초록 ▼

A pneumatic tool includes: a main cylinder having an operating lever for on-off control for the supply of compressed air into the pneumatic tool, a barrel member resiliently coupled to the main cylinder and having a tool unit secured at its front end portion, and an automatically closed throttle val

A pneumatic tool includes: a main cylinder having an operating lever for on-off control for the supply of compressed air into the pneumatic tool, a barrel member resiliently coupled to the main cylinder and having a tool unit secured at its front end portion, and an automatically closed throttle valve held in the main cylinder, whereby upon touching on a working object when starting the pounding job, the barrel member will be retracted to open the throttle valve for performing the pneumatic operation by the pneumatic tool; and when subjected to no load condition, the throttle valve will be restored and closed automatically to temporarily stop the pounding of the pneumatic tool to minimize vibration hazard, and an air cushion is inherently formed between the barrel member and the main cylinder for dampening or absorbing the vibration shock of the pneumatic tool.

대표청구항 ▼

A pneumatic tool comprising: a main cylinder (1) having a grip portion (16) secured thereto and an operating lever (17) for opening or closing a compressed air into said main cylinder (1); a barrel member (2) having a rear end thereof resiliently secured to the main cylinder (1); an automatically cl

A pneumatic tool comprising: a main cylinder (1) having a grip portion (16) secured thereto and an operating lever (17) for opening or closing a compressed air into said main cylinder (1); a barrel member (2) having a rear end thereof resiliently secured to the main cylinder (1); an automatically closed throttle valve (14) resiliently mounted in said main cylinder (1) by a restoring spring (15) for closing said throttle valve (14) normally for stopping the supply of a compressed air; an oscillating valve (3) mounted in a rear portion of said barrel member (2) for controlling the compressed air for reciprocatively moving a piston means (4) in said barrel member (2) for pounding a tool unit (5) secured to a front end portion of said barrel member (2) by a tool connector (7); said barrel member (2) operatively opening said automatically closed throttle valve (14) when said tool unit (5) is contacted with a working object to retract said tool unit (5) and said barrel member (2) for directing the compressed air into said barrel member (2) as controlled by said oscillating valve (3) for reciprocating said piston means (4) for pounding said tool unit (5) on said working object, and whereby upon an empty percussion of said tool unit (5) under no load condition, said barrel member (2) will not be retracted by the working object and said throttle valve (14) will be forwardly restored and closed for interrupting the compressed air for stopping the pounding of said tool unit (5) for preventing vibration shock caused by said tool unit (5); and said main cylinder (1) including: a rear housing portion (11) secured with said grip portion (16) having said operating lever (17) pivotally mounted in the grip portion (16) for controlling on and off of a compressed air supply directed into a main air inlet port (19) of the main cylinder (1) through an inlet air adapter (18) and a main inlet air hose portion (80); a bell member (12) generally cylindrical shaped having a rear connector (121) secured in the rear housing portion (11), a contracted bell portion (122) protruding forwardly from the rear connector (121) to connect a truncated-cone bell portion (123) diverging forwardly from the contracted bell portion (122), and a divergent bell portion (124) secured to the truncated-cone bell portion (123) having an inside diameter of the divergent bell portion (124) larger than that of the contracted bell portion (122); a valve socket (13) of said automatically-closed throttle valve (14) having a rear retainer disk (130) fixed in the rear housing portion (11) for retaining said restoring spring (15) for tensioning the throttle valve (14), a valve seat (131) having packing ring embedded thereon formed in the rear connector (121) of the bell member (12) for seating a valve plug (143) of the throttle valve (14), a valve inlet port (132) formed in a front portion of the valve socket (13) adjacent to a valve opening (144) formed in a valve stem (141) of the throttle valve (14), a spring chamber (133) recessed in a rear portion of the plug (143) for retaining the restoring spring (15) and a venting hole (134) formed in the valve socket (13) and communicating with an air-venting passage (121a) formed through the rear connector (121) for breathing air in the spring chamber (133) with an outer environment around the main cylinder (1); and the automatically-closed throttle valve (14) having the valve stem (141) defining central air passage (140) through the valve stem (141) and secured with a rear cap portion (211) of a rear barrel cap (21) of the barrel member (2), with the barrel member (2) and the throttle valve (14) normally restored forwardly by the restoring spring (15) for closing the plug (143) of the throttle valve (14) on the seat (131) of the valve socket (13) for closing the valve opening (144) and the valve inlet port (132) for stopping flow of compressed air into the barrel member (2) and the oscillating valve (3).