Abstract:
An injection molding press apparatus for use with a variety of different interchangeable molding tools that allows the simultaneous molding of different parts. The interchangeable molding tools are custom designed to form a desired part. Each interchangeable molding tool allows for the easy replacement of different types of molding tools for the molding of different parts without the need of an entire mold replacement. A preferred embodiment of the invention comprises a baffle sorting system for injection molding machines thereby increasing the allowing the simultaneously molded different parts to be ejected from the machine without the need of separating the different parts. This increases the speed of each production run.

Description:
CROSS REFERENCE 
     The present application is related to the following copending applications, filed herewith on Dec. 23, 1998, entitled: “ Water Jacket Apparatus For Injection Molding Systems ” and “ Baffle Sorting System For Injection Molding Machines ,” and assigned application Ser. Nos. 09/224,263 and 09/223,857 respectively. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to injection molding and more particularly, to improvements in an injection molding press apparatus with removable and interchangeable molding tools. 
     BACKGROUND OF THE INVENTION 
     Injection molding techniques have for some time been used for molding various parts, particularly of plastic. The injection molding apparatus conventionally consists of a mold formed of two halves typically, one or more pairs of fixed and movable bases (also referred to A and B mold bases respectively), which are mounted, respectively, on the top clamp plate and base support plate of the injection mold base mounted on the molding machine. Mold inserts, plural A and B mold inserts, which are adapted to fit into the fixed and movable sides of the machine usually have mold cavity defining means which are fixed in the bases in paired alignment, whereby upon closure of the base support plate toward the top clamp plate respective pairs of oppositely disposed mold inserts are brought together to close the mold cavities. Molding material is fed through the top clamp plate and A mold base thereon to a runner distribution system in the two mold sides, and molding material is delivered from such distribution system to respective mold cavities to mold parts. An ejector apparatus usually is provided to eject the molded parts from the opened mold cavities and the excess mold from the runner distribution system by means of ejector pins that extend, for example, through the base support plate, B mold base and B mold inserts mounted thereon. 
     Molds with removable mold inserts for mold frames are in use and are especially valuable for prototype or low production molding needs wherein the tooling is changed after relatively short time. However, the known molds of this type only allow for molding of several like-parts and does not allow for the molding of different parts. In order to mold a different part, the entire mold assembly must be changed. Because only the same mold inserts can be used at the same time, the molding of different parts still requires substantial changeover time. The need exists for an inexpensive and efficient mold injection apparatus that molds different parts at the same time and requires only minimal changeover time and machining operations. 
     Previous attempts to provide an injection molding apparatus containing removable interchangeable molding tools are described in U.S. Pat. No. 3,871,611 to Taketa (&#39;611 patent); U.S. Pat. No. 4,828,479 to Pleasant (&#39;479 patent); U.S. Pat. No. 4,959,002 to Pleasant (&#39;022 patent); U.S. Pat. No. 5,302,103 to Brown (&#39;103 patent); and U.S. Pat. No. 4,416,604 to Bender (&#39;604 patent) all of which are incorporated herein by reference. 
     The &#39;611 patent describes an improved mold having removable and replaceable cores (mold inserts or molding tools) and cavities, so that the need of providing a new mold base for every new part or product is eliminated. The arrangement of the mold is such that the cores and cavities can be easily and quickly removed and replaced with minimum down time of the molding apparatus. 
     The &#39;479 patent describes a molding apparatus for use with removable inserts, described in patent &#39;002. The molding apparatus comprises a cavity insert for the injection side and a core insert for the ejection side of a mold which are each shaped as a generally cylindrical, stepped body provided with circumferentially extending locking grooves and a liquid cooling or heating channel. Insert retainers and lifters having rotatable elements with locking tongues engaging the locking grooves clamp the inserts in the main mold frame. The main mold frame is provided with liquid conduits opening to opposite ends of the liquid channels so that the need for machine liquid conduits and channels for different inserts is avoided. Ejector tooling may be connected to the core insert for insertion and removal with it. 
     The &#39;103 patent describes an injection molding machine which allows batch-conversions to be performed without significant machine downtime and/or the use of specialized tools. The molding apparatus provides a frame, an injection assembly coupled to the frame, a press assembly also coupled to the frame, a mold-mounting assembly coupled with the press assembly, and a mold pallet assembly adapted to be mounted to the press assembly by the mold-mounting assembly. 
     The &#39;604 patent describes an injection molding system with plural pairs of mold inserts that are engageable for mold cavities mounted on mold bases, respectively on the relatively movable top clamp plate and base support plate of an injection molding machine. Rails on those bases hold the mold inserts in place in paired alignment. The &#39;604 patent also describes a multiple stage ejecting and stripping apparatus to strip parts from mold cavities and a technique to eject the sprue before the parts. 
     None of the devices mentioned above comprise an injection molding apparatus which simultaneously molds different components while allowing the easy replacement of each different mold insert. The &#39;611 patent describes removable mold inserts and a mold assembly which only allows for the simultaneous molding of like components. Similarly, the &#39;479 patent describes a molding apparatus which allows for removable inserts but does not allow for the simultaneous molding of different components. The &#39;103 patent describes a molding apparatus which down sizes batch conversions. Batch conversions refer to the process of changing sides of a mold assembly for the molding of various parts. Thus, the &#39;103 patent does not allow for the simultaneous molding of different components but rather only down-sizes the time in which to change-over from one type of mold to another type of mold. 
     The above inventions only allow for the use of a uniform set of removable mold inserts. Variation of the parts to be molded requires changing the entire mold assembly. Simultaneous molding of different components can only be achieved by using two separate molding apparatuses, one mold assembly containing a particular uniform set of mold inserts and another mold assembly containing another particular set of uniform of mold inserts. For example, if Customer A desires an A part and customer B desires a B part, the only solution is to use two separate injection molding apparatuses, one containing a uniform set of mold inserts, each mold insert designed to mold an A part, and another molding apparatus containing a uniform set of mold inserts, each mold insert designed to mold a B part. 
     Consequently, there is a need in the art for a molding press injection apparatus with removable inserts or molding tools, that allows the simultaneous molding of different parts. 
     There is a further need in the art for an injection molding apparatus that quickly molds the different parts. 
     Finally, there is a further need in the art to simultaneously manufacture different components, which does not require a substantial change-over time. 
     SUMMARY OF THE INVENTION 
     The above and other needs in the art are fulfilled by the provision of an injection molding apparatus comprising a mold assembly comprising an A side and a B side namely, a fixed side having a fixed molding surface and an ejector side having an ejector molding surface, respectively, wherein the molding surfaces when pressed together form a plurality of mold cavities, a plurality of interchangeable molding tools which are releasably attached to the mold assembly, a removable runner distribution system, a securing means for releasably securing the interchangeable molding tools to the mold assembly, a means for injecting a molding material into the mold cavities for forming a plurality of different components, a cooling means for effectively cooling the components once the molding material has set, a means for simultaneously releasing the different components, and a means for separating the different components once the different components are simultaneously released from the mold assembly. 
     The interchangeable molding tools each comprise a fixed tool side and an ejector tool side. Each molding tool is custom-designed for the molding of a particular shaped component. 
     The runner distribution system comprises a plurality of interchangeable runner blocks and a plurality of tool runner systems. The securing means for securing the plurality of interchangeable molding tools to the mold assembly comprises a plurality of fixed locking keys and a plurality of ejector rotating locking keys. The cooling means for cooling the different components once the material has been injected into the mold cavities comprises a water jacket apparatus for injection molding systems. The releasing means for simultaneously releasing the different components from the mold assembly once the molding material has set comprises an ejection assembly, and a means for separating the plurality of different components once the different components are simultaneously released comprises a baffle sorting apparatus. 
     An object of this invention is to provide an injection molding apparatus with removable and interchangeable molding tools that can simultaneously mold a variety of different components. 
     Another object of this invention is to provide an injection molding apparatus that allows the quick and efficient simultaneous molding of different components avoiding the necessary change over time for the replacement of interchangeable molding tools for the molding of different components. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects, advantages and features of the invention, and the manner in which the same are accomplished, will become more readily apparent upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings which illustrate preferred and exemplary embodiments, and wherein: 
     FIGS. 1A and 1B show a perspective view of each side of the mold assembly, a fixed side and an ejector side, in accordance with the present invention. 
     FIG. 2 is an enlarged perspective view of the fixed side of the mold assembly, in accordance with the present invention. 
     FIG. 3 is an enlarged perspective view of the ejector side of the mold assembly, in accordance with the present invention. 
     FIG. 4 is a sectional view taken generally transversely through the closed mold sides, to illustrate the manner in which the removable interchangeable molding tools are assembled therein, in conjunction with the ejector assembly. 
     FIG. 5 is a side view of one interchangeable molding tool, in accordance with the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, FIGS. 1A and 1B illustrate a perspective view of both sides of the molding press apparatus, a fixed side having a fixed molding surface  600  designated generally at  10  and an ejector side having an ejector molding surface  700  designated generally at  100 , respectively, which are both made in accordance with the present invention. Both sides,  10 ,  100  when pressed together form a mold assembly comprising a plurality of mold cavities. The molding press apparatus has a plurality of interchangeable molding tools  200  (shown in FIG. 5) which are substantially releaseably affixed to the mold assembly for molding a plurality of different components, a securing means for securing the interchangeable molding tools to the mold assembly (shown in FIGS.  2  and  3 ), a locking means for locking the mold assembly together when both molding surfaces are pressed together to form the plurality of mold cavities, a means for injecting a molding material into the mold cavities for forming the different components, a cooling means for cooling the different components once the molding material has been injected into the mold assembly, a removable runner distribution system for distributing the molding material to the mold cavities, a simultaneous releasing means for releasing the plurality of different components when the molding material has set, and a means for separating the plurality of different components once the different components are simultaneously released. 
     As shown in FIG. 5, the present invention includes interchangeable molding tools  200  which are custom made for molding a desired plastic component or other material-like component. Each molding tool can be customized to manufacture a desired part. The present invention allows the simultaneous manufacture of different components without the need of changing the entire mold assembly. Moreover the interchangeable molding tools  200  can be easily removed and replaced, if necessary, without the need of replacing an entire side of the mold assembly. The interchangeable molding tools  200  which releasably attach to the mold assembly of the present invention comprise a fixed tool side  210  and an ejector tool side  220 . The fixed tool side  210  of the interchangeable molding tool  200  comprises a plurality of fixed tool holder blocks  212  and a fixed tool back-up plate  214 . The ejector tool side  220  of the interchangeable molding tool  200  comprises a plurality of ejector tool holder blocks  222 , an ejector tool pusher bar retainer plate  224 , a first ejector tool back-up plate  226 , an ejector tool retainer plate  228  and at least one ejector pin  230  substantially affixed to the first ejector retainer tool back-up plate  226  and extending through the ejector tool retainer plate  228 , a second ejector tool back-up plate  234  and a tool pusher bar  232  substantially affixed to the ejector tool pusher bar retainer plate  228 . Each side of the interchangeable molding tool  200  can include a plurality of cores and cavities that are designed to form a desired part. Therefore, an interchangeable molding tool can mold either one part or several parts, depending on the size of each desired part. 
     One embodiment of an interchangeable molding tool that can be used with the present invention is a 3½ in. diameter tool. An alternate embodiment of an interchangeable molding tool that can also be used with the present invention is a rectangular 4½ by 5½ in. plate. The latter embodiment is larger and provides a larger surface area for the molding of either larger parts or an increasing number of smaller parts. Additionally, because of the larger surface area, the 4½ by 5½ in. molding tool provides a spicket that allows water to enter directly into the tool and an O Ring. This allows an even and uniform method of cooling the part. 
     The fixed side of the injection molding press apparatus  10 , shown in FIGS. 1A and 2, comprises a top clamp plate  12 , a manifold plate  14  and a fixed plate  16  having a fixed molding surface  600 , the fixed molding surface  600  having a plurality of fixed mold cavities  20  for insertion of each fixed tool side  210  of said interchangeable molding tools  200 , each fixed tool side  210  of said interchangeable molding tools having a size smaller than each fixed mold cavity  20  and each fixed mold cavity  20  having an outside fixed mold cavity perimeter  22 . 
     The ejector side of the present invention  100 , shown in FIGS. 1B and 3, comprises a plurality of movable plates, including a bottom clamp plate  110 , an ejector box assembly  120 , a first ejector support plate  130 , a second ejector support plate  140  and an ejector plate  150 , the ejector plate having an ejector molding surface  700 , the ejector molding surface  700  having a plurality of ejector mold cavities  142  for insertion of each ejector tool side  220  of said interchangeable molding tools  200 , each ejector tool side  220  having a size smaller than said ejector mold cavities  142  and each ejector mold cavity  142  having an outside ejector mold cavity perimeter  144 . 
     The removable runner distribution system comprises a plurality of interchangeable runner blocks  260  (shown in FIG.  3 ), each interchangeable runner block  260  having a sprue  262 , a fixed runner block side  264  (partially visible in FIG. 2) and an ejector runner block side  266 , a tool runner system, having a fixed tool runner side  272  (shown in FIG. 5) and an ejector tool runner side  274 . The fixed tool runner side  272  has one end located substantially adjacent to the fixed runner block side  264  and the ejector tool runner side  274  has one end located substantially adjacent to the ejector runner block side  266 . 
     In the illustrated embodiment, the means for allowing the simultaneous molding of different components comprises a baffling sorting apparatus. Because the illustrated embodiment comprises a baffle sorting apparatus, the illustrated embodiment shows a plurality of baffles  300  rigidly fixed and extending perpendicular to the fixed side  10  of the mold assembly and positioned between the fixed mold cavities  20 . Accordingly, as shown in FIG. 3, the ejector side of the illustrated embodiment comprises a plurality of slots  310  fashioned to slideably receive the baffles  300  when the fixed side  10  and the ejector side  12  are pressed together. Accordingly, due to the baffles  300  and slots  310 , shown in FIG. 2 and 3, both sides of the mold assembly comprise a plurality of equal sections  320 , each section  320  designed to receive a pair of uniform molding tools  200 . Both sides of the mold assembly  10 ,  100 , as illustrated in FIGS. 2 and 3, are designed to receive a pair of four sets of different molding tools  200 . Thus, the illustrated embodiment of the present invention is capable of simultaneously molding four different components. 
     As shown in FIGS. 3 and 4, within each section  320  of each side of the mold assembly, each interchangeable runner block system  260  is substantially centrally located between a pair of aligned interchangeable molding tools  200  (best shown in FIG.  3 ). The fixed runner block side  264  is centrally located between two fixed mold cavities  22  wherein the fixed runner block side  264  cooperates fluidly with each fixed tool runner side  272  once the fixed tools sides  210  are inserted into their respective fixed mold cavities  20 . The ejector runner block side  266  is centrally located between two ejector mold cavities  142  wherein the ejector runner block side  266  cooperates fluidly with each ejector tool runner side  274  once the ejector tool sides  220  are inserted into their respective ejector mold cavities  142 . Deterioration of either the fixed runner block side  264  or the ejector runner block side  266  can be easily replaced by simply removing either side and replacing it with another, thus eliminating the need to change the entire runner distribution system or mold assembly. 
     Additionally, a plurality of conventional removable runner inserts (not shown) can be used within both the fixed tool side  210  and the ejector tool side  220  of the interchangeable molding tools  200  to be replaced when using a highly abrasive molding material such as glass filled material. 
     The securing means for securing the interchangeable molding tools  200  to the mold assembly comprises a plurality of fixed keys (not shown) which releasably secure each fixed tool side  210  of the interchangeable molding tools  200  to the fixed side  10  of the mold assembly, the fixed molding surface  600  of the mold assembly having a plurality of fixed key holes  402  (shown in FIG. 2) located substantially adjacent to the outside fixed mold cavity perimeter  22  of each fixed mold cavity  20 , and a plurality of ejector keys (not shown) which releasably secure each ejector tool side  220  of each interchangeable molding tool  200  to the ejector side  100  of the mold assembly, the ejector molding surface  700  of the mold assembly having a plurality of ejector key holes  412  (show in FIG. 3) located substantially adjacent to the outside ejector mold cavity perimeter  144 . 
     The locking means for locking the mold assembly in a closed position when the molding material surfaces  600 ,  700  are pressed together to form the mold cavities,  22 ,  142  comprises a locking key apparatus. The locking key apparatus comprises an elongated locking bar enclosed within a locking channel bored into a mold base, the locking channel dimensioned to permit movement of the locking bar from a locked position to an unlocked position, one or more cavities within the mold base dimensioned to slideably receive one or more molds, one or more slots in the cavities which open to the locking channel, whereby when the locking bar is in a locked position, a portion of the locking bar protrudes through the slot into the mold cavity and is received by a bevel in the mold to secure the mold within the mold cavity, when the locking bar is in an unlocked position, the locking bar retracts within the slot and does not protrude through the slot to lock the mold in place. 
     In a preferred embodiment, the locking bar comprises two elongated cam shafts pivotally coupled in parallel orientation. The first cam shaft is coupled to the second cam shaft by one or more toothed hinges. The axis of the tooth hinges are offset from the axis of the first cam shaft. Rotation of the first cam shaft causes the second cam shaft to extend distal from the axis of the first cam shaft. Counterrotation of the first cam shaft causes the second cam shaft to retract towards the axis of the first cam shaft. In the unlocked position, the combined dimensions of both cam shafts is less than that of the locking channel. By rotating the first cam shaft to a locked position, the second cam shaft extends distal from the first cam shaft axis and protrudes through the slot into the mold cavity, thereby securing the mold by its bevel in a similar fashion as described above. By counterrotation of the first cam shaft, the second cam shaft recedes from the slot to unlock the mold from its cavity. 
     The rotation of the first cam shaft may be executed by hydraulic or pneumatic means whereby the linear movement of the hydraulic or pneumatic action is translated by an elongated geared arm coupled to annular gears within the mold apparatus. The linear movement of the geared arm rotates the annular gears, which radially turn the first cam shaft to an unlocked or locked position. 
     The means for injecting a molding material into the plurality of mold cavities is best shown in FIG.  4 . Once the molding surfaces are pressed together to form the mold cavities  22 ,  142 , the injection material is injected into the mold assembly for the molding of different components. The means for injecting a molding material into the mold assembly for forming a plurality of different components comprises the top clamp plate  12  of the fixed side of the mold assembly having a receiving inlet  30  for injection of the molding material by a conventional injection apparatus (not shown), an interior molding channel  32  for the travel of the molding material from the receiving inlet  30  into a conventional hot manifold system  34 , and then into an injection nozzle  36 , wherein the molding material once it is injected into the receiving inlet  30  travels through the injection channel  32  into the manifold system  34  through the injection nozzle  36  until the molding material is released by an injection exit nozzle  38  into the sprue  262  of the runner distribution system. Once the molding material is released by the injection exit nozzle  38  into the sprue  262  which is substantially centrally located within the fixed runner block side  264  and the ejector runner block side  266 , when the molding surfaces  600 ,  700  are pressed together, the molding material is distributed though the runner distribution system  250  to the fixed mold cavities  22  and the ejector mold cavities  142 , by way of the fixed runner block side  264  in conjunction with the fixed tool runner side  272 , and the ejector runner block side  266  in conjunction with the ejector tool runner side  274  . 
     The cooling means for cooling the different molded components once the molded material is injected into the mold assembly comprises a water jacket apparatus. 
     The means for simultaneously releasing the different molded components once the molding material has set comprises the use of a conventional ejection assembly that causes the simultaneous ejection of the different molded components. As shown in FIGS. 3 and 4, the ejector side  100  of the mold assembly comprises a conventional ejector box assembly  120  comprising a plurality of ejector rails  122 , an ejector box plate  124 , an ejector retainer plate  126 , and a push rod  128  substantially affixed to the ejector box plate  124  through the ejector retainer plate  126 . A hydraulic system (not shown) activates the ejector box plate  124  to move vertically upwards causing the ejector retainer plate  126  and hence the push rod  128  to vertically move upwards and abut the first ejector support plate  130  thereby pushing the tool pusher bar  232  into the ejector tool pusher bar retainer plate  224  and first tool back-up plate  226 , causing the ejector tool retainer plate  228  to move vertically upwards. As a result, the ejector pins  230 , which are substantially affixed to the ejector tool retainer plate  228 , move vertically upwards through the ejector tool side  220  of the interchangeable molding tool  200  to abut the different molded components, causing the different molded components to simultaneously eject outwards, releasing the different molded components from the ejector side  100  of the mold assembly. 
     As previously described, means for separating the different components once the different components have been simultaneously released comprises a baffle sorting apparatus. 
     Having described the invention in detail, those skilled in the art will appreciate that modifications may be made of the invention without departing from its spirit. Therefore, it is not intended that the scope of the invention be limited to the specific embodiment illustrated and described. Rather it is intended that the scope of the invention be determined by the appended claims and their equivalents.