US2418751A

US2418751A - Pipette washer

Info

Publication number: US2418751A
Application number: US533872A
Authority: US
Inventors: John H Brewer
Original assignee: Hynson Westcott and Dunning Inc
Current assignee: Hynson Westcott and Dunning Inc
Priority date: 1944-05-03
Filing date: 1944-05-03
Publication date: 1947-04-08
Anticipated expiration: 1964-04-08

Description

J. H. BREWER PIPETTE WASHER April 8, 1947.

Filed May 5, 1.944

Patented Apr. 8, 1947 UNITED STATES PATENT OFFICE PIPETTE WASHER corporation of Maryland Application May 3, 1944, Serial No. 533,872

2 Claims. (01. 137-20) This invention relates to an apparatus for washing pipettes and similar devices of tubular shape.

It has been customary heretofore to employ relatively complicated and expensive apparatus for Washing pipettes.

An object of the present invention is to provide a pipette washer which is inexpensive and of such a simple construction that it can be made by a skilled chemical laboratory technician, and simple and efficient in operation.

A further object of my'invention is to provide a pipette washer comprising a siphon device adapted to be applied to or withdrawn from a standard container or vessel for the pipettes to be washed without any permanent or temporary attachment to the container or associated interchangeably with a purality of such containers.

My invention consists of a vessel adapted to contain the pipettes or other articles to be washed and a siphon device adapted to be attached to a supply of the washing liquid which will peri-' odically fill and empty the container and thus in time repeatedly fill and empty the pipettes and thereby wash them.

The invention is illustrated in the accompany ing drawings in which:

Fig. 1 is a front elevation, partly in section. of the apparatus;

Fig. 2 is a fragmentary elevation with parts shown in section illustrating a modification of the apparatus in which the siphon tube is flattened where it passes over the edge of the container;

Fig. 3 is a fragmentary elevation with parts in section showing the obstruction of the filling tube by pinching it and;

Fig. 4 is a fragmentary elevation partly in section showing the obstruction of the filling tube by introducing an obstruction.

Referring to the drawing, l is the container which may be an ordinary graduate such as generally is available in laboratories and other places where pipettes are to be washed. In the specific embodiment illustrated in Fig 1, the container l is a 1000 cc. graduate but it will be understood that any other suitable vessel of sufficient depth to submerge the pipettes and hold them in substantially vertical position may be used. One might, for instance, use a tank of relatively large cross section with means such as a rack therein for holding the pipettes in vertical position, but it will be appreciated that in order to save washing liquid it is preferable to use a container which is only large enough to hold the number of pipettes to be washed. 2,2 are the pipettes to be washed. The siphon device consists of the filling tube 3 adapted to extend substantially to the bottom of the container I, connected to the rubber hose 4 adapted to be attached to a water faucet or other source of washing liquid and the siphon tube 5 connected to the filling tube 3 through the opening 6.

The siphon tube 5 bends up over the edge of the container 1 and then downwardly preferably to or below the level of the bottom of the container I. In the embodiment illustrated tubes 3 and 5 are made of copper but may be made of any other suitable material such as glass or synthetic resin or plastic. The bend l of tube 5 is adapted simply to rest on the edge of container 1 and may therefore be applied interchangeably to other containers of substantially equal depth.

In operation, the

pipettes

2, 2 to be washed are placed in the container l, tube 3 is inserted so that the bend l of tube 5 rests on the edge of the container, rubber hose 4 is connected to a water faucet and the water turned on at a rate of fiow which is less than (preferably about half) that at which the siphon is capable of emptying the container. The water from the faucet fiows through hose 4 and tube 3 and gradually fills the container I and

pipettes

2, 2 which do not, of course, make a liquid tight seal with the bottom of the container I. If it were found that the pipettes did make a liquid tight seal with the bottom of the container, this difliculty could be met by e. g. dropping a disc of wire gauze into the bottom of the container 1 to provide a grill for supporting the pipettes so that the wash water would fiow into and out of them freely.

When the liquid level in container l nears the top edge thereof, the liquid level in that portion of tube 5 within the container I will, of course, rise by gravity to the same level and the slight pressure in the tube 3 created by the fiow .of water from the faucet is sufficient to force the water through the bend 1 thereof and start the operation of the siphon. The siphon then functions to withdraw water from the container through tubes 3 and 5 and since the flow of water through the siphon is greater than the flow through hose 4, the container will be emptied. At this point the water column in the siphon breaks and the fiow through the siphon stops and the container l is then refilled by thecontinuing flow of water from the source, this cycle being repeated continuously so that in the course of a few hours, say over night, the pipettes will be filled and emptied a number of times.

In order to facilitate the priming of the oper- 3 ation of the siphon it is desirable to flatten the tube 5 at the bend as shown at I in Fig. 2 to reduce as much as possible the height that the washing liquid must be raised in the tube 5 above the level of the liquid in the container l. Another expedient which favors priming of the siphon is to restrict the flow of water through the tube 3 as compared with the flow from tube 3 through the opening 6 into tube 5. This may be done by pinching a restriction 8 in the tube 3 as shown in Fig. 3 or by introducing an obstruction 9 into the tube 3 below the opening 6 as shown in Fig. 4 so that as the water flows from the faucet through hose 4 and tube 3 into the container, a slight back pressure through opening 6 into tube 5 will be created sufficient to cause it to overflow the point I when the level of the liquid in the container l approaches the upper edge thereof.

As will be apparent, the siphon device 3-4"'5-6-'-7 may be applied to and Withdrawn from the container I without handlinr "be clean pipettes. The container i may be lvdded with soiled pipettes and the siphon device then applied to wash the pipettes and then withdrawn leaving the clean pipettes in the container until they are needed. The siphon may then be returned to the same container to wash another batch of dirty pipettes or it may be transferred to another container or to a plurality of containers in sequence loaded with pipettes to be washed. Thus it becomes unnecessary to provide a plurality of pipette washers or to remove clean pipettes from the washer and store them elsewhere under sterile conditions While another batch of dirty pipettes is being washed. In effect my invention makes a pipette washer and clean pipette storage container of every one of tljie available containers in a laboratory.

I. A washer comprising a siphon device having a. main tube adapted to be connected at one end to a source of washing liquid and to be positioned with its other end extending downwardly into a container and a branch tube connected to said main tube intermediate the ends thereof, said branch tube being adapted to extend over the edge of the container and downwardly outside the container when said main tube is positioned within said container, the opening through the main tube being restricted at a point between its connection to the branch tube and said other end thereof to a size which is smaller than the passageway through said branch tube including its connection to said main tube.

2. The combination with a vessel having a free upper edge and a source of supply of liquid, of a siphon device consisting of a main tube extend ing downwardly into said vessel and upwardly above the lowermost point of said edge and attached to said source of liquid, an opening in the side wall of said main tube below the level of the lowermost point of said edge and a second tube having an end connected to said opening and a portion extending upwardly over the lowermost point of said edge and substantially in contact therewith and another portion extending downwardly outside of said vessel, said source of liquid being adjustable to a rate suificient to elevate the liquid in said second tube over the lowermost point of said edge to initiate syphonic action.

JOHN H. BREWER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,319,531 Brown et a1. May 18, 19% 1,088,973 Drinkhouse Mar. 3, 1914 1,731,899 Huntworth Oct. 15, 1929 2,345,284 Myers et a1 Mar. 28, 1944