DE202004019270U1 - Lightweight multiple sprocket wheel for gearchange mechanism on bicycle is of stepped dished shape with short cylinder sections with teeth joining annular sections, all made in one piece - Google Patents

Abstract

The monolithic multiple sprocket wheel has an outer annular portion (21) with sprocket teeth (24) and curved gaps (25) between the teeth cut in its outside edge. Strips of metal (26) parallel to the shaft join the inside diameter of the outer annular portion to the outside diameter of the middle annular portion (22). Tongues attached to the outside diameter are detached from the gaps (27) between the strips of metal and are bent outward and shaped to make sprocket teeth. The middle annular portion is joined to the inner annular portion (23) in the same way. There is a central toothed aperture (230) to accommodate the shaft.

Description

technical area

The The invention relates to a transmission of integrally formed toothed discs with different diameter, the low production costs and has high strength.

State of technology

• 1. Die Zahnscheiben müssen separat gestanzt und danach über die Abstandshalter 17 und die Niete 18 miteinander verbunden werden, so daß die Herstellung kraft- und kostenaufwendig ist.
• 2. Nach einer längeren Betriebszeit können sich die Zahnscheiben, die über die Abstandshalter 17 und die Niete 18 miteinander verbunden sind, lockern.
• 3. Durch die Niete 18 wird eine Punktverbindung hergestellt, die eine niedrige Festigkeit aufweist, so daß sich die Zahnscheiben verformen können.
• 4. Die Kette kann in dem Spalt zwischen den Zahnscheiben geklemmt werden, wenn sich die Kette (aus den Zähnen) löst.
• 5. Die Zähne 14 und die Zahngründe 15 können durch die Kette verschlissen werden, da eine Stützung für die Kette nicht vorgesehen ist.

1 . 2 and 3 show a conventional gear for bicycle, which consists of three toothed discs 11 . 12 . 13 exists, the circumference teeth 14 and tooth reasons 15 exhibit. The toothed discs 11 . 12 . 13 are each with several rivet holes 16 for the rivet 18 each provided by a spacer 17 go through and connect the toothed discs. The first and second toothed disc 11 . 12 each have a center hole 110 . 120 for the pedal 19 of the bicycle. However, this transmission has the following disadvantages:

• 1. The toothed discs must be punched separately and then over the spacers 17 and the rivet 18 be connected to each other, so that the production is power and costly.
• 2. After a longer period of operation, the toothed pulleys can over the spacers 17 and the rivet 18 loosen up.
• 3. Through the rivet 18 a point connection is made, which has a low strength, so that the toothed disks can deform.
• 4. The chain can be clamped in the gap between the toothed pulleys as the chain loosens (from the teeth).
• 5. The teeth 14 and the tooth reasons 15 can be worn through the chain as support for the chain is not provided.

Task of invention

Of the Invention is based on the object, a transmission from one piece trained pulleys with different diameter too create, which has low production costs.

Of the Invention is based on a further object, a transmission one-piece toothed disks with different diameters create, which has a high strength.

Of the Invention is a still further object, a transmission made of one-piece pulleys with different diameters to create a clamping of the chain can avoid.

Short description the drawings

1 shows an exploded view of the conventional solution,

2 shows a perspective view of the conventional solution,

3 shows a sectional view of the conventional solution,

4 shows a perspective view of the invention,

5 shows a sectional view of the invention.

Ways to execute the invention

Like from the 4 and 5 it can be seen, there is the transmission according to the invention 20 from a first, second and third toothed disc 21 . 22 . 23 , the circumference of the pointed teeth 24 and arched tooth bases 25 exhibit. The third and the second 23 . 22 as well as the second and the first toothed disc 22 . 21 are circumferentially over bars 26 connected to each other, arising from the tooth reasons 25 extend and between which the column 27 are formed on the teeth of the teeth 24 are outstretched. The third toothed disc 23 has a center hole 230 in which the transmission shaft (such as pedal crank 19 of the bicycle) is attached. This allows the first, second and third toothed pulley 21 . 22 . 23 be formed in one piece.

• 1. Stanzen: Das Eisenblech wird vor der Wärmebehandlung gestanzt, wodurch die Spitzzähne 24 und die bogenförmigen Zahngründe 25 sowie die Stege 26 und die Spalte 27 erzeugt werden. Anschließend wird das Eisenblech abgestuft, wodurch das Getriebe 20 in 4 erhalten wird. Nach dem Stanzen wird das Getriebe durch Wärmebehandlung verstärkt. Daher kann das erfindungsgemäße Getriebe, die aus drei Zahnscheiben besteht, durch einmaliges Stanzen hergestellt werden, so daß die Herstellung schneller und billiger ist.
• 2. Pulvermetallurgie und Entwachsen Da die Zahnscheiben über die Stege 26 miteinander verbunden sind und zwischen den Stegen 26 die Spalte 27 gebildet sind, kann die Erfindung auch durch Pulvermetallurgie und Entwachsen geformt werden.

The invention can be prepared by the following methods:

• 1. Punching: The iron sheet is punched before the heat treatment, which causes the teeth of the teeth 24 and the arched tooth bases 25 as well as the footbridges 26 and the column 27 be generated. Subsequently, the iron sheet is stepped, whereby the transmission 20 in 4 is obtained. After punching, the gearbox is reinforced by heat treatment. Therefore, the transmission according to the invention, which consists of three toothed pulleys, can be produced by a single punching, so that the production is faster and cheaper.
• 2. Powder metallurgy and dewaxing Since the toothed disks are over the webs 26 are interconnected and between the bars 26 the gap 27 are formed, the invention can also be formed by powder metallurgy and dewaxing.

In the 4 and 5 contains the gearbox 20 three toothed discs. However, the number of toothed pulleys of the invention is not limited thereto and may be two or more than three.

• 1. Da die Stege 26 an der ganzen Umfangsseite der Zahnscheiben verteilt sind, weist die Verbindung zwischen den Zahnscheiben eine hohe Festigkeit auf, so daß eine Verformung vermieden wird.
• 2. Bei Verwendung einer Kette kann diese von den Stegen 26 gestützt werden, wodurch die Belastung auf die Zähne 24 und die Zahngründe 25 reduziert wird, so daß der Verschleiß der Zähne 24 und der Zahngründe 25 verringert wird.
• 3. Wenn sich die Kette (aus den Zähnen) löst, kann sie durch die Stützung der Stege 26 leicht abgenommen werden.
• 4. Da die Zahnscheiben einteilig ausgebildet sind, wird eine Lockerung oder Schwankung einer der Zahnscheiben vermieden.

The following further advantages of the invention are described below:

• 1. Since the webs 26 are distributed on the entire circumferential side of the toothed disks, the connection between the toothed disks on a high strength, so that deformation is avoided.
• 2. When using a chain, this can be done by the webs 26 be supported, reducing the burden on the teeth 24 and the tooth reasons 25 is reduced, so that the wear of the teeth 24 and the tooth reasons 25 is reduced.
• 3. When the chain loosens (from the teeth), it can by supporting the bars 26 be easily removed.
• 4. Since the toothed disks are integrally formed, a loosening or fluctuation of the toothed disks is avoided.

by virtue of the above facts, the invention corresponds in its availability, Progressiveness and novelty fully on the requirements for a utility model.

Claims (2)

Transmission of integrally formed toothed discs of different diameter, consisting of a first, second and third toothed disc ( 21 . 22 . 23 ), the circumference of the pointed teeth ( 24 ) and arched tooth surfaces ( 25 ), the third and the second ( 23 . 22 ) as well as the second and the first toothed disc ( 22 . 21 ) peripherally over webs ( 26 ) are connected to each other, arising from the tooth reasons ( 25 ) and between which the column ( 27 ) are formed on the teeth ( 24 ), the third toothed disc ( 23 ) a center hole ( 230 ), in which the gear shaft is fixed, whereby the first, second and third toothed disc ( 21 . 22 . 23 ) may be integrally formed, so that a reduction in manufacturing costs and an increase in strength can be achieved. Transmission according to claim 1, characterized that the Number of toothed pulleys can also be two or more than three.