Abstract: In the percussion drill rod assembly of the present invention rotary force is transmitted through a tubular member of the assembly while impact force is transmitted through the rod member centrally located in the tubular member. Either of said rod and tubular members is provided with radially extending protrusions which guide said member with respect to the other member while enabling flushing medium to pass between said members.

Abstract: A pneumatic percussion rock drilling hammer has a tubular housing for connection to a drill rod through which compressed air is introduced, the shank of a drill bit with an anvil at the top being slidable in the bottom of the housing, a piston being reciprocally slidable in the housing. Enlargements of the internal diameter of the housing define top, central and bottom pressure chambers. Air from the drill rod passes through a feed tube to an upper axial passage in the piston, and on the down-stroke of the piston a lower axial passage therein engages a sliding seal tube leading to an air passage through the bit. Pressure ports in the piston direct air from the piston's upper axial passage to the top pressure chamber when the piston is raised, and to the bottom pressure chamber when the piston is lowered, and exhaust ports in the piston conduct air between its lower axial passage and the central pressure chamber and from the central chamber to the top pressure chamber when the piston is lowered.

Abstract: In one type of pneumatic percussion drilling tool, the pneumatic motor has an anvil-bit which is slidable in the forward end of the motor casing between a normal working position and an abnormal advanced position when the tool is hanging off bottom and the pneumatic fluid is caused to bypass the hammer-piston and blow continuously through the anvil-bit. In order to prevent tapping or chattering of the hammer-piston at such time, as a result of leakage of the pneumatic fluid into the forward working chamber, this chamber is vented by means of one or more passages formed in the surface of the anvil-bit member which are open while the tool is blowing and which are closed in the normal operating position of the anvil-bit member. Since the passages are only in the surface of the anvil-bit member, the structure eliminates the need for special configurations of parts to provide interconnecting recesses and passages as in certain of the prior art.

Abstract: A machine having a housing wherein are arranged a stepped hammer piston adjoining the front portion of the machine and a stepped plunger adjoining the rear portion of said machine, said hammer piston and plunger being adapted for an axial movement in said housing. The hammer piston and the plunger are separated by resilient means. The pressure fluid fed into the housing provides for reciprocation of the hammer piston and the plunger. The hammer piston reciprocations consist of forward and return strokes. During the forward stroke the hammer piston transmits impacts to the tool. The presence of the hammer piston and the plunger with the resilient member in between increases the power of the hammer piston impacts transmitted to the tool, hence the machine efficiency. The machine may be advantageously used as a hydraulic hammer (quartering hammer) and a hydraulic percussive device for making holes and deep wells in soil.

Abstract: An impact drilling tool for rotary drilling which includes a reciprocating hammer inside a casing for striking the top of an anvil. A drilling bit is connected to the opposite end of the anvil for cutting into the earth's formations. The casing is connected in a string of drilling pipe through which a high pressure fluid flows for operating the hammer and removing cuttings. A feeder means extends through the hammer for alternately directing the high pressure fluid above and below the hammer which high pressure fluid causes the reciprocating motion of the hammer. A shuttle valve located around the feeder maintains communication of the high pressure fluid above the hammer for increased effective stroke to insure a harder driving action of the hammer against the anvil. Also the shuttle valve insures a more complete exhaust above the hammer which reduces the force needed to raise the hammer. In alternative embodiments, the shuttle may control only one of the exhaust or pressurization functions.

Abstract: An airhammer embodies an outer housing structure connectible to a rotatable drill pipe string through which compressed air is conducted. A hammer piston reciprocates in the housing structure, compressed air being directed alternately to the upper and lower ends of the piston to effect its reciprocation in the structure, each downward stroke inflicting an impact blow upon the anvil portion of an anvil bit extending upwardly within the lower portion of the housing structure. Upon elevating the airhammer off the bottom of the bore hole being drilled, the anvil bit drops downwardly of the housing structure to open one or more air bleeding grooves in the anvil bit, compressed air in the housing structure bleeding quickly through such grooves and preventing or stopping the hammer piston from reciprocating and impacting against the anvil bit.

Abstract: An impact drilling apparatus has an anvil inside a casing for receiving impact blows from a hammer. The lower end of the anvil is threadably connected to a drill bit having an external load bearing shoulder. On the lower end of the casing is attached a driver guide sub which extends downwardly around the threaded connection between the drill bit and anvil to bear on the external load bearing shoulder for transmitting down weight to the bit and simultaneously counteracting lateral forces acting on the bit and anvil. A spline connection is provided between the driven guide sub and the anvil. In the off bottom position, a shoulder of the anvil comes to rest against the top of the driver guide sub which stops the reciprocating action of the hammer while drilling fluid continues to flow.

Abstract: A rotatable airhammer including an outer housing structure in which a hollow hammer piston is reciprocable to impact against an anvil bit used in drilling a bore hole. The anvil bit has a central passage communicating with inner core sample tubing extending through the piston to the upper end of the housing structure, such tubing housing structure being connectible to a string of concentric dual drill pipe extending to the top of the bore hole. Compressed air is directed alternately to the annular space between the tubing and housing structure above and below the piston to reciprocate the latter for repeated impact action against the anvil bit, air being discharged from the lower portion of the housing structure to clear the bottom of the bore hole of cuttings and direct them into the central passage through the bit, the inner tubing and inner drill pipe portion to the top of the hole.

Abstract: Following is disclosed an improved split-type stop ring having two separable body portions forming an annular composite body with passage means useful with a fluid operated, percussion type drill motor for retaining a drill bit and enabling the by-pass of fluid when the bit is suspended above the bottom of a borehole. Fluid by-pass enables the continued flow of fluid to clean the borehole bottom while stopping the otherwise damaging piston-hammer reciprocation when the bit is suspended above bottom.

Abstract: A pneumatically operated impact drilling tool for rotary drilling, includes a reciprocating hammer, an anvil positioned under the hammer and a feeder means extending through the hammer. The drilling tool is connected in a string of drilling pipe and high pressure pneumatic fluid flowing through the drilling pipe operates the impact tool. The feeder directs and times the flow of fluid through ports in the hammer to create a first pressure zone to raise the hammer off the anvil, and a second pressure zone above the hammer to drive the hammer down against the anvil to create an impact on the drill bit. Exhaust ports in the hammer exhaust the fluid from the second pressure zone.

Abstract: An air hammer embodying an outer housing structure connectible to a rotatable drill pipe string through which compressed air is conducted. A hammer piston reciprocates in the housing structure along flexible inlet and outlet tubes, compressed air being directed alternately to the upper and lower ends of the piston to effect its reciprocation in the structure, each downward stroke inflicting an impact blow upon the anvil portion of an anvil bit extending upwardly within the lower portion of the housing structure. The piston contacts the housing structure at the upper and lower portions of the piston only, so that the piston can deviate upon flexing of the housing structure under load, and not bind in the housing structure, as permitted by the flexible inlet and outlet tubes.

Abstract: A fatigue resistant anvil bit is described for use on a percussion rock drill. The anvil bit has a shank having a substantially uniform cross section terminated in a threaded end portion. A bit head is threadably mounted on the end portion having a diameter substantially greater than the bit shank. An anvil ring is shrunk fit on the shank engaging the bit head to provide lateral support and minimize the creation of fatigue fractures.

Abstract: A drilling tool assembly comprising an elongated shank having an upper end for receiving driving forces, and having tapered threads at its lower end for engaging a drill head. The shank has first and second downwardly facing shoulders, with one of said shoulders being above the threads and the other shoulder being below the threads. A removable drill head has tapered threads for engaging corresponding shank threads along substantially the full length thereof. The drill head also has first and second upperwardly facing shoulders adapted to respectively bear against the first and second shoulders on the shank. The drill head shoulders are positioned such that they are still separated from the confronting shank shoulders by a gap when the threads of the two elements initially make up along the pitch line during their assembly. The gap optimally falls within the range of about 0.010-0.

Abstract: The disclosure includes additional features of the apparatus and technique disclosed in Applicant's U.S. Pat. No. 3,854,539 and U.S. Pat. No. 3,874,464. For example, in one embodiment, the anvil is relatively rotatably interconnected with the piston-like member, and is adapted to engage the drill rod for conjoint rotation therewith. Moreover, the inner drill bit has a port in it for discharging the exhaust fluid into the working face of the outer bit from a passage in the anvil. In another embodiment, the anvil includes a core barrel which is adapted to register with the opening in the abutment, when the anvil is engaged with the abutment. The core barrel is defined by a tube which is detachably connected with the main body of the anvil at the relatively forward end thereof.