This application claims priority to German application 10 2019 002 631.4, filed Apr. 10, 2019, the entire disclosure of which is incorporated herein by reference.
The invention relates to a convertible two-wheeler.
GB 598 235 A discloses a convertible two-wheeler with a frame and two wheels that are rotatably mounted on the frame, one of which can be steered with a handlebar. Two receptacles are attached to the frame as well as a crank assembly having a fastening element that can be connected in a form-fitting manner to the two receptacles on the frame. Both receptacles have the shape of a cylindrical rod and are held at a distance from the frame by protrusions. The fastening element has a depression in the region of one end, which depression is adapted to the shape of the cylindrical rod. A bottom bracket for crank arms is attached to the fastening element.
U.S. Pat. No. 583 022 A discloses a convertible bicycle with a removable crank assembly that is attached to the frame by means of two receptacles. A first receptacle is attached in a horizontal region of the frame, and a second receptacle is attached to a vertically inclined region of the frame.
Convertible bicycles with a removable crank assembly are also known from U.S. Pat. No. 1 907 645 A, FR 533 655 A, US 2018 0 050 760 A1, and US 2014 0 084 564 A1.
DE 32 444 661 A1 describes a convertible two-wheeler that can be used as a scooter, balance bike, or bicycle. In its basic function as a scooter with a handlebar and two wheels that are rotatably mounted on a frame, a draisienne-type balance bike can be created by adding a height-adjustable and swiveling saddle and by adjusting the height of the handlebar, and a bicycle can be realized by also adding a crank drive. However, the installation and removal of the corresponding parts requires the use of tools.
It is the object of the invention to improve the convertible two-wheeler mentioned at the outset in such a way that it can be converted in a simple manner without prior knowledge and, in particular, without tools.
This object is achieved by the features specified in the claim. Advantageous embodiments and developments of the invention can be found in the dependent claims.
The basic concept of the invention is to fasten a crank assembly to the frame of the two-wheeler by simply hooking it in. If a drive chain or a drive belt is attached, a bicycle can be created from a balance bike in just a few steps.
In one embodiment of the invention, two receptacles are attached to the frame, and a crank assembly is provided which has a fastening element that can be connected in a form-fitting manner to the two receptacles on the frame. The crank assembly contains the usual crank arms, which are connected to one another by means of a shaft, as well as a drive wheel, which can be a sprocket wheel or a drive belt wheel, and the abovementioned fastening element, which can be inserted into said receptacles.
According to a development of the invention, one of the receptacles is attached to a horizontal region of the frame, and the other receptacle is attached to a vertically inclined region of the frame, so that horizontally and vertically acting forces of the crank assembly are conducted into the frame.
According to another development of the invention, both receptacles have the shape of a rod and are each held at a distance from the frame by protrusions. The fastening element can thus be held stably between the rods and the frame.
According to another embodiment of the invention, at least one receptacle is an opening in the frame into which the fastening element can be hooked.
In the region of one end, the fastening element is embodied such that it can be attached to the frame. This can be done by means of the opening in the frame or also on the aforementioned rod. In the latter case, the fastening element has a depression in the region of one end, the shape of which depression is adapted to the rod. The depression is such that the fastening element can be hooked on the rod and swiveled there. At the opposite region of the fastening element, a recess is provided which is dimensioned such that it is able to receive the rod of the other receptacle. A displaceable latch is provided in this recess that can be inserted between the frame and the rod in order to lock the fastening element on the frame. This latch can also be biased into a closed position by means of a spring.
In general, the receptacles are arranged on the frame in such a way that, after the fastening element has been hooked in at the first hooking point, the fastening element is swiveled in such a way that the distance between the drive wheel of the crank assembly and the driven wheel increases, so that a drive chain or toothed belt is tensioned.
The latch preferably has a run-up chamfer in order to ensure better and simple tensioning of the fastening element.
Firstly,
To implement the invention, a front receptacle 10 is provided at the lower horizontal region 9 of the frame 1, and a second receptacle 12 is provided at the rear, approximately vertically inclined region 11 of the frame 1, the latter being shown only in dashed lines because it is concealed in the figure by the rear wheel swing arm 3.
To install the crank assembly 13, the fastening element 19 is pushed between the rear vertical region 11 of the frame 1 and the rod 12 such that the depression 20 engages over the rod 12. The fastening element 19 can then be swiveled together with the entire crank assembly 13 about the axis of the rod 12, so that the other end of the fastening element approaches the front receptacle 10, as is shown in
In
It can be seen from
In the embodiment of
A pivot bearing 33 for a tension lever 32 is provided on the end of the second fastening element 30 situated opposite the hook 31. Eccentrically to the pivot bearing 33, a hook 34 is attached to the tension lever 32 by means of a pivot bearing 36 and can engage in the screw bolt 27. The length of this hook 34 can be adjusted by means of a screw thread 35. If the hook 34 is hooked into the screw bolt 27 and then the tension lever 32 is swiveled in the direction of the second fastening element 30, the two fastening elements 19 and 30 are braced against one another and thus against the bottom bracket 26. The bottom bracket 26 is then fixed to the frame 1. The arrangement of the screw bolts 27 of the bottom bracket 36 and pivot bearing 33 relative to one another is configured such that the tension lever 32 assumes a so-called dead center position in the closed position, whereby the entire unit is also securely locked.
Number | Date | Country | Kind |
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10 2019 002 631.4 | Apr 2019 | DE | national |