US20110191974A1

US20110191974A1 - Utensil with wavy head

Info

Publication number: US20110191974A1
Application number: US13/025,052
Authority: US
Inventors: Spencer Clyde Holcomb; David A. Holcomb; Adam A. Jossem
Original assignee: Chefn Corp
Current assignee: Chefn Corp
Priority date: 2010-02-11
Filing date: 2011-02-10
Publication date: 2011-08-11
Also published as: WO2011100421A1

Abstract

A utensil includes an elongate handle and a head. The head has a non-planar configuration such that different regions of the head can be used to mix, fold, stir, spread, lift, or otherwise manipulate food. The head includes a wavy portion with a transverse profile that varies along a length of the head.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/303,621 filed Feb. 11, 2010. This provisional application is incorporated herein by reference in its entirety.

BACKGROUND

1. Technical Field
The invention relates generally to utensils. More particularly, the invention relates to utensils for use in the culinary field.
2. Description of the Related Art
Spatulas and spoons are commonly used to mix ingredients. Some conventional spatulas have a flat rubber blade for scraping ingredients off surfaces (e.g., an inner surface of a bowl) and for mixing ingredients. Unfortunately, conventional spatulas and spoons are often unsuitable for effectively mixing ingredients. Folding is one technique for mixing ingredients with different densities. For some recipes, eggs whites are beaten to produce whipped egg whites. The whipped egg whites are then incorporated into a denser batter by folding the whipped egg whites into the batter. It may be difficult to scoop up the dense batter to fold the batter about the whipped eggs using a flat spatula. Spoons are typically not used to fold batters because it is difficult to evenly fold dense batters with a spoon.

BRIEF SUMMARY

Some embodiments are directed to a utensil with a non-planar head that enhances mixing, beating, scraping, lifting, spreading, or otherwise manipulating food. The non-planar head, in some embodiments, can more effectively fold ingredients as compared to conventional flat blade spatulas. The non-planar head can have a serpentine or wave shaped profile. Different regions of the profile can be used to perform different functions, such as scooping, spreading, pouring, or the like. In certain embodiments, a concave surface defines a channel that can be used to scoop up and hold a batter. An adjacent convex surface can be used to spread the batter over, for example, whipped egg whites. In this manner, different regions of the non-planar head can be used to perform a wide range of different types of functions. The utensil can be held at different orientations and manipulated (e.g., twisted, rotated, etc.) to perform those functions.
In some embodiments, a spatula comprises an elongate handle and a head. The head has a longitudinal axis and includes a proximal, upper portion coupled to the elongate handle and a wavy, distal, lower portion that defines a lower end of the head. The wavy lower portion includes a first arcuate portion and a second arcuate portion. The head, in some embodiments, has a twisted configuration.
The first arcuate portion, in some embodiments, extends from the upper portion to the lower end of the head. The first arcuate portion includes a first free edge extending longitudinally along the head and a first concave surface on a back side of the head. The first concave surface extends along most of a first distance from the first free edge to the longitudinal axis. The second arcuate portion extends from the upper portion to the lower end of the head. The second arcuate portion includes a second free edge extending longitudinally along the head and a second concave surface on a front side of the head. The second surface extends along most of a second distance from the second free edge to the longitudinal axis.
In other embodiments, a spatula comprises an elongate handle and a head. The head includes a wavy portion. The wavy portion includes a tip and a transverse profile with an amplitude that increases towards the tip. In certain embodiments, the wavy portion has a smooth convex surface and an adjacent smooth concave surface. The convex surface and concave surface can cooperate to define a generally sinusoidal shaped face. The concave surface defines a channel suitable for holding flowable materials (for example, wet ingredients, batters, or the like). The head can be rotated such that flowable materials held in the channel can flow across the convex surface. The convex surface can spread flowable materials across other ingredients, across cooking surfaces, or the like.
In yet other embodiments, a spatula comprises a handle and a head coupled to the handle. The head comprises a forwardly concave surface and a rearwardly concave surface. The forwardly concave surface defines a first channel on a front side of the head. The first channel extends across most of a first distance between a longitudinal axis of the head and a first side edge of the head. The rearwardly concave surface defines a second channel on a back side of the head. The second channel extends across most of a second distance between the longitudinal axis of the head and a second side edge of the head. The second side edge is opposite the first side edge.
In some embodiments, a spatula head has a wave shaped profile to facilitate, for example, folding batter. The head can be used to scoop batter to increase the amount of batter being lifted and folded as compared to conventional flat blade spatulas. The orientation of the head can be adjusted to provide different types of lifting action. In certain embodiments, the head can be used to cut through batters. The head can be passed through the low density ingredient (e.g., beaten egg whites) lengthwise to position the head underneath the low density ingredient. The head can then scoop up and fold the dense batter over the low density ingredient. The curved faces can result in a rolling effect to increase the amount of material that is folded.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments are described with reference to the following drawings. The same reference numerals refer to like parts or acts throughout the various views, unless otherwise specified.

FIG. 1 is an isometric view of a spatula, in accordance with one embodiment.

FIG. 2 is a front elevational view of the spatula of FIG. 1.

FIG. 3 is an elevational view of a left side of the spatula of FIG. 1.

FIG. 4 is a front elevational view of a head of the spatula of FIG. 1.

FIG. 5 is a cross-sectional view of the head of FIG. 4 taken along a line 5-5 in FIG. 4.

FIG. 6 is a cross-sectional view of the head taken along a line 6-6 of FIG. 4. FIG. 7 is a cross-sectional view of the head taken along a line 7-7 of FIG. 4.

FIG. 8 is a bottom view of the head of FIG. 4.

FIG. 9 is a cross-sectional view of the head taken along a line 9-9 of FIG. 4.

FIG. 10 is a bottom view of a head of a spatula passing through a flowable material.

FIG. 11 is a bottom view of the head of the spatula of FIG. 10 passing through a flowable material.

FIG. 12 is a top plan view of a spatula.

FIGS. 13-15 are bottom views of spatula heads with different configurations.

FIG. 16 is an isometric view of a head of a spatula, in accordance with one embodiment.

FIG. 17 is a front elevational view of a head of the spatula of FIG. 16.

FIG. 18 is a cross-sectional view of the head taken along a line 18-18 in FIG. 17.

FIG. 19 is a cross-sectional view of the head taken along a line 19-19 of FIG. 17.

FIG. 20 is a cross-sectional view of the head taken along a line 20-20.

FIG. 21 is a bottom view of the head of FIG. 17.

FIG. 22 is a cross-sectional view of the head taken along a line 22-22 of FIG. 17.

DETAILED DESCRIPTION

The present detailed description is generally directed to utensils and methods of using the utensils in the culinary fields. Embodiments disclosed herein can be utensils used to prepare food, such as batters, baking mixes, dough, or the like, and/or used to cook or prepare food (e.g., lift food from cooking surfaces). Utensils can be in the form of spatulas, spoons, or other types of instruments used in the culinary field. Many specific details of certain embodiments are set forth in the following description and in FIGS. 1-22 to provide a thorough understanding of such embodiments. One skilled in the art, however, will understand that the embodiments may have additional features and may be practiced without one or more of the details described in the following description.
FIG. 1 shows a utensil in the form of a spatula 100. The spatula 100 includes an elongate handle 110 and a head 120. A user can manually grip the elongate handle 110 to mix, beat, scrape, lift, spread, or otherwise manipulate foodstuff. The illustrated head 120 has a wavy configuration (e.g., a configuration that curves alternatingly in opposite directions) and is well suited for mixing different types of ingredients using folding techniques.
Referring to FIGS. 1 and 2, the elongate handle 110 includes an upper end 130, a lower end 140, and a handle main body 150. The handle main body 150 gradually tapers inwardly from the upper end 130 toward the lower end 140. In other embodiments, the main body 150 has a generally uniform cross-section along a longitudinal axis 153 of the spatula 100. For example, the handle main body 150 can be a rod or other type of cylindrical member. The elongate handle 110 can be straight (illustrated in FIGS. 1-3), curved, or combinations thereof (e.g., a handle with both curved and linear sections), and can have a one-piece construction or a multi-piece construction. Thus, a wide range of different types of handles can be utilized.
The lower end 140 of the elongate handle 110 and the head 120 can form a necked down region 160, as shown in FIGS. 2 and 3. The lower end 140 may be integrally formed with the head 120 to prevent separation of the elongate handle 110 and the head 120. In one-piece embodiments, the head 120 and the lower end 140 can be monolithically formed via a molding process, including an injection molding process, a compression molding process, an overmolding process, or the like. In multi-piece embodiments, the head 120 can be removably coupled to the elongate handle 110 and can be replaced with another head. A wide range of different types of couplers (e.g., fasteners, screws, snaps, locks, or the like) and/or adhesives can couple the elongate handle 110 to the head 120. In some multi-piece embodiments, the head 120 is permanently coupled to the elongate handle 110.
The head 120 includes an upper portion 200 and a lower portion 220. The upper portion 200 is coupled to the lower end 140 of the handle 110. As shown in FIG. 1, the upper portion 200 has a generally planar configuration, and the lower portion 220 has a non-planar configuration. The non-planar configuration can be a wavy configuration (illustrated in FIG. 1), a sinusoidal configuration, a serpentine configuration, combinations thereof, or another configuration having one or more concave regions, convex regions, channels, ridges, crests, waveform shapes, or the like.
With continued reference to FIGS. 1-3, the lower portion 220 includes a first arcuate portion 230 and an adjacent second arcuate portion 240. The arcuate portions 230, 240 cooperate to form a front surface or face 244 and a rear surface or face 246. The first and second arcuate portions 230, 240 also define longitudinally extending free edges 260, 270, respectively.
The front surface 244 and the rear surface 246 can be relatively smooth surfaces with complementary shapes, such that the head 120 has a thickness t along its width W. In different embodiments, the head 120 can have a generally uniform or a variable thickness t across its width W. The illustrated front surface 244 includes a forwardly convex surface 273 and a forwardly concave surface 282 laterally adjacent to the forwardly convex surface 273. The rear surface 246 includes a rearwardly concave surface 280 (see FIG. 9) opposite the forwardly convex surface 273 and a rearwardly convex surface 275 (see FIG. 8) opposite the forwardly concave surface 282. The concave surfaces 280, 282 can be used for scooping food, while the convex surfaces 273, 275 can be used to spread food. In some embodiments, including the illustrated embodiment, the convex surface 273 and concave surface 282 cooperate to form a generally sinusoidal shape.
The edges 260, 270 are rounded. The head 120 can thus be moved lengthwise through a mixture of ingredients without significantly damaging the mixture, even if the mixture comprises a delicate substance, such as fluffy, whipped egg whites. Alternatively, the edges 260, 270 can be relatively sharp for scraping or flipping food. The shapes and configurations of the edges 260, 270 can be selected based on the desired use of the spatula 100.
As shown in FIG. 4, the head 120 has a generally rectangular shape and extends laterally outward from the elongate handle 110. The edges 260, 270 are generally parallel to one another, and a lower edge 276 extends between the edges 260, 270. Alternatively, the head 120 can have a generally square shape (including a rounded square shape), an elliptical shape, a circular shape, or other suitable shape for utensils.
Referring to FIGS. 4-8, the first arcuate portion 230 is concave with respect to the backside and has the first concave surface 280 and the first convex surface 273. The second arcuate portion 240 is concave with respect to the front side and has the second concave surface 282 and the second convex surface 275. The concave surfaces 280, 282 can be generally similar to each other. The convex surfaces 273, 275 can also be generally similar to each other. Accordingly, the description of one surface applies equally to the other, unless indicated otherwise.
The surfaces 280, 273 of FIGS. 6-8 extend along most of a first distance D₁(see FIG. 4) from the edge 260 to a longitudinal axis 278 of the head 120. The longitudinal axis 278 can be collinear with or parallel to the longitudinal axis 153 of the spatula 100. In some embodiments, the surfaces 280, 273 extend along at least 60%, 70%, 80%, or 90% of the distance D₁. The illustrated surfaces 280, 273 extend across substantially all of the distance D₁.
In some embodiments, including the illustrated embodiment of FIG. 8, the surfaces 280, 273 have partially circular shapes. A radius of curvature R, for example, can be less than or equal to about 0.5 inch, 1 inch, 2 inches, 3 inches, 5 inches, 10 inches, or the like. In certain embodiments, the radius of curvature R is greater than or equal to the distance D₁. In other embodiments, the radius of curvature R is greater than or equal to a distance D₃(i.e., the width of the head 120) from the edge 260 to the edge 270. In yet other embodiments, the radius of curvature is greater than the thickness t of the first arcuate portion 230.
Referring to FIGS. 6-8, the lower portion 220 has a generally sinusoidal transverse cross-section that is taken perpendicularly to the longitudinal axis 278. The amplitude of the sinusoidal cross-section increases towards the free end 277 of the head 120. Thus, the amplitude of the sinusoidal transverse profile proximate to the upper portion 200 is less than the amplitude of the sinusoidal transverse profile defined by the lower edge 276.
Referring again to FIGS. 1 and 2, the surface 282 defines a channel 330 on the front side of the head 120. The surface 280 defines a channel 300 on the back side of the head 120. Both channels 300, 330 have dimensions that vary along the longitudinal axis 278 of the head 120. In some embodiments, the channels 300, 330 have upper ends at least proximate to or extending along the upper portion 200 and have widths and depths that vary along the longitudinal axis 278.
FIG. 6 shows the shape of the upper ends of the channels 300, 330. The depths of the channels 300, 330 gradually increase with respect to the longitudinal axis 278 towards the end 277. Each channel 300, 330 can have a maximum depth that is larger than half the maximum thickness t of the lower portion 220. The maximum depths can be at the centerline of the channels 300, 330, or any other suitable location depending on the shape of the channel. Both channels 300, 330 extend along most of a longitudinal length L (see FIGS. 1 and 3) of the head 120. This allows food to be scooped up and to collect easily along most of the length L of the head 120.
As used herein, the term “channel” is a broad term that includes a groove, trough, or other type of feature or depression capable of receiving and/or holding a substance. In some non-limiting embodiments, a channel has a generally U-shaped cross-section, V-shaped cross-section, partially elliptical cross-section, or combinations thereof. The illustrated channel 330 of FIGS. 6-8 has a shallow U-shaped profile. The channel 330 has a generally uniform transverse shape along its longitudinal length. In other embodiments, one portion of the channel 300 can have one profile, and another portion of the channel 330 has a different profile. Such variable profile channels are well suited for holding different amounts of material at different locations along the channel. The channel 330 of FIG. 9 has a shallow region 350 that slopes from the upper portion 200 to a relatively deep region 360. The depth D of the channel 330 thus varies along the length L of the channel 330.
FIG. 10 shows the head 120 travelling lengthwise in a direction indicated by an arrow 362 through a material M. The rotationally symmetric head 120 can be moved in the opposite direction as indicated by an arrow 363 to achieve the same type of action. If the material M is a flowable material (e.g., a liquid batter, a liquid mix, etc.), the head 120 can pass through the material M and maintain a substantially laminar flow. If the horizontally oriented head 120 in FIG. 10 is moved vertically, the channel 330 can help capture or retain the material M on the upper face 244 of the head 120.
The head 120 can be oriented generally perpendicular to the direction of travel to push material. FIG. 11 shows the vertically oriented head 120 moving in a direction indicated by the arrow 364 to push the material M.
The spatula 100 can be used to mix (e.g., combine, incorporate, etc.) different ingredients, including ingredients having significantly different characteristics. In some embodiments, ingredients with different densities are folded, mixed, and/or beaten together. In some methods of folding, a container (e.g., mixing bowl) can hold both light ingredients (e.g., beaten egg whites) and heavy ingredients. The head 120 is moved across the middle of the bowl to cut through both the light and heavy ingredients, reaching a position near or against a lower region of the mixing bowl. The head 120 is then moved towards the bottom of the bowl and then across the bottom towards an opposing side of the bowl. The head 120 lifts and folds the heavy ingredients over the light ingredients. One of the channels 300, 330 can scoop up the heavy ingredients during the lifting process. As the head 120 is turned, the heavy ingredients can be moved along the adjacent convex surface 273, 275, to gently spread the heavy ingredients over the light ingredients. The folding action, in some embodiments, allows the light ingredients to move towards the bottom of the bowl to replace the heavy ingredients on the bottom. In this manner, regions of the head 120 with different geometries can be used to perform different functions.
The bowl can be rotated 90 degrees for each fold so that the head 120 cuts across different sections of the ingredients. Because of the rotational symmetry, the head 120 can be moved lengthwise in either direction by either a left-handed or right-handed user. The folding process can be repeated any number of times until the desired consistency is achieved. Advantageously, the spatula 100 can be used to quickly fold whipped egg whites into relatively dense heavy batters without appreciably reducing the volume of whipped egg whites, thereby producing a light, airy batter. A wide range of different types of conventional folding techniques can be used with the spatula 100.
The spatula 100 can be suitable for contacting surfaces at a wide range of temperatures. The head 120, for example, can comprise a temperature resistant material suitable for contacting surfaces at extremely high temperatures and can thus be used to scrap, lift, or otherwise move food along hot surfaces, with little or substantially no damage to the head 120. Such a high-temperature spatula 100 can be made, in whole or in part, of one or more polymers or plastics having a melt temperature equal to or greater than about 200° F., 300° F., 400° F. 500° F., 550° F., 600° F., or 650° F., as well as other melt temperatures greater than the temperature of a cooking surface. In some embodiments, the head 120 comprises silicone or other type of polymer with a melt temperature of at least about 625° F. and is well suited for flipping or lifting food from a grill or frying pan. A compliant head 120 can deform such that it can be easily slid underneath food. The head 120, in some embodiments, is made of a low temperature resistant material suitable for contacting surfaces at lower temperatures. Low-temperature heads 120 are especially well suited for mixing batters and may be made of relatively inexpensive materials.
The head 120 can have a multi-piece construction. FIGS. 4-7 show the multi-piece head 120 with an outer main body 410 surrounding a stiffener 412. The outer main body 410 can be made of a compliant material (polymer or plastic material) and the inner member 412 can be made of a generally rigid material, such as metal, a rigid plastic, composite material, or the like. Any number of stiffeners 412 can be positioned inside of the head 120. In other embodiments, the head 120 comprises a single material, including, without limitation, polymers, plastics, natural materials (e.g., wood), metal (coated or uncoated), or the like.
For convenient storage, the elongate handle 110 includes an aperture. Referring to FIG. 12, an aperture 154 extends through the handle 110. The spatula 100 can hang from hooks, loops, or other types of features using the aperture 154. In other embodiments, the handle 110 is apertureless.
FIGS. 13-15 show different profiles of heads. The profiles are taken generally perpendicularly to longitudinal axes of the heads. FIG. 13 shows a generally serpentine profile. FIG. 14 shows a generally S-shaped profile. Such an embodiment is especially well suited for scooping and retaining material within deep channels 300, 330. The deep U-shaped channels 300, 330 can easily receive and carry batters. The head 120 can be slowly rotated counterclockwise about a longitudinal axis 278 such that the material flows along the convex surface 273 and out of the channel 330. FIG. 15 shows three elongate segments 440, 442, 444 connected by arcuate segments 456, 458. The arcuate segment 456 is between the elongate segments 440, 442. The arcuate segment 458 is between the elongate segments 442, 444. Other types of configurations can also be used.
FIG. 16 shows a head with a shallow S-shaped configuration. U-shaped channels 506, 508 are especially well suited for scooping and retaining material. The width of the head 510 is larger than the head 120 discussed in connection with FIGS. 1-15. As such, the head 510 can be used to lift, fold, and/or mix relatively large amounts of wet ingredients.
Referring to FIGS. 17-21, the channels 506, 508 are relatively shallow as compared to the channels 300, 330. The thickness t of the head 510 is relatively large compared to the head 120 to provide a generally rigid head capable of withstanding relatively large forces. The head 510 can fold batters with a higher density than the batters used with the head 120.
The utensils discussed herein are discussed in the context of spatulas. In other embodiments, the wavy configurations and heads can be part of spoons. In some embodiments, a utensil in the form of a spoon has a wavy head. Thus, the features and components discussed herein can be modified for different types of utensils.
The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.

Claims

1. A spatula comprising:

an elongate handle; and

a head having a longitudinal axis and including an upper portion coupled to the elongate handle and a wavy lower portion defining a lower end of the head, the wavy lower portion including:

a first arcuate portion extending from the upper portion to the lower end of the head, the first arcuate portion including a first free edge extending longitudinally along the head and a first concave surface on a back side of the head, the first concave surface extending along most of a first distance from the first free edge to the longitudinal axis; and

a second arcuate portion extending from the upper portion to the lower end of the head, the second arcuate portion including a second free edge extending longitudinally along the head and a second concave surface on a front side of the head, the second concave surface extending along most of a second distance from the second free edge to the longitudinal axis.

2. The spatula of claim 1, wherein the upper portion is substantially planar and the wavy lower portion has a sinusoidal shaped cross-section with an amplitude that varies with respect to the longitudinal axis.

3. The spatula of claim 1, wherein at least one of the first concave surface and the second concave surface defines a channel that extends longitudinally along most of a longitudinal length of the head.

4. The spatula of claim 3, wherein the channel has a depth that increases towards the lower end of the head.

5. The spatula of claim 3, further comprising a main body of the head having a front face, a rear face, and a thickness defined from the front face to the back face, the channel having a maximum depth that is larger than half of the thickness of the main body of the head.

6. The spatula of claim 1, wherein at least a portion of the wavy lower portion has a substantially S-shaped cross-sectional profile that is taken perpendicularly to the longitudinal axis.

7. The spatula of claim 1, wherein the first arcuate portion and the second arcuate portion are substantially rotationally symmetric about the longitudinal axis.

8. The spatula of claim 1, wherein the wavy lower portion has a lower edge extending between the first free edge and the second free edge, the lower edge has a substantially sinusoidal shape as viewed along the longitudinal axis of the head.

9. A spatula comprising:

an elongate handle; and

a head including an upper portion coupled to the elongate handle and a wavy lower portion, the wavy lower portion including a tip and a transverse profile with an amplitude that increases towards the tip.

10. The spatula of claim 9, wherein the wavy lower portion includes:

a first arcuate portion extending away from a longitudinal axis of the head in a first direction, the first arcuate portion including a first free edge extending longitudinally along the head and a first concave surface on a back side of the head, the first surface extending along most of a first distance from the first free edge to the longitudinal axis; and

a second arcuate portion extending away from the longitudinal axis of the head in a second direction, the second direction being generally opposite to the first direction, the second arcuate portion including a second free edge extending longitudinally along the head and a second concave surface on a front side of the head, the second surface extending along most of a second distance from the second free edge to the longitudinal axis.

11. The spatula of claim 10, wherein at least one of the first concave surface and the second concave surface has a radius of curvature at the tip that is larger than a distance between the first and second free edges of the head.

12. The spatula of claim 10, wherein at least one of the first concave surface and the second concave surface has a radius of curvature that gradually increases towards the tip.

13. The spatula of claim 9, wherein the wavy lower portion has a front face and rear face that define a substantially uniform thickness across a width of the head.

14. The spatula of claim 9, wherein the wavy lower portion includes channels on opposite sides of the head that have depths that vary with respect to a long axis of the head.

15. The spatula of claim 9, wherein the tip has a sinusoidal edge that extends between opposing longitudinally extending side edges of the head.

16. The spatula of claim 9, wherein the head has a wavy front face and a wavy back face, the wavy front face and back face have complementary shapes.

17. The spatula of claim 9, wherein the head includes a front face and rear face, the front face includes a forwardly convex surface, a forwardly concave surface laterally adjacent to the forwardly convex surface, the rear face includes a rearwardly concave surface opposite the forwardly convex surface and a rearwardly convex surface opposite the forwardly concave surface.

18. A spatula comprising:

a handle; and

a head coupled to the handle, the head comprising

a forwardly concave surface defining a first channel on a front side of the head, the first channel extending across most of a first distance between a longitudinal axis of the head and a first side edge of the head; and

a rearwardly concave surface defining a second channel on a back side of the head, the second channel extending across most of a second distance between the longitudinal axis of the head and a second side edge of the head located opposite the first side edge.

19. The spatula of claim 18, wherein the head has a generally S-shaped transverse profile.

20. The spatula of claim 18, wherein at least one of the first channel and the second channel has at least one of a substantially U-shaped profile and a substantially V-shaped profile.