U.S. patent application number 11/398537 was filed with the patent office on 2006-10-19 for tool chuck with sliding sleeve and chuck mechanism.
Invention is credited to John E. Buck, Richard C. JR. Nickels, Daniel Puzio.
Application Number | 20060232022 11/398537 |
Document ID | / |
Family ID | 37107765 |
Filed Date | 2006-10-19 |
United States Patent
Application |
20060232022 |
Kind Code |
A1 |
Nickels; Richard C. JR. ; et
al. |
October 19, 2006 |
Tool chuck with sliding sleeve and chuck mechanism
Abstract
A tool chuck may include a chuck body defining a longitudinal
axis. A sleeve may be mounted on the chuck body for movement
between a first axial position in which the chuck body is rotatable
together with the sleeve, and a second axial position in which the
chuck body is rotatable relative to the sleeve to actuate to the
tool chuck. The chuck body may be rotatable in a first direction to
actuate the tool chuck up to a first torque threshold, and
rotatable in a second direction to actuate the tool chuck up to a
second, different torque threshold.
Inventors: |
Nickels; Richard C. JR.;
(Hampstead, MD) ; Buck; John E.; (Cockeysville,
MD) ; Puzio; Daniel; (Baltimore, MD) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 8910
RESTON
VA
20195
US
|
Family ID: |
37107765 |
Appl. No.: |
11/398537 |
Filed: |
April 6, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60672076 |
Apr 18, 2005 |
|
|
|
Current U.S.
Class: |
279/60 |
Current CPC
Class: |
Y10T 408/953 20150115;
B23B 2231/06 20130101; Y10T 279/27 20150115; B23B 2260/128
20130101; Y10T 279/20 20150115; Y10T 408/165 20150115; Y10T
279/17632 20150115; Y10T 279/32 20150115; B23B 31/1238 20130101;
B23B 2260/0445 20130101; Y10T 408/65 20150115; Y10S 279/902
20130101; Y10T 279/17615 20150115 |
Class at
Publication: |
279/060 |
International
Class: |
B23B 31/12 20060101
B23B031/12 |
Claims
1. A tool chuck, comprising: a chuck body defining a longitudinal
axis; and a sleeve mounted on the chuck body for movement between a
first axial position in which the chuck body is rotatable together
with the sleeve, and a second axial position in which the chuck
body is rotatable relative to the sleeve to actuate to the tool
chuck, the chuck body rotatable in a first direction to actuate the
tool chuck up to a first torque threshold, and rotatable in a
second direction to actuate the tool chuck up to a second,
different torque threshold.
2. The tool chuck of claim 1, further comprising: a clutch
mechanism configured to engage and disengage the chuck body
3. The tool chuck of claim 2, wherein the clutch mechanism is
actuatable by a sliding button or rotating sleeve with cam
surface.
4. The tool chuck of claim 2, wherein the clutch mechanism includes
a clutch part on the sleeve for engaging a cooperating clutch part
as the sleeve is in the second axial position, the clutch part
having a working surface facing a direction perpendicular to the
longitudinal axis.
5. The tool chuck of claim 2, wherein the clutch mechanism includes
a clutch housing which is keyed using one or more splines to a
cooperating portion of a tool housing encompassing the tool chuck,
so as to enable axial movement of the cooperating clutch part to
engage a latch ring of the tool chuck while preventing rotation of
the clutch housing relative to the tool housing.
6. The tool chuck of claim 5, further comprising: a bias spring and
a pawl spring provided between the cooperating clutch part and the
chuck body wherein, as the cooperating clutch part is moved axially
forward against the bias spring to engage the chuck body, the
cooperating clutch part is pushed radially inward against the pawl
spring into the clutch housing
7. The tool chuck of claim 6, wherein the latch ring includes a
plurality of recesses, and as the clutch housing moves axially
toward the clutch body, the cooperating clutch part springs outward
radially to engage the recesses.
8. The tool chuck of claim 1, wherein the chuck body has a rear end
fixedly mounted on a spindle of a power driver and a forward end
including a plurality of passageways that slidably support a
plurality of chuck jaws.
9. The tool chuck of claim 8, wherein the chuck jaws are inclined
so that forward ends thereof converge toward the longitudinal
axis.
10. The tool chuck of claim 8, wherein the sleeve carries a nut,
and the chuck jaws include radially outward facing threads
interacting with radially inward facing threads of the nut for
advancement or retraction of the chuck jaws.
11. The tool chuck of claim 1, wherein the sleeve carries a nut,
and a bearing is interposed between the nut and chuck body to
facilitate relative rotation between the nut and chuck body.
12. A tool chuck, comprising: a chuck body, a sleeve mounted on the
chuck body for movement between a first axial position and a second
axial position, the sleeve including a first clutch part engagable
to a second clutch part when the sleeve is in the second axial
position, the first clutch part configured to slip relative to the
second clutch part in a first direction upon application of a first
torque threshold, and in a second direction upon application of a
second torque threshold.
13. The tool chuck of claim 12, wherein the first torque threshold
and the second torque threshold have different magnitudes.
14. A tool chuck, comprising: a chuck body, a first sleeve, a
second sleeve, a first clutch part on the first sleeve, and a
second clutch part on the second sleeve, the first clutch part
disengaging the second clutch part upon tightening of the tool
chuck so that the first sleeve is urged forward toward a rear of
the chuck body.
15. The tool chuck of claim 14, wherein the chuck body includes one
or more recesses at a rear end thereof for receiving one or more
detent portions of the first chuck part, so as to engage the detent
portions to prevent relative motion between the first sleeve and
the chuck body.
16. A tool chuck of a tool having a tool motor, comprising: a chuck
body, a plurality of chuck jaws selectively securing an accessory
of a power driver therein, and a sleeve mounted on the chuck body
for movement between a first axial position and a second axial
position based on actuation of an axially spring-loaded
actuator.
17. The tool chuck of claim 16, wherein the actuator actuates under
user control so as to operate the tool motor to loosen or tighten
the chuck jaws.
18. A tool chuck, comprising: a chuck body defining a longitudinal
axis, a plurality of chuck jaws selectively securing an accessory
of a power driver therein, a sleeve mounted on the chuck body, and
a clutch mechanism adapted to move axially forward to engage the
fixed sleeve to prevent inadvertent loosening or tightening of the
chuck jaws.
19. A tool chuck, comprising: a chuck body defining a longitudinal
axis, a sleeve mounted on the chuck body for movement between a
first axial position and a second axial position, the sleeve
including a clutch part that engages with a cooperating clutch part
when the sleeve is in the second axial position, the clutch part
having a working surface facing in a direction perpendicular to the
longitudinal axis.
20. A tool chuck of a power driver having a motor, comprising: a
chuck body, and a clutch ring actuatable by a user of the power
driver for engaging or disengaging the motor to provide accessory
retention and/or disengagement.
Description
PRIORITY STATEMENT AND CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C.
.sctn.119(e) to U.S. Provisional Patent Application Ser. No.
60/672,076, filed Apr. 18, 2005 to Richard C. NICKELS, JR., et al.
and entitled "TOOL CHUCK WITH SLIDING SLEEVE AND CHUCK MECHANISM",
the entire contents of which are hereby incorporated by reference
herein.
[0002] This application is related to co-pending U.S. Provisional
Application Ser. No. 60/612,789 to Nickels, Jr. et al, filed Sep.
24, 2004 and entitled "TOOL CHUCK WITH SLIDING SLEEVE AND CHUCK
MECHANISM TO REMOVE OPERATOR VARIABILITY". The contents of the '789
provisional application is incorporated in its entirety by
reference herein.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates in general to tool chucks for
attachment of accessories to power drivers.
[0005] 2. Description of Related Art
[0006] A variety of tool chucks have been developed in which the
chuck jaws may be opened and closed via a relative rotation between
parts of the tool chuck. In some applications, the tool chuck may
include a sleeve that is rotatable manually (with or without using
a chuck key) to open and close the chuck jaws. In other
applications, power from the power driver may be utilized to open
and close the chuck jaws. For example, the tool chuck may be
provided with a sleeve that is axially moveable to a position in
which the sleeve is grounded (i.e., rotationally fixed) to the
housing of the power driver. Thus, when the driver is powered up, a
spindle of the driver (and consequently a chuck body) may rotate
relative to the sleeve. The relative rotation between the spindle
and the sleeve may open and close the chuck jaws.
[0007] Conventional keyless tool chucks are not without
shortcomings. For example, the tightening or loosening torque
applied during a chuck actuation process may vary depending on
factors such as, for example, the firmness with which the operator
manipulates the sleeve. On the one hand, if an operator manipulates
the sleeve with a relatively high force, then a relatively high
torque may be applied during the chuck actuation process. On the
other hand, if an operator manipulates the sleeve with a relatively
low force, then a relatively low torque may be applied during the
chuck actuation process.
[0008] The inconsistent application of torque may lead to problems
such as under-tightening and over-tightening of the tool chuck.
When the tool chuck is under tightened, the accessory may slip
relative to (and even inadvertently fall from) the tool chuck. When
the tool chuck is over-tightened, it may be difficult to loosen the
tool chuck to remove the accessory. Also, high speed impacts
between transmission elements of the power driver may occur when
the chuck jaws bottom out on the accessory (when tightening) or
when the chuck jaws reach the full limit of travel (when
loosening). In conventional power tool or other power devices, such
high speed impacts may damage the transmission elements, since the
torque applied during the chuck actuation process may be
unlimited.
SUMMARY OF THE INVENTION
[0009] In an example embodiment, a tool chuck may include a chuck
body supporting chuck jaws. A sleeve may be mounted on the chuck
body for movement between (1) a first axial position in which the
chuck body is rotatable together with the sleeve and (2) a second
axial position in which the chuck body is rotatable relative to the
sleeve to actuate to the tool chuck. When the sleeve is in the
second axial position, (1) the chuck body may be rotated in a first
direction to actuate the tool chuck up to a first torque threshold,
and (2) the chuck body may be rotated in a second direction to
actuate the tool chuck up to a second, different torque
threshold.
[0010] In another example embodiment, a tool chuck may include a
chuck body. A sleeve may be mounted on the chuck body for movement
between a first axial position and a second axial position. The
sleeve may include a first clutch part that engages with a second
clutch part when the sleeve is in the second axial position. The
first clutch part may slip relative to the second clutch part in a
first direction upon application of a first torque threshold and in
a second direction upon application of a second torque threshold.
The first torque threshold and the second torque threshold may have
different magnitudes.
[0011] In another example embodiment, a tool chuck may include a
chuck body defining a longitudinal axis. A sleeve may be mounted on
the chuck body for movement between a first axial position and a
second axial position. The sleeve may include a clutch part that
engages with a cooperating clutch part when the sleeve is in the
second axial position. The clutch part may have a working surface
that faces in a direction perpendicular to the longitudinal
axis.
[0012] In another example embodiment, a tool chuck of a power
driver may include a chuck body and a clutch ring. The clutch ring
may be actuated by a tool user for control of engaging or
disengaging the tool motor to provide accessory retention and/or
disengagement.
[0013] In another example embodiment, a tool chuck may include a
chuck body defining a longitudinal axis and chuck jaws. A sleeve
may be fixedly mounted on the chuck body. The tool chuck may
include a clutch mechanism adapted to move axially forward to
engage the fixed sleeve in an effort to prevent inadvertent
loosening or tightening of the chuck jaws
[0014] In another example embodiment, a tool chuck may include a
chuck body defining a longitudinal axis and chuck jaws. A sleeve
may be fixedly mounted on the chuck body. The tool chuck may
include a clutch mechanism having one or more clutch parts. Once
the tool chuck has been tightened, a first clutch part of a first
sleeve disengages a second clutch part of a second sleeve so that
the first sleeve is urged forward toward a rear of the chuck body.
The rear of the chuck body may include recesses for receiving
forward detent portions of the first chuck part, so as to engage
the detent portions to prevent relative motion between the first
sleeve and the chuck body.
[0015] In another example embodiment, a tool chuck of a tool having
a tool motor may include a chuck body, chuck jaws and a sleeve
mounted on the chuck body for movement between a first axial
position and a second axial position based on actuation of an
axially spring-loaded actuator. The actuator may actuate under user
control so as to operate the tool motor to loosen or tighten chuck
jaws of the tool chuck.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The example embodiments of the present invention will become
more fully understood from the detailed description below and the
accompanying drawings, wherein like elements are represented by
like reference numerals, which are given by way of illustration
only and thus are not limiting of the example embodiments of the
present invention.
[0017] FIG. 1 is a schematic illustration of a tool chuck according
to an example, non-limiting embodiment of the present
invention.
[0018] FIGS. 2-4 are schematic illustrations of example clutch
mechanisms that may be implemented in the tool chuck of FIG. 1.
[0019] FIG. 5 is a schematic illustration of a tool chuck according
to another example, non-limiting embodiment of the present
invention.
[0020] FIG. 6 is an exploded perspective view of example component
parts that may be mounted in the driver housing depicted in FIG.
5.
[0021] FIGS. 7-9 are schematic illustrations of example clutch
mechanisms that may be implemented in the tool chuck of FIG. 5.
[0022] FIG. 10 is a partial schematic illustration of a tool chuck
according to another example, non-limiting embodiment of the
present invention.
[0023] FIGS. 11 and 12 are schematic illustrations of an example
clutch mechanism that may be implemented in the tool chuck of FIG.
10.
[0024] FIG. 13 is an exploded perspective view of example component
parts of the tool chuck of FIG. 10.
[0025] FIGS. 14 and 15 are schematic illustrations of an example
clutch mechanism that may be implemented in the tool chuck of FIG.
10.
[0026] FIG. 16 illustrates a clutch ring mechanism adapted as a
user interface for controlling a power drill driver motor for
accessory retention/disengagement.
[0027] FIGS. 17A and 17B are schematic illustrations of an example
clutch mechanism for an example tool chuck.
[0028] FIGS. 18A and 18B illustrate a locking mechanism for a tool
chuck in accordance with an example embodiment of the present
invention.
[0029] FIG. 19 illustrates a spring-loaded actuator for providing
consistent tightening on an example tool chuck in accordance with
an example embodiment of the present invention.
DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS
I. Example Embodiment Depicted in FIGS. 1-4
[0030] FIG. 1 shows an example, non-limiting embodiment of a tool
chuck 50 that may be actuated with uniform torque and without
operator variability. The tool chuck 50 may be provided on a power
driver (e.g., a drill) for holding an accessory (e.g., a drill
bit). It will be appreciated, however, that the tool chuck 50 may
be implemented on a variety of power drivers (other than drills)
for holding a variety of accessories (other than drill bits).
A. Example Structure:
[0031] With reference to FIG. 1, the tool chuck 50 may include a
chuck body 20. The rear end of the chuck body 20 may be fixedly
mounted on a spindle 85 of a power driver. The forward end of the
chuck body 20 may have passageways that slidably support a
plurality of chuck jaws 2. The chuck jaws 2 may be inclined so that
respective forward ends of the chuck jaws 2 converge toward an axis
10 of the chuck body 20. The chuck jaws 2 may have respective
radially outward facing threads 3. For clarity of illustration,
only a single chuck jaw 2 is depicted in FIG. 1.
[0032] In this example embodiment, the chuck jaws 2 may be
characterized as "threaded" chuck jaws. That is, the chuck jaws 2
may be actuated (i.e., advanced and/or retracted) via the radially
outward facing threads 3 interacting with radially inward facing
threads 18 of a nut 16. However, the example embodiments of the
present invention are not limited in this regard. For example,
"pusher" jaws may be implemented and supported by the chuck body.
Pusher jaws are well known in this art, and therefore a detailed
discussion of pusher jaws is omitted herein for purposes of
brevity. The example embodiments of the present invention may be
implemented with a variety chuck jaw types that may be opened and
closed through a relative rotation between tool chuck parts (e.g.,
a nut and a chuck body).
[0033] The chuck body 20 may support a front sleeve 30 and a rear
sleeve 40. The front sleeve 30 and the rear sleeve 40 may be
rotatable relative to each other. As will be discussed in more
detail below, a clutch mechanism (inclusive of two cooperating
clutch parts 32, 42) may be provided between the front sleeve 30
and the rear sleeve 40. The clutch mechanism may rotationally lock
the front sleeve 30 and the rear sleeve 40 together up to a given
torque threshold. Once the given torque threshold is reached, the
clutch mechanism may give way (or slip) to limit the torque that
may be applied during the chuck actuation process. Further, the
clutch mechanism may be designed so that the given threshold for
tightening the tool chuck may be less than the given threshold for
loosening the tool chuck.
[0034] The front sleeve 30 may be supported so that it is axially
fixed to the chuck body 20 and rotatable relative to the chuck body
20. The front sleeve 30 may fixedly carry the nut 16. In this
example embodiment, the front sleeve 30 and the nut 16 may be
separate and distinct elements to facilitate assembly of the tool
chuck 50. It will be appreciated, however, that the front sleeve 30
and the nut 16 may be of a unitary, one-piece construction. The
rear end of the front sleeve 30 may include the clutch part 32.
[0035] The rear sleeve 40 may be supported so that it is axially
moveable relative to the chuck body 20 (and thus the front sleeve
30) between the axial forward position depicted in FIG. 1 and an
axial rearward position. The rear sleeve 40 may also be rotatable
relative to the chuck body 20. The forward end of the rear sleeve
40 may include the clutch part 42. The clutch part 42 may interact
with the clutch part 32 of the front sleeve 30. The rear end of the
rear sleeve 40 may include lugs 44. The lugs 44 may interact with
cooperating lugs 92 of the power driver housing 90.
[0036] A compression spring 25 may be captured between the front
sleeve 30 and the rear sleeve 40. The compression spring 25 may
influence the rear sleeve 40 to the axial forward position shown in
FIG. 1.
B. Example Clutch Mechanism:
[0037] Structural and functional aspects of the clutch mechanism
may become more apparent with reference to FIGS. 2-4, which are
partial sectional views (taken perpendicular to the axis 10) of
example, non-limiting embodiments of the cooperating clutch parts
that may be implemented in the tool chuck 50 of FIG. 1. In FIGS.
2-4, the rear sleeve is depicted in the axial rearward position so
that the clutch parts may be operatively engaged. In this
condition, one clutch part may be located radially inward of the
other clutch part.
[0038] The cooperating clutch parts may include respective working
surfaces. In this specification, the term "working surface" refers
to the surface of the clutch part that may frictionally engage with
the working surface of the cooperating clutch part. In FIGS. 2-4,
the working surfaces of the clutch parts may face in directions
that are perpendicular to the axis 10 of the tool chuck. That is,
as shown in FIGS. 2-4, the working surfaces of the various clutch
parts may face in directions that are parallel to the plane of the
drawing sheet, while the axis 10 is perpendicular to the plane of
the drawing sheet.
B(1). Example Clutch Mechanism of FIG. 2:
[0039] As shown in FIG. 2, the clutch part of the front sleeve 30'
may be in the form of an arm 32', and the clutch part of the rear
sleeve 40' may be in the form of a detent 42'. The arm 32' may be
mounted on the front sleeve 30' via a pin 33 so that the arm 32' is
pivotable about the pin 33. The front sleeve 30' may also include
two shoulders 34, 35 flanking the arm 32' and limiting the pivot
action of the arm 32' about the pin 33.
[0040] During a chuck actuation process (occasionally hereafter
also referred to as a "chuck actuation mode"), and when the tool
chuck 50 is not fully opened or closed (e.g., while the chuck jaws
are still opening or closing), the arm 32' may abut against the
detent 42', which in turn may influence the arm 32' to pivot about
the pin 33 and abut against one of the shoulders 34, 35. At this
time, the front sleeve 30' and the rear sleeve 40' may be
rotationally locked together. When the tool chuck fully closes
(with or without an inserted accessory) or fully opens, a
rotational force applied by the arm 32' to the detent 42' may
increase. Here, the rotational force may increase to a threshold at
which the detent 42' may be driven in a radial outward direction
(causing the rear sleeve 40' to elastically deform) so that the arm
32' may slide underneath and past the detent 42'. In this way, the
clutch mechanism may give way (or slip), thereby limiting the
torque that may be applied during the chuck actuation process.
[0041] The magnitude of the rotational force necessary to drive the
detent 42' in a radial outward direction may be affected by, for
example, the elastic properties of the material from which the rear
sleeve 40' is fabricated and the degree to which the working
surface of the arm 32' is inclined (or slanted) relative to a
radial reference line R extending from the axis 10. Consider the
incline of the working surface; the smaller the angle between the
working surface and the radial reference line R, the greater the
rotational force necessary to make the clutch mechanism slip. Put
differently, the steeper the working surface relative to a
circumferential reference line (which would be perpendicular to the
radial reference line R), the greater the rotational force
necessary to make the clutch mechanism slip.
[0042] As shown in FIG. 2, the shoulder 34 of the front sleeve 30'
may be higher (in a radial direction) than the shoulder 35. Thus,
as compared to the shoulder 34, the shoulder 35 may allow the arm
32' to pivot about the pin 33 to a greater extent (i.e., through a
greater angular displacement) from the radial reference line R.
Thus, when the arm 32' abuts against the shoulder 35 (as shown in
FIG. 2), the working surface of the arm 32' may be inclined
(relative to the radial reference line R) to a greater degree than
when the arm 32' abuts against the shoulder 34. In this way, the
rotational force (or torque threshold) causing the clutch mechanism
slip in a first direction (i.e., when the detent 42' slides over
the arm 32' abutted against the shoulder 35, as shown in FIG. 2)
may be less than the rotational force (or torque threshold) causing
the clutch mechanism slip in a second direction (i.e., when the
detent 42' slides over the arm 32' abutted against the should 34).
This torque threshold differential may be implemented so that a
given torque threshold for the chuck tightening process may be less
than a given torque threshold for the chuck loosening process.
[0043] Numerous modifications of the example clutch mechanism
depicted in FIG. 2 may be readily apparent to those skilled in this
art. For example, rather than being pivotable, the arm 32' may be
cantilevered from the front sleeve 30' and elastically deformable.
Here, the detent 42' may elastically bend the cantilevered arm 32'
against one of the shoulders 34, 35 so that the detent 42' may
slide over the cantilevered arm 32'. Since the shoulder 34 may be
higher (in a radial direction) than the shoulder 35, the shoulder
35 may provide less support for the cantilevered arm 32'. In this
way, the rotational force (or torque threshold) causing the clutch
mechanism slip in a first direction (i.e., when the detent 42'
elastically bends the cantilevered arm 32' toward the shoulder 35,
as shown in FIG. 2) may be less than the rotational force (or
torque threshold) causing the clutch mechanism slip in a second
direction (i.e., when the detent 42' elastically bends the
cantilevered arm 32' toward the shoulder 34).
B(2). Example Clutch Mechanism of FIG. 3:
[0044] As shown in FIG. 3, the clutch part of the front sleeve 30''
may be in the form of a raised feature 32'', and the clutch part of
the rear sleeve 40'' may be in the form of a detent 42''. The
raised feature 32'' may include two ramps 36, 37.
[0045] During a chuck actuation process, and when the tool chuck 50
is not fully opened or closed, the raised feature 32'' may abut
against the detent 42'' so that the front sleeve 30'' and the rear
sleeve 40'' may be rotationally locked together. When the tool
chuck fully closes or fully opens, a rotational force applied by
the raised feature 32'' to the detent 42'' may increase to a
threshold at which the detent 42'' may be driven in a radial
outward direction (causing the rear sleeve 40'' to elastically
deform) so that the raised feature 32'' may slide underneath and
past the detent 42''.
[0046] As shown in FIG. 3, a working surface of the ramp 36 may be
inclined (relative to the radial reference line R) to a greater
degree than a working surface of the ramp 37. In this way, the
rotational force (or threshold torque) causing the clutch mechanism
slip in a first direction (i.e., when the detent 42'' is driven in
a radial outward direction via the working surface of the ramp 36)
may be less than the rotational force (or threshold torque) causing
the clutch mechanism slip in a second direction (i.e., when the
detent 42'' is driven in a radial outward direction via the working
surface of the ramp 37). This threshold torque differential may be
implemented so that a given torque threshold for the chuck
tightening process may be less than a given threshold for the chuck
loosening process.
B(3). Example Clutch Mechanism of FIG. 4:
[0047] The example clutch mechanism of FIG. 4 is somewhat similar
to the one depicted in FIG. 3 to the extent that the clutch part of
the front sleeve 30''' may be in the form of a raised feature 32'''
including two ramps. Differences are discussed below.
[0048] As shown in FIG. 4, the clutch part of the rear sleeve 40'''
may be in the form of a detent 42''' that may be biased in a radial
inward direction by a compression spring 43. The compression spring
43 and the detent 42''' may be received in a pocket 41 of the rear
sleeve 40'''.
[0049] During a chuck actuation process, and when the tool chuck 50
is not fully opened or closed, the raised feature 32''' may abut
against the protrusion 42''' so that the front sleeve 30''' and the
rear sleeve 40''' may be rotationally locked together. When the
tool chuck fully closes or fully opens, a rotational force applied
by the raised feature 32''' to the protrusion 42''' may increase to
a threshold at which the protrusion 42''' may be driven in a radial
outward direction (and into the pocket 41) against the influence of
the compression spring 43 so that the raised feature 32''' may
slide underneath and past the detent 42'''. The compression spring
43 may then influence the detent 42''' to return to a radial inward
position (as shown in FIG. 4). In this example embodiment, the
clutch mechanism may slip without the rear sleeve 40'''
experiencing any elastic deformation.
[0050] As in the previous example embodiments, a threshold torque
differential may be implemented so that a given torque threshold
for the chuck tightening process may be less than a given threshold
for the chuck loosening process.
C. Example Operation:
[0051] The tool chuck 50 may operate differently depending on the
axial position of the rear sleeve 40. When the rear sleeve 40 is in
the axial forward position, as shown in FIG. 1, the power driver
may be operated in a normal operating mode. Here, the rear sleeve
40 may be rotatable relative to the front sleeve 30 since the
clutch parts 32, 42 may be disengaged (i.e., the clutch mechanism
is inactive). The rear sleeve 40 may also be rotatable relative to
the housing 90 of the driver since the lugs 44, 92 may be
disengaged. When the driver is powered up, the spindle 85 may
rotationally drive the chuck body 20, which in turn may
rotationally drive the chuck jaws 2. The chuck jaws 2 may rotate
together with the nut 16, the front sleeve 30, and the rear sleeve
40 due to friction between the component parts. Thus, the entire
tool chuck 50 may rotate together as a single unit.
[0052] An operator may push the rear sleeve 40 to the axial
rearward position and with sufficient force to compress the spring
25 so that the power driver may be operated in a chuck actuation
mode. Here, the front sleeve 30 and the rear sleeve 40 may be
rotationally locked together up to a given torque threshold via the
engagement of and interaction between the clutch parts 32, 42
(i.e., the clutch mechanism is active). Also, the rear sleeve 40
and the housing 90 may be rotationally locked together via the
engagement of the lugs 44, 92.
[0053] When the driver is powered up, the spindle 85 may
rotationally drive the chuck body 20, which may rotate together
with the chuck jaws 2. The chuck body 20 (and thus the chuck jaws
2) may rotate relative to the nut 16 and the front sleeve 30. This
is because the front sleeve 30 may remain rotationally locked to
rear sleeve 40 (via the clutch mechanism), and the rear sleeve 40
may remain rotationally locked to the housing 90 (via the lugs 44,
92). The relative rotation between the nut 16 and the chuck body 20
(and thus the chuck jaws 2) may drive the chuck jaws 2 opened or
closed (depending on the rotation direction of the spindle 85) by
virtue of the interaction between the radially inward facing
threads 18 and the radially outward facing threads 3.
[0054] As the tool chuck 50 reaches a fully opened or closed
position, the nut 16 may become tightened onto the jaw threads 3.
At this time, increased rotational forces may be transmitted from
the chuck body 20 (and the chuck jaws 2), through the nut 16, and
to the clutch part 32. The rotational force may increase to a
threshold at which the clutch mechanism may give way (or slip). In
this way, the clutch mechanism may limit the torque that may be
applied during the chuck actuation process.
[0055] The driver may be powered up in opposite rotational
directions to respectively tighten or loosen the tool chuck 50. In
this regard, and with reference to FIGS. 2-4, the tool chuck 50 may
be designed so that when tightened, the clutch mechanism may slip
in a direction so that the front sleeve rotates clockwise relative
to the rear sleeve. For example, the designer will appreciate that
the threads 3 of the chuck jaws 2 and the threads 18 of the nut 16
may be left-handed threads or right-handed threads to achieve the
desired chuck jaw actuation. In this way, a given torque threshold
for the chuck tightening process may be less than a given torque
threshold for the chuck loosening process. Once the clutch
mechanism slips, the operator may release the rear sleeve 40,
allowing the spring 25 to return the rear sleeve 40 to the forward
axial position.
II. Example Embodiment Depicted in FIGS. 5-9
[0056] FIGS. 5-9 show another example, non-limiting embodiment of a
tool chuck 150 that may be actuated with uniform torque and without
operator variability. In this example embodiment, the clutch
mechanism may be provided between the rear sleeve and the power
driver housing.
A. Example Structure:
[0057] With reference to FIG. 5, the tool chuck 150 may include a
chuck body 120. The rear end of the chuck body 120 may be fixedly
mounted on a spindle 185 of a power driver. The forward end of the
chuck body 120 may have passageways that slidably support a
plurality of chuck jaws (not illustrated). The chuck jaws and how
they interact with the nut (and the forward sleeve) may be similar
to that of the previous example embodiment. Accordingly, a detailed
discussion of the same is omitted herein for purposes of brevity.
As in the previous example embodiments, the invention may be
implemented with a variety chuck jaw types that may be opened and
closed through a relative rotation between tool chuck parts.
[0058] The chuck body 120 may support the front sleeve (not
illustrated) and a rear sleeve 140. The front sleeve and the rear
sleeve 140 may be coupled together so that the rear sleeve 140 is
axially moveable relative to the front sleeve and rotationally
fixed to the front sleeve. By way of example only, and not as a
limitation of the example embodiments of the present invention, the
front sleeve may include a longitudinal spline that is received by
a cooperating feature provided on the rear sleeve 140. Numerous and
varied couplings may be implemented as is known in this art.
[0059] The rear sleeve 140 may be supported so that it is axially
moveable relative to the chuck body 120 (and thus the front sleeve)
between an axial forward position and an axial rearward position.
In FIG. 5, the top half of the tool chuck 150 (i.e., above the axis
110) is illustrated with the rear sleeve 140 in the axial rearward
position, while the bottom half of the tool chuck 150 (i.e., below
the axis 110) is illustrated with the rear sleeve 140 in the axial
forward position. A compression spring 125 may be captured between
the rear sleeve 140 and the chuck body 120. The compression spring
125 may influence the rear sleeve 140 to the axial forward
position.
[0060] As will be discussed in more detail below, a clutch
mechanism (inclusive of two cooperating clutch parts 142, 192) may
be provided between the rear sleeve 140 and the power driver
housing 190. The clutch mechanism may rotationally lock the rear
sleeve 140 and the housing 190 together up to a given torque
threshold. Once the given torque threshold is reached, the clutch
mechanism may give way (or slip) to limit the torque that may be
applied during the chuck actuation process.
[0061] The rear end of the rear sleeve 140 may include legs 145
that project in an axial rearward direction. Each leg 145 may
include an intermediate section in which a groove 148 is provided.
Each groove 148 may have a bottom surface facing in a radial
outward direction. Each leg 145 may also have a distal end
supporting the clutch part 142.
[0062] The housing 190 may fixedly support a retainer 170. The
housing 190 may also support the clutch part 192 that may interact
with the clutch part 142 of the rear sleeve 140. The clutch part
192 may be rotationally fixed to the housing 190 and axially
moveable relative to the housing 190. To this end, the housing 190
and the clutch part 192 may be spline coupled together. Such spline
couplings (as well as other alternative couplings) are well known
in this art, and therefore a detailed description of the same is
omitted herein for purposes of brevity.
[0063] The clutch part 192 may be biased in an axial forward
direction by a spring mechanism 175. The spring mechanism 175
depicted in FIG. 5 may be in the form of a wave plate. However, the
example embodiments of the present invention are not limited in
this regard and other conventional spring mechanisms may be
implemented.
B. Example Clutch Mechanism:
[0064] The structural and functional aspects of the clutch
mechanism will become more apparent with reference to FIGS. 6-9,
which show example, non-limiting clutch parts that may be
implemented in the tool chuck 150 of FIG. 5.
[0065] FIG. 6 is an exploded perspective view of the retainer 170,
the clutch part 192, and the spring mechanism 175', all of which
may be mounted in the housing 190. The retainer 170 may include a
radial inward edge along which notches 171 and tabs 172 may be
alternately arranged. The retainer 170 may interact with the legs
145 of the rear sleeve 140 as follows. The notches 171 may
accommodate an axial movement of the legs 145. That is, when the
rear sleeve 140 is moved to (and from) the axial rearward position,
the legs 145 may slide in an axial direction through the notches
171 of the retainer 170. The tabs 172 may enter into the grooves
148 of the legs 145 when the rear sleeve 140 (positioned in the
axial rearward position) is rotated. In this way, the tabs 172 of
the retainer 170 may retain the rear sleeve 140 in the axial
rearward position.
[0066] In this example embodiment, the clutch part 192 may have one
side provided with a plurality of detents 193. The detents 193 may
project in an axial direction from the clutch part 192. The detents
193 may interact with the clutch part 142 of the rear sleeve 140.
In FIG. 6, the spring mechanism 175' may be in the form of a body
having one side that supports a plurality of compression springs
176. The compression springs 176 may abut against the clutch part
192. The example embodiments of the present invention are not
limited to a particular spring mechanism. For example, as noted
above, the spring mechanism may be in the form of a wave plate (as
shown in FIG. 5) or some other conventional spring mechanism.
[0067] In FIGS. 7-9, the rear sleeve is depicted in the axial
rearward position so that the clutch parts may be operatively
engaged. Further, the tabs 172 may be positioned in the grooves 148
of the legs 145 so that the retainer 170 may retain the rear sleeve
140 in the axial rearward position (against the influence of the
spring mechanism 175 and the compression spring 125).
B(1). Example Clutch Mechanism of FIG. 7:
[0068] As shown in FIG. 7, the clutch part of the rear sleeve may
be in the form of a raised feature 142' provided on the distal end
of the leg 145'. The raised feature 142' may include two ramps 136,
137. The raised feature 142' may interact with the detent 193' of
the clutch part 192' mounted in the housing.
[0069] During a chuck actuation process, and when the tool chuck
150 is not fully opened or closed (e.g., while the chuck jaws are
still opening or closing), the raised feature 142' may abut against
the detent 193' so that the rear sleeve and the housing may be
rotationally locked together. When the tool chuck fully closes
(with or without an inserted accessory) or fully opens, a
rotational force applied by the raised feature 142' to the detent
193' may increase. Here, the rotational force may increase to a
threshold at which the detent 193' (together with the clutch part
192') may be driven in an axial rearward direction (against the
influence of the spring mechanism) so that the raised feature 142'
may slide across and past the detent 193'. In this way, the clutch
mechanism may give way (or slip), thereby limiting the torque that
may be applied during the chuck actuation process.
[0070] The magnitude of the rotational force necessary to drive the
detent 193' in the axial rearward direction may be affected by, for
example, the strength of the spring mechanism 175 and the degree to
which the working surface of the raised feature 142' is inclined
(or slanted) relative to the axis 110. The smaller the angle
between the working surface and the axis 110, the greater the
rotational force necessary to make the clutch mechanism slip.
[0071] As shown in FIG. 7, a working surface of the ramp 136 may be
inclined (relative to the axis 110) to a greater degree than a
working surface of the ramp 137. In this way, the rotational force
(or threshold torque) causing the clutch mechanism slip in a first
direction (i.e., when the detent 193' is driven in the axial
rearward direction via the working surface of the ramp 136) may be
less than the rotational force (or threshold torque) causing the
clutch mechanism slip in a second direction (i.e., when the detent
193' is driven in the axial rearward direction via the working
surface of the ramp 137). This threshold torque differential may be
implemented so that a given torque threshold for the chuck
tightening process may be less than a given threshold for the chuck
loosening process.
B(2). Example Clutch Mechanism of FIG. 8:
[0072] As shown in FIG. 8, the clutch part of the rear sleeve may
be in the form of a raised feature 142'' provided on the distal end
of the leg 145''. The raised feature 142'' may include two
shoulders. The detent 193'' of the clutch part 192'' mounted in the
housing may include two ramps 196, 197.
[0073] During a chuck actuation process, and when the tool chuck
150 is not fully opened or closed, the raised feature 142'' may
abut against the detent 193'' so that the rear sleeve and the
housing may be rotationally locked together. When the tool chuck
fully closes or fully opens, a rotational force applied by the
raised feature 142'' to the detent 193'' may increase. Here, the
rotational force may increase to a threshold at which the detent
193'' may be driven in an axial rearward direction (against the
influence of the spring mechanism) so that the raised feature 142''
may slide across and past the detent 193''. In this way, the clutch
mechanism may give way (or slip), thereby limiting the torque that
may be applied during the chuck actuation process.
[0074] As shown in FIG. 8, a working surface of the ramp 196 may be
inclined (relative to the axis 110) to a lesser degree than a
working surface of the ramp 197. In this way, the rotational force
(or threshold torque) causing the clutch mechanism slip in a first
direction (i.e., when the detent 193'' is driven in the axial
rearward direction via the working surface of the ramp 196) may be
less than the rotational force (or threshold torque) causing the
clutch mechanism slip in a second direction (i.e., when the detent
193'' is driven in the axial rearward direction via the working
surface of the ramp 197). This threshold torque differential may be
implemented so that a given torque threshold for the chuck
tightening process may be less than a given threshold for the chuck
loosening process.
B(3). Example Clutch Mechanism of FIG. 9:
[0075] The example clutch mechanism of FIG. 9 is somewhat similar
to the example clutch mechanisms depicted in FIGS. 7 and 8.
Differences are discussed in detail hereafter. For example, as
shown in FIG. 9, the cooperating clutch parts 142''', 192''' may
have working surfaces with complementary profiles. Also, the
working surfaces of the clutch parts may be curved. The interaction
between the clutch parts 142''', 192''' may be similar to that
described above with respect to the examples illustrated in FIGS. 7
and 8.
C. Example Operation:
[0076] The tool chuck 150 may operate differently depending on the
axial position of the rear sleeve 140. When the rear sleeve 140 is
in the axial forward position, as shown in the bottom half of FIG.
5 (i.e., below the axis 110), the power driver may be operated in a
normal operating mode. Here, the rear sleeve 140 may be rotatable
relative to the housing 190 since the clutch parts 142, 192 may be
disengaged (i.e., the clutch mechanism is inactive). When the
driver is powered up, the spindle 185 may rotationally drive the
chuck body 120, which in turn may rotationally drive the chuck
jaws. The chuck jaws may rotate together with the nut, the front
sleeve, and the rear sleeve 140. Thus, the entire tool chuck 150
may rotate together as a single unit.
[0077] To achieve a chuck actuation mode, an operator may push the
rear sleeve 140 to the axial rearward position and with sufficient
force to compress the spring 125. As the rear sleeve 140 moves in
the axial rearward direction (relative to the front sleeve, the
chuck body 120, and the housing 190), the legs 145 may pass through
the notches 171 of the retainer 170. The legs 145 may penetrate
axially through the notches 171 by a sufficient distance so that
the clutch parts 142 of the legs may press the clutch part 192 of
the housing 190 in an axial direction against the influence of the
spring mechanism 175.
[0078] The operator may then turn the rear sleeve 140 so that the
tabs 172 of the retainer 170 may enter into the grooves 148 of the
legs 145, as shown in the top half of FIG. 5 (i.e., above the axis
110). At this time, the operator may release the rear sleeve 140,
which may remain in the axial rearward position by virtue of the
tabs 172 being inserted into the slots 148. In this condition, the
rear sleeve 140 and the housing 190 may be rotationally locked
together up to a given torque threshold via the engagement of and
interaction between the clutch parts 142, 192 (i.e., the clutch
mechanism is active).
[0079] When the driver is powered up, the spindle 185 may
rotationally drive the chuck body 120, which may rotate together
with the chuck jaws. The chuck body 120 (and thus the chuck jaws)
may rotate relative to the nut and the front sleeve. This is
because the front sleeve may remain rotationally locked to the rear
sleeve 140 (via the spline coupling), which in turn may remain
rotationally locked to the housing 190 (via the clutch mechanism).
The relative rotation between the nut and the chuck body 120 (and
thus the chuck jaws) may drive the chuck jaws opened or closed
(depending on the rotation direction of the spindle 185).
[0080] As the tool chuck 150 reaches a fully opened or closed
position, the nut may become tightened onto the chuck jaws. At this
time, increased rotational forces may be transmitted from the chuck
body 120 (and the chuck jaws), through the nut and the front
sleeve, and to the clutch part 142. The rotational force may
increase to a threshold at which the clutch mechanism may give way
(or slip). In this way, the clutch mechanism may limit the torque
that may be applied during the chuck actuation process.
[0081] The driver may be powered up in opposite rotational
directions to respectively tighten or loosen the tool chuck 150. In
this regard, and with reference to FIGS. 7-9, the tool chuck 150
may be designed so that when tightened, the clutch mechanism may
slip in a direction so that the legs 145', 145'', 145''' may move
to the left relative to the retainer 170. In this way, a given
torque threshold for the chuck tightening process may be less than
a given torque threshold for the chuck loosening process.
[0082] When the clutch mechanism slips, the rear sleeve 140 may
rotate relative to the housing 190 (and thus the retainer 170).
During this relative rotation, the legs 145 may enter into the
notches 171 of the retainer 170, and at the same time the tabs 172
of the retainer 170 may slide through and exit from the grooves 148
of the legs 145. Once the tabs 172 exit from the grooves 148, the
spring 125 may return the rear sleeve 140 to the axial forward
position. This may give the operator an audible and/or visual
indication that the chuck actuation process is complete.
III. Example Embodiment Depicted in FIGS. 10-15
[0083] FIGS. 10-15 show another example, non-limiting embodiment of
a tool chuck 250 that may be actuated with uniform torque and
without operator variability. In this example embodiment, the
clutch mechanism may be provided between an outer sleeve and the
power driver housing.
A. Example Structure:
[0084] With reference to FIG. 10, the tool chuck 250 may include a
chuck body 220. The rear end of the chuck body 220 may be fixedly
mounted on a spindle 285 of a power driver. The forward end of the
chuck body 220 may have passageways that slidably support a
plurality of chuck jaws 202. The chuck jaws 202 may be inclined so
that respective forward ends of the chuck jaws 202 converge toward
an axis 210 of the chuck body 220. The chuck jaws 202 may have
respective radially outward facing threads 203. The chuck jaws 202
may be actuated (i.e., advanced and/or retracted) via the radially
outward facing threads 203 interacting with radially inward facing
threads 218 of a nut 216. As in the previous example embodiments,
the invention may be implemented with a variety chuck jaw types (as
opposed to the illustrated "threaded" chuck jaws) that may be
opened and closed through a relative rotation between tool chuck
parts.
[0085] The chuck body 220 may support an inner sleeve 230 and an
outer sleeve 240. The inner sleeve 230 and the outer sleeve 240 may
be coupled together so that the outer sleeve 240 is axially
moveable relative to the inner sleeve 230 and rotationally fixed to
the inner sleeve 230. By way of example only, and not as a
limitation of the example embodiments of the present invention, the
inner sleeve 230 may include a longitudinal spline 231 that is
received by a cooperating feature 249 provided on the outer sleeve
240. Numerous and varied couplings between the inner and the outer
sleeves may be implemented as is known in this art.
[0086] The inner sleeve 230 may be supported so that it is axially
fixed to the chuck body 220 and rotatable relative to the chuck
body 220. The inner sleeve 230 may fixedly carry the nut 216. A
bearing 207 may be interposed between the nut 216 and the chuck
body 220 to facilitate a relative rotation between the nut 216 and
the chuck body 220.
[0087] The outer sleeve 240 may be supported so that it is axially
moveable relative to the chuck body 220 (and thus the inner sleeve
230) between an axial forward position and an axial rearward
position. In FIG. 10, the tool chuck 250 is illustrated with the
outer sleeve 240 in the axial forward position. A compression
spring 225 may be captured between the inner sleeve 230 and the
outer sleeve 240. The compression spring 225 may influence the
outer sleeve 240 to the axial forward position.
[0088] As will be discussed in more detail below, a clutch
mechanism (inclusive of two cooperating clutch parts 242, 292) may
be provided between the outer sleeve 240 and the housing 290 of the
driver. The clutch mechanism may rotationally lock the outer sleeve
240 and the housing 290 together up to a given torque threshold.
Once the given torque threshold is reached, the clutch mechanism
may give way (or slip) to limit the torque that may be applied
during the chuck actuation process.
[0089] The rear end of the outer sleeve 240 may support a latch
ring 260. The latch ring 260 may have a distal end with a cam
surface 262 facing in an axial rearward direction and a stop
surface 263 facing in an axial forward direction. The cam surface
262 may be inclined relative to the axis 210, while the stop
surface 263 may be perpendicular to the axis 210. The latch ring
260 may also include the clutch part 242.
[0090] The housing 290 may support the clutch part 292 that may
interact with the clutch part 242 of the outer sleeve 240. The
clutch part 292 may be rotationally fixed to the housing 290 and
moveable relative to the housing 290 in a radial direction. To this
end, the housing 290 may include a pocket 291 in which the clutch
part 292 is slidably provided. The clutch part 292 may be biased in
a radial outward direction via a spring mechanism 275. The spring
mechanism 275 depicted in FIG. 10 may be in the form of a leaf
spring, but the invention are not limited in this regard. For
example, the spring mechanism may be in the form of a wave plate, a
coil spring, an elastomeric member, or some other conventional
spring mechanisms may be implemented.
[0091] In this example embodiment, and turning briefly to FIG. 13,
the outer sleeve 240, the cooperating feature 249, and the latch
ring 260 may be provided as separate and distinct elements, and
this may facilitate assembly of the tool chuck 250. However, the
example embodiments of the present invention are not limited in
this regard since the outer sleeve 240, the cooperating feature
249, and the latch ring 260 may be of a unitary, one-piece
construction. Similarly, the nut 216, the inner sleeve 230, and the
spline 231 may be provided as separate and distinct elements, and
this may facilitate assembly of the tool chuck 250. However, the
example embodiments of the present invention are not limited in
this regard since the nut 216, the inner sleeve 230, and the spline
231 may be of a unitary, one-piece construction.
[0092] In this example embodiment, two clutch parts 292 may be
mounted on the housing 290. It will be appreciated, however, that
the example embodiments of the present invention are not limited to
any specific number of clutch parts 292. For example, a single
clutch part 292 (or more than two clutch parts 292) may be
implemented. Also, a single spring mechanism 275 may be provided to
bias all of the clutch parts 292 in the radial outward direction.
It will be appreciated, however, that additional spring mechanisms
275 may be implemented. For example, a spring mechanism 275 may be
individually provided for each of the clutch parts 292.
B. Example Clutch Mechanisms:
[0093] Structural and functional aspects of the clutch mechanism
may become more apparent with reference to FIGS. 11, 12, 14 and 15,
which show example, non-limiting clutch parts that may be
implemented in the tool chuck 250 of FIG. 10. In FIGS. 11, 12, 14,
and 15, the outer sleeve is depicted in the axial rearward position
so that the clutch parts may be operatively engaged. In this
condition, one clutch part 292 may be located radially inward of
the other clutch part 242. The working surfaces of the clutch parts
may face in directions that are perpendicular to the axis 210 of
the tool chuck 250.
B(1). Example Clutch Mechanism of FIGS. 11 and 12:
[0094] As shown in FIGS. 11 and 12, the clutch part of the outer
sleeve 240' may be in the form of a raised feature 242' provided on
the latch ring 260'. The raised feature 242' may include two ramps
236', 237'. The clutch part mounted in the housing 290' may be in
the form of a detent 292'.
[0095] During a chuck actuation process, and when the tool chuck
250 is not fully opened or closed (e.g., while the chuck jaws are
still opening or closing), the raised feature 242' may abut against
the detent 292' so that the rear sleeve 240' and the housing 290'
may be rotationally locked together. When the tool chuck fully
closes (with or without an inserted accessory) or fully opens, a
rotational force applied by the raised feature 242' to the detent
292' may increase. Here, the rotational force may increase to a
threshold at which the detent 292' may be driven in a radial inward
direction (and deeper into the pocket 291') against the influence
of the spring mechanism 275' so that the raised feature 242' may
slide across and past the detent 292'. In this way, the clutch
mechanism may give way (or slip), thereby limiting the torque that
may be applied during the chuck actuation process.
[0096] The magnitude of the rotational force necessary to drive the
detent 292' in the radial inward direction may be affected by, for
example, the strength of the spring mechanism 275' and the degree
to which the working surface of the raised feature 242' is inclined
(or slanted) relative to the radial reference line R. The smaller
the angle between the working surface and the radial reference line
R, the greater the rotational force necessary to make the clutch
mechanism slip.
[0097] As shown in FIG. 11, a working surface of the ramp 236' may
be inclined (relative to the radial reference line R) to a greater
degree than a working surface of the ramp 237'. In this way, the
rotational force (or threshold torque) causing the clutch mechanism
slip in a first direction (i.e., when the detent 292' is driven in
the radial inward direction via the working surface of the ramp
236') may be less than the rotational force (or threshold torque)
causing the clutch mechanism slip in a second direction (i.e., when
the detent 292' is driven in the radial inward direction via the
working surface of the ramp 237'). This threshold torque
differential may be implemented so that a given torque threshold
for the chuck tightening process may be less than a given threshold
for the chuck loosening process.
[0098] In this example embodiment, and with reference to FIG. 12,
the stop surface 263' of the latch ring 260' may press in an axial
forward direction against the axial rear end of the detent 292'.
The interaction between the stop surface 263' and the detent 292'
may not provide a cam action that would cause the detent 292' to
move in the radial inward direction against the influence of the
spring mechanism 275'. In this way, the detent 292' may retain the
outer sleeve 240' in the axial rearward position (and against the
influence of the compression spring 225). The rear sleeve 240' may
be axially retained in this fashion until the raised feature 242'
slides across the detent 292', thereby driving the detent 292' in a
radial inward direction and into the pocket 291'.
B(2). Example Clutch Mechanism of FIGS. 14 and 15:
[0099] As shown in FIGS. 14 and 15, the clutch part of the outer
sleeve 240'' may be in the form of a raised feature 242'' provided
on the latch ring 260''. The raised feature 242'' may include two
ramps 236'', 237''. The clutch part mounted in the housing may be
in the form of a detent 292''. The detent 292'' may have a
spherical shape.
[0100] During a chuck actuation process, and when the tool chuck
250 is not fully opened or closed, the raised feature 242'' may
abut against the detent 292'' so that the rear sleeve 240'' and the
housing may be rotationally locked together. When the tool chuck
fully closes or fully opens, a rotational force applied by the
raised feature 242'' to the detent 292'' may increase. Here, the
rotational force may increase to a threshold at which the detent
292'' may be driven in a radial inward direction against the
influence of the spring mechanism 275'' so that the raised feature
242'' may slide across and past the detent 292''. In this way, the
clutch mechanism may give way (or slip), thereby limiting the
torque that may be applied during the chuck actuation process.
[0101] As shown in FIG. 14, a working surface of the ramp 236'' may
be inclined (relative to the radial reference line R) to a greater
degree than a working surface of the ramp 237''. In this way, the
rotational force (or threshold torque) causing the clutch mechanism
slip in a first direction (i.e., when the detent 292'' is driven in
the radial inward direction via the working surface of the ramp
236'') may be less than the rotational force (or threshold torque)
causing the clutch mechanism slip in a second direction (i.e., when
the detent 292'' is driven in the radial inward direction via the
working surface of the ramp 237''). This threshold torque
differential may be implemented so that a given torque threshold
for the chuck tightening process may be less than a given threshold
for the chuck loosening process.
[0102] In this example embodiment, and with reference to FIG. 15,
the stop surface 263'' of the latch ring 260'' may be contiguous
with the ramps 236'', 237'' of the raised feature 242''. For
example, the latch ring 260'' may be provided with a groove that
defines the ramps 236'', 237'' and the stop surface 263''. Here, a
radial inward facing wall of the groove may define the ramps 236'',
237'', while an axial forward facing wall of the groove may define
the stop surface 263''. In FIG. 15, the groove may extend into the
plane of the drawing sheet.
[0103] The stop surface 263'' may press in an axial forward
direction against the axial rear end of the detent 292''. The
interaction between the stop surface 263'' and the detent 292'' may
not provide a cam action that would cause the detent 292'' to move
in the radial inward direction against the influence of the spring
mechanism 275''. In this way, the detent 292'' may retain the outer
sleeve 240'' in the axial rearward position (and against the
influence of the compression spring 225). The rear sleeve 240'' may
be axially retained in this fashion until the raised feature 242''
slides across the detent 292'', thereby driving the detent 292'' in
a radial inward direction.
C. Example Operation:
[0104] The tool chuck 250 may operate differently depending on the
axial position of the outer sleeve 240. When the outer sleeve 240
is in the axial forward position, as shown in FIG. 10, the power
driver may be operated in a normal operating mode. Here, the outer
sleeve 240 may be rotatable relative to the housing 290 since the
clutch parts 242, 292 may be disengaged (i.e., the clutch mechanism
is inactive).
[0105] As the driver is powered up, the spindle 285 may
rotationally drive the chuck body 220, which in turn may
rotationally drive the chuck jaws 202. The chuck jaws 202 may
rotate together with the nut 216, the inner sleeve 230, and the
outer sleeve 240. Thus, the entire tool chuck 250 may rotate
together as a single unit.
[0106] To achieve a chuck actuation mode, an operator may push the
outer sleeve 240 to the axial rearward position and with sufficient
force to compress the spring 225. As the outer sleeve 240 moves in
the axial rearward direction (relative to the inner sleeve 230, the
chuck body 220, and the housing 290), the cam surface 262 of the
latch ring 260 may slide over the clutch part 292, thereby driving
the clutch part 292 in the radial inward direction against the
influence of the spring mechanism 275. Eventually, the stop surface
263 of the latch ring 260 may move in the axial rearward direction
beyond the clutch part 292. At this time, the spring mechanism 275
may drive the clutch part 292 in the radial outward direction and
into engagement with the clutch part 242 (as shown in FIG. 12 or
FIG. 15, for example).
[0107] When the clutch parts 292, 242 engage, the operator may
release the outer sleeve 240. The outer sleeve 240 may remain in
the axial rearward position by virtue of the clutch part 292
abutting against the stop surface 263 of the latch ring 260. In
this condition, the outer sleeve 240 and the housing 290 may be
rotationally locked together up to a given torque threshold via the
engagement of and interaction between the clutch parts 242, 292
(i.e., the clutch mechanism is active).
[0108] When the driver is powered up, the spindle 285 may
rotationally drive the chuck body 220, which may rotate together
with the chuck jaws 202. The chuck body 220 (and thus the chuck
jaws 202) may rotate relative to the nut 216 and the inner sleeve
230. This is because the inner sleeve 230 may remain rotationally
locked to the outer sleeve 240 (via the spline 231 and the
cooperating feature 249), which in turn may remain rotationally
locked to the housing 290 (via the clutch mechanism). The relative
rotation between the nut 216 and the chuck body 220 (and thus the
chuck jaws 202) may drive the chuck jaws 202 opened or closed
(depending on the rotation direction of the spindle 285).
[0109] As the tool chuck 250 reaches a fully opened or closed
position, the nut 216 may become tightened onto the chuck jaws 202.
At this time, increased rotational forces may be transmitted from
the chuck body 220 (and the chuck jaws 202), through the nut 216
and the inner sleeve 230, and to the clutch part 242. The
rotational force may increase to a threshold at which the clutch
mechanism may give way (or slip). In this way, the clutch mechanism
may limit the torque that may be applied during the chuck actuation
process.
[0110] The driver may be powered up in opposite rotational
directions to respectively tighten or loosen the tool chuck 250.
Accordingly, as in the previous example embodiments, a given torque
threshold for the chuck tightening process may be less than a given
torque threshold for the chuck loosening process.
[0111] When the clutch mechanism slips, the outer sleeve 240 (and
thus the latch ring 260) may rotate relative to the housing 290.
During this relative rotation, the clutch part 292 may be driven in
the radial inward direction (via the clutch part 242). The clutch
part 292 may separate from the stop surface 263 so that the spring
225 may return the rear sleeve 240 to the forward axial position.
This may give the operator an audible and visual indication that
the chuck actuation process is complete.
[0112] FIG. 16 illustrates a clutch ring mechanism adapted as a
user interface for controlling a power drill driver motor for
accessory retention/disengagement. The clutch ring mechanism to be
described in further detail below may be applicable to any of the
example tool chuck with clutch mechanisms as shown and described in
FIGS. 1-15. Referring to FIG. 16, a clutch ring 410 on a power
drill driver 400 may be used as user control for engaging or
disengaging the drill's motor to provide bit retention. For
purposes of explanation only, the following modes will be
described: tighten mode, drilling mode and accessory release mode.
In this example, the accessory may be a drill bit, although the
example embodiments are not so limited.
[0113] In the tighten mode, with a user's finger off of the trigger
420, the use may pull back the clutch ring 410 (which may be spring
loaded, for example), so as to engage a mechanical linkage 430
(shown in FIG. 16 as a shaft running longitudinally with the tool,
although this is merely one example of a linkage 430). As the
clutch ring 410 is pulled back (shown by arrow 437), linkage 430
moves rearward against a spring 435, so as to prevent the chuck 440
from rotating. For example, the linkage 430 mechanically grounds
the sleeve (such as any of the outer sleeves 40, 140, 240, etc.
shown here above), through the clutch mechanism, to the body of the
tool before the switch contacts are made. Linkage 430 also may be
adapted to bypass trigger 420 so as to possibly lock out the
trigger 420 (not shown for purposes of clarity). As the clutch ring
410 is fully pulled back (depressed), the linkage 430 closes a
contact 445 on the tool's switch 450 to start the tool motor,
tightening the bit within jaws 442 of the chuck 440.
[0114] In an example, and to provide audible feedback that the
clutch mechanism (not shown, but any of the clutch mechanisms shown
in FIGS. 1-15) is working as desired, a ratcheting noise may be
emitted from the tool 400 during the time elapsed as the bit is
being tightened (typically a few seconds), as is known to one of
ordinary skill in this art. Once the bit is tightened, the user
releases the clutch ring 410 so that the clutch ring 410 returns to
a neutral position. With the clutch ring in a neutral position
(drilling mode), the torque on the chuck 440 may be adjusted as
desired and the trigger 420 depressed for typical drill driver 400
power operations in a drilling mode.
[0115] In a bit release mode, the user may push or slide the clutch
ring 410 forward toward chuck 440, so as to lock out trigger 420.
Linkage 430 may be extended in direction 439 to close a second
contact 447 on the tool's switch 450 to reverse the motor, opening
jaws 442 to release the bit. No trigger 420 action is necessary for
bit disengagement.
[0116] The push/pull action of the clutch ring 410 is thus
intuitive for ease of use and understanding. Because the chuck 440
is prevented from rotation for either locking or unlocking a bit,
the chuck 440 does not need to be gripped tightly during rotation,
providing additional user comfort. Since one hand of the user is on
the tool handle 460 and the other manipulating the clutch ring 410,
bit retention is possible without requiring a tight grip on a
rotating clutch ring 410, potentially improving the securing of the
bit within the jaws 442 of the chuck 440
IV. Example Embodiment Depicted in FIGS. 17A-17B
[0117] FIGS. 17A and 17B show another example, non-limiting
embodiment of a tool chuck 350 with clutch mechanism that may be
actuated with uniform torque and without operator variability. In
this example embodiment, the chuck sleeve does not move axially;
rather the clutch mechanism moves axially to engage an axially
fixed sleeve 340. FIGS. 17A and 17B thus illustrate another example
clutch mechanism which may provide consistent tightening on a chuck
body 320, so as to prevent inadvertent loosening of the chuck jaws
302 caused by contact between a chuck sleeve 340 and the work
piece.
[0118] In previous example embodiments as shown in FIGS. 1-15, one
of an inner and/or outer sleeve moves axially to engage a clutch
mechanism which grounds the sleeve to the tool housing, allowing
the chuck jaws to be loosened or tightened. The clutch mechanism
then releases the sleeve at a given torque setting. In some
applications, it may be possible for the user to cause the chuck
body to contact the work piece such that the sleeve would move,
causing it to inadvertently engage the clutch mechanism. However,
as will be shown in FIGS. 17A and 17B, the sleeve does not move
axially, but rather the clutch mechanism moves axially forward to
engage a fixed sleeve in an effort to prevent inadvertent loosening
or tightening of the chuck jaws.
[0119] FIG. 17A illustrates a tool chuck 350 with clutch mechanism
(comprised of clutch part 342 and cooperating clutch part 392)
shown as disengaged. In FIG. 17A, the tool chuck 350 may include a
chuck body 320. The rear end of the chuck body 220 may be fixedly
mounted on a spindle 385 of a power driver. The forward end of the
chuck body 320 may have passageways that slidably support a
plurality of chuck jaws 302. The chuck jaws 302 may be inclined so
that respective forward ends of the chuck jaws 302 converge toward
an axis 310 of the chuck body 320. The chuck jaws 302 may have
respective radially outward facing threads 303. The chuck jaws 302
may be actuated (i.e., advanced and/or retracted) via the radially
outward facing threads 303 interacting with radially inward facing
threads 318 of a nut 316. As in the previous example embodiments,
the invention may be implemented with a variety of chuck jaw types
(as opposed to the illustrated "threaded" chuck jaws) that may be
opened and closed through a relative rotation between tool chuck
parts.
[0120] Unlike the previous example embodiments, the chuck body 320
supports only a single outer sleeve 340, which remains fixed to the
chuck body 320 and does not slide axially. Sleeve 340 may fixedly
carry the nut 316. A bearing 307 may be interposed between the nut
316 and the chuck body 320 to facilitate a relative rotation
between the nut 316 and the chuck body 320.
[0121] FIG. 17B shows the clutch mechanism in an engaged position.
Referring to both FIGS. 17A and 17B, the clutch mechanism may
include a clutch part 342 interfacing a cooperating clutch part
392, which may be referred to as a latch pawl 392. Unlike previous
example embodiments, the clutch mechanism housing 395 may be keyed
to the front of the tool housing 390 using splines 341, allowing
the latch pawl 392 of the clutch mechanism to move axially to
engage a latch ring 360 while preventing rotation of the clutch
mechanism housing 395 relative to the tool housing 390, as shown in
FIG. 17B.
[0122] Further as shown with reference to both FIGS. 17A and 17B,
when the latch pawl 392 is moved forward axially against a bias
spring 325 to engage the chuck body 320, the latch pawl 392 may be
pushed radially inward against a pawl spring 375 into the clutch
mechanism housing 395, as shown in FIG. 17A. As the clutch
mechanism housing 395 continues to move axially towards the chuck
body 320, the latch pawl 392 springs outward radially to engage the
recesses or pockets 391 in the latch ring 360. The tool motor can
then be run forward/reverse as needed to loosen/tighten the chuck
jaws 302. At a given torque, the latch pawl 392 may slip out of the
latch ring pockets 391, and the bias spring 325 returns the clutch
mechanism housing 395 to the disengaged position. The clutch
mechanism may be actuated by a sliding button or rotating sleeve
with cam surface, or other user desired means as would be evident
to one skilled in the art.
[0123] Desired clearance between splines 341 on the tool housing
390 and splines (not shown) on the clutch mechanism housing 395 may
be provided to permit limited rotation of the clutch mechanism
housing 395 relative to the tool housing 390. This may assist
ensuring a desired engagement of the latch pawl 392 and latch ring
pocket 391 without rotation of either the chuck body 320 or the
sleeve 340.
[0124] The example clutch mechanism in tool chuck 350 may thus
provide a simple, intuitive operation, potentially achieving
improved tightening and loosening torque to the chuck 350 than a
user can apply using a conventional method of gripping a chuck
sleeve while turning on the motor. The example embodiment shown in
FIGS. 17A and 17B may thus be adapted to apply consistent
tightening torque to prevent the chuck jaws 302 from being
over-tightened. Further, the example embodiment may be adapted to
existing tool designs without a complete re-design of the tool
transmission.
[0125] FIGS. 18A and 18B illustrate a locking mechanism for a tool
chuck in accordance with an example embodiment of the present
invention. The locking mechanism to be described may be applicable
to any of the aforementioned tool chucks described in FIGS. 1-15
and 17A-17B which includes a chuck sleeve configured for sliding
and/or axial movement. FIG. 18A illustrates a tool chuck 550 in an
example `chuck actuation mode`, and FIG. 18B illustrates the tool
chuck 550 locked in an example `drilling/screwing Mode`. Several
features of the chuck mechanism as shown in detail in any of FIGS.
1-15, 17A and/or 17B have been removed for purposes of clarity.
[0126] Referring now to FIG. 18A, tool chuck 550 is shown with
chuck body 520 attached to spindle 585. A clutch part of a front
sleeve 530' may be in the form of a raised feature 532, and a
clutch part of a rear sleeve 540 may be in the form of a detent
542, for example. During a chuck actuation process, and when the
tool chuck 550 is not fully opened or closed, the raised feature
532 may abut against the detent 542 so that the front sleeve 530
and the rear sleeve 540 may be rotationally locked together. When
the tool chuck fully closes or fully opens, a rotational force
applied by the raised feature 532' to the detent 542 may increase
to a threshold at which the detent 542 may be driven in a radial
outward direction (causing the rear sleeve 540 to elastically
deform) so that the raised feature 532 may slide underneath and
past the detent 542.
[0127] Thus, once the chuck 550 has been tightened, the clutch part
532 of sleeve 530 disengages clutch part 542 of sleeve 540 and
sleeve 530 and is urged forward due to compressive spring 525.
However, since the rear of the chuck body 520 includes recesses
522, these recesses 522 receive a forward detent portion 532' of
raised feature 532, so as to engage the detent portions 532' to
prevent relative motion between the sleeve 530 and the chuck body
520. If desired, surfaces within the recesses 522 and on the detent
portions 532' may have a tooth-like profile so as to facilitate
engagement. Accordingly, the example locking methodology locks the
chuck 550 in a relatively simple design that is automatic.
[0128] Although the corresponding shapes of the recesses 522 and
detent portions 532' are shown as generally rectangular, it would
be evident to one skilled in the art to fashion the shapes of the
recesses and detent portions in a different shape to facilitate
connective engagement as a locking mechanism.
[0129] FIG. 19 illustrates a spring-loaded actuator for providing
consistent tightening on an example tool chuck in accordance with
an example embodiment of the present invention. Referring to FIG.
19, an example portion of a spring-loaded actuator 600 is shown,
which may be adapted for inclusion as part of any of the example
tool chucks (50, 150, 250, 350, etc.) shown hereinabove.
[0130] For example, an axially spring-loaded actuator 600 may
operate the tool motor to loosen or tighten the chuck jaws (i.e.,
jaws 2, 102, 202, 302, etc.) of the tool chuck. The actuator 600
may be mechanically connected to a forward-off-reverse slide switch
610 that electrically connects the motor to the battery or line
cord. Actuator 600 may also be mechanically connected to a
`tightening` sleeve, such as a portion of the outer sleeve 640
shown in FIG. 19, through any of the example clutch mechanisms
described above.
[0131] To loosen the chuck jaws, the actuator 600 may be pushed
forward (shown at 615) towards a tool accessory such as a drill
bit. The actuator 600 first engages the clutch mechanism (not
shown) and grounds the sleeve 640 to the tool housing (such as
housing 90 in FIG. 1, housing 390 in FIG. 17A, etc., for example).
Continued forward motion of the actuator 600 then moves the slide
switch 610 to a reverse position, turning on the motor to power the
jaws open.
[0132] To tighten the chuck jaws, the actuator may be pulled back
(see arrow 625) away from the drill bit. The actuator 600 again
engages the clutch mechanism and grounds the sleeve 640 to the tool
housing 90. Continued backwards motion of the actuator moves the
slide switch 610 to the forward position, turning on the motor to
tighten the jaws. It is evident to one skilled in the art that the
actuator 600 may be configured so that pushing the actuator 600
forward tightens the chuck jaws and pulling back the actuator 600
loosens the jaws. Further, and as described in previous example
embodiments, the clutch mechanism may rotationally lock the inner
and outer sleeves together until a given torque threshold is
reached, upon which the clutch mechanism may give way (or slip) to
prevent excessive torque from being applied to the chuck tightening
mechanism. The clutch mechanism may also be configured in an effort
to assure that the torque available to tighten the jaws is less
than the torque available to loosen the jaws.
[0133] Although the actuator 600 shown in FIG. 19 may be embodied
by a slide button 605, it is evident to one skilled in the art to
use a collar, switch or other equivalent type of mechanism may be
used for actuator 600.
[0134] Accordingly, use of a spring-loaded actuator 600 may provide
a simple, intuitive operation, providing higher tightening and
loosening torque to the tool chuck than what the user may be able
to apply using conventional methodologies of gripping a keyless
chuck sleeve while turning on motor. The chuck may apply consistent
tightening torque, and may be configured to prevent the chuck jaws
from being over-tightened. Further, the actuator of FIG. 19 may be
adapted to existing tool designs without a complete re-design of
the power tool transmission.
[0135] Several example clutch mechanism have been described above.
The example embodiments of the present invention are not, however,
limited to the specific details of the disclosed example clutch
mechanisms. Numerous and varied modifications of the clutch
mechanisms may become readily apparent to those skilled in the
art.
[0136] For example, the respective locations of the cooperating
clutch parts may be reversed. For example, and with respect to the
clutch mechanisms depicted in one or more of FIGS. 2-4, the clutch
parts provided on the front sleeve may instead be provided on the
rear sleeve, and the clutch parts provided on the rear sleeve may
instead be provided on the front sleeve. Similarly, and with
respect to the clutch mechanisms depicted in one or more of FIGS.
7-9, 11, 12, 14 and 15, the clutch parts provided on the rear
sleeve (or outer sleeve) may instead be provided on the housing,
and the clutch parts provided on the housing may instead be
provided on the rear sleeve (or outer sleeve).
[0137] Additionally, the clutch parts are not limited to the
specific geometrical shapes illustrated in one or more of FIGS.
2-4, 7-9, 11, 12, 14 and 15. In this regard, numerous and
alternative shapes may be implemented. For example, the clutch
parts may have symmetrical or asymmetrical shapes. The working
surfaces of the clutch parts may be planar and/or curved. The
cooperating clutch parts may have working surfaces with
complementary profiles or different profiles.
[0138] Further, the example embodiments of the present invention
are not limited to a specific number of clutch part elements. For
example, a clutch part may include one or more detents, arms,
raised features, etc. When a clutch part includes more than one
clutch part element, it may be desirable to uniformly space the
clutch part elements around the axis of the tool chuck, but the
example embodiments of the present invention are not limited in
this regard. Also, the number of clutch part elements of one clutch
part may or may not equal the number of clutch part element of the
cooperating clutch part.
* * * * *