Driving tool having piston and driver blade

Abstract

A fastener driving tool includes a housing, a cylinder supported to the housing, a piston, and a driver blade. The piston is reciprocally movable in the cylinder in an axial direction thereof. The piston includes a piston body and a boss integrally extending from the piston body in the axial direction. The boss is formed with a fitting groove extending in the axial direction, and the driver blade having a fitting portion is inserted into the fitting groove. Brazing material is distributed between the fitting groove and the fitting portion. The boss is in cylindrical shape, and the driver blade has a pair of protrusions extending in the axial direction and spaced away from each other by a diameter of the boss.

What is claimed is:  
     
         1 . A fastener driving tool comprising: 
 a housing;    a cylinder supported to the housing and having an axis providing an axial direction;    a piston reciprocally movable in the cylinder in the axial direction; and    a driver blade fixed to the piston and extending therefrom in the axial direction, the driver blade being fixed to the piston by brazing with a brazing material.    
     
     
         2 . The fastener driving tool as claimed in  claim 1 , wherein the piston comprises a piston body and a boss integrally extending from the piston body in the axial direction, the boss being formed with a fitting groove extending in the axial direction, the driver blade having a fitting portion inserted into the fitting groove, the brazing material being distributed between the fitting groove and the fitting portion.  
     
     
         3 . The fastener driving tool as claimed in  claim 2 , wherein the driver blade is provided with at least one positioning section engageable with an external contour of the boss, the external contour being extending in the axial direction.  
     
     
         4 . The fastener driving tool as claimed in  claim 3 , wherein the positioning section comprises a pair of protrusions extending in the axial direction and spaced away from each other by a distance, and 
 wherein the boss has an external width defining a width of the fitting groove in a direction perpendicular to the axial direction, the external width being substantially equal to the distance.    
     
     
         5 . The fastener driving tool as claimed in  claim 1 , wherein the brazing material is made from a material having a melting point higher than a quenching temperature of the piston and the driver blade.  
     
     
         6 . The faster driving tool as claimed in  claim 5 , wherein the piston and the driver blade are made from iron, and the brazing material is made from copper.