Rotational unit for a rotor of a dual centrifuge

Abstract

The invention relates to a rotational unit (10) for a rotor of a dual centrifuge, said rotational unit having a bearing (14) and a rotational head (24) which is connected to the bearing (14), is mounted therein such that it can rotate about an axis of rotation and can be driven relative to the rotor by an additional rotational mechanism of the centrifuge, the rotational head (24) being detachably connected to the receiving unit (40, 80) for conjoint rotation, which receiving unit comprises a sample container receptacle (60, 70, 100, 110) for at least one sample container. The invention is characterized in that the receiving unit (40, 80) and the rotational head (24) are connected by a frictional connection in which some portions of the receiving unit (40, 80) and the rotational head (24) engage in each other in a wedge-like manner, and the frictional connection increases with a movement of the receiving unit (40, 80) along the axis of rotation of the rotational unit (10) in the direction toward the rotational head (24).

Claims

1. Rotational unit (10) for a rotor of a dual centrifuge, comprising: a bearing (14); a rotational head (24) connected to said bearing (14); a housing; said bearing mounted in said housing such that it can rotate about an axis of rotation and can be driven relative to said rotor by an additional rotational mechanism of said centrifuge, said rotational head (24) being detachably connected to a receiving unit (40, 80) for conjoint rotation; said receiving unit comprises a sample container receptacle (60, 70, 100, 110) for at least one sample container; and, said receiving unit (40, 80) and said rotational head (24) are connected by a frictional connection in which some portions of said receiving unit (40, 80) and said rotational head (24) engage in a wedge-like manner, and said frictional connection increases with a movement of said receiving unit (40, 80) along said axis of rotation of said rotational unit (10) toward said rotational head (24).

2. Rotational unit according to claim 1, further comprising: said rotational unit is obliquely mounted in said rotor such that increasing rotation will cause said receiving unit (40, 80) to be urged into said frictional connection.

3. Rotational unit according to claim 1, further comprising: said frictional connection is effective between an underside (42a, 82a) of said receiving unit (40, 80) and a bottom (30) of said rotational head (24).

4. Rotational unit according to claim 1, further comprising: said receiving unit (40, 80) includes frusto-conical feet and said rotational head (24) has matching recesses (32); and, said frusto-conical feet (52, 84) of said receiving unit (40, 80) and said recesses (32) of said rotational head (24) engage.

5. Rotational unit according to claim 4, further comprising: the longitudinal axes of said frusto-conical feet (52, 84) are aligned in parallel to said axis of rotation of said rotational head (24); said frusto-conical feet (52, 84) are of a rotationally symmetric design, and that a line resulting from a longitudinal section through the surface of said conical portion of said frusto-conical feet defines an angle () of 15 with the axis of rotation (D).

6. Rotational unit according to claim 4, further comprising: either of said feet (52, 84) and said receiving unit (40, 80) or said feet (52, 84) and said rotational head (24) are integrally formed from the same material.

7. Rotational unit according to claim 4, further comprising: the number and size of said feet (52, 84) are adapted to the shearing strength of the material of said feet (52, 84) with respect to the forces resulting from the alternating rotational stress in operation of said centrifuge.

8. Rotational unit according claim 4, further comprising: the ratio of the diameter of the base area of the truncated cone of a foot (52, 84) relative to the height of the truncated cone is 10:6.

9. Rotational unit according to claim 7, further comprising: the material used for said receiving unit (40, 80) is polyamide plastic; and, the material used for the rotational head (24) and the sample container receptacles is aluminum alloy EN AW-Al Zn5Mg3Cu-T6.

10. Rotational unit according to claim 4, further comprising: an even number of feet (52, 84), at least four feet, are arranged in a rotationally symmetric manner and uniformly spaced from each other.

11. Rotational unit according to claim 4, further comprising: said feet (52, 84) are located on the edge of said receiving unit (40, 80).

12. Rotational unit according to claim 1, further comprising: said rotational head (24) has a safety vessel (28) which is open toward the top, said safety vessel (28), when mounted, will completely laterally surround said receiving unit (40, 80) with the sample container receptacle (60, 70, 100, 110) therein.

13. Rotational unit according to claim 1, further comprising: a peripheral safety channel (31) is provided in said bottom (30) of said rotational head (24).

14. Rotational unit according to claim 1, further comprising: a safety vessel (28): a lid for said safety vessel (28); and, said lid is connected to said safety vessel by means of a quick-release fastener or a screw connection.

15. Rotational unit according to claim 1, further comprising: a peripheral safety channel (31) is provided in the said bottom (30) of said rotational head (24); said receiving unit has feet (52); and, said bottom (30) of said rotational head (24) has recesses for connection to said feet (52) of said receiving unit (40, 80).

16. Rotational unit according to claim 13, further comprising: a safety vessel (28); and, said safety vessel (28) is connected to said rotational head (24) by a rivet means.

17. Rotational unit according to claim 1 further comprising: said rotational head (24) and said safety vessel (28) are integrally formed as one component of the same material.

18. Rotational unit according to claim 1, further comprising: said receiving unit (40, 80) includes a lateral surface; a safety vessel, said safety vessel includes a perimeter wall; and, said frictional connection acts on said lateral surface of said receiving unit (40, 80) and on said perimeter wall of said safety vessel (28).

19. Rotational unit according to claim 13, further comprising: said sample container receptacle (60, 70, 100, 110) is inserted into said receiving unit (40, 80) and is detachably mounted therein.

20. Rotational unit according to claim 19, further comprising: a set of receiving units (40, 80) is provided for different designs of sample container receptacles (60, 70, 100, 110).

Description

(1) Throughout the description, the claims and the drawings, those terms and associated reference signs are used as are listed in List of Reference Signs which follows below. In the drawings,

(2) FIG. 1 is an exploded view of a rotational unit according to the present invention;

(3) FIG. 2 is a perspective view of a receiving unit according to the present invention for sample container receptacles;

(4) FIG. 2a is a bottom view of the receiving unit of FIG. 2;

(5) FIG. 2b is a lateral view of the receiving unit of FIG. 2;

(6) FIG. 3a is a perspective view of a sample container receptacle;

(7) FIG. 3b is a top view of the sample container receptacle of FIG. 3a;

(8) FIG. 4a is a perspective view of another sample container receptacle;

(9) FIG. 4b is a top view of the sample container receptacle of FIG. 4a;

(10) FIG. 5 is a perspective view of a receiving unit according to the invention for sample container receptacles;

(11) FIG. 5a is a bottom view of the receiving unit of FIG. 5;

(12) FIG. 5b is a lateral view of the receiving unit of FIG. 5;

(13) FIG. 6 is a perspective view of a sample container receptacle according to the invention;

(14) FIG. 7 is a perspective view of another sample container receptacle according to the invention;

(15) FIG. 8 is a perspective view of a receiving unit according to the invention formed integrally with a sample container receptacle, and

(16) FIG. 8a is a detailed view of the wedge element illustrated in FIG. 8.

(17) FIG. 1 is an exploded view of a rotational unit 10 according to the invention for a rotor of a centrifuge. The rotational unit 10 has a cup-shaped housing 12 in which a bearing 14 is concentrically mounted. On its open side, the housing 12 has a flange 19 which extends around its entire periphery and which has eight uniformly spaced bores 20. These bores 20 are matched to bores 18 in a cover disk 16 which is screw-connected to the housing by means of cylinder screws 22 and thus closes the open side of the housing 12.

(18) The bearing 14 has a concentric opening 14a, and the cover disk 16 has a concentric opening 16a. A bearing shaft 34 of a rotational head 24 passes through opening 14a via opening 16a, thus mounting the rotational head 24 in the bearing 14 for concentric rotation therein.

(19) The rotational head 24 has a bottom 30 and a wall 28 which is circumferentially arranged on the bottom 30. The bottom 30 and the wall 28 form a closed safety vessel. A circumferential safety channel 31 is provided in the bottom 30, directly adjacent to the wall 28, which will serve to collect any sample material leaking from the centrifuge in the case of a defect during operation.

(20) Adjacent to its free end, the wall 28 has four positioning pins 29 uniformly spaced from each other along its periphery as well as a single positioning pin 29a. Provided in the bottom 30 are eight holes 32 that are uniformly spaced from each other and located adjacent to the wall 28. The function of said positioning pins 29, 29a and said holes 32 will be explained below with reference to the following figures. Toothing 26 extends circumferentially along the entire periphery of the wall 28 and is connected to the wall for conjoint rotation therewith. Said toothing 26 meshes with a gear, not shown for the sake of clarity, of a conventional gear drive of another rotation mechanism of the centrifuge. The use of gear drives as a further rotation mechanism is well known and has already been described in the prior art, for which reason no further explanations are required here.

(21) FIG. 2 is a perspective view of a receiving unit 40 according to the invention for sample container receptacles. FIG. 2a is a bottom view of the receiving unit 40 of FIG. 2. FIG. 2b is a lateral view of the receiving unit 40 of FIG. 2. The receiving unit 40 has an essentially circular bottom 42 with an underside 42a and two pairs of partition walls 44 each arranged in parallel to each other and having ends 56. The circumference of the bottom 42 has been chosen such that the receiving unit 40 can be inserted with only mirror clearance in the rotational head 24 with the safety vessel. Any sample material leaking from the centrifuge during operation in the event of a defect can thus flow downward through a gap between the circumference of the bottom 42 and the inner circumference of the rotational head 24 of FIG. 1 and the wall 28 and into the safety channel 31 where it is then collected.

(22) The two pairs of partition walls 44 are arranged perpendicular to each other in the shape of a double cross. After the receiving unit 40 has been introduced into the rotational head 24, this will thus result in a total of five recesses 46a, 46b for receiving sample container receptacles 60, 70 as described with reference to the following FIGS. 3a, 3b, 4a and 4b. The recesses 46a, 46b are limited laterally by parts of the partition walls 44 of the same length and partially by the wall 28 of the rotational head 24, which wall 28 has been omitted from FIG. 2 for the sake of clarity. The recess 46a located at the center of the double cross is limited on four sides by parts of the partition walls 44 and has a square base area. On each side of the recess 46a there is an adjacent recess 46b which is limited on three sides each by portions of the partition walls 44. Another four recesses 46c which are limited by portions of the partition walls 44 on two sides each, are located between two recesses 46b each, as viewed along the periphery of the bottom 30. In each recess 46a and 46b a projection 54 is formed on at least part of a partition wall 44, which projection serves to guide the sample container receptacles 60, 70 during their insertion.

(23) A sample container receptacle 60, 70 whose outer circumference is adapted to the base area of the recess 46a is also fixed in position without clearance in each direction parallel to the bottom 30 of the receiving unit 40, since the ends 56 of the partition walls 44 form stops together will the wall 28 of the rotational head 24, which stops prevent the sample container receptacles 60, 70 from being moved beyond the end 56. Consequently, the receiving unit 40 is suited to accommodate up to five sample container receptacles 60, 70 at a time for centrifugation.

(24) For enhanced stability of the partition walls 44, each recess 46c is provided with a rounded outer wall 48 which is adapted to the area of the wall 28 of the rotational head 24 associated with the receiving unit 40 when inserted, which wall 48 connects the two associated ends 56 of the partition walls 44. A stabilizing rail 48a is mounted at the center of each of the four outer walls 48, which rail 48a rests against the wall 28 of the rotational head 24 in the inserted state of the receiving unit 40. During insertion of the receiving unit 40 into the rotational head 24, the four stabilizing rails 48a additionally cooperate with the positioning pins 29 in the wall 28 as illustrated in FIG. 1 and thus serve to guide the receiving unit 40. Moreover, the positioning grooves 48a and their associated positioning pins 29 act together to support the receiving unit 40 in the rotational head 24 for conjoint rotation. Furthermore, a single guide rail 49 is provided on one of the four outer walls 48 which rail 49 has the positioning pin 29a associated with it. The interaction of the guide rail 49 with the positioning pin 29a ensures the correct alignment of the receiving unit 40.

(25) The recesses 46c accommodate essentially cylindrical taper pins 50 which extend through the bottom 42 of the receiving unit 40 and are firmly connected to said bottom 42. On the underside 42a of said bottom 42, the free end of each taper pin 50 forms a frusto-conical foot 52 which is dimensioned so as to match its associated hole 32 in the bottom 30 of the rotational head 24. As a result, once the receiving unit 40 has been inserted, the feet 52 and the holes 32 will yield a reliable wedging/clamping effect.

(26) On the side opposite the underside 42a of the bottom 42, the taper pins 50 are oriented perpendicular to said bottom 42 and extend vertically almost up to the height of the free ends of the outer walls 48.

(27) The underside 42a furthermore has a cross-shaped arrangement of knobs 58 which act to space the underside 42a from the bottom 30 so as to minimize heat transfer. The cross-shaped configuration was chosen because it is a good compromise between stability and weight reduction.

(28) FIG. 3a is a perspective view of an embodiment of a sample container receptacle 60. FIG. 3b is a top view of the sample container receptacle 60.

(29) The sample container receptacle 60 has a bottom wall 61 matching the recesses 46a and 46b illustrated in FIG. 2 and having an edge 62a, another edge 62c which is parallel to the edge 62a, an edge 62b and another edge 62d which is parallel to the edge 62b, with all these edges being of the same length. There are four edges 62e which extend perpendicular to the bottom wall 61. An insertion wall 63 delimited by edge 62a and two edges 62e has six bearing recesses 68a provided therein, in which up to six centrifuge tubes can be stored horizontally. Parallel to the bottom wall 61, a top wall 67 of the sample container receptacle 60 is arranged. Six bearing recesses 68b are provided in the top wall 67 in which up to six centrifuge tubes (not shown for the sake of clarity) can be accommodated vertically. A positioning groove 64 is provided in a sidewall 66 which is delimited by the edge 62b and two edges 62e, which groove 64 is associated with a projection 54 as shown in FIG. 2 and serves to correctly position said projection 54 in the recess 46a, 46b as the sample container receptacle 60 is inserted.

(30) FIG. 4a is a view of an alternative embodiment of a sample container receptacle 70. FIG. 4b is a top view of the sample container receptacle 70.

(31) The sample container receptacle 70 differs from the sample container receptacle 60 merely in that it has nine bearing recesses 78b provided in its top wall 77 instead of the six bearing recesses 68b in the top wall 67, and in that a single bearing recess 78a is provided in its insertion side 73 instead of the six bearing recesses 68a in the front side 63.

(32) The two embodiments of the sample container receptacles 60, 70 only show two options of how the correspondingly designed sample container receptacle can be used to accommodate cylindrical tubes of different sizes and number in a rotational unit 10 according to the invention. Sample container receptacles suitable for other requirements can be manufactured easily.

(33) FIG. 5 is a view of an alternative embodiment of a receiving unit 80 according to the invention. FIG. 5a is a bottom view of the receiving unit 80 of FIG. 5. FIG. 5b is a lateral view of the receiving unit 80 of FIG. 5.

(34) The receiving unit 80 differs from the receiving unit 40 in that it is adapted to receive a single sample container receptacle 100 (see FIG. 6) or 110 (see FIG. 7) and therefore has no partition walls similar to the partition walls 44 of receiving unit 40. Secondly, in contrast to receiving unit 40, receiving unit 80 has a safety wall 88 which is arranged circumferentially on the outer contour of a bottom 82. As regards the insertion of the receiving unit 80 into the rotational head 24 as well as the resulting wedging effect between the feet 84 provided on the underside 82a of the receiving unit 80 and the holes 32 provided in the rotational head 24, receiving unit 80 does not differ from what was described with reference to FIG. 2, 2a, 2b.

(35) An inner contour 88a of the safety wall 88 delimits a cross-shaped receiving space 86. Two rectangular legs 86a and 86b of the receiving space 86 are arranged so as to be perpendicular to each other, with the surface areas of the first leg 86a and of the second leg 86b being identical and corresponding to the surface areas of the sample containers 100, 110 shown in FIG. 6 and FIG. 7.

(36) The first leg 86a is adapted to receive the sample container receptacle 100. For this purpose, a recess 90 has been provided in the safety wall 88 in either end of leg 86a, both said recesses 90 being arranged diametrically to one another relative to the leg 86a. The recesses 90 serve to ensure reliable wedging of the sample container receptacle 100 with inserted sample container in the receiving unit 80, as will be explained in more detail with reference to FIG. 6.

(37) The second leg 86b serves to receive the sample container receptacle 110. For this purpose, one end of the leg 86b has a recess 92a in the safety wall 88 and the second end of the leg 86b has two recesses 92b in the safety wall 88. These recesses 92a, b serve to ensure secure wedging of the sample container receptacle 110 in the receiving unit 80, as will be explained in more detail with reference to FIG. 7.

(38) For enhanced protection of the rotational unit from contamination by sample material in the event of damage to a receptacle, it is also conceivable to insulate the safety wall 88 from the outside and to provide a lid for the receiving unit 80 on the safety wall 88. This will limit potential leakage of sample material from the sample container receptacles 100, 110 to the receiving unit 80.

(39) FIG. 6 is a view of a first sample container receptacle 100 according to the invention, whichas described with reference to FIGS. 5, 5a and 5bis adapted to be received in the first leg 86a of the receiving unit 80.

(40) The sample container receptacle 100 has an opening 104a, b each in two front sides 102a, b which can receive a centrifuge tube each (not shown for the sake of clarity) for vertical storage therein. An end of the centrifuge tube (lid side) which protrudes from the respective opening 104a, b on either front side 102a, b engages an associated recess 90 provided in the safety wall 88. This results in a wedging action which firmly clamps the sample container receptacle 100 in the receiving unit 80.

(41) FIG. 7 is a view of a second sample container receptacle 110 according to the invention which is adapted to be received in the second leg 86b of the receiving unit 80.

(42) In FIG. 7, on the front side 112a facing the observer, the sample container receptacle 110 has an opening 114a and on the front side 112b facing away from the observer, it has two openings 114b. These openings 114a, b can be used to receive centrifuge tubes (not shown here for the sake of clarity) so as to vertically accommodate them therein. Similar to the solution shown in FIG. 6, the ends of a centrifuge tube which protrude from the respective opening 114a, b on either front side 112a, b engage an associated recess 92a, b made in the safety wall 88. This produces a reliable wedging action between the sample container receptacle 110 and the receiving unit 80.

(43) FIG. 8 is a view of a receiving unit 120 which is integrally formed with a sample container receptacle 124 and adapted to horizontally receive two sample containers.

(44) Similar to the receiving units 40 and 80 described with reference to FIGS. 2 and 5, the receiving unit 120 has an essentially circular bottom 122 whose circumference matches the inner circumference of the rotational head 24 of FIG. 1 and the wall 28 so as to allow the receiving unit 120 to be fitted without any clearance into the rotational head 24 with the safety vessel. On the bottom 122 a sample container receptacle 124 is horizontally disposed and adapted to receive two sample containers (vials, not shown here) in a horizontal position. The sample container receptacle 124 comprises two parallel receiving tubes 124a, 124b integrally formed from the same material. At their opposite ends, with respect to their longitudinal extension, the receiving tubes 124a, 124b have a receiving opening 126 each, into which the vials can be introduced.

(45) Four wall members 123 are arranged vertically on the bottom 122 and distributed along its periphery, which members 123 are adapted to center the receiving unit 120 as it is introduced into the rotational head 24 and to stabilize it once it has been fully inserted. These members therefore function in a way that can be compared to the ends 56 of the partition walls 44 of the receiving unit 40.

(46) A closing plate 128 each is provided to seal each receiving opening 126, as can be seen in FIG. 8a. The surface area of this closing plate 128 is defined by a semicircular portion 128a followed by a rectangular portion 128b. This closing plate 128 can be introduced in a direction of insertion 132 by means of a recess in the bottom 122 which cannot be seen from this perspective, which recess is followed by a groove (not visible in this view) which each extends in the region adjacent to the receiving opening 126 within the receiving tubes 124a, 124b. This groove serves to guide and secure the closing plate 128. The thickness of the closing plate 128 as well as the width of the groove are essentially adapted to each other, with the thickness of the rectangular portion 128b slightly increasing against the direction of insertion 132. This results in a wedging effect once the closing plate has been fully inserted in the groove. This wedging effect prevents the closing plate 128 from accidentally falling out of the recess in the bottom 122. Furthermore, a wedging effect is produced between the fully inserted closing plate 128 and the introduced vial.

(47) The closing plate 128 has a web 130 mounted thereon which serves as a handle for the user.

LIST OF REFERENCE SIGNS

(48) 10 rotational unit 12 housing 14 bearing 14a concentric opening 16 cover disk 16a concentric opening 18 bores 19 flange 20 bores 22 cylinder screws 24 rotational head 26 toothing 28 wall 29 positioning pin 29a positioning pin 30 bottom 31 safety channel 32 holes 34 bearing shaft 40 receiving unit 42 bottom 42a underside 44 partition walls 46a, b, c recesses 48 exterior walls 48a stabilizing rails 49 guide rail 50 taper pins 52 feet 54 projection 56 ends 58 knob assembly 60 sample container receptacle 61 bottom wall 62a, b, c, d, e edges 63 insertion wall 64 positioning grooves 66 sidewall 67 top wall 68a, b bearing recesses 70 sample container receptacle 73 insertion wall 77 top wall 78a, b bearing recesses 80 receiving unit 82 bottom 82a underside 84 feet 86 receiving space 86a first leg 86b second leg 88 safety wall 88a interior profile 90 recesses 92a, b recesses 100 dual sample container receptacle 102a, b front sides 104a, b openings 110 triple sample container receptacle 112a, b front sides 114a, b openings 120 receiving unit 122 bottom 123 wall members 124 sample container receptacle 124a, b receiving tubes 126 receiving apertures 128 closing plate 128a semicircular area 128b rectangular area 130 web 132 direction of insertion angle D axis of rotation