This invention relates generally to so-called “in-line” skates; that is, skates that are designed to be used on pavement or other hard surfaces and that include a series of rollers or wheels disposed in line.
A conventional in-line skate includes a relatively rigid body or frame in which the wheels are fixed for rotation. The wheels are disposed in a straight-line configuration.
The prior art contains examples of attempts to provide an in-line skate with improved turning performance. For example, U.S. Pat. No. 6,161,846 (Soderberg) discloses a skate in which front and rear wheels are carried by a beam and the beam is attached at its center to a backbone frame of the skate. The intention is that the beam will flex from side-to-side in turns so that the wheels or rollers will more closely follow the curve of the turn. The beam is essentially a flat plate disposed on edge in a plane at right angles to the sole of the skate boot. Examples of other prior art patents that were considered in the preparation of this application are:
An object of the present invention is to provide an in-line skate which will have enhanced turning characteristics akin to those that are experienced when a skier “carves” a turn on snow.
The skate provided by the invention includes a boot for receiving a wearer's foot and having a sole which defines a plane below the foot. The boot has an inner side and an outer side corresponding to inner and outer sides respectively of the wearer's foot. A beam extends longitudinally of and beneath the sole of the boot and has front and rear end portions and means coupling the beam to the sole intermediate the end portions. At least three rollers or wheels are provided and are coupled to the beam at positions spaced longitudinally thereof so that there is a front roller, an intermediate roller and a rear roller. The beam is flexible with respect to the attachment means both in a first plane generally towards and away from the sole and in a second plane generally laterally with respect to the first plane. The beam is oriented with the first plane angled upwardly towards the outer side of the boot so that the beam will flex laterally in response to outwardly-directed lateral forces exerted on the boot by a skater in use. The front and rear rollers are disposed in a common plane parallel to the beam and the intermediate roller is offset outwardly from that plane.
An important feature of the invention is the fact that the beam is flexible in the second plane referred to above. For example, in an embodiment in which the beam has the configuration of a flat rail of rectangular cross-section, the beam will be disposed on edge but tilted or canted outwardly at the top. As such, when the skater is standing upright and imposing a vertical load on the beam, the load will be applied to the center region of the beam, so that the beam would bow outwardly at its center but for the presence of the intermediate roller. The outward offset of the intermediate roller with respect to the front and rear rollers means that, when the skater leans into a turn, the intermediate roller of the outer skate moves out of contact with the ground, allowing the beam to bend. The load imposed on the beam will be a vector comprising a component of the weight of the skater, and the effect of centrifugal force as the skater goes around the turn. In other words, this design ensures that the beam does indeed bend in a turn.
In a preferred embodiment of the invention, there are two intermediate rollers disposed outwardly along the beam from its attachment point to the boot.
While it is possible for the rollers to be mounted to the inside and/or to the outside of the beam, in a preferred embodiment, the rollers are mounted on the outside of the beam and there are two intermediate rollers that are offset outwardly with respect to the front and rear rollers. In a turn, the inside skate will be tilted towards the outer side of the wearer's foot, which means that the intermediate rollers will take all of the weight of the skater for that inside foot and the front and rear rollers will move out of contact with the ground. This will provide the inside skate with greater maneuverability since the contact patches between the skate and the ground will be relatively close to the point of attachment of the beam to the boot. In other words, the skate will have a much shorter effective wheelbase than when all of the rollers are on the ground.
The intermediate rollers may be wider than the front and rear rollers. The intermediate rollers then have a wider contact patch with the ground than the front and rear rollers and, consequently, more grip.
In order that the invention may be more clearly understood, reference will now be made to the accompanying drawings which illustrate a particular preferred embodiment of the invention by way of example, and in which:
a and 9b are detail views showing the front or rear roller of the left-hand skate boot as seen in
Referring first to
The drawings show at 22 a typical moulded boot such as might be used for skis or in-line skates. It is to be understood that the particular style of boot shown is by way of illustration only and that many different styles or types of boot may be used in accordance with the invention. In
The sole of each skate boot defines a plane below the wearer's foot, which is denoted P in the case of the left skate and seen in
This beam orientation ensures that, when the skate is loaded outwardly in a turn, the beam 26 will flex into a curved configuration creating the curve of the turn, which gives the skater enhanced control and a sensation similar to “carving” on skis. This is unlike the performance of a conventional in-line skate in which the rollers remain truly in line even during a turn.
To execute a turn to the left the skater will step laterally to the right, transferring more weight to that foot while at the same time leaning to the inside, with the left foot assuming a position further to the inside of the turn, following a path roughly concentric with that of the right foot. As this happens, the load imposed on the beam through the boot and the carrier 36 gradually increases. The load is a vector comprising a component of the weight of the skater exerted generally downwardly through the skater's body, and a lateral component produced by centrifugal force. This deflects the beam laterally outwardly in the direction of plane 40 in
In the case of the inside (left) skate on the other hand, only the two intermediate rollers are in contact with the ground (only two contact patches are shown).
The result of these actions is that the skater is able to “carve” the turn much in the manner that a skier carves a turn on snow. The turn radius is of course determined by the user by altering the speed and degree of lean.
Finally,
In
The mounting of the rollers with the axle held by one end only (instead of at both ends as with conventional in-line skates) allows for easier, quicker roller changes, while also allowing for the option of wider rollers and increased grip.
In summary, the skate design provided by the invention offers a number of advantages in terms of improved “feel” to the skater and more precision in turning. At the same time, it should be understood that the preceding description relates to particular preferred embodiments of the invention and that many modifications are possible, some of which have been indicated previously and others of which will be apparent to a person skilled in the art.
A principal modification that may be made is in the orientation and configuration of the beam itself. The preceding description indicates that wide variations are possible in the angular orientation of the beam. Increasing the angle of the beam to, say, 45 degrees would result in a skate that would initiate a turn by leaning alone (without “stepping out” to the side) much the way modern “parabolic” skis turn today under certain conditions.
It should be noted that differences are also possible in the configuration of the beam and its structure. While a narrow rectangular shape has been shown and is believed to be preferred, there is no limitation in principle on the shapes that can be used.
The beam should be able to flex more easily in the lateral direction than in the vertical direction. This can be achieved by suitable “engineering” of the beam structure or by shape, e.g. oblong, lozenge, ellipse or tall triangle. Suitable engineering could provide the required characteristics in a beam of, for example, a cylindrical rod-shaped configuration or a square cross-sectional shape. While a fiberglass reinforced resin structure has been described, other composite materials can also be used. Conversely, less exotic materials may be used, for example, spring steel or a moulded plastic material.
As to the rollers or wheels, many variations are possible. The drawings show an arrangement in which there is a front roller, a rear roller and two intermediate rollers. Other possibilities are only a single intermediate roller or additional end rollers.
Further, in the illustrated embodiment, all of the rollers are mounted on the outer side of the beam or rail. Clearly, this offers a number of advantages in terms of the preferred embodiment shown. However, it is not essential within the broad scope of the invention. For example, the front and rear rollers could be on the inner side of the beam and the intermediate roller or rollers on the outer side of the beam, or all rollers could be mounted on the inner side.
As noted previously, the turn radius is not predetermined, but rather, is determined by the user during use by altering the speed and the degree of lean. At the same time, the offset of the intermediate rollers can be changed with shim washers, altering the turn radius for a given angle of lean. Greater offset results in sharper turns, less offset results in longer radius turns and more stability.
The offset effect can even be achieved by using wider end rollers and narrower intermediate rollers. With wider, relatively flat profile end rollers and narrow intermediate rollers all with their tread centers in line, when the user leans over, the contact patch of the end rollers would tend to move to the inside (to the inside edge of the end rollers) thereby effectively creating an “offset” to the inside relative to the intermediate rollers.