US4711287A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Casting method
Assignee: JSP Corp
•
Filing: 1986-02-19
•
Granted: 1987-12-08
•
Expires: 2006-02-19
Abstract
Abstract A consumable pattern of an expanded polyolefin resin and a bulk density of 0.025-0.012 g/cm 3 is embedded in a mold body, a gating system leading to the pattern is formed in the mold body, and molten metal is poured into the gating system to volatilize and replace the pattern. The polyolefin resin is selected from noncrosslinked polypropylene resins, crosslinked polypropylene resins, crosslinked high-density polyethylene and mixtures thereof.
Inventors
- 👤 Hideki Kuwabara
- 👤 Masato Naito
- 👤 Teishiro Watanabe
- 👤 Tadatsugu Hamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:56
CPC Classifications
B; B22; B22C; B22C9/00; B22C9/02; B22C9/04; B22C9/046
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
132 words
A method of casting, comprising the steps of: providing a pattern formed of an expanded polyolefin resin and having a bulk density of 0.025-0.012 g/cm 3 , said polyolefin resin being selected from the group consisting of (a) non-crosslinked polypropylene resins which are ethylene-propylene random copolymers having an ethylene content of 0.5-10% by weight and having secondary crystals, (b) crosslinked polypropylene resins which are ethylene-propylene random copolymers having an ethylene content of 1-10% by weight, (c) crosslinked high density polyethylenes having a density of 0.94 g/cm 3 or more and (d) mixtures thereof; embedding said pattern in a mold body; forming in said mold body a gating system leading to said embedded pattern; and pouring in said gating system molten metal for volatizing and replacing said embedded pattern in said mold body.
Claim 2
Independent Claim
132 words
A method of casting, comprising the steps of: providing a pattern formed of an expanded polyolefin resin and having a bulk density of 0.025-0.012 g/cm 3 , said polyolefin resin being selected from the group consisting of (a) non-crosslinked polypropylene resins which are ethylene-propylene random copolymers having an ethylene content of 0.5-10% by weight and having secondary crystals, (b) crosslinked polypropylene resins which are ethylene-propylene random copolymers having an ethylene content of 1-10% by weight, (c) crosslinked high density polyethylenes having a density of 0.94 g/cm 3 or more and (d) mixtures thereof; embedding said pattern in a mold body; forming in said mold body a gating system leading to said embedded pattern; and pouring in said gating system molten metal for volatizing and replacing said embedded pattern in said mold body.
Claim 3
Dependent Claim
27 words
A method as claim in claim 1, wherein said polyolefin resin is selected from the polypropylene resins and said pattern has a cell size of 0.1-1.0 mm.
Claim 4
Dependent Claim
21 words
A method as claimed in claim 1, wherein said crosslinked polypropylene resin has a n-heptane insoluble content of 50% or less.
Claim 5
Dependent Claim
23 words
A method as claimed in claim 1, wherein said crosslinked polypropylene resin and said high density polyethylenes have a gel fraction of 0.01-40%.
Claim 6
Dependent Claim
46 words
A method as claimed in claim 1, wherein said expanded polyolefin is produced by a process comprising the steps of providing particles of the polyolefin resin, expanding said particles to obtain pre-expanded particles, and heating said preexpanded particles within a mold to provide said expanded polyolefin.
Claim 7
Dependent Claim
47 words
A method as claimed in claim 1, further comprising forming in said mold body one or more vent passages leading to said embedded pattern so that the gas produced by the volatilization of said pattern may be discharged through said vent passage or passages to the air.
Claim 8
Dependent Claim
33 words
A method as claimed in claim 6, wherein at least one of said vent passages extends vertically from a top portion of said pattern and opens at the top of said mold body.
Claim 9
Dependent Claim
84 words
A method as claimed in claim 6, wherein said gating system includes an ingate formed of said expanded polyolefin resin and bonded to a lower portion of said pattern, a runner formed of said polyolefin resin and bonded to said ingate, and a sprue leading to said runner and opening at the top of said mold body, so that said runner and ingate are volatilized upon contact with the molten metal to allow the molten metal to contact said pattern in said mold body.
Claim 10
Dependent Claim
19 words
A method as claimed in claim 8, further comprising forming at least one vent hole leading to said runner.
Claim 11
Dependent Claim
24 words
A method as claimed in claim 9, wherein said vent hole is oriented slantwise and opens at the side periphery of said mold body.
References Cited (Backward Citations)
BE627229A
Cited
FR1332924A
Cited
US3339620A
Cited
DE1239437B
Cited
US3374824A
Cited
US3426834A
Cited
DE2758993A1
Cited
JPS5577959A
Cited
US4291739A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-12-07 | 1991-06-08 | 1991-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-07 | 1995-06-08 | 1995-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-07 | 1999-06-08 | 1999-12-08 | $7700.00 | Window Closed / Lapsed |