Apparatus for controlling the flow of liquid

Claim 2

Molding apparatus for molding a plastic part and for using liquid carbon dioxide to cool said part after molding, comprising a mold having a mold surface against which plastic is formed into the shape of said part, a pressurized tank containing carbon dioxide in the liquid state, supply line means connected between said mold and said tank for carrying liquid carbon dioxide to said mold, a valve connected in said line, metering means having a small metering orifice therein connected in said line upstream of said valve, means for maintaining the pressure and temperature in said line between said orifice and said valve above the pressure and temperature of carbon dioxide at the triple point to prevent solidification of carbon dioxide in said line upstream of said valve, means for vaporizing a portion of the carbon dioxide in said line immediately upstream of said orifice when said valve is closed to interrupt the flow of carbon dioxide in said line, whereby, upon opening of said valve the vaporized carbon dioxide upstream of said orifice first flows through said orifice to said mold followed by liquid carbon dioxide from said tank.

Claim 3

Molding apparatus for molding a plastic part and for using liquid carbon dioxide to cool said part after molding, comprising a mold having a mold surface against which plastic is formed into the shape of said part, a pressurized tank containing carbon dioxide in the liquid state, a supply line connected between said mold and said tank for carrying carbon dioxide to said mold, a valve connected in said line, metering means having a small metering orifice therein connected in said line upstream of said valve, another line connected between a location in said supply line between said orifice and said valve and a source of gas at a pressure substantially less than that upstream of said orifice but greater than the triple point of the carbon dioxide contained in said supply line between said orifice and said valve, means for vaporizing a portion of the carbon dioxide in said line immediately upstream of said orifice when said valve is closed to interrupt the flow of carbon dioxide in said line, whereby, upon opening of said valve the vaporized carbon dioxide upstream of said orifice first flows through said orifice to said mold followed by liquid carbon dioxide from said tank.

Claim 4

Molding apparatus for molding a plastic part and for using liquid carbon dioxide to cool said part after molding, comprising a mold having a mold surface against which plastic is formed into the shape of said part, a pressurized tank containing carbon dioxide in the liquid state, a supply line connected between said mold and said tank for carrying carbon dioxide to said mold, a valve connected in said line, metering means having a small metering orifice therein connected in said line upstream of said valve, another line connected between a location in said supply line between said orifice and said valve and a source of gas at a pressure substantially less than that upstream of said orifice but greater than the triple point of the carbon dioxide contained in said supply line between said orifice and said valve, means for vaporizing a portion of the carbon dioxide in said line immediately upstream of said orifice when said valve is closed to interrupt the flow of carbon dioxide in said line, whereby, upon opening of said valve the vaporized carbon dioxide upstream of said orifice first flows through said orifice to said mold followed by liquid carbon dioxide from said tank.

Claim 5

Molding apparatus according to claim 2 wherein said source of gas comprises a pressure regulator connected to the upper portion of said pressurized tank.

Claim 6

Molding apparatus according to claim 2 wherein said means for vaporizing comprises a short length of uninsulated tubing connected upstream of said orifice in proximity thereto.

Claim 7

Molding apparatus for molding a plastic part and for using liquid carbon dioxide to cool said part after molding, comprising a mold surface against which plastic is fOrmed into the shape of said part, a pressurized tank containing carbon dioxide in the liquid state, a supply line connected between said mold and said tank for carrying carbon dioxide to said mold, a valve connected in said line, metering means having a small continually open metering orifice therein connected in said line upstream of said valve, means for maintaining the pressure and temperature in said line between said orifice and said valve above the pressure and temperature of carbon dioxide at the triple point to prevent solidification of carbon dioxide in said line upstream of said valve, means for vaporizing a portion of the carbon dioxide in said line immediately upstream of said orifice when said valve is closed to interrupt the flow of carbon dioxide in said line, said means for vaporizing comprising a short length of uninsulated tubing connected upstream of said orifice in proximity thereto, whereby, upon opening of said valve the vaporized carbon dioxide upstream of said orifice first flows through said orifice to said mold followed by liquid carbon dioxide from said tank.

Claim 8

Molding apparatus for molding a plastic part and for using liquid carbon dioxide to cool said part after molding, comprising a mold surface against which plastic is fOrmed into the shape of said part, a pressurized tank containing carbon dioxide in the liquid state, a supply line connected between said mold and said tank for carrying carbon dioxide to said mold, a valve connected in said line, metering means having a small continually open metering orifice therein connected in said line upstream of said valve, means for maintaining the pressure and temperature in said line between said orifice and said valve above the pressure and temperature of carbon dioxide at the triple point to prevent solidification of carbon dioxide in said line upstream of said valve, means for vaporizing a portion of the carbon dioxide in said line immediately upstream of said orifice when said valve is closed to interrupt the flow of carbon dioxide in said line, said means for vaporizing comprising a short length of uninsulated tubing connected upstream of said orifice in proximity thereto, whereby, upon opening of said valve the vaporized carbon dioxide upstream of said orifice first flows through said orifice to said mold followed by liquid carbon dioxide from said tank.

Claim 9

Molding apparatus according to claim 2 wherein said valve comprises a cylinder, a piston valve member axially slidable in said cylinder between valve open and closed positions, a tubular needle carried by said piston and forming the outlet for said valve for insertion of said needle through an aperture in said mold when said piston is moved to the valve open position.

Claim 10

Molding apparatus according to claim 4 wherein said valve comprises a cylinder, a piston valve member axially slidable in said cylinder between valve open and closed positions, a tubular needle carried by said piston and forming the outlet for said valve for insertion of said needle through an aperture in said mold when said piston is moved to the valve open position.

Claim 11

Blow molding apparatus comprising a mold having a mold cavity therein and a hole extending through a wall thereof to said cavity, a valve including a reciprocable valve member having an outlet port therein, a tube mounted on said valve member over said outlet port for reciprocation in said hole between a first position wherein the distal end of said tube is retracted from said cavity and a second position wherein said distal end is disposed in said cavity, a fluid supply line connected to an inlet port in said valve member, said inlet and outlet ports being mutually disconnected when said valve member is positioned to locate said tube in said first position and being mutually interconnected when said valve member is positioned to locate 300 in said second position, a source of liquid carbon dioxide connected to said fluid supply line, a small orifice connected between said fluid supply line and said source of liquid carbon dioxide, a source of pressurized gas connected to said fluid supply line to supply gas to said supply line downstream of said orifice at a pressure exceeding the triple point of the carbon dioxide in the supply line downstream of said orifice, but less than the pressure upstream of said orifice, a check valve connected between said supply line and said source of pressurized gas to prevent the flow of carbon dioxide from said orifice to said source of pressurized gas, and means for vaporizing the carbon dioxide in a predetermined length of the line between said orifice and said source of liquid carbon dioxide when said valve is closed so that when said valve is opened the vaporized carbon dioxide first flows through said orifice to said supply line and is then followed by liquid carbon dioxide, whereby said pressurized gas and said vaporized carbon dioxide first flow through said valve into said cavity and is thereafter followed by liquid carbon dioxide which solidifies in said mold to cool a plastic part contained therein.

Claim 12

Blow molding apparatus comprising a mold having a mold cavity therein and a hole extending through a wall thereof to said cavity, a valve including a reciprocable valve member having an outlet port therein, a tube mounted on said valve member over said outlet port for reciprocation in said hole between a first position wherein the distal end of said tube is retracted from said cavity and a second position wherein said distal end is disposed in said cavity, a fluid supply line connected to an inlet port in said valve member, said inlet and outlet ports being mutually disconnected when said valve member is positioned to locate said tube in said first position and being mutually interconnected when said valve member is positioned to locate 300 in said second position, a source of liquid carbon dioxide connected to said fluid supply line, a small orifice connected between said fluid supply line and said source of liquid carbon dioxide, a source of pressurized gas connected to said fluid supply line to supply gas to said supply line downstream of said orifice at a pressure exceeding the triple point of the carbon dioxide in the supply line downstream of said orifice, but less than the pressure upstream of said orifice, a check valve connected between said supply line and said source of pressurized gas to prevent the flow of carbon dioxide from said orifice to said source of pressurized gas, and means for vaporizing the carbon dioxide in a predetermined length of the line between said orifice and said source of liquid carbon dioxide when said valve is closed so that when said valve is opened the vaporized carbon dioxide first flows through said orifice to said supply line and is then followed by liquid carbon dioxide, whereby said pressurized gas and said vaporized carbon dioxide first flow through said valve into said cavity and is thereafter followed by liquid carbon dioxide which solidifies in said mold to cool a plastic part contained therein.

Claim 13

Blow molding apparatus according to claim 8 wherein said pressurized gas is caRbon dioxide at a pressure exceeding 75 p.s.i., said liquid carbon dioxide is at a pressure of about 300 p.s.i., and said orifice has a diameter of about 0.020 inch.