Stem for a handlebar, especially for a bicycle handlebar

Abstract

Stem for a handlebar, in particular for a bicycle handlebar, comprising an attachment area on a fork shaft, a receptacle for the handlebar and comprising a parallel linkage with at least two profile pairs (6, 7) aligned parallel to one another for the articulated connection of the attachment area and the receptacle to one another, characterized in that the profiles (8) of each profile pair (6, 7) are connected to one another by at least one web (12), that each web (12) has at least one opening with an internal thread and that a bolt is guided through the webs (12), which bolt has external thread sections directed opposite to one another in its extension, wherein one external thread section is assigned to one web (12) and the other external thread section is assigned to the other web (12).

Description

The invention relates to a front part for a handlebar clamp, in particular for a bicycle handlebar clamp, comprising a mounting area on a fork stem, a receptacle for the handlebar clamp and comprising a parallel linkage with at least two profile pairs oriented parallel to one another for the articulated connection of mounting area and receptacle to one another.Front frames on bicycles and on other two-wheelers are used to establish a proper and comfortable distance between saddle and handlebar. In this case, structures different from one another are known with regard to their structural lengths and their angles of attack.Also known in the art are front fittings whose angular position with respect to the fork stem can be changed. Here, the attachment area for the fork stem and the receptacle for the steering arm are connected to one another via corresponding joints. These are regularly fixed with Allen screws so that they do not adjust during travel even when more heavily loaded, for example, on a bicycle. For a change in the angle of attack, therefore, the use of tools is necessary.WO 2014 / 082 617 A1 describes a front part of the type mentioned at the beginning, the attachment region of which to the fork stem and the receptacle of which for the link are connected to a parallel linkage having at least two profile pairs oriented parallel to one another. There, the parallel linkages were also adjustable at different pitches, and a fixing was then effected with bearing shells and toothed rings.A front structure of the aforementioned type for receiving a saddle or also for a bicycle handlebar is known from DE 197 36 700 A1. There, there was already a pivotable mounting of saddle or link.The invention is based on the object of providing a front part for a steering handle, the angular adjustment of which with respect to the fork stem is made possible by the user without a tool and in particular during use of a two-wheeler, for example.This object is achieved according to the invention in that the profiles of each pair of profiles are connected to one another by at least one web, in that each web has at least one aperture with internal thread, and in that a bolt is guided through the webs, said bolt having external thread sections which are directed counter to one another in its extent, wherein one external thread section is assigned to the one web and the other external thread section is assigned to the other web.In the case of the front part according to the invention, webs are provided which connect the profiles of each pair of profiles of the parallel linkage to one another. The stability of the parallel linkage is thus already advantageously increased. The invention also uses these webs, however, for inserting a fixing means for positioning the front end into the webs. For this purpose, the webs have apertures with internal thread; in addition, the bolt is provided, which is guided through the apertures with internal thread and which has corresponding external thread sections which mesh with the internal threads.According to the invention, it is provided that external thread sections which are directed counter to one another are arranged on the bolt, for example a left-hand thread in one section and a right-hand thread in the other section. The internal threads in the webs are correspondingly designed, so that upon a rotation of the bolt opposing forces are exerted on the bolts and thus also on the webs. One web is pulled in one direction, for example, while the other web is simultaneously moved away in the opposite direction. As a result, corresponding forces act on the articulated profiles of the profile pairs, which results in a changed angular position of the front part.According to a first development of the invention, it is provided that the bolt is designed as a threaded rod. The threaded rod can have the corresponding threaded sections, their free ends can be provided with a handle on one side and with a covering cap covering corresponding ridges on the other side. The free end of the threaded rod provided with the handle can be arranged on a front part located on the bicycle, for example, on the upper side. On this side, it faces the driver, so that the driver can make changes in the position of the front part by appropriately turning on the handle and thus on the threaded rod. This change of the adjustment can even be carried out during the journey.Thus, for a trip from a city in front, the front end can first be set flat. The driver can accordingly chuck over the front part and give the wind of travel little contact surface during his longer journey. Once the city of the inside has been reached, it is possible for the driver to bring the front end to a higher position, in order to then drive through corresponding shopping roads in a more comfortable, upright manner. The handle can be designed, for example, as a knob.Alternatively, it can be provided that an electric motor is arranged at a free end of the threaded rod. In this case, a rotational force can no longer be applied manually to the threaded rod, and an electric motor can be used for this purpose. This is particularly the case when there are already electrical components including an accumulator on the two-wheeler, for example.In order to hold the electric motor on the parallel linkage, according to a further development a profile has a support profile section for the electric motor. This support profile section holds the motor and also forms a counter bearing for the motor when a change of the parallel linkage occurs as a result of a rotation of the threaded rod.A next development of the invention provides that the profiles of each pair of profiles are connected to one another by further webs. Further webs increase the stability of the front part as a whole. This is true, although each web is connected to a profile and also the profiles with attachment area and receiving area are each correspondingly articulated.Each web is preferably designed as a profile rod, it has the corresponding strength in order to be able to absorb forces. The thickness must also be selected such that, in the case of two webs, the aperture can be provided with an internal thread.Further developments of the invention relate to the design of the attachment region to the fork stem and to the receptacle for the steering arm. These components are each designed as cross members, the profiles of the parallel linkage being articulated to these. The attachment region is designed as a block-like cross member, while the receptacle for the link is designed as a head cross member with a contact region for a corresponding link clamp.In the case of the preliminary construction according to the invention, the profiled position is fixed by meshing the threads of bolts, i.e. threaded rod, and internal threads of the webs. In order to still further define a specific angular position, a development of the invention provides that at least one depression is arranged in the surface of a cross member and that at least one projection which can be projected into the depression is arranged on at least one profile on a side facing the cross member. This projection can be inserted into the depression of the cross member by a movement of the profile. If it is located there, it forms a positive connection with the depression, as a result of which the corresponding pivot position of the profile is fixed. This is especially the case when a two-wheeler is subjected to more severe stress, for example in the case of a mountain bike.Preferably, several depressions are provided. These can be arranged radially around the joint at which the profile is articulated on the cross member. The protrusion on the profile can be inserted into a plurality of depressions when the profile is pivoted about the joint. In this way, it is possible to fix a plurality of pivot positions of the profile. For the projection, an angled section can also be provided on the profile for this purpose.It is precisely when depressions and projections are provided that, according to a further development of the invention, the profiles are each articulated laterally on the cross-members and that slide bearings form between the cross-members and the profiles in the region of the cross-members. Despite the articulation of the profiles on the cross members, the slide bearings ensure that the profiles can be pivoted. The profiles should not be fixed to the slide bearings.Exemplary embodiments of the invention are illustrated in the drawing. The following are shown: FIG. 1 : a perspective view of a bicycle handlebar which is accommodated in a front part according to a first exemplary embodiment, FIG. 2 : a partially cut side view of the front part according to FIG. 1, FIG. 3 : a sectional view of the front part according to FIG. 2, FIG. 3 a : a substantially enlarged view of the detail L in FIG. 3 , FIGS. 4 and 5 : further side views of the front part according to FIG. 1, FIG. 6 : a perspective view of a bicycle handlebar which is accommodated on a front part according to a second exemplary embodiment, FIG. 7 is a partially cut side view of the front part according to FIG. 6 , FIG. 8 is a sectional view of the front part according to FIG. 7 ; and FIGS. 9 and 10 : further side views of the front part according to FIG. 6.FIG. 1 shows the cranked link 1 which is fastened to a front part 3 by means of a link clamp 2. The steering clamp 2 is part of a head cross member 4, and the attachment region to a fork stem is likewise designed as a cross member 5. The cross-member 5 and the head cross-member 4 are connected to one another via pairs of profiles 6 and 7, which in each case are two profiles 8 of the pairs of profiles 6 and 7 articulated to the cross-member 5 and the head cross-member 4 in each case via joints 9.The front part 3 is assigned a knob-like handle 10. The handle 10 is mounted on the free end of a threaded rod 11 in a rotationally fixed manner, the threaded rod 11 extending through the front part 3.In the pair of profiles 6 assigned to the knob 10, the profiles 8 each have an angled portion 14 in the region of the cross member 5; the angled portion 14 carries a projection 15 which is formed in the direction of the cross member 5; depressions 16 are arranged in the cross member 5 on the side face facing the profile 8.FIG. 2 shows the front part 3 in a flat configuration. The profile pairs 6 and 7 are brought closer to one another, and they are aligned parallel to one another. The threaded rod 11 equipped with the handle 10 extends obliquely through the profile pairs 6, 7.FIG. 3 shows that the threaded rod 11 is guided through two webs 12 which connect the mutually opposite profiles 8 of each profile pair 6 and 7 to one another. The webs 12 have apertures which are provided with internal threads. The threaded rod 11 meshes with external threads of these internal threads.The external threads of the threaded rod 11 can be seen in FIG. 2. These are two mutually opposed external threads, the external thread which is assigned to the pair of profiles 6 is, for example, a right-hand thread, while the external thread of the threaded rod 11 facing the pair of profiles 7 is a left-hand thread. The internal threads in the webs 12 are correspondingly formed.FIGS. 3 and 3 a, on the other hand, show that a bushing 17 is inserted in the web 12 in the pair of profiles 6. This bushing 17 is fixed by grub screws 18.By rotating the threaded rod 11 with the handle 10, the mutually different angles of attack of the front part 3 are achieved with respect to a fork stem, not shown in any more detail. By rotating the threaded rod 11 in one direction, the web of the pair of profiles 6 is brought closer to the handle 10, as FIG. 5 shows in particular. The web 12 in the pair of profiles 7 is guided away from the handle 10 due to the oppositely directed thread position. Since both pairs of profiles 6 and 7 are articulated on the cross members 4 and 5, the head cross member 4 is set up in this way with respect to the cross member 5 attached to the fork shank.The profiles 8 of the profile pairs 6 and 7 are also connected to one another by further webs 13, the webs 12 being in this case each rotatably accommodated in the profiles 8 via bushes. The webs 13, on the other hand, are firmly connected to the profiles 8.In the second exemplary embodiment illustrated in FIG. 6 ff., an electric motor 18 is applied to the threaded rod 11, this electric motor replacing the handle 10 from the first exemplary embodiment. In addition, identical components are identified by the same reference numerals.In contrast to the first exemplary embodiment, the profiles 8 carry support profile sections 19 for the electric motor 18. The profile 8 and the support profile curved section 19 extend in the same plane.

Claims

Front part for a handlebar clamp, in particular for a bicycle handlebar clamp, comprising a mounting region on a fork shank, a receptacle for the handlebar clamp and comprising a parallel linkage having at least two profile pairs (6, 7) aligned parallel to one another for the articulated connection of mounting region and receptacle to one another, characterized in that the profiles (8) of each profile pair (6, 7) are connected to one another by at least one web (12), in that each web (12) has at least one aperture with internal thread, and in that a bolt is guided through the webs (12), said bolt having external thread sections which are directed opposite one another in its extension, wherein one external thread section is assigned to the one web (12) and the other external thread section is assigned to the other web (12).Front part according to claim 1, characterised in that the bolt is designed as a threaded rod (11).Front part according to claim 2, characterised in that the threaded rod (11) is guided through at least one web (12) with a bushing (17).Front part according to claim 2 or 3, characterised in that a handle (10) is arranged at a free end of the threaded rod (11).Front part according to claim 2 or 3, characterised in that an electric motor (18) is arranged at a free end of the threaded rod (11).Front part according to claim 5, characterised in that at least one profile (8) has a support profile section (19) for the electric motor (18).Front part according to one of the preceding claims, characterized in that the profiles (8) of each pair of profiles (6, 7) are connected to one another by means of further webs (13).Front part according to one of the preceding claims, characterized in that each web (12, 13) is designed as a profiled rod.Front part according to one of the preceding claims, characterized in that the attachment region is designed as a block-like cross member (5).Front part according to one of the preceding claims, characterized in that the receptacle for the link is designed as a head cross beam (4) with a contact region for a link clamp (2).Front part according to claim 9 or 10, characterised in that at least one depression (16) is arranged in the surface of a cross member (4, 5) and that at least one projection (15) which can be projected into the depression (16) is arranged on at least one profile (8) on a side facing the cross member (4, 5).Front part according to claim 11, characterised in that a plurality of depressions (16) are arranged on an approximately radial line around a joint (9) for the profile (8).Front part according to one of Claims 9 to 12, characterized in that the profiles (8) are in each case articulated laterally on the cross members (4, 5) and in that slide bearings form between cross members (4, 5) and profiles (8) in the region of the cross members (4, 5).

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