MXPA97001231A - Structure for coupling with your - Google Patents

Abstract

A structure for coupling with the ground, cyclically movable such as a rim (10). The rim (10) comprises an elastically deformable body (12) having therein provided a plurality of cavities (25) each joined by a cavity wall (32). The cavities (25) are arranged to assume a cross-sectional configuration by the elastic deformation of the body under normal static load conditions, in which the configuration inhibits the formation of zones of high concentration of tension in the walls of the cavity (32). ). The configuration of the assumed cross section for each of the cavities (32) by the elastic deformation of the body can be a closed curve. The configuration of the cavities inhibits the deformation of the walls of the cavity (32) to an extension which could allow the wall sections thereof to come into contact with each other. In this form, the deformation of the walls of the cavity (32) to the extension where a set radius of curvature is formed in it, is inhibited.

Description

STRUCTURE FOR COUPLING WITH THE SOIL DESCRIPTION This invention relates to a structure that engages with the ground, movably and cyclically, to provide cushioning on a surface coupled with the ground. The structure for coupling with the ground, for example, can consist of a rim for a wheel or a structure that makes contact with the ground for an endless track. More particularly, the invention relates to such ground-engaging structures, which are not pneumatic in nature. There have been several proposals for tires without tires for vehicles, including one-piece rims and composite rims assembled from a plurality of rim segments. Examples of such tires are described in US 1365539 (Pepple), US 1414252 (Brubaker), US 1487920 (Dawson), US 1570048 (Dickensheet), US 5139066 (Jarman) and AU 502409 (Bayer).

The proposals typically comprise a rim having an annular body formed of elastomeric material such as rubber and laterally extending cavities formed in the annular body and opening on the sides thereof. The cavities are intended to provide the rim with sufficient elasticity for a cushioned mounting.

Such proposals, in most cases, seek to provide a compromise between solid tires, which are not susceptible to pitting by providing a severe ride and tires with tires, which although they provide cushioning for a comfortable ride are susceptible to the bite. With such proposals, the rim generally requires a considerable amount of elastomeric material, to have the capacity to carry required load and durability. This has several disadvantages, one that is related to the production cost of the rim, due to the amount of elastomeric material required. In addition, the amount of elastomeric material can be detrimental to the cushioning characteristics of the rim. Therefore there is a need to optimize the configuration of the cavities in the body of the rim, with the purpose of minimizing the amount of elastomeric material used for a given load carrying capacity, while providing a rim which is durable and which offers enough cushioning for a comfortable ride. In the proposals mentioned in the above, the configurations of the cavities have varied greatly from simple circular openings such as those proposed in Dickensheet and Dawson, to more complex forms such as those proposed in Pepple and Bayer. However, the proposals have not provided tires without tires, which are completely satisfactory. A typical problem is that where such a rim has sufficient elasticity to provide a cushioned path, there is a tendency under normal operating loads for the cavities to deform to an extension, which creates zones of high concentration of tension in the walls of the cavity. . These areas of high concentration of tension are produced by the formation of areas that have radii of curvature adjusted in the walls of the deformed cavities. The high voltage concentration zones are applied cyclically during the rotation of the rim, resulting in the generation of heat, which can lead to the degradation of the rim. In addition, where the rim is also subjected to high loads (such as in acceleration or braking), the cavities can deform to such an extent that the wall sections of each deformation cavity are forced into contact with each other. The rotation of the rim causes the sections of the wall of the cavity in contact to rub against each other resulting in the generation of additional heat. This problem is still likely to exist in tires without tires that have cavities which are circular in cross section. The problem will be further explained with reference to Figures 1 and 2 of the accompanying drawings, which are fragmentary, schematic side views illustrating a rim 1 without a tire comprising a body 2 of elastic material, such as rubber formed with a plurality of circumferentially spaced cavities 3, which extend completely through the body in the direction cross section from one side wall 4 to the other side wall. Each cavity 3 is joined by a wall 5 of the cavity. In Figure 1, the rim 1 is illustrated in an unloaded condition in which the cavities 3 are of circular cross-section. In Figure 2, the rim 1 is illustrated in a condition in which it deforms under a static load, which results in the formation of the zones 6 each having a radius of curvature adjusted in two sections 7, 8 of the wall 5 of the cavity, which are pushed in opposite relation. The zones 6 in which there are radii of curvature adjusted in the wall of the cavity, are applied cyclically as the rim rotates and results in the generation of heat. If the rim is subjected to a high load (which is not shown) in addition to the static load, it may deform to an extent that the wall sections 7, 8 of the cavity, opposite adjacent to one of the zones 6, are forced in contact with each other. The friction between the wall sections 7, 8 of the cavity that contracts will generate additional heat, which will accelerate the degradation of the rim. It should be advantageous to provide a rim without a tire which exceeds, or at least reduces the effect of the problem described in connection with the first proposals mentioned above for tires without tires. The present invention provides a structure for coupling with the ground, cyclically movable comprising an elastically deformable body having provided in it a cavity joined by a cavity wall, the cavity is arranged to assume a cross-sectional configuration by the elastic deformation of the body under conditions of normal static charge, in which the configuration inhibits the formation of zones of high concentration of tension in the wall of the cavity. The configuration in cross section assumed by the cavity by the elastic deformation of the body, can be a closed curve. The configuration of the cavity, preferably inhibits the deformation of the wall of the cavity to an extension, which would allow its wall sections to come into contact with each other. In this form, the deformation of the wall of the cavity to the extent where a radius of curvature is formed therein is also inhibited. The cavity can be positioned to assume the cross-sectional configuration by the elastic deformation of the body, by the appropriate selection of the initial cross-sectional shape of the cavity in the condition of the undeformed body. There may be several suitable cross-sectional shapes for the cavity in the undeformed condition of the body. A common characteristic for most, if not all, of the appropriate cross-sectional shapes of the cavity is that they are rounded without being circular. The rounded shape can, for example, be triangular with rounded corners, or polygonal with rounded corners. Another suitable rounded shape may consist of a pair of separate arcs with their concave sides in confronting relation and the intermediate lines extending between the arms. The two arcs can have radii of curvature which are equal or unequal. Where the arches are equal, the largest arch can be placed either towards the outside or the inside of the body. The intermediate lines that extend between the arcs can be curved, straight or of some other configuration. Where the intermediate lines are curved, the shape of the cavity in the cross section may be a closed curve, such as an ellipse or ovoid. Preferably, the cavity is longitudinal ee and of a substantially constant orientation along its entire length within the body. In the undeformed condition of the body, the cavity can be elongated in cross section. In such a case, the elongated cavity can be positioned, such that the main axis of the cross-sectional shape of the cavity is substantially normal to the direction of cyclic movement of the structure for engagement with the ground. For example, where the structure for engagement with the ground is a rim, the main axis of the cross-sectional shape of the cavity may be aligned with a radial axis of the rim. The characteristic by which the cavity is elongated in the cross section and oriented in such a way that the main axis of the cross-sectional shape is substantially normal to the direction of cyclic movement of the structure for coupling with the ground, is advantageous for such structure which is intended for bidirectional use. This is because the major axis of the cavity in the cross section is aligned with the vertical loads imposed on the deformation body of the structure for coupling with the ground, when subjected to static loads. In this form, the wall of the cavity is more capable of deforming into the elastic deformation of the body of the structure for coupling with the floor, without distortion to provide an area having a radius of curvature fitted within the cavity or having surfaces of the wall of the cavity that come into contact with each other. The circumstances where the structure for coupling with the ground is unidirectional use, it may be that the main axis of the cross section of the cavity is inclined with respect to the normal direction of the cyclic movement to resist torsional loads in the structure. Regardless of whether the cavity is elongated in cross section, it preferably has two opposite end portions in the cross section, which are aligned with a direction substantially normal to the direction of cyclic movement of the structure for engagement with the ground. In other words, the two end portions of the cross section are in opposite and spaced relation along a line, which extends between them normal to the direction of the cyclic movement of the structure for coupling with the ground. One of the portions may be enlarged with respect to the other. The body can be provided with a plurality of cavities.

In addition to increasing the elasticity of the body, the cavities provide ventilation to aid in the dissipation of heat. The cavities each conveniently extend transverse through the body with both ends of the opening of the cavity on the outside of the body. However, other provisions are possible. The cavities can be open at one end and closed at the other end. The cavities can also be open at both ends and closed internally. There may also be combinations of such arrangements, with some cavities having a provision and other cavities having different arrangements. Where it is advantageous to provide a rim without a tire, which looks like a tire rim, the cavities may be arranged to open only on a common side of the elastically deformable body. With this arrangement, all cavities could be visible when the rim is observed from the common side, but none of the cavities would be visible when the rim is observed from the opposite side. The opposite side can then provide the appearance of a rim with tire or at least provide a non-interrupting side wall area on which a manufacturer can engrave on and * - emboss or otherwise incorporate the brand name and / or other brands of marketing on the rim. The cavities may be in a circumferentially spaced relationship. The separations between nearby cavities can be substantially equal. The circumferential spacing between the cavities provides bands that support the load between the cavities. The cavities may consist of a first set of cavities within the elastically deformable body. There may be a second set of cavities in the elastically deformable body. The cavities in the second set can be of any suitable cross-sectional shape and not necessarily a shape which has the characteristics of the cavities of the first set. For example, the cavities in the second set may have a cross-sectional shape, which is simply circular in the undeformed condition of the body. However, it may be advantageous for the cavities of the second set to have the characteristics of the cavities of the first set particularly if in any other form they would be susceptible to the formation of zones of high concentration of tension. The cavities in the second set can be in a circumferentially spaced relationship.

The cavities in the first and second assemblies may be in a staggered relationship with respect to one another or may be in alignment between the cavities. In this latter case, each cavity in the second set may be aligned with a respective cavity in the first set along a line normal to the direction of cyclic movement of the structure for engagement with the ground. In this way, in a rim the respective aligned cavities could be aligned along a radial axis of the rim. The elastically deformable body can incorporate reinforcement for the purpose of increasing the strength and durability of the structure for coupling with the ground. In one arrangement, the elastically deformable body may have an outer surface for contact with the ground, in which case it may be provided with a tread surface formation. In another arrangement, the outer surface of the elastically deformable body may be adapted to support another structure, which provides the running surface or in any other form facilitate coupling with the ground. The elastically deformable body may have an inner surface for coupling with a cyclically movable support. In the case of a surface that engages with the ground in the form of a rim, the cyclically movable support can consist of a wheel rim. In the case of a structure for ground engagement for an endless travel, the cyclically movable support may consist of an endless band passing around the travel rollers. The structure for engagement with the floor may be of a one-piece construction or may be formed of a plurality of segments in engagement with the floor, which may be assembled together to provide a structure for engagement with the composite building floor. A structure for coupling with the floor of a one-piece construction is advantageous in that it generates less heat during operation, than a composite building structure. This is because the construction of a part does not have the interfaces between the segments, which exist in the composite construction whose interfaces are in friction contact during the cyclic movement of the structure for coupling with the ground. The invention also provides a floor engaging segment, which together with other such segments can be assembled to form a structure for ground engaging as defined above. Each segment can consist of an elastically deformable body, which has a cavity connected thereto joined by a cavity wall, the cavity is arranged to assume a cross-sectional configuration by the elastic deformation of the body under normal static load conditions, in the that the configuration inhibits the formation of zones of high concentration of tension in the wall of the cavity. The body of the segment may have a plurality of the cavities provided therein. The operating characteristics of the elastically deformable body of the structure for coupling with the floor or the segment in engagement with the floor can be increased by making them of a laminated construction. More particularly, the body may have an inner portion for placement in a cyclically movable support, an outer portion positioned outwardly of the inner portion for coupling with the ground, and an elastically deformable intermediate portion between the inner and outer portions, in which the interior, intermediate and exterior portions are formed as layers of materials having different hardness characteristics. The outer portion is preferably an elastomeric material having wear resistance characteristics, suitable for providing a tread surface structure, such as rubber having a hardness of about 63 to 75 Shore A and preferably within the range of 65. at 70 Shore A. The intermediate layer is preferably made of elastomeric material, suitable for providing load bearing and cushioning, such as rubber having a hardness of about 55 to 75 Shore A. In one arrangement, the inner portion may be formed of elastomeric material of a hardness suitable for clamping engagement with the cyclically movable support such as rubber, having a hardness of about 75 to 96 Shore A and preferably within the range of 80 to 90 Shore A. With such an arrangement, the portion interior may include reinforcement means such as circumferential reinforcing rings. In another arrangement, the inner portion may consist of a substantially rigid band such as a steel ring. The inner portion may be of integral construction or may be of a divided construction, such that it may be expanded and contracted to facilitate the installation of the rim on the support. In the case of a divided construction, the inner portion may consist of a plurality of segments placed in circumferential relation, such that the segments may move in a circumferentially spaced relation by the expansion of the inner portion.

Although the cavities of preference are located completely within the intermediate layer, they can penetrate the outer layer, the inner layer, or both of the outer and inner layers. The present invention also provides a structure for coupling to the floor, cyclically movable, comprising an annular body having an interior portion for placement on a support, an exterior portion positioned outwardly of the interior portion for engagement with the floor and an intermediate portion elastically deformable between the inner and outer portions, in which the inner, intermediate and outer portions are formed as layers of materials having different hardness characteristics. The present invention still further provides a segment for a structure for coupling to the cyclically movable floor, the segment comprising a body having an interior portion for placement on a support, an exterior portion positioned outwardly of the interior portion for engagement with the ground, an elastically deformable intermediate portion between the inner and outer portions, wherein the inner, intermediate and outer portions are formed of materials having different hardness characteristics.

The invention still further provides a cyclically movable soil-engaging structure comprising an elastically deformable body having therein provided a plurality of cavities in a circumferentially spaced relation, the cavities each having a cross section which is elongated. The elongated cross section of each of the cavities may have a major axis and wherein the cavity is oriented such that the principal axis of its cross section is substantially normal to the direction of cyclic movement. The cross section of each of the cavities comprises two end portions in opposite relation along the main axis, wherein each of the end portions comprises an arc. The end portions may be fully arched. The arcs may have equal or unequal radii of curvature. The present invention still further provides a cyclically movable floor engaging structure comprising an elastically deformable body having therein provided a plurality of cavities, the cavities comprising a first set of cavities disposed in a circumferentially spaced relation and a second set of cavities disposed in a circumferentially spaced relation, the first set of cavities is positioned outwardly of the first set in the direction separating from the inner surface, each of the cavities in the second set being aligned in a direction normal to the direction of the cyclic movement with a respective cavity of one of the cavities in the first set. The present invention still further provides a cyclically movable floor-engaging structure comprising an elastically deformable body, having therein provided a plurality of cavities, the cavities comprising a first set of cavities disposed in circumferentially spaced relation and a second set of cavities disposed in circumferentially spaced relation, the first set of cavities is placed outwardly of the first set in the direction separating from the inner surface, each of the cavities in the second set which is aligned in a normal direction with the direction of movement cyclic with a respective cavity of one of the cavities in the first set, the cavities in the first set that are of a rounded configuration in the cross section and the cavities in the second set that are circular in cross section. The present invention still further provides a structure for coupling with the floor, cyclically movable comprising an elastically deformable body, having provided therein a plurality of cavities, the cavities comprise a first set of cavities disposed in a circumferentially spaced relation and a second set of cavities disposed in a circumferentially spaced relation, the first set of cavities that is positioned outwardly of the first set in the direction away from the inner surface, at least some of the cavities in at least one of the first and second sets that are of noncircular cross section. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood by reference to the following description of several of its specific modalities. The description will be made with reference to the accompanying drawings in which: Figure 1 is a schematic view of a rim without a tire of the type known in the prior art, with the rim being illustrated in an unloaded condition; Figure 2 is a view similar to Figure 1 with the exception that the rim is illustrated in a deformed condition under a static load; Figure 3 is a perspective view of a rim according to a first embodiment of the invention; Figure 4 is a fragmentary, perspective view of the rim of the first embodiment; Figure 5 is a fragmentary, side elevational view of the rim of the first embodiment; Figure 6 is a fragmentary, schematic elevation view illustrating the rim of the first embodiment in contact with the ground and flexing under a static load condition; Figure 7 is a view similar to Figure 6 except that the rim is shown flexing under a high torsion moment load condition; Figure 8 is a side view of a wheel fitted with a rim according to a second embodiment, the rim is of composite construction comprising a mounting of rim segments; Figure 9 is a perspective view of a rim segment for the rim of Figure 8; Figure 10 is a perspective view of a rim according to a third embodiment; Figure 11 is a side view of the rim of Figure 10 shown adapted on a wheel rim; Figure 12 is an end view of the rim of the third embodiment showing the structure of the running surface; Figure 13 is a cross-sectional view along line 13-13 of Figure 11; Figures 14 to 20 inclusive are schematic views of the rim according to the third embodiment flexing under various static loads; Figure 21 is a cross-sectional view of a rim according to a fourth embodiment adapted on a wheel rim; Figure 22 is a cross-sectional view of a rim according to a fifth embodiment adapted on a wheel rim; Figure 23 is a side view of a rim according to a sixth embodiment; Figure 24 is a schematic side view of the rim of a seventh embodiment deforming under the load; Figure 25 is a fragmentary side view of the rim of the seventh embodiment showing deformation under the load; Figure 26 is a side view of a rim according to an eighth embodiment; Figure 27 is a fragmentary side view of the rim according to the eighth embodiment; Figure 28 is a side view of a rim according to a ninth embodiment; Figure 29 is a fragmented view on an enlarged scale, showing the configuration of openings in the embodiment of Figure 28; Figure 30 is a fragmentary view showing the configuration of openings in a rim according to a tenth embodiment; Figure 31 is a schematic side view of a rim according to an eleventh embodiment; Figure 32 is a cross-sectional view of the rim according to the embodiment of Figure 31; Figure 33 is a cross-sectional view of a rim according to a twelfth embodiment; Figure 34 is a schematic view of a rim segment for mounting together with other such rim segments to provide a rim according to yet another embodiment; Figures 35 to 39 inclusive illustrate various other shapes for cavities in structures in engagement with the floor according to the invention, when in an undeformed condition; Figure 40 is a schematic side view of an endless path for a crawler vehicle incorporating a structure for engagement with the ground, according to yet another embodiment; Figure 41 is a schematic, perspective view of an endless path that provides a structure for engagement with the ground according to yet another embodiment; and Figure 42 is a fragmented view of the structure for coupling with the floor of Figure 41. The embodiment shown in Figures 3 to 7 of the accompanying drawings is directed to a structure for coupling with the floor, movable cyclically in the form of a tire 10 without a tire, which is intended primarily for operation in uneven terrain and would typically be used in vehicles with a capacity of four driving wheels. The rim 10 is shown in engagement with a floor surface 11 in Figures 6 and 7 of the drawings. The rim 10 comprises an annular body 12 formed of elastomeric material, such as rubber. The annular body 12 may incorporate adequate reinforcement, although such reinforcement is not illustrated in the drawings. The annular body 12 comprises a radially inner end 13 which includes the inner surface 15 for coupling with a cyclically movable support, such as a wheel rim (not shown) and a radially outer end 17 including the outer surface 19 for contact with the floor. A rolling surface formation 21 is provided on the outer surface 19 for the fastening coupling with the floor surface. A pair of opposed side walls 23 extend between the inner portion 13 and the outer portion 17. A plurality of longitudinal, circumferentially spaced cavities 25 are provided within the annular body 12. Each cavity is joined by a cavity wall 32. The cavities they are each of a constant orientation within the annular body 12 over the entire length of the cavity. The cavities 25 provide core holes, which extend between and open on, the opposite side walls 23. In this embodiment, the cavities 25 are positioned in close proximity to the radially inner surface 15, as shown in the drawings. The circumferential spacing of the cavities 25 provides bands 27 that support the load therebetween. Each cavity 25 has a cross-sectional shape, which is a closed curve, elongated in an ovoid shape. The closed curve 26 defining the cross-sectional shape of each cavity 25 can be considered as two arcs 26a, 26b respectively, which define a radially outer end portion 25a and a radially inner end portion 25b of the cross-sectional shape of the cavity, as shown in Figure 5.

The arcs 26a, 26b are connected by intermediate lines 26c ', 26d to complete the closed curve. The intermediate lines 26c, 26d are arched. The closed, elongated curve 26 of each cavity 25 has a principal axis 28 centered along its length, as shown in Figure 5. The closed curve 26 also has another axis 29, which is transverse to the main axis 28 and which corresponds to the maximum transverse dimension (width) of the curve. The cavities 25 are each oriented in such a way that the longer end thereof is positioned towards the radially outer end of the rim. The ovoid shape of each cavity 25 and the orientation of the cavity provide an arrangement in which the centroid of the cavity is adjacent its end, which is towards the radially outer end of the rim. With this orientation, the main axis 28 of the ovoid shape extends in a radial direction of the rim. The ratio of the dimension of each cavity 25 along the main axis 28 to the dimension along the other axis 29 is up to 2: 1. More particularly, the ratio is in the range of 1.1: 1 to 1.7: 1 and preferably is 1.2: 1. The ratio of up to 2: 1 is advantageous, since it provides a rim which has sufficient elasticity for a comfortable ride, while providing adequate load support for normal working conditions. The ovoid shape of the cavities 25 is particularly useful. It provides each cavity with a raised upper limit portion 30, which provides good support for the region 31 of the annular body 12 placed out of the cavity, such that the load bearing characteristics of that region are somewhat similar to the load bearing characteristics of the neighboring regions 33 positioned outwardly of the bands 27 between the cavities. This provides a cushioned, even path as the tire rolls on the ground. If the load carrying characteristics between regions 31 and 33 are substantially different, the rim can provide an uneven path when traveling over uniform surfaces. The ovoid configuration of the cavities 25 also prevent, or at least inhibit, the formation zones having tight radii of curvature, which generate tension risers within the annular body 12, when it is under normal workloads, which are already are static charges as illustrated in Figure 6 or torque loads as illustrated in Figure 7. Indeed, under the static load as illustrated in Figure 6, the radius of curvature of each of the arcs 26a , 26b increases with the result that the configuration of the cross section of the cavity approaches a circular shape. This is opposed to the formation of interest rate strainers. The presence of the tension lifts can generate excessive heat, which contributes to the deterioration of the rim and a reduction in its service life. With particular reference to Figure 7, the rim 10 when subjected to high tensile load distortions to such an extent that the cavities develop an oblique, elongated shape but still maintain a substantially rounded condition. Accordingly, areas having adjusted radii of curvature of the type illustrated in the prior art rim shown in Figure 2 are not developed. The ovoid configuration of the cavities 25 is also beneficial in the sense that it removes elastomeric material from the annular body 12 in regions where the elastomeric material is not necessary. This serves several purposes, one is that it reduces the amount of elastomeric material used in the production of the tire and consequently produces a reduction in costs and another is that it reduces the amount of material, which can generate heat during the operation of rim.The cavities are large enough to provide good air flow characteristics through the rim to assist in heat dissipation. Although in this embodiment, the radially outer arc 26a has a greater radius of curvature than the radially inner arc 26b, a reverse arrangement can also be applied in other situations. The rim according to the first embodiment is of a one-piece construction. The second embodiment, which is illustrated in Figures 8 and 9 of the drawings, is directed to a rim 40, which is somewhat similar to rim 10 of the first embodiment with the exception that instead of being one construction of a piece, is of a composite construction, which can be assembled from a plurality of rim segments 41. Each rim segment 41 comprises a body 48 of elastically deformable tubular construction, to provide the necessary cavity 45 therein. The rim segments 41 can be placed in a circumferentially end-to-end relationship around a cyclically movable support in the form of a wheel rim 42 to provide the composite rim 40. Each rim segment 41 is adapted to be individually and removably fixed on a support surface 43 of the wheel rim 42 by any suitable means such as by attachment or by a fastening system 46, which includes a retaining plate 47 received in the cavity 45 and secured to the wheel rim 42 by securing bolts 49. Fixing the rim segments 41 to the wheel rim 42 in such a way as to allow them to be replaced on an individual basis in the event of damage. The rim segments 41 are a V-shaped as shown in Figure 9, so that they can be mounted in an inter-engagement coupling with one another on the wheel rim 42. Now with reference to Figures 10 to 20 of the drawings annexes, a rim 51 according to the third embodiment, comprises an annular body 53 formed of elastically deformable material, such as rubber. The reinforcement is incorporated into the rubber, as will be explained later. The annular body 53 has an inner portion 55 configured to fit over a wheel rim 56 and an outer portion 57, provided with a running surface 58 for contact with the ground. The body 53 also has opposite sides 59. The wheel rim 56 in this embodiment is a conventional split rim. A plurality of cavities 60 are provided in the annular body 53 to increase its elasticity for the purposes of providing a cushioned path. The cavities extend transversely through annular body 53 and open on opposite sides 59 thereof.

The cavities 60 are arranged in two sets, the cavities 63 being in a first set 61 and the cavities 65 in a second set 62. The cavities 65 in the second set 62 are placed radially inwardly of the cavities 63 in the first set 61 , as shown in the drawings. The cavities in each set 61, 62 are placed in circumferentially spaced relation. There is a one-to-one correspondence of the cavities 63 in the first set 61 with respect to the cavities 65 of the second set 62, whereby each of the cavities in the first set is aligned with one of the cavities in the second set in the radial direction of the tire. In this embodiment, the radial alignment is such that each of the cavities 63 in the first assembly 61 is centered on a radial line, which passes through the center of the respective cavities 65 in the second assembly 62. The cavities 63 in the first set 61 are of a cross-sectional area larger than the cavities 65 in the second set 62. An advantage of the cavities 63 that are of a cross-sectional area larger than the cavities 65, is that it avoids the use of excessive elastomeric material in the outer region of the rim, where the structure is unnecessary. This has two benefits; first it provides the outer peripheral region of the rim with greater elasticity than the inner region and second, it reduces the amount of elastomeric material within the rim to reduce the amount of heat probably generated during the operation of the rim. The greater elasticity of the outer peripheral region of the rim provides a relatively smooth travel under load conditions. As the load increases, the impact of the reduced elasticity of the inner peripheral region progressively increases to provide a progressively more difficult path. In this embodiment, the cavities 63, 65 are of generally triangular configuration with rounded corners. The rounded nature of the cavities 63 and 65 avoids, or at least inhibits, the formation of areas of radii of curvature adjusted to the walls of the cavities as the annular body deforms under normal workloads. The rim is shown in Figures 14 to 20 under conditions in which it is flexed under the influence of various static charges. The cavities 63 in the first assembly 61 are oriented in alternative arrangements in such a way that some cavities have a base 69 thereof more exterior and alternative cavities have an apex 73 thereof more exterior. With this arrangement, the bands carrying the load 75 defined between the neighboring cavities 63 in the first assembly 61, have a substantially constant wall thickness. The arrangement also provides the 'bands 75 with an orientation with respect to the radial direction of the rim. More particularly, the near bands 75 are inclined in opposite directions, as shown in the drawings. The characteristic by which the bands carrying the load 75 are inclined with respect to the radial direction of the rim and in opposite alternate directions, provides the rim with the ability to withstand high torque loads, the bands carrying the inclined loads 75 act as clamps to circumferentially resist rotation between the outer and inner regions of the rim, when the rim is subjected to high torque loads. The spacing between the cavities 65 in the second set 62 also provides bands carrying the load 77. Because the cavities 63 in the first set 61 are each aligned with a respective cavity of the cavities 65 in the second set 62, a The circumferential band 79 is defined between the aligned cavities 63 and 65. The arrangement of the various bands 75, 77 and 79 provides a system for distributing the vertical and tensile loads imposed on the rim, inside the rim in such a way that the loads they are not located in the region of contact with the ground. The inner portion 13 of the rim incorporates metal reinforcing cords 72. Although the cavities 63 in the first assembly 61 have been shown centered in a common spacing circle, it should be understood that they may be disposed in some other arrangement such as a stepped arrangement. Similarly, although the cavities 65 in the second assembly 62 have also been shown centered in a common separation circle, it should be understood that they may be arranged in any other suitable manner. In this embodiment, the cavities 60 extend completely through the annular body 53. There may be circumstances where it is advantageous for the cavities not to fully extend through the body. Now with reference to Figure 21, a rim according to a fourth embodiment is illustrated, which is similar to the rim of the third embodiment except that the cavities 63, 65 open on one side of the rim only. More particularly, the cavities 63, 65 extend laterally in the annular body 53 of a common side 59 thereof and terminate inwardly of the opposite side of the body. In this form, the cavities 63, 65 are not visible from the opposite side of the body 53 and thus, when viewed from that side, the rim does not have the appearance of a 'rim without a tire that incorporates cavities to provide elasticity. The opposite side of the rim provides an uninterrupted surface upon which a manufacturer may incorporate trademarked material or other markings such as information that relates to the size and load carrying characteristics of the rim. The fifth embodiment, which is shown in Figure 22, is also similar to the third embodiment, except that the cavities 63, 65 that extend laterally in the body of both sides are placed in pairs, with the two cavities of each pair which are on opposite sides of the rim and which extend laterally inward in opposite relation. The two cavities of each pair end in one of the other to define a division 66 between them. Now with reference to the sixth embodiment, which is shown in Figure 23 of the drawings, a rim 51 is shown, which is somewhat similar to that of the third embodiment, with the exception that the cavities 65 in the second set 62 are of a generally circular configuration. The rims according to the fourth, fifth and sixth modes are arranged to operate at low speed and relatively high load conditions. These conditions are usually applied in industrial and mining environments. A particular application for rims is in forklifts. There are two environments in which it is advantageous to have a tire, which works at higher speed and lower load conditions. One such arrangement would be non-pneumatic tires adapted for automobiles. The embodiment shown in Figures 24 and 25 is related to a non-pneumatic tire 80, which can operate at higher speeds than the tires according to the previous modalities. The rim according to this embodiment is somewhat similar to the rims of the previous embodiments in that the cavities in the annular body 82 elastically deformable, are arranged in two sets, which are the cavities 83 in a first assembly 81 and the cavities 85 in a second assembly 82. The cavities 83, 85 in this embodiment are, however, of a cross section which is generally of rectangular configuration with rounded corners. In the various embodiments, the openings have been described being arranged in two sets; namely, a first set which is more exterior and a second set which is more interior. However, there may be situations in which it is advantageous to provide cavities in more than two sets. In such a case, the cavities may increase in the cross-sectional area in the radially outward direction. In the embodiment which is shown in Figure 23, the cavities 63, 65 are triangular in shape, which somewhat resemble an equilateral triangle with rounded corners. The embodiment shown in Figures 26 and 27 is somewhat similar to the embodiment of Figure 23 with the exception that the cavities 63 in the first assembly 61 are of a configuration comprising two separate arcs 63a, 63b with their concave sides in confronting relation and the curved lines 63c, 63d that extend between the arcs to complete the closed curve. The closed curve looks a bit like an isosceles triangle with rounded corners. The main axis of each isosceles triangle is aligned with a radial axis of the rim. Additionally, the radius of curvature of rounding in each of the corners of the triangular shape in this mode is greater than that in the third mode, as can be seen from the drawings. The more generous rounding in the corners of this mode also helps to reduce the tendency of the corners of the fold around themselves under conditions of high load. Any such fold can create radius zones adjusted at the corners, which could lead to excessive heat generation resulting in rubber degradation and premature tire failure.

In this embodiment, the alternating cavities 63 of the first assembly 61 are displaced radially one with respect to the other in a slight extension. The embodiment shown in Figures 28 and 29 of the accompanying drawings is also somewhat similar to the embodiment shown in Figure 23. In this embodiment, at least some of the cavities 63 in the first assembly 61 are of cross section configuration generally circular. More particularly, the cavities 63 are arranged in such a way that the alternate openings are of a generally circular configuration. The remaining openings are of generally triangular configuration with rounded corners and the apex of each of said cavity placed more exterior. The embodiment shown in Figure 30 is somewhat similar to the previous embodiment except that the cavities 63 in the first set 61 are no longer staggered in relation to one another; that is, the separation between the running surface and each of the cavities 63 is substantially equal. It is believed that the tires according to two immediately preceding modes, may have improved rolling characteristics (such as to provide a more uniform noise) compared to the tires according to the above embodiments.

In the previous embodiments, the elastically deformable body of the rim has been of unitary construction. It may be advantageous, in some circumstances, to make the body of a laminated construction to increase the operating characteristics of the rim. The embodiment shown in Figures 31, 32 and 33 provides such a rim. With reference to Figures 31 and 32, the rim comprises an annular body 90 of laminated construction, comprising three layers of rubber including an inner layer 91, an intermediate layer 92 and an outer layer 93. The three layers are distinct and are joined together each other in respective interfaces 95. The characteristics of the layers are selected according to the respective functions that the layers are going to perform, as will be explained later. The inner layer 91 provides an inner portion of the rim for engagement with a support such as a wheel rim (not shown). The outer layer 93 provides an outer portion of the rim for engagement with the ground and includes a tread surface structure 97. The intermediate layer 92 is provided to support the load and cushioning purposes. Although the rubber used for the intermediate layer 92 is elastic for the cushioning purposes, the cushioning characteristics are increased by the presence of the cavities 99 formed therein. The cavities 99 'are of rounded cross-sectional shape and extend through the rim to open on the surfaces 100 on the opposite side of the annular body 91. The cavities 99 are arranged in two sets, with a first assembly 101 comprising a plurality of circumferentially spaced cavities 103 and a second set 102 comprising a plurality of circumferentially spaced cavities 105. The cavities 103 in the first assembly 101 have a larger cross-sectional area than the cavities 105 in the second assembly 102. The difference in the cross-sectional areas of the cavities 103 and 105 reduces the amount of elastomeric material used in the region. outer circumferential of the intermediate layer 92 of the rim. This helps in providing the outer region of the intermediate layer 92, with greater elasticity than its inner region and also reduces the amount of elastomeric material within the rim, to reduce the amount of heat that will likely be generated during the operation of the rim. The greater elasticity of the outer circumferential region of the intermediate layer 92 provides a relatively smooth path under loading conditions. As the load increases, the impact of the reduced elasticity of the inner circumferential region that occurs from the smaller cavities 105, increases progressively to provide a progressively more difficult route. The cavities 105 in the second assembly 102 are of generally circular cross-sectional configuration and the cavities 103 in the first assembly 101 are of generally triangular configuration with the rounded corners. The cavities 103 in the first assembly 101 are oriented in alternate arrangements, as shown in Figure 31. The inner portion provided by the inner layer 91 requires greater stiffness than the other layers, to facilitate the attachment of the rim to the rim of the tire. wheel. Such rigidity can be increased by the presence of reinforcing means 107 such as reinforcing rings 109. The outer layer 93, which provides the running surface structure 97, must be durable so as to provide good wear-resistant characteristics. In this embodiment, the hardness of the various layers 91, 92 and 93 decreases in the radially outward direction of the rim. The inner layer 91 is made of hard rubber, which is rubber having a hardness in the range of about 85 to 90 Shore A. The intermediate layer 92 is a little softer for cushioning and support of the load and has a hardness of about 70 to 75 Shore A. The outer layer 93, which provides the surface structure of rolling 17, is formed of rubber selected for wear resistance as to provide good service life and has a hardness of 63 to 65 Shore A The following modality, which is shown in Figure 33 of the drawings, is somewhat similar to the immediately preceding embodiment, in that it comprises a laminated construction body that includes an inner layer 91, an intermediate layer 92 and an outer layer 93. However, in this embodiment, the inner layer 91, which provides the inner portion of the rim for mounting on a wheel rim, comprises a rigid band 111 in the form of a steel ring. The steel ring is arranged to be adjusted on the wheel rim by means of an interference fit. The intermediate layer 92 is joined on the steel ring 111 and includes a plurality of cavities 113 in a circumferentially spaced relation and a cross section, which is generally triangular with rounded corners. The embodiment shown in Figures 8 and 9 are related to a composite rim assembled from a plurality of rim segments. It should be understood that any of the other embodiments directed to a one piece tire could also be of a composite construction. In this regard, the embodiment shown in Figure 34 of the drawings illustrates a rim segment 120, which together with such similar segments can be assembled in a wheel rim to form a composite rim. The assembled composite rim would have a first set of cavities in circumferentially spaced relation and a second set of cavities in circumferentially spaced relation, the first and second sets being radially offset with respect to one another, as illustrated in some of the first embodiments. The rim segment 120 comprises a body 121 of deformable, elastic material and a plurality of cavities provided therein. The cavities extend through the body and open at opposite ends 125 thereof. The cavities comprise ur. pair of first cavities 127 and a second cavity 129. The cavities 127, 129 are rounded in cross section as shown in the drawing. The pair of first cavities 127 form, together with the corresponding cavities in similar rim segments, the first set of cavities in the composite rim. Similarly, the second cavity 129, together with the corresponding cavities in such similar rim segments, form the second set of cavities in the composite rim.

Of the various embodiments which have been described and illustrated, it is evident that the cavities formed in the elastically deformable body, whether of a one-piece construction or segmented construction, can be of various cross-sectional shapes. Other various cross-sectional shapes may also be suitable including the shapes illustrated schematically in Figures 35 to 39 of the accompanying drawings. Each of the illustrated shapes 130 is elongated to have a main axis 132 and another axis 134 transverse to the main axis 132 in a location corresponding to the maximum width. In the manner illustrated in Figure 39, there are two such other axes. The shapes each have two end portions 131 in opposite relation along the main axis. Typically, the cavities would be arranged in such a way that each has the main axis of its cross-sectional shape, normal to the direction of the cyclic movement of the structure for coupling with the ground. Each shape 130 is a closed curve comprising a pair of arcs 133 in opposite relation and two intermediate lines 135 extending between the arcs 133 to complete the closed curve. Of the various Figures, it can be seen that the intermediate lines 135 can be straight or curved.

The various shapes 130 have a ratio of the dimension along the main axis 132 to the dimension along the secondary axis to 2: 1. In the manner illustrated in Figure 35, the preference ratio is within the range of 1.4: 1 to 1.6: 1. The various modalities, which have been described, have been related to structures for coupling with the ground in the form of wheel rims. A structure for coupling with the ground according to the invention can also be applied to an endless track for a crawler vehicle. One of such structure for engagement with the floor will now be described in relation to Figure 40 of the accompanying drawings. The structure for coupling with the ground 140 illustrated er. Figure 40 of the drawings, comprises an endless belt 141 passing around the track end rollers 143. The endless belt 141 is supported between the end rollers 143, by an upper support roller 145 and a plurality of lower support rollers 147 separated. The endless belt 141 is of a one-piece construction and consists of a body 149 formed of an elastically deformable material, such as rubber. The body may incorporate reinforcement means (not shown). The body 149 is configured to define a plurality of pads for engagement with the floor 151, each of which includes a rounded cavity 153 extending therethrough. As with the embodiment described in relation to a rim, the shape of the cavity 153 is such that it avoids, or at least inhibits the formation of zones of high stress concentration in the elastically deformable pads 151, when deformed under workloads. normal. Although the structure for coupling with the floor according to the embodiment shown in Figure 40 is of a one-piece construction, it is also possible for it to be of segmented construction. One of such construction is illustrated in the embodiment shown in Figures 41 and 42 of the accompanying drawings. In this embodiment, the structure for engagement with the floor 160 is supported on an endless, flexible band 161 having an outer surface 162.

The band 161 is adapted to be mounted for cyclic movement around track end rollers (not shown). The structure for ground engaging 160 comprises a plurality of track segments 163 having an inner surface 164 supported on the outer surface 162 of the endless band 161. Each track segment 163 comprises an elastically deformable body 165 having one or more cavities provided in it. In this embodiment, each elastically deformable body 165 has three cavities, which is a pair of first cavities 167 and a second cavity 169. The pair of first cavities 167 cooperate with such similar cavities in other track segments to provide the structure for engagement with the floor with a first set 171 of cavities. Similarly, the second cavity 169 cooperates with the corresponding cavities of other track segments to provide the structure for engagement with the ground, with a second set of cavities 172 spaced inward from the first set. The various track segments are individually secured and preferably secured releasably to the endless band 161 by any suitable means, such as by joining or a detachable fixing system. From the above, it is evident that the structures for coupling with the ground according to the various modalities, whether they relate to tires or endless tracks and in fact whether they are of a one-piece construction or a composite construction, provide a simple but highly effective arrangement to avoid, or at least reduce, the undesirable high stress concentrations in the structures for coupling with the ground, when they are deformed under normal workloads. This is achieved by the selection of the cross-sectional shape of the cavities within the elastically deformable body of the structure, such that by deformation under normal working loads, the cavities deform to closed curves without creating radius zones adjusted, which could cause desirable voltage increases or have wall sections that come into contact with each other. It should be appreciated that the scope of the invention is not limited to the scope of the various embodiments described.

Claims (81)

1. CLAIMS 1. A structure for coupling with the ground, cyclically movable, characterized in that it comprises an elastically deformable body having therein provided, a cavity joined by a cavity wall, the cavity is arranged to assume a configuration of cross section by deformation Elastic body under normal static load conditions, in which the configuration inhibits the formation of high voltage concentration zones in the wall of the cavity.
2. 2. The structure for coupling with the floor, cyclically movable according to claim 1, characterized in that the configuration in cross section assumed by the cavity by the elastic deformation of the body, comprises a closed curve.
3. 3. The structure for coupling with the floor, cyclically movable according to claim 1 or 2, characterized in that the cavity is positioned to assume the cross-sectional configuration by the elastic deformation of the body through the formation of the cavity in a cross-sectional shape, suitable in the undeformed condition of the body.
4. 4. The structure for coupling with the floor, cyclically movable according to claim 3, characterized in that the cavity comprises a longitudinal cavity having a cross-sectional shape which is rounded without being circular.
5. 5. The structure for coupling with the floor, cyclically movable according to claim 4, characterized in that the cross section of the cavity is generally triangular with rounded corners.
6. 6. The structure for coupling with the floor, cyclically movable according to claim 5, characterized in that the cross section of the cavity is generally polygonal with rounded corners.
7. 7. The structure for coupling with the floor, cyclically movable according to claim 5 or 6, characterized in that at least one side of the triangle or polygon is arched.
8. 8. The structure for coupling with the floor, cyclically movable according to claim 4, characterized in that the cross section of the cavity comprises a closed curve.
9. 9. The structure for coupling with the floor, cyclically movable according to claim 4, characterized in that the cross section of the cavity comprises a pair of arches separated inside their concave sides in confronting relation and intermediate lines extending between the arches .
10. 10. The structure for coupling with the floor, cyclically movable according to claim 9, characterized in that the arcs have radii of curvature which are different.
11. The structure for coupling with the floor, cyclically movable according to claim 9 or 10, characterized in that the lines extending between the arcs are curved.
12. 12. The structure for coupling with the floor, cyclically movable according to claim 11, characterized in that the cross section of the cavity is an ellipse or is ovoid.
13. 13. The structure for coupling with the floor, cyclically movable according to any of claims 4 to 12, characterized in that the cavity is elongated in the cross section in the undeformed condition of the body.
14. The structure for coupling with the floor, cyclically movable according to claim 13, characterized in that the elongated cavity is placed in such a way that the main axis of the cross-sectional shape of the cavity is substantially normal to the direction of movement Cyclic structure for coupling with the ground.
15. 15. The structure for coupling to the floor, cyclically movable according to any of claims 4 to 14, characterized in that the cavity has two opposite end portions in the cross section, which are substantially aligned with a direction normal to the direction of cyclic movement of the surface for engagement with the ground.
16. 16. The structure for coupling with the floor, cyclically movable according to claim 15, characterized in that one of the end portions is enlarged with respect to the other.
17. 17. The structure for coupling with the floor, cyclically movable according to any of the preceding claims, characterized in that the cavity opens on the outside of the body and extends inside the body.
18. 18. The structure for coupling with the floor, cyclically movable according to claim 17, characterized in that the cavity extends transverse through the body with both ends of the cavity that open on the outside of the body.
19. 19. The structure for coupling with the floor, cyclically movable according to claim 17, characterized in that the cavity is open at one end and closed at the other end.
20. 20. The structure for coupling with the floor, cyclically movable according to claim 17, characterized in that the cavity is open at both ends and closed internally.
21. 21. The structure for coupling with the floor, cyclically movable according to any of the preceding claims, characterized in that the cavity comprises a hole in the core.
22. 22. The structure for coupling with the floor, cyclically movable according to any of the claims, characterized in that the body is provided with a plurality of cavities.
23. 23. The structure for coupling to the floor, cyclically movable according to claim 22, characterized in that the cavities are in a circumferentially spaced relation, the spacing between the cavities provide bands supporting the load between the cavities.
24. 24. The structure for coupling with the floor, cyclically movable according to claim 22 or 23, characterized in that the cavities comprise a first set of cavities inside the elastically deformable body.
25. 25. The structure for coupling with the floor, cyclically movable according to claim 24, further characterized in that it comprises a second set of cavities in the elastically deformable body.
26. 26. The structure for coupling to the ground, cyclically movable according to claim 25, characterized in that the cavities in the second set are in a circumferentially spaced relation.
27. 27. The structure for coupling with the ground, cyclically movable according to claim 25 or 26, characterized in that the cavities in the first and second assemblies are in a staggered relationship with respect to one another.
28. 28. The structure for coupling with the floor, cyclically movable according to claim 25 or 26, characterized in that each cavity in the second set is aligned with a respective cavity in the first set along a line normal to the direction of the cyclic movement of the structure for coupling with the ground.
29. 29. The structure for coupling with the floor, cyclically movable according to any of claims 25 to 28, characterized in that the cavities of the second set are placed inwards of the cavities in the first set and are of a more cross-sectional area small that the cavities of the first set.
30. 30. The structure for coupling with the floor, cyclically movable according to any of the preceding claims, characterized in that the elastically deformable body incorporates reinforcement for the purpose of increasing the strength and durability thereof.
31. 31. The structure for coupling with the floor, cyclically movable according to any of the preceding claims, characterized in that the elastically deformable body has an outer surface for contact with the floor.
32. 32. The structure for coupling with the floor, cyclically movable according to any of claims 1 to 30, characterized in that the elastically deformable body has an outer surface adapted to support another structure, which provides a rolling surface or facilitates in any another way the coupling with the ground.
33. 33. The structure for coupling with the floor, cyclically movable according to any of the preceding claims, characterized in that the elastically deformable body has an inner surface for coupling with a cyclically movable support.
34. 34. The structure for coupling with the floor, cyclically movable according to any of the preceding claims, characterized in that it is of a one-piece construction.
35. 35. The structure for coupling with the floor, cyclically movable according to any of claims 1 to 33, characterized in that it comprises a plurality of segments for coupling with the floor, which can be assembled to provide the structure for coupling with the composite building floor.
36. 36. The structure for coupling with the floor, cyclically movable according to any of the preceding claims, characterized in that the elastically deformable body is of a laminated construction.
37. 37. The structure for coupling with the floor, cyclically movable according to claim 36, characterized in that the elastically deformable body comprises an inner portion to be placed on a cyclically movable support, an outer portion positioned outwardly of the inner portion for coupling with the ground and an elastically deformable intermediate portion between the inner and outer portions, in which the inner, intermediate and outer portions are formed as layers of materials having different hardness characteristics.
38. 38. The structure for coupling with the floor, cyclically movable according to claim 37, characterized in that the outer portion is made of elastomeric material having suitable wear resistance characteristics to provide a tread surface structure such as rubber having a hardness of approximately 63 to 65 Shore A.
39. 39. The structure for coupling with the floor, cyclically movable according to claim 37 or 38, characterized in that the intermediate layer is made of elastomeric material suitable for providing load bearing and cushioning, such as rubber that has a hardness of about 70 to 75 Shore A.
40. The structure for coupling with the floor, cyclically movable according to claim 37 or 38, characterized in that the inner portion is formed of elastomeric material of a hardness suitable for the coupling of fastening with the cyclically movable support.
41. 41. The structure for coupling with the floor, cyclically movable according to claim 40, characterized in that the inner portion comprises elastomeric material such as rubber having a hardness of approximately 85 to 90 Shore A.
42. 42. The structure for coupling with the floor, cyclically movable according to claim 40, characterized in that the inner portion comprises a substantially rigid band such as a steel ring.
43. 43. The structure for coupling with the floor, cyclically movable according to claim 40, 41 or 42, characterized in that the inner portion is of a divided construction, such that it can be expanded or contracted to facilitate installation on the support.
44. 44. The structure for coupling with the floor, cyclically movable according to claim 43, characterized in that the inner portion comprises a plurality of segments placed in circumferential relation, in such a way that the segments can move in a circumferentially separated relationship by the expansion of the inner portion.
45. 45. A segment for coupling with the ground, characterized in that together with another such segment they can be assembled to form a structure for coupling with the ground in accordance with any of the preceding claims.
46. 46. A segment for coupling with the ground, characterized in that it comprises an elastically deformable body having therein provided, a cavity joined by a cavity wall, the cavity is arranged to assume a cross-sectional configuration by the elastic deformation of the body under normal static charge conditions, in which the configuration inhibits the formation of high voltage concentration zones in the wall of the cavity.
47. 47. The segment for coupling with the floor according to claim 46, characterized in that the cross-sectional configuration assumed by the cavity by the elastic deformation of the body, comprises a closed curve.
48. 48. The segment for coupling with the floor according to claim 46 or 47, characterized in that the cavity is arranged to assume the cross-sectional configuration by the elastic deformation of the body by the formation of the cavity in a suitable cross-sectional shape in the undeformed condition of the body.
49. 49. The segment for coupling with the floor according to claim 48, characterized in that the cavity comprises a longitudinal cavity having a cross-sectional shape which is rounded without being circular.
50. 50. The segment for coupling with the floor according to claim 48, characterized in that the cross section of the cavity is generally triangular with rounded corners.
51. 51. The segment for coupling with the floor according to claim 48, characterized in that the cross section of the cavity is generally polygonal with rounded corners.
52. 52. The segment for coupling with the floor according to claim 50 or 51, characterized in that at least one side of the triangle or polygon is arched.
53. 53. The structure for coupling with the floor, cyclically movable according to claim 48, characterized in that the cross section of the cavity comprises a closed curve.
54. 54. The segment for coupling with the floor according to claim 48, characterized in that the cross section of the cavity comprises a pair of arches separated with their concave sides in confronting relation and the intermediate lines extending between the arches.
55. 55. The segment for coupling with the floor according to claim 54, characterized in that the arcs have radii of curvature which are different.
56. 56. The segment for coupling with the floor according to claim 54 or 55, characterized in that the lines extending between the arcs are curved.
57. 57. The segment for coupling with the floor according to claim 56, characterized in that the cross section of the cavity is an ellipse or an ovoid.
58. 58. The segment for coupling with the ground according to any of claims 46 to 57, characterized in that the undeformed condition of the body, the cavity is elongated in the cross section in the undeformed condition of the body.
59. 59. The segment for coupling with the floor according to claim 58, characterized in that the elongated cavity is positioned in such a way that the main axis of the cross-sectional shape of the cavity is substantially normal to the direction of the cyclic movement of the cavity. the structure for coupling with the ground.
60. 60. The segment for ground coupling according to any of claims 46 to 59, characterized in that the cavity has two opposite end portions in cross section, which are aligned with a direction substantially normal to the direction of the cyclic movement of the structure for coupling with the ground.
61. 61. The segment for coupling with the ground according to claim 60, characterized in that one of the end portions is enlarged with respect to the other.
62. 62. The segment for coupling with the floor according to any of claims 46 to 61, characterized in that the cavity opens on the outside of the body and extends inside the body.
63. 63. The structure for coupling with the floor, cyclically movable according to claim 62, characterized in that the cavity extends in cross section through the body with both ends of the cavity that opens to the outside of the body.
64. 64. The structure for coupling with the floor, cyclically movable according to claim 63, characterized in that the cavity is open at one end and closed at the other end.
65. 65. The structure for coupling with the floor, cyclically movable according to claim 62, characterized in that the cavity is open at both ends and closed internally.
66. 66. The structure for coupling with the floor, cyclically movable according to any of claims 46 to 65, characterized in that the cavity comprises a core hole.
67. 67. The structure for coupling with the floor, cyclically movable according to any of claims 46 to 66, characterized in that the body is provided with a plurality of cavities.
68. 68. A structure for coupling to the floor, cyclically movable, characterized in that it comprises an annular body, having an interior portion for placement on a support, an exterior portion positioned outwardly of the interior portion for engagement with the floor, and a intermediate portion elastically deformable between the inner and outer portions, wherein the inner, intermediate and outer portions are formed as layers of materials having different hardness characteristics.
69. 69. A segment for a structure for coupling to the floor, cyclically movable, the segment is characterized in that it comprises a body having an interior portion for placement on a support, an exterior portion positioned outwardly of the interior portion for engagement with the floor and an elastically deformable intermediate portion, between the interior and exterior portions, in which the interior, intermediate and exterior portions are formed of materials having different hardness characteristics.
70. 70. A structure for coupling with the ground, cyclically movable, characterized in that it comprises an elastically deformable body having therein provided a plurality of cavities in a circumferentially spaced relation, the cavities each have a cross section which is elongated and of substantially constant orientation throughout the body.
71. 71. The structure for coupling with the floor, cyclically movable according to claim 70, characterized in that the elongated cross section of each of the cavities has a main axis and in which the cavity is oriented, in such a way that the axis The main cross section of the same is substantially normal to the direction of the cyclic movement.
72. 72. The structure for coupling with the floor, cyclically movable according to claim 71, characterized in that the cross section of each of the cavities, comprises two opposite end portions in an opposite relation along the main axis, in the that each of the end portions comprises an arc.
73. 73. The structure for coupling with the floor, cyclically movable according to claim 72, characterized in that the arcs have radii of curvature which are different.
74. 74. A structure for coupling with the floor, cyclically movable, characterized in that it comprises an elastically deformable body having therein provided a plurality of cavities, the cavities comprising a first set of cavities arranged in a circumferentially spaced relation and a second set of cavities arranged in circumferentially spaced relation, the first set of cavities is positioned outwardly of the first set in the direction separating from the interior surface of each of the cavities in the second set which are aligned in a direction with respect to the direction of the cyclic movement with a respective cavity of the cavities in the first set.
75. 75. A structure for coupling with the floor, cyclically movable, characterized in that it comprises an elastically deformable body having a plurality of cavities provided in it, the cavities comprise a first set of cavities arranged in a circumferentially separated relation and a second set of cavities arranged in circumferentially spaced relation, the first set of cavities is positioned outside the first set in the direction separating from the inner surface, each of the cavities in the second set which are aligned in a normal direction of the direction of the cyclic movement with a respective cavity of the cavities in the first set, the cavities in the first set are of a rounded configuration in the cross section and the cavities in the second set which is circular in cross section.;
76. 76. A structure for coupling with the floor, cyclically movable, characterized in that it comprises an elastically deformable body having a plurality of cavities provided in it, the cavities comprise a first set of cavities arranged in circumferentially separated relation and a second set of cavities disposed in circumferentially spaced relation, the first set of cavities that is positioned outward of the first set in the direction separating from the interior surface, at least some of the cavities in at least one of the first and second sets that is of section cross not circular.
77. 77. The structure for coupling with the floor, cyclically movable according to claim 76, characterized in that at least some of the cavities are of a configuration rounded 'in the cross section.
78. 78. The structure for coupling with the floor, cyclically movable according to claim 76 or 77, characterized in that at least some of the cavities are of an elongated cross section.
79. 79. The structure for coupling with the floor, cyclically movable according to claim 78, characterized in that the elongated cross section has a main axis and in which the respective cavities are oriented, in such a way that each has the main axis of its cross section substantially normal to the direction of the cyclic movement of the structure for coupling with the ground.
80. 80. The structure for coupling with the floor, cyclically movable according to any of claims 70 to 75 of the composite construction, characterized in that it comprises a plurality of segments for coupling with the floor.
81. 81. The segment for coupling with the floor for assembly together with another such segment, characterized in that it provides a structure for coupling with the floor, composed in accordance with claim 80.