Abstract: An automatic output shaft locking mechanism for electric tools, and particularly a locking mechanism in which the output shaft is driven by electric power and will automatically lock in position when it is turned by an external force, including a retaining end with three equi-angular projections at one end of the output shaft in the tool, and a rotary disk having three equi-angular notches at an outer side. The outer portion of the rotary disk is fitted with a securing ring, and its three notches receive lock rollers respectively. When the retaining end turns, the three projections will push the lock rollers to engage the securing ring so that the output shaft is locked in position.

Abstract: An improved two-ended reversible drill/driver tool for use with power drills. The tool having a hollow cylindrical socket that at one end has a drive shank for insertion into a chuck of a powered drill, and, at the opposite end, has a polygonally shaped opening therein for receiving a correspondingly shaped, two-ended, reversible tool assembly. This tool assembly is sized to slide within the hollow socket, and has a combined drill bit and countersink at one end, and, at the other end, a polygonally shaped opening for accepting a screw driver bit having a shank with a polygonal cross section.

Abstract: A spindle extension, especially for drilling and milling operations is desirable to complete many modern die molds or to protect the host machine spindle from undesirable wear. The inventive spindle extension contains its own adjustable length draw bar assembly that works in tandem with the host machine power draw bar that is easily activated to provide quick and secure tool changes. Surrogate and long-reach embodiments are disclosed.

Abstract: A tool bit chuck for drilling and chiseling bits has an axially extending receiving sleeve (1) with an opening (3) therethrough in which latching elements (9) are radially displaceably supported. The latching elements (9) are radially displaceable by a spring loaded axially displaceable actuating element (10). An actuating sleeve (12) laterally encloses and is axially displaceable relative to the receiving sleeve (1). Connecting members fix (6, 13) the actuating sleeve to the receiving sleeve. The actuating sleeve (12) has a stop (14) cooperating with the actuating element (10) for applying an axial force to the actuating element for assisting in centering the drilling or chiseling bit.

Abstract: An arrangement for transmitting torque from a chuck (5) in a manually operated tool to a tool bit (1) having an axially extending chuck section (2) insertible into the chuck. The chuck section (2) has axially extending entrainment faces (31) arranged to cooperate with correspondingly shaped torque transmitting faces (6) in the chuck (5). The chuck section (2) is arranged to cooperate with a device (7) in the chuck for retaining the tool bit and affording limited axial displaceability of the bit. The chuck section (2) is formed with at least one recess (4). The device (7) in the chuck includes a locking element (8) engageable in the recess. The locking element (8) is axially and radially displaceable both to a limited extent and the axial displaceability of the tool bit is possible at least in part, by the limited axial displaceability of the locking element (8).

Abstract: A clamping device for connecting a toolhead and a toolholder on machine tools using a cylindrical or at least partly conical location hole with corresponding shank, wherein a rotatable clamping bolt with spiral guides is used, in clamping to move clamping members outwards from within, thus providing a positive and non-positive locking of the toolhead and the toolholder. The clamping bolt has at least one stop to limit the angle of rotation in clamping. The retainer for the clamping members is spring mounted in the toolholder.

Abstract: A drill has a drive unit having a front end and an output shaft projecting from the front end and centered on and rotatable about an axis, and a fan associated with the shaft for creating a moving stream of air traversing a location at the drive-unit front end. A chuck body fixed on the shaft is formed with a rear end juxtaposed with the drive-unit front end, an axially forwardly open tool recess on the axis, a plurality of angularly spaced and angled guides opening into the recess, and at least one passage extending between the chuck rear end and the recess. Respective jaws displaceable in the guides have front ends in the recess. An adjustment sleeve is rotatable about the axis on the body and interengaging formations on the sleeve and on the jaws displace the jaws radially on rotation of the sleeve about the axis.

Abstract: The chuck is used with a drill drive unit having a spindle extending along and rotatable about an axis. The chuck has a chuck body fixed on the spindle and formed with an axially forwardly open tool recess on the axis, a plurality of angularly spaced and angled guide holes opening into the recess and having inner surfaces, and a respective grit-clearing passage opening at a respective front end into each of the guide holes axially rear-ward of the recess. Respective jaws displaceable in the guide holes have outer surfaces riding on the inner surfaces of the respective guide holes and have front ends in the recess. An adjustment sleeve is rotatable about the axis on the body and interengaging formations on the sleeve and on the jaws displace the jaws radially on rotation of the sleeve about the axis.

Abstract: A tool for insertion into a tool bit chuck in a manually operated tool used for chiseling and/or percussion drilling includes an axially extending chucking shank (1) with a locking 1groove (2) closed at its ends spaced apart in the axial direction. The chucking shank (1) has two rotary entrainment grooves (3) each with an entrainment side flank arranged so that the entrainment side flanks are located diametrically opposite one another. One of the rotary entrainment grooves (3) extends in the axial direction through a part of another locking groove (4) in such a way that the locking of the tool bit in a chuck is improved. To increase the transmission of torque, the chucking shank (1) has at least one additional axially extending groove (5). With this groove arrangement of the chucking shank (1) the tool bit is useful with a correspondingly shaped tool bit chuck as well as with different commercially available chucks.

Abstract: A keyless chuck assembly for a hand-held drill includes a housing, three jaws for gripping a drill which is to be turned by the drill chuck assembly. The jaws are retained in the assembly and confined to radial motion with respect to the drive shaft by means of T-shaped guide slots in the bottom of the drive shaft and cooperating T-shaped ribs on the tops of the jaws. The jaws have a gripping surface and a cam surface. A rotatable adjusting ring engages the jaws to move them in the radial direction to secure and release the drill bit. The jaws can include a resilient material between the gripping surface and the cam surface to allow the chuck jaws to more securely grip the drill bit. A locking mechanism prevents rotation of the ring which would allow the jaws to open.

Abstract: A tool bit for insertion into a tool bit chuck in a manually operated tool used for chiseling and/or percussion drilling has an axially extending chucking shank (1). The chucking shank has two axially extending rotary entrainment grooves (2) open at its end inserted into the chuck and located diametrically opposite one another. In addition, the chucking shank (1) has a locking groove (3) closed at its ends extending transversely of the axial direction and serving to lock the tool bit in the axial direction. Further, the chucking shank (1) has an axially extending groove (4) and an additional axially extending groove (5) for providing greater surface areas in entrainment side flanks for transmitting torque. The axially extending groove (4) extends through a part of the locking groove (3) so that an end face (3a) is formed extending transversely of the axial direction.

Abstract: A tool bit for insertion into a tool bit chuck on a manually operated tool used for cutting and/or percussion drilling includes an axially extending chucking shank (1). The chucking shank has two axially extending rotary entrainment grooves (2, 3) open at a free end of the shank and located diametrically opposite one another. The transverse cross-sectional areas of the rotary entrainment grooves (2, 3) are different. A locking element displaceable into a locking groove (4) with axially displaced closed ends affords axial securement of the chucking shank in the chuck. To increase the torque to be transmitted, an axially extending groove (5) open at the free end of the shank is provided with its cross-section transverse of the axial direction corresponding at least to the transverse cross-section of the locking groove (4). Due to this arrangement, faulty locking of the chucking shank in the chuck of conventional commercially available manually-operated tools can be easily recognized by the tool operator.

Abstract: A tool bit for insertion into a tool bit chuck in a manually operated tool, used for cutting and/or percussion drilling, has an axially extending chucking shank (2) with a free end. The chucking shank (2) has two locking grooves (6, 7) located diametrically opposite one another and closed at their ends spaced apart in the axial direction. In addition, the chucking shank has two axially extending rotary entrainment grooves (8, 9) disposed diametrically opposite one another and open at the free end. The transverse cross-sectional areas of the rotary entrainment grooves (8, 9) are different. To increase the transmittable torque, an additional axially extending groove (11) open at the free end of the chucking shank extends through and is positioned asymmetrically to one of the locking grooves (7). An end shoulder face (7a) for axially securing the tool bit is formed in the end region of the locking groove located laterally outwardly from the axially extending groove (11).

Abstract: A tool bit for insertion into a tool bit chuck in a manually operated tool used for chiseling and/or percussion drilling includes a chucking shank (6). The chucking shank has two rotary entrainment grooves (7) located diametrically opposite one another and open at the end of the chucking shank to be inserted into the chuck. A pair of locking grooves (8) are located diametrically opposite one another. Axially extending grooves (9) overlap at least part of the pair of locking grooves (8) so that end faces (8a) are formed extending transversely of the axial projection and facing away from the end of the chucking shank to be inserted into the chuck.

Abstract: An improved two-ended reversible drill/driver tool for use with power drills. The tool having a hollow cylindrical socket that at one end has a drive shank for insertion into a chuck of a powered drill, and, at the opposite end, has a polygonally shaped opening therein for receiving a correspondingly shaped, two-ended, reversible tool assembly. This tool assembly is sized to slide within the hollow socket, and has a combined drill bit and countersink at one end, and, at the other end, a polygonally shaped opening for accepting a screw driver bit having a shank with a polygonal cross section.

Abstract: A device for driving impact and/or drilling tools on a hand power tool has a tool with a tool shaft having at least two drive grooves which are open toward the shaft end and at least one locking trough which is closed toward the shaft end. A driver for a radially displaceable locking body of a tool receptacle engage correspondingly in each drive groove and locking trough. For strengthening the driving, the locking body is provided with an axially extending, strip-shaped radial projection which engages in a correspondingly formed depression of the locking trough of the tool shaft for forming an additional drive flank.

Abstract: A surgical instrument has a motor including a chuck for releasably receiving a dissecting tool for rotation about an axis of the surgical instrument. The dissecting tool has a cutting end and a shaft and the surgical instrument is provided with a base releasably connected to the motor. A sleeve is releasably connected to the base to support the shaft of the dissecting tool, and the surgical instrument is further provided with sleeve connection means for selectively permitting axial movement of the sleeve relative to the base and the dissecting tool to vary the amount of protrusion of the cutting end of the dissecting tool from the sleeve.

Abstract: An annular cutter connecting apparatus includes an arbor, annular cutter fixing locking members received in holding holes formed in the lower end portion of the arbor and a sleeve member surrounding the lower end portion of the arbor, for fixing an annular cutter to the arbor. The sleeve has a first control face having an inner diameter equal to the outer diameter of the lower end portion of the arbor, for projecting the locking members into the central bore by a predetermined length when the first control face engages the locking members, and second control faces formed circumferentially in the first control face, for receiving the locking members. The sleeve is rotatable around its own axis so as to cause the locking members to selectively face the first control face and the second control faces, respectively.

Abstract: A tool bit to be inserted into a tool bit chuck of a hand tool used for chiseling, drilling and/or percussion drilling has an axially extending chucking shank (A) with two locking grooves (1) closed at the ends spaced apart in the axial direction, and two rotary entrainment grooves (2) open at a free end of the shank. In addition, two rotary entrainment faces (3) are located in the areas of the locking grooves (1).

Abstract: The tool holder is arranged to receive a tapered tool shank. The collet has a shank engaging surface which, in use, lies substantially on the surface of a notional cone which tapers in the direction of withdrawal of the shank from the tool holder.

Abstract: A quill is rotated in a spindle and carries a tool which is rotated with the quill about a common axis. The tool is held in a bore in the quill by a combination of a tool receiver, a drawbar and an attachment member which is shrunk fit to the tool. The overhang of the tool is greatly reduced and tilting takes place through the base of the attachment member rather than through edge loading of the tool in a bore.

Abstract: A hand machine tool has a rotatable spindle having a longitudinal axis and provided with a cone and an annular surface extending at an angle to the longitudinal axis, a tool holder having a conical opening which surrounds the cone, torque-transmitting elements provided between the spindle and the tool holder, and locking elements cooperating with the ring surface of the spindle, the locking elements being formed as spring wire members.

Abstract: A spindle extension, especially for drilling and milling operations is desirable to complete many modern die molds or to protect the host machine spindle from undesirable wear. The inventive spindle extension contains its own pull stud draw bar assembly that works in tandem with the host machine power draw bar that is easily activated to provide quick and secure tool changes. Surrogate and long-reach embodiments are disclosed.

Abstract: A shank 11 on a tool bit for percussion drilling or chiseling has at least two rotary entrainment grooves (13, 14, 16), however, they are not arranged in diametrically opposed relation. In addition, the shank has at least one locking groove (12). The rotary entrainment grooves (13, 14, 16) are open at the end face (17) of the shank inserted into the chuck, so that rotary entrainment members in a tool bit chuck can be inserted into the rotary entrainment grooves (13, 14, 16). Locking groove (12) is closed at its end adjacent the end (17) of the tool bit inserted into the chuck, so that a locking member of the chuck can fit into the locking groove to prevent axial displacement of the tool bit out of the chuck. To reduce significantly the wear of the shank and the chuck, the shank has an additional rotary entrainment groove (15) located diametrically opposite the locking groove (12). Further, an additional rotary entrainment member is provided opposite the locking member in the chuck.

Abstract: A tool bit shank (11) for percussion drilling or chipping has at least three rotary entrainment grooves (13, 14, 15) extending in the axial direction and at least one locking groove (12) also extending axially. The rotary entrainment grooves (13, 14, 15) open at a free end (16) of the shank (11) so that rotary entrainment members of a tool bit chuck can be inserted axially into the rotary entrainment grooves. The locking groove is closed at its end adjacent the end face (16) to prevent ejection of the tool bit when it is engaged by a locking member of the chuck. To significantly reduce the wear of the tool bit shank and the tool bit chuck, the rotary entrainment grooves (13, 14, 15) are arranged in sequence in the circumferential direction in respect to radially outwardly facing circumferentially extending openings from the largest to the smallest opening.

Abstract: A boring bar holder and removable insert member each equipped with cooperating precision locator means wherein any replacement of the insert within the boring bar holder will index the new insert with precision to the location of the previous insert. There are biasing means associated with the boring bar and the insert to wedgingly move the insert rearwardly to bias against a bore in the boring bar and to index the position of the cutting head of the insert in exact relationship to a previous insert placement.

Abstract: A plug-in holder (2) of a drilling tool has an axially extending central bore for receiving a centering drilling bit. The holder (2) has an opening (5) extending from the bore to its outer surface. A latching element (6) is radially displaceably supported in the opening (5). The bore (4) has inwardly projecting entrainment ridges (9). The latching element (6) holds the centering drill bit in the axial direction while the entrainment ridges (9) engage the bit for rotational displacement.

Abstract: In a combination tool bit and tool bit holder or chuck, rotary entrainment members (6, 7) extending over different circular arcs are formed in the tool bit holder for transmitting torque to the tool bit shank (8). Corresponding rotary entrainment grooves (9, 10), also extending over different circular arcs, are formed in the tool bit shank (8). Locking members (4) axially retain the tool bit in the holder. The locking members (4) can be displaced radially into or out of the recesses (11, 12) in the tool bit shank (8). The recesses (11, 12) are laterally closed. Due to the different configurations of the rotary entrainment members (6, 7) and the corresponding grooves (9, 10) it is possible to transmit higher torques while avoiding detrimental cross-sectional weakening of the tool bit shank (8).

Abstract: An apparatus for adapting toolholders (10) which are specifically designed for use with machine tools having quick change tooling systems so that such toolholders may be used with machine tools not equipped with such systems. The apparatus secures to the toolholder shank (45) and provides an intermediate element enabling the toolholder (10) to be secured to such machine tools.

Abstract: A collet and tool assembly for rotatable tools such as drills and taps in which the collet and tool each include mating:a) stops for limiting entrance of the tool into the holder;b) matching detents for producing an audible click when the tool is properly placed in the collet; andc) matching eccentric sections which provide positive torque transfer between the collet and the tool.

Abstract: A centrifugal spindle is described comprising a hollow shaft (1) having a collet (2) at one end for gripping a tool shank (12) and a centrifugal loading means (3) housed within the shaft (1). The loading means comprises two coaxial pistons (4,5) spaced from each other and linked by flexible connecting members (6) and intermediate bob weights (7). One piston (4) is secured axially to the hollow shaft (1) while the other piston is secured to the collet so that rotation of the shaft (1) causes the weights (7) to move radially outwards under centrifugal force to draw the piston (5) and collet (2) into the hollow shaft (1) gripping the tool shank (12). The collet may have spring loaded jaws forcing them into the closed position.

Abstract: An expandable holding device for holding a component in which the clamping force is brought about by the solidification and expansion of a fusible alloy. The alloy is contained in an expansion chamber defined in part by a thin-walled, expansion sleeve. The alloy has a low melting point and expands when it solidifies. The pressure caused by expansion of the fusible alloy radially expands the expansion sleeve causing the expansion sleeve to grip the component. To release the component, the alloy is heated and liquified so that the expansion sleeve returns to an unexpanded condition.

Abstract: A drill chips removing device, comprising a sleeve or a ring formed with a through hole at its central portion for axially passing said drill therethrough and provided with a fixing device for fixing the sleeve or the ring to the drill.

Abstract: A tool coupler is provided, comprising an elongated body having upper and lower ends and further including a non-circular first axial bore extending at least partially through the body from the upper end toward the lower end, a flange extending radially from the body, and at least one radial bore communicating between the first axial bore and the exterior of the body, the radial bore being located just above the flange. A collar is positioned around the body, the collar having upper and lower ends, an inner wall and an outer wall, and an annular retaining flange extending radially from the inner wall, the retaining flange being alignable with the radial bore. A cap is positioned in the collar, the cap having an upper surface, an annular outer surface facing the inner surface of the collar, an annular lower surface, the cap further including an axial opening at least as large as and aligned with the first axial bore in the body.

Abstract: A boring device adapted to mount boring tools for automatic tool changing, in which an eccentric mounting of relatively rotatable inner spindle 11 and main spindle (2) allows radial adjustment of the tool. Relative rotation of inner and outer spindles is accomplished by axial driving of a threaded bolt (22) by an actuator motor (67), causing rotation of a nut (19) fixed to the inner spindle (11). Continued overtravel of the threaded bolt (22) past an adjustment range (47) and safety range (51) causes releasing operation of a spring biased pull rod (36) which releases a tool clamping mechanism (14) to allow automatic tool changing.

Abstract: Disclosure is made of a bar-clamping device having a hollow spindle carrying first and second collets, each provided with a closing drive ensuring independent axial motion of one of the collets relative to the other. The closing drives of each collet are installed in the spindle and designed so that the axial efforts produced during clamping of a bar are directed in the opposite directions.

Abstract: An expandable tool holding device for holding a tool or workpiece in which the clamping force is brought about by the solidification and expansion of a fusible alloy. The alloy is contained in an expansion chamber defined in part by a thin-walled, expansion sleeve. The alloy has a low melting point and expands when it solidifies. The pressure caused by expansion of the fusible alloy radially expands the expansion sleeve causing the expansion sleeve to grip the tool or workpiece. To release the tool, the alloy is heated and liquified so that the expansion sleeve returns to an unexpanded condition.

Abstract: A quick change right angle drill head incorporates mechanism rotating components within the drill head housing thereby resulting in a more compact package which facilitates use in space-limited locations. A single push button release enlarges a chuck opening to receive a cutting tool. An internally located compression spring becomes operative when reverse thrust forces are exerted against a cutting tool. The design of the present invention may be constructed to either lock the cutting tool into the drill head chuck or release it, upon exertion of the reverse thrust forces.

Abstract: A selective drill bit attachment for a standard portable electric drill is provided and includes a housing for carrying a plurality of different sized drill bits in which one of the drill bits can be selected and manually extended into an operable position so as to be used by a standard portable electric drill. In a modification a locking mechanism is utilized to hold the selective drill bit stationary to the housing.

Abstract: A chuck assembly for a tool bit includes a spindle with a quick release mechanism and is adapted to prevent undesired axial retraction of the tool bit from the spindle. The tool bit includes a shank portion with a circumferential groove. A longitudinally extending bore is provided in the spindle for receiving the shank portion of the tool bit. The shank is retained in the bore by detent balls extending into the bore and against the circumferential groove. The balls are disposed around the shank in an opposing manner to help center the shank. Attempted axial extraction of the tool bit from the bore without release of the balls locks the balls against a retaining face and a biased locking shoulder preventing extraction of the tool bit from the bore.

Abstract: The subject of the invention is an attachment to all drilling apparatus which include one or more chucks.The attachment is made to facilitate and speed up the invention into and removal from drill holding chucks.The attachment compreses a set of two collars for every chuck. The first one of said collars is attached or forms part of the chuck and the second one is fixedly attached or forms part of the body of the respective apparatus. Within a slot in the second collar is movable a driver which can be brought into engagement with a recess in the face of the first collar. When in engagement, the driver causes the chuck to rotate and to open for insertion or to close for removal of a drill.

Abstract: The invention is a quick change holding device for tools and, more particularly, for taps. The holder has an axially movable collar cooperable with holding elements which can be placed in holding position relative to an annular groove in the tap and released therefrom. The holding elements are curved, that is arcuate individual members having rounded, that is, curved, surfaces on the outsides thereof. The inner rounded or curved surface of the holding element comes into contiguous flush mating engagement with the annular groove in the tap, whereby improved holding capability is achieved.

Abstract: A chuck for tools comprises a main body in which an axial center hole and a plurality of slanting holes extending radially from the center hole are formed, a plurality of jaws each being slidably inserted in each slanting hole and formed, at its outer surface, with a male screw, a rotary member having a female screw in meshing engagement with the male screws and mounted in the main body so as to be permitted for only rotation, a first grip integrally connected to the main body, and a second grip securely connected to the rotary member to cooperate therewith.

Abstract: A working tool holder for a drilling or chiseling device includes a holder sleeve with an axially extending conically shaped section within a holder opening or bore. A working tool to be secured in the holder sleeve, has a tool shaft with a conically shaped section to engage the conically shaped section in the holder opening. Grooves are formed in the tool shaft to receive inwardly projecting ridges in the holder opening. The tool shaft has recesses to receive the pins mounted in the holder sleeve. The tool shaft and an actuating sleeve extending around the holder sleeve each have connecting threads for securing the working tool in the holder.

Abstract: A self-tightening drill chuck has a chuck body adapted to be mounted on a drill spindle for rotation about an axis and a tightening sleeve surrounding the body and formed with a substantially frustoconical seat centered on the axis and having a front end turned away from the chuck body and formed with a plurality of radially inwardly open, angularly offset, and axially extending grooves. The sleeve is secured on the chuck body for rotation about the axis thereon but against axial movement thereon. A jaw guide in the sleeve formed with a plurality of axially forwardly open and angularly spaced slots has a front end formed with respective radially outwardly projecting ridges engaged in the grooves. Respective jaws are axially and radially displaceable in the slots and on the seat.

Abstract: A drill bit and chuck for interconnection with the end of a flexible drive shaft which axially and rotationally restrains the drill bit against becoming separated from the chuck during an operation requiring bone drilling, for example. The drill bit drive end has an eccentrically mounted boss with an enlarged head. A collet has an internal wall with an eccentric opening for receiving and locking with the drill bit boss head. The opposite end of the collet is staked onto the flexible shaft.

Abstract: An axially movable sleeve has interference members or lugs engageable with interference members or lugs associated with the split nut in a chuck. When the chuck is driven by the spindle, the axially movable interference members engage the split nut interference members and are restrained from rotation. The nut is also restrained and the chuck jaws open or close depending upon the direction of rotation of the chuck body. The sleeve is positioned to be engaged by the jaws as they approach full open position. The jaws then move the sleeve axially to disengage the interference members and stop further opening of the jaws before they reach a position to wedge or jam in the open position.

Abstract: A keyless chuck for fastening or releasing a tool, in which a plurality of oblique holes are formed in a body, jaws are inserted into these holes, and a nut engaging with rear portions of the jaws is rotated in a normal or a reverse direction so that the jaws either advance or retreat. This keyless chuck is provided with a grip member loosely fitted around the outer periphery of the body, a pair of opposed groups of lugs provided on the nut and the grip member and capable of engaging with or disengaging from each other, and at least one spring provided on one of the groups of engaging portions and adapted for constantly urging this group of engaging portions toward the other. If the grip member is fixed, the nut is rotated in the opposite direction relative to the body so as to make the jaws advance or retreat, thereby fastening or releasing the tool.

Abstract: A reversible power drill having a drill chuck tightener is disclosed. The drill has a body and chuck reversibly rotatable with respect to the body. The tightener comprises a lever or a contact post attached to the body of the drill and an impact button attached to the back portion of the chuck of the drill wherein the lever or post impacts the impact button as the chuck rotates, thereby tightening or loosening the chuck depending upon the direction of rotation of the drill. The lever or post is biased by a spring into a position which disengages it from the impact button when not in use.

Abstract: Improvements in tool holders in the field of machine tools; quick change connectors for replacing one tool holder with another in chucks mounted on rotary machine tool drive shafts and spindles; tool changing attachment permitting rapidly changing or switching one drilling, cutting or milling tool holder or collet for another involving removably engaging connectors employing mere operator hand force in effecting engaging or disengaging of the collets or tool holding adapters with the driving chuck; employing a coil compression spring as a locking element in tool holding apparatus between a chuck and a tool carrying collet, the spring captured in compressive engagement between bearing surfaces carried by the chuck and the collet, one such bearing surface provided in a nut threading on the chuck operable to hold and force the spring against a bearing surface on the collet.