Abstract: A hand held router (2) includes a rotatable member (22) having screwthread engagement with the housing (4) of the router (2). Rotation of the rotatable member (22) causes adjustment of the depth of cut of the router bit (18) protruding through the rotatable member (22). A releasable detent means (30) engages with latching members (28) in the rotatable member (22) thereby to enable locking of the depth of cut mechanism.

Abstract: The subject invention controls the penetration of a drill or router into a cutting surface by preventing excessive downward travel by a spindle once a preset depth is reached. This is achieved by placing a mechanical stop on the pressure foot linkage and providing a compression means to absorb the excessive downward travel. The compression can be absorbed within the select cylinder volume by reducing operating pressure appropriately, or within an added compression cylinder, or by a compression spring.

Abstract: An improved drill stand is provided which includes a stand column slidably connected to a bearer unit so that the position or height of the bearer unit with respect to the stand column may be adjusted. The bearer unit includes a gear segment which is biased toward the retracted position by a reset spring. The gear segment is meshed with a geared slide rod. The geared slide rod may be disposed parallel to or perpendicular to the stand column. The slide rod is connected to a machine receiving part. Rotation of the gear segment with respect to the bearer unit against the bias of the reset spring results in movement of the slide rod in the machine receiving part towards an extended position. The machine receiving part is also connected to a bit stop rail. The bit stop rail is connected to a bit stop. The position of the bit stop along the bit stop rail is also adjustable. Movement of the machine receiving part towards the extended position is limited by engagement of the bit stop with the bearer unit.

Abstract: A stop device that can be readily interconnected with a variety of commercially available vertical milling machines to precisely control the vertical travel of the quill mechanism of the milling machine. The bolt-on stop device of the invention includes three vertically adjustable stop mechanisms, each of which includes adjustable slide elements that can be horizontally extended or retracted relative to the quill mehanism of the milling machine. When extended the slide element moves directly into the path of vertical travel of a follower member, or depth indicator, provided on the quill mechanism of the machine. When retracted, the slide will clear the follower member of the quill mechanism so as to enable its engagement with the next adjacent stop or slide element of the device.

Abstract: A multistage bit is provided with a base part having a profile of stepped conical body with its tip cut off, and with a tip drill having a blade B of the smaller diameter than the blade B which is formed on the stage 2 at the foremost end of the base part A, the latter being provided freely detachably at the tip of the base part A.The stopper S for the above multistage bit comprises a ring shaped member having elasticity in the radial direction with its free diameter slightly smaller than the diameter of each stage of the multistage bit, a part of said ring shaped member being cut, and at least one cut end 18 thereof is bent to the center side of the ring so as to be stopped in the vertical groove 19 formed on the outer periphery of the multistage bit, and the height of the ring H is constituted to be equal to or slightly higher than the height of the stage 2.

Abstract: A screwdriver of the present invention is designed for use with power tools. The screwdriver provides an automatic disengagement mechanism to prevent excess penetration of the screw into a work surface. The screwdriver has a housing enclosing the motor and a bracing member inserted into the housing, in which the bracing member is shaped to slide inside the housing. A sleeve member adjustably secured to the bracing member so that when the sleeve member is in a fully extended position in relation to the bracing member the spindle containing a driver bit is engaged to the motor through a transmission assembly, such as clutches or ball bearings. Alternatively, if the sleeve member is in a retracted position, then the spindle is disengaged from the motor thus stopping the rotation of the screw even if the motor is still rotating.

Abstract: The fixed-base router has an annular base member supporting a cylindrical base member. A cylindrical motor housing is telescopingly received within the cylindrical base member; the motor housing includes three vertically aligned notches. A vertically disposed rod is rotatably mounted by the cylindrical base member. The rod includes an external threaded area in threading engagement with a threaded bore in a lever. The lever includes a latch for engagement with a selected one of the notches for coarse vertical adjustment. Fine vertical adjustment is obtained by rotating the rod with the latch in engagement with one of the notches.

Abstract: A drywall cutting tool has a removable depth guide. The depth guide may be removed from and installed on the tool housing by rotating the guide relative to the tool. The use of a fastener or separate tool is not required. The depth guide may be adjusted for controlling the depth of penetration of the cutting element.

Abstract: A depth stop is provided that is selectively attachable to a cutting tool at an operator-selected location. The end of the depth stop that comes into contact with a work piece during operation is covered with a rotating cap. The cap prevents the work piece from being marred because the cap stops rotating when it comes into contact with the work piece while the cutting tool and the rest of the depth stop continue to rotate. The cap is rotatably mounted on the depth stop by a flange that engages a groove formed in the depth stop. An annular ring is provided between the cap and the end of the depth stop body to facilitate the rotatability of the cap with respect to the body.

Abstract: A quill stop for a milling machine, drill press, or other like machine. The quill stop includes means for automatic control of coolant flow. The quill stop includes a passage through which high pressure air flows. A valve in the passage controls the air flow. The valve is activated by contact of the quill stop with a dog stop on the machine. The quill stop may also include a self contained mist unit activated by the valve.

Abstract: A device and method for boring pocket-holes in frame members having a miter joint to prepare them for final assembly. Two frame members are placed on the positioning frame of the invention and clamped against the positioning frame and together at the miter joint with a moveable clamp, which has a clamp member having resilient clamping pads to contact the face surfaces of the picture frame members. The clamp member also includes a guide assembly which causes the clamping pads to apply clamping force to each of the frame members to hold them securely and to urge them together at the miter joint. A drill assembly supports a drill bit and carries the drill bit along a path to drill a pocket-hole having a centerline passing through the frame member on the first surface, passing obliquely across the miter joint and into the frame member on the second surface.

Abstract: A tool for removal of rivets includes three main sections--a tubular body section, a base, and a drive shaft assembly. The drive shaft assembly includes an upper portion to be received in the chuck of a rotational source of power and a lower portion to be received in the bore of the tubular body. An internally threaded drill receiving socket is disposed at a lower end of the lower portion of the drive shaft. The body section includes a coil spring for retracting the drill and a drill stop bushing for limiting the depth of penetration of the drill bit into the rivet. The base includes an upper disc and a larger diameter lower disc and three equally spaced tubular legs connect the upper disc to the lower disc. The bottom of the base includes a non-slip polymeric pad for contacting a work surface surrounding the rivet and stabilizing the cutting path of the drill.

Abstract: A drill assembly including a drill and depth stop assembly is disclosed. The drill includes a housing, an electric motor and a chuck operatively driven by the electric motor about a drill axis. The depth stop assembly includes a depth stop rod, a mounting block, a fastener and a rotatable handle. The mounting block has a mounting surface adapted to cooperate with the housing, a first aperture spaced from the mounting surface for supporting the depth stop rod generally parallel to the drill axis, and a second aperture extending about a fastener axis generally normal the mounting surface. The fastener extends through the mounting block second aperture about the fastener axis and has two ends respectively cooperative with the housing and the handle to releasably entrap the mounting block therebetween to enable a user to adjustably position the depth stop rod relative to the housing. Preferably the fastener threadedly attaches to a threaded aperture in the drill housing.

Abstract: A dust extraction housing for a rotary drill has a rear collar 10 which attaches to a stationary boss 14 of the drill and a concertina tube 18 extending forward to enclose the drill bit 22. A forward end piece 24 of the housing has an outlet 26 for attachment of a vacuum source and an air inlet 34 fitted with a removable filter 36.

Abstract: A depth adjusting system particularly for power-driven screwdrivers comprising an adjustment collar that is releasably fitted to the housing of the tool and a depth locator which screws onto the collar for non-rotational axial movement relative to the housing. The adjustment collar has a rearward cylindrical portion that includes an inner circumferential surface having a circumferential groove and a plurality of axially extending recesses. The depth adjusting system further comprises a pair of arcuate spring members attached to the nose portion of the housing and formed to include an arcuate rib portion for engaging the circumferential groove. The arcuate spring members also include a plurality of cantilevered spring fingers for biasing the arcuate rib portions into engagement with the circumferential groove.

Abstract: A depth stop for a drill press includes a block having a passage defined centrally therein and a cut-away laterally defined therein which communicates with the passage, an oblong element received in the block from the cut-away and a resilient element disposed between the oblong element and the block, the oblong element having an oblong hole defined therein and having a threaded portion defined in an inner periphery of the oblong hole for engagement with a threaded rod which extends through the block and the oblong element, the block is freely moved along the threaded rod by pushing the oblong element to bias the resilient element to disengage the threaded portion from the threaded rod.

Abstract: A quick stop device for abruptly interrupting the cutting of a workpiece by a cutter is disclosed. The quick stop device employs an outer housing connected to an inner workpiece holder by at least one shear pin. The outer housing includes an appropriate shank designed to be received in the spindle of a machine, such as a machine tool. A cutter, such as a drill bit, is mounted in a stationary position and the workpiece, mounted to the workpiece holder, is rotated during engagement with the cutter. A trigger system includes at least one spring loaded punch disposed for movement into engagement with the workpiece holder to abruptly stop rotation of the workpiece holder. This action shears the shear pin and permits continued rotation of the spindle and outer housing without substantially disturbing the chip root formed during cutting.

Abstract: A patella planer for preparing a resected surface on a patella in a single operation. The patella planer has an adjustable stop which can be used on either side of the planer so that the planer may be used on the right or left knee. The adjustable stop has a floating zero pointer which can be set to accommodate varying thickness of the patient's patella. The amount of patella material to be removed can be selected by adjusting an offset stop pin.

Abstract: A drilling machine for drilling securing holes for furniture fittings, for example hinges, includes a drive motor which drives drills by way of a multispindle drilling head with a drill gearing and a plurality of drilling spindles. A stop rule with adjustable stop blocks and a feed device for the feed drill are provided, as well as a press-in die for mounting the furniture fittings on a furniture part. The drilling machine is equipped with a set of replaceable multispindle drilling heads and a set of replaceable stop rules which can be exchangeably fixed to the drilling machine by quick-action clamping devices which can be operated without the use of a tool.

Abstract: A depth adjusting system particularly for power-driven screwdrivers comprising an adjustment collar that is releasably fitted to the housing of the tool and a depth locator which screws onto the collar. The adjustment collar has a forward cylindrical portion and an enlarged rearward cylindrical portion that includes a pair of diametrically opposed, axially extending cantilevered spring fingers for detachably connecting the adjustment collar to a circular opening in the housing. The free ends of the spring fingers are provided with a hook and groove that are adapted to engage and mate with a corresponding circumferential groove and rib in the housing opening, thereby permitting relative rotation of the adjustment collar to the housing which serves to set the relative axial position of the depth locator.

Abstract: An apparatus for controlling depth machining in a space and with the use of jigs, includes a body having two sliding parts biased by a spring and suitable for a drilling tool, with some clearance. One part is provided with couplings for assembling on a machine-tool, and the other is provided with a presser and a drill guide. Another spring which is suitable for keeping the tool centered is included and a relative stroke between the two sliding parts is longer than the drilling stroke of the tool.

Abstract: A precision depth spindle is mounted to rotate within a cartridge but is restrained against axial movement with respect to the cartridge. The cartridge is mounted for axial sliding movement within a housing, but cannot rotate with respect to the housing. A tool chuck is fixed to one end of the spindle for movement with the spindle, the tool chuck supporting a cutting tool. A spindle stop is mounted to the tool chuck and can rotate with respect to the chuck. This allows the spindle stop to be maintained stationary while the tool chuck and the cutting tool rotate. The spindle stop is finely adjustable axially with respect to the tool chuck, thus determining the depth to which the cutting tool will enter a workpiece. The cartridge has a limited axial motion range with respect to the housing, and both the spindle and cartridge are urged toward the workpiece with respect to the housing by a suitable spring or pressure means.

Abstract: An adjustable stop assembly for use with a drill press including a ratchet bar adapted to be vertically positioned between spaced ears on the housing of the press and adapted to pass through an annular quill stop carried by the quill of the press so that the quill stop moves up and down the ratchet bar in response to vertical movement of the quill. A slide assembly is positioned on the ratchet bar and includes a slide, a ratchet dog, a stop nut, and a lock nut. The slide includes a lower annular base portion, an upper externally threaded barrel portion, and a central bore slidably passing the ratchet bar. The ratchet dog comprises a spring biased plunger mounted in the slide base portion and having an inner tip for ratcheting engagement with the ratchet bar. The stop nut and the lock nut are threaded onto the externally threaded barrel portion of the slide.

Abstract: A tool including a shaft having a drive portion, a lateral stop portion, and an intermediate portion straddled by the drive and lateral stop portions, the drive portion being adapted for detachable engagement with a rotary drive; a router blade mechanism retained by the intermediate portion of the shaft and projecting radially outwardly therefrom; a first coupling keying rotation of the shaft to the router blade mechanism so as to form a rotatably engaged unit; a longitudinal stop defining a bearing surface projecting radially outwardly from the router blade mechanism; and a second coupling securing the longitudinal stop to the unit and permitting axial adjustment between the router blade mechanism and the bearing surface.

Abstract: A plunge type router including a mechanism for setting the depth of cut of the router. The mechanism is a compact and self-contained assembly which provides for fine adjustment, locking and quick release, all at a single location on the tool.

Abstract: A guide is provided for a shaping tool having a substantially cylindrical housing, a rotatable shaping member extending from one end of the housing and a drive motor for rotating the shaping member. The guide includes an elongated hollow member, a shaft telescoped within the hollow member such that a portion of the shaft projects outwardly from one end of the hollow member, and a tip adapted to at least partially surround the shaping member such that the shaping member protrudes a predetermined distance beyond a distal end of the tip member. A first mounting bracket is provided for mounting the hollow member with respect to the housing and for retaining the shaft in a predetermined fixed position with respect to the hollow member.

Abstract: Quality control attachment adapted to be fitted onto a threaded depth control bar of a drill press machine includes a sleeve having an axial opening for fitting onto the control bar and being longitudinally movable relative to the bar. The sleeve carries a pawl and an elastic O-ring which urges an edge portion of the pawl into engagement with the threads of the control bar for enabling one-way movement of the control bar downwardly through the sleeve. An actuator pin is slidably disposed in a bore which extends through the sleeve and is movable downwardly in response to contact with a stop-nut disposed on the bar when the drill press has advanced to a preset depth represented by the position of the stop-nut.

Abstract: An adjustable stop assembly for use with a drill press including a ratchet bar adapted to be vertically positioned between spaced ears on the housing of the press and adapted to pass through an annular quill stop carried by the quill of the press so that the quill stop moves up and down the ratchet bar in response to vertical movement of the quill. A slide assembly is positioned on the ratchet bar and includes a slide, a ratchet dog, a stop nut, and a lock nut. The slide includes a lower annular base portion, an upper externally threaded barrel portion, and a central bore slidably passing the ratchet bar. The ratchet dog comprises a spring biased plunger mounted in the slide base portion and having an inner tip for ratcheting engagement with the ratchet bar. The stop nut and the lock nut are threaded onto the externally threaded barrel portion of the slide.

Abstract: There is provided by this invention an apparatus for drilling composite materials which provides controlled depth drilling. In a first embodiment of the invention, a drill motor is integrated within a microstop cage and retained by a lock nut, such that by extending or shortening the microstop cage the depth of the hole drilled is decreased or increased, respectively. The drill motor is urged towards the composite surface against spring pressure which, in conjuntion with a stop collar, limits the depth of the hole drilled. Furthermore, the spring facilitates the retraction of the drill bit from the composite surface. Alternatively, the depth of a hole may be incrementally controlled by the amount that a stop cage is threaded onto an attachment sleeve that in turn is attached to the drill motor. The further the stop cage is threaded onto the attachment sleeve, the deeper the hole drilled will be as more of the drill bit will be exposed beyond the stop cage.

Abstract: A quick adjust depth gage includes a handle-clamp assembly wherein the clamp includes an opening in which a cylindrical shaft with suitable depth measurement markings thereon is received. Turning the handle on the clamp enables the gage to be set to the desired depth.

Abstract: A guide/drill stop in the form of a hollow one-piece cylindrical sleeve for frictional engagement with a cutting tool, e.g., a drill bit, to regulate the desired depth of a hole to be drilled. The guide/drill stop sleeve extends optionally over the portion of the shank of the drill bit inserted into the collet or chuck of the machine or drill to enable the collet or chuck to secure the positioning of the drill stop during drilling. Alternatively, in another embodiment, the guide/drill stop sleeve may cover only a portion of the drill bit such that the sleeve does not encompass the section of the shank of the drill bit received into the collet or chuck of the particular machine or drill. In general a drill stop, constructed of various materials in various lengths and diameters, to enable precise regulation of drilled holes of varying depth is provided.

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: A controlled depth cartridge case chamfering tool and method for use thereof in firearm cartridge loading and reloading operations, which enables the adjustably set repeatedly uniform taper chamfering of the mouth interior of a sized and trimmed cartridge case to provide a consistently uniform radially aligned and squarely disposed truncated conically shaped gradual taper therewithin and thereby allow for a greater ease of insertion and smoothness of seating of a bullet tip during loading or reloading operations without the otherwise inherent hazard of heel and base marring or damage thereto.

Abstract: A small, lightweight spot weld drill guide attached to a conventional drill motor and includes a guide housing having a reference surface defining a reference position that is positionable against a surface being drilled, a drill shaft disposed partly within the guide housing, a bearing supporting the drill shaft within the guide housing and a locking assembly controlling the length of travel of the drill shaft within the guide housing. Windows adjacent the reference surface of the guide housing enable the drill bit to be accurately positioned over a spot weld prior to drilling to a precise, predetermined bore depth.

Abstract: An auxiliary handle for a drill includes a unitary member with an elongated handle portion and a collar portion. The collar portion has a circular opening sized to accomodate therein a cylindrical shoulder at the forward end of the drill. The unitary member is formed with an open slot extending from the circular opening of the collar portion into the handle portion, the open slot providing a separation in the collar portion. A clamping arrangement extends across the slot for selectively narrowing the slot to reduce the circumference of the circular opening so as to clamp the handle on the drill shoulder accommodated therein.

Abstract: An axially moveable portable tool, such as a drill, and a guide for the tool are disclosed. The tool is provided with a gripping means and an internal guideway parallel to the axis of tool movement on the grip side of the tool. The guide has a base with a post and a handle attached to and extending from the base. The post and handle are positioned so that a projection of the line of force applied during use to the tool grip and to the handle, both fall substantially within the base footprint. The portable tool can be attached to the post to assume a specific angle with the base and can be easily removed from it for independent use.

Abstract: A sleeve is axially aligned with the bore which is to be cut by a cutting bar rotated in the sleeve. The sleeve is placed and held in proper position by radially projecting brackets having holes in them. These holes are aligned with holes in a member having its holes in preselected positions remote from the axis of the bore. The sleeve also serves as a stop to prevent excessive forward or rearward longitudinal travel of the cutting bar by abutment with collars detachably secured at suitable positions on the bar.

Abstract: This invention relates to an improved gadget and method for the relative positioning and locking of a first externally threaded device with respect to a second device. The gadget includes a means for translating garduated markings around the outside circumference into longitudinal movement. The use of this device with 1/2" 20 thread size on the quill of a Bridgeport type milling machine to accurately control the movement limitation of the quill is described as an example.

Abstract: A drilling guide for providing stability, direction, force and depth control for precise drilling comprises a hollow shaft attached to drill shaft casing, a telescopic housing connected to hollow shaft with a close coil spring, a depth measuring scale and a set of locknuts as depth controlling device. The threaded portion of hollow shaft provides means for depth measuring and controlling surface and nonthreaded portion and outward flange provides means for direction guidance for the housing. The housing which could protect adjacent objects from drilling relatively moves upwardly during downward movement of hollow shaft and stops at where locknuts are located. The housing comprises a serrated edge for aiding stability and vented holes for exiting drilling byproduct. The close coil spring can provide consistent resistance to prevent unexpected plunging of drill bit and can bring the drill bit back to the original position following the same path of drilling.

Abstract: A holding fixture for drilling pocket joints with a stepped drill bit. The fixture includes an L-shaped body member having a guide leg that carries an angularly disposed drill guide channel and a clamp leg that supports a clamping mechanism for securing a wooden workpiece flush against the planar surface of the guide leg. The drill guide channel has an upper stop flange and a lower end that terminates flush with the planar surface of the guide leg at a point spaced above the junction of the guide leg and the clamp leg. The stepped drill bit is secured in the chuck of a portable drill and an adjustable stop collar is positioned on the bit. The stop collar engages the stop flange so that the end of the bit is prevented from contacting the surface of the clamp leg. The wooden workpiece is secured flush to the planar surface of the guide leg by the clamp and the pocket and pilot hole are drilled.

Abstract: A portable electric tool including an electric motor for driving a cutter to cut an object to be machined. The electric tool comprises a bracket for supporting the electric motor and handles attached to handle-mounting sections of the bracket for keeping the electric tool in cutting operation. Also included in the electric tool is a coupling mechanism for mechanically coupling each of the handles to each of the handle-mounting sections of the bracket. The coupling mechanism includes first and second annular members which are respectively attached to the handle-mounting section thereof and the handle so as to be coaxially arranged in confronting relationship to each other. Each of the first and second annular members has elongated recess portions and elongated projection portions which are alternately and successively arranged at a predetermined angular interval with respect to its own center.

Abstract: A position indicating mechanism for a milling machine or the like includes a position indicator having a rail and a position indicating scale slidably mounted thereto to provide a digital readout of the position of the scale along the length of the rail. A rail mounting bracket is adapted for mounting to the milling machine and for affixing the rail to the milling machine. A scale mounting plate is adapted for connection to the slidable scale, and also for interconnection with a movable collar of the milling machine which moves synchronously with movement of the work-performing component of the machine.

Abstract: A key manufacturing machine utilizing a drilling assembly adapted to perform a drilling operations including a rotating assembly having a number of attaching block assemblies circumferentially spaced at its top portion. Each of the attaching block assemblies has a setting wheel which includes an integral wheel part and a shaft part, and which is turnable to set a desired position. A number of set screws are each disposed within a corresponding threaded hole on the wheel part of the attaching block assembly to be adjustable to respective depths. A sensing device is utilized to sense the depth of each set screw for controlling the drilling depth during the drilling operation.

Abstract: A motor operated, hand held apparatus for dislodging and removing of accumulated earwax within the canal of a hearing aid. This apparatus utilizes a narrow elongated tool which has a spiral exterior surface which is to be inserted within the canal of the hearing aid and operated at high speed to remove and move the earwax exteriorly of the canal. Associated with this tool is a cover which is to be movable to different positions to limit the amount of extension of the tool to within the canal to thereby eliminate any potential damage to the electronic mechanism of the hearing aid.

Abstract: A drilling device for drilling blind holes to a preselected depth in a work piece is provided. The drilling device includes a drill which rotatably drives a spindle which spindle drives a drill bit. Guide means for mounting the drill member for axial movement to perform the drilling operation are provided. A rod member is secured to and extends from the drill member and is moveable axially therewith as the drill performs its drilling function. An adjustable member is threadably mounted on the rod and is moveable relatively axially on the rod. Adjusting means including a wheel and detent are provided which are connected to the adjustable member and the rod member to rotate the adjustable member with respect to the rod member to thereby cause relative axial movement of the rod member and adjustable member which will change the relative position of the adjustable member on the rod member.

Abstract: An auxiliary handle is attachable by a band-shaped clamping member of a clamping device to a housing part of a hand tool such as a drill. A bearing part, supportable on the housing part, has alignable through openings for an axially extending depth stop. A U-shaped separate part is in engagement with the clamping member and has a through guide alignable with the through openings. When the clamping member is tightened on the housing part, it displaces the separate part transversely of the axis of the through opening for clamping the depth stop in the through openings.

Abstract: An adjustable stop member, comprises three parts which are mounted in longitudinal alignment, with the overall length of the aligned parts being adjustable. The first part is an elongate cylindrical member which has one closed end and a threaded, elongate bore extending inwardly from the other end. The second part is an elongate rod which has external threads for mutual engagement with the internal threads of the first part. The second part further has a flat extending longitudinally along the surface thereof and an index line extending longitudinally along the surface thereof and an index line extending along the length of the flat. The third part is a nut which is threaded on the second part. The nut can be tightened against the first part for firmly securing the parts together in a releasable, fixed position. The nut has equally spaced markings around its circumference which form a scale used with the index line on the second part in setting a desired overall length of the stop member.

Abstract: A hand drill guide comprising an annular base and a plurality of telescopic leg assemblies distributed along the base. Each assembly has a hollow cylinder, fixed perpendicularly at one end to the base, and a rod slidably mounted in the cylinder, the rod extending out of the cylinder through an opening. The drill guide also comprises an annular positioning head to which the other ends of the rods are fixed, and an annular drill holding assembly mounted for selective location on the cylinders. The rod has a retaining ring rigidly connected thereto at a given distance from its upper end to prevent the rod from escaping from the cylinder. A ring is floatingly mounted on the upper portion of the rod inside the cylinder and two springs act on the floating ring: one between it and the upper end of the cylinder and the other between it and the retaining ring, both springs being uncompressed when the retaining ring is adjacent to the bottom end of the cylinder.

Abstract: A drilling tool for removing spot welds includes a central shaft having a threaded portion which extends through a center nut and washer assembly. A pair of oppositely opposed compression springs bear on the center nut and washer assembly to maintain it in a fixed position. Stops located on the shaft engage the center nut and washer assembly to limit the forward travel of the drill bit. This ensures that the drill bit has a predetermined stroke length. The springs provide compression for the drill bit as the shaft rotates thus forcing the drill bit into the workpiece, but with some resilience so that the drill does not bind up.

Abstract: A drill head which enhances the accuracy of a drill, is attachable thereto and which includes an inner cylinder which is retractable into an outer cylinder and means to adjust such retractable distance, which distance is determinative of the exact depth of the hole to be drilled.