US 3384100 A
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Description (OCR text may contain errors)
May 21, 1968 w, oss ET AL 3,384,100
WASHING CONTAINERS Filed June 2, 1966 1 WILLIAM 3'. Pass ALEXANDER EBoL-roN B m Mf we orneys United States Patent 3,384,100 WASHING CONTAINERS William J. Ross and Alexander R. Bolton, Edinburgh, Scotland, assignors to Ross Scientific Company Limited Filed June 2, 1966, Ser. No. 554,737 7 Claims. (Cl. 134-166) This invention relates to apparatus for use in washing the interior of containers, especially small containers such as cells or cuvettes for spectrophotometers, hereinafter referred to as apparatus for the purpose aforesaid.
According to the present invention we provide apparatus for the purpose aforesaid comprising a main tube having an upper end and a lower end, a branch tube extending externally from the main tube to a reservoir for washing liquid, an upwardly directed jet tube within the main tube connected at its lower end to the branch tube, and a passage between the jet tube and main tube, the arrangement being such that, when the lower end of the main tube is connected to a source of vacuum, and the reservoir contains liquid, and the upper end of the main tube is closed by the mouth of a container, the liquid is ejected as a spray from the jet tube into engagement with the interior walls of the container, and thereafter flows down through said passage.
Preferably, the upper end of the main tube opens into the bottom of a cup, and a resilient washer is provided on the base of the cup for receiving the mouth of the container.
An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing which shows a part-sectional side elevation of one embodiment of apparatus for the purpose aforesaid according to the present invention.
Referring to the drawing, apparatus for the purpose aforesaid consists generally of a main upright tube 1, a branch tube 2 extending externally from the main tube 1 to a reservoir 3 with which it is integral, an upwardly directed jet tube 4 within the tube 1 and connected at its lower end to the branch tube 2, and a passage 5 between the jet tube 4 and the tube 1.
The upper end of the tube 1 opens into the flat bottom of the cup 6 which is integral with the tube 1, and a resilient washer 7 made of rubber or synthetic resinous material rests on the bottom of the cup 6. The jet tube 4 is substantially co-axial with the tube 1 and projects a short distance about the bottom of the cup 6 and into the central hole 7a of the washer 7, and its upper end lies slightly above the level of the top of the reservoir 3 and centrally spaced from the peripheral Wall of the hole 7a.
In use, the tube 1 is connected at its lower end by a stopper 8 to the mouth of a flask 9. The flask 9 has a nozzle 10 which is connected to a vacuum pump, not
shown. A quantity of washing liquid, Which may be water, acetone or any other suitable liquid, is placed in the reservoir 3, and the container to be Washed is placed with its mouth on the Washer 7 surrounding the hole 7a, so as to close the upper end of the tube 1. In the drawing, the container is shown as a cell 11 for a spectrophotometer.
When the vacuum pump is started, the flask 9 and the tube 1 and the cell 11 are evacuated, and the vacuum pressure, and the dimensions of the bore of the jet tube 4 are such that the liquid from the reservoir 3 is ejected from the jet tube 4 in the form of a fine spray which sprays interior faces of the top and side walls of the cell 11 and washes same. The liquid runs down the walls of the cell 11, through the hole 7a and is collected in the flask 9. When all the liquid from the reservoir 3 has been ejected from the jet tube 4, air is then ejected and "Ice dries the interior of the cell. The cell is then removed, a fresh supply of liquid is placed in the reservoir 3, and another cell to be Washed is placed on the washer 7.
It is explained that cells for spectrophotometers are of elongated box shape and of rectangular or square cross-sectional area and are small. In one example of such a cell, the cell is 4 /2 crns. long and 1 cm. square, but the cell may be of even smaller width. The cells have two opposed transparent side walls, and the other s de walls and the base are translucent. In use, each cell contains a liquid to be analysed by the spectrophotometer, and, after use, the cell is emptied, and the cell has to be washed clear of any liquid still adhering to the wall thereof. Due to the elongated and narrow shape of the cells, through washing and drying of the interior is difficult and the cells are easily damaged, and it is important that the cells do not become damaged, for optical reasons and due to their relatively high cost of replacement. In this connection, it may be mentioned that if a stream or jet of liquid is used, as distinct from a spray, the interior face of the transparent walls of a cell can be damaged by any small particles which may be present in the washing liquid.
In the above described embodiment of the invention, the cells are washed by a fine spray and can be dried by the same apparatus, handling of each cell is reduced to minimum, the cell only requires to be placed on and be lifted oif the Washer 7, and the fiow through the jet tube 4 stops immediately the cell is removed. Cells can then be washed thoroughly, quickly and easily with no danger of damage by the washing liquid.
Modifications may be made without departing from the scope of the invention as claimed in the appended claims. For example, in a larger size apparatus, there may be two or more jet tubes all connected to the one branch or each connected to one of a corresponding plurality of branch pipes. In this case, the upper ends of the jet tubes are spaced apart and open into spaced holes n the washer so that a plurality of cells can be' washed simultaneously with each one closing a hole in the washer. Alternatively, the upper end of the jet tube 4 may have a plurality of upwardly directed branch jet tubes.
In another modification, a plurality of main tubes 1 may be connected to the one evacuating receptacle.
The vacuum pump above mentioned may be replaced by a device consisting of a water tube which is connected at one end to a water tap and has a branch tube connected to the nozzle 10, so that when water under pressure flows through the water tube, the flask is evacuated through the branch pipe of the water tube.
Two or more apparatus may be used successively for washing a cell, in which case acetone or other liquid is used in one apparatus and water in another.
When the apparatus has a plurality of jet tubes and only one evacuating flask or other chamber, provision is made for maintaining the vacuum when there are .insufiicient cells to close all the holes in the washer. This may be efiective by using a washer with the required number of blind holes for the jets not in use instead of or on tOp of the existing washer or by otherwise closing the jets or the holes not required in the washer at the time.
While the invention has been described with reference to the washing of cells for spectrophotometers, it may be applied to the washing of other containers, specially small containers.
In the drawing, the numeral 12 indicates a stay between the reservoir 3 and the cup 6.
The cup 6 may be replaced by a flat peripheral flange on the top of the main tube 1, but the cup 6 is preferred as it facilitates location of the washer, and helps to protect the upper end of the jet tube from damage.
1. Apparatus for washing the interior of containers comprising a main tube having an upper end and a lower end, a branch tube extending externally from the main tube to a reservoir for Washing liquid, an upwardly directed jet tube within the main tube connected at its lower end to the branch tube, and a passage between the jet tube and main tube, the arrangement being such that, when the lower end of the main tube is connected to a source of vacuum, and the reservoir contains liquid, and the upper end of the main tube is closed by the mouth of the container, the liquid is ejected as a spray from the jet tube into engagement with the interior walls of the container, and thereafter flows down through said passage.
2. Apparatus as claimed in claim 1, in which the upper end of the main tube is closed by a resilient washer hav ing a hole, and the upper end of the jet tube projects in said hole, and there is a passage between the jet tube and the peripheral wall of said hole.
3. Apparatus as claimed in claim 2, in which the upper end of the main tube opens into a cup on the base of which the washer rests.
4. Apparatus as claimed in claim 3, in which the cup is integral with the main tube and has a flat bottom.
5. Apparatus as claimed in claim 1, in which the branch tube is integral with the reservoir.
6. Apparatus as claimed in claim 1 in which the lower end of the main tube is connected to a source of vacuum.
7. Apparatus as claimed in claim 6 in which the lower end of the main tube is connected by a stopper to the mouth of a flask, the flask having a nozzle connected to a vacuum pump or other means for evacuating the flask.
References Cited UNITED STATES PATENTS 2,745,418 5/1956 Balcom et al. 134-166 XR FOREIGN PATENTS 57,664 7/ 1891 Germany.
CHARLES A. WILLMUTH, Primary Examiner.
ROBERT L. BLEUTGE, Examiner.