Manufacturing a foldable toothbrush

Abstract

A method is disclosed of securing filaments to a toothbrush handle that is foldable along a longitudinal axis to acquire a functional configuration, the method includes providing a mold device for the toothbrush handle, the mold device comprising an upper member and a lower member positionable to define a mold cavity therebetween and a corresponding parting line therebetween, positioning filaments partially within the mold cavity, the filaments arranged linearly within the mold cavity in a plane that is parallel to the parting line, injecting a flowable plastic material into the mold cavity, and allowing the plastic material to cool and at least partially solidify within the mold cavity.

Description

BACKGROUND

[0001] The present invention relates to manufacturing a foldable toothbrush.

[0002] Foldable toothbrushes typically include a formed handle portion and a filaments portion that extend from the handle portion. The formed handle portion may be foldable along one or more hinges formed therein. Generally, a foldable toothbrush can be configured for either storage or use, usually depending on whether it is folded or unfolded.

SUMMARY OF THE INVENTION

[0003] One aspect of the invention features a method that includes securing filaments to a toothbrush handle that is foldable along a longitudinal axis to acquire a functional configuration. This method includes providing a mold device for a toothbrush handle. The mold device includes an upper member and a lower member that are positionable to define a mold cavity therebetween and a horizontally disposed parting line. This aspect also includes linearly positioning filaments partially within the mold cavity and extended beyond the mold cavity in a plane that is parallel to the parting line. Additionally, this method includes injecting a flowable plastic material into the mold cavity and allowing the plastic material to cool and at least partially solidify within the mold cavity.

[0004] The mold cavity may include a projection (i.e., a rib) that extends linearly along a longitudinal axis of the mold cavity to form a living hinge in a formed toothbrush handle. In such an embodiment, positioning the filaments includes ensuring that the filaments traverse the projection in a substantially orthogonal manner. Other implementations can include using the projection to compress a portion of the filaments within the mold cavity. The filaments may be compressed to a height of less than approximately 0.5 millimeters or to a height of approximately 0.2 millimeters.

[0005] Certain implementations include applying a shaping force to a portion of the filaments that is extended beyond the mold cavity. Other implementations include cutting the filaments to define ends of bristles that extend from a toothbrush handle formed around the filaments.

[0006] According to another aspect of the invention, a method of securing filaments to a toothbrush handle is disclosed that includes providing a toothbrush biscuit having a formed portion and bristles extending from the formed portion, positioning the formed portion at least partially within a mold cavity so that the bristles extend beyond the mold cavity in a plane that is substantially parallel to a parting line of the mold cavity, injecting a flowable plastic material into the mold cavity and allowing the plastic material to cool and at least partially solidify within the mold cavity. Generally, the biscuit is foldable along a hinge in the formed portion. The biscuit is positioned so that the hinge aligns with a linear projection in the mold cavity.

[0007] Creating the biscuit can include providing a first length of filaments, providing a welding device having a first surface and a second surface positionable relative to the first surface to define a welding region and a parting line therebetween, positioning a portion of the first length within the welding region and imparting energy to the portion of the first length with the welding device to at least partially melt the portion. To facilitate ease of description, the first length of filaments can be characterized as including a leading end, a trailing end and a midsection disposed therebetween. In some instances, positioning the portion of the first length within the welding region includes positioning the midsection within the welding region in a substantially linear fashion with the leading end extended beyond the welding region at a first side of the welding region and with the trailing end extended beyond the welding region at an opposite side of the welding region. Certain embodiments may include applying a shaping force to the leading end and to the trailing end with a first shaper die and a second shaper die, respectively, while imparting energy to the portion of the first length of filaments and while allowing the portion to subsequently cool. The first shaper die and the second shaper die can have cross-sectional contours that approximate sinusoidal patterns or any other convenient pattern, either repetitive or random, for example, saw tooth or step function patterns.

[0008] Some arrangements include a projection that linearly traverses an internal surface of the welding region to define a narrow strip within the welding region. In such cases, positioning a portion of the first length within the welding region includes ensuring the first length of filaments traverses the narrow strip of the welding region in a substantially orthogonal manner. In some embodiments the projection is configured to impart a compressive force upon the first length of filaments positioned within the welding region when the first surface and the second surface are moved toward each other.

[0009] The recited method also includes allowing the at least partially melted portion of the first length of filaments to cool and at least partially solidify within the welding region and subsequently advancing the first length of filaments in a substantially linear direction to remove the portion from the welding region. In some instances, the method includes creating a perforation or perforations in the cooled and at least partially solidified portion. Certain instances include coupling the first length of filaments to a cutting device and cutting the filaments with the cutting device at a leading edge of the leading end and at a trailing edge of the trailing end to define edges of the biscuit. Still other instances include providing a second length of filaments having a second leading end attached to the trailing end of the first length of filaments, wherein advancing the first length of filaments further comprises positioning a portion of the second length of filaments within the welding region. Such an embodiment would also include imparting energy to the portion of the second length of filaments within the welding region to at least partially melt the portion of the second length of filaments.

[0010] Certain embodiments include imparting energy to the portion of the first length within the welding region by causing the filaments to vibrate with an ultrasonic welder and thereby creating heat. Other embodiments include using a conventional heating element.

[0011] Another aspect of the invention includes a method of fabricating a toothbrush biscuit having a formed portion and a filament portion, wherein the biscuit is foldable along an axis that is substantially perpendicular to a direction in which the filament portion extends from the formed portion. The method includes providing a first length of filaments, providing a welding device having a first surface and a second surface positionable relative to the first surface to define a welding region therebetween, positioning a portion of the first length of filaments within the welding region and imparting energy to the portion of the first length with the welding device to at least partially melt a portion of the first length of filaments.

[0012] Some implementations of the method include positioning a midsection of the length of filaments within the welding region in a substantially linear fashion, so that a leading end extends beyond the welding region at a first side of the welding region and so that a trailing end extends beyond the welding region at an opposite side of the welding region. Certain embodiments include applying a shaping force to the leading end with a first shaper die while imparting energy to the portion of the first length of filaments and/or applying a shaping force to the trailing end with a second shaper die while imparting energy to the portion of the first length of filaments. The first shaper die and the second shaper die can have cross-sectional contours that approximate sinusoidal patterns or any other conceivable pattern. In certain embodiments, one surface has a rib that extends toward the opposite surface and linearly traverses the first surface to define a narrow strip within the welding region. In this case, positioning a portion of the first length within the welding region would likely include ensuring that the portion traverses the narrow strip of the welding region in a substantially orthogonal manner. Moreover, the rib can be configured so as to impart a compressive force upon the first length of filaments positioned within the welding region when the two surfaces are moved toward each other.

[0013] According to yet another aspect of the invention, a welding device includes a first member having a first surface, a second member having a second surface that substantially faces the first surface thereby defining a welding region therebetween, wherein the welding region is adaptable to receive a first length of filaments for subsequent welding and a first shaper member having a first shaper surface that is positionable to contact a second length filaments, wherein the second length is contiguous to the first length, and wherein the second length extends beyond the welding region.

[0014] In some embodiments, the welding device has a first shaper member that is secured to the first member and movable therewith. The first shaper member can be adaptable to contact the second length of filaments and to maintain contact throughout welding of an associated first length of filaments within the welding region. In certain implementations, the first shaper surface follows a cross-sectional contour that approximates a sinusoidal pattern. The peak-to-peak amplitude associated with the approximately sinusoidal pattern is typically between about 2 millimeters and 5 millimeters. The period associated with the approximately sinusoidal pattern is between about 5 millimeters and 12 millimeters. In some embodiments, the welding device includes a second shaper member having a second shaper surface that is positionable relative to the first shaper surface to define a shaping region therebetween, and the second shaper surface is positionable to contact the second length of filaments. The second shaper surface can also follow a cross-sectional contour that approximates a sinusoidal pattern having a peak-to-peak amplitude between about 2 millimeters and 5 millimeters and a period of between about 5 millimeters and 12 millimeters. Other patterns are also imaginable.

[0015] According to another aspect of the invention, a welding device includes a first member having a first surface, a second member having a second surface that substantially faces the first surface thereby defining a welding region therebetween, wherein the welding region is adaptable to receive a first length of filaments for subsequent welding, wherein the second surface comprises an extension toward the first surface, and wherein the extension linearly traverses the second surface to define a narrow strip within the welding region and an indexing device adaptable to position the first length of filaments within the welding region in such a manner that the first length traverses the narrow strip of the welding region in a substantially orthogonal manner. The space between the first and surface and the second surface at the narrow strip during a welding process is typically less than approximately 0.5 millimeters. The space between the first and surface and the second surface at the narrow strip during a welding process is typically less than approximately 0.3 millimeters. More specifically, the space between the first and surface and the second surface at the narrow strip during a welding process is approximately 0.2 millimeters.

[0016] In some implementations, one or more of the following advantages may be present. Filaments may be secured to a foldable toothbrush handle in a simple reliable fashion. Accordingly, associated manufacturing costs may be desirably minimized. Maintenance of assembly equipment may be desirably simplified. Speed and efficiency associated with toothbrush manufacturing can be enhanced. Higher quality toothbrushes can be manufactured with improved accuracy in positioning of filaments that extend from toothbrush handles.

[0017] Other features and advantages will be readily apparent from the following detailed description, the accompanying drawings and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is an elevation view of a mold device with filaments positioned therein.

[0019] FIG. 2 is a general flow diagram for manufacturing a foldable toothbrush.

[0020] FIG. 3 is an elevation view of a foldable toothbrush.

[0021] FIGS. 4A and 4B are perspective views of toothbrush biscuits.

[0022] FIG. 5 is a system view of a foldable toothbrush manufacturing facility.

[0023] FIG. 6 is a detailed flow diagram for manufacturing a foldable toothbrush.

[0024] FIGS. 7A through 7C are elevation views of a welding device at various stages of operation.

[0025] FIGS. 8A and 8B are side elevation views of a welding device and shaper elements at various stages of operation.

[0026] FIGS. 9A and 9B are elevation views of foldable toothbrushes.

[0027] FIGS. 10A and 10B are perspective views of a mold cavity and toothbrush biscuits.

DETAILED DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 illustrates a mold device 100 having an upper member 102 and a lower member 104 positionable to define a mold cavity 106 therebetween. The mold cavity 106 defines a parting line 108 that, in the illustrated embodiment is substantially horizontal. A plurality of filaments 110 are positioned at least partially within the mold cavity 106 and are arranged in a linear fashion therein. The filaments 110 extend beyond the mold cavity 106 at a leading edge 112 of the mold cavity 106 and at a lagging edge 114 of the mold cavity. The filaments are positioned to traverse the mold cavity in a substantially linear manner and are disposed in a plane that is substantially parallel to the parting line 108 of the mold cavity 106.

[0029] The upper member 102 and the lower member 104 respectively include internal contoured surfaces 112, 114. These surfaces 112, 114 are desirably contoured to define a narrow strip 116 that projects into the mold cavity 106 and is disposed linearly across the length of the mold cavity 106. The narrow strip 116 is configured to form a living hinge along a longitudinal axis of a toothbrush formed within the mold cavity. The filaments 110 are desirably positioned within the mold cavity to traverse the narrow strip 116 in a substantially orthogonal manner. The surfaces 112, 114 are also contoured to define exit regions 118, 120 of the mold cavity 106.

[0030] In a typical embodiment, cutting elements (not shown) can be provided to cut the filaments 110 and thereby define ends of the toothbrush bristles. Additionally, shaper elements (not shown) can be provided adjacent to the mold device 100 to apply a shaping force during the mold process to the portions of filaments 110 that extend beyond the mold cavity 106 at either or both of the leading edge 112 and the lagging edge 114. Also, a nozzle (not shown) will typically be available for injecting a flowable plastic material into the mold cavity 106.

[0031] Cross referencing FIG. 1, the method detailed in FIG. 2, includes providing 202 a mold device 106 having an upper member 102 and a lower member 104 that are positionable to define a mold cavity 106 therebetween. The method also includes positioning 204 a plurality of filaments 110 in a linear fashion at least partially within the mold cavity 106 and extended a distance beyond the mold cavity 106 in a plane that is parallel to a parting line 108 of the mold cavity 106. In some implementations, the distance that the filaments 110 extend from the mold cavity 106 may determine the length of the bristles on the subsequently formed toothbrush. The filaments 110 may be automatically or manually fed into the mold cavity 106 from a reel (not shown in FIG. 1) of filaments. Next, the method includes injecting 206 a flowable plastic material into the mold cavity 106, allowing 208 the plastic material to cool and at least partially solidify within the mold cavity 106. In this way, a toothbrush handle is molded around the filaments that are positioned within the mold cavity 106. In some implementations, the method can include cutting 210 the filaments to define the ends of the bristles of the toothbrush.

[0032] FIG. 3 illustrates a particular toothbrush 302 in a fully opened, but not fully functional position. Such a toothbrush could be manufactured according to the techniques described above. The toothbrush 302 includes a formed handle portion 308 having a living hinge 304 disposed along a longitudinal centerline axis 306. A first group of filaments 312a extends from the handle 308 in a direction that is perpendicular to the longitudinal centerline axis 306 and a second group of filaments 312b extends in an opposite direction from the handle 308 and is also perpendicular to the longitudinal centerline axis 306. The toothbrush 302 is foldable along the longitudinal axis 306 to bring the groups of filaments 312a and 312b together and to thereby realize a functional configuration. The toothbrush is illustrated in an open (non-usable) position.

[0033] FIGS. 4A and 4B illustrate exemplary toothbrush biscuits 402, 414 that may be positioned within a mold cavity, such as mold cavity 106, in lieu of the loose filaments 110 discussed above. Turning first to FIG. 4A, the biscuit 402 includes a relatively solid middle portion 404 that consists primarily of formed nylon. The biscuit 402 also includes two filament portions 406a, 406b that extend from opposite sides of the partially solidified middle portion 404. The biscuit 402 is generally foldable along an axis 408 that is substantially perpendicular to the direction in which the bristle portions 406a, 406b extend from the middle portion 404. Two parallel rows of holes 410 extend through the middle portion 404 in a direction that is substantially perpendicular to the direction of bristle portion 406a, 406b extension. Each row of holes 410 is situated on an opposite side of the axis 408. The holes 410 generally extend through the middle portion 404 entirely. The holes 410 can aid in securely fastening the biscuit 402 to a toothbrush formed around it by allowing the injected flowable plastic material to seep into the holes 410. Accordingly, the specific number of holes 410 and the patterns they are arranged in may vary depending on the specific application. In fact, in certain instances it may be desirable to altogether discard the holes 410.

[0034] The middle portion 404 includes edges 412a, 412b from which each bristle portion 406a, 406b extends. These edges 412a, 412b include melted nylon that is generally not displaced. In a typical embodiment, each bristle portion 406a, 406b includes approximately 30% of air by volume.

[0035] Referring now to FIG. 4B, an alternate biscuit 414 configuration is shown. The illustrated configuration includes a formed portion 416 at one side of the biscuit 414 with a single bristle portion 418 extending outward from the formed portion 416. A series of holes 410 are arranged along the formed portion 416. Again, these holes 410 are optional and their pattern and size is modifiable.

[0036] FIG. 5 illustrates a system 500 for manufacturing a toothbrush having a handle that is foldable along a longitudinal axis. Typically, two sets of bristles would extend from the foldable handle of such a toothbrush, each set extended in an opposite direction from the other when the handle is in an open, unfolded position. When the toothbrush is folded, however, the two sets of bristles align to extend in the same direction and the toothbrush acquires a functional configuration.

[0037] The illustrated system 500 includes a biscuit maker 501, a biscuit positioning member 548 and a molding device 550. The biscuit maker 501 can manufacture biscuits. The molding device 550 can manufacture a toothbrush that is foldable along a horizontal axis and can simultaneously attach one or more biscuits to the toothbrush.

[0038] A reel 502 is loaded with a plurality of filaments 504 that are suitable to form biscuits and suitable to be attached to a foldable toothbrush handle. The filaments 504 may include, for example, a plurality of filaments 504 wound upon the reel 502 and capable of being unwound and routed through the illustrated system in a parallel configuration.

[0039] A welding device 506 includes a first member 508 and a second member 510 that define a welding region 512 disposed therebetween. In the illustrated embodiment, the first member 508 is movable in an up and down direction as indicated by arrow 514. The first member 508 is positionable to impede upon the path of the filaments 504 through the welding region 512 and to at least partially contact the portion of filaments 504 positioned within the welding region 512. The welding device 506 is generally operable to at least partially melt the portion of filaments 504 positioned within the welding region 512. In certain implementations, the welding device 506 may employ ultrasonic welding technology, causing the filaments 504 within the welding region 514 to vibrate and melt through the absorption of frictional heat. In other implementations, the welding device may employ other heating technologies that implement, for example, steam, hot water or electricity to produce a suitably high temperature to melt the filament material positioned therein. In such implementations, the heat source may be located in at least one of either the first or second members 508, 510. Typically, heat can be applied to the filament material positioned within the welding region 512 when the first member is in a lowered position. Also, heating of the filament material can typically be suspended prior to returning the first member 508 to a raised position. This suspension of heating can allow cooling and at least partial solidification of the melted filament material therein. After cooling, the first member is usually moved to a raised position to allow the partially solidified filament material to be indexed (i.e., moved) out of the welding region 512.

[0040] First shaper members 516a, 516b are positioned adjacent to the welding region 512 proximate its entrance and exit, respectively. The first shaper members 516a, 516b are movable up and down as indicated by arrows 518a, 518b, respectively. The first shaper members 516a, 516b are positionable to impede upon and to apply a deforming/shaping force to portions of filaments that extend beyond the welding region 512 at its entrance and at its exit, respectively. The first shaper members 516a, 516b may be configured to impart a pattern to portions of the filaments 504 that extend beyond the welding region. Certain implementations may include a first shaper member at only one of either the entrance or the exit of the welding region 512. Typically, the first shaper members 516a, 516b impose upon the portion of filaments while the welding device 506 imparts energy to the portion of filaments within the welding region 512. The first shaper members also usually maintain their position during the cooling and partial solidification process of the filaments inside the welding region 512. When the first member 508 is moved to a raised position and the filaments are ready to be indexed, the first shaper members can typically be returned to a raised position.

[0041] An indexing device 520 is movable between a first position 522 and a second position 524, as indicated by arrow 538. Indexing device, such as the one described here, are well known in the art. Here for example, the indexing device 520 includes a gripping element 526 that is operable to grip and move the filaments 504 as the indexing device 520 travels from the first position 522 to the second position 124. The indexing device 520 is further operable to release the filaments 504 as the indexing device 520 returns from the second position 524 to the first position 522. In the illustrated embodiment, the filaments 504 are advanced through the system 500 in indexed movements, the distance of such movements being approximately equal to a length along the filaments 504 that corresponds to a biscuit's length created by the biscuit maker 501. Alternately, other indexing device arrangements may be implemented as may be generally known in the art.

[0042] A hole punch 528 is movable in an up and down direction as indicated by arrow 529. The hole punch 528 is positioned so that each time the length of filaments 504 is indexed, a partially solidified portion of the bristles will be coupled to the hole punch 528 to be punched. The illustrated embodiment includes two punch elements 530a, 530b that protrude from a bottom surface of the hole punch 528. Corresponding recesses 532a, 532b are provided in a structural element 534 to receive the punch elements 530a, 530b, respectively. The hole punch 528 is positionable so that the punch elements 530a, 530b can penetrate the partially solidified portion of the filaments 504 and mate with recesses 532a, 532b. In some instances, it may be desirable for the recesses 532a, 532b to be bottomless and to open into a trash bin (not shown).

[0043] A cutting device 536 is movable in an up and down direction as indicated by arrow 540. The cutting device 536 includes a cutting element 542 that may include, for example, one or more cutting blades suitable to cut through the filaments 504 at a cutting surface 546. The cutting device 536 typically cuts the filaments 504 to define a biscuit having at least one partially solidified formed portion and at least one portion consisting primarily of filaments.

[0044] A collecting surface 544 is positioned adjacent to the cutting surface to receive biscuits that are cut by the cutting device 536. The illustrated embodiment includes a simple flat surface. However, the collecting surface 544 may include any one of several imaginable configurations. For example, the collecting surface 544 may include a collecting bin, a conveyer belt, or other collecting or transporting mechanism or combination thereof.

[0045] A molding device 550 includes an upper mold element 552 and a lower mold element 554. The upper mold element 552 is movable in upward and downward directions as indicated by arrow 555. The upper mold element 552 and the lower mold element 554 are matable to each other to define an internal mold cavity (not illustrated) having a substantially horizontal parting line 553 between the two mold elements 552 and 554. The molding device 550 also includes a nozzle 556 for delivering flowable plastic material into the mold cavity.

[0046] A positioning member 548 is movable in essentially any direction and is operable to lift a biscuit from the collecting surface 544 and subsequently position the biscuit at least partially within the mold cavity of the molding device 550. The positioning member 548 may employ any technique generally known in the art to lift the biscuit by employing, for example, a vacuum source, an adhesive material or a robotically controlled mechanical limb.

[0047] The illustrated system 500 may be modified in a number of ways as will be readily understood by one possessing sufficient skill in the art. For example, in certain implementations a hole punch 528 may be deemed unnecessary and thereby not included. In other implementations, an alternate arrangement may be used to cut the filaments. In still other implementations, the relative arrangement and order of components within the system may be modified. For example, the relative positions of the indexing device 520 and the hole punch 528 may be swapped. It is also conceivable that the relative positions of the hole punch 528 and the cutting device 536 could be swapped. Additionally, other system components not specifically illustrated may be included as will be readily understood by one possessing sufficient skill in the art.

[0048] FIG. 6 details a particular method of manufacturing a toothbrush using, for example, the apparatus described above. According to the method, a first step 602 involves a toothbrush manufacturer providing a first length of filaments having a leading end, a trailing end and a midsection disposed therebetween. The first length of filaments may be provided, for example, from a reel of filaments. In a typical embodiment, the filaments are a nylon material. The first length of filaments may be between approximately 20 millimeters and 50 millimeters long, but more preferable, may be approximately 30 millimeters to 40 millimeters. Most preferably, the first length of filaments will be about 34.5 millimeters. Additionally, the first length of filaments may include, for example, between about 1000 and 2000 strands of filament. More preferably however, the first length of filaments will include approximately 1500 strands of filaments. In a typical embodiment, each strand will have a diameter that is between about 0.003 inches and 0.008 inches. More preferably, however, the diameter will be about 0.006 inches.

[0049] A second step 604 of the method involves a toothbrush manufactures providing a welding device, for example, welding device 508, having a first surface and a second surface that is positionable relative to the first surface to define a welding region 512 therebetween. In some implementations, the first and second surfaces may be contoured to define a narrow portion of the welding region 512 that extends linearly from one side of the welding region 512 to an opposite side. Such a welding device 508 may employ, for example, ultrasonic welding technology, steam heating, hot water heating, electrical heating, etc.

[0050] The next step 606 of the method includes positioning at least a portion of the midsection of the first length of filaments within the welding region 512. Typically, the midsection will be so positioned that it traverses the narrow portion of the welding region in a substantially orthogonal manner, so that the leading end and the trailing end both extend beyond the welding region at opposite ends thereof. The method also includes the step 608 of applying a deforming force to the leading end and to the trailing end of the first length of filaments. Shaper members, for example, shaper members 516a, 516b, may apply this deforming force.

[0051] Next, the method includes the step 610 of imparting energy to the portion of the midsection that is positioned within the welding region to at least partially melt it. Depending on the type of technology implemented, the imparted energy may take the form of either directly applied heat, vibration, or other forms. Typically, the applied deforming force will be maintained throughout the process of imparting energy to the portion of the midsection. Moreover, the deforming force is typically maintained even after the imparting of energy is suspended.

[0052] The next step 612 involves allowing the at least partially melted portion of the midsection to cool and at least partially solidify. Once the melted portion cools, the manufacturer typically removes 614 the deforming force from the leading and the trailing ends of the length of filaments. In this manner, the filaments can substantially maintain their relative positions after removal of the deforming force.

[0053] Next, the method recites the step 616 of maneuvering the welding device 506 to allow removal of the first length of filaments from the welding region. Such maneuvering might include, for example, moving the first surface away from the second surface. After such maneuvering, the manufacturer removes 618 the first length of filaments from the welding device 506. Such moving may be accomplished either manually or automatically and may include indexing the first length of filaments.

[0054] The next step 620 of the method includes advancing the first length of filaments to a hole punch area. In a typical embodiment, the advancing mechanism will include an indexing device capable of linearly translating the length of filaments in discrete steps, each step being approximately equal in distance to the length of the first length of filaments. Once coupled to the hole punch, the manufacturer punches 622 a hole in the first length of filaments. Such hole punching is typically performed through the melted and formed portion of the first length of filaments. The size of the hole, the number of holes and the configuration/arrangement of holes may vary.

[0055] The next step 624 of the recited method includes advancing the first length of filaments to a cutting area. A cutting element cuts 626 the first length of filaments, thereby defining a discrete biscuit having a leading end comprising loosely packed filament strands, a central portion that is at least partially solidified and formed, and a trailing end comprising loosely packed filament strands.

[0056] The next step 628 is coupling to a mold device so that the formed portion is positioned at least partially within the mold cavity of the mold device. The manufacturer then injects 630 a flowable plastic material into the mold cavity. After injecting, the next step 632 includes allowing the plastic material to cool and at least partially solidify within the mold cavity. In the last step 634 the cooled and at least partially solidified plastic material is removed from the mold device. It will be understood that by one of ordinary skill in the art that the recited method may be modified sequentially and substantially in many ways.

[0057] Referring now to FIGS. 7A through 7C, a welding device 506 is depicted at various stages of operation. Specifically, FIG. 7A illustrates the first member 508 and the second member 510 so positioned to define a welding region 512 therebetween. A length of filaments 504 includes a leading end 702, a trailing end 704 and a midsection 706 disposed therebetween. The first member 508 is illustrated in a raised position, but is generally movable up and down as indicated by arrow 514. First shaper members 516a, 516b are coupled to the first member 508 for motion therewith and are so arranged that they impede upon the trailing end 704 and the leading end 702 of the length of filaments 504, respectively when the first member is moved to a lowered position. Additionally, second shaper members 716a, 716b are coupled to the second member 510. The first shaper members are positionable relative to the second shaper members to define a shaping regions 718a, 718b respectively therebetween.

[0058] FIG. 7B illustrates the upper member 508 in a lowered position. In this position, the welding region 512 is configured to define a number of discrete areas. Controlled contour areas 708 are defined at the entrance and exit of the welding region. In these areas, the height between the first member 508 and the second member 510 is approximately uniform. The height is between about 1 millimeter and 1.5 millimeters, but is more preferably, between about 1.1 millimeters and 1.2 millimeters.

[0059] Two expansion cavities 710 are also defined. The height between the first and second members 108, 110 at the expansion cavities varies. The range of variance is typically from approximately 0.2 millimeters near the center of the welding region to approximately 2.0 millimeters at the highest portion. The greatest height of the expansion cavity is preferably greater than 1.5 millimeters and most preferably approximately 1.75 millimeters. A narrow portion 712 of the welding region 512 extends linearly across a width of the welding region in a direction that is substantially orthogonal the direction that the length of filaments 504 is arranged within the welding region 512.

[0060] When the first member 508 is in the lowered position, the shaper regions 718a, 718b typically have a height of between approximately 1.3 millimeters to 2.0 millimeters, but more preferably, about 1.65 millimeters.

[0061] FIG. 7C illustrates at least partially melted nylon 714 within the expansion cavities 710 and the narrow portion 712 of the welding region 512. The nylon filaments within the controlled contour areas 708 are partially melted and partially in strand form.

[0062] FIGS. 8A and 8B illustrate side views of the welding device 506 depicted in FIGS. 7A and 7B, respectively. FIG. 8A shows that the first shaper member 516b and the second shaper member 716b each have a contoured surface facing the shaping region 718b. The contoured surfaces define a pattern in the shaping region 718b that is approximately sinusoidal. As shown, the peak-to-peak amplitude associated with the approximately sinusoidal pattern is between about 2 millimeters and 5 millimeters and the period associated with the approximately sinusoidal pattern is between about 5 millimeters and 12 millimeters. Other patterns are imaginable, for example, a saw tooth pattern or a step function type pattern. The shaper members 516b, 716b are secured to the welding device 506 by securing elements 802.

[0063] FIG. 8B illustrates the first shaper member 516b in a lowered position. The shaper members 516b, 716b, as shown, are imposing a deforming force upon the length of filaments 504 that extends beyond the welding region. In the illustrated embodiment, the deforming force imposes a sinusoidal shape upon the filaments 504.

[0064] FIG. 9A illustrates a foldable toothbrush 902 manufactured according to some of the techniques described herein, without the application of shaper members. The foldable toothbrush 902 is in a folded, operational configuration and includes two substantially linear, parallel rows 904 of bristles.

[0065] FIG. 9B illustrates a similar foldable toothbrush 906 that includes two sets 908 of bristles that follow a substantially sinusoidal contour.

[0066] Referring now to FIG. 10A, a bottom section 1002 of a molding device for manufacturing a toothbrush handle that is foldable along a longitudinal axis is illustrated. The bottom section 1002 defines a bottom portion 1003 of a mold cavity and a bottom portion of two bristle receiving compartments 1012a, 1012b. The bottom portion is matable with a corresponding upper portion (not illustrated) at a parting line 1014 of the mold cavity. The mold cavity is adapted to receive flowable plastic material therein. The bristle receiving compartments 1012a, 1012b, however, are adapted to be fluidly isolated from the mold cavity. Such isolation is achieved by barriers 1016a, 1016b installed therebetween. The illustrated biscuit 1004 includes a formed portion, foldable along a longitudinal axis 1008 and two bristle portions 1010a, 1010b that extend from opposite ends of the formed portion 1006 in a direction that is perpendicular to the folding axis 1008. The biscuit 1004 includes several holes 1012 passing through from an upper surface to a lower surface of the biscuit 1004.

[0067] The biscuit 1004 can be coupled to the molding device in such a manner that at least part of the formed portion 1006 is positioned within the mold cavity 1002. When so coupled, the upper section of the molding device can be positioned to define a complete mold cavity, and flowable plastic material can be injected into the mold cavity. The flowable plastic material will desirably flow through the holes 1012 machined in the formed portion of the biscuit 1004. The biscuit material typically has a higher melting point than that of the flowable plastic material. As the flowable plastic material cools and solidifies within the mold cavity, it becomes molded to the formed portion 1006 of the biscuit 1004.

[0068] FIG. 10B illustrates an arrangement wherein two biscuits 1018a, 1018b, each having a single formed portion 1020a, 1020b and a single bristle portion 1022a, 1022b can be coupled to a molding device as indicted. As discussed above, a portion of each formed portion 1020a, 1020b is positioned within the mold cavity. Each bristle portion is positioned within a bristle-receiving cavity that is isolated from the mold cavity by a partition disposed therebetween.

[0069] Various features of the techniques and apparatus' described herein can be modified.

[0070] Other implementations are within the scope of the following claims.

Claims

1. A method of securing filaments to a toothbrush handle that is foldable along a longitudinal axis to acquire a functional configuration, the method comprising: providing a mold device for a toothbrush handle, the mold device comprising an upper member and a lower member positionable to define a mold cavity therebetween and a corresponding parting line therebetween; positioning filaments partially within the mold cavity, the filaments arranged linearly within the mold cavity in a plane that is parallel to the parting line; injecting a flowable plastic material into the mold cavity; and allowing the plastic material to cool and at least partially solidify within the mold cavity.

2. The method of claim 1 wherein positioning the filaments partially within the mold cavity comprises positioning the filaments within the mold cavity.

3. The method of claim 1 wherein the filaments are extended beyond the mold cavity at a leading edge of the mold cavity and extended beyond the mold cavity at an opposite, lagging edge of the mold cavity.

4. The method of claim 1 wherein the mold cavity is contoured to define a narrow strip that extends linearly along a longitudinal axis of the mold cavity, the narrow strip configured to form a living hinge in a toothbrush handle formed within the mold cavity; and wherein positioning the filaments comprises ensuring that the filaments traverse the narrow strip in a substantially orthogonal manner.

5. The method of claim 4 further comprising using the narrow strip to compress a portion of the filaments within the mold cavity.

6. The method of claim 5 wherein compressing the portion of the filaments comprises compressing the portion of the filaments to a height of less than approximately 0.5 millimeters.

7. The method of claim 5 wherein compressing the portion of the filaments comprises compressing the portion of the filaments to a height of approximately 0.2 millimeters.

8. The method of claim 1 further comprising applying a shaping force to a portion of the filaments that is extended beyond the mold cavity.

9. The method of claim 1 further comprising cutting the filaments to define ends of bristles that extend from a toothbrush handle formed within the mold cavity.

10. The method of claim 1 wherein positioning the filaments comprises positioning a pre-formed biscuit at least partially within the mold cavity.

11. A method of securing filaments to a toothbrush handle that is foldable along an axis to acquire a functional configuration, wherein the axis is oriented perpendicularly from the intended orientation of filaments to be secured to the handle, the method comprising: providing a toothbrush biscuit having a formed portion and a plurality of filaments that extend from the formed portion; positioning the formed portion at least partially within a mold cavity so that the bristles extend beyond the mold cavity in a plane that is substantially parallel to a parting line of the mold cavity; injecting a flowable plastic material into the mold cavity; and allowing the plastic material to cool and at least partially solidify within the mold cavity.

12. The method of claim 11 wherein the mold cavity comprises a projection configured to form a hinge along the longitudinal axis of the toothbrush handle; wherein providing the toothbrush biscuit comprises providing a biscuit that is foldable along a hinge in the formed portion that is perpendicular to the bristles; and wherein positioning the formed portion comprises aligning the hinge with the projection.

13. The method of claim 11 wherein providing the toothbrush biscuit comprises: providing a first length of filaments; providing a welding device having a first surface and a second surface positionable relative to the first surface to define a welding region there between; positioning a portion of the first length within the welding region; and imparting energy to the portion of the first length with the welding device to at least partially melt the portion.

14. The method of claim 13 wherein the first length of filaments comprises a leading end, a trailing end and a midsection disposed therebetween; and wherein positioning the portion of the first length within the welding region comprises positioning the midsection within the welding region arranged in a substantially linear fashion with the leading end extended beyond the welding region at a first side of the welding region and with the trailing end extended beyond the welding region at an opposite side.

15. The method of claim 14 further comprising applying a shaping force to the leading end and to the trailing end with a first shaper die and a second shaper die, respectively, while imparting energy to the portion of the first length of filaments.

16. The method of claim 15 wherein the first shaper die and the second shaper die have cross-sectional contours that approximate sinusoidal patterns.

17. The method of claim 12 wherein the second surface comprises a projection that linearly traverses the second surface to define a narrow strip within the welding region and wherein positioning a portion of the first length within the welding region comprises ensuring the first length traverses the narrow strip of the welding region in a substantially orthogonal manner.

18. The method of claim 17 wherein the projection is positionable to impart a compressive force upon the first length of filaments positioned within the welding region and wherein imparting energy to the portion of the first length further comprises applying a compressive force to the first length of filaments with the extension.

19. The method of claim 12 further comprising allowing the at least partially melted portion of the first length of filaments to cool and at least partially solidify; and advancing the first length of filaments in a substantially linear direction to remove the portion from the welding region.

20. The method of claim 19 further comprising creating a perforation through the cooled and at least partially solidified portion.

21. The method claim 19 further comprising: coupling the first length of filaments to a cutting device; and cutting the filaments with the cutting device at a leading edge of the leading end and at a trailing edge of the trailing end to define the biscuit.

22. The method of claim 19 further comprising: providing a second length of filaments having a second leading end attached to the trailing end of the first length of filaments; wherein advancing the first length of filaments further comprises positioning a portion of the second length of filaments within the welding region.

23. The method of claim 22 further comprising imparting energy to the portion of the second length of filaments within the welding region to at least partially melt the portion of the second length of filaments.

24. The method of claim 12 wherein providing the welding device comprises providing an ultrasonic welder and wherein imparting energy to the portion of the first length comprises causing the filaments to vibrate with the ultrasonic welder thereby creating heat.

25. The method of claim 12 wherein providing a welding device comprises providing a conventional heating element.

28. The method of claim 12 wherein the first length of filaments comprise a first section and a second section that is contiguous to the first section, and wherein positioning the portion of the first length within the welding region comprises positioning the first section within the welding region in a substantially linear fashion so that the second end section extends beyond the welding region.

27. The method of claim 26 further comprising applying a shaping force to the second section with a shaper die while imparting energy to the first section.

28. The method of claim 27 wherein the shaper die follows a cross-sectional contour that approximates a sinusoidal pattern.

29. The method of claim 26 further comprising: coupling the first length of filaments to a cutting device; and cutting an end of the first section and an end of the second section to thereby define edges of the biscuit.

30. A method of fabricating a toothbrush biscuit comprising a formed portion and a filament portion, wherein the biscuit is foldable along an axis that is substantially perpendicular to a direction in which the filament portion extends from the formed portion, the method comprising: providing a first length of filaments; providing a welding device having a first surface and a second surface positionable relative to the first surface to define a welding region therebetween; positioning a portion of the first length within the welding region; and imparting energy to the portion of the first length with the welding device to at least partially melt the portion.

31. The method of claim 30 wherein the first length of filaments comprises a leading end, a trailing end and a midsection disposed therebetween, and wherein positioning the portion of the first length within the welding region comprises positioning the midsection within the welding region in a substantially linear fashion, so that the leading end extends beyond the welding region at a first side of the welding region and so that the trailing end extends beyond the welding region at an opposite side of the welding region.

32. The method of claim 31 further comprising: applying a shaping force to the leading end with a first shaper die while imparting energy to the portion of the first length of filaments; and applying a shaping force to the trailing end with a second shaper die while imparting energy to the portion of the first length of filaments.

33. The method of claim 32 wherein the first shaper die and the second shaper die have cross-sectional contours that approximate sinusoidal patterns.

34. The method of claim 30 wherein the second surface comprises a rib that extends toward the first surface and linearly traverses the second surface to define a narrow strip within the welding region and wherein positioning a portion of the first length within the welding region comprises ensuring the portion traverses the narrow strip of the welding region in a substantially orthogonal manner.

35. The method of claim 34 wherein the rib is positionable to impart a compressive force upon the first length of filaments positioned within the welding region and wherein imparting energy to the portion of the first length further comprises applying a compressive force to the first length of filaments with the extension.

36. The method of claim 30 further comprising allowing the at least partially melted portion of the first length of filaments to cool and at least partially solidify; and advancing the first length of filaments in a substantially linear direction to remove the portion from the welding region.

37. The method of claim 36 further comprising creating a perforation through the at least partially cooled and solidified portion of the first length of filaments.

38. The method claim 36 further comprising: coupling the first length of filaments to a cutting device; and cutting the filaments with the cutting device at a leading edge of the leading end and at a trailing edge of the trailing end to define edges of the biscuit.

39. The method of claim 36 further comprising: providing a second length of filaments having a second leading end attached to the trailing end of the first length of filaments; wherein advancing the first length of filaments further comprises positioning a portion of the second length of filaments within the welding region.

40. The method of claim 39 further comprising imparting energy to the portion of the second length of filaments within the welding region to at least partially melt the portion of the second length of filaments.

41. The method of claim 30 wherein providing the welding device comprises providing an ultrasonic welder and wherein imparting energy to the portion of the first length comprises causing the filaments to vibrate with the ultrasonic welder thereby creating heat.

42. The method of claim 30 wherein providing a welding device comprises providing a conventional heating element.

43. The method of claim 30 wherein the first length of filaments comprise a first section and a second section that is contiguous to the first end section, and wherein positioning the portion of the first length within the welding region comprises positioning the first section within the welding region so the filaments are arranged in a substantially linear fashion and so that the second section extends beyond the welding region.

44. The method of claim 43 further comprising applying a deforming force to the second section with a shaper die while imparting energy to the first section.

45. The method of claim 44 wherein the shaper die comprises a cross-sectional contour that approximates a sinusoidal pattern.

46. The method of claim 43 further comprising: coupling the first length of filaments to a cutting device; and cutting the first section and the second section to define edges of the biscuit.

47. A welding device comprising: a first member having a first surface; a second member having a second surface that substantially faces the first surface thereby defining a welding region therebetween, wherein the welding region is adaptable to receive a first length of filaments for subsequent welding; and a first shaper member having a first shaper surface that is positionable to contact a second length filaments, wherein the second length is contiguous to the first length, and wherein the second length extends beyond the welding region.

48. The welding device of claim 47 wherein the first shaper member is secured to the first member and movable therewith.

49. The welding device of claim 47 wherein the first shaper member is adaptable to contact the second length of filaments and to maintain contact throughout welding of an associated first length of filaments within the welding region.

50. The welding device of claim 47 wherein the first shaper surface follows a cross-sectional contour that approximates a sinusoidal pattern.

51. The welding device of claim 50 wherein the peak-to-peak amplitude associated with the approximately sinusoidal pattern is between about 2 millimeters and 5 millimeters.

52. The welding device of claim 50 wherein the period associated with the approximately sinusoidal pattern is between about 5 millimeters and 12 millimeters.

53. The welding device of claim 44 further comprising a second shaper member having a second shaper surface that is positionable relative to the first shaper surface to define a shaping region therebetween, and wherein the second shaper surface is positionable to contact the second length of filaments.

54. The welding device of claim 53 wherein the second shaper surface follows a cross-sectional contour that approximates a sinusoidal pattern.

55. The welding device of claim 54 wherein the peak-to-peak amplitude associated with the approximately sinusoidal pattern is between about 2 millimeters and 5 millimeters.

56. The welding device of claim 54 wherein the period associated with the approximately sinusoidal pattern is between about 5 millimeters and 12 millimeters.

57. A welding device comprising: a first member having a first surface; a second member having a second surface that substantially faces the first surface thereby defining a welding region therebetween, wherein the welding region is adaptable to receive a first length of filaments for subsequent welding, wherein the second surface comprises an extension toward the first surface, and wherein the extension linearly traverses the second surface to define a narrow strip within the welding region; and an indexing device adaptable to position the first length of filaments within the welding region in such a manner that the first length traverses the narrow strip of the welding region in a substantially orthogonal manner.

58. The welding device of claim 57 wherein the space between the first and surface and the second surface at the narrow strip during a welding process is less than approximately 0.5 millimeters.

59. The welding device of claim 57 wherein the space between the first and surface and the second surface at the narrow strip during a welding process is less than approximately 0.3 millimeters.

60. The welding device of claim 57 wherein the space between the first and surface and the second surface at the narrow strip during a welding process is approximately 0.2 millimeters.