The present invention relates to the design of ice skate blades and methods of grinding such blades.
In winter sports such as ice skating and hockey the blades of an ice skate are the point of contact for all of the forces generated in turns, spins, jumps, stops, gathering speed etc. Ice skates typically have a convex shape along a length of the skate blade and a concave shape across the width of the blade, defining two edges along the lengthwise edges of the blade. A skater can use either of these two edges in executing maneuvers on the ice surface.
With time the profiling of ice skates has evolved as former recreational sports such as skating evolved into Olympic sports with multiple disciplines including long-track speed skating, short-track speed skating, ice dance, ice etc and “shinny” hockey on frozen ponds, lakes, and rivers became a multi-billion dollar sporting franchise globally with individual players being remunerated in contracts of tens of millions of dollars. Alongside multiple equipment manufacturers jostle for an edge in the sports equipment market for the over 1.5 million registered hockey players globally and tens of millions of skaters globally who spend anything up to $1,000 on a pair of skates to keep up with their heroes, given the winning edge, etc.
As such ice skate blade profiles have evolved into a science with different profiles of blade between speed skating and ice dance, defender, goalie, attacker, short speed and long speed. Additionally atop these differences that science is establishing from research are the individualities of the various players and the intuitive, difficult to quantify “feel” of their skates. However, despite this the overall fundamental design of an ice skate blade has remained essentially unchanged remaining as outlined above a single concave lateral profile on the bottom of the blade with an essentially longitudinally convex profile.
This design, despite significant research expenditure by the major equipment manufacturers of ice skates and ice skate sharpening equipment, is limiting as the single blade provides trade-off between a single hollow with a small surface area for gliding and two edges for providing fraction in maneuvering. Speed skates, as opposed to hockey skates, for example have much longer blades and hollows for the express purpose of increasing the surface area in contact with the ice. Hence, after several hundred years ice skate blades have progressed more in recent years from refinements in materials and preparation, with grinding and now multiple polishing steps, with changes to profile occurring incrementally over the years allowing the skate to evolve to its current design and construction of a skate boot, a single skate blade holder, and a single skate blade with a single hollow which are, however, essentially the same as the original design.
Within the prior art several approaches to adapting the design of ice skates have been presented. These include K. Hall in U.S. Pat. No. 4,907,813 entitled “Ice Hockey Skate Blade” wherein there is taught a skate design comprising a top edge, a skating edge, and a toe portion. The skating edge has a gliding portion behind the toe portion which has a width less than the top edge of the blade and the toe portion of the blade. The front toe portion of the blade allows contact with the ice and has a width equivalent to standard hockey ice skate widths, while the gliding portion of the blade behind the toe section has a narrower width corresponding to ice skate racing blades. In contrast J. Swande in U.S. Pat. No. 5,826,890 entitled “Ice Skate Blade” teaches to a blade cross-section that varies between a central portion and the front and rear edges. Swande identifies a limitation in adapting the blade design to the requirements of defensive hockey players who favor shorter central gliding sections to obtain better turning ability unlike attacking hockey players who longer central sections for increased acceleration and gliding. Accordingly Swande teaches to introducing a main central runner and lateral side runners to reduce the surface pressure applied so as to limit the depth the blade bites into the ice wherein deep biting is undesirable. Accordingly Swande teaches to a three-section lateral profile that varies from having a central section with the resultant four blade edges on a substantially common level to front and rear sections of the blade where the outer blade edges are set to a higher level than the central pair. The blade design of Swande being symmetric along the blade centre line at all points. The prior art of Swande is discussed below in respect of
H. Redmond et al in U.S. Pat. No. 4,392,658 describes a similar structure to Swande in some embodiments with the concept of a central blade having two edge portions and a flat portion such that the central portion is in contact with the ice during gliding but the raised side portions are engaged during turning as they are disposed vertically away from the flat portion and thence are not in contact during gliding. As evident from
However, these prior art designs suffered two drawbacks, first being that they do not address the fact that the current blade and hollow configuration was designed to create a turning and gliding surface with specific properties. Second, no corresponding method of sharpening them was developed which impacted their deployment as they are not compatible with the standard skate machining systems that operate with a profile grinding wheel. It has been determined that the current skate blade configuration generates friction between the blade and the ice, which creates a film of water between the blade and the ice, the film provides for the gliding properties of the blade. The proposed invention, by utilizing multiple hollows creates increased blade friction and thereby increases the water film for gliding and will therefore increase the gliding performance of the blade without compromising the turning capability which has already been designed into the current blade configuration whilst providing for both asymmetric variations of the blade and variations of the blade profile along the blade. Additionally the designs are compatible with a new grinding system that accommodates complex profiles which may be unique even to a specific pair of ice skates for an individual.
It is, therefore, desirable to provide increased ice skate performance by reducing drag and contact friction as well as providing improved flexibility in varying the profile of the ice skate along its length between toe, middle and heel. It is also desirable to provide a means of sharpening such skates which are incompatible to existing skate sharpening machines.
It is an object of the present invention to obviate or mitigate at least one disadvantage of the prior art.
In accordance with an embodiment of the invention there is provided an ice skate blade comprising:
In accordance with an embodiment of the invention there is provided a method comprising:
In accordance with an embodiment of the invention there is provided a method comprising:
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:
The present invention is directed to ice skate blades and methods of grinding such blades.
Reference may be made below to specific elements, numbered in accordance with the attached figures. The discussion below should be taken to be exemplary in nature, and not as limiting of the scope of the present invention. The scope of the present invention is defined in the claims, and should not be considered as limited by the implementation details described below, which as one skilled in the art will appreciate, can be modified by replacing elements with equivalent functional elements.
The geometry shown in CA 110 is with the circular arc centered with the blade, considered to be the best arrangement, and is known as “edges even condition”. The interrelation between the variables can be determined from Equations (1) and (2) below.
h
max
=r(1−cos(a sin(w/2r)) (1)
φ=90−a sin(w/2r) (2)
There are two variables that can be changed in the above equations; namely, the width of the skate blade, w, and the radius of the groove, r. The width of the blade, w, is dependent upon the type of skating being done, with the typical hockey blade being 0.110 inches (2.8 mm) wide. The typical radius, r, used by hockey players varies from 0.250 (6.35 mm), such as shown by profile 140B for sharper turns but making gaining speed harder, to 2.00 (50.8 mm) inches, such as shown profile 140A making turns difficult but gaining speed easier. A common radius being 0.50 (12.70 mm) inches to provide a trade-off between these demands from the skater. Typical values of groove radius, r, when applied to hockey skates, 0.110 inches (2.8 mm) wide, will give the values of maximum depth, hmax, and the edge angle as shown below in Table 1.
It is worth noting that the range of edge angles, φ, and depths, h, is very limited. It is common knowledge in the ice skating world that a smaller radius provides better turning ability along with a slower glide speed, while a larger radius provides superior glide speeds along with poorer turning ability.
Now considering the FBC 120 then the cross-section through an ice skate blade is shown where a flat bottom has been added to the traditional circular arc profile, leaving the two interior circular arc profiles. In this case, the edge angle, φ, will remain the same as those calculated for circular arc profiles of various radii, r, as shown in Table 1 above but the depth of the flat, h, will be adjustable to any value less than the maximum depth, hmax, under the blade as calculated for the circular arc. The depth of the flat, h is the distance between a line joining the two blade edges, and the flat bottom of the skate blade. The width of the flat bottom, d, is given by Equation (3) below.
d=2[r2−(r−hmax+h)2]1/2 (3)
The advantage of this profile over the traditional circular arc profile is that the edge angle, φ, can be maintained while the depth, h, of the profile is reduced from, hmax, leading to a potentially faster skate with less drag. A nomenclature for FBC profiles used by some manufacturers is FBC-XXX-YY where XXX is the radius, r, of the circular arc in thousandths of an inch and YY is the depth of the flat, h, in thousandths of an inch.
Now referring to FBV 130 then this groove profile on an ice skate blade is an attempt to overcome the primary shortcoming of the traditional circular arc profile; the fact that the edge angle, φ, and the maximum depth of the groove, hmax, are linked. This is a major constraint of the CA 110 profile. This profile is named flat bottom ‘v’ (FBV) as the two lower internal profile lines would intersect in a V if there were projected, and the bottom of the ice skate blade forms a flat bottom for the V shape resulting from that projection. There are a few geometric properties that define the shape of the FBV 130 ice skate blade profile; the blade width, w, the width of the flat bottom, d, and the depth of the flat bottom, h. The height under the blade, h, is the distance between a line joining the two blade edges and the flat bottom. The edge angle, φ, at the blade edge, in the case of a symmetrical (central to the blade width) location of the blade bottom is given by Equation (4) below.
φ=a tan(w−d)/2h (4)
As can be seen from this formula; once a blade width, w, is known, a value of blade bottom width, d, can be chosen in conjunction with the depth of the flat, h, to obtain a wide range of edge angle, φ, values. A similar nomenclature as that for FBC 120 is used by some manufacturers, being FBV-XXX-YY, where XXX represents the width of the flat bottom, in thousandths of an inch, and YY represents the flat depth, h, in thousandths of an inch.
The ability to vary the blade profile being shown by profiles 150A through 150D whereby moving from first profile 150A to second profile 150B are variations for constant bottom width, d, but varying depth of flat, h, giving better turns. Moving from first profile 150A to third profile 150C is decreasing bottom width, d, for constant depth of flat, h, giving more speed. Moving diagonally from first profile 150A to fourth profile 150D is decreasing bottom width, d, and increasing depth of flat, h, trying to balance speed and turning.
Referring to
Considering these zones then the toe 212 generally is used for starts, acceleration, and final toe snap and may represent 1 second of a stride when this zone is in contact with the ice. The front 214 is primarily used for acceleration and ankle dekes and typically represents 1-3 second of stride movement. The middle 216 is used most for gliding, stopping, forward strides of several seconds, and provides balance and pivot point in motion. Finally the heel 218 is used in stop-turns, extension and backward pushes for backward skating as well as crossovers, direction changes and balance. Typically the toe 212 and heel 214 represent 20% of the blade length, the middle 216 60%, and the heel 218 20%.
Referring to
Also shown in
In first profile 331 through sixth profile 336 blade geometries according to the prior art of Redmond in U.S. Pat. No. 4,392,658 entitled “Skate Blade” which have first and second longitudinal extending edges upwardly and inwardly rising from the outermost cutting edges together with longitudinal extending middle face centrally disposed between these edge faces. The progression of first profile 331 to sixth profile 336 evolving from essentially a FBV 130 design through to a design such as comparable to the front 301 of Swanke in ice skate 310 wherein the central portion is in contact with ice in the upright position and the side runners are not in contact.
Referring to
It would be apparent to one of skill in the art that these profiles many be adapted according to the left or right skate of the user. Accordingly there is shown fifth blade cross-section 450 which is the mirror image of fourth blade cross-section 440, and hence representing for example the left skate of the user wherein fourth blade cross-section represents the right skate of the user. Depending upon the characteristics of the user in terms of weight, skating profile, position, etc then the left and right skate blades may not be mirror images of one another but different in terms of number of profile sections, depth of each profile section, type of profile section (e.g. FCA, FBV etc). Similarly the profile on different sections of the skate such as described above in respect of hockey skate 210 may be different, for example the front 214 and heel 218 may be designed primarily for biting into the snow for stopping, accelerating, and maneuvering. Middle 216 may be designed for gliding only or vary along its length according to the users balance etc for gliding weight to the front and maneuvering at the rear for example.
Accordingly a profile as taught provides for a first profile formed longitudinally along a predetermined portion of one side of a blade designed for gliding upon an ice surface with two edges, a second profile formed longitudinally on the opposite side of the blade in the same predetermined portion designed for edging into said ice surface with two edges, where the first and second profiles share a common edge. It would be evident to one skilled in the art that alternatively the blade may be formed from multiple discrete blades, each with one of the profile segments of the final blade. Optionally such multiple discrete blades may be formed from different materials and the edges may be treated differently, for example different anneals or surface finishes.
Whilst considering the design of an ice skate blade it is important to also consider how that ice skate blade will be sharpened as with use the sharp edges become dulled and blunt so that optimum performance is only achieved after the blade is re-sharpened. At present commercial blade sharpening systems employ a pre-formed grinding wheel that has a predetermined profile. This profile is therefore applied to the entire length of the blade. Accordingly if a user wishes to have a different profile at the middle and heel of a skate blade that already presents a significant issue to the operator of the grinding machine. Now consider a profile that varies from say an FCA on the toe to a symmetric dual FBV at the middle to a dual FCA/FBV profile such as shown in third blade cross-section 430 of
Clearly such profiles are incompatible with prior art skate sharpening systems unless multiple grinding wheels with the different profiles are stocked and changed several times per skate blade sharpened. Accordingly such difficulties have limited the evolution of ice skate blade profiles as they cannot be re-sharpened such that perhaps high profile speed skaters, figure skaters, and hockey players may pay for a quantity of blades that are essentially use once and thrown away or skate sharpening machine manufacturers are willing to invest time supporting these high profile athletes as part of their marketing activities. But that is not representative of the vast majority of skaters who would benefit from enhanced ice skate profiles even if they were more limited to perhaps a small number for defenseman, several for attackers, some for goaltenders etc as well as profiles that are tailored to novices as well as experts. As such it would be beneficial to provide a highly flexible ice skate blade sharpening system that allows complex geometries to be ground and polished as well as providing high flexibility to account for substantial variations between sequential skates being sharpened.
Now referring to
According to one embodiment of the invention drive 570 may be manually adjusted, second stage 580 rigidly mounting the frame 585 to the base 530 and first stage 590 be manually controlled. According to another embodiment of the invention the first stage 590, second stage 580 and drive 570 may all be controlled through a central microprocessor to automate the process of grinding a desired profile thereby improving the reproducibility of the profile applied to the blade 510B. It would be evident to one skilled in the art that the programme may be varied allowing an operator to simply key in an identity of a skater for example to retrieve their custom profile and reapply this to the skates.
It would also be evident to one of skill in the art that in both manual and automatic approaches that a measurement and indication of pressure between the blade 510B and grinding wheel 550 may be made/displayed allowing increased control of the grinding process. Optionally if a conductive grinding wheel 550 is employed then an electrical contact may be made to both the grinding wheel 550 and blade 510B such that initial contact of the blade 510B to the grinding wheel 550 can be detected or monitored to detect errors in position as contact is lost for example.
Now referring to
Grinding sub-system 600B comprises a grinding disc 685 that is mounted to a mounting plate 680 and thereby to spindle 670 which is driven by drive belt 660 from a motor, not shown for clarity. These elements being mounted to drive sub-frame 650 which is mounted to second stage 655. First stage 620 provides motion longitudinally with respect to the skate blade 640, i.e. along an axis perpendicular to the plan of the side view. Second stage 665 provides motion both in a linear axis perpendicular to the axis of motion of first stage 620, i.e. across the width of the skate blade 640, and rotational motion about a point “P” that is established as being at a point representing the expected interface between the grinding disc 685 and skate blade 640. As such the combined action of first stage 620 and second stage 665 is to provide four axis of movement between the skate blade 640 and grinding disc 685 allowing the grinding disc 685 to follow complex surfaces of movement such as those necessary to implement the profiles according to embodiments of the invention such as first to fifth blade cross-sections 410 through 450 respectively in
Referring to
Second and third schematics 700B and 700C depict sharpening a skate blade according to embodiments of the invention. Second schematic 700B depicts a dual FBV profile 750 on a skate blade that is ground and/or polished with thin profile blade 740. Third schematic 700C depicts a FCA/FBV blade 790 along with first through third blades 760 to 780 respectively. These blades providing different grinding profiles which may be employed along with thin profile blade 740 alone or in combination with a skate sharpening system such as described supra in respect of skate sharpening systems 600 and 700 in
It would also be evident to one of skill in the art that in skate sharpening systems 600 and 700 that a measurement and indication of pressure between the blade and grinding wheel may be made/displayed/utilized allowing increased control of the grinding process. Optionally if a conductive grinding wheel is employed then an electrical contact may be made to both the grinding wheel and blade such that initial contact of the blade to the grinding wheel can be detected or monitored to detect errors in position as contact is lost for example.
Now referring to
The skate mount 800A provides for mounting of left skate 850A and right skate 850B with corresponding left blade 840A and right blade 840B with each being clamped via a levered mechanism engaged via first and second handles 860A and 860b respectively. Skate mount 800A further comprising skate stage 870. As with skate sharpening system 600 in
It would be evident to one skilled in the art that whilst the simplest design is the stacking of a pair of skate sharpening systems 600 to form skate sharpening system 800 that under appropriate computer control the relative motions of first and second grinders 800B and 800C may be controlled such that they operate without requiring a minimum complete clear separation between them such that the vertical height of the skate sharpening system 800 may be reduced. Accordingly skate sharpening system 800 can provide complex blade profiles to each of the left and right skates of a user with accurate cross-referencing of the profile of one blade to the other.
It would be evident to one skilled in the art that the ice skate blade may be formed from a variety of materials according to the cost, strength, weight, rigidity, and performance tradeoffs that the skate manufacturer is working within. Such blades may for example be formed from carbon steel, high strength low alloy steel, low alloy steel, stainless steel, as well as metals such as titanium. Alternatively blades may be formed from a variety of composite materials which are engineered materials that comprise two or more components including for example polymer composites that combine reinforcing fibers such as carbon fiber, glass fiber, basalt fibers, or other reinforcing fibers with a thermosetting or thermoplastic polymer resin such as epoxy, nylon, polyester, polypropylene, or other resins wherein the reinforcing fibers provide stiffness and strength in the direction of the fiber length, and the resin provides shape and toughness and transfers load between and among the fibers. Optionally, the blades may be formed from one or more ceramic materials including for example oxides such as alumina, beryllia, ceria, and zirconia; non-oxides such as carbides, borides, nitrides, and silicides; as well as ceramic composite materials including for example particulate reinforced, fiber reinforced, and combinations of oxides and non-oxides.
The above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.
This patent application claims the benefit of U.S. Provisional Patent Application U.S. 61/409,650 filed Nov. 3, 2010 entitled “Ice Skate Blade” and U.S. Provisional Patent Application 61/409,650 filed Nov. 2, 2010 entitled “Multiple Blade Sharpening Apparatus and Method”
Number | Date | Country | |
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61409142 | Nov 2010 | US | |
61409650 | Nov 2010 | US |