Bicycle stem with adjustable elastomer damping and limited swivel range

Abstract

A sprung stem (1) for bicycles, in particular for racing bikes and gravel bikes, for a spring-loaded connection between the handlebars and the head tube and / or fork steerer tube, comprising: • a static mounting device (2) for attaching the stem to the head tube and / or fork steerer tube, • a handlebar clamp (3) for connecting the stem to the handlebars, • a suspension device and / or coupling device (4) for suspending the handlebars and for mechanically coupling the static mounting device (2) and the handlebar clamp (3), • wherein the suspension device and / or coupling device (4) comprises two connecting parts (5, 6), each of which connects the mounting device (2) and the handlebar clamp (3), • wherein the suspension device and / or coupling device (4) is mounted on the static mounting device (2) and on the handlebar clamp (3) via two pivot axes (7, 8), • wherein the Connecting parts (5,6) each rotatably connected to the fastening device (2) on one side and to the handlebar mount (3) on the other side via one of the axes of rotation (7, 8) such that the distance between the two axes of rotation (7, 9; 8, 10) which are connected to each other by the same connecting part (5, 6) is constant, and / or the side lengths of the formed parallelogram are constant, • wherein the axes of rotation (7, 8, 9, 10) are parallel to each other and are arranged such that the axes of rotation (7, 8, 9, 10) intersect a plane perpendicular to the axes of rotation (7, 8, 9, 10) in such a way that the points of intersection form the vertices of a parallelogram, • wherein a coupling device (4) is provided for the mechanical coupling of the connecting parts (5, 6), which comprises an elastomer body (13) which is mounted in such a way that it deforms is characterized in order to absorb force and dampen the relative movement between the handlebar and the head tube,that at least one connecting web (52, 53) is provided for connecting the static mounting device (2) and the handlebar bracket (3), which is arranged between the two connecting parts (5, 6), wherein the at least one connecting web (52, 53) is rotatably mounted on the mounting device (2) and on the handlebar bracket (3) respectively and is designed such that it pivots together with the connecting parts (5, 6) and, from a certain deflection, comes into contact with one of the two connecting parts (5, 6) and / or with one of the axes of rotation (7, 8, 9, 10), so that the pivoting movement cannot be continued and the connecting web (52, 53) thus forms a stop (70, 71).

Description

The invention relates to a sprung front part for bicycles, as can be used in particular in racing bicycles and gravel bikes, according to the preamble of claim 1.From the prior art, for example, WO 2013 / 033 674 A1 discloses a bicycle front part which is formed by two parallel-guided arms. The arms are each fastened via pivot joints at fixed points to the head tube and to the link so that these pivot points form a parallelogram. The intrinsic pivoting movement of the front part is braked by a spring.In addition, DE 10 2022 117 288 A1 discloses, for example, a bicycle front part with continuously adjustable damping, in which a type of wedge is inserted into the elastomer body until the desired degree of damping is reached. Further sprung front sections are shown in U.S. Pat. No. 2021 / 0 155 307 A1, U.S. Pat. No. 2021 / 0 300 492 A1, U.S. Pat. No. 5,253,544 A and U.S. Pat. No. 5,833,255 A.It is the object of the invention to propose a front structure for bicycles, in particular for racing bicycles and gravel bikes, which enables an improved damping, which is particularly suitable for practice and can be implemented cost-effectively.The object is achieved, starting from a front end of the type mentioned at the beginning, by the features of claim 1.By means of the measures mentioned in the dependent claims, advantageous embodiments and further developments of the invention are possible.The sprung front part according to the invention is particularly suitable for racing bicycles and gravel bikes. The front part connects the steering arm to the head tube or the fork. Especially when travelling off road or over rough road, the front wheel is subjected to abrupt impacts. These shocks load the wrists very heavily without adequate damping because the blows are transmitted directly to the hands or wrists via the fork or the head.However, the steering arm itself does not have to be a separate component connected to the fork or the head tube via the front part. In principle, the invention can just as well be used in link front-end units from one piece. The sprung front part is thus an integral component of the link.The invention is based, inter alia, on elastomer bodies being used to implement a damping effect, because the springs which are otherwise frequently used in the prior art can absorb the shock, ideally however virtually completely emit the energy again. Springs as damping elements are therefore rather unsuitable in the actual sense, since the energy absorbed is only temporarily stored, but is not dissipated or destroyed to a substantial extent.Advantages of a Negative Spring Travel (Sag):In particular, the invention makes it possible to provide a so-called negative spring travel (sag). The springs used hitherto can be subjected to pressure loads in particular. During off-road travel, the head tube or fork can in principle be moved in both directions (towards the roadway or opposite). For in the case of heavily uneven terrain, the impacts finally transmitted via the fork to the hands of the driver or to the wrists can occur in both directions, toward the ground and in the opposite direction, perpendicularly toward the roadway or vice versa. If conventional springs are used according to the prior art, the biker then feels the mechanical stops in the boundary regions of the springs: when the front wheel impacts the ground, for example, the mass formed by the handlebar and the biker supported thereon with the hands is also moved in the direction of the ground and then braked; the spring is compressed until it forms a mechanical stop at its maximum possible compression, so that an impact is transmitted to the handlebar and the hands. The path up to this point is called the positive spring path. Due to the elastic spring action, a springback in the opposite direction usually subsequently takes place, which can have an unpleasant effect on the hands.If the spring is loaded inversely to tension, a conventional spring according to the prior art can usually hardly expand, since no spring that can be loaded to compression and tension is used. A corresponding negative spring travel practically does not exist, so that a mechanical stop in the hands is to be sensed directly.According to the invention, however, instead damping with a positive suspension travel (in the case of a force action in the direction of the roadway) and with a negative suspension travel (in the case of a force action in the opposite direction) is advantageously provided, and a harsh driving feeling due to a hard stop is avoided.The invention thus makes it possible to use a number of advantages over the prior art by providing the negative spring travel:A conventional suspension fork does not have this negative spring travel without load, in contrast to the invention.Due to the static weight distribution, a so-called sag is present due to which the mass present is present without prestressing due to impacts. The weight is primarily applied to the saddle and the crank.In contrast to the suspension fork, this sag is usually not present in a sprung front part, since the driver of the two-wheeler is supported with little force via the steering arm.The introduction of force via the steering rod only increases in certain driving situations, for example during braking.It is therefore advantageous to provide a construction with sag already from the rest state, as is possible according to the invention.It also contributes to improving the feeling of travel that the front part according to the invention has a parallelogram-like structure and the cushioning movement does not have a single pivot point about which the front part is tilted, as is customary in some conventional front parts according to the prior art. The sides of the parallelogram always remain parallel, even if the front part absorbs a shock and the link moves relative to the fork or the head tube. This has the result that, in the case of the parallelogram structure, the link shifts with respect to its position to the fork or to the head tube, but the link is not rotated or tilted during the resilient compensating movement of the front part. Such tilting would have the disadvantage that the hands or wrists together with the handlebar would also be tilted and thus be loaded more, especially even if impacts on fork, head tube, handlebar and wrists are to be expected in principle during off-road travel.At the same time, according to the invention, there is the advantage of being retrofitted. As an alternative solution to the sprung front part, there is also the option of using a suspension fork, so that the front wheel is directly spring-mounted. However, such a suspension fork cannot be easily retrofitted, unlike a sprung front end. A sprung front end has therefore proven to be particularly advantageous in the case of so-called gravel bikes, which are fundamentally derived from racing bicycles but which are intended to facilitate the travel of ballast roads, but also do not have to be designed for pure off-road travel of the highest overall load level.The fork-side or head tube-side part of the front part is designed as a static fastening device, wherein the term "static" refers to the fastening device not changing position with respect to the main part of the wheel, the frame. The static fastening device is firmly fastened to the fork, more precisely to the head tube or the fork stem.In contrast, the free end of the front part forms or opens out in a link holder for connecting the front part to the link.Between the handle holder and the static fastening device, the suspension device and / or coupling device of the front part is located. It serves for the mechanical coupling of the handle holder and the static fastening device, which is to be designed such that impacts on the front wheel or the fork are to be cushioned with respect to the handle. The suspension device forms two parallel sides of the parallelogram already mentioned above. It is thus at least divided into two and comprises two parallel-guided arms which act as connecting parts in each case between the static fastening device and the link holder. Each connecting part is mounted on the static fastening device and on the link holder such that it can be pivoted about an axis of rotation. The axes of rotation run parallel. In an upright bicycle, the axes of rotation extend horizontally to the ground.The two other sides of the parallelogram are each located in the region of the static fastening device or of the link holder. The distance between the two axes of rotation on the static fastening device is constant. The position of these axes of rotation with respect to one another is also not changed when the front part springs. Likewise, the distance between the two axes of rotation on the link holder is also constant, and their relative position is also not changed with respect to one another when the front part springs. However, relative positions of the static fastening device and the link holder to one another generally change when sprung by the front end, i.e. the two sides of the parallelogram along the connecting parts can be pivoted to the parallelogram side on the head tube side or link side in each case.The pivoting movement of the connecting parts is damped in that the connecting parts are additionally mechanically coupled to one another. This coupling device comprises an elastomer body which brings about the coupling on the one hand and the damping effect on the other hand. The elastomer body reversibly deforms upon the action of a force from the outside. This deformation is formed when the force effect is re-absorbed. However, energy is also consumed during the deformation, i.e. there is no purely elastic effect in which the entire energy is spontaneously dissipated again. The force is exerted by the connecting parts or arms, which each perform a pivoting movement. The at least one elastomer body is mounted such that it is deformed in the process.The intrinsic pivoting movement of the front part is limited with respect to the angular range. The maximum deflection in the direction of the positive or negative spring travel can be limited in a defined manner by a stop. The stop is possibly subjected to strong mechanical loads. An embodiment of the invention is characterized in that a connecting web is introduced between the static fastening device and the link holder in the region of the coupling device, which connecting web can absorb the intrinsic pivoting movement. The connecting web is moved together with the connecting parts during intrinsic pivoting. When the connecting web is sheared, starting from a certain deflection angle, the connecting parts block further pivoting.The connecting web can be rotatably mounted on the static fastening device and the link holder, respectively. Preferably, the connecting web can be mounted on the static fastening device and the link holder between the respective axes of rotation of the static fastening device and the link holder. The connecting web can accordingly extend skew to the axes of rotation.If the parallelogram is sheared during intrinsic pivoting, the connecting web between the parallelogram sides can be in the way from a certain deflection. For this purpose, the shape of the connecting web and the connecting parts can be adapted. The wider the connecting web or the connecting parts are formed perpendicular to their longitudinal extent, the more they can abut each other during intrinsic pivoting and block the pivoting movement, in particular when the contours of the connecting web and connecting part are also correspondingly adapted to each other. The shape can therefore define the maximum angle and thus the stop or the stop time.With respect to the parallelogram, the connecting web can thus form a further axis through the parallelogram, which is arranged parallel to two opposite sides of the parallelogram.The shape of the connecting web and connecting part can be adapted in such a way that the stop angle is defined therewith. During the pivoting, the distance between the connecting web and the connecting parts changes, since a rotation about the axes of rotation or the mounting of the connecting web takes place.In general, it is also conceivable in an embodiment of the invention that an additional elastomer for a soft stop is applied to the end stop, e.g. on the connecting web and / or the connecting part, where the connecting web and connecting part come into contact when the stop occurs, a two-stage spring characteristic curve including the end stop then results. There may be a single elastomer, applied only to the connecting web or the connecting part, or both elastomer is applied to the connecting web and the connecting part, respectively. In the latter case, the two elastomers initially strike one another on the spring travel, so that the force initially increases only slightly due to the deformation of the elastomers. If one of the elastomers is fully compressed on the further spring path, the force increases again more, because only one elastomer presses against a fixed part. If both elastomers are completely compressed, the force again rises more steeply for a short time. Advantageously, the force with the elastomers increases correspondingly somewhat more uniformly and less abruptly, so that a lower impulse acts on the wrists of the driver. The stop is thus damped once again.The connecting parts and connecting webs can be shaped such that parallel contours meet at the stop, so that the contours meet flat, in which the force extends to a larger area and the pressure is thus lower. In this respect, the connecting parts and the connecting web can have a shape which is partially complementary. The shaping refers to the plane in which the movement takes place during intrinsic pivoting.Due to the flat stop along the contour and the distribution of the force flow through connecting parts and connecting webs, the force flow in the front part takes place in such a way that the forces are each transmitted to at least two bearing points, the axes of rotation in the connecting parts or the bearing devices of the connecting webs, which are each attached to the static fastening device and to the link holder. As a result, the front part or the coupling device is particularly stable per se.The stop according to an exemplary embodiment of the invention can be realized cost-effectively on the one hand, but is distinguished by a high mechanical stability and a high durability.Depending on the application, depending on the type of terrain being traveled on and on the personal feeling of driving, it is advantageous to be able to adjust the damping of the front end. A further development of the invention implements this by changing the coupling device. In the prior art, wedges are, for example, pushed between two elastomer bodies lying next to one another, so that the damping effect is changed by a hard intermediate layer being pushed into the material to be compressed or sheared during the deflection for damping, wherein the damping becomes progressively harder the further the wedge or the like is introduced between the elastomer bodies. The preferred development of the invention is now distinguished in that the elastomer body has a recess into which an insert can be introduced. This insert ensures that, during the deformation of the elastomer body, the coupling device overall forms a higher mechanical resistance when the static fastening device is pivoted with respect to the link holder.It has been found that a continuously variable adjustment of the damping, as can be realized with wedges in the prior art, is not required as frequently in practice, however. Often, even only two settings of damping are sufficient, a harder and a softer damping. Such an insert can therefore be fixedly inserted into the elastomer body. A continuously variable method or adjustment of the insert can therefore be dispensed with. In order to be able to continuously adjust the damping, its own mechanism is generally required, which makes this possible. This mechanism or such an adjusting device, as was used for adjustable positioning of the wedges, can therefore be dispensed with according to the invention. In addition, an insert can be positioned very stably, as a result of which the front part becomes particularly robust with respect to mechanical loads.However, in order to be able to adjust the damping hardness, the insert may have different thicknesses in cross section in different directions perpendicular to its longitudinal axis. If the insert is inserted into the elastomer body in such a way that the thicker cross section runs in the force flow during pivoting of the front part, the resistance or the damping is higher than if the insert is rotated in such a way that a thinner region of the cross section is in the force flow.With regard to its extension in cross section, the insert is thus of different thickness in the direction of (at least) two axes, which are referred to here as anisotropy axes; it is anisotropic in its extension. In one embodiment of the invention, the cross section can be elliptical, for example. The anisotropy axes in this case correspond to the two major things of the ellipse. By inserting them differently into the recess, the damping can thus be adjusted. If the insert is rotated in such a way that the longer main axis is in the force flow, the damping effect is the highest, and if the short main axis is in the force flow, the damping effect is the smallest.Accordingly, the insert can be rotated in the recess or at least inserted into the recess with different alignment.The recess in the elastomer body does not have to have the same thickness as the insert. The elastomer body can also be compressed by the insert where it is wider than the recess. If the damping is adjusted by inserting the insert into the recess in different ways or orientations, the insert will compress the elastomer body more or less in these directions depending on the orientation. The recess can be formed, for example, cylindrically, wherein the diameter of the cross section corresponds to the shortest extension of the insert in cross section. The diameter of the recess can correspond, for example, to the smallest cross-sectional dimension of the insert, so that no gap is formed between the elastomer body and the recess, regardless of the orientation of the insert.In the particularly preferred embodiment, the elastomer body is advantageously formed in one piece, so that its installation and the production of the front part can be simplified. A one-piece elastomer body also has the advantage that the positive or negative spring travel does not cause a large hysteresis, as a result of which the central position of the front end portion would remain undefined, which is undesirable, however, since the biker always wants to find the same position of the link in the unloaded state. The front part can thus also damp more reliably, especially as the parts of the elastomer body cannot slip with respect to one another.A two-part design of the elastomer body is conceivable in principle, in particular if the links have side walls. However, this usually means an additional weight.In order to achieve a uniform damping effect, the recess and / or the insert can pass completely through the elastomer body, because otherwise stresses could occur during the mechanical load of the coupling device due to the non-uniform force flow. If the insert passes completely through the elastomer body, the insert can also be held particularly simply and stably. The damping effect can be achieved solely by the orientation of the insert in the elastomer body, i.e. at which angle the anisotropy axes are oriented in the plane perpendicular to the axes of rotation.In principle, it is also possible to design the insert rotatably in the elastomer body. In the case of a continuous change in the cross-sectional thickness along the outer contour, a continuous, continuously variable adjustment of the damping can nevertheless be realized in this case. However, this is often not required in practice. In order to make handling easier for the user and to make the setting of the damping reproducible, the insert can be used, for example, simply rotated by 180°. The orientation of the longitudinal axis remains parallel to its previous orientation.The axes of rotation of the coupling device vertically penetrate a plane and thus form the vertices of a parallelogram. The axis of anisotropy can be oriented during the insertion of the insert into the recess such that it vertically passes through two diagonally opposite axes of rotation. This also ensures that the anisotropy axis is in the force flow in the event of a reduction in the parallelogram.If the anisotropy axes are perpendicular to one another, the contribution of the respective other anisotropy axis can be virtually eliminated if one of the anisotropy axes is in the flux of force. Thus, the change in damping can be maximized with different design designs of the insert.In one embodiment, the elastomer body can be mounted in a stable manner, for example by having recesses in its corners, through which the axes of rotation can run, so that they hold the elastomer body in its position. The elastomer body can thus be mounted independently of the connecting parts.In order to mount or hold the insert in a stable manner, in particular in a rotationally stable manner, a mounting web can be provided in an advantageous development of the invention.In a particularly preferred embodiment variant, the connecting web is identical to the bearing web.The bearing web can be connected to the insert. It can also be detachably connectable to the insert, in order in particular to facilitate the installation of the insert in the recess and thus also the adjustment of the damping hardness. The bearing web thus on the one hand allows the insert not to slide out of the recess. On the other hand, the bearing web also allows the insert to maintain an orientation within the elastomer body that is dependent on the intrinsic pivoting but is defined and does not rotate unintentionally, for example when pivoting the front end. As a securing wire, it does not support the elastomer body. Rather, the elastomer body ensures that the wire cannot slip out of the axes of rotation (shafts) to be secured. The wire in combination with the elastomer body thus ensures a positive locking of the axes of rotation or shafts. The wire is preferably made of spring steel in order to obtain an elastic effect. Other materials, in particular other steels, are also conceivable in principle. If the axes of rotation or shafts are provided with a groove or a circumferential puncture running around the shaft, the wire can be mounted therein without itself slipping laterally. The puncture can be arranged centrally with respect to the longitudinal extent of the shaft / axis of rotation.In a further development of the invention, it is sufficient to provide a single coherent elastomer body which is so large that the sides of the described parallelogram, through the corner points of which the axes of rotation extend, penetrate the elastomer body. The advantage of this refinement is that the front part can comprise fewer parts and a single elastomer body can be installed or replaced more easily.The elastomer body can also be designed as a closed ring. To adjust the degree of hardness of the front part, it may therefore be sufficient to introduce or remove a hard core into the resulting recess, so that the overall structure of the elastomer body becomes correspondingly harder or softer, depending on the extent to which this core is located in the elastomer body.The elastomer body is smaller in terms of its expansion in the unloaded state along the connecting line between the fastening device and the link holder than transversely to this direction. In the case of a positive or negative spring travel, therefore, the elastomer body is more likely to be distorted than it is a compression. As a result, the damping effect can be advantageously improved. In addition, a greater spring travel can be provided geometrically than in the case of a mere squeezing of the elastomer body.Moreover, the base height at which the link is located or the angle which the coupling device encloses with the fork or the head tube can also be influenced by the shape of the elastomer body. In one embodiment variant of the invention, the elastomer body is formed in a step shape on its outer jacket. Overall, it can be designed to be axially symmetrical with respect to an axis of symmetry. With regard to its envelope, the elastomer body resembles, for example, two cuboids displaced with respect to one another. If the perpendicular to the respective sides of the parallelogram is considered, the elastomer body is consequently not mirror-symmetrical. This measure also makes it possible for the elastomer body to be adapted to the positive and negative spring travel by virtue of its shape, because the corresponding sections of the elastomer body are arranged diagonally offset about the central axis of rotation of the front part and the elastomer body is more adapted to the shape of a parallelogram. In another refinement, the elastomer body may also have the shape of a parallelogram (instead of the step shape), in particular of a parallelogram which:a similar size with respect to edge length and area as the parallelogram formed from the axes of rotation, and / orbeing arranged rotated with respect to the parallelogram formed from the axes of rotation.Exemplary Embodiments:Exemplary embodiments of the invention are illustrated in the drawings and are explained in more detail below with the specification of further details and advantages. In detail, the following show: FIG. 1 is a schematic illustration of a front part according to the invention, FIG. 2 : a representation of a schematic section through the front part from FIG. 1, FIG. 3 is a view showing the structure of the insert; and FIG. 4 is a detail showing the coupling device with further elastomers in the stop region.FIG. 1 shows a side view of a sprung front part 1 with a static fastening device 2 which can encompass the fork stem or the head tube, a link holder 3 which in turn can encompass the link, and with a suspension device and / or coupling device 4 which connects the fastening device 2 to the link holder 3. The suspension device and / or coupling device 4 comprises two connecting parts 5, 6 between the static fastening device 2 and the handlebar mount 3. Only the lower connecting part 6 is shown in FIG. 1. two axes of rotation 7, 8 are arranged on the fastening device 2, and two axes of rotation 9, 10 are arranged on the handlebar mount 3. Each connecting part 5, 6 is mounted on one side on the fastening device 2 and on the other side on the link holder such that it can be pivoted via the axes of rotation 7, 9 and 8, 10, respectively. The connecting lines of the axis of rotation 7 to the axis of rotation 9 to the axis of rotation 10 to the axis of rotation 8 and back again to the axis of rotation 7 form a parallelogram.As can be seen even more clearly in FIG. 2, the elastomer body 13 is mounted between the connecting parts 5, 6, wherein it is possible, 9, 10, for example, to centrally guide or hold a puncture in the form of a notch which runs around the shaft axis and has a smaller diameter, with the result that the wire is also guided or held laterally.In addition to the elastomer body 13, the coupling device K also includes the insert 50, which is introduced into a recess 14 of the elastomer body 13. With the insert 50, the damping or the spring characteristic curve can be adjusted.The detailed construction of the insert is shown in Fig. 3. It comprises a central piece 51 which has an ellipsoidal cross section and is hollow in the interior. At the ends of the central piece 51 there are mounting webs 52, 53 attached or attachable. In the present case, the bearing web 53 is firmly connected to the central piece 51. The bearing web 52 is removable on the opposite side, and the central piece 52 of the insert 50 can thus be inserted into the recess 14 of the elastomer body 13 from both sides. If the insert 50 passes completely through the elastomer body 13, the bearing web 52 can also be connected to the central piece 51 on the opposite side. In addition, a support rod 54 is slid through the support web 53 and the hollow center piece 51 and can snap into the support web 52. The rod 54 can be detachably connected to the bearing webs 52, 53 via a bayonet connection.The bearing web 52, 53 is located centrally in the parallelogram and parallel between two sides of the parallelogram. The two bearing webs 52, 53 are also oriented parallel to one another. The components of the insert 50 are advantageously held together, for example, by a bayonet lock, so that they are always aligned in the same way with respect to one another. However, the central piece 51 firmly connected to the bearing web 53 also always receives the same alignment with respect to the bearing webs 51, 53 in this construction.On the side of the static fastening device 2, a bearing device, here a blind hole for inserting the bearing pins 56 which are opposite one another at the bearing webs 52, 53, is provided between the axes of rotation 7, 8. This is also correspondingly present on the side of the link holder 3, i.e. a blind hole between the axes of rotation 9, 10 for the bearing pins 57.A rotational axis runs through the two bearing pins 56 and through the two bearing pins 57, respectively, so that the bearing webs 52, 53 are rotatably mounted about these two axes under mutual constraints. The recess 14 has two openings, and the insert 50 can be inserted into this recess 14 from both sides. However, the insert 50 must be rotated through 180°, because the bearing web 53 is fixedly attached to the central piece 51 and is larger than the cross section of the recess 14. Thus, the alignment of the anisotropies A 1, A 2 also rotates with respect to the elastomer body 13.In FIG. 1, the stops 70, 71 are also shown with double files. When the spring travel is positive, the link is pivoted downward and the bearing webs 52, 53 strike the connecting parts 5, 6 in the region 71 when the deflection is maximum. In the case of a negative spring travel, the bearing webs 52, 53 strike the connecting parts 5, 6 in the region 70 when the deflection is maximum. The contours of the bearing webs 52, 53 and connecting parts 5, 6 are adapted in such a way that planar surfaces abut one another in the stop 70, 71 and the pressure on these components does not become too great.FIG. 4 again shows an enlarged view of the coupling device K with elastomer bodies E in the region of the stop 70, 71 at the connecting webs 52, 53 and the connecting parts 5, 6 for positive and negative spring travel.List of reference numbers:1 Front part 2 Static fastening device 3 Link holder 4 Coupling device (suspension device) 5 Connecting part (shell) 6 Connecting part (shell) 7 Axis of rotation 8 Axis of rotation 9 Axis of rotation 10 Axis of rotation 13 Elastomer body 14 Recess in the elastomer body (center) 50 Insert 51 Center piece of the insert 52 Bearing web 53 Bearing web 54 Holder rod 55 Spring 56 Bearing pins 57 Bearing pins 60 Wire 61 Wire 70 Stop 71 Stop E Further elastomers (in the stop region) K Coupling device

Claims

Sprung front part (1) for bicycles, in particular for racing bicycles and gravel bikes, for the sprung connection between the handlebar and the head tube and / or the fork stem, comprising: • a static fastening device (2) for fastening the front part to the head tube and / or the fork stem, • a handlebar holder (3) for connecting the front part to the handlebar, • a suspension device and / or coupling device (4) for suspending the handlebar and for the mechanical coupling between the static fastening device (2) and the handlebar holder (3), • wherein the suspension device and / or coupling device (4) comprises two connecting parts (5, 6) which both connect the fastening device (2) and the handlebar holder (3), respectively, • wherein the suspension device and / or coupling device (4) via two axes of rotation (7, 7, 8 ) is mounted on the static fastening device (2) and on the link holder (3) via two axes of rotation (9, 10), • wherein the connecting parts (5, 6) are each connected rotatably to the fastening device (2) on the one hand via one of the axes of rotation (7, 8) and are connected rotatably to the link holder (3) on the other hand via another of the axes of rotation (9, 10), such that the distance between the two axes of rotation (7, 9; 8, 10) which are connected to one another by the same connecting part (5, 6) is constant, and / or the side lengths of the parallelogram formed are constant, • wherein the axes of rotation (7, 8, 9, 10) run parallel to one another and are arranged such that the axes of rotation (7, 8, 9, 10) penetrate a plane perpendicular to the axes of rotation (7, 8, 9, 10) in such a way that the points of penetration form the corner points of a parallelogram, • wherein a coupling device (4) for mechanically coupling the connecting parts (5, A connecting rod (6) comprising an elastomer body (13) which is mounted so as to be deformed in order to absorb force and damp the relative movement between the link and the head tube, characterised in that at least one connecting rod (52, 53) is provided for connecting the static fastening device (2) and the link holder (3), which connecting rod is arranged between the two connecting parts (5, 6), wherein the at least one connecting rod (52, 53) is mounted rotatably in each case on the fastening device (2) and on the link holder (3) and is designed such that it is pivoted together with the connecting parts (5, 6) and comes into contact with one of the two connecting parts (5, 6) and / or with one of the axes of rotation (7, 8, 9, 10) from a certain deflection, such that the pivoting movement cannot be continued and the connecting rod (52, 53) thus forms a stop (70, 71).Front part (1) according to claim 1, characterised in that: • the at least one connecting web (52, 53) is arranged skew to the axes of rotation (7, 8, 9, 10), and / or • the static fastening device (2) and the link holder (3) each comprise a bearing device which in each case rotatably supports the at least one connecting web (52, 53), and / or • wherein in particular the bearing devices are arranged between the axes of rotation (7, 8, 9, 10).Front part (1) according to one of the preceding claims, characterized in that: • the connecting web (52, 53) or at least one of the connecting webs (52, 53) and / or • at least one of the connecting parts (5, 6) has / have a further elastomer (E) for damping the end stop at the location where the stop (70, 71) takes place.Front part (1) according to one of the preceding claims, characterized in that the at least one connecting web (52, 53) has a contour perpendicular to its longitudinal extent between the bearing devices and the connecting parts (5, 6), such that, when the stop (70, 71) is made, the contours run parallel to one another at the point at which they touch one another.Front part (1) according to one of the preceding claims, characterized in that the elastomer body (13) is formed in one piece.Front part (1) according to one of the preceding claims, characterized in that the elastomer body (13) has a recess (14) into which an insert (50) is introduced, so that, during the deformation of the elastomer body (13), during the pivoting of the static fastening device (2) with respect to the link holder (3), the coupling device (4) overall forms a higher mechanical resistance, wherein the insert (50) introduced into the recess (14) comprises at least two anisotropy axes (A1, A2) in the plane which passes through the elastomer body (13) perpendicularly to the axes of rotation (7, 8; 9, 10), along which it has a different extent, wherein the insert (50) can be positioned, in particular rotated, in such a way that the orientation of the anisotropy axes (A1, A2) in this plane can be changed.Front part (1) according to claim 6, characterised in that the recess (14) and / or the insert (50) fully penetrates / penetrates the elastomer body (13).Front part (1) according to one of claims 6 to 7, characterised in that the insert (50) can be introduced into the recess (14) in each case in both orientations and / or rotated through 180° along its longitudinal axis.Front part (1) according to one of Claims 6 - 8, characterized in that the insert (50) is of elliptical configuration in cross section.Front part (1) according to one of Claims 6 - 9, characterized in that the insert (50) can be introduced into the recess (14) in such a way that at least one of the anisotropy axes (A1, A2) intersects in each case two diagonally opposite axes of rotation (7, 8; 9, 10) perpendicularly.Front part (1) according to one of Claims 6 - 10, characterized in that the anisotropy axes (A1, A2) are perpendicular to one another.Front part (1) according to one of Claims 6 - 11, characterized in that the at least one connecting web (52, 53) is designed as a bearing web for pivotably mounting and / or retaining the insert (50) on the static fastening device (2) and on the link holder (3), and on the other hand the static fastening device (2) and the link holder (3) each comprise a bearing device which is releasably engaged with the respective bearing web (52, 53).Front part (1) according to one of Claims 6 - 12, characterized in that the bearing web (52, 53) can be connected and / or detachably connected to the insert (50).Front part (1) according to one of Claims 12 - 13, characterized in that the two points at which the bearing device is in each case in engagement with the bearing web (52, 53) on one side form a line which intersects the longitudinal axis of the insert (50) and which runs parallel to the two sides of the parallelogram which connect the link holder (3) and the static fastening device (2), wherein in particular the anisotropy axes (A1, A2) run 45° to the line.Front part (1) according to claim 1, characterised in that the connecting parts (5, 6): • are each rigid and / or • are each formed as shells (5, 6) and the at least one elastomer body (13, 14, 15, 16) is at least partially accommodated therein, • wherein in particular the shells (5, 6) of two of the connecting parts (5, 6) are each oriented facing each other, so that the elastomer body (13) or the elastomer bodies (13, 14, 15, 16) is / are mounted in the shells (5, 6) between the connecting parts (5, 6), preferably without contact and / or without a cohesive connection between elastomer body (13, 14, 15, 16) and the respective shell (5, 6).Front part (1) according to one of the preceding claims, characterized in that a normal position is provided in which the coupling device (K) assumes a position without an external force, in particular apart from the link weight, acting on it, and / or in that the coupling device (K) is designed to be deflected about the axes of rotation (13, 14, 15, 16) in both rotational directions in order to provide a positive and a negative spring travel.Front part (1) according to one of the preceding claims, characterized in that a wire (60, 61) is arranged on the fastening device (2) and / or on the link holder (3) as an assembly aid in each case between the corresponding axes of rotation (7, 8) on the fastening device (2) or between the corresponding axes of rotation (9, 10) on the link holder (3) in order to hold the axes of rotation (7, 8, 9, 10) during installation and to prevent axial slipping out.Front part (1) according to one of the preceding claims, characterized in that the elastomer body (13) and / or an individual one of the elastomer bodies is pierced by the respective connecting lines between the fastening device (2) and the link holder (3), which perpendicularly intersect the respective two mutually opposite axes of rotation (7, 8, 9, 10), in particular by the sides of the parallelogram, wherein the elastomer body (13) is in particular designed and arranged such that it is smaller in the direction of the connecting lines between mutually opposite axes of rotation (7, 8, 9, 10) than with respect to its extension between the two shells and / or connecting parts (5, 6), such that the elastomer body (13) is preferably sheared rather than compressed.Front part (1) according to one of the preceding claims, characterized in that the elastomer body (13) is configured as a parallelogram in cross section along the plane, through the corners of which the axes of rotation (7, 8; 9, 10) and / or the bearing shafts run along the axes of rotation (7, 8; 9, 10).Front part (1) according to one of the preceding claims, characterized in that the link holder (3) also comprises the link in an integrated manner.

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