Patent Publication Number: US-11389934-B2

Title: Attachment assembly to be connected with a hand tool

Description:
The present invention is a Continuation-In-Part application of applicant&#39;s former application with the application Ser. No. 15/851,740, filed on Dec. 21, 2017. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Fields of the Invention 
     2. Descriptions of Related Art 
     A conventional transmission tool, such as U.S. Pat. No. 7,703,356, includes three body groups  40   a / 40   b / 40   c  that are sequentially pivotally connected. Each body group  40   a / 40   b / 40   c  includes a body  42 , a cover  43 , a plurality of joints  45 , and a first ratchet wheel  52 , a second ratchet wheel  54  and a third ratchet wheel  56 . The bottom of the first receiving groove  46  defined in the body  42  is provided with hole-shaped a first pivoting portion  47   b , a second pivoting portion and a third pivoting portion  49   b . A curved surface-shaped locking portion  48  is defined on the outer circumference of one end of the body  42 . The locking portion  48  is provided with first engaging teeth  62 . The first ratchet wheel  52 , the second ratchet wheel  54  and the third ratchet wheel  56  are pivotally disposed in the first pocket  46 . Each cover  43  is movably assembled with an arc-shaped restrict member  60  which has second engaging teeth  61  for switching to engage with the first engaging teeth  62  or not to control the body group  40   b  to rotate with respect to body groups  40   a / 40   c  or not. However, the prior patent has disadvantages: (1) The restrict member  60  is exposed on the outside of each body group  40   a / 40   b / 40   c , which is not only unsightly, but also easily touched during operation, so that the second engaging teeth  61  and the first engaging teeth  62  accidentally disengaged, and so that the two body groups are arbitrarily rotated to cause inconvenience; (2) The second engaging teeth  61  and the first engaging teeth  62  have a small number of meshing teeth (8 teeth at most), so that the meshing rigidity is not good; and (3) The first engaging teeth  62  of the locking portion  48  is exposed outside the body  42  and is not aesthetically pleasing. 
     The present invention intends to provide an attachment unit for being connected with a hand tool so as to transfer large torque to objects. 
     SUMMARY OF THE INVENTION 
     The present invention relates to an attachment assembly for being connected with a hand tool, and comprises an active unit, a passive unit and a switching shaft. The active unit includes a first base and a first cover. A front wheel, a middle wheel and a rear wheel are rotatably received in a space between the first base and the first cover in sequence. The front, middle and rear wheels are engaged with each other. The passive unit includes a second base and a second cover. A first wheel and a second wheel are rotatably received in a space between the second base and the second cover. The first and second wheels are engaged with each other. The switching shaft pivotably connects the active unit and the passive unit which is pivotably connected to the active unit. The switching shaft switches the active unit and the passive unit being rotatable or not. 
     The primary object of the present invention is to provide an attachment assembly for being connected with a hand tool, wherein the active and passive units are pivotable relative to each other. The engagement between the front, rear, middle, first and second wheels provides features for different work tasks. 
     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 
         FIG. 1  is an exploded view of the attachment assembly of the present invention; 
         FIG. 2  is an exploded view of the active unit of the attachment assembly of the present invention; 
         FIG. 3  is a perspective view to show the attachment assembly of the present invention; 
         FIG. 4  is a side view to show the attachment assembly of the present invention; 
         FIG. 5  is a cross sectional view, taken along line A-A of  FIG. 4 ; 
         FIG. 6  shows is a top view to show the attachment assembly of the present invention; 
         FIG. 7  shows is a cross sectional view, taken along line B-B of  FIG. 6  to show the switching shaft being positioned at first position; 
         FIG. 8  shows is a cross sectional view, taken along line B-B of  FIG. 6  to show the switching shaft being positioned at second position; 
         FIG. 9  shows the active unit and the passive unit of the attachment assembly of the present invention having an inclined angle; 
         FIG. 10  shows the attachment assembly of the present invention being cooperated with two hand tools; 
         FIG. 11  is a perspective view to show two passive units of the attachment assembly of the present invention connecting together; 
         FIG. 12  is a perspective view to show the active unit and two passive units of the attachment assembly of the present invention connecting together and having an inclined angle respectively; 
         FIG. 13  shows the attachment assembly of the present invention being cooperated with two hand tools and connected with a workpiece; 
         FIG. 14  is a perspective view to show the second embodiment of the attachment assembly of the present invention, and 
         FIG. 15  is a cross sectional view of the second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1 to 6 , the attachment assembly of the present invention comprises an active unit  10 , a passive unit  20  and a switching shaft  30 . 
     The active unit  10  comprises a first base  11  and a first cover  15  which is mounted to the first base  11 . Each of the first base  11  and the first cover  15  has a front end and a rear end. A front wheel  12 , a middle wheel  14  and a rear wheel  13  are rotatably received in the space between the first base  11  and the first cover  15  in sequence. The first base  11  has a front recess  111 , a middle recess  112  and a rear recess  113 . The front recess  111  has a front pivotal hole  1111  defined through the bottom thereof. A first opening  1121  is defined in communication between the front and middle recesses  111 ,  112 . The rear recess  113  opens to the rear end of the first base  11 . A second opening  1131  is defined in communication between the middle and rear recesses  112 ,  113 . The rear recess  113  has a rear pivotal hole  1132  defined through the bottom thereof. A lateral slot  1130  defined from a lateral wall of the rear recess  113  and through a rear end of the first base  11 . Multiple first engaging teeth  11320  are defined on the inner periphery of the rear pivotal hole  1132 . A first mounting hole  114  is defined through the front end of the first base  11  such that the front recess  111  is located between the first mounting hole  114  and the middle recess  112 . The first base  11  includes four even-spaced locking holes  115 . In one preferred embodiment, the number of the multiple first engaging teeth  11320 , the multiple second engaging teeth  2161  and the multiple third engaging teeth  32  are 10˜20 respectively. 
     The front wheel  12 , the middle wheel  14  and the rear wheel  13  are respectively and rotatably received in the front recess  111 , the middle recess  112  and the rear recess  113 . The front wheel  12 , the middle wheel  14  and the rear wheel  13  have the same diameter. Each of the front wheel  12 , the middle wheel  14  and the rear wheel  13  has teeth  121 / 131 / 141  defined in an outside thereof. A polygonal engaging portion  122  is defined centrally in the front wheel  12  for connecting a workpiece. The teeth  121  of the front wheel  12  are engaged with the teeth  141  of the middle wheel  14  via the first opening  1121 . The teeth  141  of the middle wheel  14  are engaged with the teeth  131  of the rear wheel  13  via the second opening  1131 . The rear wheel  13  has an axial hole  132  defined centrally therethrough. An enlarged receiving hole  133  is defined in the bottom portion of the axial hole  132  so that the inner diameter of the enlarged receiving hole  133  is larger than that of the axial hole  132 . The middle wheel  14  includes a first receiving portion  142  and an annular groove  143  located around the first receiving portion  142 . A ring-shaped resilient member  144  is engaged with the annular groove  143 . 
     The first cover  15  has two bores  151 ,  152  respectively located close to the front end and the rear end of the first cover  15 . The two bores  151 ,  152  are respectively located corresponding to the front recess  111  and the rear recess  113 . The front wheel  12  is rotatably engaged between the front pivotal hole  1111  and the bore  151  located close to the front end of the first cover  15 . The engaging portion  122  and the axial hole  132  are respectively exposed. The rear wheel  13  is rotatably engaged between the rear pivotal hole  1132  and the bore  152  located close to the rear end of the first cover  15 . The first base  11  and the first cover  15  each have even-spaced locking holes  115 ,  155 . Multiple rivets  16  are riveted through the locking holes  115 ,  155  to connect the first base  11  and the first cover  15 . The first cover  15  covers up the middle wheel  14 . The ring-shaped resilient member  144  is engaged with the annular groove  143  and contacts the first cover  15  so that when the middle wheel  14  is rotated, a damper is generated by the ring-shaped resilient member  144 . 
     The passive unit  20  includes a second base  21  and a second cover  210  which is mounted to the second base  21 . A first wheel  22  and a second wheel  23  are rotatably received in the space between the second base  21  and the second cover  210 . The teeth  221  of the first wheel  22  is engaged with teeth  231  of the second wheel  23  and teeth  131  of the rear wheel  13 . 
     The second base  21  has a recessed area  214 , a first recess  211  and a second recess  212  defined therein. A third opening  2111  is defined in communication between the recessed area  214  and the first recess  211 . The second recess  212  has a third bore  213  defined through the bottom thereof. The inner diameter of the second recess  212  is larger than that of the third bore  213 . A fourth opening  2121  is defined in communication between the first recess  211  and the second recess  212 . The rear end of the active unit  10  is rotatably located in the recessed area  214 . The rear recess  113  of the active unit  10  communicates with the first recess  211  via the third opening  2111 . The first wheel  22  has a circular second receiving portion  222 , and the second wheel  23  has a polygonal engaging portion  232  defined axially therethrough for engaging with a workpiece or a tool bit. The recessed area  214  has a first bore  216  defined through the bottom thereof. An enlarged circular recess  215  is defined in the bottom portion of the first bore  216  so that the inner diameter of the enlarged circular recess  215  is larger than that of the first bore  216 . Multiple second engaging teeth  2161  are defined on inner periphery of the first bore  216 . The second cover  210  has a second bore  218  corresponding to the first bore  216  of the second base  21 . An enlarged circular recess  219  is defined in the top portion of the second bore  218 . The first and second wheels  22 ,  23  are respectively and rotatably received in the first and second recesses  211 ,  212 . The outer teeth  221  of the first wheel  22  are engaged with the outer teeth  231  of the second wheel  23  via the fourth opening  2121  so that the first wheel  22  and the second wheel  23  can be rotated simultaneously. The outer teeth of the first wheel  22  are engaged with the outer teeth  131  of the rear wheel  13  via the third opening  2111  and lateral slot  1130  so that the first wheel  22  and the rear wheel  13  can be rotated simultaneously. Two ends of the second wheel  23  is rotatably engaged between the third bore  213  of the second recess  212  and another third bore  213  of the second cover  210 . Multiple rivets  24  extend through the locking holes  217  to connect the second cover  210  to the second base  21 . The second cover  210  is the same shape as the second base  21  but only the second bore  218  of the second cover  210  has no the multiple second engaging teeth  2161  of the first bore  216 . 
     A switching shaft  30  movably extends through the first bore  216  of the recessed area  214 , the rear pivotal hole  1132  of the first base  11 , the axial hole  132  of the rear wheel  13  and the second bore  218  of the second cover  210 . A spring  38  sleeves on the switching shaft  30  for providing an elastic force for the switching shaft  30  so that the switching shaft  30  can axially move back from a second position to a first position. A cylinder body  33  is defined at a top portion of the switching shaft  30 . The cylinder body  33  pivots through the axial hole  132  of the rear wheel  13  and the second bore  218  of the second cover  210 , so that the active unit  10  and the passive unit  20  are pivotable about the switching shaft  30  to adjust the inclined angle between the active unit  10  and the passive unit  20 . The switching shaft  30  has a head  31  defined on the bottom end thereof, and multiple third engaging teeth  32  are surrounding defined on a middle portion of the switching shaft  30  for engaging with the second engaging teeth  2161  and/or the first engaging teeth  11320 . A screwed hole  35  is defined on top end of the switching shaft  30  for connecting with a screw  39 . The outer diameter of the head  31  is larger than that of the third engaging teeth  32 . The outer diameter of the third engaging teeth  32  is larger than that of cylinder body  33 . The head  31  of the switching shaft  30  and the head  390  of the screw  39  are respectively received in the enlarged recess  215  of the second base  21  and the enlarged recess  219  of the second base  21 , and the end faces  34 / 391  of the heads  31 / 390  are respectively restricted by the corresponding bottoms of the enlarge recesses  215 / 219  so as to restrict the switching shaft  30  from dropping from the bores  216 / 218  and the axial hole  132 . 
     Referring to  FIGS. 1, 7, 8, 9, 14 and 15 , when the switching shaft  30  is supported by the spring  38  to position at the first position, the third engaging teeth  32  simultaneously engage with the second engaging teeth  2161  and the first engaging teeth  11320 , the active unit  10  and the passive unit  20  cannot be rotated with respect to each other. When the user provides a force to press the head  31  of the switching shaft  30  so that the switching shaft  30  move from the first position to the second position and compress the spring  38  to have an elastic force, and the third engaging teeth  32  does not engage with the second engaging teeth  2161  but only engage with the first engaging teeth  11320 , the active unit  10  and the passive unit  20  can be rotated with respect to each other. Referring to  FIGS. 1, 7 and 8 , in one embodiment of the present invention, the spring  38  is positioned in the enlarged circular recess  215  and bias between the bottom of the enlarged circular recess  215  and end face  34  of the head  31  of the switching shaft  30 , and top end portions of the third engaging teeth  32  are received in the enlarged receiving hole  133  when the switching shaft  30  is positioned at the second position. Referring to  FIGS. 14 and 15 , in another embodiment of the present invention, the spring  38  is positioned in the enlarged circular recess  219  and bias between the bottom of enlarged circular recess  219  and the end face  391  of the head  390  of the screw  39 . 
     As shown in  FIGS. 1, 2, 10 and 13 , when the users want to pick out the bolt  51  at the object  52 , because there is a distance  54  between the two objects  53 , the active and passive units  10 ,  20  can be adjusted an angle so that the passive unit  20  is inserted into the distance to be mounted to the bolt  51 . The engaging portion  232  is mounted to the bolt  51 , and the two hand tools  40 ,  41  are respectively connected with the engaging portion  122  and the first mounting hole  114 . When rotating the hand tool  40 , the front wheel  12  drives the middle wheel  14 , the rear wheel  13 , the first wheel  22  and the second wheel  23 . The bolt  51  is able to be rotated and picked out from the object  52 . 
     As shown in  FIGS. 11 and 12 , there are two passive units  20 . The second wheel  23  of one of the two passive units  20  is located in the recessed area  214  of the other one of the two passive units  20 . A pin  300  extends through the engaging portion  232  of the second wheel  23  and the recessed area  214  to connect the two passive units  20 . 
     As shown in  FIGS. 1 and 2 , the second base  21  and the second cover  210  have same shapes of recessed area  214 , first recess  211 , second recess  212  coaxially bore  213 , third opening  2111  and fourth opening  2121 . The second base  21  and the second cover  210  cover with each other and receive the first and second wheels  22 ,  23  in the first and second recesses  211 / 212 . 
     The advantages of the present invention are that the active and passive units  10 ,  20  are pivotably connected to each other. The front wheel  12 , the middle wheel  14 , the rear wheel  13 , the first wheel  22  and the second wheel  23  are co-rotated. Therefore, the operational status can be easily adjusted to meet different work tasks as shown in  FIGS. 4 and 5 . The attachment assembly can be cooperated with two hand tools  40 ,  41  as shown in  FIG. 10 , the users can easily grip the hand tools  40 ,  41  to output torques. As shown in  FIGS. 11 and 12 , there can be cooperated with multiple passive units  20  to extend the length of the combination of the attachment assemblies, and multiple angles can be set to deal with different work requirements. As shown in  FIGS. 7, 8 and 15  especially, the switching shaft  30  is axially movable to switch rotatable status and un-rotatable status between the active unit  10  and the passive unit  20 . 
     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.