Front fork stand pipe device and bicycle

Abstract

The invention relates to a front fork stem arrangement (1) for a bicycle (100), in which an upper front fork stem (3) at least partially surrounds a lower front fork stem (2) in an overlap region (6), and in which an outer clamping element (5) rests on the outer side of the upper front fork stem (3) in the overlap region (6), and is provided for applying an inwardly directed force to the outer side of the upper front fork stem (3). The invention further provides a bicycle (100).

Description

Technical Field

[0001] The invention relates to a front fork stem device for a bicycle and a bicycle. Background Art

[0002] Bicycles usually require a high degree of flexibility in adjusting the handlebar height. It is not uncommon to wish to adjust the handlebar height to a higher height than originally envisaged. In this case, the length of the fork stem usually limits the upward adjustment range. In order to still be able to adjust beyond the set maximum height, so-called toothless adapters are known from the prior art, which are clamped onto the fork stem and extend the stem. The disadvantage of such adapters is that they can only be used for steel fork stems.

[0003] In addition to the desire for further adjustability upwards, there is also a desire to position the bicycle cockpit and the classic stem with handlebars lower than originally intended. To this end, cyclists often use washers that are mounted above the cockpit or simply shorten the fork stem with a saw. Both come at the expense of safety. Sawing off the fork stem is particularly detrimental to the subsequent resale of the bicycle. Summary of the invention

[0004] The object of the present invention is to provide a stem arrangement which provides a high level of safety and at the same time allows for maximum flexibility in terms of height adjustability.

[0005] This object is achieved by the front fork stem device according to claim 1 .

[0006] According to the invention, the stem arrangement comprises a lower stem, an upper stem and an outer clamping element. The upper stem is preferably an industry standard stem with an outer diameter of 28.6 mm. The upper stem preferably has an inner diameter of 24.2 mm. The upper stem at least partially surrounds the lower stem in the overlap region. For this purpose, the lower stem has an outer diameter in the overlap region which corresponds at most to the inner diameter of the upper stem. It is conceivable that the lower stem has an outer diameter of 24 mm in the overlap region. It is conceivable that the lower stem has an inner diameter of 20 mm around the overlap region. It is preferably provided that the lower stem has a smaller outer diameter in the overlap region than below the overlap region. It is also conceivable that the lower stem has a first region with a larger diameter and a second region with a smaller diameter. For this purpose, it is conceivable that the transition region between the first region and the second region is designed to be conical. The overlap in the overlap region of the stems ensures a high stability and thus a high safety.

[0007] However, it is also conceivable as an alternative that the lower stem tube is preferably an industry standard stem tube with an outer diameter of 28.6 mm. The upper stem tube at least partially surrounds the lower stem tube in the overlapping region. For this purpose, the upper stem tube has an inner diameter in the overlapping region which is at least equivalent to the outer diameter of the lower stem tube. It is preferably provided that the upper stem tube has a smaller outer diameter above the overlapping region than in the overlapping region. It is also preferably provided that the upper stem tube has a smaller inner diameter above the overlapping region than in the overlapping region. It is particularly preferably provided that the upper stem tube has an outer diameter of 28.6 mm above the overlapping region and an inner diameter of 28.8 mm in the overlapping region. It is also preferably provided that the upper stem tube has an outer diameter of 33 mm in the overlapping region. It is also conceivable that the upper stem tube has a first region with a larger diameter and a second region with a smaller diameter. For this purpose, it is conceivable that the transition region between the first region and the second region is designed to be conical. The overlap in the overlap region of the stem ensures a high stability and thus a high level of safety.

[0008] The outer clamping element is arranged in such a way that it bears against the outer side of the upper stem in the overlapping region. According to the invention, the outer clamping element exerts an inwardly directed force on the outer side of the upper stem. This significantly increases the strength of the fixing of the upper stem and the lower stem relative to one another.

[0009] Advantageous embodiments and developments of the invention can be gathered from the dependent claims and the subsequent description with reference to the drawings.

[0010] According to a preferred embodiment of the present invention, the stem device comprises an inner clamping element, wherein the inner clamping element is arranged to abut with a lower portion against an inner side of the lower stem and with an upper portion against an inner side of the upper stem, wherein the inner clamping element is provided for applying an outwardly directed force to the inner side of the lower stem and to the inner side of the upper stem.

[0011] The inner clamping element is arranged so that its lower part abuts against the inner side of the lower stem tube. Furthermore, the inner clamping element is arranged so that its upper part abuts against the inner side of the upper stem tube. According to the invention, it is provided that the inner clamping element exerts an outwardly directed force on the inner side of the lower stem tube and exerts an outwardly directed force on the inner side of the upper stem tube. As a result, the inner stem tube and the outer stem tube are clamped and fixed relative to each other.

[0012] If the inner and outer clamping elements are released so that they exert no or only little force on the inner or outer side of the stem, the positioning of the upper stem can be adapted. For example, it is conceivable to pull the upper stem further upwards or downwards. It is also conceivable that the upper stem is replaced by a longer or shorter upper stem after the inner and outer clamping elements have been released. This allows a very high degree of flexibility when adjusting the steering height. It is also advantageous that upper stems of different configurations can be interchanged with one another to meet different requirements. This allows, for example, a large height adjustment.

[0013] According to a preferred embodiment of the present invention, the outer clamping element is configured to exert an inwardly directed force on the outer side of the upper stem tube, so that the inner side of the lower stem tube is pressed against the lower part of the inner clamping element, thereby advantageously improving the fixing stability of the upper stem tube and the lower stem tube.

[0014] It is preferably provided that the inner clamping element is an expander, wherein the outer diameter of the lower part of the inner clamping element is matched to the inner diameter of the lower stem tube, and the outer diameter of the upper part of the inner clamping element is matched to the inner diameter of the upper stem tube. This makes it possible to advantageously transmit the force of the expander to the lower stem tube and the upper stem tube. In the sense of the invention, the outer diameter and the inner diameter do not necessarily have to be limited to a circular outer contour or inner contour, but only describe the geometry of the outer contour or inner contour of the upper or lower stem tube based on a plane that is orthogonal to the main extension direction of the upper or lower stem tube. In the sense of the invention, matching means that the outer contour of the inner clamping element rests at least partially flush against the inner side of the upper or lower stem tube. For example, it is particularly provided that the inner diameter of the upper stem tube is elliptical and the outer diameter of the upper part of the inner clamping element is at least partially elliptical. It is also particularly provided that the inner diameter of the lower stem is oval and the outer diameter of the lower part of the inner clamping element is at least partially oval.

[0015] According to another preferred embodiment of the invention, the lower part of the inner clamping element and the upper part of the inner clamping element are arranged side by side in the vertical direction, wherein the lower part of the inner clamping element has a smaller dimension than the upper part of the inner clamping element in a transverse direction orthogonal to the vertical direction. The resulting shape of the inner clamping element allows the inner clamping element to fit very well against the inner side of the upper and lower stem tubes. The vertical direction in the sense of the invention corresponds here to the main extension direction of the lower and upper stem tubes.

[0016] Preferably, the outer clamping element is a clamping washer. The clamping washer in the sense of the invention is an element which surrounds the upper fork stem and is provided to space elements apart in the vertical direction above and below the clamping washer. The clamping washer preferably has a screw, with which an inwardly directed force can be generated by rotating the screw.

[0017] According to another preferred embodiment of the invention, it is provided that the outer side of the lower stem tube has an elliptical cross section at least in the overlapping region, and the inner side of the upper stem tube has an elliptical cross section at least in the overlapping region. This advantageously ensures that the upper stem tube and the lower stem tube do not twist relative to each other. It is conceivable that the outer side of the lower stem tube has an elliptical cross section along the entire length of the lower stem tube, and the inner side of the upper stem tube has an elliptical cross section along the entire length of the upper stem tube. It is also conceivable that the outer side of the lower stem tube has a non-circular cross section, such as a polygonal cross section, at least in the overlapping region, and the inner side of the upper stem tube has a non-circular cross section, such as a polygonal cross section, at least in the overlapping region. It is preferably provided that the outer side of the upper stem tube has a circular cross section. Furthermore, it is preferably provided that the inner side of the lower stem tube has a circular cross section.

[0018] Furthermore, it is preferably provided that the outer side of the lower stem has at least one flat region at least in the overlapping region. Furthermore, the inner side of the upper stem preferably has at least one flat region at least in the overlapping region. Here, the flat region of the upper stem is arranged to lie against the flat region of the lower stem.

[0019] It is conceivable that the outer clamping element is matched to the outer diameter of the upper stem tube. In particular, it is provided that the inner diameter of the outer clamping element is at least partially matched to the outer diameter of the upper stem tube.

[0020] Preferably, provision is made for the upper stem to have lateral slots, thereby ensuring a significantly better transmission of force.

[0021] Furthermore, it is preferably provided that the tensioning element of the inner clamping element is arranged such that it can be actuated from the interior of the upper stem, wherein the tensioning element is provided to cause and / or to bring about the application of an outwardly directed force to the inner side of the lower stem and to the inner side of the upper stem. In other words, it is provided that the tensioning element is actuated from above. However, it is also conceivable that the tensioning element can be actuated via the lateral slot or via another lateral slot of the upper stem and / or the lower stem.

[0022] It is conceivable that the tensioning element has a screw for screwing into the inner clamping element, wherein the screwing in causes the clamping element to expand against the inner side surfaces of the upper and lower stem tubes.

[0023] In order to improve the installation of lines along the stem, it is preferably provided that the inner clamping element has a line guide. This advantageously enables lines, such as brake lines or electrical lines, to be routed from the bicycle cockpit through the interior of the upper and lower stem. In addition to the visually pleasing arrangement, this saves particularly installation space and protects the lines from mechanical influences. It is also particularly advantageous that the previously customary and laborious routing of the lines through enlarged bearings is dispensed with.

[0024] It is preferably provided that the lower stem is made of a carbon material and the upper stem is made of a carbon material. According to another alternative and preferred embodiment of the invention, it is provided that the lower stem is made of a carbon material and the upper stem is made of metal, preferably of aluminum. This advantageously achieves that the advantages of the stem made of carbon, in particular its low weight, are combined with the advantages of the stem made of metal. By making the upper stem of metal, further advantages are obtained with regard to the safety of the upper stem and its greater possibility of being pulled out. The combination of carbon and metal materials also provides, in particular, the possibility of adjusting the elasticity of the stem arrangement. Thus, when the upper stem is pulled out further, the stem arrangement achieves a greater elasticity. If the upper stem is pushed further onto the lower stem, the stem arrangement becomes rigid. It is also conceivable that the upper stem is made of a carbon material and the lower stem is made of metal, preferably of aluminum. Aluminum in the sense of the present invention includes not only aluminum but also any aluminum alloys.

[0025] Another subject matter that achieves the objects mentioned at the outset is a bicycle having a stem arrangement according to the invention. For this purpose, it is preferably provided that the upper stem is supported on the head tube of the bicycle by means of a bearing, wherein the upper bearing cap of the bearing is 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.

[0026] All details, features and advantages disclosed above in connection with the front fork stem arrangement according to the invention also apply to the bicycle according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Further details, features and advantages of the invention are obtained from the drawings and the following description of preferred embodiments based on the drawings. The drawings illustrate only exemplary embodiments of the invention and do not restrict the inventive concept.

[0028] The accompanying drawings show:

[0029] Figure 1 : A first cross-sectional view of a front fork stem device for a bicycle according to an exemplary embodiment of the present invention,

[0030] Figure 2 : A second cross-sectional view of a front fork stem device for a bicycle according to an exemplary embodiment of the present invention,

[0031] Figure 3 : Another view of a front fork stem device for a bicycle according to an exemplary embodiment of the present invention,

[0032] FIG. 4 is a schematic diagram of an inner clamping element of a front fork stem device according to an exemplary embodiment of the present invention,

[0033] Figure 5 : A cross-sectional view of an overlap region of a front fork stem device along a vertical axis according to an exemplary embodiment of the present invention, and

[0034] Figure 6 : A third cross-sectional view of a front fork stem device for a bicycle according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0035] In the drawings described below, the same elements are always denoted by the same numerals or letters and are therefore not described multiple times.

[0036] Figure 1 , Figure 2 and Figure 6 1 and 2 show schematic cross-sectional views of a front fork stem device 1 according to an exemplary embodiment of the present invention, which is used for a bicycle 100 according to an exemplary embodiment of the present invention.

[0037] The stem arrangement 1 has a lower stem 2, which is at least partially surrounded by an upper stem 3 in an overlap region 6. Preferably, the upper stem 3 is an industry standard stem, i.e. the upper stem 3 has an outer diameter of 28.6 mm. The upper stem 3 can be made of a carbon material or a metal, such as aluminum, for example. The lower stem 2 has an outer diameter, at least in the overlap region 6, that allows the upper stem 3 to be pushed onto the lower stem 2. The lower stem 2 can be made of the same material as the upper stem 3. However, it is also conceivable that the upper stem 3 is made of another material, for example a metal, such as aluminum.

[0038] In order to adjust the steering height, the upper stem tube 3 is moved relative to the lower stem tube 2 in the vertical direction H. Once the steering height has been adjusted, the upper stem tube 3 and the lower stem tube 2 must be fixed relative to each other. For this purpose, two clamping elements 4, 5 are provided. The inner clamping element 4 with its lower part 4.1 rests against the inner side of the lower stem tube 2. The upper part 4.2 of the inner clamping element 4 rests against the inner side of the upper stem tube 3. With the help of the tensioning element 4.3 of the inner clamping element 4, an outwardly directed force can be applied to the inner sides of the lower stem tube 2 and the upper stem tube 3. The tensioning element 4.3 can be approached either from above through the upper stem tube 3 (FIG. 4(a)) or laterally (FIG. 4(b)) through the slot 3.1 in the upper stem tube 3. The outer clamping element 5, which is designed as a clamping washer, rests against the outer side of the upper stem tube 3 in the overlap region 6. The outer clamping element 5 is provided for exerting an inwardly directed force on the upper stem tube 3 and, via the upper stem tube 3, on the inner stem tube 2 and finally on the inner clamping element 4. The outer clamping element 5 is adapted to the outer contour of the upper stem tube 3 so that the outer clamping element 5 rests on the outer side of the upper stem tube 3 over the largest possible area.

[0039] 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 matched to the inner diameter of the lower stem tube 2, so that the lower part 4.1 is arranged at least partially to abut against the inner side of the lower stem 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 matched to the inner contour of the lower stem tube 2 in the overlap region 6. Similarly, the outer diameter of the upper part 4.2 of the inner clamping element 4 is matched to the inner diameter of the upper stem tube 3. The upper part 4.2 at least partially abuts against the inner side of the upper stem 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 matched to the inner contour of the upper stem tube 3 in the overlap region 6. Therefore, the inner clamping element 4 has different dimensions in the vertical direction H and in the transverse direction Q, which is orthogonal to the vertical direction H.

[0040] To prevent twisting of the lower and upper stem tubes 2, 3, it can be provided that the lower and upper stem tubes 2, 3 are designed to be non-circular at least in the overlapping region 6. For example, it is conceivable that the stem tubes 2, 3 are designed to be oval or have a flat region 10.

[0041] A good force-locking connection is achieved by the upper stem tube 3 having a lateral slot 3 . 1 . This allows the upper stem tube 3 to be clamped onto the lower stem tube 2 over a large area.

[0042] If the stem device 1 is installed in the bicycle 100, the stem device 1 is rotatably supported in the head tube 8 of the bicycle 100 by means of at least one bearing 7 of the headset of the bicycle 100. Here, the outer clamping element 5 can form an upper bearing cap of the bearing 7. The stem 12 of the bicycle 100 is arranged on the upper stem 3 and is spaced apart from the outer clamping element 5 by means of a washer 9. The toothless top cap 13 fixed by means of a toothless top cap screw 13.1 forms the upward end. The toothless top cap screw 13.1 engages in the thread of the tensioning element 4.3 of the inner clamping element 4, so that the toothless top cap screw 13.1 can be tightened and fixed on the inner clamping element 4 by turning the toothless top cap screw 13.1.

[0043] In order to adjust the steering height, the toothless top cap screw 13.1 can then be easily loosened and the toothless top cap 13 can be removed. At this point, the stem 12 can be loosened and also removed. Since the outer clamping element 5 itself initially remains on the bearing 7 when the bicycle cockpit is removed, the bearing play of the headset also remains fixed in this case. Depending on the design, the inner clamping element 4 can be unloaded laterally (Figure 4(b)) or from above (Figure 4(a)), thereby eliminating the outwardly directed forces of the inner clamping element 4. By additionally unloading the outer clamping element 5, the inwardly acting forces are eliminated and the upper fork stem 3 and the lower fork stem 2 are thus released from fixation and can be moved relative to each other. In this way, a new steering height adjustment is achieved.

[0044] The inner clamping element 4 has a line sleeve 4.4. Lines 11, such as brake cables, brake lines or electrical lines, are guided through the line sleeve 4.4. This makes it possible to guide the lines 11 through the interior space 3.2 of the upper fork stem 3 and the lower fork stem 2. The laborious guiding through the bearing 7 of the headset of the bicycle 100 can be omitted.

[0045] The front fork stem device 1 according to the present invention can achieve a steering height adjustment with a large adjustment range. Visually, the front fork stem device 1 is difficult to distinguish from a conventional front fork stem device.

[0046] Reference numerals list

[0047] 1 Front fork seat tube device

[0048] 2 Lower fork seat tube

[0049] 2.1 Lateral slotting

[0050] 3 Upper fork seat tube

[0051] 3.1 Lateral slotting

[0052] 3.2 Internal Space

[0053] 4 Inner clamping element

[0054] 4.1 Lower part

[0055] 4.2 Upper part

[0056] 4.3 Tensioning elements

[0057] 4.4 Line casing

[0058] 5 External clamping element

[0059] 6 Overlapping Area

[0060] 7 Bearings

[0061] 8 Head tube

[0062] 9 Washer

[0063] 10 Flat Area

[0064] 11 lines

[0065] 12 Stem

[0066] 13 Ahead-Kappe

[0067] 13.1 Threadless cover screws

[0068] 100 Bicycles

[0069] H vertical direction

[0070] Q Horizontal direction

Claims

1. A front fork stem device (1) for a bicycle (100), comprising a lower front fork stem (2), an upper front fork stem (3), and an outer clamping element (5), wherein the upper front fork stem (3) at least partially surrounds the lower front fork stem (2) in an overlapping area (6), wherein the outer clamping element (5) abuts against the outer side of the upper front fork stem (3) in the overlapping area (6) and is configured to apply an inwardly directed force to the outer side of the upper front fork stem (3).

2. The front fork stem device (1) according to claim 1, characterized in that: The stem device (1) has an inner clamping element (4), wherein the inner clamping element (4) is arranged to abut with a lower portion (4.1) against an inner side of the lower stem (2) and with an upper portion (4.2) against an inner side of the upper stem (3), wherein the inner clamping element (4) is configured to apply an outwardly directed force to the inner side of the lower stem (2) and the inner side of the upper stem (3).

3. The front fork stem device (1) according to claim 2, characterized in that: The outer clamping element (5) is provided for exerting an inwardly directed force on the outer side of the upper stem (3) so that the inner side of the lower stem (2) is pressed against the lower part (4.1) of the inner clamping element (4).

4. A stem device (1) according to any 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) matches the inner diameter of the lower front fork stem (2), and the outer diameter of the upper part (4.2) of the inner clamping element (4) matches the inner diameter of the upper front fork stem (3).

5. A stem device (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 the 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) orthogonal to the vertical direction (H).

6. A stem device (1) according to any one of the preceding claims, characterized in that The outer clamping element (5) is a clamping washer.

7. A stem device (1) according to any one of the preceding claims, characterized in that The outer side surface of the lower front fork stem (2) has an elliptical cross section at least in the overlapping area (6), and the inner side surface of the upper front fork stem (3) has an elliptical cross section at least in the overlapping area (6).

8. A stem device (1) according to any one of the preceding claims, characterized in that The outer side surface of the lower stem tube (2) has at least one flat region (10) at least in the overlapping region (6), and the inner side surface of the upper stem tube (2) has at least one flat region (10) at least in the overlapping region (6), wherein the flat region (10) of the upper stem tube (3) is arranged to abut against the flat region (10) of the lower stem tube (2).

9. A stem device (1) according to any one of the preceding claims, characterized in that The upper front fork riser (3) has a lateral slot (3.1).

10. A stem device (1) according to any one of the preceding claims, characterized in that The tensioning element (4.3) of the inner clamping element (4) is arranged so that it can be operated from the interior space (3.2) of the upper stem (3), wherein the tensioning element (4.3) is provided to cause and / or promote the application of an outwardly directed force to the inner side of the lower stem (2) and the inner side of the upper stem (3).

11. The front fork stem device (1) according to claim 9, characterized in that: The tensioning element (4.3) has a screw for screwing into the inner clamping element (4), wherein the screwing in causes the clamping element (4) to expand against the inner side surfaces of the upper stem (3) and the lower stem (2).

12. A stem device (1) according to any one of the preceding claims, characterized in that The inner clamping element (4) has a line bushing (4.4).

13. A stem device (1) according to any one of the preceding claims, characterized in that The lower front fork stem (2) is made of carbon material, and the upper front fork stem (3) is made of metal, preferably aluminum.

14. A bicycle (100) having a stem device (1) according to any one of the preceding claims.

15. The bicycle (100) according to claim 13, characterized in that: The upper front fork stem (3) is supported on the head tube (8) of the bicycle (100) by means of a bearing (7), wherein the upper bearing cap of the bearing (7) is formed by the outer clamping element (5).

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