DE102023118876B4 - Bicycle stem with adjustable elastomer damping and limited swivel range - Google Patents

Abstract

Suspension stem (1) for bicycles, especially for racing bikes and gravel bikes, for a suspension connection between the handlebars and the head tube and/or fork steerer tube, comprising:
• a static fastening device (2) for fastening the stem to the head tube and/or fork steerer tube,
• a handlebar mount (3) for connecting the stem to the handlebars,
• a suspension device and/or coupling device (4) for suspending the handlebar and for mechanically coupling between the static mounting device (2) and the handlebar mount (3),
• wherein the suspension device and/or coupling device (4) comprises two connecting parts (5, 6) each connecting the fastening device (2) and the handlebar mount (3),
• wherein the suspension device and/or coupling device (4) is mounted on the static mounting device (2) via two pivot axes (7, 8) and on the handlebar mount (3) via two pivot axes (9, 10),
• wherein the connecting parts (5, 6) are 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 parallelogram formed 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) form a plane perpendicular to the axes of rotation (7, 8, 9, 10)pierce such 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 is deformed in order to absorb force and dampen the relative movement between the handlebar and the steering tube, characterized in that at least one connecting web (52, 53) is provided for connecting the static fastening 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 fastening device (2) and on the handlebar bracket (3) respectively and is designed in such a way 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 stem for bicycles, such as can be used in particular on racing bikes and gravel bikes, according to the preamble of claim 1.

For example, the state of the art shows that... WO 2013/ 033 674 A1 A bicycle stem is known that consists of two parallel arms. The arms are each attached to the head tube and handlebars at fixed points via pivot joints, so that these pivot points form a parallelogram. The stem's inherent pivoting motion is dampened by a spring.

Furthermore, from the DE 10 2022 117 288 A1 For example, a bicycle stem with continuously adjustable damping is known, in which a kind of wedge is inserted into the elastomer body until the desired degree of damping is reached. Other sprung stems show the US 2021 / 0 155 307 A1 , US 2021 / 0 300 492 A1 , US 5 253 544 A and US 5,833,255 A.

The object of the invention is to propose a stem for bicycles, in particular for racing bikes and gravel bikes, which enables improved damping that is particularly practical and can be implemented cost-effectively.

Starting from a front section of the type mentioned at the outset, the problem is solved by the features of claim 1.

The measures mentioned in the dependent claims make advantageous embodiments and further developments of the invention possible.

The sprung stem according to the invention is particularly suitable for racing bikes and gravel bikes. The stem connects the handlebars to the head tube or fork. Especially when riding off-road or over uneven terrain, the front wheel is subjected to abrupt impacts. Without sufficient damping, these impacts put a great strain on the wrists because the shocks are transmitted directly to the hands and wrists via the fork or head tube.

According to the invention, the handlebar itself does not need to be a separate component connected to the fork or head tube via the stem. In principle, the invention can also be used with handlebar-stem units made from a single piece. The sprung stem is thus an integral part of the handlebar.

The invention is based, among other things, on the use of elastomeric bodies to implement a damping effect, because while springs, which are often used conventionally in the prior art, can absorb the shock, they ideally release almost all of the energy again. Therefore, springs are rather unsuitable as damping elements in the true sense, since the absorbed energy is only temporarily stored, but not dissipated, or not to a significant extent.

Advantages of negative suspension travel (sag):

In particular, the invention makes it possible to provide so-called negative spring travel (sag). The springs used up to now are primarily designed to withstand compression. When riding off-road, the head tube or fork can, in principle, move in both directions (towards the road or in the opposite direction). This is because, on very uneven terrain, the shocks that are ultimately transmitted via the fork to the rider's hands or wrists can occur in both directions: towards the ground and in the opposite direction, perpendicular to the road or vice versa. If conventional springs are used according to the prior art, the rider then feels the mechanical stops at the spring's limits: If the front wheel, for example, hits the ground, the mass formed by the handlebars and the rider's hands is also moved towards the ground and then decelerated; the spring is compressed until, at its maximum possible compression, it reaches a mechanical stop, thus transmitting a shock to the handlebars and hands. The travel up to this point is called positive spring travel. Due to the elastic spring action, a rebound in the opposite direction usually follows, which can be unpleasant for the hands.

When a spring is subjected to tension, a conventional spring, according to current technology, can usually hardly extend at all, since it is not a spring capable of withstanding both compression and tension. A corresponding negative spring travel is practically non-existent, so a mechanical stop is immediately felt in the hands.

According to the invention, however, damping with positive spring travel (in the case of a force acting towards the road) and with negative spring travel (in the case of a force acting in the opposite direction) is advantageously provided instead, thus avoiding a harsh driving feel as a result of a hard stop.

• - Eine herkömmliche Federgabel besitzt ohne Belastung im Unterschied zur Erfindung diesen negativen Federweg nicht.
• - Durch die statische Gewichtsverteilung ist ein sog. Sag durch die die vorhandene Masse ohne Vorbelastung durch Stöße vorhanden ist. Die Gewichtskraft lastet primär auf Sattel und Tretkurbel.
• - Dieser Sag ist bei einem gefederten Vorbau meistens im Gegensatz zur Federgabel so nicht vorhanden, da sich der Fahrer des Zweirads mit wenig Kraft über den Lenker stützt.
• - Die Krafteinleitung über den Lenker steigt erst bei bestimmten Fahrsituationen an, z.B. beim Bremsen.
• - Daher ist es vorteilhaft, bereits aus dem Ruhezustand, wie es erfindungsgemäß möglich ist, eine Konstruktion mit Sag bereitzustellen.

The invention thus makes it possible to provide a range of negative spring travel. to take advantage of the benefits compared to the current state of the art:

• - Unlike the invention, a conventional suspension fork does not have this negative travel when unloaded.
• - Due to the static weight distribution, a so-called sag occurs, whereby the existing mass is present without pre-loading from impacts. The weight force primarily rests on the saddle and crank arm.
• - This sag is usually not present with a sprung stem, unlike with a suspension fork, because the rider of the two-wheeler supports themselves with little force via the handlebars.
• - The force applied via the handlebars only increases in certain driving situations, e.g. when braking.
• - Therefore, it is advantageous to provide a construction with sag already from the resting state, as is possible according to the invention.

The improved riding experience is further enhanced by the fact that the stem according to the invention has a parallelogram-like design and the damping movement does not have a single pivot point around which the stem tilts, as is common with some conventional stems according to the prior art. The sides of the parallelogram always remain parallel, even when the stem absorbs an impact and the handlebars move relative to the fork or head tube. This means that, although the handlebars shift in position relative to the fork or head tube, they are not rotated or tilted during the stem's damping movement. Such tilting would have the disadvantage that the hands and wrists would also tilt along with the handlebars and thus be subjected to greater stress, especially when off-road riding involves impacts to the fork, head tube, handlebars, and wrists.

At the same time, the invention offers the advantage of retrofitting. As an alternative to a suspension stem, a suspension fork can be used, so that the front wheel is essentially directly suspended by a spring. However, unlike a suspension stem, such a suspension fork cannot be easily retrofitted. A suspension stem is therefore particularly advantageous for so-called gravel bikes, which are essentially derived from road bikes but are designed to facilitate riding on gravel roads, while not necessarily being built for the most demanding off-road riding conditions.

The fork-side or head tube-side part of the stem is designed as a static mounting device, the term "static" referring to the fact that the mounting device does not change its position relative to the main part of the bicycle, the frame. The static mounting device is permanently attached to the fork, more precisely to the head tube or steerer tube.

In contrast, the free end of the stem forms or terminates in a handlebar mount to connect the stem to the handlebars.

Between the handlebar clamp and the static mounting bracket is the stem's suspension and/or coupling device. It serves to mechanically couple the handlebar clamp and the static mounting bracket, designed to absorb shocks to the front wheel or fork relative to the handlebars. The suspension device forms two parallel sides of the parallelogram mentioned above. It is thus at least divided into two parts and comprises two parallel arms that act as connecting elements between the static mounting bracket and the handlebar clamp. Each connecting element is pivotally mounted on the static mounting bracket and the handlebar clamp about an axis of rotation. The axes of rotation are parallel. When the bicycle is upright, the axes of rotation are horizontal to the ground.

The two other sides of the parallelogram are located within the area of the static mounting bracket and the handlebar clamp, respectively. The distance between the two pivot points on the static mounting bracket is constant. The relative position of these pivot points remains unchanged even when the stem compresses. Similarly, the distance between the two pivot points on the handlebar clamp is constant, and their relative position also remains unchanged when the stem compresses. However, the relative positions of the static mounting bracket and the handlebar clamp generally change when the stem compresses; that is, the two sides of the parallelogram along the connecting parts can pivot towards the head tube side and the handlebar side, respectively.

The pivoting motion of the connecting parts is dampened by an additional mechanical coupling of the parts. This coupling device comprises an elastomeric body that provides both the coupling and the damping effect. The elastomeric body deforms reversibly when an external force is applied. This deformation returns to its original state when the force is removed. However, energy is also consumed during deformation; that is, it is not a purely elastic effect where all the energy is spontaneously released. The force is applied by the connecting parts or arms, each of which performs a pivoting movement. At least one elastomeric body is mounted in such a way that it is deformed during this process.

The intrinsic pivoting movement of the stem is limited with respect to its 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 may be subject to significant mechanical loads. One embodiment of the invention is characterized by the inclusion of a connecting bridge between the static mounting device and the handlebar mount in the area of the coupling device, which can absorb the intrinsic pivoting movement. The connecting bridge moves along with the connecting parts during the intrinsic pivoting. During shearing, the connecting bridge blocks further pivoting of the connecting parts from a certain deflection angle.

The connecting link can be rotatably mounted on both the static mounting device and the handlebar mount. Preferably, the connecting link can be mounted on both the static mounting device and the handlebar mount between their respective axes of rotation. Accordingly, the connecting link can be skewed relative to these axes of rotation.

If the parallelogram is sheared during intrinsic pivoting, the connecting link between the parallelogram sides can obstruct the movement beyond a certain deflection. The shape of the connecting link and its components can be adapted to prevent this. The wider the connecting link or components are perpendicular to their longitudinal extent, the more likely they are to collide and block the pivoting motion during intrinsic pivoting, especially if the contours of the connecting link and components are also adapted accordingly. Therefore, the maximum angle, and thus the point of contact or the point at which the components meet, can be defined by their shape.

With respect to the parallelogram, the connecting bridge can thus form another axis through the parallelogram, which is arranged parallel to two opposite sides of the parallelogram.

The shape of the connecting link and the connecting piece can be adapted to define the stop angle. When pivoting, the distance between the connecting link and the connecting pieces changes because of the rotation around the axes of rotation or the bearing of the connecting link.

In general, in one embodiment of the invention, it is also conceivable 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 at the end stop. This results in a two-stage spring characteristic including the end stop. A single elastomer may be present, applied only to the connecting web or the connecting part, or an elastomer may be applied to both the connecting web and the connecting part. In the latter case, during the spring travel, the two elastomers initially collide, so that the force initially increases only slightly due to the deformation of the elastomers. If one of the elastomers is fully compressed during further spring travel, the force increases more sharply again because only one elastomer is pressing against a fixed part. If both elastomers are fully compressed, the force briefly increases more steeply again. The force increases more evenly and less abruptly with the elastomers, resulting in a smaller impact on the rider's wrists. The impact is therefore further dampened.

The connecting parts and connecting webs can be shaped so that parallel contours meet at the stop, resulting in a surface-level contact of the contours. This distributes the force over a larger area, thus reducing the pressure. In this respect, the connecting parts and the connecting web can have partially complementary shapes. The shape refers to the plane in which the movement occurs during intrinsic pivoting.

Due to the flat contact along the contour and the distribution of force flow through connecting parts and connecting bridges, the force flow in the stem is such that the forces are transferred to at least two bearing points: the axes of rotation for the connecting parts and the bearing devices for the connecting bridges, which are each attached to the static mounting device and the handlebar bracket. This makes the stem or coupling device particularly stable.

The stop according to one embodiment of the invention can be implemented cost-effectively, but is characterized by high mechanical stability and high durability.

Depending on the application, the type of terrain, and personal riding preferences, it is advantageous to be able to adjust the damping of the stem. A further development of the invention achieves this by modifying the coupling device. In the prior art, for example, wedges are inserted between two adjacent elastomer bodies, thus altering the damping effect by introducing a hard intermediate layer into the material that is compressed or sheared during deflection for damping purposes. The damping becomes progressively firmer the further the wedge or similar element is inserted between the elastomer bodies. The preferred further development of the invention is characterized by the fact that the elastomer body has a recess into which an insert can be placed. This insert ensures that, when the static mounting device pivots relative to the handlebar mount, the coupling device as a whole exhibits higher mechanical resistance during deformation of the elastomer body.

It has been found that stepless damping adjustment, as can be achieved with wedges in the prior art, is not frequently needed in practice. Often, just two damping settings are sufficient: a firmer and a softer setting. Such an insert can therefore be permanently installed in the elastomer body. A stepless adjustment of the insert is thus unnecessary. To enable stepless damping adjustment, a separate mechanism is generally required. According to the invention, this mechanism, or such an adjustment device as used, for example, for the adjustable positioning of wedges, can be omitted. Furthermore, the insert can be positioned very stably, making the stem particularly robust with regard to mechanical loads.

However, in order to adjust the damping stiffness, the insert can have different thicknesses in its cross-section in various directions perpendicular to its longitudinal axis. If the insert is placed in the elastomer body so that the thicker cross-section is in the force path when the stem pivots, the resistance or damping is higher than if the insert is oriented so that a thinner area of the cross-section is in the force path.

With regard to its cross-sectional dimensions, the insert therefore has a different thickness in the direction of (at least) two axes, which are referred to here as axes of anisotropy; it is anisotropic in its extent. In one embodiment of the invention, the cross-section can, for example, be elliptical. In this case, the axes of anisotropy correspond to the two principal axes of the ellipse. By inserting the insert differently into the recess, the damping can thus be adjusted. If the insert is oriented so that the longer principal axis is in the force flow, the damping effect is greatest; if the shorter principal axis is in the force flow, the damping effect is least.

Accordingly, the insert can be rotated in the recess or at least inserted into the recess with different orientations.

The recess in the elastomer body does not need 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 its orientation. The recess can, for example, be cylindrical, with the diameter of its cross-section corresponding to the shortest dimension of the insert. The diameter of the recess can, for example, correspond to the smallest cross-sectional dimension of the insert, so that no gap forms between the elastomer body and the recess, regardless of the insert's orientation.

Advantageously, in the particularly preferred embodiment, the elastomer body is formed in one piece, thus simplifying its installation and the manufacturing of the stem. A one-piece elastomer body also has the advantage that the positive or negative spring travel does not result in large hysteresis, which would otherwise leave the stem's center position undefined. This is undesirable, as the rider always wants the handlebars to be in the same position when unloaded. The stem can therefore also dampen more reliably, especially since the parts of the elastomer body cannot slip against each other.

A two-part design of the elastomer body is conceivable in principle, especially if the links have sidewalls. However, this usually means additional weight.

To achieve a uniform damping effect, the recess and/or insert can/can completely penetrate the elastomer body, because otherwise, stresses could occur under mechanical load on the coupling device due to the uneven force distribution. If the insert completely penetrates the elastomer body, it can also be made particularly simple and stable. The damping effect can be achieved solely by the orientation of the insert within the elastomer body, i.e., the angle at which the anisotropy axes are oriented in the plane perpendicular to the axes of rotation.

In principle, it is also possible to design the insert within the elastomer body to be rotatable. Even with a continuous change in cross-sectional thickness along the outer contour, a continuous, stepless adjustment of the damping can still be achieved in this case. However, this is often unnecessary in practice. To facilitate handling for the user and to make the damping adjustment reproducible, the insert can, for example, simply be rotated 180°. The orientation of the longitudinal axis remains parallel to its previous orientation.

The axes of rotation of the coupling device intersect a plane perpendicularly, thus forming the vertices of a parallelogram. When inserting the component into the recess, the axis of anisotropy can be oriented so that it perpendicularly intersects two diagonally opposite axes of rotation. This ensures that the axis of anisotropy remains within the force flow during shearing of the parallelogram.

If the anisotropy axes are perpendicular to each other, the contribution of the other anisotropy axis can be practically eliminated if one of the anisotropy axes is in the force flow. This allows the change in damping to be maximized for different installation methods.

In one embodiment, the elastomer body can be stably mounted by, for example, having recesses in its corners through which the axes of rotation can pass, thus holding the elastomer body in its position. The elastomer body can therefore be mounted independently of the connecting parts.

In order to mount or hold the insert stably, in particular in a rotationally stable manner, a bearing rib can be provided in an advantageous further development of the invention.

In a particularly preferred embodiment, the connecting web is identical to the bearing web.

The bearing ridge can be permanently attached to the insert. It can also be detachably connected to the insert, particularly to facilitate installation of the insert in the recess and thus also the adjustment of the damping stiffness. The bearing ridge prevents the insert from slipping out of the recess. Furthermore, it ensures that the insert maintains a defined orientation within the elastomer body, dependent on its intrinsic pivoting, and does not rotate unintentionally, for example, when the front section is pivoted. As a locking wire, it does not support the elastomer body. Rather, the elastomer body prevents the wire from slipping out of the pivot points (shafts) to be secured. Thus, the wire, in combination with the elastomer body, provides a positive locking mechanism for the pivot points or shafts. The wire is preferably made of spring steel to achieve an elastic effect. Other materials, particularly other types of steel, are also conceivable. If the axes of rotation or shafts are provided with a groove or recess running around the shaft, the wire can be stored in it without slipping laterally. The recess can be located centrally with respect to the longitudinal extent of the shaft/axis of rotation.

In a further development of the invention, it suffices to provide a single, continuous elastomer body large enough that the sides of the described parallelogram, through whose vertices the axes of rotation pass, penetrate the elastomer body. The advantage of this further development is that the protrusion 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 stiffness of the stem, it may therefore be sufficient to insert or remove a hard core from the resulting recess, so that the overall structure of the elastomer body becomes correspondingly harder or softer, depending on how far this core is located within the elastomer body.

The elastomer body, in its unloaded state, has a smaller extent along the line connecting the mounting device and the handlebar mount than perpendicular to this direction. Therefore, shearing of the elastomer is more likely to occur with positive or negative suspension travel. The elastomer body is compressed rather than simply compressed. This allows for a significant improvement in damping performance. Furthermore, a greater spring travel can be achieved geometrically than with a mere compression of the elastomer body.

• - eine ähnliche Größe in Bezug auf Kantenlänge und Fläche besitzt wie das aus den Drehachsen gebildete Parallelogramm, und/oder
• - gegenüber dem aus den Drehachsen gebildeten Parallelogramm gedreht angeordnet ist.

Furthermore, the basic height at which the handlebars are located, or the angle that the coupling device forms with the fork or the head tube, can also be influenced by the shape of the elastomer body. In one embodiment of the invention, the elastomer body has a stepped outer surface. Overall, it can be axially symmetrical with respect to an axis of symmetry. With respect to its envelope, the elastomer body resembles, for example, two cuboids offset from each other. If one considers the perpendiculars to the respective sides of the parallelogram, the elastomer body is therefore not mirror-symmetrical. This measure also makes it possible for the elastomer body to be adapted to the positive and negative spring travel by its shape, because the corresponding sections of the elastomer body are arranged diagonally offset around the central axis of rotation of the stem, and the elastomer body is more closely adapted to the shape of a parallelogram. In another embodiment, the elastomer body can also have the shape of a parallelogram (instead of the stepped shape), in particular a parallelogram that:

• - has a similar size in terms of edge length and area as the parallelogram formed by the axes of rotation, and/or
• - is arranged rotated relative to the parallelogram formed by the axes of rotation.

Examples of implementation:

• 1: eine schematische Darstellung eines Vorbaus gem. der Erfindung,
• 2: eine Darstellung eines schematischen Schnitts durch den Vorbau aus 1,
• 3: eine Darstellung zum Aufbau des Einsatzes, sowie
• 4: einen Ausschnitt, der die Kopplungsvorrichtung mit weiteren Elastomeren im Anschlagsbereich darstellt.

Exemplary embodiments of the invention are shown in the drawings and are explained in more detail below, including further details and advantages. Specifically, the drawings show:

• 1 : a schematic representation of a porch according to the invention,
• 2 : a representation of a schematic section through the porch made of 1 ,
• 3 : a description of the deployment structure, as well as
• 4 : a section showing the coupling device with other elastomers in the stop area.

1 Figure 1 shows a sprung stem 1 in side view with a static mounting device 2, which can grip the fork steerer tube or the head tube, a handlebar clamp 3, which in turn can grip the handlebar, and a suspension and/or coupling device 4, which connects the mounting device 2 to the handlebar clamp 3. The suspension and/or coupling device 4 comprises two connecting parts 5, 6 between the static mounting device 2 and the handlebar clamp 3. This is shown in Figure 1. 1 Only the lower connecting part 6. The mounting device 2 has two pivot axes 7, 8, just as the handlebar mount 3 has two pivot axes 9, 10. Each connecting part 5, 6 is pivotally mounted on one side to the mounting device 2 and on the other side to the handlebar mount via the pivot axes 7, 9 and 8, 10, respectively. The lines connecting the pivot axis 7 to the pivot axis 9, to the pivot axis 10, to the pivot axis 8, and back to the pivot axis 7 form a parallelogram.

As in 2 As can be seen even more clearly, the elastomer body 13 is mounted between the connecting parts 5, 6, whereby it , 9, 10 can, for example, have a central indentation in the form of a notch circumferential around the shaft axis with a smaller diameter, so 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 inserted into a recess 14 of the elastomer body 13. The damping or spring characteristic can be adjusted using the insert 50.

The detailed setup of the operation is in 3 The insert 50 comprises a central section 51, which has an elliptical cross-section and is hollow inside. Bearing webs 52 and 53 are attached or can be attached to the ends of the central section 51. In this case, the bearing web 53 is fixedly connected to the central section 51. The bearing web 52 on the opposite side is removable. The central section 52 of the insert 50 can thus be inserted into the recess 14 of the elastomer body 13 from either side. If the insert 50 completely passes through the elastomer body 13, the bearing web 52 can also be connected to the central section 51 on the opposite side. Furthermore, a retaining rod 54 is pushed through the bearing web 53 and the hollow central section 51 and can snap into the bearing web 52. The rod 54 can be detachably connected to the bearing supports 52, 53 via a bayonet fitting.

The support strut 52, 53 is located centrally and parallel between two sides of the parallelogram. The two support struts 52, 53 are also aligned parallel to each other. Advantageously, the components of the insert 50 are held together, for example, by a bayonet fitting, so that they are always aligned in the same way with respect to each other. Furthermore, the central piece 51, which is firmly connected to the bearing rib 53, also always maintains the same orientation relative to the bearing ribs 51 and 53 in this design.

On the side of the static mounting device 2, a bearing device is provided between the pivot axes 7, 8, in this case a blind hole for inserting the bearing pins 56, which are located opposite each other on the bearing webs 52, 53. A corresponding feature is also provided on the side of the handlebar mount 3, i.e., a blind hole between each of the pivot axes 9, 10 for the bearing pins 57.

Each of the two bearing pins 56 and the two bearing pins 57 has a pivot axis, 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 either side. However, the insert 50 must be rotated by 180° because the bearing web 53 is fixed to the central piece 51 and is larger than the cross-section of the recess 14. Consequently, the orientation of the anisotropy axes A1, A2 also rotates relative to the elastomer body 13.

In 1 The stops 70 and 71 are also shown using double files. With positive spring travel, the handlebar pivots downwards, and the bearing blocks 52 and 53 abut the connecting parts 5 and 6 in area 71 at maximum deflection. With negative spring travel, the bearing blocks 52 and 53 abut the connecting parts 5 and 6 in area 70 at maximum deflection. The contours of the bearing blocks 52 and 53 and the connecting parts 5 and 6 are adapted so that flat surfaces meet at stops 70 and 71, and the pressure on these components does not become too great.

4 In turn, an enlargement of the coupling device K with elastomer bodies E in the area of the stop 70, 71 on the connecting bridges 52, 53 and the connecting parts 5, 6 for positive and negative spring travel is shown.

Reference symbol list:

1

stem

2

static fastening device

3

handlebar mount

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

Elastomeric body

14

Recess in the elastomer body (center)

50

Mission

51

middle section of the insert

52

Storage platform

53

Storage platform

54

Support rod

55

Feather

56

Storage pins

57

Storage pins

60

wire

61

wire

70

stop

71

stop

E

other elastomers (in the impact area)

K

Coupling device

Claims (20)

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 via a the axes of rotation (7, 8) are rotatably connected to the fastening device (2) on one side and to the handlebar bracket (3) on the other side 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 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) run 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 is deformed in order to absorb force and to dampen the relative movement between the handlebar and the head tube, characterized in that at least one connecting web (52, 53) is provided for connecting the static mounting device (2) and the handlebar mount (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 mount (3) and is designed in such a way 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). Extension (1) after Claim 1 , characterized in that: • the at least one connecting web (52, 53) is arranged at an angle to the axes of rotation (7, 8, 9, 10), and/or • the static fastening device (2) and the handlebar bracket (3) each comprise a bearing device which 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). Protrusion (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 a further elastomer (E) for damping the end stop where the stop (70, 71) takes place. Protrusion (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 extension between the bearing devices and the connecting parts (5, 6) such that at the stop (70, 71) the contours run parallel to each other at the point where they touch. Protrusion (1) according to one of the preceding claims, characterized in that the elastomer body (13) is formed in one piece. The stem (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 placed, so that when the elastomer body (13) is deformed during pivoting of the static fastening device (2) relative to the handlebar mount (3), the coupling device (4) as a whole forms a higher mechanical resistance, wherein the insert (50) placed in the recess (14) comprises at least two anisotropy axes (A1, A2) in the plane which passes through the elastomer body (13) perpendicular to the axes of rotation (7, 8; 9, 10), along which it has a different extent, wherein the insert (50) is positionable, in particular rotatable, such that the orientation of the anisotropy axes (A1, A2) in this plane can be changed. Extension (1) after Claim 6 , characterized in that the recess (14) and/or the insert (50) completely penetrates the elastomer body (13). Extension (1) after one of the Claims 6 - 7 , characterized in that the insert (50) can be inserted into the recess (14) in both orientations and/or rotated by 180° along its longitudinal axis. Extension (1) after one of the Claims 6 - 8 , characterized in that the insert (50) has an elliptical cross-section. Extension (1) after one of the Claims 6 - 9 , characterized in that the insert (50) can be inserted into the recess (14) such that at least one of the anisotropy axes (A1, A2) intersects two diagonally opposite rotation axes (7, 8; 9, 10) perpendicularly. Extension (1) after one of the Claims 6 - 10 , characterized in that the anisotropy axes (A1, A2) are perpendicular to each other. Extension (1) after one of the Claims 6 - 11 , characterized in that at least a connecting web (52, 53) is designed as a bearing web for pivoting the mounting and/or holding of the insert (50) on the static fastening device (2) and on the handlebar bracket (3), and on the other hand the static fastening device (2) and the handlebar bracket (3) each comprise a bearing device which is detachably engaged with the respective bearing web (52, 53). Extension (1) after one of the Claims 6 - 12 , characterized in that the bearing support (52, 53) is connected to the insert (50) and/or detachably connectable. Extension (1) after one of the Claims 12 - 13 , characterized in that the two points where the bearing device engages with the bearing web (52, 53) on one side each 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 handlebar bracket (3) and the static fastening device (2), wherein in particular the anisotropy axes (A1, A2) run at 45° to the line. Extension (1) after Claim 1 , characterized in that the connecting parts (5, 6): • are each rigidly formed and/or • are each formed as shells (5, 6) and the at least one elastomer body (13, 14, 15, 16) is at least partially received therein, • wherein in particular the shells (5, 6) of two of the connecting parts (5, 6) are oriented towards each other, so that the elastomer body (13) or the elastomer bodies (13, 14, 15, 16) is/are stored between the connecting parts (5, 6) in the shells (5, 6), preferably without contact and/or without a material bond between the elastomer body (13, 14, 15, 16) and the respective shell (5, 6). Stem (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 any external force acting on it, in particular apart from the handlebar weight, and/or that the coupling device (K) is designed to be deflected about the axes of rotation (13, 14, 15, 16) in both directions of rotation in order to provide a positive and a negative spring travel. Stem (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 handlebar mount (3) between the corresponding axes of rotation (7, 8) on the fastening device (2) and between the corresponding axes of rotation (9, 10) on the handlebar mount (3) as an assembly aid in order to hold the axes of rotation (7, 8, 9, 10) during installation and to prevent axial slippage. The stem (1) according to one of the preceding claims, characterized in that the elastomer body (13) and/or a single elastomer body is pierced by the respective connecting lines between the fastening device (2) and the handlebar mount (3), which perpendicularly intersect the two opposing 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 opposing axes of rotation (7, 8, 9, 10) than with respect to its extent between the two shells and/or connecting parts (5, 6), so that the elastomer body (13) is preferably sheared rather than compressed. Protrusion (1) according to one of the preceding claims, characterized in that the elastomer body (13) is designed in cross-section along the plane as a parallelogram, through whose corners the axes of rotation (7, 8; 9, 10) and/or the bearing shafts along the axes of rotation (7, 8; 9, 10) run. Stem (1) according to one of the preceding claims, characterized in that the handlebar mount (3) also includes the handlebar.