The present invention relates to a light device attached to the foot of an individual, conceived to enable him to roll on a dedicated track as well as on an average quality road.
This sort of movement is traditionally and mostly carried out using roller skates equipped with four small wheels placed under a sole, or using in line skates equipped with several small wheels (generally four or five) aligned under the sole, and in its axis.
The main disadvantage of these devices is that their use is reasonably limited to a smooth, hard surface without gravels, therefore on special tracks or on particularly well maintained roads.
Their ability to roll on ordinary roads with a rough surface therefore isn't satisfactory.
Another disadvantage resides in the difficulty of learning the technique and in the impractical hold or stop position on these types of skates. As a matter of fact, there is no truly practical system to keep a stable stop position, to get back into the right trajectory or to slow down.
In a more limited extend, other types of roller skates with, for example, medium sized wheels having in some instances their axes moved on top of the sole for four-wheeled skates (the wheels are therefore outside the sole's imprint), or for in line skates the use of only two medium size wheels, one in front of and the other one behind the sole, create harder steering that considerably limits the performances.
In the same way, the use of two medium size wheels on the same side of the skate with a vertical rotation plane, or even with a rotation plane inclined in order to bring the contact zone of the roller with the ground doser to the main axis under the sole, has the disadvantage either of putting the reaction of the skate out of the ankle's axis, or of causing a rotation movement of the skate towards the outside of the trajectory and a rapid wearing of the wheels.
The invention, allows remedy these drawbacks and introduces additional features.
According to a first feature, it includes for each skate, two wheels, off centered from the main axis of the sole: one big wheel in front, generally between 150 and 300 mm in diameter (1), on the outside of the foot, and a medium size wheel at the rear (2) (100 to 150 mm) on the inside of the foot. The rotation axis of each wheel is situated in a plane parallel to, but not identical to the plane of the sole (4) and is perpendicular to the longitudinal axis of this sole, so positioning the rotation planes of the wheels parallel to the movement of the sole when it is in a horizontal plane.
According to a second feature, the diameter of the rear and front wheels (1) and (2) may vary individually between 75 and 300 mm. This gives several possible combinations of large, medium size or relatively small wheels, larger in any case than those of the usual skates.
The rotation axis of the wheels (1c) or (2c) is located at about the level of the plane of the sole (4) for a 100 mm wheel, is located lower for smaller wheels and higher for larger wheels. This layout places the sole (4) on a parallel plane situated about 50 mm above the ground. The skate is therefore quite lowered and stabilized as compared to the axis of the big wheels in a standard configuration.
The foot is fitted inside a semi-rigid high-top shoe (3), with a forward/backward joint at the level of the ankle (3c). This type of shoe is identical to the type used in “in line” skates. According to a seventh feature, less rigid shoes can also be used.
Following the nature of the terrain mostly used and the type of ride, the diameter of the wheels and the material of the standard tread of wheels made of synthetic rubber, either full or semi full, can be replaced by a light tire, or even an all terrain type bicycle tire. The tires are adequate for the high pressures used for inflating.
The rim and tread of the front wheel (1a) are shifted in relation to the linking radii (or disc) (1b) of the wheel towards its hub in order to place the foot the nearest possible to the rotation plane.
The axis of the tread is therefore about 40 mm away from the geometrical axis of the foot. The rear wheel (2) will in the same way be moved the closest possible to the outside plane of the shoe. The goal of this layout being to limit contact of the overall device with the ground and to avoid contact with the other foot or with outside elements, but above all to bring the axis joining the two points of contact of the wheels with the ground as close as possible to the projection of the reaction points of the foot in the shoe on the ground but always on the same side in order to avoid effects of sideway swaying stress on the ankle as well as being in a momentarily unstable position during the pushing movement.
In a third feature, rubber blocks at the front (6) and at the back (5) of each skate are situated at the opposite of the wheels in relation to the main axis of the sole and at a height of 35 mm above the ground at the front and 20 mm at the back. Thanks to the off centered position of the wheels (the front one on the outside of the foot and the rear one on the inside), and the small height of the sole, they can be used for stopping, slowing down, maintaining a hold or moving position. To do this, one just has to put them in contact with the ground with a slight inward or outward rotation of the foot with a change in the orientation of the sole by a simultaneous tilting action of the ankle and the knee. The legs then takes the “X” shape of skiers in a snow plough position for the use of the front blocks or a “< >” shape when leaning on the rear blocks. When starting from a high speed, stopping and slowing down is preferably done by dragging the back foot on its front rubber block or furthermore as in classical skating by turning sharply and making a breaking-stop.
The front block (6) is also used to adhere to the ground and propel the skater when the axis of the foot is only slightly outside of the axis of the movement. Normally the axis of the foot is directed toward the outside of the axis of the movement, at about 30° to take advantage of the reaction of the wheels which therefore are not in their normal rotating plane. This either strong or light pressure on the front block comes from the pressure of the foot on the inside of the line that joins the two points of contact of the wheels with the ground and produces a rotation of the plane of the sole (4) favoring once again contact with the ground.
Seen from above, the position of the axes of the front (1c) and rear (2c) wheels in relation to the length of the sole (4) of the shoe (3) are situated inside the imprint of this sole, at the level of the heel for the rear wheel and of the foot and toes junction for the front wheel. This layout of the axes on the inside of the imprint allows an easy movement when switching the foot from the pushing function to the carrying function. This would require a much more considerable effort is the wheels were placed well in front of and well behind the sole.
The dimensions of the two wheels and the type of tread allow an efficient use of the skates even on a rough road. The choice of these dimensions depends on the type of road, on the type of ride carried out and on the shoe size of the skater. In principle this choice can be made at purchase, or following a sixth feature, it can be made later on by changing the wheels. A provision to adapt two consecutive wheel diameters can be anticipated on pieces (4b), and (4c) of the sole/ board (4). The large diameter of the front wheel and the elasticity of the tread lead to a remarkable rolling capacity that limits energy losses, and allow to swallow obstacles (gravels, small holes) without a shock effect or a sharp slow down that could cause an imbalance of the skater towards the front, and without any feeling of uncomfortable vibrations. The rear wheel with a large diameter has the same advantages, and in the case of a smaller diameter, it would in theory swallow the obstacles less efficiently, but, the effect of the beginning of an eventual imbalance of the skater towards the front would automatically “release” the weight applied on the rear wheel and therefore reduce its slowing down effect.
The sole of the foot of the shoe (3b) is rigidly fastened directly onto the sole/board (4) of slight thickness (less than 10 mm) but sufficiently resistant to the torsion in the direction of its large axis (it is however possible to increase of the section in the middle of the board). The rotation axis of the wheels (1c) and (2c) is directly fixed to this board (4a) for a size of 100 mm, or in a slightly raised (or lowered) position in relation to this board (4a) using an angle bracket (4c) for the rear wheel or an angle bracket (4b) for the front wheel.
Besides the shoe (3) which is a commercialized item, the choice of the materials for the other parts must be guided by concerns of weight and inertia in rotation. This applies particularly to the front wheel (1) to which a large diameter would induce considerable gyroscopic effects if it were not balanced by a decreased rotational speed and a reduced momentum of inertia with a choice of light materials and in small quantities.
According to a fourth feature, the rotation axis of the front wheel (1c) can be tilted in relation to the plane of the sole (4) to move the contact point of the skate and the ground closer to the axis of the foot and free the top part of the shoe. Generally, the angle of this inclination won't exceed 10° to limit the rotation effect generated toward the outside of the foot.
According to a fifth feature, the system can be adapted onto a commercial in line skate that has simply been deprived of its wheels. The previous sole/board (4a) is then replaced by a “U”-shaped profile (4d) assembled underneath and surrounding the braces of the small “in line” wheels. The fastening is carried out by 4 or 5 bolts passing through the holes of the axis of the 4 or 5 removed small wheels.
The accompanying drawings illustrate the invention. They illustrate the left foot skate.
The dimensions are approximately in proportion to the length of an average adult foot 28 to 30 cm long:
FIG. 1/10 represents the simplified front view of the standard system.
FIG. 2/10 represents the simplified side view of the system
FIG. 3/10 represents the simplified top view of the system
FIG. 4/10 represents the simplified perspective view of the system
FIG. 5/10 represents the perspective view of a simple form of the board/sole and a detail of the folding of the angle bracket (4b).
FIG. 6/10 represents the simplified section of a wheel with different types of treads:
standard in full synthetic material (1a), in a light tire version (1a′) and in an all terrain bicycle type tire version (1a″). The details of the rim (1d) and of the inflating valve (1e) are for the tire versions.
FIG. 7/10 represents the simplified front view of the system according to the fourth feature with the tilted axis of the front wheel.
FIG. 8/10 represents the simplified front view of the fifth layout mounted onto an in line skate deprived of its wheels. Braces (3d) of the dismantled wheels and the linking bolts (3e) are added under the foot part of the shoe (3c). The board/sole (4a) is replaced by the “U”-shaped profile (4d) mounted onto (3d), and the angle brackets (4b and 4c) are modified with gussets to be fixed onto (4d).
FIG. 9/10 represents the simplified side view of the fifth layout.
FIG. 10/10 represents the broken down perspective of the pieces of the fifth layout (3d), (3e), (4d), (4b), (4c), (1c) and (2c).
In reference to these drawings, the system includes:
(1) A front wheel of large diameter with its hub (1c), its radii/disc (1b), and tread (1a), (1a′) or (1a″).
(2) A rear wheel of medium or large diameter with its hub (2c), its radii/disc (2b), and tread (2a), (2a′) or (2a″).
(3) A semi-rigid high-top shoe articulated at the ankle, in line skate type, with its ankle part (3a), its foot part (3b) and its articulating pivots (3c), as well as braces for wheels (3d) and bolts (3e) for the fifth layout.
(4) A board to fix the shoe and the axes of the wheels with its sole part (4a) (or (4d) for the fifth layout), its front angle bracket (4b) and its rear angle bracket (4c).
(5) A rubber block to stop or maintain a position under the rear part of the sole.
(6) A rubber block to stop or maintain a position under the front part of the sole.
A typical way to manufacture the invention, for a skate with a front wheel of 200 mm and a rear wheel of 125 mm, consists of:
One commercial semi rigid shoe (3) molded in plastic material with cloth lining. The shoe is fixed with rivets onto the sole (4).
A support sole (4) in a light aluminum alloy molded by injection with reinforcement fins on the bottom, or made of carbon fiber. The sole is about 27 cm long, 8 cm wide and 7 mm thick. The angle brackets (4b) and (4c) are either of the same material and molded directly with the sole, or made in steel sheet 2 mm thick (with addition of reinforcements for rigidity 8 mm wide obtained by folding/stamping) and fixed by screws under the sole. This way angle bracket (4b) will have the following dimensions: a/ base plate fixed under the sole 30×45 mm, b/ triangular part normal to the sole and going up until the axis of the wheel: width 45 mm on the bottom and 25 mm at the level of the wheel's axis, height between base plate and wheel's axis: 50 mm. The fold for rigidity is located at the bottom of the base plate, opposite to the surface in contact with the bottom of the sole, on the wheel side at a height of 25 mm (see drawing 5/10), c/ at the level of the fixation of the axis of the wheel, a stamped boss with a 12 mm fine thread tapping; a second tapped boss is anticipated 20 mm underneath the first one for the option with a 160 mm diameter wheel.
Angle bracket (4c) will have the following dimensions : a/ base plate 30×45 mm, b/ triangular part width 45 mm on the bottom and 25 mm at the level of the wheel's axis, height between base plate and wheel's axis: 17 mm. the rigidity fold is located at the bottom of the base plate, opposite to the surface in contact with the bottom of the sole, on the wheel side at a height of 10 mm, c/ at the level of the fastening of the wheel's axis, a stamped boss with a 12 mm fine thread tapping.
Rubber blocks with a 20 mm diameter and 10 mm wide for part (6) and 20 mm wide for part (5) are fixed under the sole (4a) by a screw inserted into the block.
The axes of the steel wheels are screwed onto the angle brackets. For large wheels, the axe/hub sets are similar to those of bicycle wheels, forming an “X” mounted ball bearing. For smaller wheels, one would use needle bearings with steel brass thrusts or deep groove ball bearings.
The wheels are illustrated on drawing 6/10. For the all terrain bicycle tire version, one can find bicycle wheels in stores, starting from a 12″ diameter (300 mm), and wheels used for three-wheeled prams or orthopedic wheelchairs. Only simple adaptations need to be carried out
Manufactured wheels will be in light steel sheet. The material used for the full treads is identical to the ones used for in line skates.
The main uses of the road skates are for leisure, riding on the road, for easy and rapid rides in a city and the other applications of traditional or in line skates. The use is submitted if need be to the obligations of the highway code, the civil code and insurance codes, and to wearing authorized individual protection equipment.
Number | Date | Country | Kind |
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0500485 | Jan 2005 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/FR06/00040 | 1/10/2006 | WO | 00 | 7/16/2007 |