Note: Descriptions are shown in the official language in which they were submitted.
~o~
MANDREL FOR USE IN
ASSEMBLIN~ BU~HINoS
THE INVENTION
The present lnvention relates to an improved
apparatu~ for the assembly of bushlngs, and in particular,
to an improved mandrel for use in ~sembling bushings
having an annular elastomeric in~ert between a pair o~
concentric sleeves.
BAC GROUND OF THE INVENTION
Bushings having an annular rubber or elastomeric
insert between a pair of concentric sleeves have been
~nown and used for many year~. Generally, the bushing
is used for mounting a second member, e.g. a motor, to
a first member, e.g. an automobile frame, where the
members must move relative to each other. The inner
sleeve i8 secured, for example by a pin or bolt, to the
first member, and the outer sleeve is secured to the
second member. The relative axial, lateral, and
rotational movement between the two members is accomodated
by the elastomeric or rubber annular insert.
By radially compressing the rubber insert
between the inner and outer sleeves, increased load
béaring and lifetime can be achieved. In such a bushing
the molded rubber insert is cured prior to a~sembly and
held in place under radial compression; the restorative
tendencies of the rubber aid in preventlng relative
motion between the insert and the sleeves.
; , ' ~ ' ~ '
A number Or method~ and Apparatus have been
used ~or assembling the elaRtomerlc in~ert for radial
compre~iOn between the inner and outer sleeve members.
See, for example, United State~ Patent NOB. 2,690,001
and 2,660,780. Generally, apparatus ~or assembling
rubber-metal bushings includes a ~upport member upon
which is mounted an open ended gulde funnel. A clamping
mechanl3m is located at the small end of the funnel and
in axial alignment therewith, for posltloning the outer
sleeve. A plunger is provided in axial alignment with
and advanceable axially into the large end of the ~unnel
face. A mandrel i8 located at the opposite end o~ the
support and in an axially aligned positlon wlth the
funnel member. m e mandrel i8 U ually of a tapered or
~rusto conical profile with its smallest diameter approxi-
mately equal to or ~maller than the annular opening in
the rubber 1nsert and its larger diameter substantially
equal to the outside diameter o~ the inner sleeve. m e
inner sleeve member is posltioned behind the larger
diameter of the mandrel for insertion into the insert.
To ~esemble the bushing3 the annular elastomeric
insert i6 positioned between the plunger and large end
of the funnel, and i6 in~erted into the outer sleeve
by means of the plunger forcing the insert through the
large end o~ the funnel ~or compression into the outer
sleeve po6itioned at the opposite end o~ the funnel. The
mandrel, with the inner sleeve positioned behind it,
is then forced through the annular opening in the insert
to position the inner ~leeve member therein. m e plunger
3 and mandrel are retracted to expose the completed assembly.
.
~V~3~
Improved appar~tu~ has been proposed for the
construction and as~embly of rubber-metal bu~hing~. See, :
for example, United stateB Patent No. 3,555,655. In this
improved apparatus, a mandrel assembly and A nesting
5 assembly are axially aligned and ~paced apart from one
another. The mandrel ~ssembly comprlses an elon~ted
enclosed mandrel cylinder and a pl8ton ther~in. A ~irst
abutment surface is provided to contact one end of the
ela~tomeric insert. m rough the abutment surface extends
an elongated rod, one end of whlch i8 ~oined to the
plston and the other end o~ which ~orm~ a he~d including
both a tapered tip and a fru~to conical portion, the
diameter of which decreases toward the aperture through
which it extends. me ~unction between the tlp and
frusto conical portlon ~orm~ a shoulder for engagement
with one end oi the inner sleeve. m e ~irst abutment
sur~ace and the mandrel are both capable o~ independently
moving to and from a nesting ~ssembly. The ne~ting
assembly includes an annular ~tationary holder ~or the
outer sleeve o~ the bushing. A plunger is pro~ided
which is movable through the holder in a direction to
and rrom the mandrel, and includes an insert abutment -
shoulder and a positionlng pin for the inner sleeve.
In operation, the mandrel inclUding the tip and conical
portlon ~irst passe~ through the ~ree or unconstricted
inner annular opening o~ the elastomeric insert9 a~ter
which the abutment surface o~ the mandrel engages the
insert and ~orces it into the outer sleeve which i8 posi-
tioned in the nesting assembly. AB the fir~t abutment
-;" ' '',
~ V~39~
aurface o~ th~ mQndr~l ~n~l~e~ ~nd torces the annul~r
insert lnto the outer sleeve, the tapered tlp and
shoulder of the frusto conical portlon engages the inner
sleeve member positloned on the plunger o~ the nesting
assembly. The plunger and mandrel are then ~orced back
through the annular opening in the insert to positlon
the inner 8 leeve therein.
Both types of device~ require a mandrel for
radially enlarging the opening in the compressed
elastomeric insert for the lnæertion of the inner
sleeve member Both me~ns of assembling the inner sleeve
require a large axial force not only because of the
high radial forces of the compressed insert, but also
because of the inherently high axial frictional forces
of the elastomeric or rubber insert~ In addition to
the high axial force~ re~uired, the operation of
assembling the bushing, particularly the inner sleeves,
produces high noise levels which are not satisfactory.
SUMMARY OF THE INVENTION
m e present invention ovèrcomes the disadvan-
tages associated with the prior art apparatus by providing
a novel mandrel for use in such apparatus which improve~
flow control or the flow rate of the elastomeric insert
during as~embly. The mandrel of the present invention
provides a more uniform contacting of the elastomeric
insert and inner sleeve to render the stress and strain
throughout the assembly more uniform. Further, a
reduction in power as well as noise during assembly is
achieved by the present invention.
--4--
. .
~V439~
The present invention provides an improved mandrel which is adapt-
able for use in both new and existing apparatus for the assembly of bushings.
According to this invention there is provided a mandrel for use in
assembling bushings which comprises an outer sleeve; an inner sleeve; an
annular elastomeric insert to be radially compressed between said sleeves;
and means for mounting said insert in compression within said outer sleeve,
wherein the mandrel provides the means for expanding the interior of said
insert when mounted within said outer sleeve and for mounting said inner
sleeve within said insert as expanded to place said insert in radial com-
pression between said sleeves and wherein the mandrel precedes said inner
sleeve through said insert and expands the interior of said insert at a
predetermined rate of expansion to mount said inner sleeve within said insert
when so expanded; and wherein said mandrel defines a preselected radial
profile along its length tl extending from its point of minimum working dia-
meter at its leading end, equal or slightly less than the inner diameter of
the compressed insert, to its point of maximum working diameter at its
trailing end, equal or slightly more than the outer diameter of the inner
sleeve, which causes said mandrel to radially expand said interior of said
insert along said mandrel length as said mandrel is forced through said insert,
said profile being in accordance with the reiationship:
X7 = 1/2 ~ X6 - --- Q ~ 1/2 ~ -
I - l ty ~
wherein: X7 = the radius of said mandrel at every point ty extending from the
leading end of said mandrel along the length tl thereof; wherein: X0 = inner
diameter of said insert when uncompressed within said outer sleeve; Xl = .
effective length of said insert when uncompressed; X2 = length of any exten-
sion portion to said insert when uncompressed which contributes to its elonga-
tion; X2 = 0 without contribution to elongation; X3 = outer diameter of said
~ - 5 -
.
~Q~3~3~
insert when uncompressed; X4 = leading diameter of X2; X4 = 0 when X2 = 0;
X5 = inner diameter of said insert when mcompressed; X6 = inner diameter of
said outer sleeve and outer diameter of said insert when compressed therein;
and X7 = outer diameter of said inner sleeve and inner diameter of said insert
when compressed between said sleeves; and
Q = (Xl + X2) ~X3 - X5) + X2 ~X42 _ X52);
R = r Q ~ Q - 1 1 ;.
L~x62 X27) ~X6 - Xo)~ tl ,'~
and n = a positive integer selected from the numbers 1 and 2.
This invention also provides a method for assembling a resilient
bushing, having an outer sleeve, an inner sleeve and an annular elastomeric
insert radially compressed between said sleeves comprising: mounting said
insert in compression within said outer sleeve; and expanding the interior
of said insert when mounted within said outer sleeve and mouting said inner
sleeve within said insert as expanded to place said insert in radial compres-
sion between said sleeves with means including a mandrel preceding said inner
sleeve through said insert and expanding the interior of said insert at a
predetermined rate of expansion to mount said inner sleeve within said insert
when so expanded; and wherein said mandrel defines a preselected radial profile
along its length tl extending from its point of minimum working diameter at
its leading end, equal to or slightly less than the inner diameter of the
compressed insert, to its point of maximum working diameter at its trailing
end, equal to or slightly more than the outer diameter of the inner sleeve,
which causes said mandrel to radially expand said interior of said insert
along said mandrel length as said mandrel is forced through said insert, said
profile being in accordance with the relationship:
X'7 = 1/2 ~X6 - Q ~ 1/7
~X6 ~ X0) + tn R
-~P5a -
:
~0~3S~
wherein: X7 - the radius of said mandrel at every point ty extending from
the leading end o said mandrel along the length tl thereof; wherein: XO =
inner diameter of said insert when compressed within said outer sleeve; Xl =
effective length of said insert when uncompressed; X2 = length of any exten-
sion portion to said insert when uncompressed which contributes to its elonga-
tion; X2 = O without contribution to elongation; X3 = outer diameter of said
insert when uncompressed; X4 = leading diameter of X2; X4 = O when X2 = 0;
X5 = inner diameter of said insert when uncompressed; X6 = inner diameter of
said outer sleeve and outer diameter of said insert when compressed therein;
and X7 = outer diameter of said inner sleeve and inner diameter of said in-
sert when compressed between said sleeves; and
Q = (Xl + X2)(X3 - X5) + X2 (X4 - X5);
.. .. .... . . .
R = Q _ Q
.
~X6 - X27) (X6 - X20) tln -
and n a a positive integer selected from the numbers 1 and 2. ~: ;
Further, we provide apparatus for assembling a resilient bushing
including the components of said bushing in combination during assembly, com-
prising: an outer sleeve; an inner sleeve; an annular elastomeric insert :
adapted to be radially compressed between said sleeves; means for moDnting ~ .
said insert in compression within said outer sleeve; and means for expanding
the interior of said insert when mounted within said outer sleeve and for
mounting said inner sleeve within said insert as expanded to place said insert
in radial compression between said sleeves; said means for expanding including
a mandrel for preceding said inner sleeve through said insert and expanding :
the interior of said insert at a predetermined rate of expansion to mount said ~::
inner sleeve within said insert when so expanded; and wherein said mandrel
defines a preselected radial profile along its length tl extending from its
point of minimum working diameter at its leading end, equal or slightly less
- 5b -
. . . : .
10~35~
than the inner diameter of the comprassed insert, to its point of maximum
working diameter at its trailing end, equal or slightly more than the outer
diameter of the ~r sleeve, which causes said mandrel to radially expand
said interior of said insert along said mandrel length as said mandrel is
.forced through said insert, said profile being in accordance with the rela-
tionship:
X7 = 1/2 X62 _ .. Q _ 1/2
__
(X6 ~ X0) + ty R
wherein: X7 = the radius of said mandrel at every point ty extending from
the leading end of said mandrel along the length tl thereof; wherein: X0 =
inner diameter of said insert when compressed within said outer sleeve; Xl =
effective length of said insert when uncompressed; X2 = length of any exten- :~ .
sion portion to said insert when uncompressed which contributes to its elonga- -
tion; X2 = 0 without contribution to elongation; X3 = outer diameter of said
insert when uncompressed; X4 = leading diameter of X2; X4 = 0 when X2 = 0;
X5 = inner diameter of said insert when uncompressed; X6 = inner diameter of
said outer sleeve and outer diameter of said insert when co~pressed therein;
and X7 = outer diameter of said inner sleeve and inner diameter of said insert .~
~.
when compressed between said sleeves; and :
Q = ~Xl + X2)(X3 - X5) + X2 ~X4 - X5); ~ .
R =¦ Q ~ Q
L~X62 _ X72) ~X6 - XO) J t
and n = a positive integer selected from the numbers 1 and 2.
The mandrel employed in the method and apparatus of the present
invention is adaptable for use in both new and existing apparatus for the
assembly of bushings.
GenerallyJ the smallest diameter of the mandrel is located at the
- 5c -
~439~
end or tip adapted for initially entering into the radially compressed insert.
The diameter increases along its length to the back portion which is used as
a shoulder upon which the leading peripheral edge of the inner sleeve abuts.
Preferably, the tip has a diameter less than that of the insert opening when
radially compressed by the outer sleeve. The diameter of the shoulder is
preferabl~ slightly larger than the outer diameter of the inner sleeve. The
tip may be either elongated or blunt nosed and the shoulder may include there-
with either an elongated or stub nosed extension for axially positioning the
inner sleeve. The radial profile ~X7) at every point (ty) (where t~ is
numerically equal to the axial distance from the forward point of the mandrel
profile to the point at which X7 is to be determined) along the axial profile
length tl of the mandrel portion of the present invention varies according to
the relationship:
~ ~'
~ 5d -
. . .
1/2
X7 ~: 1/2 X6 - t- ty R
2 --2
(X6 - Xo )
: whe re
R ~ X7 ) ( X6 - ~o ) l n
and whcrc Q 1~ a conetant determlned by the dlametral
Mnd length parameter~ Or the bu8hing insert; where n
i9 a posltlve lnteger e~ual to l or 2.
A better under~tanding o~ the nature o~ the
present lnventlon a~ well a~ the pro~ile relationships
ls 3et forth in the rollowlng detalled de~criptlon of
a present:ly preferr~d ~mbodlment taken in connection
wlth the drawlnB~.
~IEF DESCRIPTION OF T~E DRAWINGS
Figure l 18 an ele~ation in par~lal sectlon
of the princip~l component~ o~ an app~ratu~ ~or the
a~embly of rubber-metal bushings;
Flgure 2 18 a ~ec tlon of the elas tomerlc
insert wlth variou~ rel~tional par~meters;
-6-
. ~0~3~
.
~! ~'lgure 3 1~ a ~ectlon of thc ns~embled elasto-
merlc ln~ert ~nd`sleeve~ flnd relatlon~l par~meterq;
~` Figure 4 1~ a partial section of a mandrel
and inner sleeve engaging the ahoulder'or the mandrel,
snd , - .
~ Flgure 5 i8 an elevatlon showlne the dl~metric
:. relationshlp between the mandrel pro~iles for n~l and n=2.
, :
DESCRIPTION OP PRESENTLY PR~EFERRED EMBODIMENTS
; 10 For the purposea Or understanding the present
lnventlon, Figure 1 repre~entB the princlpAl components
! ln a ~ tandArd appara tu~ 10 for a~embling rubber-metAl
type bushlngs. Appflratu~ 10 compri3es a pcir Or vertlcal
support guide~ 11 mounted upon ba~e 12. Slid~bly mounted
upon support guides 11 i8 an upper cros~ member 13 and ~-
a lower cro~s member 14. S~id members include be~rings
15 for slldable engagement wlth the guides. Upper
croa~ member 13 lncludes ~ pneumstic cylindrical plunger
. 16 having an annular faclng ~urface 17 of a cros~ aectlon
adapted for en~agement wlth ~laatomerlc lnsert A. Plunger
16 i8 operably connected to ~ pneumAtic cyllnder ~nd
power source (not 8 hown).
Upper cross member 13 18 connected flt lts lnner
extremity to a pair of con~ecting r~ds 18 which ~re
themselves connected with pl~tons tpneumatlc or hydrau-
lically ~ctuated), not shown, ~or movlng member 13 along
guides 11. Membe~ 13 nl~o lncludes ~ dependlng funn~l
support member 19 to which 1~ mounted ~unnel 21 in axlal
3S~
alignment with plunger 16. Spnced between funnel 21
and plunger 16 and in axial allgnment therewith i8
cylindrical insert holder 22. Holder 22 is mounted
to upper cross member 13 and is preferably of a diameter
substantially equal to the outside diameter of insert A.
~ Located at the outer extremities of member 13
; are a pair of pneumatic or hydraulic cylinders 23. Each
cylinder is preferably mounted to the top of member 13
and includes a cylinder rod 24 depending therefrom and
passing through opening 26 in member 13. The ends of
cylinder rods 24 are connected to the outer extremities
of lower cross member 14. Cylinder 23 and c~linder rods
24 are adapted to move upper and lower members 13 and 14
relative to each other.
15Lower cross member 14 includes an outer sleeve
annular nesting member 27 for securely holding the outer
sleeve ~in an axial aligned position to funnel 21,
plunger 16~ and insert A. Nesting member 27 includes
a fir~t inner annular land 28 for preventing axial move- ~.
ment of outer sleeve B. A second inner land 29 iR
provided for holding a cylindrical insert stop 310 Stop
31 includes a flange 32 for seating engagement with second
land 29 and for axially aligning stop 31 within nesting
member 27. Cylindrical opening 33 in stop 31 i~ of a
diameter slightly larger than the outer diameter of inner
sleeve C. The cross-sectional area of flange 32 and StQp
31 is adapted to be of a æize sufficient to retain insert
A from axial movement during insertion beyond the stop.
3S~S~3
Mounted to base 12 1~ a m~ndrel adapter holder
34. A mandrel ~dapter 36 is po~itioned wlthin holder
34. Both adapter 36 and holder 34 are axially aligned
with nesting member 27 and funnel 21. Adapter 36 includes
cavity 37 for securely holdlng and positioning mandrel
38. Mandrel 38 includes an end portion 40 having a
diametric relationship to lts length in accordance
with the present invention and more fully explained ~-
herelnafter. For present purpo~es, the tip of portion
40 i8 of a diameter equal to, but pre~erably less than,
the diameter of the ennular opening through lnsert A
when fully inserted in outer sleeve B. The back or `!
shoulder of portion 40 has a diameter equal to, but
preferably larger than, the outside diametèr of inner
sleeve C. Mandrel 38 include8 an elongated cylindrical
portion 41 which is adapted to engage within cavity 37.
The dlameter of cyllndrlcal portion 41 is sllghly less
than the inside di~meter of inner sleeve C.
In operation of Apparatus 10, cross member~
13 and 14 are initially placed in a fully extended and
spaced apart relatlon to one another. Plunger 16 is
fully retracted. An annular elastomeric lnsert A i8
posi~ioned in holder 223 outer sleeve B iA placed ln
ne~tlng member 27; and inner sleeve C i9 placed on portlon
41 of mandrel 38 which is then positioned in holder 34.
Upper cro~s member 13 is lowered so that the small fac~
cf funnel 21 i8 abuttingly allgned wlth peripheral end
portion of sleeve B. Plunger 16 is then actuated to
abut its surface 17 wlth the end of in~ert A and force
: ,
lnsert A through the lflrge openlng o~ funnel 21 thon
through the ~m~ll openlng into sleeve B. Tr~vel Or
plun~er l6 i8 ~topped by ~ppropriate llmlt BWltches
or the like when lnsert A contacts stop 31. Thereafter,
both upper and lower cros~ members 13 ~nd 14 are lowered
by connectlng rods 18 80 that mandrel 38 and portlon 40,
in particul~r, passes through opening 33 of stop 31,
and eng~glngly pa~ses through and opens the compressed
annular opening ln lnsert A. Portlon 40 oP mQndrel
exlts from ln~ert A lnto op~nlng 42 Or plunger 16.
After portion 40 of mandrel 38 haa Pully exlted from
ln~ert A~ lnner sleeve C i~ properly ln~erted and ali~ned
wlthln the ~sembly. Plunger 16 Rnd cro8~ members 13 and
14 ore retracted and the ss~embled bushing i~ removed.
Referrlng to Figur~ 2 and 3, the varlou~ :
relatlonal parameters need~d for calcul~ting the radi~l
pr-o~lle (the r~dius Or the mandrel at every point ~ty)
along the axial proflle length tl Or portion 40) o~
man~rel 38 are di~cloced thereln and summarlzed a~
follows:
Xo 8 the compreaaed lnner dlQmeter oP lnsert A
a~ter insertlon into outer sleeve ~nd
berore insertlon of inner sleeve;
xl = the effective length o~ in~ert A;
2~ X2 = the ef~ectlve length added by the beveled
portlon o~ in~ert A (Figure 2);
X3 = the outer dl~m~t~r~ uncompre~ced, Of
insert A;
-10-
~3~
x4 = the diameter of the leading edge of insert A of
Figure 2;
x5 = the uncompressed inner diameter of insert A;
X6 = the inner diameter of outer sleeve B;
X7 = the outer diameter of inner sleeve C.
ty is numerically equal to the axial distance from the ;
forward point of the mandrel profile to the point at which X7 is to
be determined.
tl is the axial length of the mandrel profile 40.
If the beveled portions of insert A ~Figure 2) are only
extensions thereof and do not contribute to the elongation of the
insert, then for the purpose of calculating the radial profile of ~-
the mandrel x2 and X4 are both deemed to be equal to zero. It
should be further noted that it is preferred that for purposes of
calculating the maximum radius X7 of the mandrel, X7 should be
taken as slightly larger in value than the actual outer diameter of ``
the inner sleeve ~see Figure 4). For example, X7 = O.D. of C + .030"
for a plain end and xl = O.D. of C ~ .050" for a serrated end.
Furthermore, the diameter of the leading edge or tip of
mandrel
~,' `
, -,
~)4~
portion 40, X0~ should be slightly less than the inner diameter of compressed
insert A to facilitate entry therein, for example 0.030".
Figure 5 shows the profile relationship between mandrel profile
geometries for n = 1 and n = 2. The profile for n = 1 is shown in solid
line and the profile for n = 2 in broken line.
The radial profile of tapered portion of tne mandrels ~where n = 1
or 2) conform to the present invention wherein the radius (X7) of the mandrel
at every point ty along its length tl, of 40 is:
[ 6 ~ ¦
where
[ ~ 7) ~ o2) ]
Q = tXl ~ X2)~X3 - X5) ~ X2 ~X42 _ X5), and
n = a positive integer selected from the numbers 1 and Z.
The profile does not require that n be constant over the entire
length tl of the mandrel; for example n = 2 for a first portion of the length
tl and n = 1 for a following portion, and the like.
In Table I a diametrical comparison is provided of the profiles
of Figure 5. The length tl of mandrel portion 40 was equal to 5.625 inches,
X0 was 1.88 inches and X7 was 2.836 inches.
- 12 _
' ., - :. .- ~ : ' ' :
~43g93 : `:
TABLE I
t (in inches) 2 . X7 = Diameter2 . X7 = Diameter
Y (in inches)(in inches)
for n = 2 for n = 1
0.5 1.8946 2.0324
1.0 1.9372 2.1614
1.5 2.004 2.2728
2.0 2.0892 2.3702
..
2.5 2.1876 2.4564
3.0 2.2932 2.5334
3.5 2.4020 2.6026
4.0 2.5104 2.6652 -
.. .. . .
-13-
~ .
" . , , ,, ~
~35~3
TABLE I
(continued)
4.5 2,6156 2.7222
5.0 2.716 2.7742
Various mandrel lengths having both profiles were compared with
conventional tapered mandrels of the prior art. The conventional mandrels - :
used for comparison were a two inch ~tl) straight taper ~P) and a two inch
(tl) straight taper with a blunt nose ~B). The mandrel profiles of the
present invention used for comparison included:
Mandrel tl Profile :
2.5 A 2.5" n = 2
2.5 V 2.5" n = 1
1.75 A 1.75" n = 2
1.75 V 1.75" n = 1 ``
1.00 V 1.00" n = 2
l.OO V 1.00" n = 1
Table II shows the comparative assembly forces required for the
in.certion of inner sleeve C into the radially compressed insert A, between ~"
the conventional mandrels, P and B, and the above profiled mandrels. ~ ~;
'.,`' ~.'`
- 14 ~
:ti ~, ,
''' . ' ' ~` .`' , . "' , ' ' '
3~3
T~BBE II
Inner Sleeve Assembly Forces with Various Man~rel Desi~ns
Average Inner Metal Force of
ree Assemblies per Test (lbs.)
. 5 Mandrel Four Test
Desi~n Test 1 Tesk ? ~ Test 4 ~ e
2.5 A 117 129 100108 113.5
2.~ V 161 107 13~ g~ 4.0
p 2~7 178 233223 230.25
B 187 170 168143 167.0
1-75 A 126 123 121113 120.75
1.75 V 157 lG6 138153 138.5
1.00 A 160 179 158203 175.0
1.00 V 157 139 196178 167.5
C OnB tants
A. Shootinf~ Machlne`Settings
1. Main piston - 70 psi
2. Plunger piston - 45 p8i
B. Heavy Lubricating Oil
Table III shows comparatively the ave.rage ~orce
re~uired ~or insertion of heavily phosphated coated metal
inner sleeves between the conventional mandrel and those
of the present invention.
;' , ~
', ' ;~
~ ~
- a _~
39~3
~ .
TABLE I II
, .
Henvil;y Phosphatls Coated_Metals
Mnndrel Averag~ Force (lbs.)
2.5 A 161
52.5 V 190
P 450 (Heavy 011 Required )
B 425
1 . 75 A 223
1.75 V 236
101.00 A 391 (Heavy 011 Required)
1.00 V 302
Note: Sun 2150 W~18 the heavy oil u~d~
A~ cAn be seen rrom Tables II and III, the
force required ror inserting the lnner sleeve wlthin
the compressed elastomerlc insert 1B substantlally reduced
by means o~ mandrels used in accordance with the present
invention.
Attendant reduction ln noise during assembly i~ al60
provlded by the mandrels of the preeent irlvention.
Whlle lt la prefe.r~ble th~t the pro~ile conform
to the relationships set ~orth above ~t every point ty
along the length of th~ mandrel, it ia clear that straiBht
llne approxim~tion8 bet~een small increments of ty as indica
ted in Table 1 achieve substantially the same results while
reducing the costs of machining the mandrel profile.
-16-
L3~3
Further, it 1~ clear that the tlp of mand.rel
portion 40 can be rounded~ ~igure 13 or blunted~ ~ ~ure 5
or it may be elong~ted as in Figure 4. For example~
in the ca~e of the mandrel di~closed in Figure 4, the
elongation of the tip is approximately one-half inch.
At every polnt along the tip, the diameter is equal to
xO. Elongation of the tip would be re~uired where the
mandrel of the present invention is used in apparatus
. such as that disclosed in United States Patent No.
3,555~655-
` Whiie presently preferred embodiments of the
inventlon have been shown and described in particularity~
the invention may be otherwise embodied within the scope
of the appended claims.
,'' ' . ~ ,.
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