Abstract: A template 20 with which pipework may be correctly positioned in a wall for connection to a wall mounted unit, the template comprising first apertures 24 for guiding drills at desired positions of pipes in the wall, and second apertures 22 for screwing the template to a wall, wherein the second apertures 22 are spaced and dimensioned such that the wall mounted unit may be mounted on the wall using the screw holes created by the second apertures 22 and be correctly aligned with pipework positioned according to the first apertures 24, each of the first apertures 24 may comprise a centrally mounted annular member 28 defining an aperture through which a center hole may be drilled.

Abstract: A drill guide, for use in the preparation of a dental implant site, having a tubular body with a screw thread along at least a section thereof. The drill guide has a stent with screw threads that are complementary screw threads allow the removable attachment of the tubular body to the stent and allows the axial advancement of the tubular body toward the bone. The complementary screw threads are provided on a matrix material of the stent.

Abstract: The drill/countersink nosepiece assembly of the present invention permits the fabrication of a precise hole and countersink in a structural assembly workpiece in a single operation with the aid of a drill plate or other hole template. The small size of the nosepiece tip enables multiple holes to be closely spaced without interference between drill plate engagement slots. A close fit between the shaft of the rotating drill/countersink bit and the inner surface of the sleeve prevents the bit from wandering upon repeated or heavy use. The drill/countersink nosepiece comprises a combination drill/countersink bit to be received by a drill motor chuck, a bushing to be received by a fixed housing portion of the drill motor, a sleeve telescopically mounted within the bushing, a spring within the bushing to bias the sleeve forward, and fingers or other features at the end of the sleeve for engaging an alignment slot in a drill plate.

Abstract: A drill jig for installing a lockset in a hanging door with an aperture for the lockset. The drill jig has a plate with a plug on one side dimensioned to fit into the aperture. An array of drill bushings is mounted in the plate aligned with a level on the top edge of the plate. Rubber feet protect the the door from being marred by the plate. The plate is positioned against the door in preparation for drilling holes through the drill bushing into the door.

Abstract: A device (10) for use in combination with a hole saw (12) of the type including a cylindrical hollow body (14) having a circular lower cutting edge (16), a top mandrel (18) with a shank (20) in engagement with a chuck (22) of a drill (24) and a pilot bit (26) for guiding the hole saw (12) when cutting a new opening in a workpiece (28) having a predrilled opening (30), in which the center of the new opening lies within the predrilled opening (30). The device (10) comprises a dowel plug (32) having a plurality of holes (34) therethrough. The dowel plug (32) is inserted into the predrilled opening (30), so that the pilot bit (26) of the hole saw (12) can be positioned in a rotatable manner into one of the holes (34) in the dowel plug (32) on center or off center with the predrilled opening (30) in the workpiece (28).

Abstract: A signal transmitter for transmitting control signals is fitted to a key element so that signals can be transmitted to an operating device with which the key is used. Illustrative is the fitting of an automobile ignition key to a fob housing in which the signal transmitter is carried. The head part of an ignition key is subjected to a punching operation to shear off a first portion of the head part leaving a remaining head part portion with wings disposed laterally at opposite sides of the key shank part. Holes are drilled in the remaining head part portion and the remaining head part portion is received in an anchorage in the housing with the key shank extending through a notch in the housing. The remaining head part is then secured to the housing with screws passing through the lateral wing openings and into anchorage posts formed in the housing.

Abstract: A tool for preparing broken stud bolts or the like for extraction by screw extractors has a guide for centering a center punch and/or a drill on a broken face of a stud. The guide is a nut and a shaft assembly. The nut has a central bore therethrough having a first portion threaded to mate with the stud threads and a second portion bored to just slide over the stud threads. The shaft assembly has a cylindrical shaft having a first end and a second end and an axial bore therethrough. The shaft includes a first externally threaded portion extending from the shaft first end of threads similar to those of the broken stud and an expandable sleeve attached to the shaft second end such that threading movement of the nut toward the shaft second end axially compresses the sleeve whereby the sleeve expands radially outward. The second end of the shaft has a conical end face.

Abstract: An adjustable drill jig for precisely locating and drilling one or more holes in a workpiece such as a kitchen cabinet component (side panel, door, drawer, etc.) or the like. The adjustable drill jig is versatile in its applications and is composed of components that can be readily assembled (or disassembled) to form various modifications of the drill jig for different applications. The adjustable drill jig is composed of at least one elongated element with at least one rule on a surface thereof, at least one adjustable drill guide which has a drill bushing therein and is slidably movable along the length of the elongated element, and a stop plate attached to an element which is slidably movable along the at least one elongated element.

Abstract: A drill centering device for use in combination with a drill bit for drilling centered holes in an end of a generally longitudinal piece of stock, comprises a guide box having a centrally aligned inner channel dimensioned for directing a drill bit therethrough and an annular rim extending from one end of the guide box. The annular rim is symmetrical about the inner restrictive channel of the guide box and dimensioned to receive a piece of stock for drilling centered holes in the same.

Abstract: An adjustable depth drill bushing assembly in which the concentricity of the drill bushing and the mounting bushing is maintained by providing flat cylindrical mating surfaces between the drill bushing and mounting bushing, even when threads are present in the mating area. Cooperating structure is provided between the two bushings which permits both precise axial adjustment and rigid interengagement. The drill bushing is adapted to move axially of the mounting bushing in the released configuration, and is rigidly locked in place in the engaged configuration.

Abstract: A bushing system for guiding a bore forming apparatus within a machine tool includes a guide bushing with a central bore allowing passage of a rotating and axially moving tool, with the bushing having a generally cylindrical body with a radially extending flange having a free end and a stepped area adapted for engagement with the retainer. The retainer includes a complementary arcuate relief formed in an outer cylindrical surface for allowing the retainer to engage a stepped area formed in the guide bushing's radially extending flange. The retainer further includes a second radially extending flange with a diameter larger than the diameter of the retainer's body such that the second radially extending flange with abuttingly engage the free end of the guide bushing to maintain the bushing in axial register with a machine tool mounting fixture.

Abstract: Apparatus for opening, or removing without damage, automotive side-bar type ignition locks, comprises a combination tool with a plurality of projections extending horizontally and forwardly from the combination tool to engage the lock's keyway, at least one balanced pair of recesses in the lock's face, or, optionally, when the tool is used as a lock-remover, the inner walls of the lock's hollow wing-nut cylinder cap. When used as a lock-forcing opener, the combination tool is placed in position on the lock cylinder's face and a conventional wrench gripping the tool's hexagonally-shaped portion is turned to create torque applied by the tool's projections against the walls of the lock's recesses, forcing the lock cylinder to turn to its ON position and start the vehicle's engine.

Abstract: A method of assembling a headed bushing from a headless bushing and a bushing head, and the resulting headed bushing. Selecting a bushing head which has a deformable flange and a bushing engaging sector on its inside cylindrical wall. Selecting a headless bushing and forming a groove on its exterior surface to engage with the deformable flange, and a head engaging sector to engage with the bushing engaging sector. Assembling the two together and upsetting the flange into the groove to hold the assembly together.

Abstract: An assembly, for providing a passage for liquid between a first member comprising a liquid reservoir such as a concentrate container or storage vessel and a second member such as a liquid outlet, includes a first connector which is adapted to be mounted on the second member and comprises a piercing assembly by which an opening can be provided in the first member, and a second connector which is undetachably connected to the first member. While in use, the first and second connectors are connected to each other, and the first connector is moved relative to the second connector in such a manner that the piercing assembly forces an opening in the first member, whereby the passage is effected.

Abstract: A fixture for engagement with a duct or raceway of the type having a base and an integral cover, wherein the fixture includes a pair of arms for maintaining the cover in the open position. The fixture includes pilot guide holes for locating drilling positions for mounting the duct to a wall.

Abstract: A drill bushing is provided with a central passage therethrough for guiding a drill bit, reamer or tap in a production operation. The drill bushing includes a generally cylindrical body extending along the longitudinal axis, and first and second ends. An enlarged head is formed integral with the first end of the body and includes a first concave recess in the periphery of the head which forms a shoulder for facilitating the securing of the drill bushing to a jig plate with a locking screw. A second liner recess is also formed on the periphery of the head. The second recess forms a second shoulder which facilitates, in the alternative, the securing of the drill bushing to the jig plate, with either a locking screw or a clamp bar.

Abstract: A method of drilling elongated holes through wood beams having extra large depths to match the holes in structural hold down hardware by mounting a template over the beam with holes matching the holes in the hardware and using a drill press with multiple auger bits aligned with the template holes to drill the required holes through the beam.

Abstract: A device and associated method for drilling a hole in the center of a broken element that is engaged within a bore, thereby enabling the broken element to be retracted by engaging the newly drilled hole. The present invention includes a collar member that defines an open central channel between two opposite ends. The collar member includes a male region adapted to engage the bore should the broken element be broken within the bore below the surface. The collar assembly also includes a female region adapted to engage the broken element, should the broken element extend out of the bore. Regardless of whether the male region engages the bore or the female region engages the broken element, the collar member aligns the open central channel over the center of the broken element. A drill bit is then advanced through the open central channel, whereby the open central channel acts as a drill guide and prevents the drill bit from wandering away from the center of the broken element.

Abstract: A chip breaker drill bushing assembly (11) for a fluted drill bit (37) is disclosed. The assembly comprises a drill bushing housing (13) and a sleeve (15). The drill busing housing (13) includes a body (17) and an outwardly protruding guide shaft (19). The guide shaft has a smooth end (31) for tightly contacting the surface of a work piece (63) to be drilled. The sleeve (15) is located in the body (17) of the housing (13), in alignment with the guide shaft. The end of the sleeve (15) facing the tip (29) of the guide shaft (19) includes a chip breaker (41). The chip breaker (41) includes two spaced-apart teeth (46a, 46b) that are defined by two helical troughs (47a, 47b) that protrude into the sleeve (15). The two helical troughs (47a, 47b) are aligned with two longitudinal apertures (33) in the outwardly protruding guide shaft (19).

Abstract: An installation method for security switches located in door jambs and connection into security system wiring is provided together with a mounting fixture for simplifying the installation. To avoid wall damage, with cylindrically packaged security switches inserted snugly in a hole drilled part way through a door jamb a few inches from the floor, an installation fixture holding a drill at an angle is inserted into the switch mounting hole for drilling at a desired angle a system wire passageway hole into the switch mounting hole wall to extending downwardly through the floor. Another drill held in the fixture at a different angle permits routing of the mounting hole wall form a wire transit channel axially adjacent to an inserted switch for passing the system wires back to connect with the security switch.

Abstract: Apparatus and method for removing side-bar automotive ignition locks without damage, a tool kit being provided containing a drill guide block, an adjustably molted drill bit, a side-bar pressure tool for insertion into the access opening created by the drill bit, and a wafer pressure tool for insertion into the keyway of the ignition lock to urge the lock wafer elements into alignment at the same time the side-bar pressure is being applied, causing retraction of the side-bar and consequent opening of the lock to permit its removal. Plugs are provided to reseal the drilled access opening.

Abstract: A drill and tap guide comprises a block having appreciable thickness and one or more guide holes therethrough. The guide holes are sized to suit different diameter taps and/or drills. The guide holes are perpendicular to the plane of a block first face. The first face of the drill and tap guide is placed on a flat surface of a workpiece. A drill or tap is inserted through the appropriate guide hole, which guides the drill or tap to remain perpendicular to the workpiece flat surface during a hand drilling or tapping operation. The block may have a circular or rectangular periphery. Different combinations of guide holes to suit different size drills, tap drills, and taps can be formed in the block. In all cases, the guide holes are located close to the block periphery. A magnet can be embedded in the block to aid in holding the block on ferrous workpieces.

Abstract: A drilling tool for drilling a curved hole. The tool includes a curved guide tube for positioning the tube in drilling position against a wall and a flexible shaft extending through the guide tube having a drill bit on the end thereof adjacent the outlet end of the tube and a shank on the opposite end engaged in a drill tool chuck. Operation of the drill tool rotates the drill bit and the tube guides and directs the bit to drill a curved or angled hole. The drill bit can be a spade bit, a spiral bit or a ball mill.

Abstract: A tool, for preparing broken stud bolts or the like for extraction by screw extractors and more specifically is a guide for centering a center punch and/or a drill on a the broken face of a stud, comprises a nut and a shaft assembly. The nut has a central bore therethrough having a first portion threaded to mate with the stud threads and a second portion bored to just slide over the stud threads. The shaft assembly has a cylindrical shaft having a first end and a second end and an axial bore therethrough. The shaft includes a first externally threaded portion extending from the shaft first end of threads similar to those of the broken stud and an expandable sleeve attached to the shaft second end such that threading movement of the nut toward the shaft second end axially compresses the sleeve whereby the sleeve expands radially outward. The second end of the shaft has a conical end face.

Abstract: A device and method are disclosed for forming the S-video record enable I.D. hole in VHS, 8 mm and VHS-C videocassettes. Three specially adapted hole forming implements and their method of use are described. These implements are adapted to avoid forming loose debris from the hole forming process and to prevent such debris which is created from entering the cassette mechanism. The invention provides for automatic positioning of the hole forming implements and for control of their movement by use of positioning plates which are specially adapted to fit on the videocassettes in a singular and specific manner. The invention further provides for controlling the operation and movement of the hole forming implements by use of guide bushings which are integral to the positioning plates. The methods used for forming the hole include cutting, piercing and melting through the plastic cassette shell.

Abstract: A device is provided for fixing and locking a tool such as a pneumatic drill on a support or grid on which are mounted sockets. According to the invention, the tool is fixed by rotation of a crown and penetrating fingers of the crown into grooves in the socket under the action of a cylinder driving a toothed sector.

Abstract: A hole saw guide for alignment of a hole saw used to enlarge an existing hole. The hole saw guide includes a perforated cylindrical plug fitted to an existing hole. The perforation accepts the hole saw pilot drill member permitting free rotation. The perforated cylindrical plug includes a stop which prevent passage of the plug through the existing hole. The hole saw guide may include mechanisms for diametric adjustment to lock the plug in the existing hole.

Abstract: A tool for locating the positions where holes are to be drilled in a contoured workpiece includes several thin, flexible plates stacked on one another, conforming to the contour of the workpiece, and held together by fasteners. The intermediate plate has holes through its thickness sized to receive the nose bushing of a drilling machine, the holes being spaced along the length of the workpiece. The innermost plate, which contacts the workpiece and the outermost plate, include slotted holes aligned with the holes of the intermediate plate.

Abstract: An index-locator pin passes through an aligned hole formed through a drill plate and juxtaposed pack-up and is displaced by a power fastener tool. A gauge pin is transversely positioned within the index-locator pin and pushes the pack-up against a drill plate in response to displacement of the index-locator pin. By maintaining the drill plate in clamping relationship against a multi-layer pack-up, a hole pattern in the drill plate may be replicated in the pack-up with high precision.

Abstract: A shielded universal joint having a pivot head defining a primary axis. The pivot head has a ball and a neck. The ball has a longitudinal slot. The slot has a throat at the center of the ball. The imperfect socket head is provided having a socket and a pin. The socket defines a secondary axis. The socket has a cavity concentric with the secondary axis. The cavity closely receives the ball. The socket has a continuous margin. The pin is joined to the socket in spaced relation to the margin. The pin extends through the passage. The pin defines a first pivot axis extending longitudinally through the pin. The pin and the throat define a second pivot axis extending through the throat and the pin perpendicularly to the first pivot axis. The socket head is simultaneously pivotal relative to the ball about both of the pivot axes.

Abstract: In drilling a bore in a structural component (3) using a hollow cylindrical core drill bit (4) initially a guide such as a disk (1) or a template (12) is secured to the surface of a structural component (3) for guiding one of the inner or outer circumferential periphery of the core drill bit. At the commencement of the drilling operation, the core drill bit (4) is guided by the disk or template and maintains the bit in a centered position. The guide can be fixed to the surface of the structural component (3) in a known manner, such as by an adhesive or by fastening elements (2, 6) driven directly into the structural component. Generally core drill bits of smaller diameter can be guided by the outer circumferential periphery of the guide (2) or by the inside circumferential periphery of the template (12).

Abstract: A door preparation drill jig is usable to prepare a door to receive a lockset provided with through-bolt mounting studs in a main bore provided in the door. The drill jig has a planar body, drill guides, and a cylindrical body. The front surface of the planar body has a portion for the placement of installation instructions and the attachment of a C-clamp. Each drill guide is arranged to receive a drill bit used to drill one of the mounting holes for receiving a mounting stud of the lockset. The cylindrical body has a chamfered edged latch slot which receives a portion of the latch extending into the main bore of the door. Additional tabs appended to the cylindrical body flex to ensue the chamfered edges around the border of the latch slot firmly engage the latch in the main bore and another flexible tab flexes to ensure a tight fit of the jig in the main bore of the door.

Abstract: A chip breaker drill bushing is provided for a metal drilling apparatus. The bushing has a central channel through which a drill bit or drilling tool extends and rotates. The bushing is shaped at the workpiece end to collect metal offal carried up by the drill. Angled troughs guide the offal up and away from the workpiece and cutting edges on the end of the bushing chop the strands into small, easily handled chips.

Abstract: A drilling jig for holding cutting chips and other debris has two separable sections. A cylindrical body has one closed end and one open end. A circular cap is adapted to fit in or over the open end of the cylindrical body. Aligned axial holes are provided though the closed end of the cylindrical body and through the cap. An adhesive layer temporarily adheres the jig to a workpiece.

Abstract: An automated drilling station for use in a computer controlled manufacturing system comprising an adjustable frame structure for releasably clamping a work piece in a planar work position, a chuck assembly adapted to operatively receive a selected drill bit, a drive train for selectively moving the chuck assembly on an axis perpendicular to the plane of the work position, feed racks for storing a plurality of drill bits of various predetermined sizes, a robot assembly for transferring a selected drill bit between the feed racks and the chuck assembly at a transfer station remote from the work position, a drive train for selectively translating the chuck assembly between the transfer station and work position and between locations on one side of the work piece aligned with predetermined drilling locations in the work position and a selectively rotatable turret having bushings of various sizes disposed about the periphery thereof for selective disposition in opposed relation to the chuck assembly at each predet

Abstract: Barrel casing attached to the housing of a hand-held drill. A retractable guide arm is cantilevered from one end of the barrel casing. The cantilevered end of the guide arm has a passageway for the drill bit, and thereby guides it. A rate limiter is attached to the other end of the barrel casing and in axial alignment with it. On the inside of the barrel casing, the rate limiter is connected to the guide arm by abutment.

Abstract: In the business of supplying bushings as tool guides for machine operations a minimum of two types of bushings need to be stocked. One type is a headless press fit sleeve. The other type is a slip fit sleeve with a head at one end. The headed slip fit type is desirable but greatly more costly. Such a great number of different sizes need to to stocked by the supplier that the cost of maintaining two complete inventories, one of each type, often becomes prohibitively expensive. The invention here involved makes use of only one complete inventory of bushings of the less costly and simpler press fit type and a partial inventory of separate heads which can be fitted on the press fit sleeve, modified to only a minor degree, and in this way to supply an order for the normally more costly headed slip fit bushing.

Abstract: A device for use in removal/replacement of single rivets or other fasteners in lines of same, by holding a drill bushing holder rigidly above the defective fastener. The unique features are a tongue and groove joint midway along the device, which can then be locked at any angle, and multiple narrow holddown slots which slide on the anchoring bolts in one direction only, expediting position adjustment.

Abstract: A rotary tool holder of the type including a stationary shell adapted to be reciprocally positioned within a bushing plate and a shaft mounted rotatably within the stationary shell. An annular space is provided between the shaft and the shell and the shell includes an enlarged diameter collar portion proximate one end of the shell and a reduced diameter pilot portion extending from the collar portion to the other end of the shell. The pilot portion is slidably received in the bushing plate and the collar portion receives a pressurized coolant fitting. Needle bearings are provided in the annular space between the shell and the shaft proximate the pilot portion and a pair of annular seals are provided in the annular space between the shell and the shaft proximate the collar portion. The annular seals are positioned on opposite sides of a radial passage formed through the collar portion and through the shaft for communication with a central axial bore in the shaft.

Abstract: There is provided by this invention a chip extraction apparatus for extracting chip swarf from a workpiece for collection in an external vacuum source. The chip extraction apparatus is comprised of a nosepiece assembly which houses a spring/atmospheric pressure actuated piston for providing telescopic capabilities to a drill bushing. The drill bushing contains an air inlet port for allowing air to be drawn into the interior fo the drill bushing where it will mix with chip swarf. The air application assists chip flow and contributes to efficient vacuum withdrawal of chip swarf from the drill flutes into the vaccum chamber of the nosepiece assembly. The chip swarf is eventually expelled through a vacuum port in the nosepiece assembly to the external vacuum source. Alternative drill bushing configurations are disclosed to provide consistent chip extraction rates for different material requirements and cutting tool types.

Abstract: A drilling jig for staircase rails includes a base plate having a first block fixed thereto and a second block adjustably mounted thereon. Rotatably adjustable drill guides with bushings are provided on the first and second blocks to permit adjustment of the guides to a predetermined angle to the base plate. A demountable section of the base plate can be removed to permit drilling of a rail at a point close to an obstruction, such as a knule post. A third block is adjustably disposed on said demountable base plate section and include an adjustable aligning pin guide. The jig is preferably part of a kit which includes a set of drill bits of various sizes, each bit having an elongated shank of the same diameter adapted to fit the bushings of the drill guides. The jig kit further includes a set of aligning pins sized to match the drill bits, the pins having a common shank size to fit the third block aligning pin guide.

Abstract: A device for removing a collar coaxially fixed to a projecting end of a fastener axially extending through the surface of a substrate, the device comprising a jig having opposed base and top surfaces and a cavity open at the base surface and disposed to coaxially receive the collar when the base surface is disposed on the substrate, at least one drill bit bushing extending through the jig on an axis generally parallel to and spaced a predetermined distance from the axis of the cavity, the bushing being disposed to guide a drill bit into engagement with the collar when disposed in the cavity, and an adjustable screw for controlling the axial length of drill bit extending through the bushing.

Abstract: A tool set for gauging and repairing concentricity of a workpiece bore axial section with the pitch diameter of the internal threads in the bore includes a gauge sleeve, a gauge rod, a reamer, and a stop collar. For gauging concentricity of the internal threads with the axial section, the sleeve is first inserted within the bore and threaded into a concentric relationship with the bore internal threads, and, then, the rod is inserted through the sleeve. The rod has an inner end which can extend from the sleeve and within the bore axial section such that the rod inner end will extend through a predetermined distance if the axial section of the bore is concentric with the sleeve and thus with the pitch diameter of the internal threads within the bore.

Abstract: A fluid supply pipe (1) is drilled and tapped using a saddle (2) adhered to its surface, the drilling and tapping tools being attached to the saddle. The saddle (2) comprises a sole plate (3) snugly fitting on the pipe, and an upstanding collar (4) with a through bore (20) through which the cutting and tapping tools pass. During adhering the saddle to the pipe, adhesive is prevented from entering the bore (20) by provision of a closure member (21).

Abstract: A number of drill guides are provided for quickly setting up to drill construction holes, door handle holes, hinge holes, and drawer front panel attachment holes for construction of cabinets without excessive jigging setup time. Several tools are described for quickly squaring up cabinet panels and clamping them together while glue dries.

Abstract: A mechanical drilling aid serves for guiding a drilling tool (42) when drilling a bore into an object, in particular into a wall (39), eccentrically to an existing faulty bore (20), when the cross-sections of the faulty bore (20) and the correct bore intersect each other or extend immediately adjacent each other. In order to ensure simple and exact guiding of the drill during the drilling operation, the mechanical drilling aid comprises a guide element (14) provided with a cylindrical opening (25) for guiding the drilling tool (42).

Abstract: A mechanical drilling aid serves for guiding a drilling tool (42) when drilling a bore into an object, in particular into a wall (39), eccentrically to an existing faulty bore (20), when the cross-sections of the faulty bore (20) and the correct bore intersect each other or extend immediately adjacent each other. In order to ensure simple and exact guiding of the drill during the drilling operation, the mechanical drilling aid comprises a guide element (14) provided with a cylindrical opening (25) for guiding the drilling tool (42).

Abstract: The invention concerns a nose piece adaptor for a manual or power feed drill. The adaptor has a hollow cylindrical sleeve (11) surrounding the drill bit and having on the outer surface of one end thereof a taper lock (13) for engagement with location studs (17) in a template (16). At its other end the sleeve (11) can be threadedly engaged or integral with the drill. The sleeve (11) has a sprung, quick-release ball (25) lock mechanism for engaging with or disengaging from a peripheral locking groove (26) of a nose piece (14) inserted into the bore of the sleeve (11). The nose piece (14) is a simple cylindrical rod with a bore (30) for the drill bit.

Abstract: The invention relates to a method of and apparatus for making an undercut in a drilled hole in a fixed base, such as concrete, masonry or the like. The shank of a milling cutter is supported and held eccentrically in the drill hole by means of a supporting sleeve which can be extended into the drill hole when the milling cutter is running. The supporting sleeve has an outside diameter slightly less than the diameter of the cylindrical drill hole so as to fit therein, and is formed with a receptacle groove extending longitudinally of the sleeve and opening at the periphery of the sleeve. The shank of the milling cutter is positioned in the groove, the axis of which is parallel to but radially outwardly spaced from the coaxial axes of the drill hole and sleeve. Rotation of the sleeve can be by a hand wheel interconnected to the sleeve, with the milling cutter rotating with the sleeve to form the undercut.

Abstract: In a device for aligning and guiding a reciprocatingly movable drill rod (11) for drillling a hole (A', B') through at least either the tibia (B) or the femur (A) forming the knee joint, the hole being intended to receive one end of an anterior cruicate ligament, which is then attached to the bone. The device includes a first tube-like aligning and guiding element (5) which is intended to be introduced into and aligned in the space between the condyles of the femur (A) over the plateau of the tibia (B) and the ends of which are spaced apart at a distance corresponding to the length of the cruciate ligament, and a second aligning and guiding element (9) which is in line with the first element and located externally of the aforementioned space, and which is located from the first element at a distance which is at least partially bridged by a part of the tibia or femur located adjacent the space.