LOCKING KNUCKLE-TYPE JOINT AND APPARATUS EMPLOYING SAME

JOINT ARTICULE VERROUILLABLE ET DISPOSITIF COMPORTANT CE JOINT

English Abstract

A locking knuckle-type joint pivotably
interconnects first and second members that are
moveable at least along an axis intersecting the joint
and pivotable at least about the axis between selected
locked positions. The joint includes first and second
complementary, interlockable faces on the first and
second members, respectively, and a respective
plurality of mating teeth on each of the faces. Each
tooth has a peak edge extending substantially radially
from the center point, and each pair of adjacent teeth
defines a valley edge extending substantially radially
from the center point between the adjacent teeth. The
first and second faces are oppositely disposed at the
joint and are adapted for substantially mating contact
with one another. The joint also includes a screw for
adjusting the distance along the axis between the
oppositely disposed first and second complementary,
interlockable faces on the first and second members for
removably interlocking the first and second members
into one of a plurality of angular orientations
relative to one another. The joint couples handles or
other fittings to a pair of gripper jaw portions to
facilitate gripping a polishing stone or other tool.
The joint also couples a tool head to a handle to
define a more general modular tool.

Claims

- 18 -
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A locking knuckle-type joint for pivotably
interconnecting first and second members that are
movable at least along an axis intersecting the joint
at a center point thereof, and pivotable at least about
the axis between selected locked positions, the joint
comprising:
first and second complementary, interlockable
faces on the first and second members, respectively;
a respective plurality of mating teeth on each of
the first and second faces, wherein each tooth has a
peak edge extending substantially radially
substantially from the center point, and each pair of
adjacent teeth defines a valley edge extending
substantially radially substantially from the center
point between the adjacent teeth such that each tooth
is bounded by a pair of adjacent valley edges, and
wherein the first and second faces are oppositely
disposed at the joint and are adapted for mating
contact with one another such that the teeth of the
first and second faces are substantially matingly
interlocked with one another; and
adjusting means having first and second states for
adjusting the distance along the axis between the
oppositely disposed first and second complementary,
interlockable faces on the first and second members;
wherein the first and second members are freely
and independently pivotable about the axis when the
adjusting means is in the first state; and

- 19 -
wherein the first and second members are locked
into one of a plurality of angular orientations
relative to one another and the first and second faces
are disposed in substantially mating contact with one
another in the selected locked positions when the
adjusting means is in the second state.
2. The joint of claim 1, wherein each tooth has
a pair of surfaces, each of which is bounded between a
respective one of the valley edges bounding the tooth
and the peak edge of the tooth, wherein the surfaces of
the teeth of each of the first and second faces
together substantially completely define the first and
second faces.
3. The joint of claim 2, including N teeth,
wherein each tooth subtends a first angle .theta.
substantially equal to <IMG>, and wherein the surfaces
of each tooth are disposed at a second angle .alpha. with
respect to one another, and wherein a third, acute
angle .PHI. is defined between the axis and each of the
peak edges and each of the valley edges, wherein the
angles .PHI. and .alpha. are related substantially according to
the following equation: .PHI. = 90 - arccos <IMG> .

- 20 -
4. The joint of claim 1, wherein each pair of
adjacent valley edges defines a first angle, and
wherein all of the first angles defined by pairs of
adjacent valley edges are substantially equal to one
another.
5. The joint of claim 4, wherein all of the
first angles defined by pairs of adjacent valley edges
are substantially equal to fifteen degrees.
6. The joint of claim 5, wherein each of the
first and second faces includes twenty-four teeth.
7. The joint of claim 1, wherein a second, acute
angle is defined between the axis and each of the peak
edges and each of the valley edges.
8. The joint of claim 7, wherein all of the
second angles are substantially equal to one another.
9. The joint of claim 8, wherein all of the
second angles are substantially equal to 86°15'.
10. The joint of claim 1, wherein the adjusting
means includes means for releasably holding the first
and second members together with the first and second
faces disposed substantially in mating contact with one
another so that the teeth thereof are substantially
interlocked.

- 21 -
11. The joint of claim 10, wherein the holding
means includes a screw.
12. The joint of claim 10, wherein the holding
means includes a screw extending through a first hole
defined by the first member and threadedly received by
a second hole defined by the second member.
13. The joint of claim 10, wherein the adjusting
means is in the second state when the screw is
sufficiently tight to hold the first and second members
together such that the first and second members cannot
pivot with respect to one another and in the first
state when the screw is sufficiently loose to enable
the first and second members to rotate freely and
independently about the axis.
14. The joint of claim 1, wherein the teeth of
the first and second faces are integral with the first
and second members, respectively.
15. The joint of claim 1, wherein at least one of
the first and second members is composed of a metal.
16. The joint of claim 15, wherein at least one
of the first and second members is composed of a
conductive metal.

- 22 -
17. The joint of claim 15, wherein at least one
of the first and second members is composed of a
conductive metal and the teeth thereof are formed by
electrical discharge machining.
18. The joint of claim 1, wherein at least one of
the first and second members is composed of plastic.

- 23 -
19. A locking knuckle-type joint for pivotably
interconnecting first and second members that are
movable at least along an axis intersecting the joint
at a center point thereof, and pivotable at least about
the axis between selected locked positions, the joint
comprising:
first and second complementary, interlockable
faces on the first and second members, respectively;
a respective plurality of mating teeth on each of
the first and second faces, wherein each tooth has a
peak edge extending substantially radially
substantially from the center point, and each pair of
adjacent teeth defines a valley edge extending
substantially radially substantially from the center
point between the adjacent teeth such that each tooth
is bounded by a pair of adjacent valley edges, and
wherein the first and second faces are oppositely
disposed at the joint and are adapted for mating
contact with one another such that the teeth of the
first and second faces are substantially matingly
interlocked with one another; and
means for releasably locking the first and second
members with the respective faces matingly interlocked.

- 24 -
20. In combination with the locking knuckle-type
joint of claim 1, an apparatus for gripping a tool, the
apparatus comprising:
a pair of gripper jaw portions coupled together by
a pair of tightening screws, wherein the jaw portions
together define a variable-gauge jaw adapted for
securely gripping a tool; and
at least one fitting coupled to one of the first
and second jaw portions via a first locking knuckle-
type joint, such that the fitting and the jaw portion
to which the fitting is coupled are the first and
second members, respectively, of the first joint.
21. The apparatus of claim 20, wherein at least
one fitting comprises a handle.
22. The apparatus of claim 20, wherein at least
one fitting includes means for receiving a handle.
23. The apparatus of claim 22, wherein at least
one fitting comprises at least two fitting portions
coupled together via a second locking knuckle-type
joint, such that the two fitting portions are the first
and second members, respectively, of the second locking
knuckle-type joint.
24. The apparatus of claim 22, wherein at least
one fitting includes means for receiving a shank
enabling the apparatus to be used with a power
reciprocating tool.

- 25 -
25. An apparatus for gripping a tool, comprising:
a pair of gripper jaw portions coupled together by
a pair of tightening screws, wherein the jaw portions
together define a variable-gauge jaw adapted for
securely gripping a tool; and
a pair of handles, one coupled to each of the
first and second jaw portions.
26. In combination with the locking knuckle-type
joint of claim 1, a modular tool comprising:
a tool head; and
a handle coupled to the tool head via a first
locking knuckle-type joint, such that the tool head and
the handle are the first and second members,
respectively, of the first locking knuckle-type joint.
27. The modular tool of claim 26, wherein the
handle includes a handle portion and a fitting, coupled
together via a second locking knuckle-type joint, such
that the handle portion and the fitting are the first
and second members, respectively, of the second locking
knuckle-type joint, and wherein the tool head and the
fitting are the first and second members, respectively,
of the first locking knuckle-type joint.

Description

- 1 - PATENT APPLICATION
28429/32247
2168537
LOC~ING ~Nu~E-TYPE JOINT
AND APPARAT~S EMPLOYING SAME
Technical Field
The present invention relates generally to
knuckle-type joints and more particularly to a locking
knuckle-type joint useful for pivotably interconnecting
first and second tool members and locking them in a
plurality of angular orientations with respect to one
another.
Back~round Art
Ordinarily, when two structures, such as tool
members, must be interconnected such that they are
pivotable with respect to one another, a'nd lockable in
a plurality of angular orientations with respect to one
another, a locking knuckle-type joint (i.e., a joint
that permits rotational movement about a single axis)
is provided. These joints generally include a pair of
contacting surfaces, one of which is disposed on each
of the two structures. When in contact, the surfaces
inhibit rotation of one of the structures with respect
to the other in order to maintain a desired angular
orientation between the two structures.
Prior-art, locking, knuckle-type joints accomplish
this locking function either by providing means for
maintaining frictional engagement between the
contacting faces such that the two structures cannot
easily be rotated with respect to one another or by
providing means for interlocking the faces in one of a

` - 2 - PATENT APPLICATION
2 1 6 8 5 3 7 28429/32247
plurality of predetermined positions. The frictionally
engaging joint often provides continuous rotational
movement so that any desired angular orientation
between the two structures may be obtained, but this
type of joint does not provide sufficient holding power
for those applications where appreciable torque is
applied to the two structures. In contrast, the
interlocking joint may be interlocked in a plurality of
discrete angular orientations and provides somewhat
greater holding power than the frictional joint. The
contacting faces of prior interlocking joints have not
been designed to provide adequate mating with one
another, however. As a result, prior-art interlocking
joints do not provide satisfactory holding power in
high-torque applications.
Further, many prior-art knuckle joints do not
provide stable mating between the faces of the two
joint halves; instead, the joint halves contact one
another primarily along the circumference thereof,
resulting in poor high-torque performance, or they
contact one another primarily in the center thereof,
such that the faces may pivot about the center and rock
with respect to one another, resulting in poor holding
performance altogether. Still further, prior locking
knuckle-type joint designs have not been capable of
miniaturization while maintaining a reasonably high
degree of holding power for small joints.

- 3 - PATENT APPLICATION
2 1 6 8 5 3 7 28429/32247
Summary of the Invention
According to the present invention, a locking
knuckle-type joint pivotably interconnects first and
second members which are moveable at least along an
axis intersecting the joint and pivotable at least
about the axis between selected locked positions. The
joint includes first and second complementary,
interlockable faces on, and preferably integral with,
the first and second members, respectively, and a
respective plurality of mating teeth on each of the
first and second faces. Each tooth has a peak edge
extending substantially radially from the center point,
and each pair of adjacent teeth defines a valley edge
extending substantially radially from the center point
between the adjacent teeth such that each tooth is
bounded by a pair of adjacent valley edges. The first
and second faces are oppositely disposed at the joint
and are adapted for substantially mating contact with
one another such that the teeth of the first and second
faces are substantially matingly interlocked with one
another. A joint according to the present invention
also includes adjusting means having first and second
states for adjusting the distance along the axis
between the oppositely disposed first and second
complementary, interlockable faces on the first and
second members. When the adjusting means is in the
first state, the first and second members are freely
and independently pivotable about the axis relative to
one another. When the adjusting means is in the second
state, the first and second members are locked into one

-
- 4 - PATENT APPLICATION
2 1 6 ~ 5 3 7 28429/32247
of a plurality of angular orientations relative to one
another, and the first and second faces are disposed in
substantially mating contact with one another in the
selected locked position.
In accordance with a particular aspect of the
present invention, each tooth has a pair of surfaces,
each of which is bounded between the peak edge of the
tooth and a respective one of the valley edges bounding
the tooth, wherein the surfaces of the teeth of each of
the first and second faces together substantially
completely define the first and second faces.
In one embodiment of the present invention, each
face includes N teeth, each tooth subtending a first
angle ~ substantially equal to 3N degrees. Also in
that embodiment, the surfaces of each tooth are
disposed at a second angle ~ with respect to one
another; and a third, acute angle ~, defined between
the axis and each of the peak edges, and also between
the axis and each of the valley edges, is related to
the first angle ~ and the second angle ~ substantially
according to the following equation:
tan(~)
= 90 - arccos 4
tan(2)
Each pair of adjacent valley edges defines a first
angle, and all of the first angles defined by pairs of
adjacent valley edges are substantially equal to one
another and are preferably substantially equal to
fifteen degrees, whereby each of the first and second
faces includes twenty-four teeth.

- 5 PATENT APPLICATION
2 1 6 8 5 3 7 28429/32247
_
In addition, a second acute angle is defined
between the axis and each of the peak edges and each of
the valley edges, and all of the second angles are
substantially equal to one another, and are preferably
substantially equal to 8615'.
According to another aspect of the present
invention, the adjusting means includes means for
releasably holding the first and second members
together with the first and second faces disposed in
substantially mating contact with one another so that
the teeth thereof are interlocked. Preferably, the
holding means includes a screw extending through a
first hole defined by one of the members and threadedly
received by a second hole defined by the other member.
Also preferably, the adjusting means is in the second
state when the screw is sufficiently tight to hold the
first and second members together such that the first
and second members cannot pivot with respect to one
another and in the first state when the screw is
sufficiently loose to enable the first and second
members to rotate freely and independently about the
axis.
In accordance with a particular embodiment of the
present invention, at least one of the first and second
members is composed of a conductive metal, and the
teeth thereof are formed by electrical discharge
ma~h;n~ng. One or both of the first and second members
may alternatively be composed of plastic or any other
suitable material, if desired.

- 6 - PATENT APPLICATION
2 1 6 8 5 3 7 28429/32247
One application for which the locking knuckle-type
joint of the present invention is particularly useful
is an apparatus, combined with the locking knuckle-type
joint described herein, for gripping a polishing or
grinding stone or other tool. Such an apparatus
includes a pair of gripper jaw portions coupled
together by a pair of tightening screws, wherein the
jaw portions together define a variable-gauge jaw
adapted for securely gripping a tool, and at least one
fitting coupled to one of the first and second jaw
portions via a first locking knuckle-type joint, such
that the fitting and the jaw portion to which the
fitting is coupled are the first and second members,
respectively, of the first joint.
Preferably, at least one fitting of such an
apparatus includes either a handle or means for
receiving a handle. One fitting may include two or
perhaps more fitting portions coupled together via
further locking knuckle-type joints such that any two
adjacent fitting portions are the first and second
members, respectively, of the further locking knuckle-
type joints. In one embodiment, one fitting may
include means for receiving a shank for enabling the
apparatus to be used with a power reciprocating tool.
Another application embodying the locking knuckle-
type joint of the present invention is a modular tool
including a tool head and a handle coupled to the tool
head via a first locking knuckle-type joint such that
the tool head and the handle are the first and second
members, respectively, of the first locking knuckle-

- 7 - PATENT APPLICATION
28429/32247
2168537
type joint. Preferably, the handle of the modular tool
includes a handle portion and a fitting, coupled
together via a second locking knuckle-type joint, such
that the handle portion and the fitting are the first
and second members, respectively, of the second locking
knuckle-type joint, the tool head and the fitting being
the first and second members, respectively, of the
first locking knuckle-type joint. Of course, any
desired number of such intenmediate fittings may
interconnect the handle portion and the tool head.
Brief Description of the Drawin~
The features of this invention which are believed
to be novel are set forth with particularity in the
appended claims. The invention may be best understood
by reference to the following description taken in
conjunction with the accompanying drawings, in which
like reference numerals identify like elements in the
several figures and in which:
Fig. 1 is a fragmentary isometric view of first
and second members coupled together by a locking
knuckle-type joint according to the present invention;
Fig. 2 is an exploded fragmentary isometric view
of the locking knuckle-type joint of Fig. 1;
Fig. 3 is a fragmentary plan view of one of the
first and second members of the locking knuckle-type
joint of Fig. 1;
Fig. 4 iS sectional view of the locking knuckle-
type joint taken along the lines 4--4 of Fig. 3;

- 8 - PATENT APPLICATION
28429/32247
21 68537
Fig. 5 is a fragmentary elevational sectional view
taken along the lines 5--5 of Fig. 4;
Fig. 6 is a view similar to Fig. 3, but depicting
an alternative embodiment of the locking knuckle-type
joint;
Fig. 7 iS a fragmentary view similar to Fig. 4 of
the alternative embodiment of the locking knuckle-type
joint depicted in Fig. 6;
Fig. 8 is a view similar to Fig. 5 of the locking
knuckle-type joint of Fig. 6;
Fig. 9 is an isometric view of a tool-gripping
apparatus embodying the locking knuckle-type joint of
Fig. 1;
Fig. 10 is an exploded isometric view of the tool-
gripping apparatus of Fig. 9;
Fig. 11 is a plan view of a modular tool embodyingthe locking knuckle-type joint of Fig. 1;
Fig. 12 is a fragmentary elevational view of the
modular tool of Fig. 11, taken along the lines 12--12
of Fig. 11;
Fig. 13 is a fragmentary plan view of a variant of
the modular tool of Fig. 11 including an
expander/reducer fitting; and
Fig. 14. iS an fragmentary plan view of another
variant of the modular tool of Fig. 11 including an
extender fitting.
Description of the Preferred Embodiment~
Referring initially to Fig. 1, a locking knuckle-
type joint 20 according to the present invention

- 9 - PATENT APPLICATION
28429/32247
2168537
pivotably interconnects first and second members 22,
24. The first and second members 22, 24 are
independently movable at least along an axis 26
inter~ecting the joint 20 at a center point 28 (shown
only in Fig. 2) thereof, and are pivotable at least
about the axis 26 between selected, discrete, locked
positions as indicated by the arrow 30 in Fig. 1. To
illustrate the locked positions or angular orientations
of the first member 22 relative to the first member 22,
a replica 32 of the second member 24 is shown in
phantom lines in Fig. 1. Of course, any desired number
of such locked positions may be provided in accordance
with the present invention.
Referring now to Fig. 2, the joint 20 includes
first and second complementary interlockable faces 34,
36 on the first and second members 22, 24,
respectively, and a respective plurality of mating
teeth 38 on each of the first and second faces 34, 36.
Each tooth 38 has a peak edge 40 extending
substantially radially from the center point 28, and
each pair of adjacent teeth 38 defines a valley edge 46
extending substantially radially from the center point
- 28 between the adjacent teeth 38 such that each tooth
38 is bounded by a pair of adjacent valley edges 46.
As shown by Figs. 1 and 2 together, the first and
second faces 34, 36 are oppositely disposed at the
joint 20 and are adapted for substantially mating
contact with one another such that the teeth 38 of the
first and second faces 34, 36, including the respective
peak edges 40 and opposite valley edges 46, are

- 10 - PATENT APPLICATION
2 1 6 8 ~ 3 7 28429/32247
substantially matingly interlocked with one another as
best shown in Fig. 1. As a result, the joint 20 does
not suffer from the disadvantages described above in
connection with prior-art knuckle-type joints.
The joint 20 also includes a screw 54 or any other
suitable means for adjusting the distance along the
axis 26 between the oppositely disposed first and
second complementary, interlockable faces 34, 36 on the
first and second members 22, 24. The adjusting means
has first and second states corresponding, for example,
to loose and tight in the case of the screw 54. When
the adjusting means is in the first state thereof, the
first and second members 22, 24 are freely and
independently pivotable about the axis 26. When the
adjusting means is in the second state thereof, the
first and second members 22, 24 are locked into one of
the plurality of angular orientations relative to one
another, and the first and second faces 34, 36 are
disposed in substantially mating contact with one
another in the selected locked positions. Where the
adjusting means is a screw 54, the adjusting means is
in the first state when the screw is sufficiently loose
to enable the first and second members 22, 24 to rotate
freely and independently about the axis 26 with respect
to one another and in the second state when the screw
54 is sufficiently tight to hold the first and second
members 22, 24 together such that they cannot pivot
about the axis 26 with respect to one another.
AS shown in Fig. 2, the screw 54 extends through a
first hole 56 defined by the first member 22 and is

- 11 - PATENT APPLICATION
2 1 6 8 ~ 3 7 28429/32247
threadedly received by a second hole 58 defined by the
second member 24. Alternatively, the adjusting means
may include any other means for releasably holding the
first and second members 22, 24 together with the first
and second faces 34, 36 disposed in substantially
mating contact with one another so that the teeth 38
thereof are substantially matingly interlocked. For
example, a clamp (not shown) may be used for releasably
holding the first and second members 22, 24 together.
Each tooth 38 of the joint 20 has a pair of
slanting surfaces 60, 62, each of which is bounded
between a respective one of the valley edges 46 and a
respective one of the peak edges 40. The respective
slanting surfaces 60, 62 of a tooth 38 intersect along
and define the respective peak edges 40. Together, the
surfaces 60, 62 of all of the teeth 38 of each face 34
or 36 preferably substantially completely define that
face.
Referring now to Figs. 1-5, in one embodiment of
the joint 20, each face 34, 36 may include any desired
number N of teeth 38, and each tooth 38 subtends an
angle ~ substantially equal to 3N degrees (Fig. 3).
The surfaces 60, 62 of each tooth 38 are disposed at an
angle ~ with respect to one another ~ Fig . 5), and an
acute angle ~ is defined between the axis 26 and each
of the peak edges 40 and each of the valley edges 46
(Fig. 4). The angle ~ is related to the angles ~ and

- 12 - PATENT APPLICATION
2 1 6 ~ ~ 3 7 28429/32247
substantially according to the following equation:
tan(~)
= 90 - arccos 4 degrees. Thus, for example,
tan(2)
if it is desired that a joint have N=24 teeth 38 (such
that ~=15), and that the teeth 38 have surfaces 60, 62
disposed at an angle ~=90, then the peak edges 40 and
the valley edges 46 must define an angle ~
approximately equal to 8615' with the joint axis 26.
Referring now to Figs. 6-8, a variant embodiment
of the above-described locking knuckle-type joint 20
will now be described. The only difference between
this embodiment and the previously described embodiment
is that, as shown in Figs. 6-8, the peak edges of the
teeth 38 are fully, or at least partially, removed so
that each tooth 38 has a flat surface 64 between the
surfaces 60, 62. Consequently, while the surfaces 60,
62 of each tooth 3 8 are defined by a peak edge that
extends substantially radially from the center point 28
of the joint 20 in this embodiment, the flattening of
the teeth may eliminate their peak edges in whole or in
part. As shown in Figs. 7 and 8, the removal of the
peak edges from the teeth 38 of each mating face 34, 36
creates a void 66 between each flat surface 64 and the
corresponding mating valley of the opposing face. Of
course, it will be evident to those skilled in the art
that if too much of the peak of each tooth 38 iS
removed, the faces 34, 36 of the first and second
members 22, 24 will not mate properly, and the holding
power of the joint 20 of the present invention will be

- 13 - PATENT APPLICATION
28429/32247
21 68537
compromised or lost. Generally, if less than half of
each tooth 38 is removed, the faces 34, 36 of the first
and second members 22, 24 will mate properly, but the
holding power of the joint 20 varies directly with the
amount of surface contact between the mating faces 34,
36.
It should be noted that the first and second
toothed faces 34, 36 are shown to be integral with the
first and second members 22, 24, but they can also be
separate, toothed members suitably secured to the first
and second members 22, 24.
In addition, at least one of the first and second
members 22, 24 preferably is composed of a metal and,
more particularly, a conductive metal. Further, the
teeth 38 of the conductive metal member 22 or 24
preferably are formed by electrical discharge
marh;n;ng. Alternatively, however, one or both of the
first and second members 22, 24 may be composed of
plastic or any other suitable material, if desired.
Referring now to Figs. 9 and 10, a tool-gripping
apparatus 70 embodying the locking knuckle-type joint
20 of the present invention is now described in detail.
A polishing, cutting, or grinding stone or other
tool 72 is often used in ma~hin;ng metal, such as in
producing dies for molding plastic parts. Because
these tools 72 are typically quite small, it is often
difficult for users of these tools 72 to hold them
securely while applying sufficient force to polish,
cut, grind, or otherwise treat the object (not shown)
being tooled. Accordingly, the present tool-gripping

. - 14 - PATENT APP~ICATION
- 2 1 6 ~ 5 3 7 28429/32247
apparatus 70 iS provided to facilitate a user's
gripping of the tool 72.
The tool-gripping apparatus 70 includes a pair of
oppositely disposed gripper jaw portions 74, 76 coupled
together by a pair of tightening screws 78, 80. The
jaw portions 74, 76 together define a jaw 82 which
securely grips the tool 72. The size of the jaw 82 iS
adjusted by turning the screws 78, 80, So that a tool
72 of any shape and size can be accommodated between
the jaw portions 74, 76. The jaw portions 74, 76 are
tightened to securely grip the stone or tool using the
screws 78, 80. Of course, screws 78, 80 of any desired
length may be provided to permit an arbitrarily large
tool 72 to be held within the jaw 82.
Handles 84, 86 are secured to the first and second
jaw portions 74, 76, respectively. The handles 84, 86
permit a user of the tool-gripping apparatus 70 to
comfortably grip, manipulate, and apply pressure to the
stone or tool 72 while keeping his hands clear of the
20 working area. In fact, to provide m~;ml-m convenience
and comfort for the tool worker, each handle 84 and 86
is adjustable and interchangeable.
For adjustability, each handle 84, 86 iS provided
with one or more locking knuckle-type joints 88, 89, 90
of the present invention as described above. The
knuckle-type joints 88, 89, 90 permit a wide range of
adjustment of each of the handles 84, 86. Notably, the
handle 84 is coupled to a fitting portion 92 by one
knuckle-type joint 88, and the fitting portion 92, in
turn, is coupled to the gripper jaw portion 74 by

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28429/32247
- 216~537
another knuckle-type joint 89. This arrangement
permits the handle 84 to be rotated about the tool 72
in three ~;m~n~ions so that the handle 84 can be locked
in a wide range of different positions, depending upon
the needs of the user of the gripping tool 70 in any
desired application thereof. Of course, a tool-
gripping apparatus 70 that is to be dedicated only to
one particular application may be constructed with
stationary handles (i.e. without the knuckle-type
joints 88-90), if desired.
With regard to interchangeability, each handle 84,
86 can be removed and replaced by a handle of a
different size or shape as desired. Of course, any
type of handle may be used in place of the generally
ovate handles 84, 86 shown in Figs. 9 and 10. In
addition, at least one of the handles (e.g., the handle
84) can be replaced by a shank 94 (as shown in Fig. 10)
so that the tool-gripping apparatus 70 can be used in
conjunction with a power reciprocating tool (not shown)
for automatically reciprocating the polishing stone or
other tool 72 with respect to a workpiece (not shown).
The interchangeability of the handles 84, 86 can be
achieved by disconnecting the handles 84, 86 at their
respective knuckle-type joints and substituting other
desired handles. Alternatively, the handles 84, 86 are
provided with threaded connecting screws 95 by which
the handles 84, 86 can be unscrewed to permit
replacement thereof.
Finally, to facilitate the convenient application
of polishing or lubricating fluid, a flexible hose 96

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is secured to one of the gripper jaw portions 74 or 76
by any conventional means. A fluid reservoir or
squeeze bottle (not shown) is connected to the end of
the hose 96 remote from the tool-gripping apparatus 70
so that a user can easily add polishing fluid or
lubricant directly to the working area, such as by
squeezing the squeeze bottle or opening a valve to
permit fluid in the fluid reservoir to flow through the
hose 96 to the working area.
Referring now to Figs. 11-14, a modular tool 100
embodying the locking knuckle-type joint 20 of the
present invention is now described in detail.
The modular tool 100 includes a tool head 102 and
a handle 104 coupled to the tool head 102 either
directly via a locking knuckle-type joint or indirectly
via one or more fittings which may be interconnected by
locking knuckle-type joints. For example, as shown in
Figs. 11 and 12, the tool head 102 is coupled to a
fitting 106 by a locking knuckle-type joint 108 of the
type described herein. In turn, the fitting 106 is
coupled to another fitting 110 by a second locking
knuckle-type joint 112 which is coupled to the handle
104 by a third locking-knuckle type joint 114.
The fittings 106, 110 may be one of two types.
The fittings 106, 110 shown in Figs. 11, 12, and 14 are
extenders which are designed simply to connect two
other members with knuckle-type joints of equal size.
Alternatively, a fitting may be an expander/reducer,
such as the fitting 116 (shown in Fig. 13) which is
designed to connect a handle (or a fitting) 118 having

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a knuckle-type joint 120 of one size with a tool head
(or another fitting) 122 having a knuckle-type joint
124 of a different size, whether smaller, in the case
of a reducer (shown in Fig. 13), or larger, in the case
of an expander (not shown).
As illustrated by Figs. 11-14, the tool head 102
of the modular tool 100 may be virtually any type of
torque- or force-applying tool. Possible tool heads
102 include, for example, open-end wrenches (Figs. 11-
13), box-end wrenches (Fig. 14), crescent wrenches,
pipe wrenches, pliers, shears, pry bars, and h~mm~r
among others.
The foregoing description is for the purpose of
teaching those skilled in the art the best mode of
carrying out the invention and is to be construed as
illustrative only. Numerous modifications and
alternative embodiments of the invention will be
apparent to those skilled in the art in view of this
description. The details of the disclosed structure
may be varied substantially without departing from the
spirit of the invention, and the exclusive use of all
modifications within the scope of the appended claims
is reserved.

Representative Drawing