초록 ▼

A pneumatically operated fastener driving device includes a pilot pressure operated main valve movable from a normally closed position into an opened position allowing a supply of air under pressure to be communicated with a piston chamber to initiate and effect the movement of a piston and fastener

A pneumatically operated fastener driving device includes a pilot pressure operated main valve movable from a normally closed position into an opened position allowing a supply of air under pressure to be communicated with a piston chamber to initiate and effect the movement of a piston and fastener driving element through a fastener drive stroke. A first passage structure communicates a pilot pressure chamber and an exhaust port. A secondary valve member is mounted with respect to the first passage structure so as to be movable between an opened position permitting communication between the pilot pressure chamber and the exhaust port and a closed position preventing such communication. A second passage structure communicates the piston chamber with the secondary valve member. An operative cycle is initiated upon exhausting pilot pressure in the pilot pressure chamber causing the main valve to move to its opened position thereby initiating the fastener drive stroke. A build-up of pressure over the drive piston in the piston chamber communicates with the secondary valve member moving it to its closed position thereby preventing communication between the pilot pressure chamber and the exhaust port and causing the main valve to move to its closed position. The secondary valve member is constructed and arranged to move in response to changes in air pressure over the drive piston occurring in the piston chamber to cause the main valve to reciprocate thereby causing the drive piston to move through repeated operating cycles as long as the trigger member is in its operative position.

대표청구항 ▼

[ What is claimed is:] [1.] A pneumatically operated fastener driving device comprising:a housing assembly including a cylinder therein, said housing assembly defining a fastener drive track,a drive piston slidably sealingly mounted in said cylinder for movement through an operative cycle including

[ What is claimed is:] [1.] A pneumatically operated fastener driving device comprising:a housing assembly including a cylinder therein, said housing assembly defining a fastener drive track,a drive piston slidably sealingly mounted in said cylinder for movement through an operative cycle including a drive stroke and a return stroke,a fastener driving element operatively connected to said piston and mounted in said fastener drive track for movement therein through a drive stroke in response to the drive stroke of the piston and a return stroke in response to the return stroke of the piston,a fastener magazine assembly carried by said housing assembly for feeding successive fasteners laterally into the drive track to be driven therefrom by said fastener driving element during the drive stroke thereof,a piston chamber defined at one end of said cylinder and communicating with said drive piston,an air pressure reservoir communicating with said piston chamber,an exhaust path defined in said housing assembly communicating the piston chamber with the atmosphere when the exhaust path is in an opened condition,a pilot pressure operated main valve movable from a normally closed position into an opened position closing the exhaust path and allowing a supply of air under pressure from the air pressure reservoir to be communicated with the piston chamber to initiate and effect the movement of the drive piston and fastener driving element through the fastener drive stroke thereof, said main valve having a first pressure area defining with a portion of said housing assembly a pilot pressure chamber, and a second pressure area in opposing relation to said first pressure area and being exposed to the supply of air under pressure,a feed orifice communicating the air pressure reservoir with the pilot pressure chamber,an actuator mounted for movement with respect to an exhaust port for controlling pressure in the pilot pressure chamber, said actuator being (1) normally disposed in an inoperative position closing the exhaust port such that pressure within said air pressure reservoir may communicate with said pilot pressure chamber via said feed orifice as pilot pressure therein, and (2) movable in response to a manual actuating procedure into an operating position opening the exhaust port and exhausting the pilot pressure in said pilot pressure chamber through the exhaust port to atmosphere,a trigger member mounted with respect to said housing assembly for manual movement from a normal inoperative position to an operative position for moving the actuator to its operating position,a first passage structure between the pilot pressure chamber and the exhaust port,a secondary valve member mounted with respect to said first passage structure so as to be movable between an opened position biased by said air under pressure permitting communication between said pilot pressure chamber and said exhaust port, and a closed position biased by air pressure over the drive piston in said piston chamber preventing communication between said pilot pressure chamber and said exhaust port, anda second passage structure communicating said piston chamber with said secondary valve member such that the air pressure over the drive piston is in communication with said secondary valve member,wherein an operative cycle is initiated upon movement of said trigger member to its operative position which moves said actuator to its operating position exhausting pilot pressure in said pilot pressure chamber and causing said main valve to move to its opened position thereby initiating the fastener drive stroke,wherein a build-up of air pressure over said drive piston occurring in said piston chamber communicates with said secondary valve member to move said secondary valve member to its closed position preventing communication between said pilot pressure chamber and said exhaust port such that pressure within said air pressure reservoir may communicate with said pilot pressure chamber via said feed orifice to increase the pilot pressure in said pilot pressure chamber thereby causing said main valve to move to its closed position, andwherein said secondary valve member is constructed and arranged to move in response to changes in air pressure over said drive piston occurring in said piston chamber to cause said main valve to reciprocate between its opened and closed positions thereby causing said drive piston to move through repeated operating cycles as long as said trigger member is in its operative position.