US-20260126318-A1 - WEIGHING SYSTEM AND COUPLING STRIP

US20260126318A1US 20260126318 A1US20260126318 A1US 20260126318A1US-20260126318-A1

Abstract

A weighing system having a lever with a first arm ( 241 ), a second arm ( 242 ) and a coupling belt ( 30 ) with two functional areas having reduced width and reduced thickness compared to immediately adjacent areas, namely a thin-section joint ( 32 ), having a thickness that, in the longitudinal direction of the coupling belt, initially decreases and, after reaching a minimum thickness, increases, to define a localized first pivot axis ( 321 ) extending parallel to the width direction and perpendicular to the longitudinal direction of the coupling belt, and a resilient region ( 34 , 34 ′) having a thickness that, in the longitudinal direction of the coupling belt, initially decreases, then, after reaching a minimum thickness, remains constant over a distance corresponding to at least its width, and then increases again in order to define a continuous array of second pivot axes ( 341 ) parallel to the first pivot axis.

Inventors

Matthias Geisler
Michael Mueller
Ulrich Bajohr

Assignees

SARTORIUS LAB INSTRUMENTS GMBH & CO. KG

Dates

Publication Date: 20260507
Application Date: 20251229
Priority Date: 20230629

Claims (20)

1 . A weighing system comprising a base, a load receptor coupled to the base by a parallel linkage arrangement so as to be vertically movable, and a lever articulated to the base by a lever joint so as to be pivotable, the lever having a first lever arm arranged on one side of the lever joint and a second lever arm arranged on an opposite side of the lever joint and configured to accommodate a sensor arrangement, wherein the first lever arm is coupled to the load receptor by a coupling belt so as to transmit vertical forces, the coupling belt being fixed both to the first lever arm and to the load receptor, and wherein the coupling belt has two functional areas which have reduced width and reduced thickness compared to immediately adjacent areas of the coupling belt, namely a thin-section joint, which has a thickness that, in a longitudinal direction of the coupling belt, initially decreases and then, after reaching a minimum thickness at a specific point, increases again in order to define a localized first pivot axis extending parallel to a width direction of the coupling belt and perpendicular to the longitudinal direction of the coupling belt, and a resilient region which has a thickness that, in the longitudinal direction of the coupling belt, initially decreases, then, after reaching a minimum thickness, remains constant over a distance corresponding to at least a width of the coupling belt, and then increases again so as to define a continuous array of second pivot axes parallel to the first pivot axis.
2 . The weighing system according to claim 1 , wherein the thin-section joint has, in the longitudinal direction, a biconcave thickness profile or a bifacially V-shaped thickness profile.
3 . The weighing system according to claim 1 , wherein the thin-section joint has a width that, in the longitudinal direction, initially decreases and then increases again after reaching a point-like minimum width colocalized with the minimum thickness.
4 . The weighing system according to claim 3 , wherein the thin-section joint has, in the longitudinal direction, a biconcave width profile or a bilaterally V-shaped width profile.
5 . The weighing system according to claim 1 , wherein the thin section joint has a length between 2 mm and 20 mm.
6 . The weighing system according to claim 1 , wherein the thin-section joint has a thickness between 10 μm and 100 μm, at the minimum thickness of the thin-section joint.
7 . The weighing system according to claim 1 , wherein end regions of the resilient region have, in the longitudinal direction, a bifacially rounded or sloping thickness profile.
8 . The weighing system according to claim 1 , wherein the resilient region has a width that, in the longitudinal direction, initially decreases and then increases again after reaching a minimum width that is colocalized with the minimum thickness.
9 . The weighing system according to claim 1 , wherein the resilient region has a length between 5 mm and 50 mm.
10 . The weighing system according to claim 1 , wherein the resilient region has a thickness between 50 μm and 150 μm in the area of the minimum thickness of the resilient region.
11 . The weighing system according to claim 1 , wherein the coupling belt has a plurality of the resilient regions.
12 . The weighing system according to claim 11 , wherein the plurality of resilient regions are arranged parallel to each other.
13 . The weighing system according to claim 1 , wherein the coupling belt has a lateral swivel area arranged in the longitudinal direction between the thin-section joint and the resilient region, consisting of at least one parallel web extending in the longitudinal direction of the coupling belt, and wherein the at least one web has a width that is less than the thickness of the coupling belt in the lateral swivel area.
14 . The weighing system according to claim 13 , wherein the width of the coupling belt outside of the functional areas and outside of the lateral swivel area is between 5 mm and 10 mm.
15 . The weighing system according to claim 1 , wherein a length of the coupling belt is between 20 mm and 150 mm.
16 . The weighing system according to claim 1 , wherein the width of the coupling belt outside the functional areas is between 5 mm and 10 mm.
17 . A coupling belt consisting of a sheet metal strip and configured for coupling a load receptor of a weighing system and a first lever arm of a lever of the weighing system so as to transmit vertical forces, wherein the coupling belt has two functional areas formed at a distance from each other in a longitudinal direction of the sheet metal strip, which have a reduced width and a reduced thickness compared to areas immediately adjacent to the functional areas, namely a thin-section joint, which has a thickness that, in the longitudinal direction of the coupling belt, initially decreases and then, after reaching a minimum thickness at a specific point, increases again in order to define a localized first pivot axis extending parallel to a width direction of the coupling belt and perpendicular to the longitudinal direction of the coupling belt, and a resilient region which has a thickness that, in the longitudinal direction of the coupling belt, initially decreases, then, after reaching a minimum thickness, remains constant over a distance corresponding to at least a width of the coupling belt, and then increases again so as to define a continuous array of second pivot axes parallel to the first pivot axis.
18 . The coupling belt according to claim 17 , wherein the resilient region comprises a plurality of resilient regions.
19 . The coupling belt according to claim 18 , wherein the plurality of resilient regions are arranged parallel to each other.
20 . The coupling belt according to claim 17 , produced by providing a coupling belt blank made of a spring-elastic metal sheet, laser processing the coupling belt blank to form length sections of different thicknesses and/or widths.

Description

CROSS REFERENCE TO RELATED APPLICATION This is a Continuation of International Application PCT/EP2024/066972, which has an international filing date of Jun. 18, 2024, and the disclosure of which is incorporated in its entirety into the present Continuation by reference. This Continuation also claims foreign priority under 35 U.S. C. § 119(a)-(d) to and also incorporates by reference, in its entirety, German Patent Application DE 10 2023 117 237.9 filed on Jun. 29, 2023. FIELD The invention relates to a weighing system comprising a base, a load receptor coupled to the base by a parallel linkage arrangement so as to be vertically movable, and a lever articulated to the base by a lever joint so as to be pivotable, the lever having 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 configured to accommodate a sensor arrangement, wherein the first lever arm is coupled to the load receptor by a coupling belt so as to transmit vertical forces, coupling belt the coupling belt being fixed both to the first lever arm and to the load receptor. BACKGROUND The invention further relates to a coupling belt consisting of a sheet metal strip, for coupling a load receptor of a weighing system and a first lever arm of a lever of the weighing system so as to transmit vertical forces. Conventional weighing systems and coupling belts for them are known from DE 30 12 344 A1. The central component of an electronic scale, in particular one perating on the principle of electromagnetic compensation, is its weighing system. The term “weighing system” is understood here to mean the mechanical lever mechanism with which a weighing goods carrier of the scale, which serves to hold the material to be weighed, is connected to the electronic sensor of the scale, typically a moving coil arrangement with optical lever position detection. The weighing system comprises a base by which it can be fixed to a platform or housing of the scale. A load receptor is articulated to this base via a parallel linkage arrangement, often referred to as a Roberval mechanism. The weighing goods carrier mentioned above is fixed directly or indirectly to the load receptor when the scale is in its final assembled state. The parallel linkage arrangement serves to prevent the load receptor or the weighing goods carrier from tilting, at least in the case of small deflections of the load receptor, which occur roughly on a circular arc with a radius equal to the length of the parallel linkage. Furthermore, a typical weighing system comprises a lever for transmitting distance and force, which is articulated at the base via a lever joint. A first lever arm of this lever is coupled to the load receptor in order to transmit its movement caused by the weight of the weighing material to the lever. A second lever arm of the lever is typically equipped with a mount for lever-side components of an electronic sensor, in particular a moving coil, which interacts in a manner that is generally known and thus not further relevant here, with other base-side sensor components mounted on the base, in particular a magnetic pot. Such a weighing system thus represents the “heart” of a scale, wherein similar weighing systems can be used in scales that are otherwise equipped differently. The coupling between the first lever arm and the load receptor mentioned above requires a connection, often referred to as a coupling, which is suitable for transmitting vertical forces between the load receptor and the first lever arm on the one hand, and which is sufficiently flexible on the other hand to achieve decoupling with regard to any non-vertical force components. As mentioned, a parallel linkage mechanism can prevent the load receptor from tilting, but it cannot prevent its circular arc movement comprising horizontal movement components alongside the vertical ones. However, these must not be transferred to the lever, as the corresponding non-vertical force components would distort the measured weight value, which is unacceptable, especially in the case of extremely high-resolution precision scales. In order to combine both requirements, namely vertical coupling and non-vertical decoupling, the aforementioned couplings, as described in the aforementioned background publication, can be configured in the form of thin sheet metal strips, i.e. as so-called coupling belts. If the coupling belt is sufficiently thin, non-vertical decoupling sufficient even for extremely high-resolution scales can be achieved. However, it has been found that such weighing systems are extremely susceptible to lateral acceleration forces, such as those typically occurring during transport, especially when shipping scales. Therefore, great care must be taken when packaging the scales to ensure that they arrive at the recipient with the coupling belts intact. The theoretical approach of fixing the coupling belt to the load receptor and first lever