Claims
- 1. In a molding method for a speaker grille formed of a synthetic resin, said speaker grille comprising; a grille plate having a plurality of through holes and a frame integrally formed with said grille plate to surround an outer periphery of said grille plate, said speaker grille being molded by charging said synthetic resin into a metal mold having a cavity provided with a grille plate forming portion having a plurality of pins for forming said through holes and also provided with a frame forming portion around said grille plate forming portion; a ring-shaped dam for blocking flow of said molding resin in said metal mold is provided at a boundary between said grille plate forming portion and said frame forming portion of said cavity to surround said pins.
- 2. A molding method for a speaker grille according to claim 1, wherein said metal mold comprises an upper mold for forming a front surface of said speaker grille and a lower mold for forming a back surface of said speaker grille, said upper mold having a cavity provided with said pins and said dam, said lower mold having a cavity provided with a lattice-shaped groove for forming a lattice-shaped reinforcing rib, said molding resin being charged from a central portion of said lower mold into said metal mold, whereby said resin is allowed to fast flow in said groove of said lower mold having a small flow resistance and then reach said frame forming portion, and is then blocked by said dam to thereby prevent said resin from flowing from said frame forming portion into said grille plate forming portion, whereas said resin is allowed to slowly flow in said grille plate forming portion of said upper mold having a large flow resistance and then reach said frame forming portion, and is then blocked by said dam to thereby prevent said resin from flowing from said grille plate forming portion into said frame forming portion, thus finally filling said cavity of said metal mold with said resin to thereby mold said speaker grille comprising said grille plate having said pins and said frame integrally formed with said grille plate so as to surround the outer periphery of said grille plate, said reinforcing rib being formed on the back surface of said grille plate.
Priority Claims (1)
Number |
Date |
Country |
Kind |
6-101956 |
Apr 1996 |
JPX |
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Parent Case Info
This is a divisional of application Ser. No. 08/408,786 filed Mar. 23, 1995 now, U.S. Pat. No. 5,623,133.
US Referenced Citations (11)
Foreign Referenced Citations (4)
Number |
Date |
Country |
0422322 |
Apr 1991 |
EPX |
5619496 |
May 1981 |
JPX |
5927627 |
Aug 1984 |
JPX |
59-179325 |
Oct 1984 |
JPX |
Divisions (1)
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Number |
Date |
Country |
Parent |
408786 |
Mar 1995 |
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