EP3669992A1 - Connection structure - Google Patents

Abstract

The invention relates to a connection structure (100) between the centrifuge rotor (102) and the drive shaft (104) of a laboratory centrifuge (200), which enables one-hand operation, for which no additional tools are required. The connection structure (100) is constructed in such a way that the locking (118, 132, 134) is always ensured, whereby locking elements (118, 134) cannot be jammed or blocked.

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.

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 mounted so as to be pivotable about an axis. This makes the lever function particularly easy to implement. 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 extent 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 designed such that centrifugal force causes it to engage the second locking element. This locks itself automatically when the centrifuge is in operation.

Alternatively or additionally, it can be provided that the first locking element is biased in the direction of engagement with the second locking element. As a result, locking can also take place without centrifugal force, that is to say automatically without regard to the operating state 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. If the preload is used in addition to the centrifugal force, then the rotation of the centrifuge rotor increases the locking by the centrifugal force.

In an advantageous development it is provided that the first locking element is arranged on the centrifuge rotor. As a result, the essential elements can be arranged in the centrifuge rotor, preferably its hub, which improves longevity because the drive shaft itself does not have to have any moving parts for the connection construction. It is then advantageously provided that there are at least two first locking elements, preferably three first locking elements. This makes locking particularly secure.

In an advantageous development it is provided that the second locking element is a projection of the drive shaft, which the first locking element engages behind 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 contact surface runs inclined in the axial direction of the shaft axis. As a result, levers arranged pivotably about an axis can be unlocked very easily. The counter abutment surface is then best 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 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. To provide the latching connection, the first connecting element would preferably be pretensioned in the direction of engagement with the second locking element. On the other hand, the center of gravity of the first locking element could be arranged in such a way that the locking takes place automatically when the centrifuge rotor is placed on the drive shaft.

Fig. 1

die erfindungsgemäße Verbindungskonstruktion in einer 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 preferred exemplary embodiments in connection with the figures. Here, purely schematically, show:

Fig. 1

the connection construction according to the invention in a 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 100 according to the invention is shown in a preferred embodiment in different views.

It can be seen that the connecting structure 100 between a centrifuge rotor 102, which is only partially shown, and a drive shaft 104, which is only partially shown, of a centrifuge motor (not shown further) has, as first locking elements 106, three levers 106, which are each pivotably mounted about axes 108.

These axes 108 are arranged in the hub 110 of the centrifuge rotor 102 such that the levers 106 extend concentrically around a receiving space 112 for the drive shaft 104, with an angular spacing of 120 ° in each case.

The levers 106 each have a first lever arm 114 and a second lever arm 116, which are arranged opposite the axis 108, a hook 118 pointing to the shaft axis W being arranged on the first lever arm 114.

The receiving space 112 for the drive shaft 104 has a machined hexagon socket 120 which corresponds to a corresponding hexagon socket 122 of the drive shaft 104 and is used for torque transmission. This hexagon socket 120 is preferably made of a hard material than the hub 110 and is fixed in this hub 110, for example screwed or shrunk.

The transmission of the torque from the drive shaft 104 to the centrifuge rotor 102 thus takes place via a positive connection 120, 122. As an alternative to the hexagonal configuration shown, another polygonal configuration, for example an octagonal configuration, could exist, or the positive connection could be by a tongue and groove connection or also a drive pin-groove connection or other form-fitting connections that allow torque transmission.

In addition, the hub 110 has an inner cone 124, which corresponds to a conical section 126 of the drive shaft 104 and serves for the perfectly aligned fit of the centrifuge rotor 102 on the drive shaft 104 and for a frictional engagement. This inner cone 124 merges into an inner cylinder 128, which is formed by a 129 bearing block 130 screwed to the hub 110, on which there are arms 131 on which the axes 108 are arranged. Biasing means, for example in the form of springs (not shown), may also exist on this bearing block 130, which bias the first lever arms 114 with the hooks 118 toward the shaft axis W. However, such separate pretensioning means are not provided in the exemplary embodiment shown.

The drive shaft 104 has a groove 132 with an upper projection 134 above the conical section 126, a chamfer 136 extending above the upper projection 134. This projection 134 forms the second locking element.

It can also be seen that the groove 132 has a circumferential configuration in the form of an external hexagon 137, which is aligned parallel to the external hexagon 122. As a result, each hook 118 is always parallel to a surface of the external hexagon 137 assigned to it.

The hooks 118 have chamfers 138 which are oriented towards the inner cone 124. In the locked state, the hooks 118 engage in the groove 132 and engage behind the upper projection 134.

Furthermore, the hub 110 has a cylindrical cavity 140 above the bearing block 130, which is delimited at the top by a lid-shaped closure element 142. In this closure element 142, which can be screwed 143 into the hub 110, for example, there is an opening 144 in which the actuating element 146 is slidably received.

The actuating element 146 has a body 148 designed as a push button 148, which in its lower section has a collar 150 which projects radially outwards and, when the actuating element 146 is not pressed in, bears on the closure element 142.

A projection 152 is arranged below on the collar 150, a section 154 with a conical inner contour consisting of a conical inner contour at the transition between the body 148 and the projection 152 opposite the collar 150, which section acts as a contact surface which corresponds to a counter-contact surface 156 of the lever 106.

The bearing block 130 has an elevation 158 through the cantilevers 131 to form a recess 160 (cf. Fig. 2 ). A spiral spring 162 is arranged in this recess 160 on the one hand and between the projection 152 and the outer circumference of the cavity 140 on the other hand and prestresses the actuating element 146 in the upward direction, that is to say counter to the actuating direction B of the actuating element 146. The coil spring 162 thereby provides an automatic return of the actuating element 146 from the actuated to the non-actuated state.

It is in Fig. 3 can also be seen that the opening 144 has a section 164 with a conical inclination, which corresponds to a conical counter section 166 of the actuating element 146. This effectively prevents the actuating element 146 from tilting when being moved by the spiral spring 162 against the actuating direction B.

This connection structure 100 now works as follows:
In in Fig. 1 shown state, the centrifuge rotor 102 is placed with its hub 110 on the drive shaft 104 of the centrifuge motor. The hooks 118 with their chamfers 138 come into contact with the chamfer 136 of the drive shaft 104, as a result of which the first lever arm 114 is deflected outward with respect to the shaft axis W until the hooks 118 engage in the groove 132 and thereby engage behind the upper projection 134 ( see. Fig. 2 ). The two chamfers 136, 138 thus provide a locking aid in that they prevent the hooks 118 from tilting or getting caught on the drive shaft 104.

The center of mass M of the levers 106 is on the outside and above with respect to the axes 108, so that a snap-in takes place before the operation of the centrifuge rotor 102.

The starting position of the lever 106 is limited by the conical inner surface 154 of the actuating element 146. As a result, the second lever arms 116 cannot tilt outwards and prevent the centrifuge rotor 102 from being fitted. Tilting inward is also not a problem, since the drive shaft 104 presses these levers 106 back into the correct position when the centrifuge rotor 102 is attached. An inward tilting could, however, also be avoided constructively by appropriate contact points in the bearing block 130 (not shown).

During operation of the centrifuge rotor 102, the center of gravity of the levers 106 arranged above the axis 108 causes the second lever arms 116 to shift outward, as a result of which the hooks 118 are pressed firmly into the groove 132 and the locking is thereby carried out securely. There is only one relocating element 106, so that the locking function is not prone to errors.

In order to release the lock, the push button 148 must be shifted downward in the actuation direction B. As a result, the contact surface 154 becomes a contact with the counter contact surface Brought 156, which runs parallel to the shaft axis W in the non-pivoted state.

When the push button 148 is pressed further in the actuation direction B, the counter abutment surface 156 slides on the abutment surface 154, as a result of which a force is exerted on the second lever arms 116, as a result of which the hooks 118 are displaced radially outward until they are completely removed from the groove 132 (see. Fig. 3 ). As a result, the hooks 118 are no longer in contact with the upper projection 134 and the hub 110 can be pulled off the drive shaft 104, the push button 148 sliding upwards after being released by the spiral spring 162 until the collar 150 abuts the closure element 142 ( see. Fig. 1 ).

Even if an example was shown above in which levers 106 pivotable about an axis 108 were used, levers pivotable about an axis can also be used, which are arranged on the drive shaft.

In addition, the actuating element 146 does not necessarily have to be arranged on the hub 110 of the centrifuge rotor 102, it can also be arranged on the drive shaft.

In Fig. 7 A laboratory centrifuge 200 is shown which is equipped with the connection structure 10 according to the invention.

It can be seen that this laboratory centrifuge 200 is designed in a conventional manner and has a housing 202 with a control panel 206 arranged on its front side 204 and a cover 208 which is provided for closing the centrifuge container 210. A fixed-angle rotor 12, which can be driven by the drive shaft of a centrifuge motor (neither shown), is arranged in the centrifuge container 210 as a centrifuge rotor.

It has become clear from the above illustration that the present invention provides a connection structure 100 between centrifuge rotor 102 and drive shaft 104 of a laboratory centrifuge 200, by means of which one-hand operation is possible is possible for which no additional tools are required. The connecting structure 100 is constructed in such a way that the locking 118, 132, 134 is always ensured, wherein locking elements 118, 132, 134 cannot be jammed or blocked.

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, objective features reformulated can also be used as procedural features and procedural features reformulated as objective features. Such reformulation is thus automatically disclosed.

Reference symbol list

100

Connection construction according to the invention in a preferred embodiment

102

Centrifuge rotor

104

drive shaft

106

Lever, first locking elements

108

Axes of levers 106

110

hub

112

Receiving space for the drive shaft

114

first lever arm

116

second lever arm

118

hook

120

Hexagon socket of hub 110

122

External hexagon of the drive shaft 104

124

Inner cone of hub 110

126

conical section of the drive shaft 104

128

Inner cylinder of hub 110

129

Bolting of bearing block 130 to hub 110

130

Bearing block

131

Boom on bracket 130 for axles 108

132

Groove

134

upper projection of the groove 132, second locking element

136

Chamfer on drive shaft 104

137

Circumferential design of the groove 132 in the form of an external hexagon

138

Chamfer on the hook 118

140

cylindrical cavity of the hub

142

lid-shaped closure element

143

Screwing the closure element 142 to the hub 110

144

opening

146

Actuator

148

Push button, actuator body 146

150

collar

152

head Start

154

Section with a conical inner contour, contact surface

156

Counter abutment surface of the lever 106

158

Bearing block 130 increased

160

deepening

162

Coil spring

164

Section with a conical inclination of the opening 144

166

conical counter portion of the actuator 146

200

Laboratory centrifuge

202

casing

204

Front of housing 202

206

Control panel

208

cover

210

Centrifuge container

B

Actuating direction of the actuating element 146

M

Center of mass of levers 106

W '

Shaft axis

Claims (12)

Connection structure (100) between the centrifuge rotor (102) and a drive shaft (104) of a centrifuge motor extending along a shaft axis (W), wherein on one of the elements centrifuge rotor (102) and drive shaft (104) a first locking element (106) and on the other a second locking element (134) is arranged for the elements of the centrifuge rotor (102) and drive shaft (104), the first locking element (106) engaging with the second locking element (134) in the locked state of the connection and not in the unlocked state , characterized in that there is an actuating means (146) on one of the centrifuge rotor (102) and drive shaft (104), the actuation of which causes the first locking element (106) to disengage from the second locking element (134), whereby the Centrifuge rotor (102) from the drive shaft (104) is removable. Connection structure (100) according to claim 1, characterized in that the first locking element is a lever (106), the lever arm (114) of which is preferably movable in a plane parallel to the shaft axis (W), the lever arm (114) in particular in one plane is movable, which includes the shaft axis (W). Connecting structure (100) according to claim 2, characterized in that the lever (106) is pivotally mounted about an axis (108). Connecting structure (100) according to one of the preceding claims, characterized in that the first connecting means (106) has at least one chamfer (138) which serves as a locking aid, the chamfer (138) preferably lying parallel to the longitudinal extension of the lever (106). Connecting structure according to one of the preceding claims, characterized in that the first locking element is biased in the direction of engagement with the second locking element. Connecting structure (100) according to one of the preceding claims, characterized in that there are at least two first locking elements (106), preferably three first locking elements (106). Connecting structure (100) according to one of the preceding claims, characterized in that the first locking element (106) is arranged on the centrifuge rotor (102). Connecting structure (100) according to one of the preceding claims, characterized in that the second locking element (134) is a projection (134) of the drive shaft (104) which the first locking element (106) engages behind in the locked state. Connecting structure (100) according to one of the preceding claims, characterized in that the actuating means (146) has a contact surface (154) for a counter-contact surface (156) of the first locking element (106), one of the two surfaces contact surface (154) and counter-contact surface in The actuation direction (B) of the actuation means (146), at least in the locked state of the connecting structure (100), has an inclined course such that actuation of the actuation means (146) causes the first locking element (106) to pivot, the contact surface (154) preferably runs inclined in the axial direction of the shaft axis (W). Connecting structure (100) according to one of the preceding claims, characterized in that the actuating means (146) is designed as a push button (148) which is designed to be biased (162) against the actuating direction (B). Connecting structure (100) according to one of the preceding claims, characterized in that the actuating means (146) on the centrifuge rotor (102). Connecting structure according to one of the preceding claims, characterized in that the connecting structure provides a latching connection, the locking taking place within the framework of a clip connection which is designed to be detachable.

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