Patent Publication Number: US-7581468-B2

Title: Control device for angle adjustable hand tool

Description:
BACKGROUND OF THE INVENTION 
   (1) Field of the Invention 
   The present invention relates to a control device for angle adjustable hand tool. 
   (2) Description of the Prior Art 
   A conventional angle adjustable hand tool is disclosed in U.S. Pat. No. 7,131,356 which includes a spring and a positioning plate at the front end of the adjusting member and the positioning plate supports the driving head when the adjusting member is disengaged from the teeth of the driving head such that the driving head does not fall suddenly. However, extra parts are required and the assembly processes becomes complicated and difficult. 
   Another conventional angle adjustable hand tool is disclosed in U.S. Pat. No. 7,131,346 which includes a button and a hole is defined in the center of the button so as to accommodate a second connection member. This requires a larger area for the button. When a small scale of hand tool is manufactured, the area button becomes a difficult part to be manufactured and a small area of button might be broken when drilling the hole at its center. 
   The present invention intends to provide a control device for an angle adjustable hand tool which includes a simple and compact structure and effectively control the driving head during the process for setting its angle. 
   SUMMARY OF THE INVENTION 
   The present invention relates to an angle adjustable hand tool which comprises a handle having a first connection end and a first hole is defined axially in the first connection end so as to receive a spring and a pawl therein. A second hole is defined in the first connection end and perpendicularly communicates with the first hole so as to receive another spring a button therein. A driving head includes a driving member and a second connection end which is pivotably connected to the first connection end and includes a first engagement end. The pawl includes a second engagement end which is removably engaged with the first engagement end. At least one first flat surface is defined in a shank of the pawl and a first contact surface is connected the first flat surface. The button includes at least one second flat surface which is matched with the first flat surface of the pawl. A recess is defined in the button and located substantially perpendicular to the at least one second flat surface. A second contact surface is connected the recess. 
   When the button is pushed, the second contact surface is disengaged from the first contact surface and the pawl is then located in the recess of the button so that the driving head can be pivoted and the first engagement end of the driving head moves over the second engagement end of the pawl to adjust the angle of the driving head relative to the handle. The second engagement end of the pawl is engaged with the first engagement end again when releasing the button. 
   The primary object of the present invention is to provide a control device for adjusting the driving head relative to the handle, the driving head is kept being engaged with a pawl when pivoting to a new angle. The control device is easily to be assembled and operated. 
   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 to show the control device of the angle adjustable hand tool of the present invention; 
       FIG. 1-1  shows the button and the spring for biasing the button; 
       FIG. 1-2  shows the pawl and the spring for biasing the pawl; 
       FIG. 2  shows that the pawl is engaged with the teeth of the driving head; 
       FIG. 3  shows a partial cross sectional view of the control device of the hand tool; 
       FIG. 3-1  is a cross sectional view taken along line a-a in  FIG. 3 ; 
       FIG. 4  is an enlarged cross sectional view to show that the pawl is engaged with the teeth of the driving head; 
       FIG. 5  is a plain view to show the button is pushed and pawl is not positioned by the button; 
       FIG. 6  is a side partial cross sectional view to show that the button is pushed and the driving head is pivoted; 
       FIG. 6-1  is a cross sectional view taken along line b-b in  FIG. 6 ; 
       FIG. 7  is an enlarged cross sectional view to show the pawl is located in the recess of the button when the button is pushed; 
       FIG. 8  is an exploded view to show another embodiment of the control device of the present invention; 
       FIG. 8-1  shows the button and the spring for biasing the button of the embodiment in  FIG. 8 ; 
       FIG. 8-2  shows the pawl and the spring for biasing the pawl of the embodiment in  FIG. 8 ; 
       FIG. 9  is a plain view to show the button is pushed and pawl is positioned by the button for the embodiment of  FIG. 8 ; 
       FIG. 10  is a side partial cross sectional view to show that the button is not pushed and the pawl is engaged with the driving head for the embodiment of  FIG. 8 ; 
       FIG. 10-1  is a cross sectional view taken along line c-c in  FIG. 10 ; 
       FIG. 11  is a cross sectional view to show that the pawl is engaged with the teeth of the driving head; 
       FIG. 12  is a plain view to show the button is pushed and pawl is not positioned by the button for the embodiment of  FIG. 8 ; 
       FIG. 13  is a side partial cross sectional view to show that the button is pushed and the driving head is pivoted for the embodiment of  FIG. 8 ; 
       FIG. 14  is a cross sectional view taken along line d-d in  FIG. 13 ; 
       FIG. 15  shows that the driving member is a ratchet driving member; 
       FIG. 16  shows that the driving member is a box end; 
       FIG. 17  is a plain view to show yet another embodiment of the hand tool; 
       FIG. 18  is a side view of the control device and the hand tool in  FIG. 17 , and 
       FIG. 19  shows that the pawl is engaged with the teeth in the pin for the hand tool in  FIG. 17 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIGS. 1 to 7 , the angle adjustable hand tool of the present invention comprises a handle  10  having a first connection end  11  and a first hole  114  is defined axially in the first connection end  11 . The first connection end  11  includes two protrusions  112  and a space  111  is defined between the two protrusions  112 . A second hole  115  is defined in the first connection end  11  and perpendicularly communicates with the first hole  114 . Two respective springs “A”, “B” are received in the first and second holes  114 ,  115  respectively. A driving head  40  includes a driving member  41  such as an open end as show in  FIG. 1  or a ratchet driving member as shown in  FIG. 15  or a box end as shown in  FIG. 16 . A second connection end  42  which is pivotably connected between the two protrusions  112  of the first connection end  11  by extending a pin “C” through the two respective first pin holes  113  in the two protrusions  112  and the second pin hole  44  defined through the second connection end  42  of the driving head  40 . A first engagement end  43  is fixed on one end of the second connection end  42  and includes teeth defined therein. The teeth are shaped to include a V-shaped space or U-shaped space defined between the teeth of the first engagement end  43 . 
   A pawl  20  is movably received in the first hole  114  and biased by the spring “A”, the pawl  20  includes a second engagement end  21  which is a wedge end and removably engaged with the teeth of the first engagement end  43 . A first flat surface  22  is defined in a shank of the pawl  20  and a first contact surface  23  is connected the first flat surface  22 . A first guide surface  25  is connected the first contact surface  23  of the pawl  20 . 
   A button  30  is engaged with the second hole  115  and biased by the spring “B”. The button  30  includes a second flat surface  31  which is matched with the first flat surface  22  of the pawl  20 . A recess  32  is defined in the button  30  and located substantially perpendicular to the second flat surface  31 . A second guide surface  34  is connected between the recess  32  and a second contact surface  33 . As shown in  FIG. 4 , the pawl  20  is pushed by the second contact surface  33  and the spring “B” so that the second engagement end  21  is engaged with the teeth of the second connection end  42  of the driving head  40 . 
   As shown in  FIGS. 5 ,  6 ,  6 - 1  and  7 , when the button  30  is pushed by the user, the button  30  is lowered and the second contact surface  33  is disengaged from the first contact surface  23 , the pawl  20  is then located in the recess  32  of the button  30 . The pawl  20  is not longer positioned by the second contact surface  33  so that the driving head  40  can be pivoted and the first engagement end  43  of the driving head  40  moves over the second engagement end  21  of the pawl  20  to adjust the angle of the driving head  40  relative to the handle  10 . When releasing the button  30 , the second engagement end  21  of the pawl  20  is engaged with the first engagement end  43  again and the pawl  20  is positioned by the button  30 . 
     FIGS. 8-14  show another embodiment of the control device of the present invention, wherein the pawl  20  includes a slot  24  defined axially therein so as to define two first flat surfaces  22  in two facing insides of the slot  24 . Correspondingly, the button  30  includes two second flat surfaces  31  and the recess  32  is located at two respective ends of the two second flat surfaces  31 . The shank of the button  30  is movably engaged with the slot  24  and the two second flat surfaces  31  are engaged with the first flat surfaces  22 . By this way, the button  30  cannot rotate. The second contact surface  33  is connected the recess  32  via the second guide surface  34  which is a curved and convex surface. The operation processes are the same as the first embodiment of the control device. 
     FIGS. 17 to 19  show that the first connection end  11  is fixed on one end of the handle  10  and the second connection end  42  of the driving head  40  includes two protrusions with a space defined therebetween so that the first connection end  11  of the handle  10  is pivotably connected between the two protrusions of the second connection end  42  by the pin “C”. The pawl  20  is movably inserted in the first hole in the first connection end  11  and the button  30  is perpendicularly engaged with the pawl  20  in the first connection end  11 . The pin “C” includes a first engagement end “C 1 ” which includes teeth and located in the space between the two protrusions. The second engaged end  21  of the pawl  20  is engaged with the first engagement end “C 1 ”. 
   When the button  30  is pushed, the second contact surface  33  is disengaged from the first contact surface  23  of the pawl  20  and the pawl  20  is then located in the recess  32  of the button  30 . The driving head  40  can be pivoted and the first engagement end C 1  of the pin “C” moves over the second engagement end  21  of the pawl  20  to adjust the angle of the driving head  40  relative to the handle  10 . The second engagement end  21  of the pawl  20  is engaged with the first engagement end “C 1 ” again when releasing the button  30 . 
   The pawl  20  and the button  30  are directly in contact with each other and the pawl  20  is activated when the button  30  is pushed so that the number of parts can be minimized and the driving head  40  does not drop suddenly when the button  30  is pushed. 
   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.