COLLET BIT RETAINER

A bit retainer is configured to couple a tool bit to an output spindle of a power tool. The bit retainer includes a body coupled for co-rotation with the output spindle about a rotational axis, a collet including a plurality of jaws positioned at least partially within the body, the collet defining a bore between the plurality of jaws configured to receive the tool bit, a wedge surface engageable with the collet, and a sleeve surrounding the body. The sleeve is movable relative to the body to engage the wedge surface against the collet and compress the plurality of jaws around the tool bit.

FIELD

The present disclosure relates to power tools, and, more particularly, to bit retainers for power tools.

BACKGROUND

Power tools, and particularly rotary power tools such as impact drivers, impact wrenches, drills, powered screwdrivers, etc., typically include a bit retainer. Adjustable three-jaw chucks are commonly used on drills to clamp and retain tool bits with both round and non-round (e.g., hex, square, etc.) shank geometries. Such chucks may be relatively heavy, long, and may take time and several rotations to change and clamp different tool bits. Quick-release bit retainers are commonly used with impact drivers and powered screwdrivers to retain non-round shank geometries. Quick-release bit retainers are typically compact and facilitate efficiently swapping tool bits, but such bit retainers only accept one shank size and may have greater runout than three-jaw chucks.

SUMMARY

One aspect of the disclosure provides a bit retainer configured to couple a tool bit to an output spindle of a power tool. The bit retainer includes a body coupled for co-rotation with the output spindle about a rotational axis, a collet including a plurality of jaws positioned at least partially within the body, the collet defining a bore between the plurality of jaws configured to receive the tool bit, a wedge surface engageable with the collet, and a sleeve surrounding the body. The sleeve is movable relative to the body to engage the wedge surface against the collet and compress the plurality of jaws around the tool bit.

Another aspect of the disclosure provides a bit retainer configured to couple a tool bit to an output spindle of a power tool. The bit retainer includes a body coupled for co-rotation with the output spindle about a rotational axis, a standardized collet including a plurality of jaws positioned at least partially within the body, the collet defining a bore between the plurality of jaws configured to receive the tool bit, and a sleeve surrounding the body. The sleeve is movable relative to the body to compress the plurality of jaws around the tool bit.

Another aspect of the disclosure provides a power tool including a housing, a motor supported within the housing, an output spindle extending from the housing and driven by the motor to rotate about a rotational axis, and a bit retainer configured to couple a tool bit to the output spindle such that the tool bit co-rotates with the output spindle about the rotational axis. The bit retainer includes a body coupled for co-rotation with the output spindle, a collet including a plurality of jaws positioned at least partially within the body, the collet defining a bore between the plurality of jaws configured to receive the tool bit, a wedge surface engageable with the collet, and a sleeve surrounding the body. The sleeve is movable relative to the body to engage the wedge surface against the collet and compress the plurality of jaws around the tool bit.

DETAILED DESCRIPTION

The present disclosure provides, among other things, embodiments of a bit retainer for a power tool, which include a collet coupled to or formed as a part of an output spindle of the power tool. In some embodiments, the collet includes a plurality of jaws that press against a tool bit to retain the end of the tool bit within the collet. The embodiments described and illustrated herein may advantageously provide reduced runout, or wobbling of the tool bit, while still maintaining quick-change functionality and, in some embodiments, without increasing the overall length of the tool. For example, bit retainer embodiments described and illustrated herein may provide an approximately 80% reduction in runout relative to a conventional quick-change bit retainer (e.g., a standard impact driver hex shank bit retainer). In some embodiments, the bit retainers may advantageously accept both hexagonal shank and round shank bits. The adjustable nature of the collet may also allow a wider range of bits to be used, and the collet may be interchanged with standard collets of various sizes in some embodiments.

FIG.1illustrates an exemplary power tool10in the form of an impact driver. The illustrated power tool10includes a housing14with a motor housing portion18, a front housing portion or gear case22coupled to the motor housing portion18(e.g., by a plurality of fasteners), and a handle portion26disposed underneath the motor housing portion18. The handle portion26includes a grip27that can be grasped by a user operating the power tool10. In the illustrated embodiment, the handle portion26and the motor housing portion18are defined by cooperating clamshell halves29a,29b. In some embodiments, the clamshell halves29a,29bmay also define at least a portion (e.g., a rear portion) of the gear case22.

With continued reference toFIG.1, the power tool10has a battery pack34removably coupled to a battery receptacle38located at a bottom end of the handle portion26. The battery pack34includes a housing39supporting battery cells40(FIG.2), which are electrically connected to provide the desired output (e.g., nominal voltage, current capacity, etc.) of the battery pack34. A battery power display53indicates the power level remaining in the battery pack34(FIG.1). In other embodiments, the power tool10may include a power cord for electrically connecting the power tool10to a source of AC power. As a further alternative, the power tool10may be configured to operate using a different power source (e.g., a pneumatic power source, etc.).

Referring toFIG.2, a motor42, supported within the motor housing portion18, receives power from the battery pack34when the battery pack34is coupled to the battery receptacle38. In the illustrated embodiment, the motor42is a brushless direct current (“BLDC”) electric motor having a stator46and a rotor or drive shaft50. A button52, extending laterally from the housing14, allows an operator to change the direction that the motor42rotates the drive shaft50that is rotatable about an axis54relative to the stator46. In other embodiments, other types of motors may be used. A fan58is coupled to the drive shaft50(e.g., via a splined connection) behind the motor42.

The power tool10also includes a switch62(e.g., trigger switch) supported by the housing14for operating the motor42via suitable control circuitry provided on one or more printed circuit board assemblies (“PCBAs”) that control power supply and command of the motor42. In other embodiments, the power tool10may include a power cord for connecting to a source of AC power. As a further alternative, the power tool10may be configured to operate using a non-electrical power source (e.g., a pneumatic or hydraulic power source, etc.). In some embodiments, the switch62that is coupled to the handle portion26and actuatable to selectively electrically connect the motor42and the battery pack34to provide DC power to the motor42.

With reference toFIG.3, the illustrated power tool10includes a gear assembly66coupled to the drive shaft50and a drive assembly or impact assembly70coupled to an output of the gear assembly66. The gear assembly66is at least partially housed within the gear case22. The gear assembly66may be configured in any of a number of different ways to provide a speed reduction between the drive shaft50and an input of the drive assembly70.

Referring toFIGS.2and3, the gear assembly66includes a pinion82formed, pressed, or otherwise coupled for co-rotation with the drive shaft50, a plurality of planet gears86meshed with the pinion82, and a ring gear90meshed with the planet gears86and rotationally fixed within the gear case22. The planet gears86are mounted on a camshaft94of the drive assembly70such that the camshaft94acts as a planet carrier. Accordingly, rotation of the drive shaft50rotates the planet gears86, which then orbit along the inner circumference of the ring gear90and thereby rotate the camshaft94. The gear assembly66thus provides a gear reduction ratio from the drive shaft50to the camshaft94. The drive shaft50is rotatably supported by a first or forward bearing98and a second or rear bearing102.

The drive assembly70of the power tool10includes an output spindle200, which in the illustrated embodiment is an anvil, extending from the gear case22. A bit holder or retainer202coupled to the output spindle200to support a tool bit99(e.g., a screwdriver bit, drill bit, etc.), which can be retained and driven by the output spindle200to perform work on a workpiece (e.g., a fastener, plank, etc.). With specific reference toFIG.2, the tool bit99may have a hexagonal (e.g., cross-section) body or shank100with a groove101, such as a power groove, formed in a portion of the shank100. As described in greater detail below, the groove101may be configured to receive one or more ball detents104to inhibit removal of the tool bit99from the bit retainer202.

The drive assembly70is configured to convert the continuous rotational output or torque provided by the motor42and gear assembly66to a striking rotational force or intermittent applications of torque to the output spindle200when the reaction torque on the output spindle200(e.g., due to engagement between the tool bit99and a fastener being worked upon) exceeds a certain threshold. In the illustrated embodiment of the power tool10, the drive assembly70includes the camshaft94, a hammer204supported on and axially slidable relative to the camshaft94, and the output spindle200.

The illustrated drive assembly70further includes a spring208biasing the hammer204toward the front of the power tool10(i.e., toward the left inFIG.3). In other words, the spring208biases the hammer204in an axial direction toward the output spindle200, along the axis54. A thrust bearing212and a thrust washer216are positioned between the spring208and the hammer204. The thrust bearing212and the thrust washer216allow for the spring208and the camshaft94to continue to rotate relative to the hammer204after each impact strike when hammer lugs218on the hammer204engage with corresponding anvil lugs220on the output spindle200and rotation of the hammer204momentarily stops. A washer may be located between the output spindle200and a front end of the gear case22in some embodiments. The camshaft94further includes cam grooves224in which corresponding cam balls228are received. The cam balls228are in driving engagement with the hammer204and movement of the cam balls228within the cam grooves224allows for relative axial movement of the hammer204along the camshaft94when the hammer lugs218and the anvil lugs220are engaged and the camshaft94continues to rotate.

Referring still toFIGS.1-3, the output spindle200is rotatably supported by a bushing236fixed within a front portion of the gear case22. During operation of the power tool an operator depresses the switch62to activate the motor42, which continuously drives the gear assembly66and the camshaft94via the drive shaft50. As the camshaft94rotates, the cam balls228drive the hammer204to co-rotate with the camshaft94, and the hammer lugs218engage driven surfaces of the anvil lugs220to provide an impact and to rotatably drive the output spindle200and the tool bit99. In some embodiments, such as those illustrated inFIGS.7A-11B and14, the output spindle200may alternatively be supported by one or more bearings238.

After each impact, the hammer204moves or slides rearward along the camshaft94, away from the output spindle200, so that the hammer lugs218disengage the anvil lugs220. As the hammer204moves rearward, the cam balls228situated in the respective cam grooves224in the camshaft94move rearward in the cam grooves224. The spring208stores some of the rearward energy of the hammer204to provide a return mechanism for the hammer204. After the hammer lugs218disengage the respective anvil lugs220, the hammer204continues to rotate and moves or slides forwardly, toward the output spindle200, as the spring208releases its stored energy, until the drive surfaces of the hammer lugs218re-engage the driven surfaces of the anvil lugs220to cause another impact.

FIGS.4A-18illustrate embodiments of bit retainers which may be incorporated into the power tool10described above with reference toFIGS.1-3(e.g., in place of the bit retainer202) for coupling the tool bit99to the output spindle200. Although the bit retainers may be described herein with reference to the power tool10, it should be understood that the bit retainers may be implemented in other power tools with output spindles, including, but not limited to, impact wrenches, drills, powered screwdrivers, ratchets, precision torque tools, etc. The bit retainers described herein may also, in some embodiments, be configured as adapters to interface with existing bit retainers on such power tools.

With reference toFIGS.4A-6B, a bit retainer202A embodying aspects of the present disclosure includes a body221having a driving end portion222opposite a receiving portion223, which receives torque from an output spindle of a power tool, such as the output spindle200of the power tool10. In some embodiments, the receiving portion223is coupled to the output spindle200by a threaded connection, a press-fit, or any other suitable mechanical connection allowing the bit retainer202A to co-rotate with the output spindle200. In other embodiments, the body221may be an integral portion of the output spindle200.

With reference toFIGS.4A and4B, the illustrated bit retainer202A is configured to interface with a tool bit, such as the tool bit99illustrated inFIGS.2-3, so that that the tool bit99is coupled for co-rotation with the output spindle200. A receiving aperture244extends into the driving end portion222. The bit retainer202A further includes a sleeve300co-axially supported on the body221and surrounding the driving end portion222. The sleeve300is moveably supported on the body221and selectively moveable along a rotational axis54A of the bit retainer202A by a user. The axis54A may be coaxial with the axis54(FIG.3).

In the illustrated embodiment, a spring304is constrained between the sleeve300and the body221to bias the sleeve300in a rearward direction (i.e. to the right inFIG.4A). The sleeve300includes a spring retainer308that surrounds the body221and supports the sleeve300on the body221. The spring retainer308constrains one end of the spring304while the body221retains an opposing end of the spring304, such that the spring304bears against the spring retainer308to bias the sleeve300rearwardly.

The bit retainer202A further includes a collet312at least partially received within the receiving aperture244of the body221and selectively compressible by the body221in response to movement of the sleeve300. As illustrated inFIGS.4A-5, the collet312includes a plurality of jaws316each separated by a slot320. In the illustrated embodiment, each slot320is open to an opposite end relative to an adjacent slot320. Each of the jaws316terminates at a shoulder328that converges with a slot or groove332extending around the collet312. An axially opposite side of the groove332converges with teeth336that define a front face344of the collet312. Each of the jaws316includes a first or rearward wedge surface324and a second or forward wedge surface340separated from the rearward wedge surface324by a gap formed by a groove adjacent the shoulder328. In some embodiments, the collet312is a standardized collet, such as an ER-20 collet, or an ER-11 collet. In some embodiments, the collet312may be interchangeable with other collets of different sizes and/or geometries.

The first wedge surfaces324of the illustrated collet312and a corresponding first clamping surface248of the receiving aperture244are each frustoconically shaped. The second wedge surfaces340and a corresponding second clamping surface345on an inner side of the sleeve300are also frustoconically shaped. The first wedge surfaces324and the first clamping surface248are engageable with one another, and the second wedge surfaces340and second clamping surface345are engageable with on another, to displace the jaws316inwardly and/or rearwardly, thereby compressing the jaws316around the tool bit99to clamp the tool bit99with the collet312.

The illustrated collet312includes detents104A integrally formed with jaws316of the collet312. The detents104A are configured to engage the groove101on the tool bit99(FIG.3) to axially retain the tool bit99. The sleeve300includes a lip348positioned in the groove332on the collet312such that axial movement of the sleeve300controls movement of the collet312relative to the body221. For example, as the sleeve300is moved forwardly against the bias from the spring304, the collet312is pulled-out or moved away from the receiving aperture244, such that the jaws316are not compressed by the body221. Alternatively, the sleeve300may be released by the user, such that the bias from the spring304pulls or draws the collet312into the receiving aperture244to compress the jaws316. As the jaws316compress, the detents104A are pressed inwardly to engage the tool bit99.

With reference toFIGS.6C-6E, the bit retainer202A may include an alternate collet312areceivable in the body221and selectively compressible by the body221in response to movement of the sleeve300. The alternate collet312asupports ball detents104B in apertures106that may be integrally formed with jaws316aof the alternate collet312a. In the illustrated embodiment, the alternate collet312aincludes three apertures106radially offset relative to each other by an angle, such as approximately 120 degrees. Each aperture106may be formed in the jaws316aof the alternate collet312abetween radially adjacent slots320a. As illustrated inFIG.6D, the apertures106may be tapered to retain the ball detents104B in each of the apertures106between the body221and the groove101on the tool bit99. While the ball detents104B engage the groove101and the alternate collet312ais compressed by the body221, the bit retainer202A inhibits removal of the tool bit99.

FIGS.7A-8Billustrate a bit retainer302according to another embodiment. The bit retainer302, like the bit retainers described above, is usable with the power tool10(or other power tools) to couple the tool bit99for co-rotation with the output spindle200. In the illustrated embodiment, the bit retainer302is incorporated into the output spindle200, such that the output spindle200defines a body of the bit retainer302; however, the bit retainer302may include a separate body coupled to the output spindle200in any suitable manner in other embodiments. The bit retainer302is similar in some aspects to the bit retainer202A described above, and features of the bit retainer302corresponding with features of the bit retainer202A are given like reference numbers plus ‘100,’ and the following description focuses primarily on differences between the bit retainer302and the bit retainer202A.

As illustrated inFIGS.7A-8B, a spring retainer408is coupled to the output spindle200and provided adjacent the front face444of the teeth436. The lips448of the sleeve400rest in the groove432of the collet412and are separated by axially extending tabs452. The tabs452are received in the output spindle200and axially constrained relative to the sleeve400, such that the sleeve400is moveable relative to the output spindle200, and the spring retainer408is not. Stated another way, the sleeve400is biased rearwardly but moveable against the bias by the user to move the collet412out of the output spindle200via the lips448on the sleeve400engaging the jaws416on the collet412.

FIGS.9A-10Billustrate a bit retainer402, according to another embodiment. The bit retainer402, like the bit retainers described above, is usable with the power tool10(or other power tools) to couple the tool bit99for co-rotation with the output spindle200. The bit retainer402is similar in some aspects to the bit retainer302described above, and features of the bit retainer402corresponding with features of the bit retainer302are given like reference numbers plus ‘100,’ and the following description focuses primarily on differences between the bit retainer402and the bit retainer302.

As illustrated inFIGS.9A-10B, the spring504is in the form of a retaining ring mounted on the output spindle200to engage both the output spindle200and the sleeve500. As illustrated inFIG.9C, the spring504may be triangular and abut against a helical groove554formed in the sleeve500. The spring504includes generally circular or curved portions504aseparated by flatter or pointed portions504b. As illustrated inFIGS.10A and10B, the curved portions504aengage the output spindle200and the pointed portions504bengage the helical groove554, which include axially offset detent portions. As the sleeve500is moved axially between the detent portions, the spring504rides the helical groove554, which causes the sleeve500and collet512to move axially relative to the output spindle200. During movement of the sleeve500between the detent portions, the lips548extend from the sleeve500and into the groove532formed in the collet512to move the collet512with the sleeve500relative to the output spindle200.

In some embodiments of the bit retainer402, as illustrated inFIGS.11A and11B, the helical groove554may be formed on the output spindle200rather than on the sleeve500. In such embodiments, the sleeve500includes a second lip548aextending from the sleeve500and into the helical groove554. The first lip548extends into the groove532formed in the collet512. As the sleeve500is rotated about the output spindle200, the second lip548aengages the helical groove554to move the sleeve500axially relative to the output spindle200. In turn, the first lip548engages the groove532in the collet512to move the collet512into/out of the output spindle200(e.g., axially). In other words, the sleeve500may be rotated to convert rotational movement of the sleeve500into axial movement of the collet512.

FIGS.12A-13Cillustrate a bit retainer502, according to another embodiment. The bit retainer502, like the bit retainers described above, is usable with the power tool10(or other power tools) to couple the tool bit99for co-rotation with the output spindle200. The bit retainer502is similar in some aspects to the bit retainer302described above, and features of the bit retainer502corresponding with features of the bit retainer302are given like reference numbers plus ‘200,’ and the following description focuses primarily on differences between the bit retainer502and the bit retainer302.

As illustrated inFIGS.12A and12B, the spring retainer602is a spring retaining assembly that includes first and second spring retainers602a,602bpositioned between the output spindle200and the sleeve600. Specifically, the first spring retainer602amay be a flexible O-ring or snap ring slotted in a receiving groove662formed in the output spindle200. The second spring retainer602bencircles the collet612an engages with the sleeve600. The bit retainer502further includes a puller666seated in the groove632at one end and bearing against the output spindle200and/or the sleeve600at another opposing end. In the illustrated embodiment, the puller666is positioned between the second spring retainer602band the collet612. As the sleeve600is moved axially the puller666engages and moves the collet612.

In the illustrated embodiment, the puller666includes an annular band670that is seated in the groove632and legs674extending from the annular band670. The legs674support feet678extending outwardly. As illustrated inFIGS.13A-13C, the spring604is positioned between the first and second spring retainers602a,602band the output spindle200in an area separated from the puller666so as to not interfere with the engagement between the puller666and the sleeve600.

In some embodiments, as illustrated inFIG.14, the collet612may be replaced with a plurality of axially offset ball detents104. One or more sets of the ball detents104may be coupled to a carrier682that is axially moveable relative to the output spindle200. The carrier682supports the ball detents104in an angled or tapered arrangement, which may provide a polygonal (e.g., hexagonal) profile to drivably engage the tool bit99. The carrier682is biased by the springs604to push the carrier682and ball detents104away from the output spindle200. When pressed away, the tool bit99can fit into the aperture244of the output spindle200. Once released, the spring604pushes the carrier682forward until the ball detents104engagement with the tool bit99. In other embodiments, each of the ball detents104may be supported by a respective, and independently movable, carrier. The two carriers may be coupled to a sleeve for axial movement with the sleeve relative to the output spindle200.

In some embodiments, as illustrated inFIG.15, an alternate output spindle200amay be usable with the power tool10and/or the various bit retainer embodiments described herein. The alternate output spindle200amay include slots722, such as cuts or kerf cuts, similar to the slots320of the bit retainer202A ofFIG.4A. The slots722may be formed between radially offset and adjacent jaws726, which may be selectively compressed inwardly or separated outwardly. In the illustrated embodiment, the slots722are formed in the driving end portion222aopposite the impact receiving portion223a. Some embodiments of the alternate output spindle200ainclude a flat, hexagonal, or axial inner surface730. Other embodiments of the alternate output spindle200ainclude an angled or tapered inner surface730. In some embodiments, the jaws726may be compressed inwardly (e.g., in response to movement of a sleeve of a bit retainer described herein) to apply additional clamping force to the jaws of the collet. In some embodiments, the jaws726may be sufficiently flexible and apply a sufficient clamping force directly to the tool bit99, such that the collet may be omitted.

FIGS.16-18illustrate a bit retainer1202according to another embodiment of the present disclosure. The bit retainer1202, like the bit retainers described above, is usable with the power tool10(or other power tools) to couple the tool bit99for co-rotation with the output spindle200.

The illustrated bit retainer1202includes a sleeve1206(FIGS.16and18) surrounding a body1210, a cap1214, a collet1218, a ring1222, a nut1226, and a ratchet assembly1230. The body1210is configured to be coupled for co-rotation with the output spindle of a power tool (e.g., the output spindle of a drill, the output spindle200of the power tool10, etc.), such that the body1210is rotatable about a rotational axis R.

Best illustrated inFIG.17, a flange1234is formed adjacent a front end of the body1210. The flange1234includes a plurality of slots1238that receive rearward extensions1242of the cap1214to couple the cap1214for co-rotation with the body1210. The extensions1242are slidably received by the slots1238, such that the cap1214may translate along the rotational axis R relative to the body1210. In the illustrated embodiment, the flange1234includes three slots1238equally spaced from one another by 120 degrees, and the cap1214includes three corresponding rearward extensions1242. In other embodiments, the flange1234and cap1214may include other numbers and/or arrangements of slots1238and extensions1242. In yet other embodiments, the cap1214may be coupled for co-rotation with the body1210by other arrangements that also permit translation of the cap1214relative to the body1210.

With continued reference toFIG.17, the collet1218in the illustrated embodiment is a standardized collet, such as an ER-20 collet. The ER-20 collet may be able to accept bit shanks having nominal diameters in a range of 1 to 13 millimeters (0.039 to 0.512 inches). The collet1218may be interchangeable with other standardized collets, such as an ER-11 collet. The ER-11 collet may be able to accept bit shanks having nominal diameters in a range of 0.5 to 7 millimeters (0.20 to 0.276 inches). The bit retainer1202thus allows for a user to accommodate a wide range of common tool bit sizes, using standardized collets. In the illustrated embodiment, the collet1218has a hexagonal bore1246defined between a plurality of jaws1250of the collet1218, such that the collet1218is configured to receive hexagonal shank tool bits; however, in other embodiments, the collet1218may have a round bore, a square bore, or a bore of any other desired shape. In other embodiments, collet1218may be any of the collets described and illustrated herein.

With reference toFIG.18, each of the jaws1250of the illustrated collet1218is positioned at least partially within the body1210and includes a forward wedge surface1254and a rearward wedge surface1258. The forward wedge surface1254and rearward wedge surface1258are oriented at oblique angles relative to the rotational axis R and relative to one another. A groove1262is defined between the forward wedge surface1254and the rearward wedge surface1258, and the forward wedge surface1258and rearward wedge surface1258each converge toward the rotational axis R in directions away from the groove1262. The grooves1262in the jaws1250are aligned and receive an inwardly-projecting rib1264formed on the cap1214. In the illustrated embodiment, the grooves1262are wider in the axial direction that the rib1264, such that limited axial movement of the cap1214relative to the jaws1250is permitted (e.g., when clamping the tool bit99, as described in greater detail below). The rib1264is also engageable with the ends of the grooves1262to cause the collet1218to translate with the cap1214along the rotational axis R (e.g., to remove and replace the collet1218, as described in greater detail below).

With continued reference toFIG.18, the cap1214has a first inner clamping surface1266engageable with the forward wedge surfaces1254of the jaws1250, and the body1210has a tapered bore1270defining a second inner clamping surface1274engageable with the rearward wedge surfaces1258of the jaws1250. The wedge surfaces1254,1258and clamping surfaces1266,1274are frustoconical in the illustrated embodiment; however, in other embodiments, the wedge surfaces1254,1258and clamping surfaces1266,1274may have non-round cooperating tapered geometries, such as a tapered hexagonal geometry.

Referring toFIGS.17-18, in the illustrated embodiment, the rearward extensions1242of the cap1214have external thread segments1278threadably coupled to internal threads1282of the nut1226. As such, rotation of the nut1226relative to the cap1214causes the cap1214to translate along the rotational axis R by virtue of the threaded coupling. In the illustrated embodiment, the nut1226is coupled to the ring1222via the ratchet assembly1230, and the ring1222is coupled for co-rotation with the sleeve1206(e.g., by cooperating splines or any other suitable geometry on the outer surface of the ring1222and the inner surface of the sleeve1206). As described in greater detail below, the ratchet assembly1230provides a tactile indication to a user once a proper clamping force on the tool bit99has been achieved and may also prevent or inhibit over-tightening by interrupting torque transmission from the ring1222to the nut1226above a predetermined torque threshold. In some embodiments, the ratchet assembly1230may be omitted, such that the nut1226may be directly coupled to the ring1222for co-rotation therewith; or, the nut1226and the ring1222may optionally be formed as a single component coupled for co-rotation with the sleeve1206. The ratchet assembly1230, nut1226, and ring1222are retained around the body1210of the bit retainer1202between the flange1234and a washer1286. The washer1286is axially secured by a retaining ring1290coupled to the sleeve1206.

In use, a user inserts a selected tool bit99into the bore1246between the jaws1250of the collet1218. To clamp the tool bit99between the jaws1250, the user grasps the sleeve1206and rotates the sleeve1206in a tightening direction (e.g., clockwise) about the rotational axis R. The ring1222co-rotates with the sleeve1206(e.g., due to the spline connection between the ring1222and the sleeve1206) and causes rotation of the nut1226through the ratchet assembly1230. As the nut1226rotates, the cap1214retracts inwardly (i.e., to the right with reference to the orientation ofFIG.18), due to the threaded coupling between the thread segments1278on the rearward extensions1242and the threads1282of the nut1226. As the cap1214retracts, the inner clamping surface1266of the cap1214engages the forward wedge surfaces1254of the jaws1250of the collet1218, causing the jaws1250to move inwardly and rearwardly (i.e., to the right inFIG.18). As the jaws1250move rearwardly, the second inner clamping surface1274engages the rearward wedge surfaces1258of the jaws1250, further causing the jaws1250to move inwardly. This continues until the tool bit99is firmly clamped between the jaws1250of the collet1218.

In the illustrated embodiment, once a predetermined torque is reached on the sleeve1206corresponding with a proper clamping force on the tool bit99, the ratchet assembly1230begins to slip, producing tactile and/or audible feedback to the user indicating that the tool bit99is secured. As the ratchet assembly1230slips, torque transmission from the ring1222to the nut1226is interrupted to prevent or inhibit overtightening.

To remove the tool bit99, the user grasps the sleeve1206and rotates the sleeve1206in a loosening direction (e.g., counterclockwise) about the rotational axis R. This causes the cap1214to extend (i.e., move to the left inFIG.18), which allows the jaws1250of the collet1218to move away from the tool bit99and release the clamping force on the tool bit99. In some embodiments, the sleeve1206is rotated 360 degrees or less from a secured position, in which the tool bit99is firmly clamped between the jaws1250(e.g., at the predetermined torque threshold of the ratchet assembly1230) and a release position, in which the tool bit99may be freely withdrawn from the bit retainer1202. In some embodiments, the sleeve1206is rotated by a displacement of 180 degrees or less from the secured position to the release position. In yet other embodiments, the sleeve1206is rotated 90 degrees or less from the secured position to the release position. In yet other embodiments, the sleeve is rotated 60 degrees or less from the secured position to the release position. In yet other embodiments, the sleeve1206is rotated between 30 degrees and 40 degrees from the secured position to the release position.

If the user desires to replace the collet1218(e.g., to interchange the collet1218with another standardized collet able to accommodate a different range of sizes and/or geometries of tool bit), the user may continue rotating the sleeve1206in the loosening direction. By doing so, the cap1214continues to extend (to the left inFIG.18), until the thread segments1278on the rearward extensions1242decouple from the threads1282of the nut1226. At this point, the user can remove the cap1214from the remaining assembly of the bit retainer1202and then remove the collet1218from the cap1214. The replacement collet1218can then be positioned in the cap1214, and the cap1214reattached to the remaining assembly of the bit retainer1202by inserting the rearward extensions1242into the slots1238and rotating the sleeve1206in the tightening direction to re-establish the threaded coupling between the thread segments1278and the threads1282of the nut1226.

Various features and aspects of the present disclosure are set forth in the following claims.