The current disclosure is generally directed at skates and more specifically, the current disclosure is directed at a skate blade system with dynamic movement.
Skates, such as figure skates, hockey skates or roller skates, are commonly used by individuals who either compete in ice sports or wish to exercise. With ice skates, such as hockey or figure skates, the users glide along an ice surface to move from one location to the next. For roller skates, the users typically skate along a smooth surface although other surfaces may be traversed.
The technology behind skates has been ever improving, however, many companies developing and selling skates have been focusing on increasing skating speed by reducing the weight of their skates.
The main drawback to this strategy is that limits are being reached in mechanical strength and weight of the utilized materials. For example, two millimeters of carbon fiber may offer the same strength as four millimeters of plastic and weigh half the amount. However, there may not be adequate material that can be used to replace carbon fiber for increased weight reduction in subsequent designs. As a result the required strength and thicknesses of skate materials are being pushed to their limits, leaving little room for optimization in subsequent models. This transition to significantly lighter materials has also resulted in a more expensive product for the customer. Many companies developing and selling skates have been focusing on increasing skating speed by reducing the weight of their skates.
Therefore, there is provided a novel skate blade system with dynamic movement.
The disclosure is directed at a skate system with dynamic movement.
In one embodiment, the disclosure is directed at a skate system which may increase skating speed through a more efficient usage of the skater's energy. In this embodiment, the disclosed skate system stores a portion of the user's input energy which would otherwise be lost in cracking the ice or dissipated through the user's joints and then provides the stored energy back to the skater in order to help propel them in the desired direction. One advantage of this system is that less input energy from the user will be converted into wasted energy and the user's skating technique may become more efficient.
In another embodiment, the skate system generates longer contact durations between the blade portion and the ice surface due to the deflection of energy storage within the skate system. This increased contact time will result in a greater change in momentum.
In a further embodiment, the skate system absorbs impacts to reduce joint damage by storing impact energy and later supplying the stored energy as a propulsive force. In a preferred embodiment, the disclosed skate system reduces joint damage by absorbing a portion of the impact energy generated when the user's foot comes into contact with the ice surface. Through absorbing a portion of this impact, less energy will be transmitted and dissipated through the user's joints. The skate system may also utilize the stored impact energy to propel the user forward as their foot leaves the ice surface and the device is unloaded (where the blade is no longer in contact with the ice surface).
In one aspect of the disclosure, there is provided a skate system which improves skating speed while providing impact absorption to reduce joint damage and player fatigue in a safe and reliable manner.
In another aspect, the disclosure provides a skate system which is as safe as current skates and is able to withstand vertical forces from a skater's feet impacting the ice surface, lateral forces from a skater attempting to stop and turn, and longitudinal forces generated by friction resistance and hitting bumps in the ice surface.
In another aspect, there is provided a skate system which requires little or no maintenance whereby the skate blade is easy to detach and reattach to the blade housing, or skate blade holder, should it ever need replacing.
In yet a further embodiment, there is provided a skate blade system including a boot portion; a blade housing, mounted to a bottom of the boot portion; and a blade portion having a heel and a toe end; wherein the blade portion is fastened at the heel end to the blade housing in a fixed relationship and is not engaged in a fixed relationship to the blade housing at the toe end.
Embodiments of the present disclosure will now be described by way of example only, with reference to the attached Figures.
a to 12c are schematic diagrams of a cantilever embodiment of a blade portion and blade housing;
d is a perspective view of an alternative embodiment of a blade housing for use with the cantilever embodiment of
e is a perspective view of a fastener block for use with the blade housing of
f is a side view of the blade housing of
g is a side view of the blade housing of
a to 13e are schematic diagrams of a spring mechanism embodiment of a blade portion and blade housing;
a is a side view of a further embodiment of a blade portion;
b is a perspective view of the embodiment of
c is a perspective view of the embodiment of
d is a perspective view of the embodiment of
e is a side view of the embodiment of
f is a perspective view of the blade portion of
f is a side view of a spring mechanism embodiment with a cut out portion for viewing purposes;
g is a side view of a spring mechanism embodiment with a cut out portion for viewing purposes and the blade portion outlined;
a to 16c are side views of further embodiments of blade portions for use with the cantilever embodiment; and
The current disclosure is directed at a skate blade system with dynamic movement. The skate blade system includes a skate having a boot portion and a blade portion. The blade portion is connected to the boot portion via a mechanical mechanism that allows for dynamic movement of the blade portion with respect to the boot portion when the skate is in use. More specifically, the blade portion is housed within a blade housing located at a bottom of the boot portion as will be described below. In a preferred embodiment, the blade portion is easily accessible when the skate is not in use which also allows for simple blade removal or attachment.
Turning to
As shown in
In current technology, the majority of hockey skate manufacturing companies utilize two different designs to attach the blade portion 14 to the blade housing 16.
In a first design (as shown in
In a second design, as schematically shown in
Turning to
When the skate is loaded such that the user is applying pressure on the blade portion 14 such as during use, the blade portion 14 rotates and compresses the spring portion 30 thereby storing mechanical energy within the spring portion 30. When the skate is unloaded such that the user is not applying pressure on the blade portion 14, the spring portion 30 will return to its equilibrium position and use the stored energy to propel the user in the desired direction.
One advantage of the spring mechanism embodiment is that energy and fatigue calculations are easy to calculate, especially if a metallic compression spring is used as the spring mechanism.
Turning to
In the current embodiment, a bracket 36 includes one end which slides into the groove 32 and a second end which is secured to a bottom of the blade housing via fasteners 38 (shown in dotted lines in
Turning to
The advantages of the cross flexure joint embodiment include, but are not limited to, the fact that the pivoting motion can be achieved through the deflection of two fixed struts such that the design does not need lubrication.
Turning to
Advantages of this design include, but are not limited to, easier maintenance and serviceability of the components when repair is necessary. Also, through simple loosening a couple fasteners (integrating the blade portion and the blade housing), the blade portion can be quickly and easily detached. The deflection of the blade can also be modeled in finite element method programs to estimate the blade deflection. Finally, various blade profiles can be created for different skate users.
Turning to
The effects of torsion and shear deformation on the pin will result in a pivoting motion of the blade portion about the center point of the pin. This design can easily be assembled and disassembled should maintenance be required. Furthermore, this design only requires a small number of parts to be manufactured, which results in a low cost for production.
Turning to
One advantage of the torsional spring embodiment includes the benefit of being able to use different springs or to interchange different rated springs for different users.
Turning to
In a preferred embodiment, the leaf spring deflects and store mechanical energy when loaded and when the skate is unloaded, the leaf spring will spring back to its original position and the stored energy will be provided back to the user.
The advantages of this embodiment include that the blade can easily be removed by removing the fastener which is connected through the hole 56 in the heel end 24. The user can also remove the fasteners which connect the leaf spring to the blade housing in order to change the leaf spring if they prefer to use a leaf spring with a lower or higher rating.
Turning to
When the skater loads the skate, the piston, or tab 64, which is engaged with the chamber 66 moves to decrease the volume of material 68 in the chamber 66, thus increasing the pressure of the contained material 68 within the chamber 66. When the skate is unloaded, the tab 64 lowers and the material 68 will return to an equilibrium pressure and the resulting change in pressure would increase the volume of the chamber. The increase in volume would in turn push the tab 64 which would push the blade portion of the skate, giving the user a propulsive force in the desired direction. One advantage of this system is that the initial equilibrium pressure level of fluid can be set to an appropriate pressure for each user.
Turning to
In
The profile height of the blade portion may be adjusted in order to achieve the desired skate blade deflection and mass requirements for various users. As potential customers may weigh between 0-135 kg (0-300 lbs), different blade portions may be designed such that each blade will deflect a nominal amount when loaded to reduce impacts in the users joints and provide a propulsive force to the user. For example, if a light user was using a skate blade designed for much higher loadings, then the blade will not deflect very much and thus would not store as much energy.
For example, three different blade portions can be designed; one for users between 0-45 kg (0-100 lbs), another for users between 45-90 kg (100-200 lbs), and a third for users between 90-135 kg (200-300 lbs). These blade designs can be seen in the
In assembly of the blade portion and the blade housing, the blade portion 14 is preferably attached to the blade housing 16 via a pair of threaded fasteners 74 (see
The cantilever embodiment allows the profile of the blade portion 14 to deflect and store mechanical energy when loaded. Through fixing the heel end 24 of the blade portion 14 to the blade housing 16, the entire length of the blade portion will deflect when loaded. The deflection of the beam or blade portion will be proportional to the cross sectional area, moment of inertia, and material properties of the blade. When the skate is unloaded the blade portion will spring back to its original geometry and the stored mechanical energy will be used to propel the user in the desired direction.
Further advantages of the cantilever embodiment include, but are not limited to, that the maintenance and serviceability of the components will be easy for the user. Through simply loosening a couple fasteners, the blade portion can be detached. The deflection of the blade can also be modeled in finite element method programs to estimate the blade deflection.
In a preferred embodiment, the blade portion for this cantilever embodiment has been designed to have similar amounts of secured surface area within the holder as current skate blades, however, the surface area will change as the blade height changes to accommodate for different users. Each of these blades preferably have a protruding portion at the toe end 28 which will allow to blade portion to remain secured in the slot 73 of the blade housing 16. Without this protruding portion extending into the blade housing, the blade portion may be susceptible to twisting and bending in the horizontal or lateral direction. Furthermore, this small protrusion 72 allows for the blade portion to remain aligned with the blade housing and will not shift laterally. The cantilever embodiment preferably includes an adequate amount of secured blade surface area within the blade housing to withstand anticipated loads in the lateral direction.
d is a perspective view of another embodiment of a blade housing 16 for use with a cantilever embodiment. Within the blade housing 16 is a cut-out portion 200 for receiving a fastener block 202 (such as the one shown in
A side view of the fastener block 202 inserted into the blade housing 16 is shown in
Turning to
As shown in
Current blade housings gradually increase in width as they continue upwards from the blade portion towards their connection point to the boot portion. Due to this tapered geometry, the spring mechanism 80 may require an attachment (such as the extension portion 88) to connect the blade portion 14 with the spring portion 86. This will allow the spring portion 86 to be mounted closer to the boot portion where more space is available.
In one specific embodiment, which is not meant to be narrowing with respect to the overall scope of the disclosure, the blade portion could be attached to the blade housing with a threaded fastener fastened through the hole 76 at the heel end. At the toe end, the extension portion 88 engages with the blade portion 14. The spring mechanism which houses the spring could be riveted along with the housing to the bottom of the boot portion to ensure it is securely fixed.
In other embodiments, different springs with different spring ratings or spring sizes could be utilized (potentially with different adaptor sizes to house and attach the spring portion). Furthermore, in order to withstand the anticipated loads in the axial and transverse directions, for both the cantilever and spring mechanism embodiments (
Although designed for use with ice skates, the spring model chosen is also applicable to figure skates, roller skates, Rollerblades™, which could utilize the same blade holder integrated with wheels.
Turning to
c is a perspective view of a blade portion 14 with the extension portion 88 mounted.
The dynamic nature and operation of the spring mechanism and therefore the skate is described above with respect to
In general, to improve skate dynamics, It is advantageous for the skate blade system of the disclosure to increase the amount of contact time in which the blade portion is on the ice as seen in the Linear Impulse of Momentum equation below.
∫t1t2Force*dt=Mass*ΔVelocity
Through increasing dt (the duration of time in which the blade portion is in contact with the ice), increases in the user's change in velocity will be obtained, allowing them to accelerate faster and reach higher maximum speeds.
The motions in skating and running are very similar and result in comparative forces in the individual's body. Studies have proven that the repeated impact forces on a runner's foot can reach three times their body weight. The accelerometer data depicted that the maximum absolute acceleration of the skater was 25 m/s2. It is expected that high caliber and professional hockey players could accelerate up to 30 m/s2, which would generate impact forces approximately three times their body weight. Note that the accelerometer was located at the skater's sternum to accurately approximate their centre of gravity.
In order to determine a maximum repeated force which a skate or blade portion would need to withstand, the maximum acceleration of a skater would need to be multiplied by the maximum weight of the skater as shown through Newton's Second Law below.
Force=Mass*Acceleration
For a skater that weighs approximately 125 kg, multiplying the maximum expected mass of 125 kg by the maximum expected acceleration of 30 m/s2 one can determine that a skate will have to endure repeated loads of 3750N.
In this case, for the cantilever embodiment, blade deflection can be found through finite element analysis due to the abnormal blade geometry. In some experiments, the finite element simulations predicted the needed clearance between the top of the blade portion and the bottom of the blade housing along the length of the blade portion. Hand calculations for a constant cross section cantilever beam were also performed to get a rough deflection estimate and can be seen in the Figures. A strength analysis of the fasteners and the blade housing were also conducted to determine the safety factor from shearing, bending, and bearing failure.
Finite element analysis was conducted to observe the maximum stresses and amount of deflection in the cantilever blade profile. The profile of a blade portion for use in the cantilever embodiment was fixed and a load was applied at the tip of the blade portion. As can be seen, the maximum stresses were located at the filleted region where the blade increases in area to allow for the fasteners to connect it to the holder. The fillet could be adjusted to save weight, while at the same time ensuring that the maximum stresses are below the material's yield strength. The finite element analysis is shown in
For the spring mechanism embodiment, it is desired that the spring mechanism does not deflect such that the user is unable to remain balanced and skate securely. Too much deflection may require longer adaptive periods for the user due to the increased instability. The selected spring should also fit into the blade housing without needing to modify the housing to reduce the cost of manufacturing a skate and also so that this skate blade system with dynamic movement may be fitted into existing skates. Note that the spring material could be longer if it were smaller in diameter or shorter if it were wider in diameter.
In order to determine a preferred spring, fatigue failure and energy calculations were performed on the spring. The maximum spring energy storage was calculated to be 4.7 J based off a 5.1 mm deflection at a 1855N applied load. The stresses experienced during the dynamic loading of 1855N will allow for infinite spring life.
Furthermore, with respect to the spring mechanism embodiment, individual components for each mechanism were selected from different options. For the spring mechanism, there are various components that can be chosen as fasteners for the blade portion and the blade housing, fasteners for the blade housing and the boot portion, and various types and materials of springs can be used.
In other words, the fasteners for fastening the blade portion to the blade housing via the hole may be a nut and bolt combination, a fastener or a hinge. The apparatus for mounting the blade housing to the bottom of the boot portion may be accomplished via a rivet, a set of screws or adhesives. Finally, the material for the spring may preferably be selected from a metallic spring, a non-metallic spring, a compressible material or a piece of polymer which has spring-like properties.
In the preferred embodiment, the spring mechanism embodiment uses a chrome-silicone closed and ground steel spring, blind hole screw fasteners, and rivet connectors.
The above-described embodiments are intended to be examples only. Alterations, modifications and variations can be effected to the particular embodiments by those of skill in the art without departing from the scope, which is defined solely by the claims appended hereto.
This application claims the benefit of U.S. Provisional Application No. 61/784,436 filed Mar. 14, 2013 which is hereby incorporated by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/CA2014/050220 | 3/12/2014 | WO | 00 |
Number | Date | Country | |
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61784436 | Mar 2013 | US |