Handheld electric grinder

Abstract

A handheld electric grinder comprises a first shell body and a second shell body. The first shell body contains an electric motor therein, and is connected to the electric motor via a drive shaft. The electric motor is driven to let the drive shaft generate a first rotating speed. A first adapter is disposed at one end of the drive shaft. The first adapter can be directly connected with accessories such as hexagonal socket, screwdriver, brush and electric grinding head, or can be connected with a connector of a speed-change gear set in the second shell body. After the speed-change gear set changes the first rotating speed to a second rotating speed, a driven shaft outputs the second rotating speed. The first adapter and the second adapter can be connected with accessories such as hexagonal socket, screwdriver, brush and electric grinding head.

1 . A handheld electric grinder comprising:
 a first shell body having a first connection portion on a surface thereof;   an electric motor located in said first shell body;   a drive shaft with one end thereof being connected with said electric motor and other end thereof being an adapter and protruding out of said first shell body, said drive shaft being used to send a first rotating speed generated by said electric motor;   a second shell body having a second connection portion thereon said first connection portion and said second connection portion being connected together;   a connector with one end thereof lapping the first adapter and other end thereof lapping a speed-change gear set located in said second shell body;   a driven shaft located on said second shell body, one end of said driven shaft lapping said speed-change gear set;   a second adapter located at other end of said driven shaft;   whereby after said first rotating speed is output by said electric motor and sent to said speed-change gear set via said drive shaft and then speed-changed by said speed-change gear set, said driven shaft outputs a second rotating speed.   
   
   
       2 . The handheld electric grinder as claimed in  claim 1 , wherein said first connection portion and said second connection portion is connected together by means of button fitting, snap fitting, screw fitting. 
   
   
       3 . The handheld electric grinder as claimed in  claim 1 , wherein said first connection portion includes a first thread and a first snap portion, and said second connection portion includes a second thread and a second snap portion matched with said first connection portion. 
   
   
       4 . The handheld electric grinder as claimed in  claim 1 , wherein a fan is disposed on said drive shaft and located between said electric motor and said connector. 
   
   
       5 . The handheld electric grinder as claimed in  claim 1 , wherein said speed-change gear set is a planetary gear set. 
   
   
       6 . The handheld electric grinder as claimed in  claim 1 , wherein said speed-change gear set increases said first rotating speed to said second rotating speed, or decreases said first rotating speed to said second rotating speed. 
   
   
       7 . The handheld electric grinder as claimed in  claim 1 , wherein a positioning hole is disposed on said second shell body, a movable positioning clip is slide in said positioning hole to fix said speed-change gear set on said second shell body. 
   
   
       8 . The handheld electric grinder as claimed in  claim 1  further comprising a push-button device, wherein said push-button device is located on said first shell body, and said drive shaft is fixed and thus cannot rotate when a pressure is applied to said push-button device. 
   
   
       9 . The handheld electric grinder as claimed in  claim 8 , wherein an elastic component is fixed on said first shell body to support actuation of said push-button device. 
   
   
       10 . The handheld electric grinder as claimed in  claim 1 , wherein said first shell body contains a battery area therein for placing a primary battery or a secondary battery. 
   
   
       11 . The handheld electric grinder as claimed in  claim 1 , wherein said first shell body is connected to a power cord, and said power cord provides electric power to drive said electric motor. 
   
   
       12 . The handheld electric grinder as claimed in  claim 11 , wherein said power cord has an AC/DC adapter. 
   
   
       13 . The handheld electric grinder as claimed in  claim 1 , wherein said electric motor is a DC motor. 
   
   
       14 . The handheld electric grinder as claimed in  claim 10 , wherein a switch sticks out of an outer surface of said first shell body, battery and said electric motor are close-circuit when said switch is on, and said battery and said electric motor are open-circuit when said switch is off. 
   
   
       15 . The handheld electric grinder as claimed in  claim 14 , wherein a locking device is disposed on the outer surface of said first shell body, and said locking device is used to lock on/off state of said switch. 
   
   
       16 . The handheld electric grinder as claimed in  claim 1 , wherein said second adapter is connected with a hexagonal socket, a screwdriver, a brush, or an electric grinding head. 
   
   
       17 . The handheld electric grinder as claimed in  claim 1 , wherein when said second shell body and said first shell body are not connected together, said first adapter is connected with an electric grinding head or a brush. 
   
   
       18 . The handheld electric grinder as claimed in  claim 1 , wherein when said second shell body and said first shell body are connected together, a screw-fitting device at lapping position of said connector and said first adapter is used to fix said connector and said first adapter.