TRI-POINT SKATE BOOT

Abstract: A roller skate comprising a frame, a plurality of wheels rotatably mounted to said frame, a boot connected to said frame, wherein said boot comprises a sole provided with three force transmission points adapted to transmit the force exerted by the skater's foot to the frame. The points substantially correspond to the heel, the first metatarsal and the fifth metatarsal of a wearer's foot of said boot. The points are provided with cushions or reinforcements. The invention also provides a cushion adapted to the roller skate of the invention.

Description: TRI-POINT SKATE BOOT FIELD OF THE INVENTION The present invention relates to skate boots and more particularly to in-line roller skate boots having an improved sole and frame design. BACKGROUND OF THE INVENTION Over the past few years roller skating and particularly inline roller skating has enjoyed an immense resurgence in popularity. No longer limited to indoor rings specifically designed for that purpose, skating today has become an outdoor leisure activity, an economic and healthy means of transportation, and a competitive sport. The changes in the nature of skating have necessitated appropriate changes in the design and manufacture of skates themselves. Today's skaters demand skates which are much lighter in weight and easier to control than the bi-axle quad-wheeled skates of the past. The original design of modern in-line skates was relatively simple. Generally, such skates consisted of a wheel frame attached to a skate boot. The skate boot itself was customarily based on either an ice skate boot or a downhill ski boot. While the former had a relatively flat sole interfacing with the planar surface of the foot and was made of conventional material such as a thermoplastic rubber, the latter was typically a molded plastic boot with an integral structure. Conventional roller skate boots comprise a boot upper attached to a sole. The sole interfaces with the plantar surface of the foot and protects it, while the boot upper surrounds and secures the remaining portions of the foot instep (e.g. dorsal portion). Soles may either be formed from a layer of a single material or from several layers of a single or different materials. In the latter case, the layers are bonded together to form a laminate. In both cases, at any particular point on the sole, the matehal(s) of which the sole is formed is (are) identical to those at every (or almost every) other point on the sole. The wheel frame typically consisted of two parallel rails connected by a bridging portion to form a long inverted "U"-shaped structure. The wheels would be mounted within the frame by being rotatably mounted on the rails. The bridging portion served to connect the rails together and it was a point of attachment for the wheel frame to the skate boot too. In this respect, the bridging portion was also generally flat, would interface with the underside of the boot sole and be secured thereto by suitable fasteners, such as bolts or rivets. A relatively thin planar attachment plate might have been placed between the frame and the sole in some skates. It has been realized that an important consequence of this construction is that the bridging portion serves as the point of force transfer between the boot and the wheel frame. However, this construction is not optimal for several reasons. Biomechanical studies have shown that the entire weight of the body rests on three points: the heel, the first metatarsal and the fifth metatarsal. These points are thus important for the skater as they represent the points of force transmission from his body to the skate. When the skater is in a static position, the weight is generally distributed as follows: 45% on the heel, 40% on the first metatarsal and 15% on the fifth metatarsal. During the skater's movement, the weight distribution between these points shifts. By shifting his weight between these points, the skater can control his movement. That is one of the main means for movement control. So for the skater, these points are definitely important as they represent the zones of transmission of the force necessary to his movement. The bridging portion of conventional wheel frames however generally interfaces with the sole of the skate at two different places. The first place is a forward point generally in the ball region of the foot, and the second place is a rearward point generally in the middle of the heel portion of the foot. Thus, some of the forces generated by the skater will be wasted in the flexion of the sole about the bridging portion instead of being transmitted to the frame and to the skating surface. It has been realized that in order to avoid wasting the skater's energy in the flexion of the sole, the sole should generally be made of rigid material. Rigid materials, however, may or may not be desired specifically at the force transmission points depending on the degree of "feel" (absorption / transmission) sought. Furthermore, it may be wished to have different levels of absorption/transmission at each of the force transmission points. Preferably, the point of force transfer from the skater to the skate should be as near the skating surface as possible in order to allow the greatest possible control. Transferring force at the bridging portion thus represents a significant loss of control. Thus, there is a need in the industry to provide a skate boot and an in-line roller skate allowing a more efficient transfer of force between the foot and the frame and that alleviates the drawbacks of prior art designs. OBJECTS AND STATEMENTS OF THE INVENTION It is thus an object of the present invention to provide a skate boot and an in-line roller skate with such a design that it can allow a more efficient transfer of force between the skater's feet and the skating surface as compared with conventional boots. It is another object of the present invention to provide a skate boot and an in-line roller skate that takes the fundamentals of the foot biomechanics into consideration. A further aim of the present invention is to provide a skate boot and an inline roller skate that offers the skater the possibility to modify some of the most important skating characteristics of his skates, for instance performance and comfort. As embodied and broadly described herein, the present invention provides a roller skate comprising a frame, a plurality of wheels rotatably mounted to said frame, a boot connected to said frame, wherein said boot comprises a sole provided with three force transmission (or transfer or contact) points adapted to transmit the force exerted by the skater's foot to the frame. Heretofore it has been recognized that the material of which the skate boot sole is made is important for skating performance and control. However, it has not previously been sought to optimize the sole design by varying the material at each of the force transmission points in relation to other points. By doing so, the skater's force or energy is more easily transmitted to the skate frame while providing improved efficiency. Advantageously, the points substantially correspond to the heel, the first metatarsal and the fifth metatarsal of a wearer's foot. According to the biomechanical tests performed by the inventors, these points are of major importance with relation to the force produced by the skater's foot. The present invention provides a mechanical link between these points and the frame of the skate. Thus, more force or energy can be transmitted to the skating surface, resulting in more power and speed. According to a first preferred embodiment, said points are provided with cushions. These cushions provide many advantages. For instance, they can be made of almost any type of material like plastic, rubber, metal or the like, or any combination thereof. With such a large flexibility, many types of rigidity, hardness or even to some extend damping can be provided. Depending on the desired characteristics of the skate, more or less force transmission or absorption may be obtained in using appropriate cushions. A more rigid material absorbs less energy and transmits more force. A resilient material absorbs more energy and thus transmits less force. However, a more resilient material absorbs shocks and vibrations and can thus provide increased comfort for the skater. The cushions may advantageously be removable. The skater can then exchange the cushions either individually or in a set to modify, as desired, either the skating characteristics or the degree of comfort. For instance, a set of rigid cushions may be exchanged for a set of more resilient ones. Cushions of different rigidity and/or materials, shape or thickness may be provided on the same skate, allowing to get a customized skate. Preferably, the sole is provided with seats adapted for connection of the cushions to the sole. Advantageously, the shape and dimensions of the seats substantially correspond with those of the cushions. It is therefore quick and easy to install and/or remove the cushions. This is of particular interest, especially with the variant in which the cushions are removable. According to given variants, the seats include a cavity or an aperture. In the first case, the sole thickness is reduced in the area of the cushions. At this point, the force or energy is thus transmitted through the sole. In the second case, the cushion extends across the sole. All the force or energy is thus transmitted through the cushion. Preferably, the roller skate of the invention comprises attachment means connected, in one end, to the frame and, in the other end, to portions of said boot substantially corresponding to said force transmission points. As embodied and broadly described herein, the present invention also provides a cushion for a roller skate adapted to be used with the roller skate of the invention. As embodied and broadly described herein, the present invention also provides a roller skate set comprising a pair of roller skates according to the invention and a set of cushions according to the invention. The set may advantageously be provided with a plurality of inserts of different hardness. It is then easy for the skater to customize his pair of skates according to the desired skating performance and characteristics. According to another preferred embodiment, the points are provided with reinforcements. These reinforcements provide additional rigidity to the sole where it is more submitted to stress and others mechanical forces. In this way, it is ensured that all forces or energy coming from the foot are received. The reinforcements are achieved by the addition (or substitution) of a material of even higher rigidity than that of the material of the sole. Furthermore, the sole is preferably not planar but rather in the shape of an inverted shell, in order to accommodate the foot and better prevent its unwanted shifting within the boot. The boot upper is attached to the sole by conventional means. Other features of the invention will become apparent by reference to the following specification and to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS The invention will further be described, by way of example only, of preferred embodiments, reference being made to the accompanying drawings, in which: Figure 1 is a perspective view illustrating a roller skate according to the present invention; Figure 2 is a perspective view of the skate boot (partly cut-away) and of interface of the skate of figure 1 ; Figure 3 is a side elevational view from the bottom of the skate boot sole according to the invention; Figure 4 is an elevational view of the skate boot provided with cushions according to the invention; Figure 5 is a fragmentary view of the sole provided with a variant of a cushion according to the invention; Figure 6 is a fragmentary view of the sole provided with a further variant of a cushion according to the invention; Figure 7 is an exploded view of another embodiment of the skate of the invention provided with reinforcements; Figure 8 is a perspective view of the boot of the embodiment of figure 7 (partly cut-away) and of the interface. Throughout the drawings, the same reference numerals designate identical or similar elements. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Figures 1 to 6 illustrate a first embodiment according to the invention. A skate boot sole 20 is provided with seats 23. The seats 23 are formed in the area of the first metatarsal 5, the fifth metatarsal 7 and the heel 3. Such a sole may be manufactured according to conventional methods, for instance molding. Cushions 21 are inserted into said seats. The cushion materials are selected to provide the desired degree of force transmission/absorption. For instance, they can be made of plastic type materials like polyurethane. Such materials are advantageous as they can be produced with different densities. The cushions 21 may or may not be of the same material or density in all seats. The cushions are removable or permanently affixed to the sole or are even integrally formed therewith. In the second case, they can be maintained by a tight fit or by other known means like gluing. The removable cushions may also be pre-attached by a tight fit. They are then secured when the skate frame is connected to the boot. The frame may be removed from the boot and the cushions changed for instance for those having different characteristics. Figures 4, 5 and 6 illustrate variants with different types of cushions 21. In figure 5, the cushions are provided on the skating surface side 13 of the sole. They are housed in seats 23 shaped as cavities. The remaining adjacent sole layer is thinner and can thus easily transmit the force coming from the foot. Figure 6 shows a variant with the cavities provided on the foot side of the sole. The foot is thus in direct contact with the cushion for increased force transmission. In these two variants the cushions may De flush mounted or may extend outwardly from the sole surface for better force transmission, as shown in dotted lines. Figure 4 illustrates a variant in which the seats are shaped as apertures to house cushions that extend from one sole face to the other. The force is thus transmitted directly from the foot to the frame of the skate for optimal efficiency. The cushions preferably extend outwardly from the foot side of the sole. On the skating surface side, the cushions may extend outwardly from the sole surface as shown in dotted lines. A sole may be comprised of cushion/seat assemblies of different types. The wheel frame 16 preferably comprises two parallel rails 38 interconnected by bridging portions 40. Wheels 42 are conventionally rotatably mounted within the frame 16. The frame 16 is secured to the interface 14 by conventional means, for instance bolt and nut assemblies at connection points 44, rivets or the like. The frame is made of lightweight conventional materials such as aluminum, plastics, composite, in accordance with known methods. Advantageously, the skate frame is adapted to be attached to the skate boot in portions substantially corresponding to the three points identified herein above. The frame 16 can be of a single piece, but preferably comprises two or more separate portions, one of which is an attachment plate 14 capable of being attached to the skate boot at the three above mentioned points. The attachment plate 14 can optionally be provided with housings to house at least partially the extending portions of the cushions 9 (figure 2). The sole 20 of the boot can be made of one or more layers of the same or different materials. Figures 7 and 8 illustrate a second embodiment of the present invention. A roller skate 10 comprises a skate boot 12, an interface 14 and a wheel frame 16. The skate boot comprises a boot upper 18 and a sole 20. The sole is preferably in the form of an inverted shell that will house the skater's foot. The sole 20 is made of a main material, for instance a rigid plastic material or rubber or the like. In order to prevent unwanted flexion of the sole and associated energy loss, the sole is preferably made of a rigid material. The sole may advantageously be manufactured with known type molding techniques. Additional materials and/or layers may be provided. According to this embodiment, the sole is provided with reinforcements 22, corresponding substantially to the area of the heel, the first and the fifth metatarsal of the skater's foot. The reinforcements are made of a material more rigid than the remaining portion of the sole. They may be set, for instance, by duplicate molding or simply fixed on the sole surface, for instance by gluing, sewing, or any mechanical or chemical fixation means. The boot upper 18 is made according to known methods, with traditional materials, for instance, plastic, leather, fabrics, composite, etc. When the skater wears the boots, the first and the fifth metatarsal of the skater's feet are located adjacent to the reinforcements. This provides increased force transfer towards the frame and therefore increased power, speed and general performance of the skater. The interface 14 has a forward surface 24 and a rear surface 26 interconnected by an interconnecting link 28. Extending from the surfaces are projections 30 and 32 respectively adapted to receive and secure the wheel frame 16. The interface is manufactured by conventional methods with a rigid material, preferably of plastic or composite type. The interface is secured to the sole 20 by conventional means. The wheel frame 16 preferably comprises two parallel rails 38 interconnected by bridging portions 40. Wheels 42 are conventionally rotatably mounted within the frame 16. The frame 16 is secured to the interface 14 by conventional means, for instance bolt and nut assemblies at connection points 44, rivets or the like. The frame is made of lightweight conventional materials such as aluminum, plastics, composite, in accordance with known methods. Advantageously, the skate frame is adapted to be attached to the skate boot in portions substantially corresponding to the three points identified herein above. The frame can be of a single piece, but may comprise two or more separate portions, one of which is an attachment plate capable of being attached to the skate boot at the three above mentioned points. The above description of preferred embodiments should not be interpreted in a limiting manner since other variations, modifications and refinements are possible without departing from the spirit of the present invention. The scope of the invention is defined in the appended claims and their equivalents.

Claims: CLAIMS 1. A roller skate comprising a frame, a plurality of wheels rotatably mounted to said frame, a boot connected to said frame, wherein said boot comprises a sole provided with three force transmission points adapted to transmit the force exerted by the skater's foot to the frame. 2. A roller skate according to claim 1 , wherein said points substantially correspond to the heel, the first metatarsal and the fifth metatarsal of a wearer's foot. 3. A roller skate according to claim 1 or 2, wherein said points are provided with cushions. 4. A roller skate according to any one of preceeding claims, wherein said sole is provided with seats adapted for connection of said cushions to said sole. 5. A roller skate according to claim 4, wherein said seats are comprised of a cavity. 6. A roller skate according to claim 4, wherein of said seats are comprised of an aperture. 7. A roller skate according to any one of preceeding claims, wherein said cushions are removable. 8. A roller skate according to claim 1 or 2, wherein said points are provided with reinforcements. 9. A roller skate according to any one of preceding claims, wherein said frame comprises attachment means connected, in one end, to the frame and in the other end, to portions of said boot substantially corresponding to said force transmission points. 10. A cushion for a roller skate according to any one of claims 1 to 7. 11.A roller skate set comprising a pair of roller skates according to any one of claims 1 to 7 and a set of cushions according to claim 10. 12. A roller skate set according to claim 11 , comprising a plurality of cushions of different hardness.

Inventors: FULLUM JEAN FRANCOIS, FULLUM, JEAN, FRANCOIS
Applicants: BAUER INC, FULLUM JEAN FRANCOIS, BAUER INC., FULLUM, JEAN, FRANCOIS
Application year: 1998
Main classification: A43B5
IPC codes: A43B5, A43B13, A63C17