BACKGROUND OF THE INVENTION: Skates-, roller skis-and skis have been known to have devices, which enable the pivoting of the foot plane in respect to the surface plane for well over hundred years. In general those devices are intended to make the movement of feet, ankles etc. more natural and thereby improve the over all effectiveness. For ice skating it can be said that;-a more natural motion pattern is created,-speed reductions caused by the point of the skate scraping the ice when it is lifted at a lower forward speed than the body, are avoided,-the length of the energy transfer stroke is increased. The tendency at the moment is to use existing devices from skis, roller skis and ice skates on roller skate. The requirements for roller skates are however incongruent with the requirements of skiing, roller skiing or ice-skating. Roller-skating, especially the outdoor variety, is done on uneven surfaces causing the load on the individual wheels to vary constantly. The roller skater has a higher motion rhythm, a shorter stroke and cannot resort to an as deep crouch as the ice-skater, thereby reducing the required pivot angle between skating-and surface plane. A reduction of the pivot angle also reduces dramatically the scraping effect when lifting the skate at the end of a stroke. The scraping effect is further reduced because the front of the skate is a rotating wheel and does not stick out as far from the foot as the speed skate. In roller-skating during the end part of each stroke both feet are placed alongside each other, but spaced wider apart than in ice

skating, in order to allow the wheels of each skate to reach the same rotational velocity as the speed of motion. Than the centre of gravity is gradually transferred from the first foot to the second foot, in the process of ending the stroke, whereby the first foot pushes of the second foot. It should be understood that this is a gradual process in which both feet work together.

After the second foot has well commenced the first part of its stroke, the first foot is lifted of the ground. As soon as the centre of gravity rests on the second foot the centre of gravity is moved in order to get additional acceleration. At the end of the stroke the process is repeated on the other foot. Resulting in a motion where the centre of gravity and the body move in a pendulous way, over both roller skates at the moment they are more or less next to each other. Whereby it is understood that the skates are working in tandem during the greatest part of the motion cycle and they cross together the line of the motion direction on each stroke. This is contrary to ice skating where the feet move one at each at its side of the motion direction.

The pendulum motion has as its centre the skate over which the centre of gravity is located. Both legs are now parallel and inclined to the ground, to reach all wheels from both feet to the ground, the leg, that is reaching the end of its push of, has to be crooked, while the skate on the other leg has to be inclined to an uncomfortable angle. Leading to a shortening of the effective stroke and a body alien position leading to symptoms as muscle fatigue and muscle numbness. Another difference is the surface one drives on and its reaction on the foot/leg/body. Ice-skating is done on a flat surface, while roller skis and normal skis divide the loads over a long surface. Roller-skating however is done over a relatively short wheel base divided up in the spaces between wheels. The surface on which to roller-skate is uneven and not plain, unexpected shocks may make it difficult to keep the feet in the desired position. Especially skating at higher speeds will increase these problems. It has to be born in mind that in, especially roller skating, is as important to preserve speed as well as maintain it by motion. So kick off, or jumping from one foot to the other, which has no rotating wheels, is except at lower speeds and in the start moment not the case. The contrary happening, one never activates a skate unless all the wheel have

a rotational speed equal to the motion velocity, only than the gravity is loaded on this skate and the rest of the motions such as pushing of can start. Finally it needs remarking that because the wheels have ground contact the bigger part of the motion cycle and work a lot in tandem, it needs quit some acrobatics to contort the body in order to achieve this.

Examples of previously known devices of this kind is known from WO 96/37269, destined for ice skate but also used on roller skates. The whole foot has to pivot around a hinge on a very complicated device, which is by its great chain of levers and hinge points prone to accumulation of wear and thereby malfunction. Furthermore is the viability of economic mass reproduction at constant reproducible quality, geared to meet the specific demands of the individual, questionable. To accompany the skating motion all forces are concentrated and divided over one point, once the heel starts the pivoting motion. The result of the concentration and distribution of all forces from the front part of the foot results in an uneven distribution of force to ground along the length of the skate.

Because of the uneven distribution also the transfer of motion energy is uneven distributed along the length of the skate. In ice skating in which the surface contact is smooth and divided along a stiff solid member this does not create a big problem.

However in roller-skating this is a problem where the force is divided over small contact areas on the surface of the wheels, and where the reaction force of the surface vary, due to its unevenness, on one or all the wheels, results in oscillating, loss of ground contact, loss of concentration and amplification of the vibration on one point and no steady operation. The foot rotates as a whole, thereby foregoing the natural programmed foot motion of the flexing and de-flexing of the toes. The rotation of a straight foot also includes the lowering of one side around the final hinge, to avoid contact between the shoe and the frame the foot has to be placed higher, or the hinge has laterally be brought forward along the frame. While this might not create problems with an ice skate it will cause problems in a roller skate because of the roller diameter, also greater flexibility is required as to the hinge position along the skate frame.

Examples of previous known devices of this kind are also known from E 0192312. Although this device does not pretend to be used for roller skates and by virtue of its construction it is not useable, conformity may wrongly appear at first glance. The shoe has a flexible nose, which makes it possible to flex the toes when the skate frame plane is pivoted in respect to the skating plane. However when doing so the fastenings of the shoe to the foot will deteriorate, because the material from the nose upward will crinkle in order to accommodate the change, thereby reducing the length of any cross bindings. The hinge mechanism under the heel cannot take thrust loads. The construction is complicated and is not easy to adapt to the individual. The load of body mass and motion energy cannot be re-routed along the length of the skate. A lock is required. The working of the hinge mechanism cannot be inverted. The construction has no insulation against vibration or shock absorbers.

The existing solutions have part of the characteristic remaining that, the skate and foot have to be kept in plane with the skating surface for as long as possible, because in this position maximum motion energy can be transferred. While the remaining part of energy transfer, during the pivoting motion transfer is seen as a bonus on top of a more ergonomic skate movement. The construction is by virtue of the central function of the hinge not equipped to receive and counter act thrust loads at the heel. In the skating motions on ice, although not natural but somewhat compensated by the swerve in order to get grip on the ice and the neatly divided stroke pattern, pivoted skates are used with better results than fixed skates. In roller-skates however with there nearby parallel stroke pattern, crossing the line of motion and strokes with double pushes, they do not lead to an effective use.

OBJECT OF THE INVENTION: The purpose of the invention is to avail to the roller skater the means to skate in a continuously flowing motion, where it is possible to have both roller skates at the ground and operate them in tandem, without the need to adapt difficult and tiresome positions. Thereby enabling the roller skater to practice his

sport effectively and more comfortable, while also the stroke pattern changes to such an effect that more motion energy can be transferred. The roller skates are combined with shoes that tighten around the feet at the moment the highest strains are encountered and loosen up when the roller skates are not in ground contact.

SUMMARY OF THE INVENTION: The present invention relates to a roller skate with a pivot mechanism comprising a shoe with a pre-stressed lower part, that connects at the frontal part of the shoe to the main frame of the roller-skate and at the backside of the shoe to a spring loaded hinge which in its turn is connected to the main frame.

The shoe is pre-formed and acts like a blade spring under load.

The shoe and the main frame are in unloaded position separated from each other by said blade spring effect and require on longer skate the assistance of a spring and hinge. The springs are produced in a wide range and can easily be exchanged to suit the individual. A front wheel is fixed rotationally in the main frame in order to control the motion direction. A number of wheel casings are pivotally assembled to the main frame. Said wheel casings can pivot at one end. A permanent elastic spring with progressive growing tensile stress elongation characteristics is connected between one end of the wheel casings and the mainframe. Said spring has been pre-stressed in order to compensate for the initial elongation. Said spring can be assembled by external deformation and is produced in a wide range in order to fit the requirements of the individual user.

Within said wheel casing a wheel is rotationally connected.

Loads and vibrations on the wheels will be led over said wheel casings and the springs which will act as load dividers and vibration insulators between said wheels and the main frame by rotating and flexing.

The invention also serves the purpose of fitting an equaliser to the shoe fastening system, which can be adapted to the individual and which will start to function in situations of overload.

The said purpose is full filled with a roller skate and shoe embodiment within the scope of the present claims.

BRIEF DESCRIPTION OF THE DRAWINGS: Detailed description of the invention will now be given with reference to the accompanying drawings of which: Fig. 1 shows a three-dimensional view of a roller skate, with its wheel de-mounted, with a spring loaded pivot mechanism according to the present invention.

Fig. 2 shows a side elevation of the device shown in fig. 1 with a flexible shoe when pivoted.

Fig. 3 shows a side elevation of the device shown in fig. 1 and fig. 2 not pivoted and under load.

Fig. 4 shows a detail of the backside of the device shown in fig. 1,2,3 with the spring put out of action.

Fig. 5 shows a detail of the back of the device as shown in fig. 1,2,3 prior to the loading of the spring.

Fig. 6 shows a binding diagram connected to the device as shown in fig. 2.

Fig. 7 shows a binding diagram connected to the device as shown in fig. 3.

Fig. 8 shows a side elevation of a roller skate operated only by the blade spring action of the lower shoe part.

DESCRIPTION OF THE INVENTION: The embodiments hereafter described is showing a roller skate with flexible load adjusting, vibration insulation, shock absorbing, shoe with binding system and a spring loaded hinge which prevents the formation of a rigid body structure for the accompaniment of the skate movements.

Fig. 1 shows the roller skate with a main frame 1 with the five wheels de-mounted. Each wheel 2 (See fig. 2) is rotationally

fixed with a bolt 3 to a wheel axle and four of the wheels to four identical wheel casings 4, which are pivotally fastened to the main frame 1 with axle bolts 5. In the wheel casings 4 is one set with smaller wheels 2 rotationally fixed (See fig. 2) and one set bigger wheels 6 (See fig. 2) with axle bolts 41. The wheel casings pivot round a hinge axle 7 and are connected with a pinion 8 (see fig. 2) to a spring 9. The spring 9 has been fitted by deformation on to a hub 10, which forms part of the main frame 1. The spring, which is made of well vulcanised rubber, well polymerised EPDM or similar, well pre-stressed to compensate for the initial elongation, has a progressive growing tensile strength elongation capacity and becomes stiffer during deformation and therefore presses with a force against the hub ends 11. The force will also keep the pinion 8 and thereby the wheel casing 4 and wheels 2,6 in place. A force at ground level on the wheels 2 and 6 will form a moment of force over the axle bolt 5, counter acted by the force acting on the hub end 11. The spring 9 is made in a wide capacity variety and when the correct spring is attached, the wheel 2,3 and the wheel casing 4 hardly move inward when the body weight is placed on the skate. If a wheel gets a higher load it moves elastically inward, till the other wheels have taken the surplus load. The wheels of the skate will therefore follow the unevenness of the road and keep ground contact. The same can be said about wear, in a normal in- line roller skate all wheels have to have the same diameter, would they have different diameters the smaller wheel would wear faster and consequently lose road contact. In the skate according to the invention the excessive wear on one wheel, will be compensated for by the other wheels elastically moving inward. Thereby a situation arises that wheels with equal diameters do not have such a high priority anymore. The surplus of space below the heel can therefore be used to install bigger wheels without making the skate higher, thereby reducing roller resistance. When the load should elastically move the wheels 2, 3 and the wheel casing 4 to far inside the main frame the spring 9 will contact a buffer 12 mounted on the main frame 1 and only the shock damping will remain within the material of the spring 9 between the buffer 12 an the pinion 8. Every time the spring 9 is activated the pinion 8 will lift the spring from hub 10, on recoil the damping will take place in the part of the spring 9

between the pinion 8 and the hub 10. The spring 9 will be kept in place by the body of wheel casing 4. Thereby is a economical mass production system created with a minimum of parts.

Fig. 2 shows a stiff front plate 13 of a shoe 100, which is fastened to the mainframe 1 by screws 14. Behind the front plate 13 a flexible elastic spring zone 15 is arranged which can be elastically bent backwards under pressure. The flexible zone 15 is created, by filling grooves 16 in the sole with permanent elastic material 17, causing the shoe to resemble the image shown in fig. 3 when no loads are applied. A binding 18 are fastened with the shoe in the position as shown. The binding 18 passes through a hole 150 permanent elastic equaliser 19 fitted in a guide 36 on top of the front part of the shoe, and shall be tensioned until the extremity of the equaliser is more or less at a mark 20 on top of the front part of the shoe. The force with which to pull the bindings 18 is moderate and is light comparing with the forces used today. At the lower end of the shoe 100 a base hinge plate 21 is fixed to the shoe 100 with screws 22 An upper hinge half 23 is pivotally connected with the base hinge plate 21 over a pinion 24. A lower hinge half 25 pivots with the upper hinge half 23 at a halves connecting pinion 26. The lower hinges half pivots around a pinion 27 attached to the main frame 1. The hinge halves thus functions as an elbow type of lever mechanism. A permanent elastic spring 28 is connected to a sprocket part of pinion 26 on both sides of the main frame 1 and to a pinion 30 on a handle 29 which pivots in the main frame 1 round a pivot 31. The handle abuts a buffer 37 and can therefore not rotate. The spring 28 pulls at both the pinions 26 and 30 and tries to move the both hinge halves 23 and 25 inwards, which is impossible because an extended part of the hinge half 23 has made contact with the, not hard, underside of the sole at a contact area 32. Both the forces of the spring zone 15 and the spring 28 try to separate the mainframe 1 from the shoe 100 at the back side resulting in a separating force 101, situated well back of the front connection between the shoe and the main frame 1. The position showed resembles the beginning of the stroke. In which, the skate has to be brought in ground contact, in order to get the wheels spinning and bring the skates next to each other. In order to pendulum over the

centre of gravity and start the mutual push of, while the body is still tilted away, normally the tilted away leg should now have to crook while the foot on this roller skate should rotate backwards to bring the wheels parallel to the ground. With the device according to the invention this will not be necessary.

The relative shortness of the leg, of which the roller skate has to reach the ground, is compensated by the rotation of the mainframe 1 in respect to the shoe 100. Thereby avoiding the crooking of the other leg, which can continue with its outward push and the turning of the foot under an angle, which is not natural. While the changing of centre of gravity can be done easily. The position shown also resembles also the situation in which the roller skate makes its final push of, which is also done with the other roller skate at the ground and again the rotation of the main frame 1 in respect to shoe 100. Again avoiding the crooking of the other leg and a rotating of the shoe backward to an ineffective and not natural position.

Herewith we see that it is important to be able to pivot as well as in the beginning of a stroke as well as on the end of a stroke. Shown is also that the push of and body weight force 102 is placed further towards the end of the shoe, than in the usual pivotal skates. This creates a better balance, which is needed especially on uneven surfaces. Another point is that motion energy is stored in both the flexible sole 33 of the shoe 100 and in the spring 28 when pressing the heel of the foot down.

The energy will be returned to the motion, when the heel of the foot is lifted again.

Fig. 3 shows the hinge halves 23 and 25 folded inwards by the downward movement of the heel. The pinion 26 has rotated with the spring 28 together with the hinge half 25. The pinion 26 has therewith moved in a widening spiral from the pinion 30 and has consequently tensioned the spring 28. Working on the main frame 1, the wheel holders 4 and the springs 28 constitutes the push off force and the body weight forces 102 on the shoe 100 and on the main frame 1, while in between main frame and shoe work in the opposite direction to the reaction forces 104. A middle part 105 of the shoe 100 has moved rotating backwards as a gradient of the compressed permanent elastic fillers 17 and its connection to the sole 33. An upper part 106 of the shoe 100

has slightly rotated forward. The equaliser 19 has expanded.

Closing the gap A between the equaliser 19 and the shoe 100 more, while at the same time opening an additional gap B between the shoe 100 and the lower edge of the middle part 105 of the shoe and an additional gap C between the middle part 105 of the shoe and the upper part 106 of the shoe 100. The whole of the motion resulting in a tighter fit of the shoe around the foot, when loads are the highest and a tight fit is required. Contrary to this movement is unloaded situation when the foot is less tight within the shoe, allowing for a breathing period for muscles and veins. The shoe 100 is also shown that the shoe parts 105 and 106 are moved apart, indicating that the space could be used to install an extra elastic part, adding and complementing to the function of sole 33.

Fig. 4 shows the handle 29 turned counter clockwise. First resulting in a widening gap between pinion 26 and 30 and consequently stretching of spring 28, thereafter as soon as pinion 30 has crossed the centreline between pinion 26 and 31 the gap between pinions 26 and 30 becomes smaller. Rendering the spring tensionless. Bringing the heel down will not result in any tensioning of spring 28; instead the spring will idle between pinion 26 and 30 and not partake in the operation. This can be done when driving on flat surfaces and the balance support of the spring 28 and the hinge halves 23,25 is not needed. This operation can also be done during driving and therefor the pinion 30 protrudes slightly. The hinge halves 23 and 25 will continue to keep the shoe and mainframe in-line with each other, also onto the main frame at thrust forces.

Fig. 5 shows the spring 28 and handle 29 prior to click them in function by pressing and pushing at a pressing and pulling area 34. The tension of the spring is such that this can be done. The handle 29 and pinion 30 will start rotating around pinion 31 thereby increasing the distance between the pinions 26 and 30, until the centre line between pinion 31 and 26 is passed. After that, the handle will under influence of the tension of the spring 28 rotate around pinion 31 until the side of handle 29 abuts the buffer 37 (See also Fig. 2).

Fig. 6 shows the equaliser 19, which fits into attached guides 36 in the shoe 100. The equaliser 19 is produced in a permanent elastic well-vulcanised rubber, a well-polymerised EPDM and/or alternatives thereof with a progressive growing tensile stress elongation. It has been pre-stressed to compensate for initial elongation. The equalisers 19 are produced in several capacities. Through the equaliser hole 150, (See Fig. 2) and rows of eyelet 38 the binding 18 is threaded conforming the pattern shown. The pattern shown is a spread view related to fig. 2 and consists of two connected sets divided by an upper gap 39, at one end looped through an equaliser at the opposite end tightened in a knot. The binding is drawn until the front side of the equaliser 19 comes close to the mark 20 on the shoe 100 (see fig. 2), thereafter the knot 35 has to be tied. Also a lower gap 40 is defined between the mark 20 and the lowest pair of eyelets. Other configurations with for example more holes or different patterns are possible as well as the substitution of the binding, providing the fastener means consists of at least two connected patterns, which are separated more when the heel of the shoe 100 is moved downwards.

Fig. 7 shows the equaliser 19, which has now been elongated. The spread view shown relates to fig. 3 and compared with fig. 6 the gaps 40 and 39 have grown, while a higher tension is brought to the binding, because of the increased tension of equaliser 19.

The distances X and Y represent the length with which the first binding part has increased in the gaps 39 and 40. The distances T and V represent the length the second binding parts have to be reduced in order to compensate for the aforementioned lengthening. While the distances U and V give an indication of how much the eylets 38 are approximately moved towards each other, which will lead to a tightening of the shoe around the foot. The whole process is tension controlled by the equaliser 19, which avoids a too tight fit of the shoe around the foot.

Fig. 8 shows the shoe 100 previously described with another embodiment of the roller skate which is a shorter roller-skate.

The roller-skate has a main frame 50 holding a wheel 51 rotationally fixed with a wheel axle 52 and two identical wheel casings 53, which are pivotally fastened to the main frame 50

with a bolt 5 arranged to pivot round an hinge axle 54. In the wheel casings a set of larger wheels 55 is rotationally fixed with an axle/bolt 56. The wheel casings 53 are connected over a pinion 57 with a spring 58. The spring 58 has been fitted by deformation onto a hub 59, which forms part of the main frame 50. The spring which is made of well vulcanised rubber, well polymerised EPDM or similar, well pre-stressed to compensate for the initial elongation has a progressive growing tensile strength elongation capacity and becomes stiffer during deformation and presses therefore with the force 60 against the hub 59 ends. The force will also keep the pinion 57 of the wheel casing 53 and the wheels 55 in place. A force at ground level on the wheels 55 will form a moment of force over axle bolt 54, counter acted by a force on a surface 60 of the wheel casing on the axle bolt 54. The spring 58 is made in a wide capacity variety and when the correct spring 58 is installed, the wheels 55 and the wheel casings 53 will hardly move inwards when the body weight is placed on the skate. If a wheel receives a higher load it moves elastically inwards, until the other wheels have taken over the surplus load. The wheels of the skate will therefore follow the unevenness of the road and keep ground contact. The same can be said about wear, in a normal in-line roller skate all wheels have the same diameter, if they would have different diameters the smaller wheel would wear faster and consequently loose road contact. The skate, according to the invention, compensates the excessive wear on one of the wheels by the other wheels when it moves elastically inwards. Thereby a situation arises that the wheels with equal diameters do not have such a high priority anymore. The surplus of space below the heel can therefore be used to install bigger wheels without making the skate higher, thereby reducing the roller resistance and wear. When a load elastically moves the wheel casing and the wheels to far inside the main frame 50, the spring 58 would contact a buffer 61 on the main frame 50 and the shock damping will only remain within the material of the spring 58 between the pinion 57 of the wheel casing 53 and the buffer 61. Every time the spring 58 is activated by pinion 57 it will lift the spring 58 of the hub 59 a recoil of the damping will take place in the part of the spring 58 between the pinion 57 and the hub 59. The spring 58 is kept in place by the body of wheel casing

53. A permanent elastic profile 62 as a bending spring is pivotally assembled with one end connected to a pinion 63 fixed to the base plate 64 and with the other end connected to a screw bolt 65 to the main casing 50 in order to control the opening between the shoe 100 and the main frame 50. When the heel is brought down, the profile will fold in the position indicated by the dashed lines of the profile 62. Although the main function of the profile 62 is to control the opening it still functions as a spring. Due to the fact that the skate is short, the screws 66, with which the mainframe is connected to the shoe, suffice to keep the shoe and main frame in line and even to accept thrust forces on the main frame. The elastic zone 15 of the delivers enough hinge power, on this short skate, to guarantee operation. The fastening and bindings are on this skate/shoe combination identical to the ones discussed under Fig. 6,7.