Abstract:
A ratchet wrench includes a tubular body, a ratchet unit, a driving head, a control unit and a connection unit. The ratchet unit is operated in either rotation mode or spinning mode. The control unit controls the ratchet unit to rotate clockwise or counter clockwise. The connection unit is connected with a tool. When the body is rotated, the ratchet unit drives the driving head to rotate an object connected to the driving head. When the tool is span relative to the body, the ratchet unit also drives the driving head to rotate an object.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Fields of the invention 
         [0002]    The present invention relates to a ratchet wrench, and more particularly, to a ratchet wrench for efficiently driving an object. 
         [0003]    2. Descriptions of Related Art 
         [0004]    The conventional ratchet wrench is disclosed in U.S. Pat. No. 6,311,584, and comprises a handle having an internal gear formed in a head. One or more ring gears are rotatably received in the head and engaged with a bevel gear which is received in the handle for rotating the ring gears. A seat is rotatably received in the head and has a driving stem and includes two rotatable pawls each having two end teeth for selectively engaging with the internal gear and for selectively driving the driving stem. One or more rods are engaged between the ring gears and the seat to drive the seat and the driving stem with the ring gears. 
         [0005]    However, the handle and the rods have no proper restriction mechanism to secure the connection therebetween so that there is a relative rotation between the handle and the rod. When a user holds the handle to rotate the rod, the handle spin slightly and this may cause unexpected result. The ratchet wrench cannot be cooperated with the normal screwdriver with a fixed handle, such that the range of use is restricted. 
         [0006]    The present invention intends to provide a ratchet wrench to eliminate the shortcomings mentioned above. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention relates to a ratchet wrench and comprises a tubular body, a ratchet unit, a driving head, a control unit and a connection unit. The ratchet unit is operated in either rotation mode or spinning mode. The control unit controls the ratchet unit to rotate clockwise or counter clockwise. The connection unit is connected with a tool. When the body is rotated, the ratchet unit drives the driving head to rotate an object connected to the driving head. When the tool is span relative to the body, the ratchet unit also drives the driving head to rotate an object. 
         [0008]    The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is an exploded view of the ratchet wrench of the present invention; 
           [0010]      FIG. 2  is an exploded view of the ratchet unit of the ratchet wrench of the present invention; 
           [0011]      FIG. 3  is a perspective view to show the ratchet unit of the ratchet wrench of the present invention; 
           [0012]      FIG. 4  is an exploded view of the connection unit of the ratchet wrench of the present invention; 
           [0013]      FIG. 5  shows the inner arrangement of the sleeve of the connection unit of the ratchet wrench of the present invention; 
           [0014]      FIG. 6  shows the tool to be connected with the ratchet wrench of the present invention; 
           [0015]      FIG. 7  shows the parts in the tool in  FIG. 6 ; 
           [0016]      FIG. 8  is a top view of the tool in  FIG. 7 ; 
           [0017]      FIG. 9  is a side view of the tool in  FIG. 7 ; 
           [0018]      FIG. 10  is a perspective view to show that the tool is connected with the ratchet wrench of the present invention; 
           [0019]      FIG. 11  is a side view of the combination in  FIG. 10 ; 
           [0020]      FIG. 12  is a cross sectional view, taken along line A-A in  FIG. 12 ; 
           [0021]      FIG. 13  is an enlarged view of the circled portion “B” in  FIG. 12 ; 
           [0022]      FIG. 14  is an enlarged view of the circled portion “C” in  FIG. 12 ; 
           [0023]      FIG. 15  is a cross sectional view to show that the tool is separated from the ratchet wrench of the present invention; 
           [0024]      FIG. 16  is an enlarged view of the circled portion “C” in  FIG. 15 ; 
           [0025]      FIG. 17  is a perspective view to show that the tool is separated from the ratchet wrench of the present invention; 
           [0026]      FIG. 18  shows that the tool is spanned by operating the ratchet wrench of the present invention; 
           [0027]      FIG. 19  is a cross sectional view, taken along line F-F in  FIG. 19 , and 
           [0028]      FIG. 20  is an enlarged view of the circled portion “G” in  FIG. 19 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0029]    Referring to  FIGS. 1 to 10 , the ratchet tool of the present invention comprises a tubular body  10 , a ratchet unit  20 , a driving head  21 , a control unit  30  and a connection unit  40 . The body  10  has a function end  100  at the first end thereof, the function end  100  is a ring-like end and has a toothed portion  11  defined in an inner periphery thereof. A top circular slot  12  and a bottom circular slot  13  are respectively defined in the function end  100 , and the toothed portion  11  is located between the top and bottom circular slots  12 ,  13 . A passage  14  is defined axially in the body  10 . A first connection portion  15  is formed at the second end of the body  10  and has inner teeth. 
         [0030]    The ratchet unit  20  is located in the function end  100  and includes the driving head  21 . The control unit  30  is connected to the function end  100  to control the ratchet unit  20  to rotate clockwise or counter clockwise. When the body  10  is rotated, the driving head  21  is rotated to rotate an object connected to the driving head  21 . The driving head  21  has an operation portion  215  which is able to be connected with a rectangular recess of a socket, a rod or an adaptor. 
         [0031]    As shown in  FIGS. 2 and 3 , the ratchet unit  20  includes the driving head  21 , a ring  22 , a bottom toothed ring  23 , two first pins  24 , two second pins  25 , two pawls  26 , a top toothed ring  27  and a seat  28 . The driving head  21  has two first circular holes  211  and two second circular holes  212  on the top thereof, wherein the first circular holes  211  are larger than the two second circular holes  212 . The top section of the driving head  21  includes a cylindrical portion  210  which has two recessed areas  214  defined in two sides thereof. Each recessed area  214  has a flat first contact face  213 . The driving head  21  has a rectangular driving portion  215  extending from the lower section thereof so as to be connected with a rectangular recess of a socket, a rod or an adaptor. The ring  22  is mounted to the cylindrical portion  210 , wherein the diameter of the hole of the ring  22  is the same as the outer diameter of the cylindrical portion  210 . The outer diameter of the ring  22  is larger than the diameter of the flange  216  on the middle portion of the driving head  21 . The bottom toothed ring  23  has first teeth  231 , the bottom toothed ring  23  is rotatably mounted to the cylindrical portion  210  and rested on the ring  22 . A portion of the first inner periphery  232  of the bottom toothed ring  23  faces the first contact face  213  to form the recessed area  214 . The first pins  24  are inserted into the first circular holes  211 , and the second pins  25  are inserted into the second circular holes  212 . The two pawls  26  are connected to the top of the driving head  21 . Each pawl  26  has engaging teeth  260  formed in each of the two ends thereof so as to be engaged with the toothed portion  11 . The pawls  26  each have a first pivot hole  261  which is in alignment with the first circular hole  211  so that the first pin  24  extends through the first pivot hole  261  and the first circular hole  211  corresponding thereto. The top toothed ring  27  has the same diameter as the bottom toothed ring  23 . The top toothed ring  27  has second teeth  271  which are located corresponding to the first teeth  231 . The top toothed ring  27  has a second inner periphery  272 . The seat  28  is located above the driving head  21 . The top toothed ring  27  is mounted to the lower section of the seat  28 . The seat  28  has two third circular holes  281  and two fourth circular holes  282  which are respectively located corresponding to the first circular holes  211  and the second circular holes  212 . The first pins  24  extend through the third circular holes  281 , and the second pins  25  extend through the fourth circular holes  282 . The seat  28  has two recessed areas  280  defied in two sides of the lower end thereof, each recessed area  280  of the seat  28  has a flat second contact face  283  which is located on the same plane as the first contact face  213  corresponding thereto. The seat  28  has a central hole  284  defined therethrough. The second clip  60  is mounted to the outside of the driving head  21  to restrict the ratchet unit  20  from dropping from the function end  100 . 
         [0032]    As shown in  FIGS. 1 and 11-13 , the control unit  30  has a controller  31 , two first resilient members  32  and two pivots  33 . The controller  31  has a protrusion  311  which has two notch  3110  on two sides thereof. The protrusion  311  extends through the central hole  284 . The top of the controller  31  is exposed from the seat  28  so that the user can operate the controller  31  by rotating the top of the protrusion  311 . The first pins  24  extend through the first pivot holes  261 , and two ends of each first pin  24  are engaged with the first circular hole  211  and the third circular hole  281 . The second pins  25  respectively extend through the first resilient members  32 . The two ends of each of the resilient members  32  contact the protrusion  311  and the pivot  33  corresponding thereto. The two ends of each second pin  25  are respectively engaged with the second circular hole  212  and the fourth circular hole  282  corresponding thereto. Each first resilient member  32  has a convex curved portion which is pivotably engaged with the notch  3110  of the protrusion  311  corresponding thereto. Each first resilient member  32  has a concaved curved portion which is pivotably engaged with the pivot  33  corresponding thereto. Each of the two pivots  33  contacts the recessed area  214  of the driving head  21  corresponding thereto. One of the two ends of each pivot  33  is located between the first contact face  213  and the first inner periphery  232 , and the other end of the pivot  33  is located between the second contact face  283  and the second inner periphery  272 . When rotating the controller  31  to pivot the pawl  26  to rotate about the first pin  24 ,, the controller  31  drives the first resilient member  32  which moves the pivot  33  in the recessed area  214  so as to control the direction of rotation of the ratchet unit  20 . The engaging teeth  260  of the pawl  26  are engaged with the toothed portion  11 . 
         [0033]    As shown in  FIGS. 4 and 5 , the connection unit  40  has a tube  41 , the driving member  42 , a fixing member  43 , a sleeve  44 , a spring  46 , a bead  47  and a sealing member  48 . The tube  41  extends through the passage  14  defined axially in the body  10  and has a room  411  defined axially therein. The room  411  of the tube  40  has a restriction portion  412  formed at the first end of the tube  40 . A second connection portion  413  with threads is formed at the outside of the middle portion of the tube  41  and is connected to the second connection portion  15  of the body  10 . A flange  414  extends outward and radially from the outside of the tube  41 . A hole  416  is defined radially in the wall of the tube  41  and communicates with the room  411 . The driving member  42  is fixedly connected to a driving block  49  which is rotatably received in the room  411 . The restriction portion  412  restricts the driving block  49  from dropping from the tube  40 . The driving block  49  has a first engaging portion  493  extending from one end thereof so as to be connected with a second engaging portion  511  of a rod  51  of a tool  50  which has a handle  58 . The first engaging portion  493  is a hexagonal rod and the second engaging portion  511  is a hexagonal recess. The driving block  49  has a non-circular extension  491  extending from the other end thereof. The extension  491  has a receiving hole  492  in which threads are defined. The extension  491  is co-rotatably inserted in the driving member  42  by using the fixing member  43 . The driving member  42  is exposed from the first end of the tube  40 . The third teeth  421  are engaged with the first and second teeth  231 ,  271  simultaneously so as to rotate the ratchet unit  20  within the function end  100 . 
         [0034]    The sleeve  44  is mounted to the tube  40  and axially movable along the tube  40  between a releasing position and an engaging position. The sleeve  44  has an anti-slip surface  446  which includes multiple ridges. The sleeve  44  has a reception area  441  defined in the first end thereof. A front stop  443  and a rear stop  445  respectively extend inward from the inner periphery of the sleeve  44 . The front stop  443  has a step face  442  facing the first end of the sleeve  44  which is located corresponding to the flange  414  of the tube  41 . The spring  46  is mounted to the tube  40  and received in the reception area  441 . The spring  46  is biased between the stop face  442  and the flange  44  to provide a force to move the sleeve  44  between the releasing portion and the engaging position. The bead  47  partially protrudes from the hole  416  of the tube  41 . The sealing member  48  contacts against the rear stop  445  and located outside of the tube  40  to restrict the sleeve  44  and the spring  46  from dropping from the tube  40 . The tube  40  has a groove  417  defined in the outside thereof. The sealing member  48  is a C-shaped clip which has a portion engaged with the groove  417 , another portion of the sealing member  48  protrudes from the groove  417  and contacts the rear stop  445 . 
         [0035]    As shown in  FIGS. 6 to 9 , the rod  51  of the tool  50  is connected to the driving block  49  so as to drive the driving member  42 . The tool  50  includes the cylindrical rod  51 , a switch unit  52 , a ratchet unit  53 , a differential unit  54 , a planet gear set  55 , a connector  56 , an outer sleeve  57  and a handle  58 . The rod  51  rotatably extends through the room  411  of the tube  41 , and has a hexagonal second engaging portion  511  which is connected to the first engaging portion  493 . When spinning the rod  51 , the driving block  49  and the driving member  42  are rotated about the passage  14 . The rod  51  has a groove  512  which is located corresponding to the hole  416  for receiving the bead  47 , such that the bead  47  is engaged with the groove  512 . The rod  51  is restricted by the bead  47 , and the second engaging portion  511  is restricted by the first engaging portion  493 . The ratchet unit  53  provides the tool  50  with the ratcheting function. The switch unit  52  allows the user to change the direction of rotation of the ratchet unit  53 . The differential unit  54  makes the rod  51  to rotate clockwise regardless of the rotation of the ratchet unit  53 . When operating the switch unit  52 , the differential unit  54  makes the rod  51  to rotate counter clockwise regardless of the rotation of the ratchet unit  53 . The differential unit  54  includes four bevel gears  540 / 541 , wherein the two bevel gears  540  are perpendicularly engaged with the other two bevel gears  541 . The planet gear set  55  allows the rod  51  to be rotated at high speed. The connector  56  is fixed to the tool  50  and is connected to the planet gear set  55 . 
         [0036]    As shown in  FIGS. 6-10 , the outer sleeve  57  is mounted to outside of the ratchet unit  54  and the planet gear set  54  to stably receive the ratchet unit  54  and the planet gear set  54  in the tool  50 . The handle  58  is connected to the tool  50  and the connector  56  so that a user can hold the handle  58  to rotate the rod  51 . If the tool  50  is a screwdriver, then the switch unit  52 , the ratchet unit  53 , the differential unit  54 , the planet gear set  55 , the connector  56  and the outer sleeve  57  can be omitted. The handle  58  is directly connected to the rod  51 . If the tool  50  is a ratchet screwdriver, the differential unit  54  and the planet gear set  55  will be not necessary, and the connector  56  is directly connected to the ratchet unit  53 . 
         [0037]    As shown in  FIGS. 12, 14 , the sleeve  44  is mounted to the tube  41 , and the spring  46  provides a force to move the sleeve  44  between the releasing position and the engaging position. When the sleeve  44  is located at the engaging position, the bead  47  is pushed inward by the front stop  443  and engaged with the groove  512 . The rod  51  is fixed to the tube  41 . The tool  50  is connected to the connection unit  40 . 
         [0038]    As shown in  FIGS. 15, 16 , when the sleeve  44  is pushed toward the ratchet unit  20  to the releasing position, the spring  46  is compressed so that the annular groove  444  faces the hole  416 , and the front stop  443  no longer pushes the bead  47  which is released from the groove  512 . The rod  51  is not fixed to the tube  41 , so that the rod  51  can be pulled out from the tube  41  as shown in  FIG. 17 . The second engaging portion  511  of rod  51  can be used to be connected with other tool or part. 
         [0039]    As shown in  FIGS. 18-20 , when the user rotates the handle  58  360 degrees, the rod  51 , the driving block  49  and the driving member  42  are rotated, the driving member  42  then drives the bottom toothed ring  23 , the top toothed ring  27  and the ratchet unit  20  360 degrees, so that the operation portion  215  can drive another tool. 
         [0040]      FIGS. 4 and 6  show that first engaging portion  493  and the second engaging portion  511  can be hexagonal engagement. 
         [0041]    The advantages of the present invention are that the tool  50  is connected to the connection unit  40  to be a wrench when the sleeve  44  is located at the engaging position as shown in  FIGS. 11 and 14 . As shown in  FIG. 16 , when sleeve  44  is located at the releasing position, the rod  51  can be separated from the tube  41  and the tool  50  can be used individually as shown in  FIG. 17 . The connection unit  40  can be directly connected with existed tools. The connection unit  40  is easily assembled to or separated from the body  10  to conveniently replace the driving member  42 . As shown in  FIG. 17 , when the body  10  is not long enough, a long connection rod can be easily connected to the body  10 . 
         [0042]    While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.