Composite push rod and process

Claim 2

A composite push rod for use in an engine, comprising: an elongated, thermoplastic, amide-imide resinous polymeric rod having opposite ends; end caps connected to the opposite ends of said amide-imide rod, said end caps being selected from the group consisting of metal end caps and thermoplastic amide-imide resinous polymeric end caps and including a lifter cap connected to one end of said rod for engaging a valve lifter; and a rocker arm cap connected to the other end of said rod for engaging a connector secured to a rocker arm; and said thermoplastic amide-imide rod, said lifter cap, and said rocker arm cap maintaining their structural integrity at engine operating conditions.

Claim 3

A composite push rod in accordance with claim 1 wherein at least one of said caps and the end of said rod to which said cap is connected define connection parts, and one of said connection parts has a stud extending outwardly therefrom and the other connection part defines a hole having a diameter slightly smaller than the diameter of said stud for press-fittingly receiving said stud.

Claim 4

A composite push rod in accordance with claim 2 where said cap has said stud and said rod defines said hole.

Claim 5

A composite push rod in accordance with claim 2 wherein said cap is a metal cap selected from the group consisting of aluminum and steel.

Claim 6

A composite push rod in accordance with claim 1 wherein said rod and said caps define an oil hole extending axially through said push rod and said end caps have rounded ends.

Claim 7

A composite push rod in accordance with claim 1 wherein said lifter cap is shaped complementary to said connector.

Claim 8

A composite push rod in accordance with claim 6 wherein said lifter cap has a generally cap-shaped outer end defining a socket.

Claim 9

A composite push rod in accordance with claim 1 wherein said lifter cap and said rocker arm caps are thermoplastic, amide-imide resinous polymeric caps.

Claim 10

A composite push rod in accordance with claim 1 including a thermoplastic, amide-imide resinous polymeric, push rod guide defining a hole for slidably receiving said rod.

Claim 11

A composite engine part in accordance with claim 1 wherein said rod and thermoplastic caps comprise a reaction product of a trifunctional carboxylic acid compound and at least one diprimary aromatic diamine.

Claim 12

A composite engine part in accordance with claim 10 wherein said rod and thermoplastic caps comprise at least one of the following moieties: ##STR8## 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 13

A composite engine part in accordance with claim 11 wherein R 1 is ##STR9## and R 2 is ##STR10## or wherein R 1 is ##STR11## and R 2 is ##STR12##

Claim 14

A composite engine part in accordance with claim 11 wherein Z is a trivalent benzene ring, R 1 is ##STR13## R 2 is ##STR14## 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 15

A composite engine part in accordance with claim 11 wherein said rod and thermoplastic caps comprise from 40% to 100% by weight amide-imide resinous polymer.

Claim 16

A composite engine part in accordance with claim 14 wherein said rod and thermoplastic caps comprise from 65% to 75% by weight amide-imide resinous polymer.

Claim 17

A composite engine part in accordance with claim 11 wherein at least one of said thermoplastic parts of said composite push rod comprises a fibrous reinforcing material selected from the group consisting essentially of graphite and glass.

Claim 18

A composite engine part in accordance with claim 16 wherein said thermoplastic part comprises from 10% to 50% by weight graphite.

Claim 19

A composite engine part in accordance with claim 17 wherein said thermoplastic part comprises from 30% to 34% by weight graphite.

Claim 20

A composite engine part in accordance with claim 17 wherein said thermoplastic part comprises 30% to 34% by weight glass.

Claim 21

A composite engine part in accordance with claim 16 wherein said thermoplastic part comprises 10% to 60% by weight glass.

Claim 22

A composite engine part in accordance with claim 16 wherein said fibrous reinforcing material has a polymeric sizing that substantially maintains its structural integrity at engine operating conditions.

Claim 23

A composite engine part in accordance with claim 16 wherein said rod comprises not greater than 3% by weight polytetrafluoroethylene.

Claim 24

A composite engine part in accordance with claim 22 wherein said rod comprises from 1/2% to 1% by weight polytetrafluoroethylene.

Claim 25

A composite engine part in accordance with claim 16 wherein said rod comprises not more than 6% by weight titanium dioxide.

Claim 26

A process for forming a composite push rod for use in an engine comprising the steps of: injection molding a thermoplastic, amide-imide resinous polymer to form an elongated rod; allowing said thermoplastic amide-imide rod to cool below its plastic deformation temperature; post curing said amide-imide rod by solid state polymerization to enhance the strength and integrity of said amide-imide rod; connecting a lifter cap selected from the group consisting of a metal lifter cap and a thermoplastic amide-imide resinous polymeric lifter cap to one end of said amide-imide rod; and connecting a rocker arm cap selected from the group consisting of a metal rocker arm cap and a thermoplastic amide-imide resinous polymeric rocker arm cap to the other end of said amide-imide rod.

Claim 27

A process for forming a composite push rod for use in an engine comprising the steps of: injection molding a thermoplastic, amide-imide resinous polymer to form an elongated rod; allowing said thermoplastic amide-imide rod to cool below its plastic deformation temperature; post curing said amide-imide rod by solid state polymerization to enhance the strength and integrity of said amide-imide rod; connecting a lifter cap selected from the group consisting of a metal lifter cap and a thermoplastic amide-imide resinous polymeric lifter cap to one end of said amide-imide rod; and connecting a rocker arm cap selected from the group consisting of a metal rocker arm cap and a thermoplastic amide-imide resinous polymeric rocker arm cap to the other end of said amide-imide rod.

Claim 28

A process in accordance with claim 25 wherein said caps are metal and are cold forged.

Claim 29

A process in accordance with claim 25 wherein said caps are metal and are formed on a screw machine.

Claim 30

A process in accordance with claim 27 wherein said polymer comprises from 30% to 34% by weight graphite fibers.

Claim 31

A process in accordance with claim 28 wherein: an axial hole is drilled through said amide-imide rod; said caps have studs; and said connecting includes press fitting said studs into said axial hole at the end of said rod.

Claim 32

A process in accordance with claim 25 wherein said caps are metal caps selected from the group consisting of steel and aluminum.

Claim 33

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

Claim 34

A process in accordance with claim 25 wherein said caps comprise thermoplastic, amide-imide resinous polymer.

Claim 35

A process in accordance with claim 25 including grinding said rod.

Claim 36

A process in accordance with claim 25 including: injecting molding a thermoplastic, amide-imide resinous polymer to form a push rod guide; allowing said push rod guide to cool below its plastic deformation temperature; post curing said push rod guide by solid state polymerization; and drilling a hole in said push rod guide for slidably receiving said push rod.

Claim 37

A process in accordance with claim 34 wherein said rod is inserted into the hole of said push rod guide before said caps are press fitted.

Claim 38

A process in accordance with claim 25 wherein said amide-imide polymer is prepared by reacting a trifunctional carboxylic acid compound with at least one diprimary aromatic diamine.

Claim 39

A process in accordance with claim 36 wherein said amide-imide polymer comprises one of the following moieties: ##STR15## 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 40

A process in accordance with claim 37 wherein R 1 is ##STR16## and R 2 is ##STR17## or wherein R 1 is ##STR18## and R 2 is ##STR19##

Claim 41

A process in accordance with claim 37 wherein Z is a trivalent benzene ring, R 1 is ##STR20## R 2 is ##STR21## 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 42

A process in accordance with claim 37 wherein said polymer comprises from 10% to 50% by weight graphite fibers.

Claim 43

A process in accordance with claim 37 wherein said polymer comprises from 10% to 60% by weight glass fibers.