WO1998041295A1

WO1998041295A1 - Wheel and belt drive with transversal brake

Info

Publication number: WO1998041295A1
Application number: PCT/DE1998/000767
Authority: WO
Inventors: Viktor Schatz
Original assignee: Viktor Schatz
Priority date: 1997-03-17
Filing date: 1998-03-14
Publication date: 1998-09-24
Also published as: AU7204698A

Abstract

The invention relates to a wheel for a roller skate, comprising a round, spiral tyre ring rotationally mounted in a V-shaped groove in the wheel rim. As the tyre becomes narrower in diameter as a result of wear, it moves further into the groove. This ensures that wear is automatically compensated and guarantees centering. The tyre ring is produced by welding at the ends of an originally straight section, with the result that it rotates easily and evenly around its torus axle. The frictional forces normally keep the tyre fixed to the rim. However, when the side forces become too great, for example because of transversal braking, the tyre turns with a certain resistance and causes deceleration. In special designs, the rotatable tyre is enlarged to form a belt and mounted using several rims. The use of a closed, metallic, flat spiral spring as a tyre -on a rubber-coated floor covering- is also of interest. It is also possible to produce a ring tyre with a smooth surface.

Description

Wheel and belt drive with cross brake.

The invention relates to wheels and belt drive for roller skates and other foot sports equipment, preferably for "in-line" skates, which are hereby equipped with a braking function for transverse braking.

State of the art If the braking direction is used as a criterion, there are only two types of braking: braking direction in the running direction of the rollers - or transverse to it.

A few patents are known which propose a wheel with transverse rollers integrated in its tread, which allow the wheel to move laterally:

U.S. 5,383,715 A.Homma; Wheel provided with subwheels;

U.S. 5,312,165 G.F. Spletter; Combination brake and wheel

System A large number of small disc wheels made of hard-elastic polyurethane are impaled on a ring-shaped, closed axle and the whole thing is held together from the outside with two disc-shaped discs, which together form a semicircular rim groove, "semi-tight" - Measures to compensate for this are not provided.

U.S. 5,246,238 N.R. Brown; U.S. 3,789,947 J.F. Blumrich;

U.S. 4,715,460 R.E. Smith; US 4,926,952 J. Farnam "wheelchair" /

US 5,213,176 self-propelled vehicle; US 5,685,550;

U.S. 1,305,535 J. Grabowiecki 1919; DE 822660 Ch. Fuchs, a wheel with cross rollers; CA 475,792 T. Souman, US 3,253,632 W. Dalrymple, Boeing Co .; DE 3702660 AI Schneider G. US 5,716,074 and US 5,720,529 use balls as transverse rollers.

Although these writings have the same and correct type - additional transverse rolling elements in the tread of a wheel - do not lead to any usable solution for inline skates - a number of problems that are difficult to solve from a technical point of view partially destroy the good approach: insufficient stability of the construction, great complexity, inadequate braking devices, loss of properties after a slight abrasion, large interruptions in the running track - these are properties , which make practical, robust and reliable execution impossible.

A technological approach to the present invention proposes a ring tire, or a belt, made of straight, round-profiled bars, the ends of which are welded or vulcanized. The prior art for this is as follows: only drive belts that are manufactured in a similar way are known, with weldable elastic materials (polyurethanes) or types of rubber to be glued or vulcanized being used, and thus belts of any length can be produced. A deliberate pressure and tension distribution in the ring is not important - the drive belt is usually of a much larger diameter than the diameter of the elastic cords.

Technical problem The object of this invention is therefore to propose a technical solution that enables braking with in-line roller skates as on ice - by placing the two roller skates at right angles to the direction of travel. There are a number of sub-tasks which define further technical problems that have arisen in practical implementation: a) automatically compensate for the wear of the tire; b) to mount the tire on the wheel rim in such a way that the friction is reduced - and this friction can be structurally influenced in a sufficiently large adjustment range; c) to realize a load dependency, both the driving of sharp curves, as well as braked sideways spinning the transverse rolling elements guaranteed. In addition, a third regime should also be possible - easy turning of the transverse rolling elements when turning on the spot in order to ensure the best maneuverability; d) to solve the stress relaxation problem in the elastic ring tire according to the present invention; e) propose alternative solutions that lead to comparable results by other means;

Here, technical conditions are exploited which are mutually beneficial: when braking at a lateral angle, higher forces occur in the initiation phase than when driving at an angle in the bends; static friction is significantly higher than sliding friction; and the frictional forces are dependent on the acting load forces. The basic idea of the technical teaching according to claim 1 is to tire the wheel (or several rims at the same time) with an elastic ring tire, preferably a round cross-section, the frictional forces (or the rolling resistance) holding the ring tire during normal driving on the rim. With lateral braking, however, the lateral forces exceed which try to twist the ring tire in itself. They overcome the static friction and twist the ring tire around its torus axis - as a result, the roller driver slips with the wheels turned sideways. The rubber tire will reduce the kinetic energy due to the friction in its seat - this will be converted into heat.

The rotatable tire can be stored in rolls, or can only be held in the friction surfaces of the rim.

As the tire wears out, its cross-section is reduced, making it looser in its seat. In order to still reliably hold the thinner tire on the rim, we first propose the holding rolling elements, or to attach friction surfaces movably in special holders, which in turn are pressed against the tire ring by spring elements.

The arrangement of the rolling elements for the tire guide can be done in a variety of ways - if you want to restrict yourself to just two rows of rollers, these rollers should be as close as possible to the ideal line to the center of the tire cross-section so that reliable tire guidance is ensured even after the tire has worn out .

The use of an elastic, prestressed ring tire further simplifies the construction: due to its own tensile forces, it presses itself into the holding rollers or into the friction surfaces. Even after wear, the tire still reliably presses into its guide elements. This eliminates the need for special movable brackets for the holding rolling elements, and the spring elements themselves.

Instead of the holding rolling elements, friction surfaces can be used which are made of slidable materials. In the best case, there are simply two cone surfaces that run obliquely to each other in the rim. The tire ring inside is centered on the two contact surfaces - even after wear and tear with the then smaller cross-section.

The tire ring must be manufactured using special technology: a straight section of an elastic rod (or hose or spiral) with a round cross-section must be bent and firmly connected at its ends. The result is a tire ring with symmetrical stress distribution that can be easily and evenly rotated around its circular axis / torus axis. Shaping processes are completely unsuitable because this creates a tension-free tire ring, the uneven one Material distribution in the inner and outer areas severely hinders the turning of the tire.

The fixed connection at the ends of the elastic rod can mean welding, gluing, vulcanizing or also mechanical screwing (or plug-in connection) by means of fastening parts previously let into the rod.

A rope core previously placed in the tire bar enables assembly in which tires are pushed onto the core. As a result, the outer surface, the tread of the finished wheel, can be made completely or partially stress-free - important because elastic material under tension would otherwise be easily "vulnerable" and would burst on the smallest cracks. The compression on the inside of the tire of course continue to increase - but there it does not impair the function.

If the tension in the tread does not play a role with a suitable material, you can do without the rope core and connect the tire ends themselves.

Furthermore, a cylindrical spiral spring can be installed in the tire ring instead of a non-stretchable core rope. This spring can be inserted tension-free as well as used under considerable tension. In both cases, this counteracts the disturbing effect of the stress relaxation in the elastic material of the tire: Polyurethanes in particular have poorer relaxation properties - a physical process in which the stresses in the material are slowly lost.

Advantages can also be expected if a cavity is created in the tire ring and inflated with compressed air through a nipple opening: it saves material and weight and improves damping. A sensible further development brings advantages through the use of an extended tire ring, which is mounted over several rims - similar to a chain drive. This partially eliminates the stress relaxation problem and enables a special application, such as off-road, because a larger ground contact area is created.

A side development is also possible that uses cylindrical spiral springs made of metal or plastic instead of elastic tire rings. Here, the rims only need to have simple semicircular grooves - because there is no abrasion on the spring tire and therefore does not have to be compensated. The friction surfaces could ensure the necessary friction ratio through the choice of material and surface quality. This variant can only be used on elastic, rubber-like floor coverings that are suitable for sufficient friction with metal springs - especially in the halls.

Because the coil is the most effective at relieving stress relaxation, it is also suitable for an elastic polymer version. The tread, which is interrupted by turns, causes a noticeable driving vibration - but allows a fully functional and inexpensive solution. If the spiral is also cut in a zigzag course, the turns interlock and overlap the gaps - resulting in a smoother process.

Composite material also helps against the stress relaxation in the tire ring: inserts made of harder, wear-resistant elastomer are sunk into a carrier made of soft, stretchy elastomer or mixed in as particles.

An inexpensive and manufacturable solution to both tension relaxation and concentricity is promised by an elastic rod made of a soft, stretch-resistant core and an approximately 2-3 mm thick outer layer made of abrasion-resistant Elastomer is applied, and a suitable tire pattern is cut around the rod in this outer layer by means of grooves. The depth of the grooves extends to the soft core, and their width and course leave the hard outer layer free of expansion / compression, and at the same time ensure the greatest possible overlap of the gaps. Only the very soft core expands and must master the stress relaxation.

It can be advantageous not to make the elastic rod for the ring tire completely round, but rather polygonal.

The proposed wheels with braking function can also be used for "skate boards" and classic quad roller skates, as well as for skis on wheels.

The invention is described with reference to drawings for some advantageous exemplary embodiments. Show it:

Fig.l balance of forces on the wheel in an inclined position. 2 shows a ring tire with screw connection, made of composite material. FIG. 3 from the cross section of a wheel with a stretched tubular tire that is rotatably mounted in two rows of rollers. FIG. 4 isometric illustration of FIG

Fig.5ab a wheel with two tires, which are mounted in three rows of rollers Fig.6ab Cross section of a wheel with a stretched ring tire, which is rotatably mounted in friction surfaces

7 a cross-section of a wheel with a stretched ring tire, which is rotatably mounted in two obliquely arranged friction surfaces, FIG. 8 a ring tire composed of conical disks and a spiral spring

Fig. 9 rod made of composite material for the production of the

Tire rings Fig. 10 isometric view of Fig. 7 with detail

- and a spring core

Fig. 11 isometric view of Fig. 7 with detail

- With a cast-in spring core and modified friction surfaces

Fig.12 a wheel with tires, which consists of a cylindrical

Spring is formed Fig.13 a wheel with a tire, which is formed as a spiral spring made of elastic material Fig.14 a tire which is expanded to form a belt and was pulled over several wheel rims Fig.15 a rod for producing the ring tire, the

Spiral but cut in a zigzag

In Fig. 1 a roller skate is shown in an inclined position, such as e.g. is the case when cornering or braking sideways. All wheels on both skates participate equally in the generation of the braking forces if they are in contact with the ground.

The frictional forces between the ring tire (1) and the V-shaped rim (2) normally hold the tire in place - this results in a static friction torque (M _r ). This moment (M _r ) provides resistance to the torque (M _z ) which arises from the centrifugal force (F _z ) with the lever (R).

If the centrifugal torque (M _z) remains below the static friction torque (M _r ), the picture is a normal cornering with a fixed tire.

If, due to rapid transverse movement, the force (F _z ), which in this case results directly from the inertia, temporarily takes on larger values, so that (M _z ) becomes larger (M _r ), this results in the tire spinning (1). After the slipping has been initiated, much lower sliding friction conditions occur - that's why the slipping maintained, even if the force (F _z ) is now lower. The runner slips on the brakes in the direction of travel with transverse rollers - whereby a delay is guaranteed by the friction.

The reactions shown in the force diagram are:

G weight per roll

F _z centrifugal force or inertia

S total force from both of the above forces α angle of inclination of the rollers to the track

M _r friction torque

M _z centrifugal torque, or slip torque

R tire radius

F _z = S x cos = G x ctgα; M _z = F _z ^χ R = G ^χ R ^χ ctgα

As can easily be seen from the formula, the slip torque M _{z is} directly dependent on the weight of the runner G, the angle of inclination α, which reflects the intensity of the steering or braking maneuver, and the radius R of the tire, which in this case is the lever forms.

The tension relaxation in the elastic material of the tire, if it does not become too large, can help to expand the force limit between slipping when braking and holding the tire when cornering, and thus make it clearer.

In Fig.2 a ring tire (1) can be seen in cross section, which is screwed tightly at its ends. The screw (5) is anchored with its ball head (3) rotatably in the ball seat (4) and embedded with it in the elastic rod of the ring tire - overmoulded or vulcanized. At the other end of the elastic rod, a screw insert (7) with thread is embedded in the same way - into which the screw (5) is screwed. A cross hole (6) in the screw (5) is used to hold a pin tool the screw is turned. The ends of the elastic rod contract and form a contact surface - even then the pen tool can still be rotated by pushing the pin against certain force in the contact surface. Instead of the pin tool, a flat hexagon tool can also be used, according to which a hexagonal position on the screw (5) can be realized.

This type of fastening is advantageous if the ring tires are brought to the customer as a straight rod to eliminate the stress relaxation, and only then is the customer assembling them ready for use. With natural rubber, in addition to stress relaxation, there is also the problem of increased material aging under tensile stress. By dismantling, the customer can repair the ring tire already deformed by Relaxion.

It can also be seen that the elastic rod for the ring tire (1) is composed of two materials: on the inner relaxation-free carrier (14) there are abrasion-resistant inserts (13) as a tire pattern. Because the gaps in the tire pattern are chosen so that the hard inserts (13) do not have to participate in the expansion and compression of the tire, the problem of stress relaxation only remains for the soft core (14). This core is made of a very soft and stretchy elastomer which can be used to eliminate the relaxation. The tire pattern is also designed in such a way that the gaps overlap as much as possible and thereby achieve a fairly smooth rolling surface.

Fig. 3 a) b) shows in half cross-section the rotatable mounting of the tire ring (1). The tire is under tension and presses itself against the rollers (8) - even if it becomes thinner due to wear

(Fig.3b). In a certain work area, the roles are fulfilled its function continues until eventually it is put to an end - through wear.

The solution according to FIG. 3 can be seen three-dimensionally in a detail in FIG.

The rollers (8) made of spiral springs are interrupted here - to ensure their greater mobility, because while the tire is twisted in itself, spiral springs have limited torsional capabilities. Of course, balls or olive-shaped rollers can be used here instead of the springs.

The tire (1) shows no core inside - it is a tube that has been inflated with compressed air. The compressed air can be loaded at the manufacturer as a one-time charge, or it can be pumped up using a nipple embedded in the tire. The wall thickness of the hose must be selected in such a way that sufficient function is guaranteed even at the end of use after wear.

The rim can be made in two parts or in one part. In the latter case, the tire must be stretchable so that it can be mounted on the rim.

Fig. 5 a) b) shows a special solution with two tires (1), which are stored in three rows of rollers. The middle spring roller (9) also serves both tires. The tires are self-pulling and thus compensate for wear. Under a) the arrows indicate the direction of rotation of the two tires (1) and the central roller spring (9).

Fig. 6 a) b) shows a simplification, which is achieved by using flexible ribs (10). They form holding and sliding elements of the rim, in which the tire (1) is rotatably mounted. The ribs are pre-tensioned and contract when the tire wears. The ribs could also be made straight V-shaped. Fig. 7 a) b) shows an advantageous variant that only needs two friction surfaces that are positioned at an angle to one another - when using the self-pulling tire (1). The tapered surfaces provide the tire with support both in its initial cross-section (a) and in the reduced cross-section after wear (b). The oblique friction surfaces in the rim (2) can be cut straight or be slightly curved. The tire can hardly pop out because it is pressed into the V-shaped groove of the rim in every position by its own tensile force and the load forces. The angle of inclination of the friction surfaces can deviate slightly from 45 ° in order to influence the braking properties.

A ring tire composed of individual conical disks (12) can be seen in FIG. The washers are rotatably impaled on the spring core (11) and are supported on the inside with their slightly conical side surfaces. This arrangement is particularly suitable for making the disks from hard material so that they can be used on rubber floors. The rim is then best equipped with a round groove. It is a special form of the solution according to Fig. 12 - only this wheel can be used to perform turning maneuvers particularly well on the spot because each disc can be rotated independently. This would make the wheel suitable for figure skating, especially as the front wheel.

In Fig.9 is a rod made of composite material for the production of the

See tire rings. Friction-resistant inserts (13) made of a harder polymer are attached to an elastic carrier (14) made of a stretch-free, relaxation-free elastomer.

The friction-resistant insert (13) is here preferably only of spiral design.

The stress relaxation is switched off by composite material and is nevertheless a relatively wear-resistant and smooth

Wheel surface reached. The polymers can both

Polyurethanes as well as rubber compounds. Relaxation can also be remedied by a mixture of elastic carrier and mechanically crushed friction-resistant insert. The tire ring is made as usual by welding, screwing or vulcanization at the ends of the rod. A cavity, as seen in Fig. 9, can also be created and possibly inflated, or equipped with a spring core.

10 shows isometrically the solution according to FIG. 7 a) b) with conical friction surfaces (15) as guide elements - and a tire (1) with the core spring (11).

The rim can be made in two or even one piece - from a slidable material, e.g. Metal or polyethylene, or Teflon etc.

The tire is manufactured using the technology described, only the core is designed as a spiral spring. This coil spring can be easily connected at the ends - by winding a few turns of smaller diameter at one end and inserting them into the other end with force.

The conical friction surfaces (15) could also be completely designed with balls, each of which is placed in its own seat. As a result, the torsional resistance can be further reduced, which is e.g. is necessary if rubber tires are used instead of polyurethane.

11 shows an advantageous modification of the variant in FIGS. 7 and 10.

The conical friction surfaces are divided into areas that allow sliding - the sliding ribs (16) - and braking surfaces (17), which are roughened. The sliding ribs (16) stand out above the braking surfaces (17) - the tire (1) does not touch the braking surfaces (17) under normal load and can therefore be rotated more easily - for example for turning maneuvers on the spot.

Under additional forces caused by centrifugal forces in the curve or when braking, the tire (1) is pushed through and rubs against the roughened braking surfaces (17). This results in a higher torsional resistance, which is necessary when cornering and braking.

This means that three different operating modes are realized: easy turning on the spot under normal load, cornering with high lateral forces, and braking with adjustable forces.

The tire (1) with a core spring (11) is produced according to the described method - but with a cast-in spiral spring and cavity inside. The surface of the V-shaped groove can be designed as a sheet metal part in the plastic fig.

The cavity in the tire could also be filled with compressed air via a simple nipple opening - if this brings advantages, for example to dampen road roughness.

12 shows a wheel with a spiral spring as a tire - spring tire (18), which is mounted in a semicircular groove (19) in the rim. This simple solution is only suitable on elastic, rubber-like floors - such as in sports halls.

The friction surface (19) can also be designed as a conical friction surface according to Figure 7 - but does not have to, since there is no wear on the hard spring tires (18). Of course, here too, the friction surface (19) can be divided into different areas in order to achieve certain driving characteristics and braking characteristics.

It is also conceivable to use a belt-like spring over several rims, as in Fig. 14 - but also only for rubber floors.

Fig. 13 shows a further development of the variant in Fig. 12, wherein a spiral wound tire (20) made of elastic

Material is used. The distances between turns allow the tension to be reduced considerably - and thus the

To prevent stress relaxation.

This spiral tire is also manufactured according to the same process: first a straight spiral section was bent and welded or vulcanized at the ends, then it is stretched onto the rim slightly stretched.

Something similar is achieved if the tire rod is manufactured as a core with disks, the diameter of the

Core area defines the tensile forces. Basically that's almost it

The same can be achieved with a strongly depressed tire tread.

The combination with the V-shaped groove of a rim results in a very simple and functional solution consisting of only 2 parts, which only has a slight disadvantage due to the slight uneven running.

Fig. 14 shows an advantageous further development in which a common belt tire (21), like a belt over several rims (2) is mounted.

The rims have V-shaped grooves, as previously described in Fig.7 - but can also use springs or rollers. The floor contact area is much larger due to the straight belt part, which should welcome a special group of off-road skaters - you can also drive on softer grounds. For very soft reasons, such as grassy areas, a widespread belt tire is also conceivable, which then no longer needs to be rotatable - as a special application. Two parallel rows of rotatable belts could also be used for this purpose.

Because there is more space between the front and rear rims, additional rims can be added in the middle - to further reduce the surface pressure.

15 shows a rod made of an elastomer for producing the ring tire, which is cut in a spiral shape but zigzag. The spiral tire according to Fig. 13 causes a certain uneven running. The zigzag spiral (22) has interlocking turns, which partially overlap the spaces between the turns - resulting in a smoother rotation.

Annotation:

It should be noted that the large number of detailed exemplary embodiments should by no means be misunderstood as the exhaustive solution set according to the present invention.

15 drawings on 7 sheets

List of reference signs

1 tire ring

2 rim

3 ball head of the screw

4 ball seat

5 screw

6 cross hole for tool

7 screw insert

8 rolling elements, spiral spring

9 medium roller spring

10 ribs, sliding ribs

11 innerspring

12 conical washers

13 friction-resistant insert

14 relaxation-free straps

15 friction surfaces

16 sliding ribs

17 braking surfaces

18 spiral spring tires, metallic

19 round rim groove

20 elastic spiral tires

21 belt tires

22 zigzag spiral, with interlocking turns

Claims

claims

1.Wheel with peripheral rolling elements in the tread, that is, the tread is formed by a one-piece tire by bending an elastic rod, preferably a round cross-section, to form a ring, and this tire ring is rotatably mounted on at least one rim.

2. The wheel according to claim 1, because the tire is a closed ring made of elastic material that is under its own tension and is prayed in guidance elements on the rim that enable the ring tire to be rotated about its own circular axis.

3. Wheel according to claim 1, because the tire is a closed ring made of elastic material, and is prayed in pivotable guide elements on the rim, which are pressed against the tire by special spring elements.

4. A method for producing tires for the wheel according to claim 1, 2 or 3, characterized in that ß sections of a, preferably round profile, hose, cords, or spiral bent from elastic material and firmly connected at the ends so that a Ring results.

. A method of manufacturing tire for the wheel according to claim 1, 2 or 3, characterized in that ß sections of a hose made of elastic material are drawn onto a flexible core, and this core is so much shorter that after its ends the tube sections are firmly connected are overcompressed.

6. Wheel according to claim 1 and 2 or 3, d a d u r c h g e k e n n e e c h n e t, that the guiding elements are rotatable rolling elements which lie in two round-profiled grooves in the rim.

7. Wheel according to claim 1 and one of the other claims, that the guide elements are resilient friction surfaces, and, preferably, are formed from a plurality of narrow ribs.

Wheel according to claim 1 and one of the other claims, that the guide elements are two friction surfaces in the rim groove, which form a V-shaped groove.

9. Wheel according to claim 2 or 3, d a d u r c h g e k e n n z e i c h n e t, d a ß the rolling elements of the rim in at least two axially arranged rows surround the tire laterally.

10. Wheel according to one of the claims, characterized in that ß differently designed partial friction surfaces are attached in the groove of the rim, which act on the inside of the tire.

11. Wheel drive for roller skates according to claim 1 and one of the other claims, d a d u r c h g e k e n n z e i c h n e t, d a ß the tire expanded into a belt, and is mounted over several rims.

12. Wheel according to one of the claims, d a d u r c h g e k e n n z e i c h n e t, d a ß the tire, or tire belt, is formed from a coil spring which is closed to form a ring.

13. Tire ring for the wheel according to claim 1 and one of the other claims, and method for manufacturing according to one of the claims, that a d u r c h g e k e n n z e i c h n e t, that a straight section of a tube is bent into a ring and firmly connected at its ends, and inflated with compressed air.

14. Tire ring made of elastic spiral according to one of the claims, d a d u r c h g e k e n n z e i c h n e t, d a ß the spiral turns are interlocking.

15. Tire ring made of elastic rod according to one of the claims, d a d u r c h g e k e n n z e i c n e t, that the elastic rod is composed of soft carrier material and inserts made of wear-resistant material.

16. Tire ring made of elastic rod according to one of the claims, that a tire pattern is formed by grooves all around in the surface of the elastic rod.

17. Tire ring made of elastic rod according to one of the claims, characterized in that ß a spiral spring is accommodated in the elastic rod along the rod axis.

18. Tire ring for the wheel according to one of the claims, d a d u r c h g e k e n n z e i c h n e t, that a plurality of conically cut discs are impaled on a prestressed coil spring.

19. Wheel and belt drive according to one of the claims, d a d u r c h g e k e n n z e i c h n e t, d a ß two ring tires run parallel next to each other.