Abstract: A sealing and venting system including an improved piston is for a drill assembly. The drill assembly includes a fluid distributor within the casing with an elongated guide portion having an outer surface, a passage through the guide portion and a port between the outer surface and the passage. The improved piston is slidable within the casing and has an interior surface disposeable about the outer surface of the guide portion. A valve chamber, an exhaust chamber and a drive chamber are defined within the casing. The system includes a sealing surface disposed within the piston passage and slidably engageable with the outer surface of the guide portion to provide a seal between the piston and the distributor. The sealing surface prevents fluid communication between the drive chamber and the exhaust chamber when the sealing surface engages the outer surface of the guide portion, and is provided by an interior surface section of the piston body or by a separate ring seal.

Abstract: A piston for a fluid-actuated, percussive, down-the-hole drill is provided with self-lubricating bearings and self-lubricating seals. The piston includes an elongated body member terminating in a front end and a back end and having a longitudinal bore therethrough. A bearing and seal combination is positioned adjacent each end of the piston and an undercut portion of the piston body extends therebetween. The bore and undercut portions of the body form a portion of fluid passageways in the drill, when the piston is reciprocated in the drill. The seals float in their grooves, being movable axially, radially and circumferentially. The bearings are substantially nonmovable axially and radially.

Abstract: A chuck and drill bit combination for insertion into a front end of a percussive, down the hole drill forming a part of a cluster drill assembly, for selectively engaging and disengaging the chuck and drill bit during drilling operations includes the bit and chuck each having splines and grooves adapted to overlap and engage each other in a first stop position and further adapted to disengage from each other in a second stop position, whereby the bit is restrained from rotational movement but capable of axial movement in the first stop position and capable of both axial and rotational movement in the second stop position, to provide automatic indexing of the bit so as to position the bit's gage drilling buttons in a preferred position outboard of the drill centerline, to maintain maximum borehole diameter.

Abstract: A piston for a fluid-actuated, percussive, down-the-hole drill is provided with self-lubricating bearings and self-lubricating seals within the drill to provide a drill requiring no oil lubrication.

Abstract: A device for use within the backhead of a down hole percussive drill, for removing debris from a drillhole, includes a flow control member in the drill backhead for inducing cyclonic flow of percussive fluid, to concentrate the heavier water and other matter away from the lighter percussive gases, a separator in the backhead that separates the water and other matter, passageways in the backhead for ejecting the separated water and other matter, a sealing member for sealing the backhead passageways against back flow of debris from the drillhole annulus, and an indexing member for positioning the separator so as to permit a pre-selection of flow amounts of removed water and other matter.

Abstract: A reversible casing for a fluid-actuated, percussive, down-the-hole drill is provided with a tubular body having an internal surface forming a bore extending along a longitudinal axis. The internal surface has a profile that is a mirror image about a centerline axis perpendicular to the longitudinal axis. The profile is provided with alternating undercut portions and land portions, with a portion of the undercut portions being in an annular scalloped configuration comprising a plurality of longitudinally extending parallel grooves in the internal surface.

Abstract: A fluid-actuated, percussive, down-the-hole drill having a piston slidingly supported in a casing and passageways for transmitting flow of percussive fluid to actuate the piston is provided with self-lubricating bearings and self-lubricating seals within the drill to provide a drill requiring no oil lubrication.

Abstract: An apparatus for a percussive, down-hole drill, for positioning a split retaining ring against an internal surface of a drill casing including a chuck with a tapered top surface, a bit bearing with a tapered bottom surface, and a reversible split retaining ring sandwiched therebetween, the split ring having a tapered top and bottom surface, each tapered surface subtending an angle between 5.7 and 25 degrees, as measured from a perpendicular to a drill longitudinal axis, whereby a portion of any longitudinal load on the split ring is developed into a preselected maximum and minimum amount of radial load, to position the split ring in the casing, without damaging the casing.

Abstract: A filter having a filter element is provided for a rockdrill. The filter can be operated in three modes, namely, filtering or drilling, rinsing and back-flushing. As the filter element becomes clogged a handle on the filter can be turned to a back-flushing mode position whereby the flow of fluid through the filter element is reversed and the flow of fluid thereby expels dirt and debris accumulated in and on the filter element to the atmosphere through the a outlet port. When the handle is turned back to a filtering mode position ports in a support shaft in the filter pass through the rinsing mode which washes dirt that may have accumulated on the filter element during the back-flushing mode and expels it to the atmosphere through the vent outlet port. When the handle is positioned in the filtering mode position the filter element is clean.

Abstract: A reversible casing for a down-the-hole drill has a predetermined snap ring groove length centered between the casing ends, based upon the casing bore, the snap ring groove depth and the snap ring body length, whereby a snap ring will be retained in the snap ring groove, while permitting lengthwise movement of the snap ring during reverse orientation of the casing.

Abstract: An on-off valve is provided for a rockdrill which is operable by a hydraulic fluid under pressure and which is controlled by a hydraulically biassed valve. The rockdrill is turned on and off by opening and closing the on-off valve. When the valve is turned off hydraulic pressure from an inlet line and a supply pin line to a valve line of the hydraulically biassed control valve is cut off, thereby eliminating the pressure on the supply pin. This interrupts the operating cycle of the control valve and thereby shuts off the operation of the hydraulic drill. When the on-off valve is opened the hydraulic pressure from the inlet line via the supply pin line is re-established to the valve line and to the supply pin, and the operating cycle of the control valve is re-established.

Abstract: A device for use within a backhead of a down-the-hole percussive drill, for removing debris from a drillhole, includes a separator for separating water and other matter from the percussive fluid prior to the percussive fluid actuating the piston of the drill. The water and other matter are exhausted out the drill bit, to remove the debris. The device includes a one-way flow valve to prevent backflow of debris and water into the drillhead during periods when the percussive fluid flow ceases. The device can be added to existing drill backheads, or included as part of newly manufactured units.

Abstract: A filter apparatus for a percussion device to be powered by fluid pressure, which when the apparatus is in an assembled position, comprises a filter recess formed within a housing encasing the percussion device. An assembly fastener is disposed within the recess. A first filter is disposed about the assembly fastener. A filter support is disposed about the first filter. A second filter is mounted around the filter support. Both the first and the second filter have a filtering gauge size, and the filtering gauge of the first filter exceeds the filtering gauge of the second filter.

Abstract: A clutch assembly transmits rotary motion in a percussive apparatus to a drill steel. The clutch assembly includes a first hub having a first cylindrical surface formed thereon. A second hub which is substantially rotationally coupled to the drill steel has a second cylindrical surface formed thereon. The second cylindrical surface is coaxial with the first cylindrical surface. A wrap spring engages a portion of both the first cylindrical surface and the second cylindrical surface, wherein relative rotary motion between the first hub and the second hub is permitted in a first direction and restricted in a second direction. The wrap spring clutch transmits motion supplied from a rifle bar assembly as well as a plunger bar arrangement.

Abstract: A device for use adjacent to a down-the-hole percussive drillhead, for removing debris from a drillhole, includes a separator for removing water and other matter from the percussive fluid prior to the percussive fluid entering the drillhead. The water and other matter are ejected into the drillhole to remove the debris, and the separator includes a one-way flow valve to prevent backflow of debris and water into the drillhead during periods when the percussive fluid flow ceases.

Abstract: A method for removing debris from a drillhole, includes positioning a separator adjacent to a down-the-hole percussive drillhead, for removing water and other matter from the percussive fluid prior to the percussive fluid entering the drillhead. The water and other matter are ejected into the drillhole to remove the debris, and backflow of debris and water into the separator and drillhead is prevented, during periods when the percussive fluid flow ceases.

Abstract: A clutch assembly transmits rotary motion in a percussive apparatus to a drill steel. The clutch assembly includes a first hub having a first cylindrical surface formed thereon. A second hub which is substantially rotationally coupled to the drill steel, has a second cylindrical surface formed thereon. The second cylindrical surface is coaxial with the first cylindrical surface. A wrap spring engages a portion of both the first cylindrical surface and the second cylindrical surface, wherein relative rotary motion between the first hub and the second hub is permitted in a first direction and restricted in a second direction. The wrap spring clutch transmits motion supplied from a rifle bar assembly as well as a plunger bar arrangement.

Abstract: A filter apparatus for a percussion device powered by fluid pressure includes a percussion device housing having a fluid inlet and a fluid outlet. A valve is displaced between an open and a closed position. A filter recess is formed within the housing. A filter is inserted within the filter recess for moving the valve from the closed to the open position, thereby permitting fluid pressure to be supplied from the inlet to the outlet.

Abstract: Disclosed is a device for converting pressure fluid input of one fluid to pressure fluid output of a second fluid without contaminating either fluid. The transformation is accomplished by a unique H section piston which cooperates the internally protruding endcaps enclosed in a double ended cylinder; the piston having a central control valve which reverses the piston on control pin end of stroke contact. Positive reverse action is obtained by means of endcap plungers which operate in response to piston position and pressure of the one fluid. The device is double acting and is enclosed totally within a single cylindrical module which is compact and inexpensive to manufacture.