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Publication numberUS1791829 A
Publication typeGrant
Publication dateFeb 10, 1931
Filing dateApr 6, 1928
Priority dateApr 6, 1928
Publication numberUS 1791829 A, US 1791829A, US-A-1791829, US1791829 A, US1791829A
InventorsRobert F Mccrackan
Original AssigneeRobert F Mccrackan
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Sanitary attachment for pipettes
US 1791829 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

Feb. l0, 1931. -RL F. MccRAcKAN v SANITARY` ATTACHMENT FOR PIPETTES Filed April 6. 1928 2 Sheets-Sheet l y In ventor eM @6km/rw;

Feb. l0, 1931. R. F. MccRAcKAN SANITARY ATTACHMENT FOR PIPETTES 2 Sheets-Sheet 2 Filed April 6. 1928 VPatented Feb. Y10, 1331 ROBERT r. lvmolteorinIv,4 or RICHMOND, VIRGINIA siiivlrrluzm ATTAGHMENT FOR rIIrE'r'IEs 1 applicati@ medi Abril e, 192s. serial no. 267,998.A

lThis invention-relates to a new applianceto v:be used in assoclation'with a liquid'm'eastiring-pipette, and itfhasV more particular reference to la structureof this class which is f 5 in the ormot a sanitaryattachmentvfor a conventionalform of pipette'. f Y

My principali-aim is to generally improve upon structures of this class, by providing one whichis characterized by exceptional simplicity, and inexpensiveness, and which is such in construction as to better ulll the requirements of a deviceof thisclass.

The invention is carried into efect in the .first application, through the medium of two different embodiments, each of which includes the commonfeature of an individual sanitary mouth-piece removably heldin op- -erative position.

Also, from a generic standpoint, these 720 forms vof the invention, each embody an open-top cup carrying yan integral irreguf rlarly shaped stem and means for quick separable connection with the conventional measuring pipette.

The other more specific features of construction willbecome more readily apparent from the ollowingdescription and drawings.

In the drawings Figure 1 is a side elevational view of one embodiment of the invention', showing it attached to the pipette.

Fig. 2 is a sectional view detailing the Vparts and their relative association more emphatically. Y 1

Fig. 8 is a perspective view of the individual removable mouth-piece. Y v Fig. 4 is a View like Fig. 1, showing a diiierent embodiment of the invention.

Fig. 5 isv a sectional view through the' principal part of this embodiment.

Fig. 6 is a fragmentary sectional `and elevational view showing the method of use.

Attention is first invited tofFigs. 1 -to 3 inclusive, wherein it will be observed that the pipette is generally designated by the ref-k erence character" 7. This comprises an elongated container 8 having customary restricted discharge end 9, and a reduced tube 10 'at the top.

The principal of the attachment isV n y generally designatedby the? numeral ll'fand this includes a glassibody havinganopen top cup 12 equipped with atapered bottoni 13, and a vacuum release pipe 14.1 .'Ihelup-A 55 per endoffthis' pipe extendsV intothe cup" f and terminates belowthetop ofthe cup and above the `Vpoints shown. The 'lower-end.;A .Y

portion l'15 `is'- tapered, and adapted to receive a'rubber` V'sleeve-like.v coupling 16, whichas 60 shown in Fig. `2, is"connected with thetube 10 ofthe pipett Extending from one side of the cup` adja-. cent the upper end of the pipe 14 is a hollow ward fbend 18-V forming a suspension hook, by means of whichthe attachment may be s ispended: from Vthe supporting nail or'the 1 e. i;

Connected'with the endJ portion. 19 .of them? stem is a VAcoupling 20 into the'opposite end.' of which the mouthpiece 21V lits.k It 'willv benoted .from-"Fig 3 thatv the mouth piecel has a tapered end'22 which-merely telescopes: into the'coupling20. j 'lhis is important in 7,5* that it -is desirable in a structure of this classA tovprovide individual sanitary mouth pieces, thus rendering .the invention more'des'irable for use by diflerent'rpersons.'v

It has of course been noted that l' Attention Yis now invited' to' `Figs.fl4 to"V 6 inclusive.V Here ythe pipette is designated bythe numeral 23, andV as is usual, itin-r 'cludes a reduced suction .tube 2,1, on its rtop 85 28, with which the coupling29 is connected, 901 the coupling to receive the aforesaidmouth Vpipe 21. .y Y

YInpthis form ofthe invention, @a taperedstopper 30 is provided, this having a central yopening thru which the tube 24' extends. 951A This stopper is locatedin the truncated bot'- tom portion 27' of the cup, as Yshown inthe assembled view in Fig. .4. Y,Attention is invited to vthe factthat'the .open bottom of the cup is of a Ydiameter to f 100 A thepipe :V 14 is formed integral with the cup 12.

permit the pipette 23 to be inserted downwardly therethrough. Thus, the cork ork rubber stopper 30, may be assembled on the,

tube 24, and the pipette inserted downwardly through the ciip to bring the stopper into place. Theil the pipette is adjusted so that the extending portion oi` the tube 24 Yis located, ,in downwardly spaced relation t the upper edge of the cup. Y In some instances, it is desirable indeed to have the upper end of the tube 24 beveled as indicated at 3l in Fig. G in order to pei'- niit the end ot the finger to be conven'ientlj7 placed thereover in operating 'tliedeviceu In operation, it is obvious that the user must place the lower end of the pipette in the liquid to be drawn after which the hand is placed over top of the cup. Then byplacing'the mouth on themoutliepiece and drawing.' in an obvious mannensuieient suction is produced to `draw the` liquid into the pipette to the desired elevation. Infact theV .liquid is always drawn to a point above the desired graduation. Then the f hand is slipped ott thecup in at manner ltol .permit the finger to be placed over theiipper. ond of the tube 24 in Fi gs. 4 to 6, or the part'll in Figs.` 1 to 3g Then by gently liftingthe linger, some of the liquid in the pipette can be allowed to drop out to bring the liquidv down to the desired level vor graduation, to' insure proper measure. Y Y

\ With this arrangement,it is -obvious that Vthe suction cupis not intended as `an overl flow, but as, ai convenient means for drawing Y the liquid into thepipette, andlthen releas-y ing it gradually by the linger asexplained. The cup is very small, andprovides a novel means of attachment for the'sanitary mouth piece. The entire structure'is comparatively inexpensive, yet highly eiiioient in use and operation. Y v he structure is dependable, compact and y convenient, and otherwise advantageous 'for 45 1 use in the 'capacity stated.

The simplicity of the invention is such' as, to permit a clear understanding of the lsame to be hadfafter considering the description in connection with the drawings. VTherefore, a more; lengthy description is regarded iinnecessary. Y

Minor `changes in shape, size, andinate-v rials, and arrangement of parts, coming within the vfield ofinvention claimed may,-

be resorted to if desired;

I-Iaving thus described my invention, what I claim as new is v 1. In combination a pipette including a graduated container, a cup opened at `its top,a suction tube in (longitudinal alinement with said container and having one end thereof interiorly of lsaid cup tov facilitate the placingof the finger over the last. mentioned end of said suction tube to hold` or stem. y f

discharge the liquid contents of said' graduated container.

2. Ina device of thecharacter described,

and in combination, a pipette including a` graduated container terminating `at one end into la suction tube, a cup opened at its top andhaving a truncated conical bottom porf tion,"l a ,tapered stopper fitted into the truntube to hold or discharge the liquid contents o said graduated container, said cup being formed on one side tliereof'with a hollow In testimony whereot` I affix signature.:



Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2692503 *Jul 9, 1952Oct 26, 1954Owens Illinois Glass CoPipette
US2737812 *Jun 23, 1952Mar 13, 1956Paul O K HaakPipette
US2994349 *Oct 29, 1957Aug 1, 1961Peter T DemosPipette control device
US3734358 *Jul 27, 1971May 22, 1973Gen ElectricMeans for applying suction having automatic cutoff of displacement volume
US3938392 *Sep 20, 1973Feb 17, 1976Rodrigues Associates, Inc.Pipette
US5218875 *Jan 13, 1992Jun 15, 1993Volpe Stephen JCombination glass/plastic pipet tip assembly
U.S. Classification73/864.3, 222/420, 222/158, 422/922, 73/427
International ClassificationB01L3/02
Cooperative ClassificationB01L3/0213, B01L3/021
European ClassificationB01L3/02C1, B01L3/02C