Plastic article or earthenware shaping or treating: apparatus – Female mold and charger to supply fluent stock under... – With means to heat or cool
Reexamination Certificate
2001-08-03
2003-05-06
Mackey, James P. (Department: 1722)
Plastic article or earthenware shaping or treating: apparatus
Female mold and charger to supply fluent stock under...
With means to heat or cool
C425S450100, C425S810000
Reexamination Certificate
active
06558152
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a disc-molding mold for molding discs.
2. Description of the Related Art
Conventionally, in an injection molding machine for molding disc substrates, resin heated and melted within a heating cylinder is charged into a cavity formed in a disc-molding mold. The molten resin is cooled and solidified within the cavity to thereby obtain a molded disc substrate.
FIG. 1
is a sectional view of a conventional disc-molding mold.
In
FIG. 1
, a stationary-side mold assembly
12
is fixed to an unillustrated stationary platen by use of unillustrated bolts. The stationary-side mold assembly
12
includes a base plate
15
; a disc plate
16
fixed to the base plate
15
by use of bolts
17
; a locating ring
23
disposed on the base plate
15
in such a manner as to face the stationary platen and adapted to position the base plate
15
with respect to the stationary platen; and a sprue bushing
24
disposed adjacent to the locating ring
23
. A front end (the left end in
FIG. 1
) of the sprue bushing
24
faces a cavity C, and a die
28
is formed in the front end of the sprue bushing
24
. In communication with the die
28
, a sprue
26
is formed in the sprue bushing
24
in order to allow passage of resin injected from an injection nozzle of an unillustrated injection unit.
A movable-side mold assembly
32
is attached to an unillustrated movable platen by use of unillustrated bolts. The movable-side mold assembly
32
includes a base plate
35
; an intermediate plate
40
attached to the base plate
35
by use of bolts
37
; a disc plate
36
attached to the intermediate plate
40
by use of bolts
42
; a cylinder
44
which is disposed within the base plate
35
in such a manner as to face the movable platen and which is attached to the intermediate plate
40
by use of bolts
45
; and a cut punch
48
which advances and retracts (moves rightward and leftward in
FIG. 1
) along the cylinder
44
and which has a shape corresponding to the die
28
.
A depression is formed on the surface of the disc plate
36
facing the disc plate
16
, in order to define the cavity C. When the movable platen is moved toward the stationary platen through operation of an unillustrated mold clamping apparatus to thereby perform mold closing and mold clamping, the disc plate
36
is pressed against the disc plate
16
to thereby form the cavity C therebetween.
A flange
51
integrally formed with the cut punch
48
is disposed within the cylinder
44
such that it can advance and retract. The rear end (the left end in
FIG. 1
) of the flange
51
is received by the cylinder
44
. A cut-punch return spring
52
is disposed on the front side (on the right side in
FIG. 1
) of the flange
51
. The cut-punch return spring
52
urges the flange
51
rearward (leftward in FIG.
1
).
When, in the mold-closed state, the flange
51
is advanced (moved rightward in
FIG. 1
) through feed of oil to an unillustrated drive cylinder, the cut punch
48
is advanced and enters the die
28
. As a result, a hole is punched in an unillustrated disc substrate of resin molded within the cavity C.
Meanwhile, the mold assemblies
12
and
32
are aligned with each other by means of guide posts
54
. Four guide post holes
53
(two of which are shown in
FIG. 1
) are formed in the base plate
15
through grinding such that they are arranged on a concentric circle relative to the center of the mold assembly
12
. The guide posts
54
are press-fitted into the corresponding guide post holes
53
in such a manner as to project toward the mold assembly
32
. Furthermore, the guide posts
54
are fixed to the base plate
15
by use of corresponding bolts
55
.
Guide bushing holes
56
are formed through grinding in the intermediate plate
40
at positions corresponding to the guide post holes
53
. Guide bushings
57
are press-fitted into the corresponding guide bushing holes
56
. The guide bushings
57
guide the corresponding guide posts
54
. During mold closing, the guide posts
54
enter the corresponding guide holes formed in the guide bushings
57
via unillustrated ball bearing portions of the guide bushings
57
, whereby the mold assemblies
12
and
32
are aligned with each other.
Temperature control medium passages
61
and
62
are formed in the disc plates
16
and
36
, respectively. A medium, such as water, oil, or air, is fed into the temperature control medium passages
61
and
62
so as to cool the disc plates
16
and
36
, respectively.
However, the conventional disc-molding mold involves the following problem. As resin injected from an injection nozzle passes through the sprue
26
and is charged into the cavity C, a difference in thermal expansion arises between the mold assembly
32
and the mold assembly
12
. Specifically, in the mold assembly
32
, heat of resin contained in the cavity C is transmitted to the guide bushings
57
via the disc plate
36
and the intermediate plate
40
. In the mold assembly
12
, not only is the heat transmitted to the guide posts
54
via the disc plate
16
and the base plate
15
, but also heat of resin passing through the sprue
26
is transmitted to the guide posts
54
via the sprue bushing
24
and the base plate
15
. Thus, a difference in thermal expansion arises between the guide bushings
57
and the guide posts
54
. As a result, the guide posts
54
may fail to smoothly enter the corresponding guide holes, resulting in a failure to reliably align the mold assemblies
12
and
32
with each other or resulting in galling of a guide post
54
.
SUMMARY OF THE INVENTION
An object of the present invention is to solve the above-mentioned problem in the conventional disc-molding mold and to provide a disc-molding mold capable of reliably aligning a stationary-side mold assembly and a movable-side mold assembly with each other and preventing galling of a guide post.
To achieve the above object, the present invention provides a disc-molding mold, comprising a first support plate disposed at a stationary side of the mold; a first mirror-surface disc attached to the first support plate; a first guide ring disposed radially outside the first mirror-surface disc and attached to the first support plate; a second support plate disposed at a movable side of the mold; a second mirror-surface disc attached to the second support plate; a second guide ring disposed radially outside the second mirror-surface disc and attached to the second support plate; a guide post attached to either the first or second guide ring and projecting towards the other guide ring; and a guide bushing attached to the other guide ring and adapted to guide the guide post.
The first and second guide rings each have a temperature control medium passage formed therein in order to allow passage of a temperature control medium.
Since a temperature control medium flows through the temperature control medium passages formed in the first and second guide rings, the first and second guide rings are equal in thermal expansion. Thus, the guide post can smoothly enter a guide hole formed in the guide bushing , whereby the mold assemblies can be reliably aligned with each other, and galling of the guide post can be prevented.
The temperature control medium passages can be formed in the first and second guide rings more easily than in the first and second support plates, thereby lowering manufacturing cost of the disc-molding mold.
Preferably, the guide post is positioned with respect to the guide ring to which the guide post is to be attached.
Preferably, a guide post hole is formed in the guide ring to which the guide post is to be attached. The guide post is press-fitted into the guide post hole.
Preferably, the guide bushing is positioned with respect to the other guide ring.
Preferably, a guide bushing hole is formed in the other guide ring. The guide bushing is press-fitted into the guide bushing hole.
Preferably, a ball bearing portion is formed on an outer circumferential surface of the guide post in order to enhance sliding
Sakamoto Yasuyoshi
Sawaishi Hiroyuki
Yasuda Katsuyuki
Heckenberg Donald
Mackey James P.
Seikoh Giken Co. Ltd.
Squire Sanders & Dempsey LLP
LandOfFree
Disc-molding mold does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Disc-molding mold, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Disc-molding mold will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3082078