TWI849791B - Steerer tube assembly and bicycle - Google Patents

Abstract

A steerer tube arrangement for a bicycle is proposed, in which an upper steerer tube at least partially encloses a lower steerer tube in an overlapping area, wherein an outer clamping element in the overlapping area abuts the outside of the upper steerer tube and is intended to exert an inward force on the outside of the upper steerer tube. A bicycle is also proposed.

Description

Front fork seat tube assembly and bicycle

The present invention relates to a front fork stem device for a bicycle and a bicycle.

Bicycles often 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 was originally envisaged in the design. In this case, the length of the fork stem (Gabelschaft) often limits the upward adjustment range. In order to still be able to adjust beyond the set maximum height, so-called threadless adapters (ahead adapters) are known from the prior art, which are clamped onto the fork stem and extend the stem. A disadvantage of such adapters is that they can only be used for steel fork stems.

In addition to the desire for further adjustability upwards, there is also a desire to place the bicycle seat pan (Fahrradcockpit) and the classic stem with handlebars lower than they would otherwise be. To this end, cyclists often use washers mounted above the seat pan or simply saw off the front fork stems. Both come at the expense of safety. Sawing off the front fork stem is particularly detrimental to the subsequent resale of the bicycle.

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

This object is achieved by the front fork seat tube device as described in claim 1.

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. To this end, 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. Preferably, provision is made for the lower stem to have 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 large diameter and a second region with a small 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 therefore a high safety.

Alternatively, however, it is also conceivable 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 overlap region. For this purpose, the upper stem tube has an inner diameter in the overlap region that is at least equal to the outer diameter of the lower stem tube. Preferably, provision is made that the upper stem tube has a smaller outer diameter above the overlap region than in the overlap region. It is also preferably provided that the upper stem tube has a smaller inner diameter above the overlap region than in the overlap region. It is particularly preferably provided that the upper stem tube has an outer diameter of 28.6 mm above the overlap region and an inner diameter of 28.8 mm in the overlap region. Furthermore, it is preferably provided that the upper stem has an outer diameter of 33 mm in the overlap region. It is also conceivable that the upper stem has a first region with a large diameter and a second region with a small 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 safety.

The outer clamping element is arranged such that it bears against the outer side of the upper front fork stem in the overlap region. According to the invention, the outer clamping element applies an inwardly directed force to the outer side of the upper front fork stem. This significantly increases the fixing strength of the upper front fork stem and the lower front fork stem relative to each other.

Advantageous designs and improvements of the invention can be derived from the description given in the appended items and with reference to the drawings.

According to a preferred embodiment of the present invention, the front fork stem device has an inner clamping element, wherein the inner clamping element is arranged to abut with a lower part against the inner side surface of the lower front fork stem and with an upper part against the inner side surface of the upper front fork stem, wherein the inner clamping element is configured to apply an outwardly directed force to the inner side surface of the lower front fork stem and the inner side surface of the upper front fork stem.

The inner clamping element is arranged so that its lower part abuts against the inner side surface of the lower stem tube. Furthermore, the inner clamping element is arranged so that its upper part abuts against the inner side surface of the upper stem tube. According to the invention, the inner clamping element applies an outwardly directed force to the inner side surface of the lower stem tube and an outwardly directed force to the inner side surface 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.

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 exchanged for 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. Furthermore, it is advantageous that upper stems of different configurations can be exchanged for one another in order to meet different requirements. This makes it possible, for example, to make large height adjustments.

According to a preferred embodiment of the present invention, the outer clamping element is configured to apply an inwardly directed force to the outer side surface of the upper front fork stem, so that the inner side surface of the lower front fork stem is pressed against the lower portion of the inner clamping element, thereby advantageously improving the fixing stability of the upper front fork stem and the lower front fork stem.

Preferably, the inner clamping element is an expander, wherein the outer diameter of the lower part of the inner clamping element matches the inner diameter of the lower stem tube, and the outer diameter of the upper part of the inner clamping element matches the inner diameter of the upper stem tube. This allows the force of the expander to be advantageously transmitted to the lower stem tube and the upper stem tube. In the sense of the present invention, the outer diameter and the inner diameter do not necessarily have to be limited to a circular outer or inner contour, but only describe the geometry of the outer or inner contour of the upper or lower stem tube based on a plane orthogonal to the main extension direction of the upper or lower stem tube. Matching in the sense of the present invention means that the outer contour of the inner clamping element lies 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 tube is elliptical and the outer diameter of the lower part of the inner clamping element is at least partially elliptical.

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.

Preferably, the outer clamping element is a clamping washer. In the sense of the invention, the clamping washer is an element which surrounds the upper fork stem and is provided to space the 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.

According to another preferred embodiment of the invention, the outer side of the lower stem tube has an elliptical cross section at least in the overlap region, and the inner side of the upper stem tube has an elliptical cross section at least in the overlap 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 surface of the lower front fork stem has a non-circular cross-section, such as a polygonal cross-section, at least in the overlapping area, and the inner side surface of the upper front fork stem has a non-circular cross-section, such as a polygonal cross-section, at least in the overlapping area. Preferably, it is provided that the outer side surface of the upper front fork stem has a circular cross-section. Furthermore, it is preferably provided that the inner side surface of the lower front fork stem has a circular cross-section.

Furthermore, it is preferably provided that the outer side surface of the lower front fork stem has at least one flat area at least in the overlapping area. Furthermore, the inner side surface of the upper front fork stem preferably has at least one flat area at least in the overlapping area. Here, the flat area of the upper front fork stem is arranged to be in contact with the flat area of the lower front fork stem.

It is conceivable that the outer clamping element matches the outer diameter of the upper front fork stem. In particular, it is provided that the inner diameter of the outer clamping element at least partially matches the outer diameter of the upper front fork stem.

Preferably, provision is made for the upper fork stem to have lateral slotting, thereby ensuring a significantly better force transmission.

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 cause an outwardly directed force to be applied 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.

It is conceivable that the tensioning element has a screw for being driven into the inner clamping element, wherein the driving-in causes the clamping element to expand against the inner side faces of the upper and lower stem tubes.

In order to improve the installation of the 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 seat compartment 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 common and laborious routing of the lines through enlarged bearings is dispensed with.

Preferably, it is 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 a stem made of carbon, in particular its low weight, are combined with the advantages of a stem made of metal. By making the upper stem of metal, further advantages are achieved with regard to the safety of the upper stem and its greater possibility of being pulled out. By the combination of carbon and metal materials, in particular, the possibility of adjusting the elasticity of the stem arrangement is also provided. As a result, the stem arrangement achieves a greater elasticity when the upper stem is pulled out further. 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 carbon material and the lower stem is made of metal, preferably aluminum. Aluminum in the sense of the present invention includes any aluminum alloy in addition to aluminum.

Another object of achieving the object 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 seat pan is removed.

All details, features and advantages previously disclosed in connection with the front fork seat tube device according to the present invention also apply to the bicycle according to the present invention.

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

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

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 industrial 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, which 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.

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 (inner clamping element 4, outer clamping element 5) are provided. The inner clamping element 4 rests with its lower part 4.1 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 accessed either from above through the upper stem tube 3 (FIG. 4a) or from the side (FIG. 4b) through the slot 3.1 in the upper stem tube 3. An outer clamping element 5 designed as a clamping washer rests against the outer side of the upper stem tube 3 in an overlap region 6. The outer clamping element 5 is provided to exert an inwardly directed force on the upper stem tube 3 and via the upper stem tube 3 onto the lower stem tube 2 and ultimately onto the inner clamping element 4. The outer clamping element 5 is adapted to the outer contour of the upper stem tube 3 so that it rests against the outer side of the upper stem tube 3 over the largest possible area.

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 matches the inner diameter of the lower front fork stem 2, so that the lower part 4.1 is at least partially arranged to abut against the inner side surface of the lower front fork stem 2. For this purpose, it is provided that the outer contour of the lower part 4.1 of the inner clamping element 4 matches the inner contour of the lower front fork stem 2 in the overlap area 6. Similarly, 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. The upper part 4.2 at least partially abuts against the inner side surface of the upper front fork stem 3. For this purpose, it is also provided that the outer contour of the upper part 4.2 of the inner clamping element 4 matches the inner contour of the upper front fork stem 3 in the overlap area 6. Therefore, the inner clamping element 4 has different dimensions along the vertical direction H and along the transverse direction Q, which is orthogonal to the vertical direction H.

In order to prevent the lower stem tube 2 and the upper stem tube 3 from twisting, it can be provided that the lower stem tube 2 and the upper stem tube 3 are designed to be non-circular at least in the overlapping area 6. For example, it is conceivable that the stem tubes (lower stem tube 2, upper stem tube 3) are designed to be elliptical or have a flat area 10.

Good force locking is achieved by the upper front fork stem 3 having lateral slots 3.1. This allows the upper front fork stem 3 to be clamped onto the lower front fork stem 2 over a large area.

If the stem tube device 1 is installed in the bicycle 100, the stem tube 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 the upper bearing cap of the bearing 7. The stem 12 of the bicycle 100 is arranged on the upper stem tube 3 and is spaced apart from the outer clamping element 5 by means of a washer 9. The threadless top cap 13 fixed by means of a threadless top cap screw 13.1 forms the upward end. The toothless top cover screw 13.1 is engaged in the thread of the tensioning element 4.3 of the inner clamping element 4, so that the toothless top cover screw 13.1 can be tightened and fixed on the inner clamping element 4 by rotating the toothless top cover screw 13.1.

In order to adjust the steering height, the threadless top cap screws 13.1 can then be easily loosened and the threadless top cap 13 removed. The stem 12 can now be loosened and also removed. The bearing play of the headset also remains fixed in this case, as the outer clamping element 5 itself initially remains on the bearing 7 when the bicycle seat is removed. Depending on the design, the inner clamping element 4 can be unloaded laterally (FIG. 4b) or from above (FIG. 4a), thereby canceling the outwardly directed forces of the inner clamping element 4. By additionally unloading the outer clamping element 5, the inwardly acting forces are canceled and the upper stem tube 3 and the lower stem tube 2 are thus released from fixation and can be moved relative to each other. This enables a new steering height adjustment.

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 line 11 through the inner space 3.2 of the upper front fork stem 3 and the lower front fork stem 2. The laborious guidance through the bearing 7 of the headset of the bicycle 100 can be omitted.

The front fork stem device 1 according to the present invention can realize the steering height adjustment in a large adjustment range. Visually, the front fork stem device 1 is difficult to distinguish from the traditional front fork stem device.

1: Front fork stem assembly 2: Lower front fork stem 2.1: Lateral slots 3: Upper front fork stem 3.1: Lateral slots 3.2: Internal space 4: Inner clamping element 4.1: Lower part 4.2: Upper part 4.3: Tensioning element 4.4: Cable sleeve 5: Outer clamping element 6: Overlap area 7: Bearing 8: Head tube 9: Spacer 10: Flat area 11: Cables 12: Stem 13: Ahead-Kappe 13.1: Ahead-Kappe screws 100: Bicycle H: Vertical direction Q: Horizontal direction

More details, features and advantages of the present invention are obtained from the drawings and the following description of preferred embodiments according to the drawings. The drawings illustrate only exemplary embodiments of the present invention and do not limit the inventive concept. The drawings show: FIG. 1 is a first cross-sectional view of a front fork stem device for a bicycle according to an exemplary embodiment of the present invention; FIG. 2 is a second cross-sectional view of a front fork stem device for a bicycle according to an exemplary embodiment of the present invention; FIG. 3 is another view of a front fork stem device for a bicycle according to an exemplary embodiment of the present invention; FIG. 4a and FIG. 4b are schematic diagrams of an inner clamping element of a front fork stem device according to an exemplary embodiment of the present invention; FIG. 5 is a cross-sectional view of an overlapped area of a front fork stem device along a vertical straight axis according to an exemplary embodiment of the present invention; and FIG. 6 is a third cross-sectional view of a front fork stem device for a bicycle according to an exemplary embodiment of the present invention.

1: Front fork seat tube device

2: Lower front fork seat tube

3: Upper front fork seat tube

4: Internal clamping element

4.1: Lower part

4.2: Upper part

4.3: Tensioning element

4.4: Line casing

5: External clamping element

7: Bearings

9: Gasket

11: Line

12: Stem

13: Ahead-Kappe

13.1: Threadless top cover screws

100:Bicycle

H: vertical direction

Q: Horizontal direction

Claims (13)

A front fork stem device is used for a bicycle, comprising: a lower front fork stem; an upper front fork stem; and an outer clamping element, wherein the upper front fork stem at least partially surrounds the lower front fork stem in an overlapping area, wherein the outer clamping element abuts against the outer side surface of the upper front fork stem in the overlapping area and is configured to apply an inwardly directed force to the outer side surface of the upper front fork stem; wherein the front fork stem device has an inner clamping element, wherein the inner clamping element is arranged The lower part is abutted against the inner side surface of the lower front fork stem and the upper part is abutted against the inner side surface of the upper front fork stem, wherein the inner clamping element is configured to apply an outwardly directed force to the inner side surface of the lower front fork stem and the inner side surface of the upper front fork stem; wherein the outer clamping element is configured to apply an inwardly directed force to the outer side surface of the upper front fork stem, so that the inner side surface of the lower front fork stem is pressed against the lower part of the inner clamping element. The fork stem device as described in claim 1, wherein the inner clamping element is an expander, wherein the outer diameter of the lower portion of the inner clamping element matches the inner diameter of the lower fork stem, and the outer diameter of the upper portion of the inner clamping element matches the inner diameter of the upper fork stem. As described in claim 1, the fork stem device, wherein the lower portion of the inner clamping element and the upper portion of the inner clamping element are arranged side by side along the vertical direction, wherein the lower portion of the inner clamping element is smaller than the upper portion of the inner clamping element in a transverse direction orthogonal to the vertical direction. A fork stem device as described in claim 1, wherein the outer clamping element is a clamping washer. The front fork stem device as described in claim 1, wherein the outer side surface of the lower front fork stem has an elliptical cross-section at least in the overlapping area, and the inner side surface of the upper front fork stem has an elliptical cross-section at least in the overlapping area. A front fork stem device as described in claim 1, wherein the outer side surface of the lower front fork stem has at least one flat area at least in the overlapping area, and the inner side surface of the upper front fork stem has at least one flat area at least in the overlapping area, wherein the flat area of the upper front fork stem is arranged to be in contact with the flat area of the lower front fork stem. The front fork stem device as described in claim 1, wherein the upper front fork stem has a lateral slot. A fork stem device as described in claim 1, wherein a tensioning element of the inner clamping element is arranged so that the tensioning element can be operated from an internal space of the upper fork stem, wherein the tensioning element is configured to cause and/or facilitate the application of an outwardly directed force to the inner side surface of the lower fork stem and the inner side surface of the upper fork stem. The fork stem device as described in claim 8, wherein the tensioning element has a screw for screwing into the inner clamping element, wherein the screwing causes the clamping element to expand and press against the inner side surfaces of the upper fork stem and the lower fork stem. As described in claim 1, the fork riser device, wherein the inner clamping element has a line sleeve. A front fork stem device as described in claim 1, wherein the lower front fork stem is made of carbon material, and the upper front fork stem is made of metal, preferably aluminum. A bicycle having a fork seat tube device as described in claim 1. A bicycle as described in claim 12, wherein the upper front fork stem is supported on a head tube of the bicycle by a bearing, wherein an upper bearing cover of the bearing is formed by the outer clamping element.