Control structure for a pneumatic sealant gun

Claim 1

A control structure for a pneumatic sealant gun comprising: a handle with an air-supply trigger assembly having a valve base hole being in communication with an intake passage, and one end of said intake passage being in communication with an air passage of an intake connector; an outer end of said valve base hole having a screw hole for receiving a valve seat, of which the center has a valve stem hole for receiving a valve stem; a valve disk being mounted near the inner end of said valve seat, and said valve disk having two short studs extended in opposite direction to each other; said two short studs each being mounted with a spring; and said valve stem having an air-exhaust hole in the center thereof; said valve stem having a minor diameter portion nearing said valve disk; and said valve seat having a ring-shaped groove with a through hole in communication with said valve stem hole; said ring-shaped groove being in communication with a valve switch via an intake passage; said valve switch being mounted on said handle by means of a bush member, in which a valve seat is mounted for receiving a valve stem; said valve seat having two symmetrical washer grooves and washers near the outer ends thereof; said valve stem having two symmetrical ring-shaped grooves; and said bush member having a through hole in communication with an intake passage of said air-supply trigger assembly; and a rear side of said handle having two screw holes for mounting two connectors are aligned with two air passages respectively in the bush member, being in communication with the valve seat; and said two connectors are connected with two ducts respectively, while the other ends of the two ducts are connected with two points respectively on the sizing assembly; the outer portion of said two air passages are furnished with two symmetrical exhaust holes; a sizing assembly on said handle including a cylinder with a front hood and a rear hood; and said rear hood having a screw hole for mounting a rear connector, and said front hood having screw hole for mounting a front connector; said cylinder having a piston with at least one guide shaft having a push disk mounted on one end thereof near a connecting base; and said front connector on said front hood being connected with a connector on said valve switch through a duct; and said rear connector on said rear hood being connected with a connector on said valve switch through a duct.