Method for making a lip type shaft seal having a resin liner
First Claim
Patent Images
1. A method for molding an annular lip type shaft seal of the type having an annular elastomeric shaft seal element and a resin liner integrally molded therewith and bonded thereto, said method comprising the steps of:
- (a) placing a resin liner element having a thickness t, an elastomeric preform and a seal shell in a mold having an annular lip forming surface;
(b) providing, on said lip forming surface, an annular shoulder having a shoulder surface facing said liner element and adapted to contact an outer edge of said liner element during molding for preventing said resin liner element from flowing axially past said shoulder, said shoulder being located axially between a liner forming surface and an elastomeric seal element forming surface, said shoulder making an angle α
with said liner forming surface and having a perpendicular height d above said liner forming surface;
(c) providing α and
d with the values α
≦
85° and
d≧
t; and
(d) operating said mold for forming said liner element into said liner and causing said elastomer to flow to form said shaft seal element and applying heat and pressure thereto for forming said seal.
5 Assignments
0 Petitions
Accused Products
Abstract
A method for molding an annular lip type shaft seal 10 of the type having an annular elastomeric shaft seal element 12 and a resin liner 14 (preferably polytetrafluoroethylene) integrally molded therewith and bonded thereto, including providing a step or shoulder 36 on the mold core 26 to prevent the resin liner 14 from flowing axially beyond a predetermined location during molding. The method includes providing a certain range of acute angles "α" between the shoulder surface 42 and the liner forming surface 38 of the mold core surface 34, and a certain range of shoulder heights "d" relative to the liner thickness "t", for various values of the initial viscosity of the elastomeric preform 18. The percentage of rejects due to undesired flow of the resin liner 14 during molding has been greatly reduced.
37 Citations
23 Claims
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1. A method for molding an annular lip type shaft seal of the type having an annular elastomeric shaft seal element and a resin liner integrally molded therewith and bonded thereto, said method comprising the steps of:
-
(a) placing a resin liner element having a thickness t, an elastomeric preform and a seal shell in a mold having an annular lip forming surface; (b) providing, on said lip forming surface, an annular shoulder having a shoulder surface facing said liner element and adapted to contact an outer edge of said liner element during molding for preventing said resin liner element from flowing axially past said shoulder, said shoulder being located axially between a liner forming surface and an elastomeric seal element forming surface, said shoulder making an angle α
with said liner forming surface and having a perpendicular height d above said liner forming surface;(c) providing α and
d with the values α
≦
85° and
d≧
t; and(d) operating said mold for forming said liner element into said liner and causing said elastomer to flow to form said shaft seal element and applying heat and pressure thereto for forming said seal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for molding an annular lip type shaft seal of the type having an annular elastomeric shaft seal element and a resin liner integrally molded therewith and bonded thereto, comprising:
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(a) placing a resin liner having a thickness t and an elastomeric preform in a mold having a mold core with a radially outwardly facing lip forming surface, (b) forcing the elastomeric preform to flow in said mold and form said liner against said lip forming surface, (c) providing on said lip forming surface an annular shoulder located axially between a liner forming surface and an elastomeric seal element forming surface, said shoulder having a shoulder surface facing said liner and adapted to contact an outer edge of said liner during molding and to prevent said liner from flowing past said shoulder, said shoulder surface making an acute angle α
with said liner forming surface and having a perpendicular height d above said liner forming surface, and(d) providing α and
d with the values;
α
≦
85° and
d≧
t. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A method for molding an annular lip type shaft seal of the type having an annular elastomeric shaft seal element and a resin liner integrally molded therewith and bonded thereto, said method comprising the steps of:
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(a) placing a flat washer of resin liner material having a thickness t, an elastomeric preform and a seal shell in an open mold having an annular lip forming surface facing radially outwardly and axially inwardly; (b) providing on said lip forming surface an annular shoulder having an axially inwardly facing shoulder surface for preventing said resin liner material from flowing axially outwardly beyond said shoulder, said shoulder being located axially between a liner forming surface and an elastomeric seal element forming surface of said lip forming surface, said liner forming surface being recessed radially inwardly relative to said seal element forming surface, said providing step including providing an angle α
between said shoulder surface and said liner forming surface, and providing a height d for the perpendicular height said shoulder surface extends above said liner forming surface;(c) providing α
≦
85° and
providing d≧
t;(d) closing said open mold and applying heat and pressure thereto; (e) forming said flat resin washer into a resin lip liner; (f) flowing said elastomeric preform into a lip type shaft seal element substantially simultaneously with said forming step during said closing step; (g) bonding said lip liner to said seal element and substantially simultaneously curing said elastomer while said mold is closed; (h) opening said mold; (i) removing the formed, cured and bonded semifinished seal assembly from the mold; and (j) trimming an excess portion of the resin lined seal lip off of said assembly to form a finished shaft seal. - View Dependent Claims (19, 20, 21, 22, 23)
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Specification
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Current AssigneeColtec Industries Incorporated (Enpro Industries Incorporated)
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Original AssigneeGarlock Inc. (Enpro Industries Incorporated)
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InventorsCather, Douglas A. Jr., Bainard, Dean R., O'Neal, Robert D.
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Primary Examiner(s)LOWE, JAMES
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Application NumberUS06/219,364Time in Patent Office1,009 DaysField of Search264/262, 264/266, 264/268, 264/127, 264/138, 264/163, 425/DIG. 47, 29/527.1, 29/469.5US Class Current264/138CPC Class CodesB29C 43/027 having an axis of symmetry ...B29C 43/18 incorporating preformed par...B29C 70/84 by moulding material on pre...B29D 99/0053 Producing sealings B29D99/0...B29K 2021/00 Use of unspecified rubbers ...B29L 2031/26 Sealing devices, e.g. packa...F16J 15/328 Manufacturing methods speci...Y10S 425/047 Seal ringY10T 29/49906 Metal deforming with nonmet...
