CENTRIFUGE ROTOR

Abstract

The invention relates to a rotor 10 of a centrifuge 100 having a rotor axis R, a receiving space 18 for samples to be centrifuged, a lid 40 which limits the receiving space 18 at the top, which is concentrically mounted relative to the rotor and which has, on its side remote from the receiving space 18, a handle 44 for carrying the rotor and the lid 40, and a locking mechanism of lid 40 and rotor, which mechanism is mounted in a support 52, 54 in the lid 40, said locking mechanism 50, 34b comprising a locking element 50 adapted to be movable between a locking position and an unlocking position and which has an actuating member 56 and a latching element 58, with the actuating member 56 and the latching element 58 being axially spaced from each other relative to the rotor axis R. The invention is characterized in that the locking element 50 is formed by a tilt lever which has the actuating member 56 mounted on its upper end and the latching element 58 mounted on its lower end, with its pivot axis being aligned perpendicular to the rotor axis R.

Claims

1-19. (canceled)

20. A rotor (10) of a centrifuge (100), comprising: a rotor axis (R); a receiving chamber (18) in said rotor for a sample container to be centrifuged; said receiving chamber includes a top; a lid (40); said lid resides at said top of said receiving chamber (18); said lid is concentrically mounted relative to said rotor; a handle (44) for carrying said rotor and said lid (40); said handle (44) mounted remotely with respect to said receiving chamber (18); a locking mechanism for locking said lid (40) to said rotor; a support (52, 54) in said lid (40); said locking mechanism is mounted in said support (52, 54) in said lid (40); said locking mechanism (50, 34b) includes a tilt lever; said locking mechanism is adapted to be movable between a locking position when said lid is affixed to said rotor and an unlocking position when said lid is not affixed to said rotor, said locking mechanism comprises: a tilt lever, said tilt lever includes an upper end. a lower end, and a pivot axis aligned perpendicular to said rotor axis (R); an actuating member (56) and a latching element (58); said actuating member resides on said upper end of said tilt lever and a latching element resides on said lower end of said tilt lever, said actuating member (56) and said latching element (58) being axially spaced from each other relative to said rotor axis (R), and, said tilt lever being rotatable about said pivot axis enabling locking of and unlocking of said lid and said rotor.

21. The rotor as claimed in claim 20, further comprising; a recess in said rotor; and, said latching element (58) in said locking position engages said recess of said rotor.

22. The rotor as claimed in claim 20, further comprising: a plurality of tilt levers arranged symmetrically to each other relative to said rotor axis (R).

23. The rotor as claimed in claim 20, further comprising: said pivot axis subdivides said tilt member (50) into said actuating member (56) and said latching element (58).

24. The rotor as claimed in claim 20 wherein said latching element (58) and said actuating member (56) are of the same length.

25. The rotor as claimed in claim 20, further comprising: said rotor includes a pin; said pin of said rotor resides in said receiving chamber (18); said pin (34) of said rotor is coaxial with said rotor axis (R); and, said pin includes recess (34b) for engaging said latching element (58).

26. The rotor as claimed in claim 25 wherein said recess (34b) of said pin (34) is an annular groove.

27. The rotor as claimed in claim 25, further comprising: said lid includes an aperture (42a); said pin (34) at least partly engages said handle (44) through said aperture (42a) in said lid (40).

28. The rotor as claimed in claim 25, further comprising: said pin (34) has an end; said pin is partially conical and tapers toward an end.

29. The rotor as claimed in claim 28, further comprising: said pin (34) is on a coaxial shoulder (35) of said rotor; a seal (43) is mounted in said coaxial shoulder and surrounds said pin (34); said lid (40), when in said locking position, abuts and engages said seal (43); said seal (43) is adapted to seal said receiving chamber (18) of said rotor from said pin (34); and, said seal (43) is adapted to seal receiving chamber (18) of said rotor from said aperture (42a) of said lid (40).

30. The rotor as claimed claim 20, further comprising: said tilt lever (50) is spring-loaded in the direction of said locking position; and/or said handle (44) is operatively connected to a blocking element (48b) which, when activated, secures said tilt lever of said lid (40) and said rotor in said locking position.

31. The rotor as claimed in claim 30, further comprising: said support (52, 54) of said locking mechanism (50, 34b) is embedded in a bearing body (46); said support (52, 54) is arranged concentrically to said lid (40) and is connected thereto.

32. The rotor as claimed in claim 30, further comprising: said handle (44) is concentrically mounted relative to said bearing body (46) and mounted so as to be movable relative to said bearing body (46).

33. The rotor as claimed in claim 30, further comprising: said handle (44) is integrally formed with said blocking element (48b) which, when activated, said handle (44) being adapted to be moved, together with said blocking element (48b), on said bearing body (46) between a first position which blocks said tilt lever (50) in said locking position, and a second position which releases said locking element (50), which tilt lever (50) is movable from said locking position into said releasing position when in a second position.

34. The rotor as claimed in claim 33, further comprising: said handle (44) is movable on said bearing body (46) along said rotor axis (R) from said first position to said second position and vice versa.

35. The rotor as claimed in claim 33, further comprising: moving said handle (44) with said blocking element (48b) away from said lid (40) corresponds to a movement into a first position; and, moving said handle (44) with said blocking element (48b) towards said lid (40) corresponds to a movement into a second position.

36. The rotor as claimed in claim 33, further comprising: said handle (44) is spring-loaded in the direction of said lid (40).

37. The rotor as claimed in claim 20, further comprising: a blocking device (22, 24, 26) fixing said rotor relative to a drive shaft (104) of a centrifuge (100); and, said blocking device (22, 24, 26) can be operated via the lid (40) placed on said rotor.

38. A centrifuge (100) in combination with a rotor, comprising: a drive (102); a drive shaft (104); said drive shaft includes a support (106); said support includes a free end; said free end of said support engages said rotor.

Description

[0033] Throughout the description, claims and drawings, those terms and associated reference signs are used as are listed in the List of Reference Signs which follows below. In the drawings,

[0034] FIG. 1 is a lateral sectional view of the rotor according to the invention with the lid in place, in which the locking of the lid has been activated;

[0035] FIG. 2a is a lateral sectional view of the lid of FIG. 1, in which locking has been activated and blocking deactivated;

[0036] FIG. 2b is a lateral sectional view of the lid, in which locking has been activated and blocking activated;

[0037] FIG. 2c is a lateral sectional view of the lid, in which both locking and blocking have been deactivated;

[0038] FIG. 3 is a lateral sectional view of the rotor of FIG. 1 with the lid removed, as well as of the rotor receiving space of the drive shaft of a centrifuge (section through rotor shaft);

[0039] FIG. 3a is a view of a detail marked III a in FIG. 3;

[0040] FIG. 3b is a perspective view of a blocking element;

[0041] FIG. 4 is a perspective sectional view of the rotor, similar to the view of FIG. 1; and

[0042] FIG. 5 is a lateral sectional view of a centrifuge of the invention.

[0043] FIG. 1 is a lateral sectional view of a rotor 10 according to the invention with the lid 40 in place and activated locking of the lid 40.

[0044] The rotor 10 has the basic shape of a truncated cone which tapers toward the top. Provided in a rotor head 12 in a conventional manner and uniformly spaced from each other are receiving units 14 for sample containers 16. The longitudinal extension of the receiving units 14 is parallel to the lateral surface 12a of the rotor head 12. FIG. 1 shows four sample containers 16 inserted in the receiving units 14. Sealing caps 16a of the sample containers 16 protrude from the respective receiving units 14 into a receiving chamber 18 of the rotor 10.

[0045] Mounted concentrically in the bottom 12b of the rotor head 12 is a rotor seat 20 which is associated with the support 106 of the centrifuge 100. The rotor seat 20 has a frusto-conical first portion 20a which tapers in a removal direction E and which is joined by a cylindrical second portion 20b in an axial direction. The upper boundary of the rotor seat 20 is a boundary surface 20c which is perpendicular to the rotor axis R. Concentrically mounted on this boundary surface 20c is a locking ball 22 which faces the support 106 of the centrifuge 100 and extends away from the boundary surface 20c along the rotor axis R. The function of this locking ball 22 will be described in more detail with reference to FIGS. 3, 3a and 3b.

[0046] Above the locking ball 22, a shoulder 35 is formed in the receiving chamber 18 which is concentric to the rotor axis R. Likewise concentrically formed on said shoulder 35 is a rotor pin 34 whose external contour 34a tapers towards its free end. The rotor pin 34 is shown in more detail in FIG. 3 and in particular in the detail illustrated in FIG. 3a.

[0047] Placed on the rotor 10 is a lid 40 which seals the receiving chamber 18 from the outside in an aerosol-tight manner. Mounted concentrically relative to the lid 40 is a handle 44 which can be used to place the lid 40 on the rotor 10 and to remove the lid 40 from the rotor 10. The handle 44 is partially inserted in a blind hole shaped cylindrical recess 42 of the lid 40 and firmly connected to the lid 40 in a conventional manner. The recess 42 has an aperture 42a which is concentric to the rotor axis R and provided in the cylindrical bottom of the recess, and through which the free end of the rotor pin 34 engages the handle The axial extension of the recess 42 is dimensioned such thatin the state of the lid 40 in place on the rotor 10the front face 42b of the recess 42 which faces the rotor seat 20 will extend right up to a front face 35a of the shoulder 35. A seal 43 provided in the front face 35a of the shoulder 35 seals the lid 40 from the shoulder 35 so as to prevent leakage of sample material from the receiving chamber 18 into the handle 44 and thus into the environment in the event of a vessel rupture or the like.

[0048] For the sake of clarity, the handle 44 is illustrated in detail in the views of FIGS. 2a, 2b and 2c. The handle 44 has a cylindrical bearing body 46 which has a wall 48 mounted for movement in an axial direction on its outer wall. Within said bearing body 46, two tilt levers 50 are mounted opposite each other relative to the rotor axis R. The longitudinal extension of the tilt levers 50 is essentially aligned axially. Provided approximately in the middle of the cross-section of the tilt levers 50 is a thickened portion 52 which points toward the bearing body 46 and which is rounded. A strut 54 each, which has been omitted from this view for reasons of clarity, extends through these thickened portions 52, over which the tilt levers 50 can be tilted. The strut 54, together with its associated recess in the thickened portion 52, thus forms a pivot joint for the tilt lever with respect to the bearing body 46 and the wall 48 which completely sur-rounds at least parts of the latter. On the upper end of the tilt lever 50, there is an actuating member 56 which faces in a direction away from the rotor axis R. Moreover, each tilt lever 50 tapers in cross-section toward the upper end. The tilt lever 50 also tapers in cross-section toward the lower end, on which a latching element 58 each pointing to the rotor axis R is mounted on the tilt lever 50.

[0049] The actuating members 56 each have an associated recess 46a in the bearing body 46 and a recess 48a in the wall 48 through which the actuating members 56 partially protrude laterally from the handle 44.

[0050] At the upper end of each tilt lever 50 is a recess 60 each which is engaged by an end of a spring 62, more specifically a leaf spring, which is arranged along the bearing body 46 of the handle 44. The ends of the springs 62 which are remote from the recesses 60 are clamped onto the bearing body 46 and radially preloaded toward the outside. The spring 62 will thus urge the upper ends of the tilt levers 50 radially outwards, if, as shown in FIG. 2a, no force is applied manually from the outside, causing said to abut on the bearing body 46, and the actuating members 56 will protrude laterally from the handle 44 to a maximal extent. At the same time, the tilt levers 50 will be tilted about the struts 54 in such a way that the lower ends will be spaced from the bearing body 46. The latching elements 58 will latch into engagement with a circumferential groove 34b made in the external contour 34a of the rotor pin 34. In this position of the tilt levers 50 as shown in FIG. 2a, the rotor 10 and the lid 40 are locked together.

[0051] FIG. 2b shows the handle 44 with the tilt levers 50 in a position identical to the one of FIG. 2a, i.e. the locked position. Here, the wall 48 of the handle 44 has been moved axially relative to the bearing body 46 in a removal direction E. This relative change in position of the wall 48 with respect to the bearing body 46 is brought about by an operator grasping the handle 44 and lifting it without releasing the locking of lid 40 to rotor 10, rather than applying force to the actuating members 56 so as to tilt the tilt levers and release the latching elements 58 from the nut 34b made in the external contour 34a of the rotor pin 34.

[0052] The relative change in position of the wall 48 also displaces a projection 48b which is located on the end of the wall 48 that points in the direction of the receiving space 18, and extends in the direction of the rotor axis R and which penetrates a recess (not shown) in the bearing body 46. Lifting the wall 48 in the removal direction E will cause the projection 48b to abut on the tilt lever 50 in the area between the thickened portion 52 and the latching element 58. This will block the tilt lever 50 so as to keep it from being tilted about the strut, and the latching element 58 will thus be secured within the groove 34b. The locking effected between the rotor 10 and the lid 40 cannot be released in this blocked position.

[0053] A force which acts in a direction opposite to that of the removal direction E is applied to the wall 48 by a spring which is not shown for the sake of clarity. As soon as the operator turns off the rotor 10 or places it inside a centrifuge 100 and thus neutralizes the weight force acting on the handle 44, the wall 48 will return to its initial position and the blocking of the tilt levers 50 by each projection 48b will be released. The projection 48b of wall 48 thus constitutes a safety element which either blocks or allows actuation of the tilt lever 50, as required, depending on its respective position.

[0054] As can be seen in FIG. 3, a bent free end 49 of the bearing body 46 and a shoulder 49a associated with the free end 49 and formed in the wall 48 together form a stop, thus limiting the axial displacement of the wall 48 on the bearing body 46.

[0055] In FIG. 2c, the wall 48 of the handle 44 is illustrated in its initial position again. The projection 48b is again below the tilt levers 50, which thus eliminates the blocking of the tilt levers 50 as shown in FIG. 2b. The tilt levers 50 are tilted about their pivot joints formed by a strut 54 and respective associated recess in the thickened portion 52, and the latching elements 58 are outside the groove 34b. The locking between the rotor 10 and the lid 40 has been released, and the lid 40 can be removed from the rotor 10.

[0056] The essentially axial design and arrangement of the tilt levers 50 allows for numerous possible designs of the locking of the lid 40 to the rotor 10. The rotor pin 34 could be made much more compact, for example, and the recess 42 of the lid 40 could be made longer so thatwith the lid removedmore space is available in the receiving chamber 18 for sample containers 16 which then can simply be removed from the rotor or placed inside the rotor. Furthermore, the length of the tilt levers 50 and the length ratio of a leg associated with the actuating member 56 and a leg associated with the latching element 58 can be varied relative to each other and thus adapted to the respective conditions. In any case, the lid 40 will be firmly locked onto the rotor 10 by a latching element 58 mounted in the lid which engages a recess 34b made in the rotor 10, and the locking can be released via actuating members 56 arranged above the lid 40 at a position which can be reached conveniently by the operator.

[0057] FIG. 3 is a lateral sectional view of the rotor 10rotated by 90 relative to the views of FIGS. 2a to 2cin an exploded view with the lid 40 removed, as well as of a support 106 of a centrifuge 100 which is also shown schematically in FIG. 5

[0058] When the rotor 10 is placed onto the support 106 of the centrifuge 100, the locking ball 22 will engage an aperture 110 of an abutment insert 108 which is concentrically arranged on the support 106 and screwed together with the latter. The aperture 110 is dimensioned so as to allow passage of the locking ball 22 with minimum clearance. Following after the aperture 110 is an internal contour 112 of the abutment insert 108 which widens conically in a direction opposite to the direction of removal E.

[0059] Arranged in a cylindrical inner area 114 of the support 106 is a spring 24 in which a blocking unit 26 is mounted to which a spring force is applied which acts in the removal direction E, which blocking unit 26 is separately shown in FIG. 3b for reasons of clarity. The blocking unit 26 has four blocking springs 30 which are interconnected via a connecting ring 28 and each have a blocking element 30a mounted on their respective ends. The shape of the blocking elements 30a is essentially adapted to the external contour of the locking ball 22. Placing the rotor 10 onto the support 106 of the centrifuge 100 will cause the blocking elements 30a and thus the entire blocking unit 26 to be initially pressed downward, by the locking ball 22 entering the aperture 110, into the area of the internal contour 112 in the abutment insert 108 which is larger than the aperture 110 so that the blocking elements 30a can then be pressed apart. The blocking elements 30a then slide along the locking ball 22 to the point where they will ultimately surround the locking ball 22 with the rotor 10 completely in place on the support 106. The spring force will cause the blocking unit 30 to again move in the removal direction E, and the blocking elements 30a will abut on the internal contour 112 of the abutment insert 108. With the blocking elements 30a in abutment, the circumference of the locking ball 22 with the blocking elements 30a will increase to such an extent that it will no longer be able to pass through the aperture 110 of the abutment insert 108. The abutment of the blocking elements 30a on the internal contour 112 of the abutment insert 108 will thus prevent any movement of the blocking elements 30a in a radial direction. The rotor 10 is thus securely fixed in an axial direction on the support 106 of the centrifuge 100.

[0060] The locking ball 22 is penetrated by a bore 32. The bore 32 extends from the locking ball 22 through the rotor head 12 and the adjacent rotor pin 34. As viewed in the removal direction E, the inner diameter of the bore 32 widens at a first shoulder 32a and again at a second shoulder 32b.

[0061] Reaching through the bore 32 is an unlocking pin 36 which in turn has a first shoulder 36a which is associated with the first shoulder 32a of the bore 32, and a second shoulder 36b which is associated with the second shoulder 32b of the bore 32. For reasons of clarity, the area marked III a in FIG. 3 which shows the unlocking pin 36 inserted in the bore 32 is illustrated in detail in FIG. 3a. In the areas respectively associated with each other, the diameter of the unlocking pin 36 and the internal diameter of the bore 32 are adapted to each other so as to allow axial movement of the unlocking pin 36 within the bore 32. Axial movement of the unlocking pin 36 in the direction of the support 106 is limited and possible up to a final position in which the respective corresponding shoulders 32a and 36a as well as the shoulders 32b and 36b will then abut on each other.

[0062] The longitudinal extension of the unlocking pin 36 is dimensioned such that a free end 38 thereof will be made to protrude from the locking ball 22 as the unlocking pin 36 is moved against the removal direction E, will engage the blocking unit 26 and increasingly displace the blocking unit 26 against the force of the spring 24, with the blocking elements 30a also moving along the locking ball 22 into the area of the internal contour 112 which is wider than the aperture 110 of the abutment insert 108, thus allowing the blocking elements 30a to bend outwardly. Once unlocking pin 36 reaches the above described final position, the blocking unit 26 has been moved by a distance s.sub.s to such an extent that the blocking elements 30a will completely release the locking ball 22, i.e. as the locking ball 22 passes the blocking elements 30a, the latter will be bent radially outwardly. The locking ball 22 will then be able to pass through the aperture 110 of the abutment insert 108 again, and the rotor 10 can be taken off the support 106 of the centrifuge 100.

[0063] It is also conceivable to interchange the positions of the locking ball 22 and of the blocking unit 30, i.e. to have the locking ball 22 arranged on the side of the shaft, to mount the blocking unit 30 for axial movement in the rotor 10, with the internal contour 112 of the abutment insert 110 consequently tapering in the removal direction E.

[0064] For activating the unlocking pin 36, an actuating pin 74 is provided in the handle 44, whichtogether with the unlocking pin 36forms an activating element 36,74.

[0065] For this purpose, a support insert 70 is incorporated in the bearing body 46 of the handle 44, concentrically to the rotor axis R, which is flush with the handle pieces 45 on the side facing away from the rotor 10. An axial bore 72 runs through the support insert 70 and tapers in steps at the end facing the rotor 10 so as to form an aperture 72a there which is smaller in diameter than the diameter of the bore 72.

[0066] The actuating pin 74 is movably mounted within the bore 72 and comprises a cylindrical first portion 76 which is adapted in diameter to the internal diameter of the bore 72, as well as a cylindrical second portion 78 which is adapted in diameter to the internal diameter of the aperture 72a. The second portion 78 runs through the aperture 72a and engages an inner space 47 of the handle 44 which is delimited laterally by the bearing body 46. A shoulder 80 formed between the first portion 76 and the second portion 78 thus serves as a boundary for axially moving the actuating pin 74 into a final position, against the removal direction E. The free end of the first portion 76 is designed as a pushbutton 82 which, in its non-depressed state, projects completely from the support insert 70 and is of a height h.sub.D. When the pushbutton 82 is completely depressed, it will be flush with the free side of the support insert 70, and the actuating pin 74 will be moved against the removal direction E by a distance s.sub.B which corresponds to the height h.sub.D. The actuating pin 74 is thus moved into its above described final position.

[0067] As the lid 40 is placed onto the rotor 10, the rotor pin 34 housing the unlocking pin 36 will enter the inner space 47 of the bearing body 47 of the handle 44 through the aperture 42a. Centering the lid 40 will be facilitated by the conically tapering external contour 34a on the free end of the rotor pin 34.

[0068] The lengths of the unlocking pin 36 and the actuating pin 74 have been chosen such that their ends which face each other will abut on each other once the lid 40 is completely in place on the rotor 10. Thus the unlocking pin 36 and the actuating pin 74 together form an activating element 36, 74 which can be used to move the blocking unit 26 axially by the distance s.sub.s into a release position even with the lid 40 in place, and the lock between the rotor 10 and the shaft 104 can be deactivated in the manner described above, thus allowing the rotor 10 to be taken off the support 106.

[0069] In the present embodiment, the height h.sub.D of the pushbutton 82 is of the same length as the distance s.sub.B and the distance s.sub.s. The pushbutton 82 may also be designed to be higher, in which case it will also protrude from the support insert 70 in its activated state. However, the height h.sub.D must not be smaller or not much smaller than the length of the distances s.sub.B and s.sub.s, else the required height of stroke of the blocking unit 26 for unlocking will not be obtained and unlocking cannot be reliably ensured anymore.

[0070] Similarly, it is possible to form the activating element 36, 74 as one piece and optionally either mount it in the handle 44 of the lid 40 or in the receiving chamber 18 of the rotor 10, in the rotor pin 34. When the activating element 36, 74 is mounted in the handle 44, the rotor pin 34 can be of a more space-saving design, or the rotor pin 34 can almost completely be omitted.

[0071] The perspective view of FIG. 4 illustrates how the locking mechanism 50, 34b for interlocking the lid 40 and the rotor, and the blocking device 22, 24, 26 for securing the rotor 10 to the drive shaft 104 are embedded in the handle 44. The operator will thus only need one hand to operate the two unlocking means, and will not have to change the position of his hand much, either. Since the pushbutton 82 will have to be pressed down vertically to unlock the blocking device 22, 24, 26 which secures the rotor 10 to the shaft 104, whereas unlocking the device which secures the lid 40 to the rotor 10 is accomplished by exerting horizontal pressure on both sides of the two actuating members 56, the risk of incorrect use is low.

[0072] FIG. 5 is a lateral sectional view of a centrifuge 100 according to the invention, from which a housing and a base have been omitted for reasons of clarity.

[0073] As already described with reference to FIG. 3, the rotor 10 illustrated in FIGS. 1 to 4 is connected to the drive shaft 104 via the support 106 and rotates about rotor axis R. The drive shaft 104 is driven by the motor 102 underneath it.

[0074] For safety and soundproofing reasons, the rotor 10 is surrounded by a safety vessel 116. The motor 102 engages the safety vessel 116 via an aperture 116a.

[0075] Provided above the safety vessel 116 is a centrifuge lid 118 which is connected to the housing (not shown) in a conventional manner and seals the centrifuge 100 at its top.

LIST OF REFERENCE SIGNS

[0076] 10 rotor [0077] 12 rotor head [0078] 12a lateral surface [0079] 12b bottom [0080] 14 receiving units [0081] 16 sample containers [0082] 16a sealing caps [0083] 18 receiving chamber [0084] 20 rotor seat [0085] 20a first portion [0086] 20b second portion [0087] 20c boundary surface [0088] 22 locking ball [0089] 24 spring [0090] 26 blocking unit [0091] 28 connecting ring [0092] 30 blocking springs [0093] 30a blocking elements [0094] 32 bore [0095] 32a first shoulder [0096] 32b second shoulder [0097] 34 rotor pin [0098] 34a external contour [0099] 34b groove [0100] 35 shoulder [0101] 35a front face [0102] 36 unlocking pin [0103] 36a first shoulder [0104] 36b second shoulder [0105] 38 free end [0106] 40 lid [0107] 42 recess [0108] 42a aperture [0109] 42b front face [0110] 43 seal [0111] 44 handle [0112] 45 handle pieces [0113] 46 bearing body [0114] 46a recess [0115] 47 inner space [0116] 48 wall [0117] 48a recess [0118] 48b projection [0119] 49 free end [0120] 49a shoulder [0121] 50 tilt lever [0122] 52 thickened portion [0123] 54 strut [0124] 56 actuating member [0125] 58 latching element [0126] 60 recess [0127] 62 springs [0128] 70 support insert [0129] 72 bore [0130] 72a aperture [0131] 74 actuating pin [0132] 76 first portion [0133] 78 second portion [0134] 80 shoulder [0135] 82 pushbutton [0136] 100 centrifuge [0137] 102 motor [0138] 104 shaft [0139] 106 support [0140] 108 abutment insert [0141] 110 aperture [0142] 112 internal contour [0143] 114 inner area [0144] E removal direction [0145] R rotor axis [0146] h.sub.D pushbutton height [0147] s.sub.B activation distance of actuating pin [0148] s.sub.S activation distance of blocking unit