Patent Application
20150028504
This disclosure relates to molding machines, and in particular relates to a system for rapidly and efficiently moving molds into and out of an injection mold machine.
It is known that injection molding processes involve a molding machine, plastic material, and a mold. Most molding machines have some basic structures that allow molds and plastic materials having common standards to be used interchangeably with the machines. One mold machine can accept hundreds of different molds that can be changed hourly, weekly or yearly depending on the need for production of varying parts made by different molds. A typical mold machine includes a frame that supports a fixed platen (which is a flat, firm, strong support surface) and a moving platen that moves within the frame toward the fixed platen. A mold is usually produced in two halves, with a cavity half of the mold secured to the fixed platen, and a core half of the mold secured to the moving platen. The mold machine applies great pressure in sliding the moving platen to force the two mold halves together. Molten plastic, or other moldable material, is then injected into the mold cavity, rapidly cooled, and then the moving platen is pulled away to separate the mold halves so that the cooled plastic part may be removed from the mold. This process is repeated automatically, and it is not uncommon for such mold machines to cycle production of many such parts in one mold having many mold cavities in cycle times of only a few seconds, or less.
After a predetermined number of such parts are produced, it typically becomes desirable to remove the mold from the mold machine and utilize another mold in the same mold machine. The most common way to remove and secure a particular mold in the machine is to use bolts and standard “L-shaped” clamps with a locating ring between the mold and the platens of the mold machine. Once the mold is situated in the machine typically a level is used on top of the mold to make sure the mold is installed level with respect to variability of fastening bolts, clamps, etc. This system while universal can be timely and therefore costly to work because of the alignment of the molds. Moreover, while installing the bolts, nuts and “L-shaped” clamps to secure edges of a mold to a platen, a worker needs access to both sides of the molding machine, which takes time, and gives rise to risk of injury to the worker.
Many efforts have been undertaken to simplify the process of replacing molds within mold machines. Some such molds, for example, those molds utilized in production of large components of automobiles, weigh thousands of pounds and require substantial effort and risk in securing the molds within, and removing the molds out of, a mold machine. For example, U.S. Pat. No. 5,096,404 that issued on Mar. 17, 1992 discloses a “quick mold change arrangement” that includes utilization of slide rails secured to a quick change plate that is affixed to a mold platen. While the guide rails assist lowering a very heavy mold into the machine, the mold nonetheless has to be fastened to the quick change plate with traditional fasteners that are located on both an operator side and a back side of the mold machine. Another “quick change system for mold bases” is disclosed in U.S. Pat. No. 5,562,935 that issued on Oct. 8, 1996. This patent teaches a U-shaped clamp plate that is secured to an adapter plate that includes guide rails and a stop member into which ear plates attached to each half of the mold slide to position the mold within the machine in a correct alignment. After such positioning, however, traditional threaded clamp fasteners are used on both sides of the mold machine to rigidly affix the mold within the machine.
More recently, a “quick mold change clamping plate and support brackets” type of invention was disclosed in U.S. Pat. No. 6,814,560 that issued on Nov. 9, 2004. This Patent teaches use of “double wedges” attached between a clamp plate and a mold, wherein the double wedges are located on opposed sides of the mold. After this system quickly locates correct positioning and alignment of the mold half within the machine, traditional threaded fasteners and “L-shaped” brackets secure the mold to the platen of the mold machine. Similar quick mold change apparatus now also utilize hydraulic clamps that may be variably positioned within elongate slots on clamping plates to hydraulically clamp a mold to the plate until permanent mechanical locks secure the mold to the clamp plate. Such a system is available from the PFA Incorporated company of Germantown, Wis., U.S.A., under the brand name “HYDRA-JAWS Quick Mold Change”. Like the previously described disclosures, however, the “HYDRA JAWS” requires an operator to access the clamp plate from both sides of the mold machine, and to utilize traditional mechanical fasteners after the hydraulic clamps position the mold on the clamp plate.
Other known systems currently on the market use, for example, a bayonet apparatus with a male section on the mold and a female ring plate that is installed in the mold machine. A drawback of this system is a limited load that the bayonet can handle and a substantial expense of manufacturing and maintaining the bayonet apparatus. Additionally, it is common that a first party may own the mold, while a second party is the owner of the mold machine and molding business. Therefore, for economic reasons, many molds are transferred from one molding company to another. Consequently, any mold retention features must be efficiently removable from the mold. Hence, the bayonet apparatus has met with only limited success due to its complexity, cost, and load limitations.
Accordingly there is a need for a system to facilitate more efficient installation and setup of a mold in a mold machine.
The disclosure is a system to significantly reduce the time and labor to change molds in a molding machine. The quick change mold system includes a mold that defines a mating surface configured to secure the mating surface to a platen surface of a mold machine. At least one lock pin extends away from the mating surface of the mold, and the lock pin defines an elongate body having a reduced-diameter lock valley in the body. The lock pin also includes a lock head at an end of the lock pin farthest from the mating surface of the mold. The lock head has a longest diameter greater than a longest diameter of the reduced-diameter lock valley. (The phrase “longest diameter” is defined herein to mean a longest straight line across the lock head or across the lock valley, wherein the diameter is parallel to a plane perpendicular to a longitudinal axis of the lock pin. Therefore, the “longest diameter” includes cylindrical and non-cylindrical lock pins, such a rectangular, or octagonal, etc. lock pins.)
The system also includes a coupling plate secured to and adjacent at least one of the platen surfaces of the mold machine, wherein the coupling plate has a front surface and an opposed back surface. The front surface of the coupling plate is configured for engaging and securing the mating surface of the mold to be adjacent the front surface of the coupling plate. The coupling plate defines at least one throughbore dimensioned to permit the lock pin to pass into the throughbore within the coupling plate.
Additionally, the system includes a clamping mechanism that is affixed to the coupling plate. The clamping mechanism includes a bar defining at least one “butternut-squash shaped” key-slot configured so that the key-slot is adjacent the throughbore of the coupling plate. The key-slot includes a wide-opening portion having an adequate diameter to permit the lock head of the lock pin to pass through the wide-opening portion. Adjacent and contiguous with the wide-opening portion is a narrow-opening portion of the key-slot that is configured to permit the narrow-opening portion to slide within the valley defined by the reduced-diameter lock valley of the pin. When the bar moves to position the narrow-opening portion of the key-slot within the valley of the reduced-diameter section of the lock pin, the lock pin is prohibited from movement of the lock head of the pin in a direction away from the front surface of the coupling plate through the narrow-opening portion of the key-slot in the clamping mechanism bar. The clamping mechanism bar is slidably engaged with the coupling plate so that the bar may selectively slide between a receiving position that permits the lock head of the lock pin to pass through the coupling plate throughbore and into the key-slot, and a locking position wherein the bar and key-slot defined within the bar slides to engage the reduced-diameter lock valley in the narrow-opening portion of the key-slot. In the locking position, the lock pin and mold cannot move in a direction away from the front surface of the coupling plate.
The bar of the clamping mechanism may be positioned between the receiving position and the locking position by movement of a handle secured to the bar and extending beyond an exterior perimeter of the coupling plate. A major benefit of the quick change mold system clamping mechanism is that the handle may be moved between positions by an operator accessing the handle from only one side of the mold machine. For purposes of explanation, the coupling plate will therefore be defined to have an operator side and an opposed back side, and the handle extends beyond an exterior perimeter of the operator side of the coupling plate.
The bar of the clamping mechanism may include a plurality of key-slots that are constructed to receive a corresponding plurality of lock pins passing through a corresponding plurality of throughbores defined within the coupling plate. In an embodiment of the present disclosure, the bar of the clamping mechanism may be a circular bar that defines a plurality of key-slots. A handle extends from the circular bar beyond the perimeter of the operator side of the coupling plate so that an operator may move the handle up and down to position the clamping mechanism between the receiving and locking positions. Additionally, the back surface of the coupling plate may define a circular groove dimensioned to receive the bar so that the bar is flush-mounted with the back surface of the coupling plate. Alternatively, the bar may be secured within cooperatively defined passageways within the coupling plate, such as where the coupling plate is formed of two halves, with the passageways for receiving the bar defined in one or both halves, so that the bar is slidably secured within the passageway when the two halves of the coupling plate are joined together.
The bar of the clamping mechanism may also take any form that permits the bar to slidably engage the key-slot with the lock pin as described above. For example, instead of a circular bar, the bar may take the form of a sideways “n” wherein two parallel bars are slidably secured to the coupling plate, and a handle is secured to the bar and extends beyond the operator side perimeter of the coupling plate to move the bar between the locking and receiving positions.
By selectively sliding or activating the clamping mechanism, the mold can very quickly be either captured or released by the mold machine having the coupling plate and clamping mechanism. Activating the clamping mechanism may also work to disengage or engage heating and/or cooling connections, electrical and/or control connections and any information system interface passing from the mold machine into the mold.
Preferably, the lock pin of the system is a pin wherein the reduced-diameter lock valley defined in the pin cuts into approximately 20% of the outer surface of the lock pin forming the reduced-diameter lock valley. The lock pin may be secured to the mold through a standard threaded bolt hole with treads on a mold end of the lock pin, or through a flanged head with a retaining plate, etc. Alternatively, threads may be machined on the end of the lock pin in a manner similar to a standard “shoulder bolt” and then attached to mold. The lock pin optimally protrudes out from the mating surface of the mold a distance that is approximately one hundred percent of the longest diameter of the pin. In other words, a lock pin having a 1″ (one inch) diameter would protrude 1″ from the mating surface of the mold. The coupling plate may also include one or more mounting holes to attach the plate to the platen surface of the mold machine. The coupling plate may also define holes for water lines and passageways for wiring, etc.
Accordingly, it is a general purpose of the present disclosure to provide a quick change mold system that overcomes deficiencies of the prior art.
It is a more specific purpose of the present disclosure to provide quick change mold system that reduces time and effort necessary to change molds and that also enables securing and removing molds from mold machines while accessing the molds from only an operator side of the mold machine. These and other purposes and values of the present disclosure will become apparent in the following detailed description and the accompanying drawings.
Referring to the drawings in detail, the present quick change mold system is shown in
The system 10 also includes a coupling plate 28 secured to and adjacent at least one platen surface 16 of the mold machine 30 (shown in
Additionally, the system 10 includes a clamping mechanism 38 shown best in
The bar 40 of the clamping mechanism 38 is slidably engaged with the coupling plate 28. This means that the bar 40 may selectively slide between a receiving position that permits the lock head 24 of the lock pin 18 to pass through the coupling plate 28 throughbore 36A and into the wide-opening portion 44 of the adjacent key-slot 42D. The slidable bar 40 may then be moved by an operator (not shown) into a locking position wherein the bar 40 and the key-slot 42D defined within the bar 40 slides to engage the reduced-diameter lock valley 22 in the narrow-opening portion 46 of the key-slot 42D. In the locking position, the lock pin 18 and mold 12 secured to the lock pin 18 cannot move in a direction away from the front surface 32 of the coupling plate 28.
The bar 40 of the clamping mechanism 38 may be moved between the described receiving and locking positions by movement of a handle 48 secured to the bar 40 and extending beyond an exterior perimeter 50 of the coupling plate 28. As described above, a major benefit of the quick change mold system 10 clamping mechanism 38 is that the handle 48 may be moved between the receiving and locking positions by an operator (not shown) accessing the handle 48 from only one side of the quick mold change system 10. As shown in
In an embodiment of the present disclosure, the bar 40 of the clamping mechanism 38 may be a circular bar 40 that defines the plurality of key-slots 42A, 42B, 42C, 42D. Additionally, the back surface 34 of the coupling plate 28 may define a circular groove 56 surrounding a central ring 57 of the back surface 34. The circular groove 56 is dimensioned to receive the bar 40 so that the bar is flush-mounted with the back surface 34 of the coupling plate 28. Being “flush-mounted” means that the back surface 34 of the coupling plate 28 and an outer surface 58 of the bar 40 are co-planar. This facilitates assembly of the system 10 adjacent the planar platen surface 16. Prior to securing the coupling plate 28 to the platen surface 16, the bar 40 may be retained within the coupling plate 28 by any retaining means for securing the bar 40 within the plate 28 while permitting the bar 40 to be slidably secured adjacent or within the plate 28. For example and as shown in
Alternatively, the bar 40 may be secured within cooperatively defined passageways (not shown) within the coupling plate 28, such as where the coupling plate 28 is formed of two halves (not shown), with the passageways for receiving the bar 40 defined in one or both halves, so that the bar is slidably secured within the passageway when the two halves of the coupling plate 28 are joined together. As described above, in alternative embodiments, the bar 40 may be one or more straight bars (not shown) slidably secured within the coupling plate 28, and defining similar key-slots to engage lock pins 18. In other words, the disclosure is not limited to the efficient circular bar 40 shown in
As best shown in
By selectively sliding or activating the clamping mechanism 38, the mold can very quickly be either captured or released by the mold machine 30 having the coupling plate 28 and clamping mechanism 38. Activating the clamping mechanism may also work to disengage or engage heating and/or cooling connections, electrical and/or control connections and any information system interface passing from the mold machine 30 through the coupling plate 28 and into the mold 12.
Preferably, the lock pin 18 of the system 10 is a pin 18 wherein the reduced-diameter lock valley 22 defined in the pin 18 encircles the pin 18 and cuts into approximately 20% of a diameter of the body 20 of the lock pin 18 to thereby form the reduced-diameter lock valley 22. The lock pin 18 may be secured to the mating surface 14 the mold 12 through standard fastening means, such as threaded bolts and corresponding holes, etc. on a mating surface end 26 of the lock pin 18, or through a flanged head with a retaining plate (not shown), etc. The lock pin 18 optimally protrudes out from the mating surface 14 of the mold 12 a distance that is at least approximately one hundred percent of the longest diameter of the pin 18. In other words, a lock pin having a one inch diameter would protrude at least one inch from the mating surface 14 of the mold 12. Also, the quick change mold system 10 may include a handle-lock (not shown) for securing the handle 48 in a locked position while the mold 12 is secured within the mold machine 30.
The present disclosure also includes methods of using the quick change mold system 10 to efficiently secure a mold 12 or mold-half 12 to, and remove the mold 12 or mold-half from the mold machine 30. The method of using the quick change mold system 10 includes positioning the bar 40 of the clamping mechanism 38 in a receiving position so that the lock head 24 of at least one lock pin 18 passes through a throughbore in the coupling plate 28 and then passes through the wide-opening portion 44 of the key-slot 42D defined within the bar 40. Then, the bar 40 is positioned in the locking position wherein the narrow-opening portion 46 of the key-slot 42D engages the lock valley 22 of the lock pin 18 to thereby prevent the lock pin 18 and the mold 12 secured to the lock pin 18 from moving in a direction away from the coupling plate 28, and from moving in any direction. The method also includes removing the mold 12 from the mold machine 30 by positioning the bar 40 back in the receiving position so that the wide-opening portion 44 of the key-slot 42D is moved to surround the lock valley 22 and lock head 24 of the lock pin 18. Then, the mold 12 can simply be pulled away from the coupling plate 28 so that the at least one lock pin 18 passes out of the key-slot 42D and adjacent throughbore 36A of the coupling plate 28 to thereby release the mold 12 from the molding machine 30.
While the present disclosure has been presented above with respect to the described and illustrated embodiments of quick change mold system, it is to be understood that the disclosure is not to be limited to those alternatives and described embodiments. For example, while a traditional “molding machine” is an plastic injection molding machine, it is to be understood that the present disclosure is to include any machine that secures a mold 12 within the machine. Additionally, optimal use of the quick change mold system 10 would be that both a stationary platen surface 16 and a movable plate surface (not shown) would include quick change mold systems 10. In other words, a cavity half of the mold 12 would be secured to the stationary platen surface 16 by the quick change mold system 10, as described above. And within the same molding machine 30, a core half (not shown) of the mold would be secured by a second and virtually identical quick change mold system (not shown) to the moving platen surface (not shown) that moves the core half of the mold into contact with the cavity half of the mold 12, in a manner known in the art. Accordingly, reference should be made primarily to the following claims rather than the forgoing description to determine the scope of the disclosure.
This Application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/636,145 that was filed on Apr. 20, 2012 entitled “QUICK CHANGE MOLD SYSTEM”.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US13/36277 | 4/12/2013 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 61636145 | Apr 2012 | US |
