Patent Description:
A driver for medical wires as known from document <CIT> has a hollow drive shaft rotatable about a rotation axis. The hollow drive shaft has a distal end and a proximal end. A plurality of clamping jaws penetrates under an angle into the hollow drive shaft close to its distal end. The clamping jaws are moved into or out of the hollow drive shaft by means of a jaw guide mounted slidable parallel to the rotation axis and movably connected to the clamping jaws. An actuator is provided to shift the jaw guide parallel to the rotation axis and therefore modify the penetration depth of the clamping jaws.

A collet of the type which comprises at least three gripping members of rigid material angularly space about a common axis arranged to tilt to provide toggle action is described in document <CIT>. In said collet, each of said members has a gripping edge parallel with said axis and a tool-engaging projection laterally spaced from said gripping edge.

The prior art did not address the need to quickly and easily insert and clamp a shaft in a jaw chuck as may be needed for use during surgical procedures.

An example chuck includes a jaw guide, a plurality of interleaving jaws, and an inclined engagement surface. The jaw guide defines a longitudinal axis and includes jaw channels circumferentially distributed about the axis. The jaws are slidably disposed in the jaw channels. Each jaw has a clamping surface facing the axis and a driving surface substantially opposite the clamping surface and a protrusion on a first lateral side and a cavity on a second lateral side. The protrusion of each jaw is disposed at least in part in the cavity of an adjacent jaw. The engagement surface is on an inner surface of the jaw guide, and is substantially centered about the axis and substantially parallel to the driving surface. Displacement of the jaws relative to the engagement surface in a clamping direction displaces the clamping surfaces toward the axis.

A chuck for a wire driver according to claim <NUM> comprises an axially extending jaw guide, a plurality of interleaving jaws, and an engagement sleeve. The axially extending jaw guide defines a longitudinal axis and includes a first plurality of jaw channels circumferentially distributed about the axis. The plurality of interleaving jaws is slidably disposed in the jaw channels. Each jaw has a clamping surface facing the axis and a driving surface substantially opposite the clamping surface and a protrusion on a first lateral side and a cavity on a second lateral side. The protrusion of each jaw is disposed at least in part in the cavity of an adjacent jaw. The engagement sleeve has an inclined engagement surface on an inner surface thereof. The engagement surface is substantially centered about the axis and is substantially parallel to the driving surface. Displacement of the jaw guide relative to the engagement sleeve in a clamping direction or displacement of the jaws relative to the engagement surface in a clamping direction displaces the clamping surfaces toward the axis, respectively.

Such chucks may comprise additional features as set forth below, such features being included separately or in combination with each other, with such combinations being limited only by mutual exclusivity.

The jaws may define a receiving aperture accommodating receipt and clamping of shafts ranging from a first diameter to a larger second diameter with the protrusions being disposed in the cavities when the jaws are positioned to clamp shafts of the first diameter.

The channels and the jaws may be evenly distributed about the axis and the protrusion of each jaw is substantially complementary to the cavity in the adjacent jaw.

The jaws may have each of a protrusion and a cavity on each of the first lateral side and the second lateral side and the protrusion of the first lateral side of each jaw may be disposed at least in part in the cavity of the second lateral side of an adjacent jaw. The protrusion of the second lateral side of each jaw may be disposed at least in part in the cavity of the first lateral side of the adjacent jaw.

The jaws and the protrusions may each have a sloped distal surface that is shorter at the clamping surface.

The jaws and the protrusions each may have a sloped proximal surface that is shorter at the clamping surface.

The jaws and the protrusions may each have a sloped distal surface that is shorter at the clamping surface and have a sloped proximal surface that is shorter at the clamping surface.

The protrusions may extend into a gap between facing lateral sides of adjacent jaws proximate to the clamping surfaces.

The protrusions may extend towards the axis beyond the clamping surface.

A chuck may further comprise a substantially cylindrical housing and a clamping lever. The jaw guide, the jaws, and the engagement sleeve may be rotatably disposed inside the substantially cylindrical housing. The clamping lever may be pivotably mounted to the housing and connected to one of the jaw guide and the engagement sleeve for axial displacement thereof.

The chuck may have a ratio of a largest shaft to a smallest that can be accommodated by the chuck without pinching substantially equal to <NUM>:<NUM>.

The chuck may further comprise a substantially cylindrical housing and a clamping lever. The jaw guide, the jaws, and the engagement sleeve may be rotatably disposed inside the substantially cylindrical housing. The clamping lever may be pivotably mounted to the housing and connected to one of the jaw guide and the engagement sleeve for axial displacement of the engagement sleeve.

The jaw guide may be substantially fixed relative to the engagement sleeve. The chuck may further comprise an axially displaceable actuation head in axial engagement with the jaws. Axial displacement of the actuation head in an engagement direction may push the driving surfaces of the jaws against the inclined engagement surface and axially displace the jaws relative to the engagement sleeve.

The jaws may have threaded surfaces disposed thereon in threaded engagement with threads disposed on the sleeve.

The jaw guide may be at a distal end of the drive shaft.

Another example chuck for a wire driver comprises a substantially cylindrical housing, an axially extending drive shaft, a plurality of jaws, an engagement sleeve, an actuator sleeve, a first positioning bearing, a second positioning bearing and a clamping actuator. The substantially cylindrical housing defines a longitudinal axis. The axially extending drive shaft is rotatably disposed within the housing on the longitudinal axis for selective rotation thereabout. The drive shaft includes a jaw guide at a distal end of the drive shaft. The jaw guide includes a first plurality of jaw channels circumferentially distributed about the axis. The plurality of jaws is slidably disposed in the jaw channels. Each jaw has a clamping surface facing the axis and a driving surface substantially opposite the clamping surface. An engagement sleeve is rotatably disposed within the housing on the longitudinal axis for selective rotation thereabout. The engagement sleeve has an inclined engagement surface on an inner surface thereof. The engagement surface is substantially centered about the axis and is substantially parallel to the driving surface. The engagement surface is disposed at least in part in axial alignment with and radially outward of the driving surface and is in selective engagement with the driving surface. The actuator sleeve is slidably and non-rotatably disposed on the longitudinal axis proximal to the engagement surface and in selective axial engagement with the engagement sleeve in each of a first axial direction and a second axial direction. The first positioning bearing is an axial-radial load bearing disposed between the drive shaft and the housing proximal to the actuator sleeve. The second positioning bearing is a substantially radial-only load bearing disposed between the engagement sleeve and the housing distal to the actuator sleeve. The clamping actuator is connected to the actuator sleeve by a clamping linkage for axial displacement of the engagement sleeve. Displacement of the engagement sleeve relative to the jaw guide in a clamping direction displaces the clamping surfaces toward the axis.

The example chuck of the preceding paragraph may comprise additional features as set forth below, such features being included separately or in combination with each other, with such combinations being limited only by mutual exclusivity.

The example chuck may further include a bearing support sleeve disposed on and fixed to the drive shaft with an inner race of the first positioning bearing fixed thereto.

The bearing support sleeve may include threads on an inside diameter thereof and a first shoulder on the inside diameter on a proximal end of the threads. The drive shaft may include threads on a tail portion of the drive shaft and a second shoulder on an outside diameter of the drive shaft on a proximal end of the threads. The threads of the bearing support sleeve may be in threaded engagement with the threads of the tail portion and the respective shoulders may be in engagement with each other.

The clamping actuator may comprise a clamping lever pivotably mounted to the housing. The clamping linkage may comprise a yoke portion of the lever in engagement with the actuator sleeve. Displacement of the engagement sleeve relative to the jaw guide in a clamping direction may displace the clamping surfaces toward the axis.

A first thrust bearing may be disposed between a distal end of the actuator sleeve and the engagement sleeve. A second thrust bearing may be disposed between a proximal end of the actuator sleeve and the engagement sleeve.

Relative orientations and directions (by way of example, upper, lower, bottom, rearward, front, rear, back, outboard, inboard, inward, outward, lateral, left, right, proximally, distally) are set forth in this description not as limitations, but for the convenience of the reader in picturing at least one embodiment of the structures described. Here, "proximally" is understood to mean towards the surgeon holding a handpiece <NUM>, away from the surgical site to which a wire <NUM> or drill bit may be applied. "Distally" is understood to mean away from the surgeon and towards the site to which the wire <NUM> or drill bit is applied.

<FIG> illustrate an example chuck <NUM> coupled to an example handpiece <NUM> that may collectively comprise a wire driver. The chuck <NUM> includes a longitudinal axis <NUM> coincident with an axis of rotation of certain parts of the chuck <NUM> and the handpiece <NUM>.

The handpiece <NUM> may include a motor <NUM>, a controller <NUM>, a first actuator button <NUM>, a second actuator button <NUM> and a power source <NUM>, consistent with commercially available handpieces, e.g., the Stryker® RemB® U Driver. The power source <NUM> is schematically represented with example types of power sources including a battery and a power cord. The identified power sources are not intended to be limiting. Examples of yet additional alternative sources of power include pneumatic power and hydraulic power.

The example chuck <NUM>, best illustrated in <FIG>, is substantially oriented along the longitudinal axis <NUM>. The longitudinal axis <NUM> may also serve as an axis of rotation for the chuck <NUM>. The chuck <NUM> includes a chuck housing <NUM> in which rotatable parts may be disposed. The housing <NUM> may be substantially cylindrical in shape and centered on the axis <NUM> and may define the axis <NUM>.

The chuck <NUM> may further include an example clamping actuator, e.g., a clamping lever <NUM>, which may be pivotably connected to the housing <NUM> by a pivot axle, i.e., a pin <NUM> passing through a lever pivot aperture <NUM> in the lever <NUM> and associated lever mounting apertures <NUM> in a mounting trunnion <NUM> of the housing <NUM>. Screws <NUM> may be used to retain the pin <NUM> in the lever <NUM> and the trunnion <NUM>. A grip portion <NUM> may be separated from a yoke portion <NUM> of the lever <NUM> by the pivot aperture <NUM>.

The yoke portion <NUM> may be substantially disposed within the housing <NUM>, passing through an opening <NUM> in the housing <NUM> aligned with the trunnion <NUM>. The yoke portion <NUM> is slidably disposed in an actuator slot <NUM> of an actuator sleeve <NUM>, thus connected with the actuator sleeve <NUM>. The actuator sleeve <NUM> is slidably disposed within the housing <NUM> for movement along the axis <NUM>. The engagement of the yoke portion <NUM> with the sleeve <NUM> causes axial movement of the sleeve <NUM> along the axis <NUM> with pivoting of the lever <NUM> about the pin <NUM>. A release spring <NUM>, e.g., a compression coil spring, may be disposed in the housing <NUM> between the housing and the sleeve <NUM> to bias the sleeve <NUM> to a released position, and with it, the lever <NUM> to a released position away from a grip handle <NUM> of the handpiece <NUM>.

A clamping linkage between the lever <NUM> and more particularly the grip portion <NUM> and the actuator sleeve <NUM> may include the yoke portion <NUM>, the trunnion <NUM> and the actuator slot <NUM>. An alternative arrangement may include an actuator in the form of an electric drive motor and a switch therefor in place of the lever, and a clamping linkage in the form of a gear drive disposed between the drive motor and the actuator sleeve <NUM>.

A drive shaft <NUM> is rotatably disposed within the housing <NUM> and on the longitudinal axis <NUM> for selective rotation thereabout. The drive shaft <NUM> may compromise a jaw guide <NUM> for unitary rotation therewith. The jaw guide <NUM> is axially extending in that it extends axially along the axis <NUM> and may define the axis <NUM> and may be at a distal end of the drive shaft <NUM>. The jaw guide <NUM> includes a plurality of jaw channels <NUM>, three being an example number, in which jaws <NUM> are slidably disposed. The channels <NUM> are circumferentially evenly distributed around the axis <NUM>, e.g., the channels being separated by <NUM>° with three channels <NUM>. The drive shaft <NUM> may include an engagement end <NUM> for coupling with a rotative drive element (not shown) driven by the motor <NUM> of the handpiece <NUM>. A first positioning bearing <NUM>, e.g., a roller bearing <NUM>, may be placed between the drive shaft <NUM> and the housing <NUM> to facilitate rotation therebetween. The bearing <NUM> is schematically illustrated as an annular ring with a solid cross-section for the purpose of showing the space that may be occupied by the bearing <NUM>. However, the bearing <NUM> may include rollers (e.g., ball rollers, cylindrical rollers, tapered roller, needle rollers), an inner race, an outer race and a roller cage. The bearing <NUM> may be an axial-radial load bearing, i.e., able to sustain and accommodate both thrust loads, i.e., axial loads, and radial loads.

The first positioning bearing <NUM> may be mounted on a bearing support sleeve <NUM> fixed to the shaft <NUM>. The bearing support sleeve <NUM> may have first threads <NUM> on an inside diameter in threaded engagement with the drive shaft <NUM> which may have second threads <NUM> on an outside diameter. Relative positioning of the sleeve <NUM> and the shaft <NUM> may be established by engagement of an internal diameter first shoulder <NUM> in the sleeve <NUM> engaging an outer diameter second shoulder <NUM> of the drive shaft <NUM>. The shoulders <NUM>, <NUM> may be parallel, and each may have an angle of <NUM>°. Such an arrangement may, when the sleeve <NUM> is installed, induce a tensile load the sleeve <NUM> and a compressive load in the drive shaft <NUM> between the respective threads <NUM>, <NUM> and shoulders <NUM>, <NUM>.

A distal end of the drive shaft <NUM> may have a nose cap <NUM> disposed thereon for rotation therewith. The nose cap <NUM> may aid in retaining a leaf spring disposed between the nose cap <NUM> and the jaw guide <NUM>. The nose cap <NUM> may be surrounded in part by a nose housing <NUM> that is fixed to a distal end of the drive shaft <NUM> by a threaded engagement therebetween.

The leaf spring <NUM> may be employed to aid in retaining the jaws <NUM> in the jaw channels <NUM>. The leaf spring <NUM> may include a plurality of spring fingers <NUM>, equal in number to the number of jaws <NUM>, to engage each of the jaws <NUM>. The fingers <NUM> may each extend from a circular base <NUM>.

An engagement sleeve <NUM> includes a head portion <NUM> with an inclined engagement surface <NUM> on an inner surface of the engagement sleeve <NUM>. The inclined engagement surface <NUM> is disposed at least in part in axial alignment with and radially outward of the jaws <NUM>, at least partially enclosing the jaws <NUM> in an engaged position as best shown in <FIG>. The engagement surface <NUM> may be in selective engagement with the driving surface <NUM>. The engagement sleeve <NUM> may include a tail portion <NUM> that extends axially away from the head portion <NUM> in a proximal direction and helps maintain the head portion <NUM> centered on the axis <NUM>. A second positioning bearing <NUM>, e.g., a roller bearing <NUM>, may be disposed between the engagement sleeve <NUM> and the housing <NUM>. More specifically, an inner race (not shown) of the bearing <NUM> may be in engagement with the head portion <NUM>. An outer race (not shown) of the bearing <NUM> may be in engagement with the nose housing <NUM> which, as noted above, is fixed to the housing <NUM>. Rollers and a roller cage (not shown) may be disposed between the races of the bearing <NUM>. The bearing <NUM> may be configured to accommodate substantially radial-only loads.

The actuator sleeve <NUM> may be slidably disposed on the tail portion <NUM> for axial movement therealong and relative rotation therebetween. Axial movement of the sleeve <NUM> along the tail portion <NUM> in a proximal direction may be limited by a first retaining ring <NUM> that may be removably disposed on a proximal end of the tail portion <NUM>. Axial movement of the sleeve <NUM> along the tail portion <NUM> in the distal direction may be limited by the head portion <NUM> of the engagement sleeve <NUM>.

First and second thrust bearings <NUM>, <NUM>, e.g., roller bearings <NUM>, <NUM>, may be disposed at opposite ends of the actuator sleeve <NUM> to reduce frictional resistance against relative rotation of the engagement sleeve <NUM> to the actuator sleeve <NUM>, particularly when the actuator sleeve <NUM> is biased to either an extreme proximal or distal position on the tail portion <NUM>.

The actuator sleeve <NUM> may be in selective axial engagement with the head portion <NUM> of the engagement sleeve <NUM> when the actuator sleeve <NUM> is disposed in a first axial direction, e.g., the distal direction, such engagement including indirect engagement as may occur with a first thrust plate <NUM> and the thrust bearing <NUM> intermediate between the actuator sleeve <NUM> and the head portion <NUM>. Similarly, the actuator sleeve <NUM> may be in selective axial engagement with the proximal end of the tail portion <NUM> indirectly through the retaining ring <NUM> when the actuator sleeve <NUM> is disposed in a second direction, e.g., a proximal direction, such engagement including engagement as may occur with a second thrust plate <NUM> and a thrust bearing <NUM> intermediate between the actuator sleeve <NUM> and the retaining ring <NUM>.

The first thrust bearing <NUM> that may include rollers and a roller cage may be disposed between the head portion <NUM> and the actuator sleeve <NUM>. The first thrust plate <NUM> may be disposed between the thrust bearing <NUM> and the head portion <NUM>. Each of the thrust plate <NUM> and the head portion <NUM> may define opposed bearing races. A plurality of shim washers <NUM>, collectively a shim stack, may be disposed between the first thrust plate <NUM> and the head portion <NUM>. Another thrust plate, not sown, may be disposed between the head portion <NUM> and the bearing <NUM>. Yet alternatively, the bearing <NUM> may include integral opposed bearing races, eliminating the need to form races in the head portion <NUM> or the thrust plate <NUM>.

The second thrust bearing <NUM> may be disposed over the tail portion <NUM> between the actuator sleeve <NUM> and the first retaining ring <NUM>. The tail portion <NUM> of the engagement sleeve <NUM> may carry the second thrust plate <NUM> between the second thrust bearing <NUM> and the first retaining ring <NUM>. The second thrust plate <NUM> may be diametrally sized for axial engagement by the second thrust bearing <NUM> and retention by the ring <NUM>. The alternative bearing structures described for the first thrust bearing <NUM> may be employed here as well. A third thrust plate <NUM> may be disposed between the second thrust bearing <NUM> and the second thrust plate <NUM>. A spring washer <NUM> may be disposed between the thrust plates <NUM>, <NUM>. The drive shaft <NUM> may have a proximal portion <NUM> terminating at a proximal end <NUM> of the drive shaft <NUM>. An input shaft guide <NUM> may be slidably disposed over the proximal portion <NUM>. The input shaft guide <NUM> and the proximal portion <NUM> may include complementary features, with an axial passage through the guide <NUM> having a sectional profile complementary to a sectional profile of the proximal portion <NUM>. Such a profile may include features allowing the guide to axially translate along the proximal portion <NUM> while resisting relative rotation between the input shaft guide <NUM> and the drive shaft <NUM> and may be a substantially constant axially extending non-circular section, e.g., opposed flats, splines, and similar configurations. A second retaining ring <NUM>, e.g., a snap ring <NUM>, may be disposed in a circumferential groove in the proximal portion <NUM> near the proximal end <NUM>. A drive spring <NUM>, e.g., a compression coil spring <NUM>, may be disposed over the proximal portion <NUM> between the bearing support sleeve <NUM> and the input shaft guide <NUM>. The drive spring <NUM> may be in engagement with each of the bearing support sleeve <NUM> and the input shaft guide <NUM>, pressing the input shaft guide <NUM> against the second retaining ring <NUM>. The input shaft guide <NUM> may be used to drivingly connect the drive shaft <NUM> with an input shaft (not shown) of the handpiece <NUM>. The input shaft may be disposed between and drivingly connect the motor <NUM> and the drive shaft <NUM> when the chuck <NUM> is mounted to the handpiece <NUM>.

The jaws <NUM> each have a clamping surface <NUM> facing the axis <NUM>, and a driving surface <NUM> substantially opposite the clamping surface <NUM>. The jaws <NUM> further have a protrusion <NUM> on a first lateral side <NUM>, and a cavity <NUM> in a second lateral side <NUM>. The jaws may have a spring slot <NUM> that intersects the driving surface for receipt of one of the fingers <NUM> of the leaf spring <NUM>.

The lateral sides <NUM>, <NUM> of the jaws <NUM> may be separated by an angle α substantially equal to <NUM>° divided by the number of jaws. In the present example, with three jaws <NUM>, the angle α may be substantially equal to <NUM>°. Chucks having a larger number of jaws will have a proportionately lower value for the angle α. Facing lateral sides <NUM>, <NUM> of adjacent jaws <NUM> may be substantially parallel to each other, i.e., at an angle of <NUM>° to each other. A shaft <NUM> disposed between facing lateral side <NUM>, <NUM> might be pinched between two adjacent jaws <NUM>. However, the protrusion <NUM>, as shown in <FIG>, provides an angle β between a facing surface <NUM> of the protrusions <NUM> and the facing lateral sides <NUM> relative to the angle β between the facing sides <NUM>, <NUM>. The increase in the angle β may cause a shaft <NUM>, e.g., a wire, a pin, a tool bit, disposed between the surface <NUM> and the side <NUM>, to be pushed toward the axis <NUM> as the surface <NUM> and the side <NUM> move closer together, rather than being pinched.

The example of <FIG> shows the angle β being increased from <NUM>°, without the protrusion <NUM>, to <NUM>° with the introduction of the protrusion <NUM>. The protrusion <NUM> of each jaw <NUM> is disposed at least in part in the cavity <NUM> of an adjacent jaw <NUM> in at least one position of the chuck <NUM>, such a position being illustrated in <FIG> so that the jaws <NUM> are interleaving. The protrusion <NUM> of each jaw <NUM> may be substantially complementary to the cavity <NUM> in the adjacent jaw <NUM>.

The inclined engagement surface <NUM> of the engagement sleeve <NUM> is substantially centered about the axis <NUM> and is substantially parallel to the driving surface <NUM>. The engagement surface <NUM> may include a plurality of circumferentially distributed engagement segments. Displacement of the jaws <NUM> relative to the inclined engagement surface <NUM> in a clamping direction displaces the clamping surfaces <NUM> toward the axis <NUM>. The clamping direction for the surface <NUM> and the jaws <NUM> is consistent with movement of the engagement surface <NUM> towards the jaws <NUM>, e.g., with the sleeve <NUM> moving in a leftward direction relative to the housing <NUM> in <FIG> with clamping, with the jaw guide <NUM> remaining laterally stationary relative to the housing <NUM>.

The jaws <NUM> and the protrusions <NUM> may each have a sloped distal entry surface, <NUM> and <NUM> respectively, to receive a shaft <NUM> from a distal end of the chuck <NUM> and the handpiece <NUM>. The sloped distal surfaces <NUM>, <NUM> may taper in a proximal direction toward the axis <NUM> in an installed condition. Such sloped distal surfaces <NUM>, <NUM> may aid in directing an end of the shaft <NUM> that comes into engagement with the sloped surfaces <NUM>, <NUM> to slide both axially and radially further along the surfaces <NUM>, <NUM> and into a receiving aperture <NUM> between the jaws <NUM>. As the jaws <NUM> move together, the shaft <NUM> is moved to a clamping position within the aperture <NUM> between the clamping surfaces <NUM> of the jaws <NUM>. The jaws <NUM> are able to receive a small diameter shaft <NUM>', i.e., a shaft <NUM> of a diameter at a small diameter end of a clamping range of the chuck <NUM>, when the protrusions <NUM> are disposed at least in part in the cavities <NUM> in the adjacent jaws <NUM>.

The jaws <NUM> and the protrusions <NUM> may each similarly have a sloped proximal entry surface, <NUM> and <NUM> respectively, to receive a shaft <NUM> from a proximal end of the handpiece <NUM> and the chuck <NUM>. The sloped proximal surfaces <NUM>, <NUM> may taper in a proximal direction toward the axis <NUM> in an installed condition. Such sloped proximal surfaces <NUM>, <NUM> may aid in directing an end of the shaft <NUM> that comes into engagement with the sloped surfaces <NUM>, <NUM> to slide both axially and radially further along the surfaces <NUM>, <NUM> and into the receiving aperture <NUM> between the jaws <NUM>. As the jaws <NUM> move together, the shaft <NUM> is moved to a clamping position within the aperture <NUM> between the clamping surfaces <NUM> of the jaws <NUM>.

The jaws <NUM> may also include a flange portion <NUM> opposite the clamping surface <NUM> that may incorporate in part the driving surface <NUM>. The flange portion <NUM> of each jaw <NUM> may extend laterally beyond side walls <NUM> of the jaws <NUM> that are slidably disposed within walls of the channels <NUM>. Engagement of a lower side of the flange portion <NUM> with the jaw guide <NUM> may prevent the jaws <NUM> from over-travel within the channels <NUM>, and may prevent the clamping surfaces <NUM> from moving past the axis <NUM>.

The jaws <NUM> may have alternative configurations of protrusions <NUM> and cavities <NUM>. An alternative example configuration jaw <NUM>' is illustrated in <FIG> and <FIG>. A protrusion <NUM>' may extend from a first lateral side <NUM>' at an outboard edge, beyond the clamping surface <NUM>', to define a facing surface <NUM>'. An angle β' between the facing surface <NUM>' and a second lateral side <NUM>' may be <NUM>°. The protrusion <NUM>' may be received at least in part by a complementary cavity <NUM>'. The jaws <NUM>' and the protrusions <NUM>' may each have a sloped distal entry surface, <NUM>' and <NUM>' respectively. The jaws <NUM>' and the protrusions <NUM>' may each similarly have a sloped proximal entry surface, <NUM>' and <NUM>' respectively. The jaws <NUM>' may collectively define a receiving aperture <NUM>'.

Another alternative configuration of a jaw <NUM>", illustrated in <FIG> and <FIG>, may have a first protrusion <NUM>" and a first cavity <NUM>" on a first lateral side <NUM>", and a second protrusion <NUM>‴ and a second cavity <NUM>‴ on a second lateral side <NUM>". An angle β" between the facing surfaces <NUM>", <NUM>‴ may be <NUM>°. The jaws <NUM>" and the protrusions <NUM>" may each have a sloped distal entry surface, <NUM>" and <NUM>" respectively. The protrusions <NUM>‴ may have a sloped distal entry surface and <NUM>‴. The jaws <NUM>" and the protrusions <NUM>" may each similarly have a sloped proximal entry surface, <NUM>" and <NUM>" respectively. The protrusions <NUM>‴ may have a sloped proximal entry surface <NUM>‴. The jaws <NUM>" may collectively define a receiving aperture <NUM>".

The chuck <NUM> may be used in the following manner. The chuck <NUM> may be installed on the handpiece <NUM> in a known manner, drivingly connecting the drive shaft <NUM> with the motor <NUM>. The chuck <NUM> as illustrated in <FIG> is in a disengaged, i.e., released, position. The chuck <NUM> as illustrated in <FIG> is in an engaged or clamped condition, in receipt of the small diameter shaft <NUM>'. The chuck <NUM> as illustrated in <FIG> is also in the engaged or clamped condition, in receipt of a large diameter shaft <NUM>", i.e., a shaft <NUM> of a diameter at a large diameter end of the clamping range of the chuck <NUM>. An example clamping range may be from. <NUM> to <NUM>, yielding a ratio of largest to smallest of <NUM>:<NUM>. An alternative example range of. <NUM> to <NUM> would yield a ratio of <NUM>:<NUM>. The clamping of the shaft <NUM>' in <FIG> and the shaft <NUM>" in <FIG> is responsive to an application of a force F against the grip portion <NUM>, biasing the grip portion <NUM> towards the grip handle <NUM> is moved towards the grip handle <NUM>.

The shaft <NUM>, <NUM>', <NUM>" may be inserted into the chuck <NUM> by passing it through the one of a rear entry aperture <NUM> in a rear <NUM> of the housing <NUM> as shown in <FIG>, and a front entry aperture <NUM> through the nose cap <NUM> as shown in <FIG>. If through the front entry aperture <NUM>, the shaft <NUM> may engage the distal entry surface <NUM>, <NUM>', <NUM>" of one of the jaws <NUM>, <NUM>', <NUM>" or the distal entry surface <NUM>, <NUM>', <NUM>", <NUM>‴ of one of the protrusions <NUM>. If through the rear entry aperture <NUM>, the shaft <NUM> may engage the proximal entry surface <NUM> of one of the jaws <NUM>, <NUM>', <NUM>", or the proximal entry surface <NUM>, <NUM>', <NUM>", <NUM>‴ of one of the protrusions. To accommodate entry of the shaft <NUM>, <NUM>', <NUM>" from the rear, the drive shaft <NUM> may include a drive shaft passage <NUM> therethrough, coaxial with the axis <NUM>. A diameter of the passage <NUM> may serve as a limit on a maximum permissible diameter of the shaft <NUM>, <NUM>', <NUM>" that may be received by the chuck <NUM>.

An end of the shaft <NUM>, <NUM>', <NUM>" is directed by the entry surfaces, <NUM>, <NUM>', <NUM>" and <NUM>, <NUM>', <NUM>", <NUM>‴ on the distal end, or <NUM> and <NUM>, <NUM>', <NUM>", <NUM>‴ on the proximal end, toward the axis <NUM>. The lever <NUM> may be gripped on its grip portion <NUM> by an operator's, i.e., a surgeon's, fingers and the lever <NUM> squeezed towards the grip handle <NUM>. The lever <NUM> pivots about the pivot axle <NUM>. The yoke portion <NUM> tips in a distal direction and, by way of the engagement of the yoke portion <NUM> with the actuator sleeve <NUM> at the slot <NUM>, displaces the actuator sleeve <NUM> in the distal direction as well. The second positioning bearing <NUM> may be axially restrained on a distal side. An annular reaction plate <NUM> may be disposed on a proximal side of the second positioning bearing <NUM> for engagement by the release spring <NUM>. The release spring <NUM> may be compressed between the first thrust plate and the reaction plate <NUM>. The release spring <NUM> resists displacement of the sleeve <NUM> in the distal direction. The actuator sleeve <NUM> is also in axial engagement, i.e., axially connected, through the first thrust bearing <NUM>, the thrust plate <NUM> and the shim washers <NUM>, with the head portion <NUM> of the engagement sleeve <NUM>. The lever <NUM> may thus be connected to the engagement sleeve <NUM>. Squeezing the lever <NUM> may cause the inclined engagement surface <NUM> of the engagement sleeve <NUM> to engage the driving surfaces <NUM> of the jaws <NUM> and displace the jaws <NUM>, <NUM>', <NUM>" and the clamping surfaces <NUM> toward the axis <NUM>.

Describing the displacement of the jaws <NUM>, <NUM>', <NUM>" in more detail, axial displacement of the sleeve <NUM> in the distal direction yields axial displacement of the head portion <NUM> and the entire engagement sleeve <NUM> and the first thrust bearing <NUM> in the distal direction. Distal axial displacement of the head portion <NUM> along the axis <NUM> causes the inclined surface <NUM> of the engagement sleeve <NUM> to act against the driving surfaces <NUM> of the jaws <NUM>, <NUM>', <NUM>". The jaws <NUM>, <NUM>', <NUM>" are restricted to radial movement, i.e., movement toward and away from the axis <NUM>, by the jaw channels <NUM> responsive to the force of the head portion <NUM> against the jaws <NUM>, <NUM>', <NUM>". Thus, axial movement of the sleeve <NUM> results in a sliding of the inclined surface <NUM> across the driving surface <NUM>, and radial displacement of the jaws <NUM>, <NUM>', <NUM>' toward the axis <NUM>, such displacement being limited by engagement of the clamping surfaces <NUM> against the shaft <NUM>, <NUM>', <NUM>". As the clamping surfaces <NUM> move closer together, the lateral sides <NUM>, <NUM>', <NUM>" of the jaws <NUM> and/or the facing surfaces <NUM>, <NUM>', <NUM>", <NUM>‴ of the protrusions <NUM>, <NUM>', <NUM>", <NUM>‴ drive the shaft <NUM> toward the axis <NUM>.

Jaws featuring complementary protrusions and cavities may be incorporated into any other style of chuck that employs jaws. One alternative construction of a chuck for a wire driver may have a lever connected to a jaw guide adapted for axial movement, not illustrated here, is illustrated in patent publication <CIT>. The jaw guide and the jaws disposed therein may be axially displaced by squeezing the lever. The axial displacement of the jaw guide may press the driving surfaces of the jaws against the inclined engagement surface of the engagement sleeve, resultingly displacing the clamping surfaces of the jaws toward the axis. Other example alternative configurations are illustrated in <FIG>.

<FIG>, B and C illustrate example interleaving jaws <NUM> for use with an example keyless chuck <NUM> illustrated in <FIG> and <FIG>. Keyless chucks are commercially available, with an example chuck available as part of a Stryker® System8 power tool set. The example keyless chuck <NUM> clamps a shaft <NUM> disposed on a longitudinal axis <NUM> without the use of a lever like the lever <NUM> of the chuck <NUM>. Instead, clamping may be achieved by stalling an exterior engagement sleeve <NUM> by gripping the sleeve <NUM> with one's hand while using a handpiece like the handpiece <NUM> to rotate a drive shaft <NUM> in a tightening direction. Clamping may also be achieved by manually gripping both the sleeve <NUM> and a collar <NUM> and rotating the collar <NUM> and the sleeve <NUM> relative to each other in the tightening direction.

An axially extending jaw guide <NUM>, defining and centered on the longitudinal axis <NUM> that also serves as an axis of rotation, slidably retains jaws <NUM> in jaw channels <NUM> formed therein. The jaws <NUM> have a clamping surface <NUM> facing the axis <NUM>, and a driving surface <NUM> substantially opposite the clamping surface <NUM>. The jaws <NUM> each have a protrusion <NUM> on a first lateral side <NUM> and a cavity <NUM> on a second lateral side <NUM>. As illustrated for jaws <NUM>, <NUM>' and <NUM>", adjacent jaws <NUM> have the protrusion <NUM> of one jaw <NUM> disposed in the cavity <NUM> of another jaw <NUM> when the jaws <NUM> are sufficiently radially close to the axis <NUM>.

Like the jaws <NUM> and the protrusions <NUM>, the jaws <NUM> and the protrusions <NUM> may each have a sloped distal entry surface, <NUM> and <NUM> respectively, to facilitate receipt of the shaft <NUM> from a distal end of the chuck <NUM> and the handpiece <NUM>. Similarly, the jaws <NUM> and the protrusions <NUM> may each have a sloped proximal entry surface, <NUM> and <NUM> respectively, to receive the shaft <NUM> from a proximal end of the handpiece <NUM> and the chuck <NUM>.

Such sloped distal surfaces <NUM>, <NUM> may aid in directing an end of the shaft <NUM> that comes into engagement with the sloped surfaces <NUM>, <NUM> to slide both axially and radially further along the surfaces <NUM>, <NUM> and into a receiving aperture <NUM> between the jaws <NUM>. The aperture <NUM> may be defined at least in part by a facing surface <NUM> of the protrusions <NUM> and the second lateral sides <NUM> of the jaws <NUM>. As the jaws <NUM> move together, the shaft <NUM> is moved to a clamping position within the aperture <NUM> between the clamping surfaces <NUM> of the jaws <NUM>.

To accommodate entry of the shaft <NUM>, the jaw driver <NUM> may include a driver passage <NUM> therethrough, coaxial with the axis <NUM>. A diameter of the passage <NUM> may serve as a limit on a maximum permissible diameter of the shaft <NUM> that may be received by the chuck <NUM>.

The engagement sleeve <NUM> includes an inclined engagement surface <NUM> thereon, i.e., therein. The inclined engagement surface <NUM> is disposed at least in part radially outside of the jaws <NUM>, at least partially enclosing the jaws <NUM> in an engaged position as best shown in <FIG>. The engagement surface <NUM> is substantially centered about the axis <NUM> and is substantially parallel to the driving surface <NUM>. The axially extending jaw guide <NUM> may be substantially fixed relative to the engagement sleeve <NUM>. The engagement sleeve <NUM> may be fixedly coupled to a supplemental sleeve <NUM>.

The drive shaft <NUM> may be fixed to a driving sleeve <NUM> for unitary rotation therewith about the axis <NUM>. The driving sleeve <NUM> may be in threaded engagement with a shank portion <NUM> of a jaw driver <NUM>. The jaw driver <NUM> includes an axially displaceable actuation head <NUM> that is rotatably fixed to, but slidably disposed in the jaw guide <NUM>. Such a relationship may be achieved by providing a plurality of circumferentially distributed finger slots <NUM> in the jaw guide <NUM> and an equal number of axially extending engagement fingers <NUM> on the head <NUM>. The finger slots <NUM> may be aligned with and connected with and open to the jaw channels <NUM>. A plurality of distal abutment surfaces <NUM>, equal in number to the number of jaws <NUM>, may be disposed on the head <NUM>, circumferentially interposed between the fingers <NUM>. The abutment surfaces <NUM> may be in engagement with proximal abutment surfaces <NUM> of the jaws <NUM> at a proximal end of the jaws <NUM>.

Inward radial movement of the jaws <NUM> is induced by axial displacement of the head <NUM> against the jaws <NUM>. More specifically, with relative rotation of the drive shaft <NUM> in a first direction relative to the engagement sleeve <NUM>, the driving sleeve <NUM> rotates relative to the jaw driver <NUM>. The threaded engagement between the jaw driver <NUM> and the driving sleeve <NUM> results in relative axial displacement between the driver <NUM> and the sleeve <NUM> in an engagement direction. The distal abutment surfaces <NUM> of the jaw driver <NUM> axially engage and push against the proximal abutment surfaces <NUM> of the jaws <NUM>, forcing the driving surfaces <NUM> of the jaws <NUM> against the inclined surface <NUM> of the engagement sleeve <NUM> and axially displacing the jaws <NUM> in the engagement direction relative to and against the engagement sleeve <NUM>. Movement of the jaws <NUM> along the axis <NUM>, with the driving surfaces <NUM> sliding across the inclined surface <NUM>, pushes the clamping surfaces <NUM> of the jaws <NUM> against the shaft <NUM> to clamp the shaft <NUM>.

A Jacobs keyed chuck <NUM> may also incorporate jaws <NUM> with complementary protrusions and cavities. Jacobs keyed chucks are commercially available, with an example chuck available as part of a Stryker® System8 power tool set. The example Jacobs keyed chuck <NUM>, shown in <FIG>, has three substantially cylindrical jaws <NUM> slidably disposed in holes, i.e., channels <NUM>, in an axially extending and substantially cylindrical jaw guide <NUM>. The channels <NUM> may be at an angle γ to a longitudinal axis <NUM> that may be defined by the jaw guide <NUM>. The longitudinal axis <NUM> may also serve as an axis of rotation. Rotation of a driving sleeve <NUM> relative to the jaw guide <NUM> about the axis <NUM> in a first relative rotative direction drives the three jaws <NUM> axially distally, and simultaneously, due to the angle γ, radially inwardly toward the axis <NUM> for engagement with and clamping of a shaft <NUM> by clamping surfaces <NUM> of the jaws <NUM>. Relative rotation between the sleeve <NUM> and the jaw guide <NUM> in a second rotative direction, opposite the first rotative direction, drives the jaws <NUM> both axially proximally toward the handpiece <NUM>, and radially away from the axis <NUM> and the shaft <NUM>. A chuck key, not shown, may be used to rotate the sleeve <NUM> relative to the jaw guide <NUM>.

The clamping surface <NUM> of each of the jaws <NUM> face the axis <NUM>. A driving surface <NUM> is located on the jaws <NUM> substantially opposite the clamping surface <NUM> at a distal end of the jaws <NUM>. The jaws <NUM>, as illustrated in <FIG>, may have a first protrusion <NUM> and a first cavity <NUM> on a first lateral side <NUM>, and a second protrusion <NUM>' and a second cavity <NUM>' on a second lateral side <NUM>. As illustrated for jaws <NUM>", adjacent jaws <NUM> may have the protrusion <NUM>, <NUM>' of one jaw <NUM> disposed in the cavity <NUM>', <NUM> of another jaw <NUM> when the jaws <NUM> are sufficiently radially close to the axis <NUM>. The jaws <NUM> and the protrusions <NUM>, <NUM>' may each have a sloped distal entry surface <NUM>, <NUM>, and <NUM>' respectively, to facilitate receipt of the shaft <NUM> from a distal end of the chuck <NUM> and the handpiece <NUM>.

Such sloped distal surfaces <NUM>, <NUM>, <NUM>' may aid in directing an end of the shaft <NUM> that comes into engagement with the sloped surfaces <NUM>, <NUM>, <NUM>' to slide both axially and radially further along the surfaces <NUM>, <NUM>, <NUM>' and into a receiving aperture <NUM> between the jaws <NUM>. The aperture <NUM> may be defined at least in part by facing surfaces <NUM>, <NUM>' of the protrusions <NUM>, <NUM>' and the clamping surfaces <NUM>. As the jaws <NUM> move together, the shaft <NUM> is moved by the facing surfaces <NUM>, <NUM>' to a clamping position within the aperture <NUM> between the clamping surfaces <NUM> of the jaws <NUM>.

To accommodate entry of the shaft <NUM> into the jaw guide <NUM> proximally beyond the jaws <NUM>, the jaw guide <NUM> may include a guide passage <NUM> therethrough, coaxial with the axis <NUM>. A diameter of the passage <NUM> may serve as a limit on a maximum permissible diameter of the shaft <NUM> that may be received by the chuck <NUM>.

The jaw guide <NUM> includes an example inclined engagement surface <NUM> therein collectively disposed in the channels <NUM>, opposite the axis <NUM>. The inclined engagement surface <NUM> is disposed at least in part radially outside of its associated jaw <NUM>, at least partially enclosing the jaws <NUM> in an engaged position as best shown in <FIG>. The inclined engagement surface <NUM> is substantially centered about the axis <NUM> and is substantially parallel to the driving surface <NUM> of the associated jaw <NUM>.

The jaw guide <NUM> may include an axially extending drive shaft <NUM> for unitary rotation therewith about the axis <NUM>. The drive shaft <NUM> may be selectively engaged with the handpiece <NUM>. The driving sleeve <NUM> may drive, i.e., axially displace, the jaws <NUM> through a threaded connection therebetween. An outward facing threaded surface <NUM> of each jaw <NUM> on a side opposite the axis <NUM>, and at a proximal end of the jaws <NUM>, may be engaged by providing inner, i.e., female threads <NUM> within the driving sleeve <NUM>. The sleeve <NUM> may include a split nut <NUM> disposed over the jaws and pressed into the sleeve <NUM>. The sleeve <NUM> has a circle of chuck sleeve teeth <NUM> distributed on a distal end of the sleeve <NUM> centered on the axis <NUM>, and a plurality of, e.g., three, pin holes <NUM> in the jaw guide <NUM> distally beyond the sleeve <NUM>. The chuck key (not shown) may include a pin surrounded by chuck key teeth.

As with the chucks <NUM> and <NUM>, inward radial movement of the jaws <NUM> of the chuck <NUM> is induced, as when clamping the shaft <NUM>, by relative axial displacement of the jaws <NUM> relative to the inclined surface <NUM> engaged by the driving surfaces <NUM> of the jaws <NUM>. Such relative axial displacement may be provided with use of the chuck key. The chuck key is engaged with the chuck when the pin of the key is disposed in one of the pin holes <NUM> and the teeth of the key are meshed with the chuck sleeve teeth <NUM>. Once engaged, the key is rotated in a tightening direction, thereby rotating the sleeve <NUM> relative to the jaw guide <NUM> in a first, i.e., tightening, direction. Rotation of the sleeve <NUM> relative to the jaw guide <NUM> may also be achieved manually by engaging the sleeve with one's fingers while using the handpiece <NUM> to rotate the jaw guide <NUM>. Rotation of the collar <NUM> may rotate the drive shaft <NUM> therewith. Such manual clamping may be following by using the key to tighten the jaws <NUM> against the shaft <NUM>. With rotation of the sleeve <NUM> and the nut <NUM> therewith relative to the jaw guide <NUM> in the first direction, the jaws <NUM> are driven axially distally by the action of the nut threads <NUM> on the threaded surfaces <NUM> of the jaws <NUM>. The threaded engagement between the jaws <NUM> and the driving sleeve <NUM> results in relative axial displacement between the guide <NUM> and the sleeve <NUM>. The driving surfaces <NUM> of the jaws <NUM>, acting against the inclined surface <NUM> of the jaw guide <NUM>, cause the clamping surfaces <NUM> of the jaws to move radially inwardly. Movement of the jaws <NUM> along the axis <NUM>, with the driving surfaces <NUM> sliding across the inclined surface <NUM>, pushes the clamping surfaces <NUM> of the jaws <NUM> against the shaft <NUM> to clamp the shaft <NUM>. Rotation of the key in the opposite direction releases the shaft <NUM>. <FIG> shows the jaws <NUM> clamped against a small diameter shaft <NUM>'. <FIG> shows the jaws <NUM> clamping a large diameter shaft <NUM>".

A jaw chuck with interleaving jaws has been disclosed.

In the drawings, the same reference numbers indicate the same elements. Further, some or all of these elements could be changed within the scope as defined by the claims. With regard to the media, processes, systems, methods, heuristics, etc. described herein, it should be understood that, although the steps of such processes, etc. have been described as occurring according to a certain ordered sequence, such processes could be practiced with the described steps performed in an order other than the order described herein. It further should be understood that certain steps could be performed simultaneously, that other steps could be added, or that certain steps described herein could be omitted. In other words, the descriptions of processes herein are provided for the purpose of illustrating certain embodiments, and should in no way be construed so as to limit the claims.

Accordingly, it is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments and applications other than the examples provided would be apparent upon reading the above description. The scope should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims. It is anticipated and intended that future developments will occur in the technologies discussed herein, and that the disclosed systems and methods will be incorporated into such future embodiments. In sum, it should be understood that the application is capable of modification and variation.

As used herein, the adverb "substantially" means that a shape, structure, measurement, quantity, time, etc. may deviate from an exact described geometry, distance, measurement, quantity, time, etc., because of imperfections in materials, machining, manufacturing, transmission of data, computational speed, etc..

All terms used in the claims are intended to be given their ordinary meanings as understood by those knowledgeable in the technologies described herein unless an explicit indication to the contrary is made herein. In particular, use of the singular articles such as "a," "the," "said," etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary.

Claim 1:
A chuck (<NUM>, <NUM>) for a wire driver, the chuck (<NUM>, <NUM>) comprising:
an axially extending jaw guide (<NUM>, <NUM>) defining a longitudinal axis (<NUM>, <NUM>) and including a first plurality of jaw channels (<NUM>, <NUM>) circumferentially distributed about the axis (<NUM>, <NUM>); and
a plurality of interleaving jaws (<NUM>, <NUM>', <NUM>", <NUM>) slidably disposed in the jaw channels (<NUM>, <NUM>) and each jaw (<NUM>, <NUM>', <NUM>", <NUM>) having a clamping surface (<NUM>, <NUM>) facing the axis (<NUM>, <NUM>) and a driving surface (<NUM>, <NUM>) substantially opposite the clamping surface (<NUM>, <NUM>);
wherein the chuck (<NUM>, <NUM>) further comprises:
an engagement sleeve (<NUM>, <NUM>) having an inclined engagement surface (<NUM>, <NUM>) on an inner surface thereof, the engagement surface (<NUM>, <NUM>) substantially centered about the axis (<NUM>, <NUM>) and substantially parallel to the driving surface (<NUM>, <NUM>), wherein displacement of the jaw guide relative to the engagement sleeve in a clamping direction displaces the clamping surfaces toward the axis or wherein displacement of the jaws (<NUM>, <NUM>', <NUM>", <NUM>) relative to the engagement surface (<NUM>, <NUM>) in a clamping direction displaces the clamping surfaces (<NUM>, <NUM>) toward the axis (<NUM>, <NUM>); and characterised in that each jaw (<NUM>, <NUM>', <NUM>", <NUM>) further comprises a protrusion (<NUM>, <NUM>', <NUM>", <NUM>'", <NUM>) on a first lateral side (<NUM>, <NUM>', <NUM>", <NUM>) and a cavity (<NUM>, <NUM>', <NUM>", <NUM>‴, <NUM>) on a second lateral side (<NUM>, <NUM>', <NUM>", <NUM>) with the protrusion (<NUM>, <NUM>', <NUM>", <NUM>'", <NUM>) of each jaw (<NUM>, <NUM>', <NUM>", <NUM>) disposed at least in part in the cavity (<NUM>, <NUM>', <NUM>", <NUM>'", <NUM>) of an adjacent jaw (<NUM>, <NUM>', <NUM>", <NUM>).