Abstract:
A gripper includes a) a first element that includes a plurality of male components; and b) a second element that includes a plurality of female components dimensioned to receive the male components. The first element and the second element are moveable from an open position to a closed position and the male components engage the female components when the elements are in a closed position. The individual male components and the individual female components are capable of maintaining a plurality of bristles in fixed relation to each other when the elements are in a closed position.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to gripping filaments. 
     Oral brushes, e.g., toothbrushes, often include a handle, a head and tufts of bristles extending from the head. 
     The bristles of the oral brush are often made from filaments. In some oral brush manufacturing processes filaments are provided in the form of a hank that is circular in cross section, has a height ranging from a few centimeters to several meters, and includes a band around its circumference. The band holds the filaments together. 
     Prior to incorporation into the oral brush, the hanks, and thus the filaments, are cut to a length of a few centimeters. The band is then removed and the filaments can be transferred to a magazine for further processing. Once the band is removed these short filaments become very difficult to handle. 
     SUMMARY OF THE INVENTION 
     In one aspect, the invention features a gripper that includes a) a first element that includes a plurality of male components, and b) a second element that includes a plurality of female components dimensioned to receive the male components. The first element and the second element are moveable from an open position to a closed position; the male components engage the female components when the elements are in a closed position. The individual male components and the individual female components are capable of maintaining a plurality of bristles in fixed relation to each other when the elements are in a closed position. In one embodiment, the female component or the male component is spring loaded. In another embodiment, the gripper further includes a spring extending from one of the first element or the second element to one of the female component or the male component. In one embodiment, the spring exerts a force against the female component in the direction of the male component. In other embodiments, the gripper further includes a means for biasing one of the female component or the male component against the other of the female component or the male component. 
     In some embodiments, the female components are removable from the second element. In other embodiments, the male components are removable from the first element. In some embodiments, the male components are removable from the first element, and the female components are removable from the second element. 
     In other embodiments, the gripper further includes a transport connected to the gripper. In one embodiment, the transport is capable of moving the gripper from a first position to a second position. In some embodiments, the transport is capable of rotating the gripper. In another embodiment, the female components include an entrance defmed by a first side wall, a second side wall, and a seat disposed between the first side wall and the second side wall. In one embodiment, the first side wall includes a tapered surface. In other embodiments, the second side wall includes a tapered surface. 
     In another embodiment, the male components include a finger. In one embodiment, the male components include a finger, a first guide member extending from the finger, and a second guide member extending from the finger. 
     In some embodiments, the gripper is automated. In other embodiments, the male components and the female components are capable of maintaining a plurality of tufts of bristles having two unfused ends in fixed relation to each other. In another embodiment, the male components and the female components are capable of maintaining a plurality of tufts of bristles in fixed relation to each other where the tufts have a fused end. 
     In another aspect, the invention features a method of transferring a plurality of tufts of bristles using an above-described automated gripper. The method includes 1) closing the elements of the gripper such that a plurality of tufts of bristles are maintained in fixed relation to each other between the male components and the female components of the gripper, and 2) moving the gripper. In one embodiment, the method further includes releasing the tufts of bristles. In some embodiments, the step of releasing includes placing individual tufts of bristles in openings in an article, e.g., a carrier bar or a mold insert. In other embodiments, the step of moving the gripper includes moving the gripper from a first position to a second position. 
     In other aspects, the invention features a gripper holding bristles that includes a first element, a second element, and a plurality of tufts of bristles having two unfused ends. The gripper maintains the tufts in fixed relation to each other between the first element and the second element. In one embodiment, the first element includes a male component. In other embodiments, the second element includes a female component. 
     In another aspect, the invention features a method for transporting tufts of bristles having two unfused ends, the method includes gripping a plurality of tufts of bristles having two unfused ends such that the tufts are maintained in a fixed relation to each other, and moving the plurality of tufts. 
     In other aspects, the invention features a bristle processing system that includes 1) a station that includes a plurality of tufts of bristles, and 2) an automated gripper for gripping the tufts, where the gripper includes a) a first element that includes a plurality of male components, and b) a second element that includes a plurality of female components dimensioned to receive the male components, the first element and the second element being moveable from an open position to a closed position, wherein the male components engage the female components when the elements are in a closed position. The individual male components and the individual female components are capable of maintaining the tufts of bristles in fixed relation to each other when the elements are in a closed position. 
     In one embodiment, the bristle processing system further includes a fusing apparatus that includes a heat source, where the fusing apparatus is capable of fusing the ends of the bristles to form fused tufts of bristles. 
     In another aspect, the invention features a method of processing a plurality of tufts of unfused bristles. The method includes 1) gripping a plurality of tufts of bristles having two unfused ends between a first element and a second element of an automated gripper, 2) transporting the tufts of unfused bristles in fixed relation to each other, and 3) releasing the tufts of unfused bristles. In one embodiment, the method further includes fusing one of the ends of the tufts of bristles. 
     The grippers can be used to grip and transport a number of tufts of bristles simultaneously. The grippers can also simultaneously shape a number of tufts. 
     The male and female components that constitute the gripper elements can be removable from the gripper. If a male component or a female component becomes damaged and needs replacing, the entire gripper remains useful because the individual component can be removed and replaced with a functioning component. In addition, the gripper can include any number of gripper elements (i.e., male and female component pairs), which enables the gripper to be constructed to simultaneously grip a desired number of tufts of bristles. The gripper can be modified as needed to include any number of gripper elements and any type of gripper element (e.g., gripper elements defining various tuft shapes and more than one tuft shape on a single gripper). 
     One of the male component or the female component can also be spring loaded such that it is biased toward the other component. The bias allows the gripper to comply with the variances that are inherent in simultaneously gripping multiple tufts that include multiple bristles. Such variances include, e.g., variances that influence the cross-sectional dimension of the tuft including, e.g., a variance in the number of bristles in the tuft or a variance in the diameters of the bristles within the tuft. 
     The grippers are useful for transferring tufts of bristles from and to stations were the bristles undergo processes including, e.g., end rounding, fusing, cutting, and tufting. 
     Other features and advantages of the invention will be apparent from the following description of the preferred embodiments thereof, and from the claims. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 is a perspective top view of tufts of bristles held by a gripper. 
     FIG. 2 is a top view of the gripper of FIG. 1 with the tufts of bristles removed. 
     FIG. 3 is a top view of the gripper of FIG. 2 in an open position. 
     FIG. 4 is an enlarged view of the female component and male component of the gripper of FIG.  1 . 
     FIG. 5 is a top view of the male component engaged with a female component of the gripper of FIG.  1 . 
     FIGS. 6 and 6A are top views of the bristles located at two positions between a male component and a female component. 
     FIG. 7 is a top view of an indexer that includes three grippers. 
     FIG. 7A is a top view of a picker bar. 
     FIG. 8 is a top view of a gripper according to a second embodiment of the invention. 
     FIGS. 9A-C are enlarged views of bristles located at various positions between the male component and the female component of the gripper of FIG.  8 . 
     FIG. 10 is a top view of a spring loaded gripper according to a third embodiment of the invention. 
     FIG. 11 is a side view of a fusing apparatus including the gripper of FIG.  8 . 
     FIG. 12 is a perspective top view of a second embodiment of a male component and a female component of the gripper. 
     FIG. 13A is a cross sectional view of an embodiment of the gripper that includes a jaw that includes female components that include a spring loaded mechanism. 
     FIG. 13B is a top view of the bristle receiving surface of the female components of FIG.  13 A. 
     FIG. 13C is a side view of the spring loaded mechanism of FIG.  13 A. 
    
    
     DETAILED DESCRIPTION 
     Referring to FIGS. 1-6, gripper  10  includes two gripper elements, e.g., jaws  14 ,  16 , arranged in a plane and capable of moving from a first open position to a second closed position. In the closed position, gripper  10  is capable of gripping a number of tufts  8  of bristles  6 , where the tufts  8  of bristles include fused ends, unfused ends or combination thereof. 
     Jaw  14  includes a number of female components  18  that include an entrance  20 , defined by side walls  22   a,    22   b  and seat  24 . The side walls  22   a,    22   b  preferably include tapered ends  23   a,    23   b  to guide bristles  6  of tuft  8  toward seat  24  of female component  18 . The female component is dimensioned to accommodate the tuft and preferably is dimensioned to define at least a portion the shape of the tuft. Examples of useful shapes defined by female component  18  include v-shaped, square, rectangular, circular, elliptical, oval, and step shaped. 
     Jaw  16  includes a number of male components  26  extending from a surface  28  of jaw  16 . Male components  26  include a finger  30  dimensioned to fit within female components  18 . Finger  30  includes a bristle contacting end  32  and preferably includes guide members  33   a,    33   b  that assist in guiding bristles  6  into female component  18 . Bristle contacting end  32  and guide members  33   a,    33   b  can also assist in shaping tuft  8 . The male component  26  can also include a foot  35  extending from the finger  30 . The foot  35  can be dimensioned to assist in shaping the tuft  8 . 
     The gripper  10  includes a means  34  that moves the gripper jaws  14 ,  16  from an open position to a closed position. Examples of useful gripper moving means include actuators, e.g., pneumatic, electric, and hydraulic actuators, cams, and links. As gripper  10  closes jaws  14 ,  16  move toward each other, male components  26  and female components  18  engage each other, and male component  26  passes into female component  18  a predetermined distance. As male component  26  slides into entrance  20  of female component  18 , male component  26  presses bristles  6  against seat  24  of female component  18  such that bristles  6  become sandwiched between (i.e., gripped by) male component  26  and female component  18 . 
     The bristles  6  are held in position (i.e., gripped) by the male  26  and female  18  components with a force sufficient to maintain the bristles in the gripper  10 . When the gripper  10  opens, the gripper jaws  14 ,  16  separate and the tufts  8  are released or are available for release from the gripper  10 . 
     Referring to FIGS. 8-9, gripper  110  includes a number of gripper pairs  112  each of which includes a female component  118  attached to a first gripper jaw  114  and a male component  126  attached to a second gripper jaw  116 . Gripper pairs  112  are removably attached to jaws  114 ,  116  and can be attached to or removed from jaws  114 ,  116  as desired. Preferably the gripper pairs  112  are attached to the jaws  114 ,  116  by a fastener. The fastener feature can be realized by, e.g., screw, dowel pin, clamp, rivet, solder, and combinations thereof. 
     Referring to FIG. 10, female component  118  is preferably attached to jaw  114  with a spring loaded mechanism  120 . The spring loaded feature can be realized by, e.g., coil spring, torsion spring, gas spring, e.g., air spring, and elastomer spring. Spring  122  of spring loaded mechanism  120  biases female component  118  in the direction of male component  126  and allows female component  118  to move along a linear path when a sufficient force is exerted on female component  118  in a direction opposing the force of spring  120 . When male component  126  and female component  118  come together to grip a tuft  8  that is larger than a predetermined dimension, the force exerted by male component  126  and the dimension of tuft  8  causes female component  118  to press against spring  122 , which causes spring  122  to compress. By displacing female component  118 , gripper pairs  112  are able to adjust for variances that occur in the dimensions of the numerous tufts  8  that are being simultaneously gripped by gripper  110 . 
     In FIG. 10, for example, each spring loaded female component  118  of the individual gripping pairs  112  on gripper  110  obtains a position that varies depending upon the dimension of the tuft being gripped. Relatively larger tuft  8 A displaces spring loaded female component  118 A to a greater extent relative to the displacement exhibited by spring loaded female component  8 B that grips relatively smaller tuft  8 B. 
     Referring to FIGS. 13A-C, a hole  133  exists below the seat  24  of the female component  18 . A spring loaded mechanism  134  is positioned in the hole  133  located at the seat  24  of female component  18 , which extends from jaw  14 . The spring loaded mechanism  134  includes a spring  138  that is attached to jaw  14  at one end, and to a button  136  that defines at least a portion of the seat  24  of the female component  18  at a second end. 
     Gripper  10  is preferably attached to a transport  36  that is capable of moving the gripper  10  from one position to another position. Transport  36  can be constructed and programmed to move gripper  10  as desired including, e.g., translationally, rotationally, vibrationally, and combinations thereof. The transports feature can be realized by, e.g., actuators that are capable of moving the gripper. Examples of suitable actuators include pneumatic, mechanical, and electrical linear actuators and rotary actuators, and combinations thereof. 
     The gripper is useful in a variety of applications and in a variety of processes including, e.g., to pick and place bristles, to hold bristles while additional processing steps are conducted on the bristles, to transport bristles from one position to another, and combinations thereof. 
     In one application, the gripper picks bristles from a first station and places bristles at a second station. At each station a variety of processes can occur including, e.g., fusing, end rounding, shaping, cutting, trimming, tufting, and combinations thereof. Mechanisms for performing these processes are described, for example, in U.S. Pat. Nos. 5,927,819, and 5,224,763, which are incorporated herein. 
     Referring to FIG. 7, for example, gripper  10  is attached to transport  36  that is in the form of an indexer and is constructed to operate in a pick and place mode. Gripper  10  travels along the predetermined path of the indexer as it indexes from one station  50  to the next. When gripper  10  indexes to first station  50 A, which includes tufts  8  of bristles  6  extending from openings  54  in a picker bar  52 , gripper  10  opens, positions itself to grip tufts  8 , and closes such that tufts  8  become sandwiched between jaws  14 ,  16 . Gripper  10  then clears first station  50 A, e.g., the gripper moves upward or picker bar  52  moves downward. Gripper  10  then transports tufts  8  to a second station  50 B, e.g., a carrier bar  6  that includes blind holes  58 . Gripper  10  can then place tufts  8  at second station  50 B or hold tufts  8  while tufts  8  are subjected to a process. 
     Referring to FIG. 11, in another application a fusing apparatus  60  includes gripper  110  and heat source  130 . Carrier bar  132  filled with tufts  8  extending from blind holes  134  in the carrier bar  132  is positioned such that tufts  8  extend between female component  118  and male component  126  of gripper  110 . Male components  126  and female components  118  of the gripper move toward tufts  8  of bristles  6 . When female components  118  and male components  126  reach an intermediate position at which the tufts  8  are in contact with male components  126 , gripper  110  pauses. 
     Heat source  130 , e.g., heated compressed air, is then applied to the exposed ends of bristles  6  for a period sufficient to allow the ends of the bristles  6  to melt and fuse together. When male  126  and female  118  components are at the intermediate position bristles  6  disposed between the two components  118 ,  126  are spaced apart from each other, which allows heat to transfer down the length of bristles  6 , which, in turn, exposes a greater extent of the bristles  6  to the heat, which increases the length of melt along the bristles. While the ends of the bristles  6  are still molten jaws  114 ,  116  move to the closed position such that male  126  and female  118  components press against bristles  6  to compress and shape tuft  8 . 
     Heat source  130  is removed from bristles  6  and jaws  114 ,  116  are held in the closed position for a few seconds to allow bristles  6  to cool, which freezes the shape of the tuft  8 . Heat source  130  can be removed after the bristle ends have melted, e.g., while male  126  and female  118  components are at the intermediate position, or after jaws  114 ,  116  have closed. The resulting fused tufts  8  are then available for transfer to another station for additional processing. 
     Other embodiments are within the claims. For example, the male components can also be spring loaded. A variety of bristles having a variety of dimensions and cross sectional shapes can be gripped by the gripper. The gripper is preferably capable of gripping tufts and bristles having a length of from about 0.005 in to about 2 in, and a cross sectional dimension of from about 0.004 in to about 0.500 in, more preferably from about 0.006 in to about 0.275 in.