Patent Publication Number: US-6905221-B2

Title: Screwdriver with light device

Description:
FIELD OF THE INVENTION 
   The present invention relates to screwdriver having a light device connected to an end surface of the handle and an annular switch is rotatably connected to the handle. 
   BACKGROUND OF THE INVENTION 
   A conventional screwdriver with a light device is developed for a period of time and the light device provides illumination feature for the user in a dark work site. This feature is convenient for the users and welcomed in the market, nevertheless, the light device is simply attached to a screwdriver as an extra attachment so that the light bulb generally protrudes from the outer periphery of the handle and could impede the operation of the screwdriver in a narrow space. Besides, the appearance of the handle is not satisfied by three users because the light device and the switch both protrude from the handle. Furthermore, the conventional light device can only be attached to a periphery of the handle so that the light beam cannot be focused onto the same spot where the object is to be tightened or loosened by the screwdriver. 
   The present invention intends to provide a screwdriver that has a light device located at an end surface of the handle and the switch is in flush with the outer surface of the handle. 
   SUMMARY OF THE INVENTION 
   In accordance with one aspect of the present invention, there is provided a screwdriver that includes a handle with a plastic gear mechanism received therein and a bit engaging device is connected to a first end of the gear mechanism. A power source is connected to the gear mechanism. A positive plate and a negative plate are respectively connected to the gear mechanism. A light frame is received in the handle and at least one light bulb is connected to the light frame. A positive ring and a negative ring are respectively engaged with the light frame. A spring is mounted to the bit engaging device and connected between the negative ring and the negative plate. The at least one light bulb is connected to the positive ring and the negative ring. A gap is defined between the positive plate and an extension of the positive ring. 
   An annular switch is rotatably mounted to the gear mechanism and includes a touch piece which contacts both of the position plate and the extension of the positive ring to light the at least one light bulb. 
   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 a perspective view to show a screwdriver of the present invention; 
       FIG. 2  is an exploded view to show the light device and the gear mechanism for the screwdriver of the present invention; 
       FIG. 3A  is a cross sectional view to show the contact piece of the annular switch contacts the position plate and the extension of the positive ring; 
       FIG. 3B  is a cross sectional view to show the contact piece of the annular switch is removed not to contact the position plate and the extension of the positive ring; 
       FIG. 3C  shows the light bulbs connected to the light frame; 
       FIG. 4  shows the arrangement of the positive plate, the negative plate and the light frame; 
       FIG. 5  shows another embodiment of the light device of the present invention; 
       FIG. 6  is a side cross sectional view to show the embodiment shown in  FIG. 5 ; 
       FIG. 7  shows the arrangement of the positive plate, the negative plate, the positive ring of the embodiment shown in  FIG. 5 ; 
       FIG. 8  is an exploded view to show yet another embodiment of the present invention; 
       FIG. 9A  is a cross sectional view to show the contact piece of the annular switch contacts the position plate and the extension of the positive ring shown in  FIG. 8 ; 
       FIG. 9B  shows the light bulbs connected to the light frame in the embodiment in  FIG. 8 ; 
       FIG. 10  is a perspective view to show the status as shown in  FIG. 9A ; 
       FIG. 11  is a perspective view to show the screwdriver cooperated with a torque adjusting device; 
       FIG. 12  is an exploded view to show the light device, the gear mechanism and the torque adjusting device for the screwdriver of the present invention shown in  FIG. 11 ; 
       FIG. 13  is a cross sectional view to show the embodiment as shown in  FIG. 11 , and 
       FIG. 14  is a perspective view to show the status when the contact piece of the annular switch contacts the position plate and the conductive port. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIGS. 1 ,  2 ,  3 A,  3 B,  3 C and  4 , the screwdriver  10  of the present invention comprises a handle  20  having a plastic gear mechanism  30  and a bit engaging device  35  is connected to a first end of the gear mechanism  30  so that a sleeve “a” can be connected to the bit engaging device  35 . A power source  100  is connected to the gear mechanism  30  so as to provide electric power to the gear mechanism  30  to rotate the sleeve “a”. The gear mechanism  30  includes a ring  31  which includes teeth defined in an inner periphery thereof so as to drive gears (not shown) in the gear mechanism  30 . Two ridges  311  extending from an outer periphery of the ring  31  and are engaged with grooves  32  (only one is shown) defined longitudinally in the gear mechanism  30 . A positive plate  33  and a negative plate  34  are respectively inserted into the grooves  32  via openings  321  in the first end of the gear mechanism  30 . 
   A light frame  40  is connected to the gear mechanism  30  and includes two bulb receiving members  421  on a flange  42  of an inner periphery of the light frame  40 . Two light bulbs “b” are connected to the bulb receiving members  421  of the light frame  40 . The light frame  40  includes a connection end  41  which is connected to the gear mechanism  30 . A positive ring  45  and a negative ring  43  are respectively engaged with the light frame  40 . The positive ring  45  has two connection pieces  451  inserted in the two bulb receiving members  421  and the negative ring  43  has two connection pieces  431  which are inserted in the two bulb receiving members  421  so that the two light bulbs “b” are connected to the positive ring  45  and the negative ring  43 . A fixing collar  44  is engaged in a groove  351  defined in an outer periphery of the bit engaging device  35  so as to press the negative ring  43  in position. 
   A fixing ring  60  which is engaged with the first end of the gear mechanism  30  and includes a central hole through which the bit engaging device  35  extends. Two positioning holes and two bulb holes  61  are defined through the fixing ring  60 . The light frame  40  includes two positioning rods  422  which extend through the positioning holes and the light bulbs “b” extend through the two bulb holes  61 . 
   A spring  36  is mounted to the bit engaging device  35  and connected between the negative ring  43  and the negative plate  34 . A gap is defined between the positive plate  33  and an extension  452  of the positive ring  45  to form an open circuit for the light bulbs “b”. 
   An annular switch  50  is rotatably mounted to the light frame  40  and includes a touch piece  51  which protrudes inward from an inner periphery of the annular switch  50  and can be moved to contact both of the position plate  33  and the extension  452  of the positive ring  45  by rotating the annular switch  50  to light the light bulbs “b”. 
   The light bulbs “b” are located at the end of the gear mechanism  30  and the annular switch  50  is in flush with the outer periphery of the handle  20  so that the present invention improves the shortcomings of the conventional light device on the screwdriver. 
   Referring to  FIGS. 5  to  7 , another embodiment of the screwdriver is shown and comprises a handle  20  having a plastic gear mechanism  30  received therein and a bit engaging device  37  is connected to a first end of the gear mechanism  30  which is connected to a power source  100  (not shown). The gear mechanism  30  includes a ring  31  which includes teeth defined in an inner periphery thereof so as to drive gears (not shown) in the gear mechanism  30 . Two ridges  311  extending from an outer periphery of the ring  31  and are engaged with grooves  32  (only one is shown) defined longitudinally in the gear mechanism  30 . A positive plate  33  and a negative plate  34  are respectively inserted into the grooves  32  via openings  321  in the first end of the gear mechanism  30 . 
   A light bulb “b” is inserted in a bulb receiving member  371  on the first end of the gear mechanism  30 . A positive ring  38  is mounted to the bit engaging device  37  and includes a positive lug  381  and a negative lug  382 . The light bulb “b” is connected to the positive lug  381  and the negative plate  34 . A gap is defined between the positive plate  33  and the negative lug  382 . 
   A fixing ring  60  is engaged with the first end of the gear mechanism  30  and includes a central hole through which the shank of the bit engaging device  37  extends. Two positioning holes and a bulb hole  61  are defined through the fixing ring  60 . Two positioning rods  422  extend from the first end of the bit engaging device  37  and extend through the positioning holes and the light bulb “b” extends through the two bulb holes  61 . 
   An annular switch  50  is rotatably mounted to the gear mechanism  30  and includes a pressing portion  52  to press onto the positive ring  38  and a touch piece  51  protrudes inward from an inner periphery of the annular switch  50 , the touch piece  51  contacting both of the position plate  33  and the negative lug  382  of the positive ring  38  to light the light bulb “b”. 
   Referring to  FIGS. 8 ,  9 A,  9 B and  10 , yet another embodiment of the screwdriver comprises a handle (not shown) having a metal gear mechanism  30  and a bit engaging device  35  is connected to a first end of the gear mechanism  30 . A power source  100  (not shown) is connected to the gear mechanism  30  so as to provide electric power to the gear mechanism  30  to rotate the sleeve “a”. The gear mechanism  30  includes a ring  31  which includes teeth defined in an inner periphery thereof so as to drive gears (not shown) in the gear mechanism  30 . Two ridges  311  extending from an outer periphery of the ring  31  and are engaged with a groove  32  defined longitudinally in the gear mechanism  30 . A positive plate  33  is inserted into the grooves  32  via openings  321  in the first end of the gear mechanism  30 . 
   A light frame  40  is connected to the gear mechanism  30  and includes two bulb receiving members  421  on a flange  42  of an inner periphery of the light frame  40 . Two light bulbs “b” are connected to the bulb receiving members  421  of the light frame  40 . The light frame  40  includes a connection end  41  which is connected to the gear mechanism  30 . A positive ring  45  and a negative ring  43  are respectively engaged with the light frame  40 . The positive ring  45  has two connection pieces  451  inserted in the two bulb receiving members  421  and the negative ring  43  has two connection pieces  431  which are inserted in the two bulb receiving members  421  so that the two light bulbs “b” are connected to the positive ring  45  and the negative ring  43 . A fixing collar  44  is engaged in a groove  351  defined in an outer periphery of the bit engaging device  35  and a spring ring  46  is sandwiched between the negative ring  43  and the fixing collar  44  so as to press the negative ring  43  in position and form a loop circuit. 
   A fixing ring  60  which is engaged with the first end of the gear mechanism  30  and includes a central hole through which the bit engaging device  35  extends. Two positioning holes and two bulb holes  61  are defined through the fixing ring  60 . The light frame  40  includes two positioning rods  422  which extend through the positioning holes and the light bulbs “b” extend through the two bulb holes  61 . A gap is defined between the positive plate  33  and an extension  452  of the positive ring  45  to form an open circuit for the light bulbs “b”. 
   An annular switch  50  is rotatably mounted to the connection end  41  of the light frame  40  and includes a touch piece  51  which protrudes inward from an inner periphery of the annular switch  50  and can be moved to contact both of the position plate  33  and the extension  452  of the positive ring  45  by rotating the annular switch  50  to light the light bulbs “b”. 
   Referring to  FIGS. 11  to  14 , a screwdriver  10  with a torque adjusting device  70  is shown and comprises a handle  20  having a metal gear mechanism  30  received therein and a bit engaging device  35  is connected to a first end of the gear mechanism  30  so that a sleeve “a” can be connected to the bit engaging device  35 . A power source  100  is connected to the gear mechanism  30  so as to provide electric power to the gear mechanism  30  to rotate the sleeve “a”. The gear mechanism  30  includes a ring  31  which includes teeth defined in an inner periphery thereof so as to drive gears (not shown) in the gear mechanism  30 . Two ridges  311  extending from an outer periphery of the ring  31  and are engaged with a grooves  32  defined longitudinally in the gear mechanism  30 . A positive plate  33  is inserted into the groove  32  via openings  321  in the first end of the gear mechanism  30 . 
   A torque adjusting device  70  is mounted to the bit engaging device  35  and has a base  71 , a collar  72 , a torque scale plate  73 , a rotatable cap  74  and an end piece  75 . The base  71  has a flange  711  and a threaded tube  712  connected to the flange  711 , the collar  72  is mounted to the threaded tube  712 . The flange  711  has a plurality of holes  7111  and each have a spring  721  extending therethrough. An end of each spring  721  contacts a pin  722  which urges a bead  723  received in recesses  39  defined in an end surface of the handle  20 . The other end of each spring  721  contacts the collar  72 . The torque scale plate  73  is mounted to the threaded tube  712  and the rotatable cap  74  is threadedly connected to the threaded tube  712  and compresses the torque scale plate  73 . A plurality of beads are engaged between the torque scale plate  73  and the rotatable cap  74 . 
   A positive plate  33  is connected to the torque adjusting device  70  and connected to a power source  100 . The flange  711  of the base  71  is engaged with a positioning ring  80  and has an extension  7112 . A conductive port  7122  is connected to the extension  7112  and a conductive ring  7121  is connected to an end of the threaded tube  712 . An end of the positive plate  33  is connected to the extension  7112  and a gap is defined between the conductive port  7122  and the positive plate  33 . 
   A light frame  40  is connected to a negative ring  43  which has two connection pieces  431  and a connection portion  47  is connected to an end of the light frame  40 . A fixing collar  44  is engaged in a groove  351  defined in an outer periphery of the bit engaging device  35  so as to press the negative ring  43  in position. The connection portion  47  is connected with the positioning ring  80  and a position ring  45  is connected to the connection portion  47 . The positive ring  45  has two connection pieces  451  so that two light bulbs “b” inserted in two bulb receiving members  421  on the light frame  40  are connected to the two connection pieces  451  and two connection pieces  431  of the negative ring  43 . The springs  721  pushes the conductive ring  7121  on the threaded tube  712  to contact the positive ring  45 . 
   A fixing ring  60  which is engaged with the first end of the gear mechanism  30  and includes a central hole through which the bit engaging device  35  extends. Two positioning holes and two bulb holes  61  are defined through the fixing ring  60 . The light frame  40  includes two positioning rods  422  which extend through the positioning holes and the light bulbs “b” extend through the two bulb holes  61 . 
   An annular switch  50  is rotatably mounted to the positioning ring  80  and has a touch piece  51  which contacts the positive plate  33  and the conductive port  7122  to light the light bulbs “b”. 
   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.