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.

What is claimed is:  
     
         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.