The instant application should be granted the priority dates of Jan. 28, 2009, the filing date of the corresponding German patent application 10 2009 006 500.8, as well as Jan. 26, 2010 the filing date of the International patent application PCT/EP2010/000427.
The present invention relates to a laboratory grinder comprising at least one grinding beaker carrying out a rotary movement about the central axis thereof, the grinding beaker being connected to at least one line for conducting a liquid or gaseous medium.
Such a laboratory grinder is known, for example, in the form of a vibration grinding mill or a planetary ball mill having a ratio of 1:−1. To the extent that it is known that brittle materials can be reduced in size particularly efficiently in such laboratory grinding mills, there is effected in appropriate cases an additional embrittlement of the material that is to be ground by cooling with liquid nitrogen. For this purpose, the liquid nitrogen must be continuously supplied to the moving grinding beaker, and must be withdrawn therefrom. In this connection, it is known to carry out the supply of the grinding beaker with the liquid or gaseous medium, for example nitrogen, by means of appropriately arranged flexible hoses. In this connection, the hoses are secured directly to the grinding beaker holder, whereby a fluidic connection can then exist between the grinding beaker holder and the inserted grinding beaker. During practical use, however, these hose connections have a shorter useful life due to the great amplitude of the alternating stress brought about by the movement of the grinding beaker. In particular during the use of liquid nitrogen, additional safety precautions are therefore necessary in order to preclude the endangerment of personnel should the hose connections fail.
In addition to the nitrogen application, other applications of mechanical energy during the grinding process utilize the brief local release of large quantities of energy for the introduction of chemical reactions. Depending upon the reactions that occur, under certain circumstances the grinding beaker must be cooled or heated. This also requires the continuous supply of the grinding beaker with a medium for tempering the reaction chamber.
In yet other applications, during the reduction in size of the material that is to be ground gases are released that can be the subject matter of a further analysis. These gases must therefore be continuously withdrawn from the grinding beaker, and the withdrawn volume must be compensated for by a corresponding supply of gas.
All of the previously addressed applications have the problem of conducting liquid or gaseous media to a moving grinding beaker, and it is therefore an object of the present invention to provide a laboratory grinding mill having the aforementioned features that ensures a reliable connection of the correspondingly required lines or conduits for conducting liquid or gaseous media therethough.