US2598869A - Pressure operated pipette filler - Google Patents

Description

June 1952 -J. A. WHITE 2,598,869

PRESSURE OPERATED PIPETTE FILLER Filed May 5, 1949 INVENTOR. "Jana-s 19. h fl/ r:

19 TTOH/YEYS fatented june 3, 1 .952"

UNITED STATES PATENT 2,598,869 PRESSURE OPERATED "PIPETTE FILLER;

James Adelb'ert White, Seattle, Wasln Application May 3, 1949;, SerialNo. 31,183

1 Claim. 1

'This'invention relates to laboratoryapparatus. and more particularly to a device for filling pipettes by gas pressure, so that it is not .necessary to use the mouth for this purpose or to attach a suction device to each pipette.

It is among the objects of the invention'tov provide a pipette-filling device into which conventional pipettes can be quickly and easily inserted for filling and from which'they may be readily withdrawn when filled, which utilizes a low, manually-controlled gaspressure which may be supplied from either a hand-operated or powerdriven pump or compressor, which receives standard or conventional pipettes of various sizes and. accurately fllls such pipettes without'wasteof reagent, 'Which'is readily portable and requires an insignificant amount of laboratory space. and which is simple and durable'in construction, economical to manufacture, easy to use, and arranged for quick and easy replacement of the only parts subject to wear.

Other objects andladvantageswill become apparent from'a consideration of thefollowingdescriptionand the appended claim in conjunction with the accompanying drawing,'whereinz Figure 1.is a top vplan view of alpipette-filling device illustrative of theinvention;

Figure .2 is a longitudinal cross-section on the line 2-"2 oiFigure 1;

Figure 3 is a plan view of a sealing gasket constituting-an 'operative'component of the device;

Figure 4 is a transverse cross-section on an enlarged scale on the line 4-4 of Figure 2;

Figure 5 is a longitudinal crossesection on anenlarged scale of a fragmentary portion of the device and is taken on the line 55 of Figure 2.

With continued referenceto the drawingthe deviceincludesin general, a container H), acD tainer coverll, a sealing gasket 12 detachably secured to the cover I I, -a 'gas conduit 1.3 connected'at'one end to the cover, and a suitabl gas pumppr compressor H connected 11304 16 opposite end of'the conduit.

The container I0 is preferably formed. of a material which is substantially chemically inert, such as. glass, and is provided with an .open end surrounded by a cylindrical neck ['5 and provided with an annular bead l6 and external screw-threads I! between the bead and the open end of the container.

The cover H comprises a cylindrical center portion IB marginally provided with an internally-screw-threaded, annular flange l9, which flange is threadable upon the screw-threads l1 zeal-1 12) of the container neck, the annular'bead [:5 providing'a'stop shoulder for the edgeofthisflange, Within the flange 19 the cover provided with anannularrecess or groove 20 which receives the end of theneck 15 of the containerand a'gaslget 2| is mounted in this groove and bears upon the end of the container neck toprovide aggastight seal between the cover and the container; An aperture 22 is provided through the center po tion of't c r. nd this pr lle 9 h size to loos ly receive s an ard qr chh htiehel pip ttes. su h a ep phtt iil 9 QifiQ 12 An l -scre h aded 'cyl hdr celib s fl surrounds the aperture .22 and projects iron; h ner sid f t e c e nwa dly eithe; miner hen the o e 'iseperatlv ly as embled t n a r. a i lustrated l ieu elh at its nd opp site the ss 24. th .aherthre' here 22 is O C lHY O J lEQ SQ K, asih lqat h 1th t r ide a do nwa d y and inw rdlyap "he un gu de th end of t e. nineties l ltg i h aperture 22.

e al ng ask t '12 is fiat circ la disc 9.1 suitab resilient mate ial, such na ural .or syn h t c rh benhavi e ahoutsid slleihetersutst n ally equa to the outside sllemeteref'lhe boss .24 and having entral o en n pfl diameter slight less than t diamete .o the smallest p pette o b ihseresl i o the tentainer so that the gaske wil 5: sely surrellhd t pipett s and pro ide a gas between the pipe tes and the cover he p pettes are inse ted th hheh t e gasket in h the con er-- in ernally-scr w*thmadek lan huh... r aded .onto the bos 2.4 in pos tioh such tha i s'fianee'me eine ly ove lies t e sealin aske [2 tor ta' n the seal ng ga ketinnosi o bath end Qf' e'b SS- P fe a l a asher- .8 i in erpose be weeh he s in ask t and thafihh of the mitzl sp that the gasketillem e hi torted whe the nuti th eaded tl htlyh te he boss.

..A gas in e c anne 31 i ro ided-11h the @11- r lpor icn l o t ceve M al tio aces from the abu e .24 and a ubula f itting '3! heel-- mu i at Witht is h nhe -hndlpr-oietsradially from theicentral por o h t e bass ataloc liqi spaced from the adjacent side of the flange l9.

The gas conduit l3 may comprise a piece of conventional rubber tubing fitted at one end upon the fitting 3| and having a hole 32 therein which may be covered by the thumb to increase the air or gas pressure in the container and uncovered to release such pressure from the container.

The pump M, as illustrated, i a hand bulb of a valve ball 39 in the housing cooperating with the tubular portion of the housing in a manner to permit free entry of air into the bulb while precluding passage of air out of the bulb at this outer end of the latter.

A check valve 40 is disposed inthe tubular sleeve 33 and may be also of conventional construction, including a centrally-apertured plug 41' threaded into an internally-screwthreaded portion 42 of the sleeve, a perforated ball cage 43 secured to the plug 4| at the side thereof remote from the valve 36 and overlying the central aper ture 44 in the plug, and a valve ball 45 retained in the cage 43, which ball cooperates with a valve seat provided in the plug 4| surrounding the central aperture 44 to permit passage of gas or air from the bulb into the conduit l3 while precluding return of air from the conduit into the bulb. In operation, after a pipette 23 has been inserted into the container through the resilient sealing gasket [2 to a position such that the lower end of the pipette is below the surface of liquid reagent in the container, the bulb I4 is grasped in the hand and the thumb of the same hand placed over the hole 32, in the conduit l3. The bulb is then squeezed to force air through the channel 30 into the container above the liquid reagent contained therein. The bulb may be squeezed and released as many times as necessary to build up in the container suificient air or gas pressure to force the liquid reagent upwardly in the pipette to a position at or slightly above the desired graduate indication on the pipette. The forefinger of the other hand is then placed over the top end of the pipette to stopper such pipette end and the thumb is removed from the hole 32, whereupon the air in the container escapes, reducing the air pressure in the container to atmospheric pressure. The finger on the top end of'the pipette may then be slightly moved to restrictively admit air into the upper end of the pipette until the level of the liquid in the pipette falls to the exact level of the desired'graduation, whereupon, the upper end of the pipette is again securely closed by the finger and the pipette removed from the filling device and carried to the receptacle intowhich its contents are to be placed. When the bottom end of the pipette is over such receptacle, removal of the finger from the upper end of the pipette will permit the liquid content of the pipette to fiow into the receptacle in the well known manner.

The container 10, the cover II, the nut 21 and the sealing gasket [2 should all be made of a material substantially innate to the particular reagent being used, and it is desirable that these components be made of material innate to as 4 large a class of reagents as possible, so that the same pipette-filling device can be used with a large number of different reagents.

While a hand-operated bulb has been illustrated for the purpose of building up the necessary air or gas pressure in the container to fill the pipettes, it is to be understood that the conduit 13 may be connected to a suitable powerdriven pump or compressor supplying air or gas at low pressure, if desired. The pressure in the container will still be controlled by stoppering the hole 32 in the conduit by the thumb or finger in the manner indicated above.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claim rather than by the foregoing description, and all changes which come within thev meaning and range of equivalency of the claim are, therefore, intended to be embraced therein.

I claim:

A pipette-receiving device comprising an openended container, a cover detachably secured to said container in covering relationship to the open end of the latter, a sealing gasket, means detachably securing said sealing gasket to said cover, and a tubular gas conduit connected to said cover, said cover comprising a substantially cylindrical center portion having a pipette-receiving bore countersunk at one end for guiding pipettes into said bore, and a gas channel therein, an internally-screw-threaded annular flange surrounding said center portion for attaching said cover to said container, an internally-screwthreaded boss surrounding said bore at the end of the latter opposite said countersunk end, and a tubular conduit fitting extending outwardly from said center portion and communicating with said gas channel, said sealing gasket comprising a'thin disc of resilient material having therein a pipette-receiving opening registering with the bore in said cover, and said means detachably securing said sealing gasket to said cover comprising a flange nut threaded onto said cover boss and marginally engaging said sealing gasket to clamp said gasket against the outer end of said boss.

JAMES ADELBERT WHITE.

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

UNITED STATES PATENTS Number Name Date 398,528 Molin Feb. 26, 1889 581,491 Richardson Apr. 27, 1897 641,079 Clayton et al Jan. 9-, 1900 816,345 Lockwood Mar. 27, 1906 1,009,980 Leisure et al. Nov, 28, 1911 1,953,102 Brown Apr. 3, 1934 FOREIGN PATENTS Number Country Date 317,702 France Sept. 23, 1902

Images