Abstract:
A disposable reversible skate blade for an ice skate comprising a thin runner blade held around the edges of a light-weight composite core, and a pair of opposed blade supports, which may be individually replaceable or which may be formed as an integral part of the core. The entire blade assembly is lightweight, easily removable, reversible and replaceable in a skate with little or no requirement for tools, and is inexpensive enough to manufacture that the blade is disposable.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to a double-edged skate blade that is easily removable and reversible in an ice skate and that further has a simple enough construction to make the blade and supports disposable. 
       BACKGROUND OF THE INVENTION 
       [0002]    Ice hockey skates today generally comprise a sharpened metal blade or runner fastened to a holder, which is in turn fastened to a skate boot. Goaitender skates are similar, but further have a cowling to protect the lower portion of the skate boot, which might be connected to or formed integrally with the holder. Speed skates also generally comprise a sharpened metal blade held by a holder, which is then fastened to a skate boot, although the overall look and configuration of the skate is different than an ice hockey skate. In all cases, when the blade of a skate becomes dull, the surface of the blade that contacts the ice surface is re-sharpened, either to provide a hollow between a set of opposed inner and outer edges, or, in the case of a goalie skate, to provide offset or flatter edges across the thicker blade. 
         [0003]    Current methods of skate sharpening generally require that the skate be removed from a wearer&#39;s foot. If a skater notices that a blade has become dull while he or she is on the ice, it is generally necessary to remove the skate, take it to a skate sharpening machine, sharpen the blade, and replace the skate on the skater&#39;s foot before returning to the ice. During a hockey or ringette game or a skating competition, this may be an unacceptable amount of time to be away from the ice. If there is no skate sharpener readily available, the time away from the ice is necessarily increased. The alternative is to skate on dull blades, which adversely affects the skater&#39;s speed, mobility and ability to perform necessary manoeuvres. 
         [0004]    It is therefore preferable to be able to replace a dull blade or to simply replace an unsatisfactory blade without having to remove the skate boot from a skater&#39;s foot. U.S. Pat. No. 1,591,778 discloses a reversible blade made of a single piece of metal shaped into a generally I-shaped cross-section. The blade is meant to be reversed when one edge gets dull, and then both edges must be sharpened once both edges have become dull. There exist several other examples of removable blade systems, such as U.S. Pat. No. 6,419,241 to Chenevert, U.S. Pat. No. 6,485,033 to Nicoletti et al. and Applicant&#39;s co-pending PCT App. No. PCT/CA20121000968, which disclose a skate blade that may be removed from a skate by removal of one or more threaded fasteners, and replaced with a new blade that is then secured with those fasteners. However, while having a reversible blade will help alleviate the urgency of finding a way to provide a freshly sharpened blade when a minimal amount of time is available, or when a skilled sharpener is not available, it is possible that a skater will suddenly find that he has used and dulled both edges of a blade. 
         [0005]    As a further consideration, each time the blade is sharpened using standard sharpening machines and techniques, metal is physically removed from the ice-contacting or runner portion of the blade; each time metal is removed during a sharpening, the balance and feel of the skate may change. Over time the skate will eventually run out of metal blade available for sharpening, necessitating complete replacement of the blade. Because of the configuration of many skates, especially ice hockey skates, this often results in the need to either replace the entire holder or even the entire skate. Further, many skaters are particular about how their blades are sharpened, in terms of having the desired profile (radius and rocker) and hollow radius, as changes to those parameters can adversely affect the feel of the skates, and therefore the performance of the skater in a game or competition. A skater therefore must find a person who can consistently sharpen the blades to the skater&#39;s preferences, and would obviously then prefer to take the skates to that person every time. This can result in difficulty if, for example, the skater has travelled to another rink or another city for a game or competition. It is therefore preferable to provide a skate blade that does not ever need sharpening, so that when it is replaced, it reliably and consistently has the exact properties that the skater is expecting. 
         [0006]    Further, different ice surfaces will have different properties; temperature, humidity and water quality vary from rink to rink and will produce ice surfaces that may be harder or softer than the skater is used to. As the skater may not realize how the ice feels until he has been on it for a while, such as after a warm-up, it may not be convenient or even possible to have a skate blade sharpened especially for that surface. The same considerations might even arise during a game or competition, as the temperature and humidity of the air around the rink can change substantially over time, for example if there are many spectators surrounding the rink. Again, it is likely inconvenient or impossible to have the skates sharpened for such changing conditions, as well as of course removing the metal from the blade even faster. 
         [0007]    In such situations, it can be preferable to have a number of blades, each with varying characteristics such as with blade thicknesses, profiles (radius and rocker) and hollow radii, so that a dull or unsuitable blade can quickly be replaced with another having the properties required for the current ice surface and skating conditions. However, the cost of buying several sets of reversible, blades, as well as the cost of having each sharpened twice as it becomes dull, can become prohibitive. 
         [0008]    U.S. Pat. No. 2,242,870 discloses a reversible, double-edged blade composed of a single shaped piece of metal having a generally I-shaped cross-section. This blade is specified to be disposable, as no sharpening of the blade is contemplated. However, the presence of a substantially thinned area along the central length of the blade may tend to destabilize the blade under the lateral torque forces typically created during the skating stride and when performing other manoeuvres. A blade made completely of metal, while strong and tough, also tends to be heavy and expensive to manufacture. 
         [0009]    Providing solid metal blades that have to be machined into various configurations, is therefore unlikely to help reduce the costs associated with carrying several sets of blades. 
         [0010]    Because of the limitations of an all-metal blade, it is therefore known to provide a disposable blade made up of a combination of materials. U.S. Pat. No. 5,769,434 discloses a disposable blade of light, inexpensive material plus a contact blade of more expensive, harder material. However, the blade is relatively complex, including a stabilization rail of metal, carbon fibre surrounded by the blade, and a contact blade comprising a metal band either glued onto the bottom surface of the blade or held in place below the blade by an embedded strip of gripping ridges. 
         [0011]    Another composite blade is disclosed in U.S. Pub. No. 2009/0206563, which describes a blade comprising a pair of metal plates separated by one or more metal webs, all partially encompassed by a rigid polymeric portion, which may be carbon fibre-reinforced epoxy. The metal plates form the edges of the contact blade, while the metal webs extend between the plates, leaving voids which are filled with plastic, though internal voids may be left empty. U.S. Pat. No. 6,761,363 shows a blade comprising a lower ice-contacting portion runner primarily made of metal, having a narrowed upper section around which a polymer is injection moulded, including spaced holes in the metal for secure bonding with the polymer. It is also known to sandwich a hard plastic or composite filler material between metal blade sides, as in Chinese Patent App. No. 101244334. In each case, the presence of metal substantially throughout the blade means that the blade is relatively heavy, compared to a blade comprising mostly a polymeric or other lighter material. 
         [0012]    Canadian Patent No.  2786312  discloses a disposable composite blade comprising a metal ice-contacting edge bonded to metal foil, which is in turn wrapped around a plastic core. Additional layers may be added between the core and foil, or as external layers bonded to the foil, to increase the stiffness of the blade. A reinforcing mat pre-impregnated with epoxy/resin may be added as another wrapping layer to further increase the strength of the blade without adding substantial weight to the blade. However, the need for many layers of foil and a number of parts makes this blade relatively complex to manufacture, which tends to increase the cost of the finished product. The use of a single piece of plastic as the core may also limit the ability to optimize the blade properties. 
         [0013]    U.S. Pat. No. 5,248,156 discloses a runner that takes the form of a thin flexible strip of metal to be secured directly to the blade holder of a skate, or to a blade inserted into the holder. The thinness and small size of the metal strip means that it may be easily disposed of, although the durability of same may be questionable. Further, the skate radius or other properties are not easily altered without permanently grinding the blade holder, and the connection mechanism is relatively complicated. Finally, the runner cannot be sharpened, nor is it reversible, meaning that it is necessary to carry a spare set of runner strips in case the blade is damaged unexpectedly. 
         [0014]    It is therefore an object of the invention to provide a double-edged disposable blade for an ice skate that overcomes the foregoing deficiencies. 
         [0015]    It is yet a further object of the invention to provide a reversible, disposable skate blade for a skate blade assembly having supports on either side of a skate blade to allow fast and secure removal and installation of the blade without having to remove the skate from the foot. These supports may be formed with the blade for simplicity of use, or may be separate pieces to allow for greater flexibility in replacing the various components of the blade assembly. 
         [0016]    These and other objects of the invention will be appreciated by reference to the summary of the invention and to the detailed description of the preferred embodiment that follow. It will be noted that not all objects of the invention are necessarily realized in all possible embodiments of the invention as defined by each claim. 
       SUMMARY OF THE INVENTION 
       [0017]    The invention relates to a disposable double-edged skate blade comprising a blade made of inexpensive materials, and constructed in a simple, cost-effective manner. In a further aspect, the invention relates to a disposable double-edged skate blade assembly comprising a disposable blade and blade supports to provide a snug fit within a blade holder. 
         [0018]    In one aspect, the invention comprises a reversible disposable blade for an ice skate, the blade comprising a core having a pair of opposed planar sides bounded by two opposed edges and two curved ends; and at least one ice-contacting runner on each of the opposed edges, the ice-contacting runners and the core being composed of different materials. The runner may extend along at least one of the opposed edges and over at least one of the curved ends. 
         [0019]    The core may be composed of materials such as aluminum, ballistic nylon, epoxy resin, fibre-reinforced polymer, fibreglass, carbon fibre, aramid polymer fibre and para-aramid polymer fibre, or combinations of these or similar materials. The core may have a thickness between the two opposed flat sides, which thickness tapers along the blade. The core may have at least one aperture through the core to accommodate a fastener to attach the blade to an ice skate. 
         [0020]    The runner may be composed of at least one material selected from the group consisting of stainless steel, carbon steel, aluminum, titanium and ceramic, or combinations of these or similar materials. The runner may comprise a channel along its outer length and may further have a filler material in the channel. 
         [0021]    In a further aspect, the runner and core may be connected with glue, or they may be compression molded together, or joined during an injection molding process during which the core is formed. A physical connection between the core and the runner may be provided by a plurality of protrusions on the runner, where the protrusions are embedded into the core, and/or an extension along the inner length of the runner, where the extension is embedded into the core. 
         [0022]    In yet a further aspect, the core may be strengthened through means such as a reinforcing core within the core and/or at least one reinforcing bar extending between the opposed edges of the core. 
         [0023]    In a further aspect, the reversible disposable blade of the invention may further include at least one blade support on each of its opposed planar sides. The blade and blade supports may be inseparable, or the blade supports may be separable from the core. If the blade supports are separable from the core, the core may further comprise at least one aperture adapted to interlock with at least one corresponding protrusion on the blade supports, and/or at least one extension adapted to interlock with at least one corresponding aperture on the blade supports. 
         [0024]    In another aspect, the invention comprises an ice skate comprising a boot; a blade holder extending from the boot; and a detachable and reversible skate blade comprising a core having a pair of opposed planar sides bounded by two opposed edges and two curved ends; and at least one ice-contacting runner on each of the opposed edges; the ice-contacting runners and the core being composed of different materials; wherein the skate blade is disposable. 
         [0025]    The foregoing was intended as a broad summary only and of only some of the aspects of the invention. It was not intended to define the limits or requirements of the invention. Other aspects of the invention will be appreciated by reference to the detailed description of the preferred embodiment and to the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    The preferred embodiment of the invention will be described by reference to the drawings in which: 
           [0027]      FIG. 1 a    is a side view of a first embodiment of the double-edged disposable skate blade; 
           [0028]      FIG. 1 b    is a plan view of a long edge of the skate blade shown in  FIG. 1   a;    
           [0029]      FIG. 1 c    is an end view of the skate blade shown in  FIG. 1   a;    
           [0030]      FIGS. 1 d -1 g    are sectional views of the skate blade shown in  FIG. 1 a   , taken along lines d-d through g-g respectively; 
           [0031]      FIG. 2 a    is a side view of a second embodiment of the double-edged disposable skate blade; 
           [0032]      FIG. 2 b    is an end view of the skate blade shown in  FIG. 2   a;    
           [0033]      FIGS. 2 c -2 e    are sectional views of the skate blade shown in  FIG. 2 a   , taken along lines c-c through e-e respectively; 
           [0034]      FIG. 3 a    is a side view of a third embodiment of the double-edged disposable skate blade; 
           [0035]      FIG. 3 b    is a plan view of a long edge of the skate blade shown in  FIG. 3   a;    
           [0036]      FIGS. 3 c  and 3 d    are end views of the skate blade shown in  FIG. 3   a;    
           [0037]      FIGS. 3 e -3 h    are sectional views of the skate blade shown in  FIG. 3 a   , taken along lines e-e through h-h respectively; 
           [0038]      FIG. 4 a    is a side view of a fourth embodiment of the double-edged disposable skate blade; 
           [0039]      FIGS. 4 b -4 e    are sectional views of the skate blade shown in  FIG. 4 a   , taken along lines b-b through e-e respectively; 
           [0040]      FIG. 5 a    is a side view of a pair of blade supports for use with the disposable skate blade of the invention; 
           [0041]      FIG. 5 b    is a plan view of the pair of blade supports shown in  FIG. 5   a;    
           [0042]      FIG. 5 c    is an end view of the pair of blade supports shown in  FIG. 5   a;    
           [0043]      FIGS. 5 d -5 f    are sectional views of the pair of blade supports shown in  FIGS. 5 a  and 5 b   , taken along lines d-d through f-f respectively; 
           [0044]      FIGS. 5 g  and 5 h    are views of the inside surfaces of the pair of blade supports shown in  FIG. 5   a;    
           [0045]      FIG. 6 a    is a side view of a fifth embodiment of the double-edged disposable skate blade; 
           [0046]      FIG. 6 b    is a plan view of a long edge of the skate blade shown in  FIG. 6   a;    
           [0047]      FIG. 6 c    is an end view of the skate blade shown in  FIG. 6   a;    
           [0048]      FIGS. 6 d -6 f    are sectional views of the skate blade shown in  FIG. 6 a   , taken along lines d-d through f-f respectively; 
           [0049]      FIG. 7 a    is a side view of a sixth embodiment of the double-edged disposable skate blade; 
           [0050]      FIG. 7 b    is a plan view of a long edge of the skate blade shown in  FIG. 7   a;    
           [0051]      FIGS. 7 c  and 7 d    are end views of the skate blade shown in  FIG. 7   a;    
           [0052]      FIGS. 7 e -7 g    are sectional views of the skate blade shown in  FIG. 7 a   , taken along lines e-e through g-g respectively; and 
           [0053]      FIGS. 8-18  are enlarged views of embodiments of a blade hollow for use with any of the embodiments of the disposable skate blade of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0054]    Referring to  FIGS. 1 a   - 1   g,  a removable double edged disposable blade  10  for an ice skate includes a core  12  with an ice-contacting portion or runner  14  attached to its outer edge  16 . 
         [0055]    The core  12  may comprise a flat elongated elliptical piece having opposed flat sides  18  edged by a pair of opposed long edges  20 , which comprise part of outer edge  16 . It will be understood that “lower” as used in this description means the edge of the blade  10  that would contact the ice when the skate is in use, while “upper” means the portion of the blade  10  that is away from the ice and within the blade holder, but given that the blade  10  is reversible, each of the long edges  20  is interchangeable with the other and each may at any given time be the upper or lower ice-contacting edge. Each long edge  20  of the blade  10  is preferably substantially flat along its length, and is separated from the opposed long edge  20  by opposed front  22  and rear  24  curved ends, which may or may not have identical curvatures to each other. 
         [0056]    The core  12  may be composed of any suitably strong and lightweight material, such as aluminum, ballistic nylon, an epoxy resin, a fibre-reinforced polymer such as fibreglass, carbon fibre or aramid or para-aramid polymer fibre such as Kevlar®, or a similar composite or thermoplastic material. The core may be fabricated in any manner lending itself to fast and inexpensive mass manufacture, such as injection molding, vacuum molding, compression moulding, resin transfer moulding, press moulding, autoclave moulding, transfer moulding, pultrusion composite moulding, filament winding, casting, centrifugal casting, continuous casting, vacuum infusion, wet lay-up, and thermoplastic moulding. 
         [0057]    One or more reinforcing bars  26  may be provided to stiffen the core  12  against torsional forces, and to secure runner  14  to the edges of core  12 . Although three reinforcing bars  26  are illustrated in this embodiment, it will be understood that the number and location of reinforcing bars  26  within core  12  in the figures is for illustrative purposes only, and that the number and location may vary as necessary to provide the desired balance between stiffness and weight of the blade. 
         [0058]    The runner  14  is preferably a thin piece of stainless steel, but may also be formed of other materials, such as carbon steel, aluminum, titanium, ceramic, combinations of these materials, or other suitable material capable of holding an edge. It may be provided with different shapes and may comprise one or more filler materials to assist with gliding, as will be discussed later with reference to  FIGS. 8-18 . It may extend only partially around the outer edge  16  of blade core  12 , as in the embodiment illustrated in  FIG. 1   a,  or it may completely encompass the blade core  12 , as best shown in  FIG. 6   a.  The runner  14  is firmly secured to outer edge  16 , such as by being in the mold during an injection moulding process, by being compression moulded to the outer edge  16 , by being glued the outer edge  16  or any other suitable process to ensure firm and permanent connection to the outer edge  16 . Runner  14  is relatively thin, which decreases both the cost of manufacturing the blade and the overall weight of the blade, without sacrificing the ability to provide a strong, sharp edge for optimal skating performance. 
         [0059]    Blade core  12  may be a substantially uniform thickness along its length, as shown in  FIG. 1   b.  In this configuration, it is possible to place the blade  10  within a blade holder in any one of four different configurations, as either of curved ends  22 ,  24  may be at the toe end of the holder, if they are identical to each other and as long as the blade  10  fits properly into the blade holder. This can simplify installment of the blade  10 , because it is not necessary to be concerned about which curved end  22  or  24  is at which end of the holder. However, it is also contemplated that the thickness of the blade core  12  may be tapered from toe  22  to heel  24  along its length, as shown most clearly in  FIGS. 3 b -3 d   , which may provide improved gliding characteristics. However, it is then necessary when reversing the blade  10  to ensure that the thick end is always the front end  22 , and is placed toward the front of the holder, It is also necessary to ensure during manufacture that runner  14  properly tapers along with blade core  12 . 
         [0060]    One or more apertures  30  may be provided in blade  10  through which a locking means may be used to secure the blade  10  to a holder on a skate blade. Apertures  28  may also be provided to accommodate blade supports, as will be discussed later. It will be understood that the number and placement of the apertures  28  and/or  30  may differ from that shown in the figures, as long as sufficient strength and stability characteristics may be achieved. 
         [0061]    In a second embodiment, shown in  FIGS. 2 a -2 e   , the runner  14  is provided with an extension  34 , which protrudes from its inner surface (inner being the non-ice-contacting surface), and about which core  12  is formed. In the embodiment shown in  FIG. 2 a   , the core  12  simply surrounds the extension  34  directly; extensions  34  may be provided with one or more holes  36  through which the resin holding the core  12  together can flow, thereby firmly bonding the core  12  to the extension  34  and to the runner  14 . 
         [0062]    Alternatively, as best shown in the embodiment of  FIGS. 3 a -3 h   , the inner surface of runner  14  may comprise a plurality of smaller studs or pins  38 , which may be gripped by the resin holding the core  12  together, thereby firmly bonding the core  12  to the studs  38  and to the runner  14 . 
         [0063]    In another embodiment, the blade  10  may be provided with a reinforcing core  40  within blade core  12 . Reinforcing core  40  may be used with any of the embodiments earlier described, but as illustrated in  FIGS. 4 a -4 e   , it preferably meshes or otherwise accommodates or is accommodated by any portions of the runner  14  (such as the runner extension  34  shown in  FIG. 4 a   ) such that reinforcing core is solidly connected to blade core  12  and runner  14 . Again, holes  36 ,  42  may be provided in the runner extension  34  and/or reinforcing core  40  through which the resin holding the core  12  together can flow, thereby firmly bonding the core  12  to the reinforcing core  40 , the extension  34  and to the runner  14 . 
         [0064]    It is contemplated that the foregoing blade embodiments may be combined with a pair of the blade supports shown in Applicant&#39;s co-pending PCT App. No. PCT/CA2012/000968 to form the blade assembly system shown therein. A pair of blade supports  44 ,  46 , best shown in  FIGS. 5 a -5 h   , will provide additional strength and stability through at least a portion of the length of a blade  10  (not shown in  FIGS. 5 a -5 h   ). Blade supports may also provide additional strength against lateral forces. In case of a very strong lateral force, such as a puck striking the side of the blade, particularly near the centre of the blade, the force may be sufficient to deform the blade, rendering it unusable. However, with the addition of blade supports, the blade supports themselves will crack and break first, dissipating the lateral forces before they can irreversibly damage the blade. This can increase the lifetime of a blade. 
         [0065]    Blade supports  44 ,  46  comprise a pair of opposed protruding ridges  52 , on which the bottom of the blade holder will rest when the blade is inserted into the blade holder. Any downward force applied to the blade  10  through the skate boot and holder, such as by a skater jumping on or onto the ice, stepping, or taking strong strides, is distributed along the blade supports  44 ,  46 . Ridges  52  may be discontinuous, as shown, or continuous, in any configuration which substantially supports the underside of the blade holder. Blade supports  44 ,  46  may also serve as a means to physically interlock the blade  10  with the blade holder, by providing suitable means to engage the blade supports  44 ,  46  and the holder. One example of such engaging means is a set of teeth  54  provided at one or more locations along the blade supports  44 ,  46 . When the blade  10  is inserted into a holder having matching engaging means, such that the holder meshes with teeth  54  at one or more locations, the blade  10  is securely held together with the holder, preventing it from falling out unless enough force is applied to pull the blade  10  out of its engagement with the holder. Further, the meshing of the two engaging means prevents the blade  10  from moving longitudinally within the holder. When properly engaged, apertures  50  on blade supports  44 ,  46  line up with apertures  30  in blade  10 , to accommodate a locking mechanism if required. 
         [0066]    Blade supports  44 ,  46  may comprise an inner surface  56  containing alignment means to mate it with the side of blade  10 , such as one or more projections  58 , which align with apertures  28  in blade  10 . It will be understood that any suitable alignment means may be used to correctly align the blade support  44  with blade support  46  transversely through blade  10 . For example, it is also possible to mate the pieces in the opposite manner, i.e. by providing projections on blade  10  that correspond to apertures on one or both of blade supports  44 ,  46 . 
         [0067]    In order to ensure that the blade supports  44 ,  46  hold securely about the blade  10 , connecting means  48  may be provided to allow the opposed blade supports to connect with each other, For example, blade support  44  may be provided with studs  48   a,  which mate with cavities  48   b  on opposed blade support  46  in a manner similar to a toy building block. It will be appreciated that other connecting mechanisms may be used, as well as different embodiments of this connecting means  48 , such as more or fewer numbers of matching studs  48   a  and cavities  48   b,  or differently shaped studs  48   a  and/or cavities  48   b.    
         [0068]    In the embodiment shown in  FIGS. 6 a -6 f   , blade  10  is substantially the same as that shown in  FIGS. 1 a   - 1   g,  but an integral blade support  60  is further provided on the sides  18  of the blade  10 . Blade support  60  is preferably formed as a unitary piece with core  12 , such that the blade  10  has the same external features of blade supports  44 ,  46 , such as one or more protruding ridges  52 , and teeth  54  to engage a blade holder. Similarly, the other embodiments of  FIGS. 1-4  may be provided with integral blade supports  60 ; as a further example,  FIGS. 7 a -7 g    correspond to the embodiment shown in  FIGS. 3 a   - 3   e.    
         [0069]    It is contemplated that the blade  10 , while being of substantially the configuration shown, can be made with variations in blade thickness, profile (radius and rocker) and hollow radius, to, suit the needs of different sports, different ice conditions, different skater size, weight, strength and skill levels, and different playing roles. For example, softer ice will require a different blade hollow radius than harder ice. A speed skater will use a thinner blade than a hockey player. A heavier skater will require a different profile than a lighter skater. A hockey player playing in a forward position may prefer a different blade profile to allow for increased maneuverability than a player playing on defense, who may skate backward more frequently than forward. A hockey goaltender will have a substantially different profile compared to a player who plays out; goalie blades are typically flat, or substantially flatter, than skater blades, and the height of one edge may differ from the height of the other edge. 
         [0070]    Generally, both of the opposed edges  20  may have similar characteristics, such as being made of the same material, and shaped with the same hollow, profile and/or taper, such that the blade  10  comprises two opposed long edges  20  that are truly interchangeable with each other, However, it is contemplated that a blade  10  may be provided with differing characteristics between the edges  20 , such as being made of different materials, or having different hollow radii and/or different profiles, such that a skater can choose which blade edge will perform best in a particular situation or under specific ice conditions without having to carry around too many replacement blades. Further, because the blades are disposable, and are therefore not intended to be sharpened, skaters who prefer specific hollow sizes and shapes can select which is the best for them, in one or more different situations. The skater can therefore know what performance characteristics to expect out of a blade each time he or she changes the blade. 
         [0071]    Some examples of different blade configurations are shown in  FIGS. 8-18 . In each case, runner  14  comprises a pair of opposed edges  70 , separated by a channel  72 . Channel  72  may be shaped in various ways, and may be provided with a filler  74 . Filler  74  may be a suitable material, chosen to improve the gliding characteristics of the blade, such as Teflon®, another polymer or a ceramic. Filler  74  may be selected to be a hydrophobic material to affect the way that the blade interacts with water that collects within the channel. A specific blade shape and hollow can be created either by physically shaping the metallic opposed edges  70  and channel  72  of the runner  14 , or by using filler material  74  to provide essentially the same shape and hollow, regardless of the shape of the runner  14 . This point is illustrated by a comparison of, for example,  FIGS. 8-11 , which show all-metal runners, with  FIGS. 12-15 , which show runners filled to create a matching channel shape. This provides flexibility in blade shape, composition, weight and cost of manufacture, while providing an almost unlimited number of possible blade configurations, without significantly changing the blade manufacturing process or cost.  FIGS. 16-18  more clearly illustrate that several different blade channel  72  configurations may be provided using a single runner configuration, simply by providing different amounts and shapes of filler  74  between opposed runner edges  70 . 
         [0072]    In order to protect double-edged blades from damage, or from injuring the skater while not in use on a skate, a sleeve may be provided. The sleeve may also be used as a hand guard, to protect the skater&#39;s hand while removing or inserting a blade from the skate. 
         [0073]    In the foregoing specification, the invention has been described with reference to specific embodiments thereof. However, it will be appreciated by those skilled in the art that other variations to the preferred embodiment described herein may be practised without departing from the scope of the invention, such scope being properly defined by the following claims. The scope of the claims should therefore not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.