DE9309353U1 - Foldable bike - Google Patents

Description

RICHARDGLAWE, Dr.-Ing. (1952-1985) KLAUS DELFS, Dipl.-Ing., Hamburg WALTER MOLL, Dipl.-Phys. Dr. rer. nat., Munich ULRICH MENGDEHL, Dipl.-Chem. Dr. rer. nat., Hamburg HEINRICH NIEBUHR, Dipl.-Phys. Dr. phil. habil., Hamburg ULRICH GLAWE, Dipl.-Phys. Dr. rer. nat., Munich Stephan Jung BERNHARDMERKAU ₁ DiPL-PhVs ₁₁ MUnChOn

Hardebek

PO Box 26 01 62 PO Box 13 03 91

80058 Munich 20103 Hamburg

Liebherrstrasse 20 Rothenbaumchaussee

80538 Munich 20148 Hamburg

Phone (089) 22 46 65 Phone (040) 4 10 20 08

Fax (089) 22 39 38 Fax (040) 45 89 84

Tel. 5 22 505 Tel. 17 403 156

HAMBURG

&rgr; 15596/93 FB/Em # 123

Dismountable bicycle

The present invention relates to a bicycle. Bicycles are often transported to their actual place of use by car. The dimensions of conventional bicycles make it necessary to transport them outside the car, for example on the roof or on a separate trailer. This impairs the driving characteristics of the car, increases fuel consumption, and the bicycles are exposed to environmental influences, especially when transported on the roof. There is also an increased risk of theft.

Folding bikes are known from obvious previous use, which can be folded up using various mechanisms and then transported in the trunk of a car. However, the appearance and driving characteristics of such folding bikes are usually unsatisfactory.

The invention is based on the object of creating a bicycle that largely corresponds to conventional bicycles in terms of appearance, handling characteristics and stability, but which can nevertheless be transported in the trunk or interior of most cars.

VAT identification number: DE 118 319 199 Dresdner Bank AG Hamburg 04 030 448 00 (bank code 200 800 00) Postgiro Hamburg 1476 07-200 (bank code 200 100 20)

The invention solves this problem by providing a detachable connection between the steering spindle and the front fork lower part.

In the context of the invention, a detachable connection is understood to mean any connection that can be detached and re-established with little time and tool expenditure. In the bicycle according to the invention, the front wheel can be removed together with the lower part of the front wheel fork. The largest remaining component is now the bicycle frame including the rear wheel. This component has a length of approx. 1300 mm for 26" wheels and a length of approx. 1350 mm for 28" wheels. It can therefore be stowed in the trunk of almost all saloons and, at least after folding down the back seat, in the interior of almost all cars with a tailgate. In the context of the invention, it is also conceivable that the front wheel fork together with the steering spindle can be easily removed from the frame.

The detachable connection is advantageously designed as a conical connection. A conical connection is understood to mean any connection in which a conical body engages in a conical opening in a form-fitting manner. Such a conical connection is equivalent in its mechanical properties to a weld or solder, so that the stability and driving characteristics of the bicycle according to the invention are unchanged compared to conventional bicycles.

This conical connection is expediently designed so that the fork bridge of the front wheel fork has a conical opening and the steering spindle has a cone that interacts with this opening.

Advantageously, the steering spindle and the front fork lower section have additional cooperating positioning devices for determining their relative position with respect to the steering axis. These positioning devices ensure that the steering spindle and the front fork lower section are correctly positioned during assembly.

the fork ensures the correct alignment of the handlebars to the front wheel. For example, they can have a positioning pin that is eccentrically arranged with respect to the spindle axis (steering axis) and a positioning hole that interacts with this positioning pin.

To secure the cone connection, an additional screw connection is provided between the lower part of the front fork and the steering spindle. For example, a screw bolt can be screwed from the underside of the fork bridge into an internal thread of the steering spindle. Since cone connections are known to be very strong, hardly any force needs to be transmitted via this additional screw connection.

Since the tight press fit of the cone connection can cause difficulties when releasing it, it is advisable to provide a forcing device for releasing the cone connection. The forcing device can, for example, be designed as a forcing screw that is turned from the underside of the fork bridge against a forcing surface on the steering spindle.

As is well known, the lower part of the front fork of a bicycle, due to the steering geometry, must have a fork bend of the order of 40 - 60 mm in order to ensure stable driving characteristics. This fork bend is usually achieved by bending the fork tubes downwards and forwards. However, within the scope of the invention, it can be provided that instead of this or in addition to this, the fork bridge of the front wheel fork has a bend pointing in the direction of travel of the bicycle. This has the additional advantage that the cone fit of the fork bridge, including the assembly and forcing screws or bolts, is easier to access. A quick-release device is also advantageously provided for connecting the steering spindle and handlebars. In this way, the handlebars can also be removed and reassembled very easily if necessary.

A particular advantage of the invention is that all conventional bicycles can be retrofitted to bicycles according to the invention by installing a corresponding front fork lower section and a steering spindle. The visual appearance of the bicycle according to the invention corresponds to that of conventional bicycles, the unsightly "folding bicycle design" does not occur. If required, the bicycle according to the invention can be equipped with front wheel suspension. When removing the front fork lower section together with the front wheel, only the cable connection to the front wheel brake and any cable connection for the lighting must be disconnected. However, interacting contacts can also be provided in the fork bridge and steering spindle, which automatically close the lighting circuit when the bicycle is assembled.

An embodiment of the invention is explained below with reference to the drawings:

Fig. 1 is a schematic representation of a bicycle according to the invention in a side view;

Fig. 2 the quick release device for holding the handlebars;

Fig. 3 the lower part of the steering spindle with the connecting cone;

Fig. 4 a sectional drawing through the fork bridge with cone fit;

Fig. 5 a view of the fork bridge from above.

The bicycle shown only schematically in Fig. 1 basically has a frame 1, in whose front frame tube 2 the steering spindle 3 shown in Fig. 3 is arranged so that it can rotate. The handlebar 4 can be inserted into the upper end of the steering spindle 3; it is attached by means of the screws shown in Fig. 2.

quick-release device 5 provided. At the lower end of the steering spindle 3 there is a centrally arranged cone. This cone 4 has a central internal thread 5 that continues into the steering spindle 3. In Fig. 3, the bearings 6 indicate the bearings with which the steering spindle 3 is rotatably mounted in the frame tube 2. Below the bearings 6, the steering spindle 3 expands into a radially outward-pointing edge flange 7.

The fork bridge 8 of the front wheel fork 9 is bent in the direction of travel of the bicycle (arrow A in Fig. 5) in order to generate the caster of the front wheel necessary for driving stability. Seen from above, it has the shape of a V that is open in the direction of travel. The cone fit 10, into which the cone 4 can be inserted with a press fit, is used to connect it to the steering spindle 3. A positioning pin 11 is arranged on the fork bridge 8, which interacts with the positioning hole 12 of the edge flange 7 of the steering spindle 3 and thus ensures that the front wheel 9 assumes the correct relative position to the handlebar 4 when assembled. The positioning pin 11 and the positioning hole 12 are arranged eccentrically with respect to the axis of rotation of the steering spindle 3. The bottom of the cone fitting 10 has a bore 13 that is centric to the steering spindle axis, through which a mounting bolt 14 can be screwed into the internal thread 5 of the cone 4 and the steering spindle 3 from the underside of the fork bridge 8. In order to be able to handle this mounting bolt 14, it is necessary that there is a free space of about 20 mm between the front wheel or the mudguard and the fork bridge. The mounting bolt 14 serves to additionally secure the cone connection.

To release the conical connection, the fork bridge 8 has a forcing hole 15 through which a forcing bolt (not shown) can be screwed in from below (in the direction of arrow B in Fig. 4), which, when screwed in, presses against the forcing surface 16 formed by the axial surface of the edge flange 7.

and thus releases the conical connection. In order to prevent the cone from tilting when it is released, several forcing holes can be provided, preferably arranged symmetrically around the conical fitting 10.

When dismantling the bicycle according to the invention, first the cable connection to the front wheel brake is unhooked and if necessary the cable connection of the lighting is loosened. If necessary, the handlebar 4 can also be removed from its handlebar mount (quick release device 5) and is then conveniently hung over the frame 1. The assembly bolt 14 is then unscrewed and the conical connection is released by screwing the forcing bolt into the forcing hole 15. The lower part of the front fork together with the front wheel is removed from the steering spindle and can be stowed separately. The mudguard, brake and other attachments remain on the lower part of the front fork.

To assemble, first the forcing bolt is turned back in the forcing hole 15, then the cone 4 is inserted into the cone fitting 10. The angular position of the steering spindle 3 and the fork bridge 8 relative to each other is selected so that the positioning pin 11 engages in the positioning hole 12. The cone connection is then additionally secured by screwing in the assembly bolt 14. The handlebar 4 is clamped into the handlebar mount 5, then the cable connections to the front wheel brake and, if necessary, the cable connection of the lighting are restored.

Claims (10)

Protection claims 1. Bicycle, characterized in that a detachable connection of the steering spindle (3) and the front fork lower part (8, 9) is provided. 2. Bicycle according to claim 1, characterized in that the detachable connection is designed as a conical connection (4, 10). 3. Bicycle according to claim 2, characterized in that the fork bridge (8) of the front wheel fork (9) has a conical opening (10) and the steering spindle (3) has a cone (4) cooperating with this opening (10). 4. Bicycle according to one of claims 1 to 3, characterized in that the steering spindle (3) and the front fork lower part (8, 9) additionally have cooperating positioning devices (11, 12) for determining their relative position with respect to the steering axis. 5. Bicycle according to claim 4, characterized in that the cooperating positioning devices have at least one positioning pin (11) arranged eccentrically with respect to the steering axis and at least one positioning bore (12) cooperating with this positioning pin. 6. Bicycle according to one of claims 2 to 5, characterized in that an additional screw connection (14, 5) is provided between the front wheel fork lower part (8, 9) and the steering spindle (3) to secure the conical connection (4, 10). 7. Bicycle according to one of claims 2 to 6, characterized in that a pressing device (15) is provided for releasing the conical connection (4, 10). 8. Bicycle according to claim 7, characterized in that these forcing devices are designed as forcing screws. 9. Bicycle according to one of claims 1 to 8, characterized in that the fork bridge (8) of the front wheel fork (9) has a bend pointing in the direction of travel of the bicycle. 10. Bicycle according to one of claims 1 to 9, characterized in that a quick-release device (5) is provided for connecting the steering spindle (3) and handlebar (4).