Backflow-preventing valves for injection-molding machines
AssigneeNGK Insulators, Ltd.
InventorNobuo Tsuno
Life of this patent
Estimating the term…
Abstract
A backflow-preventing valve for use in a screw head of a screw injection-molding machine which has an annular shape and comprises a ceramic member is disclosed and a metallic member. At least a surface portion of a backflow-preventing valve which is brought into contact with a material to be injected and a screw groove or a valve seat is constituted by a ceramic material.
Claims10
An annular backflow-preventing valve for use in a screw head of a screw type injection-molding machine, comprising:
- an annular ceramic member having a first end for accommodating an injection-molding screw therein and a second end opposing said first end;
- and
- an annular metallic member disposed on an outer peripheral surface of said ceramic member at said second end thereof;
- wherein said first end of said ceramic member constitutes an entire injection-molding screw receiving end of said valve and said ceramic member defines an entire inner peripheral surface of said valve.
An annular backflow-preventing valve for use in a screw head of a screw type injection-molding machine, comprising:
- an annular metallic member at a first end of said valve for accommodating an injection-molding screw therein;
- and
- an annular ceramic member at a second end of said valve opposing said first end of said valve, abuttingly joined to said metallic member;
- wherein said metallic member at said first end constitutes an entire injection-molding screw receiving end of said valve and said ceramic member at said second end constitutes an entire opposing end of said valve.
An annular backflow-preventing valve for use in a screw head of a screw type injection-molding machine, comprising:
- an annular metallic member having a first end for accommodating an injection-molding screw therein and a second end opposing said first end;
- and
- an annular ceramic member disposed on an inner peripheral surface of said metallic member at said second end thereof;
- wherein said first end of said metallic member constitutes an entire injection-molding screw receiving end of said valve.
A backflow-preventing valve for use in a screw head of a screw-type injection-molding machine, said backflow-preventing valve having an annular structure and comprising a ceramic member and a metallic member brazed together, wherein at least a surface portion of the backflow-preventing valve which contacts a material to be injected comprises a ceramic material, and among joining layers existing between the ceramic member and the metallic member a joining layer adjacent the ceramic member comprises an alloy of:
- 5 to 50 % by weight of nickel;
- 30 to 70 % by weight of silver;
- 15 to 40 % by weight of copper;
- and 1 to 10 % by weight of titanium.
A backflow-preventing valve for use in a screw head of a screw type injection-molding machine, said backflow-preventing valve having an annular structure and comprising:
- a ceramic member and a metallic member brazed together;
- and
- an escape portion formed in a part of an outer peripheral surface of backflow-preventing valve;
- wherein at least a surface portion of the backflow-preventing valve which contacts a material to be injected comprises a ceramic material and among joining layers existing between the ceramic member and the metallic member a joining layer adjacent the ceramic member comprises an alloy of:
- 5 to 50 % by weight of nickel;
- 30 to 70 % by weight of silver;
- 15 to 40 % by weight of copper;
- and 1 to 10 % by weight of titanium.
A backflow-preventing valve for use in a screw head of a screw type injection-molding machine, said backflow-preventing valve having an annular structure and comprising a ceramic member and a metallic member brazed together, wherein the entire surface portion of the backflow-preventing valve, which contacts a material to be injected and a valve seat, comprises a ceramic material, and among joining layers existing between the ceramic member and the metallic member a joining layer adjacent the ceramic member comprises an alloy of:
- 5 to 50 % by weight of nickel;
- 30 to 70 % by weight of silver;
- 15 to 40 % by weight of copper;
- and 1 to 10 % by weight of titanium.
A backflow-preventing valve for use in a screw head of a screw type injection-molding machine, said backflow-preventing valve having an annular structure and comprising:
- a ceramic member and a metallic member brazed together;
- and
- an escape portion formed in a part of an outer peripheral surface of the backflow-preventing valve;
- wherein the entire surface portion of the backflow-preventing valve which contacts a material to be injected and a valve seat comprises a ceramic material, and among joining layers existing between the ceramic member and the metallic member a joining layer adjacent the ceramic member comprises an alloy of:
- 5 to 50 % by weight of nickel;
- 30 to 70 % by weight of silver;
- 15 to 40 % by weight of copper;
- and 1 to 10 % by weight of titanium.
Dependencies are inferred from the claim text.