US3148146A - Centrifuge - Google Patents

Description

Set.8

P 1964 M. A. ASNES ETAL CENTRIFUGE 3 Sheets-Sheet 1 Filed Ma 25 1962 INVENT ATTonuEy p 8, 1964 M. A. ASNES ETAL 3,148,146

CENTRIFUGE Filed May 25, 1962 3 Sheets-Sheet 2 INVENTORS MARVIN A. ASNES (550/2015 GODA BY m 6. [M

ATTORNEY M. A. ASNES ETAL I NTRIF Filed May 25, 1962 VENTQ R ASNES v 01265 GODA BY v United States Patent 3,148,146 CENTRIFUGE Marvin A. Asnes and George Goda, New York, N.Y.,

assignors to Clay-Adams, 130., New York, N.Y., a corporation of New York Filed May 25, 1962, Ser. No. 197,685 9 Claims. (Cl. 233-11) This invention relates to a centrifuge and more particularly, concerns a device used in rnicrohematocrit determinations.

An object of this invention is to provide an improved centrifuge construction particularly adapted to centrifuge capillary tubes in making microhematocrit determinations, wherein the specimen contents of the tubes are maintained at optimum temperature conditions during the centrifuging operation.

As centrifuges operate at very high rates of speed and air currents incident to the operation of the device are used for ventilating and cooling purposes, it has been found that such devices operate with a relatively high noise level which is apparently due to the air currents.

Accordingly, another object of this invention is to provide an improved centrifuge construction which includes means effective to markedly reduce the noise level during operation, yet allowing optimum utilization of the incident air currents for ventilation and cooling.

Still another object of this invention is to provide in a device of the character described, improved capillary tube holder means which includes cover means which is conveniently in place at all times, thus avoiding the inadvertent operation of the device without the cover means; the cover means being quickly manipulated to allow removal or insertion of capillary tubes in the holder; or to move the same into its operative tube enclosing position when the centrifuge is ready for operation.

Yet another object of this invention is to provide an improved centrifuge for hematocrit determinations wherein the head thereof includes a tube holder and a direct reading scale which permits readings to be taken while the tubes are still on the head; the construction of the device being such as to facilitate the reading of the scale.

A further object of this invention is to provide a centrifuge having an improved cover construction which is tightly sealed in its closed, latched position and is retained in its closed position after unlatching for a time interval after the motor has been deenergized.

Still another object of this invention is to provide an improved centrifuge having a head for carrying calibrated microhematocrit tubes, together with percentage scales on the head to allow for direct readings of the centrifuged tubes, without removing the same from the head.

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

In the drawing,

FIG. 1 is a vertical sectional view of a centrifuge embodying the invention;

FIG. 2 is a top plan view thereof, with parts cut away;

FIG. 3 is a partial side elevational view thereof showing the magnifier means; and

FIG. 4 is a top plan view of a modified form of reader closure member incorporating magnifier means.

Referring in detail to the drawing, designates a centrifuge embodying the invention. The same comprises a casing, generally indicated at 11; a motor 12 mounted ICC therein for rotating a flat disc head 13 disposed in the upper open end of the casing; and a cover 14 hingedly connected to the rim of said casing and disposed over the head 13, when in its closed position.

Casing 11 comprises a lower portion 15 of truncated conical shape, the side wall 16 thereof terminating at its lower end in a recessed, peripheral edge 17 which is enclosed in a footing gasket 18. Casing portion 15 includes at its upper end a radial flange portion 19 lying in a plane slightly tilted relative to the horizontal. Ribs 20 extend radially from the inner surface of wall 16 at equiangular intervals. Side wall 16 is formed with a plurality of ventilating openings 21 at the lower skirt portion thereof.

Motor 12 is adjustably mounted on a bracket 22 which includes an angularly disposed arm 23 disposed in a horizontal position and secured to a circular mounting plate 24, as by welding or the like. Plate 24 is resiliently mounted in the lower end of casing portion 15 by grooved rubber mountings 25 which receive cut out peripheral edge portions of plate 24 in the grooves thereof. Mountings 25 are secured to the lower ends of ribs 20 by a screw and washer 26 threaded into bushings 27 fixed in said ribs.

As indicated in FIG. 1, bracket 22 is of an angular form so as to dispose motor 12 with its longitudinal axis slightly tilted with respect to the vertical, for the purpose hereinafter appearing. The upper end of motor 12 projects through the opening 28 defined by flange portion 19, with the side wall of the motor in spaced relation to the edge of flange portion 19 at said opening.

Casing 11 further includes a tilted bowl shaped upper portion 29 which comprises a circular side wall 30, and an angularly related bottom wall portion 31 having an inwardly extending radial flange 32 defining a peripheral edge 33 and which is secured to flange 19 of lower casing portion 15 by screws 33A. Peripheral edge 33 is coextensive with the flange edge at opening 28.

A pan 34 is mounted on upper casing portion 29, the same comprising a bottom wall 35 formed with a central opening 36 to pass the upwardly extending motor shaft 37. Pan 34 further comprises a circular side wall 38 and an inverted channel shaped rim 39 extending over and secured to the upper edge of wall 30.

The fiat disc head 13 carries on its upper face a molded plastic capillary tube holder 40, in which are disposed capillary tubes C which are to be centrifuged. Holder 40 comprises an open rectangular shaped frame member 41 having a central transverse flat wall portion 42 and cross rib portions 43, 43A adjacent the opposite ends thereof. Wall portion 42 is formed with parallel grooves 44 which open at the outer end edges thereof and terminate at the inner ends thereof slightly short of a centrally located through opening 45. Rib portions 43, 43A are formed with parallel grooves 46 which are respectively aligned with grooves 44; thus providing means for receiving the tubes C therein.

The outer end walls 47 of frame member 41 are provided with thin resilient gasket means 48 on the inner surfaces thereof for receiving the outer ends of tubes C in abutting relation thereto. Frame member 41 also comprises a circular hub portion 49 depending the underside thereof, the same extending through a central openingin disc 13. Hub portion 49 is formed with a shouldered bore 50 which communicates with a central opening 45 in holder wall portion 42. Scale sheets 51 showing uniformly spaced percentage lines are secured to disc 13 and 3 are located within the open frame ends of frame member 41. The upper surfaces of holder wall portion 42 and ribs 43, 43A are recessed relative to the upper frame edges, thereby providing a seat for a snugly fitting rectangular closure member 52.

Closure member 52 is provided with a swivel nut member 53 on the center thereof. Tilted motor shaft 37, at right angles to disc head 13, terminates in a threaded portion 37A which projects through opening 45 to receive a lock unt 37B to secure disc 13 and its associated holder 40 to motor shaft 37. The nut member 53 is screwed on the upper end of threaded shaft portion 37A; and, when only partially screwed on, said threaded shaft portion, allows the closure member 52 to be swivelled to the position indicated in dotted lines, in FIG. 2, thereby exposing the grooved portions of the holder 46 for inserting or removing tubes C. The closure member 52 may also be swivelled to the position indicated in full lines in FIG. 2 and the nut member 53 is then screwed down to lock the closure member 52 to its seat on frame member 40.

Tubes C carrying blood specimens are readily mounted in the holder 40 on head 13, to be centrifuged when motor '12 is energized for a given time interval. When head 13 stops rotating and closure member 52 is swivelled to its open position, the forward tilt of head 13 facilitates reading the demarcation lines of the stratified contents of tubes C by direct reference to scale sheets 51 on the head.

The cover 14 overlying the upper end of casing portion 29, is hinged to side wall by a hinge bracket 14A secured to cover 14 and pivoted on a block 143 fixed to wall 30. Cover 14 is held in its closed position by latch means 54 with an interposed gasket 55 on rim 39 providing a seal therebetween.

Latch means 54 comprises an angle member 56 which is pivoted on a bracket 54A fixed on the underside of a plate 57 which is secured to cover 14 and projects forwardly of the edge thereof. A vertical arm portion 56A of latch member 56 is releasably engageable between a pair of laterally related opposed spring pressed detents 58 on a keeper bracket 58A secured to wall 30.

Gasket 55 comprises an inverted channel portion including peripheral flange portions 55A, 55B, and a hollow head portion 59, which abuts the underside at the periphery of cover 14. The outer flange portion 55A of gasket 55 is secured to the opposed portions of rim 39, as by adhesive; while the inner flange portion 55B of said gasket means is in unsecured relation to the opposed portions of rim 39, for the purpose hereinafter appearing.

Cover 14 is formed of transpartent plastic such as methyl methacrylate or the like to permit viewing the tube holder 40 and its closure member 52 so as to make sure that the latter is in proper operative position and to establish when disc head 13 has ceased to rotate. Cover 14 is formed with a central ventilating inlet opening 6b. Thus, when the disc head 13 is rotating at high speeds, air currents are set in motion from inlet opening 66, swirl over the top surface of disc head 13 and holder 40, pass downwardly about the edge of said disc head 13 and move radially inward between the underside of said disc head and the opposed pan wall to opening 36 therein, and thence by way of opening 33 to the interior of lower casing portion 15, about motor 12 and out the ventilating outlet openings 21; all as indicated by arrows.

Thus, heat from motor 12, as well as frictional heat developed by said air currents, is readily dissipated and the blood specimens in tubes C are not adversely affected during centrifuging by excessive heat conditions. To further insulate tubes C from radiated and conducted heat, an insulating sheet 61 is disposed between scale sheets 51 and the disc 13.

Also, the air current flow gives rise to excessive noise when device 10 is in operation. It has been found that such noise may be markedly reduced, when the cover 14 is tightly sealed to rim 39 of casing portion 29. Thus, the unsecured flange 55B of gasket 55 is displaced, as indicated by dotted lines, in FIG. 1, towards the underside of cover 14, to attain a seal of maximum tightness uniformly about the periphery of rim 39. Furthermore, the pressure in the upper portion of casing 11 is reduced so as to form a partial vacuum which retains cover 14 in its closed position for an interval after motor 12 has been deenergized. Thus, thed isc head 13, is not prematurely exposed while still rotating under its inertia.

A conventional timer and switch 62 with a setting knob 62A is mounted on wall 16 of casing portion 15, for suitable electrical connection to motor 12 and current supply cord 63, to regulate the time interval of rotation of head 13. Also, a safety switch 64 is mounted on the underside of pan wall 35, with its spring pressed actuating pin 65 projecting through an opening in wall 30 for engagement by latch member 56A. Thus, in the open position of cover 14, switch 64 is effective to leave motor 12 in open circuit. Switch 64 is closed only when cover 14 is in its latched position, and latch portion 56A has pressed switch pin 65 inwardly.

To facilitate reading of the scale sheets 51, magnifying means 66 is mounted on the casing 11 for the convenience of the technician using the device. Magnifying means 66 comprises angular bracket means 67 fixed to wall 30 at a point laterally adjacent latch 56 and having an upright arm 68 disposed adjacent gasket 55. A swivel arm 69 is pivoted at one end to bracket arm 68, by a pivot screw 7t). Swivel arm 69 has fixed to the outer end thereof a magnifying glass 71.

The disposition of bracket means 67 and swivel arm 6? is such as to locate magnifying glass 71 in its operative position, over a major portion of the scale sheet 51 when the holder 40 is aligned with latch means 56. Of course, cover 14 is listed to its open position and closure member 52 is swivelled when a reading is to be taken. When the magnifying glass 71 is not in use it is swung by its arm 69 to an inoperative depressed position adjacent casing portion 29.

Alternatively, as shown in FIG. 4, closure member 52 is provided with magnifier inserts 72, 73, which are located over the scale sheets 51 for direct reading, after the centrifuging operation is completed and without the need for swivelling closure 52 to its open position.

It is understood that capillary tubes C are of the calibrated type which are filled with a predetermined quantity of blood specimen, thus allowing a uniformly spaced percentage scale to be used on scale sheets 51; the lower end of the column in said tubes being registrable with the 0 marking on said scale sheets to give a direct percentage reading at the demarcation point between the blood cells and plasma. However, uncalibrated tubes may also be centrifuged in device 10, in which case, the centrifuge tubes are read on an accessory reader, not shown.

As various changes may be made in the embodiment of the invention herein shown without departing from the spirit thereof, it is understood that all matter herein described or illustrated is not limiting except as set forth in the appended claims.

What is claimed is:

l. A centrifuge for capillary tubes comprising a casing having a lower portion and an upper circular portion, motor means within the lower portion of said casing and in spaced relation to the inner surface portions of the side walls thereof, shaft means extending upwardly from said motor means, a flat head member for carrying capillary tubes on the top surface thereof disposed within the upper portion of said casing and operatively engaged with said shaft means, ventilating openings in lower portions of the side walls of said casing, a cover movably mounted on the upper edge of the upper circular portion of said casing and overlying said head member, said cover having a centrally located ventilating opening, gasket means for sealing said cover to the rim of said casing in the closed position thereof, pan means mounted on the upper circular portion of said casing with side and bottom wall portions thereof respectively spaced from the peripheral edge and bottom surface of said head member, the bottom wall portion of said pan means being formed with a central ventilating opening with said shaft means passing therethrough to allow air currents incident to the rotation of said head member and entering the opening of said cover to pass radially outward along the upper surface of said head member, downwardly about the peripheral edge thereof, radially inward alongthe under surface thereof and downwardly through the ventilating opening in the bottom wall of said pan means about said motor means and outwardly through said ventilating openings in the lower portions of said casing to cool and ventilate the interior of said casing above and below the rotating flat head member.

2. A centrifuge as in claim 1 wherein said gasket means is channel shaped in cross section, the outer flange of said gasket means being secured to opposed outer side wall portions of the upper portion of said casing, the inner flange of said gasket means being in unsecured relation to opposed inner side wall portions of the upper portion of said casing, whereby air flow about said flat head member during rotation thereof is effective to lift the inner flange of said gasket means toward the underside of said cover at the periphery thereof to increase the sealing effect of said gasket means relative to said cover.

3. In a centrifuge for capillary tubes, a flat circular head, means for rotating said head about a vertical axis, elongated tube holder means extending diametrically on the upper surface of said head, said holder means comprising grooved portions for receiving said capillary tubes, an elongated closure member for said holder means, means for swivelly mounting the midportion of said closure member on said rotating means for movement between one position thereof angularly related to said holder means for exposing the capillary tubes in said holder means, and another position thereof to enclose the capillary tubes in said holder means, and means for locking said closure member in either position thereof.

4. A centrifuge as in claim 3 wherein said holder means comprises a rectangular shaped holder member disposed diametrically of said head and secured thereto, said holder member comprising recessed portions for seating said closure member, screw means extending upwardly from a midportion of said holder member, a nut memher on said screw means, the midportion of said closure member being swivelly mounted on said nut member for movement between a position overlying said holder member and seated on the recessed portions of said holder member and covering said capillary tubes, and a position at an angle to said holder member for exposing said capillary tubes, said nut member being in engaged relation to said screw means in either position of said cover memher.

5. A centrifuge for capillary tubes comprising a casing, motor means within said casing, a flat head member within said casing and rotated by said motor means, capillary tube holder means on the upper surface of said head member, a cover on said casing and overlying said holder means, said casing comprising upper and lower portions, said upper casing portion comprising a circular side wall, a pan mounted on the side wall of said upper casing portion, said pan having a circular side wall portion spaced from the periphery of said head member and a bottom wall spaced from the bottom wall of said head member, the bottom wall of said pan being formed with an enlarged central opening to pass the upwardly extending shaft of said motor means, said head member being secured to said shaft and within said pan portion, a central opening in said cover, said cover and said pan providing a path of movement for air entering said opening about the upper :and lower surface portions of said head member, a major portion of said motor means being disposed within said lower casing portion, ventilating openings in the lower end of the side Wall of said lower casing por- 6 tion, whereby air currents from said upper casing portion pass through the opening in saidpan to said lower casing. about said motor means and out through said ventilating openings.

6. A centrifuge as in claim 5 and further including channel shaped gasket means on the top edge of the side Wall of-said upper casing portion, the peripheral portions of said cover in the closed position-thereof abutting said gasket means, said gasket means comprising an'inner flangeporti-on in unsecured relation to the inner surface of the side wall of said upper casing portion and movable in a direction to more tightly abut the underside of said cover at the periphery thereof in response to the movement of said air currents.

7. A centrifuge for capillary tubes comprising a casing, motor means within said casing, shaft means extending upwardly from said motor means, a flat disc head secured to said shaft means, capillary tube holder means secured to the upper surface of said head, a cover member hinged to the rim of said casing, gasket means on the rim of said casing, means for latching said cover member in a closed position and in sealed relation to said gasket means, ventilating outlet openings in lower portions of said casing, a ventilating inlet opening in said cover, means for directing air entering said inlet opening in a path about the upper and lower surface of said disc head, downwardly about said motor means and out through said outlet openings, said gasket means including movable flange portions responsive to the directed air to move into abutting and sealing relation to the underside of said cover member at the periphery thereof.

8. A centrifuge comprising a casing, a motor within said casing and including an upwardly extending motor shaft, a disc head secured to said shaft, capillary tube holding means on said head, said casing comprising a lower portion and an upper bowl shaped portion, said bowl shaped portion including an annular side wall, a pan member Within said bowl shaped portion, said pan member including an annular rim portion mounted on the upper edge of the side wall of said bowl portion, said pan member having a bottom wall formed with a central opening for passing said motor shaft, a cover hinged to said rim, latch means on said side Wall and said cover for retaining said cover in its closed position, safety switch means for controlling said motor and located between the bowl shaped portion and said pan, said switch means being normally open and in circuit with said motor and including activating means extending through said sidewall for operation by said latch means in the cover latching position thereof to close said safety switch means.

9. A centrifuge comprising a casing having an open top portion, a disc head Within the upper end of said casing, a motor within said casing for rotating said head, capillary tube holder means on said head, a cover hinged to the open end of said casing, said cover having a central opening therein, means for latching said cover to said casing in closed position thereof, resilient gasket means of channel cross section on the rim of said casing and in abutting relation to the underside of said cover, said gasket means including an inner flange portion in unsecured relation to the inner surface of said casing opposed thereto, said inner flange portion of the gasket means being movable to abut the underside of said cover to tightly seal the same in its latched position in response to the movement of air currents incident to the rotation of said head.

References Cited in the file of this patent UNITED STATES PATENTS 446,248 Cooper Feb. 10, 1891 495,653 Augustenborg et al Apr. 18, 1893 1,312,358 Robinson Aug. 5, 1919 1,648,369 Svedberg et al. Nov. 8, 1927 (Other references on following page) 7 UNITED STATES PATENTS Jordan et a1. June 4, 1935 Brosnan Nov. 14, 1939 Tice Dec. 30, 1941 Barranco Aug. 12, 1952 MacLeod Nov. 4, 1952 Allen et a1. Jan. 11, 1955 Jones June 19, 1956 Grela et a1. Mar. 5, 1957 Weichselbaum Apr. 22, 1958 10 8 Pickels et a1 Mar. 24, 1959 Danielsson et a1. May 5, 1959 Walker Feb. 7, 1961 Polanyi Nov. 21, 1961 FOREIGN PATENTS Canada May 26, 1959 Great Britain Mar. 14, 1962 Germany Apr. 30, 1958 Germany July 17, 1958

Claims (1)

1. A CENTRIFUGE FOR CAPILLARY TUBES COMPRISING A CASING HAVING A LOWER PORTION AND AN UPPER CIRCULAR PORTION, MOTOR MEANS WITHIN THE LOWER PORTION OF SAID CASING AND IN SPACED RELATION TO THE INNER SURFACE PORTIONS OF THE SIDE WALLS THEREOF, SHAFT MEANS EXTENDING UPWARDLY FROM SAID MOTOR MEANS, A FLAT HEAD MEMBER FOR CARRYING CAPILLARY TUBES ON THE TOP SURFACE THEREOF DISPOSED WITHIN THE UPPER PORTON OF SAID CASING AND OPERATIVELY ENGAGED WITH SAID SHAFT MEANS, VENTILATING OPENINGS IN LOWER PORTIONS OF THE SIDE WALLS OF SAID CASING, A COVER MOVABLY MOUNTED ON THE UPPER EDGE OF THE UPPER CIRCULAR PORTION AND SAID CASING AND OVERLAYING SAID HEAD MEMBER, SAID COVER HAVING A CENTRALLY LOCATED VENTILLING OPENING, GASKET MEANS FOR SEALING SAID COVER TO THE RIM OF SAID CASING IN THE CLOSED POSITION THEREOF, PAN MEANS MOUNTED ON THE UPPER CIRCULAR PORTION OF SAID CASING WITH SIDE AND BOTTOM WALL PORTIONS THEREOF RESPECTIVELY SPACED FROM THER PERIPHERAL EDGE AND BOTTOM SURFACE OF SAID HEAD MEMBER, THE BOTTOM WALL PORTION OF SAID PAN MEANS BEING FORMED WITH A CENTRAL VENTILATING OPENING WITH SAID SHAFT MEANS PASSING THERETHROUGH TO ALLOW AIR CURRENTS INCIDENT TO THE ROTATION OF SAID HEAD MEMBER AND ENTERING THE OPENING OF SAID COVER TO PASS RADIALLY OUTWARD ALONG THE UPPER SURFACE OF SAID HEAD MEMBER, DOWNWARDLY ABOUT THE PERIPHERAL EDGE THEREOF, RADIALLY INWARD ALONG THE UNDER SURFACE THEREOF AND DOWNWARDLY THROUGH THE VENTILATING OPENING IN THE BOTTOM WALL OF SAID PAN MEANS ABOUT SAID MOTOR MEANS AND OUTWARDLY THROUGH SAID VENTILATING OPENINGS IN THE LOWER PORTIONS OF SAID CASING TO COOL AND VENTILATE THE INTERIOR OF SAID CASING ABOVE AND BELOW THE ROTATING FLAT HEAD MEMBER.

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