CH656811A5 - SHAKER DEVICE AND METHOD FOR OPERATING SUCH A. - Google Patents

Abstract

The shaking device has a frame, a support which is held by the latter so as to be movable along an orbit and power generating units for driving the support. A crank (5) which is in operative connection with the support has a disc (9) which is provided on its circumferential face (9a) with cams (9b) and recesses (9c). The latter constitute multi-digit binary numbers, each of which is assigned to a region of the orbit along which the support is moved. The different digits of the binary number can be read simultaneously with one reader (71, 73, 75) in each case. This permits a relatively high resolution to be achieved when determining the position of the support using a small number of readers (71, 73, 75). <IMAGE>

Description

The invention relates to a shaking device according to the preamble of claim 1.

From the Swiss patent 585 585 a shaking device with a frame and a carrier movable with cranks along a circular path is known. Four electromagnets are attached to the frame and four permanent magnets are attached to the carrier. One of the cranks is provided with a commutator, which is scanned by brushes and reverses the direct currents supplied to the electromagnets after every half of the carrier revolution.

Since shaking devices are often operated for long periods in continuous operation or with short interruptions, the control by means of a brush commutator is inappropriate due to the wear of the brushes. Otherwise, the number of revolutions can only be changed within relatively narrow limits when using such a commutator.

Manufactured and marketed in Switzerland shaking devices are equipped with three electromagnets to drive the carrier. One of the cranks used to support the carrier is provided with a disk which serves for balancing the carrier and for representing its position and, for the latter purpose, has a cam which extends approximately along a 120 ° circular sector. Arranged on the frame are three inductively working readers, which are distributed around the crank in question and which generate electrical signals as they pass the cam and feed them to an electronic control device. The latter temporarily turns on the electromagnet associated with that reader each time the cam reaches a reader.

In the case of these shaking devices, the position of the carrier is thus represented by two characters which can be distinguished from one another by the readers, namely by the cam and the remaining cam-free peripheral part of the disk. The current position of the carrier can therefore only be determined with an accuracy of approximately 120 °. This low resolution when determining the position has a disadvantageous effect on various operating properties of the shaking device.

Now it would be possible per se to improve the resolution in determining the position by increasing the number of readers, for example doubling it. However, since inductive readers and their assembly are relatively expensive, this measure would make the device considerably more expensive.

The invention is therefore based on the object of providing a shaking device which, with a small number of readers, enables a relatively precise position determination of the carrier.

This object is achieved by a shaking device of the type mentioned in the introduction, which according to the invention

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is characterized by the features of claim 1. Appropriate configurations of the shaking device result from claims 2 to 8.

The invention further relates to a method according to the preamble of claim 9. The method according to the invention is characterized by the features of this claim.

The shaker can be used, for example, for mixing and emulsifying liquids, dispersing and dissolving solids in liquids, for shaking liquid substrates containing microorganisms and for general laboratory use.

The invention will now be explained with reference to an embodiment of a shaking device shown in the drawing.

1 shows a plan view of a shaking device, FIG. 2 shows a section through the shaking device along the line II — II of FIG. 1,

3 shows a plan view of the crank holding the carrier in the central part, on a larger scale,

FIG. 4 shows a section along the line IV — IV in FIG. 3

5 shows a development of the peripheral surface of the disk of the crank shown in FIGS. 3 and 4, FIG. 6 shows the electrical block diagram of the shaking device,

FIG. 7 shows a diagram to illustrate the operating mode when the number of rotations is low; and FIG. 8 shows a diagram to illustrate the operating mode when the number of rotations is high.

The shaking device shown in simplified form in FIGS. 1 and 2 has a frame 1 and a carrier 3. The latter is held approximately in the middle with a crank 5 and in the vicinity of two of its corners with two cranks 7 movable in the frame. The crank 5 has a disk 9, a vertical shaft 11 and an eccentric, vertical pin 13. The cranks 7 each have a somewhat elastic arm 15, a vertical shaft 17 and an eccentric vertical pin 19. The shaft 11 is supported with at least one bearing 21 in the frame 1 and the shafts 17 are supported with bearings 23 in the frame. The crank pin 13 is mounted with at least one bearing 25 in the carrier 3 and the crank pin 19 is supported with bearings 27 in the carrier 3. The bearings 21, 23, 25, 27 can be designed, for example, as roller bearings. The carrier 3 is thus held and guided on the frame 1 with the cranks 5, 7 such that it can be moved along a flat, horizontal, closed path, namely along a circular path.

The carrier 3 has a flat, horizontal plate 29 which forms a table for carrying the shaking material accommodated in one or more containers. The bearings 25, 27 can be directly rigidly connected to this plate 29.

However, it would also be possible to provide, in a known manner, in addition to the plate 29, a separate table arranged above it and serving as a support for the bulk material container, which can be connected to the support either rigidly or movably. In the case of the rigid connection, the table would perform the same movement as the carrier during operation. Otherwise, the table could be connected to the frame in the vicinity of its one edge so as to be pivotable about a fixed, vertical axis. The movable connection of the table to the carrier would then be such that the table is pivoted back and forth once during a full revolution of the carrier.

On the plate 29 three downwardly projecting, uniformly on a concentric to the bearing 25 and thus coaxial to the crank pin 13 distributed plate 31 are rigidly attached. On the frame 1, three electromagnets 33 are rigidly attached, which are evenly distributed on a circle coaxial to the shaft 11 and each have a coil 35 and a core 37 with a horizontal axis. One end of the cores 37 faces one of the plates 31 and thus forms a magnetic pole. The other end of the cores is connected to a body 39 which projects upwards to approximately the plate 29, so that it is separated from it only by a narrow gap. The plate 29, the platelets 31, the cores 37 and the bodies 39 consist of a ferromagnetic, magnetically soft material and, if necessary, can be provided with a coating which serves as corrosion protection. The electromagnets 33 together with the plates 31 and the sections of the plate 29 which close the magnetic circuits form three force generating units 41, 43, 45 with which to drive the carrier 3 parallel to the plane of the carrier, i.e. horizontally directed forces, namely tensile forces, can be generated and exerted on the carrier.

The design of the disk 9 and the crank 5 will now be explained in more detail with reference to FIGS. 3, 4 and 5. The circumferential surface of the disk 9 is generally coaxial to the axis of rotation of the shaft 11. The disk 9 serves as a flywheel mass, but has an asymmetrical mass distribution with respect to the shaft 11 mounted in the frame 1, the disk being in the half in which the ground plan is the crank pin 13 is located, is provided with two openings and has a smaller mass than in its other half. The mass and the mass distribution of the disk 9 are determined in such a way that the disk compensates for the imbalance caused by the carrier 3 which acts on the disk 9 eccentrically with respect to the axis of rotation of the shaft 11.

The disc 9, which is in a rotationally operative connection with the carrier 3, also serves as a means for representing the current position of the carrier 3. For this purpose, the outer surface or peripheral surface 9a of the disc is in three circumferential, offset in the direction of the axis of rotation Ring strips 51, 53, 55 and divided into six sectors 57, 59, 61, 63, 65, 67 each extending over an arc or central angle of 60 °. The peripheral surface 9a, of which a development is shown in FIG. 5, therefore has a total of 18 fields. In each of these fields there is either a radially projecting cam 9b extending along an arc approximately over a central angle of 60 ° or a cam-free section, i.e. there is a recess 9c extending along an arc approximately over a central angle of 60 °. In this case, adjacent cams 9b are connected without a visible limit. Similarly, adjacent recesses 9c merge into one another without any visible limits.

The cams 9b and recesses 9c represent two types of distinguishable characters. For reading and reading these characters, three readers 71, 73, 75 are detachably and adjustable with angular holders, but rigidly attached to the frame 1, with the three readers along the shaft 11 are offset from each other. The reader 71 is arranged in such a way that it can read the characters located in the uppermost ring strip 51. The reader 73 is used to read the characters of the middle ring strip 53 and the reader 75 to read the characters of the lowest ring strip 55. The two readers 71 and 73 are located in the one shown in FIGS. 1 and 3, projected parallel to the axis of rotation of the shaft 11 Floor plan on top of each other, ie at the same radial line and circumferential point of a circle concentric to the shaft 11, while the reader 73 is at a radial line and circumferential point of the circle which is offset by 120 ° from the readers 71 and 75.

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The disc 9 consists of a ferromagnetic, magnetically soft metal, for example a castable metal, such as gray cast iron. Readers 71, 73, 75 are designed as inductive proximity switches and have coils, the inductance of which is changed by the approach of a ferromagnetic cam 9b. The readers can, for example, have resonant circuits and an electronic switching element and can be designed such that a cam 9b that comes into the vicinity of the coil of a reader causes a detuning of an oscillating circuit and thereby a change in the switching state of the electronic switching element. The switching elements can switch an electrical current or a voltage on and off during operation and emit an electrical pulse, for example, during the period during which a cam 9b is located, whereas no pulse is generated when a recess is passed.

The three readers 71, 73, 75 read a character simultaneously in every possible rotational position of the disk 9. One can now understand the three characters read at the same time as a three-digit, binary number, with, for example, the character on the ring strip 51 and read by the reader 71 the first digit, the character lying on the ring strip 53 and read by the reader 73 the second digit and the character belonging to the ring strip 55 and read by the reader 75 forms the third digit of the number.

A three-digit binary number can represent eight different numerical values. As can be seen from FIGS. 3, 4 and 5, six different numbers are read during a full rotation of the disk 9, each of which denotes a 60 ° sector of the orbit of the carrier. By means of the disk 9 and the three readers 71, 73, 75, it can thus be electronically recorded and displayed in which 60 ° sector of the orbit or in which 60 ° phase angle range of the movement the carrier 3 is located, this position determination is possible both when the carrier is at rest and when it is moving.

As already mentioned, the two readers 71 and 75 are arranged one above the other in plan, while the reader 73 is offset by 120 ° relative to them. This makes it possible to distribute the cams 9b and recesses 9c for the representation of six different numbers such that there is no recess between two cams in any of the six sectors 57, 59, 61, 63, 65.67 seen along the shaft 11. In those sectors in which the central ring strip 53 has a recess 9c, a cam 9b is therefore present in at most one of the two outer ring strips 51, 55. This enables all the cams and recesses to be formed in the manufacture of the disk 9 by casting using a relatively simple casting mold consisting of two parts which are separable from one another in the direction of the shaft 11.

The device is also provided with an electronic control device 81, which is attached to the frame 1 on one side and has display elements and manually operated control elements. As can also be seen in FIG. 6, the three readers 71, 73, 75 are connected via conductors to the control device 81 and in this, via adaptation elements (not shown), to inputs of a logic part 83 and to inputs of a circulation monitoring part 85. The latter is connected to a manually adjustable setting element 87, for example formed by a potentiometer, for setting the number of cycles required, with a display element 89 for digitally displaying the actual value of the number of cycles, and to a manually adjustable setting element 99 for setting a limit value for the number of cycles. The circulation number monitoring part 85 also has outputs which are connected to the logic part 83 and a voltage regulator 91. The outputs of the logic part 83 are connected to a switching part 93 which has electronic switching elements. The voltage regulator 91 has an output which is connected directly to the one terminals of the coils of the electromagnets 33 of the three power generating units 41, 43, 45 and an output which is connected via the three switching elements of the switching part 93 to one of the other coil terminals. Furthermore, a power supply unit 95 is also provided in order to generate the various DC voltages required for operation from the AC mains voltage. The power supply unit 95 has at least one manually operable on / off switching element 97 in order to switch the shaking device and in particular its drive device on and off.

The mode of operation of the shaking device and further details of the control device 81 will now be explained with reference to the diagrams shown in FIGS. 7 and 8.

When the shaker is in operation, the electromagnets 33 exert tensile forces on the plates 31, as a result of which the carrier 3 is moved, so that each point of the carrier 3 moves along a circular path. These circular orbits are all the same, i.e. all have the same diameter.

A circular path 101 is shown in FIGS. 7 and 8, which represents the phase angle of the movement of the carrier 3. For illustration purposes, however, it can also be assumed that the spatially separated plates 31 and the electromagnets which together form the force generating units 41, 43, 45 are displaced along the horizontal plane spanned by the plate 29 of the carrier 3 in such a way that the centers of the plates 31 coincide and move along the circular path 101, but the electromagnets are not drawn to scale.

The circular path 101 is divided into six sectors of equal size, each of which is assigned a binary number readable by the readers 71, 73, 75. The boundaries between the different sectors, i.e. The different phase angle or path ranges correspond to those positions of the carrier 3 at which the cam flanks delimiting the cams 9b and recesses 9c are located precisely at the reader 71, 73, 75 in question, and are designated in FIGS. 7 and 8 with 103, 105, 107, 109, 111, 113. Those path points or phase angles at which the plates 31 are closest to the poles of the associated electromagnets are offset by 120 ° in terms of phase angle and lie on the sector boundaries 105, 109, 113.

During operation, the readers 71, 73, 75 supply the logic part 83 of the control device 81 with electronic signals which represent the binary numbers mentioned. The logic part 83 has a decoder for processing these signals and controls the electronic switching elements of the switching part 93 on the basis of these signals in such a way that the electromagnet 33 of the power generating units 41, 43, 45 in certain, evenly distributed phase or orbit regions a direct current is supplied.

During operation, the carrier 3 is driven, for example, in such a way that it moves counterclockwise in the plan view. As will be explained below, the number of revolutions of the carrier 3 can be changed and divided into two areas. When the carrier 3 starts up and the number of revolutions is low, the electromagnets are controlled according to the diagram shown in FIG. on and off. The electromagnet belonging to the power generating unit 41 is inserted4 during the movement section of the associated plate 31 represented by the arrow 121

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switches. Accordingly, the electromagnet of the power generation unit 43 is switched on during the movement section illustrated by the arrow 123 and the electromagnet of the power generation unit 45 during the movement section illustrated by the arrow 125. Each electromagnet is therefore always in a phase angle range of 180 °, i.e. switched on during half a revolution of the carrier 3 and then switched off during a half revolution.

The electromagnet of the power generating unit 41 is switched on at the point in time at which the associated plate 31 is on its path at the sector boundary 103 and has the greatest possible distance from the end or pole of the magnetic core 37 facing it. The electromagnet then remains switched on until the plate has moved on its path up to sector boundary 109 and is closest to the pole of the electromagnet.

The other electromagnets are switched on and off in an analogous manner, so that the switch-on areas of the three electromagnets are uniformly distributed in terms of phase angle and overlap one another. When the carrier 3 rotates, one electromagnet or two electromagnets are therefore alternately switched on in successive 60 ° sectors.

If the carrier 3 is located, for example, at one of the sector boundaries 103 or 109, the tensile force generated by the force-generating unit 41 is directed transversely to the direction of movement of the carrier 3, so that the force-generating unit 41 therefore has a certain dead center there. In these two carrier positions, however, the force generating unit 45 or the force generating unit 43 is additionally switched on, so that the total force generated in these two carrier positions also has a component directed in the direction of movement of the carrier. The same applies to the cases where the carrier is at one of the remaining sector boundaries.

The operating mode illustrated by FIG. 7 therefore results in good starting behavior of the carrier 3, i.e. the latter starts immediately from any rest position when the drive device formed by the power generating units is put into operation. However, the operating mode illustrated by FIG. 7 ensures reliable drive even at low number of revolutions after starting. The carrier 3 is moved at a nearly constant speed even with relatively small number of rotations, which are significantly smaller than the intended maximum number of rotations nmax.

If the number of revolutions is comparatively large, the control device 81 switches the electromagnets 33 of the power generating units 41, 43, 45 on and off according to the diagram shown in FIG. The electromagnet of the power generation unit 41 is switched on during the phase angle or orbit region represented by the arrow 131, the electromagnet of the power generation unit 43 during the phase indicated by the arrow 133 and the electromagnet of the force generation unit 45 during the phase represented by the arrow 135.

In the operating mode illustrated by the diagram in FIG. 8, the switch-on points of the electromagnets are fixed in the same way as in the diagram shown in FIG. In contrast, the switch-off points according to FIG. 8 are defined differently than according to FIG. 7.

The electromagnet belonging to the power generation unit 41 is therefore switched on according to FIG. 8 when the associated plate 31 passes the sector boundary 103. If the plate 31 reaches the sector boundary 107 in the course of its movement, the electromagnet is switched off again. The electromagnet is therefore already out 656 811

switches when the plate 31 is at a point on its path that is 60 ° in phase angle from the path point closest to the pole of the electromagnet.

The other electromagnets are switched on and off in an analogous manner. With high circulation numbers, i.e. According to the diagram shown in FIG. 8, each electromagnet is therefore switched on during a 120 ° orbit or phase angle range, the three regions being evenly distributed over the entire orbit and therefore connecting without gaps without overlapping one another. The fact that more than one electromagnet is never switched on in each phase angle or orbit region means that the energy losses arising in this and in its supply voltage regulating circuit can be kept low, so that particularly in the operating mode illustrated by FIG. 8 there is very good efficiency.

Because of the self-induction and the hysteresis of the electromagnets 33, the build-up and breakdown of the magnetic fields take time and may follow the switching on or off of the electromagnets with a certain delay. If the disk 9 is rotated during operation, the readers 71, 73, 75 may also result in small delays in reading, so that the electronic signaling of the sector boundaries is somewhat less than when the edges of the cams 9b actually pass the readers may be delayed.

When the number of revolutions of the carrier 3 is low and in particular when it starts up, the delays of the magnetic fields are very small in terms of phase angle, so that the phase angle or orbit regions during which the electromagnets 33 generate magnetic fields are practically the same as those shown in FIG. 7 by the arrows 121, 123, 125 Regions match and are at most slightly offset against them in the direction of rotation of the carrier 3. In the case of large numbers of rotations of the carrier, the magnetic fields and forces generated by the electromagnets 33 of the force-generating units can possibly be shifted noticeably in phase angle with respect to the duty cycle of the electromagnets. If, therefore, the electromagnets were also controlled with large numbers of revolutions according to FIG. 7, it could happen, for example, that the electromagnet of the force-generating unit 41 would still generate a magnetic field and would exert a tensile force on the associated plate 31 if it already exceeded the sector boundary 109 would have. This would slow down the carrier 3. However, such a braking is avoided by the operating mode actually used in the case of high numbers of rotations and illustrated by FIG. 8. If, for example, one looks at the power generation unit 41, its electromagnet 33 is switched off in the idealized case when the associated plate 31 passes the sector boundary 107. Even if the plate 31 should move up to the sector boundary 109 until the magnetic field is reduced and the tensile force disappears, this tensile force is still driving and not braking. This results in a reliable drive and a uniform carrier speed even with large numbers of rotations.

The change in the operating mode and the control of the power generating units, which takes place as a function of the number of revolutions, therefore makes it possible to vary the number of revolutions of a specific shaking device in a relatively large range and to achieve optimum operating properties in the entire number of revolutions. The number of rotations can, for example, be set in a range which is from 10 to 10% or even from Joss iOu and others

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intended maximum number of rotations nmM extends. For example, if nmax is set to a value of 400 revolutions per minute, the number of revolutions can be set between 40 and 400 or even between 20 and 400 revolutions per minute.

The electrical signals generated by the readers 71, 73, 75 during operation are also fed to the circulation monitoring part 85. This has, inter alia, a pulse shaper which generates an electrical pulse when the carrier is moved at each sector boundary 103,105,107,109,111,113. The time intervals of these pulses give a measure of the number of cycles, the latter being inversely proportional to the pulse intervals. The number of cycles, or more precisely, its actual value, are displayed digitally when the display element 87 is operated.

The monitoring part 85 also has means for comparing the current number of revolutions with a limit value that can be set with the setting element 99. The monitoring part 85 then feeds signals to the logic part such that the electromagnets 33 are controlled according to the diagram shown in FIG. 7 when the number of revolutions is below the limit value and when the number of revolutions is higher according to the diagram shown in FIG. The limit value can be adjustable with the setting element 99, which is designed as a potentiometer, in a range that extends approximately from at least 2% to at most 50% and, for example, from 5% to 25% of the intended maximum number of cycles. If, for example, the latter is 400 revolutions per minute, the limit value mentioned can be adjustable in a range that lies between the number of revolutions of at least 8 and at most 200 revolutions per minute and extends for example from 20 to 100 revolutions per minute. The setting member 99 is expediently arranged such that it is inaccessible from the outside in the normal state of the device and can only be made accessible by removing a cover or the like. The optimum size of the limit value can be determined in a few tests during the testing and commissioning of a device or a series of similar devices and then determined accordingly.

The monitoring part 85 also has a control amplifier which compares the instantaneous actual value of the number of cycles with the target value set by means of the setting element 87. If the actual value is less than the setpoint, the control amplifier generates a control voltage proportional to the difference between the setpoint and the actual value. If, on the other hand, the actual value is equal to or greater than the setpoint, the control voltage has the value zero, i.e. the control voltage disappears. The control voltage is fed to the voltage regulator 91. This regulates a DC voltage serving as a supply voltage for the electromagnets in a range between a lower and an upper limit value such that it is proportional to the control voltage.

The number of revolutions is thus regulated by changing the voltage applied to the coils 35 of the electromagnets 33, whereas the on-time of the electromagnets for regulating the number of revolutions is not changed. Instead of voltage regulation, current regulation could also be carried out.

When the shaking device is in operation, a malfunction may occur in which the carrier comes to a standstill, even though the device and its drive device are actually in the operating state. Such a fault condition can occur, for example, if a person touches and blocks the moving carrier during operation in order to carry out any manipulations on the material to be shaken.

The circulation monitoring part 85 therefore also has electronic circuit means in order to compare the time intervals which the carrier 3 needs to cover the path area present between two adjacent sector boundaries 103, 105, 107, 109, 111, 113 with a predefined, possibly adjustable limit time interval. As long as the time intervals required for the passage of a 60 ° sector are smaller than the limit time interval, the shaking device is in the normal operating state, in which it operates according to one of the operating modes described with reference to FIGS. 7 and 8. If, on the other hand, the carrier 3 does not pass through one of the path areas corresponding to a 60 ° sector within the limit time interval, the monitoring part 85 supplies the logic part 83 with at least one electrical signal which characterizes the fault condition. This causes the logic part 83 to switch off the electromagnet that has just been switched on or the two that are just switched on for a predetermined period of time and then switch it on again for a likewise predefined period of time and repeat this alternately periodically until the fault condition disappears, i.e. until the carrier moves again after the blocking has been released or until the shaking device or at least its drive device is put out of operation by manually actuating the switching element 97. During the fault state, the electromagnets are thus controlled according to a fault mode, in which each electromagnet that is switched on when the fault state occurs, but no other electromagnet, is alternately switched on and off, the lengths of these switching periods and the switch-off and switch-on intervals being constant are. As soon as the carrier moves again, the electromagnets are then controlled again in accordance with one of the normal operating modes explained with reference to FIGS. 7 and 8.

The mentioned limit time interval can be approximately in the range from 0.5 to 20 seconds and can be, for example, 1 to 5 seconds. The time intervals during which the or each electromagnet that is switched on is switched off and then on again in the fault mode of operation can be defined in such a way that the operating time of each electromagnet is at most 70%, preferably at most 50% and, for example, even when the carrier is blocked 30% of the full off / on switching period is. The interruptions can be, for example, 0.7 seconds and the switch-on times 0.3 seconds.

Since the electromagnets in the two normal operating modes are switched on for at most three consecutive 60 ° phase angle sectors, each electromagnet can be switched on permanently during a blockage at most during a time interval whose size is equal to three times the limit time interval. The limitation of the time for the passage of the carrier through a web area extending over a 60C sector also results in an indirect limitation of the time intervals during which a magnet is continuously switched on. Otherwise, one could of course limit the duty cycle of the electromagnets instead of the time mentioned for the passage of a predetermined path area or in addition to it. The electromagnets can therefore never be overloaded even with a relatively small dimensioning and the carrier starts again automatically in the event of a temporary blockage.

The shakers can be modified in various ways.

In the case of high numbers of revolutions, the power generation unit 41 could be switched on between the sector boundaries 105 and 109 instead of the way illustrated in FIG. 8

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will. The switch-on ranges of the other power generating units would then be shifted analogously, so that there is again a uniform distribution of the switch-on ranges in terms of phase angle.

Furthermore, it would be possible to change the operating mode again when the number of revolutions is extremely high and to switch on each power generation unit per revolution only during a 60 ° sector.

In the exemplary embodiment described above, the drive device for driving the carrier has three force-generating units. However, one could also provide six power generating units, each with an electromagnet. This is useful, for example,

if the orbit has a relatively large diameter and then, in certain carrier positions, there are correspondingly large air gaps between the electromagnet and the plate attracted by it. The six electromagnets would then be distributed evenly and the shaft 11 of the crank would be distributed around. The electromagnets could then be switched on analogously to the diagrams in FIGS. 7 and 8 in each case during low rotation numbers during 180 ° sectors and at high rotation numbers during 120 ° sectors. However, one could switch on each electromagnet only at 120 ° for low revolutions and only during 60 ° sectors with high revolutions. For example, the electromagnet that corresponds to the power generation unit 41 could be switched on between the sector boundaries 105 and 109 when the number of rotations is low and between the boundaries of the sector 105 and 107 when the number of rotations is high.

Furthermore, four or eight electromagnets and an equal number of platelets corresponding to platelets 31 could also be provided. The electromagnets and platelets would then be arranged in such a way that the force generating units formed by them could generate forces during path sections that were uniformly distributed in terms of phase angle. Instead of disk 9, a disk would then be provided with which eight 45 ° sectors could be identified by a three-digit binary number. The electromagnets could then be controlled in such a way that each of them generates a tractive force per revolution at most during a 180 ° sector, that the switch-on times overlap when the number of rotations is low and that the electromagnets are switched on at a high number of rotations per revolution during a phase angle that is at least 45 ° smaller than with low circulation figures.

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Instead of a plurality of separate plates 31, a polygonal block could also be attached to the carrier, which faces a surface for each electromagnet. Another possibility would be to replace the plates 31 with permanent magnets. This would enable the electromagnets to alternately generate attractive and repulsive forces.

It would also be possible to attach the electromagnets to the movable support and to rigidly connect the parts corresponding to the plates 31 to the frame.

It would also be possible to provide power generating units that have pneumatic or hydraulic cylinders with pistons instead of electromagnets. These cylinders could then be controlled in the same way as the electromagnets.

It would also be possible to provide only two readers or more than three readers instead of the three readers 71. In addition, the device could be equipped with other non-contact readers, such as optical readers, or even with non-contact readers, such as pushbuttons, instead of inductive readers. Furthermore, the characters readable by the readers could also be attached directly to the movable support instead of on the disc of a crank. In addition, the characters used to identify the position of the carrier could be fixed in place on the frame and the readers could be arranged immovably with the carrier.

Furthermore, the control device could be modified in such a way that in the event that the movement of the carrier is interrupted while the drive device is in the operating state and the aforementioned malfunction occurs, the force generating units are cyclically switched on and off independently of the position of the carrier. It would be possible to switch on either only one power generation unit or two at the same time. This cyclical control should take place in such a way that at least one power generation unit is switched off during each cycle phase. The cyclical forced switching would also be anticipated at a constant frequency, which corresponds to a relatively small number of cycles. The cyclical forced switchover could take place, for example, with a number of cycles that corresponds to 2 to 10% of the intended maximum number of cycles. If the carrier moves again, the system would then switch back to the normal operating mode, in which the power generation units are controlled as a function of the carrier position.

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3 sheets of drawings

Claims (9)

656811 PATENT CLAIMS 1. Shaking device with a frame (1), a carrier (3) movably held along a path (101) by the latter, various types of position representation characters (9b, 9c), further comprising readers (71, 73 , 75), and with means (5,9,81) for moving the characters (9b, 9c) and readers (71,73,75) with respect to each other when the carrier (3) is moved and the To determine the position of the carrier (3), characterized in that the characters (9b, 9c) represent at least two-digit numbers and that a reader (71, 73, 75) is available for reading each digit. 2. Shaking device according to claim 1, characterized in that the characters (9b, 9c) represent a binary number. 3. shaking device according to claim 1 or 2, characterized in that the carrier (3) along a flat, closed path (101), preferably a circular path, which is divided into at least four areas, each of which is different by the Character (9b, 9c) is assigned to the number shown. 4. Shaking device according to claim 3, characterized in that the position representation characters (9b, 9c) are arranged on a body (5) which is mounted in a rotationally operative connection with the carrier (3) and is rotatably about an axis of rotation in the frame (1) and the different digits of the number representing characters are arranged on different ring strips (51, 53, 55) coaxial with the axis of rotation. 5. Shaking device according to claim 4, characterized in that the characters represent a three-digit binary number and formed by radially outwardly protruding cams (9b) and recesses (9c) of a one-piece body (9) and three along the axis of rotation of the body (9) staggered ring strips (51, 53, 55) and a number of sectors (57,59, 61, 63, 65, 67) are distributed so that each character (9b, 9c) at least approximately along the body (9) to the whole extends in the sector belonging to the sector concerned and that no sector (57, 59, 61, 63, 65, 67) of the body (9) has a recess (9c) between two cams (9b) present in this sector. 6. Shaking device according to claim 5, characterized in that the characters (9b, 9c) are distributed over six sectors (57,59,61, 63,65, 67), that the readers (71, 75) read the on the two outer ring strips (51, 55) arranged characters (9b, 9c) in a projection parallel to the axis of rotation at the same circumferential point of a circle concentric to the axis of rotation and that for reading the characters (9b, 9c) of the middle ring strip (53) Reader (73) is offset in the above projection on the circle by 120 ° against the other two readers (71, 75). 7. shaking device according to one of claims 1 to 6, characterized in that the characters (9b, 9c) are designed such that the sections of the web (101) by reading the characters (9b, 9c) identifiable and distinguishable from each other are, at least approximately seamlessly connected to each other. 8. Shaking device according to one of claims 1 to 7, characterized in that at least two power generating units (41, 43, 45) which serve to drive the carrier (3) and can be switched on and off separately and one with these and the readers (71, 73 , 75) are connected to the control device (81) and that the latter has means (83,93) in order to determine the position of the carrier (3) and the electrical signals supplied by the readers (71,73,75) Switch the power generation units (41, 43, 45) on and off at specified positions. 9. A method of operating the shaker according to claim 1, wherein a carrier (3) is moved along a path (101), readers (71, 73, 75) and mutually distinguishable types of position-indicating characters (9b, 9c) with respect to one another are moved and the position of the carrier (3) is determined by reading the characters (9b, 9c), characterized in that the characters (9b, 9c) represent at least two-digit numbers that are read by the readers, and that all digits of a number represented by one character (9b, 9c) can be read simultaneously.