| 摘要 |
<p>545,864. Drilling. CHICAGO PNEUMATIC TOOL CO. Aug. 8, 1941, No. 10095. Convention date, Oct. 5, 1940. [Class 83 (iii)] [Also in Group XXVIII] A drilling-tool, especially for forming rivet holes in superposed aluminium sheets, is provided with a casing on the front of the tool including a plunger 41 which holds the work down and is axially bored to receive the drill and allow air to be drawn through into the casing and through a hose 27 to a dust-bag ; the air current may be induced by a jet of compressed air led into the hose or into a casing enclosing a wire mesh bag to which several drills may be connected. Air holes 61, 62 may be formed in the casing and plunger. The plunger is pressed forwards by a spring. The part 39 of the casing is held in a position adjusted to the length of the drill by an adjustable wire clip 54 engaging a slot in its end. The casing and plunger can be advanced and retracted by a ring 47 provided with locking balls. The air exhauster and drill motor may be started together automatically.</p> |
