Frame of the Bicycle

Technical Field

The invention relates to a bicycle frame containing a main tube with a head tube in the front and with a bottom bracket down on an extended end. To the frame is fixed a rear fork by the holder. The holder is situated above the bottom bracket. The rear fork is fixed as immovably or by swing way.

Background Art

With respect to the static solidity of the frame it is the optimal way, when the connection of the rear fork is in the place of the bottom bracket, where also a saddle tube used to be fixed. With respect to the efficiency during the pedalling it is advantageous, when the placement of the rear fork is situated above the bottom bracket. This connection of the rear fork, as immovable or by swing way, does not bring a guarantee of the solidity of the connection with the frame enough. The extending end of the main tube, which keeps the bottom bracket with the crank set is during the pedalling excessively stressed.

Disclosure of Invention

The bicycle frame contains a main tube with a head tube in the front and with a bottom bracket down on an extended end. To the frame is fixed a rear fork by the holder. The holder is situated above the bottom bracket. The rear fork is fixed as immovably or by swing way. The holder is formed from a tube and it is joined to the adjacent wall of the main tube and eventually also with a saddle tube. To increase the solidity of the frame is the holder with the main tube and also eventually with the saddle tube joined by a weld.

When the holder goes through the adjacent wall of the main tube and eventually through the saddle tube and those components are welded together, the junction

will be better and the whole solidity of the construction is considerably increased.

When the hole is made on the opposite wall of the main tube, is possible to weld the end of the holder in the place of touching the opposite wall of the main tube. By this way will the solidity of the construction still increase.

It is suitable, when from the center a fastening bar extends upwards and goes at least partly through the holder. Thereby the connection of the bottom bracket and the main tube becomes a solid component with the holder.

If the fastening bar goes through the holder at least partly out of the main tube, it is possibile to weld the fastening bar with the holder and with the main tube altogether. This connection eliminates deformations, which could be to induce some stressing cracks.

Brief Description of Drawings

FIG.l is the whole view of the frame (in longitudinal section) in the version of an immovable rear fork. FIG.2 is the view with a swing rear fork, whereas the FIG.3 shows the longitudinal section through the bottom part of the frame before putting the bottom bracket with fastening bar into this section. Bottom bracket with fastening bar is on FIG.4 and FIG.5 describes the frame, after the bottom bracket with the fastening bar is putted into its place of the frame and it is welded together.

Modes for Carrying Out of Invention.

A bicycle frame R which contains a main tube 1 with a head tube 12 and a saddle tube 17. Down at an extended end VL of the main tube 1 a bottom bracket 13 is fixed. To the frame R is by the holder UL situated above the bottom

bracket B, fixed a rear fork V. By realization according FIG.l is rear fork V fixed immovably and by realization according FIG.2 is rear fork V fixed in swing way by means of a joint 2. Between the main tube I and the fork V is integrated a spring 3. The holder 14 goes through the adjacent wall Ia of the main tube I and touches the opposite wall Ib. With the main tube I at the adjacent wall Ia is the holder 14 joined by a weld. The opposite wall Ib is in the place of touching the holder 14 provided by a hole 16, in which is the holder 14 welded together with the main tube 1. From the bottom bracket H extends upwards a fastening bar 15 and it goes through the holder 14- The fastening bar 15 goes through the holder 14 partly out of the main tube 1. This position allows the fastening bar 15 to be welded with the holder 14 and with the main tube 1 alltogether.

To set the frame R together, it is made an aperture in the main tube 1. Then it is possible to insert the holder 14 into the main tube 1 until the holder 14 gets in touch with the opposite wall Ib. To the holder 14 is enclosed with the saddle tube 17. In the place of touching the holder 14 on the opposite wall Ib of the main tube 1 is made a hole 16. The end of the holder 14. which becomes accessible by consequence of the existing hole 16, is joined to the main tube by a weld. From the extended end H of the main tube L ₁ upwards through the adjacent wall Ia of the main tube 1, there is drilled an aperture, which goes through the holder 14. The fastening bar JL5 goes to the holder 14 through the adjacent wall Ia out of the frame R, and therefore it is accessible for the welding. All places of touching the fastening bar 15 with the holder 4, the main tube 1 and the saddle tube 12, are welded together and the bottom bracket 13 with the main tube 1 as well.