Note: Descriptions are shown in the official language in which they were submitted.
2S~
1 BACKGROUND OF Tl-IE INVENTION
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Ihis invention relates to devices providing a
lining for a valve guide to receive the stem of a recipro-
cating type poppet valve in an internal combustion engine
and, more particularly, to an insert particularly adapted
to line or reline a worn valve guide to return it to its
original or better operating condition.
Inserts -for lining or relining worn valve guides
in internal combustion engines are well known. Typically,
the worn valve guide of an internal combustion engine is
bored out to receive a cast iron insert having an inside
diameter which receives the stem of a valve Eitted there-
through. The cast iron sleeve is force fitted into or
otherwise retained in the bored-out valve guide passageway.
Cast iron inserts of this type suffer from two
major disadvantages. They are relatively expensive to
manufacture, the meeting of tolerances with respect to wall
thickness and concentricity requiring generally repeat ma-
chining of either the inner or outer insert surfaces fol-
lowing initial machining of the insert. The wear charac-
teristics of these cast iron inserts, most importantly, leave
much to be desired. They do offer the advantages~ however,
of having good heat transfer characteristics and have for
years been produced in standard O.D. sizes minimizing the
number of specialized tools required for installation.
Materials possessing wear characteristics sub-
stantially better than cast iron have been known for a
substantial period of time. In this inventor's prior U.S.
patents 3,828,415 and 3,828~756 entitled METHOD AND APPARA-
TUS FOR REBUILDING VALVE GUIDES issued August 13, 1974,
there is disclosed an insert fabricated from spring-tempered
phosphor bronze and a
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1 method of installing the same. This insert has achieved
substantial commercial success and affords, when installed,
wear characteristics markedly better than those attained
with cast iron. There has been a significant problem,
however, with the installation o-f these inserts. The
physical characteristics of the insert material, its mode of
installation and the rather high cost of the material, more
particularly, have dictated that its wall thickness be kept
; as thin as practical. I'hese clictates have resulted, for any
given valve stem O.D., in a liner having an installed O.D.
requiring a peculiarly sized reamer or other boring tool to
form the passageway within which the insert is to be in-
stalled. These reamers are very expensive and, in many
cases, mechanics, repairmen and the like have chosen to
continue installing the clearly inferior cast iron guides in
order to avoid the time and expense involved in the purchase
and selec-tion of these peculiarly sized tools.
Simllar problems are encountered where an engine
has been previously rebuilt using standard sized toolings.
Removal of the now-worn replacement guide, as will be
readily appreciated, leaves little choice but to rebuild
with a cast iron or other guide having the same O.D.
The present invention provides an insert which
retains the salient features o-f the insert described and
claimed in the aforenoted patents. At the same time,
however, the inventlon preserves all significant advantages
inherent in the prior art cast iron and similar inserts,
particularly with respect to avoiding totally the necessity
for peculiarly specialized tooling at the installation
situs.
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:J109Z919
1 SUMMARY OF THE INVFNTION
The present invention provides a multi-layercd
insert for lining or relining valve guides of internal
combustion engines including separately formed and sub-
sequently assembled outer and inner cylindrical tubes or
sleeves fitted one within the other. The outer or carrier
cylindrical sleeve has a standard outside diameter adapted
to substantially match the diameter of a reamed or bored
valve guide to be lined or relined, such reaming or boring
having been accomplished with standard tools already on hand
in virtually all shops. The inner cylindrical sleeve is
substantially coterminous with and extends the entire length
of the outer sleeve. The inner sleeve also has an outside
wall surace slightly larger than the inside wall surface of
the outer sleeve and adapted to tightly frictionally engage
and be retained within the inside wall sur-face o-f the outer
sleeve when inserted therewithi`n. The Inner sleeve also has
an inside diameter adapted to receive a valve stem there-
through.
In a specific, preferred embodiment of the Pverall
invention the outer sleeve or tube is cut and roll fPrmed
~` from sheet stock with the resulting longitudinally extending
seam welded and the tube being redrawn to eliminate the weld
~ flash. Alternately, the seam may be left open for later
;~ 25 ~ coDtraction within a reamed valve guide. The outer sleeve
may also be foTmed as a seamless, extruded tube in the
first instance.
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,
1 Also, in a preferred embodiment of the overall
invention, the inner sleeve or tube is also cut and roll
formed and includes a longitudinally extending seam. The
opposing edges of the seam are tightly abutted against one
another to form a substantially seamless tube when that
inner sleeve is either inserted within the outer sleeve of
the closed and welded or seamless variety, or co~bined with
an open seam, outer sleeve and inserted within a valve
guide.
The present insert provides significant advantages
over prior known valve guide inserts. In addition to the
high wear resistance, lubricity and the excellent heat
transfer properties in the multi-layered insert as mentioned
above, the separate formation and subsequent assembly of the
inner and outer sleeves or tubes provide precise and accurate
control over dimensions and tolerances such as wall thickness
and concentricity for both the individual and combined
sleeves or tubes. Such control can be consistently maintained
on a high volume basis without costly and time-consuming
machining operations being necessary. Such increased
control over dimensional tolerances provides the ability to
consistently produce inserts which accurately fit the reamed
or bored valve guides. Further, it is not necessary to
utilize specially sized reamers or boring tools which have
been previously necessary to fit irregularly sized inserts.
Standard sized tools may be used with the consistently
obtalned tolerances providing an excellent fit for the
present insert.
These and other objects, advantages, ~urposes and
,
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~9 ~
1 :Eeatures of the invention will become more apparent -Erom a
study o-f the ollowing description taken in conjunction with
the drawings.
B~I:EF DE~sc~IpTIoN OF TH~3 D~AWII~GS
Fig. 1 is a perspective view of a first embodiment
of the lnsert -for lining/relining valve guides;
Fig. 2 is an exploded, perspective view o the
inner and outer sleev:es or tubes prior to assembly to form
the insert shown in Fig. l;
Pig. 3 ls a sectional view of the insert taken
along plane III-III of Fig. l;
Fig. 4 is an end view of the insert shown in Figs.
1 and 3;
Fig. 5 is a perspective view of a second embodi-
ment of the insert, both the inner and outer tubes having
longitudinally extending seams;
Fig. 6 is an end vlew of the insert shown in Fig.
5;
Fig. 7 is an exploded, perspective view of the
inner and outer sleeves or tubes of the insert o Figs. 5
and 6 prior to their assembly;
Fig. 8 is a sectional elevation of the inner
sleeve or tube being inserted;into the outer sleeve or tube
to form an insert such as is shown in Fig. l;
Fig. 9 is a plan view of a blank of metallic
material prior to roll forming into an inner or outer tube
of the present invention;
Fig. 10 is a block diagram of the steps of the
preferred method or manufacturing the insert o the present
lnvention;
Fig. 11 is a fragmentary, sectional view o-f the
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1 insertion of an insert of the type shown in ~igs. 1-~ into
the bored or reamed valve guide of an internal combustion
engine; and
Fig. 12 is a fragmentary, sectional elevation of
the insertion of an insert o-f the type shown in Figs. 5-7
into a bored or reamed valve guide of an internal combustion
engine.
DESCRIPTION OP T~IE PREFERR~.D EMBODIMENTS
Referring now to the drawings in greater detail,
Figs. 1-4 illustrate a first embodiment 10 of the valve
guide insert of the present invention. Insert 10 is a right
circular cylindrical tube having multi-layered walls providing
the tubes with both high wear resistance and lubricity as
well as excellent heat transfer characteristics and strength.
Insert 10 includes a right circular cylindrical outer or
carrier sleeve or tube 12 preferably formed from steel (alumi-
num has also been utilized and other materials including cast
iron may be utilized) and having a predetermined wall thick-
ness, concentricity, and inside and outside diameters. Tube
or sleeve 12 is preferably roll formed from a precut, planar
sheet of steel or aluminum (Fig. 9) into the right circular
cylinder such that it includes a longitudinally extending
seam 14. Seam 14 may be straight or include an aligning
step or ofset as desired. The cylinder is welded at seam
14 and redrawn to elimlnate the resulting flash. The welded
tube is therefore a continuous, seamless outer tube within
which is fitted the inner tube or sleeve 16. Alternately9
as will be more fully explained below, tube or sleeve 12 may
be formed from extruded, seamless tubing of a predetermined
wall thickness.
Fitted within tube or sleeve 12 is an inner tube
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1 or sleeve 16 preferably roll formed from a precut blank or
planar sheet (Fig. ~ of spring-tempered phosphor bronze
metallic material such that it includes a longitudinally or
axially extending seam 18 extending its entire length in one
portion o its wall. In order to maintain axial alignment
of the ends of the tube and also the side edges of the tube
which oppose one another across seam 18, a step or o~fset
is included in seam 18 including opposing edge portions 19,
20 each of which extend in a plane extending generally
transverse to the longitudinal or axial direction of the
tube.
Alternately, although not presently preferred,
inner sleeve or tube 16 may be formed from extruded, seam-
less phosphor bronze tubing of an outside diameter slightly
greater than the inside diameter of welded or seamless outer
tube or sleeve 12 so that the inner tube or sleeve 16 may be
press-fitted into tight, frictional engagement within the
outer tube or sleeve 12.
In either case the thickness of the sheet material
is chosen such that the O.D. of carrier tube 12 will be such
as to fit wlthin a valve guide formed to a stand~rd diameter
by a standard sized tool--i.e., 1/2", 5/8", 7/16", etc.
As is seen in Figs. 1-3, the sleeve or tube 16 is
press fitted within owter sleeve or ~ube 12 such that it
fits coaxially therein with the end surfaces of the two
tubes or sleeves being coterminous with one another. A
chamfer or bevel 22 is formed on the inside diameter at one
end of the outer sleeve 12 to facilitate insertion by press-
fitting of the inner sleeve or tube 16 within the outer
sleeve or tube 12 in the manner shown in Fig. 8. Preferably7
the outside diameter and edges at both ends o~ the insert 10
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1 are cham:fered or beveled at 24 to facilitate insertion of
the insert in a valve guide after manu-facture as is shown in
Figs. 11 and 12.
The pre-ferred wall thicknesses for insert 10 are
-5 approximately 0.0~9 to O.Q80 inches for sleeve 12, depending
on the.overall size of the insert~ and approx.imately 0.016
inches for sleeve 16.
The O.D. of the Einished insert 10 shbuld exceed
the diameter of the reamed passageway in wllich it is to be
installed by approximately 0.0015-0.002 inches to insure a
prope.r press-fit. The O,D. of the phosphor bronze liner
16 (when circumferentially compressed), similarly should
exceed the I.D. of carrier tube 12 by approximately 0.002
inches to insure'its positive retention in the carrier tube.
Thus, where the guide'is to be reamed with a one-half inch
reamer or other tool (typical), the O.D. of the composite
liner should be 0.5015-0.502 inches.
Insertion of inner tube or sleeve 16 within outer
tube or sleeve 12 causes con~raction or compression o-f the
inner sleeve or tube closing seam 18 tightly such that the
side~edges of the roll formed blank press tightly against
and abut one another. The inner tube or sleeve is thus
substantially and effectively seamless after insertion as
shown in Figs. 3 and 4. A spiral groove 26 knurling or ~he
like may be formed on the inside surface o-f the inner tube
16 after insertion wlthi'n the outer tube by machining such
as knurling or the like. The machining forces the inner
tube out~ardl~ against t.he outer tube to facilitat.e fric-
: tional retent:ion of the' inner tube within the'outer tube.
:: 30 Alternatel'y, machining of the groove or knurling may be
performed prior to roll: forming of the' planar blanks of
. ~
1~)9;;~919
1 material into the right cylindrical cyli,nders.
Finally, the I.D. of the composite'line 10 may be
finished after installation to match closely the'diameter of
the valve stem it is to carry. This is particularly advan-
tageous since valve stem diameters for a nominal size often
vary as much as Q.QQ5 lnche's depending upon the particular
manufacturer and extent of use.
Referring now to Figs. 5-7, a second embodiment 30
of the insert -for lining and relining valve guides is
illustrated including an outer sleeve 32 roll formed from a
blank or planar sheet of aluminum or steel into a right
circular,cylinder. Sleeve 32 includes a longitudinally
extending seam 34 formed by the side edges of the precut
blan~ or she~et being axially and radially aligned with one
another but slightly spaced apart circumferentially. In
order to prevent axial misalignment of the side edges
across seam 34, a step or offset formed by transversely
extending edges 36, 38 is provided at at least one position
~ along the seam 34. Instead of closing and welding outer
tube 32 as is done with tube 12 in insert embodiment 10, the
outer sleeve is left~with an open seam to be closed later
upon pTess-fitting within the valve guide of an internal
combustion engine.
The inner right circular cylinder 40 is also
~; 25 ~ preferably roll ormed but from a blank or precut sheet of
phosphor bronze of a predet~ermined thickness. Sleeve 40
includes a longitudinally extending seam 42 formed by the
circumferentially spaced, aligned side edges of the roll
; ' formed blank. Seam 42 also includes transversely extending,
opposing edge portions 44, 46 in at least one portion along
its length'to pre~ent axial misalignment of the' side edges
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10~'~9~19
l which form the walls of the tube or sleeve.
As is best seen in Figs. 5 and 6, inner tube or
sleeve 40 is inserted within outer tube or sleeve 32 with
seams 34, 42 respectively being~ left open. Seams 34, 42
need not be in any special relationship to one another
because both wi'll be tightly closed when insert 30 is posi-
tioned in a valve guide ~s in Pig. 12. Thus khe seams may
be in registry, spaced 180 apart or at any position in
between without affecting the' ultimate'operation of the
insert. Frictional engagement between the tubes or sleeves
holds them together until they are'inserted in an internal
combustion engine valve guide in the manner shown in ~ig. 12
utilizing a special insertion tool having a tapered opening
~hich substan~iall~ matches the bored or reamed size of the
valve guide. Insertion in the valve guide compresses or
closes' both of the seams 34, 42 in the outer and inner
sleeves so that the sleeves become essentially seamless
a~ter insertion to prevent loss of oil or abnormal wear. '~n
this case, the spiral groove, knurling, or broaching opera-
tion to provide an oil-retaining groove or the like within
the inner sleeve is performed after insertion in the valve
guide. Alternately, the blank or sheet phosphor bronze
material may be grooved or knurled prior to roll forming
into the right circular cylinder.
As an example of the diameters of the sleeves or
- tubes 32, 40 of insert 30, for a one-hal-f inch valve guide
bore, auter sleeve or tube 32 has a maximum uncompressed or
free diamet'er of 0.562 inches. In its -free state, the inner
sleeve or tube, before insertion in the' outer sleeve is
0.432 inches'. ~hen the' seams 34 and 42 are closed, the
outer slee`ve or tube~has-a diameter of 0.5Q2 inches designed
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1 to be press-fitted into an 0.500'inch bore or valve guide.
The inside diameter of the outer sleeve or tube 32 in its
free state is 0.401 inches. These dimensions include
tolerances for spring back after forming and before pressing
into the cylinder head of the internal combustion engine.
The preferred wall thicknesses for insert 30 are the same as
those discussed in connection with insert 10.
Like insert 10, the end outer diameter edges of
outer sleeve 32 may be chamfered or beveled at 31 to facili-
tate insertion in the valve'guide. At least one inner end
edge of sleeve 32 may also be chamfered or beveled to
facilitate insertion of inner sleeve or tube 40.
Referring now to Figs. 8-10, the preferred embodi-
ments 10 and 30 of the valve guide insert both include inner
and outer sleeves or tubes pre-ferably formed from flat
metallic sheet stock of appropriate desired thickness,
precut or fashioned into a blank as shown in Fig. ~. The
side edges of the blank, insofar as liners 16 and 40 are
concerned, are preferably precut to include the trans~erse
edge portions which prevent axial misalignment in the
finished cylindrical tubes. The thickness of the blank is
' chosen for the desired wall thicknes's of the finished tube
or sleeve. The widths of the blanks for sleeves 12 and 32
or 16 and 40 ? denoted as dimension "A" in Fig. 9 7 are
selected to effect a tight, press-fitted engagement with the
reamed or bored valve guide being repaired or the inside
surface~of the outer sleeves, respectively9 after rolling
and when the seams of the resulting right circular cylinders
are closed.
Each blank is formed by conventional progressive
rolling to its desired diameter depending on wll'e'ther it will
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1 be used -Eor an inner or outer sleeve or tube. Such rolling
allows the concentricity of the' tubes being formed to be
precisely and accurately controlled while the wall thickness
of the res'ulting tube or sleeve is maintained because of the
uniform thic~ness ~of the precut blank.
In the case o-f sleeve'or tube 12 shown in Figs. 1-
4, whi'ch is preferably roll -formed from sheet steel, the
side edges' of the rolled blank are'axially and radially
aligned, abutted together, and welded by el0ctrical resist-
ance welding along the resulting butt joint to form a
closed, seamles's tube. Therea-fter, the closed, seamless~
welded tube is redrawn to remove any wel'ding flash and to
obtain the ~rue desired diameter for the outer ~ube. The
inside wall surfaces of the outer tube are finish machined
to the proper size designed to receive the inner sleeve or
tube~, after which ~he ou~er tube is cut to length and
chamfered or beveled on its outer diameter end edges and at
least one of its inner diameter end edges. The outside
diameter of the outer tube is then centerless ground to the
exact desired size for insertion into the reamed or bored
valve~guide being repaired.~
In the case of outer sleeve or tube 32, the blank
of materiaI shown in Fig. 9 preferably either steel or
aluminum is roll formed to the desired diameter but the seam
between the opposing, aligned side edges is left open. The
inner sleeve or tubes 16 or 40, formed from sheet phosphor
bronze material of desired ~all thickness for the inner
tubes, are roll -formed in the same manner as outer sleeve 32
with their se-ams 18, 42 being left open.
After ormation of the inner and outer sleeves or
tubes,~the'two are assembled together in slightly differing
~O~
l manners depending on embodiment 10 or 30. Insert 10 is
asse~nbled as shown in Fig. 8 wherein the outer closed
seamless or welded tube 12 is positioned in an upstanding
manner in a fixture 50 on a supporting sur-face. A cylin-
drical, hbllow insertion tool ti2 is positioned on the top
end ~dge of sleeve 12 such that its lowermost inside diameter
is coaxial with and aligned with the inside diameter of
sleeve 12. The inside diameter o:~ tool 52 is equal to or
slightly less than that of sleeve or tube 12. The upper end
of the tool 52 tapers at 54 to the desired inside diameter
of the inner sleeve 12 such that the inner sleeve or tube 16
or 40 can be easily inserted in its expanded, free state in
the upper end and driven downwardly to compress and contract
the size of the inner tube and inserted or press-fitted
within the outer sleeve or tube 12. Such insertion or
press-fitting is accomplished by driving sleeve 16 through
;~ tool 52 with a shouldered cylindrical ~ool 56 located in the
upper free end of inner sleeve 16. Tool 52 has a length at
; least as long as the length of sleeve 16 for fully supporting
~20~ the relatively thin side ~alls of sleeve 16 during such
insertion. Sleeve 16 is driven completely through tool 52
into place within sleeve l2 such that it is coterminous and
aligned therewith.
In the case of the assembly of insert 30, tool 52
as explained above may also be used; however, because outer
sleeve or tube 32 is expandable because of the open seam 34,
inner tube or sleeve 4Q may be more easily pressed or fitted
within outer sleeve 32 since tight, gripping frictional
engagement of the two tubes does not result until the insert
30 is in place within the cylinder`head.
Following press~-fitting of the tubes` 12 and 16
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~9:;~9~9
1 together for insert 10, the inside wall sur~ace of the inner
tube 16 is spiral rolled or knurled to provide an oil-
retaining groove to -facilitate lubrication o-f the valve stem
when inserted therethrough in the cylinder head. Such
spiral rolling or knurling which may also be accomplished by
ball broaching or othe~ machining operation, also forces or
expands the inner tube outwardly against the outer sleeve or
tube to facilitate frictional engagement and retention of
the tubes within one another to prevent separation of the
tubes when in use. Altho'ugh this latter step' may also be
performed after tubes 32 and 40 are assembled together, it
more pre-ferably is accomplished after insertion of insert 30
in the cylinder head. Alternatively, the blanks as shown in
Fig. 9 from which the inner and outer sleeves or tubes are
roll formed, may be knurled or grooved prior to rolling.
After assembly in the above manner, inserts 10 or
30 are inserted in the bored or reamed valve guides being
repaired as shown in Figs. 11 and 12. In the case o-f insert
I0, one of the chamfered ends of insert 10 is placed against
a valve guide 60 to be repaired which has been previously
reamed or bored to a standard diameter. Thereafter, a
driving tool 58 having a shoulder at one end and a cylin-
drical locating projection coaxial therewith is placed over
the end of insert 10 (Fig. llj and the insert is driven into
:: :
~25 place within the bored or reamed valve guide. ~ecause insert
10 is completely closed and compressed to its ultimate
outside diameter, it is not necessary to use any tapering
insert tool 52 or to support the side walls of insert 10
during such insertion.
Howe'~er, in the' case'of insert 30 as shown in Fig.
12, both'the' outside tube 32 and the inner tube or sleeve
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~9 2 ~ ~
1 40 are in an expanded condition larger than their u]timate
sizes when inserted in the valve guide 60'. In such case,
when using insert 30, an insert tool 62 having one end
matching or slightly smaller than the desired inside dia-
meter of the valve guide 60' is placed ato-p the valve guide
while the other end includes a taper 6~ allowing easy
insertion of the expanded insert 3Q but narrowing to the
desired diameter at the lower end. A tool 58 having a
standard diametçr equivalent to the inside diameter of guide
60' and the lower end of to~l 62 is used to drive insert 30
through insert tool 62 into the valve guide. Tool 62 thus
compresses or contracts both the inner and outer sleeves
during such insertion to their final, ultimate diameters
wherein seams 34, 42 are closed tightly to -form a substantially
seamless insert as in the-case of insert-10 which is completed
prior to assembly in the valve guide. Tool 62 preferably
has a length at least as long as insert 30 so as to provide
~ ~ support or the side walls of the insert during such insertion
; in the valve guide 60'. After insertion of the inserts 10
and 30 as shown in Figs. 11 and 12, slight finishing, boring,
or reaming of the inside diameter to assure matching to the
diameter of the valve stem fitted therethrough may be
necessary. This is particularly true when the lnsert has
been shlpped in "unsized" condition so that minor variations
in valve stem diameter may be accommodated in the field.
The inserts may either be~finished in specified lengths
which have been preselected to match the engine being
overhauled or manufactured, or may be cut off after install-
ation by stanclard techni~ues.
After such insertion of either insert 10 or 30,
the valve stem of the poppet valve may be inserted through
-16-
1 the inside diameter of the insert and the remainder of the
valve train assembled on the cylinder head. As with insert
10, insert 30 in its compressed state has an outside diameter
slightly greater than the inside diameter o~ valve guide 60'
S so as to be tightly press-fitted therewith and to stay in
place during use.
The present invention, therefore, provides a valve
guide insert for lining or relining during repair of worn
valve guides including multi-layered walls, the interior o
which is highly wear resistant and self-lubricating or
lubricious because of the use of phosphor bronze, and the
exterior of which is size accommodated to standard diameter
tools. Other materials having these qualities may also be
used. The outer tube or sleeve provides strength and
support for the inner sleeve or tube. Not only does the
separate formation and subsequent assembly of the two
different types of inner and outer sleeves or tubes result
in the above advantages but also importantly allows accurate
and precise control of dimensionaI tolerances for the insert
including wall thickness, concentricity inside and outside
diameters and the like. Finally, because such outside
diameters can be so precisely controlled, standard sized
reaming and boring tools used to prepare the valve guides
for insertion of the insert may be used.
~ While several forms of the lnvention have been
shown and described, other forms wlll now be apparent to
those skilled in the art. Therefore, it will be understood
that the embodiments shown in the drawings and described
above are merely for illustrative purposes, and are not
intended to limit the scope of the invention which is
defined by the claims which follow.
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