US2202055A - Reducing piece for glass instruments for laboratory technics - Google Patents

Description

May 28, 1940. w. JUFFA 2,202,055

REDUCING PIECE FOR GLASS INSTRUMENTS FOR LABORATORY TECHNICS Filed July .15., 1937 "00 mag .W/LHELM JUFFA Patented May 28, 1940 UNITED STATES REDUCING PIECE FOR GLASS INSTRU- MENTS FOR LABORATORY TECHNICS Wilhelm Jnfl'a, Ihnenau, Germany Application July 15, 1937, Serial No. 153,730

In Germany March 16, 1937 3 Claims.

For filtering liquids it is known to use more or less-large bottles provided at one side with a suction pipe connection for producing a pressure which is below atmospheric in the interior of thebottle, while a specially-constructed filter head can befitted on the neck of the bottle.

This head consists of a large funnel with a molten-in so-called sinter-plate. To obtain an air-tight closing, the filter funnel has a stemoratory methods.

tube which extends into the bottle neck and on which a rubber ring can be mounted.

Therefore, filter funnels of various size and also special tightening materials, also of various size, are required.

The novelty of the present invention consists in that all these parts are omitted. The invention is based on the utilization of the teaching, given in applicant's U. S. A. Patent 2,052,713, to employ for liquid containers reducing glass pieces, ground air-tight on the inner side and on the outer side, and inserted one into the other for connecting the container with tubes of diflerent diameter. By means of a loose filter plate which is simple to insert and to remove these reducing pieces can serve at the same time as a filter funnel.

The reducing pieces of known type open at the top and at the bottom are thus made useful for a new purpose, for which they are particularly suitable, as, according to the U. S. A. patent cited above, they have conical glass surfaces ground outside and inside. Thus, the filter funnels,

hitherto required can be dispensed with as well as the packing material, since a number of reducing pieces according to the U. S. A. patent above cited, when inserted one into the other possess the advantage of compensating for all the various sizes. With a single set of such reducing pieces air-tight reduction from any external diameter to any internal diameter can be carried out.

At the same time, the application of the reducing pieces in the new combination, and for the new purpose as filter funnel with automatic tightening is particularly simple since only a simple sinter plate has to be inserted loosely in the reducing piece from the top. If, afterwards the filter funnel is again to be used as a reducing piece, it is only necessary to remove the loose filter plate.

The invention, however, results in another surprising efiect: By means of the reducing pieces a multiple filtration may be carried out. This is especially advantageous for many chemical lab- As, according to the above cited U. S. A. patent, several reducing pieces can be put together without appreciablylengthening the apparatus, it is possible, if the sinter plate has been loosely inserted into the inner reducing piece right at the bottom, to insert sinter plates in the same way loosely into the second or even into the third reducing piece, as the height of the single sinter plates is lower than the corresponding distance between the bottom edge of the first reducing piece and that of the second reducing piece and so forth.

Therefore, it is also an essential feature of'the invention that the sinter plate is loosely placed on the bottom edge of the corresponding reducing piece. Thus, according to the invention, it is possible to filter several times in bottles of any size, with the aid of a few simple sinter plates which i have the normal size of the conical reducing pieces,'because reducing pieces of various size are already available.

The reducing piece, open at the top end and at the bottom, according tov the above cited U. S. A. patent, can therefore also serve, according to the present invention (1) As a filter funnel,

(2) As packing means,

(3) As a filter funnel and packing means of various sizes, fitting into every bottle neck,

(4) As a multifold filtering apparatus, and selectively:

(5) Either as a single, double or triple filtering apparatus, etc.

An embodiment of the invention is illustrated by way of example in the accompanying drawing, in which Fig. 1 shows the bottle ready for use and Figs. 2 and 3 show the loose filter or sinter plate, suitable for normal reducing pieces.

I is the filter bottle, provided with a lateral connection 2 for the evacuation tube. A charging funnel 3 can be inserted into the neck of the bottleby means of one or a number of reducing pieces 4, 5.

The reducing piece or pieces has or have airtightly ground outer and inner surfaces so that by inserting a number of such reducing pieces it is possible to reduce the charging funnel to any desired cross section.

According to the invention, this normal reducing piece or these reducing pieces are used for a further purpose, i. e. as filtering container by the loose insertion of a filter or sinter plate 6, which can be easily removed in the same manner. Therefore, when the filter plate is inserted, the reducing pieces engage each other air-tightly shutting off filtering funnels and, after the easily 55 removable filter plates have been taken out, the reducing pieces are again suitable for reducing purposes. As it is possible to only use one reducing piece, or, as shown in the drawing, several such pieces telescoped one into the other, the reducing pieces can serve as air-tight filtering funnels of any desired size.

If a filter plate 6 orrespectively is inserted, not only into the outer but also into the irmer reducing piece, the reducing pieces can also serve as multi-filters, i. e. as double or triple filters. The charging tunnel 3 remains nevertheless insertable. In this case the filter plates are placed on the bottom edge of the outer and of the inner reducing piece. The liquid poured into the charging funnel 3 and drawn down by the vacuum into the bottle 1, therefore, passes successively through the filter plates 1 and 6.

The filter plates are made in known manner of glass, porcelain or the like.

I claim:

1. In combination with a container and a tubular member; a device for interconnecting said container and said tubular member, said device comprising at least one hollow conical reducing piece consisting of glass, said reducing piece reducing the cross-section of said container and having surfaces establishing an airtight connection between said container and said tubular member, and a loose filter plate removably mounted within said reducing piece to provide a filtering funnel.

2. In combination with a container and a tubular member; a device for interconnecting said container and said tubular member, said device comprising a plurality of frusto-conical hollow reducing pieces consisting of glass, each of said frustro-conical reducing pieces having an exterior ground surface and an interior ground surface, said surfaces being concentric and extending over substantially the same portion of the length of the pieces, said reducing pieces telescoping with each other, the exterior surface and the interior surface of each reducing piece being adapted to establish an airtight connection with an adjacent surface, the outer reducing piece engaging said container and the inner reducing piece engaging said tubular member, whereby the cross-section of said container is reduced by the reducing pieces, a loose filter. plate removably mounted within the outer reducing piece and a loose filter plate removably mounted within the inner reducing piece, whereby the telescoping reducing pieces serve as multi-filtering funnels.

3. A liquid container, a hollow member, a hollow conical reducing piece consisting of glass and situated between said container and said member to reduce the cross-section of said container, said reducing piece having a bottom edge; and a loose removable conical filter plate situated within said reducing piece and adjacent said bottom edge.

WILHELM JUFFA.

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