U.S. patent application number 09/736762 was filed with the patent office on 2001-08-23 for locking chuck.
Invention is credited to Barton, Christopher B., Buck, William C., Steadings, Stephen W..
Application Number | 20010015530 09/736762 |
Document ID | / |
Family ID | 22233789 |
Filed Date | 2001-08-23 |
United States Patent
Application |
20010015530 |
Kind Code |
A1 |
Steadings, Stephen W. ; et
al. |
August 23, 2001 |
Locking chuck
Abstract
A chuck for use with a manual or powered driver having a housing
and a rotatable drive shaft extending therefrom is provided. The
chuck includes a generally cylindrical body member having a nose
section and a tail section. Each of a plurality of jaws is slidably
positioned in one of a plurality of angularly disposed passageways
in the body. Each jaw has a jaw face formed on one side thereof and
threads formed on the opposite side thereof. A nut is rotatably
mounted on the body in engagement with the jaw threads so that
rotation of the nut moves the jaws axially within the passageways.
A locking member, in a first axial position, is rotatable with
respect to the driver housing. In a second axial position, it
operatively engages the housing and the nut so that the locking
member is rotationally held to the housing and the nut so that the
nut is rotationally held to the housing. The locking member is
axially reciprocal between the first axial position and the second
axial position.
Inventors: |
Steadings, Stephen W.;
(Seneca, SC) ; Buck, William C.; (Clemson, SC)
; Barton, Christopher B.; (Seneca, SC) |
Correspondence
Address: |
NELSON MULLINS RILEY & SCARBOROUGH, LLP
1330 Lady Street
Columbia
SC
29201
US
|
Family ID: |
22233789 |
Appl. No.: |
09/736762 |
Filed: |
December 13, 2000 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09736762 |
Dec 13, 2000 |
|
|
|
09593726 |
Jun 13, 2000 |
|
|
|
6179301 |
|
|
|
|
09593726 |
Jun 13, 2000 |
|
|
|
09092552 |
Jun 5, 1998 |
|
|
|
6073939 |
|
|
|
|
Current U.S.
Class: |
279/62 ; 279/140;
279/902 |
Current CPC
Class: |
Y10T 279/32 20150115;
Y10S 279/902 20130101; B23B 31/1238 20130101; B23B 2231/44
20130101; B23B 2231/06 20130101; Y10T 279/17632 20150115; B23B
31/123 20130101; Y10T 408/953 20150115; B23B 2231/38 20130101 |
Class at
Publication: |
279/62 ; 279/140;
279/902 |
International
Class: |
B23B 031/12 |
Claims
What is claimed is:
1. A chuck for use with a manual or powered driver having a housing
and a rotatable drive shaft extending therefrom, said chuck
comprising: a generally cylindrical body having a nose section and
a tail section configured to rotate with said drive shaft, said
nose section having an axial bore formed therein and a plurality of
angularly disposed passageways formed therethrough and intersecting
said axial bore; a plurality of jaws slidably positioned in each of
said angularly disposed passageways, each of said jaws having a jaw
face formed on one side thereof and threads formed on the opposite
side thereof; a nut rotatably mounted on said body in engagement
with said threads on said jaws so that rotation of said nut moves
said jaws axially within said passageways; a sleeve disposed about
said body, wherein said sleeve is rotationally held to said
housing; and a clutch disposed operatively between said nut and
said sleeve, wherein said clutch, in a first position with respect
to said sleeve and said nut, rotationally holds said nut with
respect to said sleeve, and wherein said clutch, in a second
position with respect to said sleeve and said nut, rotationally
disengages said nut and said sleeve.
2. The chuck as in claim 1, wherein said clutch includes an annular
ring axially reciprocally disposed about said body, wherein said
annular ring and said nut include respective angled engaging
surfaces disposed so that rotational force between said annular
ring and said nut is applied at said engaging surfaces, wherein
said chuck includes a spring in engagement with said annular ring
and biasing said annular ring toward said nut, wherein said
engaging surfaces are angled so that said rotational force urges
said nut and said annular ring apart, and wherein said spring
biases said annular ring so that said annular ring remains
rotationally held to said nut until said rotational force reaches a
predetermined level forcing said engaging surfaces to pass over
each other.
3. The chuck as in claim 2, wherein said sleeve is selectively
adjustable with respect to said housing between two positions, and
wherein said sleeve is rotationally held with respect to said
housing in a first said position and is rotatable with respect to
said housing in a second said position.
4. The chuck as in claim 3, including a detent disposed on said
body in communication with said sleeve so that said detent retains
said sleeve in either of said first position and said second
position.
5. The chuck as in claim 2, wherein said spring is disposed
operationally between said nut and said body.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to chucks for use
with drills or with electric or pneumatic power drivers. More
particularly, the present invention relates to a chuck of the
keyless type which may be tightened or loosened by hand.
[0002] Both hand and electrical or pneumatic tool drivers are well
known. Although twist drills are the most common tools on such
drivers, the tools may also comprise screw drivers, nut drivers,
burrs, mounted grinding stones, and other cutting or abrading
tools. Since the tool shank may be of varying diameter or of
polygonal cross section, the device is usually provided with a
chuck that is adjustable over a relatively wide range. The chuck
may be attached to the driver by a threaded or tapered bore or any
other suitable means.
[0003] A variety of chuck types have been developed that are
actuated by relative rotation between a chuck body and an annular
nut. In a typical oblique jawed chuck, for example, a body member
includes three passageways disposed approximately 120.degree. apart
from each other. The passageways are configured so that their
center lines meet at a point along the chuck axis forward of the
chuck body. Three jaws are constrained by and movable in the
passageways to grip a cylindrical tool shank disposed approximately
along the chuck center axis. The nut rotates about the chuck's
center and engages threads on the jaws so that rotation of the nut
moves the jaws in either direction in the passageways. The body and
nut are configured so that rotation of the nut in one direction
(the closing direction) with respect to the body forces the jaws
into gripping relationship with the tool shank, while rotation in
the opposite direction (the opening direction) releases the
gripping relationship. Such a chuck may be keyless if it is rotated
by hand. Examples of such chucks are disclosed in U.S. Pat. Nos.
5,125,673 and 5,193,824, commonly assigned to the present assignee
and the entire disclosure of each of which is incorporated by
reference herein. Various configurations of keyless chucks are
known in the art and are desirable for a variety of
applications.
[0004] Keyless chucks actuated by relative rotation between a nut
and a chuck body include means to control the rotational position
of the nut and the body. For example, a first sleeve may be
provided in communication with the nut while a second sleeve, which
is independent of the first sleeve, may be attached to the body.
Thus, a user may rotate the first sleeve with one hand while
gripping the second sleeve with the other hand, thereby holding the
body still. Alternatively, in some devices in which only a single
sleeve is provided, a user may grip the single sleeve and actuate
the tool driver to rotate the spindle, thereby rotating the chuck
body with respect to the sleeve. In addition, a mechanism may be
located in a driver to lock the spindle of the driver when the
driver is not actuated, thus enabling use of a single sleeve
chuck.
SUMMARY OF THE INVENTION
[0005] The present invention recognizes and addresses the foregoing
considerations, and others, of prior art constructions and
methods.
[0006] Accordingly, it is an object of the present invention to
provide an improved chuck.
[0007] It is a further object of the present invention to provide
an improved drill.
[0008] It is a still further object of the present invention to
provide a chuck having an improved mechanism for loosening and
tightening the chuck.
[0009] These and other objects are achieved by a chuck for use with
a manual or powered driver having a housing and a rotatable drive
shaft extending therefrom. The chuck includes a generally
cylindrical body member having a nose section and a tail section.
The tail section is configured to mate with the drive shaft so that
the body rotates with the drive shaft. The nose section has an
axial bore formed therein and a plurality of angularly disposed
passageways formed therethrough and intersecting the axial bore.
Each of a plurality of jaws is slidably positioned in one of the
annularly disposed passageways. Each of the jaws has a jaw face
formed on one side thereof and threads formed on the opposite side
thereof. A nut is rotatably mounted on the body in engagement with
the threads on the jaws so that rotation of the nut moves the jaws
axially within the passageways. A locking member is, in a first
axial position, rotatable with respect to the driver housing. In a
second axial position, it operatively engages the housing and the
nut so that the locking member is rotationally held to the housing
and to the nut so that the nut is rotationally held to the housing.
The locking member is axially reciprocal between the first axial
position and the second axial position.
[0010] In another preferred embodiment, a chuck includes a
generally cylindrical body member having a nose section and a tail
section. The tail section is configured to mate with the drive
shaft so that the body rotates with the drive shaft. The nose
section has an axial bore formed therein and a plurality of
angularly disposed passageways formed therethrough and intersecting
the axial bore. Each of a plurality of jaws is slidably positioned
in one of the angularly disposed passageways. Each jaw has a jaw
face formed on one side thereof and threads formed on the opposite
side thereof. A nut is rotatably mounted on the body in engagement
with the threads on the jaws so that rotation of the nut moves the
jaws axially within the passageways. The chuck also includes an
axially reciprocal sleeve and a clutch mechanism disposed
operatively between the body and the nut. The sleeve is
rotationally held to, and axially movable with respect to, the
clutch mechanism in at least one axial position of the sleeve. The
clutch mechanism and the nut include respective engaging surfaces
disposed so that the clutch mechanism and the nut are rotationally
held to each other when engaged by a rotational force applied at
the engaging surfaces by at least one of the clutch mechanism and
the nut and so that the clutch mechanism is urged axially away from
the nut upon application of the rotational force. A biasing
mechanism is in operative communication with the clutch mechanism
and opposes axial movement of the clutch mechanism away from the
nut. The biasing mechanism is configured with the clutch mechanism
to resist disengagement of the engaging surfaces until the
rotational force exceeds a predetermined level.
[0011] Other objects, features and aspects of the present invention
are discussed in greater detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] A full an enabling disclosure of the present invention,
including the best mode thereof to one of ordinary skill in the
art, is set forth more particularly in the remainder of the
specification,
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] Reference will now be made in detail to presently preferred
embodiments of the invention, one or more examples of which are
illustrated in the accompanying drawings. Each example is provided
by way of explanation of the invention, not limitation of the
invention. In fact, it will be apparent to those skilled in the art
that modifications and variations can be made in the present
invention without departing from the scope or spirit thereof. For
instance, features illustrated or described as part of one
embodiment may be used on another embodiment to yield a still
further embodiment. Thus, it is intended that the present invention
covers such modifications and variations as come within the scope
of the appended claims and their equivalents.
[0014] In the embodiments illustrated in the figures, a drill chuck
has a body configured for attachment to a drill spindle and having
passages in which jaws are held. The jaws reciprocally move (in
either an opening or closing direction) by a threadedly engaged
nut. In these embodiments, a locking member in the form of a
generally cylindrical sleeve is axially moveable to either of two
positions. In the first position, the sleeve rotates with respect
to the drill housing. In the second position, it is rotationally
held to the housing and to the nut. That is, the locking sleeve
does not rotate with respect to the housing or to the nut. In the
embodiment shown in FIGS. 1-4, the locking sleeve remains in the
second position throughout opening and closing of the chuck once
the operator moves the locking sleeve into the appropriate
position. In the embodiments shown in FIGS. 6A-9, however, the
locking sleeve is held to the nut through a clutch mechanism that
rotationally locks the sleeve and housing to the nut as long the
clutch mechanism or nut does not substantially resist the
rotational torque applied by the other component, as is described
in more detail below. When the resistance does overcome this
torque, the nut teeth and clutch teeth slip over each other,
allowing the nut to rotate with the body with respect to the
locking sleeve, thereby preventing over tightening. It should be
understood, however, that the present invention is not limited to
such embodiments.
[0015] Referring to FIGS. 1-4, a chuck 10 includes a front sleeve
12, a body 14, jaws 16 and a nut 18. Body 14 is generally
cylindrical in shape and comprises a nose or forward section 20 and
a tail or rearward section 22. An axial bore 24 is formed in nose
section 20. Axial bore 24 is dimensioned somewhat larger than the
largest tool shank that the chuck is designed to accommodate. A
threaded bore 26 is formed in tail section 22 and is of a standard
size to mate with a drive shaft 28 of a powered or hand driver
indicated in part at 30. The bores 24 and 26 may communicate at a
central region of body 14. While a threaded bore 26 is illustrated,
such bore could be replaced with a tapered bore of a standard size
to mate with a tapered drive shaft or with any other suitable
connection mechanism.
[0016] Passageways 32 are formed in body 14 to accommodate each jaw
16. Three jaws 16 are employed, and each jaw is separated from the
adjacent jaw by an arc of approximately 120.degree.. The axes of
the passageways 32 and the jaws 16 are angled with respect to the
chuck axis and intersect the chuck axis at a common point ahead of
chuck body 14. Each jaw 16 has a tool engaging portion 34, which is
generally parallel to the axis of chuck body 14, and threads 36 on
its opposite or outer surface. Threads 36 may be constructed in any
suitable type and pitch.
[0017] Body 14 includes a thrust ring member 38 which, in a
preferred embodiment, may be integral with the body. In an
alternate embodiment, thrust ring 38 may be a separate component
from the body member. Thrust ring 38 may also include a ledge
portion to receive a bearing assembly 40. Thrust ring 38 includes a
plurality of jaw guideways 42 formed around its circumference to
permit retraction of the jaws 16 therethrough.
[0018] Nut 18 is a one piece nut which includes threads 44 for
mating with threads 36 on jaws 16. Nut 18 is positioned about the
body in engagement with the jaw threads so that when the nut is
rotated with respect to body 14, the jaws will be advanced or
retracted. A nut retainer 46 is pressed to nose section 20 of body
14 and engages nut 18 at a forward ledge 48 thereof. Thus, retainer
46 secures nut 18 in the axial direction with respect to the
body.
[0019] Nut 18 also includes a plurality of notches 50 receiving
drive dogs 52 of front sleeve 12 by which front sleeve 12 and nut
18 are rotationally held to each other. A nose piece 54 is pressed
to forward section 20 of body 14 and retains front sleeve 12 in the
axially forward direction by an annular lip 56 of sleeve 12.
[0020] The outer circumferential surface of sleeve 12 may be
knurled or may be provided with longitudinal ribs or any other
configuration to enable a user to grip it securely. The sleeve may
be fabricated from a structural plastic such as polycarbonate, a
filled polypropylene, for example glass filled plypropylene, or a
blend of structural plastic materials. Other composite materials
such as, for example, graphite filled polymerics may also be
suitable in a given environment. In one embodiment, the sleeve is
constructed from a 30% glass filled nylon 66 material. As would be
appreciated by one skilled in the art, the materials for which the
chuck of the present invention is fabricated will depend on the end
use of the chuck, and the above are provided by way of example
only.
[0021] A pair of rear body flanges 58 and 60 are pressed to rear
portion 22 of body 14 at knurled portion 62. An O-ring 64 sits in
an annular shoulder 66 of rear body flange 60 to limit axial
movement of a rear sleeve 68 in both the forward and rearward
directions as is discussed below. Although rear body flanges 58 and
60 are illustrated in this embodiment as separate members from body
14, it should be understood that they may be constructed integrally
therewith.
[0022] Rear sleeve 68 is axially reciprocal with respect to body
14. In the position of rear sleeve 68 shown in FIG. 1, axially
aligned teeth 70 extending radially inward from an inner
circumferential surface 72 of rear sleeve 68 engage axially aligned
teeth 74 (referring also to FIG. 4) extending radially outward from
outer circumferential surface 76 of rear body flange 58. Thus, rear
sleeve 68 is rotationally held to body 14 through rear body flange
58. O-ring 64 and rear body flange 60 prevent further rearward
axial movement of rear sleeve 68. Using this axial rear sleeve
position, an operator may operate chuck 10 as a two-sleeve keyless
chuck. By gripping rear sleeve 68 and front sleeve 12, the operator
holds body 14 and nut 18, respectively. Rotating the sleeves with
respect to each other rotates the body and nut with respect to each
other, thereby opening or closing the chuck depending upon the
direction of relative rotation.
[0023] As shown in FIG. 2, however, forward axial movement of rear
sleeve 68 disengages teeth 70 from teeth 74, and teeth 70 move
toward axially aligned teeth 78 extending radially outward from an
outer circumferential surface 80 of front sleeve 12. Teeth 78 are
disposed far enough forward of teeth 74 so that teeth 70 clear
teeth 74 before engaging teeth 78. This allows for any slight
rotation of sleeve 68 necessary to align teeth 70 with the gaps
between teeth 78. It should be understood, however, that teeth 78
may be disposed more closely to teeth 74 so that teeth 70 engage
teeth 78 before entirely disengaging teeth 74.
[0024] As teeth 70 engage teeth 78, axially aligned teeth 82, which
extend radially inward from inner circumferential surface 84 of
rear sleeve 68, engage axially aligned teeth 86, which extend
radially outward from an outer circumferential surface 88 of drill
housing 90. Referring to FIGS. 3 and 4, in the rear sleeve's
axially forward position, rear sleeve teeth 82 and 70 engage teeth
86 and teeth 78 of drill housing 90 and front sleeve 12,
respectively. Further forward axial movement of rear sleeve 68 is
prevented by O-ring 64, upon which bears shoulder 92 of rear sleeve
68. In this position, teeth 70 have completely disengaged teeth 74
of rear body flange 58.
[0025] Accordingly, in the rear sleeve axial position shown in FIG.
3, nut 18 is rotationally held to housing 90 by front sleeve 12 and
rear sleeve 68. At the same time, nut 18, front sleeve 12 and rear
sleeve 68 are rotatable with respect to body 14, which rotates with
spindle 28. Accordingly, activation of drill 30 to rotate spindle
28 rotates body 14 with respect to nut 18, thereby opening or
closing chuck 10 depending upon the spindle's rotational direction.
Because opening and closing of the chuck with sleeve 68 in this
position requires only one of the operator's hands (to operate the
drill), the operator may use his other hand to hold a drill bit or
other tool being locked into or released from the chuck.
[0026] Rear sleeve 68 may have the same or similar construction as
front sleeve 12.
[0027] It should be understood that various suitable locking
mechanisms may be used to rotationally hold the rear sleeve to the
body, the front sleeve, the housing and/or any other chuck
component as appropriate in a given embodiment of the present
invention. For example, the teeth 86 as illustrated in FIG. 5 are
wider and more spaced apart than the teeth 86 illustrated in FIG.
4. Correspondingly, teeth 82 at the rear of rear sleeve 68 are
wider to fill the gaps between teeth 86. In further embodiments,
discussed in more detail below, radially extending teeth may be
replaced by axially extending teeth. Moreover, it should be
understood that any suitable locking mechanism construction and
configuration is within the scope and spirit of the present
invention.
[0028] In the embodiment illustrated in FIGS. 6A, 6B and 9, front
sleeve 12 is pressed onto a nose piece 100 at 102. Nose piece 100
is, in turn, pressed onto forward section 20 of body 14.
Accordingly, unlike the embodiment illustrated in FIGS. 1-4, front
sleeve 12 is rotationally held to body 14 rather than nut 18.
[0029] Rear sleeve 68 is rotationally held to nut 18 during normal
operation through a clutch mechanism including an annular clutch
plate 104. Axially aligned teeth 106 extend radially outward from
an outer circumferential surface 108 of clutch plate 104 and are
received by grooves 110 between axially aligned teeth 112 extending
radially inward from an inner circumferential surface of a forward
section 114 of rear sleeve 68. Rear sleeve 68 is axially reciprocal
with respect to clutch plate 104 by the interaction between teeth
106 and grooves 110.
[0030] Clutch plate 104 is held in position between body 14 and nut
18 by a wave spring 116. Wave spring 116 bears on one side on body
14 through nose piece 100 and on the other side directly on clutch
plate 104. Wave spring 116, which may include one or more
individual springs, biases clutch plate 104 axially toward nut 18.
A lubricant may be provided on one or both sides of wave spring 116
and/or one or both surfaces of clutch ring 104 and nose piece 100
to facilitate relative rotation between the clutch plate and the
nose piece.
[0031] An engaging surface of clutch plate 104 includes a pair of
lugs 117 extending axially forward from annular surface 118 of the
engaging surface. Sides 120 of each lug 117 are disposed at an
oblique angle with respect to a plane 122 including the chuck axis
124.
[0032] One side 120 of each lug 117 abuts an opposing side 126 of a
lug 128 extending axially from an annular surface 130 of an
engaging surface of nut 18 as nut 18 is rotated with respect to
body 14. As with sides 120, sides 126 are disposed at an oblique
angle with respect to plane 122.
[0033] Rear sleeve 68 is biased forwardly by a wave spring 132,
here formed by a plurality of wave springs, bearing on one side on
body 14 through a rear body plate 134 pressed onto body 14 at 136
and on the other side on rear sleeve 68 through a rear sleeve
flange 138. Although not illustrated in FIG. 9, it should be
understood that surface 1.36 may be knurled to facilitate the press
fit between it and rear body plate 134. Furthermore, while rear
sleeve flange 138 is illustrated as being attached to rear sleeve
68 by dowels 140, it should be understood that any suitable
attachment mechanism may be employed. For example, the rear sleeve
flange may be integral with the rear sleeve or may be a separate
piece integrally molded with the rear sleeve. One or both sides of
spring 132 and/or one or both of the sides of rear body plate 134
and rear sleeve flange 138 on which it directly bears may include a
suitable lubricant to facilitate relative rotation between sleeve
68 and body 14.
[0034] In its axial position illustrated in FIG. 6A, rear sleeve 68
is rotatable with respect to body 14, and chuck 10 may be operated
as a two-sleeve keyless chuck. For example, an operator may grip
front sleeve 12 to rotationally secure body 14 and may grip rear
sleeve 68 to rotationally secure nut 18, which is rotationally held
to sleeve 68 through clutch ring 104 and the interface between lugs
117 and 128. Thus, relative rotation between front sleeve 12 and
rear sleeve 68 opens or closes chuck 10 depending upon the
direction of relative rotation.
[0035] When chuck 10 reaches a fully opened or a fully closed
position, further movement of jaws 16 is prevented by the abutment
of face 142 of jaws 16 against nut 18 or by the abutment of jaw
faces 34 against each other or a tool. Nut 18 then tightens onto
threads 36 of jaws 16 and resists further rotation.
[0036] Because of the angled interface between sides 126 and 120 of
lugs 128 and 117, respectively, part of the rotational force
applied by sleeve 68 to nut 18 through clutch ring 104 is
translated to an axial force tending to separate the clutch ring
and the nut. During normal operation, this force is resisted by the
bias of spring 116. Because nut 18 is tightened onto the jaw
threads as chuck 10 reaches a fully opened or closed position,
however, nut 18 resists the rotational force applied by the clutch
plate, and additional rotational force is required to further
rotate the nut. When the force applied between sides 126 and 120
creates a separation force exceeding the counter force provided by
biasing spring 116, clutch plate 104 is moved axially forward,
compressing spring 116. Lugs 117 and 128 thus ride over one
another, thereby allowing sleeve 68 to rotate with respect to nut
18 and preventing over tightening of the nut.
[0037] The force necessary to cause clutch plate 104 to ride over
nut 18 is primarily determined by the strength of spring 116 and
the angle of the sides 126 and 120. In one preferred embodiment,
spring 116 includes two 22 lb. wave springs, and sides 120 and 126
are disposed at an angle of approximately 600 from surfaces 118 and
130, respectively. It should be understood, however, that the
construction and dimensions of these components may be varied as
suitable for a given chuck construction.
[0038] The chuck illustrated in FIGS. 6A, 6B and 9 may also be
opened and closed through operation of the drill spindle.
Accordingly, referring to FIGS. 6B and 9, rear sleeve 68 may be
pushed axially rearward against the bias of spring 132 so that
axially aligned teeth 144 extending radially inward from inner
circumferential surface 146 of rear sleeve 68 engage axially
aligned teeth 148 extending radially outward from an outer
circumferential surface of drill housing 90. Rear sleeve 68 slides
axially rearward with respect to clutch plate 104 but remains
rotationally held thereto through the cooperation of grooves 110
and teeth 106. Thus, nut 18 is rotationally held to housing 90
through clutch plate 104 and rear sleeve 68. While holding sleeve
68 in the axially rearward position illustrated in FIG. 6B, an
operator may activate the drill to rotate spindle 28, thereby
rotating body 14 with respect to nut 18 to open or close chuck 10
depending on the spindle's rotational direction. The clutch
mechanism operates as discussed above with respect to FIG. 6A to
prevent over tightening, except that rotational force is applied
through nut 18 rather than through clutch plate 104.
[0039] The embodiment illustrated in FIGS. 7A and 7B operate
similarly to the embodiment illustrated in FIG. 6A and FIG. 6B,
primarily except for the rotational engagement between rear sleeve
68 and housing 90. For purposes of clarity, wave spring 132 (FIGS.
6A and 6B) is not illustrated in FIGS. 7A and 7B. It should be
understood, however, that this spring is present in the embodiment
illustrated in FIGS. 7A and 7B to perform a function similar to
that discussed above. For example, the spring biases rear sleeve 68
forward to the axial position shown in FIG. 7A.
[0040] Rather than employing radially extending teeth, rear sleeve
flange 138 includes radially aligned teeth 150 extending axially
rearward from rear sleeve flange 138. A housing plate 152 includes
radially aligned teeth 154 extending axially forward therefrom and
opposing teeth 150. In the axial position illustrated in FIG. 7A,
rear sleeve 68 is rotatable with respect to body 14 and housing 90,
and chuck 10 may be operated as a two-sleeve keyless chuck as
described above with respect to FIG. 6A.
[0041] As shown in FIG. 7B, rear sleeve 68 may be pulled rearwardly
against the biasing spring to engage teeth 150 and 154, thereby
rotationally holding sleeve 68 to housing 90. Sleeve 68 slides
rearwardly with respect to, but remains rationally held to, clutch
plate 104. Thus, nut 18 is rotationally held to housing 90 through
clutch plate 104 and rear sleeve 68. Activation of the drill to
rotate spindle 28 thus rotates body 14 with respect to nut 18,
thereby opening or closing chuck 10 depending upon the spindle's
rotational direction.
[0042] The embodiment of chuck 10 illustrated in FIGS. 8A and 8B is
constructed and operates similarly to the embodiment illustrated in
FIGS. 7A and 7B, primarily except that the rear biasing spring 132
(FIGS. 6A and 6B) and rear body plate are replaced by a detent
mechanism including a coil spring 156 and a ball 158. In one
preferred embodiment, the detent mechanism is a self-contained
mechanism that threads into body 14. A collar or other suitable
stop is provided to prevent ball 158 from being pushed entirely out
of the mechanism by spring 156.
[0043] Referring to FIG. 8A, rear sleeve 68 is held in the forward
axial position by ball 158 bearing against rear sleeve flange 138.
With rear sleeve 68 in this position, chuck 10 may be operated as a
two-sleeve keyless chuck as described above with respect to FIGS.
6A and 7A.
[0044] When rear sleeve 68 is pulled rearwardly, rear sleeve flange
138 presses ball 158 downward, compressing spring 156. If
sufficient rearward axial force is applied, rear sleeve 68 passes
over ball 158 so that teeth 154 engage teeth 150 to rotationally
hold rear sleeve 68 to housing 90, thereby rotationally holding nut
18 to housing 90 through clutch plate 104 and rear sleeve 68. Chuck
10 may then be opened or closed through activation of the drill as
discussed above with respect to FIGS. 6B and 7B, except that it is
not necessary for the operator to grip rear sleeve 68 during this
operation. The rear sleeve is retained in the rearward axial
position as shown in FIG. 8B by ball 158 bearing upon rear sleeve
flange 138. Spring 156 is strong enough to hold rear sleeve 68 in
the rearward axial position as shown in FIG. 8B during opening and
closing of chuck 10 but yet compressible enough so that an operator
may move rear sleeve 68 between the forward and rearward axial
positions.
[0045] While one or more preferred embodiments of the present
invention are described above, it should be appreciated that
various suitable embodiments are encompassed by the present
invention. For instance, in another preferred embodiment, the
reciprocal locking sleeve is mounted about the chuck body and is
axially movable to either of two operative positions. In the first,
the locking sleeve is rotationally held to the body by opposing
teeth on the sleeve and the body as at 70 and 74 in FIGS. 1 and 4
above. With the locking sleeve in this axial position, the chuck
may be operated as a two-sleeve keyless chuck by relative rotation
between the locking sleeve and a second sleeve rotationally held to
the nut. The second sleeve may be forward of the locking sleeve. A
suitable biasing mechanism may be provided to bias the locking
sleeve to the first axial position.
[0046] In this axial position, the locking sleeve does not
rotatably engage the nut and is therefore rotatable with respect to
the nut. Opposing lugs, such as lugs 117 and 128 on clutch plate
104 and nut 18 in FIG. 9, are provided on the nut and the locking
sleeve so that when the locking sleeve is moved axially into
engagement with the nut, the locking sleeve is rotationally held to
the nut. While an operator grips the locking sleeve, activation of
the drill to rotate the drill spindle opens or closes the chuck
depending upon the rotational direction of the spindle. The lugs on
the locking sleeve and nut have angled sides as described above
with respect to the lugs on the clutch plate and nut in FIGS. 6A
and 6B, creating a clutch to prevent over tightening of the
nut.
[0047] The clutching action causes the locking sleeve to move
axially away from the nut. Thus, enough space is provided so that
the locking mechanism between the locking sleeve and the body in
the first axial position does not reengage during the clutching
action. A clutch spring may be provided between the nut and the
body so that the nut moves away from the locking sleeve, with
respect to the body, when the nut and locking sleeve are pushed
apart.
[0048] In a still further embodiment, the locking sleeve as
described with respect to the previous embodiment is always
rotationally held to the drill housing during the chuck's
operation. The sleeve may be held in any suitable manner, for
example by an axially toothed interface, so that the locking sleeve
may move axially, but not rotationally, with respect to the drill
housing. A spring bears on one end on the chuck body and on its
other end against the locking sleeve to bias the locking sleeve
away from the nut. Thus, during normal operation, the locking
sleeve does not engage the nut. To open or close the chuck, an
operator axially moves the locking sleeve against the spring bias
to engage the nut. As above, opposing angled teeth are provided on
the nut and the locking sleeve to rotationally hold them to each
other. When the drill is thereafter activated to rotate the
spindle, the body rotates with respect to the nut, thereby opening
or closing the chuck depending on the spindle's rotational
direction. When the chuck is fully opened or closed, the nut and
locking sleeve are pushed apart with respect to each other,
allowing the nut to again rotate with the body and thereby
preventing over tightening. A clutch spring is provided between the
nut and the body so that the nut moves away from the locking
sleeve, with respect to the chuck body, when the nut and locking
sleeve are pushed apart, thereby reducing the axial force applied
to the locking sleeve opposing the operator's grip.
[0049] Furthermore, it should be understood that the identification
of a "rear" sleeve in the embodiments in the figures is for
illustrative purposes only. Moreover, it should be understood by
those skilled in this art that the chuck components described above
may be arranged and configured in various suitable manners within
the present invention. For example, the locking and biasing
mechanisms may be arranged so that the locking sleeve is pushed
forward, rather than rearward to hold the nut to the drill housing.
Thus, various modifications and variations to the present invention
may be practiced by those of ordinary skill in the art without
departing from the spirit and scope of the present invention, which
is more particularly set forth in the appended claims. In addition,
it should be understood that aspects of the various embodiments may
be interchanged both in whole or in part. Furthermore, those of
ordinary skill in the art will appreciate that the foregoing
description is provided by way of example only, and is not intended
to be limitative of the invention so further described in such
appended claims.
* * * * *