DE19856994A1 - Automatic transmission for bicycles - Google Patents

Abstract

The automatic transmission has two outer discs, serving as guide discs, and fastened to the main shaft. A single or dual-row inner control disc is fastened to a spring, which is fixed to the main shaft. The six guides in the guide discs may be radial or curved. Six toothed gear or V-belt pulley segments fastened to shafts, are automatically guided in the guides of the outer discs towards the larger or smaller diameter, dependent upon the force applied by the feet. The control disc has six levers to ensure that all segments always move on the same diameter. The pedal force is taken-up by the central torsion spring.

Description

State of the art

Today the translations (gears) are achieved as follows:

• - In the rear axle (torpedo) 3-speed, 5-speed, 7-speed, or
• - with chainrings (front) and sprockets (sprockets, rear), or
• - a combination of the two variants.

The gears are shifted using levers that are preferably on attached to the handlebars, or with twist grips.

The purpose of the number of courses is:

• - If possible, the different ones with constant foot pedaling power Coping with driving situations (uphill, downhill, on the plain),
• - A gradation that is as constant as possible and not too large To achieve transitions from one gear to another.

With the derailleur you can have more gears than with the Achieve torpedo control. But there are many gears for this necessary (chainrings and sprockets), and yet are in Relatively few gears in relation to the number of gears usable because the aisle sizes overlap.

With the derailleur you can achieve, for example

• - Largest ratio i max. of approx.3.86 (number of teeth ratio 54: 14), and
• - a minimum translation i min. of about 1.33 (32:24), i.e. H.
• - a total transmission ratio (gain, i max: i min) of 3.86: 1.33 = 2.89.

Terms

Gear ratio = diameter (or teeth) at the front divided by diameter (or teeth) at the back,
Reinforcement = largest translation: smallest translation.

Disadvantages of derailleur gears

• - Chain wear due to the chain starting up at an angle the chainrings and the sprockets
• - complicated gear change mechanism
• - Exercise with the gears
• - expensive.

Automatic transmissions in general

With an automatic transmission, manual shifting of the Gears. The translation automatically adapts to the terrain. With constant effort (foot pedaling force) changes the driving speed accordingly: one drives in the plane faster, uphill slower.

Description of the invention "bicycle automatic"

Firmly connected to the main shaft 2 (two) Guide discs, each with 6 (six) radial or arcuate Guides.

These guides determine the careers and the orientations of 6 (six) toothed or V-belt segments, depending on whether Chain or V-belt drive is used.

One sits firmly on the main shaft between the guide washers Mega spring loaded on torsion (Megi socket, rubber spring)  On this mega spring there is a fixed 1 (one) control disc controls the 6 (six) segments using 6 (six) levers. The control disc can be 1-row or 2-row.

So there are four construction variants:

• - 1-row control disc and radial guides ( Fig. 1)
• - 2-row control disc and radial guides ( Fig. 2)
• - 1-row control disc and curved guides ( Fig. 3)
• - 2-row control disc and curved guides ( Fig. 4).

In the variants with the 2-row control disc, the Translation can be interpreted larger than with the 1-row Control disc.

The axes on which the toothed or V-belt segments are fixed sit in the straight or curved guides of the led external discs.

Due to the control disc, all segments always move at the same level, d. H. on the same diameter of action.

The spring force that counteracts the foot pedal force is from the Megifeder creates and grows proportionally with the rotation of the Control disc, or the mega spring.

The drive ratio changes automatically depending on the one entered by the cyclist on the pedals Torque: is z. B. when driving uphill the necessary foot pedal powerful, the axes, with their attached to them Segments, pressed inwards (the diameter of the segments gets smaller), the levers act on the control disc, and this turns the mega spring until the growing and counteracting mega spring force the balance to the foot force manufactures.  

The largest or smallest translation can be found with the length of the Determine guides and the length of the lever within certain limits.

The achievable gain of an automatic is in the range 1.5-1.7. Therefore, a combination with a z. B. 3-course Torpedo circuit, or a second automatic, recommended.

The automatic system can either only be in the front or only in the rear, or front and rear.

If the automatic system is installed both at the front and rear, the chain or V-belt length remains in all driving situations constant, a tensioner is not necessary.

Advantages of the automatic

• - no manual shifting of gears necessary
• - Automatic adaptation of the speed to the existing ones Driving conditions, with constant pedaling force
• - no chain wear due to chain skew.

Claims (6)

1. Automatic transmission, consisting of 2 (two) outer disks as Guide discs, firmly connected to the main shaft, one internal control disc, firmly seated on the mega spring. The mega spring sits firmly on the main shaft. The 6 (six) guides in each of the guide washers can be radial or arcuate. The control disc is 1-row or 2-row. 2. 6 (six) gear or V-belt pulley segments, depending on Use of chain or V-belt drive, fixed on axles are automatically installed in the guides of the external discs for small or large diameters (inwards or outwards), depending on the pedaling force. 3. The control disc uses 6 (six) levers to ensure that all segments always have the same effective diameter move. 4. The central mega spring (rubber spring) subjected to torsion takes over the pedal force. 5. There can be gear or V-belt pulley segments be used. 6. The automatic system can be on the front, rear or front of the bike and be installed at the rear. You can also use a Torpedo circuit can be combined.