This application relates to the field of cutting food products, such as fruit or vegetables.
This application relates to blade assemblies for making cut food products. More particularly, this application relates to blade assemblies comprising a plurality of slitter blades for cutting food products into helical food pieces.
In a first aspect, a rotary blade assembly for cutting a food product into helical strips is provided. The rotary blade assembly may comprise a substantially spiral-shaped blade holder for mounting in a food product flow path and a plurality of axially extending slitter blades connected to the blade holder. The blade holder may comprise an axis of rotation, an upstream surface, an upstream end and a downstream end. The upstream end may be axially spaced apart from the downstream end to define a radial slot. A radial cutting edge may be adjacent the radial slot. Each slitter blade may extend upstream of the upstream surface, and include a slitter cutting edge. At least a portion of the slitter cutting edge of at least one of the slitter blades may extend substantially non-perpendicularly to the upstream surface toward or away from the axis of rotation.
In some embodiments, at least a portion of each slitter cutting edge may be curved.
In some embodiments, at least one of the slitter blades of the plurality of slitter blades may be in contact with an adjacent other slitter blade of the plurality of slitter blades.
In some embodiments, the slitter cutting edge of at least one of the slitter blades may form a closed shape.
In some embodiments, the slitter cutting edge may comprise at least a first portion and a second portion, the first and second portions extending in different directions in the plane that is substantially parallel to the axis of rotation.
In some embodiments, the slitter cutting edge of alternate slitter blades may be substantially perpendicular to the upstream surface.
In some embodiments, the portion of each slitter cutting edge may be undulating.
In some embodiments, the slitter cutting edge of each slitter blade may be arcuate.
In some embodiments, the slitter cutting edge of each slitter blade may be crescent shaped.
In some embodiments, the slitter cutting edge of each slitter blade may be circular.
In some embodiments, the slitter cutting edge of each slitter blade may be zigzagged.
In some embodiments, each slitter blade may extend from the downstream end to the upstream end of the blade holder.
In some embodiments, the rotary blade assembly may further comprise a slitter pack removably mounted to the blade holder, the slitter pack including the plurality of slitter blades.
In some embodiments, each of the plurality of slitter blades may be positioned a different radial distance from the axis of rotation.
In some embodiments, the blade holder may further comprise a slab blade removably mounted proximate the upstream end, the slab blade including the radial cutting edge.
In another aspect, a rotary blade assembly for cutting a food product into helical strips is provided. The rotary blade assembly may comprise a blade holder and a plurality of slitter blades. The blade holder may have an axis of rotation, an upstream surface, and a radially extending leading edge spaced from at least a portion of the upstream surface to define a slot having an axial height and a radial width. Each slitter blade may extend axially away from the upstream surface and include a cutting edge. At least a portion of the cutting edge of at least one of the slitter blades may extend substantially non-perpendicularly to the upstream surface in a plane substantially parallel to the axis of rotation.
In some embodiments, at least a portion of each cutting edge may be curved.
In some embodiments, at least one of the slitter blades of the plurality of slitter blades may be in contact with an adjacent other slitter blade of the plurality of slitter blades.
In some embodiments, the cutting edge of at least one of the slitter blades may form a closed shape.
In some embodiments, the cutting edge of each of the plurality of slitter blades may include at least a first portion and a second portion, the first and second portions extending in different directions in the plane that is substantially parallel to the axis of rotation.
In another aspect, a rotary blade assembly for cutting a food product into helical strips is provided. The rotary blade assembly may comprise a blade holder and a plurality of slitter blades. The blade holder may have an axis of rotation, an upstream surface, and a radially extending leading edge spaced from at least a portion of the upstream surface to define a slot having an axial height and a radial width. Each slitter blade may extend axially away from the upstream surface and include a cutting edge. At least a portion of the cutting edge of at least one of the slitter blades may extend toward or away from the axis of rotation when viewed in profile through a viewing plane that is parallel to the axis of rotation.
Numerous embodiments are described in this application, and are presented for illustrative purposes only. The described embodiments are not intended to be limiting in any sense. The invention is widely applicable to numerous embodiments, as is readily apparent from the disclosure herein. Those skilled in the art will recognize that the present invention may be practiced with modification and alteration without departing from the teachings disclosed herein. Although particular features of the present invention may be described with reference to one or more particular embodiments or figures, it should be understood that such features are not limited to usage in the one or more particular embodiments or figures with reference to which they are described.
The terms “an embodiment,” “embodiment,” “embodiments,” “the embodiment,” “the embodiments,” “one or more embodiments,” “some embodiments,” and “one embodiment” mean “one or more (but not all) embodiments of the present invention(s),” unless expressly specified otherwise.
The terms “including,” “comprising” and variations thereof mean “including but not limited to,” unless expressly specified otherwise. A listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms “a,” “an” and “the” mean “one or more,” unless expressly specified otherwise.
For convenience, the description below will refer to potatoes as the food product being cut. Those skilled in the art will appreciate that the embodiments of the blade assembly and food cutting device described herein may be used to cut any suitable product, including without limitation food products (such as fruit and vegetables), wood, and fibrous materials (such as bamboo).
In the illustrated example, pump 20 circulates water 18 from tank 16 to thereby entrain food products 12 to travel through conduits 24 to knife fixture 22. In some examples, conduits 24 are sized to receive food products 12 in single file. For example, conduits (e.g. pipes) 24 may have a diameter that is greater than a diameter of one food product 12, and less than the diameter of two food products 12. In alternative embodiments, conduits 24 may be sized to receive two or more food products 12 in parallel. For example, conduits 24 may have a diameter that is greater than a diameter of at least two food products 12.
In the example shown, food products 12 travel through conduits 24 toward knife fixture 22 at a velocity imparted to them by pump 20. Knife fixture 22 includes an embodiment of a blade assembly (not shown in
Reference is now made to
Blade holder 104 may have any configuration suitable for cutting potatoes into spiral slabs. In the illustrated example, blade holder 104 is substantially spiral shaped. As shown, upstream surface 108 extends from an upstream end 120 around axis 116 and axially downstream to a downstream end 124. Preferably, blade holder 104 extends at least one rotation (i.e. about 360 degrees) around axis 116 between upstream and downstream ends 120, 124, respectively. In this case, axially spaced apart upstream and downstream ends 120 and 124 may define a radially extending slot 128. A radially extending cutting edge 132 may be provided along the upstream edge 140 of slot 128.
As used herein and in the claims, a cutting edge refers to an exposed edge intended to cut a food product. For example, a cutting edge may be sharpened or sufficiently thin to slice into a food product that strikes the cutting edge. A cutting edge may have any suitable edge finish, such as straight, serrated, and saw-toothed. Further a cutting edge may be configured to form an incision with any suitable texture. For example, a cutting edge may be straight for making straight cuts, wavy for making wavy cuts, or crinkled for making crinkle cuts.
Cutting edge 132 may be integrally formed with blade holder 104, or attached thereto. In the illustrated example, cutting edge 132 is integrally formed with blade holder 104 along the upstream edge 140. Alternatively, a cutting edge may be provided adjacent slot 128 by attaching a discrete slab blade to upstream end 120. In this case, the attached slab blade is preferably mounted to blade holder 104, which may permit the slab blade to be removed and replaced, e.g. if the slab blade becomes dull or damaged.
Preferably, cutting edge 132 is located along an upstream edge 140 of slot 128. Cutting edge 132 extends radially from an inboard cutting edge end 144 to an outboard cutting edge end 148 across a radial width 152 of slot 128. In the illustrated example, slot 128 extends in width from an inboard side 156 to an open outboard side 160. As shown, inboard end 144 of cutting edge 132 may be adjacent, or more preferably coterminous, with inboard side 156 of slot 128. Alternatively, inboard end 144 may be spaced radially inwardly or outwardly from inboard side 156. Further, as shown, outboard end 148 of cutting edge 132 may be spaced radially inwardly from outboard side 160 of slot 128. Alternatively, outboard end 148 of cutting edge 132 may be adjacent to, coterminous with, or radially outboard of outboard side 160.
Inboard side 156 of slot 128 may be closed or open ended. In the illustrated example, blade assembly 100 includes an optional central support 164 joined to blade holder 104. As shown, central support 164 extends axially along axis 116 of rotation of blade holder 104. Central support 164 may include an axially extending sidewall 168 that defines a closed inboard side of slot 128. In one aspect, central support 164 may provide structural support to blade assembly 100 for withstanding repeated impacts of food products. In another aspect, central support 164 may help to keep food products axially aligned with axis 116 as they are cut by blade assembly 100. By axially puncturing each food product as it passes through blade assembly 100, central support 164 may inhibit the food product from moving off-axis.
Central support 164 may include a pointed upstream tip for spearing each food product, or as shown, may be configured as a hollow cylinder for coring (i.e. cutting out the core of) each food product. As shown, axial sidewall 168 is cylindrically shaped and defines a hollow interior that extends from an upstream end 172 to a downstream end 176. Preferably, a cutting edge 180 is provided along an edge 184 bordering upstream end 172. Cutting edge 180 may be integrally formed with edge 184 (e.g. by sharpening edge 184 or providing edge 184 with a diminutive thickness) as shown, or a discrete coring blade (not shown) may be mounted (e.g. removably mounted) to edge 184. A diameter of central support 164 may define the diameter of the bore that central support 164 cuts into each food product. In some embodiments, central support 164 is removably mounted to blade holder 104. This may permit central support 164 to be removed and replaced when dull or damaged.
In alternative embodiments, blade assembly 100 may not include a central support 164. In this case, an inboard side 156 of slot 128 may be open. For example, inboard side 156 may be defined between an axial line extending from an inboard end of edge 140 and the portion of upstream surface 108 below.
Outboard side 160 of slot 128 may be open or closed. In the illustrated example, outboard side 160 is an open side defined by an axial line extending between outboard edge 188 of upstream end 120, and outboard edge 192 of downstream end 124. In alternative embodiments, blade holder 104 or blade assembly 100 more generally, may include a perimeter wall (not shown) that defines a closed outboard side to slot 128.
Slot 128 may extend in width radially outwardly away from axis 116 across any suitable portion of blade holder 104. In the illustrated example, inboard side 156 is spaced radially inboard of axis 116 and corresponds to sidewall 168 of central support 164. In alternative embodiments, such as where blade assembly 100 does not include a central support 164, inboard side 156 may be coincident with axis 116. As shown, outboard side 160 is coincident with the outermost edge 196 of blade holder 104. In alternative embodiments, outboard side 160 may be positioned inboard of outer edge 196 of blade holder 104. For example, slot 128 may be defined by an upstanding flap on a planar disc-shaped blade holder, such described in U.S. Pat. No. 5,010,796.
Reference is now made to
After potato 200 contacts upstream surface 108, cutting edge 132 makes a spiral cut through potato 200 until sliced potato piece 204 is formed. Note that for clarity, sliced potato piece 204 does not account for the entirety of potato 200. Some pieces, such as the front and rear ends, have been omitted. As shown, potato piece 204 has a spiral shape with a cross-sectional height 212 that correspond to the axial height 216 of slot 128. Accordingly, axial height 216 of slot 128 may be chosen to select a cross-sectional height 212 of the resultant potato pieces.
Preferably, blade assembly 100 includes a plurality of slitter blades for dividing the spiral slab cut by blade holder 104 into smaller potato pieces. Various embodiments of slitter blades are disclosed herein which form potato pieces having non-rectangular (and non-square) cross-sections. In some cases, the size and cross-sectional shape of the potato pieces cut by these slitter blades may provide better grip, improved condiment application, visual appeal, more even cooking, and/or other benefits.
Reference is now made to
Preferably, an axial height 236 of each slitter blade 224 from lower end 228 to upper end 232 (as measured in parallel to axis 116) is equal to or greater than axial height 216 of slot 128. This may permit each slitter blade 224 to cut across the entire cross-sectional height 212 of potato piece 204 to divide potato piece 204 into discrete smaller pieces 240. In alternative embodiments, the axial height 236 of a slitter blade may be less than the axial height 216 of slot 128. For example, this may permit a slitter blade that forms a closed shaped (examples described below) to cut the entire cross-sectional shape of a smaller potato piece 240.
Each slitter blade 224 includes a leading cutting edge 244. Cutting edge 244 may be integrally formed with leading edge 248 of slitter blade 224 (e.g. by sharpening leading edge 248, or by providing leading edge 248 with a diminutive thickness) as shown, or a discrete blade may be mounted to leading edge 248. Further, each cutting edge 244 may extend the full length of leading edge 248, or extend along only a portion of leading edge 248. In the example shown, each cutting edge 244 extends from lower end 228 to upper end 232. In alternative embodiments, lower and upper ends of cutting edge 244 may be different from lower and upper ends of slitter blades 224.
Preferably, each slitter blade 224 is positioned at a different radial distance from axis 116 than each other slitter blade 224. This may permit each slitter blade 224 to form distinct cuts across the cross-section of potato piece 204. In the illustrated example, slitter blades 224 are aligned next to each other. As shown, an upper end 232 of each cutting edge 244 is in contact with an upper end 232 of an adjacent cutting edge 244, and a lower end 228 of each cutting edge 244 is spaced apart from a lower end 228 of an adjacent cutting edge 244. Optionally, one or more contacting pairs of cutting edge ends 228 or 232 may be permanently joined together in any suitable fashion, such as by welding. This may enhance the structural rigidity of slitter blades 224 for withstanding cutting stresses. Alternatively, any two or more slitter blades 224 may be integrally formed. As used herein and in the claims, “a plurality of slitter blades” means a plurality of discrete slitter blades, whether connected or disconnected from each other, or an integrally formed plurality of slitter blades provided as a unitary slitter blade.
Preferably, slitter blades 224 cut potato piece 204 to form smaller potato pieces 240 having a non-rectangular (and non-square) cross-section. Generally, square or rectangular cross-sectional profiles are formed by pairs of radially spaced apart slitter blades 224 that extend substantially in parallel with axis 116 or substantially perpendicularly to upstream surface 108. Such blades 224 may form right-angled cuts in combination with cutting edge 140 of blade holder 104.
In the illustrated example, slitter blades 224 in combination with blade holder 104 cut potato 200 into a plurality of smaller potato pieces 240 having right-angled triangular cross-sections. As shown, slitter blades 224 include a plurality of alternating slitter blades 224a and 224b. Slitter blades 224a have cutting edges 244 that extend substantially in parallel to axis 116 of rotation. Slitter blades 224b have cutting edges 244 that extend non-perpendicularly to the upstream surface 108 away from the axis 116 of rotation. In this example, slitter blades 224b may be described as extending at an angle to (i.e. non-perpendicularly to) upstream surface 108 in a plane 252 parallel to axis 116. Generally, when a slitter blade is seen to angle toward or away from axis 116 when viewed in profile from a plane parallel to axis 116 (such as plane 252 for example), that slitter blade may produce a non-orthogonal cut such that the resultant potato piece 240 may have a non-rectangular (and non-square) cross-section.
Slitter blades 224 may be positioned at any suitable circumferential position about axis 116. In the illustrated example, all of slitter blades 224 are positioned in a same circumferential position, such that they align with a common radius. As shown, slitter blades 224 are positioned between upstream and downstream ends 120, 124 of blade holder 104. Preferably, slitter blades 224 are connected to upstream and downstream ends of blade holder 104 in any suitable fashion, such as by welding. In alternative embodiments, one or more of slitter blades 224 may be positioned in a different circumferential position about axis 116. For example, slitter blades 224 may be distributed between a range of circumferential positions about axis 116.
Optionally, blade assembly 100 may include a plurality of slitter blades removably mounted to blade holder 104. This may permit the slitter blades to be removed and replaced when dull or damaged. Reference is now made to
Base 268 may have any configuration suitable for supporting slitter blades 272 and for removably mounting to blade holder 104. Generally, slitter blades 272 may be arranged in any configuration described above with respect to slitter blades 224, and base 268 may be sized to accommodate the slitter blades. In the example shown, base 268 is sized to provide a common base to all of slitter blades 272. In alternative embodiments, base 268 may extend below only a portion of slitter blades 272. For example, base 268 may extend below and directly connect to a first group of slitter blades 272, while the other slitter blades 272 may be directly or indirectly connected to at least one of the slitter blades 272 in the first group of slitter blades 272.
Slitter pack 264 may be removably connected to blade holder 104 in any suitable fashion for positioning slitter blades 272 to extend axially between upstream and downstream ends 120 and 124. In the illustrated example, slitter pack 264 is fastened to upstream surface 108 by fasteners 276. In alternative embodiments, slitter pack 264 may be fastened by welds, or bolts. Optionally, blade holder 104 may include a recess for receiving at least a portion of slitter pack 264. In the example shown, upstream surface 108 includes a recess 280 for receiving base 268 of slitter pack 264. Preferably, base 268 is flush with the surrounding upstream surface 108. This may prevent base 268 from interfering with potatoes which are in contact with upstream surface 108 during cutting. Also, the fastening means (e.g. welds or screws) are preferably level with or recessed below the surrounding upstream surface 108 for the same reason.
In alternative embodiments (not shown), slitter pack 264 may be mounted to downstream surface 112. For example, base 268 may be mounted in contact with downstream surface 112 with slitter blades 272 extending upstream, through an aperture (not shown) in upstream surface 108, to above upstream surface 108.
In some embodiments, blade holder 104 includes one or more axial apertures 284. Where blade assembly 100 is positioned in a flow path of a hydraulic cutting system (such as cutting system 10), apertures 284 may provide passages for hydraulic fluid (e.g. water) to pass through blade assembly 100. In turn, this may reduce the pressure exerted upon blade assembly 100 by the hydraulic fluid that propels food products into blade assembly 100. Further, this may reduce the impedance by blade assembly 100 to the flow of hydraulic fluid, which may permit the hydraulic fluid to flow at higher velocities and flow rates.
Optionally, blade assembly 100 may further include a mounting fixture that secures to blade holder 104 for making blade assembly 100 compatible for mounting in a cutting device. Preferably, the mounting fixture is releasably secured to the blade holder 104. This may permit the blade holder to be removed and replaced if damaged or to change the cutting pattern. This may also permit the blade holder 104 to be mounted in different mounting fixtures, which may provide compatibility with different cutting devices.
Reference is now made to
Mounting fixture 288 may be permanently or removably mounted to blade holder 104 in any suitable fashion. For example, mounting fixture 288 may be secured to blade holder 104 by screws 300 as shown, bolts, welds, or rivets. In the illustrated example, upstream portion 292, and blade holder 104 include screw apertures 302 that align with threaded screw bores 308 in downstream portion 296, for screws 300. In some embodiments, slitter pack 264 may be secured to mounting fixture 288 (e.g. by fasteners, or welds) instead of fastening to blade holder 104. In this case, mounting the mounting fixture 288 to blade holder 104 may position slitter blades 272 of slitter pack 264 between upstream and downstream ends 120 and 124.
Preferably, the upstream portion 292 and downstream portion 296 of mounting fixture 288 are shaped to mate with upstream and downstream surfaces 108 and 112, respectively, of blade holder 104. This may permit mounting fixture 288 to provide structural rigidity to blade holder 104 for withstanding stresses from impacts by potatoes and from cutting potatoes. In the illustrated example, a downstream surface 308 of upstream portion 292 has a spiral shape that conforms to the spiral shape of blade holder upstream surface 108, and an upstream surface 312 of downstream portion 296 has a spiral shape that conforms to the spiral shape of blade holder downstream surface 112. This allows downstream surface 308 to lie flush against upstream surface 108, and allows upstream surface 312 to lie flush against downstream surface 112 (as best shown in FIG. 5C). In alternative embodiments, mounting fixture 288 may not be shaped to mate with upstream and downstream surfaces 108 and 112 of blade holder 104. For example, there may be one or more gaps between upstream portion 292 and upstream surface 108, and between downstream portion 296 and downstream surface 112.
Reference is now made to
Referring now to
Reference is now made to
In the illustrated example, slitter blades 354 in combination with blade holder 104 cut potato 200 into a plurality of smaller potato pieces 358 having triangular cross-sections. As shown, slitter blades 354 include a plurality of slitter blades 354a which alternate in radial position with a plurality of slitter blades 354b. Slitter blades 354a have cutting edges 244 that extend non-perpendicularly to the upstream surface 108 toward the axis 116 of rotation. Slitter blades 354b have cutting edges 244 that extend non-perpendicularly to the upstream surface 108 away from the axis 116 of rotation. Cutting edges 244 of each of slitter blades 354a and 354b may form any suitable angle with upstream surface 108 and axis 116. For example, cutting edges 244 of each of slitter blades 354a and 354b may be angled approximately 60 degrees from upstream surface 108 or approximately 30 degrees from axis 116 for cutting potato pieces 358 with equilateral triangular cross-sections as shown.
Alternatively, cutting edges 244 of slitter blades 354a and 354b may be angled at a plurality of differing angles to upstream surface 108 or axis 116 for providing potato pieces 358 having a variety of triangular cross-sections. This may provide a more varied “homestyle” appearance, which may be appealing to some consumers.
Reference is now made to
In the illustrated example, slitter blades 374 are radially distributed and spaced apart from each other. Each of slitter blades 374 is shown including a wavy (i.e. undulating) cutting edge 244. Each cutting edge 244 has an axial wavelength and a radial amplitude. Cutting edges 244 may each include any suitable number of waves (e.g. 1 to 25 waves), and may include the same or a different number of waves compared to the cutting edges 244 of other slitter blades 374. In the illustrated example, each slitter blade 374 includes a cutting edge 244 having approximately two and a half waves.
Whereas the cutting edges 244 of slitter blades 224 (
Referring particularly to
Reference is now made to
In the illustrated example, slitter blades 374 are radially distributed and spaced apart from each other. Each slitter blade 374 includes a zigzagged cutting edge 244. As shown, each cutting edge 244 includes a plurality of alternating hills 408 and valleys 412 having an axial wavelength 416 and a radial amplitude 420. Cutting edges 244 may each include any suitable number of hills and valleys (e.g. 1 to 25 hills and valleys), and may include the same or a different number of hills and valleys compared to the cutting edges 244 of other slitter blades 404. In the illustrated example, each slitter blade 404 includes a cutting edge 244 having three valleys between four hills.
Reference is now made to
In the illustrated example, each of slitter blades 444 has a cutting edge 244 with a curved shape, where a concave side faces radially outwardly (i.e. away from axis 116). Preferably, cutting edges 244 are arcuate and form a sector of a circle or oval. Each cutting edge 244 may form any portion of a circle or oval. For example, each cutting edge 244 may form from 10 degrees to 180 degrees of a circle or oval. In the illustrated example, cutting edges 244 each form approximately 180 degrees of a circle.
Each cutting edge 244 may be identical in shape as shown, or alternatively one or more of cutting edges 244 may be differently shaped (e.g. form a greater portion of a circle or oval). Further, each cutting edge 244 may be spaced apart from each other cutting edge 244 as shown, or in contact with the cutting edge 244 of an adjacent slitter blade 444 (and optionally joined permanently together at the point of contact).
In use, blade assembly 440 may be used to cut a plurality of potato pieces 448 from a potato. As shown, potato piece 448 has a spiral shape with a convex interior surface 452 and a concave exterior surface 456.
Referring to
Reference is now made to
In the illustrated example, each slitter blade 484 includes a cutting edge 244 that forms a closed crescent shape. As shown, each cutting edge 244 includes an arcuate upstream portion 488 and a downstream portion 492 which meet and are joined together at opposite radially inboard and outboard ends 496 and 500 of the cutting edge 244. In the example shown, upstream and downstream portions 488 and 492 each have an upstream surface 504 that is convex to form a crescent shape. In an alternative embodiment, the upstream surface 504 of upstream and downstream portions 488 and 492 may be concave. Optionally, slitter blades 484 may contact and be optionally joined to radially adjacent slitter blades 484 at radially inboard and outboard ends 496 and 500 as shown.
In use, blade assembly 480 may be used to cut a plurality of potato pieces 508 from a potato. As shown, potato piece 508 has a spiral shape with a concave downstream surface 512 and a convex upstream surface 516.
Reference is now made to
In the illustrated example, cutting edge 244 of each slitter blade 544 has a closed circular shape. Preferably, cutting edge 244 of each slitter blade 544 forms a circle, as shown, however in alternative embodiments one or more of slitter blades 544 may include a cutting edge 244 that form an oval. As shown, slitter blades 544 may be positioned side-by-side in touching relationship, so that each slitter blade 544 is in contact with one or more adjacent slitter blades 544. Optionally, the cutting edge 244 of each slitter blade 544 may be in contact with the cutting edge 244 of one or more adjacent cutting edges 244. This may reduce the quantity of waste potato after cutting.
In use, blade assembly 540 may be used to cut a plurality of potato pieces 548 from a potato. As shown, potato piece 548 has a spiral shape with a circular cross-section.
Reference is now made to
In the illustrated example, each slitter blade 564 includes a cutting edge 244 that forms a closed triangular shape with wavy (i.e. undulating) sides 568. The triangular shape may be arranged in any suitable orientation. In the example shown, one side 568a is oriented substantially parallel to and extending along upstream surface 108, and two sides 568b and 568c extend from different ends of side 568a upstream at an angle to axis 116 and join together at an upstream side 140 of slot 128. In alternative embodiments, the triangular arrangement of sides 568 may be rotated in a plane parallel to axis 116 (e.g. such that side 568a is parallel to and extending along upstream side 140 of slot 128).
As shown, wavy sides 568 of cutting edge 244 are characterized by a wavelength and amplitude. Wavy sides 568 may have any suitable wavelength and amplitude. Preferably, the wavelength and amplitude of wavy sides 568 is consistent across cutting edge 244. Optionally, the wavelength and amplitude of wavy sides 568 may vary from one side 568 to another, and/or within each side 568.
In the illustrated example, sides 568 form an equilateral triangle. It will be appreciated that in alternative embodiments, sides 568 may be arranged to form any other triangle, such as an isosceles triangle, a scalene triangle, an acute triangle, a right angled triangle, or an obtuse triangle. Further, in an alternative embodiment, sides 568 of cutting edge 244 may be zigzagged instead of wavy as shown in
While the above description provides examples of the embodiments, it will be appreciated that some features and/or functions of the described embodiments are susceptible to modification without departing from the spirit and principles of operation of the described embodiments. Accordingly, what has been described above has been intended to be illustrative of the invention and non-limiting and it will be understood by persons skilled in the art that other variants and modifications may be made without departing from the scope of the invention as defined in the claims appended hereto. The scope of the claims should not be limited by the preferred embodiments and examples, but should be given the broadest interpretation consistent with the description as a whole.