Claims:We claim,
1. A molding apparatus 100 for performing a complete molding operation, said operation including a plurality of functions, said apparatus 100 comprising:
a plurality of carriers 102, said each of the carriers 102 support at least one mold assembly 108;
a clamping means to secure said mold assembly 108 to said carrier 102;
a conveyor means 112 for supporting said carrier 102 and to move said carrier 104 to a plurality of work stations defined along a predefined mold conveying path;
a driving means 114 to move or rotate said conveyor means 112 along said predefined mold conveying path; and
a control unit 132 in communication with said conveyor means 112, said plurality of work stations, and said drive means 114,
wherein,
said conveyor means 112 being capable of selectively indexing said mold assembly 108 to said plurality of work stations; and
said plurality of work stations having operating means located thereat for simultaneously performing at least one function of said molding operation at each work station.

2. The molding apparatus 100 as claimed in claim 1, wherein said plurality of work stations includes an injection station 116, a processing station 118, a removal station 120, a cleaning station 122 and a loading station 124.

3. The molding apparatus 100 as claimed in claim 1, wherein said conveyor means 112 includes a predetermined length L, said length L is adapted such that time required for completion of the function at each of the stations is equal.

4. The molding apparatus 100 as claimed in claim 1, wherein said clamping means includes at least two gripper arms 110, said gripper arms 110 having a first end 110a attached to an upper surface of said mold assembly 108 and said gripper arms 110 having a second end 110b connected to a first actuating means.

5. The molding apparatus 100 as claimed in claim 1, wherein said conveyor means 112 is in constant rotation during said molding operation and is configured to move linearly along said predefined mold conveying path at a constant predetermined speed.

6. The molding apparatus 100 as claimed in claim 1, wherein said conveyor means 112 is further configured to rotate intermittently during said molding operation.

7. The molding apparatus 100 as claimed in claim 1, wherein said predefined mold conveying path is selected from at least one of oval, circular, and rectangular.

8. The molding apparatus 100 as claimed in claim 1, wherein said first actuating means includes at least one first pneumatic cylinder to assist in clamping of said mold assembly 108 to said carrier 102.

9. The molding apparatus 100 as claimed in claim 1, wherein said processing station 118 includes at least one temperature sensor.

10. A method of producing a mold part or article, comprising:
providing a plurality of carriers 102, said each of the carriers 102 supports at least one mold assembly 108;
attaching a clamping means to secure said mold assembly 108 to said carrier 102;
providing a conveyor means 112 for supporting said carrier 102 and to move said carrier 102 to a plurality of work stations defined along a predefined mold conveying path;
installing a driving means 114 to move said conveyor means 112 along said predefined mold conveying path;
connecting a control unit 132 in communication with said conveyor means 112, said driving means 114 and said plurality of work stations;
injecting a moldable resin composition into said mold assembly 108 through at least one nozzle 130 at said injection station 116 located along said predefined mold conveying path to form an injection-filled mold assembly;
rotating said mold assembly 108 about its axis and delivering said injection-filled mold assembly to a processing station 118 to form a mold part;
rotating said mold assembly 108 about its axis and delivering the mold part from processing station 118 to a removal station 120 to ejecting said mold part from said injection-filled mold assembly;
cleaning said mold assembly 108; and
loading the cleaned mold assembly 108 to said conveyor means 112 for next cycle of operation.
, Description:TECHNICAL FIELD
[001] The embodiments herein generally relate to molding apparatus, more particularly but not exclusively to an injection molding apparatus having a conveyor means to selectively position work members, such as a mold assembly, to a plurality of work stations predefined along a mold conveying path of the injection molding apparatus in accordance to successive manufacturing steps.
BACKGROUND
[002] Usually molding machines are of two types, i.e. horizontal injection molding machine and vertical injection molding machine. An apparatus for holding and turning molds or mold parts in a horizontal injection molding machine is disclosed which includes mold mounting plates between which a turret (mold center platen) is slideable in longitudinal direction of the machine and provided as mold carrier with prismatic cross section which is supported for rotation about an axis extending perpendicular to the longitudinal axis of the machine. In order to shift the turret in longitudinal axis of the machine, on the one hand, and to rotate the turret about an axis extending perpendicular to the longitudinal axis of the machine, a system is provided in which the turret is rotatably supported in carriers, with the carriers slideably guided and supported at least on both lower tie bars of the injection molding machine or on all four tie bars. To permit a precise guidance of the carrier and of the attached turret, support and guiding elements are required which are of highly precise construction and sized in narrow tolerances and which are arranged at great distances from one another as a result of the system. Thus, this support reacts sensitively to temperature fluctuations, i.e. during cool-down period and accompanying shrinkage, the clearance in the bearings increases whereas during heating period and accompanying expansion there is a risk that the support and guiding elements get jammed on the tie bars. To prevent the latter, the tolerances in the support and guiding elements should not be too narrow, i.e. sized not too precisely. A further drawback resides in the fact that the tie bars are loaded by a significant weight (inadmissible bending) depending on the design of the turret and the carriers, and that the torques encountered during rotation of the turret must be absorbed entirely by the tie bars, resulting in particular during starting and braking of the rotational movement in significant stresses.
[003] Further, vertical injection molding machines consist of an injection unit mounted in a vertical orientation and a clamp system oriented vertically to hold the two mold halves together under force sufficient to resist the pressure exerted by the molten plastic. The vertical injection molding machine according to the different needs of the work, different modules are installed on the fixed substrate, which comprises a turntable module. The current vertical injection molding machine turntable module is prone to wear or bending movement which in turn leads to drop in control precision causing damage to the components.
[004] In many molding machines, a mold having a predefined cavity is used to form a single part. In this case, the molds are positioned at a work station and are secured in any conventional fashion. While these previously available molding machines have proven satisfactory where only a single type of part is produced by the mold, in many different situations, it is necessary to change the mold at the work station in order to generate different types of parts. Furthermore, in a production facility, the cycle time for the mold parts forms a critical part of the overall manufacturing operation. Consequently, where it is necessary to change the mold in the molding machine in order to generate different types of parts, it is desirable that the time necessary to change the mold at the work station be as short as possible.
[005] Therefore, there is a need for an injection molding apparatus that obviates the aforementioned drawbacks.
OBJECT OF THE INVENTION
[006] The principal object of the embodiments of this invention is to provide an injection molding apparatus having a conveyor means to selectively position work members, such as a mold assembly, to a plurality of work stations predefined along a mold conveying path of the apparatus in accordance to successive manufacturing steps.
[007] Another object of the embodiments of this invention is to provide an injection molding apparatus which is compact, simple in construction and less expensive.
[008] Yet another object of the embodiments of this invention is to provide a method of producing a mold part or article using an injection molding apparatus.
[009] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF DRAWINGS
[0010] The embodiments of this invention are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0011] FIG. 1 is a top view of an injection molding apparatus, according to an embodiment as disclosed herein;
[0012] FIG. 2 is a front view of an injection molding apparatus, according to an embodiment as disclosed herein;
[0013] FIG. 3 is a front view of a mold assembly, according to an embodiment as disclosed herein; and
[0014] FIG. 4 is a flowchart depicting a method of producing a mold part using an injection molding apparatus.

DETAILED DESCRIPTION
[0015] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0016] The embodiments herein achieve an injection molding apparatus having a conveyor means to selectively position work members, such as a mold assembly, to a plurality of work stations predefined along a mold conveying path of the apparatus in accordance to successive manufacturing steps. Further, the embodiments herein achieve an injection molding apparatus, which is compact, simple in construction and less expensive. Referring now to the drawings, and more particularly to FIGS. 1 through 4, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0017] FIG. 1 is a top view of an injection molding apparatus, according to an embodiment as disclosed herein. In an embodiment, the injection molding apparatus 100 includes a plurality of carriers 102, at least one die or mold cavity 104 mounted on each of the carrier 102, a metal insert 106, a mold assembly 108, a clamping means having at least two gripper arms 110, said gripper arms having a first end 110a, a second end 110b, a conveyor means 112, a driving means 114, a plurality of work stations having an injection station 116, a processing station 118, a removal station 120, a cleaning station 122, a loading station 124, a control unit 132 and a power supply 126.
[0018] The injection molding apparatus 100 includes the plurality of carriers 102. The plurality of carriers 102 are disposed on the conveyor means 112. The conveyor means 112 is configured to shift the plurality of carrier 102 to a plurality of work stations. Each carrier 102 is configured to support at least one mold assembly 108. The mold assembly 108 includes at least one of a mold cavity or a die set 104 as shown in FIG. 3. Further, the mold assembly 108 may further include at least one metal insert 106. However, it is also within the scope of the invention to use or omit the metal insert and also to provide any other type of rubber grommet or washer and the like without otherwise deterring the intended function of the supporting as can be deduced from the description.
[0019] The injection molding apparatus 100 further includes the clamping means (not shown). The clamping means includes at least two gripper arms 110. The gripper arms 110 includes a first end 110a which is attached to an upper surface of the mold assembly 108 and a second end 110b which is connected to at least one first actuating means (not shown). The first actuating means may include at least one first pneumatic cylinder (not shown). However, it is also within the scope of the invention to provide any other type of actuating means without otherwise deterring the intended function of the actuator as can be deduced from the description. The pneumatic cylinder (not shown) includes an actuator (not shown), which is operated to move between an extended position and a retracted position. The actuating means is activated to move the gripper arms 110 to a lock position, to lock the mold assembly 108 to the carrier 102. Similarly, the actuating means is deactivated to move the gripper arms 110 to an unlock position, to unlock the mold assembly 108 from the carrier 102. The clamping means is configured to apply a predetermined pressure P on said mold assembly 108. In an embodiment, the predetermined pressure P may vary from 30 to 100 kg/cm2.
[0020] The injection molding apparatus 100 further includes the conveyor means 112. The conveyor means 112 is configured to support the plurality of carriers 102 and move the carriers 102 along a predefined mold conveying path. In an embodiment, the mold conveying path of the conveyor is selected from at least one of oval, circular, and rectangular. Further, the conveyor means 112 communicates with the control unit 132 to move or shift the plurality of carriers 102 to the plurality of work stations such that each work station includes at least one of the carriers 102. The plurality of work stations are defined along the predefined mold conveying path. The injection molding apparatus 100 further includes the driving means 114 to move the conveyor means 112 along said predefined mold conveying path. The conveyor means 112 is selected from at least one of chain driven conveyor, belt driven conveyor, roller driven conveyor. The conveyor means 112 is capable of selectively indexing the mold assembly 108 to the plurality of work stations. Further, the conveyor means 112 includes a predetermined length L. The length L is adapted such that time required for completion of a function of molding operation at each of the stations is equal.
[0021] FIG. 2 is a front view of an injection molding apparatus, according to an embodiment as disclosed herein. The injection molding apparatus 100 further includes the control unit 132. The control unit 132 is configured to communicate with the conveyor means 112, the driving means 114, and the plurality of work stations. The control unit 132 is configured to operate the injection molding apparatus 100 to perform the entire molding operation. Further the injection molding apparatus 100 is connected to the power supply 126 to operate the injection molding apparatus 100.
[0022] The injection molding apparatus 100 further includes the plurality of work stations having the injection station 116, the processing station 118, the removal station 120, the cleaning station 122 and the loading station 124. The plurality of work stations includes operating means located thereat for simultaneously performing at least one function of the molding operation at each work station at same time.
[0023] The injection station 116 of the injection molding apparatus 100 includes at least one first chamber 128 comprising a moldable resin composition (such as rubber rope or rubber strip) and at least one nozzle 130 to discharge the moldable resin composition from the first chamber 128 into the mold assembly 108. The injection station 116 may further include plurality of nozzles (not shown) to discharge the moldable resin composition into mold assembly 108 having multiple mold cavities. The moldable resin composition is injected into the mold assembly 108 through the nozzle 130 at the injection station 116 located along the predefined mold conveying path to form an injection-filled mold assembly (not shown). The injection station 116 communicates with the control unit 132 to perform at least one of discharge the resin composite from the nozzle 130, discharge a predetermined quantity of resin composite into the mold assembly 108 and the like. The injection-filled mold assembly is shifted to next work station by the conveyor means 112 in accordance to successive manufacturing step.
[0024] The injection molding apparatus 100 includes the processing station 118. The processing station 118 may further include at least one of a heating system (not shown) and a cooling system (not shown). The heating system and the cooling system may be disposed in a second chamber (not shown). In the processing station 118 the injection-filled mold assembly is subjected to at least one of heating and/or cooling for a predetermined time period T. The second chamber (not shown) is provided with insulation 136 to prevent exposure of heating or cooling from the second chamber. The processing station 118 may further include at least one temperature sensor (not shown) connected at a predetermined location of the second chamber to measure temperature inside the processing station 118. Further, the processing station 118 may be adapted to hardening or toughening of the injection-filled mold assembly to form a mold part. The processing station 118 communicates with the control unit 132 to determine the predetermined time period T and the temperature to which the injection-filled mold assembly has to be exposed and the like. The mold part from the processing station 118 is shifted to next work station by the conveyor means 112 in accordance to successive manufacturing step.
[0025] The injection molding apparatus 100 further includes the removal station 120. The mold part from the processing station 118 enters the removal station 120 in accordance with the successive manufacturing steps. The mold part is removed from the mold assembly 108 by at least one second actuating means 134. The second actuating means 134 may include a second pneumatic cylinder. However, it is also within the scope of the invention to provide any other type of actuating means without otherwise deterring the intended function of the actuator as can be deduced from the description. The second pneumatic cylinder is configured to eject the mold part from the mold assembly 108. The control unit 132 communicates with the removal station 120 to activate and deactivate the second pneumatic cylinder.
[0026] The injection molding apparatus 100 further includes the cleaning station 122. The mold assembly 108 enters the cleaning station 122 in accordance with the successive manufacturing steps. The mold assembly 108 is subjected to a cleaning process in the cleaning station. The cleaning process may be provided in accordance to any one of conventional cleaning methods. The cleaned mold assembly 108 is shifted to next work station in accordance to successive manufacturing step. The cleaned mold assembly 108 is shifted to the loading station 124 to start the injection molding cycle again.
[0027] FIG. 4 is a flowchart depicting a method of producing a mold part using an injection molding apparatus. A method of producing a mold part or article is provided. At step 402, the method includes providing a plurality of carriers 102, said each of the carriers 102 supports at least one mold assembly 108. At step 404, the method includes attaching a clamping means to secure said mold assembly 108 to said carrier 102. At step 406, the method includes providing a conveyor means 112 for supporting said carrier 102 and to move said carrier 102 to a plurality of work stations defined along a predefined mold conveying path. At step 408, the method includes installing a driving means 114 to move said conveyor means 112 along said predefined mold conveying path. At step 410, the method includes connecting a control unit 132 in communication with said conveyor means 112, said driving means 114 and said plurality of work stations. At step 412, the method includes injecting a moldable resin composition into said mold assembly 108 through at least one nozzle 130 at said injection station 116 located along said predefined mold conveying path to form an injection-filled mold assembly. At step 414, the method includes rotating said mold assembly 108 about its axis and delivering said injection-filled mold assembly to a processing station 118 to form a mold part. At step 416, the method includes rotating said mold assembly 108 about its axis and delivering the mold part from processing station 118 to a removal station 120 to ejecting said mold part from said injection-filled mold assembly. At step 418, the method includes cleaning said mold assembly 108. At step 420, the method includes loading the cleaned mold assembly 108 to said conveyor means 112 for next cycle of operation.
[0028] For the purposes of this description and ease of understanding, the embodiments of this invention are explained considering the injection molding apparatus. However, it is also within the scope of this invention to extend the embodiments for similar apparatus, compression machines, and the like.
[0029] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.