Patent ID: 7556183
Filing Date: 2009-07-07
Classification: B25C

Abstract:
1. A control device for nail hitting of a pneumatic nail gun, a trigger valve being disposed in a gun body of the pneumatic nail gun, high pressure air being introduced from a main air flow passage to urge to open a main air valve to hit nails, a safety slide pole disposed in the gun body, and a control valve disposed in the main air flow passage between the trigger valve and the main air valve, the control valve comprising: a valve base defining an inlet opening in a top portion thereof, the inlet opening communicating with the trigger valve via the main air flow passage, the valve base defining at least one outlet opening in a side wall thereof, the at least one outlet opening communicating with the main air valve via the main air flow passage; a valve cover disposed in the valve base, the valve cover defining an upper neck hole and a lower through hole, the upper neck hole communicating with the lower through hole, a diameter of the through hole being larger than a diameter of the neck hole, the neck hole communicating with the inlet opening, the valve cover defining at least one air guiding hole in an inner wall thereof communicating with the outlet opening, a bottom air chamber communicating with the through hole disposed between a bottom valve cover and an inner wall of the valve base; and a valve bolt slidably disposed in the valve cover, the valve bolt having a stressed end face at a top portion thereof adjacent to the inlet opening, the valve bolt being capable of moving down driven by the high pressure air exerting on the stressed end face, a bottom portion of the valve bolt extending to a position abutting to a top portion of the safety slide portion, the safety slide pole being capable of moving down pushed by the valve bolt or moving up released by the bolt valve to an original position, the valve bolt having a valve plug at an outer wall of the valve bolt, the valve plug being slidably disposed in the neck hole on top of the air guiding hole to block the high pressure air; wherein when the safety slide pole moves down to a predetermined height, the valve bolt moves down with the safety slide pole, the valve plug moves into the neck hole below the air guiding hole, the air communication between the inlet opening and the outlet opening is opened, the air communication between the inlet opening and the bottom air chamber is closed, the high pressure air is guided into the main air flow passage to hit nails; when the safety slide pole moves down to a position which is higher than the predetermined height, the valve plug moves into the neck hole on top of the air guiding hole, the air communication between the inlet opening and the outlet opening is closed, the air communication between the inlet opening and the bottom air chamber is open, the main air flow passage is shut off; when the safety slide pole moves down to a position which is lower than the predetermined height, the valve plug moves into the through hole, the air communication between the inlet opening and the bottom air chamber is open, the high pressure air is guided into the bottom air chamber to drive the valve cover to move up, the air communication between the inlet opening and the outlet opening, and the air guiding hole and the outlet opening are closed, and the main air flow passage is shut off.