
     a switch member pivotally mounted to the head and including a first end engaged with the pawl to move therewith and a second end for manual operation, the switch member being pivotally movable between two positions to optionally cause the biasing means to engage with one of the operative sections of the pawl, thereby allowing change in ratcheting direction of the ratcheting tool. 
     A web area between the handle and the head includes a cavity for receiving the biasing means. The biasing means includes a ball partially received in the cavity for releasably engaging with one of the operative sections and an elastic member in the cavity for biasing the ball toward said one of the operative sections. 
     Each operative section is a groove having a rectilinear section that is at an angle with a longitudinal direction of the handle. The rectilinear sections of the grooves are spaced by a ridge. The pawl is disengaged from the gear wheel and the ball slides over the ridge during transition from said one of the grooves to the other of the grooves. 
     The pawl includes a vertical slot, and the first end of the switch member includes a peg slidably received in the vertical slot such that pivotal movement of the switch member causes the peg to slide along the vertical slot and thus urge the pawl to move relative to the gear wheel and the biasing means. 
     The gear wheel may include an inner periphery for releasably engaging with a fastener. Alternatively, the gear wheel includes a drive member extended therefrom for releasably engaging with a socket. 
     In a preferred embodiment of the invention, a ratcheting tool comprises: 
     a handle; 
     a head extending from the handle and having a first compartment and a second compartment communicating with the first compartment, a web area being defined between the head and the handle and including a cavity; 
     a gear wheel rotatably mounted in the first compartment, the gear wheel including an inner periphery adapted to be engaged with a fastener and an outer periphery with a plurality of first teeth; 
     a pawl mounted in the second compartment and including a first side with a plurality of second teeth facing the first teeth of the gear wheel and a second side facing away from the gear wheel, the second side of the pawl including two grooves spaced by a ridge, the pawl further including a vertical slot; 
     a ball partially received in the cavity and in operative contact with one of the grooves of the pawl; 
     an elastic member mounted in the cavity for biasing the pawl toward the gear wheel such that the second teeth of the pawl mesh with the first teeth of the gear wheel and for biasing the pawl to bear against a wall defining the second compartment; and 
     a switch member pivotally mounted to the head and including a first end engaged with the pawl and a second end for manual operation, the switch member being pivotally movable between two positions to optionally cause the ball to engage with one of the grooves of the pawl, thereby allowing change in ratcheting direction of the ratcheting tool, the first end of the switch member including a peg slidably received in the vertical slot such that pivotal movement of the switch member causes the peg to slide along the vertical slot and thus urges the pawl to move relative to the gear wheel and the ball. 
     In another preferred embodiment of the invention, a ratcheting tool comprises: 
     a handle; 
     a head extending from the handle and having a first compartment and a second compartment communicating with the first compartment, a web area being defined between the head and the handle and including a cavity; 
     a gear wheel rotatably mounted in the first compartment, the gear wheel including a drive member extending therefrom and adapted to be engaged with a fastener, the gear wheel further including an outer periphery with a plurality of first teeth; 
     a pawl mounted in the second compartment and including a first side with a plurality of second teeth facing the first teeth of the gear wheel and a second side facing away from the gear wheel, the second side of the pawl including two grooves spaced by a ridge, the pawl further including a vertical slot; 
     a ball partially received in the cavity and in operative contact with one of the grooves of the pawl; 
     an elastic member mounted in the cavity for biasing the pawl toward the gear wheel such that the second teeth of the pawl mesh with the first teeth of the gear wheel and for biasing the pawl to bear against a wall defining the second compartment; and 
     a switch member pivotally mounted to the head and including a first end engaged with the pawl and a second end for manual operation, the switch member being pivotally movable between two positions to optionally cause the ball to engage with one of the grooves of the pawl, thereby allowing change in ratcheting direction of the ratcheting tool, the first end of the switch member including a peg slidably received in the vertical slot such that pivotal movement of the switch member causes the peg to slide along the vertical slot and thus urges the pawl to move relative to the gear wheel and the ball. 
     The ratcheting tool in accordance with the present invention may bear much higher torque and has a minimum free rotating angle that is very useful when operating in a limited space. In addition, the ratcheting direction can be changed by easy operation of the switch member. The arrangement for achieving the ratcheting direction switching is simple and thus keeps the head to a minimum size by means of providing a switch member with a peg that is received in the vertical slot of the pawl. 
     Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view, partly exploded, of a reversible ratcheting tool in accordance with the present invention; 
     FIG. 2 is a perspective view of the reversible ratcheting tool in accordance with the present invention; 
     FIG. 3 is a sectional view, in an enlarged scale, of an end portion of the reversible ratcheting tool in accordance with the present invention; 
     FIG. 4 is a sectional view similar to FIG. 3, wherein the gear wheel of the reversible ratcheting tool is rotated through 1°; 
     FIG. 5 is a sectional view similar to FIG. 3, wherein the gear wheel of the reversible ratcheting tool is rotated through 2°; 
     FIG. 6 is a sectional view similar to FIG. 3, wherein the gear wheel of the reversible ratcheting tool is rotated through 3°; 
     FIG. 7 is a sectional view similar to FIG. 3, wherein the gear wheel of the reversible ratcheting tool is rotated through 4°; 
     FIG. 8 is a sectional view similar to FIG. 3, wherein the gear wheel of the reversible ratcheting tool is rotated through 5°; 
     FIG. 9 is a sectional view similar to FIG. 3, wherein the ball is retained in one groove in the pawl; 
     FIG. 10 is a sectional view similar to FIG. 9, wherein the ball is moved to a position between the two grooves in the pawl; 
     FIG. 11 is a sectional view similar to FIG. 9, wherein the ball has been moved into the other groove in the pawl; 
     FIG. 12 is a perspective view, partly exploded, of a second embodiment of the reversible ratcheting tool in accordance with the present invention; 
     FIG. 13 is a perspective view of the reversible ratcheting tool in FIG. 12; and 
     FIG. 14 is an exploded perspective view of a conventional ratcheting tool. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 through 13 and initially to FIGS. 1 and 2, a ratcheting tool in accordance with the present invention is designated by  100  and has a handle  101  and a head  10  extended from the handle  101 . The head  10  includes a relatively larger first compartment  11  and a relatively smaller compartment  12  communicating with the first compartment  11 . A wall that defines the second compartment  12  includes a cavity  13  which is preferably located in a web area (not labeled) between the handle  101  and the head  10 . The head  10  further includes a recessed section  14  in a top face thereof, the recessed section  14  including a ledge  15  proximal to the second compartment  12 . 
     Rotatably mounted in the first compartment  11  is a gear wheel  20  that includes an inner periphery  21  for engaging with a fastener (e.g., a nut or bolt head) to be tightened or loosened and a plurality of teeth  22  in an outer periphery thereof. A pawl  30  is mounted in the second compartment  12  and includes an arcuate first side  31  facing the gear wheel teeth  22 . The arcuate first side  31  has a plurality of teeth  311  for engaging with the gear wheel teeth  22 . The pawl  30  further includes a second side  32  facing away from the gear wheel  20 . The second side  32  includes two operative sections, e.g., two arcuate grooves  34  spaced by a ridge  33 . Preferably, each arcuate groove  34  includes a rectilinear section  36  (FIG. 3) that is adjacent to the ridge  33  and at an angle with a longitudinal direction of the handle  101 . The pawl  30  further includes a vertical slot  35  that is preferably aligned with the ridge  33 . 
     A biasing means  40  is mounted in the cavity  13 . In this embodiment, the biasing means  40  includes a ball  41  engaged with either one of the grooves  34  and an elastic member  42  for biasing the ball  41  to engage with the rectilinear section  36  of the groove  34 . 
     A cover  50  configured corresponding to the head  10  is mounted in the recessed section  14  and includes a first opening  51  that aligns with the first compartment  11  and a second opening  52  that aligns with the second compartment  12 . The cover  50  further includes two holes  53  aligned with two screw holes  141  in the recessed section  14 . Screws  54  are mounted through the holes  53  and  141  to secure the cover  50  to the head  10 . 
     A switch member  60  includes a protrusion  61  formed on an end thereof and extended through the second opening  52  of the cover  50  into the second compartment  12 . A peg  63  projects from the protrusion  61  into the vertical slot  35  of the pawl  30 . The protrusion  61  further includes an annular groove  62  in an outer periphery thereof, and a C-clip  64  is mounted in the annular groove  62  for pivotally retaining the switch member  60  in the second compartment  12  of the head  10 . The protrusion  61  rests on the ledge  15  of the recessed section  14  to provide a stable support for the switch member  60 . 
     The ratcheting tool after assembly is shown in FIG.  3 . It is appreciated that the pawl  30  engages with the gear wheel  20  by at least twelve ( 12 ) teeth and thus may bear higher torque during ratcheting. It is noted that the ball  41  exerts a force on the rectilinear section  36  of the groove  34  of the second side  32  of the pawl  30  under the action of the elastic member  42 . As a result, the force is imparted into a radial force to urge the pawl  30  along the radial direction (the horizontal direction, as seen from FIG. 3) to securely engage with the teeth  22  of the gear wheel  20  and a downward force (as seen from FIG. 3) to urge the pawl  30  to bear against the wall defining the second compartment  12 . Thus, the torque acting on the pawl  30  during ratcheting is transmitted to the wall defining the second compartment  12 . 
     FIGS. 4 through 8 illustrate free rotation of the gear wheel  20 . It is noted that the pawl  30  re-engages with the gear wheel teeth  22  after the gear wheel  20  is rotated through 5° (for a gear wheel with seventy-two (72) teeth). More specifically, the ratcheting tool has a minimum free rotating angle during ratcheting, which is impossible to be achieved by conventional ratcheting tools. 
     The ratcheting tool shown in FIG. 9 is in a status ready for ratcheting clockwise. Namely, counterclockwise rotation of the gear wheel  20  is free rotation. When the ratcheting direction is to be changed, the user may pivot an operative end  65  of the switch member  60  (by the thumb of the hand that grasps the handle  101 ) from its upper position (see FIG. 9) to a middle position shown in FIG.  10 . The peg  63  of the switch member  60  moves from an end of the slot  35  of the pawl  30  that is proximal to the ball  41  to the other end of the slot  35  that is distal to the ball  41 . The pawl  30  actuated by the operative peg  63  moves toward the ball  41  and thus urges the ball  41  into the cavity  13  and compresses the elastic member  42 . As illustrated in FIG. 10, the pawl  30  disengages from the gear wheel teeth  22  when the operative end  65  of the switch member  60  is in its middle position. 
     Referring to FIG. 11, further pivotal movement of the operative end  65  of the switch member  60  to its lower position causes the peg  63  of the switch member  60  to move from the other end of the slot  35  of the pawl  30  that is distal to the ball  41  back to the end of the slot  35  that is distal to the ball  41 . The pawl  30  actuated by the operative peg  63  moves away from the ball  41  under action of the elastic member  42  to re-engage with the gear wheel teeth  22 . In addition, the ball  41  slides over the ridge  33  into the other groove  34 . Thus, ratcheting tool shown in FIG. 11 is in a status ready for ratcheting counterclockwise. Namely, clockwise rotation of the gear wheel  20  is free rotation. The ball  41  exerts a force on the rectilinear section  36  of the other groove  34  under the action of the elastic member  42 . The force is imparted into a radial force to urge the pawl  30  along the radial direction to securely engage with the teeth  22  of the gear wheel  20  and a downward force to urge the pawl  30  to bear against the wall defining the second compartment  12 . Thus, the torque acting on the pawl  30  during ratcheting is transmitted to the wall defining the second compartment  12 . 
     FIGS. 12 and 13 illustrate another embodiment of the invention, wherein like elements are designated by like reference numerals except that the reference numerals are suffixed with a prime. In this embodiment, the ratcheting tool  100 ′ has a handle  101 ′ and a head  10 ′ extended from the handle  101 ′. The head  10 ′ includes a relatively larger first compartment  11 ′ and a relatively smaller compartment  12 ′ communicated with the first compartment  11 ′. A wall that defines the second compartment  12 ′ includes a cavity  13 ′ which is preferably located in a web area (not labeled) between the handle  101 ′ and the head  10 ′. A top face of the head  10 ′ includes a first opening  16 ′ that communicates with the first compartment  11 ′ and a second opening  17 ′ that communicates with the second compartment  12 ′. A sector-like recessed section  18 ′ is formed around the second opening  17 ′. The head  10 ′ further includes a recessed section  14 ′ in a bottom thereof, the recessed section  14 ′ including two screw holes  141 ′. 
     Rotatably mounted in the first compartment  11 ′ is a gear wheel  20 ′ that includes a plurality of teeth  22 ′ in an outer periphery thereof. A drive member  23 ′ extends from the gear wheel  20 ′ for releasably engaging with a socket and. A pawl  30 ′ is mounted in the second compartment  12 ′ and includes an arcuate first side  31  ′ facing the gear wheel teeth  22 ′. The arcuate first side  31  ′ has a plurality of teeth  311 ′. The pawl  30 ′ further includes a second side  32 ′ facing away from the gear wheel  20 ′. The second side  32 ′ includes two operative sections, e.g., two arcuate grooves  34 ′ spaced by a ridge  33 ′. Preferably, each groove  34 ′ includes a rectilinear section that is adjacent to the ridge  33 ′ and at an angle with a longitudinal direction of the handle  101 ′. The pawl  30 ′ further includes a vertical slot  35 ′ that is preferably aligned with the ridge  33 ′. 
     A biasing means  40 ′ is mounted in the cavity  13 ′. In this embodiment, the biasing means  40 ′ includes a ball  41 ′ engaged with either one of the grooves  34 ′ and an elastic member  42 ′ for biasing the ball  41 ′ to engage with the groove  34 ′. Thus, the pawl  30 ′ will engage with the gear wheel teeth  22 ′ by at least twelve (12) teeth such that the ratcheting tool may bear higher torque during ratcheting. 
     A cover  50 ′ configured corresponding to the head  10 ′ is mounted in the recessed section  14 ′ and includes an opening  51 ′ through which the drive member  23 ′ extends. The cover  50 ′ further includes two holes  53 ′ aligned with the screw holes  141 ′ in the recessed section  14 ′. Screws  54 ′ are mounted through the holes  53 ′ and  141 ′ to secure the cover  50 ′ to the head  10 ′. 
     A switch member  60 ′ is pivotally mounted in the sector-like recessed section  18 ′ of the head  10 ′. The switch member  60 ′ includes a protrusion  61 ′ formed on an end thereof and extended through the second opening  17 ′ into the second compartment  12 ′. A peg  63 ′ projects from the protrusion  61 ′ into the vertical slot  35 ′ of the pawl  30 ′. The protrusion  61 ′ further includes an annular groove  62 ′ in an outer periphery thereof, and a C-clip  64 ′ is mounted in the annular groove  62 ′ for pivotally mounting the switch member  60 ′ to the head  10 ′. The switch member  60 ′ further includes an operative end  65 ′ for proceeding with pivotal movement, which is identical to the above embodiment. 
     The embodiment shown in FIGS. 12 and 13 provides a ratcheting tool structure for engaging with sockets of various sizes. Detailed ratcheting direction switching operation and ratcheting operation of this embodiment are identical to those of the first embodiment and therefore not described in detail to avoid redundancy. 
     According to the above description, it is appreciated that the ratcheting tool in accordance with the present invention may bear much higher torque and has a minimum free rotating angle that is very useful when operating in a limited space. In addition, the ratcheting direction can be changed by easy operation of the switch member. The arrangement for achieving the ratcheting direction switching is simple and thus keeps the head in a minimum size by means of providing a switch member with a peg that is received in the vertical slot of the pawl. 
     Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.