It is usually desired to minimize the mass of any footwear and this is especially true for footwear used in competitive sports such as ice hockey and figure skating. The mass of a steel blade conventionally used for ice skates is significant and comprises a large component of the mass of the overall skate assembly. Strip-blade technology has been used for many years, an example of such a blade technology is described in U.S. Pat. Nos. 2,150,964 and 3,947,050 which are incorporated by reference herein in their entireties, and whereby the strip-blade is hooked or otherwise connected at each end and tensioned over the rocker of the strip-blade holder. As described by these patents, tension in the strip-blade is required to meet the desired requirements of skating.
Prior art strip-blade technologies utilized relatively massive and complex blade tensioning mechanisms. As a result, this technology does not offer a significant weight reduction. The pre-sharpened strip-blades are typically sold in pairs at retail stores and vending machines to be mounted by consumers on skates equipped with the special mounting fixture and blade-tensioning device. The technology has gained limited popularity based upon other benefits, as follows. The strip-blades are made available to consumers at a price approximately the same as it costs to sharpen conventional skates that utilize conventional single piece steel blades. As such, the strips are typically disposed after they become dull from use. The consumer then replaces the dulled strip-blades with newly purchased pre-sharpened strip-blades. It is thus more convenient for the consumer to use the strip-blades then to have his or her skates re-sharpened. Furthermore, the pre-sharpened strip-blades are typically sharpened on accurate and repeatable factory machines that provide much higher reliability in sharpening quality then the sharpening typically done at ice rinks, arenas, and sporting goods shops—usually by unskilled operators utilizing poor equipment.
Thus, the strip-blade technology provides a convenient and preferred method of procuring high quality sharp blades over conventional re-sharpening. This is important because reliable blade sharpness is a key factor for consistent, maximum performance for hockey and figure skating, for example. Spare strip-blades can be kept on hand, ready for use as soon as blades in use become dull. This avoids the undesired consequence of skating on dull blades because the skater was unaware of the need to sharpen his or her skates. This occurs frequently because the rate of dulling is variable, as it depends on many factors, and thus knowing when to re-sharpen is unpredictable. Replaceable strip-blade technology provides an immediate fix to dull skate blades, even during a game or competition, whereas conventional sharpening technology is employed after the event—when it is too late. It also saves time otherwise waiting for skates to be sharpened.
The degree of success of the strip-blade technology has been limited due primarily to complexities in design in the holder and tensioning devices that resulted in excessive cost to manufacture and devices that are not convenient to use. Examples of such holder and tensioning devices are described in U.S. Pat. Nos. 2,108,128; 5,383,674; and 5,988,683, which are incorporated by reference herein in their entireties.
Apparatus for attaching a replaceable blade to an ice skate, comprises a holder adapted to be mounted to a boot. The holder includes a fixed first portion and a second portion pivotally mounted to the first portion. The first and second portions include respective receptacles for receiving a first end and a second end of the replaceable blade, respectively. The replaceable blade is under tension when the second portion is aligned with the first portion, and the second portion is at an angle with respect to the first portion when the replaceable blade is free from tension. The holder has a member for fixing the second portion in alignment with the first portion.
U.S. Provisional Patent Application Nos. 60/519,435 filed Nov. 12, 2003, 60/588,823 filed Jul. 16, 2004, and 60/604,664, filed Aug. 26, 2004 are incorporated by reference herein in their entireties.
An embodiment described herein reduces the mass of the steel blade by utilizing a smaller height strip-blade fastened to the bottom of a lightweight holder made of material such as aluminum or other materials such as steel with lightening (i.e., weight reducing) holes, for example. The use of replacement strip blades allows for larger lightening holes than conventional blades that require re-sharpening due to the fact that lightening holes for conventional blades reduce the life of the blade by reducing the number of sharpenings allowed before the edge sharpened by grinding reaches the lightening holes.
The exemplary embodiment overcomes prior art complexities by providing a superior means for blade removal, replacement and tensioning by utilizing a much simpler, convenient, design. The exemplary device provides for removal, replacement and tensioning that is integral to the removable strip-blade holder that takes the place typically occupied by a conventional solid steel or stainless steel blade. However, the exemplary embodiment is not limited to the same thickness and could be thicker or thinner, and could have a variety of profile shapes, other than the conventional skate blades rectangular profile.
The exemplary embodiment overcomes difficult design requirements. For example, the relatively high tensions required for the strip-blade, and the requirement for quick easy mounting, makes it difficult to conceive of any apparatus, device, or method to apply and maintain this tension in the very tight space of the skate strip-blade holder. The problem is made much more inconceivable given the fact that any tensioning device most likely will be subjected to high impact loading and high stresses during its use in hockey or figure skating, for example. In addition, the skate blade holder described below can be directly fastened to current skate plastic superstructure, designs, as described in U.S. Pat. No. 4,074,909 (which is incorporated by reference herein in its entirety), and number #14 in FIG. 1 of that patent, without having to change the molded skate plastic superstructure. This direct fastening reduces the cost to consumers to utilize strip-blade technology over designs requiring the removal of the plastic superstructure. In addition the blade holder described herein provides for unlatching of the tensioned strip-blades using a commonly available prying instrument such as a common screwdriver. Some embodiments are used in conjunction with a prying instrument by shaping a tab on the end of the strip-blade. In the preferred embodiment, means are provided for tensioning the strip-blade by exploiting the moment arm provided by the rear segment and a strategically positioned pivot. The arrangement minimizes the forces required to tension and latch the strip-blade. Preferably, the weight of the skater provides the means to tension the strip as he or she presses down on the heel of the strip-blade holder assembly to tension and automatically latch the strip-blade. A simple levering hand tool can also be used to tension and latch the assembly.
The mass of the preferred embodiment as specified herein for size 10 hockey skates was found to permit about a 50% reduction in mass over a conventional steel blade.
For the exemplary embodiment described herein, as shown in
In a preferred embodiment, automatic latching is provided as follows: Latch 113 is preferably made of spring steel, such as hardened C1050 steel to Rockwell C45-C50, for example, or high tensile drawn 302 stainless steel wire, for example, and is composed of spring-arm 115, tab 116 and hook 117, shown in
The geometry of the pivot and hook slots is such that the majority of the reaction-force to tension from strip-blade 102 is carried by pin 118 because the force vector from the tensioned strip-blade passes in close proximity of pivot point 106. Latch 113 carries the light bending forces in strip-blade 102 and any minor load component resolved perpendicular to the aforementioned majority force vector that passes through pivot point 106. This arrangement results in a light latching force required, which make for easy unlatching of latch tab 116 in hole 114. Prying from behind spring-arm 115 at gap 119 with a prying instrument such as a common screwdriver unlatches the latch. Once unlatched, rear segment 105 pivots by hand around pin 118 thus releasing tension on strip-blade 102 and provides for strip-blade to be removed and replaced by hand. Once the new strip-blade is hooked at 109 and 110, tension in the strip-blade is preferably applied by the skater applying his or her weight force on the heel of the skate until latch 113 automatically latches, as described above. The relatively high tension force in the strip-blade of approximately 250 pounds is applied with a relatively low weight force due to the strategic arrangement of pivot 106 and slot 109 which provides levered advantage.
A preferred ice skate assembly is shown in
Components are preferably assembled as follows: A superstructure (which may be conventional molded plastic superstructure 101 or other superstructure) is fastened (for example, with rivets 121) to skate boot 100. Front segment 104 of blade holder 103 is fastened to plastic superstructure 101 as conventionally done for example, utilizing 2 screws (not shown) or preferably using screw 122 or tab 123 as illustrated in
A preferred method of removing replaceable strip-blade 102 is as follows: any suitable prying tool 137, such as a common screw driver, as shown, is inserted into gap 119 between segment 105 and under latch spring-arm 115. Alternatively, a convenient prying tool can be made by grinding a flat prying section 138 on the end of the replacement strip-blade as shown in
A preferred method of installing replacement strip-blade 102 is a two step process as follows: The first step is for the skater to sit on a chair or bench, for instance, with the skate on his or her foot with strip-blade 102 removed from holder 103. He or she securely takes hold of rear holder segment 105 between index finger and thumb and opens it by rotating it approximately 45 degrees out of slot 130 and around pinned connection 131. This effectively shortens the distance between hook connection slots 109 and 110 of blade holder 103. New strip-blade 102 is hooked, by hand, into the ends of blade holder 103 at slots 109 and 110. Rear segment 105 is then partially closed by rotating it by hand upward to increase the distance between hook connections 109 and 110. This is done while ensuring tongue 139 enters groove 140 during rotation until tension is felt as a result of strip-blade 102 limiting rotational travel of rear segment 102 due to the-geometric relationship of specific components, as described below. Combined friction from the tongue and groove connection 141; latch tab face 135 pressing on rear segment face 136; and rear segment snuggly entering groove 130 of plastic superstructure 101 effectively holds the position of rear segment. At this point the assembly is ready for the second and final step for tension to be applied to strip-blade 102 and latching of latch 113. To accomplish this next and final step, the skater, stands up and, with their weight, presses the heel of the skate blade 142 against any firm surface, such as the floor they are standing on. This action continues closing rotation of rear segment 105 as tongue 139 enters groove 140 along the entire mating length of the strip-blade and strip-blade holder and rear segment 105 fully enters groove 130 of plastic superstructure 101. Tension to strip-blade 102 is thus applied, as described in detail below, until tab 116 aligns with mating hole 114. At this point in the rotation approximately 250 pounds-forces tension resides in strip-blade 102 and tab 116 automatically enters hole 114 by the force supplied by the elastic pre-load bending of latch spring-arm 115. Tab 116 enters hole 114 until the inner surface of spring-arm 115 stops by contact with side face 136 of rear segment 105. At this point, hook 117 at the end of tab 116 elastically sprints up to catch on the exit end of hole 114 at 143 to provide a latching of latch 113. Effectively at this home point, rear segment 105 is latched by latch 113 and latch 113 is latched by hook 117 to form a double latch. This double latch protects against latch 113 from being dislodged by any impact to blade assembly 98.
Tensioning of strip-blade 102 occurs during the closing of rear segment, as described above, due to specific geometric relationships between the components of holder assembly 98, as follows. As rear segment 105 is closed, the distance between slots 109 and 110 increases past the distance between crotches 111 and 112 of strip-blade 102 thus straining strip-blade 102 to tension it.
Alternative methods of closing segment 105 may be used by anyone skilled in the art of mechanical design. Such methods may include, for example, the use of pliers type tools conventionally used to extract retaining ring fasteners, for example (not shown). These types of tools provide for high leveraged mechanical advantage that overcomes the forces to close segment 105. Holes (not shown) to accept the tips of such tools would be required on either side of split 108 segment in the area between tangent arc 144 and notch 146. The exemplary method, as described herein, avoids the need and associated cost of such tools. Also, if the person is strong enough to apply approximately 30 pounds-force by hand, tensioning and latching can be accomplished by arm force.
Alternative latching means may also replace the latching means as described above. Such means may include a separate latch or key to hold closed segment 105 in the closed position. Such latch might straddle splits 108 in the area between tangent arc 144 and notch 146. Such separate latching devices are not required to be automatic and may require manual insertion. They may be completely detachable.
More detailed descriptions of both the preferred embodiments and other exemplary embodiments are described below.
A preferred strip-blade holder assembly 98 is comprised of components as follows: subassembly holder 103 comprising of segments 105 and 104; pin 118; and, latch 113. It is preferred to have the holder assembly 98 the approximate same height, length and thickness dimensions as a conventional new steel blade, but other dimensions may be used. Length is variable and dependent on size and type of skate. A smaller height holder assembly 98 is possible and may be desired for reduced weight or reduced stresses but it may be more difficult to provide space for slots 109 and 110 and space for latch 113. Holes 147 in holder 103 might be preferred if reduced weight is desired, but holes 147 are not necessary for functionality. Front segment 104 is connected to plastic superstructure 101 using the fasteners designed for use with the particular plastic superstructure. This fastening is typically accomplished using either two screws as described in U.S. Pat. No. 4,074,909 or a single screw and tab 123 as shown in
Removal of the holder assembly 98 from the plastic superstructure 101, as illustrated, is accomplished as follows: Threaded nut 125 is unscrewed and removed from screw 122. Holder assembly 98 is pulled by hand from its snug fit in plastic superstructure slot 130, pulling the attached screw 122 with it through passage 126. The holder assembly 98 is simultaneously pulled axially forward to unhook tab 123 from its receiving cavity 128 in plastic superstructure 101. Replacement of holder assembly 98 to plastic superstructure 101 is the reverse of the aforesaid operations to remove it. When a front screw is used (not shown) in place of tab 123, the plastic superstructure 101 is first removed from the sole of the boot 100 by removing rivet fasteners 121, typically used, for example.
In the preferred embodiment, rear segment 105 is connected to front segment 104 through a pinned connection 132, to provide a secured pivot. Holder 103 has a constant thickness (which may be approximately 0.115″), depending upon the particular plastic superstructure used, along its length to fit into plastic superstructure slot 130 as described above. An exemplary pinning design, as illustrated in
The preferred clevis design is shown in
Other clevis or hinge connection designs may be used by someone skilled in the art of design.
Pinned connection 132 provides pivot rotation and retention of rear segment 105 when strip-blade 102 is removed. Pinned connection 132 also prevents segment 105 from pulling out of groove 130 if a pulling force to strip-blade 102 is ever applies when strip-blade 102 is installed and tensioned. As mentioned above, connection 132 provides a means to rotate rear segment 105 to effectively shorten the length of holder 103 to facilitate removal and replacement of strip-blade 102, as described above.
Other pivot arrangement (not shown) are possible, for example whereby clevis 132 is removed resulting in rear segment 105 to bear on front segment 105 at arced radius bearing surface. In this embodiment, front segment 104 is shaped to provide a matched radius bearing surface 154. This bearing surface and arrangement provides for unsecured pivot rotation or rear segment. The rear segment 105 can be completely detached after strip-blade 102 is removed. The preferred clevis 132, as mentioned above, provides for secured pivoting of rear segment 105.
A variation of the above pivot design is shown in
The thickness of a portion 119 of segment 104 surrounding pin 118 is less than (e.g., approximately one half of) the thickness of the major portion 104t of segment 104. The major portion 104t includes all of segment 104t except the lightening holes, tongue 139 (
As illustrated, the mating interleaving faces (158 mating with 159, and 119 mating with 149) in the two areas on the two segments 104 and 105 oppose each other, as shown, to provide joint rigidity to the assembled segments 104 to 105 when the faces 158 and 159 are engaged. This engagement occurs by rotating segment 105 around pin 118 into a latched position. This interleaving arrangement provides exceptional strength at this pivoting clevis or hinge.
Also shown in
In these alternative embodiments, latch 113 is oriented such that the spring latching action, as described above for other embodiments, is in the plane of the strip blade holder 103. As illustrated in
Although other locations are possible, the preferred location for pivot point 106 is as shown in
The free-body force diagram as shown in
By inspection of the free-body diagram of
Many standard materials and methods of fabrication are possible for holder 103 with varying degrees of cost and performance. The design must provide for stresses anticipated, including the compressive load at pivot point 106 and latch 113. Anyone skilled in calculation of stresses and selection of materials and manufacturing process can effectively evaluate and determine preferred materials and methods of manufacture depending on desired specific material strength and stiffness and cost. Generally a preferred material for holder 103 is 6061 T6 aluminum for cost effectiveness, machinability and material properties such as flexural modulus and strength. It can be machined using a standard milling machine or CNC milling machine, for example. Such material can be anodized or coated to a variety of colors, if desired. Any other suitable material or alloy can be used such as magnesium, titanium or steel in virtually any grade. A preferred such stainless steel traditionally used for ice skate blades is 12C-27 supplied by Sandvik A B, located at SE-811-81 Sandviken, Sweden, hardened to 40 to 60 on the Rockwell C scale. Other material options include molded thermoset composite material such as glass epoxy, carbon epoxy, or molded thermoplastic composite material such as glass nylon, glass polycarbonate, carbon nylon, carbon polycarbonate, for example. Either continuous strand composite or chopped long or short fiber composites are possible materials. Other materials such as molded or milled non-reinforced thermoplastic material or wood could be used in limited light duty applications as they do not offer the preferred specific strength and modulus offered by metal alloys and composites.
The shape of the bottom of the holder 103 in terms of rocker can take any desired shape while strip-blade 102 is made to conform to follow this shape either flexibly or exactly. Connection of strip-blade 102 to holder 103 at the ends can be accomplished by any of the methods described in the referenced patents, for example.
Alternative locations for pivot 106 and latch 113 are possible and one such exemplary arrangement is shown in
It is preferred to manufacture holder assembly 103 by automated methods using single flow processing whereby parts progress continuously in a single flow pattern through a series of process steps. An exemplary method is as follows: sheet metal, in final thickness form from coil stock is straightened and leveled (preferred), or from blank stock from a magazine supply, for example, is fed by conveyor (preferred) or robot, for example, into a stamping press (preferred) or numerically controlled (CNC) mill, for example. In the press, or mill, all edge surfaces are cut except for the bottom edge with tongue 139, but including all holes. From the press, a conveyor (preferred) or robot, for example, transports the partially cut stock, to the next process step, whereby clevis assemblies as shown in
As shown in
The clip 113′ (as described with reference to
A pull handle bend 300′ (
Although the invention has been described in terms of exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly, to include other variants and embodiments, which may be made by those skilled in the art without departing from the scope and range of equivalents of the invention.
This application claims the benefit of U.S. Provisional Patent Application Nos. 60/519,435 filed Nov. 12, 2003, 60/588,823 filed Jul. 16, 2004, and 60/604,664, filed Aug. 26, 2004.
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/IB04/04458 | 11/12/2004 | WO | 3/7/2007 |
Number | Date | Country | |
---|---|---|---|
60519435 | Nov 2003 | US | |
60588823 | Jul 2004 | US | |
60604664 | Aug 2004 | US |