Abstract:
The present document describes a blade sharpening system comprising a blade sharpening device, a blade holding apparatus and a controller operatively coupled to the blade sharpening device and said blade holding apparatus to control sharpening of said blade, and methods of using the same.

Description:
BACKGROUND 
     (a) Field 
     The subject matter disclosed generally relates to blade sharpening and more specifically to blade sharpening apparatuses and methods of using the same to produce sharpened skate blades. 
     (b) Related Prior Art 
     Blade sharpening devices for sharpening of all types of blades ranging from cutting blade and skating blades are known. 
     For example, cutting blade sharpening devices are known which have two or more pairs of grinding rollers or wheels located in mutually facing positions with their respective lateral grinding surfaces in adjacent relation. The blade is sharpened by being interposed between the two rollers with the blade edge contacting the grinding surfaces and causing the rollers to rotate about respective parallel axes with opposite directions of rotation. 
     A first drawback of such a solution consists in that rigidly held grinding rollers provide a blade having a profile, whose quality is not always acceptable. An additional drawback of these known solutions is that, during sharpening, the blade has to be pressed against the roller, and is thus heated, which may cause loss of hardness of the material, usually steel. Another drawback is that the top-to-bottom rotation of the grinding surfaces of the rollers causes burr build-up that forces frequent process stops for burr removal. 
     A further drawback is that prior art sharpening devices are mounted to fixed shells which set an operating position thereof, and introduction of the blades to be sharpened from both sharpening sides between the grinding members, for better sharpening, requires users to repeatedly move around the device for direct access to each side. 
     Another drawback is that, during blade sharpening, the user that holds the blades may inadvertently introduce them through an excessive distance between the grinding members, with the blade handles possibly contacting the latter and being damaged by their fast rotation, as soon as contact occurs. 
     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 length of the blade. A skater can use either of these two edges in executing maneuvers on the ice surface. To maintain a desired blade configuration, a skate sharpening apparatus must be employed to re-grind the lower surface of the blade to create a groove along the length of the blade according to the preferred profile 
     Skate blades differ from one pair to another. In the prior art, such as Canadian Patent 2,309,222C, the operator of a skate sharpening machine is required to first dress a grinding wheel, which is usually carried out using a single point diamond dresser that is pivoted about an axis generally perpendicular to an axis of rotation of the grinding wheel. The single point diamond dresser intersects the outer periphery of the grinding wheel, removing material from the wheel to create and define a grinding wheel contour. 
     A drawback of such solution is that to have the desired contour applied to the skate blade, one must manually ensure that during the grinding process the centerline of the contour on a wheel coincides with the centerline of the blade along its full length. When each centerline is not carefully matched, an irregular groove will be created along the length of the blade, with one edge being higher/lower than the other. The contour formed on the grinding wheel may range from a convex arcuate surface with a radius typically in the range of 0.25 inch to 2 inches through to a triangular profile. Therefore, ice skate blade profiles have evolved into different profiles of blade between speed skating and ice dance, defender, goalie, attacker, short speed and long speed. 
     Accordingly it would be desirable to provide an ice skate blade sharpening machine that allows for sharpening multiple blades simultaneously allowing accurate alignment of profiles for example within a single player&#39;s pair, across multiple pairs for a user or simply to reduce time and cost in retail establishments offering blade sharpening services. 
     SUMMARY 
     According to an embodiment, there is provided a blade sharpening system which may comprise:
         a blade sharpening device configured to contact the blade according to a predetermined shape of the blade comprising
           a grinding assembly having a grinding wheel demountably attached to a spindle operatively coupled to a grinding wheel drive system, the grinding wheel configured to contact the blade with a constant grinding pressure and a constant grinding rotation speed;   
           a blade holding apparatus to slide the blade over the blade sharpening device, comprising
           parallel first and second gripping members for contacting opposite sides of the blade and align an edge of the blade with the grinding wheel for sharpening; and   
           a controller operatively coupled to the blade sharpening device and the blade holding apparatus to control sharpening of the blade.       

     The blade holding apparatus may further comprises adjustable grip tuning members for abutting the first and second parallel gripping members to provide a substantially even gripping pressure along the blade to straighten the blade. 
     The constant grinding pressure may be according to a type and/or a make of the blade. 
     The blade sharpening device may further comprise a lever configured to pivot the grinding assembly according to the predetermined shape of the blade. 
     The blade sharpening device may further comprise an arm pivotally coupled to the lever to pivot the lever according a predetermined shape of the blade. 
     The blade sharpening device may further comprise a cam coupled to the arm to actuate the arm. 
     The blade holding apparatus may further comprises a stage having at least one longitudinal slot in longitudinal alignment with the grinding wheel. 
     The parallel first and second gripping members may be slidably mounted on the stage over the longitudinal slot, for aligning the blade within the longitudinal slot. 
     The centerline of the grinding wheel may be configured to be in longitudinal alignment with a centerline of the edge of the blade. 
     The grinding wheel may comprise a contour having a convex arcuate surface with a radius from about 0.25 inch to about 3 inch. 
     The blade holding apparatus may further comprise an actuating member to bring the first and second parallel gripping members in proximity. 
     The blade holding apparatus may further comprise a blade extremity rest to abut a blade extremity to position the blade in the blade holding apparatus. 
     The blade sharpening device may further comprise a balancing mechanism to counterbalance weight of the grinding assembly. 
     The balancing mechanism may be a weight. 
     The controller may be operable to
         control the grinding rotation speed of the grinding wheel;   control the constant grinding pressure of the grinding wheel;   control position of the blade sharpening device according to the predetermined shape of the blade; and   control motion of the blade holding apparatus.       

     The controller may further comprise one or more processor, and a memory. 
     The controller may be further operable to receive and store a blade sharpening parameter set. 
     The blade sharpening parameter set may comprise a height of the grinding wheel with respect to the blade at start of grinding, a height of the grinding wheel with respect to the blade at end of grinding, an initial point of contact with the blade, acceleration time of the blade holding apparatus, speed of the blade holding apparatus, cam speed, cam acceleration time, grinding wheel drive system delay, a predetermined shape of a blade, a constant grinding pressure for a given blade, a constant grinding rotation speed for a given blade, the number of sharpening cycles, and combinations thereof. 
     The blade sharpening system may be further operable to be accessible from a computer network. 
     The blade sharpening system may be further comprising a dust collecting apparatus, for collection of dust generated from grinding the blade. 
     According to another embodiment, there is provided a method of sharpening blades with a blade sharpening system of the present invention comprising the step of:
         a) moving at least once the blade holding apparatus having a blade mounted thereon toward the grinding wheel in alignment with the blade, to contact the blade with the grinding wheel with a constant grinding pressure, and a constant grinding rotation speed, according to a predetermined shape of the blade, to sharpen and prevent deformation of the blade.       

     The method may be further comprising step b) 
     b) accelerating the blade holding apparatus up to the speed of the blade holding apparatus when the grinding wheel is at a point of contact near the extremity of the blade. 
     The following terms are defined below. 
     The term “predetermined shape” is intended to mean that the shape of the blade being sharpened is known to the blade sharpening system. It may have been previously measured and may be for example stored in the controller of the system, or may be accessible for an available source. The predetermined shape of the blade is dependent upon the type (e.g. ice skating, figure skating, speed skating blade) and/or the make (e.g. CCM, Bauer, Easton) of the blade being sharpened. 
     The term “constant grinding pressure” is intended to mean that the pressure applied on the blade being sharpened is constant over the entire length of the surface/edge being sharpened. By pressure, it is meant the weight and/or force applied by the grinding wheel on the blade. Maintaining a constant pressure ensure an even sharpening over the entire length of the edge being sharpened, thereby avoiding waves along the blade&#39;s edge. 
     The term “constant grinding rotation speed” is intended to mean that the rotation speed of the grinding wheel is maintained constant over the entire length of the surface/edge being sharpened. Maintaining a constant rotation speed prevents unnecessary heating of the blade being sharpened, which prevent deformation and hardening of the blade during sharpening. 
     Features and advantages of the subject matter hereof will become more apparent in light of the following detailed description of selected embodiments, as illustrated in the accompanying figures. As will be realized, the subject matter disclosed and claimed is capable of modifications in various respects, all without departing from the scope of the claims. Accordingly, the drawings and the description are to be regarded as illustrative in nature, and not as restrictive and the full scope of the subject matter is set forth in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which: 
         FIG. 1  illustrates a blade sharpening system according to an embodiment of the present invention; 
         FIG. 2  illustrates a blade sharpening device and a blade holding device from a blade sharpening system according to an embodiment of the present invention; 
         FIG. 3  illustrates a blade holding device over a blade sharpening device from a blade sharpening system according to an embodiment of the present invention. 
         FIG. 4  illustrates a side view of a blade sharpening device and a blade holding device from a blade sharpening system according to an embodiment of the present invention. 
         FIG. 5  illustrates a view of a cam and arm of a blade sharpening device from a blade sharpening system according to an embodiment of the present invention. 
         FIG. 6  illustrates a blade sharpening system according to an embodiment of the present invention. 
     
    
    
     It will be noted that throughout the appended drawings, like features are identified by like reference numerals. 
     DETAILED DESCRIPTION 
     In a first embodiment there is disclosed a blade sharpening system comprising:
         a blade sharpening device  20  configured to contact said blade according to a predetermined shape of said blade comprising
           a grinding assembly  30  having a grinding wheel  32  demountably attached to a spindle  34  operatively coupled to a grinding wheel drive system  36 , said grinding wheel configured to contact said blade with a constant grinding pressure and a constant grinding rotation speed;   
           a blade holding apparatus  40  to slide said blade over said blade sharpening device  20 , comprising
           parallel first and second gripping members  41 ,  42  for contacting opposite sides of said blade and align an edge of said blade with said grinding wheel  32  for sharpening; and   
           a controller  50  operatively coupled to said blade sharpening device and said blade holding apparatus to control sharpening of said blade.       

     In a second embodiment, there is disclosed a method of sharpening blades with a blade sharpening system of the present invention, comprising the step of:
     a) moving at least once said blade holding apparatus having a blade mounted thereon toward said grinding wheel in alignment with said blade, to contact said blade with said grinding wheel with a constant grinding pressure, and a constant grinding rotation speed, according to a predetermined shape of said blade, to sharpen and prevent deformation of said blade.   

     Referring now to the drawings, and more particularly to  FIGS. 1 to 5 , which illustrates a blade sharpening system  10  according to the present invention. The blade sharpening system  10  of the present invention may be used for sharpening at the same time one or more blades, and therefore, when the present invention is described as containing one element or part, it is within the purview of the person skilled in the art to adapt the disclosed subject matter to include more than one such element. For example, a system of the present invention could be designed to sharpen two blades at the same time. 
     The blade sharpening system  10  of the present invention comprises a blade sharpening device  20  configured to contact the blade according to a predetermined shape of the blade. The blade sharpening device  20  includes a grinding assembly  30  having a grinding wheel  32  demountably attached to a spindle  34  operatively coupled to a grinding wheel drive system  36 . The grinding wheel  32  is configured to contact the blade with a constant grinding pressure and a constant grinding rotation speed. 
     According to another embodiment, the centerline of the grinding wheel  32  may be configured to be in longitudinal alignment with the corresponding centerline of the edge of the blade. According to another embodiment, the grinding wheel  32  may comprise a contour having a convex arcuate surface with a radius from about 0.25 inch to about 3 inch. The perfect alignment results in a perfectly concave edge on the blade being sharpened, resulting in an optimal skating blade. 
     According to another embodiment, the blade sharpening device  20  may further comprise a lever  22 , which is configured to pivot the grinding assembly  30  according to the predetermined shape of the blade. For example, lever  22  may be pivotally mounted on pivot  24 . According to another embodiment, the blade sharpening device  20  may further comprise an arm  26 , which is pivotally coupled to the lever  22  to actuate and pivot the lever  22  according the predetermined shape of the blade. Now referring to  FIG. 5 , according to another embodiment, the blade sharpening device  20  may further comprise a cam  29 , which is coupled to an arm  26 . Rotational movement of the cam  29  actuates the arm  26 , which is pivotally coupled to the lever  22  to actuate and pivot the lever  22  according the predetermined shape of the blade. According to an embodiment, the lever  22 , arm  26 , and cam  29  may all be operatively coupled to a drive means which is controlled by the controller  50  to move these parts and pivot the grinding assembly  30 . 
     According to another embodiment, the blade sharpening device  20  may further comprise a balancing mechanism to counterbalance weight of the grinding assembly  30 . For example, the balancing mechanism may be a weight, a retaining arm, or the likes or a combination thereof. Preferably, the balancing mechanism is a weight. For example, according to an embodiment, the weight may be a series of weights  28  mounted in lever  22  in order to equilibrate the weight of the grinding assembly  30  mounted at the extremity of the lever  22 . 
     The blade sharpening system  10  of the present invention also includes a blade holding apparatus  40 , which slides the blade over the blade sharpening device  20 . The blade holding apparatus  40  may be slided by any suitable means or assembly capable of smoothly sliding it. For example, one or more rails operatively coupled to drive to move back and forth the blade holding apparatus  40  could be used. The blade holding apparatus  40  may be mounted on wheels and operatively coupled to drive to move it back and forth. The blade holding apparatus  40  may be mounted on a linear bearing and operatively coupled to drive to move it back and forth. According to an embodiment, the blade holding apparatus  40  may be coupled to a linear bearing  45 . The blade holding apparatus  40  includes parallel first and second gripping members  41 ,  42 , that contact opposite sides of the blade and align an edge of the blade with the grinding wheel  32  for sharpening. 
     The blade holding apparatus may further comprise a stage  46 , having at least one longitudinal slot  48  in longitudinal alignment with the grinding wheel  30 . According to another embodiment, the parallel first and second gripping members  41 ,  42  may be slidably mounted on the stage  46  over the longitudinal slot  48 , for aligning the blade within said longitudinal slot. 
     According to another embodiment, the blade holding apparatus  40  may further comprise an actuating member  60  to bring said first and second parallel gripping members  41 ,  42  in proximity to one another. When the first and second parallel gripping members  41 ,  42  are brought in proximity in this fashion, the blade to be sharpened is held between the parallel gripping members  41 ,  42 . The actuating member  60  may be any suitable means of bringing the first and second parallel gripping members  41 ,  42  in proximity. For example, the actuating member may push on the external sides of the parallel gripping members  41 ,  42  to bring them near one another and clamp on the blade. Alternatively, the actuating member  60  may push or pull on the parallel gripping members  41 ,  42  to bring them near one another and clamp on the blade. Now referring to  FIG. 3 , there is shown actuating members  60  comprising levers  62  connected to spring loaded rods  64 . Rods  64  are connected to the first and second parallel gripping members  41 ,  42 , which are pulled upon during actuation of the lever  62 . Guiding members  66 , inserted in slots in the first and second parallel gripping members  41 ,  42  ensure that the first and second parallel gripping members  41 ,  42  slide toward each other and clamp on the blade there between. 
     According to another embodiment, the blade holding apparatus  40  further comprises adjustable grip tuning members  44  that abut the first or the second parallel gripping members  41 ,  42  to provide a substantially even gripping pressure along the blade and straighten the blade prior to sharpening. According to another embodiment, the adjustable grip tuning members  44  allow the first or the second parallel gripping members  41 ,  42  to slide against the adjustable grip tuning members  44 , which in combination with the guiding members  66 , guide the first or the second parallel gripping members  41 ,  42  against one another to clamp around a blade there between. 
     According to another embodiment, the blade holding apparatus  40  may further comprises a blade extremity rest  49 , to abut a blade extremity to position the blade in the blade holding apparatus  40 . 
     The blade sharpening system  10  of the present invention also includes a controller  50 , which is operatively coupled to the blade sharpening device  20  and the blade holding apparatus  40 , to control sharpening of the blade. According to an embodiment, the controller  50  is operable to
         control the grinding rotation speed of the grinding wheel  32 ;   control the constant grinding pressure of the grinding wheel  32 ;   control the position of the blade sharpening device  20  according to the predetermined shape of the blade; and   control motion of the blade holding apparatus  40 .       

     According to an embodiment, the controller  50  may comprise one or more processor, and a memory. The controller  50  may be further operable to receive and store a blade sharpening parameter set. For example, the blade sharpening parameter set may be stored in the memory of the controller  50 . The blade sharpening parameter set may include numerous parameters, non-limiting examples of which include: 
     The height of the grinding wheel  32  with respect to the blade at start of grinding. This parameter specifies the position of the grinding wheel  32  at the entry (e.g. the tip) of the blade to begin grinding, and will be different according to the type and/or the make of the blade. This parameter may empirically determined by measurements provided and stored in the system. 
     The height of said grinding wheel with respect to the blade at end of grinding Is a parameter that specifies the position of the grinding wheel  32  when it is at the end of the blade. Specifically, it locks the position of the grinding wheel  32  (e.g. through locking arm  26 ) after sharpening of the blade to prevent the blade sharpening device  30  from moving upwards toward the bottom of a skate and damage the boot of the skate. It may also position the grinding wheel  32  in such a manner that it prevents deformation of the blade upon exit. 
     The initial point of contact with the blade (with the grinding wheel  32 ). This parameter is a point in space just before the contact is initiated between the grinding wheel  32  and the blade; Depending of the make and/or shape of the blade, the initial point of contact will range from about 10 thousandth of an inch to 70 thousandth of an inch (from about 250 μm to about 1800 μm). 
     Speed of the blade holding apparatus, is a parameter that specifies the speed at which the blade holding apparatus travels during the grinding of the blade. The speed of the blade holding apparatus  40  is also held constant during grinding, and it may vary from about 1 inch to 2 inches per seconds (2.54 cm/sec to about 5.08 cm/sec). 
     Acceleration time of the blade holding apparatus is a parameter that determined how much time the blade holding apparatus will take to achieve the travelling speed of the blade holding apparatus  40  when it is grinding the blade, from a completely stationary (stopped) position. According to an embodiment, the acceleration time of the blade holding apparatus may be from about 0.5 seconds to about 2 seconds, or from about 0.5 seconds to about 1.5 seconds, or from about 0.5 seconds to about 1.0 seconds. 
     Cam speed may also be specified to move the cam according to a constant speed in order to stabilize the blade grinding process and prevent deformation of the blades. Cam speed may vary from about 0 degree (stopped) to about 90 degrees per second. 
     Cam acceleration time may also be specified in order to further stabilize the grinding process and prevent deformation of the blades. The acceleration time specifies how long the cam will accelerate from a complete stop position to the desired cam speed. The acceleration may be from about 10 degrees per second to about 30 degrees per second. 
     The grinding wheel drive system delay is also a parameter that may be specified. This parameter specifies how long the grinding wheel drive system will be turned on before grinding begins. This prevents cases where the grinding wheel and the blade are put into contact while the wheel is stopped or has not reached the desired grinding rotation speed. 
     The predetermined shape of a blade is the shape of the blade that is being sharpened based on measurements made prior to sharpening. 
     The constant grinding pressure for a given blade, represents the pressure (or weight) being applied on the blade during grinding. This pressure may be from about 5 ounces to about 12 ounces (about 56 grams to about 336 grams). 
     The constant grinding rotation speed may be from about 6250 feet/min to about 7860 feet/min (about 1905 m/min to about 2394 m/min. 
     The number of sharpening cycles simply specifies the number of times the blade will be sharpened by the grinding wheel until the system is stopped. 
     According to another embodiment, the blade sharpening system  10  may be further operable to be accessible from a computer network, and/or it may comprise suitable connections to allow a user to input external data, such as new blade sharpening parameter sets. 
     According to another embodiment, the blade sharpening system of the present invention may further comprise a dust collecting apparatus (such as a vacuum pump, a vacuum cleaner, a filter connected to a negative pressure source, or the likes) for collection of dust generated from grinding the blade. 
     According to another embodiment, in use, the blade sharpening system  10  of the present invention sharpens blades according to a constant grinding pressure (ex. 5 to 12 ounces-56 to 336 grams of pressure/weight) and a constant grinding rotation speed (ex. 6250 feet/min to about 7860 feet/min (about 1905 m/min to about 2394 m/min) of the grinding wheel. Both of these parameters are predetermined and available to the blade sharpening system  10  of the present invention according to the type and/or make of the blade being sharpened. According to another embodiment, the constant grinding rotation speed may be the same for all blades, irrespective of the types and makes of blades. According to an embodiment, the pressure applied on the blade being sharpened is maintained constant over the entire length of the surface/edge being sharpened. This is to ensure an even sharpening over the entire length of the edge being sharpened and avoid grooves and waves along the blade&#39;s edge, resulting in an imperfect and non-optimal blade. According to an embodiment, the speed of the blade holding apparatus  40  is also held constant, also to ensure an even sharpening over the entire length of the edge being sharpened resulting in an imperfect and non-optimal blade. 
     According to another embodiment, a constant grinding rotation speed is maintained over the entire length of the surface/edge being sharpened to prevent unnecessary heating of the blade being sharpened, which prevents deformation and hardening of the blade during sharpening. 
     According to an embodiment, the constant grinding pressure and constant grinding rotation speed are also influenced by the weight of the grinding assembly  30 , and balancing said weight with a balancing mechanism contributes to the system&#39;s blade sharpening device stability and its ability to deliver such constant grinding pressure and rotation speed. According to another embodiment, actuation and pivoting of the lever  22  by arm  26  with cam  29  also allows the system of the present invention to ability to deliver such constant grinding pressure and rotation speed. 
     According to another embodiment, there is disclosed a method of sharpening blades with a blade sharpening system of the present invention. The method comprises the step of:
         a) moving at least once the blade holding apparatus  40  having a blade mounted thereon toward the grinding wheel  32  in alignment with the blade, to contact the blade with the grinding wheel  32  with a constant grinding pressure, and a constant grinding rotation speed, according to the predetermined shape of the blade, to sharpen and prevent deformation of the blade.       

     The grinding assembly  30  is positioned according to the blade sharpening parameter set provided for a given blade, and the blade holding apparatus  40  is moved toward the grinding assembly  30 , which then contacts the blade and sharpen it according to the constant grinding pressure, and the constant grinding rotation speed of the grinding wheel  30 , according to the predetermined shape of the blade. This may be repeated as many times as required in order to obtain an adequately sharpened blade. The combination of the constant grinding pressure, and the constant grinding rotation speed of the grinding wheel  30 , with the predetermined shape of the blade results in an even and highly reproducible sharpening of the blade. The blade is straightened just prior to sharpening, and the constant grinding pressure and rotation speed prevent the introduction of undesired alterations to the blade, such as grooves and hardened sections. 
     According to yet another embodiment, the method may be further comprising step b)
         b) accelerating the blade holding apparatus  40  up to the speed of the blade holding apparatus when the grinding wheel  32  is at the point of contact near the extremity of the blade.       

     Prior to contacting the extremity of the blade, the grinding wheel  32  is rotating at a constant speed. Once the grinding wheel  32  reaches the point of contact the blade holding apparatus  40  is promptly accelerated to the targeted blade holding apparatus speed, which is then kept constant until the end of the sharpening cycle of the blade. According to an embodiment, the point of contact may be from about 0.01 inch to about 0.07 inch (from about 250 μm to about 1800 μm) from the extremity of the blade. 
     The blade is contacted within a fraction of second when the acceleration is completed. Contacting the blade directly without accelerating the blade holding apparatus  40  would potentially distort the blade, while contacting the blade with an accelerating blade holding apparatus  40  does not. 
     While preferred embodiments have been described above and illustrated in the accompanying drawings, it will be evident to those skilled in the art that modifications may be made without departing from this disclosure. Such modifications are considered as possible variants comprised in the scope of the disclosure.