Patent Publication Number: US-2019193251-A1

Title: Attachment assembly to be connected with a hand tool

Description:
BACKGROUND OF THE INVENTION 
     1. Fields of the Invention 
     The present invention relates to an attachment assembly for being connected with a hand tool so as to transfer torque to objects. 
     2. Descriptions of Related Art 
     The conventional attachment to be used in conjunction with a ratchet wrench know to applicant is disclosed in U.S. Pat. No. 4,279,314, and comprises a housing having an internal compartment. An access opening is formed within the housing and connected with the internal compartment. A primary drive gear is rotatably mounted within the internal compartment. The primary drive gear has a socket opening centrally located within the primary drive gear. The socket opening connects with the access opening. A secondary drive gear is rotatably mounted within the internal compartment. The secondary drive gear is operatively connected through an idler gear to the primary drive gear. A spring assembly is connected to both the primary and the secondary drive gears. The spring assembly is windable by rotating the socket opening. The socket opens to connect with a socket plug. The spring assembly causes rotation of the socket plug. A movable pawl is mounted on the housing and located within the internal compartment. The movable pawl is movable between an engaging position and a disengaging position. The engaging position connects the movable pawl with one of the drive gears and prevents rotation of the socket opening by the spring assembly. 
     However, the attachment is a rectangular part and cannot be bent an angle when the polygonal shaped opening is connected with an object, so that the combination of the wrench and the attachment cannot be rotated in a small area. Besides, there are the idler gear, the secondary driving gear and the socket sleeve received in the attachment which has a limited room, so that when the wrench rotates the socket plug, the significant torque cannot be generated by the attachment itself. The attachment has to contact against the wrench by the pin. Furthermore, the length of the attachment is limited, when the polygonal shaped opening is connected with an object, only a limited torque is generated and this restricts the range of use of the attachment. 
     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 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 shaft pivotably connects the active unit and the passive unit which is pivotably connected to the active unit. 
     The primary object of the present2invention 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  5 - 5  of  FIG. 4 ; 
         FIG. 6  shows is a cross sectional view, taken along line  5 - 5  of  FIG. 4  to show another operational status; 
         FIG. 7  shows the attachment assembly of the present invention is cooperated with two hand tools; 
         FIG. 8  is a perspective view to show the second embodiment of the attachment assembly of the present invention; 
         FIG. 9  shows another operational status of the second embodiment of the attachment assembly of the present invention; 
         FIG. 10  is an exploded view of the third embodiment of the attachment assembly of the present invention; 
         FIG. 11  is a perspective view to show the third embodiment of the attachment assembly of the present invention; 
         FIG. 12  is an exploded view of the fourth embodiment of the attachment assembly of the present invention; 
         FIG. 13  is an exploded view of the active unit of the fourth embodiment of the attachment assembly of the present invention; 
         FIG. 14  is an exploded view of the passive unit of the fourth embodiment of the attachment assembly of the present invention; 
         FIG. 15  is a perspective view to show the fourth embodiment of the attachment assembly of the present invention; 
         FIG. 16  is a side view to show the third embodiment of the attachment assembly of the present invention; 
         FIG. 17  is a cross sectional view, taken along line  17 - 17  of  FIG. 16 . 
     
    
    
     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 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 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 . 
     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 . 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. 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 cover  15  has a second mounting hole  154  defined through the front end thereof. The first and second mounting holes  114 ,  154  are located corresponding to each other and have the same shape. 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 bore  213  defined through the bottom thereof. 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 . The recessed area  214  has a bore  215  defined through the bottom thereof. The first and second wheels  22 ,  23  are respectively and rotatably received in the first and second recesses  211 ,  212 . The first wheel  22  is engaged with the rear wheel  13  via the third opening  2111 . The second wheel  23  is engaged with the first wheel  22  via the fourth opening  2121 . The second wheel  23  is rotatably engaged between the bore  213  of the second recess  212  and another 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 . 
     A shaft  30  extends through the bore  215  of the recessed area  214  and the axial hole  132  of the rear wheel  13  so that the active unit  10  and the passive unit  20  are pivotable about the shaft  30  to adjust the angle between the active unit  10  and the passive unit  20 . The shaft  30  has a head  31  on the top end thereof, and a groove  32  is defined in the lower end thereof. A clip  35  is engaged with the groove  32 . The head  31  and the clip  35  are respectively received in the two respective enlarged recesses  216  so as to restrict the shaft  30  from dropping from the bore  215  and the axial hole  132 . 
     As shown in  FIGS. 1, 2 and 7 , 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. 8 and 9 , 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. 10 and 11 , the second base  21  and the second cover  210  have different shapes. The second base  21  includes two extensions between which the recessed area  214  is located. The second cover  210  includes the bore  213  which is co-axially located corresponding to the second recess  212 . The second cover  210  covers the first and second wheels  22 ,  23  in the second base  21 . 
     As shown in  FIGS. 12 to 17 , the first base  11  includes a first base board  110  and a first top part  1101  which is connected to the first base board  110 . The first base board  110  includes the front recess  111 , the middle recess  112 , the first opening  1121  and the second opening  1131 . The first top part  1101  includes the front pivotal hole  1111 . The first top part  1101  and the first base board  110  each have the first mounting hole  114  and multiple locking holes  115 . The ring-shaped resilient member  144  is received in the first receiving portion  142 . The rear wheel  13  and the shaft  30  are integrally formed as a one piece. The shaft  30  includes two grooves  32  respectively defined in two ends thereof, and the two grooves  32  are exposed beyond the rear wheel  13 . The bore  152  of the first cover  15  is mounted to one end of the shaft  30 . The second base  21  includes a second base board  2101  and a second top part  2102  which is connected to the second base board  2101 . The rivets  24  extend through the locking holes  217  of the second base  21 , the second cover  210 , and the second top part  2102 . The second base board  2101  includes the first recess  211 , the second recess  212 , the third opening  2111  and the fourth opening  2121 . The second top part  2102  includes the two bores  213 ,  215 , and the two bores  213 ,  215  are respectively co-axial with the second recess  212  and the recessed area  214 . The bore  215  that is co-axial with the recessed area  214  is pivotably connected to the other end of the shaft  30 . The rear wheel  13  is engaged with the middle wheel  14  and the first wheel  22  via the second opening  1131  and the third opening  2111 , so that the front wheel  12 , the middle wheel  14 , the rear wheel  13 , the first wheel  22  and the second wheel  23  are co-rotated. 
     In another embodiment, the groove  32  is a threaded portion which is connected with the clip  35 . The engaging portion  232  is a rectangular protrusion. 
     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. 6 and 7 . The attachment assembly can be cooperated with two hand tools  40 ,  41  as shown in  FIG. 7 , the users can easily grip the hand tools  40 ,  41  to output torques. As shown in  FIGS. 8 and 9 , 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. 
     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.