Abstract
An automated skate sharpening machine is provided. The machine includes a grinding wheel operable to rotate about a first axis by a grinding wheel motor; one or more skate holders to clamp a skate blade with its edge facing the grinding wheel; wherein at least one of the grinding wheel motor and the one or more skate holders are rotatable about a second axis perpendicular to the first axis. The machine also includes a control system coupled to at least one of the grinding wheel motor and the one or more skate holders, the control system operable to move the grinding wheel motor and/or the one or more skate holders relative to each other along any one of three directional axes to engage the grinding wheel with the skate blade, wherein the control system is further operable to rotate the grinding wheel motor and/or the one or more skate holders about the second axis to orient the grinding wheel in a first position relative to the one or more skate holders to cross-grind the skate blade, or a second position relative to the one or more skate holders that is longitudinally aligned with the skate blade to sharpen the skate blade.
Claims
1. An automated skate sharpening machine, comprising: a grinding wheel operable to rotate about a first axis by a grinding wheel motor; one or more skate holders to clamp a skate blade with its edge facing the grinding wheel; wherein at least one of the grinding wheel motor and the one or more skate holders are rotatable about a second axis perpendicular to the first axis; and a control system coupled to at least one of the grinding wheel motor and the one or more skate holders, the control system operable to move the grinding wheel motor and/or the one or more skate holders relative to each other along any one of three directional axes to engage the grinding wheel with the skate blade, wherein the control system is further operable to rotate the grinding wheel motor and/or the one or more skate holders about the second axis to orient the grinding wheel in a first position relative to the one or more skate holders to cross-grind the skate blade, or a second position relative to the one or more skate holders that is longitudinally aligned with the skate blade to sharpen the skate blade.
2. The machine of claim 1, comprising a pair of grinding wheels and a pair of control systems to enable multiple skates to be handled at the same time.
3. The machine of claim 2, wherein each grinding wheel is operable to be rotated between the first and second positions independently.
4. The machine of claim 2, wherein each grinding wheel is fixed or primarily held in one of the first position and the second position.
5. The machine of claim 1, wherein the control system is further operable to rotate the grinding wheel motor about the second axis to at least one intermediate position between the first position and the second position to increase a radius of the grinding wheel that engages the skate blade to provide a variable bite angle.
6. The machine of claim 1, wherein at least one of the one or more skate holders comprises a clamping mechanism, the clamping mechanism comprising a jaw opposite a rotatable anvil, the rotatable anvil comprising a plurality of sides, each side providing a different area of contact opposite the jaw to permit clamping skate blades of different lengths.
7. The machine of claim 6, wherein each side comprises a different length of contact.
8. The machine of claim 6, wherein each side comprises a discontinuous surface broken in at least one place along the corresponding side.
9. The machine of claim 1, wherein at least one of the one or more skate holders comprises at least one floating connection point, each floating connection point comprising a pair of opposing magnets of the same polarity to repel each other and oppose the weight of the skate holder and skate or blade clamped therein.
10. The machine of claim 1, further comprising a dressing bit, the machine being configured to engage the grinding wheel with the dressing bit to dress the grinding wheel.
11. The machine of claim 1, further comprising a form dressing wheel the machine being configured to engage the grinding wheel with the form dressing wheel to dress the grinding wheel.
12. The machine of claim 1, further comprising a fluid applicator to apply a fluid to the skate blade or the grinding wheel.
13. The machine of claim 1, further comprising a temperature sensor to measure a temperature of a skate blade being sharpened, the control system being further configured to adjust a skate sharpening process according to a measured temperature.
14. The machine of claim 1, wherein the control system is implemented using a computer numerical control (CNC) machine.
15. A method of automatically sharpening a skate blade, comprising: positioning a grinding wheel motor having a rotating grinding wheel or one or more skate holders clamping the skate blade relative to each other to achieve a first position to cross-grind the skate blade; moving the grinding wheel motor or one or more skate holders relative to one another to engage the grinding wheel with the skate blade to perform a cross-grinding operation; rotating the grinding wheel motor or the one or more skate holders to achieve a second position to sharpen the skate blade; and moving the griding wheel motor or one or more skate holders relative to one another to engage the grinding wheel with the skate blade to perform a sharpening operation.
16. The method of claim 15, further comprising engaging the grinding wheel with a dressing bit or form dressing wheel prior to performing the sharpening operation.
17. A method of applying a variable bite angle to a skate blade using the machine of claim 1, the method comprising: rotating a grinding wheel having been dressed with a first radius about a first axis, and engaging the grinding wheel with a first portion of the skate blade; rotating the one or more skate holders or the grinding wheel about a second axis that is perpendicular to the first axis by a first selected angle while continuing to rotate the grinding wheel about the first axis to enlarge the first radius to become a second radius, and continuing to engage the grinding wheel with a second portion of the skate blade to vary a bite angle between the first and second portions.
18. The method of claim 17, further comprising rotating the one or more skate holders or the grinding wheel about the second axis by a second selected angle to enlarge or reduce the second radius to provide a third radius and further vary the bite angle along a third portion of the blade.
19. The method of claim 18, repeated at least one additional time.
20. A computer readable medium storing computer executable instructions that when executed by a process cause an automated skate sharpening machine to automatically sharpening a skate blade, comprising instructions for: positioning a grinding wheel motor having a rotating grinding wheel or one or more skate holders clamping the skate blade relative to each other to achieve a first position to cross-grind the skate blade; moving the grinding wheel motor or one or more skate holders relative to one another to engage the grinding wheel with the skate blade to perform a cross-grinding operation; rotating the grinding wheel motor or the one or more skate holders to achieve a second position to sharpen the skate blade; and moving the griding wheel motor or one or more skate holders relative to one another to engage the grinding wheel with the skate blade to perform a sharpening operation.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Embodiments will now be described with reference to the appended drawings wherein:
[0031] FIG. 1 is a perspective view of an automated skate sharpening system.
[0032] FIG. 2 is a schematic view of an automated skate sharpening system in a cross-grinding/contouring configuration.
[0033] FIG. 3a illustrates a multiple radii contour.
[0034] FIG. 3b illustrates a skate blade radius of hollow.
[0035] FIGS. 3c, 3d, and 3e illustrate the pitch/lie of a skate blade.
[0036] FIG. 4a is a schematic view of an automated skate sharpening system in a sharpening configuration.
[0037] FIG. 4b is a schematic view of an automated skate sharpening system in a dual grinding wheel configuration with rotatable grinding wheels.
[0038] FIG. 4c is a schematic view of an automated skate sharpening system in a dual grinding wheel configuration with fixed grinding wheels in cross-grind and sharpening configurations.
[0039] FIGS. 5a and 5b illustrate varying the radius of hollow applied to a skate blade.
[0040] FIGS. 6a, 6b, and 6c illustrate a rotational movement applied to a grinding wheel to create a variable bite angle along the length of a skate blade.
[0041] FIGS. 7a, 7b, 7c, and 7d illustrate a variable bite angle using a grinding wheel dressed with a inch radius.
[0042] FIGS. 8a, 8b, 8c, and 8d illustrate a variable bite angle using a grinding wheel dressed with a inch radius.
[0043] FIG. 9 is a graph comparing effective radius to rotation angle in a variable bit angle process.
[0044] FIG. 10 is a perspective view of a skate holder.
[0045] FIG. 11 is an enlarged partial top view of a clamping portion of the skate holder of FIG. 10.
[0046] FIG. 12 is a top view of the skate holder of FIG. 10.
[0047] FIG. 13 is a front view of the skate holder of FIG. 10.
[0048] FIG. 14 is a front view with partial cross-section of the skate holder of FIG. 10.
[0049] FIG. 15 is an enlarged view of a floating mount for the skate holder of FIG. 10.
[0050] FIGS. 16, 17 and 18 illustrate a floating system for the skate holder.
[0051] FIG. 19 is a perspective view of the automated skate sharpening machine of FIG. 1 with panels removed to expose interior components.
[0052] FIG. 20 is a front view of the automated skate sharpening machine of FIG. 19.
[0053] FIG. 21 is a side view of the automated skate sharpening machine of FIG. 18.
[0054] FIG. 22 is a partial bottom perspective view of a portion of the automate skate sharpening machine of FIG. 18.
[0055] FIG. 23 is a flow chart illustrating a process for automate skate sharpening.
[0056] FIG. 24 is a flow chart illustrating a process for automated temperature control.
[0057] FIG. 25 is a flow chart illustrating a process for automated application of fluids and/or compounds prior to a finish pass operation.
[0058] FIG. 26 is a schematic block diagram illustrating an automated skate sharpener system in a different configuration in which a skate holder is moveable relative to a stationary rotatable grinding wheel.
DETAILED DESCRIPTION
[0059] In the following disclosure, the terms skate and ice skate may be used interchangeably and may generally refer to any type of ice skate, including, without limitation, a recreational skate, an ice hockey skate (of any size, such as youth, junior, senior), goalie skate, speed skate, or figure skate. The system described herein may therefore be used with, configured for, and adapted to sharpen any such skate or ice skate and reference to any of these terms is not meant to be limiting.
[0060] Referring now to the figures, FIG. 1 illustrates an automated skate sharpening system 10, which is embodied within a unit or housing, which may also be referred to herein as an automated skate sharpening machine, sharpening machine, or machine more generally and is given reference numeral 12. The system 10 may include the machine 12 and any accessory or feature that may be integrated with or be optionally attached thereto, including an exhaust system (not shown), peripheral computing devices such as point of sale or other retail equipment, etc. As such, the following may refer to the system 10 or the machine 12 interchangeably to refer generally to a unit, system, kit, or other combination of elements that perform the operations described herein. While shown as a standalone unit by way of example in FIG. 1, the system 10 may also integrate the machine 12 into an existing or customized retail bench or workstation (not shown) to accommodate a particular installation and use.
[0061] Further details of the machine 12 are described later but shown in FIG. 1 are a working surface 14 into which one or more skate holders 16 are integrated (a pair of skate holders 16 are shown in FIG. 1 by way of example). The skate holder 16, described in greater detail below, allows a user to clamp a skate or only the skate's blade (detached from the skate boot and holder) into place for an internally operable grinding wheel to come into contact with the blade for sharpening, cross-grinding and contouring operations as desired. While the skate holder 16 shown in FIG. 1 illustrates the example implementation described below (e.g., see FIG. 10) it can be appreciated that the machine 12 may instead utilize one or more fixed clamp-style skate holder (not shown). A front portion of the machine 12 in this example includes a control panel 18, which may be embodied using a touch screen, buttons, or a combination of the two. It can be appreciated that additionally, or alternatively, the control panel 18 may be implemented using a mobile app utilized on a user's mobile device (not shown). A viewing window 20 is also provided to enable the user to peer into the machine 12 during its operation. The viewing window 20 also enables diagnostics and maintenance requirements to be identified and observed.
[0062] FIG. 2 illustrates a schematic view of the machine 12 in a cross-grind configuration with various details omitted for ease of illustration. In this example schematic, a skate 22 is shown in a clamped position on the machine 12. The skate 22 includes a boot 24 to which a blade holder 26 or chassis is secured. The blade holder 26 can fixedly or removably hold a skate blade 28 as is known in the art. As such, the skate holder 16 can clamp the entire skate 22 or only the blade 28 when positioning the blade 28 towards the interior of the machine 12. The machine 12 houses a control system 30, which may also be referred to herein as a CNC system 30 to illustrate one particular example of such a control system 30. The system 30 includes a gantry 32 to permit longitudinal movement of a grinding wheel 38 along the length of the skate blade 28 as is illustrated using dashed lines for a first position compared to solid lines for a second position (further along the length of the skate blade 28 moving in a heel-to-toe direction). The gantry 32 can also permit transverse or crosswise movements to align the grinding wheel 38 with the skate blade 28 as described further below. The gantry 32 supports an extendible arm 34 that can move towards and retract away from the skate blade 28 for cross-grinding, sharpening and contouring operations as discussed further below. The arm 34 supports a grinding motor 36 that operates a grinding wheel 38. As illustrated in FIG. 2, the grinding wheel 38 rotates about a first axis (A1). The grinding motor 36 is also configured to be rotatable about an axis (A2) that is perpendicular to axis A1 to permit a variable bite angle to be applied as discussed in greater detail below. For a cross-grinding operation, the grinding wheel 38 is rotated about the axis A2 by 90 degrees relative to a sharpening position. Normal rotation of the grinding wheel 38 about axis A1 would apply the cross-grind to the skate blade 28 to remove the hollow. A CNC-type control system 30 that provides control in five (5) axes may be used, namely the standard XYZ Cartesian directions as well as a variable speed control about a grinding wheel spindle (i.e., axis A1) and a rotational axis about the radius of the grinding wheel (i.e., axis A2). Electronic components, including processors, memory, etc. may be located in an easy-to-access compartment within the machine 12 (e.g., below 112 shown in FIG. 19). For example, a drawer or compartment that extends or rotates outwardly towards the user may be provided to make the electronic components and software interfaces easily accessible for servicing, upgrades, etc.
[0063] Referring to FIG. 26, it can be appreciated that while the example shown in FIG. 2 and features described below include a moveable and rotatable grinding wheel 38 and grinding motor 36, other configurations are possible that enable movement of the grinding motor 36 and grinding wheel 38 relative to the skate holder 16 to perform sharpening and cross-grinding operations. For example, as shown in FIG. 26, the skate holder 16 may be moveable in both the X and Y directions toward, away and across the grinding wheel 38 to perform similar operations as described herein. In this example, the system 30 may still be rotatable about the axes A1 and A2. In other examples, both the skate holder 16 and the system 30 may be moveable and rotatable in any one or more of the directions and about any one or more of the axes shown to permit any combination of relative movements to bring a grinding wheel 38 towards and against a skate blade 28, e.g., as described in the examples below.
[0064] As is known in the art, a cross-grinding operation rotates the grinding wheel 38 across the skate blade's width to remove the edges and thus flatten the hollow. Cross-grinding is an optional process that may be used as a starting point prior to sharpening the skate blade 28. In the example shown in FIG. 2, the arm 34 and motor 36 may be moved along the gantry 32 from the heel of the skate blade 28 to the toe of the skate blade 28 while extending the arm 34 towards and away from the blade 28 according to the contour that has been applied to the blade 28. That is, the CNC control system 30 moves the grinding wheel 38 into a position that engages it with the skate blade 28 to apply the appropriate operation, in this case a cross-grinding operation that is not meant to change the contour but to follow it only to remove the edges and hollow of the blade 28 for a subsequent sharpening process. If the two-dimensional view shown in FIG. 2 provides the X and Y axes, the Z axis would be directed into and out of the image. The gantry 32 may therefore provide movement in both the X and Z directions to position the grinding wheel 38 relative to the skate blade 28 while the arm 34 provides movement in the Y direction to align or center the grinding wheel 38 relative to the skate blade 28 when rotated as shown in FIG. 4, described below. It can be appreciated that the CNC control system 30 can be programmed to move the grinding motor 36 towards, away from, and along the skate blade's length as a human operator would in applying the desired operation such as a cross-grinding or contouring operations shown in FIG. 2. Positioning and pressure applied to the skate blade 28 can be controlled using sensors utilized by the CNC control system 30, such as pressure (force) sensors, laser or other light sensor, vision (camera) analysis, etc. By integrating CNC-type control with the grinding motor 36 and grinding wheel 38, the machine 12 can be selectively configured to perform multiple skate sharpening operations.
[0065] For example, as shown in FIGS. 3a-3d, the same positioning shown in FIG. 2 can be used to apply a contouring process in which the grinding wheel 38 in a cross-grind position is applied to the skate blade 28 according to a varying contour along the length of the blade 28. FIG. 3a illustrates an example of a radius of contour (RoC), which refers to the lengthwise curvature of the skate blade 38. The RoC is often referred to as the profile or rocker of the blade and the process of defining a profile or rocker is referred to as contouring as mentioned above. Skates 22 commonly have a single radius of contour, for example, 9 foot or 11 foot. Contouring systems that are currently available can be used to optimize performance by applying multiple radii or more complex shapes to skates, such as the 9 foot/2 foot/10 foot profile shown in FIG. 3a. In this way, a pitch (or lie) can be created by moving the apex or balance point of the blade 28 forward or backward. When a skater is standing erect, they should be directly on the high point of the contour, balanced between falling forward or backward. A player's role or position typically dictates a preference for the pitch/lie, with defensive players often choosing a backward lie and offensive players choosing a neutral or forward pitch/lie. The blade pitch or lie is shown in FIG. 3e.
[0066] The RoC, pitch and the radius of hollow (RoH)shown in FIG. 3bmay be considered 2D concepts projected onto a 3D object (i.e., the skate blade). For discussion purposes, consider the 3D cartesian XYZ representation of the skate 28 shown in FIG. 3c. In this figure, the ice surface itself is the plane formed by the X and Y axes (Z=0), and the Z-axis is perpendicular to the tangent of the blade contour (i.e., blade tangent is parallel to the ice). This representation maps to that shown in FIG. 2 relative to the grinding wheel 38. The origin is located at the point of contact with the ice surface, assumed for convenience to also be at the balance point (apex) of the skate 22. The origin could theoretically be located at other points along the blade 28 when they are in contact with the ice, for example near the toe as shown in FIG. 3d (e.g., while pushing off during stride).
[0067] Using this framework, the contour (profile/rocker) of the blade 28 is effectively the 2D shape (i.e. cross-section) of the blade in the YZ-plane, when the origin is located at the apex. It remains constant regardless of where you intersect this plane along the X-axis (within the width of the blade itself). Blade pitch (or lie) is achieved by translating a given contour (i.e., 2D shape in YZ plane) either positively or negatively in the Y-axis:
[0068] (Contour_pitched {X,Y,Z}.fwdarw.Contour_orig {X,Y+offset,Z}, whereas other solutions may have modelled pitch as a rotation of a given contour about the X-axis to achieve a similar effect (i.e., change the natural lie of the skate).
[0069] The RoH is the inverse of the shape of the grinding wheel 38, which is applied or imparted on the skate blade 28 when sharpened (i.e., is not required to be a radius). It has been demonstrated that the significant variable that affects skating performance is the bite angle (), or the angle between the blade groove surface tangent and the ice surface. Smaller radii have larger (i.e., less acute) bite angles, resulting in the blade digging deeper into the ice, increasing control during maneuvers while simultaneously increasing drag. Thus, the historical trade-off between bite and glide when varying the RoH. Less conventional shapes (e.g., BFD, FBV, or Z-channel) maintain that this trade-off can be minimized, but they all principally vary the bite angle to effect changes in blade performance.
[0070] The RoH is effectively the 2D shape (cross-section) of the blade surface in the XZ-plane (shown at Y=0 in FIG. 3c). With the grinding wheel 38 positioned in the traditional manner, this shape also remains constant (and therefore so does the bite angle) if the origin (i.e., point of intersection with the ice) is located at other points along the blade contour (see FIG. 3d). For completeness, the cross-section in the XY-plane is irrelevant to this discussion since its 2D representation of the blade 28 would simply be two dots (points), each the width of the blade itself, at the point of contact with the ice (i.e., Z=0).
[0071] The CNC control system 30 can therefore be programmed, when in the position shown in FIG. 2, to move the arm 34 and grinding motor 36 towards and away from the skate blade 28 in a manner that applies a desired RoC to the blade 28, which would include removing more blade material along portions than others, compared to an evenly applied removal that results from a cross-grinding operation.
[0072] The ability to rotate the griding motor 36 and thus the grinding wheel 38 about axis A2 permits an automatic reconfiguration between the cross-grinding/contouring position shown in FIG. 2, and the sharpening position shown in FIG. 4. As shown in both FIGS. 2 and 4, a housing or other element of the grinding motor 36, or some other moveable object within the machine 12 may support a temperature sensor 58, e.g., an infrared temperature sensor to measure the temperature of the blade 28 to determine if certain temperature thresholds have been exceeded. Operations utilizing the temperature sensor 58 are described below in relation to FIG. 24. Also shown is a fluid/compound applicator 59, shown as being mounted on/with the grinding motor 36 for ease of illustration only. Such an applicator 59 can be mounted in any suitable configuration or be mounted on a separate arm or other element to enable a lubricant, compound or other fluid to be applied to the skate blade 28 or to the grinding wheel(s) 38, as discussed further below in connection with FIG. 25.
[0073] Referring now to FIG. 4a, at step 1 illustrated in dashed lines, the arm 34 and grinding motor 36 are rotated 90 degrees about axis A2 and moved to the heel position at step 2, also shown in dashed lines. It can be seen that the axis A1 (in dashed lines) also rotates with the grinding motor 36 such that it aligns with the Z axis shown in the image. At step 2, the axis A1 is therefore directed into or out of the page as illustrated. In this way, the grinding wheel 38 rotates in the longitudinal direction of the skate blade 38 in contrast to the transverse or crosswise direction in the cross-grinding position. The outer shape of the grinding wheel 38, commonly referred to as the radius (although can take other shapes and contours), will then impart a RoH onto the blade as illustrated in FIGS. 5a and 5b. As illustrated in FIG. 5a, the blade 28, when sharpened, includes a RoH (R), a depth of hollow (D), and a thickness (T). The enlarged view in FIG. 5b illustrates that the same blade 28 having a thickness T can be sharpened to have different RoHs, e.g., 0.25 (or inch), 0.5 (or inch), and 0.75 (or inch) as shown. The RoH is imparted based on the convex surface of the grinding wheel 38, which is normally applied using a dressing tool 50. Such a dressing tool 50 is shown schematically in FIGS. 2 and 4 for illustrative purposes, which includes a dressing bit 52 that is arcuately applied over the edge of the grinding wheel 38 to impart the desired curvature that will impart the desired RoH as is known in the art. The dressing tool 50 in this example may be movable relative to the CNC control system 30 to interact with the grinding wheel 38 or the grinding wheel 38 may be brought into contact with the dressing bit 50 using an arcuate path executed by the control system 30.
[0074] While not shown in FIG. 4a, it can be appreciated that step 2 may include a dressing sub-step in which the grinding wheel 38 is brought into contact with the dressing bit 52 prior to moving the wheel 38 into contact with the blade 28 for the sharpening operation at step 3. It can also be appreciated that while the machine 12 shown herein includes a dressing bit 52 and a grinding wheel 38 that is capable of being dressed to utilize different ROHs, the machine 12 may be adapted to use diamond or other abrasive-coated wheels that do not require dressing and have a constant unchangeable hollow. In such an implementation, the grinding wheel 38 would either have a fixed hollow or be changeable with other wheels 38 that have other fixed hollows. This may include incorporating an automated wheel changer (not shown), similar to a tool-changer used on a CNC machine to determine, obtain, and change a diamond-coated (i.e., non-dressable) wheel from a catalogue of coated-abrasive wheels, each being prepared with a certain desired hollow. In this way, the machine 12 may be configured to select different wheel compositions for different purposes. For example, for contouring it may be desired to use a very aggressive wheel to remove material more quickly. Moreover, as shown in FIG. 4b, when multiple grinding wheels 38 are used at the same time, each could use a different diamond or abrasive-coated wheel that does not require dressing.
[0075] Similarly, as shown in FIGS. 2 and 4, alternatively, or additionally, a form-dresser 54 that operates a form dressing wheel 56 may be utilized by the machine 12. For example, one or more form dressers 54 may be mounted inside the machine 12 for the wheel 38 to contact and dress. It may be noted that form dressing wheels 56 are particularly flexible in terms of what shapes can be imparted on the wheel 38 as an alternative to the dressing bit 52 that may have restricted geometry. Both a dressing bit 52 and one or more form dressers 54 may be incorporated as desired to provide additional flexibility, namely to allow both flexible ROH application and the use of other shapes such as a flat bottom profiles.
[0076] Step 3 involves moving the grinding motor 36 and grinding wheel 38 towards and away from the blade 28 to make contact with and impart the desired RoH by controlling the CNC control system 30 similar to how a human operator would pass the grinding wheel 38 longitudinally along the blade 28 in a manual sharpening process. It can be appreciated that the system 30 may include a suitable processor or other computing device, e.g., single-board computer with custom software located and/or mounted in any suitable or convenient location. Moreover, the gantry 32, arm 34 and grinding motor 36 can utilize, for example, open-loop stepper motors 120 (see FIGS. 18-21 described below) to enable movement along all axes with the exception of the spindle (axis A1) which is provided by the rotation of the grinding motor 36. It can be appreciated that close-loop servo controllers may also be used, as well as any actuator that is configurable to provide similar operations.
[0077] Accordingly, the CNC-type control of the control system 30 enables the grinding wheel 38 to be operated in its intended manner (i.e., to rotate as intended), to be rotated about axis A2 in order to switch between cross-grinding/contouring (FIG. 2) and sharpening (FIG. 4a) positions, to move towards and away from the skate blade 28 and follow an intended path (i.e., to create a contour or to follow such a contour), and to align the grinding wheel's curvature with the skate blade 28 to center the wheel 38 with the blade 28 and thus apply even edges. The degrees of freedom provided by the control system 30 therefore enable automated operation of the machine 12 in a manner that mimics a manual skate sharpening process with additional accuracy by avoiding human error and leveraging any sensor data available.
[0078] In other embodiments, the machine 12 may be adapted to include multiple control systems 30 each operating a respective grinding wheel 38. For example, as shown in FIG. 4b, a first control system 30a operating a first grinding wheel 38a and a second control system 30b operating a second grinding wheel 38b are included in the same machine 12 to enable the machine 12 to sharpen a pair of skates 22 at the same time, each being clamped in a respective skate holder 16a, 16b. In this example, each control system 30 can rotate the grinding wheel 38a, 38b (e.g., as shown in FIGS. 2 and 4a) between cross-grind and sharpening configurations to independently handle two skates at the same time.
[0079] In another example, shown in FIG. 4c, a first control system 30a with a first grinding wheel 38a is fixed (or primarily held in the) sharpening position while a second control system 30b with a second grinding wheel 38b is fixed (or primarily held in the) cross-grind/contouring position. In this example a single skate 22 and skate holder 16 are shown, but it can be appreciated that the control systems 30a, 30b may be operable to move about the interior of the machine 12 such that even if held fixed can handle two (or more) skates at the same time, advantageously a pair of skates 22.
[0080] Referring now to FIGS. 6-9, the CNC-type control system 30 also enables intermediate rotational positions (about axis A2) that enable what may be referred to herein as a variable bite angle or VBA along the length of a skate blade. As discussed above and illustrated in FIG. 3b, the bite angle is defined by the angle between the blade groove surface tangent and the ice surface. The VBA can be adopted using the machine 12 to provide another degree of freedom to the skater by allowing them to vary the bite angle and therefore the degree of bite/glide at different locations (L) along the contour of the blade 28.
[0081] Only a portion of the blade surface is in contact with the ice at any given time. Different areas of the blade 28 may be more critical than others for certain skating motions (e.g., gliding, pushing off, crossovers, stopping, etc.), or may not even be used at all. Therefore, it follows that a constant bite angle throughout the entire blade contour may be sub-optimal for skating performance. Precisely how the bite angle should be varied may be determined based on the biomechanics of skating. When determined, the control system 30 may be programmed to impart varying angular positions about axis A2 to have the grinding wheel 38 impart a varying bite angle.
[0082] Varying the bite angle along the contour of the blade 28 presents certain technical challenges. First, when considering physically imparting the variable bite angle it is noted that current skate sharpening machines using traditional bonded abrasive (or diamond-coated) wheels which are dressed (or machined) with a single constant shape to impart on the blade. As such, the bite angle cannot be changed without redressing (or replacing) the grinding wheel. Second, smooth transitions between bite angles should be provided. Given that the skate blade 28 glides across the ice, bumps/edges/steps or anything other than smooth transitions should be avoided as the bite angle changes. The control system 30 and rotatable grinding motor 36 described herein can be further adapted to overcome these challenges to impart a VBA.
[0083] The mechanism is shown schematically in a simplified illustration in FIGS. 6a-6c. It can be appreciated that the illustrations shown in FIGS. 6a-6c are not to scale and certain proportions may be exaggerated for the purpose of illustrating the mechanism by which the VBA can be applied. Referring to FIG. 6a, the grinding wheel 38 in this view is in the normal or perpendicular alignment in which the curvature (C) of the edge of the grinding wheel 38 is imparted onto the edge of the skate blade 28 according to the dressing applied. For example, if the grinding wheel 38 is dressed at a 0.5 or inch radius, a corresponding RoH would be applied to the skate blade 28. In FIG. 6a the portion of the skate blade 28 that receives the dressed RoH is referred to as length L1.
[0084] Referring now to FIG. 6b, by rotating the grinding wheel 38 about axis A2 the curvature C changes to C, which has a larger radius or gentler curve as the face 60 of the grinding wheel 38 enlarges the curvature to become C. The change between C and C is dictated by the angle of rotation about axis A2 as described in more detail below. Consequently, the length of blade L2 receives a different bite angle than L1. FIG. 6c illustrates that a partial reverse rotation about axis A2 can create yet another curvature C that provides more of a bite angle than L2 along length L3 but less of a bite angle than along L1. The control system 30 can therefore rotate the grinding motor 36 and grinding wheel 38 about axis A2 while moving along the gantry 32 during a sharpening operation (e.g., see FIG. 4) according to transition points that dictate the interfaces between L1, L2 and L3 in this example. It can be appreciated that while three length portions are shown in FIG. 6, more or fewer may be utilized according to the desired sharpening geometry. The control system 30 can leverage its smooth operability through the transitions to avoid bumps or ledges along the blade 28 via fine-tuned motor control. Such fine-tuned control can be determined by executing calibration routines.
[0085] It is therefore proposed that both aforementioned challenges with applying a VBA can be addressed using a traditional grinding wheel 38, dressed (or machined) at a constant and conventional radius (e.g. inch), by gradually rotating the grinding wheel 38 about its radius by an angle (). FIGS. 7a-7d depict this for a wheel dressed at a inch radius, where the rotation angle () is 5 degrees. The consequent change in the effective bite angle imparted on the blade 28 is the equivalent to that imparted by a wheel dressed with a radius of 0.503
[0086] While this example includes only a minor variation in bite angle, it can be appreciated that at increasing angles of rotation (), the difference is exaggerated. FIGS. 8a-8d illustrate an angle () of 30 degrees for a wheel dressed originally at inch (0.375). From this image it can be seen that the effective width of the blade is increased from 0.110 (standard) to 0.816, and the bite angle is now equivalent to that imparted by a wheel dressed at 0.481 (i.e., nearly ). It may be noted that most experienced skaters (e.g., hockey players) can readily feel the difference between and and thus such a variation would be considered meaningful.
[0087] From a practical standpoint, it should be noted that by varying the wheel angle () the machine 12 increases the effective radius of the dressed wheel 38. The equivalent bite angle is consequently reduced (made more acute), resulting in an edge that is less sharp (has lower bite). Therefore, to complete a blade sharpening the wheel 38 should be dressed at the lowest desired radius (i.e., the sharpest setting) and rotated wherever higher radii (less bite) is needed. An example range as to how much the effective radius can be increased by rotating the grinding wheel, as shown in FIG. 9 and Table 1 below.
TABLE-US-00001 TABLE 1 Effective Radius vs. Rotation Angle () Original Angle of Rotation (, degrees) 0 5 10 15 20 25 30 35 40 45 0.375 0.378 0.385 0.398 0.418 0.445 0.481 0.529 0.592 0.675 0.5 0.503 0.513 0.531 0.556 0.591 0.638 0.699 0.778 0.883 0.625 0.629 0.641 0.662 0.693 0.735 0.79 0.863 0.956 1.077 0.75 0.755 0.769 0.793 0.828 0.877 0.94 1.022 1.127 1.261
[0088] Regarding the desired smooth transitions between different bite angles, geometric and mathematical treatments can be used to determine suitable angles and transitions. Once determined, these can be pre-programmed into the machine's memory such that the computer can access predetermined VBA profiles that provide the desired transition. It may be noted that so long as the wheel is rotated smoothly during a sharpening pass this should result in smooth features along the blade surface. Corresponding speeds/feeds can be determined during development and calibration stages to store the logic used to impart the desired transitions.
[0089] The control system 30 provides the ability to perform various blade inspection and validation operations. By adopting CNC control (e.g., axis resolution<0.001), coupled with a laser distance sensor, there exists an opportunity, with a high degree of precision, to both (a) inspect an incoming blade 28 and (b) validate the result of sharpening/contouring afterwards. In this way, various manual tools can be automated in the machine 12, for example, a squaring tool to check level/squareness of blade edges, a hollow depth indicator to measure the depth of hollow (to determine radius), a blade straightness checker to measure blade straightness along a contour, a contour gauge which provides a template gauge to identify/match contour, and a boot gauge to locate a balance point and contour end points.
[0090] Additionally, the control system 30 can be leveraged to indicate when a blade needs to be contoured by calculating how far it deviates from a desired shape (e.g., 9). The control system 30 may detect the skate cowling and thus measure the blade height, giving the operator an indication of remaining useful blade life.
[0091] Each of the capabilities above can be used for validating operation success (sharpening or contouring), or for self-testing (e.g., in a production or quality control environment). These functions may also be useful for sales/marketing and training purposes.
[0092] It is also recognized that there exists minimal information in the public domain that helps a skater/player determine how they should customize their blade. Instead, there are various general guidelines that offer nothing definitive, only suggestions. Examples include that heavier players should use larger radii (shallower depth of hollow); that younger, more inexperienced skaters should use a smaller (sharper) radius of hollow; defensive players should pitch their blades backwards, offensives players forward; or shorter contours (e.g., 9 vs. 11) allow for more agility, longer contours more speed.
[0093] The computing capabilities of the machine 12 and its control system 30 may also be leveraged to provide an expert system (or wizard) that, upon collecting some basic player information, could recommend a solution for each blade characteristic. Such a system might ask for a player's height, weight, age, position, skill level, boot size, type of steel, or what they want to change about their existing sharpening (e.g., I want more straight-line speed or I want to corner better). Some parameters could also be measured automatically and a library or other database of sharpening routines could be accessed along with any stored player profiles to apply an overall sharpening routine that applies or fixes a desired contour, and sharpens the skates to a desired bite angle including any VBA that is to be applied.
[0094] Additionally, the machine 12 and control system 30 may be equipped with network connectivity to enable the computing system to capture and record skater preferences and store these preferences in a database. For example, the computing system could also be used to, in effect, capture and record skater blade preferences. Preferences and parameters to track and record might include RoH, contour, pitch, player position, boot size, skate/steel make/model, etc. Such a database can be used to provide automated sharpening services at various locations (e.g., skater can apply their preferences regardless which location they use). The variables and parameters may also be used anonymously to refine sharpening routines to update the library of logic control operations used to apply certain variations in sharpening techniques.
[0095] Normally, many players are not very familiar with what they put on their blades, relying on a store operator to decide for them what is most appropriate (many simply default to a RoH). Operators, rather than ask a player their preferences, could then measure the incoming blade with various tools, or could simply look up in a database what is required for this customer. That database may be located onboard the machine 12, be located online, or stored/keyed based on a barcode sticker on the boot (or alternatively an RFID tag). That is, various methods can be employed to determine, store and access preference-related information for a skater that can be used at various machines 12 in a connected ecosystem or individually where applicable.
[0096] Referring now to FIGS. 10-17, the skate holder 16 is shown in greater detail. The skate holder 16 clamps the skat blade 28 (with or without the rest of the skate 22) in place above the grinding wheel 38 to enable the control system 30 to bring the grinding wheel 38 to the skate blade 28 and contact same as discussed above. The skate holder 16 provides a floating clamp and a variable length anvil 76 for clamping skate blades 28 of different sizes (i.e., whether the blade 28 is clamped on its own or currently in a cowling attached to the boot). FIG. 10 illustrates a perspective view of the skate holder 16 in isolation. The skate holder 16 includes a clamp frame 70 which defines an opening 72 into which the blade 28 of a skate 22 is inserted to be clamped in place. The clamping mechanism is provided by a movable jaw 74 and a variable length anvil 76. The anvil 76 has a plurality of rotatable positions each providing a different side. Each side provides a different amount of clamping area to accommodate skate blades 28 of different lengths. The anvil 76 is connected to a selector knob 80 via a flexible shaft 82. The selector knob 80 is supported by a mounting block 78 that can be secured to the upper surface 14 of the machine 12. By turning the selector knob 80, the flexible shaft 82 rotates the anvil 76 to a desired position. Each position provides a different length anvil for clamping the skate blade 28. The variable length capability allows skate blades 28 of varying lengths to be accommodated by the same machine 12. In this example, lengths of 4, 6, and 8 are available by their corresponding sides. FIG. 11 provides a closer view of the anvil 76. Referring to FIGS. 10 and 11, a clamping assembly 86 is also shown, which includes a die spring 90 to provide pressure on the blade 28. Pulling a clamp handle 88 down and away from center will open the jaw 74 relative to the anvil 76 to allow the blade 28 to be inserted.
[0097] FIG. 10 also illustrates a floating arm connection 84, which provides a floating connection between the skate holder 16 and the machine 12. The floating connection includes a number of other components described below. The clamp frame 70 therefore sits within an opening in the upper surface 14 of the machine using a floating connection to enable the skate holder 16 to simulate how a manual grinding process occurs, using the mass of the clamp frame 70 (with or without a clamped skate 22 and/or blade 28) and with the assistance of gravity as discussed further below.
[0098] FIG. 12 provides a top view and FIG. 13 a side view of the skate holder 16. From the top view, the variably sided anvil 76 can be observed. By providing different lengths, the amount of contact surface and thus support of the blade 28 can be varied to account for the length of the blade, for example, for youth versus senior sizes, goalie skates, figure skates, etc. It can be appreciated that the rotating variable length anvil 76 and other features of the skate holder 16 can also be applied to standalone skate holders used with manual or semi-manual machines.
[0099] Additionally referring to FIGS. 14 and 15, the floating connection will now be described in further detail. As seen in FIG. 13, the floating arm connection 84 includes a base portion 98 that secures to the upper surface 14 of the machine 12 and an upper end that connects to an end portion 94 of the holder frame 70. The end portion 94 hangs over a pair of magnet holders 96 also seen in FIGS. 14 and 15. Magnets 100 are positioned opposite each other with like poles facing each other repel each other at four corners of the frame 70 to offset the mass of the skate blade 28 and frame 70 to provide the floating effect. That is, the base portion 98 and magnet holders 96 are secured to the upper surface of the machine 12 and the arm connection 84 positions the frame 70 above the magnet holders 96 and spanning the opening in the upper surface 14. It can be appreciated that a similar connection is provided on the opposite side of the frame 70 as shown in the figures. FIGS. 16 and 17 illustrate cross-sections of the ends of the arm connections 84, which include a forward facing dowel pin 110 and horizontal pins 112 to keep the clamp frame in a known range of vertical positioning. This in turn will allow the frame to react to a grinding wheel 38 while it touches the blade 28, ensuring an even pressure being applied to the blade 28. FIG. 18 provides another view of the floating system. In this view, it can be appreciated that the pair of horizontal pins 112 restrict movement in the forward and reverse directions, while the forward facing pin 110 restricts left to right movement. These allow the movement of the frame 70 to float while restricting the motion in certain axes.
[0100] FIGS. 19-22 illustrate an example of a configuration for the machine 12 based on the form factor shown in FIG. 1 and by adopting and integrating the features described herein. Referring to FIG. 19, a perspective view of a skate sharpening system 10 is shown, which includes a skate sharpening machine 12. As with the examples provided above, the system 10 may include other components such as an exhaust system and interfaces with retail equipment and/or shop bench, etc., details of which are omitted here for clarity of illustration. The machine 12 includes an internal shelf 112 which supports the gantry 32. The gantry utilizes a first (stepper/servo/hybrid/other actuator) motor 120a to control longitudinal movement (relative to the skate blade 28not shown in FIG. 19) and a second controlled motor 120b for crosswise or transverse movements. This enables the gantry 32 to move the arm 34 along the Z and X axes as shown in FIGS. 2 and 4 to move the grinding wheel 38 along the blade 28 and to center the grinding wheel 38 therewith.
[0101] The arm 34 extends upwardly from the gantry 32 within the machine's body and utilizes a third controlled motor 120c to permit movement towards and away from the skate blade 28 as discussed above. This causes the arm 34 to extend upwardly and retract downwardly relative to the gantry 32. The arm 34 can be telescopic or utilize another configuration that permits it to extend and retract. The grinding motor 36 is supported at the distal end of the arm 34 as shown in FIG. 19 and includes a fourth controlled motor 120d to permit the grinding motor 36 to rotate about axis A2, e.g., to switch between cross-grinding/contouring and sharpening configurations and/or to permit intermediate rotations for applying a VBA to the skate blade 28.
[0102] FIG. 19 also illustrates the upper surface 14 through which a pair of skate holders 16a, 16b is positioned to enable a pair of skate blades 28 to be clamped at a given time. FIG. 20 provides a front view of the machine 12, which illustrates the area of travel in the X and Y directions, which permits the grinding wheel 38 to be aligned with a skate blade 28 that has been mounted in a skate holder 16a/16b and to travel along the length of the blade 28 to perform the various operations described above. FIG. 21 provides a side view of the machine 12, which illustrates the area of travel in the Z and Y directions to permit the grinding wheel 38 to be centered with the skate blade 28 and to permit rotation of the grinding motor 36. FIG. 19 also shows a dressing tool 50 and dressing bit 52 that is mounted at the upper surface 14 and projects into the machine 12. This positions the bit 52 in an area that permits the stepper motors 120a-120c to move the grinding wheel 38 over the bit 52 to dress the wheel to the desired radius by moving the grinding wheel 38 across the bit 52 in the Z and Y axes as appropriate to impart the desired radius or for more complicated shapes/provides such as FBV or BFD. The dressing tool 50 includes a knob (also referred to as a quill) to permit the bit 52 to be rotated about the axis of the quill to expose fresh facets of the diamond used for the bit 52 as it wears. FIG. 22 provides a partial bottom perspective view that further illustrates the positioning of the dressing tool 50 and bit 52 relative to the grinding wheel 38.
[0103] FIG. 22 also illustrates a rotatable collar 130 that is driven by the fourth motor 120d to permit the grinding motor 36 and grinding wheel 38 to be rotated about axis A2. It can be appreciated that while the motors 120 are embodied as stepper motors 120a-120d in this example, any suitable actuator may be used to permit the translational and rotational movements of the control system 30 described herein.
[0104] FIG. 23 provides a flow chart illustrating example operations that may be performed by the control system 30 in executing a sharpening sequence.
[0105] At block 200 the machine 12 determined the parameters to be used for the automated sharpening routine to be executed. This may include stored parameters from a stored customer (e.g., player) profile 202 and/or one or more inputs 204 received from an app or the control panel 18. For example, the input(s) 204 and/or profile 202 may specify a desired ROH, whether cross grinding is desired, and whether the blades 28 are to be contoured (e.g., change in contour or contouring for new blades 28).
[0106] At block 206, the machine 12 determines whether a sharpening routine(S) has been requested, or if a contouring routine (C) has been requested. It can be appreciated that, as described below, a contouring routine may lead to a subsequent sharpening routine and may or may not include a cross grinding operation depending on the current state of the blades 28. At block 208, when a sharpening routine(S) is determined, the user or operator may also have indicated that a cross grind operation is to be applied prior to sharpening. While cross grinding is optional, some operators or users may desired to have their blades 28 subjected to cross grinding prior to sharpening.
[0107] At block 210, the machine 12 positions the grinding wheel 38 (if necessary) in the cross grind orientation as shown in FIG. 2 and executes the cross grind operations at block 212. Once the cross grinding has been applied, the machine 12 rotates the grinding wheel 38 to the sharpening position at block 214 and determines the ROH to be applied to the blade(s) 28. As shown in FIG. 23, if a cross grind operation is not executed, the machine may skip to block 214 to orient the grinding wheel 38 and determine the ROH for the upcoming sharpening operation. At block 216, the control system 30 moves the grinding wheel 38 across the bit 52 as discussed above, to dress the grinding wheel 38 to provide the desired ROH.
[0108] At block 218, the sharpening operations are applied to the blades 28, e.g., as described above and shown in FIG. 4. It can be appreciated that block 218 may, optionally, include the application of a VBA, wherein the sharpening operation would include additional rotational movements of the grinding wheel 38 about axis A2.
[0109] At block 220, the machine 12 has been instructed to perform contouring operations. Since a contour can be applied to either new or used blades 28, the machine first orients the grinding wheel 38 in the cross grind/contouring orientation (if necessary). If the blades 28 are used or otherwise require a cross grinding routine, this may be executed at block 222 (optionally as illustrated in dashed lines).
[0110] At block 224, the machine 12 determines the ROC (or multiple ROCs) to be applied to the blade(s) 28 and executes the contouring operations at block 226. Since the blades 28 would be flat at this stage, the machine 12 may determined at block 228 whether the user or operator has selected that the contoured blades 28 be sharpened. If not, the process ends at block 230. If so, control may advance to block 214 to have the sharpening operations executed as discussed above.
[0111] It can be appreciated that the operations shown in FIG. 23 are illustrative and may be repeated stepwise or at the routine level for multiple skates 28 that are currently loaded in the machine 12. That is, the routine(s) shown in FIG. 23 can be adapted to be applied in the same manner to multiple skate blades 28 in a given session. Subsequent to block 230, various other operations may be performed, such as updating a player profile, applying charges (e.g., via a point of sale system), data logs collected, etc.
[0112] Referring now to FIG. 24, as noted above, optimal grinding may be implemented by way of temperature monitoring and control. For example, the temperature sensor 58 may be positioned and operated to read the temperature of the blade 28 during the sharpening and/or contouring operations. The temperature readings can be provided as a feedback variable to the operator but may also be used for automated temperature-based control as illustrated in FIG. 24. For example, the control system 30 may be configured to adjust the feed/speed rates of the grinding wheel 38 or may introduce a delay to allow the blade temperature to lower in temperature and prevent present maximum or problematic temperatures from being exceed. At block 300, the control system 30 obtains a temperature reading for the skate blade 28 being sharpened or contoured. At block 302, the control system 30 determines if a temperature threshold has been exceeded. If not, it may continue monitoring temperature at block 300. If a temperature threshold is met or exceeded at block 302, the control system 30 may; then adjust the feed/speed rates and/or execute a delay at block 304. The adjustments and/or delays may be preprogrammed depending on the type of operation, type of blade material, operator preferences, etc.
[0113] Referring to FIG. 25, as noted above, a sharpening process (e.g., as executed at block 218 in FIG. 23) may include several passes of the grinding wheel 38 along the blade 28 and a final finish pass operation. Optimal grinding may also make use of lubricants or other anti-weld fluids, compounds or other products applied during the sharpening process. Such products can be used to apply a polish as well as to treat the blade to inhibit rust among other things. As shown in FIG. 25, at block 310, one or more sharpening passes may be executed to perform the sharpening operation and apply a ROH or other bottom profile. At block 312, one or more finishing fluids or compounds can be applied to the blade(s) 28 and/or grinding wheel(s) 38, e.g., using applicator 59 shown in FIGS. 2 and 4a. At block 314, following the application of the fluids/compounds, a finish pass may be executed to complete the sharpening process. As such, the application of other grinding sub-steps may be integrated into the control system 30 and machine 12 in general to automate operations normally applied manually by an operator.
[0114] For simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the examples described herein. However, it will be understood by those of ordinary skill in the art that the examples described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the examples described herein. Also, the description is not to be considered as limiting the scope of the examples described herein.
[0115] It will be appreciated that the examples and corresponding diagrams used herein are for illustrative purposes only. Different configurations and terminology can be used without departing from the principles expressed herein. For instance, components and modules can be added, deleted, modified, or arranged with differing connections without departing from these principles.
[0116] It will also be appreciated that any module or component exemplified herein that executes instructions may include or otherwise have access to computer readable media such as transitory or non-transitory storage media, computer storage media, or data storage devices (removable and/or non-removable) such as, for example, magnetic disks, optical disks, or tape. Computer storage media may include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data. Examples of computer storage media include RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transitory computer readable medium which can be used to store the desired information and which can be accessed by an application, module, or both. Any such computer storage media may be part of the skate sharpening system 10, any component of or related thereto, etc., or accessible or connectable thereto. Any application or module herein described may be implemented using computer readable/executable instructions that may be stored or otherwise held by such computer readable media.
[0117] The steps or operations in the flow charts and diagrams described herein are provided by way of example. There may be many variations to these steps or operations without departing from the principles discussed above. For instance, the steps may be performed in a differing order, or steps may be added, deleted, or modified.
[0118] Although the above principles have been described with reference to certain specific examples, various modifications thereof will be apparent to those skilled in the art as having regard to the appended claims in view of the specification as a whole.
