Multifunctional dust-abating gun

A dust-abating gun comprising a main coupler for engaging with one of an inflation means and a quick coupler, the main coupler including a hexagonal head with an inner screw hole for coupling with all kinds of tools and a hollow shank extending from the hexagonal head, the shank including an outer threading so as to be attached to the dust-abating gun by threading engagement, a through-hole being extended through the hexagonal head and the shank through which compressed air from the dust-abating gun is outputted;

• the quick coupler including a first main body and a fitting with an outer threading for engaging with the inner screw hole of the main coupler, the fitting including a nut integrally formed around a mediate portion thereof to separate the outer threading into two portions, the first main body including a first end, a second end, and a U-shaped groove defined in a mediate portion thereof and having a side opening, a screw hole being defined in the first end of the main body and communicated with the U-shaped groove, a U-shaped flange being formed in the second end of the first main body to thereby define a U-shaped opening that also communicates with the U-shaped groove, the U-shaped groove being adapted to receive a coupling member of a tool, the coupling member of the tool including a first annular groove in an outer periphery thereof, the coupling member further including an end with an end face having an annular groove for receiving a rubber seal ring to bear against an end face of the fitting of the quick coupler, thereby providing quick positioning and preventing leakage;
• and
• the inflation means including a second main body having a longitudinal stepped through-hole for pivotally receiving a pivotal plug, thereby allowing free rotational movement of the second main body, the pivotal plug including a threaded shank, an inflation fitting including a first end threadedly engaged with the threaded shank of the pivotal plug and a second end threadedly engaged with the screw hole of the main coupler and thus attached to the dust-abating gun, the longitudinal stepped through-hole including an end, a hose being threadedly engaged in the end of the longitudinal stepped through-hole, a pressure gauge being attached to the second main body to indicate the air pressure, a relief valve being attached to the second main body of the inflation means, the relief valve including a base with a stepped through-hole for slidably receiving a relief plug, a spring being mounted around the relief plug and including an end attached to a peripheral wall that defines the stepped through-hole of the base, the relief plug including a first end extended beyond the stepped through-hole of the base and a second end, an O-ring being mounted to the second end thereof for sealing the stepped through-hole of the base under the action of the spring on the relief plug.