Patent Description:
While substantial efforts have been made to modify the cleaning elements of toothbrushes to improve the efficiency of the oral cleaning process, the industry continues to pursue arrangements of cleaning elements that will improve upon the existing technology. In typical oral care implements, bristles having circular transverse cross-sectional profiles are bundled together in a bristle tuft and mounted within tuft holes having circular transverse cross-sectional profiles. However, such a configuration results in gaps being present between adjacent bristles in the tuft and between the bristles of the tuft and the walls of the tuft holes, thereby resulting in a looser packing of the tuft hole and a less than optimal packing factor. These gaps can also reduce the effectiveness of the oral care implement and can cause the oral care implement to effectuate an uncomfortable feeling during brushing. Therefore, a need exists for an oral care implement having an improved arrangement of bristles.

<CIT> describes an oral care implement implementing a cleaning element arrangement having diverging cleaning elements. In one aspect, the invention is an oral care implement comprising a handle and a head. A plurality of cleaning elements extend from the first surface of the head so as to form a ring about an axis extending from the first surface of the head. Each of the cleaning elements extend from the first surface of the head at an inclined orientation so as to radially diverge from the axis. In one embodiment, a cleaning element wall also extends from the first surface of the head and circumferentially surrounds the plurality of cleaning elements. In another aspect, the invention may be an apparatus for incorporation into an ansate oral care implement that utilizes the aforementioned arrangement of cleaning elements.

A tooth brush according to <CIT> comprises a brush head having a working point, said working point comprising successive tufts of bristles disposed in units of tubular formation, the free ends of the tubular units being formed in substantially inverted arches, said free ends of said units also being beveled from the low portions of the inverted arches up toward, but short of, the high portions of the arches.

<CIT> discloses a cleaning section for an electric oral hygiene device that has at least a first carrier mounted for driven rotation or oscillating rotation around a rotation axis, at least a plurality of first cleaning elements mounted on the first carrier with their bases arranged on the vertices of a first star-shaped polygon around the rotation axis, wherein all of the first cleaning elements are inclined in a circumferential direction such that the free end of each of the first cleaning elements is farther away in the circumferential direction than the base of the respective first cleaning element, and wherein at least one cleaning element property alternates between adjacent first cleaning elements or between clusters of first cleaning elements.

A manual toothbrush of <CIT> has oral hygiene elements arranged in polygons with an oral hygiene element at each apex, and having plural polygons nested within each other. The oral hygiene elements may be bristles, which may be of two different types, or elastomer elements and may contain tooth-polishing additive. The toothbrush head surface may be flat or may have its region distal from the handle angled up.

A toothbrush known from <CIT> includes a head having a prophylaxis polishing cup closely surrounded by cleaning elements in the form of a bristle ring extending above the upper surface of the cup. Alternatively, the cups could be in the form of arrays of densely packed cleaning elements. The area formed by these configurations retains toothpaste on the toothbrush during use. Additional cleaning elements may be arranged about the periphery of the toothbrush head. The toothbrush may be a powered toothbrush wherein the cups and/or bristle rings rotate, oscillate or reciprocate to better clean teeth.

<CIT> describes a toothbrush having a head with brush bristles arranged in coaxial circles, wherein the brush bristles end at different heights relative to a brush bristle carrier of the head so as to have a convex profile when viewed in longitudinal cross section through the head.

According to a method of manufacturing an oral care implement of <CIT>, a member and a group of non-parallel tooth cleaning elements that together define therebetween a conically-shaped cavity are provided, wherein the tooth cleaning elements extend through a passage formed in the member so that respective first portions of the tooth cleaning elements are disposed on a first side of the member and respective second portions of the tooth cleaning elements are disposed on a second side of the member. Then, the second portions of the tooth cleaning elements are fixed together at the second side of the member.

A method for manufacturing brushes allowing anchor-free attachment of brush bristles to a brush body is known from <CIT>.

A tooth brush having brush bristle walls arranged on a brush plate in a spaced manner to allow receipt of at least one tooth inbetween the brush bristle walls is disclosed in <CIT>.

According to a tooth brush of <CIT>, a brush head comprises a central tuft of bristles, and an annular arrangement of spaced individual tufts of bristles encircles said central tuft and protrudes at their outer ends beyond the outer end of said central tuft.

The present invention according to claim <NUM> is directed to an oral care implement that includes a handle and a head coupled to the handle, the head comprising a front surface and extending from a proximal end to a distal end along a longitudinal axis. A plurality of tooth cleaning elements extend from the front surface. The plurality of tooth cleaning elements comprise a conical tuft comprising a bristle wall that may be continuous. The conical tuft has an inner surface that defines a cavity. The cavity has a transverse cross-sectional area that increases with distance from the front surface of the head. A central cleaning element may also be located within the cavity. The bristle wall of the conical tuft has an annular top surface that undulates in height relative to the front surface of the head. Furthermore, in some embodiments arcuate cleaning elements may be arranged in a loop that surrounds the conical tuft. According to claim <NUM>, the annular top surface comprises first and second peak portions and first and second valley portions. A longitudinal reference plane that is substantially parallel to the longitudinal axis and perpendicular to the front surface of the head intersects the first and second valley portions. A transverse reference plane that is substantially perpendicular to the longitudinal axis and perpendicular to the front surface of the head intersects both the first and second peak portions.

In one exemplary aspect, an oral care implement comprises: a handle; a head coupled to the handle, the head comprising a front surface; a plurality of tooth cleaning elements extending from the front surface of the head; the plurality of tooth cleaning elements comprising a conical tuft comprising a continuous bristle wall having an inner surface defining a cavity along a cavity axis, the cavity having a transverse cross-sectional area that increases with distance from the front surface of the head; and the plurality of tooth cleaning elements comprising a central cleaning element located within the conical cavity.

In another exemplary aspect, an oral care implement comprises: a handle; a head coupled to the handle, the head comprising a front surface; a plurality of tooth cleaning elements extending from the front surface of the.

head; the plurality of tooth cleaning elements comprising a conical tuft comprising a bristle wall having an inner surface defining a cavity along a cavity axis, the cavity having a transverse cross-sectional area that increases with distance from the front surface of the head; and wherein the bristle wall of the conical tuft terminates in an annular top surface that undulates in height relative to the front surface.

In yet another exemplary aspect, an oral care implement comprises: a handle; a head coupled to the handle, the head comprising a front surface; a plurality of tooth cleaning elements extending from the front surface of the head; the plurality of tooth cleaning elements comprising a conical tuft comprising a bristle wall having an inner surface defining a cavity along a cavity axis, the cavity having a transverse cross-sectional area that increases with distance from the front surface of the head; and the plurality of tooth cleaning elements comprising a plurality of arcuate cleaning elements arranged in a spaced apart manner about a loop that surrounds the conical tuft.

It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

The present invention will become more fully understood from the detailed description and the accompanying drawings. The following embodiments of <FIG> are not according to the claimed invention, however, they are useful for the understanding of the invention as claimed and with an embodiment of the invention as shown in <FIG>.

In the description of embodiments of the disclosure disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Moreover, the features and benefits of the disclosure are illustrated by reference to the exemplified embodiments.

Referring first to <FIG> concurrently, an oral care implement <NUM> is illustrated in accordance with one embodiment of the present disclosure. In the exemplified embodiment, the oral care implement <NUM> is in the form of a manual toothbrush. However, in certain other embodiments the oral care implement <NUM> can take on other forms such as being a powered toothbrush, a tongue scraper, a gum and soft tissue cleanser, a water pick, an interdental device, a tooth polisher, a specially designed ansate implement having tooth engaging elements or any other type of implement that is commonly used for oral care. Thus, it is to be understood that the inventive concepts discussed herein can be applied to any type of oral care implement unless a specific type of oral care implement is specified in the claims.

The oral care implement extends from a proximal end <NUM> to a distal end <NUM> along a longitudinal axis A-A. The oral care implement <NUM> generally comprises a head <NUM> and a handle <NUM>. The handle <NUM> is an elongated structure that provides the mechanism by which the user can hold and manipulate the oral care implement <NUM> during use. In the exemplified embodiment, the handle <NUM> is generically depicted having various contours for user comfort. Of course, the disclosure is not to be limited by the specific shape illustrated for the handle <NUM> in all embodiments and in certain other embodiments the handle <NUM> can take on a wide variety of shapes, contours, and configurations, none of which are limiting of the present invention unless so specified in the claims.

In the exemplified embodiment, the handle <NUM> is formed of a rigid plastic material, such as for example without limitation polymers and copolymers of ethylene, propylene, butadiene, vinyl compounds, and polyesters such as polyethylene terephthalate. Of course, the disclosure is not to be so limited in all embodiments and the handle <NUM> may include a resilient material, such as a thermoplastic elastomer, as a grip cover that is molded over portions of or the entirety of the handle <NUM> to enhance the gripability of the handle <NUM> during use. For example, portions of the handle <NUM> that are typically gripped by a user's palm during use may be overmolded with a thermoplastic elastomer or other resilient material to further increase comfort to a user. Furthermore, materials other than those noted above can be used including metal, wood or any other desired material that has sufficient structural rigidity to permit a user to grip the handle <NUM> and manipulate the oral care implement <NUM> during toothbrushing.

The head <NUM> of the oral care implement <NUM> is coupled to the handle <NUM> and comprises a front surface <NUM> and an opposing rear surface <NUM>. In the exemplified embodiment, the head <NUM> is formed integrally with the handle <NUM> as a single unitary structure using a molding, milling, machining, or other suitable process. However, in other embodiments the handle <NUM> and the head <NUM> may be formed as separate components which are operably connected at a later stage of the manufacturing process by any suitable technique known in the art, including without limitation thermal or ultrasonic welding, a tight-fit assembly, a coupling sleeve, threaded engagement, adhesion, or fasteners. Thus the head <NUM> may, in certain embodiments, be formed of any of the rigid plastic materials described above as being used for forming the handle <NUM>, although the disclosure is not to be so limited in all embodiments and other materials that are commonly used during toothbrush head manufacture may also be used.

The oral care implement <NUM> also comprises a plurality of tooth cleaning elements <NUM> extending from the front surface <NUM> of the head <NUM>. The details of certain ones of the plurality of tooth cleaning elements <NUM> will be discussed below, including specific details with regard to structure, pattern, orientation, and material of such tooth cleaning elements <NUM>. However, where it does not conflict with the other disclosure provided herein, it should be appreciated that the term "tooth cleaning elements" may be used in a generic sense to refer to any structure that can be used to clean, polish, or wipe the teeth and/or soft oral tissue (e.g. tongue, cheek, gums, etc.) through relative surface contact. Common examples of "tooth cleaning elements" include, without limitation, bristle tufts, filament bristles, fiber bristles, nylon bristles, spiral bristles, rubber bristles, elastomeric protrusions, flexible polymer protrusions, combinations thereof and/or structures containing such materials or combinations. Thus, any combination of these tooth cleaning elements may be used within the tooth cleaning elements <NUM> in some embodiments. However, as described herein below, in certain embodiments one or more of the tooth cleaning elements <NUM> may be formed as tufts of bristles.

In embodiments that use elastomeric elements as one or more of the tooth cleaning elements <NUM>, suitable elastomeric materials may include any biocompatible resilient material suitable for uses in an oral hygiene apparatus. To provide optimum comfort as well as cleaning benefits, the elastomeric material of any such tooth or soft tissue engaging elements may have a hardness property in the range of A8 to A25 Shore hardness. One suitable elastomeric material is styrene-ethylene/butylene-styrene block copolymer (SEBS) manufactured by GLS Corporation. Nevertheless, SEBS material from other manufacturers or other materials within and outside the noted hardness range could be used.

Referring to <FIG> concurrently, one manner in which the tooth cleaning elements <NUM> are secured to the head <NUM> will be described. Specifically, in the exemplified embodiment the tooth cleaning elements <NUM> are formed as a cleaning element assembly on a head plate <NUM> such that one or more of the tooth cleaning elements <NUM> are mounted onto the head plate <NUM> and then the head plate <NUM> is coupled to the head <NUM>. In such an embodiment, the head plate <NUM> is a separate and distinct component from the head <NUM> of the oral care implement <NUM>. However, the head plate <NUM> is connected to the head <NUM> at a later stage of the manufacturing process by any suitable technique known in the art, including without limitation thermal or ultrasonic welding, any fusion techniques such as thermal fusion, melting, a tight-fit assembly, a coupling sleeve, threaded engagement, adhesion, or fasteners. Thus, the head plate <NUM> and the head <NUM> are separately formed components that are secured together during manufacture of the oral care implement <NUM>.

In certain embodiments, the head plate <NUM> may comprise a plurality of holes <NUM> formed therethrough, and the tooth cleaning elements <NUM> may be mounted to the head plate <NUM> within the holes <NUM>. This type of technique for mounting the tooth cleaning elements <NUM> to the head <NUM> via the head plate <NUM> is generally known as anchor free tufting (AFT). Specifically, in AFT a plate or membrane (i.e., the head plate <NUM>) is created separately from the head <NUM>. The tooth cleaning elements <NUM> (such as bristles, elastomeric elements, and combinations thereof) are positioned into the head plate <NUM> so as to extend through the holes <NUM> of the head plate <NUM>. The free ends of the tooth cleaning elements <NUM> on one side of the head plate <NUM> perform the cleaning function. The ends of the tooth cleaning elements <NUM> on the other side of the head plate <NUM> are melted together by heat to be anchored in place. As the tooth cleaning elements <NUM> are melted together, a melt matte <NUM> is formed. After the tooth cleaning elements <NUM> are secured to the head plate <NUM>, the head plate <NUM> is secured to the head <NUM> such as by ultrasonic welding. When the head plate <NUM> is coupled to the head <NUM>, the melt matte <NUM> is located between a lower surface <NUM> of the head plate <NUM> and a floor <NUM> of a basin <NUM> of the head <NUM> in which the head plate <NUM> is disposed. The melt matte <NUM>, which is coupled directly to and in fact forms a part of the tooth cleaning elements <NUM>, prevents the tooth cleaning elements <NUM> from being pulled through the holes <NUM> in the head plate <NUM> thus ensuring that the tooth cleaning elements <NUM> remain attached to the head plate <NUM> during use of the oral care implement <NUM>.

Of course, techniques other than AFT can be used for mounting the tooth cleaning elements <NUM> to the head <NUM>, such as widely known and used stapling techniques or the like. In such embodiments the head plate <NUM> may be omitted and the tooth cleaning elements <NUM> may be coupled directly to the head <NUM>. Furthermore, in a modified version of the AFT process discussed above, the head plate <NUM> may be formed by positioning the tooth cleaning elements <NUM> within a mold, and then molding the head plate <NUM> around the tooth cleaning elements <NUM> via an injection molding process.

Although described herein above with regard to using AFT, in certain embodiments any suitable form of cleaning elements and attachment may be used in the broad practice of this disclosure. Specifically, the tooth cleaning elements <NUM> of the present invention can be connected to the head <NUM> in any manner known in the art. For example, staples/anchors or in-mold tufting (IMT) could be used to mount the cleaning elements/tooth engaging elements. In certain embodiments, the disclosure can be practiced with various combinations of stapled, IMT or AFT bristles. Alternatively, the tooth cleaning elements <NUM> could be mounted to tuft blocks or sections by extending through suitable openings in the tuft blocks so that the base of the tooth cleaning elements <NUM> is mounted within or below the tuft block.

Although not illustrated herein, in certain embodiments the head <NUM> may also include a soft tissue cleanser coupled to or positioned on its rear surface <NUM>. An example of a suitable soft tissue cleanser that may be used with the present disclosure and positioned on the rear surface of the head <NUM> is disclosed in <CIT> to the assignee of the present application. In certain other embodiments, the soft tissue cleanser may include protuberances, which can take the form of elongated ridges, nubs, or combinations thereof. Of course, the disclosure is not to be so limited and in certain embodiments the oral care implement <NUM> may not include any soft tissue cleanser.

With continued reference to <FIG>, the oral care implement <NUM>, and specifically the tooth cleaning elements <NUM> of the oral care implement <NUM>, will be further described. In the exemplified embodiment, the plurality of tooth cleaning elements <NUM> comprises a conical tuft <NUM>. The conical tuft <NUM> is a tuft or grouping of bristles that are arranged together into a tuft and then secured into a single tuft hole within the head <NUM> (or within the head plate <NUM>). The conical tuft <NUM> is described herein as being conical due to the conical tuft <NUM> having a conical shape. More specifically, as can best be seen in <FIG>, the conical tuft <NUM> is in the shape of a truncated cone wherein the portion of the conical tuft <NUM> that is positioned within the head <NUM> is the truncated (i.e., cut off) portion of the cone such that the conical tuft <NUM> is in the shape of an inverted truncated cone.

The conical tuft <NUM> comprises a continuous bristle wall <NUM> having an inner surface <NUM> and an outer surface <NUM>. The inner surface <NUM> of the continuous bristle wall <NUM> of the conical tuft <NUM> defines a cavity <NUM> that extends along a cavity axis C-C. The conical tuft <NUM> extends in a <NUM>° manner about the cavity axis C-C. The cavity <NUM> of the conical tuft <NUM> has an open top end and is bounded by the inner surface <NUM> of the continuous bristle wall <NUM> and by the front surface <NUM> of the head <NUM>. As noted above, the conical tuft <NUM> in the exemplified embodiment is formed by a plurality of bristles. Specifically, in the exemplified embodiment the plurality of bristles are clumped together and positioned collectively into a single tuft hole so that the plurality of bristles collectively form the conical tuft <NUM> having no gaps in the continuous bristle wall <NUM> for its entire <NUM>° extension about the cavity axis C-C. Thus, the term continuous bristle wall <NUM> is intended to mean that the conical tuft <NUM> is a single tuft of bristles that are clumped together into a single tuft hole in a non-spaced apart manner.

Thus, in the exemplified embodiment the conical tuft <NUM> is a single bristle tuft formed from a plurality of individual bristles that are positioned together within a single tuft hole. As a result, the conical tuft <NUM> has the continuous bristle wall <NUM> that extends without discontinuity about the cavity axis C-C. Thus, in the exemplified embodiment there are no gaps formed into the outer surface <NUM> of the conical tuft <NUM>. Of course, in other embodiments the conical tuft <NUM> may have small gaps therein as desired while still being a single tuft positioned within a single tuft hole. Such gaps in the bristle wall may prevent dentifrice from being trapped within the cavity <NUM> of the conical tuft <NUM> by providing means of egress from the cavity <NUM>. In such embodiments, the bristle wall <NUM> of the conical tuft <NUM> may not be continuous.

Due to the conical shape of the conical tuft <NUM>, and more specifically, the inverted conical shape of the conical tuft <NUM>, the cavity <NUM> of the conical tuft <NUM> has a transverse cross-sectional area that increases with distance from the front surface <NUM> of the head <NUM>. Specifically, the transverse cross-sectional area of the cavity <NUM> of the conical tuft <NUM> only increases and never decreases with distance from the front surface <NUM> of the head <NUM>. Thus, the greater the distance between a particular axial location within the cavity <NUM> of the conical tuft <NUM> and the front surface <NUM> of the head <NUM>, the greater the transverse cross-sectional area of the cavity <NUM> at that particular axial location.

In addition to the conical tuft <NUM>, in the exemplified embodiment the oral care implement <NUM> comprises a central cleaning element <NUM> that is located within the cavity <NUM> of the conical tuft <NUM>. Thus, the conical tuft <NUM> surrounds the central cleaning element <NUM>. Of course, the central cleaning element <NUM> may be omitted in certain other embodiments if desired. However, using the conical tuft <NUM> in conjunction with the central cleaning element <NUM> may enhance cleaning by enabling the conical tuft <NUM> to surround a user's tooth while the central cleaning element <NUM> cleans in the interproximal areas and the spaces between the teeth and gums. In the exemplified embodiment, the central cleaning element <NUM> is a bristle tuft, although the invention is not to be so limited in all embodiments and in certain other embodiments the central cleaning element <NUM> may be an elastomeric element or the like as discussed above. Furthermore, the central cleaning element <NUM> may be formed with tapered bristles, rounded/non-tapered bristles, spiral bristles, or combinations thereof. As discussed above, in the exemplified embodiment the conical tuft <NUM> and the central cleaning element <NUM> are secured to the head <NUM> by anchor free tufting. Specifically, the ends of the bristles that form the conical tuft <NUM> and the ends of the bristles that form the central cleaning element <NUM> are melted together to form at least a portion of the melt matte <NUM> as discussed above.

In the exemplified embodiment the conical tuft <NUM> and the central cleaning element <NUM> extend from a single tuft hole <NUM>. Of course, the disclosure is not to be so limited in all embodiments and in certain other embodiments the conical tuft <NUM> and the central cleaning element <NUM> may extend from different tuft holes that are spaced apart from one another such that the tuft hole of the conical tuft <NUM> may substantially (or concentrically) surround the tuft hole of the central cleaning element <NUM>. Furthermore, in the exemplified embodiment the central cleaning element <NUM> and the conical tuft <NUM> extend substantially the same distance from the front surface <NUM> of the head <NUM>. Of course, the disclosure is not to be so limited and in certain other embodiments the central cleaning element <NUM> may have a height that is greater than a height of the conical tuft <NUM> or the conical tuft <NUM> may have a height that is greater than the height of the central cleaning element <NUM>.

In the exemplified embodiment, the central cleaning element <NUM> is aligned along the cavity axis C-C and the central cleaning element <NUM> is circumferentially spaced apart from the inner surface <NUM> of the conical tuft <NUM> by an annular gap <NUM>. In the exemplified embodiment, the central cleaning element <NUM> is centrally positioned within the cavity <NUM>. However, due to the conical shape of the conical tuft <NUM>, the width of the annular gap <NUM> increases with distance from the front surface <NUM> of the head <NUM>. Thus, the width of the annular gap <NUM> (or the distance between the inner surface <NUM> of the conical tuft <NUM> and the outer surface of the central cleaning element <NUM>) is greater at the terminal ends or cleaning ends of the conical tuft <NUM> and central cleaning element <NUM> than at the front surface <NUM> of the head <NUM>.

The conical tuft <NUM> circumferentially surrounds the central cleaning element <NUM> in a spaced apart manner for at least the portion of the conical tuft <NUM> and the central cleaning element <NUM> that extend above the front surface <NUM> of the head <NUM>. However, as best seen in <FIG> and <FIG>, the central cleaning element <NUM> converges with the continuous bristle wall <NUM> of the conical tuft <NUM> at a position that is below the front surface <NUM> of the head <NUM>. Specifically, the central cleaning element <NUM> and the conical tuft <NUM> converge into contact with one another at a location below the front surface <NUM> of the head <NUM> to form the melt matte <NUM> as discussed above.

Thus, the annular gap <NUM> formed between the inner surface <NUM> of the conical tuft <NUM> and the central cleaning element <NUM> extends to below the front surface <NUM> of the head <NUM>. Stated another way, the annular gap <NUM> exists between the inner surface <NUM> of the conical tuft <NUM> and the central cleaning element <NUM> for the entire portion of the conical tuft <NUM> and the central cleaning element <NUM> that extends from or protrudes beyond the front surface <NUM> of the head <NUM>. Due to the annular gap <NUM> extending to below the front surface <NUM> of the head <NUM>, independent movement of the conical tuft <NUM> and the central cleaning element <NUM> is enhanced or improved. Specifically, because the conical tuft <NUM> and the central cleaning element <NUM> converges at the very bottom portion of those bristle tufts, the conical tuft <NUM> and the central cleaning element <NUM> are spaced apart along their lengths to enable independent movement thereof. This better enables the conical tuft <NUM> to surround a user's teeth individually during tooth brushing due to the increased flexibility of the conical tuft <NUM>.

The head <NUM> extends along a longitudinal axis B-B along its length. In the exemplified embodiment, the conical tuft <NUM> and the central cleaning element <NUM> are aligned on the longitudinal axis. Furthermore, in the exemplified embodiment the conical tuft <NUM> and the central cleaning element <NUM> are also aligned along a transverse axis that is perpendicular to the longitudinal axis B-B and that divides the head <NUM> into two equal halves. Thus, in the exemplified embodiment the conical tuft <NUM> and the central cleaning element <NUM> are centrally located on the head <NUM>. Of course, in other embodiments the conical tuft <NUM> and the central cleaning element <NUM> can be positioned at other located on the head <NUM> as desired.

The plurality of tooth cleaning elements <NUM> also include a plurality of arcuate cleaning elements 170a-d that are arranged in a spaced apart manner about a loop L that surrounds the conical tuft <NUM>. In the exemplified embodiment, the plurality of arcuate cleaning elements 170a-d are depicted as tufts of bristles. However, the plurality of arcuate cleaning elements 170a-d can be formed from an elastomeric material in other embodiments as desired. Furthermore, the plurality of arcuate cleaning elements 170a-d are positioned adjacent to the conical tuft <NUM> such that there are no other cleaning element structures intervening in the spaces between the plurality of arcuate cleaning elements 170a-d and the conical tuft <NUM>. Thus, each of the plurality of arcuate cleaning elements 170a-d is positioned adjacent to the conical tuft <NUM> in a spaced apart manner such that the space between the plurality of arcuate cleaning elements 170a-d and the conical tuft <NUM> is devoid of cleaning elements.

The loop L is a reference loop that is delineated in dotted lines in <FIG> for reference. The loop L has a center point CP that is located along the cavity axis C-C. The center point CP is also the point of intersection between the longitudinal axis B-B and the transverse axis discussed above that divides the head <NUM> into two equal halves. Thus, the loop L and the conical tuft <NUM> are arranged concentrically about the cavity axis C-C with the loop L having a greater diameter than the conical tuft <NUM>. The plurality of arcuate cleaning elements 170a-d include a first arcuate cleaning element 170a, a second arcuate cleaning element 170b, a third arcuate cleaning element 170c, and a fourth arcuate cleaning element 170d. The first arcuate cleaning element 170a is positioned adjacent to and spaced apart from each of the second and fourth arcuate cleaning elements 170b, 170d. The second arcuate cleaning element 170b is positioned adjacent to and spaced apart from each of the first and third arcuate cleaning elements 170a, 170c. The third arcuate cleaning element 170c is positioned adjacent to and spaced apart from each of the second and fourth arcuate cleaning elements 170b, 170d. The fourth arcuate cleaning element 170d is positioned adjacent to and spaced apart from each of the first and third arcuate cleaning elements 170a, 170c.

Each of the plurality of arcuate cleaning elements 170a-d is an elongated bristle wall. Specifically, the first and third arcuate cleaning elements 170a, c are elongated in a direction transverse to the longitudinal axis B-B of the head <NUM> and the second and fourth arcuate cleaning elements 170b, d are elongated in a direction parallel to the longitudinal axis B-B. Each of the plurality of arcuate cleaning elements 170a-d is formed from a plurality of individual bristles that are arranged together into a single tuft hole to form the elongated bristle wall. In certain embodiments each of the plurality of arcuate cleaning elements 170a-d extends from a separate single tuft hole and the conical tuft <NUM> extends from a separate single tuft hole. Thus, each of the arcuate cleaning elements 170a-d extends from a different tuft hole than each of the other arcuate cleaning elements 170a-d and from the conical tuft <NUM>. Each of the plurality of arcuate cleaning elements 170a-d includes a concave surface <NUM> and an opposing convex surface <NUM>. Furthermore, in the exemplified embodiment the concave surfaces <NUM> of each of the plurality of arcuate cleaning elements 170a-d is facing or positioned adjacent to the conical tuft <NUM> and the convex surface <NUM> of each of the plurality of arcuate cleaning elements 170a-d is facing away from or is non-adjacent to the conical tuft <NUM>. In some embodiments the radius of curvature of the concave surfaces <NUM> of the plurality of arcuate cleaning elements 170a-d is the same as that of the conical tuft <NUM>.

Referring briefly to <FIG> and <FIG>, the outer surface <NUM> of the conical tuft <NUM> forms a first acute angle θ<NUM> with the front surface <NUM> of the head <NUM>. Furthermore, the convex surface <NUM> of each of the plurality of arcuate cleaning elements 170a-d (which also forms the outer surface of the plurality of arcuate cleaning elements 170a-d) forms a second acute angle θ<NUM> with the front surface <NUM> of the head <NUM>. In certain embodiments, the first acute angle θ<NUM> is different from the second acute angle θ<NUM>. Furthermore, in some embodiments the second acute angle θ<NUM> is greater than the first acute angle θ<NUM>. For example, in one embodiment the first acute angle θ<NUM> is between <NUM>° and <NUM>°, more specifically between <NUM>° and <NUM>°, and still more specifically approximately <NUM>°. In one embodiment the second acute angle θ<NUM> is between <NUM>° and <NUM>°, more specifically between <NUM>° and <NUM>°, and still more specifically approximately <NUM>°.

The conical tuft <NUM> is spaced apart from each of the plurality of arcuate cleaning elements 170a-d by a gap. Furthermore, because in the exemplified embodiment the second angle θ<NUM> is greater than the first angle θ<NUM>, the gap between the outer surface <NUM> of the conical tuft <NUM> and the inner or concave surfaces <NUM> of each of the plurality of arcuate cleaning elements 170a-d decreases with distance from the front surface <NUM> of the head <NUM>. Specifically, because the conical tuft <NUM> is oriented at a greater angle relative to the front surface <NUM> of the head <NUM> than the plurality of arcuate cleaning elements 170a-d, the conical tuft <NUM> becomes closer to each of the plurality of arcuate cleaning elements 170a-d the further away the conical tuft <NUM> and the plurality of arcuate cleaning elements 170a-d are from the front surface <NUM> of the head <NUM>. Stated another way, the outer surface <NUM> of the conical tuft <NUM> is spaced apart from the concave surfaces <NUM> of each of the plurality of arcuate cleaning elements 170a-d by a first distance D<NUM> at the front surface <NUM> of the head <NUM>. The outer surface <NUM> of the conical tufts <NUM> is spaced apart from the concave surfaces <NUM> of each of the plurality of arcuate cleaning elements 170a-d by a second distance D<NUM> at the terminal or free ends of the conical tuft <NUM> and of the plurality of arcuate cleaning elements 170a-d. Furthermore, the first distance D<NUM> is greater than the second distance D<NUM>. Thus, even though both the conical tuft <NUM> and the plurality of arcuate cleaning elements 170a-d are oriented at an angle relative to the front surface <NUM> of the head <NUM>, the conical tuft <NUM> leans outwardly away from the cavity axis C-C and towards each of the plurality of arcuate cleaning elements 170a-d.

As noted above, in the exemplified embodiment the ends of the bristles are melted together to form the melt matte <NUM> that becomes trapped between the lower surface <NUM> of the head plate <NUM> and the floor <NUM> of the basin <NUM> within which the head plate <NUM> is positioned. This melt matte <NUM> includes melted ends of all of the different bristles discussed herein. Thus, ends of each of the conical tuft <NUM> and the plurality of arcuate cleaning elements 170a-d are melted together to form a portion of the melt matte <NUM>. Furthermore, in embodiments that include the central cleaning element <NUM>, the ends of the central cleaning element <NUM> are also melted together to form a portion of the melt matte <NUM>. Of course, all of the other cleaning elements including those described below may be melted to form a portion of the melt matte <NUM> as has been described herein.

In addition to the conical tuft <NUM>, the central cleaning element <NUM>, and the plurality of arcuate cleaning elements 170a-d, the tooth cleaning elements <NUM> also comprise many other additional cleaning elements on the head <NUM>. Specifically, the tooth cleaning elements <NUM> include an outer loop of cleaning elements that includes the second and fourth arcuate cleaning elements 170b, 170d and an inner row of cleaning elements that includes the first and third arcuate cleaning elements 170a, 170c, the conical tuft <NUM> and the central cleaning element <NUM>.

The outer loop of cleaning elements comprises a grouping of cleaning elements that are arranged so that the outer loop is symmetric about a longitudinal axis B-B of the head <NUM> and about a transverse axis that intersects the cavity axis C-C, the center point CP and is perpendicular to the longitudinal axis B-B. In the exemplified embodiment, the entirety of the tooth cleaning elements are arranged so as to be symmetric about the longitudinal axis B-B and the transverse axis. Specifically, the outer loop of cleaning elements includes proximal cleaning elements <NUM> located at a proximal region of the head <NUM> and distal cleaning elements <NUM> located at a distal region of the head <NUM>. Each of the proximal cleaning elements <NUM> is an arcuate cleaning element located on opposing sides of the longitudinal axis B-B. Similarly, each of the distal cleaning elements <NUM> is an arcuate cleaning element located on opposing sides of the longitudinal axis B-B.

Starting from the proximal cleaning element <NUM> and working upwardly towards the distal cleaning elements <NUM>, the left side of the head <NUM> (when viewed from the front as depicted in <FIG>) has a first bristle wall <NUM>, a first bristle tuft <NUM>, the second arcuate cleaning element 170b, a second bristle tuft <NUM>, and a second bristle wall <NUM>. Starting from the proximal cleaning element <NUM> and working upwardly towards the distal cleaning elements <NUM>, the right side of the head <NUM> has a third bristle wall <NUM>, a third bristle tuft <NUM>, the fourth arcuate cleaning element 170d, a fourth bristle tuft <NUM>, and a fourth bristle wall <NUM>. Each of these bristle tufts and bristle walls is in its own tuft hole and is spaced apart from adjacent ones of the bristle tufts and bristle walls. The first bristle wall <NUM> is longitudinally aligned with the third bristle wall <NUM> on opposing lateral sides of the head <NUM>, the second bristle wall <NUM> is longitudinally aligned with the fourth bristle wall <NUM> on opposing lateral sides of the head, the first bristle tuft <NUM> is longitudinally aligned with the third bristle tuft <NUM> on opposing lateral sides of the head, and the second bristle tuft <NUM> is longitudinally aligned with the fourth bristle tuft <NUM> on opposing lateral sides of the head.

Furthermore, the first bristle tuft <NUM> is at least partially located within the space between the first arcuate cleaning element 170a and the second arcuate cleaning element 170b, the second bristle tuft <NUM> is at least partially located within the space between the second arcuate cleaning element 170b and the third arcuate cleaning element 170c, the third bristle tuft <NUM> is at least partially located within the space between the first arcuate cleaning element <NUM> and the fourth arcuate cleaning element 170d, and the fourth bristle tuft <NUM> is at least partially located within the space between the third arcuate cleaning element 170c and the fourth arcuate cleaning element 170d. In the exemplified embodiment the first, second, third, and fourth bristle tufts <NUM>, <NUM>, <NUM>, <NUM> are located outside of the loop L, but they are still adjacent to and positioned in between the plurality of arcuate cleaning elements 170a-d as noted herein above.

Similarly, working upwardly from the proximal cleaning elements <NUM> to the distal cleaning elements <NUM>, the inner row of cleaning elements comprise a fifth bristle wall <NUM>, a fifth bristle tuft <NUM>, the first arcuate cleaning element 170a, the conical tuft <NUM> and the central cleaning element <NUM>, the third arcuate cleaning element 170c, a sixth bristle tuft <NUM>, and a sixth bristle wall <NUM>. Any of the bristle tufts (or the individual bristles that form the bristle tufts) can be tapered, nontapered, rounded, spiral, or the like. Furthermore, the fifth and sixth bristle walls <NUM>, <NUM> are arcuate and have a smaller radius of curvature than the plurality of arcuate cleaning elements 170a-d. The concave surfaces of the fifth and sixth bristle walls <NUM>, <NUM> are facing each other and the conical tuft <NUM>. The proximal and distal cleaning elements <NUM>, <NUM> are also arcuate in the exemplified embodiment. The first, second, third, and fourth bristle walls <NUM>, <NUM>, <NUM>, <NUM> are not arcuate in the exemplified embodiment, but are simply elongated bristle walls, although they could be arcuate in other embodiments.

Referring now to <FIG>, an oral care implement <NUM> will be described in accordance with another embodiment of the present disclosure. The oral care implement <NUM> is similar to the oral care implement <NUM> and thus much of the description above with regard to the oral care implement <NUM> is applicable to the oral care implement <NUM>, except where the description of the oral care implement <NUM> above is contradictory to a specific description of the oral care implement <NUM> provided below. Features of the oral care implement <NUM> that are similar to features of the oral care implement <NUM> described above will be similarly numbered except that the <NUM>-series of numbers will be used. Certain features of the oral care implement <NUM> may be labeled but not described, in which case the description of the similar feature from the oral care implement <NUM> applies. Furthermore, certain features of the oral care implement <NUM> may not be labeled, it being understood that the description of the similar feature from the oral care implement <NUM> applies.

The oral care implement <NUM> generally comprises a handle <NUM> and a head <NUM>, which have the same structures, features, materials of construction, and the like as described above with regard to the oral care implement <NUM>. Furthermore, a plurality of tooth cleaning elements <NUM> are positioned on and extend from a front surface <NUM> of the head <NUM>. The plurality of tooth cleaning elements <NUM> include a conical tuft <NUM>, a central cleaning element <NUM>, and many additional cleaning elements that will not be described in detail herein. Specifically, although a specific configuration and pattern of the additional cleaning elements is provided in the drawings, the invention is not to be so limited. In certain embodiments, the conical tuft <NUM> can be used with any arrangement of additional cleaning elements, including the arrangement depicted in <FIG>. Thus, in certain embodiments the disclosure may be the arrangement of cleaning elements achieved by swapping out the conical tuft <NUM> and replacing it with the conical tuft <NUM>. Thus, the only component of <FIG> that will be discussed in detail herein is the conical tuft <NUM>, it being understood that the description of the other features above may be used with the conical tuft <NUM>.

The conical tuft <NUM> is in the shape of an inverted truncated cone much like the conical tuft <NUM> described above. The conical tuft <NUM> has a first end that is inserted within a tuft hole in the head <NUM> (or in a head plate as discussed above), and the conical tuft <NUM> extends from the front surface <NUM> of the head <NUM> and terminates in an annular top surface <NUM>. In this embodiment, the annular top surface <NUM> of the conical tuft <NUM> is an undulating or wavy surface. Thus, the side profile of the annular top surface <NUM> conical tuft <NUM> is wavy. Despite this undulating surface, the conical tuft <NUM> is still conical such that it has a circular or spherical transverse cross-sectional shape. Furthermore, in this embodiment the annular top surface <NUM> of the conical tuft <NUM> comprises sinusoidal-shaped undulations. Specifically, the annular top surface <NUM> of the conical tuft <NUM> undulates in height relative to the front surface <NUM> of the head <NUM>. In that regard, the annular top surface <NUM> of the conical tuft <NUM> comprises a plurality of peaks <NUM> and a plurality of valleys <NUM>. The plurality of peaks <NUM> are located at a first distance from the front surface <NUM> of the head <NUM> and the plurality of valleys <NUM> are located at a second distance from the front surface <NUM> of the head <NUM>, the first distance being greater than the second distance. The conical tuft <NUM> can have any number of peaks and valleys as desired.

In this embodiment, the conical tuft <NUM> has a continuous bristle wall that extends <NUM>° about an axis as discussed above with the conical tuft <NUM>. Furthermore, the outer surface of the conical tuft <NUM> has a continuous cone-like shape. The undulations are formed by having some of the bristles in the conical tuft <NUM> having a greater height than others of the bristles in the conical tuft <NUM>. By varying the height of the bristles within the conical tuft <NUM>, the various peaks <NUM> and valleys <NUM> noted herein above can be formed. The conical tuft <NUM> can be positioned at orientations other than that depicted in <FIG> by rotating the conical tuft <NUM> relative to the head <NUM> so that the location of the peaks <NUM> and valleys <NUM> can be other than that which is depicted in <FIG>.

Referring now to <FIG>, an oral care implement <NUM> will be described in accordance with yet another embodiment of the present disclosure. The oral care implement <NUM> is similar to the oral care implement <NUM> and thus much of the description above with regard to the oral care implement <NUM> is applicable to the oral care implement <NUM>, except where the description of the oral care implement <NUM> above is contradictory to a specific description of the oral care implement <NUM> provided below. Features of the oral care implement <NUM> that are similar to features of the oral care implement <NUM> described above will be similarly numbered except that the <NUM>-series of numbers will be used. Certain features of the oral care implement <NUM> may be labeled but not described, in which case the description of the similar feature from the oral care implement <NUM> or from the oral care implement <NUM> applies. Furthermore, certain features of the oral care implement <NUM> may not be labeled, it being understood that the description of the similar feature from the oral care implement <NUM> applies.

The oral care implement <NUM> generally comprises a handle <NUM> and a head <NUM>, which have the same structures, features, materials of construction, and the like as described above with regard to the oral care implement <NUM>. Furthermore, a plurality of tooth cleaning elements <NUM> are positioned on and extend from a front surface <NUM> of the head <NUM>. The plurality of tooth cleaning elements <NUM> include a conical tuft <NUM>, a central cleaning element <NUM>, and many additional cleaning elements that will not be described in detail herein. Specifically, although a specific configuration and pattern of the additional cleaning elements is provided in the drawings, the invention is not to be so limited. In certain embodiments, the conical tuft <NUM> can be used with any arrangement of cleaning elements, including the arrangement depicted in <FIG>. Thus, in certain embodiments the disclosure may be the arrangement of cleaning elements achieved by replacing the conical tuft <NUM> with the conical tuft <NUM>. Thus, the only components of <FIG> that will be discussed in detail herein is the conical tuft <NUM> and the central cleaning element <NUM>, it being understood that the description of the other features above may be used with this conical tuft <NUM>.

In this embodiment, the head <NUM> of the oral care implement extends from a proximal end <NUM> to a distal end <NUM> along a longitudinal axis D-D. The conical tuft <NUM> is positioned on the front surface <NUM> of the head <NUM> in a similar manner, location, and orientation as the conical tuft <NUM> discussed above. The conical tuft <NUM> terminates in an annular top surface <NUM> that undulates in height relative to the front surface <NUM> of the head. Specifically, the annular top surface <NUM> of the conical tuft <NUM> comprises a first peak portion <NUM>, a second peak portion <NUM>, a first valley portion <NUM>, and a second valley portion <NUM>. The first and second peak portions <NUM>, <NUM> extend a greater height from the front surface <NUM> of the head <NUM> than the first and second valley portions <NUM>, <NUM>. Furthermore, although in the exemplified embodiment the first and second peak portions <NUM>, <NUM> extend the same height from the front surface <NUM> of the head <NUM> and the first and second valley portions <NUM>, <NUM> extend the same height from the front surface <NUM> of the head <NUM>, the disclosure is not to be so limited in all embodiments and each peak portion and each valley portion may extend different heights from the front surface <NUM> of the head <NUM> in other embodiments. Differently from the conical tuft <NUM>, the annular top surface <NUM> of the conical tuft <NUM> comprises V-shaped undulations, although they can be sinusoidal shaped or otherwise shaped as desired in other embodiments.

In this embodiment, a longitudinal reference plane LRP1 that is substantially parallel to the longitudinal axis D-D and perpendicular to the front surface <NUM> of the head <NUM> intersects the first and second peak portions <NUM>, <NUM> of the annular top surface <NUM> of the conical tuft <NUM>. Furthermore, a transverse reference plane TRP1 that is substantially perpendicular to the longitudinal axis D-D and to the front surface <NUM> of the head <NUM> intersects both of the first and second valley portions <NUM>, <NUM> of the annular top surface <NUM> of the conical tuft <NUM>. Furthermore, in the exemplified embodiment of <FIG> the longitudinal reference plane LRP1 and the transverse reference plane TRP1 intersect along the cavity axis C-C. Thus, the first and second peak portions <NUM>, <NUM> of the annular top surface <NUM> of the conical tuft <NUM> are transversely aligned along the longitudinal reference plane LRP1 and the first and second valley portions <NUM>, <NUM> of the annular top surface <NUM> of the conical tuft <NUM> are longitudinally aligned along the transverse reference plane TRP1. Thus, due to the locations of the peak and valley portions <NUM>, <NUM>, <NUM>, <NUM>, when viewed from the transverse reference plane TRP1 the annular top surface <NUM> of the conical tuft <NUM> has a V-shaped or concave side profile and when viewed from the longitudinal reference plane LRP1 the annular top surface <NUM> of the conical tuft <NUM> has a convex side profile.

As noted above, the plurality of tooth cleaning elements <NUM> include the conical tuft <NUM> and the central cleaning element <NUM>. The central cleaning element <NUM> is located within the cavity that is defined by the inner surface of the conical tuft <NUM> in the same manner as discussed above with regard to the oral care implement <NUM> and <FIG>. In the exemplified embodiment, the valley portions <NUM>, <NUM> of the annular top surface <NUM> extend a first height H1 above the front surface <NUM> of the head <NUM>, the peak portions <NUM>, <NUM> of the annular top surface <NUM> extend a second height H2 above the front surface <NUM> of the head <NUM>, and the central cleaning element <NUM> terminates in a free end <NUM> that is located at a third height H3 above the front surface <NUM> of the head <NUM>. In certain embodiments the first height H1 is less than the second height H2. Furthermore, in the exemplified embodiment the third height H3 is less than the second height H2 and the third height H3 is greater than the first height H1. Of course, in other embodiments the third height H3 may be equal to or less than the second height H2 and greater than the first height H1. In still other embodiments, the third height H3 may be equal to or less than the first height H1.

Referring now to <FIG>, an oral care implement <NUM> will be described in accordance with an embodiment of the present invention. The oral care implement <NUM> is similar to the oral care implement <NUM> and to the oral care implement <NUM>, and thus much of the description above with regard to the oral care implement <NUM> and the oral care implement <NUM> is applicable to the oral care implement <NUM>, except where the description of the oral care implements <NUM>, <NUM> above is contradictory to a specific description of the oral care implement <NUM> provided below. Features of the oral care implement <NUM> that are similar to features of the oral care implements <NUM>, <NUM> described above will be similarly numbered except that the <NUM>-series of numbers will be used. Certain features of the oral care implement <NUM> may be labeled but not described, in which case the description of the similar feature from the oral care implement <NUM>, <NUM> applies. Furthermore, certain features of the oral care implement <NUM> may not be labeled, it being understood that the description of the similar feature from the oral care implement <NUM>, <NUM> applies.

The oral care implement <NUM> is identical to the oral care implement <NUM> except that the conical tuft <NUM> has been rotated ninety degrees relative to the head <NUM>. Thus, in the oral care implement <NUM> the peaks <NUM>, <NUM> were aligned along the longitudinal axis D-D of the head <NUM>, but in the oral acre implement <NUM> the valley portions <NUM>, <NUM> are aligned along the longitudinal axis D-D of the head <NUM>. Thus, in this embodiment, a longitudinal reference plane LRP2 that is substantially parallel to the longitudinal axis D-D and perpendicular to the front surface <NUM> of the head <NUM> intersects the first and second valley portions <NUM>, <NUM> of the annular top surface <NUM> of the conical tuft <NUM> and a transverse reference plane TRP2 that is substantially perpendicular to the longitudinal axis D-D and perpendicular to the front surface <NUM> of the head <NUM> intersects the first and second peak portions <NUM>, <NUM> of the annular top surface <NUM> of the conical tuft <NUM>. In this embodiment, the annular top surface <NUM> has a convex side profile (or V-shaped) when viewed from the transverse reference plane TRP2 and a concave side profile when viewed from the longitudinal reference plane LRP2.

In either of the embodiments of <FIG> and <FIG>, the central tooth cleaning element <NUM>, <NUM> may be shorter than the valley portions of the conical tufts <NUM>, <NUM>, the same height as the valley portions of the conical tufts <NUM>, <NUM>, taller than the valley portions of the conical tufts <NUM>, <NUM> but shorter than the peak portions of the conical tufts <NUM>, <NUM>, the same height as the peak portions of the conical tufts <NUM>, <NUM>, or taller than the peak portions of the conical tufts <NUM>, <NUM> as desired to achieve a particular cleaning result. Furthermore, as discussed previously the central tooth cleaning elements <NUM>, <NUM> may also be omitted in some embodiments.

Claim 1:
An oral care implement (<NUM>; <NUM>) comprising:
a handle (<NUM>; <NUM>);
a head (<NUM>; <NUM>) coupled to the handle (<NUM>; <NUM>), the head (<NUM>; <NUM>) comprising a front surface (<NUM>; <NUM>) and extending from a proximal end to a distal end along a longitudinal axis (D-D);
a plurality of tooth cleaning elements (<NUM>) extending from the front surface (<NUM>; <NUM>) of the head; and
the plurality of tooth cleaning elements (<NUM>) comprising a conical tuft (<NUM>; <NUM>) comprising a bristle wall having an inner surface defining a cavity along a cavity axis (C-C), the cavity having a transverse cross-sectional area that increases with distance from the front surface (<NUM>; <NUM>) of the head (<NUM>; <NUM>);
characterized in that the bristle wall of the conical tuft terminates in an annular top surface (<NUM>; <NUM>) that undulates in height relative to the front surface (<NUM>; <NUM>);
wherein the annular top surface (<NUM>; <NUM>) comprises first and second peak portions (<NUM>, <NUM>) and first and second valley portions (<NUM>, <NUM>); wherein a longitudinal reference plane (LRP2) that is substantially parallel to the longitudinal axis (D-D) and perpendicular to the front surface (<NUM>; <NUM>) of the head (<NUM>; <NUM>) intersects the first and second valley portions (<NUM>, <NUM>); and wherein a transverse reference plane (TRP2) that is substantially perpendicular to the longitudinal axis (D-D) and perpendicular to the front surface (<NUM>; <NUM>) of the head (<NUM>; <NUM>) intersects both the first and second peak portions (<NUM>, <NUM>).