Note: Descriptions are shown in the official language in which they were submitted.
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Descri~tion
Hand Tool
Technical Field
This invention relates to a hand tool of the type
used for expansion and/or contraction of differing types
of deformable members.
Backqround Art
Snap or retaining rings are either "internal" or
"external". The internal type of retaining ring is used
to retain elements such as bearings or shafts, within a
bore. In order to install the ring it is contracted to
allow it to pass into the bore, and then allowed to
expand for engagement with an internal groove formed
around the bore. The external type of retaining ring is
used to retain elements such as bearings, gears or
pulleys on shafts. An external ring normally engages an
annular groove formed in a shaft to inhibit axial
movement of an element mounted on the shaft. An
external ring is generally installed by expanding the
ring until its internal diameter is greater than the
shaft diameter.
The tools typically used for installing and
removing internal and external rings are substantially
different. A tool for installing and removing external
rings, for example, must expand the ring to increase its
internal diameter in order to accommodate the shaft. An
internal ring installation and removal tool, however,
must contract the ring in order to decrease its external
diameter to enable the ring to pass through a bore.
Since the function and performance required of such
tools i5 SO substantially different, retaining ring
pliers are often supplied as single purpose "internal"
and "external" tools. These single purpose pliers are
intended for use only in installing or removing one type
of retaining ring, and both types of pliers are
'~
2 , 1312454
therefore required in order to install or remove both
external and internal types of retaining rings.
One solution to the provision of a tool suitable
for either internal or external rings has been the
provision of convertible tools capable of switching
between internal and external positions. These
required manipulation of interconnected pieces, movement
of a linkage arrangement mounted on the tool or
disassembly of jaw and/or handle sections in order to
accomplish the conversion.
One such convertible tool, known as a universal
plier, is illustrated in U.S. Patent No. 4,625,379. The
tool includes a pair of pivotally interconnected
handles and a pair of jaw members coupled to the handles
by a latching mechanism having two transversely slidable
latch members. In one position, the latch members are
positioned to allow one handle member to be coupled to
one jaw member and the other handle to be coupled to
the other jaw member. Upon transversely sliding the
latch members to a second position, the one handle is
coupled to the other jaw member and the other handle is
coupled to the one jaw member. While the construction
of the referenced patent has enjoyed great success, it
is relatively complex and it contains numerous parts
which must be properly assembled and aligned during
operation to provide proper functioning. In a substan-
tially different construction, a plier is provided
whereby separate pairs of jaws and handles are pivotally
interconnected about a common axis and are arranged such
that a pair of movable pins is adapted to alternately
engage the jaw and handle pairs to shift the jaw and
handle interconnections from an internal position to an
external position and visa versa.
An additional form of plier construction provides
interconnected levers having two jaw members for simul-
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tanèous operation of the tool on internal and external
retaining rings by a pair of jaws positioned for
internal operation and a pair of jaws for external
operation.
Another convertible plier construction utilizes
linkages that must be disengaged and the tool reas-
semblad in order to change the relationship between the
handles and jaws. Such a construction is cumbersome to
use as it requires unneeded preparation time prior to
use, and may alter the configuration of the ~ool such
that it becomes uncomfortable to use. In addition at
least some such tools have significantly different
mechanical advantages in the internal and external
positions.
A proposed tool provided handles which were
intended to be relatively moveable between internal and
external positions. To accomplish this one lever
included a U -shaped slot and the other carried a pivot
which projected through the slot. Presumably the levers
can be moved from a crossed internal ring relationship
with the pivot at one end of the slot to a side by slde
external ring relationship. If the proposed tool was
operable at all, it lacked structure to maintain the
levers in a selected relationship when in use.
Summary of Invention
The present invention provides a new and improved
hand tool for removing and installing internal and
external retaining rings. The tool includes two levers
permanently connected together which nonetheless may be
easily switched between internal and external operating
positions. In each embodiment reaction forces resulting
from a work operation apply a position retention force
to maintain the levers in a selected relationship while
a work operation is performed.
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In the originally preferred embodiment, the tool
comprises right and left operating lever sections
pivotally interconnected together with driving structure
for shifting the lever sections between tool operating
S positions. Each of the lever sections includes a jaw
portion, a handle portion and a boss portion inter-
mediate the jaw and handle portions. The pivotal
interconnection of the lever sections is perpendicular
to and intersects an imaginary center line which bisects
the tool.
The interconnection of the lever sections and
position of the jaw and handle portions of the lever
sections is configured in a side by side relationship
during operation of the tool in the external position.
Thus, both the jaw and handle portions of the one lever
section operate on one side of the center line, while
the jaw and handle portions of the other lever are on
the other side of the center line. When in the internal
operating position, the portions are crossed such that
the jaw and handle portions of the one lever operate on
opposite sides of the center line, and the jaw and
handla portions of the other lever are also opposite one
another relative to the center line.
In the originally preferred construction, one lever
section and the driving structure, wh`ich comprises a
driving knob, are coupled together so that the other
lever section moves relative to the one lever section
and driving knob. As a result of this construction,
when the tool is in the external position, the lever
sections are crossed. When the driving knob is manually
rotated to shift the levers for operation in the
internal position, the lever sections move to opposite
sides of the center line in side by side relationship.
Because the tool is configured to provide a movable
relationship between the lever sections for internal
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and external positioning, there is no requirement that
discrete handle members and jaw members be selectively
interconnected for being reversibly coupled to one
another. The present invention instead provides that the
levers are shiftable between positions.
In the originally preferred embodiment, a driving
knob couples the levers. The knob includes a handle
portion, a lever engagement portion and a base portion
disposed in a circular recess in one of the levers. A
pivot connects that base portion to the other lever in
eccentric relationship. The base portion includes an
arcuate groove which is coaxial with the base portion.
The other lever includes a projection which extends into
the groove in a work position orientation relationship.
To move the tool between external and internal posi-
tions, the handle portion of the knob is manually
rotated to cause eccentric relative lever movement so
that one jaw tip passes over the other. As the knob is
rotated, the projection travels within the knob groove
following the arcuate path of the groove over an arc of
180 or more. The levers move from one of internal and
external positions to the other arriving in the other
position upon the projection reaching the other end of
the path. Upon contacting the end of the groove, the
guiding portion acts as a stop member which stops
rotation of the tool in the proper operating position.
In a similar alternate and now preferred construc-
tion of the hand tool invention, one lever section is
coupled with a driving knob at a driving connection.
The other lever section is moveable relative to the one
lever section and knob. The driving knob is used as in
the originally preferred embodiment, in that manual
rotation of the knob shifts the lever sections between
an external position to opposite sides of the center
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linè in their side by side relationship and a crossed
internal ring relationship.
The driving knob of the now preferred embodiment
comprises a drawn cup-shaped member having an annular
side wall, a bottom portion supporting the knob on the
one lever section, and a cap member engaged with the
annular wall and supported within the cup member. A
pivot connection secures the knob and lever sections
together in eccentric relationship.
The one lever section includes an arcuate groove
for engagement with the driving connection in a work
position establishing relationship, and a recessed
aperture for engagement with the driving connection in a
flush working relationship with respect to the other
lever section. Movement of the knob results in
eccentric relative lever movement so that one jaw tip
passes over the other. As the knob is rotated, the
driving connection travels within the lever groove
following the arcuate path of the groove over an arc of
180D or more. The levers thus move from one position,
and arrive at the other position when the driving
connection reaches the other end of the arcuate path.
Upon contacting the other end of the groove, the driving
connection serves as a stop member for stopping rotation
of the tool in the proper operating position.
In a third embodiment, the tool driving structure
comprises a crescent shaped slot located in the boss
portion of one lever. A pivot is connected to the other
lever and extends through the slot. The slot is
preferablv configured to include two stop locations,
where, upon movement of the lever section to one stop
location or the other, the tool is positioned in either
the internal or external operating modes. The pivot
interconnecting the lever sections is engaged through
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the slot and is engaged along one or the other of the
stop locations.
When the tool of either of the embodiments is in
use, reaction forces maintain the tool in at least one
of its adjusted positions. In the first embodimen~,
since the arcuate groove is in excess of 180 in length,
the projection passes over center and ~he reaction
forces urge the projection against the appropriate end
of the groove when in its external ring position. With
1~ the other embodiment the pivot is forced against
surfaces of the appropriate one of the stop locations in
both positions.
The tool of the preferred embodiment of the present
invention preferably includes a spring interposed
between the lever handle portions for biasing the
handles away from one another.
Use of the spring results in the handle portions
often being biased to their farthest positions. As the
farthest handle positions makes it difficult to conve-
niently store the tool, a locking device is also
provided. The device includes a locking lever arm
pivotally mounted on the handle portion of the one
lever section. The lever arm i5 positioned to lockingly
engage a notched portion in the boss portion of the
other lever section. The notched portion is configured
to engage and maintain the lever arm whereby the tool
remains in the locked and closPd position against the
bias of the spring.
In the new and now preferred construction, a raised
stop limit on the other lever section is also used to
limit the farthest handle position when the tool is in
the internal position. The stop limit engages the boss
portion of the one lever section to prevent handle
movement past a maximum open position.
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These and other features and advantages of the
present invention will be had by referring to the
following description and claims taken in conjunction
with in the accompanying drawings.
Brief Description of the Drawinqs
Figure l is a.plan view of the plier tool of the
present invention in the internal and closed position
with the locking mechanism in the locked position;
Figure 2 is a side elevational view of the plier
tool shown in Figure l;
Figure 3 is a partial view of an alternate
configuration of the tool tip of the present invention;
Figure 4 is a plan view of the one lever of the .
plier tool of Figure l;
Figure 5 is a side elevational view of the lever
shown in Figure 4;
Figure 6 is a plan view of the plier tool of the
present inv~ntion shown in the internal open position;
Figure 7 is a plan view of the operating knob of
the plier tool of the present invention on an enlarged
scale;
Figure 8 is a bottom view of the operating knob of
Figure 7;
Figure 9 is a cross-sectional view of the operating
knob of Fig~lre 7 as see,n from the plane indicated by
the line 9-9 of Figure 8;
Figure lO is plan view of the plier tool embodying
the present invention shown in solid lines in the
external closed and in phantom in external open
positions;
Figure 11 is plan view of a now preferred embodi-
ment of the plier tool of the present invention in the
external closed position;
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Figure 12 is a partial sectional view of an
internal-open position stop limit taken along the line
12-12 of Figure 11;
Figure 13 is a plan view of the one lever of the
plier tool of Figure 11;
Figure 14 is an enlarged partial sectional view of
the driving structure of the plier tool of Figure 11;
Figure 15 is a fragmentary plan view of a third
embodiment of the tool of the present invention shown in
the internal-closed position;
Figure 16 is a fragmentary plan view of the third
embodiment of the tool of the present invention shown
in the internal-open position;
Figure 17 is a fragmentary plan view of the third
embodiment of the tool of the present invention shown
in the external-closed position;
Figure 18 is a fragmentary plan view of the third
embodiment of the tool of the present invention shown
in the external-open position;
Figure 19 is a fragmentary plan view of one lever
section of the third embodiment of the plier tool of
the present invention; and
Figure 20 is a side elevational view as seen from
the plane indicated by the line 20-20 of Figure 17.
Best Mode for CarrYin Out the Invention
Three embodiments of the plier tool of the present
invention for expanding or contracting retaining members
are shown in Figures 1-10, Figures 11-14 and in
Figures 15-20, respectively. Parts described in
connection with the second and third embodiment that are
identical to those of the first have been identified
with the same reference numeral, but with a prime or
double prime designation and will not be separately
described except to the extent required for clarity.
1 31 24~4
With reference to Figures 1-10, the first embodi-
ment of the plier tool according to the present
invention, a hand tool A is adapted for expanding or
contracting resilient members in an internal or external
mode of operation. In the illustrated embodiment, the
tool A includes a pair of lever sections 10, 12 each
having a handle portion 14, covered by plastic grip
covers 15, as in Figure 10. The lever sections are
pivotally interconnected for normally permanent but
relatively movable action about a pivot pin in the form
of a threaded fastener 16.
In addition to the handle portions 14, each lever
section lO, 12 includes a jaw portion 18 having a
forwardly projecting tip 20, and a boss portion 22. As
shown in Figures 2 and 3, both tips 20 are integral with
the lever section, but removable tips may be provided.
The boss portion 22 is pos~tioned intermediate the
handle and jaw portions 14, 18. The lever sections 10,
12 are interconnected through their respective boss
portions 22 by the pivot pin 16. The tool A is
manipulated between operating modes by a shifting or
driving structure 28 which permits movement of the lever
sections 10, 12 between the external position, when the
lever sections are in a side by side relationship,
Figure 10, and the internal position, in which the lever
sections are in a crossed relationship, Figures l, 6.
When the tool is in the external position as shown in
Figure 10, the lever sections 10, 12 and their as-
sociated tips 20 are positioned next to one another.
Squeezing the handle portions 14 causes the jaw portions
18 and tips 20 to separate and assume the open position
as indicated by the phantom line tool view. The outward
movement of the tips 20 to this position enables the jaw '
portions 18 to expand an external retaining ring.
1 3 1 2454
11
By manipulating the shifting or driving structure
28, the tool A is selectively moved to the internal
mode of operation as shown in Figures 1 and 6. The
tool illustrated in Figure 6 is described as being in
the open position. In this position, the handles are
released or biased by the spring 24, and the jaw
portions and their associated tips are located away from
one another. When the handle portions 14 arc squeezed
towards one another, the jaw portions 18 and their
associated tips 20 are moved towards one another to the
closed position as shown in Figure 1.
Movement of the tool between these modes of
operation is provided by the shiftlng or driving
structure 28. In the embodiment of the tool shown in
Figures 1-10, the shift permitting structure includes a
driving knob 30. The driving knob 30, as shown in
Figures 7-9, includes a base portion 32, a handle
portion 34 and an engagement portion 36.
The engagement portion 36 has a cylindrical surface
sized for interacting engagement with walls defining a
circular recess or driving aperture 37 in one lever
section. The pivot 16 is interconnected with the knob
base portion 32 to couple the knob 30 to the lever
section 12. The attachment aperture 13, through which
the pivot pin projects, is offset such that the knob 30
is connected in an eccentric relationship. The position
of the attachment aperture and thus of the pivot 16 is
preferably based on correct tip 22 alignment, and is
obtained by appropriately sizing the radius of the
engagement portion 36 and interconnecting circular
recess 37.
As illustrated, a spring washer 16A is positioned
intermediate ahead of the pivot pin 16 and the boss
portion 22 of the levex section 12 to provide stability
to the tool,-and also provide friction forces which
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12
prevent the knob 30 from unintentionally rotating with
respect to the lever section. The distance the
engagement portion projects into the aperture 37 is
substantially less than or equal to the width of the
lever section 10. The height of the engagement portion
is necessarily limited so as to avoid interference with
the lever section 12 which abuts the lever section 10 as
shown in Figure 2.
In the external position, reaction forces resulting
from working-operation of the tool, apply a position
retention force maintaininq the tool levers in the
selected position during operation. In the internal
position, a hand force and an internal retaining ring
force operating on the tool result in a reaction force
which biases the knob in a direction out of its proper
operating position. Frictional retention forces provided
by the spring washer 16A act against the reaction force
to retain the knob and levers in their proper operating
position.
Rotation of the lever sections 10, 12 is limited
by guiding engagement structure 38 on the boss portion
22 of lever secticn 10. The guiding engagement
structure 38 limits lever rotation through operating
engagement with an arcuate groove 33 in the base portion
32 of the knob 30. As shown in Figure 5, the guiding
engagement structure 38 comprises a guide post 39
projecting from the boss portion of lever section 10.
~uring manipulation of the tool between internal and
external positions, the guide post 39 engages the
arcuate groove 33. Movable engagement of the guide post
39 within the groove 33 is permitted, since the height
and diameter of the guide post 39 are proportionate to
the depth and width of the arcuate groove 33. By
selectively rotating the handle portion of the knob 30,
the lever section 12 moves in eccentric relation, with
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13
the guide post moving within the arcuate groove 33 until
the tool i5 positioned in internal and external
operating modes when the guide post engages the,ends 40,
41 of the groove 33. The guide post 39 performs as a
stop member which stops rotation of the tool in the
internal or external operating position upcn reaching
the end of the groove corresponding to the selected
position. The tool is in the internal position when the
post 39 contacts the end of the groove 41, as shown in
Figure 1, and is in the external position when the post
39 contacts groove end 40.
The radius of the arcuate groove 33 is transverse
to the central axis of the knob and extends, as shown
in Figure 7, more than 180- about the perimeter of the
base portion 32. By extending the groove 33 in excess
of 180 about the base portion 32, eccentric movement
of lever section 12 is permitted between the crossed
relationship in the internal position, and the side by
side relationship in the external position, whereby the
jaw portion and tip of lever section 12 pass under the
jaw and tip of lever section 10 without interference.
Xnob rotation of more than 180 is preferable in order
to obtain a path of non-interfering travel between tips
20 having degrees of angulation of the type shown on
the tool in Figure 2.
Referring to Figures 11 to 14, an ~lternate and now
preferred embodiment of the hand tool A' is illustrated.
As the tool A' contains elements which are identical to
the hand tool embodiment of Figures 1-10, common
elements wili be referred to using a prime desi~nation.
The hand tool A' illustrated in Figure 11 includes a ,
pair of lever sections 10', 12' each having a handle
portion 90, covered by plastic grip covers 15'. The
lever sections are pivotally interconnected about a
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14
driving connection 90, which couples the lever sections
10', 12' and a driving knob 30'.
The driving connection 90 is in the form o~ a rivet
joint 94. Jaw portions 18' having tips 20', and boss
portions 22'; are also included as in the prior
embodiment. The knob 30' and lever sections 10', 12'
are connected by the rivet joint 94 through respective
aligned apertures 95, 96, and 97.
The tool A' is manipulated between positions by
rotation of the driving knob 30'. The lever sections
move between internal and external positions in their
side-by side relationship as described with respect to
the above embodiment. Movement between positions is
provided by a driving structure 28' which includes a
pivot connection 100 and the driving connection 90.
The pivot connection 100 interconnects the one lever
section 10' with the driving knob 30' so that the other
lever section 12' moves relative to the one lev~r
section and knob.
The pivot and driving connections 100, 90, are
best illustrated in Figure 14. The pivot connection 100
includes a rivet 101 which engages the knob 30 and one
lever section 10' through respective aligned apertures
102, 103. Both the driving and pivot connection rivets
94 and 101, which,may include spring washers (not
illustrated) similar to that shown in Figure 2 for
providing stability to the tool, preventing unintention-
al tool movement, and maintaining the tool in the
selected operating position. The rivet 101 includes a
countersunk head portion 104 for engagement with a
recessed portion 106 of the aperture 103 in the one
lever section 10', 50 that the one lever section 10' and
pivot connection 100 are flush with respect to the one
lever sectio~ 10', as shown in Figure 14, to avoid
r
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interference with the lever section 12' which abuts the
one lever section and rivet 101.
The driving knob 30' of this embodiment comprises a
drawn cup-shaped member 108 having an annular side wall
110 with an outer knurled finger-engaging surface 111, a
bottom portion 112 with an inner surface 114 and an
outer surface 116 for engaging the one lever section
10'. The driving knob 30' also includes a cap member
118 having a,plurality of finger-like portions 120 for
engaging with the annular side wall 110 to support and
secure the cap member 118 within the cup member.
The one lever section 10' further includes an
arcuate groove 122 for engagement with the driving
connection 90 in a work position establishing relation-
ship. Movement of the tool between positions is thus
provided by manual rotation of the knob which moves the
driving connection along the lever groove following the
arcuate path 122 over an arc of 180 or more. By
grasping the knob on the knurled surface 111 and
selectively rotating the knob, the other lever section
12' moves in eccentric relation with respect to the
interconnected knob 30' and one lever section 10'. The
levers 10', 12' thus move from one position, and arrive
at the other.position when the driving connection
reaches the other end of the groove. Upon contacting
the other end of the groove, the rivet 94 serves as a
stop member for stopping rotation of the tool in the
selected operating position.
Referring to Fi~ures 15-20, an alternate embodiment
of the present invention is shown. The tool B is
identical in all respects to the embodiments of
Figures 1-10 and 11-14, except that a different shifting
or d~iving s~ructure 28" is provided in the form of a
crescent shaped slot 50 in the one lever section 10".
Since the embodiment of hand tool B contains structure
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16
similar to the embodiments previously described,
reference numerals having a double prime designation
will be used.
The lever sections 10", 12" are pivotally intercon-
nected for normally permanent but relatively movable
action about a pivot pin or threaded fastener 16". The
slot 50 preferably includes stop locations 52, 53,
where, upon movement of the lever sections such that the
fastener 16" ls engaged along one stop location, the
tool is positioned in one operating position. Intercon-
nection of the lever sections 10", 12" by the pivot pin
16" is through attachment aperture 13" in lever section
12" and through the crescent slot 50 in lever section
10", as shown in Figure 20.
The tool B is manipulated between internal and
external operating modes by movement o~ tpe lever
sections 10", 12". As illu~trated in Figure 15, the
tool is in the internal-closed position, where the lever
sections 10", 12" are in a crossed relationship.
Figure 16 shows the tool B in the internal-open
position. It should be noted that orientation of the
tool in the internal operating position occurs when the
lever section 10" is moved such that the pivot pin 16"
is engaged along a stop location 52 in the boss portion
22" of lever 10". Orientation in the internal position
also results in the tips 20" being canted toward one
another.
Figures 17 and 18 illustrate the tool B in the
external operating position where the lever sections
10", 12" are in a side by side relationship. Movement
to the external position shown is accomplished by
manipulating the lever section 10" such that the piVQt
pin 16" is engaged with a stop location 53 also in the
boss portion 22" of lever 10". In this external
position, the tips 20" are canted away from one another
17 1312454
in àn outward direction to facilitate retentive gripping
of the retaining rings. Resisting engagement of the
tips 20" of the tool with the retaining ring in either
the internal'or external operating mode causes the pivot
16" to be forced against the stop locations 52, 53,
rather than inwardly along the slot and out of the
operating position.
In the embodiments shown in Figures 1 and 11, the
tool preferably includes a biasing spring 24, 24' which
urges the handles apart. The spring 24, 24' is
interconnected with the handle portions of the lever
sections 10, 12 and 10', 12' by spring mounts 26, 26'.
According to another feature of the invention a
locking mechanism is provided for locking the handles
in a closed position to inhibit their separation. As
shown in Figure 1, the mechanism includes a pivotally
mounted locking lever 56 secured to the handle portion
14 of the lever section 10 by a pivot 57 projecting
through a lock aperture 66 in the lock lever. The lever
is pivotable between lock and unlock positions, and is
generally configured to minimize tool interference dis-
engagement from the lock position upon movement or
contact with other items during storage. In the
illustrated embodiment, the lever 56 includes a spring
engagement surface 58 for engaging the spring when in a
locked position. The lever 56 also includes a latch
portion 60 engageable with a notched portion 62 formed
on the periphery of the boss portion 22 of lever section
12 as shown in Figure 1. The lever further includes a
finger engaging portion 64 which extends from the lever '-
56 and overlies the outside edge of the handle 14. The s
finger portion 64 provides for ease of manual pivoting
of the lever in and out of the lock position. It should
be apparent that when the handles are squeezed and the
latch portion 60 is disengaged from the notch portion
t312454
18
62, the spring 2~ pivotally biases the lever out of
engagement with the lever section 12 along the spring
engagement surface 58.
According to another feature of the invention, a
stop limit 130, raised from one surface of the other
lever section 12', is used to limit the internal ring
tool handle position to a maximum open position. As
shown in Figure 12, the stop limit abuts the boss
portion 22' to limit the opening of the spring biased
handle portions 14" to a maximum open position.
The present invention thus provides an inexpensive
tool for the expansion and contraction of resilient
retaining members. The tool is easily switched between
the internal and external operating modes by merely
manipulating the shiftin~ or driving structure 28.
The lever sections of the tool illustrated are
constructed from stampings, the making of which is known
by those skilled in the art. It should also be
recognized that other relatively inexpensive methods of
manufacture could be used to produce the disclosed tool
components, such as using powdered metal technology.
From the above it will be apparent that a novel
and improved,hand tool has been provided. While
preferred embodiments of this invention have been
described in detail, it will be apparent that certain
modifications or alterations can be made therein without
departing from the spirit or scope of the invention set
forth in the appended claims.
