Patent US4951920A successfully refreshed from Google Patents.
US4951920A
Expired / Lapsed
US
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Backflow-preventing valves for injection-molding machines
Assignee: NGK Insulators Ltd
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Filing: 1988-09-26
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Granted: 1990-08-28
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Expires: 2008-09-26
Abstract
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.
Inventors
- 👤 Nobuo Tsuno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:23
CPC Classifications
F; F16; F16K; F16K25/00; F16K25/005; B; B29; B29C; B29C45/00; B29C45/17; B29C45/46; B29C45/47; B29C45/50; B29C45/52; B29C2045/526
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
90 words
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.
Claim 2
Dependent Claim
90 words
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.
Claim 3
Dependent Claim
24 words
The annular backflow-preventing valve of claim 1, wherein an escape portion is formed in a part of an outer peripheral surface of said valve.
Claim 4
Dependent Claim
93 words
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.
Claim 5
Dependent Claim
93 words
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.
Claim 6
Dependent Claim
24 words
The annular backflow-preventing valve of claim 3, wherein an escape portion is formed in a part of an outer peripheral surface of said valve.
Claim 7
Dependent Claim
77 words
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.
Claim 8
Dependent Claim
77 words
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.
Claim 9
Dependent Claim
24 words
The annular backflow-preventing valve of claim 5, wherein an escape portion is formed in a part of an outer peripheral surface of said valve.
Claim 10
Dependent Claim
110 words
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.
Claim 11
Dependent Claim
110 words
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.
Claim 12
Dependent Claim
127 words
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.
Claim 13
Dependent Claim
127 words
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.
Claim 14
Dependent Claim
114 words
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.
Claim 15
Dependent Claim
114 words
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.
Claim 16
Dependent Claim
131 words
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.
Claim 17
Dependent Claim
131 words
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.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-27 | 1994-02-26 | 1994-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-27 | 1998-02-26 | 1998-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-27 | 2002-02-26 | 2002-08-28 | $7700.00 | Window Closed / Lapsed |