Patent Description:
The brush heads of both manual and power toothbrushes comprise bristles which are used to clean the teeth, tongue, and cheeks. In some toothbrushes, the bristles are stapled, or anchored, into the neck portion of the brush head. In other toothbrushes, the bristles are held in the head without staples, in methods commonly known as "anchor free tufting".

There are several ways to manufacture brush heads having anchor-free tufting. In one method, groups, or tufts, of individual bristles are melted or fused together at one end, and then the bristle tufts are overmolded with a material that then hardens, forming a brush head. In another method, bristle tufts that are fused at one end are inserted into holes in the brush neck, and either the neck material is heated to shrink around the bristle tufts, or the brush neck with the inserted bristle tufts are over-molded. However, there are limitations and difficulties with each of these current manufacturing methods such that the manufacturing methods are slow, involve multiple steps and equipment, or have higher than acceptable failure rates, resulting in loose bristles or bristle tufts which can come out of the brush head during use.

Accordingly, there is a need in the art for methods and apparatus for more efficiently manufacturing brush heads with anchor free tufting.

<CIT> discloses brush head arrangements.

<CIT> discloses brush head assembly and methods of manufacture.

<CIT> discloses a method and device for producing a brush.

The present invention is directed to a method for manufacturing a brush head with secured bristle tufts according to claim <NUM>. The invention is further directed to a brush head according to claim <NUM>.

Various embodiments and implementations herein are directed to manufacturing methods in which a tuft carrier is molded with retention elements having openings formed therethrough, which are used to retain tufts of bristles. The tuft carrier can be molded or otherwise placed on and/or in a handling plate to assist in manufacturing processes.

As one example, the tuft carrier (e.g., with handling plate) can be loaded into a stamping tool and separated into individual retention elements, or otherwise have excess portions of the tuft carrier removed. The stamping can be used to directly stamp the retention elements into corresponding recesses of a base plate also loaded into the stamping tool.

The processed tuft carriers can be set aside for further processing at a later time or immediately proceed to the next manufacturing step. This could enable different portions of the manufacturing process to occur at different times, and/or at different manufacturing locations. Additional manufacturing processes may include those such as inserting a bristle tuft into the opening of each of the retention elements, trimming one or both ends of bristle tufts, retaining a bristle tuft in a retention element, combining a brush neck with bristle tufts, and a variety of other processes. Once the bristle tufts have been inserted into the openings in the retention elements, either or both ends of the bristle tufts can be trimmed or adjusted to achieve a desired length or contour, e.g., to define what will become the brushing surface for the brush head, and/or to achieve a uniform length of the bristle tufts on the proximal side of the tuft carrier to facilitate bonding.

The processed proximal end of the bristle tufts, or in some arrangements the proximal end of the bristle tufts and a proximal side of the retention elements can be bonded or merged together, such as by using a laser or other heat source, chemical melting or adhesives to form a merged proximal end head portion by which the bristle tufts and retention elements are secured together such that merged tuft assemblies are formed. Optionally, after the bonding process, if not done previously, excess material can be removed from the tuft carrier, e.g., separated into individual merged tuft assemblies. Subsequently, the merged tuft assemblies can be overmolded, e.g., together with a neck for the brush head, in a matrix such as an elastomeric matrix. The various embodiments and implementations herein provide a cost-effective and efficient production of brush heads with anchor free bristle tufts is substantially improved.

Generally, in one aspect, a method for manufacturing a brush head with a base plate is provided. The method includes molding one or more tuft carriers, together having a plurality of retention elements, each retention element having an opening therethrough; positioning the retention elements in openings of a handling plate; removing excess material from the one or more tuft carriers; loading the plurality of retention elements into corresponding recesses of the base plate; inserting a bristle tuft into the opening of each retention element; bonding a proximal end of each bristle tuft together with a proximal side of each corresponding retention element to form a merged proximal end head portion that secures the bristle tufts and retention elements together as a plurality of merged tuft assemblies; positioning a platen of a neck of the brush head in relation to the merged tuft assemblies using a cavity in the base plate; and overmolding a matrix material in the base plate to at least partially encompass the platen and the plurality of merged tuft assemblies.

In one embodiment, the loading occurs directly as a result of the stamping. In one embodiment, the molding includes overmolding the one or more tuft carriers onto the handling plate. In one embodiment, the one or more tuft carriers are removed from the handling plate as a result of the stamping.

In one embodiment, the bristle tufts and retention elements are made of a same or similar material having the same or similar melting point. In one embodiment, the openings in the retention elements have differing shapes, sizes, or a combination including at least one of the foregoing. In one embodiment, the bonding includes applying heat to melt the bristle tufts and the retention elements together into the merged proximal end head portions.

In one embodiment, the excess material includes some or all of a carrier plate, a webbing link, or a combination including at least one of the foregoing. In one embodiment, the retention elements are loaded into the base plate interconnected by a carrier plate, a webbing link, or a combination including at least one of the foregoing.

Generally, in another aspect, a base plate for manufacturing a brush head is provided. The base plate includes a plurality of recesses, each configured to receive a retention element of a tuft carrier therein; a plurality of tuft bores extending from the recesses, each configured to receive a bristle tuft therein; a recessed area configured to position a manufacturing plate positioned above the plurality of recesses; an adjustment feature configured to set one or more characteristics of a free end of the bristle tufts; and a cavity shaped to receive a neck of the brush head and configured to at least partially encapsulate a platen of the neck and the retention elements with a matrix material injected into the cavity when the neck is positioned in the cavity and the retention elements are positioned in the recesses.

In one embodiment, the manufacturing plate is a handling plate holding the tuft carrier.

Generally, in another aspect, a manufacturing system includes a base plate and a stamping tool, wherein the base plate is configured to be loaded into the stamping tool with the tuft carrier and the handling plate, and the stamping tool is configured to stamp the retention elements from the handling plate directly into the recesses of the base plate.

Generally, in another aspect, a manufacturing system includes a base plate and a tufting unit, wherein the base plate is configured to be loaded into the tufting unit and the tufting unit is configured to insert a bristle tuft into each an opening in each of the retention elements.

In one embodiment, the manufacturing plate includes a cutting plate having a height, the cutting plate configured to set a proximal length of the bristle tuft to equal the height when the bristles are trimmed with the cutting plate installed in the base plate.

In one embodiment, the adjustment feature is configured to receive the free end of the bristle tufts and includes one or more blind holes, one or more adjustable pins, a contour insert having a contoured surface, or a combination including at least one of the foregoing.

Generally, in one embodiment, a brush head is provided. The brush head includes a plurality of merged tuft assemblies, each comprising: a plurality of bristle tufts each comprising a plurality of bristle strands and having a free end and a proximal end; a plurality of retention elements each having an opening therethough configured to receive one of the bristle tufts, the retention elements included by a tuft carrier during assembly and formed at least partially by inserting the retention elements into one or more openings of a handling plate and removing excess material from the tuft carrier using the handling plate; and a plurality of proximal end head portions each formed by bonding the proximal end of each bristle tuft to each corresponding retention element; a neck having a platen; and a matrix material at least partially encompassing the platen and the retention elements of the merged tuft assemblies.

In one embodiment, the retention elements and bristle tufts are composed of a same or similar material. In one embodiment, the proximal end head portions are formed by the bristle tufts melted together with the retention elements. In one embodiment, the plurality of merged tuft assemblies are interconnected in a tuft carrier web or a tuft carrier plate. In one embodiment, the matrix material is an elastomeric material.

The present disclosure describes various embodiments of a method for manufacturing a brush head assembly with bristle tufts retained by anchor free tufting in a retention element secured in a molded elastomeric matrix. More generally, applicants have recognized the need for improvements in manufacturing methods and products made using anchor free tufting. By molding carriers, and in some arrangements, molding carriers from the same or similar material as the bristle tufts, efficiencies in manufacturing are achieved with improved product quality.

Referring to <FIG>, in one embodiment, a schematic representation of a brush head assembly <NUM> is provided. More particularly, the brush head assembly <NUM> may include, but is not limited to, a plurality of bristle tufts <NUM> disposed within a matrix material <NUM> at a distal end of a neck <NUM>. That is, a distal portion <NUM> of the neck <NUM>, which may be referred to as a platen, may be at least partially enclosed in and connected to the matrix material <NUM>. The merged tuft assemblies <NUM> may include a tuft carrier <NUM> having one or more retention elements <NUM>, in which bristle tufts <NUM> are secured as discussed in more detail herein. The neck <NUM> can be coupled to, or form a part of, any manual or powered toothbrush shaft. For example, the neck <NUM> may be configured to be removably coupled to an actuator or drive shaft (not shown) of a powered oral care device (e.g., electric toothbrush) now known or to be developed.

Two examples for the merged tuft assemblies <NUM> are illustrated in <FIG>, designated as merged tuft assemblies 20A and 20B, respectively. It is to be appreciated that the reference numeral '<NUM>' is intended to generally refer to any of the merged tuft assemblies disclosed herein, while the assemblies 20A and 20B are used herein to facilitate discussion with respect to particular embodiments. It is also to be appreciated that many components of the merged tuft assemblies <NUM> are shared throughout embodiments, and thus referred to with the same reference numerals.

Referring to <FIG>, each bristle tuft <NUM> comprises a plurality of bristle strands <NUM>, which are secured in the retention elements <NUM> of tuft carrier <NUM>. Each bristle tuft <NUM> has a proximal end <NUM> and a free end <NUM>. The proximal end <NUM> of each bristle tuft <NUM> is retained within an opening <NUM> of each of the retention elements <NUM> of the tuft carrier <NUM>, while the free end <NUM> is located opposite to the proximal end <NUM> and forms the brushing surface force the brush head <NUM> when assembled. The bristle tufts <NUM> can be formed to a shape and diameter to match the size and shape of the openings <NUM> in the retention element <NUM>.

It is to be appreciated that the various components of the brush head <NUM> may take any desire size, shape, and/or orientation. For example, as seen in <FIG>, the retention elements and bristle tufts contained therein can be round, pentagonal, hexagonal, or a variety of other shapes, such as squares, diamonds, hexagons, heptagons, octagons, etc. Additionally, the retention elements <NUM> and the openings <NUM> therein can be of the same size, shape and arrangement as each other, or different shapes and sizes. For example, the retention element <NUM> may have a first shape defining its periphery, while the opening <NUM> has a second, different shape defining the shape of the bristle tuft <NUM> inserted therethrough.

Once the bristle tufts <NUM> are inserted in the opening <NUM> of the retention element <NUM>, the proximal end <NUM> of the bristle tufts <NUM>, or in some arrangements, the proximal end <NUM> of the bristle tufts <NUM> and at least a portion of a proximal side <NUM> of the retention element <NUM> are bonded together to form a merged proximal end head portion <NUM>. That is, the merged proximal head portion <NUM> may be formed from fused material from the bristles <NUM> alone, or the bristles <NUM> together with a portion of the retention element <NUM> adjacent to the bristles <NUM>. In one embodiment, the bristle tufts and/or the retention elements <NUM> are bonded together by any suitable process such as welding (ultrasonic, laser, etc.), melting, adhesives, etc..

In order to facilitate formation of the merged proximal head portion <NUM> such as shown in <FIG>, the tuft carriers <NUM> and the bristle tufts <NUM> are preferably made from the same material, or materials having a similar composition. Plastics such as Acrylonitrile Butadiene Styrene (ABS), polyamide (PA) or nylon, polypropylene, or variations or combinations of these or other materials can be used. Particularly useful are combinations of materials that have a similar co-efficient of melting to facilitate bonding by melting and cooling at a similar temperature and rate. In one embodiment, the bristles <NUM> are formed from PA, while the retention elements <NUM> are formed from a PA/ABS blend. It is to be appreciated that there may be some variability across the weld of the merged proximal end head portion <NUM>, e.g., based on the characteristics of the materials of the bristle strands <NUM> and/or the retention elements <NUM>, as well as the parameters utilized during welding. In particular, variation may occur if the bristle tuft <NUM> and the retention elements <NUM> are made of different materials, which may cause melting/cooling at different temperatures, or other differences due to their different chemical compositions. However, such variability is acceptable as long as the desired bonding is achieved.

The tuft carriers <NUM> and/or retention elements <NUM> can be formed in a variety of ways, such as molding, stamping, etc., as discussed in more detail herein. Various embodiments for the tuft carriers <NUM> can be appreciated in <FIG>. The reference numeral '<NUM>' as used herein is intended to refer generally to all embodiments of tuft carriers disclosed or envisioned, while alphabetic suffixes (e.g., 'A', 'B', etc.) have been provided to facilitate discussions of particular embodiments shown in the Figures. A similar naming style may be utilized with respect other components herein.

A tuft carrier 50A in <FIG> comprises a single one of the retention elements <NUM>, which will hold at least one of the bristle tufts <NUM> in the opening <NUM> of the retention element 50A. <FIG> respectively show a tuft carrier 50B and a tuft carrier 50C that each comprises a carrier plate <NUM> having a plurality of the retention elements <NUM> having openings <NUM> therethrough, connected together, e.g., arranged in a shape of the final brush head or some portion thereof. In <FIG>, tuft carriers 50D, 50E, and 50F are respectively shown. Each of the tuft carriers 50D-50F comprise a tuft carrier web that has a plurality of individual retention elements <NUM> connected to each other by a series of strands or webbing links <NUM>. In this way, it is to be appreciated that the retention elements <NUM> can be separate discrete units, or interconnected together, such as by the carrier plate <NUM> or the webbing links <NUM>. Similar to the tuft carriers 50B and 50C, the retention elements <NUM> and/or the openings <NUM> of the tuft carriers 50D-50F may be arranged in the desired pattern for the tufts <NUM> when the brush head is fully assembled, or some portion thereof.

In one embodiment, the tuft carriers <NUM> are formed via a molding operation, such as injection molding. The actual shape and size of the tuft carrier <NUM>, the number, size, and shape of the openings <NUM>, etc., can be set and determined by the mold used to form the carrier <NUM>. Once the carrier <NUM> has been formed and cooled, it can optionally be removed from the mold, and is ready for further processing, either immediately, or at a later time and/or place.

According to embodiments disclosed and envisioned herein, at least a portion of the tuft carrier <NUM> may be removed prior to assembly of the retention elements <NUM> in the brush head <NUM>. In one embodiment, the removal of excess material is performed by a stamping tool <NUM> shown in <FIG>. For example, the stamping tool <NUM> may include a press, ram, stamp, or die that forcibly engages the tuft carrier <NUM> placed in a die block or handling plate <NUM>, as shown in <FIG>, to cut apart, disconnect, or otherwise separate one or more portions of the tuft carrier <NUM> from each other.

The die block or handling plate <NUM> has a series of openings <NUM> configured to match the retention elements <NUM> in the tuft carrier <NUM> in size, shape and arrangement. Namely, the openings <NUM> of the die block or handling plate <NUM> of <FIG> correspond to the size, shape, and layout of the tuft carrier 50C from <FIG>. In this way, as shown in <FIG>, the retention elements <NUM> of the tuft carrier <NUM> can be inserted into the openings <NUM> of the die block or handling plate <NUM>. Thereafter, the tuft carrier <NUM>, can be processed, e.g., stamped by the stamping tool <NUM>. As shown in <FIG>, the stamping operation may disconnect or separate the retention elements <NUM> from excess material <NUM>. The excess material <NUM> may be recycled or discarded, while the retention elements <NUM> may remain in the openings <NUM> of the handling plate <NUM>, or be removed, for further processing. The handling plate <NUM> may be utilized to facilitate the general handling of the tuft carrier <NUM> and/or the loading of the tuft carrier <NUM> into other tools, such as a tufting unit, or other equipment used to create a finished brush head <NUM>. In one arrangement of the present invention, the handling plate <NUM> with the tuft carrier therein can be positioned on top of a base plate <NUM> with openings of similar size and shape in similar positions and the tuft carrier may be transferred from the handling plate into the base plate <NUM>. It is also noted that some or all of the excess material <NUM> of a tuft carrier <NUM> may be removed via other processes, e.g., cutting, or via multiple successive processes, at this step or other steps in the manufacturing process.

To facilitate handling of a variety of tuft carriers <NUM>, one or more die blocks or handling plates <NUM> may be used. A die block or handling plate, designated herein in particular as handling plate 101B is illustrated in <FIG>. Namely, the handling plate 101B includes openings 103B, which correspond in shape, size, and layout to the retention elements <NUM> of the tuft carrier 50D of <FIG>, as shown in <FIG>. The openings 103B in the handling plate 101B facilitate stamping of the tuft carrier 50D directly into the handling plate 101B. Additionally, the handling plate 101B may include a set of grooves or recesses <NUM>, which are shaped and sized to receive the webbing links <NUM> of the tuft carrier 50D. In this way, for example, the grooves <NUM> may assist in positioning and holding the tuft carrier 50D during manufacturing. It is noted that the handling plates <NUM> disclosed and envisioned herein may be removably separated from the base plate <NUM> or mold or other components of the stamping tool <NUM>, e.g., to facilitate further processing of the corresponding tuft carrier conveyed by the handling plate <NUM>. In this way, the handling plate 101B, together with the tuft carrier <NUM> stamped into the handling plate, may be separated from any excess material if desired, for further processing.

A handling plate 101C, according to another embodiment is illustrated in <FIG>. Unlike handling plate 101B, the handling plate 101C includes an opening 103C, which corresponds in general shape, size, and/or layout to the carrier plate <NUM> of the tuft carrier 50B of <FIG> (as opposed to the individual retention elements <NUM>). In this way, some or all the carrier plate <NUM> may remain with the retention elements <NUM> for various manufacturing steps, and/or may be included in the brush head <NUM> during final assembly. For example, in one embodiment, the stamping tool <NUM> may be configured, with a punch element to remove only a portion of the carrier plate <NUM> so as to change the shape of tuft carrier 50B to the shape of the tuft carrier 50F of <FIG>. In other words, excess portions of the carrier plate <NUM> may be removed to leave behind only the webbing links <NUM>. In other embodiments, the carrier plate <NUM> may be utilized without removing any excess portions.

In one embodiment, the tuft carrier <NUM> is formed by overmolding the tuft carrier <NUM> directly onto the corresponding handling plate or die block <NUM>. In this way, the handling plate <NUM>, together with the unprocessed instance of the tuft carrier <NUM>, can be directly placed on the base plate <NUM> and processed by manufacturing equipment, e.g., stamped by the stamping tool <NUM>. The handling plates <NUM> may be made of any desired material, such as a metal or other rigid material to facilitate handling of the tuft carrier <NUM> when engaged with the handling plate <NUM>, as well as to promote reusability of the handling plate <NUM> for multiple stampings or other manufacturing processes.

One embodiment for a base plate <NUM> is shown in <FIG> and cross-sectionally in <FIG>. The base plate <NUM> includes a recessed area <NUM> configured to receive the handling plates <NUM> or other manufacturing plates as discussed herein (as shown in <FIG>). In this way, according to one embodiment, the base plate <NUM>, together with the handling plate <NUM> placed in the recessed area <NUM>, can be used during stamping to stamp the retention elements <NUM> directly into corresponding openings <NUM> in the base plate <NUM>. The base plate <NUM> in <FIG> is illustrated having the retention elements <NUM> already inserted in the openings <NUM> via stamping as discussed above, or by some other process such as manual insertion. As noted above, the tuft carrier 50a may comprise individual retention elements <NUM>, such as shown in <FIG>, or the tuft carrier 50b, 50c, may comprise a plurality of retention elements <NUM> connected by the carrier plate <NUM>, or the tuft carrier 50d, 50e, 50f, may comprise a plurality of retention elements <NUM> connected by webbing links <NUM>.

As shown in <FIG>, the base plate <NUM> has opening <NUM> that correspond to each of the openings <NUM> in the retention elements <NUM>. Note that, the diameter or dimensions of the openings <NUM> may be configured such that the retention elements <NUM> are held by the base plate <NUM> in a desired position (e.g., the openings <NUM> may be tapered from top to bottom). The configuration of the openings <NUM> is useful for defining the shape, length, configuration, and cross-sectional shape of the bristle tufts <NUM> that will be inserted during subsequent steps of the manufacturing process. As discussed in more detail below, the base plate <NUM> may include an adjustment feature configured to assist in defining the length and/or contour of the free ends <NUM> of the bristle tufts <NUM>, such as a contour insert <NUM>.

<FIG> illustrates a tufting unit <NUM> according to one embodiment. The tufting unit <NUM> may be operated to form a plurality of bristle strands <NUM> into the bristle tufts <NUM> which are inserted into each of the plurality of openings <NUM> in the retention elements <NUM>, as shown in <FIG>. For example, as shown in <FIG>, the tufting unit <NUM> may include a tuft inserter <NUM> that can be aligned with corresponding openings <NUM> in a die block or handling plate <NUM> that is inserted in the base plate <NUM> (e.g., held in the recessed area <NUM>). The die block or handling plate <NUM> includes a plurality of openings <NUM> therethrough. The openings <NUM> in the handling plate <NUM> are aligned with the openings <NUM> in the tuft carrier <NUM>, and the openings <NUM> in the base plate <NUM>. When the various openings <NUM>, <NUM>, <NUM> in the handling plate <NUM>, tuft carrier <NUM> and base plate <NUM> are aligned, in operation, the tufting unit <NUM> forcibly injects the bristles therein (e.g., mechanically, via pressurized air, etc.) to form bristle tufts <NUM> of a shape and size that corresponds with the openings. It is to be appreciated that the handling plate <NUM> may be a die plate, a guide plate, or a different plate. It is noted that tufting may occur prior to the aforementioned stamping or cutting of tuft carriers, if desired.

As can be appreciated, the bristle tufts <NUM> must be of the proper shape, size, and diameter to fit into each respective opening. The ends of the bristle tufts <NUM> that are inside the base plate <NUM>, such as shown in <FIG>, will become the free end <NUM> of the bristle tufts <NUM> in the brush head assembly <NUM>, while the portion of the bristle tufts <NUM> that project above the base plate <NUM>, such as shown in <FIG>, will become the proximal end <NUM> of the bristle tufts <NUM>.

After tufting, the proximal ends <NUM> of the bristle tufts <NUM>, may optionally need to be trimmed to a uniform height to ensure a proper sealing during the subsequent bonding step. To perform trimming, as shown in <FIG>, a cutting plate <NUM> having a height H can be placed in the recess <NUM> on the base plate <NUM> at the proximal end <NUM> of the tuft <NUM>. The cutting plate <NUM> may be the same plate as the handling plate <NUM>, or may be a different plate. A knife or cutting implement <NUM> can be used to trim the length of the bristle tuft <NUM> by removing the excess portion of the bristle tuft <NUM> protruding above the plate <NUM>. In this way, as shown in <FIG>, the length of bristle tuft <NUM> extending out from a proximal side <NUM> of the retention element <NUM> will approximately equal the height H of the plate <NUM> when the plate <NUM> is removed. For example, this preset length of the proximal end <NUM> of the bristle tuft <NUM> can be useful to assist the consistent and predictable creation of the proximal end head portion <NUM> during bonding.

After tufting, the proximal ends <NUM> of the bristle tufts <NUM> can be bonded to the proximal side <NUM> of retention elements <NUM>, e.g., by melting, welding, adhering, or other technique, to form the merged proximal end head portion <NUM> as noted above with respect to <FIG> and also shown in <FIG>. Three different examples of the tuft carriers <NUM> after tufting are shown in <FIG>. More particularly, <FIG> illustrates the tuft carrier 50D tufted with the bristle tufts <NUM>, which extend into openings of the base plate <NUM>. <FIG> illustrates the tuft carrier 50B tufted with the bristle tufts <NUM> while carried by the handling plate 101C. <FIG> illustrates the tuft carrier 50A (a single one of the retention elements <NUM>) with the bristle tuft <NUM> melted to form a merged proximal end head portion <NUM> from at least a portion of the bristle tuft <NUM> and a portion of the proximal end of hte retention element <NUM>.

In one embodiment, bonding is accomplished by melting the bristle strands <NUM>, alone or together with a portion of the retention element <NUM>. Heat can be supplied by a heat source that comes into direct physical contact with the proximal end <NUM> of the bristle tufts and/or the proximal side <NUM> of the retention elements <NUM>, such as a laser. Alternatively, the heat can be supplied by heated air or any of a variety of other heat sources that can be in direct physical contact, merely adjacent, or directed. As noted above, forming the bristle strands <NUM> and the retention elements <NUM> from the same or a similar material composition, may advantageously improve bonding by utilizing a same or similar melting point.

Several embodiments of features to enable adjustment of the characteristics of the free end <NUM> of the bristle tufts <NUM> can be appreciated in view of <FIG>. In <FIG>, tuft bores <NUM> are arranged as blind holes that terminate within the base plate <NUM>. As discussed above, the bottom surface of the blind holes can be set as a predefined distance from openings <NUM>, in which the retention elements <NUM> are be seated during tufting. That is, the bottom of each blind hole provides a stop for the portion of the bristle strands <NUM> that will ultimately become the free end <NUM> of the bristle tufts <NUM> in the completed brush head so that the bristle tufts <NUM> are maintained at the proper length during the manufacturing process. The blind holes also support the bristle strands <NUM> during the manufacturing process when the bristle strands <NUM> are inserted (e.g., via the tufting unit <NUM>). In addition to length, the tuft bores <NUM> arranged as blind holes can be set to different shapes, sizes, or contours. For example, a first blind hole 118A is illustrated as slightly larger in diameter than the others, while a second blind hole 118B is illustrated as slightly shorter than the others and with a curved bottom surface to create a curved contouring for the free end <NUM> of the bristle tuft <NUM> that is inserted into the blind hole 118B.

The base plate <NUM> in <FIG> is illustrated as including a contour insert <NUM> also shown in <FIG>. As previously noted, the contour insert <NUM> may be used to define the shape of the free end <NUM> of the bristle tufts <NUM> in the brush head assembly <NUM>. For example, the contour insert <NUM> shown in <FIG> would generate a finished brush head that has a shape of bristle tufts that vary in length and surface angle, as set by the tufts <NUM> engaging against a surface 114a of the contour insert <NUM>. It can be appreciated that other shapes, such as a flat brushing surface, e.g., in which the free ends <NUM> of all the bristle tufts <NUM> project out the same distance, can also be achieved, based on the shape of the contour insert <NUM> that is used. The contour insert <NUM> may be arranged as a removable and interchangeable component so a variety of desired shapes of completed brush head bristles can be achieved with the same base plate <NUM>.

In another arrangement shown in <FIG>, each of the tuft bores <NUM> may be provided with a pin <NUM> of the same shape and diameter as the tuft bores <NUM>. For example, the pins <NUM> may be movable within the tuft bores <NUM> to enable the length of the tuft bores <NUM> to be adjustably set. Pins <NUM> having different surface angles on a top surface thereof can be included to change the contouring of the brushing surface resulting from the free ends <NUM>. Thus, it is to be appreciated that the pins <NUM> generally serve the same purpose and function as the contour insert <NUM> and the blind holes <NUM>, e.g., to form the desired shape, length, and contours of the bristle field and/or brushing surface of the completed brush head.

Final assembly of the brush head <NUM> can be appreciated in view of <FIG> shows a top view of the base plate <NUM> having the tuft bores <NUM> and the recesses <NUM> formed therein as described above, i.e., for receiving the bristle tufts <NUM> and the retention elements <NUM>, respectively. In this way, after stamping, tufting, bonding, etc., the merged tuft assemblies <NUM> are fully formed, and can be positioned with the retention elements <NUM> in the recesses <NUM> and the free ends <NUM> of the bristle tufts <NUM> in the tuft bores <NUM>.

The base plate <NUM> may also include a recess or cavity <NUM> in the general shape of the brush head neck <NUM> and/or the matrix material <NUM>. After the merged tuft assemblies <NUM> are created and positioned in the base plate <NUM>, the neck <NUM> may be positioned to align the platen <NUM> in relation to the merged proximal end head portions <NUM> of the tuft assemblies <NUM>. For example, as shown in <FIG>, the cavity <NUM> may properly align the platen <NUM> of the neck <NUM> with the tuft assemblies <NUM> when the neck <NUM> is placed in the cavity <NUM>. Additionally, any desired prefabricated parts (e.g., electronic parts, additional rings, springs, or any other components) can be added and held in position by the base plate <NUM> during this step of manufacturing. Any such parts can be molded into the final brush head as described in subsequent steps herein.

Thereafter, the components may be overmolded by the matrix material <NUM> by injecting material, e.g., in a liquid or flowable state, into the space formed between the platen <NUM> and the merged proximal end head portions <NUM> of the tuft assemblies <NUM>. The matrix material <NUM> solidifies to secure the neck <NUM> and the tuft assemblies <NUM> together by at least partially encompassing or encapsulating the platen <NUM> and the tuft assemblies <NUM>, as shown in <FIG>, thereby forming the brush head assembly <NUM>. According to an embodiment, the matrix material <NUM> is preferably made from an elastomeric material such as a flexible thermoplastic elastomer. It is to be appreciated that in one embodiment the neck <NUM> is not provided as a pre-formed member, but instead that the matrix material <NUM> and the neck <NUM> are formed at the same time and by the same material by injecting a suitable material into the cavity <NUM>. <FIG> respectively illustrate additional examples of the brush head <NUM> when completed.

Referring to <FIG>, in one embodiment, is a method <NUM> for manufacturing one or more of the various brush head embodiments <NUM> and implementations described or otherwise envisioned herein. In step <NUM>, a tuft carrier (e.g., any of the tuft carriers <NUM>) is formed, such as by molding by any known molding process. The tuft carrier includes one or more retention elements <NUM> having an opening formed therethrough <NUM>.

In optional step <NUM> of the method <NUM>, the tuft carrier may be processed to alter, set, or define the size or shape of the tuft carrier, or the retention elements or openings therethrough. For example, the tuft carrier may be stamped or cut to remove excess material <NUM>. For example, the tuft carrier may be a carrier plate <NUM> further processed so that or one or more webbing links <NUM> are formed, shaped, resized, or removed in the step <NUM> (e.g., with the stamping tool <NUM>, the handling plate <NUM>, or as otherwise discussed with respect to <FIG>).

At step <NUM>, the retention elements of the tuft carrier, either directly after formation in step <NUM>, or after processing in step <NUM>, are positioned in corresponding recesses <NUM> of a handling plate <NUM>. In one embodiment, the steps <NUM> and <NUM> are essentially combined in that the retention elements are directly stamped into the recesses of the handling plate simultaneously as the excess material is removed (as discussed with respect to <FIG>).

At step <NUM> of the method <NUM>, bristles are arranged in tufts and inserted (e.g., via the tufting unit <NUM>) through the openings <NUM> in the retention elements <NUM>. At optional step <NUM>, a proximal end <NUM> and/or a free end <NUM> opposite to the proximal end of the bristle tufts <NUM> may be adjusted in length, shape, size, contour, etc. For example a base plate may include an adjustment feature such as a contour insert <NUM>, or blind holes <NUM> and pins <NUM> for receiving and setting the contour of the free ends. The proximal ends of the bristle tufts may be optionally cut or trimmed to achieve a desired height using a cutting plate and a knife or cutting implement (e.g., the cutting plate <NUM> and the knife <NUM>).

At step <NUM> of the method, the proximal end <NUM> of bristles <NUM> of the bristle tufts 21are bonded together and/or to at least a portion of the proximal side <NUM> the retention element <NUM> to form a merged proximal end head portion <NUM>. Once secured together by the merged proximal end head portion <NUM>, each corresponding pair of the bristle tufts and the retention element form a merged tuft assembly <NUM>. In one embodiment, bonding is achieved by applying heat to the proximal end of the bristle tufts, or the proximal end of the bristle tufts and the proximal end of the retention elements to melt the components together. The heat can be supplied by a by laser welding, heated air or any of a variety of other heat sources that can be in direct physical contact, merely adjacent, or directed. By making the bristle strands and the retention elements from material having the same or a similar composition, and therefore the same or similar melting point, good bonding can be facilitated.

At optional step <NUM>, if not already done previously in the manufacturing process (e.g., at step <NUM>), the tuft carrier can be processed to remove any excess material. For example, as discussed above with respect to step <NUM>, this may include removing a portion or all of a carrier plate, webbing link, etc. As also discussed above, step <NUM> may not be performed, e.g., if the entirety of the carrier plate <NUM> is included in the brush head assembly <NUM> when fully assembled.

In step <NUM> of the method <NUM>, the tuft assemblies can be inserted into the base plate (if not already installed) and a neck <NUM> for the brush positioned relative to the merged tuft assemblies. For example, this may include placing the neck in a corresponding cavity (<NUM> of the base plate <NUM>, which aligns a platen <NUM> portion of the brush neck <NUM> with respect to the tuft assemblies. After positioning, a matrix material <NUM> is overmolded about at least a portion of the merged tuft assemblies and the neck by injecting material into the space between the neck and the merged tuft assemblies. The matrix material <NUM> may include an elastomeric material. Once solidified, the matrix material at least partially encompasses or encapsulates the merged tuft assemblies and the neck together, thereby forming the brush head assembly.

In accordance with embodiments disclosed and envisioned herein, it is to be appreciated that the same handling plate or base plate (<NUM>, <NUM>) may be utilized for multiple different manufacturing steps, such as molding, stamping, tufting, bonding, trimming/adjusting bristles, and/or overmolding. In other embodiments, partially-manufactured components may be transferred from one handling plate or base plate to a different handling plate or base plate. Additionally, it is to be appreciated that each of the steps in method <NUM> are optional and/or may be completed in an order other than that shown. Advantageously, these features enable flexibility in the time and location for any of the manufacturing steps, while also permitting each step to immediately follow the next if desired.

Claim 1:
A method (<NUM>) for manufacturing a brush head (<NUM>) the method comprising the steps of:
molding (<NUM>) one or more tuft carriers (<NUM>), having at least one retention element (<NUM>), each retention element having an opening (<NUM>) therethrough;
positioning the retention elements of the tuft carriers in openings (<NUM>) of a handling plate (<NUM>);
loading (<NUM>) the plurality of retention elements into corresponding recesses (<NUM>) of a base plate (<NUM>);
inserting (<NUM>) a bristle tuft (<NUM>) into the opening (<NUM>) of each retention element (<NUM>);
bonding (<NUM>) a proximal end (<NUM>) of each bristle tuft together with at least a portion of a proximal side (<NUM>) of each corresponding retention element to form a merged proximal end head portion (<NUM>) that secures the bristle tufts and retention elements together as a merged tuft assemblies (<NUM>);
positioning (<NUM>) a platen (<NUM>) portion of a neck (<NUM>) in relation to the merged tuft assemblies using a cavity (<NUM>) in the base plate; and
overmolding a matrix material (<NUM>) in a portion of the cavity in the base plate to at least partially encompass the platen and the plurality of merged tuft assemblies.