EP3669993A1 - Connection structure - Google Patents

Abstract

The invention relates to a connection structure (10) between the centrifuge rotor (12) and the drive shaft (14) of a laboratory centrifuge (100), which enables one-hand operation, for which no additional tools are required. The connection structure (10) is constructed in such a way that the locking (16, 48) is always ensured, whereby locking elements (16, 48) cannot be jammed or blocked. In addition, the lock (16, 48) is securely displayed to the user by a clear clicking sound.

Description

The present invention relates to a connection structure between the centrifuge rotor and the drive shaft of a centrifuge motor according to the preamble of claim 1.

Centrifuge rotors are used in centrifuges, in particular laboratory centrifuges, to separate the components from samples centrifuged therein, using the inertia. In order to achieve high segregation rates, ever higher rotation speeds are used. Laboratory centrifuges are centrifuges whose centrifuge rotors operate at preferably at least 3,000, preferably at least 10,000, in particular at least 15,000 revolutions per minute and are usually placed on tables. In order to be able to place them on a work table, they have in particular a form factor of less than 1 m x 1 m x 1 m, so their installation space is limited. Preferably, the device depth is max. Limited to 70 cm. However, laboratory centrifuges are also known which are designed as standing centrifuges, that is to say they have a height in the range from 1 m to 1.5 m, in order to be able to place them on the floor of a room.

Such centrifuges are used in the fields of medicine, pharmacy, biology and chemistry.

The samples to be centrifuged are stored in sample containers and these sample containers are driven in rotation by means of the centrifuge rotor. The centrifuge rotors are usually set in rotation by means of a vertical drive shaft which is driven by an electric motor. The coupling between the centrifuge rotor and the drive shaft is usually carried out by means of the hub of the centrifuge rotor.

There are various centrifuge rotors that are used depending on the application. The sample containers can contain the samples directly, or separate sample containers containing the sample are used in the sample containers, so that a large number of samples can be centrifuged simultaneously in one sample container. All Centrifuge rotors in the form of fixed-angle rotors and swing-out rotors and others are generally known.

The connection structure between these centrifuge rotors and the drive shafts of the centrifuge motors, which ensures the locking of the respective centrifuge rotor on the drive shaft during the operation of the centrifuge, is mostly independent of the type of centrifuge rotor so that different types of centrifuge rotors can be used in the same centrifuge without any problems .

Such connection structures are usually designed such that there is a screw connection between the centrifuge rotor and the shaft, as a result of which a very secure and durable connection can be produced. To lock and unlock the connection, a key is required with which the screw connection can be operated. The disadvantage of this connection construction is that the key requires additional elements that can be moved and, moreover, no one-hand operation is possible.

However, it is also known to use an automatic lock that allows one-hand operation. This system is marketed, for example, by Sigma Laborzentrifugen GmbH, An der Unteren Söse 50, 37520 Osterode am Harz, under the name "G-Lock®". The disadvantage of this, however, is that there is a complex deflection of centrifugal forces acting on eccentric elements onto coupling elements, which can be subject to numerous susceptibility to errors in both locking and unlocking, which can ultimately make the operation of this coupling device unsafe in everyday life. In addition, there is no feedback for the user about the locking, so that the actual operational safety is unknown to the user.

It is therefore an object of the present invention to at least partially overcome these disadvantages. A one-hand operation should preferably be made possible, for which no additional tool is required. In particular, the connection structure is to be constructed in such a way that the locking is always ensured, wherein locking elements cannot be jammed or blocked.

This object is achieved with the connection construction according to the invention according to claim 1. Advantageous further developments are specified in the subclaims and in the description below, together with the figures.

It was recognized by the invention that this task can be solved in a surprisingly simple manner if there is an actuating means on one of the elements of the drive shaft and centrifuge rotor that makes the locking releasable, because this enables real one-hand operation and also by means of the actuating means Jamming or the like. The locking elements is effectively prevented.

The connection structure according to the invention between the centrifuge rotor and a drive shaft of a centrifuge motor which extends along a shaft axis, a first locking element being arranged on one of the elements of the centrifuge rotor and drive shaft and a second locking element being arranged on the other of the elements of the centrifuge rotor and drive shaft, the first locking element with the second locking element In the locked state of the connection is engaged and in the unlocked state is not in engagement, it is characterized in that there is an actuating means on one of the elements centrifuge rotor and drive shaft, the actuation of which causes the first locking element to disengage from the second locking element device, whereby the centrifuge rotor can be removed from the drive shaft.

In an advantageous development it is provided that the first locking element is a lever. This makes locking particularly easy. If the lever arm of the lever is movable in a plane parallel to the shaft axis, then the connecting structure can be made particularly slim. This is all the more so if the lever arm is movable in a plane that includes the shaft axis. “Lever arm” is understood to mean that part of the lever which locks with the second locking element.

In an advantageous development it is provided that the lever is arranged on a joint. This makes the lever function even easier to implement in terms of design. The joint is preferably designed to be resilient because this creates restoring forces. The Joint can also be effected by an elastically resilient design of the lever itself.

In an advantageous development it is provided that the first connecting means has at least one chamfer which serves as a locking aid, the chamfer preferably lying parallel to the longitudinal extension of the lever. As a result, the connection structure can be locked particularly easily because the first locking means does not represent an obstacle when the centrifuge rotor is attached to the drive shaft.

In an advantageous development it is provided that the first locking element is biased in the direction of engagement with the second locking element. This means that locking can take place automatically regardless of the operating status of the centrifuge. At the same time, the pretension can also serve as a pretension for the actuating means, but a separate prestress is preferably provided for the actuating means.

In an advantageous development it is provided that the first locking element is arranged on the drive shaft. This allows the connection structure to be kept very compact. It is then advantageously provided that there are at least four first locking elements, preferably six first locking elements. This makes locking particularly secure.

In an advantageous development it is provided that the second locking element is a projection on the centrifuge rotor on which the first locking element is supported in the locked state. This makes the connection structure particularly simple.

In an advantageous development, it is provided that the actuating means has a contact surface for a counter-contact surface of the first locking element, one of the two surfaces contact surface and counter-contact surface having an inclined course in the actuating direction of the actuating means, at least in the locked state of the connecting structure, such that actuation of the actuating means occurs Swiveling the first locking element is effected. This makes unlocking particularly easy.

In an advantageous development, it is provided that the counter abutment surface in the locked state is inclined to the direction of the shaft axis. This allows levers arranged on a joint to be unlocked very easily, for example. The contact surface is then best run straight in the direction of the shaft axis, but may also have an inclination, which, however, must be dimensioned such that when the actuating means is displaced in the actuating direction, an unlocking force is exerted on the first locking element.

In an advantageous development, it is provided that the first locking element and the second locking element have contact surfaces which, when the connection structure is locked, abut one another and bring about the locking, these contact surfaces being inclined relative to a radial surface about the shaft axis. This allows the locking mechanism to grip the drive shaft early when the centrifuge rotor is slid on, so that vertical play between the centrifuge rotor and the drive shaft is minimized.

In an advantageous development it is provided that the actuating means is designed as a push button which is designed to be biased against the actuating direction. This makes unlocking particularly easy and ergonomic.

In an advantageous development it is provided that the actuating means is on the centrifuge rotor. As a result, the drive shaft can be made compact. Alternatively, however, the actuating means could also be on the drive shaft.

In an advantageous further development it is provided that the connection construction provides a snap-in connection, the locking taking place within the framework of a clip connection, which is designed to be detachable. This makes the locking particularly secure and the security that is audible for the user makes it very easy to understand the security.

Fig. 1

die erfindungsgemäße Verbindungskonstruktion in einer ersten bevorzugten Ausgestaltung im entriegelten und getrennten Zustand im Schnitt,

Fig. 2

die Verbindungskonstruktion nach Fig. 1 im verriegelten Zustand im Schnitt,

Fig. 3

die Verbindungskonstruktion nach Fig. 1 im entriegelten Zustand im Schnitt,

Fig. 4

die Nabe des Zentrifugenrotors der Verbindungskonstruktion nach Fig. 1 in einer perspektivischen Ansicht im Schnitt,

Fig. 5

die Antriebswelle des Zentrifugenrotors der Verbindungskonstruktion nach Fig. 1 in einer perspektivischen Ansicht,

Fig. 6

die Verbindungskonstruktion nach Fig. 1 in Detailansicht im Schnitt und

Fig. 7

eine Laborzentrifuge mit der erfindungsgemäßen Verbindungskonstruktion nach Fig. 1.

The features and further advantages of the present invention will become clear below on the basis of the description of a preferred exemplary embodiment in connection with the figures. Here, purely schematically, show:

Fig. 1

the connection construction according to the invention in a first preferred embodiment in the unlocked and separated state in section,

Fig. 2

the connection construction Fig. 1 in the locked state on average,

Fig. 3

the connection construction Fig. 1 cut when unlocked,

Fig. 4

the hub of the centrifuge rotor according to the connection construction Fig. 1 in a perspective view in section,

Fig. 5

the drive shaft of the centrifuge rotor according to the connecting construction Fig. 1 in a perspective view,

Fig. 6

the connection construction Fig. 1 in detail view in section and

Fig. 7

a laboratory centrifuge with the connection structure according to the invention Fig. 1 .

In the 1 to 6 The connection structure 10 according to the invention is shown in a preferred embodiment in different views.

It can be seen that the connecting structure 10 between a centrifuge rotor 12, which is only partially shown, and a drive shaft 14, which is only partially shown, of a centrifuge motor (not shown further) has eight spring elements 16 as first locking elements 16, which are arranged on a common spring collar 18.

This spring collar 18 is screwed concentrically to the drive shaft 14 by means of a screw 20, so that the spring elements 16 extend equally spaced from a cylindrical section 22 of the drive shaft 14. The spring elements 16 have projections 24 which form feet 26, the base 28 of which in FIG Fig. 6 shown relaxed state of the spring elements 16 with respect to a radial plane with respect to the shaft axis W. Furthermore, the projections 24 have bevels 30 which run inclined to the longitudinal extent of the respective spring element 16.

The spring elements 16 are connected to the spring ring 18 via joints 32, which allow an elastically reversible displacement of the feet 26 towards the shaft axis W. To provide the elasticity, the spring elements 16 are made in one piece with the spring ring 18 and are made, for example, from a thermoplastic or a spring steel.

The spring elements 16 thus form lever arms acting as first locking elements, which are designed to be pivotable relative to the spring ring 18 via the respective joints 32

At the transition between the cylindrical section 22 and the conical section 34 of the drive shaft 14 there is a radially extending step 36, the radial depth of which corresponds at least to the radial width of the feet 26, so that the feet 26 are completely on or behind the course of the conical profile of the conical section 34 can be shifted.

The hub 38 of the centrifuge rotor 12 has a receiving space 39 for the drive shaft 14 with an incorporated hexagon socket 40, which corresponds to a corresponding hexagon socket 42 of the drive shaft 14 and is used for torque transmission. This hexagon socket 40 is preferably made of a hard material than the hub 38 and is fixed in this hub 38, for example screwed or shrunk.

The transmission of the torque from the drive shaft 14 to the centrifuge rotor 12 thus takes place via a positive connection 40, 42 a drive pin-groove connection or other form-fitting connections that allow torque transmission.

The hub 38 also has an inner cone 44, which corresponds to the conical section 34 of the drive shaft 14 and serves the perfectly aligned seat of the centrifuge rotor 12 on the drive shaft 14 and a frictional connection. This inner cone 44 merges into an inner cylinder 46, the diameter of which is at least the outer diameter corresponds to step 36, but is preferably larger, being smaller than the outer diameter of feet 26 in the relaxed state of spring elements 16.

Furthermore, there is an annular step 48 above the inner cylinder 46 which is delimited radially outside by a vertical edge 50 which belongs to a circumferential elevation 52 which surrounds the step 48. This step 48 forms the second locking element. The edge 50 surrounds an inner diameter that is only slightly larger than the outer diameter of the feet 26 in the relaxed state. This ensures secure locking and at the same time allows the projections 24 to strike the edge 50 during the sudden relaxation of the spring elements 16.

Furthermore, the hub 38 has a cylindrical cavity 54 above the elevation 52, which is delimited at the top by a lid-shaped closure element 56. In this closure element 56, which can for example be screwed into the hub 38, there is an opening 58 in which the actuating element 60 is slidably received.

The actuating element 60 has a body 62 in the form of a push button 62, which in its lower section has a collar 64 which projects radially outwards and, when the actuating element 60 is not pressed in, bears on the closure element 56.

The elevation 52 merges radially on the outside into a depression 66. A spiral spring 68 is arranged in this recess 66 on the one hand and between the section 69 of the body 62 projecting from the collar 64 and the outer circumference of the cavity 54 on the other hand and biases the actuating element 60 in an upward direction, that is to say counter to the actuating direction B of the actuating element 60. The spiral spring 68 thereby provides an automatic return of the actuating element 60 from the actuated to the non-actuated state.

This connection structure 10 now works as follows:
In in Fig. 1 shown state, the centrifuge rotor 12 is placed with its hub 38 on the drive shaft 14 of the centrifuge motor. The projections 24 of the spring elements 16 with the chamfers 30 come into contact with the conical section 44 of the hub 38, the chamfers 30 and the conical section 44 thus providing a locking aid in that they tilt or catch the projections 24 on the hub 38 prevent.

At the same time, the spring elements 16 are displaced inward by continuously pushing the hub 38 onto the drive shaft 14 to such an extent that they can penetrate into the inner cylinder 46, whereby in extreme cases the spring elements 16 can be pivoted in as far as the cylindrical section 22, so that the feet 26 can be moved completely onto or behind the course of the conical profile of the conical section 34 and the step 36.

After the hub 38 has been pushed onto the drive shaft 14 to such an extent that the projections 24 are no longer in contact with the inner cylinder 46, the spring elements 16 can relax, the projections 24 automatically shifting outward due to their pretension until they touch the edge 50 concerns. The feet 26 are supported on the step 48 so that the drive shaft 14 can no longer be pulled out of the hub 38. The spring elements 16 are driven with the feet 26 radially outward with respect to the shaft axis W by the acting centrifugal forces, so that this locking is self-locking during operation.

In Fig. 6 it can be seen that the projection 48 has an inclination corresponding to the inclination of the base 28 of the feet 26. As a result, the feet 26 can be displaced early on when the centrifuge rotor 12 is pushed onto the drive shaft 14, so that excessive vertical play between the feet 26 and the projection 48 and thus vertical "rattling" of the hub 38 on the drive shaft 14 are prevented.

When the spring elements 16 are suddenly released, the projections 24 strike the edge 50, which causes a clearly audible click noise, which clearly signals to the user that the locking between the hub 38 and the drive shaft 14 has been carried out securely (cf. Fig. 2 and 6 ).

In order to release the lock, the push button 62 must be shifted downwards in the actuation direction B. As a result, the contact surface 72 on the section 69 of the body 62 projecting from the collar 64, which runs in the direction of the shaft axis W, is brought into contact with the counter-contact surface 74, which is arranged on the spring element 16 and therefore runs inclined with respect to the shaft axis W (cf. . Fig. 3 , The pivoting of the spring elements 16 inwards towards the cylindrical section 22 of the drive shaft 14 is not shown here for drawing reasons, but it actually takes place).

When the push button 62 is pressed further in the actuation direction B, the counter abutment surface 74 slides on the abutment surface 72, whereby a force is exerted on the spring elements 16, whereby the feet 26 are displaced radially inward until they are completely on or behind the course of the conical Profile of the conical section 34 can be shifted. As a result, the feet 26 are no longer in contact with the step 48 and the hub 38 can be pulled off the drive shaft 14, the push button 62 sliding upwards being driven by the spiral spring 68 until the collar 64 abuts the closure element 56 ( see. Fig. 1 ).

It can also be seen that the opening 58 has a section 76 with a conical inclination, which corresponds to a conical counter section 78 of the actuating element 60. This effectively prevents the actuating element 60 from tilting when being moved by the spiral spring 68 against the actuating direction B.

Even if the first locking elements 16 were described as lever arms 16 with projections 24 and feet 26 formed thereby, this is only one possible exemplary embodiment. The spring elements 16 could also be formed without projections 24 and feet 26. This is advantageous if the spring elements 16 are made of spring steel, because then the formation of the projections 24 and feet 26 is more complicated in terms of production technology than a formation without these elements. The locking with the second locking element 48 would then take place very simply via ends (not shown) of the lever arms 16 which are running straight out.

In Fig. 7 A laboratory centrifuge 100 is shown, which is equipped with the connection structure 10 according to the invention.

It can be seen that this laboratory centrifuge 100 is designed in the usual way and has a housing 102 with an operating panel 106 arranged on its front 104 and a cover 108 which is provided for closing the centrifuge container 110. A swing-out rotor 12, which can be driven by the drive shaft of a centrifuge motor (both not shown), is arranged in the centrifuge container 110 as a centrifuge rotor.

Even if an example was shown above in which spring elements 16 were used on the drive shaft 14, spring elements which are arranged in the hub can also be used.

In addition, the actuating element 60 does not necessarily have to be arranged on the hub 38 of the centrifuge rotor 12, it can also be arranged on the drive shaft 14.

It has become clear from the above illustration that the present invention provides a connection structure 10 between the centrifuge rotor 12 and the drive shaft 14 of a laboratory centrifuge 100, by means of which one-hand operation is possible, for which no additional tools are required. The connecting structure 10 is constructed in such a way that the locking 16, 48 is always ensured, wherein locking elements 16, 48 cannot be jammed or blocked. In addition, the lock 16, 48 is securely displayed to the user by a clear clicking sound.

Unless otherwise stated, all features of the present invention can be freely combined with one another. Unless otherwise stated, the features described in the description of the figures can also be freely combined with the other features as features of the invention. A limitation of individual features of the embodiment to the combination with other features of the embodiment is expressly not provided. In addition, representational Features rephrased also find use as process features and process features rephrased as objective features. Such reformulation is thus automatically disclosed.

Reference symbol list

10th

the connection construction according to the invention in a first preferred embodiment,

12

Centrifuge rotor

14

drive shaft

16

first locking elements, spring elements, lever arms

18th

Feather ring

20th

screw

22

cylindrical section of the drive shaft

24th

Ledges

26

Feet

28

Base, contact surface of the first connecting element 16

30th

Chamfer

32

Joints

34

conical section of the drive shaft 14

36

radial step

38

Centrifuge rotor hub 12

39

Receiving space for the drive shaft 14

40

Hexagon socket of hub 38

42

External hexagon of the drive shaft 14

44

Inner cone of hub 38

46

Inner cylinder of hub 38

48

annular step, second locking element, contact surface of the second connecting element 48

50

vertical edge

52

all-round increase

54

cylindrical cavity of the hub 38

56

lid-shaped closure element

58

opening

60

Actuator

62

Push button, actuator body 60

64

collar

66

deepening

68

Coil spring

69

Section of the body 62 protruding from the collar 64

72

Contact surface

74

Counter surface

76

Section with a conical inclination of the opening 58

78

conical counter section of the actuating element 60

100

Laboratory centrifuge

102

casing

104

Front of housing 102

106

Control panel

108

cover

110

Centrifuge container

B

Actuating direction of the actuating element 60

W

Shaft axis

Claims (13)

Connection structure (10) between the centrifuge rotor (12) and a drive shaft (14) of a centrifuge motor extending along a shaft axis (W), one of the elements of the centrifuge rotor (12) and the drive shaft (14) having a first locking element (16) and the other a second locking element (48) is arranged on the elements of the centrifuge rotor (12) and drive shaft (14), the first locking element (16) being in engagement with the second locking element (48) in the locked state of the connection and not in the unlocked state , characterized in that there is an actuating means (60) on one of the elements centrifuge rotor (12) and drive shaft, the actuation of which causes the first locking element (16) to become disengaged from the second locking element (48), whereby the centrifuge rotor (12 ) from the drive shaft (14) is removable. Connecting structure (10) according to claim 1, characterized in that the first locking element (16) is a lever, the lever arm of which is preferably movable in a plane parallel to the shaft axis (W), the lever arm being movable in particular in a plane which is the shaft axis (W) includes. Connecting structure (10) according to claim 2, characterized in that the lever (16) is arranged on a hinge (32), the hinge (32) preferably being resilient, the hinge (32) in particular by an elastically resilient design of the lever (16) itself is effected. Connecting structure (10) according to one of the preceding claims, characterized in that the first connecting means (16) has at least one chamfer (30) which serves as a locking aid, the chamfer (30) preferably being parallel to the longitudinal extension of the lever (16). Connecting structure (10) according to one of the preceding claims, characterized in that the first locking element (16) is biased in the direction of engagement with the second locking element (48). Connecting structure (10) according to one of the preceding claims, characterized in that there are at least four first locking elements (16), preferably six first locking elements (16). Connecting structure (10) according to one of the preceding claims, characterized in that the first locking element (16) is arranged on the drive shaft (14). Connecting structure (10) according to one of the preceding claims, characterized in that the second locking element (48) is a projection on the centrifuge rotor (12) on which the first locking element (16) is supported in the locked state. Connection structure (10) according to one of the preceding claims, characterized in that the actuating means (60) has a contact surface (72) for a counter-contact surface (74) of the first locking element (16), one of the two surfaces contact surface and counter-contact surface (74) in The actuation direction (B) of the actuation means (60) has an inclined course, at least in the locked state of the connecting structure (10), such that actuation of the actuation means (60) causes the first locking element (16) to pivot, the counter-contact surface (74) preferably in the locked state, inclined to the direction of the shaft axis (W). Connecting structure (10) according to one of the preceding claims, characterized in that the first locking element (16) and the second locking element (48) have contact surfaces (28, 48) which abut one another in the locked state of the connecting structure (10) and effect the locking , These contact surfaces (28, 48) being inclined with respect to a radial surface around the shaft axis (W). Connecting structure (10) according to one of the preceding claims, characterized in that the actuating means (60) is designed as a push button (62) which is designed to be biased (68) against the actuating direction (B). Connecting structure (10) according to one of the preceding claims, characterized in that the actuating means (60) on the centrifuge rotor (12). Connection structure (10) according to one of the preceding claims, characterized in that the connection structure (10) provides a latching connection (16, 48), the locking taking place within the framework of a clip connection (16, 48) which is designed to be detachable.

Images