Telescopic hand tool

Abstract

A telescopic hand tool consists of a main body, a bar and a positioning device. The bar possesses an axial hole bored axially from its one end for engaging with a telescopic bar of the main body, and a sliding groove dug around its surface, bored with a ball hole. The positioning device includes a restricting knob, a compression spring and a restricting plate. The restricting knob can slide restrictively along within the sliding groove by means of a restricting block so as to let the main body move in the bar axially. The compression spring can push elastically the restricting knob back to its original position to press on a steel ball restricted in a restricting ball hole of the main body, keeping the main body locked restrictively in the bar.

1 . A telescopic hand tool comprising:
 a main body provided with a working head formed in its front portion for engaging with a tool and a telescopic bar formed in its rear portion, said telescopic bar provided with plural restricting ball holes bored axially and a shallow groove concaved to communicate with said restricting ball holes, said restricting ball holes having a depth deeper than that of said restricting ball holes;   a bar provided with an axial hole bored axially from its one end for engaging with said telescopic bar of said main body and a sliding groove dug near an opening of said axial hole  31 , said sliding groove bored with a ball hole for fitting with a steel ball that is correspondingly to be fitted in said restricting ball hole of said main body; and   a positioning device fixed on, said sliding groove of said bar and provided with a restricting knob, a compression spring and a restricting plate, said restricting knob provided with a restricting block located at its bottom side to correspond with said sliding groove so that said restricting knob is able to slide along said sliding groove and press said steel ball to be positioned in one of said restricting ball holes, and a push key formed on an top side of said restricting knob for a user to easily push it to keep said restricting knob sliding along within said sliding groove, said restricting knob also provided with a wing formed at its two curved sides respectively to correspond to said sliding groove, said compression spring installed between said restricting block and said sliding groove and able to push elastically said restricting knob to move back to its original position after pushed away, said restricting plate provided with an elongate opening cut in its central portion to correspond with said sliding groove for fitting with said restricting knob so as to keep said restricting plate fixed at two edges of said sliding groove, and a restricting portion formed at two sides of said elongate opening respectively for pressing on said wings of said restricting knob to let said restricting knob slide along within said sliding groove.   
   
   
       2 . A telescopic hand tool as claimed in  claim 1 , wherein said sliding groove is formed as a two-step ladder for said wings of said restricting knob to attach, said wings further pressed by said restricting portion of said restricting plate to keep said restricting knob sliding restrictively along said sliding groove. 
   
   
       3 . A telescopic hand tool as claimed in  claim 1 , wherein said compression spring is installed in said sliding groove and constrained by said restricting block, keeping one end of said compression spring contacted with said sliding groove and the other one leaned on said restricting block so that said restricting knob can be pushed back to its original position by said compression spring elastically. 
   
   
       4 . A telescopic hand tool as claimed in  claim 1 , wherein said bar is provided with a projection planted longitudinally at two sides of said sliding groove respectively for fitting with a restricting hole bored correspondingly at two sides of said restricting plate to keep said restricting plate fixed on the edge of said sliding groove of said bar. 
   
   
       5 . A telescopic hand tool as claimed in  claim 1 , wherein said sliding groove of said bar is provided with two female-threaded holes bored at its two sides respectively, said restricting plate provided with two through holes bored at its two sides respectively to correspond to said female-threaded holes for screws to pass through to screw fixedly with said female-threaded holes, keeping said restricting plate fixed on the edge of said sliding groove of said bar. 
   
   
       6 . A telescopic hand tool as claimed in  claim 1 , wherein said bar is provided with a grip wrapped around some of its surface. 
   
   
       7 . A telescopic hand tool as claimed in  claim 1 , wherein said restricting knob and said restricting plate are made of metal. 
   
   
       8 . A telescopic hand tool as claimed in  claim 1 , wherein said restricting knob and said restricting plate are made of plastics. 
   
   
       9 . A telescopic hand tool as claimed in  claim 1 , wherein said restricting plate is provided with an arrow mark printed on its outer surface.