U.S. patent application number 12/284156 was filed with the patent office on 2010-03-18 for extension shaft for holding a tool for rotary driven motion.
This patent application is currently assigned to COMBINED PRODUCTS CO. #1 INC.. Invention is credited to Burton Kozak, Ira Kozak.
Application Number | 20100064860 12/284156 |
Document ID | / |
Family ID | 42006062 |
Filed Date | 2010-03-18 |
United States Patent
Application |
20100064860 |
Kind Code |
A1 |
Kozak; Burton ; et
al. |
March 18, 2010 |
Extension shaft for holding a tool for rotary driven motion
Abstract
An extension shaft for holding a tool for rotary motion of the
tool includes a first end adapted to cooperate with a chuck of a
handheld instrument and a second end including a tool holder for
holding the tool for rotary driven motion thereof. The tool holder
includes a base portion operatively connected to the extension
shaft and a swivel portion capable of holding the tool. The swivel
portion is pivotly coupled to the base portion through a pivot
assembly, wherein the tool is capable of being rotated about an
angle with respect to an axis of the chuck through rotation of the
extension shaft in response to rotation of the chuck.
Inventors: |
Kozak; Burton; (Chicago,
IL) ; Kozak; Ira; (Riverwoods, IL) |
Correspondence
Address: |
FACTOR & LAKE, LTD
1327 W. WASHINGTON BLVD., SUITE 5G/H
CHICAGO
IL
60607
US
|
Assignee: |
COMBINED PRODUCTS CO. #1
INC.
Chicago
IL
|
Family ID: |
42006062 |
Appl. No.: |
12/284156 |
Filed: |
September 18, 2008 |
Current U.S.
Class: |
81/177.6 ;
74/501.6; 81/177.85 |
Current CPC
Class: |
B25B 23/0028 20130101;
B25B 23/0014 20130101; B25G 1/025 20130101; Y10T 74/2042 20150115;
B25B 23/0021 20130101; B23B 45/005 20130101 |
Class at
Publication: |
81/177.6 ;
81/177.85; 74/501.6 |
International
Class: |
B25G 1/02 20060101
B25G001/02; B25B 23/16 20060101 B25B023/16 |
Claims
1. An extension shaft for holding a tool for rotary driven motion,
the extension shaft having an axis and capable of being adapted to
a handheld instrument having a chuck, the extension shaft
comprising, in combination: a first end adapted to cooperate with
the chuck and a second end adapted to hold the tool for rotary
driven motion, the first end of the extension shaft and the chuck
having complementarily shaped non-circular cross-sections; and, the
second end of the extension shaft including a tool holder for
holding the tool for rotary driven motion thereof, the tool holder
and the tool having complementarily shaped non-circular
cross-sections, the tool holder further including a base portion
and a swivel portion, the swivel portion being capable of holding
the tool and further being pivotly coupled to the base portion
through a pivot assembly including a ball joint having a bearing
and a socket, wherein the tool is capable of being rotated about an
angle with respect to an axis of the chuck through rotation of the
extension shaft in response to rotation of the chuck.
2. The extension shaft of claim 1 further comprising a sheath
substantially covering the pivot assembly.
3. The extension shaft of claim 1, further comprising a spacer
located about the axis of the extension shaft and proximate the
ball joint.
4. The extension shaft of claim 1, wherein the tool holder is
configured to predispose an axially aligned connection of the base
and swivel portions when the extension shaft is at rest.
5. An extension shaft for holding a tool for rotary driven motion,
the extension shaft capable of being adapted to a handheld
instrument having a chuck, the extension shaft comprising, in
combination: a first end adapted to cooperate with the chuck and a
second end adapted to hold the tool for rotary driven motion, the
first end of the extension shaft and the chuck having
complementarily shaped non-circular cross-sections; and, the second
end of the extension shaft including a tool holder for holding the
tool for rotary driven motion thereof, the tool holder and the tool
having complementarily shaped non-circular cross-sections, the tool
holder further including a base portion and a swivel portion, the
swivel portion being capable of holding the tool and further being
pivotly coupled to the base portion through a pivot assembly having
a first pin and a second pin wherein the first and second pins are
substantially perpendicular to each other and lie substantially
within a plane, and further wherein the tool is capable of being
rotated about an angle with respect to an axis of the chuck through
rotation of the extension shaft in response to rotation of the
chuck.
6. The extension shaft of claim 5, wherein the pivot assembly is a
unitary piece and the first and second pins are connected to each
other.
7. The extension shaft of claim 6, wherein the pivot assembly
includes a hub from which the first and second pins extend there
from.
8. The extension shaft of claim 7 wherein the hub includes a
geometric shape that lies substantially within the plane.
9. The extension shaft of claim 7 wherein the hub is circular.
10. The extension shaft of claim 7 wherein the hub is a
polygon.
11. The extension shaft of claim 10 wherein the hub is square.
12. The extension shaft of claim 7 wherein the hub includes a
geometric shape having a portion that extends substantially outside
the plane.
13. The extension shaft of claim 12 wherein the hub is round.
14. The extension shaft of claim 12 wherein the hub is
cylindrical.
15. The extension shaft of claim 12 wherein the hub is polygon.
16. The extension shaft of claim 15 wherein the hub is square.
17. The extension shaft of claim 5, further being flexible and
capable of being deflected with respect to the axis of the chuck so
as to position the second end of the extension shaft at an angle
relative to the axis of the chuck.
18. The flexible extension shaft of claim 17, further including a
plurality of concentric coil springs in tightly wound adjacent
relation extending between and secured to generally cylindrical
body portions proximate the first and second ends of the flexible
extension shaft to accommodate deflection of the flexible extension
shaft relative to the axis of the chuck, and including a flexible
sleeve disposed about the concentric coil springs, the flexible
sleeve having cylindrical fittings secured thereto at opposite ends
thereof so as to define a shoulder internally of each of the
fittings, the cylindrical fittings each being adapted to receive
one of the cylindrical body portions therein, the cylindrical body
portions being spaced apart by a distance greater than the distance
between the shoulders in the cylindrical fittings to permit limited
axial movement of the cylindrical body portions and the concentric
coil springs relative to the cylindrical fittings and the flexible
sleeve.
19. The flexible shaft extension of claim 18 further comprising a
shaft biasing coil spring disposed about the concentric coil
springs of the flexible extension shaft, the shaft biasing coil
spring being disposed between the shoulder in one of the
cylindrical fittings and the corresponding one of the cylindrical
body portions to normally bias the other of the cylindrical body
portions into engagement with the shoulder in the other of the
cylindrical fittings.
20. A flexible extension shaft for holding a tool for rotary driven
motion, the flexible extension shaft having an axis and capable of
being adapted to a handheld instrument having a chuck, the flexible
extension shaft comprising, in combination: a first end adapted to
cooperate with the chuck and a second end adapted to hold the tool
for rotary driven motion, the first end of the flexible extension
shaft and the chuck having complementarily shaped non-circular
cross-sections, the first end having an axis and capable of being
received by the chuck wherein the first end and the chuck cooperate
to releasably retain the first end within the chuck; the second end
of the flexible extension shaft including a tool holder for holding
the tool for rotary driven motion thereof, the tool holder and the
tool having complementarily shaped non-circular cross-sections, the
tool holder further including a base portion and a swivel portion,
the swivel portion being capable of holding the tool and further
being pivotly coupled to the base portion through a pivot assembly
including a ball joint having a bearing and a socket, wherein the
tool is capable of being rotated about an angle with respect to an
axis of the chuck through rotation of the extension shaft in
response to rotation of the chuck; a means for predisposing an
axially aligned connection of the base portion and the swivel
portions when the flexible extension shaft is at rest; the flexible
extension shaft being deflectable relative to an axis of the chuck
so as to position the second end of the flexible shaft and the tool
at an angle relative to the axis of the chuck, the tool capable of
being rotary driven by the handheld instrument through the flexible
extension shaft; and, the flexible extension shaft further
including a plurality of concentric coil springs in tightly wound
adjacent relation extending between and secured to generally
cylindrical body portions proximate the first and second ends of
the flexible extension shaft to accommodate deflection of the
flexible extension shaft relative to the axis of the chuck, and
including a flexible sleeve disposed about the concentric coil
springs, the flexible sleeve having cylindrical fittings secured
thereto at opposite ends thereof so as to define a shoulder
internally of each of the fittings, the cylindrical fittings each
being adapted to receive one of the cylindrical body portions
therein, the cylindrical body portions being spaced apart by a
distance greater than the distance between the shoulders in the
cylindrical fittings to permit limited axial movement of the
cylindrical body portions and the concentric coil springs relative
to the cylindrical fittings and the flexible sleeve.
21. The extension shaft of claim 20, wherein the means for
predisposing an axially aligned connection of the base portion and
the swivel portion of the tool holder comprising: a first annular
surface extending about the perimeter of the base portion proximate
the ball joint; a second annular surface extending about the
perimeter of the swivel portion proximate the opening of the
socket; and, a retaining device secured within the socket and about
the axis of the base portion proximate the bearing of the ball
joint.
22. The extension shaft of claim 21, wherein at least a portion of
one of the base and swivel portions being magnetized to attract
each into an axially aligned connection.
23. The extension shaft of claim 21, further comprising a bias
positioned within the socket and about the axis of the ball joint
and between the retaining device and the bearing of the ball joint,
wherein the bias exerts a force to bring the cooperating first and
second annular surfaces into engagement.
24. The extension shaft of claim 21, wherein the retaining device
is a slip nut operatively affixed and positioned within the
socket.
25. The extension shaft of claim 21, wherein the bias is a spring.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to an extension
shaft capable of holding a variety of tools to be rotary driven by
a handheld instrument; and more particularly, to providing an
extension shaft with an increased range of angular movement of the
tool with respect to the handheld instrument.
BACKGROUND OF THE INVENTION
[0002] A handheld instrument capable of being used with multiple
types of tools--e.g., drill bits, screwdriver bits, sockets, etc.
in standard and metric dimensions--is very popular because it
provides a user with the ability to readily adapt the handheld
instrument among a variety of workplace needs without requiring the
user to carry along an extensive set of individually dedicated
tools.
[0003] Each tool is fashioned to be axially inserted into a chuck
of the handheld instrument, which typically positions the tool in
close proximity to the handheld instrument's relatively large
handle. As a result, the handheld instrument may at times be rather
ineffective for use in spatially confined or difficult-to-reach
locations.
[0004] In this connection, a powered handheld instrument--corded or
cordless--may also be used. Although such a powered instrument,
e.g., screwdriver, drill; is generally relatively long in length,
it does provide the user with the ability to easily complete
various tasks with less manual effort. In addition, the powered
instrument generally includes a casing surrounding its motor that
is rather large in relation to the tools, i.e., drill bits,
screwdriver tips, sockets, and the like. For this reason, it has
been difficult to use the powered instrument in areas of limited
access.
[0005] The present invention is directed to addressing the spatial
constraints frequently encountered by today's user during use of a
handheld instrument capable of being utilized with various
tools.
SUMMARY OF THE INVENTION
[0006] Accordingly, the present invention is directed to an
extension shaft for holding a tool for rotary driven motion. The
extension shaft is capable of being adapted to a handheld
instrument having a chuck. The extension shaft includes a first end
adapted to cooperate with the chuck and be releasably retained
thereby; and a second end adapted to releasably retain the tool for
rotary driven motion. The first end of the extension shaft and the
chuck have complementarily shaped non-circular cross-sections,
wherein the first end has an axis and is capable of being
releasably retained by the chuck. The second end of the extension
shaft includes a tool holder for holding the tool for rotary driven
motion thereof. The tool holder and the tool have complementarily
shaped non-circular cross-sections. The tool holder further
includes a base portion and a swivel portion. The swivel portion is
capable of releasably retaining the tool within the tool holder and
is pivotly coupled to the base portion through a pivot assembly.
The pivot assembly may include a ball joint operatively connecting
the swivel and base portions of the tool holder. Alternatively, the
pivot assembly may include a first and a second pin, shaft, or
axle, wherein the first and second pins of the pivot assembly are
substantially perpendicular to each other and lie substantially
within a plane. In either embodiment of the pivot assembly, the
tool is capable of being rotated about an angle with respect to an
axis of the chuck or extension shaft through rotation of the
extension shaft in response to rotation of the chuck. Thus, the
tool holder of the present invention provides for the handheld
instrument's effective operability to be maintained throughout an
increase in the angular variation between the extension shaft and
the tool.
[0007] In an additional embodiment of the tool holder, the pivot
assembly includes a means for biasing the base and swivel portions
into axial alignment when the tool holder is at rest. The
predisposition of the pivot assembly to axially align the base and
swivel portions will effectively steady the swivel portion and
facilitate the insertion and/or removal of the tool.
[0008] In another embodiment of the present invention, a sheath may
be placed over the cooperating moving parts of the tool holder to
guard against contact therewith while simultaneously allowing the
extension shaft to properly operate. The sheath can be a single,
unitary piece or multiple pieces. In an alternate embodiment to
guard against contact with the moving parts of the tool holder, a
spacer can be placed proximate the pivot assembly, e.g., bearing of
the ball joint; which will assist in preventing an operator from
contacting the area around the rotating and hinging parts of the
tool holder.
[0009] In a further embodiment of the present invention, the first
or second end of the extension shaft preferably includes a
generally cylindrical body portion terminating in a male hex shank
and the other of the first or second end of the extension shaft
preferably includes a cylindrical body portion terminating in the
tool holder--e.g., base portion and swivel portion including a
female hex shank-receiving opening therein.
[0010] In yet another embodiment of the present invention, the
extension shaft is flexible and capable of deflecting relative to
the axis of the chuck such that the position of the second end of
the flexible extension shaft and the tool can be angled relative to
the axis of the chuck, wherein the tool can be rotary driven by
rotation of the chuck through rotation of the handheld instrument
and the flexible extension shaft.
[0011] The flexible extension shaft may further include a plurality
of concentric coil springs in tightly wound adjacent relation
extending between and secured to generally cylindrical body
portions near the first and second ends of the flexible extension
shaft to accommodate deflection of the flexible extension shaft
relative to the axis of the chuck, and including a flexible sleeve
disposed about the concentric coil springs. The flexible sleeve has
cylindrical fittings secured thereto at opposite ends thereof so as
to define a shoulder internally of each of the fittings. Each
cylindrical fitting is adapted to receive one of the cylindrical
body portions therein. The cylindrical body portions are spaced
apart by a distance greater than the distance between the shoulders
in the cylindrical fittings, which permits limited axial movement
of the cylindrical body portions and the concentric coil springs
relative to the cylindrical fittings and the flexible sleeve. Such
a configuration allows for the flexible extension shaft to be
deflectable relative to the axis of the chuck so as to position the
second end of the shaft and the tool at an angle relative to the
axis of the chuck, so that the tool is capable of being rotary
driven by rotation of the chuck and/or handheld instrument through
the flexible extension shaft.
[0012] A shaft biasing coil spring can be advantageously disposed
about the concentric coil springs of the flexible extension shaft.
More specifically, the shaft biasing coil spring is disposed
between the shoulder in one of the cylindrical fittings and the
corresponding one of the cylindrical body portions to normally bias
the other of the cylindrical body portions into engagement with the
shoulder in the other of the cylindrical fittings.
[0013] An object of the present invention is to provide an
extension shaft for holding a tool utilized with a handheld
instrument, wherein the extension shaft is capable of increasing
the operating capability of the handheld instrument and tool.
[0014] Another object of the present invention is to provide an
extension shaft for holding a tool utilized with a handheld
instrument, wherein the extension shaft includes a protective
mechanism to safeguard the operator from harmful contact with the
moving components of the extension shaft.
[0015] A still further object of the present invention is to
provide an extension shaft for holding a tool utilized with a
handheld instrument, wherein the extension shaft includes a tool
holder with a means for biasing a base and swivel portion into
axial alignment and thus steadying the swivel portion to facilitate
insertion and/or removal of the tool when the extension shaft is
idle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is perspective view of a rigid extension shaft in
accordance with one embodiment of the present invention;
[0017] FIG. 2 is a perspective view of the rigid extension shaft
shown in FIG. 1 and operatively attached to a handheld instrument
and a tool;
[0018] FIGS. 3A and 3B are perspective views of the tool holder of
the present invention;
[0019] FIG. 4 is a partial cross-sectional view--perpendicular to
the axis of the extension shaft--of the swivel portion of the tool
holder of the present invention;
[0020] FIG. 5 is a cross-sectional view--aligned with the axis of
the extension shaft--of the swivel portion of the tool holder of
the present invention with a tool inserted therein;
[0021] FIGS. 6A, 6B, 6C, and 6D depict various embodiments of the
pivot assembly of the present invention;
[0022] FIG. 7A is perspective view of an alternative embodiment of
the present invention depicting a flexible extension shaft
operatively attached to a powered handheld instrument and a
tool;
[0023] FIG. 7B is perspective view of an alternative embodiment of
the present invention depicting a flexible extension shaft
operatively attached to a simple handheld instrument and a
tool;
[0024] FIG. 8 is a partial perspective view of the flexible
extension shown in FIGS. 7A and 7B;
[0025] FIG. 9 is a partial cross-sectional view--perpendicular to
the axis of the extension shaft--of the flexible extension shaft of
the present invention;
[0026] FIG. 10 is a perspective view of an alternate embodiment of
the present invention wherein the pivot assembly includes a ball
joint having a bearing and a socket;
[0027] FIG. 11 is a partial cross-sectional view--perpendicular to
the axis of the extension shaft--of one embodiment of the pivot
assembly of the present invention, wherein a sheath is utilized to
cover at least a portion of the tool holder and at least a portion
of the end of the extension shaft;
[0028] FIG. 12 is a partial view of one embodiment of the pivot
assembly of the present invention, wherein a spacer is located
proximate the pivot assembly to guard against a user contacting the
moving parts of the extension shaft;
[0029] FIG. 13 is a partial view of one embodiment of the tool
holder of the present invention depicting one of the means for
predisposing the axial alignment and connection of the base and
swivel portions of the tool holder;
[0030] FIG. 14 is another partial view of the embodiment of the
tool holder of the present invention depicting the means for
predisposing the axial alignment and connection of the base and
swivel portions of the tool holder shown in FIG. 13;
[0031] FIG. 15 is a partial view of one embodiment of the tool
holder of the present invention depicting another of the means for
predisposing the axial alignment and connection of the base and
swivel portions of the tool holder; and,
[0032] FIG. 16 is a partial view of an alternate embodiment of the
sheath having multiple portions for covering at least a portion of
the moving components of the tool holder;
[0033] FIG. 17 depicts another alternate embodiment of the
extension shaft of the present invention wherein cylindrical
fittings cover portions of the tool holder; and,
[0034] FIG. 18 depicts the alternate embodiment of the extension
shaft of the present invention shown in FIG. 17 wherein a sheath is
utilized to cover at least a portion of the tool holder.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0035] While this invention is susceptible to embodiments in many
different forms, there are shown in the drawings and will herein be
described in detail, preferred embodiments of the invention with
the understanding that the present disclosures are to be considered
as exemplifications of the principles of the invention and are not
intended to limit the broad aspects of the invention to the
embodiments illustrated.
[0036] Referring to the drawings, and first to FIGS. 1 and 2, the
reference numeral 10 designates generally a handheld instrument or
piece of equipment, e.g., screwdriver, drill; having a chuck 12 for
connection to an extension shaft 18 for rotary driven motion at one
end 16 thereof. The extension shaft 18 includes a first end 20
adapted to cooperatively extend from, or attach or connect with,
the chuck 12; and, a second end 22 that may similarly be adapted
for attachment or extension there from and to hold a tool 14 for
rotary driven motion.
[0037] The first end 20 of the extension shaft 18 and the chuck 12
have complementarily shaped non-circular cross-sections, e.g.,
hexagonal, that may be similar to those shown in U.S. Pat. No.
4,876,929--the entire contents of which are fully incorporated
herein by reference. The chuck 12 has a longitudinal axis and is
adapted to receive the first end 20b of the extension shaft 18 by
means of axial insertion of the extension shaft into the chuck with
the respective non-circular cross-sections in rotationally aligned
relationship. The chuck 12 preferably also includes a means for
holding the first end 20 of the extension shaft 18 for rotary
driven motion of the shaft.
[0038] A tool holder 52 including a base portion 54 and a swivel
portion 56 extends from or is operatively connected to the
extension shaft 18 proximate the second end 22. It is to be
understood that the term operatively as used herein connotes that
the connection, attachment, coupling, integral extension there
from, etc. can be accomplished through any one of a variety of ways
known by those or ordinary skill in the art to utilize such
cooperating components and to ensure their operability. In one
instance, the base portion 54 of the tool holder 52 is integral
with or extends from a cylindrical body portion 22 as is shown in
FIG. 1. In another instance, the connection between the extension
shaft 18 and the tool holder 52 can similarly utilize the
complementarily shaped--e.g., male-female--non-circular
cross-sections of mating components utilized between the chuck 12
and the first end 20 of the extension shaft 18. Likewise, the
swivel portion 56 of the tool holder 52 is capable of retaining the
tool 14 therein and can similarly utilize the complementarily
shaped non-circular cross-sections between the tool holder's 52
swivel portion 56, 56a and the tool 14--see FIGS. 4 and 5.
[0039] As will be appreciated by referring to the figures,
particularly FIGS. 7-9, the tool 14 is rotary driven by the chuck
12 of the handheld instrument 10. The handheld instrument can be a
simple handle--see FIG. 7B--that can be manually operated, or a
powered handle--see FIG. 7A--that can be electrically operated. It
will also be appreciated that proximate either ends 20, 22 of the
extension shaft 18, a generally cylindrical body portion may be
included. One cylindrical body portion, e.g., 20a, may terminate in
a male hex shank, e.g., 20b, and the other generally cylindrical
body portion, e.g., 22a, may terminate in the tool holder 52 having
a base portion 54 and a pivotly connected swivel portion 56, which
further includes a female hex shank-receiving opening or collet 56a
capable of interconnecting with the tool 14. It will further be
appreciated that the chuck 12 includes a female hex shank-receiving
opening which, together with the male hex shank 20b, exemplifies
one embodiment of the previously described complementarily shaped
non-circular cross-section. With this arrangement, the first end 20
of the extension shaft 18 is adapted for axial insertion into the
chuck 12. So too the tool holder can be axially inserted into, or
aligned with, the second end 22 of the extension shaft; and
likewise, the tool 14 can also be axially inserted into swivel
portion 56 of the tool holder 52 proximate the second end 22 of the
extension shaft 18.
[0040] Magnetic coupling is one of a variety of means for
releasably retaining the male hex shank portion within the
cooperating female hex receiving portion. Another means for
releasably retaining the male hex shank portion within the
cooperating female hex receiving portion is shown in FIGS. 4 and 5,
which may include a ball or bearing detent 26 associated with a
female hex shank-receiving opening that can be incorporated into
the swivel portion 56 of the tool holder 52 proximate the second
end 22 of the flexible extension shaft 18. In like fashion, the
means for releasably retaining cooperatively attached
members--e.g., the tool holder 52 and the tool 14--can also be
implemented between the chuck 12 and the extension shaft 18, or the
extension shaft 18 and the tool holder 52.
[0041] A pivot assembly 58 connects the base 54 and swivel 56
portions of the tool holder 52. One embodiment of the pivot
assembly 58 is shown in FIGS. 3A, 3B, and 6A-6D and includes a pair
of pins, shafts, or axles, wherein a first pin 60 and a second pin
62 lie substantially within a single plane. Preferably, the first
and second pins 60, 62 are substantially perpendicular to each
other, and are connected together, or are integral with each other,
to form a unitary piece. FIGS. 6A, 6B, 6C, and 6D depict several
embodiments of the pivot assembly 58 showing the first 60 and
second 62 pins being integral with each other and lying within a
single plane, i.e., the plane of the paper. The integral pins 60,
62 may be attached through a hub 64; the form of which may include
one of several different shapes or geometries--e.g., ring, disk,
circular, round, rectangular, box, and diamond--and the hub may or
may not lie entirely or substantially within the same plane as the
first 60 and 62 second pins.
[0042] Referring now to FIGS. 10-12, an alternate embodiment of the
pivot assembly 58 is shown wherein a ball joint 66 is utilized to
operatively connect the base 54 and swivel portions 56 of the tool
holder 52. The ball joint 66 preferably includes a bearing 68,
e.g., hex ball-extending along a neck from the end 22 of the
extension shaft 18 or base portion 54, and resides within a socket
74 defined within an end of the swivel portion 56 opposite the end
56a that retains the tool 14. The cooperative connection between
the hex ball 68 and the socket 74 enables the swivel portion 56 of
the tool holder 52 to be angled, pivoted, or hinged with respect to
the base portion 54, and further allows the swivel portion to
rotate in response to rotation of the base portion.
[0043] In a further alternate embodiment of the pivot assembly 58,
the base portion 54 and the swivel portion 56 of the tool holder 52
are biased or predisposed to be substantially in axial alignment
when the extension shaft 18 is at rest--thus providing a beneficial
feature of a more stable or steady swivel portion to facilitate the
insertion and/or removal of the tool 14. FIGS. 13-14 depict one
means for predisposing the axial alignment of the base 54 and
swivel 56 portions of the tool holder 52 when the tool holder is
not in use. In particular, the ball joint 64 is configured such
that the base portion 54 and the swivel portion 56 of the tool
holder 52 include cooperating annular surfaces 76, 78--e.g.,
shoulders--about their respective outer perimeters. The cooperating
surfaces of the shoulders 76, 78 can be generally described as
having mating male-female portions and can include a variety of
geometric shapes, e.g., circle, square, star, octagon.
[0044] A retaining device 80, such as an internal split ring, is
positioned about the axis and neck of the base portion 54 near the
hex ball 66 and operatively secured within the socket 74 of the
swivel portion 56. The split ring 80 retains the hex ball 66 within
the socket 74 and simultaneously permits the hex ball to axially
slide a short distance within the socket. When the hex ball 66 is
fully inserted into the socket 74, the shoulder 76 of the base
portion 54 cooperatively engages with the shoulder 78 of the swivel
portion 56 to axially align the base and swivel portions and make a
more rigid tool holder 52 having a steady swivel portion with a
lesser tendency to hinge, pivot, or angle with respect to the base
portion. If the male-female segments of the cooperating shoulders
76, 78 include keyed shapes, e.g., square, star, hexagon; any
relative rotational movement between the base and swivel portions
will be considerably deterred.
[0045] For increasing the operable range of the extension shaft 18,
the swivel portion 56 can be axially slid away from the base
portion 54 a distance sufficient to disengage and clear the
cooperating shoulders 76, 78 of the base and swivel portions, thus
allowing the swivel portion the ability to hinge or pivot and be
angled with respect to the base portion. The retaining device 80
retains the hex ball 66 within the socket 74 while simultaneously
allowing the hex ball to rotate in response to rotation of the
extension shaft 18, and thus engage the socket. One of ordinary
skill in the art can readily envision that multiple tool holders 52
can be coupled together as needed.
[0046] Additional embodiments of the pivot assembly 58 that are
within the scope of the present invention include cooperating
gears, e.g., beveled, spurred; or mating balls; operatively
attached or extending from the respective base 54 and swivel 56
portions. Regardless of which embodiment of pivot assembly 58 is
employed during operation with the handheld instrument 10, the
extension shaft 18 can be disposed substantially entirely coaxial
with the chuck 12, while the tool holder's swivel portion 56, as
well as the tool 14 itself, is capable of being positioned at an
angle relative to the axis of the chuck.
[0047] The present invention further contemplates the tool holder
52 including a means for predisposing the connection or attachment
of the base 54 and swivel 56 portions through a bias 82 to axially
attract the base and swivel portions toward each other. One such
means for predisposing the connection of the base 54 and swivel 56
portions includes a section of either or both of the base and
swivel portions having a magnetized segment capable of attracting
the other of the base or swivel portions of the tool holder 52.
That is, when the extension shaft 18 and/or tool holder 52 is at
rest, or not being used, the base 54 and swivel 56 portions are
attracted to each other so that the respective shoulders 76, 78 of
each portion of the tool holder move toward each other to engage
and axially align. The magnetic coupling is sufficient enough to
attract the base 54 and swivel 56 portions toward each other to
engage the respective cooperating annular surfaces 76, 78 and
steady the swivel portion for insertion and/or removal of the tool
14--while simultaneously allowing the base and swivel portions to
be slid axially apart a short distance such that they can be angled
with respect to each other and yet remain operatively connected by
the split ring 80.
[0048] FIG. 15 depicts another embodiment of the means for
predisposing the axially aligned connection of the base 54 and
swivel 56 portions, wherein the bias 82 includes a spring
positioned about the neck of the base portion proximate the hex
ball 68 and between the split ring 80 and the inner portion of the
socket 74 that assists in the retention of the split ring therein.
The force exerted by the spring 82 brings the cooperating shoulders
76, 78 of the base 54 and swivel 56 portions together and into
engagement; thus axially aligning the base and swivel portions of
the tool holder 52 and steadying the swivel portion for insertion
and/or removal of the tool 14 when the extension shaft 18 is at
rest.
[0049] Referring to FIG. 11, a protective mechanism 70, e.g.,
sheath, can be incorporated with the extension shaft 18 of the
present invention to cover the pivot assembly 58 proximate the end
of the extension shaft and the tool holder 52. The durable sheath
70 may include a single piece or multiple pieces and is
sufficiently flexible and/or rigid so that it does not impede
movement of the swivel portion 56 or base portion 54 of the tool
holder 52. The sheath includes a material capable of protecting the
operator from harmful contact with the moving parts of the tool
holder when the swivel portion is angled, pivoted, or hinged with
respect to the base portion 54 or the extension shaft 18 during
rotation.
[0050] In one embodiment of the sheath 70 shown in FIGS. 17 and 18,
sections of the swivel 56 and base 54 portions of the tool holder
52 are retained within respective cylindrical fittings 40, 40' such
that rotation of the swivel and base portions can be achieved
without rotation of the respective cylindrical fitting. One of the
cylindrical fittings 40, 40' is positioned about at least a section
of the swivel portion 56 of the tool holder 52 and the other of the
cylindrical fittings is positioned about at least a section of the
base portion 54 of the tool holder. The outer surface of the
cylindrical fitting 40' positioned about the swivel portion 56 of
the tool holder 52 includes a diamond knurled finish (e.g.,
cross-hatched) and the outer surface of the cylindrical fitting 40
positioned about the base portion 56 of the too holder includes a
fluted knurled finish (e.g., longitudinal ridges). The sheath 70
includes a flexible rubber-type material and may also include an
outer surface that includes knurling. The sheath 70 is slid over
the cylindrical fittings 40, 40', wherein the diamond knurled
surface about the swivel portion 56 facilitates retention of the
sheath while the fluted knurled surface about the base portion 54
allows the sheath to slide back and forth when the tool holder 52
is hinged or pivoted.
[0051] If the sheath 70 includes multiple pieces, one segment of
the sheath covers over of the base 54 or swivel 56 portions and the
other segment of the sheath covers over the other of the base or
swivel portions. As shown in FIG. 16, each segment of the sheath 70
preferably includes a semi-rigid, bulbous shape, wherein one of the
sheath segments partially fits within the an opening of the other
of the sheath segments to cooperatively hold both sheath segments
together.
[0052] Another protective mechanism capable of being incorporated
with the tool holder 52 of the present invention is a spacer 72. As
shown in FIG. 12, the spacer 72 is preferably annular or toroidal
in shape and includes a durable and flexible material, e.g.,
rubber, silicon; that can be located about the axis of the
extension shaft 18 and proximate the neck of the base portion 56
and bearing 66 of the ball joint 64 to assist in preventing an
operator's hand or finger from being placed into contact with the
movable parts of the tool holder 52.
[0053] Referring again to FIGS. 7-9, another embodiment of the
present invention is shown wherein the extension shaft 18 is
flexible. The flexible extension shaft 18 includes a plurality of
concentric coil springs 30, 32, 34 in tightly wound adjacent
relation extending between and secured to the generally cylindrical
body portions 20a, 22a of the first and second ends 20, 22 of the
flexible extension shaft 18 to accommodate universal deflection of
the flexible extension shaft and/or the tool 14 relative to the
axis of the chuck 12. It will also be seen that a flexible sleeve
36 is disposed about the concentric coil springs 30, 32, 34. As
illustrated, the flexible sleeve 36 has cylindrical fittings 38, 40
secured thereto at opposite ends 42, 44 thereof to receive one of
the cylindrical body portions 20a, 22a therein and the flexible
sleeve 36 and cylindrical fittings 38, 40 define shoulders 46, 48
internally of each of the fittings 38, 40 to form stops for the
cylindrical body portions 20a, 22a.
[0054] More specifically, the cylindrical body portions 20a, 22a
are spaced apart by a distance greater than the distance between
the shoulders 46, 48 in the cylindrical fittings 38, 40 to permit
limited axial movement of the cylindrical body portions 20a, 22a
and the concentric coil springs 30, 32, 34 relative to the
cylindrical fittings 38, 40 and the flexible sleeve 36. With this
construction, a shaft biasing coil spring 50 is disposed about the
concentric coil springs 30, 32, 34 of the flexible extension shaft
18 between the shoulder 48 in one of the cylindrical fittings 40 in
the corresponding one of the cylindrical body portions 22a to
normally bias the other of the cylindrical body portions 20a into
engagement with the shoulder 46 in the other of the cylindrical
fittings 38.
[0055] It is to be understood that the flexible sleeve 36 can also
be implemented with the more rigid extension shaft shown in FIGS. 1
and 2--as would be the case when the flexible extension shaft shown
in FIGS. 7-9 is utilized in a linear configuration.
[0056] As should now be appreciated, the handheld instrument
10--especially a portable electric screwdriver--is extremely
versatile when utilized with the extension shaft 18 of the present
invention. Because the tool holder 52 is deflectable relative to
the axis of the chuck 12--as well as the axis of the extension
shaft 18--the extension shaft enables the use of the handheld
instrument 10 in hard-to-reach or spatially restricted areas
because the tool 14 can be disposed at an acute angle relative to
the axis of the chuck 12 by the pivoting, hinging, and/or swiveling
provided by the unique pivotal coupling inherent within the tool
holder 52--whether the embodiment of the pivot assembly 58 being
utilized includes the ball joint 64 (see FIGS. 10-12) or the dual
pivot pins 60, 62 of the pivot assembly 58 that lie substantially
within the same plane and preferable perpendicular to each other
(see FIGS. 3A, 3B, 6A, 6B, 6C, and 6D).
[0057] The range of angular movement for the tool 14 relative to
the axis of the chuck 12 can further be increased when the tool
holder 52 is utilized with an extension shaft 18 that is flexible.
Because the flexible extension shaft 18 is universally deflectable
relative to the axis of the chuck 12, the flexible extension shaft
18 enables the use of the handheld instrument 10 in hard-to-reach
or spatially restricted areas because the tool 14 can be disposed
at an acute angle relative to the axis of the flexible extension
shaft as well as the chuck 12 by deflecting or bending the flexible
extension shaft such as illustrated in FIG. 7. The concentric coil
springs 30, 32, 34 rotate internally of the flexible sleeve 36 and
the difference in distance between the cylindrical body portions
20a and 22a and the cylindrical fittings 38 and 40 accommodate the
arc into which the flexible extension shaft 18 is oftentimes
advantageously deflected and held during use. In this
configuration, the flexible sleeve 36 permits the user to grip the
flexible extension shaft 18 and hold it in a deflected position
during use without exposure to the moving parts.
[0058] While in the foregoing there has been set forth a preferred
embodiment of the invention, it is to be understood that the
present invention may be embodied in other specific forms without
departing from the spirit or central characteristics thereof. The
present embodiments, therefore, are to be considered in all
respects as illustrative and not restrictive, and the invention is
not to be limited to the details given herein. While specific
embodiments have been illustrated and described, numerous
modifications come to mind without significantly departing from the
characteristics of the invention and the scope of protection is
only limited by the scope of the accompanying Claims.
* * * * *