Exhibitor: Association of Hungarian Inventors - MAFE

Inventor and Invention:


NÁDAS, Béla dr: Double cardan joint


1.  The Invention



Double cardan joint


The problem the inventor(s) wanted to solve

The main aim was to create a drive for the coupling of two shafts having different shaft angle with a simple mechanism where the driving and driven shafts have always the same angular velocity.



The double cardan joint is suitable for the coupling of two shafts where the two shafts can have a larger shaft angle than that of the traditional drives and, the angular velocities of the driving and the driven shafts are always the same.



drive line the connection of the two cardan joints in series is evidently advantageous, since due to their co-action the angular region is doubled and, in addition, the resulting driving movement also becomes even. This last effect is true only if the angular deviation between the driving and driven shafts is evenly distributed by the two cardan joints. This requirement can be realised in a simple way only in case of fixed position cardan joints, while in case of two cardan joints that are connected in series and where the deviation angle between the two shafts is varying in every moment it is required to build in an auxiliary mechanism. The characteristics of the present solution is that the two cardan joints are connected to each other through a double arm hinge-joint mechanism, instead of an intermediate shaft. The arms of the hinge-joint mechanism are embedded with bearings into the respective shafts of the two cardan crosses. This simple mechanism automatically divides exactly in two any actual angular deviation between the shafts and, as a result, both the driving and driven shafts have always an equal angular velocity. An auxiliary moving frame determines the position of the crossing point of the two axis of revolution for both the driving and driven shafts. The mechanism can also precisely be balanced even in case of high operating speeds with counterweights and, at the same time, it is still operating in a deviation angle range that is twice as much as that of a single cardan joint and a more compact construction can be built-up as that of a double cardan joint where these are connected to each other with an intermediate shaft. Its lubrication and maintenance requirements are modest because it is composed of the same elements as that of a simple cardan joint.



It can be used to replace synchronous joints (e.g.: Rzeppa, Bendix-Weiss, etc.) in the machine and vehicle industry.



It allows a higher shaft angle range than that of the single cardan joint, with low friction, noiseless operation and low lubrication requirement in a way that the angular velocity of the driving and the driven shafts are the same in any moment. Its construction is simple and, thus, it can cheaply and easily be manufactured and dimensioned for versatile use.


Stage of development.

The prototype development is in course.


Documentation available:



2.  The inventor (or inventors)



NÁDAS, Béla dr


Self introduction.

The inventor lives in Budapest, he is 53 years old, he is a specialist in internal medicine. As a HOBBY, for amusement and in his free time he is interested in and deals with the technical questions and the mechanical engineering. He has various inventions.


Owner of the invention?



3.  Protection


Patent Status:

Form: patent application (Reg. no.: P0203250)



30 September, 2002.


Countries where it is in force



4.      Business intention

The inventor should like to sell the patent rights