Note: Descriptions are shown in the official language in which they were submitted.
2149~51
UNIVERSAL JOINT FOR TORQUE TRANSMITTING TOOLS
Backqround of the Invention
This invention relates to a universal joint
of the type comprising first and second parts, wherein
the first part defines a recess configured to receive a
drive stud of a torque transmitting tool and the second
part comprises a drive stud configured to engage a tool
head. At least one coupling element is positioned
between the first and second parts to transmit torque
therebetween while allowing the first and second parts
to rotate with the first part positioned in a skew
orientation with respect to the second part.
Universal joints of this type are in common
use with torque transmitting tools such as socket
wrenches. See for example the constant velocity type
universal joint described in Hazebrook U.S. Patent
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3 ~ 1
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4,941,862. Conventional universal joints include a
spring biased detent ball on the drive stud that
engages the recess of the tool head that is mounted to
the universal joint to provide a retention force that
cannot be readily altered or selected by the user.
This arrangement is not without disadvant-
ages. In particular, on some occasions it would be
preferable if a tool head were held in place in the
drive stud more securely and more positively. On other
occasions it would be preferable if a tool head could
be released from the drive stud so as to drop freely
from the drive stud and allow one hand removal of the
tool head mounted on the drive stud.
Summary of the Invention
The present invention is directed to an
improved universal joint that allows a user to control
tool head retention forces manually.
According to this invention, a universal
joint of the type described initially above is provided
with an engaging element movably mounted in the drive
stud of the second part to engage the tool head when in
an engaging position and to release the tool head when
in a releasing position. An actuator is mounted to one
of the first and second parts for manipulation by a
user between first and second positions. A linking
element is movable by the actuator and is coupled to
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the engaging element to alter effectiveness of the
engaging element in retaining a tool head on the drive
stud of the second part, thereby allowing the user to
control said retention forces manually.
In a first group of embodiments the linking
element accommodates movement of the tool head engaging
element to allow the user to release the tool head from
the second part by moving the actuator to the first
position. The quick release embodiments of this
invention described below allow one hand removal of a
tool head from a universal joint. The user can simply
manipulate the actuator to release the tool head from
the drive stud of the universal joint, allowing the
tool head to fall from the drive stud.
In a second group of embodiments the linking
element is configured to allow the tool head engaging
element to move to the releasing position when the
actuator is moved to the first position, and to hold
the tool head engaging element in the engaging position
when the actuator is moved to the second position to
retain the tool head on the drive stud of the second
part more securely when the actuator is moved to the
second position. These embodiments allow a user
selectively to enhance retention of a tool head on the
drive stud of the universal joint, again by manipulat-
ing the actuator. This can be useful in situations
where the user wishes to guard against inadvertent
2149351
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removal of the tool head from the universal joint
during use.
The invention itself, together with further
objects and attendant advantages, will best be under-
stood by reference to the following detailed descrip-
tion, taken in conjunction with the accompanying
drawings.
Brief Description of the Drawinqs
Figure 1 is a perspective view of a universal
joint which incorporates a first preferred embodiment
of this invention.
Figure 2 is a side view in partial cutaway
showing the universal joint of Figure 1 mounted to a
socket wrench and to a socket.
Figure 3 is a view in partial cutaway and
partial section taken along line 3-3 of Figure 1,
showing the socket engaging element in the engaging
position.
Figure 4 is a cross-sectional view taken
along line 4-4 of Figure 3.
Figure 5 is a fragmentary cross-sectional
view corresponding to Figure 3, showing the socket
engaging element in the releasing position.
Figure 6 is a fragmentary cross-sectional
view of a second preferred embodiment which utilizes a
circumferential ramp.
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Figure 7 is a cross-sectional view taken
along line 7-7 of Figure 6.
Figure 8 is a cross-sectional view taken
along line 8-8 of Figure 6.
Figure 9 is a fragmentary cross-sectional
view of a third preferred embodiment of this invention.
Figure 10 is a cross-sectional view taken
along line 10-10 of Figure 8, showing the element 80"
shifted in the direction of the arrows.
Figure 11 is a cross-sectional view
corresponding to Figure 10, showing the element 80"
shifted in the direction of the arrows.
Figure 12 is a fragmentary cross-sectional
view taken along line 12-12 of Figure 11.
Figure 13 is a cross-sectional view of a
fourth preferred embodiment of this invention.
Figure 14 is a partial cross-sectional view
taken along line 14-14 of Figure 13.
Figure 15 is a fragmentary cross-sectional
view taken along line 15-15 of Figure 14.
Detailed Description of the
Presently Preferred Embodiments
Turning now to the drawings, Figures 1-4
provide various views of a first preferred embodiment
of the universal joint of this invention. The
universal joint 10 includes a first part 12 and a
second part 20. The first part 12 defines a recess 14
shaped to receive the drive stud D of a torque trans-
mitting tool, which in this example is a socket
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wrench W with an extension bar (Figure 2). As used
herein, the term "torque transmitting tool" is intended
to encompass the full range of tools for transmitting
torque, including but not limited to socket wrenches,
extension bars, T-bars, braces, as well as other hand
and power tools. The first part 12 also defines a
first joint portion 16 which includes two spaced,
parallel arms 18.
The second part 20 includes a drive stud 22
shaped to engage a tool head such as a socket S, which
is in turn configured to engage a workpiece such as a
hexagonal bolt head or nut or other nonround workpiece
(not shown) of a selected dimension. As used herein,
the term "tool head" is intended to encompass the full
range of devices, including but not limited to sockets,
hex wrench heads, other types of wrench heads, tool
bits of various types, and other types of bits includ-
ing drill bits. The second part 20 also includes a
second joint portion 24 which defines two spaced,
parallel arms 26. A longitudinal axis 30 passes
centrally through the drive stud 22.
A coupling element 32 pivotably interconnects
the first and second parts 12, 20. In this embodiment
the coupling element 32 is generally rectangular in
shape, and it includes first and second orthogonally
oriented pivot pins 34, 36. The pivot pin 34 is
mounted in the first arms 18, such that the coupling
element 32 is free to pivot with respect to the first
part 12 about the first pivot pin 34. The second pivot
pin 36 is mounted to the second arms 26, such that the
second part 20 is free to pivot with respect to the
coupling element 32 about the second pivot pin 36.
The foregoing features of the universal joint
10 are conventional, and they allow the first and
second parts 12, 20 to rotate with the first part 12
217~9351
positioned at a skew orientation with respect to the
second part 20.
According to this invention, the universal
joint 10 includes a tool head engaging element which
can be a socket engaging element 50 which in this
embodiment is spherical in shape. The socket engaging
element 50 is movably mounted in the drive stud 22 such
that it can be moved between an engaging position as
shown in Figure 3 and a releasing position as shown in
Figure 5. In the engaging position of Figure 3, the
socket engaging element 50 protrudes beyond the drive
stud 22 to engage and retain the socket. In the
releasing position of Figure 5, the socket engaging
element 50 is received entirely within the drive stud
22, thereby releasing the socket.
The position of the socket engaging element
50 is controlled at least in part by a linking element
60 which in this embodiment defines a longitudinally
extending ramp 62 which is movable along the longi-
tudinal axis 30. The linking element 60 is slideably
received in a stepped bore 61 formed in the second
part 20. The ramp 62 defines an elevated portion 64
and a lowered portion 66. The linking element 60 also
includes a reduced diameter shaft 68 which terminates
in a head 69. A spring 70 which in this embodiment is
a coil compression spring, is mounted around the
shaft 68 so as to bias the ramp 62 farther into the
drive stud 32. In the rest position the elevated
portion 64 of the ramp 62 is aligned with the socket
engaging element 50, as shown in Figure 3.
An actuator 80 which in this preferred
embodiment is platelike defines an opening 82 and
peripheral gripping portions 84. The actuator 80 is
positioned between the second arms 26, in the region
between the drive stud 22 and the coupling element 32.
The shaft 68 of the linking element 60 passes through
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the opening 82, and the head 69 is secured to the
actuator 80 to prevent the shaft 68 from moving out of
the opening 82. For example, the head 69 may be welded
or riveted in place on the actuator 80.
In the rest position of Figure 3, the spring
70 holds the ramp 62 in a first position, in which the
elevated portion 64 maintains the socket engaging
element 50 in the engaging position of Figure 3. When
the user wishes to release a socket from the drive
stud 22, the user manipulates the peripheral gripping
portions 84 of the actuator 80 to move the actuator 80
to withdraw the ramp 62 partially from the drive
stud 22 in this example. When the actuator 80 reaches
a second position as shown in Figure 5, in which the
lowered portion 66 is aligned with the socket engaging
element 50, the socket engaging element 50 is free to
move radially inwardly, thereby releasing the socket.
When the socket engaging element 50 is in the releasing
position of Figure 5, the socket is free to fall by
force of gravity from the drive stud 22.
Depending upon the slope of the ramp 62, the
universal joint 10 can be made to retain the socket
with a more or less positive retention force. If the
ramp 62 has a gradual slope, relatively large forces
will be required to depress the socket engaging element
50 if the actuator 80 is not manipulated. With such an
arrangement, a user will typically manually move the
actuator 80 from the first position of Figure 3 to the
second position of Figure 5 when moving a socket onto
the drive stud 22. Alternately, if the slope of the
ramp 62 is sufficiently steep, a user will be able to
install a socket on the drive stud 22 simply by pushing
the socket into position, without independently
manipulating the actuator 80.
Figures 6-8 relate to a second preferred
embodiment 10' which is in many ways similar to the
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g
preferred embodiment discussed above in conjunction
with Figures 1-5. In the embodiment of Figures 6-8,
the linking element 60' defines a ramp 62' which
extends circumferentially around the linking element
60'. The illustrated ramp 62 is circular, but spiral
ramps are also suitable. As best shown in Figure 7,
the ramp 62' defines an elevated portion 64' and a
lowered portion 66' at respective angular positions of
the linking element 60'. In this case the actuator 80'
is a lever arm mounted to extend to a peripheral
portion of the second part 20'. The lever arm 80'
defines an extending peripheral portion 84' which is
positioned to be manipulated by a user.
The embodiment of Figures 6-8 operates
similarly to the embodiment of Figures 1-5, except that
the user controls the position of the linking element
60' by rotating the actuator 80' through an arc of
about 90. In this case the spring 70' is a compres-
sion spring which tends to hold the linking element 60'
by friction in the position in which it was left by the
user. In the position shown in Figure 7, the socket
engaging element 50 is in the engaging position. Rota-
tion of the actuator 80' by 90 aligns the lowered
portion 66' with the socket engaging element 50 to
release a socket from the drive stud of the universal
joint 10'. If desired a spring such a torsion spring
or a compression spring with a spiral ramp can be used
to bias the ramp to a selected position.
The universal joints 10, 10' provide a quick
release feature which is useful in many applications.
Figures 9-12 relate to a third preferred embodiment
which is designed to allow a user to choose between
enhanced and reduced retention of a socket on the
universal joint when desired. In this third embodi-
ment, the universal joint 10'' includes a linking
element 60'' which defines a ramp 62'' which is similar
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to that described above. In this case the shaft 68''
terminates in a stub shaft 69'', as shown in Figure 9.
The actuator 80'' is shaped as a plate which is mounted
in the second part 20'' so as to slide at right angles
to the longitudinal axis 30''. This plate 80'' defines
an opening 82'' positioned selectively to block and
allow movement of the linking element 60'' along the
longitudinal axis 30''.
In the position shown in Figure 9, the
opening 82'' is aligned with the stub shaft 69'', and
forces can be applied through the socket to the socket
engaging element 50 in the direction of the arrow A to
move the ramp 62'' toward the coupling element 32'',
and the stub shaft 69'' into the opening 82''. This
allows a user to install a socket onto the drive stud
22'' by pressing it in place and to remove it by
pulling it in the conventional manner. ~hen a user
desires to increase the forces tending to hold the
socket in place on the drive stud 22'', the user slides
the actuator 80'' so as to move the opening 82'' out of
alignment with the stub shaft 69'' (Figures 11 and 12).
In this position, the ramp 62'' is blocked from moving
toward the coupling element 32'', and the socket is
more securely held in place on the drive stud 22''.
The embodiment of Figure 9-11 does not pro-
vide a quick release function, but instead allows the
user selectively to enhance the socket retaining forces
in order to reduce the chance that a socket will inad-
vertently be removed from the drive stud.
Figures 13-15 relate to a fourth preferred
embodiment which also allows the user to choose between
enhanced and reduced retention of a socket on the
universal joint when desired. In this fourth
embodiment, the universal joint 10''' includes a tool
engaging element such as a socket engaging element 50,
the position of which is controlled at least in part by
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~1~93~1
- 11 --
a sphere 61''' which is biased toward the socket
engaging element 50 by a compression spring 70'''. The
position of the sphere 61''' is controlled in part by
the position of a slide 63''' which is slideably
mounted in a bore in the second part 20''' of universal
joint 10'''. The position of the slide 63''' is
controllable by a user by means of an actuator 80'''
which defines a recess 82'''. In this
embodiment the sphere 61''' and the slide 63'''
cooperate to form a two-piece linking element 60'''
that couples the actuator 80''' with the socket
engaging element 50.
When a user moves the actuator 80''' to the
position shown in Figure 13 the spring 70''' biases the
sphere 61''' into contact with the socket engaging
element 50. Depending upon the spring force developed
by the spring 70''', the universal joint 10''' can be
designed such that in this position the socket engaging
element 50 provides a small, moderate or large
retention force, as appropriate for the particular
application. In some embodiments the spring force
generated by the spring 70''' may be so large as
effectively to prevent a socket from being removed from
the second part 20''' in the great majority of
situations.
When a user desires to release a socket from
the second part 20''' the user can slide the actuator
relative to the second part 20''' to the left as shown
in Figure 14. This movement of the actuator 80'''
moves the slide 63''' toward the spring 70''', thereby
moving the sphere 61''' away from the socket engaging
element 50. In this position of the sphere 61''', the
socket engaging element 50 is free to move inwardly,
thereby releasing a retained socket. Intermediate
degrees of socket retaining forces can be obtained by
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- 12 -
positioning the actuator 80''' in an intermediate
position between the positions of Figures 13 and 14.
The embodiment of Figures 13-15 allows the
user selectively to enhance the socket retaining forces
in order to reduce the chance that a socket will
inadvertently be removed from the drive stud, while
still providing a quick release function.
The embodiments described above provide the
important advantage that the universal joint 10, 10',
10'', 10''' is not lengthened excessively. The
actuator 80, 80', 80'', 80''' and the linking element
60, 60', 60'', 60''' are designed such that they can be
installed in the second part 20, 20', 20'', 20'''
without any substantial increase in the length of the
second part 20, 20', 20'', 20'''. Excessive
lengthening of the second part 20, 20', 20'', 20'''
would make it more difficult or even impossible to use
the universal joint 10, 10', 10'', 10''' in some
applications where space is restricted. Excessive
lengthening of the second part may also bring a
mechanical disadvantage in some applications.
The linking elements 60, 60'', 60''' shift
axially (parallel to the longitudinal axis 30, 30'') in
use, yet even in this case the second part 20, 20'',
20''' is compact. In particular, the axial length of
the second part 20, as measured from the distal end 22a
of the drive stud 22 to the pivot axis (the center of
the pivot pin 36), is preferably no more than about
seven times a first distance, equal to the separation
between the two pivot axes (the centers of the pivot
pins 34, 36). More preferably, the length of the
second part 20 is no more than about six times the
first distance. Most preferably, the length of the
second part 20 is no more than about five times the
first distance. Similar ratios apply to the second
parts 20'', 20'''.
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In addition, the axial length of the second
part, as measured from the distal end of the drive stud
22 to the pivot axis (the center of the pivot pin 36),
is preferably no more than about 5 times the cross-
sectional width of the drive stud 22, measured between
parallel faces. More preferably, the axial length of
the second part is no more than about 4 times the
cross-sectional width of the drive stud 22. Most
preferably, the axial length of the second part is no
more than about 3 times the cross sectional width of
the drive stud. Similar ratios apply to the second
parts 20'', 20'''.
Of course, it should be understood that a
wide range of changes and modifications can be made to
the preferred embodiments described above. For
example, the foregoing preferred embodiments all
utilize a coupling member with two orthogonal pivot
axes. Alternately, this invention may be used with a
universal joint of the constant velocity type having a
plurality of spherical coupling members. Also, for
convenience various positions of the ramps, the socket
engaging elements and the actuators have been
described. It will of course be understood that the
term "position" is intended to encompass a range of
positions, as is appropriate for sockets that have
recesses of varying dimensions. Also, various other
types of quick release mechanisms can be adapted for
use with the universal joint of this invention, as can
other types of blocking mechanisms. Those skilled in
the art will recognize that various actuators and
linking elements can be used, and that some may include
multiple component parts. A wide range of ramps can be
used, including linear and non-linear ramps that
translate, rotate, or move with a combination of
rotation and translation. Many springs can be used to
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perform the biasing and holding functions described
above.
It is therefore intended that the foregoing
detailed description be regarded as illustrative rather
than limiting, and that it be understood that it is the
following claims, including all equivalents, which are
intended to define the scope of this invention.
