Weighing system and coupling belt

The innovative coupling band design with a thin-point joint, resilience region, and lateral pivoting area addresses the challenge of achieving high-resolution precision and robustness against lateral forces in weighing systems.

DE102023005463A1Active Publication Date: 2025-01-02SARTORIUS LAB INSTR GMBH & CO KG
View PDF 5 Cites 0 Cited by

Patent Information

Application Number
DE102023005463
Authority / Receiving Office
DE · DE
Patent Type
Applications
Current Assignee / Owner
Filing Date
2023-06-29
Publication Date
2025-01-02
Estimated Expiration
2043-06-29

AI Technical Summary

Technical Problem

Existing weighing systems face challenges in achieving high-resolution precision while being robust against lateral acceleration forces, particularly during transport, due to the susceptibility of conventional coupling mechanisms.

Method used

A coupling band with specific functional areas, including a thin-point joint and resilience region, designed to allow precise pivoting movements and decoupling of non-vertical forces, combined with a lateral pivoting area for enhanced robustness.

Benefits of technology

The solution provides a robust and high-resolution weighing system capable of withstanding acceleration forces, reducing packaging requirements and maintaining accurate weight measurements.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure 00000000_0000_ABST
    Figure 00000000_0000_ABST
Patent Text Reader

Abstract

The invention relates to a weighing system (10) comprising a base (14), a load sensor (18) coupled vertically to the base (14) by means of a parallel link arrangement, and a lever (24) pivotally articulated to the base (14) by means of a lever joint (22) with a first lever arm (241) arranged on one side of the lever joint (22) and a second lever arm (242) arranged on the other side of the lever joint (22) and configured to receive a sensor arrangement. wherein the first lever arm (241) is coupled to the load-bearing device (18) in a vertical force-transmitting manner by means of a coupling band (30) fixed to both it and the load-bearing device (18). The invention is characterized by three specially shaped functional areas of the coupling band (30), namely a thin-point joint (32), a resilience region (34, 34') and a lateral pivoting area (39).
Need to check novelty before this filing date? Find Prior Art

Description

Field of the invention

[0001] The invention relates to a weighing system comprising a base, a load receiver coupled vertically movably to the base by means of a parallel link arrangement and a lever pivotally articulated to the base by means of a lever joint with a first lever arm arranged on one side of the lever joint and a second lever arm arranged on the other side of the lever joint and designed to receive a sensor arrangement, wherein the first lever arm is coupled to the load receiver by means of a coupling band fixed both to it and to the load receiver in a manner that transmits vertical forces, wherein the coupling band has two functional areas which are characterized by reduced width and reduced thickness compared to immediately adjacent areas.

[0002] The invention further relates to a corresponding coupling band. State of the art

[0003] Generic weighing systems and coupling belts for them are known from US 4 703 816 A.

[0004] The central component of an electronic scale, particularly one operating according to the principle of electromagnetic compensation, is its weighing system. The term "weighing system" refers to the mechanical lever mechanism by which a load carrier of the scale, which holds the load to be weighed, is connected to the scale's electronic sensor, typically a moving coil arrangement with optical lever position detection. The weighing system comprises a base by means of which it can be fixed to a platform or housing of the scale. A so-called load receptor is hinged to said base via a parallel linkage arrangement, often referred to as a Roberval mechanism. The load carrier mentioned above is fixed directly or indirectly to the load receptor in the final assembly state of the scale.The parallel link arrangement serves to prevent tilting of the load receptor or the weighing object carrier, at least during small deflections of the load receptor, which essentially occur on a circular arc with the radius of one parallel link length. Furthermore, a typical weighing system comprises a lever that serves to transmit displacement and force and is articulated to the base via a lever joint. A first lever arm of said lever is coupled to the load receptor in order to transmit the movement caused by the weight of the weighing object to the lever. A second lever arm of the lever is typically equipped with a receptacle for lever-side components of an electronic sensor, in particular a plunger coil, which interacts in a generally known manner and not further relevant here with other base-side sensor components mounted on the base, in particular a magnet pot.Such a weighing system thus represents the “heart” of a scale, although similar weighing systems can be used in scales that are otherwise differently equipped.

[0005] For the aforementioned coupling between the first lever arm and the load receptor, a connection, often referred to as a coupling, is required. This connection is suitable for transmitting vertical forces between the load receptor and the first lever arm, while also being sufficiently flexible to achieve decoupling with respect to any non-vertical force components. As mentioned, a parallel link mechanism can prevent the load receptor from tilting, but cannot prevent its circular arc movement, along with the inherent vertical and horizontal movement components. However, these must not be transmitted to the lever, as the corresponding non-vertical force components would distort the measured weight value, which is unacceptable, especially with extremely high-resolution precision scales.In order to combine both requirements, namely vertical coupling and non-vertical decoupling, said couplings can be designed as so-called coupling bands in the form of thin sheet metal strips, as in DE 30 12 344 A1. If the coupling band is sufficiently thin, non-vertical decoupling can be achieved that is sufficient even for extremely high-resolution scales. However, it has been found that corresponding weighing systems are extremely susceptible to lateral acceleration forces, such as those typically encountered during transport, particularly when shipping scales. Therefore, a great deal of effort must be put into packaging the scales to ensure that they arrive at the recipient with undamaged coupling bands. The theoretical approach of fixing the coupling band to the load receptor and first lever arm only after the scale has been set up at the destination is practically unfeasible for legal metrology reasons.

[0006] DE 32 42 954 A1 discloses a coupling designed as a coupling rod, which has a functional area tapered in thickness and width near its respective fixing areas on the load receptor and the first lever arm. Together, these functional areas are intended to generate the elasticity of the coupling required for non-vertical decoupling. While such coupling rods are more robust than coupling strips, they cannot achieve the degree of non-vertical decoupling required for extremely high-resolution precision scales.

[0007] A plate-like coupling is known from the aforementioned US 4,703,816 A. The coupling plate disclosed therein consists of a flat, essentially rectangular, thicker upper plate and a thinner, inverted L-shaped, angled lower plate. The upper plate has an upper hole; the lower plate has two lower holes. These serve to screw the coupling plate to the load receptor or the first lever arm. The previously known coupling plate is equipped with two flexural joints spaced apart from one another in the longitudinal direction of the plate. An upper flexural joint in the upper plate is located at the level of the upper hole and consists of a through slot extending semicircularly around the upper hole and two thin sections connecting the ends of the slot to the adjacent plate edges. Each of these thin sections is formed by two grooves cut at the same height into the opposing surfaces of the upper plate.This flexure joint is designed to enable pure bending movement of the lower part of the upper plate against its upper part. The lower plate is connected to the upper plate by means of a connecting bar with a rectangular profile. The connecting bar is positioned centrally on the lower edge of the upper plate and centrally on the top side of the short L-beam of the lower plate. Its width is significantly narrower than the width of the upper and lower plates. Its thickness is about half as thick as the upper plate or the length of the short L-beam of the lower plate. This flexure joint is designed to enable both bending and torsional movement of the lower plate against the upper plate. The heavy and solid construction is no longer suitable for the resolutions achievable with modern scales.

[0008] EP 1 643 223 A1 discloses a coupling belt with two joint regions spaced apart in the longitudinal direction of the coupling belt. The joint regions are each formed by two grooves located opposite each other at the same height, extending across the entire width of the coupling belt and embedded in its respective surface. The document discloses various groove shapes that can be used for this purpose, citing those with a pointed groove base as particularly advantageous because they allow a pivot axis to be defined particularly precisely.

[0009] As examples of the preferred field of application of the present invention, comparators and high-resolution precision balances, in particular ultra-microbalances and microbalances with load ranges between 2 g and 200 g at resolutions of 0.1 µg, 1 µm or up to 5 µg, are mentioned. Task

[0010] It is the object of the present invention to provide a weighing system and a coupling belt therefor that enable the construction of extremely high-resolution and at the same time robust scales. Description of the invention

[0011] This object is achieved with the features of claim 1, namely by the special design combination of the functional areas as - a thin-point joint, which has a thickness that initially decreases in the length direction of the coupling band and then increases again after reaching a point-like thickness minimum in order to define a localized, first pivot axis that extends parallel to the width direction and perpendicular to the length direction of the coupling band, and - a resilience region which, in the length direction of the coupling band, has a thickness which initially decreases, remains constant over a distance at least corresponding to its width after reaching a minimum thickness and then increases again in order to define a continuous set of second pivot axes parallel to the first pivot axis, wherein further in the length direction between the thin-point joint and the resilience region a lateral pivot area is arranged which consists of one or more parallel webs extending in the length direction of the coupling band, each of which has a web width which is less than the thickness of the coupling band in this area.

[0012] The object is further achieved with the features of claim 15, namely by a coupling band, consisting of a sheet metal strip, for the vertical force-transmitting coupling between a load receiver of a weighing system and a first lever arm of a lever of the weighing system, wherein two functional areas are formed spaced apart from one another in the length direction of the sheet metal strip, which are distinguished from immediately adjacent areas by a reduced width and reduced thickness, namely - a thin-point joint, which has a thickness that initially decreases in the length direction of the coupling band and then increases again after reaching a point-like thickness minimum in order to define a localized, first pivot axis that extends parallel to the width direction and perpendicular to the length direction of the coupling band, and - a resilience region which, in the longitudinal direction of the coupling band, has a thickness which initially decreases, remains constant over a distance at least corresponding to its width after reaching a minimum thickness and then increases again in order to define a continuous family of second pivot axes parallel to the first pivot axis, wherein further in the longitudinal direction between the thin-point joint and the resilience region there is arranged a lateral pivot region which consists of one or more parallel webs extending in the longitudinal direction of the coupling band, each of which has a web width which is less than the thickness of the coupling band (30) in this region.

[0013] Preferred embodiments are subject of the dependent claims.

[0014] The special feature of the present invention lies in the special shape of the coupling band, which is preferably made of a resilient metal material, e.g., a copper-beryllium alloy. First, the idea of ​​multiple functional areas, which are characterized by tapering in the thickness and width directions from the immediately adjacent areas, hereinafter referred to as secondary areas, is transferred to systems with coupling bands. However, the special design of the functional areas, which cannot be adopted due to the different basic shapes of coupling rods on the one hand and coupling bands on the other, plays a key role in the effectiveness of the invention.In particular, the functional region referred to as the thin-point joint is designed to form a precisely localized, first pivot axis around which the immediately adjacent secondary regions can perform a precisely defined pivoting movement relative to one another. The second functional region, in contrast, forms a longer resilience region, which, in contrast to the thin-point joint, does not define a precisely localized pivot axis, but rather an elongated pivot region. This can be understood as a continuous set of individual, parallel, second pivot axes, whereby the secondary regions immediately adjacent to the resilience region can perform a pivoting movement relative to one another about one (arbitrary) or several of these second pivot axes simultaneously, depending on the specific forces acting in the individual case.For the purely non-vertical decoupling of the load receptor and lever, two spaced-apart thin-point joints or a sufficiently long resilience region might be sufficient. However, with regard to robustness against acceleration forces, such as those encountered during transport or shipping of weighing systems or complete scales, this special combination of thin-point joint and resilience region has proven particularly effective, without the mechanical interactions and force distributions being fully understood in detail. Rather, the robustness achieved by the invention must be viewed as an unforeseen, surprising effect.

[0015] Starting from an immediately adjacent secondary area, the thickness profile of the thin-point joint can be described such that the thickness of the coupling band decreases continuously, particularly monotonically, i.e., without any "counter-increases," and, after reaching the minimum thickness, immediately increases again, particularly monotonically, until the thickness of the adjacent secondary area is reached. It has proven advantageous to design the surface profile symmetrically, preferably both in the length direction and in the thickness direction. In particular, the thin-point joint can have a biconcave or bifacial V-shaped thickness profile in the length direction.In the first case, the surface profile on both main surfaces of the coupling band follows a circular arc, with the vertices of the circular arcs on the front and back sides being colocated in the longitudinal direction to form the sharply localized thickness minimum according to the invention. In the second case, the surface profile of the two main surfaces of the coupling band initially follows a straight-line descending and then a straight-line ascending slope (V-shape), with the two contact lines consisting of a descending and ascending slope on the front and back sides of the coupling band being colocated in the longitudinal direction to form the sharply localized thickness minimum according to the invention. Although other thickness profile shapes are conceivable in principle, the ones mentioned have proven particularly advantageous with regard to production, the preferred method of which will be discussed in more detail below.

[0016] The precise definition of the pivot axis provided by the thin-point joint can be enhanced by a width profile of the coupling band that corresponds to the thickness profile. Thus, in a preferred embodiment of the invention, the thin-point joint initially has a width that decreases monotonically in the longitudinal direction and, after reaching the punctual width minimum colocalized with the associated thickness minimum, increases again monotonically. Here, too, a symmetrical design is particularly advantageous. In particular, the thin-point joint can have a biconcave or bilaterally V-shaped width profile in the longitudinal direction.In the first case, this means that the lateral edges of the coupling band in the region of the thin-point joint each follow a circular arc, with the vertices of the circular arcs being colocated with each other in the longitudinal direction and, in particular, also with the thickness minimum. In the second case, the lateral edges of the coupling band in the region of the thin-point joint initially run in a straight line, tapered inwards, and after reaching the width minimum, immediately run again in a straight line, tapered outwards, with the two contact lines between the inward and outward-running bevels at both edges of the coupling band being colocated with each other in the longitudinal direction and, preferably, also with the thickness minimum.

[0017] The length of the thin-point joint, i.e., the distance between the two adjacent regions directly adjacent to the thin-point joint on both sides, is preferably between 2 mm and 20 mm, in particular between 4 mm and 6 mm. The thickness of the thin-point joint at its minimum thickness is preferably between 10 µm and 100 µm, in particular between 40 µm and 60 µm.

[0018] The same preferably applies to the shape of the resilience region, although—and this is the key difference between a thin-point joint and a resilience region—the region of minimal thickness extends over a larger length of the coupling band. The end regions of the resilience region, i.e., the transition regions to the immediately adjacent secondary regions, preferably have a bifacially rounded or sloped thickness profile in the longitudinal direction. In the first case, the surface profile of the two main surfaces between the immediately adjacent secondary region and the region of minimal thickness follows a circular path. In the second case, the surface profile follows a straight slope.

[0019] The resilience region is also preferably designed with a corresponding thickness and width profile. In other words, this means that the resilience region initially decreases in width along its length and then increases again after reaching a minimum width colocalized with the associated minimum thickness. The end regions of the resilience region can have a bilaterally rounded or straight-line slanted width profile along its length.

[0020] Advantageously, the length of the resilience region, i.e., the distance between the adjacent adjacent regions on both sides, is between 5 mm and 50 mm, in particular between 6 mm and 10 mm. The thickness of the resilience region in the region of its minimum thickness is preferably between 50 µm and 150 µm, in particular between 80 µm and 120 µm.

[0021] The length of the entire coupling band is preferably between 20 mm and 150 mm, in particular between 80 mm and 100 mm. The width of the coupling band in the secondary areas is preferably between 5 mm and 10 mm.

[0022] In a particular embodiment of the invention, the coupling band comprises not just one, but several resilience regions. These can interact advantageously with regard to robustness, with each resilience region acting individually with regard to non-vertical decoupling, so that the overall achievable degree of decoupling is at least not impaired, and in some cases, even improved.

[0023] As described so far, the inventive design of the coupling belt enables more (thin-point joint) or less (resilience region(s)) sharply localized pivoting movements of the secondary regions of the coupling belt around pivot axes oriented perpendicular to the length and parallel to the width direction. However, the direction of acceleration forces occurring during transport or shipping of weighing systems according to the invention is difficult to predict. Therefore, the invention further provides for the coupling belt to be additionally provided with a lateral pivoting region that enables pivoting movements around pivot axes oriented perpendicular to the length and width directions.In particular, it is provided that a lateral pivoting area is additionally arranged on the coupling belt, namely in the length direction between the thin-point joint and the resilience region. This area consists of one or more parallel webs extending in the length direction of the coupling belt, each having a web width that is less than the thickness of the coupling belt in this area. Due to this relative dimensioning, said webs are more easily bendable in the coupling belt plane defined by the length and width of the coupling belt than perpendicular to it. This thus opens up a further pivoting degree of freedom perpendicular to the pivoting degree of freedom opened up by the thin-point joint and resilience region, which allows the absorption of correspondingly directed acceleration forces. The overall robustness of the weighing system or coupling belt according to the invention is thereby further increased.

[0024] With regard to the production of a coupling band according to the invention, it has proven advantageous to use a method comprising the steps: - Providing a coupling band blank made of a spring-elastic metal sheet, - Laser processing of the coupling band blank to create lengths of varying thickness and / or width. Compared to machining processes, non-contact laser processing has the advantage of not introducing any mechanical stress into the coupling band. Compared to chemical processes, such as lithography or etching, laser processing is significantly faster and less complex. Furthermore, it has proven extremely valuable in terms of flexibility in shaping the transition areas between functional and secondary areas.

[0025] Regardless of the specific machining method, the blank will preferably have a uniform thickness over its length, which will only be changed in the functional area by machining.

[0026] Further details and advantages of the invention will become apparent from the following specific description and drawings. Brief description of the drawings

[0027] They show: Fig. 1: a schematic representation of a weighing system according to the invention, Fig. 2: a side view of a coupling band according to the invention, Fig. 3: a top view of the coupling band of Fig. 2 and Fig. 4: a plan view of an alternative embodiment of a coupling band according to the invention. Description of preferred embodiments

[0028] The same reference symbols in the figures indicate the same or analogous elements.

[0029] Fig. 1 shows a weighing system 10 according to the invention, already equipped with a load carrier 12. The weighing system 10 comprises a base that serves as the reference point for all movements within the weighing system 10. A load receptor 18 is vertically movable (vertical movement arrow 20) and articulated to the base 14 via a Roberval mechanism with two parallel links 16. The load receptor 18 is coupled to the weighing carrier 12 in such a way that the weight of a weighing object placed on the weighing carrier 12 results in a vertical force being applied to the load receptor 20.

[0030] Furthermore, the base 14 is coupled to a lever 24 via a lever joint 22. The lever 24 has a Fig. 1 left of the lever joint 22, first lever arm 241 and one in Fig. 1 to the right of the lever joint 22, second lever arm 242. The coupling between the base 14 and the lever 24 is designed such that the lever 24 in the drawing plane of Fig. 3 can perform a pivoting movement about the lever joint 22. A sensor receptacle 243 is arranged in the end region of the second lever arm 242. The sensor receptacle 243 serves to accommodate lever-side sensor components 261, which can interact with base-side sensor components 262 of an electronic sensor 26, which are fixed to the base 14. In particular, the sensor 26 can be a moving coil arrangement, which enables a gravimetric measurement according to the principle of electromagnetic compensation known to those skilled in the art. However, another type of sensor technology is also conceivable within the scope of the invention.

[0031] In order to transmit the vertical weight forces exerted by the weighing object on the load receptor 18 to the lever 24, in particular its first lever arm 241, the load receptor 20 is connected to the first lever arm 241 by means of a coupling band 30. In particular, the coupling band 30 can be screwed or otherwise fixed to the load receptor 20 on the one hand and to the first lever arm 241 on the other. Since the deflection movements of both the load receptor 20 and the lever 24 are not purely linear in nature, but follow a circular arc, while the weight forces to be measured act purely vertically, the force transmission via the coupling band requires the vertical components to be transmitted with as little loss as possible and the non-vertical components to be decoupled.

[0032] For this purpose, the coupling band 30 has two functional areas, namely a thin joint 32 and a resilience region 34, the details of which are described below in the context of the Fig. 2 and Fig. 3 should be described.

[0033] The Fig. 2 and Fig. 3 show a particularly preferred embodiment of a coupling band according to the invention, as it is used in particular for the construction of a weighing system according to Fig. 1 can be used. The Fig. 2 and Fig. 3 will be described together below.

[0034] The coupling band 30 is essentially designed as a specially shaped sheet metal strip, preferably made of a spring-elastic material, in particular a copper-beryllium alloy. Its total length can be, for example, approximately 60 mm. The coupling band 30 comprises several functional areas and areas arranged between or adjacent thereto, which are generally referred to here as secondary areas. The terminal secondary areas 36 primarily serve to fix the coupling band 30 to the load receiver 18 or to the first lever arm 241. They are provided with through holes 361 through which fixing screws can be passed for clamping the coupling band to the load receiver 18 or the first lever arm 241. As a first functional area, Fig. 2 and Fig. 3, a thin joint 32 is provided adjacent to the right terminal secondary area 36. The thin joint 32 is characterized by a taper both in the thickness direction (cf. Fig. 2) as well as in the width direction (cf. Fig. 3). In the embodiment shown, both the thickness and width tapers are symmetrical and biconcave in nature. However, the radii of the biconcave constrictions are chosen differently. In particular, the radius of the thickness taper is chosen to be significantly larger than that of the width taper. In the embodiment shown, the total length of the width taper section is approximately twice the total length of the thickness taper section. The latter can, for example, be approximately 3 mm, so that the former is approximately 6 mm with such dimensions. The thickness taper is essentially responsible for the function of the thin-point joint 32. The decisive factor here is that a well-defined, well-localized thickness minimum exists, through which a sharply localized pivot axis 321 is created.

[0035] A second functional area is the Fig. 2 and Fig. 3, a resilience region 34 adjacent to the left, terminal secondary area 36 is provided. This is also characterized by a tapering in the thickness direction (cf. Fig. 2) and in the width direction (cf. Fig. 3). The taper in the thickness direction takes the form of bifacially symmetrical inclined ramps that lead to a longer section of consistent, minimal thickness. The taper in the width direction, on the other hand, is shaped as bilateral curves that transition into a longer region of consistent, minimal width. The total lengths of the taper sections in the thickness direction and in the width direction are selected differently in the illustrated embodiment. In particular, the length of the taper section in the width direction is selected to be longer than the length of the taper section in the thickness direction. The latter can be approximately 6 mm, for example. The taper in the thickness direction is particularly responsible for the function of the resilience region 34. The decisive factor here is the existence of a longer section with consistent, minimal thickness, through which a continuous family of pivot axes 341 is created.

[0036] Furthermore, within the central secondary region 38 located between the thin-point joint 32 and the resilience region 34, a further functional region, namely the lateral pivot region 39, is provided. In the illustrated embodiment, this consists of two elongated through-holes 391 adjacent to one another in the width direction of the coupling band 30, which create a web 392 between one another and between themselves and the respective lateral edge of the secondary region 38. The width of these webs 392 is less than the thickness of the secondary region 38 at this point, so that pivoting in the coupling band plane, ie in the drawing plane of Fig. 3. Also conceivable are embodiments in which more or less than the Fig. 3 are realized. In particular, it is possible to design the through holes 391 open at the sides, so that the Fig. 3, the marginal webs are omitted, and the lateral pivoting region 39 essentially consists only of a centrally arranged web 392. This embodiment exhibits a particularly high lateral pivoting elasticity.

[0037] The interaction of the described functional areas, in particular the thin-point joint 32 and the resilience region 34, in addition to the desired non-vertical decoupling of the load receptor 18 and the lever 24, results in a particularly robust weighing system 10 against acceleration forces. The packaging required for transporting such weighing systems can therefore be significantly reduced.

[0038] Fig. Figure 4 shows an alternative design of the coupling band 30, which, instead of a single resilience region 34, has three parallel resilience regions 34' spaced laterally apart by through holes. Such a design can further increase the robustness of the weighing system without noticeably impairing the decoupling of the non-vertical force components. Furthermore, the above-mentioned Fig. 3 What has been said is referred to.

[0039] Of course, the embodiments discussed in the specific description and shown in the figures represent only illustrative embodiments of the present invention. In light of the disclosure herein, a broad spectrum of possible variations is available to those skilled in the art. In particular, there is considerable freedom regarding the choice of the base material for the coupling band. In addition to embodiments made from a single material, coupling band base bodies composed of multiple material components, for example, assembled using additive manufacturing processes, are also conceivable. The specific dimensioning must be adapted, in particular, to the intended use in scales, based on their intended load capacity and resolution. List of reference symbols 10 Weighing system 12 weighing carriers 14 Base 16 parallel links 18 load receptors 20 Vertical movement arrow 22 Lever joint 24 levers 241 first lever arm 242 second lever arm 26 Sensor 261 lever-side sensor component 262 base side lever component 30 coupling band 32 Thin joint 321 Swivel axis 34, 34' Resilience region 341 set of swivel axes 36 terminal side area 361 through hole 38 central side area 39 Lateral swivel range 391 through hole 392 jetty QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 4 703 816 [0003, 0007] DE 30 12 344 A1

[0005] DE 32 42 954 A1

[0006] EP 1 643 223 A1

[0008]

Claims

[1] Weighing system (10) comprising a base (14), a load receiver (18) coupled vertically movably to the base (14) by means of a parallel link arrangement, and a lever (24) pivotally articulated to the base (14) by means of a lever joint (22) with a first lever arm (241) arranged on one side of the lever joint (22) and a second lever arm (242) arranged on the other side of the lever joint (22) and adapted to receive a sensor arrangement, wherein the first lever arm (241) is coupled to the load receiver (18) by means of a coupling band (30) fixed both to it and to the load receiver (18) in a manner transmitting vertical forces, wherein the coupling band (30) has two functional areas which are distinguished from immediately adjacent areas by a reduced width and reduced thickness, namely - a thin-point joint (32) which has a thickness which initially decreases in the length direction of the coupling band (30) and then increases again after reaching a point-like thickness minimum in order to define a localized, first pivot axis (321) which extends parallel to the width direction and perpendicular to the length direction of the coupling band (30), - a resilience region (34, 34') which, in the longitudinal direction of the coupling band (30), has a thickness which initially decreases, remains constant over a distance at least corresponding to its width after reaching a minimum thickness, and then increases again in order to define a continuous set of second pivot axes (341) parallel to the first pivot axis (321), and wherein, further in the longitudinal direction between the thin-point joint (32) and the resilience region (34, 34'), a lateral pivot region (39) is arranged which consists of one or more parallel webs (392) extending in the longitudinal direction of the coupling band (30), each of which has a web width which is less than the thickness of the coupling band (30) in this region. [2] Weighing system (10) according to claim 1, characterized by that the thin-point joint (32) has a biconcave or bifacial V-shaped thickness profile in the length direction. [3] Weighing system (10) according to one of the preceding claims, characterized by that the thin-point joint (32) has a width which initially decreases in the longitudinal direction and then increases again after reaching a punctual width minimum colocalized with the associated thickness minimum. [4] Weighing system (10) according to claim 3, characterized by that the thin-point joint (32) has a biconcave or bilaterally V-shaped width profile in the longitudinal direction. [5] Weighing system (10) according to one of the preceding claims, characterized by that the thin joint (32) has a length between 2 mm and 20 mm, in particular between 4 mm and 6 mm. [6] Weighing system (10) according to one of the preceding claims, characterized by that the thin-point joint (32) has a thickness between 10 µm and 100 µm, in particular between 40 µm and 60 µm, at its minimum thickness. [7] Weighing system (10) according to one of the preceding claims, characterized bythat the end regions of the resilience region (34, 34') have a bifacially rounded or oblique thickness profile in the length direction. [8] Weighing system (10) according to one of the preceding claims, characterized by that the resilience region (34, 34') has a width which initially decreases in the longitudinal direction and then increases again after reaching a width minimum which extends colocalized with the associated thickness minimum. [9] Weighing system (10) according to one of the preceding claims, characterized by that the resilience region (34, 34') has a length between 5 mm and 50 mm, in particular between 6 mm and 10 mm. [10] Weighing system (10) according to one of the preceding claims, characterized by that the resilience region (34, 34') has a thickness between 50 µm and 150 µm, in particular between 80 µm and 120 µm, in the area of ​​its thickness minimum. [11] Weighing system (10) according to one of the preceding claims, characterized bythat the coupling band has several resilience regions (34'). [12] Weighing system (10) according to claim 11, characterized by that the plurality of resilience regions (34') are arranged parallel to one another. [13] Weighing system (10) according to one of the preceding claims, characterized by that the length of the coupling band (30) is between 20 mm and 150 mm, in particular between 80 mm and 100 mm. [14] Weighing system (10) according to one of the preceding claims, characterized by that the width of the coupling band (30) outside the functional areas (32; 34, 34') and - if present - the lateral pivoting area (39) is between 5 mm and 10 mm. [15] Coupling band (30), consisting of a sheet metal strip, for the vertical force-transmitting coupling between a load receiver (18) of a weighing system (10) and a first lever arm (241) of a lever (24) of the weighing system (10), wherein two functional areas are formed spaced apart from one another in the length direction of the sheet metal strip, which are distinguished from immediately adjacent areas by a reduced width and reduced thickness, namely - a thin-point joint (32) which has a thickness which initially decreases in the length direction of the coupling band (30) and then increases again after reaching a point-like thickness minimum in order to define a localized, first pivot axis (321) which extends parallel to the width direction and perpendicular to the length direction of the coupling band (30), - a resilience region (34, 34') which, in the longitudinal direction of the coupling band (30), has a thickness which initially decreases, remains constant over a distance at least corresponding to its width after reaching a minimum thickness, and then increases again in order to define a continuous set of second pivot axes (341) parallel to the first pivot axis (321), and wherein, further in the longitudinal direction between the thin-point joint (32) and the resilience region (34, 34'), a lateral pivot region (39) is arranged which consists of one or more parallel webs (392) extending in the longitudinal direction of the coupling band (30), each of which has a web width which is less than the thickness of the coupling band (30) in this region. [16] Coupling band (30) according to claim 15, characterized by that it has several resilience regions (34'). [17] Coupling band (30) according to claim 16, characterized bythat the plurality of resilience regions (34') are arranged parallel to one another. [18] Coupling band (30) according to one of claims 15 to 17, obtained by - Providing a coupling band blank made of a spring-elastic metal sheet, - Laser processing of the coupling band blank to create lengths of different thickness and / or width.

Citation Information

Patent Citations

  • electronic balance with calibration device

    DE3012344A1

  • Electronic balance

    DE3242954A1

  • Force transmission device for a weighing apparatus

    EP1643223A1

  • Mass-measuring and force-measuring device

    US4703816A

  • Photo-detection device and method

    EP1643233A1