Hand-operated apparatus for pneumatically removing dust

A hand operated apparatus connected to an air source for pneumatically removing dust, said apparatus comprising:

• handle means for holding said apparatus, said handle means having a first air passage therethrough connected to said air source;
• cylindrical main body means having a second air passage longitudinally therethrough with an inlet and a discharge end for receiving and discharging dust particles therethrough, said main body means comprised of:
• a cylindrical main body portion having said second air passage longitudinally therethrough, and
• an intake portion removably secured to the inlet end of said main body portion;
• annular member means fitted within said cylindrical body means in said second air passage and connected to said first air passage for ejecting the air flowing from said air source through said first passage into said secondary passage toward the discharge end thereof, said annular member means comprised of:
• an annular member positioned within said second air passage between said intake portion and said main body portion, said annular member having a first central opening therethrough aligned with said second air passage, the forward end of said first central opening having an inwardly tapered surface, and said annulr member further having an annular chamber spaced from and surrounding said first central opening, said annulr chamber being open at the front portion thereof toward the front of said annular member and connected to said first air passage,
• a ring plate adjacent said annular member between the outer circumference of said annular member and said annular chamber,
• a ring holder next to said ring plate on the side thereof opposite said annular member having a second central opening therethrough aligned with said first central opening through said annular member and having a slanted surface extending circumferentially inwardly toward said central openings, whereby an annular slit is formed between said ring holder and said annular member due to the presence of said ring plate thereinbetween, and whereby air in said annular chamber is forced outwardly through said annular slit and flows rearward along the tapered surface of said annulr member through said first central opening toward the discharge end of said main body portion;
• manually operable first control valve means in said first air passage for regulating the flow of air through said first air passage from said air source;
• nozzle means connected to said handle means and operatively connected to said first air passage for ejecting the air coming from said air source through said first air passage outward therethrough;
• and
• second air valve means between said first control valve means and said nozzle means for controlling the flow of air from said first air passage to said nozzle means.