Method of manufacturing waterproof nuts

Claim 1

A method of manufacturing a waterproof nut, comprising the steps of: screwing a threaded core into a threaded hole of a nut body from a front surface of the nut body in such a manner that a free end of said core projects from a rear surface of said nut body, the threaded hold of the nut body having an inner diameter sufficient to threadably accept a threaded bolt having a predetermined outer diameter, said core having an outer diameter which is larger than the predetermined outer diameter of the threaded bolt for screwing into the nut body, said threaded hole of said nut body having an inner diameter which is larger than the outer diameter of said core; setting an assembly of the engaged nut body and core in a mold which has a first section for forming a synthetic resin outer layer which covers an outer periphery of said nut body, a second section for forming a front surface covering layer which covers the front surface of said nut body and a third section for forming a cap-shaped portion which covers the rear surface of said nut body; charging molten polyamide resin into said mold while maintaining a temperature of said nut body and said core at 25° to 50° C., to prevent the molten resin from flowing into an annular clearance between said nut body and said core; hardening said resin about the nut body and the free end of said core to form the cap-shaped portion at the rear surface of the nut; and unscrewing said core from said out body to form an internal threaded hole in said cap-shaped portion. PG,23

Claim 2

A method of manufacturing a waterproof nut, comprising the steps of: screwing a threaded core into a threaded hole of a nut body from a front surface of the nut body in such a manner that a free end of said core projects from a rear surface of said nut body, the threaded hold of the nut body having an inner diameter sufficient to threadably accept a threaded bolt having a predetermined outer diameter, said core having an outer diameter which is larger than the predetermined outer diameter of the threaded bolt for screwing into the nut body, said threaded hole of said nut body having an inner diameter which is larger than the outer diameter of said core; setting an assembly of the engaged nut body and core in a mold which has a first section for forming a synthetic resin outer layer which covers an outer periphery of said nut body, a second section for forming a front surface covering layer which covers the front surface of said nut body and a third section for forming a cap-shaped portion which covers the rear surface of said nut body; charging molten polyamide resin into said mold while maintaining a temperature of said nut body and said core at 25° to 50° C., to prevent the molten resin from flowing into an annular clearance between said nut body and said core; hardening said resin about the nut body and the free end of said core to form the cap-shaped portion at the rear surface of the nut; and unscrewing said core from said out body to form an internal threaded hole in said cap-shaped portion. PG,23

Claim 8

A method of manufacturing a waterproof nut, comprising the steps of: screwing a threaded core into a threaded hole of a nut body from a front surface of the nut body in such a manner that a free end of said core projects from a rear surface of said nut body, the threaded hole of the nut body having an inner diameter sufficient to threadably accept a threaded bolt having a predetermined outer diameter, said core having an outer diameter which is larger than the predetermined outer diameter of the threaded bolt for screwing into the nut body, said threaded hole of said nut body having an inner diameter which is larger than the outer diameter of said core; setting an assembly of the engaged nut body and core in a mold which has a first section for forming a synthetic resin outer layer which covers an outer periphery of said nut body, a second section for forming a front surface covering layer which covers the front surface of said nut body and a third section for forming a cap-shaped poriton which covers the rear surface fo said nut body; charging molten ester resin into said mold while maintaining a temperature of said nut body and said core at 25° to 60° C., to prevent the molten resin from flowing into an annular clearance between said nut body and said core; hardening said resin about the nut body and the free end of said core to form the cap-shaped portion at the rear surface of the nut; and unscrewing said core from said out body to form an internal threaded hole in said cap-shaped portion.

Claim 9

A method of manufacturing a waterproof nut, comprising the steps of: screwing a threaded core into a threaded hole of a nut body from a front surface of the nut body in such a manner that a free end of said core projects from a rear surface of said nut body, the threaded hole of the nut body having an inner diameter sufficient to threadably accept a threaded bolt having a predetermined outer diameter, said core having an outer diameter which is larger than the predetermined outer diameter of the threaded bolt for screwing into the nut body, said threaded hole of said nut body having an inner diameter which is larger than the outer diameter of said core; setting an assembly of the engaged nut body and core in a mold which has a first section for forming a synthetic resin outer layer which covers an outer periphery of said nut body, a second section for forming a front surface covering layer which covers the front surface of said nut body and a third section for forming a cap-shaped poriton which covers the rear surface fo said nut body; charging molten ester resin into said mold while maintaining a temperature of said nut body and said core at 25° to 60° C., to prevent the molten resin from flowing into an annular clearance between said nut body and said core; hardening said resin about the nut body and the free end of said core to form the cap-shaped portion at the rear surface of the nut; and unscrewing said core from said out body to form an internal threaded hole in said cap-shaped portion.

Claim 11

A method of manufacturing a waterproof nut, comprising the steps of: screwing a threaded core into a threaded hole of a nut body from a front surface of the nut body in such a manner that a free end of said core projects from a rear surface of said nut body, the threaded hole of the nut body having an inner diameter sufficient to threadably accept a threaded bolt having a predetermined outer diameter, said core having an outer diameter which is larger than the predetermined outer diameter of the threaded bolt for screwing into the nut body, said threaded hole of said nut body having an inner diameter which is larger than the outer diameter of said core; setting an assembly of the engaged nut body and core in a mold which has a first section for forming a synthetic resin outer layer which covers an outer periphery of said nut body, a second section for forming a front surface covering layer which covers the front surface of said nut body and a third section for forming a cap-shaped portion which covers the rear surface of said nut body; charging molten ether resin in said mold while maintaining a termperature of said nut body and said core at 25° to 55° C., to prevent the molten resin from flowing into an annular clearance between said nut body and said core; hardening said resin about the nut body and the free end of said core to form the cap-shaped portion at the rear surface of the nut; and unscrewing said core from said out body to form an internal threaded hole in said cap-shaped portion.

Claim 12

A method of manufacturing a waterproof nut, comprising the steps of: screwing a threaded core into a threaded hole of a nut body from a front surface of the nut body in such a manner that a free end of said core projects from a rear surface of said nut body, the threaded hole of the nut body having an inner diameter sufficient to threadably accept a threaded bolt having a predetermined outer diameter, said core having an outer diameter which is larger than the predetermined outer diameter of the threaded bolt for screwing into the nut body, said threaded hole of said nut body having an inner diameter which is larger than the outer diameter of said core; setting an assembly of the engaged nut body and core in a mold which has a first section for forming a synthetic resin outer layer which covers an outer periphery of said nut body, a second section for forming a front surface covering layer which covers the front surface of said nut body and a third section for forming a cap-shaped portion which covers the rear surface of said nut body; charging molten ether resin in said mold while maintaining a termperature of said nut body and said core at 25° to 55° C., to prevent the molten resin from flowing into an annular clearance between said nut body and said core; hardening said resin about the nut body and the free end of said core to form the cap-shaped portion at the rear surface of the nut; and unscrewing said core from said out body to form an internal threaded hole in said cap-shaped portion.

Claim 14

A method of manufacturing a waterproof nut, comprising the steps of: screwing a threaded core into a threaded hole of a nut body from a front surface of the nut body in such a manner that a free end of said core projects from a rear surface of said nut body, the threaded hole of the nut body having an inner diameter sufficient to threadably accept a threaded bolt having a predetermined outer diameter, said core having an outer diameter which is larger than the predetermined outer diameter of the threaded bolt for screwing into the nut body, said threaded hole of said nut body having an inner diameter which is larger than the outer diameter of said core; setting an assembly of the engaged nut body and core in a mold which has a first section for forming a synthetic resin outer layer which covers an outer periphery of said nut body, a second section for forming a front surface covering layer which covers the front surface of said nut body and a third section for forming a cap-shaped portion which covers the rear surface of said nut body; charging molten resin in said mold while maintaining a temperature of said nut body and said core at 5° to 110° C., to prevent the molten resin from flowing into an annular clearance between said nut body and said core, wherein said synthetic resin is selected from the group consisting of sulfone resin and sulfide resin; hardening said resin about the nut body and the free end of said core to form the cap-shaped portion at the rear surface of the nut; and unscrewing said core from said out body to form an internal threaded hole in said cap-shaped portion.

Claim 15

A method of manufacturing a waterproof nut, comprising the steps of: screwing a threaded core into a threaded hole of a nut body from a front surface of the nut body in such a manner that a free end of said core projects from a rear surface of said nut body, the threaded hole of the nut body having an inner diameter sufficient to threadably accept a threaded bolt having a predetermined outer diameter, said core having an outer diameter which is larger than the predetermined outer diameter of the threaded bolt for screwing into the nut body, said threaded hole of said nut body having an inner diameter which is larger than the outer diameter of said core; setting an assembly of the engaged nut body and core in a mold which has a first section for forming a synthetic resin outer layer which covers an outer periphery of said nut body, a second section for forming a front surface covering layer which covers the front surface of said nut body and a third section for forming a cap-shaped portion which covers the rear surface of said nut body; charging molten resin in said mold while maintaining a temperature of said nut body and said core at 5° to 110° C., to prevent the molten resin from flowing into an annular clearance between said nut body and said core, wherein said synthetic resin is selected from the group consisting of sulfone resin and sulfide resin; hardening said resin about the nut body and the free end of said core to form the cap-shaped portion at the rear surface of the nut; and unscrewing said core from said out body to form an internal threaded hole in said cap-shaped portion.