HK1028447B - Force-measuring apparatus, particularly a weighing cell - Google Patents

Description

Force measuring device, in particular weighing cell

The invention relates to a force-measuring device, in particular a weighing cell, having a carrier, an adjusting device and an arm. The carrier is used for bearing the force to be measured and is guided in parallel relative to a fixing part by two arm supports which are arranged on planes which are distributed in parallel with each other, are rigid on the planes and can deflect perpendicular to the planes, wherein each arm support is connected with the carrier at one end and is connected with the fixing part at the other end opposite to the end, and the position of at least one fixing area of the fixing part for fixing one arm support can be adjusted in the direction perpendicular to the arm support plane by means of the adjusting device; the arm extends in its longitudinal direction approximately parallel to the arm support plane, is connected to the fastening element, can be pivoted about a pivot axis approximately parallel to the arm support plane and approximately perpendicular to the arm longitudinal direction, and has a fastening region and an actuating region for the actuating element for pivoting the arm about the pivot axis.

With such a weighing cell, a weight measurement value can be generated which represents a load acting on a balance or carrier plate associated with the support body, independently of the position of the load on the balance or carrier plate, since the parallel guidance of the support body by using the two arm supports prevents the otherwise occurring tilting of the support body, which is a concern when the weighing object is not placed in the center of the balance or carrier plate, which is dependent on the position of the weighing object. However, this advantage is only reliably achieved if the parallel-guided arms are arranged exactly parallel to one another. In particular for high-resolution scales, it is therefore necessary to provide an adjusting device which can be adjusted precisely with regard to the orientation of one arm relative to the other.

A weighing cell equipped with such an adjusting device is known, for example, from DE 8615750.7U 1. In the weighing cell described in this document, one end of the arm is fixed to a fixed part of the weighing cell by means of an additional parallelogram guide. In this case, a lower boundary surface of the parallelogram guide facing away from the upper fastening region for fastening the arm forms a substantially wedge-shaped gap with a counter surface which is fixed in position relative to the fastening element, in which gap a pin extending parallel to the arm surface is inserted, through which pin an adjusting screw extending substantially perpendicularly to its longitudinal direction and accommodated by a thread provided on the fastening element passes. With this adjusting screw, the bolt, which rests on the lower boundary surface of the parallel-guiding device on the one hand and on the stationary counter surface on the other hand, can be adjusted in the wedge gap. In this way, the upper fastening region of the parallel-guiding device, which is formed in the form of a fastening surface, can be adjusted, so that the arm fixed to the upper fastening region can also be adjusted in a direction perpendicular to the arm surface. By means of such an adjustment, a parallel orientation of the arm rest, which is arranged on the upper fastening region of the additional parallel guide, relative to the other arm rest can be achieved. However, this adjustment device requires a high outlay in terms of construction, since, in addition to the parallel guide for the carrier body, a further parallel guide is also required for the fastening region for fastening one arm to the fastening part.

In a weighing cell of the type mentioned by way of introduction, which is known from DE 8708485.6U 1, the fastening region, which can be adjusted by means of the adjusting device, for fastening an arm support to the fastening part is formed on an arm which is articulated to the fastening part by means of a flexural hinge. In the case of the weighing cell described in this document, this arm is formed by a slot in the fastening part, which opens out on the rear side of the weighing cell facing away from the support and runs approximately parallel to the direction of the arm support facing the support. The end of the slot facing away from the rear side of the weighing cell, together with an upper boundary surface of the fastening part, delimits a solid bridge of small thickness between the arm and the slot, which bridge forms the flexural hinge. The adjustable fastening region is arranged on the upper side of the rear end region of the arm facing away from the flexural hinge. In order to adjust the position of this fixing area in a direction perpendicular to the arm surface, in the known weighing cell an adjusting element in the form of a differential screw is provided. One threaded section of the differential screw is received in a groove through the rear end of the arm and which is threaded correspondingly, while the other threaded section of the differential screw (with the other thread pitch) is screwed onto a corresponding thread on the fixed part. By rotating the differential screw, the position of the fixing area provided on the rear end portion of the arm can be accurately adjusted.

However, when the rotation of the differential screw causes the arm of the known weighing cell to swing about the axis of oscillation between the arm and the fixed part, determined by the flexural hinge, the thread formed in the slot through the arm makes a small tilting relative to the thread formed on the fixed part. Thus, when the differential screw is operated, there are lateral forces acting on the arm which can cause undesirable twisting of the arm. In order to eliminate this drawback, in the known weighing cell, a lining element is inserted into the slot, which lining element bears linearly both on the underside of the arm facing away from the fastening area and on a boundary surface of the fastening element facing the arm, wherein the contact lines run parallel to one another.

Although the use of such an adjusting device, which is formed by an arm, a differential screw and a lining element, which are articulated to the fastening part, already achieves a considerable structural advantage compared to an adjusting device formed by the provision of an additional parallel guide for the fastening area, the manufacturing of the adjusting device of this scale is always associated with a high outlay, since, in addition to the internal thread corresponding to the thread segment of the differential screw, a lining element having two lines of contact which are exactly parallel to one another has to be provided and fitted on the arm and the fastening part.

In view of the above-mentioned problems in the prior art, it is an object of the present invention to provide a force measuring device of the type mentioned at the outset which, while guaranteeing a high measuring accuracy, also has a simple construction.

According to the invention, this object is solved by further developing the known force measuring device, which is mainly characterized in that the distance between the active region and the fixed region in the longitudinal direction of the arm is at least as great as the distance between the fixed region and the axis of oscillation, and that an adjustment movement of the active region by a predetermined distance, for example by operating a suitable adjusting element, results in a movement of the fixed region by a reduced distance.

The invention is based on the finding that an arm which is pivotably articulated to the fastening part in order to provide an adjustable fastening area can be used at the same time as a lever, by means of which the pivoting movement of the arm caused by the actuation of the actuating element is reduced in accordance with the ratio of the distance between the fastening area and the pivot axis to the distance between the active area and the fastening area. By means of this reduction, a precise adjustment of the position of the fixing region can be achieved using a simple adjusting screw with a single, precise thread, which is screwed either into a corresponding counter thread of the fixing part or into a corresponding counter thread in the active region of the arm and always rests on the other structural element.

The adjustment screw, which is screwed into only one of the corresponding threads, can be arranged such that, during the necessary pivoting of the arm during the adjustment, no transverse forces of considerable magnitude, which would lead to twisting, act on the arm, as a result of which the further development according to the invention of the force-measuring device makes it possible to precisely adjust the fastening area using a simple adjustment screw screwed into only one of the corresponding threads, without the need for a further lining element having two contact lines running exactly parallel to one another. In this way, the force-measuring device according to the invention can be produced with comparatively little outlay in terms of construction, while ensuring a high measuring accuracy.

If the arm with the fixing area is constructed in one piece with the fixing part and is connected to the fixing part by a flexural hinge which defines the axis of oscillation in the form of a solid bridge of small thickness between the arm and the fixing part, it proves to be particularly structurally suitable, since, in this configuration of the arm, the weighing cell according to the invention can be constructed with particularly few structural elements.

It is advantageous for providing a particularly compact weighing cell if the arm with the fixing region, in which the fixing region is arranged between the pivot axis and the active region, viewed in the longitudinal direction of the arm, is configured in the form of a single-armed lever. In this case, the space between the end of the arm support connected to the fastening element and the end of the arm support connected to the support can be utilized to provide an arm with a fastening region if the arm extends in a section extending perpendicular to its pivot axis from the pivot axis in the direction of the end of the arm support connected to the support. The space between the pivot axis or the flexural hinge and the fastening area can be used to accommodate the parts of the arm connected by the fastening area and the fastening part if the arm is fastened to the fastening area by a flexural bearing extending from the end of the arm remote from the support in the direction of the support. In this configuration, the arm with the fastening region is almost completely inserted into the installation space that would otherwise be necessary for the insertion of the arm support.

The pivoting movement of the arm caused by the actuation of the actuating element can be reduced particularly strongly here if the arm extends over substantially the entire length of the arm between the end of the arm connected to the fixed part and the end of the arm connected to the support.

If the fixing element also extends over substantially the entire length of the arm support, the arm hinged to the fixing element can be realized by a slot formed in the fixing element. The slot can, for example, open out at the front of the fastening element adjacent to the carrier. However, it has proven to be particularly suitable if the fastening part also has, on its front side adjacent to the support body, a coupling region for engaging a lever which transmits at least a part of the forces acting on the support body to the measuring transducer, if the arm extends between the coupling region and the pivot axis and the slot opens out at a boundary surface of the fastening part running parallel to the arm support plane, for example at its upper side.

For a construction of the force measuring device according to the invention which is as compact as possible, it has proved to be particularly advantageous if the arms extend substantially in a plane which is arranged between the arm surfaces and parallel thereto. Since with this construction the space existing between the arms can be fully used for placing the arms.

The arm of the force measuring device according to the invention with the securing region can be constructed with a particularly low weight and with a particularly high torsional strength in the securing region if a section of the arm with the securing region is thicker than a section of the arm with the active region in a direction perpendicular to the arm rest plane.

In the case of an arm having a particularly large length in order to achieve a transformation ratio which is as large as possible, a lateral stabilization of the arm can be achieved while ensuring the desired adjustment possibilities if the force-measuring device according to the invention has a stabilizing element which is connected, on the one hand, to the arm and, on the other hand, to the securing element and which is flexibly deformable, preferably elastically deformable, in a direction perpendicular to the arm surface against a deflection of the arm parallel to the arm surface. A stabilizing element of this type can be realized particularly simply in the form of a leaf spring, which is arranged between the arm and the fastening part, in the form of a connecting web which has at least one bend about a bending axis running parallel to the pivot axis, wherein the flexibility in the direction perpendicular to the course of the arm support surface can be ensured by the bend.

With such a connecting web, particularly effective stabilization of the arm in a direction parallel to the arm support surface is achieved while ensuring an elastically deformable property in a direction perpendicular to the arm support surface, if the connecting web has a substantially S-shaped cross section in a cross section extending perpendicular to the pivot axis and has a section running approximately parallel to the arm support surface, the connecting web being connected at one end to the arm by a first bend around a first bending axis running parallel to the pivot axis and a first section running perpendicular to the arm support surface, and at its other end opposite this end being connected to the fastening element by a second bend around a second bending axis running parallel to the pivot axis and a second section running perpendicular to the arm support surface.

By means of the stabilizing element in the form of a connecting web, in addition to increasing the rigidity in a direction running parallel to the web surface, it is also possible to counteract twisting of the arm about its longitudinal axis if the width of the connecting web in a direction running parallel to the pivot axis is much greater than the thickness of the web in a direction running perpendicular to the width plane. Suitably, the connecting tab has about the same width as the arm.

In order to make the construction of the invention as compact as possible, it has proved to be particularly advantageous if the stabilizing element is arranged substantially between the active region and the fixing region, viewed in the longitudinal direction of the arm. The free space between the arms can be utilized here if the stabilizing element is arranged substantially between the arms in a section plane extending perpendicularly to the pivot axis.

In terms of construction, it has proved to be particularly advantageous if the stabilizing element is formed integrally with the arm and/or the fixing part, since this arrangement serves to reduce the number of structural elements necessary for the manufacture and installation of the weighing cell according to the invention.

A particularly precise orientation of the arm support relative to the other arm support can be achieved if one arm support is connected to the fastening element via two fastening regions which are spaced apart from one another, if the positions of the two fastening regions can be adjusted independently of one another by means of the adjusting device in a direction perpendicular to the course of the arm support surface.

In terms of construction, it has proved to be particularly advantageous if the region of action has a slot which runs through the arm in a direction perpendicular to the arm support surface and which serves to receive an adjusting element in the form of an adjusting screw which is screwed into a corresponding thread on the fastening part. The adjusting screw can rest with its screw head on an outer surface of the arm facing away from the fastening part, if the adjusting device has a biasing element which presses the arm against the screw head. The fastening region can be designed in the form of a fastening surface which is higher than the remaining upper boundary surface and is penetrated by a threaded bore for fastening a bent support.

Reference is made to the following further description of the invention in relation to the details thereof that are not set forth in the above description. Shown in the attached drawings:

FIG. 1: a perspective view of the weighing cell of the present invention.

FIG. 2: the weighing cell shown in fig. 1 is seen in a side view in the direction of arrow a in fig. 1.

FIG. 3: FIG. 1 shows a cross-sectional view of a weighing cell.

The weighing cell shown in the figures is essentially composed of a fastening element, generally designated 10, an upper arm support 40, a lower arm support 50 (see fig. 2 and 3) arranged in a plane extending parallel to the plane of the upper arm support 40, and a carrier 60 guided parallel to the fastening element 10 by means of the arm supports 40 and 50.

The fixed part has two side parts 20 and 30 which are connected to one another by rigid connecting beams and extend approximately perpendicular to the plane of the arm supports 40 and 50, respectively. The side parts 20 and 30 together with the arm supports 40 and 50, which are designed in the form of rigid plates, enclose a substantially cuboid-shaped interior of the weighing cell, in which interior the support body 60 and a lever 62 for transmitting forces acting on the support body 60 to a measuring transducer (messwander) are accommodated. The lever 62 can be coupled to the fixed part 10 via the coupling regions 26 and 36 of the side parts 20 and 30 and can be coupled to the carrier via a curved bearing which is coupled to a fixing surface 62a (fig. 3) provided on the front end face of the lever 62 and to a front end face 61a of the carrier.

On each side part 20 and 30, a slot 22 or 32 is formed, which slot 22 or 32 extends from a solid bridge 24 or 34 of small thickness in the direction of the coupling region 26 or 36 and opens out on the upper surface of the fastening part 20 or 30 in a material-free space 28 or 38, which space 28 or 38 adjoins the coupling region 26 or 36 and extends approximately perpendicular to the plane of the limbs 40 and 50. By means of the slots 22 and 32 in the side parts 20 and 30, an arm 70 is formed on each side part 20 and 30, which arm 70 extends from the solid bridge 24 or 34 approximately parallel to the limbs 40 and 50 in the direction of the connecting region 26 or 36 up to the material-free space 28 or 38. Each such arm 70 has a fixing region 72 for fixing the upper arm support 40 to the fixing element 10 and an active region in the form of a slot extending through the arm 70 in a direction perpendicular to the plane of the arm supports 40 and 50 for receiving an adjusting screw (not shown). In this case, a fastening region 72 for fastening the upper arm support 40 to the fastening element 10 is arranged between the solid bridge 24 or 34 and the groove 74, wherein the distance a between the groove 74 and the fastening region 72 is greater than the distance B between the fastening region 72 and the solid bridge 24 or 34 (see fig. 2).

The upper boundary surface 72a of the fixed region 72 is slightly higher than the remaining upper boundary surface 72b of the arm 70. At the upper boundary surface 72a of the fixing area 72 of each arm 70, a fixing end 43 or 45 of the bent bearing member 42 or 44 is fixed, and the bent bearing members 42 and 44 extend from the rear end of the upper arm frame 40 away from the carrier 60 toward the carrier 60. By means of these curved supports 42 and 44, the upper arm support 40 is elastically flexibly coupled to the fixing area 72 and thus to the side parts 20 and 30 of the fixed part 10, which side parts 20 and 30 are connected to the fixing area 72 by means of the solid bridges 24 and 34. Upper arm support 40, on the other hand, is coupled to carrier 60 by curved supports 46 and 48. Likewise, the lower arm carrier 50, which is also constructed in the form of a rigid plate, is coupled to the side members 20 and 30 by bent supports corresponding to the bent supports 42 and 44, and is coupled to the carrier 60 by bent supports corresponding to the bent supports 46 and 48. Fig. 2 and 3 show the curved bearings 52 and 56, which correspond to the curved bearings 46 and 48 and are opposite them, for coupling the lower arm support 50 on the one hand to the side part 30 and on the other hand to the carrier 60.

Each arm 70 can be pivoted about a pivot axis defined by the solid bridge 24 or 34 forming the flexural hinge, extending substantially parallel to the plane of the arms 40 and 50 and perpendicular to the longitudinal direction of the respective arm, by operating an adjusting screw introduced into the corresponding slot 74. By means of this pivoting movement, the upper boundary surface 72a of the fastening region 72 can be adjusted in a direction running approximately perpendicular to the plane of the upper arm carrier 40, so that the fastening ends 43 and 45 of the bent bearing parts 42 and 44 fastened to the fastening region 72 and connected to the upper arm carrier 40 on the other hand are also adjusted in a direction running approximately perpendicular to the plane of the upper arm carrier 40. In this way, the upper arm 40 can be oriented exactly parallel to the lower arm. In this case, each arm 70 acts as a single-arm lever, by means of which the movement in the region of the groove 74 produced by the actuation of a corresponding adjusting screw is reduced in the corresponding fixing region 72, the former being more than twice the movement which is reduced later. Thus, each fastening region 72 can be adjusted precisely in a direction perpendicular to the upper arm rest surface by means of a simple adjusting screw which passes through the respective groove 74.

An undesired twisting of the arm 70 in the fastening region 72 is prevented here by the increase in the material thickness of the fastening region 72 on the one hand and by the stabilizing element 80 arranged in the slots 22 and 32 on the other hand. Each such stabilizing element 80 is formed in the form of a connecting web which is configured integrally with the respective arm 70 and the respective side piece 20 or 30 and is located between a lower boundary surface of the arm 70 and an upper boundary surface of the respective side piece 20 or 30. Here, each connecting web 80 has a substantially S-shaped cross section in a section running perpendicularly to the pivot axis defined by the solid bridge 24 or 34. To this end, each connecting web 80 has a central section 82 running approximately parallel to the plane of the limbs 40 and 50, which section 82 is connected at one end to the respective arm 70 by means of a first bend 84 running around a bend axis running parallel to the pivot axis defined by the solid bridge 24 or 34 and by means of a first end section 85 running approximately perpendicular to the plane of the limbs 40 and 50, and at the other end opposite this end is connected to the respective side part 20 or 30 by means of a second bend 86 running around a second bend axis running parallel to the respective pivot axis and by means of a second end section 87 likewise running perpendicular to the plane of the limbs 40 and 50. Each connecting tab 80 extends over the entire width of the respective arm 70 in a direction of extension parallel to the pivot axis defined by the respective solid bridge 24 or 34 and has a small material thickness in a direction perpendicular thereto. Here, each connecting tab 80 is arranged between the slot 74 and the fastening region 72, viewed in the longitudinal direction of the arm 70, and between the upper arm support 40 and the lower arm support 50 in a section extending perpendicular to the pivot axis defined by the solid bridges 24 and 34.

By means of the form of the connecting web 80 described above and shown in the drawings, an elastically deformable support of the arm 70 in a direction running perpendicular to the plane of the upper arm support 40 and the lower arm support 50 is achieved on the one hand, and an increased rigidity of the arm 70 in a direction running parallel to this plane is achieved on the other hand. Furthermore, the connecting web 80 resists a twisting of the arm 70 about its longitudinal axis.

As best shown in fig. 3, carrier 60 has a bracket 61 at its lower end that extends rearward and is substantially parallel to the plane of arms 40 and 50. The bracket 61 is bounded at its rear end by an end face 61a extending perpendicularly to the plane of the arm 40 and the arm 50, which end face 61a is aligned with a front end face 62a of the lever 62, which lever 62 is coupled to the coupling regions 26 and 36 of the side parts 20 and 30 by means of a bent bearing (not shown). The force acting on the carrier 60 can be transmitted to the lever 62 via a curved bearing arranged between the two end faces 61a and 62a of the bracket 61a and the lever 62. The lever will thereby be deflected about its lever axis which is determined by the curved bearing coupled to the coupling areas 26 and 36 and runs substantially parallel to the plane of the arms 40 and 50.

As is shown particularly clearly in fig. 3, the lever 62 extends over the entire length of the weighing cell and supports, at its rear end opposite the end face 62a, an electromagnetic coil 64, which electromagnetic coil 64 is accommodated in a permanent magnet 66 fixed relative to the fixed part 10, the coil 64 together with the permanent magnet 66 forming a force electromagnetic compensation system with which the deflection of the lever 62 caused by the force acting on the carrier 60 and transmitted to the lever 62 can be compensated. The current through the magnet coil 64 necessary for the compensation of the deflection is a quantity which is used to represent the force acting on the carrier 60. That is, this amount of current produces an electrical measurement corresponding to the force to be measured, which measurement can be further processed electrically or electronically.

It can also be seen from fig. 3 that, in addition to the side parts 20 and 30, the stationary part 10 also has a central support 12, which support 12 passes through a window in the lower arm 50, which window corresponds to the window 41 in the upper arm 40 shown in fig. 1. By means of this support 12, the weighing cell shown in the figures can be fixed on a scale base.

The invention is not limited to the embodiment discussed with the aid of the figures, but in addition embodiments are conceivable in which the slots 22 and 32 extend from the solid bridges 24 and 34 up to the front boundary surface of the side parts 20 and 30. In addition, each arm 40 and 50 may also be coupled to the carrier 60 by only one curved bearing. Likewise, it is also conceivable to couple the arms 40 and 50 with the fixed part by means of only one curved bearing. Furthermore, instead of using a lever for transmitting the forces acting on the carrier to the measuring transducer, a lever system with 2 or more levers can also be used.

Claims (20)

1. Force-measuring device, in particular weighing cell, having a carrier body (60) for receiving a force to be measured, an adjusting device and an arm (70), the carrier body (60) being guided parallel to a fixed part (10) by means of two arms (40, 50), the arms (40, 50) being arranged on two planes running parallel to one another, being rigid in these planes and being deflectable perpendicular to these planes, wherein each arm (40, 50) is connected at one end thereof to the carrier body (60) and at the opposite end thereof to the fixed part (10); the position of at least one fastening area (72) for fastening one of the arm supports to the fastening element (10) can be adjusted by means of the adjusting device in a direction perpendicular to the plane of the arm supports (40, 50); the arm (70) extends in its longitudinal direction substantially parallel to the plane of the arm support (40, 50) and is pivotably articulated on the fixing part (10) about a pivot axis extending substantially parallel to the plane of the arm support (40, 50) and substantially perpendicular to the longitudinal direction of the arm, and has a fixing region (72) and an active region (74) for an adjusting element for pivoting the arm (70) about the pivot axis, characterized in that, in the longitudinal direction of the arm (70), the distance A between the active region (74) and the fixing region (72) is at least as large as the distance B between the fixing region (72) and the pivot axis, and in that an adjusting movement of a predetermined distance of the active region (74) causes a movement of the fixing region (72) over a shorter distance.

2. Force measuring device according to claim 1, wherein the arm (70) is hinged to the fixed part (10) by means of a flexural hinge.

3. Force measuring device according to claim 2, wherein the arm (70) is constructed in one piece with the fixing part (10); and the flexural hinges are formed as a solid bridge (24, 34) of small wall thickness between the arms (70) and the fixed part (10).

4. Force measuring device according to one of the preceding claims, wherein the fixing area (72) is arranged between the axis of oscillation and the active area (74), seen in the longitudinal direction of the arm (70).

5. Force measuring device according to claim 4, wherein the arm extends in its longitudinal direction from the pivot axis in the direction of the end of the arm support (40, 50) connected to the carrier body (60).

6. Force measuring device according to claim 5, wherein the fixing part (10) extends over substantially the entire length of the arm support (40) between the end of the arm support (40) connected to the fixing part (10) and the end of the arm support (40) connected to the carrier body (60); and the arm (70) is formed by a slot (22, 32) in the fixing part (10).

7. Force measuring device according to claim 6, wherein the fixing part (10) has a coupling area (26, 36) at its end for coupling a lever (62) for transmitting at least a part of the force acting on the carrier body (60) to a measuring transformer (64, 66), which end is adjacent to the end of the arm support (40, 50) connected to the carrier body (60), and the arm (70) extends between the coupling area (26, 36) and the oscillation axis.

8. Force measuring device according to one of claims 1 to 3, wherein the arm (70) extends substantially in a plane which is arranged between and parallel to the planes of the arm supports (40, 50).

9. Force measuring device according to one of claims 1 to 3, wherein a section of the arm having the fixing area (72) has a greater thickness in a direction perpendicular to the plane of the arm support (40, 50) than a section of the arm (70) having the active area (74).

10. Force measuring device according to claim 1, wherein a stabilizing element (80) is provided which is connected to the arm (70) on the one hand and to the fixing part (10) on the other hand, which stabilizing element (80) counteracts a deflection of the arm (70) in a plane parallel to the arm supports (40, 50) and is deformable, preferably elastically deformable, in a direction perpendicular to this plane.

11. Force measuring device according to claim 10, wherein the stabilizing element has at least one connecting web (80) arranged between the arm (70) and the fixing part (10) and having at least one bending (84, 86) about a bending axis running parallel to the pivot axis.

12. Force measuring device according to claim 11, wherein the connecting tab (80) has a substantially S-shaped cross section in a section extending perpendicular to the axis of oscillation.

13. Force measuring device according to claim 12, wherein the connecting web (80) has a section (82) running substantially parallel to the plane of the arm support (40, 50), which section (82) is connected at one end to the arm (70) via a first bend (84) around a first bend axis running parallel to the pivot axis and a first section (85) perpendicular to the plane of the arm support (40, 50) and at its opposite end is connected to the fixing part (10) via a second bend (86) around a second bend axis parallel to the pivot axis and a second section (87) perpendicular to the plane of the arm support (40, 50).

14. Force measuring device according to one of claims 11 to 13, wherein the width of the connecting tab (80) in a direction parallel to the axis of oscillation is much larger than its thickness in a direction perpendicular thereto.

15. Force measuring device according to one of claims 10 to 13, wherein the stabilizing element is arranged between the active zone (74) and the fixing zone (72) in the longitudinal direction of the arm (70).

16. Force measuring device according to one of claims 10 to 13, wherein the stabilizing element is arranged substantially between the arm supports (40, 50) in a section extending perpendicularly to the pivot axis.

17. Force measuring device according to one of claims 10 to 13, wherein the stabilizing element is constructed in one piece with the arm (70) and/or the fixing part (10).

18. Force measuring device according to one of claims 1 to 3, wherein at least one arm support is connected to the fixing part (10) by means of at least two fixing areas (72) at a distance from one another; furthermore, the positions of the fixing areas (72) can be adjusted independently of one another in a direction perpendicular to the plane of the arm (40, 50) by means of an adjusting device.

19. Force measuring device according to one of claims 1 to 3, wherein the active region has a slot (74) through the arm (70) in a direction perpendicular to the plane of the arm support (40, 50) for accommodating an adjusting element in the form of an adjusting screw in a corresponding thread on the fixing part (10).

20. Force measuring device according to claim 19, wherein the adjusting screw rests with a screw head on an outer surface (72b) of the arm (70) facing away from the fixing part (10); and the adjustment device has a biasing element biasing the arm toward the screw head.