US3112081A

US3112081A - Micro-homogenizing apparatus

Info

Publication number: US3112081A
Application number: US102766A
Authority: US
Inventors: Charles J Filz
Original assignee: IVAN SORVALL Inc
Current assignee: IVAN SORVALL Inc
Priority date: 1961-04-13
Filing date: 1961-04-13
Publication date: 1963-11-26
Anticipated expiration: 1980-11-26

Description

Nov. 26, 1963 c. J. Fu.z l

MICRO-HOMOGENIZING APPARATUS 5 Sheets-Sheet l Filed April 13, 1961 o R (244/9255 rf /7 Z BY B2.; ATTO R N EY Nov. 26, 1963 c. J. FlLz MICRO-HoMoGENIzING APPARATUS Nov. 26, 1963 c. J. FlLz MICRO-HOMOGENIZING APPARATUS 3 Sheets-Sheet 3 Filed April 13, 1961 WQ v iNvENToR (2u/P455 J F/z d? United States Patent O 3,112,081 MICRO-HOMOGENIZING APPARATUS Charles J. Filz, Weston, Conn., assignor to Ivan Sorvall, Inc., Norwalk, Conn., a corporation of New York Filed Apr. 13, 1961, Ser. No. 102,766 23 Claims. (Cl. 241-285) This invention relates to macerating apparatus and more particularly to apparatus for homogenizing or comminuting 'biological and physiological specimens in small volume quantities in the order of 0.5 milliliter to 5.0 milliliters.

In biological study and analysis it is often necessary to macerate or comminute biological materials to a tine homogeneous state, and where the specimens are comparatively small in volume, it is desirable to provide suitable apparatus capable of performing this work.

The present invention comprises an apparatus driven by a high speed motor which, by way of a speed multiplying device, rotates a cutting knife within a small container in which the specimen is placed. Since it is often necessary to avoid contaminating the specimen, it is desirable to perform the macerating or homogenizing action in a small cell or container which is capable of being properly isolated from the drive mechanism as well as from the ambient atmosphere, before, during and after the time the macerating action takes place. Accordingly, a salient feature of the present invention is Ithe provision of a sealing arrangement for the chamber which effectively protects the specimen as it is being processed therein. Furthermore, the sealed chamber assembly is constructed in such a manner as to provide a quick releasable attachment means by which the sealed container including the macerating or homogenizing knife is readily connected to or disconnected from the drive mechanism of the apparatus whereby the use `of special tools is obviated.

Furthermore, -a novel arrangement of a spring loaded seal diaphragm and a cooperating seal washer is provided for maintaining the integrity of the seal for the specimen chamber and rotor shaft assembly before the latter is connected to the drive assembly, during the homogenizing process and after the chamber assembly is removed from the drive assembly. Other improved mechanical structures and arrangements are provided for facilitating the quick and easy assembly and disassembly of the various parts of the apparatus.

Still other objects and advantages of the invention will be apparent from the specification.

The features of novelty which are believed to be characteristic of the invention are set forth herein and will best be understood, both as to their fundamental principles and as to their particular embodiments, by reference to the specification and accompanying drawings, in which:

FIGURE l is a vertical elevational view of the apparatus of the present invention, some parts being in outline form;

FIG. 2 is a greatly enlarged, vertical central cross section of a portion of the apparatus shown in FIG. l, shown partly in elevation, and some parts being omitted;

FIG. 3 is an elevation View of a fragmentary portion of the apparatus shown in FIG. 2, showing two positions of the locking mechanism for the specimen container;

FIG. 4 is a view taken on line 4-4 of FIG. 3;

FIG. 5 is a greatly enlarged exploded view, partly in section and partly in elevation showing the specimen container and the connect and disconnect elements while said parts are separated;

FIG. 6 is a fragmentary view of a portion of the elements shown in FIG. 5, showing the parts in the connected position;

FIG. 7 is a view taken on line 7-7 of FIG. 6;

ICC

FIG. 8 is a very greatly enlarged elevation view of a diaphragm seal spring core;

FIG. 9 is an edge View of the spring core shown in FIG. 8; and

FIG. 10 is an alternative embodiment of a specimen cup utilized in the apparatus herein.

Referring now to the drawings in detail, and particularly to FIGS. l and 2, there is shown an electric motor 21 which is mounted on a bracket 22 that -is connected to a suitable stand or platform, not shown. Connected to the bottom of motor 21 is a shaft housing 23 which contains a drive shaft, not shown. Threadably connected into shaft housing 23 is a drive assembly body 24 made of an aluminum casting or the like, said body having an upwardly extending stub 26 threadably inserted into the lower end of shaft housing 23. Stub 26 and drive assembly body 24 are secured firmly to shaft housing .23 by means of a stainless steel lock nut 27 that threadably surrounds stub 26.

Stub 26 has a vertical aperture 28 which extends through the upper portion of body Z4, the lower portion of which also has an aperture 29 axially aligned with aperture 28. Positioned securely in apertures 28 and 2'9 are

ball bearings

31 and 32, respectively, within which is rotatably mounted drive spindle 33, of stainless steel. Connected to the upper end of drive spindle 33 by means of set screw 34 is a circular rotor shaft collar 35, the upper portion of which has a recess which accommodates by force fit a circular collar insert 36. Collar insert -36 has a circular interior surface which is fluted, and which mates with the lower yiiuted end of the drive shaft, not shown, in shaft housing 23 whereby the rotation of said drive shaft by motor 21 causes the rotation of drive spindle 33.

rive assembly body has a large horizontal recess 37 in the area intermediate the ends of drive spindle 33. Freely rotatable within said recess is drive pulley 38 made of aluminum or the like, and connected to said spindle by `means of a pair of set screws 39 extending through an upwardly extending axial stub 41 on said pulley. Interposed between the bottom surface of `drive pulley 38 and bearing 32 is a spacer bushing 4-2 of aluminum which serves to fix the axial location of drive pulley 38 and spindle 33 in respect of bearing 32 and snap ring 44 upon which said bearing rests.

Another portion of drive assembly body 24 has a pair of axially aligned vertical apertures `45 and 46 which are separated by a horizontal recess 47. Mounted in

apertures

45 and 46 is a pair of spaced

apart bearings

48 and 49, respectively. Rotatably supported by

bearings

48 and 49 isa high speed spindle 51. Vertical aperture y45 is covered by a bearing cap 52 which not only prevents external dirt from entering the apparatus but also provides access to the operating parts for cleaning or replacement purposes.

Mounted on high speed spindle 51 within recess 47 is a high speed slave pulley 53 of aluminum which has an upwardly extending stub 54 through which a pair of set screws 56 extend for secu-ring said pulley to said spindle. The peripheral surfaces of both drive pulley 38 and high speed slave pulley 53 are serrated in the form of evenly distributed laterally arrayed

4teeth

57 and 58, respectively, Iwhich are engaged by a timing belt 59 made of rubber, or .the like, the interior surface of said timing belt having a plurality of serrations or teeth rfor engaging the teeth on said pulleys. The rotation of the larger diameter pulley 38 produces the higher speed rotation of the smaller diameter slave pulley 53 whereby spindle 51 is rotated at a considerably higher speed than that of drive spindle 33.

The Working elements within drive assembly body 24 are protected by means of a suitably formed rguard 68 made of sheet metal, such as aluminum, Steel or the like,

said guard enclosing all of the open parts of said drive assembly body and being secured thereto by means of a pair of screw bolts 61. A slot `62 (lFIG. 2) is provided between an edge of guard 60 and body 24 to permit air `to circulate into the interior of the guard to cool the drive elements composed of

pulleys

38 and 53, and drive belt S9. Vibration of said guard `61 is prevented or minimized by the damping effect of isolation bushings 63 mounted between said guard and body 24 and maintained in position by washers 64 secured by the heads of bolts 62.

Drive assembly body 24 has a downwardly extending stub 66 whose central vertical aperture 67 is coaxial with aperture 46, and through which the lower portion of high speed spindle 51 extends.

Inserted into aperture 67 is a circular seal housing adapter 68 of stainless steel, the peripheral surface of which has an annular recess 71 accommodating an O-ring 72 of rubber, neoprene, or the like, which serves to hold said adapter 68 in place. The lower end of adapter 68 has an annular outwardly extending ange 73 (FIGS. 5 and 6) which extends over the lower edge of stub 66. The central bore of adapter 68 is threaded for the purpose of accommodating a suitable threaded tool to facilitate its removal, for example, when necessary to change the bearings or for cleaning the apparatus.

Mounted on the exterior of stub 66 is a pair of downwardly extending detent springs 76, made of spring tempered stainless steel and positioned diametrically opposite one another (FIGS. l, 3, 5, 6), each having at its lower end a V-shaped detent 77, the apex of which is directed inwardly toward the axial center line of stub 66. Only the upper portions of springs 76 are secured to stub 66 by means of pains of

screws

78 and 79, while their lower ends extend freely below stub 66 and are capable of ilexing laterally relative thereto.

Straddling detent springs 76 is a bowed or semi-circular locking clamp 81, of stainless steel or the like, at the ends of which are integrally formed perpendicular arms 82, the ends of which are pivotally connected by means of shoulder screw 79 to stub 66. Arms 82 form elbows 83 with locking clamp 81, said elbows having inwardly projecting bosses 84 (tFIG. 5), which, when said clamp 81 is in locking position (FIGS. 2 and 3), urge the free portions of detent springs 76 inwardly against the respective sides of stubs `66 and retain them in position. When clamp 81 is in the raised or -unlocking position as in FIGS. l and 5, detent springs 76 are free to ex outwardly -as indicated by the arrows in FIG. 5.

Removably connectible to stub 66 is a specimen chamber, rotor shaft and seal assembly, generally designated 91 (FIGS. l, 2, 5, 6) which comprises a specimen chamber cup 92 made of seamless stainless steel and having a. plurality of inwardly extending, spaced apart, vertical flutings 93 formed integrally in its walls. Cup 92 is threadably insertable into a circular seal housing element 94 made of stainless steel, said element having an integral inwardly extending circular shoulder ring 96 surrounding a central aperture 97. The bottom of ring 96 has an annular recess Iwhich partially accommodates a resilient seal ring 98 of rectangular cross-section, made of rubber, neoprene or the like, which serves to provide a liquid-tight seal between the top of cup 92 and housing element 94. Seal housing element 94 has an upwardly extending integral circular collar 99 within which its positioned a circular seal diaphragm, generally designated 101.

Seal diaphragm 101 constitutes a wafer-thin Phosphor bronze circular spring core 102 in the form of a web-like element having an outer pair of arcuate circularly arrayed slots 103 and an inner pair of arcuate circularly arrayed slots 104, the latter pair of slots being concentric with the former pair `(IFIG. 8).

Slots

103 and 104 divide core 102 into three concentric rings 10S, .105a and 105b.

Rings

105 and 105a are connected integrally by a pair of diametrically opposed bridges 106, while rings :1 and 105b are connected integrally by a pair of diametrically opposed bridges 107, said pairs of bridges being arrayed perpendicularly relative to each other. A resilient spring action is obtained when the inner portion of core 102 or ring 10511 is moved in the direction of the perpendicular axis of said core. Normally, in repose, core 102 assumes a at condition as shown in FIG. 9.

Outer ring 10S has a plurality of integrally formed spaced apart teeth `108 which are alternately bent in opposite directions perpendicular to the plane of core 102, as shown in FIG. 9. Secured firmly to the central aperture of ring 105 of core 102 is a stainless steel bushing 109. (FIG. 5). All of core 102 and a portion of bushing 109 are embedded in a ilexible coating or overlay 111 of silicone rubber, or the like, the peripheral area of said overlay enclosing .teeth 108 and being formed in a ring 112 of increased thickness 'and having an H-shaped cross-section (FIGS. 5 and 6), the upper surface of which extends somewhat above the upper edge of collar 99. Seal housing 94 is threadably insertable into top cap 113, ring 112 forming a resilient means for providing an airand liquid-tight seal between seal housing 94 and top cap 113.

It will be noted that the H-shaped arrangement of ring 112 provides top and bottom pairs of concentric, circular, resilient, spaced apart rings which serve as respective double resilient members between seal housing 94 and top cap 113 to enhance the integrity of the liquidand air-tight closure. By embedding the Phosphor bronze core in a flexible plastic overlay or coating 111, such as silicone rubber or other suitable inert resilient material, the spring function of the core is maintained while at the same time the metallic material is protected from corrosion and reciprocal contamination with the contents of the specimen cup 92.

Cap 113 has an inwardly extending flange l114 which has a central aperture 115 through which the upper stub 117 of elongated stainless steel rotor shaft 118 extends for free rotation of `the latter. Adjacent the lower end of stub 117, rotor shaft 118 has an outwardly extending integral annular shoulder 119, a portion of the top surface of which is normally urged lightly against the bottom surface of flange 114.

Shoulder 119 has a circular integral shelf 120 of reduced diameter beneath which is mounted around rotor 118 a seal washer 121 made of glass lled Teflon or the like, the upper surface of which forms a sliding bearing with the bottom surface of shelf 120.

Although seal washer `121 may be made of any suitable low friction material, the substance known as Tellon provides a substantially frictionless Surface which forms an excellent sliding bearing with the lower surface of shelf as the latter rotates with the rotation of rotor shaft 118. At the same time, the sliding mating surfaces of seal washer 1211 and shelf 120 serve to form an effective seal therebetween in order to maintain the integrity of the closure for the contents of specimen cup 92.

Positioned coaxially within bushing 109 is a seal face ring 122 whose interior bore is spaced apart from the periphery of rotor shaft 118. Formed integrally at the upper end of ring 122 is an outwardly extending llange 123, the top surface of which bears against the bottom surface of seal washer 121. The bottom surface of flange 123 may rest upon the upper surface of overlay 111 of seal diaphragm 101, but in `some embodiments, said overlay may be provided with a circular recess into which said flange is nested snugly as shown in FIGS. 5 and 6, for example. The outer periphery of ring [122 also lits snugly with the interior surface of bushing 109. Thus, by means of the close fitting of

components

109, 122, 123, 121 and 120, a sealed closure is provided for specimen cup 92.

Threadably connected to the lower end of rotor shaft 113 is a microblade 126 having a suitable shape and cutting edges, not shown, for properly macerating or homogenizing the specimen material in cup 92 when said shaft rotates freely within aperture 97 and the bore of ring 122.

When a biological or other Itype of specimen or material is to be macerated or homogenized, it is first introduced into the open cup `92 after which rotor shaft 118 surrounded by seal housing 94, seal washer 121, sem face ring V122, and spring diaphragm 101, is inserted into said cup which is then threadably secured to seal housing 94. Thereafter, top cap 113 is threadably secured to seal housing 94 to form a spill-proof specimen chamber. Under the biasing action of seal diaphragm 101, flange 114 is caused to bear lightly against shoulder 119 whereby shelf 129 is urged into contact with seal washer 121 as shown in FIG. 5, where said diaphragm is slightly bowed. Seal diaphragm 101 operates also to maintain rotor shaft 11S in properly centered position relative to the chamber assembly before the latter is coupled to the drive assembly, during the homogeniz-ing process and .after it is uncoupled from the drive assembly.

As is evident in the illustration of FIG. 5, the specimen chamber assembly 911 provides the facility for introducing the specimen to be macerated into cup 92 and enclosing it, together with the macerating blade 126, within a chamber which remains sealed while it is connected to and removed from the drive apparatus. When the specimen chamber and rotor -assembly is to be connected to the drive apparatus, no special tools are required. The assembly is merely lifted by one hand into position where stub 117 ofl rotor shaft 118 enters into an elongated central aperture 127 in the lower end of high speed spindle 51. Stub 117 has a precision dowel pin 128 extending diametrically therethrough (FIGS. 5, 6, 7), the opposite end portions of which are snugly accommodated by corresponding longitudinal diametrically opposed slots 129 in the end of high speed spindle 51 whereby rotation of the latter produces the rotation of rotor shaft 118. In order to facilitate the entry of the ends of dowel pin 128 into slots 129 when the former is not aligned with the latter, the lower end of high speed spindle 51 has a double bevel generated at surfaces 131, inclined at approximately at each side of each slot 129 whereby pin 128 is slidably guided into slots 129' should pin 12S not enter said slots directly. Rotor shaft 118 rotates freely to the extent necessary within the specimen chamber assembly for permitting said pin to enter said slots as said assembly -is moved upwardly for the coupling operation.

The top surface of cap 113 has a circular counterbore 132. When the specimen cup assembly is lifted upwardly for coupling to the drive assembly, counterbore 132 accommodates ange 73 with a snug fit (FIGS. 5, 6). When stub @117 of rotor shaft 118 is coupled with high speed spindle 51, V-shaped detents 77 move into an annular V-shaped recess 133 in the peripheral surface of top cap 113. As locking clamp 811 is moved downwardly by the operator to cause bosses 84 to secure springs 76 against outward movement, detents 77 pull the specimen cup assembly upwardly against the bottom face of ange 73 `of the seal housing adapter v68. lIt will be noted that the pulling action of detents 77 is accomplished by the upper portion thereof mating with the upper portion of recess 133, as illustrated in FIG. 6.

High speed spindle 51 has a predetermined length in relation to the bottom face of flange 73. During the procedure of coupling the specimen cup assembly to the drive assembly, the lower end of spindle 51 extends through aperture 115 of flange 114 and bears downwardly upon shoulder 119 of rotor shaft 118 to the extent of between about 0.005" and 0.010" so that the top of shoulder 119 becomes spaced apart from flange 114.

By this action shoulder 119, and accordingly, rotor shaft- 118, are given freedom to rotate with the rotation of spindle 51 without hindrance from flange 114. At the same time, the downward pressure produced by the action of spindle 51 continues to urge shelf 120 against seal washer 121 which, in turn, is urged against seal face ring 122 to preserve the seal for the specimen cup assembly while the lower surface of shelf rotates slidably against the upper surface of seal washer 121. In the operating position for macerating or homogenizing the contents of cup 92, as shown in FIG. 6, seal diaphragm 101 is bowed to a somewhat greater extent than its position in FIG. 5 whereby its spring action continues to preserve the integrity of the seal assembly formed by

elements

120, 121 and 123.

After the specimen chamber assembly has been properly coupled to the drive assembly, as shown in FIGS. l and 6, motor 21 is started to produce the high speed rotation of rotor shaft 118 whereby microblade 126 macerates or homogenizes the materials in cup 92.

After the requisite macerating or homogenizing action has taken place, motor 21 is stopped, thereby stopping the rotation of rotor shaft 118 and the specimen cup assembly may be removed from the drive assembly by lifting locking clamp 81 (FIGS. l, 5), thereby releasing detent springs 76 so that when cup 92 is pulled downwardly, detents 77 move outwardly from the recess 133 to release the specimen cup assembly. Simultaneously with the uncoupling of the specimen chamber assembly, when the lower end of high speed rotor 51 releases its pressure from the upper surface of shoulder 119, core 102 acts resiliently to move seal face 123 upwardly to its original position, as shown in FIG. 5, whereby seal washer 121 as well as shoulder 119 are also moved upwardly until the latter abuts flange 114.

Thus, while the specimen cup assembly is being removed from the drive assembly, seal diaphragm 101 is operative to maintain the seal for the specimen chamber as comprised by

elements

120, 121 and 123, and automatically moves said elements into their respective positions as shown in FIG. 5. Accordingly, by means of the structural arrangement of the parts herein, the specimen cup assembly can be uncoupled from the drive assembly and carried in a sealed condition to another location for unloading its contents, Conversely, when Various specimens are inserted into specimen cup 92 and sealed in one location of a laboratory, it can then be transported to another location in the sealed condition and coupled to the drive mechanism while maintaining the sealed condition. Accordingly, not only is contamination of the contents prevented, but also deleterious consequences to laboratory personnel as a result of possible toxic or infectious materials in the specimen chamber are avoided. The preservation of the seal of the specimen cup be-l fore, during and after the homogenizing or macerating process facilitates research in various biological, viral, bacteriological and pathological substances which would otherwise be difficult, if not impossible, to arrange. Furthermore, by utilizing such materials as stainless steel and inert plastic materials for the various components of the specimen chamber assembly, the assembly can readily be autoclaved or sterilized either in the assembled or disassembled condition.

Although spindle 51 is arranged to produce the action of separating shoulder 119 from ange 114, to free rotor shaft 118 for rotation, it is possible to arrange for the location of pin 128 lto be altered to a position where its ends abut the inner end walls of slots 129 whereby the respective locations of said pin and said walls would produce the downward motion of shoulder 119.

In some embodiments of the invention it may be desirable to view the action taking place within the specimen chamber. Accordingly, cup 92 may be replaced by a stainless steel specimen cup 141 (FIG. l0) which has a plurality of spaced apart vertical elongated apertures 142. Fitting snugly within cup 141 is a transparent or translucent inner cup 143 made of a suitable plastic material within which the specimen is positioned for maceration or homogenization. Thus, the extent of the macerating action can be viewed continuously and the operator can thereby control the timing and extent of the homogenizing process.

It is claimed:

1. Homogenizing apparatus having a body, a drive spindle rotatably mounted in said body, and a separate assembly of a specimen chamber and rotor shaft releasably connectible to said body and said drive spindle, respectively, said assembly comprising a cup, a resilient diaphragm enclosing the interior of said cup and surrounding said rotor shaft, an aperture in said diaphragm through which said rotor shaft rotatably extends, a cover on said cup enclosing said diaphragm, a seal between said diaphragm and said shaft, said rotor shaft being movable longitudinally through said cover, said shaft taking one position relative to said cover when coupled to said drive spindle and another position relative to said cover when uncoupled from said drive spindle, said diaphragm maintaining the integrity of said seal in both positions of said rotor shaft and when said assembly including said shaft is uncoupled from said body.

2. Homogenizing apparatus according to claim 1, and further comprising means on said body for releasably connecting said assembly to said body, and means on said spindle and on said rotor shaft releasably coupling one another for rotation of the latter by the former, the dimensions of the components of the apparatus being such that when said assembly is connected to said body said rotor shaft is moved from its first position to its second position.

3. Homogenizing apparatus according to claim 1, and further comprising an annular peripheral recess in said assembly, a pair of spring elements on said body, a portion of each of said spring elements adapted to mate with said recess, and a lock element pivotably mounted on said body and movable into one position for causing said spring elements to retain said assembly in position against said body, said lock element being movable into a second position where said spring elements yieldably permit said assembly to be removed `from said body.

4. Homogenizing apparatus according to claim 1, and further comprising resilient means on said body for yieldably grasping said assembly and locking means pivotably mounted on said body and movable into one position for causing said resilient means firmly to secure said assembly in position relative to said body, said locking means being movable into a second position where said resilient means yieldably permit said assembly to be removed from `said body.

5. Apparatus according to claim l, and further comprising a longitudinal recess in the end of said spindle,

said recess accommodating an end of said rotor shaft, at least one peripheral slot in said spindle, a pin in said shaft accommodated by said slot whereby the rot-ation of said spindle causes the rotation of said shaft.

6. Apparatus according to claim 1, and further comprising a longitudinal recess in the end of said spindle accommodating an end of said rotor shaft, at least one peripheral slot in said spindle, a pin in said shaft accommodated by said slot whereby the rotation of said spindle causes the rotation of said shaft, the end of said spindle being 4beveled toward the end of said slot whereby said pin is caused to move toward and become aligned with said slot when said shaft is coupled to said spindle.

7. Apparatus according to claim 1 wherein said diaphragm comprises a circular at spring element consisting of a plurality of concentric rings and integral bridges joining adjacent rings to each other, the center portion of said spring being movable laterally relative to the plane of said spring element.

8. Apparatus according to claim 1 wherein said diaphragm comprises a circular at spring element, the center portion of said element being resiliently movable laterally relative to the plane thereof, a flexible plastic coat ing bonded on and around said spring element, the periphery of said coating forming an annular resilient ring, said ring forming a seal between said cup and said cover.

9. Apparatus according to claim 1, and further comprising an aperture on said cover through which said rotor rotatably extends, a shoulder on said shaft which is yieldably urged by said diaphragm against said aperture, a central aperture yin said diaphragm through which said shaft rotatably extends, and a seal washer surrounding said shaft and continually urged by said diaphragm against a portion of said shaft to maintain a seal between said shaft and said diaphragm.

10. Homogenizing apparatus having a body, a drive spindle rotatably mounted in said body and a separate assembly of a rotor shaft and specimen chamber releasably connectible to said body and drive spindle, said assembly comprising a cup, a top cap threadably secured to said cup, a central aperture in said cap, a resilient diaphragm mounted between said cup and said cap, a central aperture in said diaphragm axially aligned with the cap aperture, an elongated rotor shaft extending through both said apertures, an annular shoulder on said shaft, an annular ring positioned between said diaphragm and one side of said shoulder and closing off said diaphragm aperture, said diaphragm normally causing said shoulder to be urged against said cap to close olf the cap aperture, means on said drive spindle and on said rotor shaft c0- operating with each other whereby the rotation of said spindle causes the rotation of said shaft, means for releasably securing said assembly to said body and cauS- Iing said rotor shaft to be coupled to said drive spindle, the dimensions of said spindle, shaft and securing means being selected to cause said shoulder on said shaft to be slightly depressed from the cap aperture when said assembly is connected to said body, said ring continuing to maintain a seal over the diaphragm aperture whereby the interior of said cup is in a closed condition when said assembly is connected to and disconnected from said body.

11. Homogenizing apparatus comprising a drive means, a specimen cup, a rotor shaft, part of said rotor shaft extending into the interior of said cup and part of said shaft extending externally of said cup, the exterior portion of said rotor being releasably connectible to said drive means, and a resilient diaphragm connecting the intermediate portion of said shaft to said cup, said diaphragrn forming an enclosed specimen chamber Within said cup and maintaining a seal between the exterior and the interior of said chamber when said rotor is connected to and disconnected from said drive means and when said rotor rotates.

12. Homogenizing apparatus according to claim 11 wherein said diaphragm contains a flat sheet metal element consisting of a plurality of concentric rings and integral bridges joining adjacent rings to each other, said shaft extending through the center of said sheet metal element.

13. Homogenizing apparatus according to claim 1l wherein said diaphragm contains a at sheet metal element consisting of a plurality of concentric rings and integral bridges joining adjacent rings to each other, said shaft extending through the center of said spring, and further comprising a seal washer positioned between said shaft and said central portion of said diaphragm, the spring action of said diaphragm causing said washer to maintain a seal between said diaphragm and said rotor shaft.

14. Homogenizing apparatus comprising a specimen cup, a removable cap on said cup, a rotor shaft, an aperture in said cap through which said rotor shaft extends and within which it freely rotates, a resilient diaphragm positioned across the interior of said cup and defining a specimen chamber within said cup, said diaphragm being retained in position by said cap, the periphery of said diaphragm forming a seal between said cap and said cup, a central aperture in said diaphragm through which said rotor shaft rotatably extends, and a seal washer positioned between said diaphragm and said rotor shaft, said diaphragm resiliently urging said seal washer against said shaft to maintain a seal for said specimen chamber while said shaft rotates and while it is at rest.

15. Homogenizing apparatus according to claim 14 wherein said shaft is movable longitudinally within said cup, and further comprising an annular shoulder on said shaft, said diaphragm normally urging said shoulder against said cap, said diaphragm maintaining said seal between said washer and said rotor shaft during all positions of the latter.

16. Hornogenizing apparatus according to claim 14 wherein said diaphragm contains a flat sheet metal element consisting of a plurality of concentric rings and integral bridges joining adjacent rings to each other, said bridges permitting the center portion of said diaphragm to move resiliently in a direction perpendicular to the normal plane thereof.

17. Homogenizing apparatus according to claim 14 wherein said diaphragm comprises a flat sheet metal element, and a exible plastic overlay in which said element is embedded, the periphery of said overlay being formed in a circular H-shaped ring, said ring forming the seal between said cap and said cup.

1S. Homogenizing apparatus according to claim 14 wherein said diaphragm comprises a liat sheet metal element, and a flexible plastic overlay, a pair of upwardly extending spaced apart concentric integral extensions at the perimeter of said overlay, a pair of downwardly extending spaced apart concentric integral extensions at said perimeter, both of said pairs of extensions forming the seal between said cap and said cup.

19. Homogenizing apparatus according to claim 14 wherein said diaphragm comprises a flat sheet metal element, and a flexible plastic overlay in which said element is embedded, the periphery of said overlay forming the seal between said cap and said cup.

20. Homogenizing apparatus according to claim 14 wherein said diaphragm comprises a flat sheet metal element, and a flexible plastic overlay in which said element is embedded, the periphery of said overlay forming the seal between said cap and said cup, and a plurality of integral teeth on the periphery of said metal element, said teeth being bent alternately in opposite perpendicular directions relative to the plane of said element and being embedded in said overlay.

21. Homogenizing apparatus according to claim 14 wherein said diaphragm includes a flat sheet rnetal element consisting of three spaced apart concentric rings, 50

each pair of adjacent rings being joined by diagonally opposed integral bridges, the bridges between one pair of adjacent rings being arrayed in a line perpendicular to the array of the other pair of bridges, the central ring being movable resiliently in a direction perpendicular to the normal plane of said diaphragm.

22. Homogenizing apparatus according to claim 14 wherein said diaphragm comprises a iiat sheet metal element consisting of three spaced apart concentric rings, each pair of adjacent rings being joined by diagonally opposed integral bridges, the bridges between one pair of adjacent rings being arrayed in a line perpendicular to the array of the other pair of bridges, the central ring being movable resiliently in a direction perpendicular to the normal plane of said diaphragm, and a exible plastic overlay in which said metal element is embedded, the periphery of said overlay being formed in a circular H- shaped ring, said ring forming the seal between said cap and said cup.

23. lelomogenizing apparatus comprising a body, a drive spindle rotatably mounted in said body, and a separate assembly of a specimen cup and rotor shaft releasably connectible to said body and said drive spindle, respectively, a removable cap on said cup, an aperture in said cap through which said rotor shaft extends and freely rotates, a resilient diaphragm positioned across the interior of said cup and delining a specimen chamber therein, said diaphragm being retained in position by said cap, a central aperture in said diaphragm through which said rotor shaft rotatably extends, an annular tlange on said rotor shaft, said rotor shaft being movable longitudinally Within said cup, a seal washer positioned between said diaphragm and said flange, said diaphragm resilientiy urging said seal washer normally against said flange to cause the latter to bear against said cap at said cap aperture and maintaining a seal between said shaft and said diaphragm for isolating said chamber from the atmosphere, means for removably connecting said assembly to said body, means removably coupling said rotor shaft to said drive spindle, said drive spindle bearing against said liange through said cap aperture when said rotor shaft is coupled to said drive spindle, the length of said drive spindle being determined to cause said rotor shaft to move inwardly into the specimen chamber against the action of said diaphragm when said coupling takes place, said diaphragm continuing to maintain the seal between said seal washer and said iiange whereby the interior of said specimen chamber continues to be isolated from the atmosphere.

References Cited in the file of this patent UNITED STATES PATENTS 2,594,399 Cornell Apr. 29, 1952 2,766,022 Bender Oct. 9, 1956 2,973,187 Wehmer Feb. 28, 1961