Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates to horizontal injection molding machinery, and
more particularly, to mold shuttle mechanisms on thal; machinery.
Techniques for injection molding of plastic and rubber articles ha~e
increased markedly over recent years, as have the quantity and variation
of those articles. One of those techniques utilizes a clamping unit comprising
a frame having a stationary die platen at one end, and an opposed movable
die platen pressurizably displaceable towards and away from the stationary
die platen. The dies have propinquous surfaces which are configured to
define a mold cavity when the platens are in an abutting relationship. 'rhe
10 stationary platen has a gate, one end of which i9 in fluid communication with
the interior of the mold cavity. The other end of the gate is in ,fluid communication
with an injector machine capable of injecting a charge of plasticated substance
into the die mold cavity.
One such injector machine may be of the reciprocating screw type.
In this type, a helically arranged screw member is rotated within a heated
chamber to melt and mix a predetermined charge of material, such as plastic
or rubber. Upon suEficient mixing and heating, the screw is drawn back
in the chamber, similar to a piston in a cylinder, to ram a charge ~hrough
the gate and into the mold cavity. The injection machine and the platens
20 may be heated to temperatures of 400F or higher.
After the plasticizer is injected into the die mold cavity, lhe plastici~er
charge soIidifies in a curing period. This time may range from a few seconds
to a few minutes. Once ~his is accomplished, the die platens are separated
to permit removal of the molded article.
The articles which are manufactured in a molding machine of this
type include automobile fenders, wheel wells, front grill units as well as
truck and bus bumper assemblies. These articles may weigh 100 pounds
or more.
Removal of these weighty articles from the clamping unit can be a
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problem. One method is to let the operator climb into the insert, between
the multiton platens which may still be hundreds of degrees hot, and pull
the heavy molding out. An added difficulty arises here where the molded
article includes a stiffening insert which must be replaced on one of the
platens, around which the plasticizer is adhered. This necessitates the
operator going back in to the clamping unit to install the insert.
An interesting arrangement for removing molded articles from a mold
is shown in U.S. Patent 3,522,838. This device would prove awkward for
large articles or for replacing inserts within the molds . U .S . Patent 3,128, 501
shows a vertical press having a transfer mechanism with an intermediate
mold for handling several small molded articles. Further art for mold article
release is shown in U.S. Patent 3,986,811, showing a foldable chute for
that purpose. Other patents showing release or ejection devices for molding
machines are U .S . Patents 3,907,483 and 3,712,781.
It is an object of the present invention to provide an apparatus for
a molding machine which will transfer large and/or heavy molded articles
from the hot injection molding area of that machine.
It is a further object of the present invention to provide a mold shuttle
apparatus for a horizontal molding machine.
It is another object of the present invention to provide a mold shuttle
mechanism which permits ~imple installation of an insert into one platen
of a mold.
The present invention comprises a horizontal injection molding machine
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comprising: a stationary mold platen, a movable mold platen,
said movable mold platen having means for empowering said
movement towards and away from said stationary mold platen,
said mold platerl being movable on a pair of horiæontally
disposed ways extending therebetween, each of said mold
platens bein~ disposed on said ways defining a rnold area
therebetween, each of said mold platen having a mold-half
disposed thereon, said mold-halves defining a mold cavity
therebetween when said empowering means pushes said movable
mold platen against said stationary mold platen, a plastic
injection apparatus communicating with said stationary mold
platen and said cavity defined by said mold-halves, to inject
under heat and pressure plasticatable material therein during
maintenance o~ said mold cavity' a shuttle apparatus provid-
ing trans~erse movement to a single shutt~e plate supported
on a first pair of upper and lower set of rails on one of
said mold platens with respect to said ways, said shuttle
apparatus comprising a stationary receiving station frame
which includes a second pair of upper and lower set of paral-
lel rails, said transversely movable single shuttle platebeing movable on and supported between said first and second
pair of upper and lower set of rails to permit translational
movement to said shuttle plate and attached mold carrying its
molded article from said mold area, facilitating unloading
of a cumbersome molded article from said transversely movable
mold-half and reloading said transversely movable mold-half
with any necessary inserts, said shuttle apparatus including
a motor disposed on said molding machine, said motor being
in a geared relationship with a rack on said transversely
movable shuttle plate to effectuate movement between said
transversely movable shuttle plate and said first and second
pairs of upper and lower parallel rails~
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According to a further broad aspect, the present
invention provides a method of manufacturing an injected
article in a horizontal injection molding machine, cornpris-
ing the steps of: moving a mold-half on a ~huttle plate on
a first set of upper and lower rails rom a load and unload
position on a receiving station to a second set of upper and
lower rails on a movable platen, on one side of said receiv-
ing station' closing the mold area off by automatically
shutting a safety gate: activating a pressurizable ram to
cause the movable platen attached therewith to move on a
pair of parallel ways; pressing said movable platen with its
mold-half attached thereto, against a stationary platen with
a corresponding mold-half attached therewith, said mold-
halves defining a mold cavity therebetween; injecting a
plasticized material under pressure into said mold cavity;
, heating said mold-halves to help cure said plasticized
-~ material therein, depressurizing said mold-halves held
against one another; withdrawing said movable platen from
said pressur.izable ram, opening the mold area by retracting
said safety gate; moving said shuttle plate and the molded
article from said second set of upper and lower rails on
: said movable platen to an unload, load position between
said first set of upper and lower rails transversely adja-
cent said movable platen; and securing said shuttle plate
to said movable platen by means of an automatically actuable
~ reciprocably movable positioning pinu
; The objects and advantages of the present inven
tion will become more apparent when viewed in conjunction
with the following drawings, in which:
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FIGURE 1 is a perspective view o-f a harizontal
injection molding machine having a mold shuttle arrangement
constructed according to the principles of the present
invention,
FIGURE 2 is another perspective view of the
horizontal injection molding machine shown frorn a different
angle,
FIGURE 3 is a view of a mold platen and shuttle
plate within the framewor~ of the mold area of a horizontal
injection molding machine, and
FIGURE 4 is a view of the shuttle plate on a mold
shuttle receiving station arrangement, after transverse
movement thereof from the mold platen.
Referring now to the drawings, and particularly
to Figures l and 2, there is shown a horizontal molding
machine lO cornprising a generally longitudinally extended
arrangement of comp~nents, including a molding machine
frame 12. A hydraulic drive unit 14 is secured within one
end (on the left as shown in Figure l), of the machine
frame 12. The machine frame 12 also encloses a pressurizable
ram 16 which extends from one side of the hydraulic drive
unit 14. The pressurizable ram 16 is attached to a movable
platen 18. The movable platen 18 is slidable on a pair of
horizontally disposed
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1 ways 20 within the frame 12. The hori~ontally disposed ways extend from
the hydraulic drive unit 14 to a stationary platen 22.
A plastic injection unit 24 Elxedly arranged on the portion of' the
frame 12 opposite to the hydraulic drive unity 14, and is positioned on the
other side of the stationary platen 22 therefrom. The plastic injection unit
24 also includes a feed screw 26 and a raw material feed hopper 28 which
permits loading of extrusion material into the injection unit 24. The feed
screw 26 is attached to the stationary platen 22 and is in fluid communication
~~~ with a mold-half 40 secured on the opposite side thereof.
The machine frame 12 includes an upper pair of tie rods 30 and a lower
pair of tie rods 32. The tie rods, 30 and 32, extend from that portion of the
frame 12 which is disposed about the hydraulic drive unity 14, through
the stationary platen 22. The upper pair of tie rods 30 each extend through
a bore and bushing 36 in the upper corners of the movable platen 18.
The movable platen 18 is glidingly supported by the tie rods 32 on
the pair of ways 20 by a support assembly 38, dispo~ed on each lower corner
thereof, as shown in Figures 3 and 4. The support assemblies 38 permit
the movable platen 18 to be slidingly pushed toward, and slidingly pulled
away from the stationary platen 22, by the pressurizable (and depressurizable)
20 ram 16.
The movable platen 18 also includes an inverted generally U-shaped
channel 42 across its upper edge and a flanged lower support rail 44 across
its lower edge. A single shuttle plate 50 is suppor~ively disposed on the front
side of the movable platen 18 between the lower support rail 44 and the U
shaped ch nnel 42 by a proper ma~ing relationship therebetween, as shown
in Figure 3. The shuttle plate 50 is properly secured in front of and correctly
juxtaposed with respect to the movable platen 18 by the mating of a reciprocable
positioning pin 46, as shown in Figure 4, with a proper detent, not shown,
on the backside of the shuttle plate 50. The positioning pin 46 extending
through the movable platen 18 secures the shuttle plate 50 theretc ~nd pro~ides
signalling means to a control circuit for the next sequence of the operation
when the positioning pin 46 is either engaged or disengaged with the detent
in the rear face of the shuttle plate 50. The shuttle plate 50 carries a mold-
half 52 on its outer or front face, as shown in Figures 3 and 4. The shuttle
plate 50 has an arm 54 extending horizontally outwardly from its leftward
uppermost corner, as shown in Figures 3 and 4. A portion of the arm 54
is also disposed just above the top surface of the shuttle plate 50 and extends
thereacross as well. That portion of the arm 54 which extends across the
10 top of the shuttle plate 50 comprises a rack 56, a portion of which is shown
in Figure 4. The rack 56 and the uppermost portion of the shuttle plate 50
are slidingly arranged within the inverted generally U-shaped channel 42.
A motor 60 is secured to the frame 12 of the machine and is disposed in the
distal end of the inverted U-shaped channel 42, which extends slightly beyond
the frame 12, as shown in Figure 3. The motor 60 has a gear, not shown,
which is in engagement with the rack 56 on the topmost portion of the shuttle
plate 50. The motor 6Q may be operated electrically or hydraulically on
the machine's hydraulic system.
The mold-halves, 40 and 52, disposed on the stationary platen 22
20 and disposed on the outer face of the shuttle plate 50, respectively, each
have an array of conduits 62 attached thereto. The conduits supply heated
pressurized oil to the mGld-halves, 40 and 52, or they may supply electrical
energy to resistance heaters therein, to heat the mold to the temperatures
400-500F, as required. The oil would be heated by heating units within
the machine's hydraulic system, and pumped through both mold-halves,
40 and 52, or both mold-halves would be heated electrically.
The shuttle plate 50 may be moved transversely between the inverted
U-shaped channel 42 or rail, and the lower support rail 44, to an outer inverted
U-shaped channel 70, or rail, and an oul:er lower support rail 72, which
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1 inverted U-shaped channel 70 and the outer lower support rail 72 are di6posed
in a stationary frame support arrangement 7a~, which is disposed immedi~kely
transversely adjacent the rearwardmost or retractedmost position of the shu~tle plate 50,
The distal end of the outer inverted U-shaped channel 70 has a pair oE limit
switches 76 disposed thereon. During outward transverse movement of the
shuttle plate 50, the distal end of the rac~ 56 strikes the limit switches
76 to slow down and finally stop transverse outward motion of the shuttle
plate 50,
A safety gate 80 is slidably arranged on an upper rail 82 and a lower
10 rail 84, each being disposed alongside and parallel to the tie rods on the
shuttle side of the molding machine 10.
A pair of spacer members 86, extend off the lower portion of the front
face of the shu~tle platen 50. The spacer members 86 act as safety devices
when the pressurizable ram 16 pushes the movable platen 18, with the shuttle
plate 50 and mold-half 52 thereon, against the mold-half 4û disposed on the
stationary platen 22.
In operation of the hori~ontal molding machine 10, the safety gate
80is withdrawn to its storage position, (nearest the hydraulic drive unit
14) as shown in Figure 2. The shuttle plate 50 is supported between the
~0 outer inverted U-shaped channel 70 and the lower support arrangement
72 of the stationary receiving station 75. The frame support arrangement
74 and its associated channel 70 and rail 72 are necessarily heavy because
the shuttle platen 50 may weigh as much as 10 tons. A machine operator
may place an insert within the half-mold 52 to provide later stiffness within
the molded article during use, after extraction thereof from the half-mold
52. The molded articles may weigh as much as 100 pounds and may be several
yards in length. A molded article is shown attached to the mold-half 52 in
the "in-position" as shown in Figure 3. Upon activation by the operator
of a proper signal on a control circuit 90, as shown in Figure 4, the motor
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60 is actuated to cause the shuttle plate 50 to move transversely from its
position in the stationary receiving station 75 to its position in front of the
movable platen 18 and is automatically locked in position therewith by the
automatic reciprocable positioning pin 46, which extends through the movable
platen 18. The positioning pin is activated to enter the detent on the rearside
of the shuttle plate 50 by a pressurizable cylinder 48, as shown in Figure
2, when the position of the shu~tle plate 50 is fully in the "in position", as
indicated by the location of the shuttle plate 50 in Figure 3. The safety gate
80 is then automatically driven by a motor, to close-off the mold area between
the movable platen 18 and the stationary platen 22. The movable platen 18
is then pushed towards the stationary platen 18 with a force of up to 2500
tons or greater, through automatic activation of the pressurizable ram 16.
The mold-halves, 40 and 52, contact each other, and between one another
define a mold cavity. The plastic injection unit 24 (which may use a rubber
or a plastic as its material) forces a heated plasticated material through the
feed screw 26 and through a communication channel in the stationary platen
22 into the mold cavity. The pressure of the molds against one another may
be held for a cycle of 10 seconds to 20 minutes duration to permit the complete
curing of the molded article in the mold cavity. The pressure is then released,
20 and the hydraulic ram 16 is retracted to withdraw the movable platen 50
to its retractedmost position ("in position") from the stationary platen 22.
The safety gate 80 is also withdrawn on its upper and lower rails ~2 and
84 to its storage position, as shown in Figure 2. The positioning pin in the
movable platen 18 is automatically retracted, unlocking the shuttle plate
S0, which through a proper circuit, automatically causes the activation of
the motor 60, causing the molded article, attached to the mold-half 52 on
the shuttle plate 50 to move transversely out from in front o~ the movable
platen 18 and its inverted U-shaped channel ~2 and lower support rail 44
to between the outer upl?er inverted U shaped channel 70 and the outer lower
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support rail 72 of the stationary receiver station 75. The extendecl rack 56
strikes the Iimit switches 76 on the distal end of the outer upper inverted
U-shaped channel 70 to slow down and ~top the motion of the shuttle plate
50, the molded article then being outside of the hot mold area. The machine
operator then simply removes the molded article from the mold-half 52 on
the shuttle plate 50. Yrior to the present invention, the operator would have
had to climb between the hot movable and stationary platens, 18 and 22,
to remove the hot heavy molded article.
It is to be noted that the shuttle plate could be adapted to fit the stationary
platen 22 to move the shuttle plate in and out of the molding area.
Thus, there has been shown a horizontal molding machine which injection
molds large heavy articles in a high temperature and pressure environment,
in a safe and efficient manner by utilization of a mold shuttle arrangement
to permit optimization of worker safety and efficiency.
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