Windshield structure for load receiving means in a weighing scale

Abstract

A weighing scale (100) is disclosed having a base (48), a plinth (46) and a load receiving arrangement (11). The base (48) and plinth (46) are positioned horizontally with respect to the ground, wherein the plinth (46) is attached to the base (48). The load receiving arrangement (11) is provided with a load receiver (20) and a wind break structure (30) such that the wind break structure (30) is arranged below the load receiver (20). The wind break structure (30) comprises a central portion (10) and a peripheral portion (34) surrounding the central portion (10). The central portion (10) further comprises a topological surface (33) having a plurality of alternating high rises (32) and low dips (31) to facilitate regulating airflow below the load receiver (20).

Description

TECHNICAL FIELD

[0001] The present invention relates to a weighing scale, in particular a laboratory weighing scale, having a load receiving device and a wind shield arrangement for such a load receiving device. BACKGROUND

[0002] A typical high precision weighing device, commonly used in laboratory installations, is known, for example, from US 4,465,152. The precision scale disclosed therein has a weighing chamber which is of course closed during weighing in order to protect the weighing pan from the influence of external air currents. In the weighing chamber, the weighing pan supports the received load from below to be weighed against the force of gravity. A floor, which is partly located below the pan and which forms a floor stand below the pan and which is not in contact with the pan, has holes which accommodate pins with play, the pins supporting the weighing pan and resting on extensions to provide a central and vertical load transmission with respect to the weighing pan. A ridge extending parallel to the glass front of the housing of the weighing chamber provides some lateral coverage for the weighing pan, although closer to the slots, thereby allowing relatively free air circulation between the weighing chamber and the chamber below. In this prior art arrangement, air movement occurs without greatly affecting the weighing pan. The ridge also has the function of preventing material from spilling over into the chamber below the weighing chamber.

[0003] In another weighing device disclosed in EP 2 530 441 A1, a circular spill barrier is provided on the weighing chamber floor stand to avoid spillage of harmful and corrosive test substances into the through hole intended for the load transmission pin of the weighing pan. The circular spill barrier is arranged radially close to the through hole on the floor stand below the weighing pan. One or more coaxially arranged wind walls surround the weighing pan to act as a wind shield against lateral air currents.

[0004] Although measures have been taken in the art to make the weighing operation of high precision weighing devices independent of the wind, there is still an interfering influence on the measured weight value in the form of error factors caused by turbulence with regard to the measurement of small masses. SUMMARY

[0005] In view of the above-mentioned problems associated with prior art devices, it is an object of the present invention to provide further improvements on a weighing scale and to achieve an improved combination of measurement accuracy and reduced waiting time between load reception and measurement on the load receiver.

[0006] This object is achieved by a further development of a weighing scale having a base body which is positioned horizontally with respect to the ground, a base table which is attached to the base body and positioned horizontally with respect to the base body, and a load receiving device. The load receiving device comprises a load receiver having a grid structure for receiving a load to be weighed, a wind screen structure which is positioned on the base table and in a non-contacting manner below the load receiver and around at least the grid structure of the load receiver. The wind screen structure comprises a peripheral portion and a central portion. The central portion of the wind screen structure is essentially characterized by comprising a plurality of alternating elevations and depressions to reduce the topology of the air flow below the load receiver.

[0007] In the framework of the present invention, it has been recognized that it is practically impossible to exclude the air flow / undulation as an error factor in the measurement of a small mass. This is because the operation of placing the sample into the weighing chamber of the weighing device inevitably generates an air flow, the duration of which can be longer than the loading operation itself. Temperature gradients can generate other air flows in different areas of the weighing device. Although it is not possible to completely prevent such air flows present below the load receiver, it is still possible to direct them in order to minimize their effect on the measured weight value of the load. By means of the topological surface, i.e. the surface morphology according to the present invention, flow restrictions and guidance are imposed, which limit the lateral flow space of the air flow, thus obtaining the beneficial effect of reducing the influence of the generated air flow on the measured weight value.

[0008] It is to be understood that the peripheral portion does not need to completely surround the load receiver in the circumferential direction, but preferably, in terms of angular extension, at least 180°, in particular at least 240°, around the load receiver.

[0009] The distribution of the elevations and depressions, the form of the elevations and depressions is not particularly limited. The elevations and depressions can also have a variable configuration and form, or they can be irregularly distributed over the central portion. Additionally, the height level of the individual depressions and the individual elevations can be configured to differ from one another. Furthermore, it is not necessary that the entire central portion must consist of said topological structure, but the central portion needs to comprise a plurality of alternating elevations and depressions.

[0010] Other preferred arrangements are summarized below. In one preferred embodiment, the topological surface of the central portion is anisotropic in order to accommodate load receivers of different grid structures. This arrangement additionally facilitates the guidance of the air flow in the form of a guidance through the base surface portion. To this end, the guidance of the topological structure is also made in one preferred embodiment such that it reduces the air flow along the depressions across the base surface portion more towards the center thereof than towards its boundaries.

[0011] In another preferred embodiment, the topographical surface comprises alternating elevations and depressions, wherein the elevation / depression height level difference between the elevations and depressions is greater than 1.2 mm and / or less than 16 mm. Furthermore, the topographical surface comprises locally adjacent elevations / depressions, wherein the height level difference between the elevations (elevation top) and the depressions (depression bottom) is greater than 1.2 mm, preferably greater than 1.6 mm, in particular greater than 2.0 mm and / or less than 16 mm, preferably less than 12 mm, in particular less than 8.0 mm. It is to be understood that "locally" does not mean locally everywhere, but that the topographical surface comprises local areas in which the height level difference is given.

[0012] In a preferred manner, the average of the height level differences of adjacent elevation / depression combinations is greater than 1.2 mm and / or less than 16 mm. Furthermore, it is preferred that the average of the height level differences of adjacent elevation / depression combinations of the topographical surface as a whole is greater than 1.2 mm, preferably greater than 1.6 mm, in particular greater than 2.0 mm and / or less than 16 mm, preferably less than 12 mm, in particular less than 8.0 mm. In particular, it is preferred that the height level difference of the local portion is greater than 1.5%, preferably greater than 2.5%, of the effective area of the load receiver and / or less than 20%, in particular less than 10%, of the effective area. It is also preferred that the average height level difference is greater than 1.5%, in particular greater than 2.5%, of the effective area of the load receiver and / or less than 20%, in particular less than 10%. In another preferred embodiment, the ratio of the size greater than the average height level of the topographical surface to the area of the load receiver less than the average height level of the topographical surface is greater than 1 / 3, preferably greater than 3 / 8, in particular greater than 3 / 7, and / or less than 3 / 4, preferably less than 2 / 3, in particular less than 5 / 8. The average height level of the topographical surface is simply the arithmetic average height, which is taken in integral form over the area of the topographical surface <h> = ∫∫ dx dy h(x, y).

[0013] In a preferred embodiment, the topographical surface comprises depressions extending at least partially linearly. Due to this arrangement, the air flow can be transported laterally more smoothly, reducing the influence of flow direction changes.

[0014] In a preferred arrangement, the topological surface comprises at least three elevations. Preferably, the topological surface comprises at least four elevations. Also preferably, there is at least one direction perpendicular to the direction of gravity in which, in a cross-section along said direction, the average spatial frequency of alternating elevations / depressions in units of 1 / cm is greater than 2 / 3, preferably greater than 1, in particular greater than 4 / 3 and / or less than 4.0, in particular less than 3.5, in particular less than 3.0. To illustrate this, for example, if one considers a cross-section of the structure along a length of 10 cm and there are seven elevations within this length, then each elevation gives two alternations (from a depression to an elevation, from said elevation to the next depression), then the average spatial frequency in units of 1 / cm is 1.4.

[0015] In a preferred manner, the elevations and depressions of the topological surface and the surrounding portions are integrally formed as a single unit. In addition, at least some of the elevations and depressions, preferably all of the elevations and depressions, are physically connected in the topological surface and are preferably made in one piece. This helps to keep the overall windscreen structure simple while maintaining the required spacing within the topological surface.

[0016] In an advantageous embodiment, at least one pair of elevations adjacent to each other comprises a cut-out portion for forming an additional spacing between the load receiver and the windscreen structure. This arrangement helps to prevent any contact between the load receiver, in particular the clips on the load receiver, and the elevations on the windscreen structure.

[0017] In a preferred manner, the surrounding portion comprises a pair of walls extending in the lateral direction of the windscreen structure and positioned opposite each other, wherein the alternating depressions and elevations are located between the two opposite walls. Each wall is of an arcuate configuration to provide additional space to accommodate sample receivers whose dimensions are slightly larger than the dimensions of the load receivers and to facilitate the removal of the weighing pans from the load receiving device.

[0018] Preferably, the surrounding portion comprises an inclined portion and said inclined portion has an inclined portion on the front portion and at least two inclined portions on the side portions such that the two inclined portions on the side portions extend in the longitudinal direction of the windscreen structure and the inclined portion on the front portion extends in the lateral direction of the windscreen structure.

[0019] Advantageously, the windscreen structure further comprises recessed portions extending in the longitudinal direction of the windscreen structure and located on both sides of the topological surface to separate the inclined portions on the side portions from the topological surface. The recessed portions are recessed inwardly to smoothly guide the fluid and facilitate cleaning.

[0020] In a preferred arrangement, the surrounding portion further comprises a plateau between the inclined portion on the front portion and the topological surface such that the weights or other weighing articles that require thermal stabilization are received on the plateau.

[0021] In an advantageous embodiment, the windscreen structure further comprises a collection pool positioned opposite the inclined portion on the front portion. In particular, the collection pool is located at the back side of the windscreen structure. The collection pool is configured for receiving fluid directed through the recessed portion.

[0022] In a preferred embodiment, at least a portion of the load receiver comprises a grid structure having open areas formed by a plurality of spaced apart grid bars. In another preferred embodiment, at least a portion of the load receiver is discontinuous at its upper surface. Preferably, it has open areas allowing air flow from above the load receiver to below the load receiver (i.e. relative to the central portion) and in particular a grid structure. On the one hand, the effective contact area between the load to be weighed and the load receiver can be reduced. On the other hand, air flow through the load receiver in counter gravity direction is possible and the floating / lifting effect is reduced. In a preferred embodiment, the grid bars of the load receiver have a cross section tapering towards the upper surface, for example having a substantially triangular structure, which reduces the effective contact area and also facilitates downward flow of any spillage. Preferably, the ratio of open areas to non-open areas of the grid structure is greater than 0.6, preferably greater than 1.0, in particular greater than 1.6 in terms of area size. In a preferred embodiment, the effective contact area of the support portion is mainly generated by such grid bars extending in particular parallel to each other. When installed in the weighing chamber, the preferred direction of extension is parallel to the rear wall of the weighing chamber separating the load receiving device from the weighing mechanism of the weighing scale. The grid structure also allows to install specially designed holding devices to receive certain types of irregularly formed or very small boxes or containers containing the material to be weighed.

[0023] In a preferred arrangement of the weighing scale, the arrangement of the open areas of the grid structure corresponds to the elevations of the topography surface and the arrangement of the depressions corresponds to the grid bars of the grid structure. There is a correlation between the grid structure and the topography surface, in that the overlap between the grid bars and the depressions and between the open areas and the elevations is greater than the reverse overlap. In another preferred embodiment, the depressions of the topography surface follow the extension of the bars of the grid structure. It is understood that the depressions need not follow the extension over the entire length of the extension of the bars, in particular the extension of the depressions can be interrupted by load receivers, e.g. structural members carrying the grid bars. Preferably, the extension of a plurality of grid bars, in particular most of the grid bars, of the grid structure is followed by a depression of the topography surface. In another preferred embodiment, one, preferably a plurality, in particular most or even all of the grid bars is embedded, at least over a portion of its extension, in particular over most of its extension, in a depression of the topography surface. In this regard, it is preferred that the topography surface comprises one or more elevations which protrude beyond the height level of the lower side of the bars of the grid, in particular by more than 10%, preferably more than 15%, in particular more than 20% of the extension of the bar height. Of course, the elevations can not reach their height level when the upper surface of the grid forms the contact area for receiving the load, and are spaced apart by a safety clearance which is preferably greater than 0.8 mm, further preferably greater than 1.2 mm, in particular greater than 1.6 mm or lower than the above-mentioned height level. In another preferred embodiment, the topography surface between adjacent elevations at least partially adapts to the shape and extension of the bars of the grid, in particular it is preferred that, seen in cross-section from a grid bar and the depression following its extension, the root mean square deviation of the distance between the grid bar and the topography surface in the area between two adjacent elevations around the grid bar from the arithmetic mean of said distance is lower than 2 / 3, preferably lower than 1 / 2, in particular lower than 1 / 3, preferably even lower than 1 / 4. It is preferred that this condition is present in at least 20%, preferably most of the overlap area. Preferably, the vertical distance between the load receiver, in particular the grid bar and the elevation (top of the elevation) height level, is not greater than twice the distance between two adjacent elevations, in particular not greater than said distance and / or not greater than 1.6 cm, preferably not greater than 1.2 cm, in particular not greater than 0.8 cm, even not greater than 0.4 cm. Preferably, the vertical distance between the load receiver, in particular the grid bar and the depression (bottom of the depression) height level, is not greater than twice the distance between two adjacent depressions, in particular not greater than said distance and / or not greater than 2.0 cm, preferably not greater than 1.6 cm, in particular not greater than 1.2 cm, even not greater than 0.8 cm.This allows the backflow generated by the downward air flow to have less harmful effects. With the arrangement of the grid structure discussed above and its correlation to the topography surface, in particular the embedding of the topography surface in the low, the main flow component of the topography surface channel is oriented parallel to the grid bars instead of perpendicular to the grid bars, so that the risk of causing turbulence transverse to the extension of the bars is reduced. Furthermore, once the embedding in the height direction is also completed, the high of the topography surface will have an additional wind barrier effect against transverse flows. Vertical flows can be deflected and run upwards along the inclination from the low to the high, thus having less effect on the load receiver. However, the above-described relative arrangement of the grid structure with respect to the topography surface is only a preferred embodiment. Even if the high is not very elongated and is also irregularly arranged, the guidance has its advantages, in particular in dealing with vertical flows. Preferably, at least no main channel crosses the floor portion and is transverse to the grid bars forming the upper surface of the load receiver.

[0024] In a preferred embodiment, the surrounding portion is slightly higher than the topography surface. In another preferred embodiment, the height level of the surrounding portion is at least partially higher than the average height level of the low, preferably at least 30%, in particular at least 60% higher than the average height level difference between the high and the low, more preferably higher than the average height level of the high, in particular up to or above the height level of the upper surface of the load receiver. This makes the wind barrier effect of the surrounding portion even more effective.

[0025] In a preferred embodiment, the surrounding portion is slightly higher than the topography surface. In another preferred embodiment, the height level of the surrounding portion is at least partially higher than the average height level of the low, preferably at least 30%, in particular at least 60% higher than the average height level difference between the high and the low, more preferably higher than the average height level of the high, in particular up to or above the height level of the upper surface of the load receiver. This makes the wind barrier effect of the surrounding portion even more effective.

[0026] In another preferred embodiment, the load receiver comprises two side bars which are spaced apart and held together by the grid structure, wherein each of the two side bars has a substantially L-shaped configuration.

[0027] In a preferred manner, the two side bars connect the load receiver to the weighing mechanism. Such an embodiment corresponds to a load receiving device for lateral load transfer, and the load is not transferred through a central vertical column extending from the support portion through an opening in the floor portion. Such an arrangement also advantageously influences the air flow at the floor portion by preferably having a closed floor portion (without through holes connecting to the outside of the weighing chamber).

[0028] In a preferred embodiment, the radially outer portion of the surrounding portion has an inclined structure, the inclination angle of which is particularly less than 60°, preferably less than 45°, particularly less than 30° and / or greater than 10°, preferably greater than 14°, particularly greater than 18°. A gap may exist between the radially inner portion of the surrounding portion and the topological surface, the gap being particularly suitable for receiving structural members of the load receiver, thereby transferring the load to the weighing mechanism of the weighing scale.

[0029] It should be understood that the inclined structure does not need to completely surround the load receiver circumferentially. For example, the weighing chamber is formed by a front wall, two side walls, a rear wall, a top wall, and a base. The rear wall separates the weighing chamber from the weighing mechanism of the weighing scale. The surrounding portion may be placed adjacent to the rear wall and have, for example, an inclined structure facing the side walls and front wall of the weighing chamber.

[0030] In an advantageous embodiment, the load receiving device of the weighing scale configured as described above includes a load receiver connected to the weighing mechanism. The load receiving device may include one or more recessed portions that receive two side rods in a non-contact manner within the recessed portions.

[0031] In another advantageous embodiment, the windshield structure of the weighing scale configured as described above includes a central portion comprising a topological surface integrally formed as a single unit and a surrounding portion. Attached Figure Description

[0032] Other features, details, and advantages of the invention will become apparent from the following description with reference to the accompanying drawings, wherein

[0033] Figure 1 A weighing scale with a load receiving device surrounded by a weighing chamber is shown in perspective view;

[0034] Figure 2 Shown in perspective Figure 1 The windshield structure of the weighing scale shown;

[0035] Figure 3 Shown in top view Figure 2 The windshield structure of the weighing scale shown;

[0036] Figure 4 The previous sectional view showed Figure 2 and Figure 3 The windshield structure of the weighing scale shown;

[0037] Figure 5 Shown in an enlarged manner Figure 2 The cutaway view of the insert shown and its central portion, and

[0038] Figure 6 yes Figure 1 The image shows a perspective sectional view of the load receiving device. DETAILED DESCRIPTION

[0039] As Figure 1 illustrated, the basic structure of the example weighing scale 100 is of a type well known in the art, with a base body 48, a load receiving device 11 and a weighing chamber 40 formed by a plinth 46, a transparent front wall 41, transparent side walls 42 and 43, a transparent top wall 45 and a rear wall 44. The rear wall 44 separates the weighing chamber 40 from a weighing mechanism 60, which is arranged and housed on the other side of the rear wall 44 (and not visible in Figure 1 the drawing, which is indicated by the dashed line of the arrow of reference 60). In Figure 1 part of the plinth 46 is omitted, so that the height adjustable feet 80 of the weighing scale 100 can be seen. Figure 1 The side wall 43, which faces the observer in Figure 1 the example embodiment illustrated, can be moved in the front-rear direction to open and close the weighing chamber 40 and is shown in the retracted position, so that the interior of the weighing chamber 40 can be accessed and, therefore, a load to be weighed can be introduced onto the load receiving device 11, more particularly onto the load receivers 20, which in the present embodiment are provided in the form of a grid structure 12. The load receivers 20 are connected to the weighing mechanism 60 via a pair of side bars 26 having a substantially L-shaped configuration. In Figure 1 the example embodiment illustrated, the load is transferred laterally to the weighing mechanism 60, rather than vertically downwards to the weighing mechanism 60 through the plinth 46 of the weighing chamber 40. Adjacent to the front wall 46 and outside the weighing chamber 40 is an operating panel 50 for operating the weighing scale 100. In the example embodiment illustrated, the weighing scale 100 is a high-precision laboratory scale, with a weighing accuracy better than 0.001 mg.

[0040] Those features of the weighing scale 100 described with reference to Figure 1 EP 1 195 586 A1 are now known from side load transfer type weighing scales, for example disclosed in EP 1 195 586 A1. The content of said document is incorporated in the present application with regard to the subject of the coupling of the side bars 26 to the weighing mechanism 60 and the possibility of coupling calibration weights to the weighing mechanism 60, which, although not illustrated, can be arranged in the base body 48 of the plinth 46 of the weighing chamber 40, as in the case of the example embodiment illustrated in Figure 1 EP 1 195 586 A1. However, the embodiments of the present application are not limited to the example embodiment illustrated in EP 1 195 586 A1 and the coupling of the side bars 26 to the weighing mechanism 60 can be configured in other known ways, outside the scope of the present application.

[0041] For the subsequent discussion, with respect to directions, although the height direction is referred to with respect to the direction of gravity (-g), the direction of extension of the lateral portion of the side bar 26 is referred to as the length direction, the length direction is thus the direction connecting the rear wall 44 and the front wall 41, the direction orthogonal to the gravity and the length direction is referred to as the transverse direction, i.e. the direction connecting the side walls 42 and 43 of the weighing chamber 40 (in the closed state). The plane resulting from the length and transverse directions and orthogonal to the gravity is referred to as the projection plane.

[0042] In Figure 1 In the embodiment shown, the surface immediately below the load receiver 20 is not the floor 46 of the weighing chamber 40, but a central portion 10 of the wind screen structure 30 placed in the weighing chamber 40 and arranged in the height direction between the load receiver 20 and the floor 46.

[0043] In addition to the load receiver 20, the load receiving arrangement 11 of the present invention comprises a wind screen structure 30, which is located on the floor 46 and positioned below the load receiver 20 such that the load receiver 20 is held in a contactless manner above the wind screen structure 30. The wind screen structure 30 will be described in more detail below with specific reference to Figure 2 The basic form of the wind screen structure 30 is in the form of a truncated pyramid. The wind screen structure 30 comprises a central portion 33 and a surrounding portion 34.

[0044] The surrounding portion 34 faces the three sides of the front wall 41 and the side walls 42, 43 of the weighing chamber 40 respectively forms an inclined portion 39a, 39b and 39c with an inclination angle of about 24°. Thus, any air flow approaching the height level of the floor 46 and directed centrally is guided to obtain a direction component counteracting the gravity. There is provided a front inclined portion 39a, there are provided side inclined portions 39b, 39c. The two side inclined portions 39b, 39c extend in the longitudinal direction of the wind screen structure 30, while the front inclined portion 39a extends in the lateral direction of the wind screen structure 30. The upwardly inclined inclined portions 39a, 39b and 39c reach a peak on the plateau 38. Thus, the plateau 38, the adjoining inclined portions 39a, 39b and 39c and the radially adjacent but not contacting the load receiver 20 portion of the surrounding portion 34, referred to as the wall 35, act as a first line of defense for the load receiver 20 against turbulent air flows. Thus, the height level of the plateau 38 is also referred to as the screen height H. The plateau 38 between the front inclined portion 39a and the top surface 33 is configured as a flat surface for receiving weights or other weighing articles requiring thermal stabilization.

[0045] The center of the windscreen structure 30 is recessed relative to the plateau 38 and comprises a central portion 10 which is arranged in the projection plane in an area below the load receiver 20 in the projection plane. The central portion 10 comprises a topological surface 33 formed by a plurality of alternating high rises 32 and low recesses 31. In this embodiment, both the high rises 32 and the low recesses 31 therebetween extend along the transverse direction. Thus, when viewed along the length direction, the high rises 32 and the low recesses 31 alternate. Between the topological surface 33 and the side portions of the plateau 38 and the inclined portions 39a, 39b and 39c, recessed portions 37i are formed to accommodate the free horizontal end portions of the side bars 26 and are contiguous with recessed portions 37e which, as seen in the projection plane, are located outside the central portion 33. The recessed portions 37i, 37e extend in the longitudinal direction of the windscreen structure 30 and are located on both sides of the topological surface 33. The recessed portions 37i, 37e separate the inclined portions 39a, 39b, 39c from the topological surface 33. The recessed portions 37i, 37e are recessed inwardly to smoothly guide the fluid and to facilitate cleaning and wiping of spillage.

[0046] When the windscreen structure 30 is placed in the weighing chamber 40, the collection pool 36 of the windscreen structure 30 faces the rear wall 44 of the weighing chamber 40. The form of the windscreen structure 30 substantially interfits with the form of the rear wall 44 so that it can be brought into an aligned fit with the rear wall 44. The peripheral portion 34 comprises a pair of walls 35 which extend in the transverse direction of the windscreen structure 30 and are located opposite one another with the alternating low recesses 31 and high rises 32 located between the two opposite walls 35. Each wall 35 is of an arcuate configuration to provide additional space to accommodate sample receivers which are slightly larger in size than the load receivers 20 and to facilitate removal of the load receivers 20 from the load receiving device 11. When viewed from the length direction, the walls 35 extend transversely and are arranged between the recessed portions 37i and 37e and between the recessed portions 37i and the plateau 38. From Figure 2 It can also be seen that one of the walls 35 is arranged between the topological surface 33 and the collection pool 36. The wall 35 also acts as a screen to prevent the airflow from approaching the bottom plateau 46 and pointing towards the front inclined portion 39a. It must be noted that the collection pool 36 is located opposite the front inclined portion 39a. The collection pool 36 is configured to receive the fluid which is guided through the recessed portions 37i, 37e.

[0047] In this embodiment, the height level of the high rises 32 (the height level of the top of the high rises 32) is below the screen height H. In the cross-sectional view Figure 5 — which is a cross-sectional view along the length direction and which is centrally located relative to the transverse direction — the screen height H is indicated by the dashed line which connects the plateau 38 to the side inclined portion 39a and the wall 35. In the cross-sectional view Figure 5In the enlarged view on the left, the gap between the top of the raised section 32 and the shielding height H (indicated by the dashed line) can be identified. Furthermore, the gap between the bottom of the recessed section 31 and the shielding height H (indicated by the dashed line) can be identified; in the illustrated embodiment, this gap is in the range of a few millimeters, specifically about 3.5 mm. In this embodiment, the surface area (the area of ​​the load receiver extended on the projection plane) is approximately 36 cm². 2 However, depending on the intended application scope, it can certainly be smaller or larger.

[0048] The topological surface 33, presented by alternating high points 32 and low points 31, influences the airflow below the load receiver 20. Airflow with streamlines possessing a large lateral component is guided laterally. By being guided upwards along the slope from the low point 31 to the high point 32, the airflow with streamlines primarily in the length direction in the low point 31 is blocked to prevent direct flow. The airflow from above, i.e., the airflow with streamlines primarily along gravity in the region of the low point 31 and ultimately blocked by the bottom of the low point 31, reaches a stagnation point, causing the branched streamlines to again receive the anti-gravity flow direction component (length direction component) obtained by deflection, and accordingly experience a channeling effect (lateral direction component).

[0049] As seen in the projection plane, the arrangement of the load receiver 20 within the surrounding portions 34 (35, 38, 39a, 39b, 39c) is not arbitrary relative to the topological surface 33 of the central portion 10, but rather correlated with it. Figure 6 As can be better seen in the figure, the overlap between the grid structure 12 of the load receiver 20 and the recess 31 is greater than the overlap with the raised section 32 (viewed in the projection plane). In the embodiment shown in the figure, the grid rods 14 of the grid structure 12 extend along the recess 31 and, viewed along the length direction, are approximately centered between two adjacent raised sections 32 (except for the outermost grid rod 14). Conversely, in Figure 6 The open area of ​​the grid structure 12, indicated by reference numeral 16 in the figure, is associated with the area of ​​the topological surface 33 where the raised areas 32 are arranged, and also covers the transition area from the recessed areas 31 to the raised areas 32, such that the streamlines of the surface near the topological surface 33 in the vertical projection plane (composed of the height direction and the longitudinal direction, i.e., the alternating directions of raised and recessed areas) extend through a portion of the open area 16 at the end of the transition guided by the recessed-raised areas.

[0050] The cross-sectional shape of the grid bars 14 is also streamlined with respect to the airflow in the direction of gravity to avoid prolonged stagnation points at their upper surface. Moreover, in the exemplary embodiment, the grid bars 14 are embedded in the depressions 31 by making the height level of the lower side of the grid 14 lower than the height level of the adjacent risers 32. This configuration of the exemplary embodiment provides an additional shielding effect for the flow transverse to the extension direction of the grid bars 14. However, even if the grid bars 14 are not embedded in the depressions 31 from the height direction, a beneficial effect can be obtained via the correlation of the grid structure 12 and the topological surface 33 in the projection plane only.

[0051] In the exemplary embodiment, the grid bars 14 are supported near their axial end portions by length bars 13 of the grid structure 12. The length bars 13 extend in the length direction and form longitudinal extension arms of the side bars 26 at their horizontal free end portions. These bars 13 are embedded in the recessed portions 37i of the wind shield structure 30 at a safe distance to avoid physical contact therewith.

[0052] It is to be understood that the present application is not limited to the grid structure 12 as shown in the exemplary embodiment. Other surface configurations of the load receiver 20 are contemplated, in particular other kinds of grid structures 12.

[0053] If the sample to be weighed is too small with respect to the grid spacing, the Figure 6 Clips 19 are shown attached to the grid structure 12 to provide a sheet-like surface with a larger contact area. It is to be understood that the clips in the form of special holders can be used in case the sample container does not have a suitable or complementary bottom surface to allow the container to stand reliably. However, it is to be understood that a (normal) sized sample can be received directly by the grid structure 12, i.e. without the clips 19. At least one pair of adjacent risers 32 comprises a cut-out portion 52 for forming an additional spacing between the load receiver 20 and the wind shield structure 30. This arrangement helps to prevent any contact between the load receiver 20, in particular the clips 19 on the load receiver 20, and the risers 32 on the wind shield structure 30.

[0054] The risers 32 and the depressions 31 of the topological surface 33 are firmly connected to each other. Preferably, as shown in the exemplary embodiment, the topological surface 33 is made in one piece and the central portion 10 is formed as a continuous surface. In the exemplary embodiment, the wind shield structure 30 is made in one piece, for example by molding using a plastic material.

[0055] In the exemplary embodiment, the depressions 31 and the transitions between the depressions 31 and the elevations 32 are curved with a predetermined radius of curvature. However, different shapes of the depression cross-section and the transitions are contemplated. In the exemplary embodiment, the grid bars 14 in the grid structure 12 are uniformly spaced apart. However, it is to be understood that the present application is not limited to such regular and uniformly spaced arrangements. In the exemplary embodiment, the load receiving device 11 is used with a load scale 100 according to the lateral load transfer type. However, it can also be applied to other types, e.g. achieving load transfer in vertical direction via vertical columns through one or more openings in the bed 46. For such embodiments, when using load receivers 20 with discontinuous contact surfaces, in particular irregularly spaced grid structures 12, it is preferred to use additional cover protection to prevent accidental spillage into said through-holes in the bed 46.

[0056] From the above it will be appreciated that the present application is not limited to the exemplary embodiments described in the specification and drawings. Rather, the features discussed in the specification and appearing in the claims below can be taken individually or in any combination.

[0057] List of reference signs

[0058] 10 central portion

[0059] 11 load receiving device

[0060] 12 grid structure

[0061] 13 length bar

[0062] 14 grid bar

[0063] 16 open area of the grid structure 12

[0064] 19 clip

[0065] 20 load receiver

[0066] 26 side bar

[0067] 30 windscreen structure

[0068] 31 depression

[0069] 32 elevation

[0070] 33 topographical surface

[0071] 34 peripheral portion

[0072] 35 wall of the peripheral portion 34

[0073] 36 collection basin

[0074] 37i, 37e recessed portion

[0075] 38 ledge of peripheral portion 34

[0076] 39 sloped portion of peripheral portion 34

[0077] 39a front sloped portion

[0078] 39b, 39c side sloped portions

[0079] 40 weighing chamber

[0080] 41 front wall

[0081] 42, 43 side walls

[0082] 44 rear wall

[0083] 45 top wall

[0084] 46 base

[0085] 48 base body

[0086] 50 operating panel

[0087] 52 pair of notched portions on adjacent ledges 32

[0088] 60 weighing mechanism

[0089] 80 height-adjustable feet

[0090] 100 weighing scale

[0091] H height of screen

[0092] Ah height difference between peripheral portion 34 and topography surface 33

Claims

1. A weighing scale (100) comprising: a base (48) horizontally positioned relative to the ground; a platform (46) attached to the base (48) and horizontally positioned relative to the base (48); a load receiving device (11) including a load receiver (20) and a windshield structure (30), the load receiver (20) having a grid structure (12) for receiving a load to be weighed, the windshield structure (30) being located on the platform (46) and positioned non-contactly below the load receiver (20), and surrounding at least the grid structure (12) of the load receiver (20); wherein, The windshield structure (30) includes a peripheral portion (34) and a central portion (10), characterized in that the central portion (10) of the windshield structure (30) has a topological surface (33) comprising a plurality of alternating elevations (32) and depressions (31) to reduce airflow around the load receiver (20). At least a portion of the load receiver (20) includes a grid structure (12) having an open area (16) formed by a plurality of spaced-apart grid bars (14), wherein the arrangement of the open area (16) of the grid structure (12) corresponds to the elevation (32) of the topological surface (33) and the arrangement of the depression (31) corresponds to the grid bars (14) of the grid structure (12).

2. The weighing scale (100) according to claim 1, wherein, The alternating highs (32) and lows (31) included in the topological surface (33) have a height difference between the highs (32) and lows (31) between the highs (32) and lows (31) greater than 1.2 mm and / or less than 16 mm.

3. The weighing scale (100) according to any one of the preceding claims, wherein, The average height difference between adjacent high (32) / low (31) combinations is greater than 1.2 mm and / or less than 16 mm.

4. The weighing scale (100) according to claim 1 or 2, wherein, The topological surface (33) includes a depression (31) that extends at least partially linearly.

5. The weighing scale (100) according to claim 1 or 2, wherein, The raised (32) and recessed (31) topographic surface (33) and the surrounding portion (34) form a single unit of terrain.

6. The weighing scale (100) according to claim 1 or 2, wherein, At least one pair of adjacent raised sections (32) include a notch (52) for forming an additional gap between the load receiver (20) and the windshield structure (30).

7. The weighing scale (100) according to claim 1 or 2, wherein, The surrounding portion (34) includes a pair of walls (35) extending in the lateral direction of the windshield structure (30) and positioned opposite each other, wherein alternating depressions (31) and elevations (32) are located between the two opposing walls (35); wherein each wall (35) is arcuately configured to provide additional space to accommodate a sample receiver slightly larger than the size of the load receiver (20) and to facilitate removal of the load receiver (20) from the load receiving device (11).

8. The weighing scale (100) according to claim 1 or 2, wherein, The surrounding portion (34) includes an inclined portion (39), and the inclined portion (39) has a front inclined portion (39a) and at least two side inclined portions (39b, 39c) such that the two side inclined portions (39b, 39c) extend in the longitudinal direction of the windshield structure (30), and the front inclined portion (39a) extends in the lateral direction of the windshield structure (30).

9. The weighing scale (100) according to claim 8, wherein, The windshield structure (30) also includes recessed portions (37i, 37e) that extend in the longitudinal direction of the windshield structure (30) and are located on both sides of the topological surface (33) to separate the lateral inclined portions (39b, 39c) from the topological surface (33), and the recessed portions (37i, 37e) are recessed inward to smoothly guide fluid and facilitate cleaning.

10. The weighing scale (100) according to claim 8, wherein, The surrounding portion (34) also includes a platform (38) located between the front inclined portion (39a) and the topological surface (33), such that weights or other weighing items requiring thermal stability are received on the platform (38).

11. The weighing scale (100) according to claim 9, wherein, The windshield structure (30) also includes a collection pool (36) for receiving fluid guided through the recessed portions (37i, 37e).

12. The weighing scale (100) according to claim 1 or 2, wherein, The surrounding portion (34) is slightly higher than the topological surface (33).

13. The weighing scale (100) according to claim 1 or 2, wherein, The load receiver (20) includes two side rods (26) spaced apart from each other and held together by the grid structure (12), wherein each of the two side rods (26) has a generally L-shaped configuration.

14. A load receiving device (11) for a weighing scale (100) according to any one of claims 1-13, the load receiving device (11) comprising a load receiver (20) connected to a weighing mechanism (60).

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