Mold locking assembly

A mold locking assembly includes a mold set with a first mold and a second mold adjacent the first mold, a catch plate rigidly attached to the first mold, and a base plate rigidly attached to the second mold. The base plate includes a pair of posts spaced apart from each other and extending from a base portion of the base plate in a normal direction. An L-shaped latch arm pivotally attached to the pair of posts is included and the L-shaped latch arm is configured to engage the catch plate and hold the first mold adjacent to the second mold.

TECHNICAL FIELD

The present disclosure relates to locking assemblies, and particularly to locking assemblies for molds used during injection molding.

BACKGROUND

An injection molding machine provides high-volume manufacturing of parts by rapidly injecting molten plastic resin into a mold cavity formed between at least two molds (a mold set), cooling the injected molten plastic resin to form a solid part, and ejecting the solid part from between the mold set. In addition, after a production run of injection molding a given part is completed, the mold set is replaced with another mold set such that a production run of injection molding a different part can begin. However, replacement or changing of mold sets takes time and decreases the overall efficiency of the injection molding machine.

The present disclosure addresses issues related to the replacing or changing a mold set of an injection molding machine and other issues related to injection molding.

SUMMARY

In one form of the present disclosure, a mold locking assembly a catch plate rigidly attached to a first mold of a mold assembly (mold set), a base plate rigidly attached to a second mold of the mold set, and an L-shaped latch arm pivotally attached to the base plate such that the L-shaped latch arm engages the catch plate and holds the first mold adjacent to the second mold.

In another form of the present disclosure, a mold locking assembly a catch plate rigidly attached to a first mold of a mold set, a base plate rigidly attached to a second mold, and an L-shaped latch arm pivotally attached to the base plate and configured to engage the catch plate and hold the first mold adjacent to the second mold. In some variations, a pneumatic actuator with an actuator piston is included and the pneumatic actuator is rigidly attached to the base plate and configured to engage and move the L-shaped latch arm between a locked position and an unlocked position.

In still another form of the present disclosure, a mold locking assembly includes a mold set with a first mold and a second mold adjacent the first mold, a catch plate rigidly attached to the first mold, and a base plate rigidly attached to the second mold. The base plate includes a pair of posts spaced apart from each other and extending from a base portion of the base plate in a normal direction. An L-shaped latch arm pivotally attached to the pair of posts is included and the L-shaped latch arm is configured to engage the catch plate and hold the first mold adjacent to the second mold. In some variations, an actuator mounting plate with an actuator access aperture is included and rigidly attached to the pair of posts, and in such variations a pneumatic actuator with an actuator piston can be included and be rigidly attached to an outward facing surface of the actuator mounting plate. And the pneumatic actuator is configured to engage and move the L-shaped latch arm between a locked position and an unlocked position.

Further areas of applicability and various methods of enhancing the above technology will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

It should be noted that the figures set forth herein are intended to exemplify the general characteristics of the methods, devices, and systems among those of the present technology, for the purpose of the description of certain aspects. The figures may not precisely reflect the characteristics of any given aspect and are not necessarily intended to define or limit specific forms or variations within the scope of this technology.

DETAILED DESCRIPTION

The present disclosure provides a mold locking assembly for use during changing mold sets of injection molding machine. Stated differently, the mold locking assembly locks or securely attaches two molds of a mold set to each other before the molds are removed from and/or installed in an injection molding machine. As used herein, the phrase “mold set” refers to a mold assembly with at least two molds that when used or installed in an injection molding machine, define a cavity (also known as a “mold cavity”) into which molten thermoplastic material is injected in order to form a part with a shape complimentary to a shape of the cavity.

The mold locking assembly includes a catch plate that rigidly attaches to a first mold of a mold set, a base plate that rigidly attaches to a second mold of the mold set, and an L-shaped latch arm that engages the catch plate and holds or locks the first mold adjacent to and/or against the second mold. The L-shaped latch arm is pivotally attached to the baseplate, and in some variations, a pneumatic actuator rigidly attached to the base plate and configured to engage the L-shaped latch arm is included.

Referring toFIGS.1A-1B, one non-limiting example of an injection molding machine10is shown. The injection molding machine10includes an injection system120and a clamping system160. Thermoplastic pellets122are introduced or fed into the injection system120via a hopper124, which feeds the thermoplastic pellets122into a heated barrel126. The thermoplastic pellets122, after being fed into the heated barrel126, progress towards a nozzle132at the end of the heated barrel126by rotation of a reciprocating screw128, and heat from the heated barrel126and compression by the reciprocating screw128melt the thermoplastic pellets122to form a molten thermoplastic material130.

An injection molding cycle to produce a part includes forcing the molten thermoplastic material130toward the nozzle132(material using the reciprocating screw128) to form a “shot” of the molten thermoplastic material130, and injecting the shot of molten thermoplastic material130through the nozzle132and into a mold cavity134(FIG.1A) between a first mold135and a second mold137of a mold set136. The molten thermoplastic material130is held together under pressure by a press or clamping unit140, takes the form (shape) of the mold cavity134, and cools to form a solid part. The press or clamping unit140then releases the mold set136, the first and second molds135,137are separated from one another (FIG.1B), and the part is ejected from the mold set136such that the injection molding cycle can begin again and another part can be formed.

After a desired number of parts are formed or manufactured with the mold set136, i.e., a production run is completed, the mold set136is removed and replaced with a different mold set for another production run to manufacture a different part (i.e., a part with a different shape). In addition, and given that typical cycle times for injection molding of parts range between about 2 seconds to about 2 minutes, time required to change a mold set results in a production loss of hundreds if not thousands of parts. Accordingly, reducing the time to exchange a mold set with another mold set is desirable.

Referring now toFIGS.2A-2B, a perspective view of a mold locking assembly20to enhance exchanging a mold set with another mold set according to one form of the present disclosure is shown inFIG.2Aand an exploded view ofFIG.2Ais shown inFIG.2B. The mold locking assembly20includes a catch plate200, a base plate210, and a latch arm220. The catch plate200includes a catch surface202and may or may not include a chamfer surface204that can cooperate with another chamfer surface222on the latch arm220as described below. In some variations, the catch plate200includes one or more apertures206that allow or provide one or more threaded fasteners208to extend therethrough such that the catch plate200can be rigidly attached to a mold (e.g., mold135) via the one or more threaded fasteners208. Accordingly, the catch plate200is configured to be rigidly attached to a mold.

The base plate210is configured to be rigidly attached to another mold. For example, in some variations the base plate210includes one or more apertures212that allow or provide one or more threaded fasteners214to extend therethrough such that the base plate210can be rigidly attached to a mold (e.g., mold137) via the one or more threaded fasteners214. And whileFIGS.2A-2Billustrate the catch plate200and the base plate210rigidly attached to the molds135,137, respectively, using the threaded fasteners208,214, respectively, in some variations, the catch plate200and/or the base plate210are rigidly attached to a respective mold with a different attachment or bonding technique, e.g., via welding, among others.

The base plate210also includes a pivot axis ‘A’ for the latch arm220to pivot about. For example, in some variations, the base plate210includes one or more posts216extending from a base member215and the one or more post216include an aperture217extending therethrough. And in such variations, a threaded fastener218(also referred to herein as a “pivot shaft”) can be coaxial with the pivot axis A and extend parallel to the base member215, pivotally attach the latch arm220to the base plate210, and the latch arm220can pivot about the pivot axis ‘A’ of the base plate210.

The latch arm220includes an elongated portion224extending between a proximal end223and a distal end225. The elongated portion224has a length dimension that is greater than a width dimension (y-direction shown inFIGS.2A-2B) and/or a thickness dimension (generally the z-direction shown inFIGS.2A-2B) of the latch arm220. An aperture228extending transversely (y-direction) through the elongated portion224can be included and the threaded fastener218or an unthreaded shaft or pin (not shown) can cooperate with the aperture228and the one or more apertures217extending through the one or more posts216to pivotally attach the latch arm220to the base plate210. In some variations, the latch arm220is an L-shaped latch arm with a head226extending from the elongated portion224as illustrated in the figures. And in such variations, the head226can include the chamfer surface222that assists in the distal end225of the latch arm220sliding over the catch plate200as the molds135and137are moved towards and adjacent to each other (+/−x-directions) and a headed aperture226athat accepts and threadingly engages a set screw226b. For example, in variations where the catch plate includes the chamfer surface204, and when the molds135and137move towards each other and into a closed position, the chamfer surface222of the latch arm220comes into contact with and slides over the chamfer surface204of the catch plate200as the latch arm220pivots upwardly (+Z direction). And as the molds135and137continue to move closer to each other, a catch surface229of the latch arm220moves beyond or past (−z direction) the catch surface202, the latch arm220pivots downwardly (−z direction), and the catch surface229engages the catch surface202of the catch plate200such that the mold locking assembly20is in a locked position and the molds135,137are securely locked to each other. In addition, the set screw226bcan be screwed into the threaded aperture226aand engage the catch surface202such that the latch arm220is securely held or positioned in the locked position.

Still referring toFIGS.2A-2B, in some variations the mold locking assembly20includes an actuator230, e.g., a pneumatic actuator or a hydraulic actuator, among others, with a fluid (e.g., air) supply line236. And in such variations, the actuator230can be rigidly attached to the base plate210. For example, in at least one variation the mold locking assembly20includes an actuator mounting plate240with one or more apertures242and an actuator access aperture245. The one or more apertures242provide for one or more threaded fasteners244to extend therethrough and rigidly attach the actuator mounting plate240to the one or more posts216by engaging with threaded apertures219. That is, the threaded fasteners244screw into the threaded apertures219such that the actuator mounting plate240is securely mounted to the posts216. In addition, the actuator230can include one or more apertures232that allow for one or more threaded fasteners234to engage one or more threaded apertures246in the actuator mounting plate240such that the actuator230is rigidly attached thereto. Accordingly, the actuator230can be rigidly attached to the base plate210through or by the rigid attachment of the actuator mounting plate240to the base plate210as illustrated inFIG.2A. In addition, the proximal end223can be proximal to an inward facing (−z direction) surface of the actuator mounting plate240and the actuator230can be rigidly attached to an outward facing (+2 direction) surface of the actuator mounting plate240. And in some variations, the actuator mounting plate240includes a latch arm slot248that allows or provides additional pivoting movement of the latch arm220in the upward direction (+z direction) shown inFIGS.2A-2B.

Referring toFIGS.1A-1B and3A-3F, illustration of the mold locking assembly20during operation of the injection molding machine10is shown. Particularly,FIG.3Aillustrates the mold set136with molds135,137before installation and/or during installation into the injection molding machine10(injection molding machine10not shown inFIGS.3A-3F). The molds135,137are locked together with a pair of mold locking assemblies20in the locked position such that the distal end225of the latch arm220is engaged with the catch plate200, i.e., the catch surface229is engaged with the catch surface202(FIG.2B). In some variations, the set screw226b, in cooperation with the threaded aperture226a(FIG.2B), is engaged with the catch surface202of the catch plate200such that the latch arm220is secured in the locked position. Accordingly, the molds135,137are securely locked to each other such that the mold set136can be securely installed into the injection molding machine10in a time efficient manner. In addition, and with the mold locking assemblies20positioned on outer surfaces of the molds135,137, whether or not the mold locking assemblies20are in the locked position can be visually (and easily) determined by an operator/individual before and/or during installation of the mold set136.

Referring particularly toFIG.3B, the mold set136is installed in the injection molding machine10, the pair of mold locking assemblies20are in the unlocked position, and molten thermoplastic material130is or has been injected into the mold cavity134while the molds135,137are held together with pressure from the press or clamping unit140. For example, and in variations where the mold locking assemblies20include the actuator230, the actuator230includes an actuating piston238that extends through the actuator access aperture245and engages the proximal end223of the latch arm220such that the latch arm220pivots about the A axis of the base plate210(FIG.2B) and the latch arm220disengages from the catch plate200. And in variations where the mold locking assemblies20include the threaded aperture226aand set screw226b, the set screw226bis disengaged from the catch surfaces202before actuating the actuator230and pivoting the latch arm220about the A axis.

Referring particularly toFIG.3C, the pair of mold locking assemblies20are in the unlocked position, the molds135,137are spatially separated from each other, and a part ‘P’ formed from and by solidification of the molten thermoplastic material130is being ejected from the mold set136and the injection molding machine10.

It should be understood that the molds135,137are subsequently moved back into the position shown inFIG.3Band another part P is formed by injection of additional molten thermoplastic material130into the mold cavity134, cooling, and ejection from the mold set136(FIG.3C). It should also be understood that this cycle (i.e.,FIG.3B—FIG.3C—FIG.3B) continues until a desired number of parts P are injection molded and formed, i.e., until the given production run is complete. Then, the molds135,137are locked together (FIG.3A) and removed from the injection molding machine10. Accordingly, the mold locking assemblies20provide for secure and easily verifiable locking of the molds135,137to each other before installation, during installation, and during removal of the mold set136from the injection molding machine10.

Referring particularly toFIG.3D, another mold set136awith molds135a,137ais locked together with another pair of mold locking assemblies20in preparation for replacement of or exchange with the mold set136. In some variations, the set screw226b, in cooperation with the threaded aperture226a(FIG.2B), is engaged with the catch surface202of the catch plate200such that the latch arm220is secured in the locked position. And after the mold set136is removed from the injection molding machine10, the mold set136ais installed.

Referring particularly toFIG.3E, the mold set136ais installed in the injection molding machine10, the pair of mold locking assemblies20are in the unlocked position, and molten thermoplastic material130is or has been injected into the mold cavity134awhile the molds135a,137aare held together with pressure from the press or clamping unit140. For example, and in variations where the mold locking assemblies include the actuator230, the actuator230includes an actuating piston238that engages the proximal end223of the latch arm220such that the latch arm220pivots about the A axis of the base plate210(FIG.2B) and the latch arm220disengages from the catch plate200. And in variations where the mold locking assemblies20include the threaded aperture226aand set screw226b, the set screw226bis disengaged from the catch surfaces202before actuating the actuator230and pivoting the latch arm220about the A axis.

Referring particularly toFIG.3F, the pair of mold locking assemblies20are in the unlocked position, the molds135a,137aare spatially separated from each other, and another part ‘Pa’ formed from and by solidification of the molten thermoplastic material130is being ejected from the mold set136aand the injection molding machine10.

It should be understood that the molds135a,137aare subsequently moved back into the position shown inFIG.3Eand another part Pa is formed by injection of additional molten thermoplastic material130into the mold cavity134a, cooling, and ejection from the mold set136a(FIG.3F). It should also be understood that this cycle (i.e.,FIG.3E-FIG.3F-FIG.3E) continues until a desired number of parts Pa are injection molded and formed, i.e., until the given production run is complete. Then, the molds135a,137aare locked together (FIG.3D) and removed from the injection molding machine10such that the mold set136and/or still another mold set can be installed in the injection molding machine10and another production run can begin.

Referring now toFIG.4, a flow chart for a method30for manufacturing different or distinct parts (i.e., parts having different shapes) using an injection molding machine with the mold locking assemblies according to the teachings of the present disclosure is shown. The method30includes installing an Nth mold set (e.g., a first mold set, i.e., N=1) in the injection molding machine at300. The Nth mold set includes at least two molds locked together during installation using two or more mold locking assemblies as described above. After the Nth mold set is installed in the injection molding machine, the two or more mold locking assemblies are unlocked at310, i.e., the two mold locking assemblies are placed in the unlocked position such that the at least two molds are operable to move towards and away from each other as dictated or commanded by the injection molding machine. The method30proceeds to320where the injection molding machine manufactures a desired number of parts having a shape complimentary with a mold cavity between the at least two or molds, i.e., a production run is completed, and then the two or more molds of the Nth mold set are locked together using the two or more mold locking assemblies at330. The Nth mold set is removed from the injection molding machine at340, and the method30determines whether or not another production run for a different part using the same injection molding machine is desired at350. If another production run is desired, the method30updates N (e.g., N is updated from 1 to 2) and returns to300to install an Nth mold set (e.g., where N=2), unlock the Nth mold set at310, execute and complete the production run at330, and removes the Nth mold set at340. This cycle (i.e.,300-310-320-330-340-350-300) continues until another production run is not desired, and the method stops at370.

The preceding description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or its uses. Work of the presently named inventors, to the extent it may be described in the background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present technology.

The systems, components, devices, processes, and/or controllers described above can be realized in hardware or a combination of hardware and software and can be realized in a centralized fashion in one processing system or in a distributed fashion where different elements are spread across several interconnected processing systems. Any kind of processing system or another apparatus adapted for conducting the methods described herein is suited. A typical combination of hardware and software can be a processing system with computer-usable program code that, when being loaded and executed, controls the processing system such that it conducts the methods described herein. The systems, components and/or processes also can be embedded in a computer-readable storage, such as a computer program product or other data programs storage device, readable by a machine, tangibly embodying a program of instructions executable by the machine to perform methods and processes described herein. These elements also can be embedded in an application product which comprises all the features enabling the implementation of the methods described herein and, which when loaded in a processing system, is able to conduct these methods.

The headings (such as “Background” and “Summary”) and sub-headings used herein are intended only for the general organization of topics within the present disclosure and are not intended to limit the disclosure of the technology or any aspect thereof. The recitation of multiple variations or forms having stated features is not intended to exclude other variations or forms having additional features, or other variations or forms incorporating different combinations of the stated features.

As used herein the term “about” when related to numerical values herein refers to known commercial and/or experimental measurement variations or tolerances for the referenced quantity. In some variations, such known commercial and/or experimental measurement tolerances are +/−10% of the measured value, while in other variations such known commercial and/or experimental measurement tolerances are +/−5% of the measured value, while in still other variations such known commercial and/or experimental measurement tolerances are +/−2.5% of the measured value. And in at least one variation, such known commercial and/or experimental measurement tolerances are +/−1% of the measured value.

As used herein, the terms “comprise” and “include” and their variants are intended to be non-limiting, such that recitation of items in succession or a list is not to the exclusion of other like items that may also be useful in the devices and methods of this technology. Similarly, the terms “can” and “may” and their variants are intended to be non-limiting, such that recitation that a form or variation can or may comprise certain elements or features does not exclude other forms or variations of the present technology that do not contain those elements or features.

The broad teachings of the present disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the specification and the following claims. Reference herein to one variation, or various variations means that a particular feature, structure, or characteristic described in connection with a form or variation or particular system is included in at least one variation or form. The appearances of the phrase “in one variation” (or variations thereof) are not necessarily referring to the same variation or form. It should also be understood that the various method steps discussed herein do not have to be conducted in the same order as depicted, and not cach method step is required in each variation or form.

The foregoing description of the forms and variations has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular form or variation are generally not limited to that particular form or variation, but, where applicable, are interchangeable and can be used in a selected form or variation, even if not specifically shown or described. The same may also be varied in many ways. Such variations should not be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.