Note: Descriptions are shown in the official language in which they were submitted.
CA 02537611 2006-02-24
LOCK NUT SYSTEM
TECHNICAL FIELD
This invention relates, generally, to fasteners, and more particularly, to
lock nuts for
inhibiting rotation of shafts engaged with such nuts.
BACKGROUND ART
Lock nut systems are often connected to shafts and utilized to inhibit
rotation of the
retaining nut relative to such shafts. For example, such systems are often
utilized on motor
vehicles, such as axies and wheel ends. Typically, a lock nut will be
engageable with a
locking member or keeper which inhibits movement of the nut relative to the
shaft. The
locking member may include a protruding portion which extends into a slot or
receiving
portion of a shaft. The locking member may also engage the nut such that there
is little or no
movement between the nut and shaft. Such locking members are often made of
stamped sheet
metal.
Also, the engagement between a locking member and a shaft may have play in it
such
that movement is possible. Such movement may cause damage to the shaft thereby
complicating or preventing removal and reattachment of the nut to the shaft.
In particular, at
moderate torques, such locking members may dig into the shaft (e.g., threads
of the shaft)
thereby damaging the shaft. For example, the locking member engagement may
create a bur
on the shaft. Such damage to the shaft, particularly those made of stamped
sheet metal, can
cause damage to the threads of the nut as the nut is removed from the shaft
and/or re-engaged
therewith. The digging in of such locking member to a shaft can therefore lead
to stripping of
the threads of the nut and/or locking member thereby making proper engagement
of the
threads of the shaft with the threads of the locking member and/or nut
difficult or impossible
or lead to failure of the retention system.
Thus, a need exists for lock nut systems which inhibit movement of shafts
relative to
retaining nuts and which are configured to inhibit damage to lock nut systems
and the shafts
engageable therewith.
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SUMMARY OF THE INVENTION
The present invention provides, in a first aspect, a lock nut system which
includes a
molded nut having a plurality of engaging teeth. A molded keeper having a
plurality of keeper
teeth is engageable with the plurality of teeth of the nut to inhibit movement
of the keeper
relative to the nut when the plurality of engaging teeth engages the keeper
teeth. The keeper
has a radially inner side configured to engage a shaft to inhibit rotational
movement of the
shaft relative to the nut when the plurality of teeth engages the plurality of
keeper teeth.
The present invention provides, in a second aspect, a lock nut system which
includes a
nut having a plurality of engaging teeth, a slot, and an outer surface axially
closest to the slot.
The slot is located axially between the plurality of engaging teeth and the
outer surface. A
keeper includes a plurality of keeper teeth engageable with the plurality of
engaging teeth to
inhibit movement of the keeper relative to the nut when the plurality of
engaging teeth
engages with the plurality of keeper teeth. A keeper retaining member is
connected to the
keeper and the keeper retaining member includes at least one leg configured to
be received in
the slot. The keeper retaining member is configured to hold the keeper axially
such that the
plurality of teeth and the plurality of keeper teeth are engaged when the at
least one leg is
received in the slot. The keeper includes a radially inner side configured to
engage a shaft to
inhibit rotational movement of the nut relative to the shaft when the
plurality of teeth engages
the plurality of keeper teeth and the radially inner side engages the shaft.
The present invention provides, in a third aspect, a lock nut system which
includes a
nut having a plurality of engaging teeth, an outer surface axially closest to
the plurality of
engaging teeth, and a shoulder. A keeper includes a plurality of keeper teeth
engaging the
plurality of engaging teeth to inhibit movement of the keeper relative to the
nut when the
plurality of engaging teeth engages the plurality of keeper teeth. The
shoulder is substantially
orthogonal to an axis of the nut and abuts and axially supports the keeper.
The keeper
includes a radially inner side configured to engage a shaft to inhibit
rotational movement of
the nut relative to the shaft when the plurality of engaging teeth engages the
plurality of
keeper teeth and the radially inner side engages the shaft.
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BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter which is regarded as the invention is particularly pointed
out and
distinctly claimed in the claims at the conclusion of the specification. The
foregoing and other
features, and advantages of the invention will be readily understood from the
following
detailed description of preferred embodiments taken in conjunction with the
accompanying
drawings in which:
FIG. 1 is a perspective view of a lock nut system which includes a lock nut
having a
keeper and a keeper retaining member engaged with the nut;
FIG. 2 is a perspective view of the lock nut of the lock nut system of FIG. 1;
FIG. 3 is a side elevational view of the keeper retaining member of FIG. 1;
FIG. 4 is a perspective view of the keeper of FIG. 1;
FIG. 5 is a top elevational view of the keeper of FIG. 1;
FIG. 6 is a perspective view of another embodiment of a lock nut system having
a lock
nut engaged with a keeper and a keeper retaining member;
FIG. 7 is a perspective view of another embodiment of a keeper connected to a
keeper
retaining member in accordance with the present invention;
FIG. 8 is a perspective view of a lock nut system which includes the keeper
connected
to the keeper retaining member of FIG. 7, which are engaged with a nut;
FIG. 9 is a side cross sectional view of the keeper connected to the keeper
retaining
member of FIG. 7;
FIG. 10 is a perspective view of a lock nut system which includes a keeper
connected
to a keeper retaining member, which are engaged with a nut;
FIG. 11 is a perspective exploded view of another embodiment of a lock nut
system
which includes a keeper engaged with a nut and a keeper retaining member shown
separated
from the nut;
FIG. 12 is a perspective exploded view of the system of FIG. 11 shown with the
keeper retaining member and the keeper separated from the nut; and
FIG. 13 is a perspective view of the system of FIG. 11 showing the keeper and
keeper
retaining member engaged with the nut.
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DETAILED DESCRIPTION
In accordance with the principles of the present invention, a lock nut system
engageable with a shaft is provided.
In an exemplary embodiment, a lock nut system 10 includes a nut 20, a key or
keeper
30 and a keeper retaining member 40, as depicted in FIGS 1-5. Lock nut system
10 may
engage a shaft (not shown). In particular, threads 50 of nut 20 may engage
threads of the shaft
(not shown). Keeper 30 and keeper retaining member 40 may engage nut 40 and
keeper 30
may engage the shaft to inhibit movement of the shaft relative to nut 20.
Nut 20 may include a plurality of engaging teeth 120 extending
circumferentially
around an inner radial surface of nut 20. For example, nut 20 may include 60
engaging teeth.
Nut 20 may also include a shoulder 24 configured to receive keeper 30. For
example,
shoulder 24 may be spaced from an outer surface 22 of nut 20 in an axial
direction relative to
nut 20 such that an axial dimension of keeper 30 relative to nut 20 is
received between outer
surface 22 and shoulder 24. Shoulder 24 may also abut and support keeper 30 in
an axial
direction. Nut 20 may be molded or formed of powdered metal, for example.
Nut 20 may include a slot 60 extending circumferentially (e.g., completely or
partially)
around nut 20. Slot 60 may be located between engaging teeth 120 and outer
surface 22 of nut
20. Also, slot 60 may have a radial depth of about 0.050 inches. Keeper
retaining member 40
may engage slot 60. For example, a first leg 42 and a second leg 43 may be
received in slot
60. Further, a nose 44 of retaining member 40 may be received in slot 60.
Keeper 30 may include a plurality of keeper teeth 32 configured to engage
engaging
teeth 120 of nut 20 such that movement between keeper 30 and nut 20 is
inhibited when
keeper teeth 32 and engaging teeth 120 are engaged to each other. Keeper 30
may include a
shaft engaging side 33 configured (e.g., shaped and dimensioned) to engage a
shaft (not
shown) to inhibit movement (e.g., rotational movement) of the shaft relative
to keeper 30,
when threads 50 of nut 20 engage threads (not shown) of the shaft, keeper
teeth 32 engage
engaging teeth 120, and keeper retaining member 40 engages slot 60. For
example, the
engagement or meshing of keeper teeth 32 and engaging teeth 120 inhibits
movement of
keeper 30 relative to nut 20 and the engagement of engaging side 33 with the
shaft inhibits
movement between keeper 30 and the shaft thereby inhibiting movement between
nut 20 and
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the shaft. As depicted in FIGS. 1 and 4-5, keeper 30 may include 15 keeper
teeth 32 evenly
spaced from one another, for example. Also, keeper teeth 30 on outer
circumferential sides 35
of keeper 30 may have an axial height (i.e., relative to nut 20) substantially
equal to a distance
from shoulder 24 to outer surface 22. Keeper teeth 32 on an inner portion 39
of keeper 30
may have a height substantially equal to a distance from shoulder 24 to slot
60 thereby
allowing nose 44 of retaining member 40 to extend into slot 60. More
specifically, keeper
teeth 32 on an inner portion 39 have an axial height less than keeper teeth 32
on outer
sides 35. The reduced axial height on inner portion 39 allow nose 44 to pass
over teeth 32 to
extend into slot 60.
Keeper 30 may include a first keeper cavity 36 and a second keeper cavity 38
configured (e.g., shaped and dimensioned) to receive keeper retaining member
40 as depicted
in FIGS. 1 and 4-5. For example, a bottom side of each of cavity 36 and cavity
38 may be
axially spaced from an outer surface 22 of nut 20 such that keeper retaining
member 40 abuts
the bottom side of such cavities when received in slot 60 and retaining member
40 is received
in a plane formed by outer surface 22 and slot 60 and cavities 36 and 38.
Also, as depicted in
FIG. 1, cavity 36 and cavity 38 may receive about 20 percent of a linear
dimension of
retaining member 40. In unillustrated examples, cavity 36 and cavity 38 along
with keeper 30
could be larger such that more of retaining member 40 is received therein. In
a further
unillustrated embodiment, keeper 30 could extend partially or entirely
circumferentially
around nut 20 (e.g., abutting shoulder 24) and could include keeper teeth 32
around an entire
outer circumference of keeper 30, which therefore could engage some or all of
engaging teeth
120.
Retaining member 40 may be elastically deformable to allow it to be received
in slot
60. For example, first leg 42 and second leg 43 may be deformed (e.g., in a
direction
substantially perpendicular to the axis of nut 20) toward one another prior to
being inserted
axially past outer surface 22 of nut 20 to allow retaining member 40, and
keeper 30 to be
attached thereto. First leg 42 and second leg 43 may then be elastically
returned toward slot
60. For example, retaining member 40 may be formed of ASTM A228 spring steel
and may
be 0.093 round wire as will be understood by those skilled in the art. Also,
retaining member
40 may be cylindrical as depicted in FIG. 1. Alternatively, retaining member
40 could be
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formed of other materials and/or formed in other shapes to allow retaining
member 40 to
received in slot 60 and/or cavities (e.g. cavity 36 and cavity 38) of keeper
30.
Further, Keeper 30 may be formed or molded of powdered metal, for example.
Also,
keeper 30 could be formed in different shapes to allow it to engage a shaft to
thereby inhibit
movement of such shaft. Further, a keeper (e.g., keeper 30) may be formed of a
shape such
that a retainer (e.g., retaining member 40) is not necessary. For example, a
keeper could be
completely or partially rounded such that keeper teeth 32 engage more (or all)
of engaging
teeth 120 than depicted in the figures.
Retaining member 40 when received in slot 60, in first cavity 36 and second
cavity 38
may align keeper 30 such that keeper teeth 32 are engaged with engaging teeth
120. Further,
retaining member 40 provides resistance in an axial direction relative to nut
20 thereby
inhibiting movement of keeper 30 axially away from shoulder 24 toward outer
surface 22.
Also, the sides of cavities 34 and 36 of keeper 30 may be coined, crimped, or
otherwise
manipulated such that retaining member 40 received in cavities 34 and 36
remains connected
to keeper 30. Alternatively, keeper 30 and retaining member 40 could be formed
integral to
one another.
In an alternate embodiment depicted in FIG. 6, a lock nut system 200 includes
a keeper
230 having keeper teeth 320 which are configured to engage engaging teeth 420
of a nut 220.
Keeper 230 may also include an engaging member 234 which protrudes radially
inwardly
relative to nut 20 to engage a slot (not shown) of a shaft. Thus, engaging
member 234 may
inhibit movement of keeper 230 relative to the shaft (not shown) and the
engagement of
engaging teeth 420 with keeper teeth 320 may inhibit movement of keeper 230
relative to
nut 220. Accordingly, movement of nut 220 relative to the shaft (not shown) is
prevented or
reduced. Nut 220 and keeper 230 may be molded or formed of powdered metal, for
example.
Such a shaft may be found on the rear axle of a vehicle, for example. In
contrast, keeper 30
described above may engage a shaft slot (not shown) of a front axle of such a
vehicle, for
example.
In a further embodiment depicted in FIGS. 7-9, a keeper 530 is connected to a
keeper
retaining member 540. A projection 535 of keeper 530 extends through an
opening 545 in
retaining member 540 when connected. Projection 535 extends substantially
perpendicular to
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a plane of retaining member 540. Projection 535 may be deformed by pressure
applied on a
top thereof (i.e. in a direction substantially perpendicular to the plane of
retaining member
540) to connect retaining member 540 with keeper 530 similar to the way a
rivet is utilized, as
will be understood by those skilled in the art. For example as best depicted
in FIG. 8, the
deformation of projection 535 may cause edges 536 of projection 535 to extend
over a top
surface of retaining member 540 thereby connecting projection 535 and keeper
530 to
retaining member 540.
Keeper 530 and retaining member 540 engage a nut 510 similar to that described
above for nut 20, keeper 30, and retaining member 40. For example, keeper 530
includes
keeper teeth 520 which are configured to engage engaging teeth 511 of nut 510.
Keeper 530
may also include an engaging member 534 which protrudes radially inwardly
relative to nut
510 to engage a slot, groove or other engaging portion (not shown) of a shaft.
Thus, engaging
member 534 may inhibit movement of keeper 530 relative to the shaft (not
shown) and the
engagement of engaging teeth 511 with keeper teeth 520 may inhibit movement of
keeper 530
relative to nut 510. Accordingly, movement of nut 510 relative to the shaft
(not shown) is
prevented or reduced. Keeper 530 may be molded or formed of powdered metal,
for example.
Keeper retaining member 540 may engage a slot 561 similar to keeper retaining
member 40
engaging slot 60 as described above. For example, a first leg 542 and a second
leg 543 may
be received in slot 561. For example, slot 561 may have a radial depth of
about 0.050 inches.
Further, a nose 544 of retaining member 540 may be received in slot 561.
Retaining member
540 when received in slot 561 may align keeper 530 such that keeper teeth 532
are engaged
with engaging teeth 511. Further, retaining member 540 provides resistance in
an axial
direction relative to nut 510 thereby inhibiting movement of keeper 530
axially away from a
shoulder 524 toward an outer surface 522.
As described above for retaining member 40, retaining member 540 may be
elastically
deformable to allow it to be received in slot 561. For example, first leg 542
and second leg
543 may be deformed (e.g., in a direction substantially perpendicular to the
axis of nut 510)
toward one another prior to being inserted axially past outer surface 522 of
nut 510 to allow
retaining member 540, and keeper 530 to be attached thereto. First leg 542 and
second leg
543 may then be elastically returned toward slot 561. Also, first leg 542 may
include a
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protruding portion 560 which protrudes radially relative to a rounded portion
565 of retaining
member 540. Similarly, second leg 543 may include a protruding portion 562.
Protruding
portion 560 and protruding portion 565 may extend into slot 561 to engage
retaining member
540 with slot 561. For example, retaining member 540 may be formed of stamped
sheet
metal, and may have a thickness in a range between 0.040-0.050 inches, as will
be understood
by those skilled in the art. Alternatively, retaining member 540 could be
formed of other
materials (e.g., powdered metal) and/or formed in other shapes to allow
retaining member 540
to received in slot 561 and to be connected to keeper 540 via projection 535.
Further, as
described above for keeper 30, keeper 530 may be formed or molded of powdered
metal, for
example. Alternatively, keeper 530 and retaining member 540 could be formed
integral to
one another.
Also, the relative axial thicknesses of keeper 530 relative to keeper 30 may
differ. In
particular, an axial thickness of keeper 530 may extend to about the same
axial thickness as
engaging teeth 511 or 120. In contrast, keeper 30 extends from shoulder 24 to
outer surface
22 in the embodiment depicted in FIG. 1. Alternatively in an unillustrated
embodiment,
keeper 30 could axially extend only the thickness of engaging teeth 120, and
keeper teeth 520
could extend a distance equivalent to the distance from shoulder 24 to outer
surface 22 except
for any keeper teeth of keeper teeth 520 located in the radial vicinity of
nose 544 which would
be as thick as engaging teeth 511 or 120.
In another embodiment depicted in FIG. 10, a lock nut system 800 includes a
keeper
830 having keeper teeth 820 which are configured to engage engaging teeth 821
of a nut 810.
Keeper 830 is connected to a keeper retaining member 840. One or more
projections 835 of
keeper 830 extends through an opening 845 in retaining member 840 when
connected.
Projections 835 extend substantially perpendicular to a plane of retaining
member 840.
Projections 835 may be deformed by pressure applied on a top thereof (i.e. in
a direction
substantially perpendicular to the plane of retaining member 840) to connect
retaining
member 840 with keeper 830 similar to keeper 530 and retaining member 540
described
above. Keeper 830 may also include an engaging member 834 which protrudes
radially
inwardly relative to nut 810 to engage a slot (not shown) of a shaft. Thus,
engaging
member 834 may inhibit movement of keeper 830 relative to the shaft (not
shown) and the
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engagement of engaging teeth 821 with keeper teeth 820 may inhibit movement of
keeper 830
relative to nut 810. Accordingly, movement of nut 810 relative to the shaft
(not shown) is
prevented or reduced. Nut 810 and keeper 830 may be molded or formed of
powdered metal,
for example. Such a shaft may be found on the rear axle of a vehicle, for
example. In
contrast, keeper 530 described above may engage a shaft slot (not shown) of a
front axle of
such a vehicle, for example.
In yet a further embodiment depicted in FIGS. 11-13, a lock nut system 600 may
include a nut 610, a keeper 630, and a retaining member 640. Nut 610 may
include a plurality
of engaging teeth 720 while keeper 620 may include a plurality of keeper teeth
630. Keeper
630 may be round such that a circumference of engaging teeth 720 engage a
circumference of
keeper teeth 620 to inhibit movement of nut 610 relative to a shaft (not
shown) as described
above for the other systems. An engaging member 634 is configured to engage a
slot or
groove of the shaft similar to engaging member 234 described above.
Retaining member 640 is also substantially circular, made of a highly elastic
material,
and includes a plurality of radial projections 644 which engage an annular
shoulder or rim
626. Radial projections 644 and/or retaining member 640 may elastically deform
(e.g.,
radially inwardly) to provide a friction fit of retaining member 640 relative
to nut 610 thereby
axially holding keeper 630 toward nut 610 and such that engaging teeth 720
engage keeper
teeth 620. For example, radial projections 644 may elastically deform radially
inwardly, and
they may at least partially elastically return to provide the frictional fit.
In an urrillustrated
embodiment, nut 610 may include an annular slot located on rim 626 which
receives
projections 644 of retaining member 640 when projections 644 engage rim 626.
Such a slot
may have a radial depth of about 0.003 inches, for example. Nut 610 and keeper
630 may be
molded metal (e.g., formed of powdered metal) while retaining member 640 may
be formed of
a plastic material. Alternatively, nut 610, keeper 630, and/or retaining
member 640 may be
formed of a plastic material (e.g., injection molded plastic).
Use of molded metals (e.g., powdered metal) as described above for the nuts
and
keepers allows a finer spacing of teeth than other materials (e.g., sheet
metal keepers) and
methods thereby allowing finer adjustment of nuts, keepers, and shafts
relative to each other,
while preventing or inhibiting movement of the keeper relative to the nuts.
For example, the
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use of powdered metal instead of stamped sheet metal for a keeper allows a
higher number of
keeper teeth to be provided per unit area thereby allowing more engagement
with
corresponding engagement teeth on the nut. The ability of the molded teeth in
the present
invention to resist torque is significantly higher that that afforded by a
stamped part of
previous inventions because of the ability to economically mold teeth with
greater axial
dimensions as well as the ability to include a greater number of engaging
teeth per unit area,
when using powdered metal instead of stamped sheet metal. A finer adjustment
may be
therefore be provided of the keeper relative to the nut due to such increased
number of keeper
teeth and corresponding increased number of engaging teeth of a nut per unit
area. For
example, a finer adjustment of bearing clearance can be achieved with the use
of the finer
pitch of the molded teeth. Further, the use of molded metals (e.g., powdered
metals) for
keeper 30 allows engaging side 33 to engage a shaft without being
significantly deformed or
significantly deforming the shaft in contrast to other materials used for this
purpose (e.g.,
stamped sheet metal) which may deform after a period in use or cause
deformation (e.g.,
stripped threads) of a shaft to which it is engaged. Additionally, such a
molded keeper may be
harder and stronger than a stamped sheet metal keeper thereby inhibiting such
damage Thus, a
higher torque loading may be provided utilizing molded metals (e.g., powdered
metal) relative
to other materials (e.g., a sheet metal stamped keeper) to form keepers and
nuts and without
resulting in failure, i.e., a risk of damage to the shaft or axle due to over
torque is minimized.
Also, engaging members (e.g., engaging member 234) of keepers may resist
deformation
when engaged with a slot of a shaft for the same reasons.
Although the above-described nuts (e.g., nut 20, nut 220, nut 510 and nut 810)
and
keepers (e.g., keeper 30, keeper 230, keeper 530, keeper 830, and keeper 630)
are described as
being molded or formed of powdered metal, these nuts and keepers could be die
cast, molded
of other materials, or formed in any other manner which would allow the teeth
of the keeper
and nut to inhibit movement relative to each other along with the keeper and
shaft inhibiting
movement relative to one another. Also, retaining members (e.g., retaining
member 40,
retaining member 540, retaining member 840 and retaining member 640) could be
formed of
the same materials as the keepers and/or nuts. Such retaining members could
also be formed
of plastic or any other material which would axially hold a keeper (e.g.,
keeper 30) such that
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the keeper teeth thereof (e.g., keeper teeth 32) are engaged with engaging
teeth (e.g., engaging
teeth 120) of a nut (e.g., nut 20). For example, such retaining members could
be formed of
plastics which satisfy this criteria.
Although preferred embodiments have been depicted and described in detail
herein, it
will be apparent to those skilled in the relevant art that various
modifications, additions,
substitutions and the like can be made without departing from the spirit of
the invention and
these are therefore considered to be within the scope of the invention as
defined in the
following claims.
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