BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view of a device for forming a blow-molded article according to an exemplary embodiment of the present invention.
FIG. 1B is a cutaway view of the device for forming a blow-molded article shown in FIG. 1A.
FIG. 2A is a perspective view of a blow-molded article formed using the device shown in FIG. 1.
FIG. 2B is another perspective view of the blow-molded article shown in FIG. 2A.
FIG. 3A is a cutaway view of the device for forming a blow-molded article shown in FIG. 1.
FIG. 3B is another cutaway view of the device for forming a blow-molded article shown in FIG. 1.
FIG. 4 illustrates an exemplary method of forming a blow-molded article according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1A shows a device 100 according to an exemplary embodiment of the present invention. The device 100, e.g., dynamic device, provides a means to create blow-molded articles, or portions thereof, having features not obtainable using static mold components. For example, the device 100 may be used for creating latch features on a case or panel assembly which are not aligned with the direction of the mold open/close. The device 100 may also used for any other complex features which are not aligned with the direction in which the article is ejected or extracted from its mold. The device 100 may be connected to or incorporated in a mold or mold assembly for manufacturing a blow-molded article or panel thereof. In some embodiments, the device 100 is a complete mold assembly and includes all mold surfaces necessary to form the blow-molded article or panel.
The exemplary device 100 includes a housing 102 manufactured from any suitable material, such as steel. The device 100 further includes a mold surface 104 including any number of elements for forming the blow-molded article and particular features thereon. The device 100 includes at least one movable insert 110 for forming a feature, such as a latch, on a blow-molded article. The insert 110 is movable from a first position to one or more second positions. In the present embodiment, the insert 110 is movable via a hydraulic cylinder 106. As explained in more detail below, the insert 110 may be moved to an extended position during a blow-molding process and moved to a retracted position to enable extraction or ejection of the blow-molded article from the device 100 and/or mold assembly. The device 100 may further include one or more packers 120 to push the plastic during the molding process and prevent blowouts or the development of weak spots in the article.
FIG. 1B shows a cutaway view of the device 100. The exemplary device 100 includes the hydraulic cylinder 106 for actuating a stroke arm 112 via a rod 108 (e.g., ½″ rod). The rod 108 may include any number of bushings as necessary. The rod 108 may be connected to the stroke arm 112 via one or more screws 114 (e.g., a 5/16-24 panhead socket head cap screw). The stroke arm 112 is connected to the insert 110, either removably or fixedly. In some embodiments, the insert 110 is removably connected to enable easy replacement of the insert 110, e.g., for manufacturing different types of blow-molded articles and features.
FIGS. 2A and 2B shown one exemplary blow-molded article 200 which may be manufactured using the device 100. The exemplary article 200 is a chest comprising a plurality of blow-molded panels, e.g., panels 202/204. The article 200 includes two latch attachments 210/212 for receiving latch mechanisms, such as metal toggle latches, or any other latch mechanisms for securing the chest. The latch attachments 210/212, also shown in FIG. 2B, may include one or more recessed portions (e.g., undercuts) or features 220. As one of the ordinary skill in the art will understand, the recessed feature 220, and/or surfaces thereof, is not aligned with the direction by which the panel 204 would normally be extracted from its mold. In the present example, the feature 220 is substantially perpendicular, or at least non-parallel, to the direction of extraction.
FIGS. 3A and 3B show cutaway views of the device 100 and a portion of the blow-molded article 200. In operation, the insert 110 of the device 100 is maintained or moved to an extended position, e.g., by actuating the cylinder 106. A molten plastic parison is then inflated (e.g., with air or fluid pressure) inside a mold assembly and against the surface 104 of the device 100. The parison is conformed to the surface 104, and/or other surfaces of the mold assembly, to form a blow-molded article or a panel of a blow-molded article. As shown, the insert 110 extends in a direction substantially parallel to the surface 104. After the molten plastic is cooled below the plastic softening point, the insert 110 is moved to a retracted position to enable extraction or ejection of the blow-molded article as shown in FIG. 3B. The blow-molded article may then be ejected with the desired feature. In the present example, a latch attachment feature 210/212 is provided.
FIG. 4 shows an exemplary method of forming a latch mechanism on a blow-molded article employable by the device 100 and/or insert 110. The method includes providing a mold assembly including at least one insert movable in a first direction from an extended position to a retracted position (step 401). The mold assembly may, e.g., include one or more mold halves having mold surfaces for forming a particular blow-molded article or portion thereof. The mold assembly may further incorporate or be connected to a device 100 according to an exemplary embodiment of the present invention. The insert is moved to and/or maintained in the first position while a parison is inflated inside the mold assembly (steps 403-405). The parison is conformed to the mold assembly (e.g., via air or fluid pressure) including the at least one insert to form an article. The article is then cooled to maintain its desired shape and the at least one insert is moved to the retracted position (steps 407-409). The article may then be removed or ejected from the mold assembly along a second direction (step 411). In some embodiments, the insert forms at least one recess extending in the first direction non-parallel to the second direction into the blow-molded article. Following ejection of the article, the insert may be returned to the first position for formation of the next part.
Although the invention has been described with reference to a particular arrangement of parts, features and the like, these are not intended to exhaust all possible arrangements or features, and indeed many modifications and variations will be ascertainable to those of skill in the art.
Patent Application
20080079198
