U.S. patent application number 12/677477 was filed with the patent office on 2011-01-06 for coupling device.
This patent application is currently assigned to Koyo Bearings USA LLC. Invention is credited to Richard D. Kraus.
Application Number | 20110000451 12/677477 |
Document ID | / |
Family ID | 40125804 |
Filed Date | 2011-01-06 |
United States Patent
Application |
20110000451 |
Kind Code |
A1 |
Kraus; Richard D. |
January 6, 2011 |
COUPLING DEVICE
Abstract
A unitized valve train assembly includes a finger follower
having a pocket and a peripheral surface adjacent the pocket, and a
hydraulic lash adjuster having a body, and a plunger extending from
the body and received within the pocket of the finger follower. The
plunger defines a longitudinal axis. The assembly also includes a
single-wire coupling device having a first arm configured to
selectively engage the finger follower, and a second arm clamped to
one of the body and the plunger. The second arm is spaced from the
peripheral surface of the finger follower when the plunger is
received within the pocket of the finger follower.
Inventors: |
Kraus; Richard D.;
(Simpsonville, SC) |
Correspondence
Address: |
Nelson Mullins Riley & Scarborough LLP;IP Department
100 North Tryon Street, 42nd Floor
Charlotte
NC
28202-4000
US
|
Assignee: |
Koyo Bearings USA LLC
|
Family ID: |
40125804 |
Appl. No.: |
12/677477 |
Filed: |
August 27, 2008 |
PCT Filed: |
August 27, 2008 |
PCT NO: |
PCT/US2008/074368 |
371 Date: |
March 10, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60973313 |
Sep 18, 2007 |
|
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|
Current U.S.
Class: |
123/90.46 |
Current CPC
Class: |
F01L 1/185 20130101;
F01L 1/2405 20130101; F01L 2305/00 20200501; F01L 2303/00 20200501;
F01L 2001/187 20130101 |
Class at
Publication: |
123/90.46 |
International
Class: |
F01L 1/18 20060101
F01L001/18 |
Claims
1. A unitized valve train assembly comprising: a finger follower
including a pocket and a peripheral surface adjacent the pocket; a
hydraulic lash adjuster including a body; and a plunger extending
from the body and received within the pocket of the finger
follower, the plunger defining a longitudinal axis; a single-wire
coupling device including a first arm configured to selectively
engage the finger follower; and a second arm clamped to one of the
body and the plunger; wherein the second arm is spaced from the
peripheral surface of the finger follower when the plunger is
received within the pocket of the finger follower.
2. The unitized valve train assembly of claim 1, wherein the second
arm includes a substantially semi-circular hook portion clamped to
the one of the body and the plunger from a direction substantially
transverse to the longitudinal axis of the plunger.
3. The unitized valve train assembly of claim 2, wherein the hook
portion defines an inner diameter, and wherein the hook portion
includes opposite ends defining therebetween a minimum gap less
than the inner diameter of the hook portion.
4. The unitized valve train assembly of claim 3, wherein the
plunger defines an outer diameter greater than the inner diameter
of the hook portion prior to clamping the hook portion to the
plunger.
5. The unitized valve train assembly of claim 4, wherein a
difference between the inner diameter of the hook portion and the
outer diameter of the plunger yields an interference between about
1% and about 8% of the outer diameter of the plunger.
6. The unitized valve train assembly of claim 3, wherein the
plunger defines an outer diameter greater than the gap between the
respective ends of the hook portion prior to clamping the hook
portion to the plunger, and wherein the respective ends of the hook
portion spread apart from each other during clamping of the hook
portion to the plunger.
7. The unitized valve train assembly of claim 6, wherein the gap
between the respective ends of the hook portion prior to clamping
the hook portion to the plunger is between about 5% and about 13%
less than the outer diameter of the plunger.
8. The unitized valve train assembly of claim 2, wherein the hook
portion is clamped to the plunger, and wherein the hook portion is
spaced from the body when the plunger is received within the pocket
of the finger follower.
9. The unitized valve train assembly of claim 2, wherein the
plunger includes a shank and a spherical end portion, and wherein
the hook portion is clamped to the shank.
10. The unitized valve train assembly of claim 9, wherein the first
arm includes an arcuate lip portion configured to selectively
engage the finger follower.
11. The unitized valve train assembly of claim 9, wherein at least
a portion of the shank is cylindrical, and wherein substantially
the entire length of the hook portion is engageable with the
cylindrical portion of the shank.
12. The unitized valve train assembly of claim 1, wherein the
coupling device is formed from a single wire having a circular
cross-sectional shape.
13. The unitized valve train assembly of claim 12, wherein the
single wire has a diameter between about 0.5 mm and about 0.75
mm.
14. The unitized valve train assembly of claim 1, wherein the
second arm includes a hoop portion clamped to the body.
15. The unitized valve train assembly of claim 14, wherein the
first arm includes dual, parallel wire segments, and wherein the
coupling device further includes dual, parallel intermediate wire
segments interconnecting the hoop portion and the respective wire
segments of the first arm.
16. A unitized valve train assembly comprising: a finger follower
including a pocket; a hydraulic lash adjuster including a plunger
received within the pocket of the finger follower, the plunger
defining a longitudinal axis; a coupling device including a first
arm configured to selectively engage the finger follower; and a
second arm including a substantially semi-circular hook portion
engageable with the plunger from a direction substantially
transverse to the longitudinal axis of the plunger; wherein the
hook portion defines an inner diameter, and wherein the hook
portion includes opposite ends defining therebetween a minimum gap
less than the inner diameter of the hook portion.
17. The unitized valve train assembly of claim 16, wherein the
plunger defines an outer diameter greater than the gap between the
respective ends of the hook portion prior to assembly of the
hydraulic lash adjuster and the coupling device, and wherein the
respective ends of the hook portion spread apart from each other
during assembly of the hydraulic lash adjuster and the coupling
device.
18. The unitized valve train assembly of claim 17, wherein the gap
between the respective ends of the hook portion prior to assembly
of the hydraulic lash adjuster and the coupling device is between
about 5% and about 13% less than the outer diameter of the
plunger.
19. A single-wire resilient clip adapted to couple a finger
follower and a hydraulic lash adjuster for use in a valve train of
an engine, the hydraulic lash adjuster having a plunger defining a
longitudinal axis, the finger follower having a pocket for
receiving the plunger, the resilient clip comprising: a first arm
configured to selectively engage the finger follower; and a second
arm including a substantially semi-circular hook portion engageable
with the plunger from a direction substantially transverse to the
longitudinal axis of the plunger; wherein the hook portion defines
an inner diameter, and wherein the hook portion includes opposite
ends defining therebetween a minimum gap less than the inner
diameter of the hook portion.
20. The single-wire resilient clip of claim 19, wherein the first
arm includes an arcuate lip portion configured to selectively
engage the finger follower.
21. The single-wire resilient clip of claim 19, further comprising
an intermediate portion interconnecting the first and second arms,
wherein the intermediate portion is oriented substantially normal
to the first arm and the second arm.
22. A method of coupling a finger follower and a hydraulic lash
adjuster for use in a valve train of an engine, the finger follower
having a pocket for receiving a plunger of the hydraulic lash
adjuster, the method comprising: providing a clip having a hook
portion defining an inner diameter, the hook portion including
opposite ends defining therebetween a minimum gap less than the
inner diameter of the hook portion; inserting the plunger into the
hook portion in a direction substantially transverse to a
longitudinal axis of the plunger; spreading the opposite ends of
the hook portion from each other during insertion of the plunger
into the hook portion; clamping the plunger with the hook portion
to secure the clip to the hydraulic lash adjuster; and positioning
the plunger within the pocket of the finger follower.
23. The method of claim 22, further comprising: providing a first
arm on the clip having the hook portion; providing a second arm on
the clip spaced from the first arm; and supporting the hydraulic
lash adjuster from the finger follower via engagement of the first
arm and the finger follower.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application Ser. No. 60/973,313 filed on Sep. 18, 2007, the entire
content of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to couplings, and more
particularly to couplings for use in connecting valve train
components of an engine.
BACKGROUND OF THE INVENTION
[0003] When creating an assembly of components, it is often
desirable to create multiple sub-assemblies, or "unitize" multiple
individual components, to simplify or facilitate the assembly
process. A valve train of an engine includes many components, and
depending on the number of cylinders in the engine, assembling all
of the valve train components may require a significant amount of
time and precision when handling and connecting the individual
components.
SUMMARY OF THE INVENTION
[0004] Unitizing two or more valve train components in an engine
can reduce the amount of time and precision required when handling
and connecting the unitized components.
[0005] The present invention provides, in one aspect, a device
adapted to couple a finger follower and a hydraulic lash adjuster
for use in a valve train of an engine. The hydraulic lash adjuster
includes a plunger defining a longitudinal axis. The finger
follower includes a pocket for receiving the plunger. The device
includes a resilient clip having a first arm configured to
selectively engage the finger follower and a second arm configured
to receive the plunger of the hydraulic lash adjuster. The second
arm of the clip includes a semi-circular or a hook portion that is
engageable with the plunger from a direction substantially
transverse to the longitudinal axis of the plunger.
[0006] The present invention provides, in another aspect, a device
adapted to couple a finger follower and a hydraulic lash adjuster
for use in a valve train of an engine. The hydraulic lash adjuster
includes a plunger defining a longitudinal axis and a body that
receives the plunger therein. The finger follower includes a pocket
for receiving the plunger. The device includes a resilient clip
having a first arm configured to selectively engage the finger
follower and a second arm configured to receive the body of the
hydraulic lash adjuster. The second arm of the clip includes a
substantially circular or hoop portion that is engageable with the
body of the hydraulic lash adjuster.
[0007] The present invention provides, in yet another aspect, a
unitized valve train assembly including a finger follower having a
pocket, a hydraulic lash adjuster having a plunger received within
the pocket of the finger follower, and a device, such as the
resilient clips described above, coupling the finger follower and
the hydraulic lash adjuster.
[0008] The present invention provides, in a further aspect, a
unitized valve train assembly includes a finger follower having a
pocket and a peripheral surface adjacent the pocket, and a
hydraulic lash adjuster having a body, and a plunger extending from
the body and received within the pocket of the finger follower. The
plunger defines a longitudinal axis. The assembly also includes a
single-wire coupling device having a first arm configured to
selectively engage the finger follower, and a second arm clamped to
one of the body and the plunger. The second arm is spaced from the
peripheral surface of the finger follower when the plunger is
received within the pocket of the finger follower.
[0009] The present invention provides, in another aspect, a
unitized valve train assembly including a finger follower having a
pocket, a hydraulic lash adjuster including a plunger received
within the pocket of the finger follower, the plunger defining a
longitudinal axis, and a coupling device. The coupling device
includes a first arm configured to selectively engage the finger
follower, and a second arm including a substantially semi-circular
hook portion engageable with the plunger from a direction
substantially transverse to the longitudinal axis of the plunger.
The hook portion defines an inner diameter. The hook portion
includes opposite ends defining therebetween a minimum gap less
than the inner diameter of the hook portion.
[0010] The present invention provides, in yet another aspect, a
single-wire resilient clip adapted to couple a finger follower and
a hydraulic lash adjuster for use in a valve train of an engine.
The hydraulic lash adjuster has a plunger defining a longitudinal
axis, and the finger follower has a pocket for receiving the
plunger. The resilient clip includes a first arm configured to
selectively engage the finger follower, and a second arm having a
substantially semi-circular hook portion engageable with the
plunger from a direction substantially transverse to the
longitudinal axis of the plunger. The hook portion defines an inner
diameter. The hook portion includes opposite ends defining
therebetween a minimum gap less than the inner diameter of the hook
portion.
[0011] The present invention provides, in a further aspect, a
method of coupling a finger follower and a hydraulic lash adjuster
for use in a valve train of an engine. The finger follower has a
pocket for receiving a plunger of the hydraulic lash adjuster. The
method includes providing a clip having a hook portion defining an
inner diameter. The hook portion includes opposite ends defining
therebetween a minimum gap less than the inner diameter of the hook
portion. The method also includes inserting the plunger into the
hook portion from a direction substantially transverse to a
longitudinal axis of the plunger, spreading the opposite ends of
the hook portion from each other during insertion of the plunger
into the hook portion, clamping the plunger with the hook portion
to secure the clip to the hydraulic lash adjuster, and positioning
the plunger within the pocket of the finger follower.
[0012] Other features and aspects of the invention will become
apparent by consideration of the following detailed description and
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a side, partial cutaway view of a unitized valve
train assembly, including a first construction of a coupling device
of the present invention coupling a roller finger follower and a
hydraulic lash adjuster, assembled onto an engine.
[0014] FIG. 2 is an opposite side view of the unitized valve train
assembly of FIG. 1.
[0015] FIG. 3 is a side perspective view of the unitized valve
train assembly of FIG. 1.
[0016] FIG. 4 is an end perspective view of a portion of the
unitized valve train assembly of FIG. 1.
[0017] FIG. 5 is an end view of the unitized valve train assembly
of FIG. 1.
[0018] FIG. 6 is a bottom perspective view of a portion of the
unitized valve train assembly of FIG. 1.
[0019] FIG. 7 is a side perspective view of the coupling device of
the unitized valve train assembly of FIG. 1.
[0020] FIG. 8 is a side view of the coupling device of the unitized
valve train assembly of FIG. 1.
[0021] FIG. 9 is an end perspective view of the coupling device of
the unitized valve train assembly of FIG. 1.
[0022] FIG. 10 is a side, partial cutaway view of a unitized valve
train assembly, including a second construction of a coupling
device of the present invention coupling a roller finger follower
and a hydraulic lash adjuster, assembled onto an engine.
[0023] FIG. 11 is an opposite side view of the unitized valve train
assembly of FIG. 10.
[0024] FIG. 12 is a side perspective view of the unitized valve
train assembly of FIG. 10.
[0025] FIG. 13 is a top perspective view of the unitized valve
train assembly of FIG. 10.
[0026] FIG. 14 is an end view of a portion of the unitized valve
train assembly of FIG. 10.
[0027] FIG. 15 is a top perspective view of a portion of the
unitized valve train assembly of FIG. 10.
[0028] FIG. 16 is a side perspective view of the unitized valve
train assembly of FIG. 10.
[0029] FIG. 17 is a side perspective view of the coupling device of
the unitized valve train assembly of FIG. 10.
[0030] FIG. 18 is an end perspective view of the coupling device of
the unitized valve train assembly of FIG. 10.
[0031] FIG. 19 is a front perspective view of a plunger of a
hydraulic lash adjuster of the unitized valve train assembly of
FIGS. 1 and 10.
[0032] FIG. 20 is a side view of the unitized valve train assembly
of FIG. 1 prior to engine assembly.
[0033] FIG. 21 is an opposite side view of the unitized valve train
assembly of FIG. 1
[0034] FIG. 22 is a side view of the unitized valve train assembly
of FIG. 10 prior to engine assembly.
[0035] FIG. 23 is a top perspective view of the unitized valve
train assembly of FIG. 10 prior to engine assembly.
[0036] Before any embodiments of the invention are explained in
detail, it is to be understood that the invention is not limited in
its application to the details of construction and the arrangement
of components set forth in the following description or illustrated
in the following drawings. The invention is capable of other
embodiments and of being practiced or of being carried out in
various ways. Also, it is to be understood that the phraseology and
terminology used herein is for the purpose of description and
should not be regarded as limiting. The use of "including,"
"comprising," or "having" and variations thereof herein is meant to
encompass the items listed thereafter and equivalents thereof as
well as additional items. Unless specified or limited otherwise,
the terms "mounted," "connected," "supported," and "coupled" and
variations thereof are used broadly and encompass both direct and
indirect mountings, connections, supports, and couplings. Further,
"connected" and "coupled" are not restricted to physical or
mechanical connections or couplings.
DETAILED DESCRIPTION
[0037] FIGS. 1-6 illustrate a unitized valve train assembly 10
including a rocker arm or a spherical-end pivoting, roller cam
follower assembly or roller finger follower 14, a hydraulic lash
adjuster ("HLA") 18, and a coupling device 22 for unitizing or
coupling the follower 14 and the HLA 18. The follower 14 includes a
ball socket having a pocket 24 in which the spherical-pivot
component of the HLA, customarily the piston or plunger 26, is
received. A similar follower 14 is shown in published PCT Patent
Application No. WO 2008/002746, the entire content of which is
incorporated herein by reference. The HLA 18 includes a housing or
body 30 in which the plunger 26 is supported, and the plunger 26
includes a shank 34 and a spherical end portion 38 which engages
the pocket 24 of the follower 14 (see FIG. 19). Such a unitized
valve train assembly 10 may be used, for example, in an engine
having an overhead camshaft configuration. FIGS. 1-3 illustrate a
cam lobe 42 of an overhead camshaft actuating the follower 14 and a
corresponding valve 46.
[0038] With reference to FIGS. 1-6, the body 30 of the HLA 18
includes a cap 50 crimped to the upper portion of the body 30,
thereby forming an integrated part of the body 30. As is known in
the art, the cap 50 axially secures the plunger 26 within the body
30 and limits the axial extent to which the plunger 26 can extend
from the body 30. Also, as shown in FIG. 19, the plunger 26 of the
HLA 18 is configured with an undercut 54, a portion of which is
defined by the shank 34. Alternatively, the plunger 26 of the HLA
18 may be configured without an undercut. Such a plunger without an
undercut is shown and described in published PCT Patent Application
No. WO 2008/002746.
[0039] With reference to FIGS. 7-9, the coupling device 22 is
comprised of a clip 58 made from a single piece of resilient
material (e.g., steel wire) that is bent or otherwise formed into
the illustrated shape. In some constructions of the clip 58, the
steel wire utilized to form the clip 58 has a diameter between
about 0.5 and about 0.75 mm. Alternatively, other wire diameters
may be utilized depending on the sizing of the other valve train
components. The wire diameter utilized to form the clip 58 also
affects the positional tolerance where the clip 58 may be attached
to the plunger shank 34. The clip 58 should be secured to the
plunger shank 34 in an axial position on the plunger shank 34 in
which no portion of the clip 58 substantially interferes with
movement of the plunger 26 or the follower 14 during operation of
the engine. As such, decreasing the wire diameter of the clip 58
proportionally increases the positional tolerance where the clip 58
may be attached to the plunger shank 34.
[0040] The clip 58 includes a first or upper arm 62 selectively
engageable with the follower 14, a second or lower arm 66
configured to engage and clamp onto the plunger 26, and an
intermediate portion 70 interconnecting the upper and lower arms
62, 66. The upper arm 62 of the clip 58 is configured to extend
around the ball socket of the follower 14 (see FIGS. 1 and 2).
Specifically, the upper arm 62 includes an arcuate lip portion 74
engageable with the ball socket of the follower 14 to facilitate
the connection of the clip 58 and the follower 14, and to provide
resistance to the disconnection of the clip 58 and the follower
14.
[0041] In the illustrated construction of the clip 58 in FIG. 7,
the lower arm 66 of the clip 58 includes a semi-circular portion or
a hook portion 78 having opposite ends 82a, 82b and a splayed end
portion 86 disposed toward the distal end of the hook portion 78.
The hook portion 78 of the clip 58 includes an inner diameter D1
less than the outer diameter D2 of the plunger shank 34 (see FIG.
19), resulting in an interference fit between the clip 58 and the
plunger shank 34 when the hook portion 78 of the clip 58 is engaged
or clamped to the plunger shank 34. Such an interference fit
substantially prevents the lower arm 66 of the clip 58 from
rotating, pivoting, or rocking with respect to the plunger 26
during operation of the engine. In some constructions of the clip
58, the interference between the inner diameter D1 of the hook
portion 78 and the outer diameter D2 of the plunger shank 34 may be
between about 1% and about 8% of the outer diameter D2 of the
plunger shank 34. In other words, the inner diameter D1 of the hook
portion 78 may be between about 92% and about 99% of the outer
diameter D2 of the plunger shank 34. Alternatively, in other
constructions of the clip 58, the interference between the inner
diameter D1 of the hook portion 78 and the outer diameter D2 of the
plunger shank 34 may be about 4% of the outer diameter D2 of the
plunger shank 34.
[0042] In addition, the respective ends 82a, 82b of the hook
portion 78, when the clip 58 is removed from the plunger shank 34
and when the clip 58 is in its undeformed or undeflected state, may
be spaced by a length or gap dimension D3 less than the outer
diameter D2 of the plunger shank 34. In some constructions of the
clip 58, the gap dimension D3 may be between about 5% and about 13%
less than the outer diameter D2 of the plunger shank 34 when the
clip 58 is removed from the plunger shank 34 and when the clip 58
is in its undeformed or undeflected state.
[0043] FIGS. 1-6 illustrate the clip 58 attached to the HLA 18. To
preassemble the clip 58 and the HLA 18, the hook portion 78 is
axially aligned with the plunger 26 and the clip 58 is moved toward
the plunger 26 in a direction substantially transverse to a central
axis 90 of the plunger 26 (see FIG. 19). After initial engagement
of the splayed end portion 86 of the clip 58 and the end 82a of the
hook portion 78, continued movement of the clip 58 in a direction
substantially transverse to the central axis 90 of the plunger 26
causes the respective ends 82a, 82b of the hook portion 78 to
separate as the plunger shank 34 is inserted between the ends 82a,
82b of the hook portion 78.
[0044] After the respective ends 82a, 82b of the hook portion 78
pass "over center" of the plunger shank 34--i.e., immediately after
the respective ends 82a, 82b of the hook portion 78 are spread such
that the gap dimension D3 is substantially equal to the outer
diameter D2 of the plunger shank 34--the hook portion 78 snaps onto
the plunger shank 34 to secure the clip 58 to the plunger 26. With
reference to FIG. 6, after the clip 58 is engaged or clamped to the
plunger shank 34, the gap dimension D3 between the respective ends
82a, 82b of the hook portion 78 is greater than the gap dimension
D3 when the clip 58 is removed from the plunger shank 34.
Specifically, in some constructions of the clip 58, the gap
dimension D3 between the respective ends 82a, 82b of the hook
portion 78 after the clip 58 is engaged to the plunger shank 34 is
about 2% to about 5% less than the outer diameter D2 of the plunger
shank 34. Because the hook portion 78 of the clip 58 cannot fully
return to its undeformed or undeflected state shown in FIGS. 7 and
9 after it is engaged with the plunger shank 34, a clamping force
is exerted on the plunger shank 34 by the hook portion 78
sufficient to generate frictional forces on the plunger shank 34
along and about the central axis 90 of the plunger 26 to
substantially prevent the hook portion 78 from rotating, pivoting,
or rocking with respect to the plunger shank 34 during operation of
the engine.
[0045] However, the clip 58 may co-rotate with the plunger 26 with
respect to the plunger body 30 and the follower 14. As shown in
FIG. 5, the intermediate portion 70 of the clip 58 may come into
contact with a side wall of the follower 14 should the plunger 26
and the clip 58 co-rotate about the central axis 90 during
operation of the engine. As such, the side walls of the follower 14
limit the extent to which the plunger 26 and the clip 58 may
co-rotate during operation of the engine.
[0046] After the clip 58 is secured to the HLA 18, the unitized
clip 58 and HLA 18 may be assembled onto the follower 14 in
substantially the same fashion as disclosed in published PCT Patent
Application No. WO 2008/002746. The follower 14 may initially be
oriented such that its pocket 24 may receive the spherical end
portion 38 of the plunger 26. As the spherical end portion 38 of
the plunger 26 is inserted into the pocket 24 of the follower 14,
the arcuate lip portion 74 of the upper arm 62 may engage an upper
surface of the follower 14, causing the clip 58 to deflect or
elastically bend to an "open" position to complete the insertion of
the spherical end portion 38 of the plunger 26 in the pocket 24 of
the follower 14. After the pocket 24 of the follower 14 receives
the spherical end portion 38 of the plunger 26, the clip 58 will
resume its undeflected shape or its "closed" position to secure the
follower 14 to the HLA 18, as shown in FIGS. 1-6.
[0047] Alternatively, the follower 14 and the HLA 18 may be
pre-assembled by positioning the spherical end portion 38 of the
plunger 26 into the pocket 24 of the follower 14, and the clip 58
may be brought in from the side of the pre-assembled follower 14
and HLA 18, in a direction substantially transverse to the central
axis 90 of the plunger 26, to engage the hook portion 78 of the
clip 58 and the plunger shank 34. Depending on the orientation of
the follower 14, the upper arm 62 may or may not be deflected to
clear the side wall of the follower 14 upon attachment of the clip
58 in this manner.
[0048] The follower 14 and HLA 18 can now be handled as a unit,
without substantial concern that the HLA 18 may be unintentionally
separated from the follower 14. To separate the HLA 18 and the
follower 14, the arcuate lip portion 74 must be forced to pass over
the upper surface of the follower 14, thereby causing the clip 58
to deflect back to its "open" position to allow removal of the
spherical end portion 38 of the plunger 26 from the pocket 24. The
resilient property of the clip 58 allows it to be bent slightly to
permit insertion and removal of the follower 14 between the upper
arm 62 of the clip 58 and the spherical end portion 38 of the
plunger 26 without permanently distorting the clip 58 to the extent
that its retention is substantially compromised.
[0049] When installed in an engine application, sufficient
clearance is provided by the geometry of the clip 58 such that the
follower 14 is able to pivot on the spherical end portion 38 of the
plunger 26 through the necessary range of operating angles without
causing damage to or binding of any components, including the
follower 14 and the HLA 18 themselves, due to interference.
Specifically, the arm 66 is positioned on the plunger shank 34 such
that it is spaced, in a direction parallel to the longitudinal axis
90, from a bottom surface of the follower 14, and particularly a
peripheral surface 92 adjacent the pocket 24, to prevent binding
between the clip 58 and the follower 14. In addition, the arm 66 is
positioned on the plunger shank 34 such that it is spaced, in a
direction parallel to the longitudinal axis 90, from the cap 50 of
the HLA 18 to prevent binding between the clip 58 and the HLA
18.
[0050] The clip 58 facilitates handling of the follower 14 and the
HLA 18 as a unit, without substantial concern that the follower 14
and the HLA 18 may become unintentionally separated, without
requiring any special features on either the follower 14 or the HLA
18, such as an undercut of the plunger shank 34, and without
impeding the intended motion of either the follower 14 or the HLA
18, particularly the rotation of the plunger 26 in the body 30.
FIGS. 20 and 21 illustrate the unitized valve train assembly 10
prior to engine installation. The clip 58 maintains the spherical
end portion 38 of the plunger 26 at least partially within the
pocket 24 of the follower 14 when only the follower 14 is grasped
and picked up. In some constructions of the clip 58, the arcuate
lip portion 74 may be spaced from the upper surface of the ball
socket of the follower 14 by as much as about 2 mm to about 3 mm to
allow sufficient play between the HLA 18 and the follower 14 yet
prevent the HLA 18 from unintentionally disengaging and separating
from the follower 14. Alternatively, depending on the sizing of the
other valve train components, more or less spacing between the
arcuate lip portion 74 and the upper surface of the follower ball
socket may be utilized.
[0051] Once installed in a fully assembled engine, the clip 58 is
no longer needed to keep the follower 14 assembled to the HLA 18.
Rather, the clip 58 is only needed to keep the follower 14 from
unintentionally separating from the HLA 18 when the engine is only
partially assembled. Therefore, during operation of the fully
assembled engine, little or no contact between the upper surface of
the follower ball socket and the underside of the upper arm 62 or
the arcuate lip portion 74 occurs because repeated contact may lead
to wear or breakage of the clip 58. Contact between the upper
surface of the ball socket and the underside of the upper arm 62 or
the arcuate lip portion 74 usually only occurs during assembly,
either when the follower 14 is installed onto the HLA 18, or when
the follower 14 is being prevented from unintentionally separating
from the HLA 18 during handling of the unitized valve train
assembly 10.
[0052] FIGS. 10-16 illustrate a unitized valve train assembly 94
including another construction of the coupling device 98. Like
components are labeled with like reference numerals. Generally,
rather than being secured to the plunger 26 of the HLA 18, the
coupling device 98 is secured to the body 30 of the HLA 18.
[0053] With reference to FIGS. 17 and 18, the coupling device 98
comprises a clip 102 made from a single piece of resilient material
(e.g., steel wire) that is bent or otherwise formed in symmetrical
halves about a plane containing the central axis 90 of the HLA 18.
In some constructions of the clip 102, the steel wire utilized to
form the clip 102 has a diameter between about 0.5 mm and about
0.75 mm. Alternatively, other wire diameters may be utilized
depending on the sizing of the other valve train components, and
the spacing between the body 30 of the HLA 18 and the follower
14.
[0054] The clip 102 includes a first or upper portion 106
selectively engageable with the follower 14, a second or lower
portion 110 configured to engage the body 30 of the HLA 18, and an
intermediate portion 114 interconnecting the upper and lower
portions 106, 110. The upper portion 106 and the intermediate
portion 114 of the clip 102 each include dual parallel segments 118
of the wire that extend from the hoop portion 126. Each wire
segment 118 comprising the upper portion 106 also includes a
splayed distal end 122 selectively engageable with the ball socket
of the follower 14 to facilitate the connection of the clip 102 and
the follower 14, and to provide resistance to the disconnection of
the clip 102 and the follower 14.
[0055] In the illustrated construction of the clip 102 in FIG. 17,
the lower portion 110 of the clip 102 includes a circular portion
or a hoop portion 126 having an inner diameter D4 less than the
outer diameter D5 of the cap 50 of the HLA 18 (see FIG. 14),
resulting in an interference fit between the clip 102 and the body
30 when the hoop portion 126 of the clip 102 is engaged to the body
30. Such an interference fit substantially prevents the lower
portion 110 of the clip 102 from rotating, pivoting, or rocking
with respect to the body 30 during operation of the engine. In some
constructions of the clip 102, in its undeformed or undeflected
state, the hoop portion 126 of the clip 102 may have a diameter D4
between about 5% and about 10% less than the effective diameter D5
of the cap 50 to yield the interference fit between the clip 102
and the body 30. Alternatively, the clip 102 may be configured with
only a single wire segment comprising the intermediate portion 114
of the clip 102, and only a single wire segment comprising the
upper portion 106 of the clip 102.
[0056] FIGS. 10-16 illustrate the clip 102 attached or clamped to
the HLA 18. To preassemble the clip 102 and the HLA 18, the hoop
portion 126 of the clip 102 is aligned with the central axis 90 of
the plunger 26, the plunger 26 is inserted through the hoop portion
126, and the individual wire segments 118 comprising the upper and
intermediate portions 106, 114 of the clip 102 are spread apart to
receive the body 30 of the HLA 18. Specifically, the wire segments
118 are spread apart to allow the hoop portion 126 to move over the
cap 50, after which the wire segments 118 may be released to allow
the clip 102 to clamp onto the cap 50 or another portion of the
body 30.
[0057] Because the hoop portion 126 of the clip 102 cannot fully
return to its undeformed or undeflected state shown in FIGS. 17 and
18 after it is engaged with the body 30, a clamping force is
exerted on the body 30 by the hoop portion 126 of the clip 102
sufficient to generate frictional forces on the body 30 along and
about the central axis 90 of the plunger 26 to substantially
prevent the hoop portion 126 of the clip 102 from rotating,
pivoting, or rocking with respect to the body 30 during operation
of the engine.
[0058] Assembly of the unitized clip 102 and HLA 18 may occur in
substantially the same fashion as described above and as disclosed
in published PCT Patent Application No. WO 2008/002746. FIGS. 22
and 23 illustrate the unitized valve train assembly 94 prior to
engine installation. The discussion above relating to the unitized
valve train assembly 10 in FIGS. 20 and 21 also applies to the
unitized valve train assembly 94 in FIGS. 22 and 23. Like the clip
58 discussed above, the arm 110 is positioned on the cap 50 such
that it is spaced, in a direction parallel to the longitudinal axis
90, from the bottom surface of the follower 14, and particularly
the peripheral surface 92 adjacent the pocket 24, to prevent
binding between the clip 102 and the follower 14.
[0059] Various features of the invention are set forth in the
following claims.
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