Weighing system with astasis lever

Abstract

The invention relates to a weighing system (10) comprising - a base (12), - a load receiver (14) articulated to the base (12) by means of a parallel link arrangement, - a transmission lever (24) pivotally connected to the base (12) by means of a transmission lever joint (25), the first transmission lever arm (241) of which is connected to the load receiver (14) via a load coupling band (28) and the second transmission lever arm (242) of which carries at least one element of an electromagnetically compensatory sensor arrangement (26), and - an astasis force generating element fixed on one side of the base (12), by means of which an astasis force can be generated which can be introduced into an introduction point (32) of the transmission lever (24), The invention is characterized by an astasis lever (36) pivotally connected to the base (12) by means of an astasis lever joint (40), the first astasis lever arm (361) of which is connected to the introduction point (32) via an astasis coupling band (34) and the second astasis lever arm (362) of which is operatively connected to the astasis force generating element. wherein at least one of the following components is axially adjustable: - the initiation point (32) in relation to the transmission lever (24), - the fixing point at which the astasis coupling band (34) is fixed to the first astasis lever arm (361), relative to and with respect to the astasis lever (36), - the astasis lever joint (40) together with the astasis lever (36), relative to the base (12) and in relation to the astasis lever (36).

Description

Field of the InventionThe invention relates to a weighing system comprisinga base,a load receiver articulated on the base by means of a parallel link arrangement,a transmission lever pivotably articulated on the base by means of a transmission lever joint, the first transmission lever arm of which is connected to the load receiver via a load coupling band and the second transmission lever arm of which carries at least one element of an electromagnetic-compensatory sensor arrangement, andan adjustment force generating element fixed on one side to the base, by means of which an adjustment force that can be introduced into an introduction point of the transmission lever can be generated.Prior ArtSuch a weighing system is known from EP 0 359 978 B1.Gravimetric measuring devices operating according to the principle of electromagnetic compensation, and therefore weighing devices, have long been known to the person skilled in the art. For example, EP 2 690 415 A1 discloses such a weighing device.The basic principle consists in that the deflection of a load receiver with respect to a base caused by the weight of a load is transmitted in a force-transmitting and displacement-transmitting manner by means of a transmission lever to a sensor which, for its part, is capable of exerting an electromagnetic force on the lever arm which is directed opposite to the deflection. This compensation force is dependent on the current with which the coil of a plunger coil arrangement generating the compensation force is energized. If the current is selected such that the load-induced deflection of the transmission lever is compensated exactly, and the lever arm is therefore in its equilibrium position despite the load being applied, the compensation current represents an exact measure of the required compensation force and therefore of the weight of the load being applied.From a technical point of view, such a system is usually implemented as follows: By means of a parallel link arrangement, the so-called load receiver, to which a weighing object receiver can be coupled, is linked to a fixed base, whereby its degrees of freedom of movement are limited to a largely vertical, tilt-free movement when the weighing device is correctly set up-at least in the case of small deflections. Via a so-called coupling band, the load receiver is linked to a transmission lever, in particular to its load receiver-side lever arm. A coupling band is understood here to mean a predominantly elongated coupling which is flexible in predominantly only one bending direction. Frequently, a thin sheet metal strip is used for this purpose, which often has thin material points in the vicinity of its terminal fixing points, so that the strip which is already predominantly only one-dimensionally flexible due to its shape is articulated at its fixing points as a result. The transmission lever is mounted pivotably on a lever joint fixed to the base, which is referred to here as transmission lever joint. The bearing point represents the boundary between the load-receiver-side lever arm, which is referred to here as the first transmission lever arm, and the sensor-side lever arm, which is referred to here as the second transmission lever arm. At the end of the sensor-side lever arm, the coil of a voice coil arrangement is usually fixed. It is immersed in the magnetic field of a base-fixed, usually pot-like magnet, usually a permanent magnet. However, inverted arrangements with a base-fixed coil and a lever-fixed (permanent) magnet are also conceivable, but unusual. The position of the transmission lever in a predetermined reference load situation (usually unloaded in the case of conventional scales, loaded in the case of comparators) represents its equilibrium position. This can be detected by means of a separate position sensor, which usually works according to an optical principle, or the lever can be adjusted in such a way that it is in a position interpreted by the position sensor as an equilibrium position in the reference load situation. When the coil is energized, a magnetic field corresponding to the coil current is generated, which interacts with the magnetic field of the permanent magnet, resulting in a force being applied to the sensor-side lever arm. Conversely, applying a load to the load receiver results in a mechanical force acting on the load receiver-side lever arm. By means of a suitable control, such a device can be operated in such a way that any (infinite) load-induced deflection of the transmission lever is detected by the position sensor and is converted into a compensatory change in the coil current. In this way, the transmission lever remains in its equilibrium position (apart from infinite deflections), wherein the current flowing through the coil at the end of a transient process is representative of the load applied to the load receiver, the weight of which can be determined very precisely by corresponding measurement of the coil current.The mechanical component of this complex system is frequently referred to in the technical jargon as a weighing system. These are very precisely manufactured, frequently monolithic devices which, despite the use of highly developed precision technology, can show deviations from an ideal system. In particular, the so-called stiffness of the joints in such a weighing system represents such a deviation from the ideal system. Stiffness is understood to mean the restoring force which a real joint (in contrast to an ideal joint) opposes its deflection. As a rule, it is not possible to define as the equilibrium position of the transmission lever that position in which the transmission lever joint is exactly unrouted, i.e. in which no stiffness-induced torque acts. Instead, a slightly deviating lever position will normally be defined as the equilibrium position by means of the position sensor. A coil current in the plunger coil arrangement, which may be required to maintain this equilibrium position against a torque caused by rigidity, is treated as offset current below. In this context, one speaks of "taring" the balance. However, a further deviation from the ideal system is the finite resolution with which the position sensor can detect the position of the transmission lever, in particular its equilibrium position. A deviation from the defined equilibrium position lying below this resolution limit therefore leads to a torque which is dependent on the rigidity but not compensated by the camouflage and which adds--positively or negatively--to the torque caused by the weight force of the weighing object. The magnitude of this "error" torque is dependent--given a positional deviation of the transmission lever--on the actual joint rigidity. The attempt is made with so-called estimation to minimize the steepness of this essentially linear dependence, so that the real deviations from the defined equilibrium position, which are unavoidable due to the finite position sensor resolution, result in the lowest possible error torque.Various estimating agents are known to those skilled in the art. As an adjusting means, it is known, for example, to design the transmission lever such that its center of gravity lies above the lever joint, i.e. above its exact pivot axis. This leads to a labileization of the equilibrium position of the transmission lever: any deflection of the lever leads, owing to the raised center of gravity, to a torque which reinforces the deflection. This counteracts the reverse stiffness torque of the lever joint. Conversely, a stabilization can be achieved by displacing the lever center of gravity below its pivot axis. A disadvantage of this approach is that both the articulation stiffness and the center of gravity position of the transmission lever are subject to manufacturing deviations and therefore compensate each other exactly only in rare exceptional cases. In addition, there is an increased tilting sensitivity of the system. The skilled person will recognize that relative orientation terms such as "above" or "above" and "below" or "below" are to be understood here in the context of an intended orientation within the scope of a functionally ready balance.As a result, a principle known from the generic EP 0 359 978 B1 mentioned at the beginning acts in a similar manner, but is less prone to tilting, in which the transmission lever carries a coupling point for one end above its lever joint a tension spring, the other end of which is fixed to the base, so that the tension spring is tensioned vertically via the transmission lever joint. As a result, the transmission lever is acted upon by a force acting vertically from top to bottom and running through the transmission lever joint. This is introduced into the transmission lever via the spring coupling point acting as the introduction point for the actuating force. The mechanical implementation of the principle which is still considered to be extremely favorable as before, which is disclosed in this publication, which was about 35 years old, is no longer compatible with modern, extremely high-resolution scales. In particular, it would be desirable to be able to reduce the force acting on the transmission lever joint in the equilibrium position in order to prevent material from flowing in the region of the joint, which is typically designed as an extremely delicate thin point. In addition, the direction of action of the spring force of the tension spring designed as a helical spring cannot be reproduced so accurately that it extends in each case exactly through the pivot axis of the transmission lever, which would be necessary, however, in the case of high-resolution, modern balances.DE 10 2021 132 094 B3 discloses a weighing system having two transmission levers which are attached to the load receiver in parallel and are each coupled to a voice coil arrangement. The two transmission levers are different, in particular opposedly owing. By suitably controlling the voice coil arrangements, it is possible to distribute the force flow to the two transmission levers in such a way that optimum adjustment is established for the total force flow. This construction is very complicated, expensive and space-intensive, in particular because of the double plunger coil arrangement.Object Setting Up To AchieveIt is the object of the present invention to provide a mechanical conversion of the estimation principle known from the generic publication compatible with modern weighing systems.DISCLOSURE OF THE INVENTIONThis object is achieved in conjunction with the features of the preamble of claim 1 by an adjustment lever pivotably articulated on the base by means of an adjustment lever joint, the first adjustment lever arm of which is connected to the introduction point via an adjustment coupling band and the second adjustment lever arm of which is operatively connected to the adjustment force generating element, wherein at least one of the following components is designed to be axially adjustable:the initiating point, with respect to the transmission lever,the fixing point at which the adjusting coupling band is fixed to the first adjusting lever arm, namely relative to the adjusting lever and with respect thereto,the astasis lever joint together with the astasis lever, namely relative to the base and in relation to the astasis lever.Preferred embodiments are the subject of the dependent claims.The basic idea of the invention is to not couple the augmentation force generating element, which is preferably designed as a spring, in particular as a tension spring, directly to the introduction point, but instead indirectly via an additional mechanism comprising augmentation lever and augmentation coupling band. By using the adjustment coupling band, the direction of the adjustment force acting on the introduction point can be defined much more precisely than if a tension spring, which is designed as a helical spring, for example, were coupled there.In addition, the deflection of the adjustment force by means of the adjustment lever allows an extension of the entire force flow path and in particular an extension of its straight end section terminating at the introduction point. The length of this end section of the force flow path--for a given actuating force--is decisive for the strength of the actuating torque which is built up upon deflection of the transmission lever from its equilibrium position. Conversely, the greater the torque that can be achieved with a given force, the less the force required to achieve the desired augmentation torque can be selected. A reduction in the actuating force introduced into the introduction point in turn results in a reduced load on the transmission lever joint in the equilibrium position of the transmission lever. The risk of material flowing in the filigrane transmission lever joint is correspondingly lower because of the permanent load exerted by the actuating force applied, for example, as a spring force. With the same installation space and the same desired adjustment torque, the indirect introduction of the adjustment force according to the invention thus permits a more delicate design of the weighing system, which makes it advantageous to adapt its sensitivity and therefore the resolution of a corresponding balance.As already indicated, also in the case of the weighing system according to the invention, the actuating force generating element is preferably designed as a spring, in particular as a tension spring. The first end of the spring is fixed to the base and the second end thereof is fixed to the second actuating lever arm. This fixing can be a linkage. As a rule, however, the spring will be sufficiently flexible in itself in order to be able to compensate for the minute deviations from a purely linear movement of the second actuating lever arm end, which occur at the expected small deflections of the actuating lever. On the other, first actuating lever arm, the compensation is effected by the properties of the coupling band, the flexibility of which is precisely defined or limited by its shape.As is known from the prior art, the introduction point for the actuating force is preferably arranged above the transmission lever joint or the pivot axis defined by it. When using a tensile force generated beyond the axis of rotation as an actuating force, this leads to a labile effect. In other words, in such an embodiment, the material- and shape-defined stiffness of the transmission lever joint is counteracted. If a stabilizing effect of the adjustment is desired in individual cases, the introduction point can instead be arranged below the transmission lever joint or the pivot axis defined by it in corresponding embodiments.Advantageously, the introduction point is axially co-located with the transmission lever joint or the pivot axis. The directional indication "axial" refers here to the direction of longitudinal extent of the transmission lever. Within the scope of this description, the shortened formulation "in relation to the lever axially" is also used for this purpose and for analogous situations. In the case of an exactly horizontal alignment of the transmission lever in its equilibrium position, the introduction point is therefore preferably arranged exactly vertically above the pivot axis. The point at which the lever-side end of the adjustment coupling band is fixed to the adjustment lever should be located as exactly as possible in the extension of the connecting line between the introduction point and the transmission lever pivot axis, and therefore in the usual embodiment exactly vertically below the transmission lever pivot axis. Particularly when using a long coupling band, however, the exactness of the position of this fixing point is less critical than the exactness of the positioning of the introduction point relative to the transmission lever joint. However, if the transmission lever joint is (also) capable of supporting non-perpendicular forces, the line of action of the adjusting force may also lie obliquely or even transversely to the perpendicular distance between the axis of rotation and the longitudinal extent of the lever. In any case, however, it should intersect the axis of rotation as exactly as possible.In particular in cases in which the introduction point is arranged above the transmission lever joint, it is advantageous if the adjustment coupling band is guided between two legs of the transmission lever having two laterally spaced legs at least in the region of the transmission lever joint. The functional transmission lever joint is then divided into two structural joints spaced apart from one another, preferably thin material points, which together form the pivot axis for the transmission lever. There is sufficient space between these two structural joints or material thin points, which each connect one of the parallel legs of the transmission lever to the base, to allow the adjustment coupling band to run through the transmission lever to the adjustment lever.Despite sophisticated manufacturing techniques, in particular in precision milling of monolithic weighing systems, there may be minor manufacturing tolerances, which also affect the above-mentioned relative positioning of the introduction point and the transmission lever joint. In order to compensate for this, a variant of the invention provides that the introduction point is designed to be axially adjustable with respect to the direction of longitudinal extent of the transmission lever. In other words, in such an embodiment, the introduction point is arranged displaceably in the direction of longitudinal extent of the transmission lever. As a result, manufacturing tolerances can be compensated in the individual case by appropriate adjustment in order to achieve that the introduction direction of the adjustment force runs exactly through the transmission lever joint or the pivot axis of the transmission lever.Such an adjustment mechanism, which should be capable of compensating deviations in the micrometer or even sub-micrometer range, is not trivial. One of various mechanical possibilities is considered to be that the introduction point is arranged on a sliding block which is axially displaceable on the transmission lever with respect to the direction of longitudinal extent of the transmission lever, and that the sliding block is acted upon indirectly by force via a wedge which can be adjusted transversely to the direction of longitudinal extent of the transmission lever against a stop which is fixedly connected to the transmission lever. A displacement of the wedge transversely to the axial direction of the transmission lever thus leads to a change in the distance of the edge of the sliding block resting on the wedge from the stop fixed to the lever. Thus, when the wedge is retracted, the axial force acting on the sliding block presses the latter in the direction of the stop. On the other hand, when the wedge is advanced, the distance increases counter to the force acting on the sliding block. The displacement of the wedge can be realized, for example, by an adjusting screw with fine thread. The force application to the sliding block can be effected, for example, by a spring. Frequently, however, the inherent elasticity of the material, usually an aluminum alloy, will also be sufficient to be able to follow the minute displacements of the sliding block required for the adjustment.Alternatively or additionally, it is provided according to the invention that the entire adjustment lever is designed to be displaceable relative to the adjustment lever, namely axially displaceable with respect to the adjustment lever, relative to the base or at least the fixing point at which the adjustment coupling band is fixed to the first adjustment lever arm. Such a displacement can also influence the oblique position of the adjustment coupling band and in particular be set such that it or the line of action of the adjustment force imparted via it runs exactly through the axis of rotation of the transmission lever. The displacement of the entire adjustment lever can be carried out in particular by a displacement of its adjustment lever joint with a suitable displacement mechanism mounted on the base. The isolated displacement of the adjustment coupling band fixing point can be carried out by means of a suitable displacement mechanism mounted on the adjustment lever. Compared to the previously described variant of displaceability of the introduction point relative to the transmission lever, such embodiments even have the advantage that the adjustment is less sensitive and therefore fundamentally mechanically easier to implement. The reason for this is the typically greater distance between the axis of rotation of the transmission lever on the one hand and the introduction point or the fixing point of the augmentation coupling band on the augmentation lever on the other hand. In practice, however, the installation space in the region of the adjustment lever is limited and / or difficult to access, so that an adjustment possibility arranged here encounters handling difficulties.Advantageously, the strength of the astasis force can be adjusted, if necessary. In the preferred case of the configuration of the actuating force generating element as a spring, in particular a tension spring, this can be realized in that the fixing position of the spring on the base is adjustable in the force action direction of the spring. In other words, the prestress of the spring is thus varied. In this way, manufacturing tolerances of the spring as well as of the joints themselves can be compensated for.Further details and advantages of the invention will become apparent from the following specific description and drawings.Brief Description of the DrawingsThe following are shown: FIG. 1 is a highly schematic representation of a weighing system according to the invention, FIG. 2 : an enlarged representation of the transmission lever joint of the weighing system of FIG. 1 in a schematic side view, and FIG. 3 shows an enlarged representation of the transmission lever joint of the weighing system of FIG. 1 in a schematic front view.DESCRIPTION OF PREFERRED EMBODIMENTSLike reference numerals in the figures indicate like or analogous elements.FIG. 1 shows a highly schematic side view of a weighing system 10 according to the invention. The base 12 of the weighing system 10, which is frequently also referred to in the technical jargon as "land" or "system carrier", is merely indicated in the figures. The weighing system 10 has a Roberval mechanism, by means of which a load receiver 14 is articulated on the base 12 via two parallel guide rods 16 a, 16 b. Both parallel links 16 a, 16 bare articulated on the one hand on the base 12 and on the other hand on the load receiver 14 by means of joints which are referred to here as Roberval joints 18 and are preferably designed as thin material joints. The load receiver 14 is connected to a load carrier 20, wherein this connection is effected via a cantilever arm 22 in the embodiment shown.Furthermore, the weighing system 10 has a transmission lever 24, which is constructed from a load-receiver-side, first transmission lever arm 241 and a second transmission lever arm 242. The boundary between the first and second transmission lever arms 241, 242 is located axially at the level of a transmission lever joint 25, which is preferably designed as a thin material area and by means of which the transmission lever 24 is pivotably articulated on the base 12. At its free end, the second transmission lever arm 242 carries components of a sensor arrangement 26; in the case shown, this is, on the one hand, the plunger coil 261 of an electromagnetic-compensatory sensor which additionally comprises a pot magnet 262 fixed to the base. Furthermore, the second transmission lever arm 242 carries the target 263 of an optical position sensor, which is not otherwise shown.The free end of the first transmission lever arm 241 is connected to the load receiver 14 via a load coupling band 28. In particular, the load coupling band 28 can consist of a sheet metal strip which has a respective coupling band joint 30 designed as a thin material location in the vicinity of its two ends.In this respect, the inventive weighing system does not differ from known weighing systems for electromagnetically compensating balances (EMF balances) and corresponds to these also with regard to its basic functionality. A weighing object placed on the weighing object carrier 20 causes a weight force on the load receiver 14, which tends to yield this force by deflection vertically downwards. The force or the resulting, tending deflection is transmitted via the load coupling band 28 to the transmission lever 24, the first transmission lever arm 241 of which tends to be pulled downward and the second transmission lever arm 242 of which tends to be pushed upward. The deflection is detected by the optical position detector and the coil 261 of the sensor 26 is energized to exactly such an extent that said deflection is completely suppressed and the transmission lever 24 is held in its equilibrium position after a transient process. The compensation current through the coil 261 required for this purpose is representative of the weight exerted by the weighing object.The particular feature of the present invention concerns the specific way of introducing an actuating force into the transmission lever 24. In FIGS. 2 and 3, however, it is shown in a section in correct adjustment. Above the transmission lever joint 25 there is an introduction point 32 which is displaceable in the longitudinal extension or axial direction of the transmission lever 24; it is shown purely schematically in the figures on the upper limb of a cantilever arm. In practice, however, it will usually be located directly on the upper side of the transmission lever 24 itself. In the operating case, as shown in FIGS. 2 and 3, the introduction point 32 should be situated exactly above the pivot axis formed by the transmission lever joint 25 or at least be capable of being brought into such a position by corresponding adjustment. This optimal adjustment is also referred to here as axial colocalization of the introduction point and the pivot axis. The introduction point 32 is connected via an adjustment coupling band 34 to the first lever arm, referred to here as the first adjustment lever arm 361, of an adjustment lever 36. The augmentation coupling band 34, like the load coupling band 28, is preferably designed as a sheet metal strip which carries a respective coupling band joint 38 designed as a thin material location in the region of its ends. In the embodiment shown, the adjustment lever 36 is arranged below the transmission lever 24 and is pivotably articulated on the base 12 via an adjustment lever joint 40, which is preferably designed as a thin material section. In particular, it is positioned such that the coupling point of its first adjustment lever arm 361 with the adjustment coupling band 34 is situated largely exactly below the pivot axis of the adjustment lever 24 formed by the adjustment lever joint 25. However, this is not absolutely necessary-at least in cases in which the transmission lever joint 25 is also able to support non-vertical forces. The second lever arm of the adjustment lever 36, which is referred to here as the second adjustment lever arm 362, is prestressed against the base 12 by a spring 42, which is designed here as a tension spring. In the illustrated embodiment, the tension spring 42 exerts an upward force on the second adjustment lever arm 362.In the case of correct adjustment, as shown in FIGS. 2 and 3, this force is deflected by means of the adjustment lever 36 and introduced into the introduction point 32 in such a way that the force acting on the transmission lever 24 in the equilibrium position of the transmission lever 24 runs exactly through the pivot axis defined by the transmission lever joint 25. It is thus supported completely by the transmission lever joint 25. No torque acting on the transmission lever 24 results. If, on the other hand, the transmission lever 24 is deflected out of its equilibrium position, in particular by the weight force of a weighing object placed on the weighing object carrier 20, the force flow line shifts and runs axially next to the pivot axis. The transmission lever joint 25 then no longer completely supports the induced augmentation force and an augmentation torque results that reinforces the deflection of the transmission lever 24 due to the weight force, by which torque an opposing torque due to the stiffness is counteracted.The only indirect introduction of the adjustment force generated by the spring 42 via the adjustment lever 36 and the adjustment coupling band 34 has the advantage that the direction of action of the introduced adjustment force is precisely defined in the region of the transmission lever joint 25, unlike if the spring 42 were coupled directly to the introduction point 32. As a result, the astasizing effect is highly reproducible or even precisely adjustable in embodiments such as that shown.FIG. 3 shows a front view of the section of the weighing system 10 shown in FIG. 2 in side view. In this preferred embodiment, the transmission lever 24 is designed in the form of two parallel legs 24 a, 24 bat least in the region of the transmission lever joint 25. In this embodiment, the transmission lever joint 25 is formed as two material thin sections 25 a, 25 b, which are spaced apart from one another and jointly define the pivot axis of the transmission lever 24. In this embodiment, the adjustment coupling band 34 can extend between the two legs 24 a, 24 bof the transmission lever 24 or the two material thin-sections 25 a, 25 bof the transmission lever joint 25.Of course, the embodiments discussed in the specific description and shown in the figures represent only illustrative exemplary embodiments of the present invention. The skilled person will be given a wide range of possible variations in the light of the disclosure here. In particular, variants are conceivable in which the spring 42 is designed as a compression spring instead of as a tension spring and / or acts on the second actuating lever arm 362 in the opposite direction of action. It is also conceivable to arrange the introduction point 32 below instead of above the pivot axis of the transmission lever 24. With regard to the special mechanics of an optionally present axial adjustability of the introduction point 32, all known and optionally still to be developed, precision mechanical implementations are available to the person skilled in the art.List of reference characters10 Weighing system 12 Base 14 Load receiver 16 a Oberer parallel link 16 b Unterer parallel link 18 Roberval joint 20 Load carrier 22 Cantilever arm 24 Transmission lever 24 a Schenkel arm 24 b Schenkel arm 24 241First transmission lever arm 242Second transmission lever arm 25 Transmission lever joint 25 aMaterial thin section of 25 25 bMaterial thin section of 25 26 Sensor arrangement 261 Voice coil 262 Pot magnet 263 Target 28 Load coupling band 30 Coupling band joint 32 Introduction point 34 Adjustment coupling band 36 Adjustment lever 361First adjustment lever arm 362Second adjustment lever arm 38 Coupling band joint 40 Adjustment lever joint 42 Spring

Claims

Weighing system (10), comprising - a base (12), - a load receiver (14) articulated on the base (12) by means of a parallel link arrangement, - a transmission lever (24) articulated on the base (12) pivotably by means of a transmission lever joint (25), the first transmission lever arm (241) of which is connected to the load receiver (14) via a load coupling band (28) and the second transmission lever arm (242) of which carries at least one element of an electromagnetic-compensatory sensor arrangement (26), and - an astasis force generating element fixed on one side to the base (12), by means of which an astasis force that can be introduced into an introduction point (32) of the transmission lever (24) can be generated, characterized byan astasis lever (36) articulated pivotably on the base (12) by means of an astasis lever joint (40), its first adjustment lever arm (361) is connected to the introduction point (32) via an adjustment coupling band (34) and its second adjustment lever arm (362) is operatively connected to the adjustment force generating element, wherein at least one of the following components is designed to be axially adjustable: the introduction point (32), namely with respect to the transmission lever (24), the fixing point at which the adjustment coupling band (34) is fixed to the first adjustment lever arm (361), namely with respect to the adjustment lever (36) and with respect thereto, the adjustment lever joint (40) together with the adjustment lever (36), namely with respect to the base (12) and with respect to the adjustment lever (36).Weighing system (10) according to claim 1, characterised in that the adjusting force generating element is formed as a spring (42), the first end of which is fixed to the base (12) and the second end of which is fixed to the second adjusting lever arm (362).Weighing system (10) according to claim 2, characterised in that the spring (42) is designed as a tension spring.Weighing system (10) according to one of the preceding claims, characterized in that the introduction point (32) is arranged above the transmission lever joint (25).Weighing system (10) according to one of the preceding claims, characterized in that the introduction point (32) - in relation to the transmission lever (24) - is axially co-located with a pivot axis of the transmission lever (24) defined by the transmission lever joint (25).Weighing system (10) according to one of the preceding claims, characterized in that the transmission lever (24) has two limbs (24a, 24b) which are laterally spaced apart from one another at least in the region of the transmission lever joint (25), and the adjustment coupling band (34) runs between these two limbs (24a, 24b).Weighing system (10) according to one of the preceding claims, characterized in that the introduction point (32) is arranged on a sliding block which - in relation to the transmission lever (24) - can be displaced axially on the latter and which is acted upon indirectly by force via a wedge which can be adjusted transversely to the axial direction of the transmission lever against a stop which is fixedly connected to the transmission lever.Weighing system (10) according to one of the preceding claims, characterized in that the strength of the adjusting force is adjustable.Weighing system (10) according to claim 8, insofar as it refers back to one of claims 2 to 3, characterised in that the fixing position of the spring (42) on the base (12) is adjustable in the force-action direction of the spring (42).

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