The present invention refers to a two or multi-layer compression spring, the cylindric spring bodies of which are disposed inside each other.
Energy has to be stored very often over a longer period, but should not be lost over the time period and it should be possible to be delivered purposeful at a certain point of time.
For this purpose very often compressed air, hydraulic or spring storages are used. Spring operating storages do have the advantage that they are simply constructed and at right dimensioning to have none or only a very restricted force or energy loss respectively. This energy loss can be further reduced by a respective dimensioning of the spring with a respective low charge below the creep limit of the material. A low utilisation of the charge of the material, however, leads to the requirement of a bigger necessary construction volume.
A further aspect of an energy storage, in particular a spring energy store, is the characteristic of the spring force over the decompression path of the spring:
Compact spring energy stores with a high initial force usually have a high spring rate with a high starting force and a low end force. Due to the high starting force, the force collecting construction parts must be disproportional strongly dimensioned so that the end force still reaches the required value. In addition, at a bad ratio of the starting force to the end force the function of the construction part intaking the force can be affected. To fulfil the requirement to a flat spring characteristics, results to a bigger required construction volume for the spring energy store.
The requirement for more energy storing per volume has been solved e.g. by introducing into each other two or more springs with different diameter, to better use the existing construction volume.
According the requirements, these springs have to be hold against each other. This can be done with different methods, e.g. by means of a jacket, which is introduced between the springs or by means of spring plates, which are positioned and locked on the spring ends. Jackets or spring plates should prevent that the springs are grating to one another or are even got stuck into each other. Besides the fact that with these approaches to the problem, an effort occurs in relation to the assembling, the result is not always sufficient.
The object of the invention is to fulfil the requirements more optimal and to eliminate or at least to reduce the disadvantages of known solutions.
The mentioned object is inventively solved by a compression spring of the initially defined manner, according the feature of the characterizing part of claim 1. Especially preferred embodiments of the inventive subject are defined within the dependent claims.
The invention is described hereafter by means of example of embodiments in more details, which are shown within the figures.
The compression spring as shown in the Figures, comprises two spring bodies 1, 2 made out of spring steel, which are disposed inside of each other, which do have different diameters, but are made out of a single, which means an interruption free piece of wire. The intersection between spring body 1 with the bigger diameter onto the spring body 2 with the smaller diameter, which means the connection between the two spring bodies takes place at one spring end. The fabrication of such a multi-layer spring is known to the specialist.
By means of the inventive very simply constructed spring, the essential disadvantages of known solutions can be avoided.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2007/050839 | 1/29/2007 | WO | 00 | 7/28/2009 |