US6505674B1 — Injector for molten metal supply system

Claim 1

Independent Claim 200 words

An injector for a molten metal supply system, comprising: an injector housing configured to contain molten metal; a molten metal supply source in fluid communication with the housing; a piston reciprocally operable within the housing, with the piston movable through a return stroke allowing molten metal to be received into the housing from the molten metal supply source and a displacement stroke for displacing the molten metal from the housing to a downstream process, and with the piston having a pistonhead for displacing the molten metal from the housing; and a gas supply source in fluid communication with the housing through a gas control valve, wherein during the return stroke of the piston a space is formed between the pistonhead and the molten metal and the gas control valve is operable to fill the space with gas from the gas supply source, and wherein during the displacement stroke of the piston the gas control valve is operable to prevent venting of gas from the gas filled space such that the gas in the gas filled space is compressed between the pistonhead and molten metal received into the housing and displaces the molten metal from the housing ahead of the pistonhead.

Claim 2

Dependent Claim 200 words

An injector for a molten metal supply system, comprising: an injector housing configured to contain molten metal; a molten metal supply source in fluid communication with the housing; a piston reciprocally operable within the housing, with the piston movable through a return stroke allowing molten metal to be received into the housing from the molten metal supply source and a displacement stroke for displacing the molten metal from the housing to a downstream process, and with the piston having a pistonhead for displacing the molten metal from the housing; and a gas supply source in fluid communication with the housing through a gas control valve, wherein during the return stroke of the piston a space is formed between the pistonhead and the molten metal and the gas control valve is operable to fill the space with gas from the gas supply source, and wherein during the displacement stroke of the piston the gas control valve is operable to prevent venting of gas from the gas filled space such that the gas in the gas filled space is compressed between the pistonhead and molten metal received into the housing and displaces the molten metal from the housing ahead of the pistonhead.

Claim 3

Dependent Claim 51 words

The injector of claim 1 , wherein the piston includes a piston rod having a first end and a second end, and wherein the first end is connected to the pistonhead and the second end is connected to an actuator for driving the piston through the return stroke and displacement stroke.

Claim 4

Dependent Claim 23 words

The injector of claim 2 , wherein the second end of the piston rod is connected to the actuator by a self-aligning coupling.

Claim 5

Dependent Claim 31 words

The injector of claim 2 , further including an annular pressure seal positioned about the piston rod to provide a substantially gas tight seal between the piston rod and the housing.

Claim 6

Dependent Claim 27 words

The injector of claim 4 , further including a cooling water jacket positioned about the housing substantially coincident with the pressure seal for cooling the pressure seal.

Claim 7

Dependent Claim 24 words

The injector of claim 2 , wherein the first end of the piston rod is connected to the pistonhead by a thermal insulation barrier.

Claim 8

Dependent Claim 42 words

The injector of claim 2 , wherein the piston rod defines a central bore, and wherein the central bore is in fluid communication with a cooling water inlet and outlet for supplying cooling water to the central bore in the piston rod.

Claim 9

Dependent Claim 22 words

The injector of claim 2 , wherein the housing, piston rod, and pistonhead are made of a high temperature resistant metal alloy.

Claim 10

Dependent Claim 24 words

The injector of claim 1 , wherein the pistonhead is made of a material selected from the group consisting of refractory material and graphite.

Claim 11

Dependent Claim 26 words

The injector of claim 1 , wherein the housing includes a liner made of a material selected from the group consisting of refractory material and graphite.

Claim 12

Dependent Claim 29 words

The injector of claim 1 , wherein the molten metal supply source contains a metal selected from the group consisting of aluminum, magnesium, copper, bronze, iron, and alloys thereof.

Claim 13

Dependent Claim 28 words

The injector of claim 1 , wherein the gas supply source is a gas selected from the group consisting of helium, nitrogen, argon, compressed air, and carbon dioxide.

Claim 14

Dependent Claim 25 words

The injector of claim 1 , further including a floating thermal insulation barrier located between the pistonhead and the molten metal received into the housing.

Claim 15

Dependent Claim 23 words

The injector of claim 1 , wherein the molten metal supply source is in fluid communication with the housing through a check valve.

Claim 16

Dependent Claim 30 words

The injector of claim 1 , wherein the injector includes an injection port connected to the housing for injecting the molten metal displaced from the housing to the downstream process.

Claim 17

Dependent Claim 34 words

The injector of claim 15 , further including a check valve located in the injection port, and wherein the molten metal supply source is in fluid communication with the housing through the check valve.

Claim 18

Dependent Claim 29 words

The injector of claim 16 , further including a second check valve located in the injection port and configured to allow the displacement of molten metal from the housing.

Claim 19

Independent Claim 172 words

A method of operating an injector for a molten metal supply system, the injector comprising: an injector housing configured to contain molten metal and a piston reciprocally operable within the housing, with the piston movable through a return stroke and a displacement stroke, and with the piston having a pistonhead located within the housing, and the housing in fluid communication with a molten metal supply source and a gas supply source, the method comprising the steps of: receiving molten metal from the molten metal supply source into the housing during the return stroke of the piston, with the pistonhead defining a space with the molten metal flowing into the housing; filling the space with gas from the gas supply source during the return stroke of the piston; and compressing the gas in the gas filled space between the pistonhead and the molten metal received into the housing during the displacement stroke of the piston to displace the molten metal from the housing to a downstream process in advance of the compressed gas.

Claim 20

Independent Claim 172 words

A method of operating an injector for a molten metal supply system, the injector comprising: an injector housing configured to contain molten metal and a piston reciprocally operable within the housing, with the piston movable through a return stroke and a displacement stroke, and with the piston having a pistonhead located within the housing, and the housing in fluid communication with a molten metal supply source and a gas supply source, the method comprising the steps of: receiving molten metal from the molten metal supply source into the housing during the return stroke of the piston, with the pistonhead defining a space with the molten metal flowing into the housing; filling the space with gas from the gas supply source during the return stroke of the piston; and compressing the gas in the gas filled space between the pistonhead and the molten metal received into the housing during the displacement stroke of the piston to displace the molten metal from the housing to a downstream process in advance of the compressed gas.

Claim 21

Dependent Claim 34 words

The method of claim 18 , further comprising the step of venting the compressed gas in the gas filled space to atmospheric pressure approximately when the piston reaches an end of the displacement stroke.

Claim 22

Dependent Claim 45 words

The method of claim 18 , further comprising the step of moving the piston through a partial return stroke in the housing after the step of compressing the gas in the gas filled space to partially relieve the pressure in the compressed gas filled space.

Claim 23

Dependent Claim 38 words

The method of claim 20 , further comprising the step of venting the gas in the gas filled space to atmospheric pressure with the piston located at about an end of the partial return stroke in the housing.

Claim 24

Dependent Claim 25 words

The method of claim 21 , further comprising the step of returning the piston to the end of the displacement stroke position in the housing.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2006-01-13	2006-07-15	2007-01-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2010-01-13	2010-07-15	2011-01-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2014-01-13	2014-07-15	2015-01-14	$7700.00	Window Closed / Lapsed

Injector for molten metal supply system

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