| 20110209919 | PRESSURIZED FLUID FLOW SYSTEM FOR A NORMAL CIRCULATION HAMMER AND HAMMER THEREOF - A pressurized fluid flow system for a normal circulation down-the-hole hammer comprises a cylinder coaxially disposed in between an outer casing and a piston that reciprocates due to changes in pressure of the pressurized fluid contained inside of a front chamber and a rear chamber located at opposites sides of the piston, wherein the flow into and out of these chambers is controlled solely by the overlap or relative position of the piston and the cylinder as a supply chamber and a discharge chamber defined by recesses on the inner surface of the outer casing and separated by a dividing wall control the flow of pressurized fluid in and out of the front and rear chambers the. A down-the-hole normal circulation hammer with this system comprises a drill bit with one or more flushing passages that extend from channels cooperatively formed between splines on the inner surface of the driver sub and splines on the outer surface of the drill bit shank, to the front face of the drill bit for discharging the pressurized fluid out of the hammer. | 09-01-2011 |
