Collet chuck device

A collet chuck device has a body member with a frustoconical recess defined therein. A collet is disposed within the recess. A nut member is rotationally configured on the body member to move the collet axially within the recess. The nut member has an outer sleeve member and an inner sleeve member concentric within the outer sleeve member. The inner sleeve member is threadedly engaged on threads defined on the body member and contains ball grooves defined on an outer circumferential surface thereof. The outer sleeve member has ball grooves defined on the inner circumferential surface thereof and rolling bodies are operably disposed in the ball grooves so that the outer sleeve member is rotatable relative to the inner sleeve member. Upon rotation of the nut member on the body member in the tightening direction, the outer sleeve member advances axially in the tightening direction relative to the inner sleeve member through engagement of the rolling bodies in the ball grooves and thereby forces the collet further into the frustoconical recess.

BACKGROUND OF THE INVENTION 
The present invention relates to a chuck device for holding tool bits to a 
drive shaft of a power tool or machine tool, and more particularly to a 
quick release chuck device incorporating a collet which is particularly 
useful in machining applications, such as routing, drilling, milling, and 
boring applications. 
Conventional tool holding devices incorporate a body member or collet tool 
holder having a tapered collet that conforms to a hollow cone or recess 
defined in the body member. In certain applications, such as routers, the 
body member may comprise the end portion of the drive shaft and the hollow 
cone or recess may be defined in the end of the shaft. Typically, a 
threaded nut is provided having a conical cam surface which matches the 
conical surface of the outer forward collet face. During operation of this 
type of conventional device, the drive spindle or chuck of the machine 
tool must be held stationary in order to tighten the collet nut 
sufficiently. Flats are defined on the outer circumferential surface of 
the nut member so that a wrench can be engaged on the nut member to 
provide a sufficient tightening torque. For this reason, most router 
chucks and tool holders utilizing collets have spindle locks or are 
provided with extra wrenches for holding the drive shaft stationary and 
tightening the nut member onto the body member. Similarly, to release the 
tool, the machine shaft or chuck body must again be held stationary while 
the nut member is loosened with a wrench. 
These known conventional devices have a number of drawbacks. For example, 
the tightening and loosening procedure has proven to be cumbersome and 
requires a separate device, such as a wrench, for locking the spindle 
shaft or for applying a tightening force to the nut member. Additionally, 
the degree of tightening of the nut member is limited by the frictional 
interface between the nut member and body member. Inconsistent nut 
tightening can create high stresses in the threads of the nut and tool 
holder causing damage in cases of overtightening. 
Various attempts have been made in the art to provide improved chuck 
devices incorporating collets, particularly for high speed machine tools 
such as routers. U.S. Pat. No. 5,511,801 issued to Kanaan et al., for 
example, provides a significant improvement in the art. The '801 patent 
discloses an integrated collet and chuck device which is actuated by 
turning a sleeve relative to a body member, with the sleeve having a nut 
fixed therein. The nut engages a screw member which is rotatably 
concentric within the nut. Rotation of the nut drives the screw member in 
the longitudinal direction and the screw member engages a collet thereby 
causing the collet to grip on a tool shank. 
The present invention provides an improvement to the state of the art of 
chuck devices utilizing collets. 
OBJECTS AND SUMMARY OF THE INVENTION 
Therefore, a principal object of the present invention is to provide a 
quick release chuck device incorporating a collet for securing a tool bit 
or working device to a drive spindle of a machine tool. 
A further object of the invention is to provide an integrated collet and 
chuck device which does not require a wrench or external device for 
applying sufficient tightening torque to the collet engaging member. 
And yet a further object of the present invention is to provide a collet 
and chuck device wherein frictional resistance of the operating member is 
substantially eliminated thereby allowing for the device to be tightened 
and loosened by manual operation. 
Still another object of the present invention is to provide an improved 
chuck device for machine tools such as routers, laminate trimmers, dry 
wall cutters, boring machines, milling machines, drills, and the like. 
Additional objects and advantages of the invention will be set forth in 
part in the description which follows, and in part will be obvious from 
the description, or may be learned through practice of the invention. The 
objects and advantages of the invention may be realized and obtained by 
means of the instrumentalities and combinations particularly pointed out 
in the appended claims. 
To achieve the objects and in accordance with the purposes of the 
invention, a chuck device is provided having a body member with a 
frustoconical recess defined therein. A collet is operationally disposed 
within the frustoconical recess. The body member has threads defined on an 
outer circumferential surface thereof. A nut member is rotationally 
configured with the body member to move the collet axially within the 
frustoconical recess. As is well understood by those skilled in the art, 
as the collet moves axially into the frustoconical recess, the gripping 
members of the collet are compressed radially inward and grip upon a tool 
shank inserted into the collet. 
A nut member is included having an outer sleeve member and an inner sleeve 
member concentric within the outer sleeve member. The inner sleeve member 
has a threaded inner circumferential surface for threaded engagement with 
the body member threads. The inner sleeve member also has ball grooves 
defined on an outer circumferential surface thereof. The outer sleeve 
member has ball grooves defined on the inner circumferential surface 
thereof radially opposite the ball grooves defined on the inner sleeve 
member. Rolling bodies, such as ball bearings, are operably disposed in 
the inner sleeve member and outer sleeve member ball grooves. Preferably, 
the rolling bodies are contained in a ball cage. The outer sleeve is 
axially movable relative to the inner sleeve member and further comprises 
a collet engaging member which engages and moves the collet axially within 
the frustoconical recess. 
With the structure noted above, upon rotation of the nut member on the body 
member in a tightening direction, the outer sleeve member and inner sleeve 
member act as a single unit as the nut member is initially threaded onto 
the body member due to a limited rotational frictional load defined 
between the outer sleeve member and inner sleeve member primarily by a 
click ring mechanism disposed between the two sleeve members. As the nut 
member is screwed further onto the body member and friction between the 
collet and body member, as well as between the threads on the inner sleeve 
member and body member, increases, the initial frictional load between the 
inner and outer sleeve members is overcome and the inner sleeve member 
will cease to rotate. At this point, the outer sleeve member will continue 
to rotate relative to the inner sleeve member through engagement of the 
rolling bodies within the ball grooves. Preferably, the pitch of the ball 
grooves is less than that of the threads between the body member and inner 
sleeve member. The outer sleeve member advances axially relative to the 
inner sleeve member and, in so doing, engages the collet and forces the 
collet further into the frustoconical recess. In this regard, a collet 
engaging member is incorporated with the outer sleeve member and, 
preferably, comprises a thrust washer or member that is rotationally 
coupled to the outer sleeve member to decrease friction between the outer 
sleeve member and the collet. 
Thus, the frictional loads between the operating members of the device are 
virtually overcome so that the nut member can be sufficiently tightened 
without the necessity of a wrench or other torquing device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Reference will now be made in detail to the presently preferred embodiments 
of the invention, one or more examples of which are illustrated in the 
drawings. Each example is provided by way of explanation of the invention, 
and not as a limitation of the invention. In fact, it will be apparent to 
those skilled in the art that various modifications and variations can be 
made in the present invention without departing from the scope or spirit 
of the invention. For example, features illustrated or described as part 
of one embodiment can be used on another embodiment to yield a still 
further embodiment. Thus, it is intended that the present invention cover 
such modifications and variations that come within the scope of the 
appended claims and their equivalents. 
The present collet holding chuck device is generally identified as element 
10 in the drawings. Device 10 is used to hold a tool bit 61 (FIG. 1) to a 
drive spindle of a power or machine tool. Chuck device 10 is particularly 
well suited for high speed applications wherein the benefits of a collet 
holding device are particularly well suited, such as with routers, 
laminate trimmers, dry wall cutters, toolholders for drilling, milling, 
boring, etc. However, this is in no way meant as a limitation of the 
invention. Chuck device 10 can be utilized in any application wherein it 
is desired to hold a tool bit to a drive spindle of a machine tool with a 
collet holding device. 
Although not particularly illustrated in the figures, it should be 
understood that the chuck device can be mounted to a drive spindle of a 
machine tool by any conventional mounting configuration. For example, a 
number of conventional systems are well known in the art for holding or 
retaining collet tool holders to a tool or drive spindle. Any and all such 
mounting configurations are within the scope and spirit of the invention 
and may be utilized to mount chuck device 10 to a tool or drive mechanism. 
For example, a threaded engagement between the body member and the drive 
spindle may be utilized, as well as a ball and detent device, mechanical 
interlocks, etc. Additionally, it is also within the scope of the 
invention to define the body member directly on the end of a drive shaft, 
as with conventional routers. The particular design and mounting system 
for the body member is not particularly relevant to the present invention 
and any and all conventional devices can be utilized. 
Referring to the figures in general, chuck device 10 includes a body member 
12 having a frustoconical chamber or recess 16 defined through the forward 
end thereof. Chamber 16 houses a removable collet 22. Collet 22 can 
comprise any conventional type of collet. For example, the typical split 
steel collet illustrated in the figures may be utilized. In an alternative 
embodiment, collet 22 may comprise a plurality of individual longitudinal 
gripping jaws held in a spaced apart relation by resilient material 
disposed between the gripping jaws, such as the Ultru.TM. Rubber-Flex.RTM. 
collets from Jacobs.RTM. Chuck Manufacturing Company. Both of these types 
of conventional collets are well known to those skilled in the art. Also, 
the operation and principles of such collets are well known and a detailed 
description thereof is not necessary for purposes of this disclosure. 
Body member 12 includes an outer circumferential surface, generally 20, 
having threads 18 defined thereon. A nut member, generally 24, is 
rotationally configured with body member 12 to move collet 22 axially 
within frustoconical recess 16. 
Nut member 24 includes an outer sleeve member 26 and an inner sleeve member 
30. Outer sleeve member 26 has an outer circumferential surface 28 with 
grip enhancing ridges 50 formed therein. It should be understood that the 
grip enhancing surface can comprise any manner of textured or formed 
surface to enhance ergonomics. Outer sleeve member 26 has an inner 
circumferential surface having ball grooves 27 formed therein. A 
circumferential band of detents 56 are disposed axially rearward of ball 
grooves 27. Outer sleeve member 26 also includes a forward end with a 
collet engaging member 40 configured therewith. In the embodiment 
illustrated, collet engaging member 40 includes a ring member 42 that is 
rotationally coupled within a forward flange section 45 of outer sleeve 
member 26. Bearings 44 are housed in radially opposite races defined in 
ring member 42 and flange member 45. Thus, it should be understood, that 
ring member 42 will move axially with outer sleeve member 26, but will 
remain rotationally stationary as outer ring member 26 is rotated. Ring 
member 42 contains a cammed surface 43 for contacting the forward end of 
collet 22. A retaining ridge or lip 47 engages within recess 21 defined in 
collet 22 so that the collet can be extracted or moved axially forward out 
of frustoconical recess 16 when outer sleeve member 26 is rotated in a 
loosening direction. 
Inner sleeve member 30 of nut member 24 includes an outer circumferential 
surface 38 having ball groves 36 defined therein. Ball grooves 36 have the 
same pitch as ball grooves 27 defined in outer sleeve member 26. Inner 
sleeve member 30 also includes a flange member 63 at the axially rearward 
end thereof and a shoulder 64 defined axially forward of flange 63. 
Threads 34 are defined on the inner circumferential surface of inner 
sleeve member 30. Threads 34 engage with threads 18 defined on body member 
12. Preferably, the pitch of ball grooves 27, 36 is less than that of 
threads 18, 34. 
Chuck device 10 includes rolling bodies 46, such as ball bearings, operably 
disposed in the ball grooves 36, 27. Preferably, rolling bodies 46 are 
held in a ball cage 48 and are equally spaced around the circumference of 
the ball grooves. Thus, outer sleeve member 26 is rotatable relative to 
inner sleeve member 30 once an initial frictional loading between the 
components is overcome, as explained in more detail. 
A seal 58 is disposed around inner sleeve member 30 adjacent to flange 
member 63. Seal 58 contains lips that seal against the inner surface of 
outer sleeve member 26, as particularly illustrated in FIGS. 1 and 2. The 
lips 59 also slide against the inner surface of sleeve member 26. 
A retaining ring 60 is fitted into a groove 61 defined in outer sleeve 
member 26. Retaining ring 60 prevents outer sleeve member 26 from being 
rotated completely off of inner sleeve member 30. However, it should be 
understood, that retaining ring 60 can be radially compressed and 
disengaged from groove 61 so that outer sleeve member 26 is removable from 
the inner sleeve member for maintenance or part replacement. 
A mechanism is provided with device 10 to securely hold or retain outer 
sleeve member 26 in a rotated position relative to inner sleeve member 30. 
In the embodiment illustrated, this device comprises a click ring 52 
press-fitted onto inner sleeve member 30 against shoulder 64. Click ring 
52 is non-rotatable under load relative to inner sleeve member 30 and 
includes a plurality of arm members 54 having protuberances 55 formed on 
the end thereof. Arm members 54 are radially compressible and 
protuberances 55 engage in detents 56 defined in the inner surface of 
outer sleeve member 26, as particularly seen in FIGS. 1 and 2. As outer 
sleeve member 26 is rotated relative to inner sleeve member 30, 
protuberances 55 alternately engage and disengage from detents 56. When 
engaged in detents 56, arm members 54 and protuberances 55 rotationally 
"lock" outer sleeve member 26 relative to inner sleeve member 30 and, 
thus, prevent inadvertent loosening of the device. Click ring 52 also 
generates an audible and physical "click" as the protuberances 55 
alternately engage and disengage with detents 56, thereby providing the 
operator with a physical feel and audible indication of the degree of 
tightening of outer sleeve member 26. 
FIG. 1 illustrates chuck device 10 in an initial untightened or loosened 
condition wherein nut member 24 with collet 22 has been initially threaded 
onto body member 12. It should be understood that inner sleeve member 30 
and outer sleeve member 26 will rotate as a single component due to the 
initial frictional loading between the components supplied primarily by 
arm members 54 engaging in detents 56. As nut member 24 is screwed further 
onto body member 12, friction increases between collet 22 which is forced 
axially further into recess 16, and body member 12, as well as between 
threads 18 and 34. At some point, this friction will overcome the initial 
frictional loading between inner sleeve member 30 and outer sleeve member 
26. At this point, inner sleeve member 30 will cease to rotate and outer 
sleeve member 26 will rotate relative to inner sleeve member 30 through 
engagement of rolling bodies 46 and ball grooves 27, 36. Thus, further 
manual rotation of outer sleeve member 26 will cause the outer sleeve 
member to advance axially rearward relative to inner sleeve member 30. As 
outer sleeve member 36 moves axially rearward, collet 22 is forced axially 
further into recess 16 through engagement of ring member 42 with the 
collet. Ring member 42 will not rotate with outer sleeve member 26 due to 
bearings 44. Thus, a substantial frictional load is overcome in this 
regard. 
FIG. 2 illustrates the device in its tightened configuration. FIG. 2 
particularly illustrates that outer sleeve member 26 has advanced axially 
rearward relative to inner sleeve member 30, and that collet 22 has been 
forced axially rearward into recess 16. As the outer sleeve member moves 
axially rearward, the lips 59 of seal 58 slide against the outer sleeve 
member and protuberances 55 of click ring 52 also move axially within 
detents 56. Outer sleeve member 26 is rotationally held in its tightened 
rotational position through engagement of the click ring and detents 56. 
To loosen the device, the operator merely rotates outer sleeve member 26 in 
an opposite loosening direction. In this manner, outer sleeve member 26 
will move axially forward relative to inner sleeve member 30 and retaining 
lip or ridge 47 will pull collet 22 out of recess 16. Click ring 52 will 
act in the same manner with detents 56 when outer sleeve member 26 is 
rotated in the loosening direction. At some point, the frictional loading 
between arms 54 of click ring 52 and detents 56 (which can be modified by 
changing the configuration of arms 54), as well as the system loading 
between the inner and outer sleeve members, will be greater than the 
frictional load generated between threads 18, 34 and the two sleeve 
members will then rotate in the loosening direction as a single unit. In 
this manner, nut member 24 can be completely unthreaded or removed from 
body member 12 for changeout or replacement of collet 22 if necessary. 
However, it should be understood, that nut member 24 does not need to be 
completely unthreaded or removed from body member 12 in order to remove 
tool shank 62 from collet 22. The device can be loosened to the position 
illustrated in FIG. 1 which allows the collet to lose its grip on tool 
shank 62. 
It should be understood by those skilled in the art that various 
modifications and variations can be made in the present invention without 
departing from the scope and spirit of the invention. It is intended that 
such modifications and variations be included in the present application 
as come within the scope of the appended claims and their equivalents.