US4433964A — Composite timing gears and process

Claim 1

Independent Claim 234 words

Composite timing gears, comprising: a thermoplastic, amide-imide resinous polymeric crankshaft gear having teeth and defining a hole for snuggly receiving a crankshaft; a thermoplastic amide-imide resinous polymeric camshaft gear having teeth for meshingly engaging and being driven by said teeth of said crankshaft gear and defining a hole for snuggly receiving a camshaft; each of said gears comprising a reaction product of a trifunctional carboxylic acid compound and at least one diprimary aromatic diamine and comprising at least one of the following moieties: ##STR10## wherein one carbonyl group is meta to and one carbonyl group is para to each amide group and wherein Z is a trivalent benzene ring or lower-alkyl-substituted trivalent benzene ring, R 1 and R 2 are different and are divalent aromatic hydrocarbon radicals of from 6 to about 10 carbon atoms or two divalent aromatic hydrocarbon radicals of from 6 to about 10 carbon atoms joined directly or by stable linkages selected from the group consisting of --O--, methylene, --CO--, --SO 2 --, and --S-- radicals and wherein said R 1 and R 2 containing units run from about 10 mole percent R 1 containing unit and about 90 mole percent R 2 containing unit to about 90 mole percent R 1 containing unit and about 10 mole percent R 2 containing unit; and said thermoplastic crankshaft and camshaft gears maintaining their shape and structural integrity at engine operating conditions.

Claim 2

Dependent Claim 234 words

Composite timing gears, comprising: a thermoplastic, amide-imide resinous polymeric crankshaft gear having teeth and defining a hole for snuggly receiving a crankshaft; a thermoplastic amide-imide resinous polymeric camshaft gear having teeth for meshingly engaging and being driven by said teeth of said crankshaft gear and defining a hole for snuggly receiving a camshaft; each of said gears comprising a reaction product of a trifunctional carboxylic acid compound and at least one diprimary aromatic diamine and comprising at least one of the following moieties: ##STR10## wherein one carbonyl group is meta to and one carbonyl group is para to each amide group and wherein Z is a trivalent benzene ring or lower-alkyl-substituted trivalent benzene ring, R 1 and R 2 are different and are divalent aromatic hydrocarbon radicals of from 6 to about 10 carbon atoms or two divalent aromatic hydrocarbon radicals of from 6 to about 10 carbon atoms joined directly or by stable linkages selected from the group consisting of --O--, methylene, --CO--, --SO 2 --, and --S-- radicals and wherein said R 1 and R 2 containing units run from about 10 mole percent R 1 containing unit and about 90 mole percent R 2 containing unit to about 90 mole percent R 1 containing unit and about 10 mole percent R 2 containing unit; and said thermoplastic crankshaft and camshaft gears maintaining their shape and structural integrity at engine operating conditions.

Claim 3

Dependent Claim 26 words

Composite timing gears in accordance with claim 1 wherein said crankshaft gear and said camshaft gear each define a keyway adjacent said hole in said gear.

Claim 4

Dependent Claim 26 words

Composite timing gears in accordance with claim 1 wherein said camshaft driven gear has twice as many teeth and twice the diameter of said crankshaft gear.

Claim 5

Dependent Claim 29 words

Composite timing gears in accordance with claim 1 wherein R 1 is ##STR11## and R 2 is ##STR12## or wherein R 1 is ##STR13## and R 2 is ##STR14##

Claim 6

Dependent Claim 73 words

Composite timing gears in accordance with claim 1 wherein Z is a trivalent benzene ring, R 1 is ##STR15## R 2 is ##STR16## and wherein the concentration range runs from about 30 mole percent of the R 1 containing units and about 70 mole percent of the R 2 containing units to about 70 mole percent of the R 1 containing units and about 30 mole percent of the R 2 containing units.

Claim 7

Dependent Claim 21 words

Composite timing gears in accordance with claim 1 wherein each gear comprises from 40% to 100% by weight amide-imide resinous polymer.

Claim 8

Dependent Claim 21 words

Composite timing gears in accordance with claim 6 wherein each gear comprises from 65% to 75% by weight amide-imide resinous polymer.

Claim 9

Dependent Claim 26 words

Composite timing gears in accordance with claim 1 wherein each gear comprises a fibrous reinforcing material selected from the group consisting essentially of graphite and glass.

Claim 10

Dependent Claim 19 words

Composite timing gears in accordance with claim 8 wherein each gear comprises from 10% to 50% by weight graphite.

Claim 11

Dependent Claim 19 words

Composite timing gears in accordance with claim 9 wherein each gear comprises from 30% to 34% by weight graphite.

Claim 12

Dependent Claim 18 words

Composite timing gears in accordance with claim 8 wherein each gear comprises 10% to 60% by weight glass.

Claim 13

Dependent Claim 18 words

Composite timing gears in accordance with claim 11 wherein each gear comprises 30% to 34% by weight glass.

Claim 14

Dependent Claim 27 words

Composite timing gears in accordance with claim 8 wherein each fibrous reinforcing material has a polymeric sizing that substantially maintains its structural integrity at engine operating conditions.

Claim 15

Dependent Claim 19 words

Composite timing gears in accordance with claim 8 wherein each gear comprises not greater than 3% by weight polytetrafluoroethylene.

Claim 16

Dependent Claim 19 words

Composite timing gears in accordance with claim 14 wherein each gear comprises from 1/2% to 1% by weight polytetrafluoroethylene.

Claim 17

Dependent Claim 20 words

Composite timing gears in accordance with claim 8 wherein each gear comprises not more than 6% by weight titanium dioxide.

Claim 18

Dependent Claim 176 words

A process for forming a composite timing gear for use in an engine, comprising the steps of: inserting a removable core pin along an axis in a cavity of a mold providing a die to define a generally gear-shaped molding chamber; injection molding a thermoplastic, amide-imide resinous polymer to form a gear-shaped blank having teeth and a diaphragm covering a hole for receiving a shaft, said injection molding including injecting said amide-imide polymer into said cavity through a sprue at a location generally opposite said core pin along said axis to substantially fill said gear-shaped molding chamber about said core pin and substantially minimize knit lines in said amide-imide gear-shaped blank; solidifying the shape and polymeric orientation of said amide-imide gear-shaped blank by allowing said amide-imide gear-shaped blank to cool below its plastic deformation temperature; removing said core pin from said mold; post curing said amide-imide gear-shaped blank by solid state polymerization to enhance the strength and integrity of said amide-imide gear-shaped blank; and removing said diaphragm covering said hole to form said composite timing gear.

Claim 19

Dependent Claim 176 words

A process for forming a composite timing gear for use in an engine, comprising the steps of: inserting a removable core pin along an axis in a cavity of a mold providing a die to define a generally gear-shaped molding chamber; injection molding a thermoplastic, amide-imide resinous polymer to form a gear-shaped blank having teeth and a diaphragm covering a hole for receiving a shaft, said injection molding including injecting said amide-imide polymer into said cavity through a sprue at a location generally opposite said core pin along said axis to substantially fill said gear-shaped molding chamber about said core pin and substantially minimize knit lines in said amide-imide gear-shaped blank; solidifying the shape and polymeric orientation of said amide-imide gear-shaped blank by allowing said amide-imide gear-shaped blank to cool below its plastic deformation temperature; removing said core pin from said mold; post curing said amide-imide gear-shaped blank by solid state polymerization to enhance the strength and integrity of said amide-imide gear-shaped blank; and removing said diaphragm covering said hole to form said composite timing gear.

Claim 20

Dependent Claim 19 words

A process in accordance with claim 17 wherein said diaphragm is removed by drilling and said hole is honed.

Claim 21

Dependent Claim 14 words

A process in accordance with claim 17 including forming a keyway adjacent said hole.

Claim 22

Dependent Claim 14 words

A process in accordance with claim 17 including mounting said gear on a camshaft.

Claim 23

Dependent Claim 14 words

A process in accordance with claim 17 including mounting said gear on a crankshaft.

Claim 24

Dependent Claim 27 words

A process in accordance with claim 17 wherein said amide-imide polymer is prepared by reacting a trifunctional carboxylic acid compound with at least one diprimary aromatic diamine.

Claim 25

Dependent Claim 151 words

A process in accordance with claim 22 wherein said amide-imide polymer comprises one of the following moieties: ##STR17## wherein one carbonyl group is meta to and one carbonyl group is para to each amide group and wherein Z is a trivalent benzene ring or lower-alkyl-substituted trivalent benzene ring, R 1 and R 2 are different and are divalent aromatic hydrocarbon radicals of from 6 to about 10 carbon atoms or two divalent aromatic hydrocarbon radicals of from 6 to about 10 carbon atoms joined directly or by stable linkages selected from the group consisting of --O--, methylene, --CO--, --SO 2 --, and --S-- radicals and wherein said R 1 and R 2 containing units run from about 10 mole percent R 1 containing unit and about 90 mole percent R 2 containing unit to about 90 mole percent R 1 containing unit and about 10 mole percent R 2 containing unit.

Claim 26

Dependent Claim 28 words

A process in accordance with claim 23 wherein R 1 is ##STR18## and R 2 is ##STR19## or wherein R 1 is ##STR20## and R 2 is ##STR21##

Claim 27

Dependent Claim 72 words

A process in accordance with claim 23 wherein Z is a trivalent benzene ring, R 1 is ##STR22## R 2 is ##STR23## and wherein the concentration range runs from about 30 mole percent of the R 1 containing units and about 70 mole percent of the R 2 containing units to about 70 mole percent of the R 1 containing units and about 30 mole percent of the R 2 containing units.

Claim 28

Dependent Claim 19 words

A process in accordance with claim 23 wherein said polymer comprises from 10% to 50% by weight graphite fibers.

Claim 29

Dependent Claim 19 words

A process in accordance with claim 26 wherein said polymer comprises from 30% to 34% by weight graphite fibers.

Claim 30

Dependent Claim 19 words

A process in accordance with claim 23 wherein said polymer comprises from 10% to 60% by weight glass fibers.

Claim 31

Dependent Claim 19 words

A process in accordance with claim 28 wherein said polymer comprises from 30% to 34% by weight glass fibers.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1987-02-27	1987-08-29	1988-02-28	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1991-02-27	1991-08-29	1992-02-28	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1995-02-27	1995-08-29	1996-02-28	$7700.00	Window Closed / Lapsed

Composite timing gears and process

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