The present invention generally relates to structures that include at least a portion constructed from blow-molded plastic and, more particularly, to blow-molded plastic structures including an undercut.
Blow-molding is a manufacturing process by which hollow plastic parts are formed. The blow-molding process typically begins with a hollow tube of molten plastic, which is commonly referred to as a parison. The parison is clamped into a mold and air is blown into the parison. The air pressure pushes the plastic into the faces of the mold so that the plastic takes the shapes of the mold. Once the plastic has cooled, the mold may be opened and the part may be ejected from the mold.
In greater detail, conventional blow-molding machines include a mold with two halves and the blow-molding process is initiated with the two mold halves spaced apart. The parison, or hollow tube of plastic, is extruded between the mold halves and then the mold halves are moved toward one another, often in a horizontal configuration or arrangement. The parison, which is disposed within the mold, is inflated with pressured gas, such as air, which is typically between about 60 psi and about 150 psi. The parison expands into contact with the inner surface of the molds and the plastic is formed into the desired shape. Thereafter, the air pressure may be reduced and the mold halves may be separated or opened to allow the blow-molded plastic article to be removed.
The blow-molding process is typically used to create hollow plastic structures such as bottles and containers. The blow-molding process may allow hollow plastic objects to be manufactured economically and in high volume. In addition, the blow-molding process may allow thin-walled objects to be quickly manufactured. Because blow-molded structures include a hollow interior portion and each mold half forms its own wall shape, a variety of different types of structures can be constructed using the blow-molding process.
The type and configuration of blow-molded plastic objects that may be formed may be limited by the hollow interior portion. Additionally, the type and configuration of blow-molded plastic objects that may be formed may be limited because pressurized air is required to stretch and push the plastic into the faces of the mold during the molding process. In addition, the outer wall thickness of a blow-molded plastic structure may be difficult to control because, as the object being manufactured is larger in size, the more the plastic may have to be stretched during the molding process.
A need therefore exists for a blow-molded structure or blow-molding process that eliminates or diminishes the above-described disadvantages and problems.
One aspect is a structure that may be constructed from plastic. For example, the structure may be constructed from molded plastic. If desired, the structure may be constructed from blow-molded plastic.
Another aspect is the structure may be an article of furniture, such as a table or chair, water sports equipment, such as a kayak or paddleboard, a container, such as a bottle or cooler, an enclosure, such as a shed, and the like. The structure could also be component such as a table top, chair seat, chair back, a component of a kayak, a component of a paddleboard, a component of a cooler, a component of a shed, a component of playground equipment, and the like. Additionally, the structure could be other suitable objects, constructions, and the like such as a panel, section, and the like.
Still another aspect is a method of manufacturing or making a blow-molded plastic structure. The method may include forming a blow-molded plastic structure with one or more features or attributes.
Yet another aspect is a blow-molded plastic structure that may include an undercut. The undercut may be disposed in a cavity or void in an outer surface of the blow-molded plastic structure and the undercut may be an absence of material. For example, the blow-molded plastic structure may include an inwardly extending portion, which may include, for example, a cavity, void, pocket, indentation, depression, and the like. The inwardly expending portion may include a wall, such as a sidewall, and an undercut may be disposed in the wall. Thus, in an exemplary embodiment, an undercut may be disposed in a sidewall of the inwardly extending portion of a blow-molded plastic structure.
Still yet another aspect is a blow-molded plastic structure that may include an outer wall with an inwardly extending portion. The inwardly extending portion may extend into the hollow interior portion of the blow-molded plastic structure. The inwardly extending portion may include one or more walls, such as one or more sidewalls, and one or more undercuts may be formed in the walls. For instance, a first undercut may be disposed on a first side of the inwardly extending portion and a second undercut may be disposed on a second side of the inwardly extending portion. The inwardly extending portion and/or the undercuts may have a symmetrical or asymmetrical configuration depending, for example, upon the intended use of the structure.
Advantageously, the undercut may allow an object to be securely connected to the blow-molded plastic structure. For example, the undercut may allow a fastener or connector to be securely connected to the blow-molded plastic structure. The undercut may also facilitate connection of another object or article to the blow-molded plastic structure. For instance, the undercut may facilitate connection of a bracket or support to a blow-molded plastic structure. In addition, the undercut may allow blow-molded plastic structures to be securely connected. For example, the undercut may facilitate connection of a plurality of panels. Thus, the undercut may facilitate connection of a plurality of structures, such as a plurality of structures constructed from blow-molded plastic. For instance, the undercut may allow a plurality of panels, such as panels constructed from blow-molded plastic, to be connected.
In greater detail, the undercut may beneficially allow a fastener or other article to be securely connected to a blow-molded plastic structure. For example, the undercut may engage a portion of a fastener, such as a thread, edge, and/or protuberance. The engagement of a portion of the fastener with the undercut may create a secure connection. In addition, the engagement of a portion of the fastener with the undercut may help prevent unintentional removal of the fastener. Further, the undercut may be angled and, depending upon the angle of the undercut, a force applied to the fastener may result in more secure connection of the fastener to the blow-molded plastic structure. After reviewing this disclosure, one skilled in the art with appreciate that the undercut may have different shapes, sizes, configurations, and arrangements depending, for example, upon the intended use of the structure. For example, the undercut may include one or more surfaces disposed at an angle. The undercut may also be disposed in an angled surface. Thus, for example, the structure may include one or more surfaces and one or more of the surfaces may be disposed at an angle. Additionally, the undercut may include one or more surfaces and one or more of the surfaces may be disposed at an angle. If desired, the structure and/or undercut may include one or more angled surfaces depending, for example, upon the intended use of the structure, and/or the size, shape, configuration, and/or arrangement of the structure, which may be constructed from blow-molded plastic.
In an exemplary embodiment, the structure could be a chair seat constructed from blow-molded plastic and an inwardly extending portion with an undercut may be formed in the chair seat. The inwardly extending portion with the undercut may allow cushioning or padding to be securely connected to the chair seat. The inwardly extending portion with the undercut may allow other structures to be connected to the chair seat, such as a frame. In another exemplary embodiment, the structure could be a tabletop and an inwardly extending portion with an undercut may allow other structures to be connected to the tabletop, such as a frame. In another exemplary embodiment, the structure could be a panel and the inwardly extending portion with an undercut may allow a fastener to be securely connected to the panel. In still another exemplary embodiment, the structure could include a generally planar portion and an inwardly extending portion with an undercut may allow a fastener to be securely connected to the structure. If desired, the inwardly extending portion may form or be part of a depression (which may also be referred to as a tack-off). The depression may extend into the hollow interior portion or a volume of the structure. The inwardly extending portion with an undercut may also have a similar size, shape, configuration, and/or arrangement to one or more adjacent depressions or other features. This may allow a structure with more uniform properties or characteristics to be created.
A further aspect is a blow-molded plastic structure that may include an inwardly extending portion with an undercut that is integrally formed during a molding process as part of a unitary, one-piece structure or construction. A unitary, one-piece, blow-molded plastic structure including an inwardly extending portion with an undercut may facilitate use of the structure. For example, the blow-molded plastic structure including an inwardly extending portion with an undercut may allow the structure to be used in different configurations, arrangements, environments, and the like. The unitary, one-piece, blow-molded plastic structure with an inwardly extending portion and an undercut may also increase the range of capabilities and/or uses of the structure. One skilled in the art, after reviewing this disclosure, will appreciate that the blow-molded plastic structure including an inwardly extending portion with an undercut may have a variety of different uses and functions. Additionally, one skilled in the art, after reviewing this disclosure, will appreciate that the blow-molded plastic structure including an inwardly extending portion with an undercut may have a variety of different features, aspects, characteristics, and the like. Further, one skilled in the art, after reviewing this disclosure, will appreciate that the blow-molded plastic structure including an inwardly extending portion with an undercut may have a variety of different shapes, sizes, configurations, and/or arrangements depending, for example, upon the intended use of the structure.
Another further aspect is a blow-molded plastic structure that may include an inwardly extending portion with an undercut that forms at least a portion of a receiving portion. The receiving portion may be disposed between the undercut and a surface, such as an upper surface, of the inwardly extending portion. For example, the receiving portion may be disposed between an upper surface of the undercut and an upper surface of the inwardly receiving portion. The receiving portion may also be formed by a portion of the undercut, a portion of a sidewall of the inwardly extending portion, and/or an upper surface of the inwardly extending portion. The receiving portion may be sized and configured to receive a portion of a fastener or connector, if desired.
A still further aspect is a blow-molded plastic structure that may include an inwardly extending portion with an undercut and the undercut may be disposed at an angle. For example, in an exemplary embodiment, the undercut may include a surface that is disposed generally parallel to or at an angle relative to a lower surface of the structure and/or an upper surface of the structure. In another exemplary embodiment, the undercut may include a surface that is disposed generally parallel to or at an angle relative to a surface, such as an upper surface, of the inwardly extending portion. In still another exemplary embodiment, the undercut may include a surface that is disposed at an angle relative to a sidewall of the inwardly extending portion. For example, the undercut may include a surface that is disposed generally perpendicular or at an angle relative to a wall of the inwardly extending portion.
Yet another further aspect is a blow-molded plastic structure that may include an inwardly extending portion with an undercut and the undercut may include a surface that is generally flat or planar. The undercut may also include a surface that is rounded, curved, or the like. Additionally, the undercut may include one or more indentations, depressions, receiving portions, and the like. As indicated above, the undercut may also be at least partially disposed in one or more indentations, depressions, receiving portions, and the like.
Still yet another further aspect is a blow-molded plastic structure that may include an inwardly extending portion with an undercut and the undercut may include a surface that is disposed generally perpendicular or at an angle relative to a sidewall of the inwardly extending portion. For example, the surface may be disposed at an acute angle relative to a sidewall of the inwardly extending portion. For instance, the undercut may include a surface that is disposed at an angle of about ninety degrees (90°) or less relative to a sidewall of the inwardly receiving portion. The undercut may also include a surface that is disposed at an angle of about eighty degrees (80°) or less relative to a sidewall of the inwardly receiving portion, an angle of about seventy degrees (70°) or less relative to a sidewall of the inwardly receiving portion, an angle of about sixty degrees (60°) or less relative to a sidewall of the inwardly receiving portion, an angle of about fifty degrees (50°) or less relative to a sidewall of the inwardly receiving portion, an angle of about forty degrees (40°) or less relative to a sidewall of the inwardly receiving portion, an angle of about thirty depress (30°) or less relative to a sidewall of the inwardly receiving portion, an angle of about twenty degrees (20°) or less relative to a sidewall of the inwardly receiving portion, an angle of about ten degrees (10°) or less relative to a sidewall of the inwardly receiving portion. The angle of the surface of the undercut may be measured, for example, relative to an upper portion of the sidewall of the receiving portion. The angle of the surface of the undercut may also be measured relative to a lower portion of the sidewall of the receiving portion.
Another aspect is blow-molded plastic structure that may include an inwardly extending portion with an undercut and the undercut may include an angled surface that extends towards or is angled towards an outer surface of the structure. The angled surface of the undercut may facilitate secure engagement of a fastener, connector, or other object with the blow-molded plastic structure. For instance, the undercut may include a surface that is disposed towards the outer surface of the structure and the surface may be disposed at an angle of about two degrees (2°) or more, about four degrees (4°) or more, about six degrees (6° or more, about eight degrees (8°) or more, about ten degrees (10°) or more. It will be appreciated that the angle of the surface of the undercut may impact the ease at which a fastener or connector may be attached or disconnected from the structure. It will also be appreciated that the angle of the surface of the undercut may be disposed at other suitable angles depending, for example, upon the intended use of the structure. It will be further appreciated that the undercut may have other suitable shapes, sizes, configurations, and/or arrangements depending, for example, upon the intended use of the structure.
Still another aspect is a blow-molded plastic structure that may include an inwardly extending portion with an undercut and a surface of the undercut may be disposed at a sharp angle. For example, the undercut may include an edge, corner, or transition that is sharp or abrupt. The transition may be disposed at an angle of less than about ninety degrees (90°). For instance, the transition may be disposed at an angle of about eighty degrees (80°) or less, about seventy degrees (70°) or less, about sixty degrees (60°) or less, about fifty degrees (50°) or less, about forty degrees (40°) or less, about thirty degrees (30°) or less, about twenty degrees (20°) or less, or about ten degrees (10°) or less. The distinct edge or transition of the undercut may facilitate attachment of a fastener, connector, or other object to the blow-molded plastic structure. In addition, the undercut may help form and/or be disposed at least proximate a relatively large receiving portion. For example, the undercut may help form a receiving portion at least partially disposed between the undercut and the inner surface of the inwardly receiving portion. The undercut may also provide a relatively large area of contact or engagement, which may further facilitate attachment of a fastener, connector, or other object to the blow-molded plastic structure. The large receiving portion, the large surface area, and/or the sharp angle or transition may facilitate secure connection of a fastener, connector, or other object to the blow-molded plastic structure.
Yet another aspect is a method of forming an undercut in a blow-molded plastic structure. The method may include forming an inwardly extending portion with an undercut in an outer surface of a blow-molded plastic structure. For example, a first undercut may be disposed on a first side of the inwardly extending portion and a second undercut may be disposed on a second side of the inwardly extending portion. The inwardly extending portion may be formed by a tool with a base and one or more fingers. The fingers may be movable or slidable relative to the base and the base may include a guide, which may help control movement of the fingers. The fingers may be disposed at an angle and the guide may include a generally wedge-shaped portion disposed between the fingers. The distal ends of the fingers may include outwardly extending portions and the outwardly extending portions may be used to form one or more undercuts. For example, in a molding position, the distal ends of the fingers may be disposed a first distance away from the base of the tool and the outermost portions of the outwardly extending portions of the fingers may be spaced a first distance apart. When the blow-molded plastic structure is formed, plastic may envelop or encircle the ends of the fingers and/or a portion of the guide, such as the wedge-shaped structure. After the inwardly extending portion with the undercuts is formed, the blow-molded plastic structure may be moved away from the face of the mold and the fingers may move inwardly and at an angle relative to the face of the mold. When the blow-molded plastic structure has moved a distance away from the face of the mold, the distal ends of the fingers may be disposed a second distance away from the base of the tool and the outermost portions of the outwardly extending portions of the fingers may be spaced a second distance apart. When the distance separating the outermost portions of the outwardly extending portions of the fingers is less than the distance separating the innermost portions of the undercuts, the blow-molded plastic structure may be removed or released from the mold.
Still yet another aspect is a method of manufacturing an undercut in a blow-molded plastic structure. The method may include placing a tool in a portion of a mold and the tool may be used to form the undercut. The method may also include forming or disposing a plastic parison within a mold and closing the mold around the parison. The parison may be inflated with a gas such as pressurized air. The undercut may be formed by the tool and then the molded structure with the undercut may be released or removed from the mold.
A further aspect is a tool that may be used to create an undercut in a blow-molded plastic structure. The tool, for example, may create an inwardly extending portion with an undercut. The tool may include a base and a surface of the base may help form a portion of the blow-molded plastic structure. For instance, an upper surface of the base may be generally aligned with a portion of the mold and the upper surface of the base may help form a portion of the blow-molded plastic structure. The base may include a first guide, such as a pathway or opening, and a first finger may be at least partially disposed in the first guide. The base may also include a second guide, such as a pathway or opening, and a second finger may be at least partially disposed in the second guide. The first guide may help control movement of the first finger relative to the base and the second guide may help control movement of the second finger relative to the base. The base may include one or more inwardly extending projection, which may also be referred to as one or more guides, and the inwardly extending projection may have a generally wedge-shaped configuration and/or the guides may be disposed in a generally wedge-shaped configuration. The guides may be sized and configured to allow the fingers to move between one or more positions relative to the base. For example, the guides may be sized and configured to allow the fingers to be disposed in a molding position and a release position. When the fingers are disposed in the molding position, the distal ends of the fingers may be disposed a first distance away from the base and the distal ends of the fingers may include outwardly extending portions. In the molding position, the outer portion of the outwardly extending portions may be separated by a distance and the outwardly extending portions may be used to form at least a portion of the undercut. When the fingers are disposed in the release position, the ends of the fingers may be spaced apart from the base of the mold by a second distance and the outmost portions of the outwardly extending portions of the fingers may be separated by a second distance. When the distance separating the outmost portions of the outwardly extending portions of the fingers is less than a distance separating the innermost portion of the inwardly extending portion of the blow-molded plastic structure, the structure may be removed or released from the tool.
Another aspect is a blow-molded plastic structure that may be constructed using a blow-molding process, the blow-molded plastic structure may include an outer surface, the blow-molded plastic structure may include an inwardly extending portion disposed in the outer surface, and an undercut may be disposed in the inwardly extending portion. The undercut may include a surface and an angled portion, the angled portion may be disposed at an angle, such as an acute angle, relative to the surface, and the angled portion may form at least a portion of an edge of the undercut. The undercut may form at least a portion of a receiving portion. The receiving portion may be at least partially formed or disposed between an upper surface of the undercut and an upper surface of the inwardly extending portion. The outer surface, the inwardly extending portion, and the undercut may be integrally formed as part of a unitary, one-piece structure during the blow-molding process.
Still another aspect is a method of manufacturing a blow-molded plastic structure using a blow-molded process, and the method may include placing a tool in a portion of a mold, forming a parison of molten plastic, disposing the parison of molten plastic in the mold, closing the mold around the parison of molten plastic, inflating the parison, and creating an inwardly extending portion with an undercut with the tool. The method may include releasing the inwardly extending portion with the undercut from the tool by moving the tool from a molding position to a release position. The method may include releasing the molded plastic structure from the mold and releasing the inwardly extending portion with the undercut from the tool. If desired, the method may include concurrently releasing the molded plastic structure from the mold and releasing the inwardly extending portion with the undercut from the tool. The method may include creating a receiving portion disposed between an upper surface of the undercut and an upper surface of the inwardly extending portion. The method may include creating an edge of the undercut and the edge may be disposed at an acute angle relative to a surface of the undercut. For example, the acute angle may be disposed at an angle less than about sixty degrees (60°), less than about fifty degrees (50°), less than about forty degrees (40°), less than about thirty degrees (30°), less than about twenty degrees (20°), or less than about ten degrees (10°) relative to a surface, such as the surface of the undercut.
Yet another aspect is a tool that may be used to create an undercut in a blow-molded plastic structure constructed using a blow-molded process, the tool may include a base, a first guide at least partially disposed in the base, a second guide at least partially disposed in the base, a first finger at least partially disposed in the first guide, the first finger being movable relative to the base between a molding position and a release position, the first finger including an elongated body and an outwardly extending portion, and a second finger at least partially disposed in the second guide, the second finger being movable relative to the base between a molding position and a release position, the second finger including an elongated body and an outwardly extending portion. When the first finger and the second finger are disposed in the molding position, an upper surface of the outwardly extending portion of the first finger and an upper surface of the outwardly extending portion of the second finger may be generally aligned in the same plane; and when the first finger and the second finger are disposed in the release position, the upper surface of the outwardly extending portion of the first finger and the upper surface of the outwardly extending portion of the second finger may be generally aligned in the same plane. When the first finger and the second finger are disposed in the molding position, an upper surface of the outwardly extending portion of the first finger and an upper surface of the outwardly extending portion of the second finger may be disposed a first distance from the base; and when the first finger and the second finger are disposed in the release position, the upper surface of the outwardly extending portion of the first finger and the upper surface of the outwardly extending portion of the second finger may be disposed a second distance from the base, the second distance may be greater than the first distance. The first finger may move along a first axis that is disposed at an angle relative to the base and the second finger may move along a second axis that is disposed at an angle relative to the base, the angle of the first axis relative to the base may be generally the same as the angle of the second axis relative to the base. The outwardly extending portion of the first finger may be disposed a first distance from the outwardly extending portion of the second finger when the first finger and the second finger are in the molding position; the outwardly extending portion of the first finger may be disposed a second distance from the outwardly extending portion of the second finger when the first finger and the second finger are in the release position; and the second distance may be smaller than the first distance to allow the outwardly extending portion of the first finger and the outwardly extending portion of the second finger to be removed from the undercut formed in the blow-molded plastic structure.
These and other aspects, features and advantages of the present invention will become more fully apparent from the following brief description of the drawings, the drawings, the detailed description of preferred embodiments and appended claims.
The appended drawings contain figures of exemplary embodiments to further illustrate and clarify the above and other aspects, advantages and features of the present invention. It will be appreciated that these drawings depict only exemplary embodiments of the invention and are not intended to limit its scope. Additionally, it will be appreciated that while the drawings may illustrate preferred sizes, scales, relationships and configurations of the invention, the drawings are not intended to limit the scope of the claimed invention. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
The following exemplary embodiments are generally described in connection with blow-molded plastic structures such as chair seats. The principles of the present invention, however, are not limited to chair seats. In particular, the principles of the present invention may be implemented in other articles of furniture and in other structures that include blow-molded plastic components. In addition, it will be understood that, with the benefit of the present disclosure, the structures can have a variety of shapes, sizes, configurations, and arrangements. Moreover, the invention disclosed herein and components thereof may be successfully used in connection with other types of structures such as furniture (e.g., tables, picnic tables, etc.), objects (e.g., storage sheds, deck boxes, coolers, garden boxes, playground equipment, sporting goods, water sports equipment, etc.), and the like.
To assist in the description of exemplary embodiments shown in the accompanying figures, words such as top, bottom, front, rear, right and left may be used. The accompanying figures may be, but are not necessarily, drawn to scale. It will further be appreciated the structures can be disposed in a variety of desired positions or orientations, and used in numerous locations, environments and arrangements. A detailed description of some exemplary embodiments of the structures, such as chair seats, now follows.
As shown in the accompanying figures, an exemplary chair seat 10 may be constructed from blow-molded plastic. The chair seat 10 may include an upper portion 12, a lower portion 14, and an outer boundary 16. The upper portion 12 may be spaced apart from the lower portion 14 by a distance. The chair seat 10 may also include a hollow interior portion 18 disposed between the upper portion 12 and the lower portion 14.
The chair seat 10 may further include one or more sides, corners, and ends. The chair seat 10, including the upper portion 12, the lower portion 14, the hollow interior portion 18, the sides, the corners, and/or the ends, may be integrally formed as part of unitary, one-piece structure during the blow-molding process. It will be appreciated that the chair seat 10 may have a variety of suitable shapes, sizes, configurations, and/or arrangements depending, for example, upon the intended use of the chair seat. It will also be appreciated that the chair seat 10 may be constructed using various materials and may include one or more features, aspects, and the like.
Although not shown in the accompanying figures, the chair may include one or more support structures or legs, which may be sized and configured to support the chair seat above a surface such as the floor or ground. The support structures may include one or more supports and the support structures may be movable between a use position and a collapsed or storage position. It will be appreciated that the chair may include any suitable number of support structures and/or legs depending, for example, upon the intended use of the chair. It will also be appreciated that the support structures and/or legs may have different shapes, sizes, configurations, and/or arrangements depending, for example, upon the type or intended use of the chair.
The chair may include a frame that is connected to the chair seat and the support structures. The frame may facilitate movement of the support structures between the use and the collapsed or storage positions. The frame may have different shapes, sizes, configurations, and/or arrangements depending, for example upon the type or intended use of the chair. It will be appreciated that the frame is not required and the chair may have other components, features, aspects, characteristics and the like, if desired.
The chair seat 10 may be covered by one or more layers such as a cover, padding, and the like. The chair seat 10 may include one or more recesses 20 and the recesses may be sized and configured to receive padding material. An exemplary embodiment of a chair including one or more layers of padding and a covering is shown in U.S. patent application Ser. No. 15/373,457, filed Dec. 8, 2016 (U.S. Publication No. US 2017-0164746), which is incorporated by reference in its entirety. It will be appreciated with the benefit of the present disclosure that the chair may include any suitable number of components and the components may have various sizes, shapes, configurations, and arrangements depending, for example, upon the intended use of the chair. It will further be appreciated that the chair may include other components, features, aspects, characteristics and the like, if desired; but none of the features, aspects or components may be required.
As shown in
The depressions 22 may be used to create a chair seat 10 with generally uniform characteristics or qualities. For example, if the depressions 22 are consistently spaced, that may allow the upper portion 12 of the chair seat to be uniformly supported. In addition, if the depressions 22 are separated by a generally constant distance, which may be measured from a center of one depression to a center of an adjacent depression, that may create a chair seat 10 with more uniform characteristics or qualities. The distance between adjacent depressions 22 may be measured longitudinally, laterally, or at an angle depending, for example, upon the arrangement of the depressions.
The depressions 22 may also be disposed in a pattern and the depressions may be generally aligned and/or disposed in predetermined locations within the pattern. The pattern may include, for example, a number of rows and/or columns of depressions 22. The rows may be disposed along a length of the chair seat 10 and the columns may extend along a width of the chair seat. The depressions 22 may also be disposed in other suitable forms and patterns, and may have other shapes, sizes, configurations and arrangements, depending, for example, upon the intended use of the chair.
The depressions 22 may extend inwardly into the hollow interior portion 18 of the blow-molded plastic structure, such as the chair seat 10. The depressions 22 may have a generally conical, curved, domed, elongated, or other suitable shape. The depressions 22 may be integrally formed during the blow-molding process as part of a unitary, one-piece structure. Thus, for example, the chair seat 10 and the depressions 22 may be integrally formed during the blow-molding process as part of a unitary, one-piece structure.
The chair seat 10 may include one or more inwardly extending portions 24, as shown in
In contrast to the depressions 22, the inwardly extending portions 24 with the undercut 26 cannot be formed with traditional blow-molding techniques. Instead, a tool 30 allows the inwardly extending portion 24 with an undercut 26 to be formed during the blow-molding process. The exemplary tool 30 shown in
The fingers 34, 36 may include outwardly extending portions and the outwardly extending portions may be sized and configured to form the undercut 26 in the inwardly extending portions. As shown in the accompanying figures, the blow-molded plastic structure, such as the chair seat 10, may include one or more undercuts 26 and/or one or more inwardly extending portions 24. For example, the first finger 34 may include an outwardly extending portion 54 and the outwardly extending portion may be sized and configured to form a first undercut 58 in an inwardly extending portion 62. The second finger 36 may include an outwardly extending portion 56 and the outwardly extending portion may be sized and configured to form a second undercut 60 in an inwardly extending portion 64. In greater detail, an outwardly extending portion 54, 56 may be disposed at the distal end 42, 44 of each finger 34, 36 and the outwardly extending portions may extend in opposing directions. For example, in the molding position, the outwardly extending portions 54, 56 may extend in opposite directions and the outwardly extending portions may be disposed in generally the same plane. The outwardly extending portions 54, 56 may include a generally planar first surface 66 and a generally planar second surface 68 that are separated by a distance. The first and second generally planar surfaces 66, 68 may be generally aligned in parallel planes. The first and second generally planar surfaces 66, 68, however, do not have to be aligned or disposed in generally parallel planes. For example, the first and second generally planar surfaces 66, 68 could be disposed at an angle depending, for example, upon the type of undercut to be formed. The outwardly extending portions 54, 56 may also include an outer edge 70, 72 or wall that extends between the first and second surfaces. Thus, the outwardly extending portion 54 of the first finger 34 may include the first surface 66, the second surface 68, and the outer edge 70. The outwardly extending portion 56 of the second finger 36 may include the first surface 66, the second surface 68, and the outer edge 72. As discussed above, the first and second surfaces 66, 68 of the outwardly extending portions 54, 56 may be generally aligned, for example, when the fingers 34, 36 are disposed in the same positions. In addition, the outer edges 70, 72 of the outwardly extending portions 54, 56 may be generally aligned in parallel planes. The surfaces 66, 68 and/or outer edges 70, 72 may also be disposed at other suitable angles and may have other shapes, sizes, configurations, or arrangements depending, for example, upon the structure to be constructed from blow-molded plastic.
When the tool 30 is disposed in the molding position, an upper surface 74 of the first finger 34, an upper surface 76 of second finger 36, an upper surface 78 of the outwardly extending portion 54, and/or an upper surface 80 of the outwardly extending portion 56 may be generally aligned and/or disposed in the same plane. The upper surfaces 74, 76 of the first and second fingers 34, 36, and/or the upper surfaces 78, 80 of the outwardly extending portions 54, 56 may also be aligned with a portion of the base 32. For example, the upper surfaces 74, 76 of the first and second fingers 34, 36, and/or the upper surfaces 78, 80 of the outwardly extending portions 54, 56 may also be aligned with a portion of the base 32, such as a guide 82. If desired, the upper surfaces 74, 76 of the first and second fingers 34, 36, and/or the upper surfaces 78, 80 of the outwardly extending portions 54, 56 may also be aligned with an upper surface 84 of the guide 82. The guide 82 may have a generally wedge or triangular-shaped configuration and the upper surfaces 74, 76 of the first and second fingers 34, 36 and/or the upper surfaces 78, 80 of the outwardly extending portions 54, 56 may be generally aligned with the upper surface 84 of the guide 82. In the molding position, the outer surfaces of the fingers 34, 36 proximate the base may be separated by a first distance D1, the outer surfaces of the fingers proximate the outwardly extending portions may be separated by a second distance D2, and the outermost ends or edges of the outwardly extending portions of the fingers may be separated by a third distance D3. The first distance D1 may be greater than the second distance D2 or the third distance D3, and this portion of the tool 30 may form a base of the inwardly extending portion 24 during the molding process. The second distance D2 may be smaller than the first distance D1 and the third distance D3, and the second distance may help identify the narrowest portion of the inwardly extending portion 24. The third distance D3 may be smaller than the first distance D1 and larger than the second distance D2, and the third distance may help identify the undercut.
When the blow-molded structure is being formed, the plastic may contact and be disposed about an upper, exterior portion of the first and second fingers 34, 36, the outwardly extending portions 54, 56, and a portion of the base 32, such as a portion of the guide 82 and/or the upper surface 46 of the base.
As shown in
As shown in
Another exemplary embodiment of a blow-molded plastic structure including an undercut is shown in
For example, in an exemplary embodiment, a blow-molded plastic structure (such as the chair seat 10 and/or blow-molded plastic structures 92, 96) may include an inwardly extending portion, such as the inwardly extending portion 24, and an undercut, such as the undercut 26. As shown in the accompanying figures, an exemplary embodiment of the undercut, such as the first undercut 58 and the second undercut 60, may include a surface 110 and the surface may have a generally planar configuration. The undercuts 58, 60 may also include an edge or angled portion 112. The undercuts 58, 60 may be aligned and/or may include a portion of an inwardly extending portion, such as a wall or sidewall 114. The angled portion 112 may be disposed at an acute angle relative to the sidewall 114, which may form a sharp edge or corner. For instance the angled portion 112 may be disposed at an angle of generally equal to or less than about ninety degrees (90°), generally equal to or less than about eighty degrees (80°), generally equal to or less than about seventy degrees (70°), generally equal to or less than about sixty degrees (60°), generally equal to or less than about fifty degrees (50°), generally equal to or less than about forty degrees (40°), generally equal to or less than about thirty degrees (30°), generally equal to or less than about twenty degrees (20°), or generally equal to or less than about ten degrees (10°).
As shown in
A blow-molded plastic structure including an inwardly extending receiving portion with an undercut may be formed as part of a process or method. For example, the blow-molded plastic structure with an undercut may be created as part of a production method. The method may include producing or manufacturing any suitable number of blow-molded plastic structures with an undercut. The undercut may be contemporaneously formed during the process or method, and the undercut may be integrally formed as part of a unitary, one-piece structure during the process or method.
As shown in
Structures constructed from blow-molded plastic may have unique and distinctive properties, and some aspects of blow-molding may not be compatible with other types of molding such as injection molding, rotational molding, vacuum fuming, and the like. For example, because a blow-molded plastic structure is formed by using air or gas to inflate a parison of molten plastic, some features or structures that can be made from some types of molding processes cannot be manufactured using known blow-molding techniques. In addition, a blow-molded plastic structure is generally formed with an outer surface of the structure engaging the face of the mold and a hollow interior that is filled with pressurized gas during the molding process. Thus, blow-molded plastic structures may not be manufactured with the devices, molds, structures, and the like of other types of molding processes because of the different properties and configurations of blow-molded plastic structures. Further, because most blow-molded plastic structures include opposing walls separated by a distance and enclosing a hollow interior portion, processes or structures that may work with a single layer of material may not work with a blow-molded structure. Accordingly, after reviewing this disclosure, one skill in the art will appreciate the significant differences between the blow-molded plastic structures and methods disclosed herein, and other types of molded plastic structures and methods.
One of ordinary skill in the art may appreciate after reviewing this disclosure that the chair seat and structures disclosed herein may have a number of different aspects, features, characteristics and configurations. Further, chair seat and structures may have any suitable number of aspects, features, characteristics and configurations depending, for example, upon the intended use of the chair or other structure.
One of ordinary skill will appreciate that the structures disclosed herein may have various suitable sizes, shapes, configurations, and/or arrangements. Other exemplary configurations are shown below:
Although this invention has been described in terms of certain preferred embodiments, other embodiments apparent to those of ordinary skill in the art are also within the scope of this invention. Accordingly, the scope of the invention is intended to be defined only by the claims which follow.
The present application claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 62/772,593, entitled Blow-Molded Plastic Structures, which was filed on Nov. 28, 2018, and is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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62772593 | Nov 2018 | US |