SPRING DAMPING SYSTEM FOR INLINE SKATE

Abstract: The present invention relates to an inline skate with a shoe or boot part and a roller blade, which are interconnected by a spring damping system in such a way that there is a rotation axis at the front end of the shoe or boot part and the front end of the roller blade. To improve the damping behaviour with respect to impacts or vibrations, it is proposed that the rotation axis (A) of the system formed by the shoe part (2) and roller blade (3), with respect to its x-coordinate, is at the same height as the axis (B) of a front roller (5) or is in front of the axis (B) of the front roller (5).

Description: Spring Damping System for Inline Skate The present invention relates to an inline skate having a shoe or boot part and a roller blade, which are so interconnected by a spring damping system that there is a rotation axis at the front end of the shoe or boot part and the front end of the roller blade. The problem arises with inline skate pairs of any price category, that the joints of the sportsman or skater are highly stressed even in the case of normal skating as a result of vibrations or impacts . When skating over flat or plate paths or the very frequently occurring composite stone pavements, these effects are so extreme that the skater can very rapidly become fatigued or suffer pain. The enjoyment of inline skating can consequently be impaired in a rapid and lasting manner, because not only is the skating comfort reduced, but in the long term there can be permanent damage, e.g. to the knee joints, as well as to the spine. Attempts have been made to alleviate this up to now in that damping materials have been used in the shoe parts or on the rollers, or embedded in the roller blade. Whilst leading to a minimum success, these measures have simultaneously led to a significant force loss in such damping mechanisms and which the skater must overcome in order to accelerate . An inline skate of the aforementioned type is disclosed in US- A-5,503,413 where, between a shoe part and a roller blade of an inline skate, a damping system is provided. Thus, in the vicinity of the front end, the shoe part is connected to a front end of the roller blade by a joint. A helical spring is located at the heel between the shoe part and the roller blade. However, this system suffers from serious disadvantages. Thus, when a front roller strikes against a ground unevenness or other obstacle, the damping system is substantially blocked. The impacts caused during skating by ground unevennesses are consequently directly transferred by a relatively rigid force coupling of the rollers to the foot of the skater and therefore have an increased effect on further parts of his skeleton. The problem of the present invention is therefore to further develop an inline skate of the aforementioned type, whilst significantly reducing the aforementioned disadvantages. According to the invention this problem is solved in that the rotation axis of the shoe part and roller blade system is positioned with respect to its x-coordinate at the same height as the axis of a front roller or in front of the axis of the front roller. The invention can also be used on a single inline skate of an otherwise identical pair. As a rule, both inline skates in a pair have a symmetrical construction. Thus, within the scope of the present invention, reference is always made to a pair of inline skates . A ground unevenness is. always encountered by the front roller and the latter is raised by said unevenness . In the case of the inventive arrangement of the rotation axis with respect to the axis of the front roller, the force introduced into said roller exerts a moment about the rotation axis of the system. This moment can be absorbed or reduced by the oppositely directed moment of the damping system. The same applies when following rollers pass over the unevenness and the front roller can reliably maintain ground contact, even under the influence of the damping system. Thus, vibrations are effec- tively reduced on skating over a branch or a plate edge, but without impairing acceleration. The force exerted by the inline skater for acceleration purposes on the front roller and having a short moment arm can only exert a negligibly small moment about the fulcrum. The force to be introduced into the damping -system is correspondingly small . This loss can be eliminated in the case of a corresponding design and adjust- ment of the system. In a preferred embodiment, the rotation axis is located in a Cartesian coordinate system with respect to its z-coordinate level with the sole of the shoe or boot part. Preferably the rotation axis is positioned above the sole of the shoe part. As a result of this measure and taking account of the aforementioned consideration of a balance of moments about the rotation axis, the response sensitivity of a damping system according to the invention is increased. The impact initiated by an obstacle or ground unevenness introduces a force into the front roller, so that a moment about the rotation axis is always produced when the rotation axis is positioned in the z- direction above the axis of the front roller and this moment must be compensated by the damping system, which leads to an overall impact stress reduction. In a preferred embodiment, in the vicinity of the front end of the shoe part, the latter is articulated to the front end of the roller blade. For this purpose, use is advantageously made of dustproof bearings, which for producing a high, lateral tilting stability in the direction of the y-axis of a Cartesian coordinate system, have a very large reciprocal spacing. A resilient restoring force of the damping system can be pro- duced in that the shoe part throughout the area of the front end is fitted in bending elastic manner to the front end of the roller blade. This simultaneously makes it possible to implement the features of an articulation and the provision of a spring tension. However, when choosing a laterally stable mounting by bearings, the articulation can e.g. be effected by a torsion spring. However, in a preferred embodiment, the spring tension is provided in the heel region of the shoe part by a spring element in the form of a helical spring. However, alternatively it is possible to have a leaf spring bent in U or V-shaped manner between the heel of the shoe part and e.g. the end of the roller blade. According to the invention, the shoe part and roller blade are at an angle a of preferably 5° to one another in a normal position about the rotation axis . The spring elongation of the damping means attainable through this spreading is preferably at least 15 mm. Advantageously, the in each case obtained maximum spring elongation is always brought about in the vicinity of the heel of the skater, from where, without use of the present invention, the impact effects would be transferred by the most direct route to the spine. Advantageously, the spring elongation of the damping system is stabilised by a lateral guide in the vicinity of the heel of the shoe part. This advantageously ensures that the inline skate is secured against lateral tilting, even in the case of high stressing. According to an advantageous embodiment, the guide comprises a rod, which is connected to the roller blade. A sleeve connected to the shoe part in the heel region is displaceably arranged over said rod. In an embodiment the rod is fixed to the roller blade. As a result of the unilateral articulation about the. rotation axis, the system moves along a short arcuate portion of a circular path. In order to ensure an unhindered and constantly jamming-free sliding of the sleeve on the rod, in horizontal cross-section the sleeve has at least partly an elongated hole, or is elliptically widened in the x-direction. Alternatively the sleeve can be replaced by a U-piece as the lateral guidance and stabilisation element . In another embodiment the rod is so articulated to the roller blade, that there is a mounting with one degree of freedom. Thus, the rod can only be tilted within the necessary limits in the vertical x-z-plane of the inline skate. The rod is held by a sleeve fixed to the shoe part. In general, contact bet- ween rod and sleeve can be made such as a result of a suitable material choice that an additional damping of the movement occurs through friction. This makes it possible to bring about a rapid oscillation of the arrangement, even in the case of limited wear. A dvantageously, at the upper end of the rod is provided a spring element, which is in contact with the displaceable sleeve or U-piece. Thus, any movement is cushioned in both directions . In an inventive damping system further at least one end stop can be integrated. The end stop is preferably constructed as a rubber part and reduces the impact in the case of a complete pressing through of the spring element or any hard engagement on a stop member. Alternatively a rubber part can also be located at the upper end of the rod in place of the previously described spring element. According to a further development, at the upper end of the rod is positioned a tensioning device for producing a preten- sion for the spring element. The spring tensions providing a normal position can consequently be adjusted e.g. as a func ¬ tion of the body weight of the skater. With this solution, it is possible to obtain a small size of the guide, including the suspension and setting, as will be shown by means of an embo- diment. It is also possible to tension the second spring ele ¬ ment. In the case of inline skates the brake commonly is used in the form of a brake block, which is located at the heelside end of the roller blade. The skater exerts a braking action there ¬ with, in that he tilts rearwards one of the inline skates and presses the brake block on the substrate, the resulting fric ¬ tion producing a braking action. In all the inventive modifi ¬ cations and/or extensions of the inline skates according to the invention proposed here, this construction of the brake can remain unchanged. However, under the action of a damping system according to the invention, the effect arises that also the brake block is cushioned with respect to the substrate during the braking process, so that the braking action is no longer hard and abrupt. It can also be proportioned within a wide range and the maximum braking force is not reduced. Thus, the inline skates according to the invention, also during braking, have more agreeable characteristics than the models known hitherto. With regards to any injury risk, it is particularly advantage- ous that the damping system can be compactly constructed in such a way that it can at least partly be integrated into the shoe part. The shoe part consists of plastics components, that are e.g. produced by injection moulding. The inventive modifications with respect to the moulds and manufacturing tools are advantageously very small. Therefore the invention can be integrated easily and inexpensively into an existing range. Inline skates according to the invention are consequently characterized by a broad design range and adaptability to existing ranges. Its damping action has no disadvantageous effect on the accelerating or decelerating behaviour. The front rollers can be used in undamped form during acceleration, so that no acceleration energy is lost in damping. Almost half the time within a movement cycle during inline ska- ting a skater only loads one foot. Thus, said foot is placed on the ground or substrate under full load. This leads to the advantageous effect of the damping according to the invention and there is a reduction of the vibrations acting on the skeleton from the substrate, via the rollers. Of late there has been a tendency with inline skates for the shoe or boot part and roller blade to be manufactured as separate and consequently interchangeable parts. Thus, the damping system according to the invention can be used as a connecting part between the shoe part and the roller blade, so that it can be in the form of a supplementary part for existing inline skate systems . Further advantages are described in greater detail hereinafter relative to embodiments and the attached drawings, wherein show-. Fig . 1 A side view of a first embodiment of inline skates. Fig . 2 A sectional representation of a front view of the inline skate of fig. 1. Fig. 3 A sectional representation of a detail of fig. l. Fig . 4 A plan view of the detail of fig. 1. FFiigg.. 55 A further embodiment of an inline skate. Fig . 6 A front view of the inline skate of fig. 5. Fig . 7 A side view of another embodiment of an inline skate. Fig. 1 shows a first embodiment of an inline skate 1 in side view. This clearly shows the subdivision made by the manufacturer to the inline skate 1 into a shoe or boot part 2 and a roller blade 3. The shoe part 2 comprises plastics shell or dish parts with an inner shoe, which can be closed by straps and/or levers about the foot of a skater in known manner. As a rule the roller blade carries four supported rollers and terminates in a brake block 3c at its heel-side end 3b. The two parts, i.e. the shoe part 2 and roller blade 3, are interconnected in articulated manner by a damping system 4. This connection has a rotation axis A, which is in front of a roller axis B of a front roller 5 in the xdirection of the Cartesian coordinate system shown. For producing a corresponding articulation 6 , the front part of the shoe part 2 is constructed passing into an eye 6a, which engages in a recep- tacle 6b of the roller blade 3 and is here fixed in rotary manner by a pin 7. Screw couplings 9 laterally fit caps 8 to the pin 7. Thus, the pin 7 is fixed in position. The articulation 6 with its rotation axis A at the height of the sole of the shoe part 3 is above the roller axis B by an amount d. To a heel part 2b of the shoe part 2 is fixed a guide 10, which belongs to the heel-side part of the damping system 4. The guide 10 largely comprises a sleeve 11, which is displace- able on a rod 12 fixed to the roller blade 3. Between the sleeve 11 and roller blade 3 there is a spring element in the form of a helical spring 13 on the rod 12. When the shoe part 2 is loaded, e.g. by the weight of a skater, the helical spring 13 is compressed by a corresponding amount by compres- sive loading, so that the sleeve 11 is moved on the rod 12 in opposition to a spring tension in the direction of the roller blade 3. A second helical spring 14 is located on rod 12 above sleeve 11. The rod 12 is terminated at its upper end by a setscrew 15, so that the helical spring 14 is also stressed as a compression spring. Therefore the helical springs 13 and 14 build up opposing forces, which move the guide 10, as a function of the loading, into a compensated position. Thus, hard impacts are not transferred to the body of a skater as a result of this system. In the embodiment of fig. 1 the length of the rod 12 is adjustable in a predetermined range by the setscrew 15. In place of the fixing by riveting or welding of the rod 12 to the roller blade 3, it is also possible for the lower end 16 of the rod 12 to be fixed by screwing in the roller blade 3. Through a correspondingly long thread and e.g. with securing by a lock nut, an alternative length adaptation method could be easily implemented. The means 17 for pretensioning the spring system constituted by helical springs 13 and 14 in both cases serves to adapt the length of the rod 12 and this can advantageously take place as a function of the weight of the skater. In the set inoperative or compensated normal position, the shoe part 2 and roller blade 3 are at an angle a of approxima- tely 5° to one another. The spring elongation w of the damping system 4 in the vicinity of the heel usable for cushioning impacts resulting from ground unevennesses is at least 15 mm. Fig. 2 is a sectional representation of a front view of the inline skate of fig. 1. It is clear that the entire inline skate is only very slightly higher than conventional inline skates as a result of the above-described, additional compo- nents . The section through the articulation of the shoe part 2 to the roller blade 3 shows that the pin 7 passes through the eye 6a and is held in dustproof bearings 18 and axially secured by caps 8. A spacing D resulting from this construction secures the rotation axis A of the articulation 6 against lateral tilting. Fig. 3 shows a sectional representation of a detail of fig. 1, namely a section through sleeve 11 with traversing rod 12. As a result of the described nature of the articulation, the guide 10 moves over distance w on a circular path. Even though the circle has a relatively large radius, a good displaceabi- lity is to be guaranteed in any permitted position. For this purpose the hole in the sleeve 11 is e.g. at least partly constructed as an elongated hole. In the broken line represen- tation is indicated a second limit position of the rod 12, in order to illustrate the good guidance characteristics of such a sleeve 11, even with a large angle change. Fig. 4 shows in a plan view of the detail of fig. 1 that the opening in the sleeve .11 is an elliptical or oval elongated hole, which is almost circular in the central area of the sleeve 11. As a result of these special elongated hole characteristics it is not possible for the rod 12 to tilt, because it is always securely guided in the direction of the y-axis. In a side view fig. 5 shows an alternatively mode for a guide 10, which is oriented with respect to the aforementioned possibilities. The rod 12 is constructed as a screw 21, which can be turned in a nut 22 over an adjustable length. The nut 22 is articulated to the heel-side end 3b of the roller blade 3. The displaceable guide 11 between the end of the screw 21 and the nut 22 in this form does not have to have such a pronounced elongated hole as was described in connection with fig. 3 as a measure for preventing jamming. As a result of a pretensioned torsion spring 19 in the articu- lation 6, it is also possible to insert a tensioned spring element on the guide between the sleeve 11 and nut 22 and which is once again implemented in the form of a helical spring 23. This form of guide 10 is very compact. It is consequently simple to integrate the sleeve 11 with all the ess- ential parts of the guide 10 in the vicinity of the heel of the shoe part. For length adjustment purposes the screw 21 could be accessible from the outside by means of knurling, which is only intimated in fig. 5, as is e.g. already known for inclination adjustment purposes in Alpine skiing boots. In general, a spring system like that of fig. 1 is conceivable, the upper helical spring 14 being replaceable by a rubber stop 24 and the compressively stressed spring 13 remaining unchanged. As a modification of the embodiment of fig. l, in the articulation 6 in fig. 5 is inserted a pretensioned torsion spring 19, e.g. a steel spiral spring. However, advantageously it is built up in the form of a rubber torsion spring 20 directly at the time of assembly of the articulation 6 in a vulcanisation stage between the eye 6a and the receptacle 6b, or inserted as a finished torsion spring element. Fig. 6 is a front view of the inline skate of fig. 5 with sectioned articulations 6, as in fig. 2. It can be seen that the cavity between the eye 6a and receptacle 6b can be advan- tageously used for housing the rubber torsion spring 20. Once again the caps 8 provide protection against axial forces and the bearings 18 support the spring element in such a way that the rubber part can act solely as a torsion spring and not as a damping element for the front rollers . This also prevents a tilting in axis A. Fig. 7 is a side view of another embodiment of the inline skate, based on fig. 1. As in the preceding description a torsion spring 19 is placed in the articulation 6. The torsion spring 19 is incorporated under pretension in inline skates 1, so that there is no need for the helical spring 13 on the guide 10. The helical spring 14 used as an absorbing and restoring spring for the setscrew 15 is retained. Alternatively in the embodiment of fig. 7 and also the preceding embodiments, the helical spring 14 can be replaced by a rubber disk or buffer in the manner of a rubber stop 24. Fig. 7 also shows the position and construction of an end stop 25 according to figs. 1 and 5 in a further variant. It is a further rubber disk, which surrounds the lower end 16 of the rod 12. Thus, in the case of complete pressing through of the torsion spring 19, there is a reduction of impact when the shoe part 2 engages on the roller blade 3.

Claims: CLAIMS 1. Inline skate with a shoe part and a roller blade, which are so interconnected by a spring damping system that a rotation axis is located at the front end of the shoe part and the front end of the roller blade, characterized in that the rotation axis (A) of the system formed by the shoe part (2) and the roller blade (3) is, with respect to its x-coordinate, at the same height as the axis (B) of a front roller (5) or is positioned in front of the axis (B) of the front roller (5) . 2. Inline skate according to claim 1, characterized in that, with respect to its z-coordinate, the rotation axis (A) is at the same height or preferably higher than the sole of the shoe part (2) , but is at least above the axis (B) of the front roller (5) . 3. Inline skate according to one of the preceding claims, characterized in that, in the vicinity of the front end, the shoe part (2) is articulated to the front end of the roller blade (3) . 4. Inline skate according to one of the preceding claims, characterized in that, in the vicinity of the front end, the shoe part (2) is fitted in bending elastic manner to the front end of the roller blade (3) . 5. Inline skate according to one of the preceding claims, characterized in that at least one spring element produces the restoring force . 6. Inline skate according to one of the preceding claims, characterized in that the spring element is a torsion spring (19) , particularly a rubber torsion spring (20) . 7. Inline skate according to one of the claims 1 to 5 , characterized in that the spring element is a helical spring (13) . 8. Inline skate according to one of the claims 1 to 5 , characterized in that the spring element is a leaf spring. 9. Inline skate according to claim 4 or 8 , characterized in that the spring element is a leaf spring bent in U or V- shaped manner and located in the heel region and/or in the area of the rotation axis (A) . 10. Inline skate according to one of the preceding claims , characterized in that a force acts as a result of the damping system (4) between shoe part (2) and roller blade (3) in such a way that an acute angle α. is obtained between the lower surface of the shoe part (2) and the upper surface of the roller blade (3) . 11. Inline skate according to one of the preceding claims, characterized in that the angle α is approximately 5°. 12. Inline skate according to one of the preceding claims , characterized in that a guide (10), particularly for lateral guidance purposes, is provided in the vicinity of the heel of the inline skate (1) . 13. Inline skate according to claim 12 , characterized in that the guide (10) comprises a rod (12) connected to the roller blade (3) and a sleeve (11) or U-piece or fork displaceable over the same and connected to the shoe part (2) . 14. Inline skate according to claim 12 and/or 13, characteri- zed in that the rod (12) is articulated to the roller blade (3) . 15. Inline skate according to claim 12 and/or 13, characterized in that the rod (12) is fixed to the roller blade (3) and . a U-piece or sleeve (11) passes displaceably over the same and which in horizontal cross-section at least part- ly has an elongated hole. 16. Inline skate according to one or more of the claims 12 to 15 , characterized in that at the upper end and/or lower end (16) of the rod (12) is provided a spring element (14, 23) , which is in contact with the displaceable sleeve (11) or the U-piece. 17. Inline skate according to claim 16, characterized in that at the upper end and/or lower end (16) of the rod (12) is provided a means (17) for producing a pretension for the spring elements (13, 14, 23). 18. Inline skate according to one or more of the preceding claims, characterized in that the damping system (4) is at least partly located in the shoe part (2) , particularly in the heel region.

Inventors: KOCH WALTER, KOCH, WALTER
Applicants: KOCH WALTER, KOCH, WALTER
Application year: 1998
Main classification: A63C17
IPC codes: A63C17