Fork shaft arrangement and bicycle

Abstract

The invention relates to a fork shaft arrangement (1) for a bicycle (100), wherein an upper fork shaft (3) at least partially encloses a lower fork shaft (2) in a covering region (6), wherein an outer clamping element (5) in the covering region (6) bears on the outer side of the upper fork shaft (2) and is provided to exert an inwardly directed force on the outer side of the upper fork shaft (2). The invention also relates to a bicycle (100).

Description

[0001] Fork stem arrangement and bicycle

[0002] The invention relates to a fork stem assembly for a bicycle and to a bicycle.

[0003] Bicycles regularly require highly flexible handlebar height adjustment. This often involves a desire to set the handlebar height higher than originally planned. In such cases, the length of the fork steerer tube typically limits the upward adjustment range. To allow adjustment beyond the intended maximum height, so-called ahead adapters are available. These adapters are clamped onto the fork steerer tube and extend it. The disadvantage of these adapters is that they can only be used with steel fork steerers.

[0004] In addition to the desired additional upward adjustability, there is also a need to position bicycle cockpits and traditional stems with handlebars lower than intended. Cyclists typically use spacers mounted above the cockpit or simply shorten the fork tube with a saw. Both methods compromise safety. Sawing off the fork tube, in particular, is detrimental to the future resale of the bicycle. The object of the invention is to provide a fork tube assembly that offers a high degree of safety while simultaneously allowing maximum flexibility with regard to height adjustability.

[0005] This object is achieved by the fork stem arrangement set out in claim 1.

[0006] According to the invention, the steerer tube assembly has a lower steerer tube, an upper steerer tube, and an outer clamping element. The upper steerer tube is preferably a steerer tube with an industry standard size having an outer diameter of 28.6 mm. The upper steerer tube preferably has an inner diameter of 24.2 mm. The upper steerer tube at least partially encloses the lower steerer tube in an overlap area. For this purpose, the lower steerer tube has an outer diameter in the overlap area which corresponds at most to the inner diameter of the upper steerer tube. It is conceivable that the lower steerer tube has an outer diameter of 24 mm in the overlap area. It is conceivable that the lower steerer tube has an inner diameter of 20 mm in the overlap area.Preferably, the lower fork steerer tube has a smaller outer diameter within the overlap area than below the overlap area. It is therefore conceivable for the lower fork steerer tube to have a first area with a large diameter and a second area with a small diameter. For this purpose, it is conceivable for a transition area between the first area and the second area to be conical. The overlap in the overlap area of ​​the fork steerers achieves a high degree of stability and thus safety.

[0007] Alternatively, it is also conceivable that the lower fork tube is preferably a fork tube with an industry standard size with an outer diameter of 28.6 mm. The upper fork tube at least partially encloses the lower fork tube in an overlap area. For this purpose, the upper fork tube has an inner diameter in the overlap area which corresponds at least to the outer diameter of the lower fork tube. It is preferably provided that the upper fork tube has a smaller outer diameter above the overlap area than in the overlap area. It is also preferably provided that the upper fork tube has a smaller inner diameter above the overlap area than in the overlap area. It is particularly preferably provided that the upper fork tube has an outer diameter of 28.6 mm above the overlap area and an inner diameter of 28.8 mm in the overlap area.Furthermore, it is preferably provided that the upper fork steerer tube has an outer diameter of 33 mm in the overlap area. It is therefore conceivable for the upper fork steerer tube to have a first area with a large diameter and a second area with a small diameter. For this purpose, it is conceivable that a transition area between the first area and the second area is conical. The overlap in the overlap area of ​​the fork steerers achieves a high degree of stability and thus safety.

[0008] The outer clamping element is arranged so that it rests against the outer side of the upper fork tube in the overlap area. According to the invention, the outer clamping element exerts an inward force on the outer side of the upper fork tube. This significantly increases the strength of the fixation of the upper fork tube and the lower fork tube relative to each other.

[0009] Advantageous embodiments and further developments of the invention can be found in the dependent claims and the description with reference to the drawings.

[0010] According to a preferred embodiment of the present invention, the fork stem assembly comprises an inner clamping element, the inner clamping element being arranged with a lower part against the inside of the lower fork stem and with an upper part against the inside of the upper fork stem, the inner clamping element being arranged to exert an outwardly directed force on the inside of the lower fork stem and the inside of the upper fork stem. The inner clamping element is arranged with a lower part against the inside of the lower fork stem. Furthermore, the inner clamping element is arranged with an upper part against the inside of the upper fork stem. According to the invention, the inner clamping element exerts an outwardly directed force on the inside of the lower fork stem and an outwardly directed force on the inside of the upper fork stem.This clamps the inner fork tube and the outer fork tube and fixes them relative to each other.

[0011] If the inner and outer clamping elements are loosened so that they exert little or no force on the inner and outer sides of the fork steerer tubes, the positioning of the upper fork steerer tube can be adjusted. For example, it is conceivable that the upper fork steerer tube is pulled further up or down. It is also conceivable that, after the inner and outer clamping elements have been loosened, the upper fork steerer tube is replaced with a longer or shorter upper fork steerer tube. This allows for a very high degree of flexibility in adjusting the steering height. Another advantage is that differently configured upper fork steerer tubes can be interchanged to meet different requirements. This makes it possible, for example, to make large height adjustments.

[0012] According to a preferred embodiment of the invention, the outer clamping element is designed to exert the inwardly directed force on the outer side of the upper fork tube in such a way that the inner side of the lower fork tube is pressed against the lower part of the inner clamping element. This advantageously increases the stability of the fixation of the upper fork tube and the lower fork tube.

[0013] Preferably, the inner clamping element is an expander, wherein the outer diameter of the lower part of the inner clamping element is adapted to the inner diameter of the lower fork tube and the outer diameter of the upper part of the inner clamping element is adapted to the inner diameter of the upper fork tube. This enables advantageous transmission of forces from the expander to the lower fork tube and the upper fork tube. An outer diameter and an inner diameter within the meaning of the present invention are not necessarily limited to a circular outer or inner contour, but merely describe the geometric design of the outer or inner contour of the upper fork tube or the lower fork tube relative to a plane that is orthogonal to the main direction of extension of the upper fork tube or the lower fork tube.In the context of the present invention, "adapted" means that the outer contour of the inner clamping element is at least partially flush with the inside of the upper fork tube or the lower fork tube. In particular, for example, it is provided that the inner diameter of the upper fork tube is oval and the outer diameter of the upper part of the inner clamping element is at least partially oval. Likewise, it is provided in particular that the inner diameter of the lower fork tube is oval and the outer diameter of the lower part of the inner clamping element is at least partially oval.

[0014] According to a further preferred embodiment of the present invention, the lower part of the inner clamping element and the upper part of the inner clamping element are arranged next to one another along a vertical direction, wherein the lower part of the inner clamping element has a smaller extent in a transverse direction arranged orthogonally to the vertical direction than the upper part of the inner clamping element. The resulting shape of the inner clamping element ensures that the inner clamping element fits perfectly against the inner sides of the upper fork tube and the lower fork tube. The vertical direction in the sense of the present invention corresponds to the main direction of extent of the lower fork tube and the upper fork tube.

[0015] Preferably, the outer clamping element is a clamp spacer. A clamp spacer in the sense of the present invention is an element that encompasses the upper fork tube and is provided for spacing elements along the vertical direction above and below the clamp spacer. The clamp spacer preferably has a screw with which the inwardly directed force can be applied by turning the screw. According to a further preferred embodiment of the present invention, the outer side of the lower fork tube has an oval cross-section, at least in the overlap area, and the inner side of the upper fork tube has an oval cross-section, at least in the overlap area. This advantageously ensures that the upper fork tube and the lower fork tube are secured against twisting relative to one another.It is conceivable that the outer side of the lower fork tube has an oval cross-section along the entire length of the lower fork tube and that the inner side of the upper fork tube has an oval cross-section along the entire length of the upper fork tube. It is further conceivable that the outer side of the lower fork tube has a non-round cross-section, for example a square cross-section, at least in the overlap area and that the inner side of the upper fork tube has a non-round cross-section, for example a square cross-section, at least in the overlap area. It is preferably provided that the outer side of the upper fork tube has a round cross-section. Furthermore, it is preferably provided that the inner side of the lower fork tube has a round cross-section.

[0016] Furthermore, it is preferably provided that the outer side of the lower fork tube has at least one flattened area, at least in the overlap area. Furthermore, the inner side of the upper fork tube preferably has at least one flattened area, at least in the overlap area. The flattened area of ​​the upper fork tube is arranged adjacent to the flattened area of ​​the lower fork tube.

[0017] It is conceivable that the outer clamping element is adapted to the outer diameter of the upper fork tube. In particular, it is provided that an inner diameter of the outer clamping element is at least partially adapted to the outer diameter of the upper fork tube.

[0018] It is preferably provided that the upper fork tube has a lateral slot. This ensures significantly better power transmission. Furthermore, it is preferably provided that a tensioning element of the inner clamping element is arranged such that the tensioning element can be actuated from an interior of the upper fork tube, wherein the tensioning element is provided to bring about and / or mediate the exertion of the outwardly directed force on the inside of the lower fork tube and the inside of the upper fork tube. In other words, it is provided that the tensioning element is operated from above. However, it is also conceivable that the tensioning element can be operated through the lateral slot or through another lateral slot in the upper and / or lower fork tube.

[0019] It is conceivable that the clamping element has a screw for screwing into the inner clamping element, whereby screwing in causes the clamping element to expand against the inner sides of the upper fork tube and the lower fork tube.

[0020] To improve the installation of cables along the fork steerer tube, the inner clamping element is preferably provided with a cable feedthrough. This advantageously makes it possible to route cables, such as brake lines or electrical lines, from the bicycle cockpit through the interior of the upper fork steerer tube and the lower fork steerer tube. In addition to a visually pleasing arrangement, this saves installation space and protects the cables from mechanical influences. Another particularly advantageous feature is that the currently common, complex routing of the cables through an enlarged bearing is no longer necessary.

[0021] Preferably, the lower fork tube is made from a carbon material and the upper fork tube is made from a carbon material. According to an alternative and preferred further embodiment of the present invention, the lower fork tube is made from a carbon material and the upper fork tube is made from a metal, preferably aluminum. This advantageously combines the advantages of a fork tube made from carbon, in particular its low weight, with the advantages of a fork tube made from metal. The fact that the upper fork tube is made from metal results in further added safety and the possibility of a greater extension of the upper fork tube. In particular, the material mix of carbon and metal also offers the possibility of adjusting the elasticity of the fork tube arrangement.For example, the fork stem assembly allows for stronger suspension when the upper fork stem is extended further. If the upper fork stem is pushed further onto the lower fork stem, the fork stem assembly becomes stiffer. It is also conceivable for the upper fork stem to be made of a carbon material and the lower fork stem of a metal, preferably aluminum. Aluminum, as used herein, includes not only aluminum but also any aluminum alloy.

[0022] A further object for achieving the initially stated problem is a bicycle having a fork stem assembly according to the invention. For this purpose, it is preferably provided that the upper fork stem is mounted on a head tube of the bicycle with a bearing, with an upper bearing cover of the bearing being formed by the outer clamping element. This advantageously ensures that the bearing play of the bearing remains fixed, even when the bicycle cockpit is removed.

[0023] All details, features and advantages previously disclosed in connection with the fork stem assembly according to the invention also relate to the bicycle according to the invention.

[0024] Further details, features, and advantages of the invention will become apparent from the drawings and the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not limit the scope of the invention.

[0025] They show:

[0026] Fig. 1: a first sectional view of a fork stem assembly for a bicycle according to an exemplary embodiment of the present invention, Fig. 2: a second sectional view of a fork stem assembly for a bicycle according to an exemplary embodiment of the present invention,

[0027] Fig. 3: another view of a fork stem assembly for a bicycle according to an exemplary embodiment of the present invention,

[0028] Fig. 4: a schematic representation of an inner clamping element of a

[0029] Fork stem assembly according to an exemplary embodiment of the present invention,

[0030] Fig. 5: a sectional view of the coverage area of ​​a fork stem assembly according to an exemplary embodiment of the present invention along the vertical axis and

[0031] Fig. 6: a third sectional view of a fork stem assembly for a

[0032] Bicycle according to an exemplary embodiment of the present invention.

[0033] In the figures described below, identical elements are always designated by the same numbers or letters and are therefore not necessarily described multiple times.

[0034] Figures 1, 2 and 6 each show a sectional, schematic representation of a fork stem assembly 1 according to an exemplary embodiment of the present invention for a bicycle 100 according to an exemplary embodiment of the present invention.

[0035] The fork stem assembly 1 has a lower fork stem 2, which is at least partially enclosed by an upper fork stem 3 in an overlap region 6. Preferably, the upper fork stem 3 is a fork stem with industry standard dimensions, i.e. the outer diameter of the upper fork stem 3 is 28.6 mm. The upper fork stem 3 can be made, for example, from a carbon material or from a metal, for example aluminum. The lower fork stem 2 has, at least in the overlap region 6, an outer diameter which allows the upper fork stem 3 to be pushed over the lower fork stem 2. The lower fork stem 2 can be made of the same material as the upper fork stem 3. However, it is also conceivable for the upper fork stem 3 to be made of a different material, for example a metal such as aluminum.

[0036] To adjust the steering height, the upper fork tube 3 is moved along the vertical direction H relative to the lower fork tube 2. Once the steering height has been adjusted, the upper fork tube 3 and the lower fork tube 2 must be fixed relative to one another. Two clamping elements 4, 5 are provided for this purpose. An inner clamping element 4 rests with a lower part 4.1 on the inside of the lower fork tube 2. An upper part 4.2 of the inner clamping element 4 rests on the inside of the upper fork tube 3. By means of a bracing element 4.3 of the inner clamping element 4, an outwardly directed force can be exerted on the insides of the lower fork tube 2 and the upper fork tube 3. The bracing element 4.3 is accessible either from above through the upper fork tube 3 (Fig. 4(a)) or from the side (Fig. 4(b)) through a slot 3.1 in the upper fork tube 3.An outer clamping element 5, designed as a clamping spacer, rests against the outer side of the upper fork tube 3 in the overlap area 6. The outer clamping element 5 is intended to exert an inward force on the upper fork tube 3 and through the upper fork tube 3 onto the inner fork tube 2 and finally onto the inner clamping element 4. The outer clamping element 5 is adapted to the outer contour of the upper fork tube 3 such that the outer clamping element 5 rests against the outer side of the upper fork tube 3 over as large an area as possible.

[0037] The inner clamping element 4 is designed as an expander. The outer diameter of the lower part 4.1 of the inner clamping element 4 is adapted to the inner diameter of the lower fork tube 2 such that the lower part 4.1 is arranged at least partially in contact with the inside of the lower fork tube 2. For this purpose, it is provided that the outer contour of the lower part 4.1 of the inner clamping element 4 is adapted to the inner contour of the lower fork tube 2 in the overlap area 6. Likewise, the outer diameter of the upper part 4.2 of the inner clamping element 4 is adapted to the inner diameter of the upper fork tube 3. The upper part 4.2 rests at least partially on the inside of the upper fork tube 3. For this purpose, it is also provided that the outer contour of the upper part 4.2 of the inner clamping element 4 is adapted to the inner contour of the upper fork tube 3 in the overlap area 6.The inner clamping element 4 thus has different extensions along the vertical direction H along a transverse direction Q, which is orthogonal to the vertical direction H.

[0038] To prevent twisting of the lower fork tube 2 and the upper fork tube 3, it can be provided that the lower fork tube 2 and the upper fork tube 3 are non-round, at least in the overlap area 6. For example, it is conceivable that the fork tubes 2, 3 are oval or have flattened areas 10.

[0039] A good frictional connection is achieved by the fact that the upper fork tube 3 can have the lateral slot 3.1. This allows the upper fork tube 3 to be clamped onto the lower fork tube 2 over a large area.

[0040] If the fork stem assembly 1 is installed in a bicycle 100, the fork stem assembly 1 is rotatably mounted in a head tube 8 of the bicycle 100 with at least one bearing 7 of a headset of the bicycle 100. The outer clamping element 5 can form an upper bearing cover for the bearing 7. A stem 12 of the bicycle 100 is arranged on the upper fork stem 3 and is spaced from the outer clamping element 5 by spacers 9. An ahead cap 13, which is secured with an ahead cap screw 13.1, forms an upper end. The ahead cap screw 13.1 engages a thread in the bracing element 4.3 of the inner clamping element 4, so that by turning the ahead cap screw 13.1, it can be screwed onto the inner clamping element 4 and fastened.

[0041] To adjust the steering height, simply loosen the ahead cap screw 13.1 and remove the ahead cap 13. The stem 12 can now be loosened and removed as well. Because the outer clamping element 5 initially remains on bearing 7 even when the bicycle cockpit is removed, the bearing play of the headset remains fixed even in this situation. The inner clamping element 4 can be relaxed, depending on the design, from the side (Fig. 4(b)) or from above (Fig. 4(a)), thus releasing the outward force of the inner clamping element 4. With the additional relaxation of the outer clamping element 5, the inward force and thus the fixation of the upper fork tube 3 and lower fork tube 2 is released, and they can be moved relative to each other. This enables a new steering height adjustment.

[0042] The inner clamping element 4 has a cable feedthrough 4.4. Cables 11, such as brake cables, brake lines, or even electrical cables, are routed through this cable feedthrough 4.4. This allows the cables 11 to be routed through the interior 3.2 of the upper fork tube 3 and the lower fork tube 2. A complex feedthrough through the bearings 7 of the headset of the bicycle 100 can be eliminated.

[0043] The fork stem assembly 1 according to the invention enables a steering height adjustment with a wide adjustment range. Visually, the fork stem assembly 1 is almost indistinguishable from a conventional fork stem assembly.

[0044] Reference list:

[0045] 1 Fork stem arrangement

[0046] 2 lower fork tube

[0047] 2.1 side slot

[0048] 3 upper steerer tube

[0049] 3.1 side slot

[0050] 3.2 Interior

[0051] 4 inner clamping element

[0052] 4.1 lower part

[0053] 4.2 upper part

[0054] 4.3 Bracing element

[0055] 4.4 Cable penetration

[0056] 5 outer clamping element

[0057] 6 Coverage area

[0058] 7 camps

[0059] 8 Head tube

[0060] 9 spacers

[0061] 10 flattened area

[0062] 11 Line

[0063] 12 Stem

[0064] 13 Ahead cap

[0065] 13.1 Ahead cap screw

[0066] 100 bicycles

[0067] H Vertical direction

[0068] Q transverse direction

Claims

Claims: Fork steerer assembly (1) for a bicycle (100), comprising a lower fork steerer (2), an upper fork steerer (3), and an outer clamping element (5), wherein the upper fork steerer (3) at least partially surrounds the lower fork steerer (2) in an overlap area (6), wherein the outer clamping element (5) bears against the outside of the upper fork steerer (3) in the overlap area (6) and is designed to exert an inwardly directed force on the outside of the upper fork steerer (3). Fork steerer assembly (1) according to claim 1, characterized in that the fork steerer assembly (1) comprises an inner clamping element (4), wherein the inner clamping element (4) has a lower part (4.1) on the inside of the lower fork steerer (2) and an upper part (4.2) is arranged abutting the inside of the upper fork steerer tube (3), wherein the inner clamping element (4) is provided to exert an outward force on the inside of the lower fork steerer tube (2) and the inside of the upper fork steerer tube (3). Fork steerer tube arrangement (1) according to claim 2, characterized in that the outer clamping element (5) is provided to exert the inward force on the outside of the upper fork steerer tube (3) such that the inside of the lower fork steerer tube (2) is pressed onto the lower part (4.1) of the inner clamping element (4). Fork steerer tube arrangement (1) according to one of the preceding claims, characterized in that the inner clamping element (4) is an expander, wherein the outer diameter of the lower part (4.1) of the inner clamping element (4) is adapted to the inner diameter of the lower fork steerer tube (2) and the outer diameter of the upper part (4.2) of the inner clamping element (4) is adapted to the inner diameter of the upper fork steerer tube (3). A fork steerer assembly (1) according to any one of the preceding claims, characterized in that the lower part (4.1) of the inner clamping element (4) and the upper part (4.2) of the inner clamping element (4) are arranged side by side along a vertical direction (H), wherein the lower part (4.1) of the inner clamping element (4) is smaller than the upper part (4.2) of the inner clamping element (4) in a transverse direction (Q) arranged orthogonally to the vertical direction (H). A fork steerer assembly (1) according to any one of the preceding claims, characterized in that the outer clamping element (5) is a clamping spacer. A fork steerer assembly (1) according to any one of the preceding claims, characterized in that the outer surface of the lower fork steerer (2) has an oval cross-section at least in the overlap area (6) and that the inner surface of the upper fork steerer (3) has an oval cross-section at least in the overlap area (6).Fork stem arrangement (1) according to one of the preceding claims, characterized in that the outside of the lower fork stem (2) has at least one flattened area (10) at least in the overlap area (6) and that the inside of the upper fork steerer tube (2) has at least one flattened area (10) at least in the overlap area (6), wherein the flattened area (10) of the upper fork steerer tube (3) is arranged abutting the flattened area (10) of the lower fork shank (2). Fork shank arrangement (1) according to one of the preceding claims, characterized in that the upper fork shank (3) has a lateral slot (3.1). Fork shank arrangement (1) according to one of the preceding claims, characterized in that a clamping element (4.3) of the inner clamping element (4) is arranged such that the clamping element (4.3) is made of an interior (3.2) of the upper fork steerer tube (3), wherein the clamping element (4.3) is provided to effect and / or mediate the application of the outwardly directed force to the inside of the lower fork steerer tube (2) and the inside of the upper fork steerer tube (3).

1. Fork steerer tube assembly (1) according to claim 10, characterized in that the clamping element (4.3) has a screw for screwing into the inner clamping element (4), wherein screwing in causes the clamping element (4) to expand against the insides of the upper fork steerer tube (3) and the lower fork steerer tube (2).

2. Fork steerer tube assembly (1) according to one of the preceding claims, characterized in that the inner clamping element (4) has a cable passage (4.4). 3.Fork steerer assembly (1) according to one of the preceding claims, characterized in that the lower fork steerer (2) is made of a carbon material and that the upper fork steerer (3) is made of a metal, preferably aluminum.

4. Bicycle (100) comprising a fork steerer assembly (1) according to one of the preceding claims.

5. Bicycle (100) according to claim 14, characterized in that the upper fork steerer (3) is mounted on a head tube (8) of the bicycle (100) by means of a bearing (7), wherein an upper bearing cover of the bearing (7) is formed by the outer clamping element (5).

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