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Publication numberUS1474812 A
Publication typeGrant
Publication dateNov 20, 1923
Filing dateJan 2, 1923
Priority dateJan 2, 1923
Publication numberUS 1474812 A, US 1474812A, US-A-1474812, US1474812 A, US1474812A
InventorsEugene D Brooker
Original AssigneeEugene D Brooker
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Haemocytometer and method of making the same
US 1474812 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Nov. 20 1923. 1,474,812 E. D. BROOKER HAEMOCYTOMETER AND METHOD OF MAKING THE SAME Filed Jan. 192s avwewtoz 9. mm.-

Patented Nov. 20, 1923.




, Application filed January 2, 1923. Serial No. 610,219.

To all whom it may concern:

Be it known that I, EUGENE D. BROOKER, a citizen of the United States, and a resident of the city, county, and State of New York, have invented certain new and useful Improvements in Haemocytometers and Methods of Making the Same, of which the following is a specification.

My invention relates to haemocytometers or instruments used for making corpuscle counts. of the blood, for making bacteria counts, and for similar purposes. Heretofore, these instruments have usually been made of glass and comprised a base, a cenl6 tral table and side tables at each side thereof, the side tables rising one tenth milli meter above the plane of the center table so that when the slide is placed on the tables there will be a space between the under sur- 80 face of the slide and the top surface of the central table of one tenth millimeter in depth to form the counting chamber. Cross lines are generally placed on the center table within which the number of corpuscles 26 or bacteria are counted under a microscope.

There are gutters formed between the several tables and sometimes across the central table, in which any excess fluid under test may run ofi without reaching the top sur- 30 faces of the side tables. Heretofore, these, instrumentshave been made in two general ways. One has been to make the base and the tables separately and to then cement the tables in place on the base with Canada hal- 86 sam. The objection to this method has been that the liquids used for cleaning the instruments often dissolved the balsam and loosened the tables, or sometimes a knock or jar loosened the tables, either detaching them entirely or loosening them enough to destroy the accuracy of the instrument. The other method has been to mill out a solid block of glass to form the tables and gutters; and the objection to this method is that of expense although the instrument is otherwise superior to those made under the first method.

The object of my invention is to provide a haemocytometer having the permanency or ruggedness of those made under the last described method but which may be produced at a much lower cost, in fact at a cost nearly as low as those made under the cementing process. My invention theretore relates to the method of making these instruments and to the product produced un-' der this method.

In the drawing forming part of this application,

Figure l is a sectional view of a haemocytometer embodying my invention in one of its forms,

Figures 2 and 3 are similar views showingl my invention in other forms, and

igure 4 is a plan view of all the several forms.

In the practice of the method of making my improved haemocytometer I provide a base which is suitably ground off on its faces, and which base is preferably of harder glass than that of which the tables are made: and on this base one or more of the tables are attached permanently by fusing the table to the base. If the table ismade of softer glass than thebase and these are subjected to fusing heat the table will soften quicker than the base and fusion will take place without distortion of the base. In one form of my invention I fuse a relatively thick table to the base and then grind 0 down the tables to the desired thickness because if a very thin table member were subjected to the fusing heat it would warp too much; whereas, if it is thick this will not occur; and the grinding down also removes 35 any irregularity in the table. In another form I employ relatively thick tables and seat them in channels in the base and then fuse them to the base. But in all cases I fuse some or all of the tables to the base. This makes the base and table practically one piece so that the use of acids or solvents will not loosen or separate the table and base, nor will shocks.

Referring first to the construction shown in Figure 1 where the instrument is shown on an enlarged scale, there is a base 1 of 7 glass consisting of a flat plate ground par allel on'its opposite surfaces 2, 3. On this base I have mounted three tables comprising a center table 4 on which a single or double counting scale or cross-line mark laterally apart asshown and parallel to, each other upon the base 1- and the base with these tables resting thereon are subjected to just suflicient heat to cause the tables and I p I I, I I I face of the center table 21. In this con- In this form of any invention thecenterf base to fuse and form an integral body, I

table 4,: after the base and side tables have been annealed, is placed upon the base and is I attached thereto bycement or Canada balsam. The center table is so placed as toleave gutters 1O, 11 between it. and the side tables for excess liquid under test to flow off from the counting chamber. The side tables 6, 7 arethenground down on their top surfaces and polished, removing the material indicate'dbythe dotted 'lines, 8, 9 until the top surfaces 12' of these tables are slightly above the plane of the top 13 of the central table 4. Then if an ordinary slip or slide (not shown) is placed upon the side tables 6, 7 there will be a slight space, generally one tenth millimeter, between the cen-' tertable surface .13, and the under surface of the.slide,forming the counting chamber to be occupied by theblood or other fluid under test. As the center table lies between the side. tables'6, 7 ,it is more or. less protected against displacement from a blow .7 by them. The construction is superlor to one in which all thetables are cemented to the basev although inferior in some respects to some ofthe other forms to be described.

In. Figure 2 I have'shown 'a device in which noneof the three tables'is cemented. In this construction I first. provide-a base 1 'which is somewhat thicker than the final base-is tobe and the base isthen ground or otherwise treated to remove the portions shown by'dotted line 14. This will leavethe final base with a central raised member,

15 integral therewith to constitute the central table. The side tables 16, 17 of greater thickness than is, ultimately required, are

placed upon the base in spaced, parallel relation, as shown, to form gutters 10, 11 between them and these side tables arethen fused to the base by being subjected to sufiicient heat to fuse theseparts together.

The portions of these; side tables represented in the dotted lines 18 are then ground off to reduce the tops of these tables to a plane slightly above the plane of the center table '15. I In the finished article the basc and all tables will be integraL In the construction shown in Figure 3 a relatively thick base 1 is milled or ground out to provide cross recesses 19, 20 sufiiciently'wide to form the gutters 10, 11 and sockets for the side tables. Thismilling or grinding leaves a center table 21 between the I shown in dotted lines 24 leaving the top surfaces'ju'st above the plane of the top surstruction all tables'be'come integraliwith the base. K V V r In Figure fl it will be seenthatjthe top appearance "of all forms may be the same and Ipreferto, run the several table's out to the full width of the base and then grind the edges 31, 32 of'the base and the ends of the several tables off even at one time. In all forms the center table'may have a single set of cross lines 5 or, in accordance with common practice the center table may have two sets of cross lines as indicated by dotted lines 33, 3a and the center table'may have the two gutters 35, 36, cut crosswise therethrough as indicated by dotted lines. In the'latter form, separate specimens maybe examined under each set. of crosslines and the gutters 35, 36 will prevent one 'specimen from flowing int the other across the center table, practice. I V v I Having described. my invention whatI claim is: v. I 1. The methodof making 'heemocytome- This v conforms present ters, which consists of providing a base,

placing thereon blocks or strips to form,

3 tables for the purpose set forth, and infusing said base and said table members together in an integral construction.

2. The method of making haemocytometers having a central table. andsidetables,

which consists in providing aIbase with a center table, in placing relatively thick; blocks, or strips on said base, in fuslng said base and said blocks together in an integral mass-and in then considerably reducing the height of said blocks by removing material from the tops thereof for the purpose set fOI'th. I;

3. A haemocytometer comprising a base and tables projecting above saidbase, said tables being'formed of separate blocks of material united with said base by fusing ghei basejand blocks together in an integral 0 y;

integral, center table proje'ctingabove the 4. A heemocytometer comprising a base. i I having portions thereof removed to leave an gar table and formed by blocks fused to said ase.

5. A heemocytometer comprising a base having spaced recesses formed therein to 5 leave an intermediate projection forming a center table, and side tables spaced from said center table and formed by blocks inserted in said recesses and each having a plurality of sides fused to the base at the side walls of said recesses.

Signed at the city, county and State of New York, this 22nd day of November 1922.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5569607 *Mar 22, 1995Oct 29, 1996Boehringer Mannheim GmbhSlide for the microscopic evaluation of liquid specimens
USRE35589 *Aug 29, 1995Aug 19, 1997Fisch; HarryBiological assembly
U.S. Classification356/39, 359/398, 356/246, 359/900
International ClassificationA61B5/145
Cooperative ClassificationY10S359/90, G01N33/49
European ClassificationG01N33/49