Patent Grant
7246416
Surface Fasteners of the Slidingly Engagable type (SEFs) were disclosed in U.S. Pat. No. 5,983,467 entitled “Interlocking Device” by the undersigned. That disclosure included a range of fastener types, each including portions with a base structure having pluralities of apertures and islands, which may be slidingly engaged by application of a relative shearing force, so that the individual islands of one portion become interlocked within complementary apertures of the other, and vice versa. SEFs may be provided in various designs including uni-directional or multi-directional orientations; may be hermaphroditic or have different male and female portions; may be configured to connect a point, an edge, a strap, a surface or other condition; may include an associated aperture opening that provides a “snap fit” prior to engagement, and may also include diverse self-alignment and coupling mechanisms.
Typically, the individual apertures of Slidingly Engagable Fasteners are designed to receive complementary islands so as to allow a relatively loose and imprecise initial alignment to result in a relatively tight and more precise engaged state, after application of a relative shearing force. Three characteristics define this aspect. First, the apertures and complementary islands are effectively tapered in at least one dimension in relation to the axis of engagement so as to provide an aperture opening that is somewhat larger in at least one dimension than the leading edge of an associated island, thereby abetting self-alignment of the elements. Secondly, each such aperture includes at least one undercut wall segment which, after application of the relative shearing force (i.e. a force applied to one of the portions in a direction generally parallel with the basal surface) to the aligned portions, engages a complementary island undercut sidewall segment so as to contain the island and prevent further movement in a direction generally perpendicular to the basal surface (vertical). Thirdly, each such aperture also includes wall segments which, upon application of the relative shearing force, engage complementary island sidewall segments so as to contain such island and prevent further movement in the direction of such applied shearing force (engagement direction) or in a direction generally perpendicular to such force and also parallel with the basal surface (lateral direction). The term “slidingly engaged” is intended to convey that the islands are caused (by the relative shearing force) to enter complementary apertures so that the island sidewalls progressively approach aperture walls until reaching a state of full contact and engagement, in which state the portions are effectively interlocked.
The profile shape of such walls and sidewalls (as viewed in cross section perpendicular to the axis of engagement), as illustrated in U.S. Pat. No. 5,983,467 include orthogonal dovetail-like shapes, ogee-like shapes, and variations of such shapes. It is apparent that any profile shape which provides the appropriate engagement and containment aspects as described above may be used. It may also be understood that any such walls or sidewalls need not be contiguous in order to provide such engagement and containment aspects. Therefore it has become known to the present inventor that Slidingly Engagable Fasteners may include elements which are discontinuous, perforated, or otherwise modified in design, provided only that the essential function and structural integrity of the device is maintained. In that a basic engineering design precept entails minimizing resources in order to achieve a particular function, it may therefore be desirable to produce Improved SEFs with such discontinuity, perforations or other modifications in order to minimize such resources. SEFs can provide significant advantages over hook-and-loop, mushroom-type and other surface fasteners, as well as a wide variety of mechanical fastening devices, for many applications. Such advantages include superior shear and tensile strength, low profile, ease of use, durability, a non-grabbing texture, and numerous other aspects. However, in order to advantageously provide these advantages, a simple and economical method of producing SEF fasteners in large or small quantities, in a variety of materials, and in a range of designs is needed.
In addition to the need for an improved method of production, a number of potential improvements to such fasteners are also desirable which may also be related to such method of production. Slidingly Engagable Fasteners should be available in a variety of materials including molded thermoplastics, other moldable materials, paper and paper board, composite and fibrous materials, and in formed metals, plastics and other malleable materials. Flexibility of the overall structure should be combined with structural integrity of individual fastening elements. SEF products should be available in a range of scales for a diversity of applications. Use and disposition of materials should be economical. Low profile and high strength aspects should be maximized. Fastener portions for many potential application environments should be self-cleaning. Self connecting fasteners in strap or linear forms should be available, including double-sided fastener straps and surfaces. Provisions for integrally attaching SEFs to various substrates should be available. SEF portions which may be integrally molded or formed as part of a larger component or product are also needed. Fasteners which combine certain of these aspects as well as other features are also needed.
Working prototypes of SEFs in various embodiments have been produced by molding, machining, forming, constructing, and die cutting diverse materials such as hard and soft plastics, wood, paper and paperboard, foam, sheet metal, ceramic materials, and composite materials. Although these models have generally been functionally successful, the need for a simple and inexpensive method of production is apparent. Molding or forming SEF fastener portions by conventional methods is complicated by the fact that such fasteners include a multiplicity of undercut surfaces. Although conventional molding or forming techniques may be employed to produce various uni-directional SEFs, multi-directional embodiments present a particular challenge. Therefore, a relatively simple method is needed which will provide for the removal of that part of the die or mold which defines the underside of such undercut surfaces without harming, weakening, or comprising the design of the product.
Several known manufacturing processes are applicable to the present invention: injection molding utilizing a reciprocating machine; continuous molding in which a substance is molded between a set of counter rotating rollers, effectively extruding a continuous product; die forming utilizing a reciprocating press; and continuous die forming in which a sheet of material is formed between a set of rotating dies. Each of these processes has been developed extensively over many years, and are not claimed herein except in relation to the present invention. Each such process also involves numerous secondary systems for pressurizing, heating, cooling, lubricating, ejecting product and waste, and other considerations which are beyond the scope of this disclosure. The common aspects of these processes are that each utilize a set of dies or, more commonly, a single die with a corresponding anvil or backing, and an apparatus designed to provide pressure on a raw material in order to produce a product of the desired shape.
Reclosable surface fasteners such as molded hook-and-loop hookstrips and mushroom type fasteners, which also include undercut surface segments, are typically manufactured of molded thermoplastics. Erb U.S. Pat. No. 3,147,528 describes a method of producing hookstrips by reciprocal injection molding. Other methods utilize a continuous web process using a belt or rotary mold. Undercut fastening elements may be formed by a complex mold with internally moving elements i.e. Menzin et al U.S. Pat. No. 3,758,657; they may be directly molded in cavities provided in such a mold and rapidly cooled before forcibly (resiliently) stripping form the mold i.e. Fischer U.S. Pat. No. 4,775,310; or they may be formed in a two step process in which a base with an array of stems is first molded and the stems are subsequently reformed into hooks or mushroom shapes, i.e. Provost et al U.S. Pat. No. 5,953,797. Yet another possible manufacturing method includes a sacrificial mold portion for forming undercuts, i.e. Torigoe et al U.S. Pat. No. 5,242,649. Recently, Kampfer et al U.S. Pat. No. 6,000,160, Miller U.S. Pat. No. 6,054,091, and Parellada et al U.S. Pat. No. 6,248,276, each disclose improved methods of forming fastener elements by the aforementioned two step process. Many other examples provide variations and refinements to similar processes. It appears that the quest for a definitive method of manufacturing fastener products is ongoing.
Utilizing a set of interengaging dies is a known method of manufacturing complex products with under-surfaces, most commonly known in paper and sheet metal stamping at least far back as Hodgson U.S. Pat. No. 299,982 of 1884, but also employed in plastic molding. Methods of producing certain designs of hook-and-loop hookstrips and mushroom type fasteners by utilizing an apparatus which includes a set of bypassing dies are also known. Kaneko U.S. Pat. No. 5,212,853 discloses injection molded surface fastener products that utilize a set of male and female interdigitating dies to form a unique mushroom-type fastener portion, although such method is not claimed. Kaneko's product includes a fastener head on two legs which are flush with the head perimeter, apparently to provide flexibility. His method includes a set of male and female dies with abutment faces, such faces being more or less perpendicular to the product surface structure. Although it is noted that the abutment faces are slightly tapered to facilitate die separation, it would appear that, without further remedy, repetitive use under heat and pressure could cause die seizure or differential movement if anything other than small portions are produced. Like other types of mushroom fasteners, Kaneko's device appears to be limited in potential strength as related to durability under repetitive use. Kayaki U.S. Pat. No. 5,067,210 appears to depend on a similar molding method which is not described. His device appears to require relatively exact positioning in two dimensions, first to align the ribs then to align alternately offset elements. It is apparent that each such fastener has limited application.
Certain other known fasteners also include a fenestrated base structure which could be produced by a method incorporating bypassing dies. Spier, U.S. Pat. No. 4,581,792, describes a press-together surface fastener comprising a plurality of perpendicular tapered projections and complementary receptacles arrayed in alternating rows each surrounded by a contiguous base structure having openings at each such projection and receptacle. Spier's device, however, appears to maintain engagement by friction rather than providing any type of interlock. It requires precise alignment of the portions, and does not appear to provide significant resistance to shear. Cousins, U.S. Pat. No. 4,183,121, and Allan, U.S. Pat. No. 5,640,744, each disclose types of surface fasteners with undercut elements which include portions having a fenestrated base structure, an engagement mechanism which may be effected by a relative shearing force, and in which openings in the fenestrated base structure at least partially align with undersurface segments of individual engagement members. However, each of these fastening devices appear to require considerable precision in aligning the elements both lineally in columns and in angular orientation. The former, Cousins, appears to require consistent pressure along the length of its axis in order to engage all elements simultaneously, and does not provide for excess overlap when adjusted. The latter, Allan, also requires longitudinal alignment ribs to prevent lateral disengagement. Both provide fastening mechanisms which are not adaptable to resist shear forces oriented in more than a single radial direction and have other limitations.
A new manufacturing method for SEFs should include certain desirable aspects. For instance, having a positive means of defining the thickness of a fastener portion throughout its area is particularly important for producing wide products with either reciprocating or rotating molding systems. Provisions for maximizing production speed are also desirable. Providing enhanced surface features for functional, aesthetic, or identification purposes is also desirable. Precise definition of the shape of individual fastening elements is important in controlling the design of strength and release characteristics. Material efficiency, weight, and flexibility should be carefully designed. Strength of individual fastening elements and profile depth require precise control. Speed, simplicity, and economy of production are important considerations as well are tooling costs. Provision of a method by which fastener portions may be readily manufactured in a one-step process as part of a larger primary product would also have significant utility. In summary, there is a need for a simple, efficient, economical, precise, and versatile method of manufacturing Slidingly Engagable Fastening products.
A first object of this invention is to provide Improved Slidingly Engagable Fasteners which can be produced inexpensively in large volume. A second object is to provide a method of economically producing such SEFs of diverse moldable or malleable materials. A further object is to provide such fasteners which are efficient in material usage. A further object is to provide such fasteners which are strong and flexible. A further object is to provide such fasteners in diverse configurations and designs. A further object is to provide such fasteners which include provisions for attachment to a substrate. A further object is to provide such fasteners which have two active sides. A further object is to provide such fasteners which include provision for extracting extraneous matter as they are engaged. A further object is to provide a method of manufacturing any such fasteners as an integral part of a larger manufactured product or product component.
The Improved SEFs disclosed herein include complementary portions each comprising: 1) a fenestrated common base structure having a plurality of fenestrations; 2) a plurality of islands each having at least one stem segment with walls, one or more undercut segments with undersides, and a top with an edge; and 3) a plurality of apertures defined by parts of island walls and parts of undersides of island undercut segments. At least a portion of the fenestrations in the common base structure are correspondent, in a direction generally perpendicular to the plane of the base structure, with corresponding undersides of the islands, and the solid segments of such base structure are generally contiguous with the stem portions of such islands. Each embodiment is designed to be slidingly engagable with a complementary portion upon application of a relative shearing force. The fenestrated base structure may also include larger fenestrations as well as other openings or surface features designed for functional or aesthetic effect.
Embodiments include examples of several types of Improved SEF: a multi-directional SEF arrayed in a quadrille pattern which aligns portions at 90 degree radial intervals and provides resistance to shear stresses of any orientation; a multi-directional portion arrayed in an alternating triangular pattern which aligns portions at 120 degree radial intervals and also provides multi directional shear resistance; a multi-directional portion arrayed in a hexagonal pattern which aligns portions at 60 degree radial intervals and provides multi-directional shear resistance; a uni-directional portion with islands and apertures arrayed in bilateral disposition; a double-sided embodiment which includes two active fastening faces on opposite sides of a common base structure thereby allowing the portion to be attached to separate complementary portions or to be doubled back and attached to itself at another location; a double-sided embodiment having a chevron configuration which provides uni-directional connection to portions on opposite sides; and an example of a product of which such improved fasteners are an integral part. Each of these embodiments are intended to schematically illustrate a range of design options and aspects which generally can be mixed or substituted within the scope of the invention. Embodiments include SEF portions which are molded and have differential profile thickness as well as other embodiments having a relatively consistent profile thickness which may be either molded or formed of a sheet material. Any of the embodiments illustrated can be molded or formed integrally with a primary product or component.
Mechanisms for attaching Improved SEF's to a substrate are also provided. These include: a backing portion having an array of pins designed to penetrate through a perforated substrate and engage with complementary receptors opening to the back side of an improved SEF portion; and an Improved SEF portion having an array of attachment devices projecting from its back side which are designed to penetrate and attach to a substrate. Improved SEFs may also be attached to a substrate by conventional means such as sewing or adhesives.
A method of manufacturing such fastener portions is also provided which incorporates an apparatus that includes a set of interengaging dies to effect a cavity which defines the shape of the resultant product. Each such die includes surface segments which are cavity walls, other surface segments which engage complementary segments of the corresponding die so as to define fenestrations in the resultant product, and associated aspects which are common to known molding or forming technology. The apparatus causes these dies to align and intermesh under sufficient pressure to cause a moldable or malleable material inserted therein to take the shape of the cavity as defined by the cavity walls. Because no portion of the dies are entrapped by any portion of the resultant product, the dies may be readily separated without stressing the undercut portion of fastener elements, and therefore the resultant product design is not limited by the difficulty of molding or forming such undercut portions, and the production process can be expedited.
This method differs distinctly from the common methods of manufacturing other types of surface fastener portions in that both the first and second dies include male and female elements and both may include surfaces which engage with corresponding surfaces of each other in interfacing positions which may be both perpendicular and normal to the common die axis, thereby defining fenestrations in the resultant product. Such fenestrations are aligned at least in part with the undersurfaces of undercut fastener islands thereby defining at least part of the walls of the apertures. The subject method also provides a mechanism for precisely controlling the thickness of molded fastener products in that the engaging surface segments of corresponding dies may be designed to define a specific cavity depth.
The associated apparatus may be of a type designed for molding a resinous or otherwise moldable substance, or the method may be used in conjunction with an apparatus designed as a cutting/bending press to form a malleable substance such as sheet metal or paper board. Such apparatus may be of a reciprocating type, such as an injection molding machine or reciprocating press, or it may be of a continuous production rotary type wherein the dies are arrayed along the surfaces of counter-rotating rollers or molding belts. Although the subject dies are typically to be designed for a specific product, material, and manufacturing technology related to the type of apparatus used, the common method is applicable to each such technology. Whichever apparatus is incorporated, it typically includes numerous basic elements commonly known to industry including means for: engaging the dies in their aligned position; applying pressure as necessary; inserting raw material; ejecting the finished product; and providing for heating, cooling, lubrication and other subsidiary parts of the process which are not claimed herein.
A significant improvement provided by the present invention is inclusion of the aforementioned fenestrated base structure. This aspect allows such Improved Fasteners to be manufactured economically of diverse materials by the method provided. The fenestrated base also provides for efficient utilization of material, enhances flexibility, provides a means for extracting foreign matter from the fastener assemblage, allows double-sided portions to be produced, allows a fastener portion to be molded or formed as part of a larger product, and provides other advantages which are apparent herein. The fenestrated base can also be designed to enhance the functions of diverting portions into self-alignment and coupling of the portions.
The Improved SEFs also provide significant other advantages including features that enhance usability for many applications. Very low profile, high strength fasteners may be produced because the effective engagement thickness may be as little as only two times the thickness of the material selected. A variety of designs can provide optional configurations and orientations, strength characteristics, functional, and aesthetic aspects. Fastener products can be reinforced or embellished by the inclusion of a reinforcing material. Flexible portions may be furnished in rolled form for shipment and installation. Double-sided SEF portions allow a greater range of application possibilities. Provision of self attachment mechanisms greatly increase the utility of SEF's for many applications and allow fastener portions to be subsequently attached to an end product by an original equipment manufacturer at another site. Provision of such a simple method of production allows fastener portions to be integrally molded or formed with a primary molded or formed product or assembly component, thereby providing such benefits as reduced assembly time and production cost, as well as improved integrated product designs.
Some of the significant advantages of producing fasteners by the method of this invention include the following: The production system is simple and economical and can be readily adopted to commonly known manufacturing systems. Molds of reciprocating or roller type may be produced by commonly known modern machining methods at lower cost than complex multipart molds. Material utilization can be optimized by designing the fenestrated product base in relation to the expected loading, and lower cost materials may be utilized where appropriate. A high degree of precision can be incorporated in the resultant product. Resultant fastener products can have a reasonable degree of flexibility due to the fenestrated base, even when manufactured of a fairly rigid material in order to maximize strength. Product design is not limited by mold release considerations. Because the product undersides may be precisely formed or molded, the strength and release characteristics of resultant fastener products may be designed precisely. Fastener products can be rapidly and economically produced in a large quantities, or fastener portions can be integrally manufactured as part of a larger molded or formed product.
Each portion 01 may also include a plurality of said islands 04, each having a top surface 05 with an associated edge 06, a stem segment 07 with sidewalls 08, and undercut segments 09 with undersides 10, wherein said edge and said undersides are also sidewalls, and further wherein said undersides are aligned, in a direction generally perpendicular to the plane of said common base structure, with at least portions of individual said perforations. It should be noted that in this and other embodiments, said stems 07 are generally located between said undercut segments, and vice versa so as to effect an island having a top surface 05 with a segmented edge 06. In this instance, each such stem can be seen to be associated with four such undercut segment sin that they are contiguous with such segments. A plurality of apertures 11 may also be included in said portion 01, each said aperture having an associated aperture opening 12, and walls 13: wherein said aperture opening is defined by said associated edge 06 of each adjacent island 04, and wherein segments of said walls are coincident with segments of said sidewalls 08 and other segments of said walls are coincident with segments of said undersides 10. The portions are designed so that ones of said apertures receive ones of said islands so that, when two such portions are aligned (i.e. ones of islands are inserted through corresponding aperture openings) and are slidingly engaged by a relative shearing force, said first and second portions become connected and interlocked. Such interlocked portions may subsequently be disconnected by reversing said relative shearing force or, when the base of at least one portion is sufficiently flexible, the portions may be sequentially peeled apart.
Said first preferred embodiment 01 also, optionally, includes a plurality of conical protrusions 14 at the center of each said top surface of each said island, and as said fenestrated base has a first surface 15 between said perforations, said surface including in this design a complementary ridge 16, so that when the tops of the islands of two said portions are caused to contact by application of a perpendicular pressure, said conical protrusions divert the islands towards adjacent aperture openings 12. Therefore, an imprecise initial alignment of the portions results in alignment at the nearest 90 degree radial interval. Thereafter, as ones of said islands are inserted through said aperture openings 12 and caused to contact ones of said ridges 16 on said first face 15, continuing perpendicular pressure causes ones of said protrusions 14 to divert toward said perforations 03 in said common base structure 02, thereby initiating engagement of the portions by effecting a relative shearing force. This type of embodiment, having a quadrille design, allows fastener portions to be aligned and slidingly engaged at 90 degree radial intervals and thence provides resistance to shearing stresses in multiple directions in that, when subjected to a shear stress of a different direction, said islands tend to relocate and engage with whichever aperture is most closely aligned with such shear stress.
Embodiments of the type 01 illustrated in
A second type of preferred embodiment 20, as illustrated in
In this type of embodiment 20, each said island 04 has a plurality of said stems 07, each such stem associated with just two adjacent undercut segments, and said islands and said common base structure 02 have a generally consistent thickness, so that such a portion may be produced either by molding a moldable substance as in the previously described embodiment or by perforating and forming a malleable sheet material utilizing said method incorporating said interengaging dies and said apparatus.
A third preferred embodiment 21, illustrated in
This embodiment 21 also includes island top surfaces having a conical protrusion 14 which is designed to help align and couple said portions. As in the previous embodiment 01, when two such portions are approximately aligned and subjected to compressive pressure, ones of said conical protrusions cause complementary sets of said islands to slide into alignment with said aperture openings so that continuing pressure causes ones of said islands to enter ones of said aperture openings. In this instance, however, the conical protrusions 14 may then be diverted into a corresponding cavity 28 on the basal surface by a relatively slight initial relative shearing force, thereby coupling said portions in an engaged state until an opposing relative shearing force is applied to reverse such engagement. An important aspect of such a hexagonal design combined with such conical protrusions is that two such fastener portions may be pressed together at virtually any radial disposition and will thence self-align at the nearest 60 degree disposition, so long as at least one portion is allowed to rotate up to 30 degrees. Therefore a press-together fastener is provided which may be connected from any initial angular disposition of the portions.
A fourth preferred embodiment, illustrated in
A fifth preferred embodiment 25, illustrated in
A sixth preferred embodiment 29, which is illustrated as the end segments of a strap, is shown in
Said backing structure 35 may be designed to provide sufficient flexibility so as to allow the entire assembly to be flexed if desirable for a particular application. Such flexibility may be useful in many applications such as in apparel. Alternatively, said backing structure 35 may be designed to enhance the rigidity of the complete assembly, thereby reinforcing said fastener portion, or a segment of same at its point of attachment, as in an application where a flexible fastening strap is to be connected to a rigid base. Corresponding to such requirements for flexibility or rigidity, said backing structure 35 may include fenestrations as illustrated to enhance flexibility or may be solid and contiguous in order to enhance rigidity.
A Method for producing Improved Slidingly Engagable Fastening Devices of various types includes the provision of a set of interengaging dies and an apparatus for engaging such dies in order to cause a material inserted or injected into a cavity provided by such dies to take the desired form of such fastening device, as further described below.
With reference to
It can be appreciated from
Referring back to
As apparatus of diverse generic types, as schematically illustrated in
Optionally, one of said first and second dies may also include a plurality of ejection slots 115, each said ejection slots being aligned with a secondary punching segment 116 of the other of said first or second dies, which surface segment is intended to punch through said malleable material so as to eject a part thereof, thereby providing said additional perforated areas 114 as otherwise described above in a molded product. It should be noted that when producing a formed fastener product of a sheet material as in this instance, dies having said interfacing gates of the second type 113 as described above are unnecessary, in that the thickness of material is generally predetermined.
In each type of apparatus 117 as described herein, said first and second dies also include other aspects common to industry including means for causing properly registered alignment, means for extracting extraneous material, means for ejecting products, means for heating and cooling, and other aspects common to industrial molding and die forming processes which are not claimed as part of the present invention.
As illustrated schematically in
A reciprocating cutting/forming press apparatus 117 is illustrated in
A continuous molding apparatus 117 is schematically illustrated in
At least one of said rotating molds 133, 134 may optionally be provided in the form of a continuous molding belt 135. This option may be included in order to expedite the production process by providing a longer mold contact time for cooling prior to product ejection, thereby allowing said rotating molds to operate at a faster speed.
Optionally, a fabric or other reinforcing material 48 may be integrally molded into said product for the purpose of reinforcing, providing selvage for sewing, or other purpose. Said reinforcing material 48 is temporarily adhered to the peripheral surface of one of said first or second counter rotating molds 133 so that said material is caused to pass through said apparatus as said moldable substance 128 fills said interconnected cavities 103, thence becoming integrally molded with said product. Such a reinforcing material 48 which has perforations which can align with protruding elements of said first or second dies 102 can be caused to substantially attach to said protruding elements prior to the introduction of said substance 128, thereby aligning and registering said substrate 136 with said interconnected cavities 103 between said perforations 109.
It is to be understood that the forgoing description and associated drawings are intended to schematically demonstrate a wide range of embodiments which may be produced by the method described or by other methods. It is the intent of these documents to describe a range of variations which may be modified or combined in diverse ways within the scope of this invention. It is further intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as schematically illustrative and not in a limiting sense. The following claims are intended to cover the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
This application claims the benefit of U.S. Provisional Applications No. 60/288,780 filed May 5, 2001 and No. 60/241,707 filed Oct. 19, 2000 in regard to Priority status as provided under 35 USC 119 (e)(1).
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|---|---|---|---|
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| Number | Date | Country | |
|---|---|---|---|
| 20030074771 A1 | Apr 2003 | US |
| Number | Date | Country | |
|---|---|---|---|
| 60288780 | May 2001 | US | |
| 60241707 | Oct 2000 | US |
