Abstract: A screw driving tool including an axially displaceable, drive spindle (5) located in the housing, a bit holder (6) having a shank (7) which releasably connects the bit holder (6) with the drive spindle (5), an axially adjustable depth stop (9) surrounding the bit holder (6) and a portion of the drive spindle (5) and connectable with the tool housing (1), and a sleeve-shaped dust-repelling member (13) arranged between the depth stop (9) and the bit holder (6) and releasably connected with the bit holder (6).

Abstract: A drive tool is shiftable between locking and releasing configurations relative to an associated tool, the drive tool including a lock member moveable between a locking position and a release position relative to the associated tool, an actuator member moveable between a locking condition and a releasing condition, and coupling structure interconnecting the actuator member and the lock member. The lock member is tiltable to a latching condition which prevents its movement to its release position. In one embodiment the coupling structure is substantially rigid so that the lock member and the actuator move in substantially the same direction, and in another embodiment the coupling structure is flexible and resilient. The coupling structure may be fixedly coupled to the actuator member or may be loosely coupled thereto and biased to a rest condition.

Abstract: A pneumatic percussion power tool has a percussion tool housing in which a drive piston and a percussion piston are movable in an axial direction. The motion of the drive piston, which is generated by a crank mechanism, is transmitted to the percussion piston through a pneumatic spring in a first chamber so that the percussion piston cyclically strikes a ram or a tool. The backward motion of the percussion piston rebounding from the ram is supported by increasing air pressure in a third chamber that is supplied with air by the drive piston through a second chamber and a communicating channel.

Abstract: A stabilizing sleeve device for an impact drill bit used in underground drilling operations. The cylindrical tubular device has arcuate keys on a bottom edge for interlocking with keyways in the shoulder of a hammer drill bit and a locking key groove in its top edge.

Abstract: An improved bushing for a heavy duty hydraulic hammer provides increased bushing life and provides cooler operation for the hammer. A Polymeric bushing is positioned near the lower end of the tool holder of a hammer surrounding the tool. The polymeric bushing is protected by a steel ring below the polymeric bushing preventing foreign objects from impacting upon the polymeric bushing.

Abstract: A hand-held pneumatic impact tool for use in fine hand working operations includes a mechanism for adjusting impacting characteristics of the device that is conveniently located and adjusted by the user. The mechanism includes an annular band protruding around the outside diameter of the body of the impact tool that may be turned for adjusting the piston stroke length and speed at which impacts occur.

Abstract: A rotary impact tool includes a housing structure with a plurality of apertures therein, an impact mechanism disposed within the housing structure, a detachable drive end mechanism coupled to the impact mechanism, and a retaining structure received by the apertures. The impact mechanism is coupled to the detachable drive end mechanism by a splined sleeve. The detachable drive end mechanism includes a detachable drive end and a collar which engages the retaining structure. Several embodiments of collars and retaining structure are disclosed.

Abstract: A functional unit for a percussion power tool and formed of a flush head (4) connectable with a chuck (3) of the power tool (1) for receiving a working tool, and a carrying handle (5) formed as a stirrup, closed carrying handle.

Abstract: The invention is based on a power tool comprising toolholder (12, 102) driveable in at least rotary fashion via a drive motor and via a driven shaft (10, 98, 100), which comprises a workholding fixture (14) for attaching tools (16, 104) actuatable in the direction of rotation of the driven shaft (10, 98, 100), and comprising a locking device (18, 86, 90), via which the driven shaft (10, 98, 100) is coupleable in torsion-resistant fashion for locking and releasing the workholding fixture (14) to and from a housing part (20, 106), and which opens automatically when torque is transferred from the drive motor to the toolholder (12, 102), and which locks automatically when torque is transferred from the toolholder (12, 102) to the drive motor.

Abstract: A power tool having a receptacle for securing a tool to a drive shaft thereof is diclosed. The receptacle comprises a receiving opening, preferably being arranged on the tool. The receiving opening engages a securing section preferably being provided in a raised fashion on the drive shaft of the power tool, thereby effecting a positive fit therebetween. The receiving opening has a cross section comprising a plurality of bulges displaced outwardly from a center axis of the drive shaft.

Abstract: A percussive drilling component includes a cylindrical male screw thread formed of a steel material. The thread includes thread crests and thread roots interconnected by thread flanks. To protect the thread against corrosion, the thread is coated with a material having a lower electrode potential than the steel material. The coating is situated at least in regions located radially inwardly of the thread flanks. The male screw thread can be attached to a female screw thread of another percussive drilling component, the female screw thread also being coated with the material.

Abstract: A breaking apparatus, which comprises a percussion device (1), and in the extension thereof, a tool (3) to which a percussion piston (2) belonging to a percussion device delivers impacts. In the axial direction, the movement of the tool is limited by means of a stopper element (15) if the movement of the tool exceeds a predetermined range of movement (B) in the direction of the impact (A). The stopper element (15) is a piece made of elastic material, which is arranged in a space between the tool and a supporting surface (16). During the stopping of the tool, the capacity of the space for the stopper element reduces, whereby the element is subjected to pressing. By the effect of the tool movement, the stopper element thus rotates about its cross-sectional central axis (21) and at the same time changes its cross-sectional shape in the reducing space. The invention further relates to a tool used in the above-described breaking apparatus.

Abstract: A stake/post driver for use with a handheld jackhammer comprising a hammer assembly including a hammer element configured to strike the upper portion of the stake or post coupled to the handheld jackhammer by a hammer spindle to mechanically drive a stake or post into the ground or other support surface and a hammer guide assembly including a hammer housing to receive the hammer element and a portion of the hammer spindle therein having an upper spindle guide formed on the upper portion thereof to receive a portion of the hammer spindle therethrough and a lower stake/post guide coupled to the lower portion thereof to receive a portion of the stake or post therethrough to cooperatively align the hammer element relative to the stake or post during operation of the stake/post driver such that the hammer element strikes the upper portion of the stake or post driving the stake or post into the ground or other support surface.

Abstract: A percussive drilling component includes a cylindrical male screw thread formed of a steel material. The thread includes thread crests and thread roots interconnected by thread flanks. To protect the thread against corrosion, the thread is coated with a material having a higher electrode potential than the steel material. The coating is situated at least in regions located radially inwardly of the thread flanks. The male screw thread can be attached to a female screw thread of another percussive drilling component, the female screw thread also being coated with the material.

Abstract: Power drivers are commonly used in production to tighten fasteners such as nuts and bolts. The socket which engages the fastener is normally coupled to the drive shaft of the power driver by a square male end on the drive shaft and a complementary square female connector on the socket. These components are not produced to close tolerances and as a result there is substantial play permitting misalignment of the rotational axes of the drive shaft and the socket and some rotational freedom between the drive shaft and the socket. In accordance with the invention an anti-vibration adaptor is provided comprising a sleeve containing a cylinder of resilient material which surrounds a portion of the drive shaft and a portion of the socket, including the point of coupling, sufficiently closely to minimize misalignment of the rotational axes of the drive shaft and the socket and reduce rotational freedom.

Abstract: A collet assembly is provided that securely holds tool bit shafts therein while allowing them to be readily and easily interchanged. The collet assembly herein has a very few number of parts and is easily assembled without the need for any special tools or machines therefor. In a preferred form, the collet assembly provides for release of the tool shaft by a forward sliding action of a collet sleeve. In this manner, rearward forces acting on the sleeve in an axial direction such as can occur during tool operations will not cause the tool shaft to be accidentally released. Another advantage is the use of a retaining member for releasably holding the shaft. The retaining member avoids the use of detent balls as in prior collets which can require ramp surfaces formed to very precise tolerances to engage and shift the balls into and out of a holding position on the shaft.

Abstract: A protective apparatus for preventing the infiltration of contaminants in a fluid-operated percussion device, having a striking tool (3) that is guided to move in a housing (2) and is driven by a percussion piston in the striking direction (arrow 1), and a seal (7) that is supported at least indirectly on the housing (2), on the one hand, and on the striking tool (3), on the other hand, and has a securing segment that is fixedly disposed with respect to either the housing or the striking tool. The seal (7) is disposed between the inner guide portion (5b) of the striking-tool guide and the theoretical striking plane (4) of the percussive piston on the striking tool (3), when seen in the direction opposite the striking direction (arrow 1), such that the countersurface (3e) for the seal, which countersurface moves relative to the securing segment (7a) of the seal (7) and is in contact with the seal, is unaffected by wear.

Abstract: A coupling for quickly and easily attaching and detaching stakes from the drive head of a horizontal directional drill. The coupling includes an upper coupler member and a lower coupler member. The lower coupler member slides into the upper coupler member, and a pin in the upper coupler member rotates into opposed, horizontal slots in the lower coupler member.

Abstract: A tool holder attachable to a spindle of a hammer and which can receive a bit, the bit having a shank with at least one retaining groove extending along part of the shank, the retaining groove having a defined length, a front end and a rear end that limit axial movement of the bit in the tool holder, which tool holder comprises a hollow cylinder having an axis, an axial bore, a rear end that can be attached to the spindle of the hammer, and a front end that can receive the shank of the bit so that the bit is slidable within the cylinder in an axial direction, at least one retaining element that is located so that it can extend radially into the bore of the cylinder and into the at least one retaining groove of the bit so that the retaining element can be hit by the rear end of the retaining groove during the transition to idling and limit the extent of axial movement of the bit within the cylinder, at least one radial restraining element limiting movement of the retaining element in the radial direction, at l

Abstract: An improved structure of multi-functional hand tool, wherein, a pushing axle rod is screw connected with a chuck, a pushing axle rod is screw connected with a driving rod; bearings are slipped over a positioning sleeve, then the positioning sleeve, the pushing axle rod and the chuck are together placed in a pipe body with the bearings. The positioning sleeve can be rotated in the bearings. A front cover is locked in the front end of the pipe body; the chuck is extended out of the front cover. The pushing member is screwed in the pipe body to render a hole on a rear enlarged threaded portion of the pushing member to be exactly located at a position limiting slot of the pipe body. The external sleeve then is slipped over the pipe body, and an inner screw hole of the external sleeve is aligned with the position limiting slot of the pipe body. Then the positioning screw rod is screwed in the inner screw hole to extend through the position limiting slot and the hole of the pushing member.

Abstract: A manually operated leak detection device used in locating fluid leaks in a ground surface includes an elongated rod and a handle transversely fixed thereto. The invention is improved by fixing an anvil on the rod; slidably mounting a first collar on the rod above the anvil; slidably mounting a second collar on the rod below the anvil; connecting and spacing the first and second collars by a pair of parallel guide rods passing through the anvil, each of the guide rods lying on one side of the rod; providing a protective sheath over the anvil, the first and second collars and the guide rods, the sheath being connected to the second collar; and slidably mounting a handle over the rod and a top portion of the first collar, the handle being secured to the sheath at the top of the first collar.

Abstract: A pneumatic hammer includes a piston rod extending from an aperture defined through the casing and a collar member is mounted to the piston rod and engaged with the aperture so as to limit the piston rod from shaking when the piston rod reciprocatingly moves. The collar member is easily removed from the aperture so as to mount a tube to the piston rod and a hammer head is therefore connected to the lower end of the piston rod.

Abstract: Disclosed is a reciprocating pneumatic tool that includes a retainer mechanism for preventing the piston from freely exiting the barrel of the tool when the retaining sleeve and workpiece are removed. The retainer mechanism does not interfere with the functional operation of the tool when the workpiece and sleeve are attached to the tool. The retainer mechanism is mounted distally around the butt of the workpiece such that no contact occurs with the retainer mechanism or the piston.

Abstract: A hand-held pneumatic impact tool and method of controlling the same for use in fine hand working operations includes a handpiece, a foot-operated flow control valve and a hand operated flow control needle valve. The handpiece includes a housing having a cavity and annular shoulder accommodating a stepped piston dividing the cavity into three chambers. The design provides a means to oscillate a piston without delivering impacts and to oscillate the piston with varying amounts of impact energy.

Abstract: A device for transmitting pulsed axial percussions to a drill (12) and including a housing (2) one end of which is releasably connectable with a housing (3) of a hand-held rotary drill, a rotation transmitting element (7, 9) rotatably supported within the housing (2) and operatively connected with a rotatable spindle (4), which projects from the rotary drill housing (3), for joint rotation therewith, a chuck (11) provided at an end of the device housing (2) opposite to the one end for receiving the drill (12), a reciprocating hammer member (15) movable into an abutting engagement with a trailing end of the drill (12), and a hammer mechanism (17-20; 21-24) arranged within the device housing (2) for imparting pulsed axial percussions to the hammer member (15) and connected with the rotation transmitting element (7, 9) for generating the pulsed axial percussions.

Abstract: A substantially tubular retainer member is provided, having a bore of substantially uniform internal diameter which can slip over the retention shoulder of the percussion bit, whether that shoulder is solid or threaded. Pins are then driven through holes in the retainer, under the retention shoulder. The pins retain the head of the bit in the event of bit breakage.

Abstract: A driver hammer for driving an elongated member into the earth and for extracting the member from the earth includes a hammer body and a forward driving anvil slidably mounted in the body that is engaged directly with the elongated member when the latter is driven into the earth. A conventional hammer drive mechanism is used to repeatedly impact the forward driving anvil to drive the member into the earth. When the member is to be extracted from the earth, a back driving lever, which is pivotally mounted on the hammer body, is pivoted into the position where the forward driving anvil can strike an impact surface on one side of the pivot point of the lever and a back driving anvil is engaged with a second impact surface on the opposite side of the pivot point of the lever and which is attached to the elongated member.

Abstract: A transmission shaft and bit mounting arrangement includes a transmission shaft, a C-shaped clamping ring fixed to the outside wall of the shaft, a chuck and locating ring fastened together and moved axially on the shaft relative to the C-shaped clamping ring, a compression spring mounted around the shaft and stopped between the C-shaped clamping ring and the locating ring, a bit mounted in a polygonal coupling hole at one end of the shaft, a magnet mounted in the polygonal coupling hole to attract the bit, and a stop member mounted in a hole on the shaft and controlled by the chuck to stop the bit in the polygonal coupling hole.

Abstract: Disclosed is a reciprocating pneumatic tool that includes a retainer mechanism for preventing the piston from freely exiting the barrel of the tool when the retaining sleeve and workpiece are removed. The retainer mechanism does not interfere with the functional operation of the tool when the workpiece and sleeve are attached to the tool. The retainer mechanism is mounted distally around the butt of the workpiece such that no contact occurs with the retainer mechanism or the piston.

Abstract: A new tool with interchangeable heads for the selection of a proper tool for the digging or manipulating of a surface for landscaping or construction purposes. The inventive device includes a shaft and interchangeable head members insertable into the shaft including a first head member with an auger head section extending from a rod section, a second head member with an mallet head section extending from a rod section, and a third head member with a chisel head section extending from a rod section.

Abstract: A hydraulic breaking hammer having a machine housing including a cylinder bore and an impact piston which is reciprocatingly movable in the cylinder bore in response to an alternating hydraulic pressure, and a tool part having: (i) a head portion fitted to a front portion of the machine housing, and (ii) a guide bore which lies in line with the cylinder bore and in which a breaking tool is slidably carried and repeatedly subjected to impact by the impact piston. A seal is arranged at the front portion of the machine housing between the cylinder bore and the impact piston for separating drive hydraulics of the breaking hammer from the tool part, and a transverse slot is formed in the front portion of the machine housing between mutually opposing side wall portions of the machine housing so as to intersect the cylinder bore forwardly of the seal.

Abstract: A portable power driven post driver. The post driver has an inner hollow cylinder open at its upper end and adapted to receive a post through a locking mechanism located at its lower end. The inner cylinder is located within an outer hollow cylinder in sliding engagement therewith, the outer cylinder having a closed upper end in contact with the upper end of a post held in said inner cylinder. Two fluid powered cylinders and associated pistons are attached to the outer surface of the outer cylinder, the longitudinal axes of the two fluid powered cylinders being in alignment. A common piston rod extends between the two pistons and is attached by a fastening member to the inner cylinder, the fastening member extending through a slot in the outer cylinder.

Abstract: Air hammer bit for use with an air hammer. The bit includes a shaft having a longitudinal axis extending therethrough. A mechanism is integral the shaft for coupling the bit to the air hammer. A bit head extends from the shaft having a center axis which is angled relative to the longitudinal axis of the shaft.

Abstract: An improved pile driving drop hammer of the free piston internal combustion engine type preferably has integral pistons on each end of a ram that reciprocates, usually vertically, in an enclosing bore. There is a combustion chamber on each end of the bore and exhaust ports situated near each combustion chamber such that the ports are opened, two cycle engine fashion, by the associated piston, after some movement of the piston, after combustion takes place to vent the active combustion chamber and then serve as intake ports when the piston moves some distance farther along the bore. At each end of the bore an anvil extends from the bore, axially movable some amount, to serve as an end to each combustion chamber. The lower anvil delivers ram impact energy to the driven piling and the upper anvil delivers impact energy from the ram to a free rising mass that is the essential element of this invention as an improvement to existing hammer designs.

Abstract: An elongated stake having a sharply pointed lower end and a polygonal shaped upper end. A hammer is slidably mounted on the stake and is limited in its travel by an upper abutment located at the upper end and a lower abutment located about midway between the upper end and the lower end. Mounted at the upper end is a first tie down ring with a second tie down ring being mounted at the lower abutment with these tie down rings facing in opposite directions. Repeatedly impactingly moving of the hammer against the lower abutment will result in the lower end of the stake to be driven into a supporting surface. A resilient cover is mounted about the hammer which includes a strap to enclose the user's hand preventing injury to the user during hammer usage. A separate tent stake is to be engageable with the upper end and repeated impacting movements of the hammer against the upper abutment is to result in driving of the tent stake into a supporting surface.

Abstract: A pile hammer for driving down hollow piles from an upper end thereof includes a hollow pile cap adapted to rest and support the hammer on a upper end of the pile being driven. The cap has an anvil surface for receiving blows from a ram which is slidably disposed on a hollow tubular base extending downwardly from the pile cap and having a lower end portion extending into the hollow pile being driven below the level of the pile cap. The ram is slidable on an upper portion of the hollow tubular base and has an annular lower end face adapted to strike the anvil surface of the pile cap when the ram is released to drop from an elevated position above the pile cap. A ram lift system is provided in an upper portion of the hollow tubular base for lifting the ram to an elevated position a selected predetermined height above the pile for release to drop downwardly and strike a driving blow against the anvil surface on the pile cap.

Abstract: An in-the-hole hydraulic hammer drill of the type having an inlet passageway for fluid and connectible to a drill string providing a source of pressurized fluid, and having pistons capable of providing downwardly directed impacts onto anvils solidly connectible to a drill bit, and having valves operated automatically by movement of the pistons to provide a continuous cycle of operation. The pistons include an upper piston and a lower piston, each capable of impacting respective upper and lower anvils solid with the drill bit, and the valves means include an inlet valve situated at the junction of the lower end of the upper piston and the upper end of the lower piston and closable by the coming together of the upper and lower pistons, and an outlet valve at the lower end of the lower piston and having a valve member operated by the lower piston.

Abstract: A bit retention device for a bit and chuck assembly of a down-the-hole, percussive drill, for retaining a head section of a bit should the head section separate from a shank of the bit includes a chuck adapted for threadable connection to a drill casing, a drill bit, a bit retaining shoulder in the the assembly; a wear collar concentric about the chuck and bit and a flexible retaining member removably connected to the assembly, the retaining member extending radially between the wear collar and bit a sufficient distance to contact the retaining shoulder should the bit drop axially downwardly.

Abstract: A grounding rod or other article is manually driven into the ground by an impact tool including an elongated guide shaft or rod having a center axis and upper and lower end portions. The lower end portion of the rod is secured by a cross pin to a coupler including a cylindrical body of electrical insulating material. The body defines a cavity extending downwardly from a metal anvil pad embedded within the body, and the cavity is formed by angularly related wedge surfaces extending from a slot. The slot opposes a threaded fastener extending radially through a flanged nut also embedded within the body. A cylindrical metal weight or hammer is slidable on the guide rod for impacting the coupler, and the hammer carries a pair of freely rotatable knobs disposed circumferentially at an angle less than 180.degree..

Abstract: A retainer for a pneumatic tool and assembly therefor is disclosed. The retainer includes a tool body having an internal surface defining a bore and an external surface having a threaded portion. A retainer cap is used with the tool body and includes an internal surface having a threaded portion adapted to engage the threaded portion of the tool body. An insert having an outer surface is rotatably mounted in the retainer cap. The insert includes an inner surface with a first inner surface portion adapted for conforming with a non-circular lug surface of a tool shank and a second inner surface portion radially offset from the first portion adapted for conforming with the non-circular lug surface.

Abstract: Fluid driven down-the-hole drilling machine. The hammer piston (2) of the down-the-hole drilling machine is adjacent to its front end provided with a cylindrical part (6). The drill bit (3) is provided with a first impact surface (41) which receives impacts during drilling, a second impact surface (42) and an annular section (7) which surrounds the cylindrical part (6) between the impact surfaces. The second impact surface (42) receives the impact energy of the hammer piston at reversed feeding of the housing (1) of the down-the-hole drilling machine for freeing the drill bit when it has become stuck.

Abstract: A method for adjusting the impact force on a hammer operated by a compressible pressure medium utilizes a hammer including a working cylinder having a to-and-fro moving percussion piston and a spindle positioned therein for striking a tool. The working cylinder is positioned inside an outer shell and the spindle is attached to the outer shell. The working cylinder is movable relative to the outer shell and the spindle. A pressure chamber is formed between the working cylinder and the outer shell and pressure medium is fed into or removed from the chamber to adjust the position of the working cylinder relative to the outer shell. In making this adjustment, the strength and frequency of impact of the piston against the opposite end of the spindle is adjusted.

Abstract: A tractor steel post driver comprising an elongated driving assembly having an upper cylindrical pipe and a lower pipe, a bracket formed of two small parallel plates, each of the plates having a free end, each of plates having an aperture therethrough with a pin positioned through the aperture of the plates and apertures at the upper end of the upper pipe with the pipe located between the plates; a pair of collar bolts positioned with their head ends interior of the lower pipes and extending radially outward through lower apertures in the lower pipe; and a collar having a cylindrical upper extent with downwardly extending recesses formed therein adapted to receive the ends of the collar bolts exterior of the tube but interiorly of the nuts with a circular plate at its lower extent having an enlarged diameter to function as a stop when used in driving posts, the collar and plate having an axial aperture for receiving the upper end of a post to be driven by inserting its upper end through the plate and lower ha

Abstract: A one piece combination chisel/hammer/crowbar device comprising a linear lower rod of a solid circular cross-sectional configuration fabricated of a rigid hard material and having an upper end and a lower end with a planar striking surface at the upper end and a linear chisel point at the lower end; a hollow tube with a circular cross-sectional configuration fabricated of a rigid hard material and having an upper end and a lower end with external threads at its upper end, the interior diameter being such as to be slidably received over the linear lower rod at the lower end of the tube and an apertured cap having internal screw threads positionable over the upper end of the tube and providing a bearing surface on the lower edge thereof; a linear upper rod of a solid cross-sectional configuration fabricated of a rigid hard material and having an upper end and a lower end with the lower end having an enlarged head with a planar striking surface for striking the striker surface, the enlarged head being such as to

Abstract: A loose crown underreamer apparatus (10) for boring into earth and other materials includes a crown (28) loosely coupled to a bit shank (12). The loose coupling mechanism (34) employed in the present invention reduces the occurrence of friction welds occurring between crown (28) and bit shank (12). Coupling mechanism (34) employed in the present invention includes a plurality of deformable polyurethane retainer balls (36) disposed in shank sockets (38) and corresponding crown sockets (40). Coupling mechanism (34) employed in the present invention allows for crown (28) to be uncoupled and re-coupled to bit shank (12) at will.

Abstract: An impact power tool for use in supporting a tool tip for hand-working operations comprises a body presenting a bore and having first and second ends. A piston is received within the bore and is shiftable relative to the body, and an anvil is received within the bore at a first end of the body and is shiftable relative to the body along the longitudinal axis thereof. The anvil includes a recess extending in a direction substantially parallel with the axis of the bore so as to define a receptacle in the anvil adjacent the first end of the bore. A tool carrier block is provided which is shaped for receipt in the recess of the anvil and which includes a set screw for permitting attachment of the carrier block to a tool tip to be supported on the impact power tool. The carrier block is retained in the anvil by friction-fit engagement sufficient to retain the carrier block in the receptacle and to permit manual removal of the carrier block.

Abstract: The present invention comprises an electrical grounding rod driving tool for use with an externally powered hammer comprising a shaft portion for insertion into a tool receiving chuck of the hammer and a base portion extending outwardly from said shaft portion which receives and retains the end of a grounding rod to which the powered hammer is applied. The base portion comprising an inwardly extending elongated tapering bore from the exterior end of said base portion which bore is identified as a conical bore, the interior terminus of said bore being truncated and terminating in a concave cap, the outer circumference of which is in tangential relationship with the walls of said inwardly extending conical bore. The diameter of said bore at said exterior is greater than the original exterior diameter of the rod to be driven, the diameter of said bore at the truncated terminus being less than the original diameter of said rod.

Abstract: A ground rod driver has a housing with upper and lower ends, and inlets and outlets for hydraulic fluid. A check assembly in the housing adjacent its lower end includes a chuck with a central bore and a multiplicity of chuck jaws slidably seated in the bore and providing spaced apart faces defining a passage therebetween. The chuck bore and the outer surfaces of said jaws have cooperating downwardly converging configurations to provide a wedging action upon relative movement of said jaws into the bore. A drive assembly effects relative movement of the jaws and the chuck bore to move the jaws inwardly of the bore to effect clamping of the ground rod and to move the jaws outwardly of the bore to release the ground rod. An anvil above the clutch assembly abuts the chuck jaws, and a drive piston assembly includes a reciprocatable hollow drive piston for impacting upon the anvil. A valve controls the flow of hydraulic fluid to effect reciprocation of the drive piston to impact upon the anvil.

Abstract: A forcible entry tool includes a hollow housing having a blind-ended bore defined therein with a stop shoulder located on a fore end of the housing and extending into the bore. A rod is slidably mounted in the housing bore and includes an abutment on a rear end thereof that is impacted by the shoulder when the housing is moved on the rod. The shoulder and the rod abutment are located inside the housing. A work element is attached to the distal end of the rod, and is engaged with a building security device, such as window bars, to pull that security device off of the building when the housing impacts the rod abutment. Various weights and weight distributions can be provided to adjust and customize the tool for the particular job or the particular user. One or more handles can be attached to the housing.

Abstract: A tool comprising a temporary attachment to a rod being driven into the ground. The tool has jaws to grip the rod and has a pressure or impact receiving surface so a kelly bar may be brought to bear on the attachment. The jaws hold the rod coaxially with the kelly bar so that application of pressure does not bias the rod, possibly causing the rod to bend or to enter the ground at an unintended angle. An extension of the frame of the attachment coaxially penetrates the kelly bar to assure alignment therebetween. The jaws are spring biased to relax the grip on the bar, and are automatically repositioned on the rod upon each successive application of force by the kelly bar. An attached chain provides a lifting handle.