Weighing scale with display unit

Abstract

To provide a balance which can protect components located inside a display unit from ingress of dirt or a high-pressure jet.SOLUTION: A balance 1 with a weighing pan 8 is provided. A display unit 2 is connected to the balance 1. The display unit 2 has a casing 3, which comprises an upper part 4 and a lower part 5, and at least one display 12. An intermediate frame 6 to produce a sealing effect is arranged between the upper part 4 and the lower part 5.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] A weighing scale with a balance pan, wherein a display unit is coupled to and / or is part of the weighing scale, the display unit having a casing consisting of an upper part and a lower part and at least one display.

[0002] Background technology The prior art is known for a number of weighing scales with display units. The display unit has a casing. The casing consists of at least an upper part and a lower part. When the casing is made of metal, it usually has an outer edge where the two casing parts abut against each other. This edge ensures a tight connection between the two parts, relying on a seal extending along this edge. When the two casing walls run parallel to each other, the tight connection is achieved via a flat seal located between the casing walls. When one casing wall runs perpendicular to the other casing wall, the sealing is achieved via a molded seal. The molded seal rests flat on one casing wall and surrounds or is embedded in the wall extending perpendicular to this casing wall.

[0003] The weighing instrument in this case preferably has a balance pan, under which a load cell is arranged, which may consist of at least one strain gauge (DMS) sensor, which may be mounted on a block, or which operates according to the principle of electromagnetic force compensation.

[0004] Furthermore, German Utility Model Publication No. 20119673 discloses a weighing scale with a display unit. The display unit is arranged in a separate casing. The casing of the display unit is primarily made of a single molded part. In this case, a cutout for the display is arranged on the top surface of the casing. This cutout is closed by an assembly unit including a display device and input buttons. A film is attached to the top surface of the casing. This film contains information about how to handle the display unit and is covered by the film. The film seals the top surface of the casing against the effects of dust and water.

[0005] German Utility Model No. 20218934 discloses a display unit for a weighing scale. The display unit has a two-shell casing. The casing has an upper casing part and a lower casing part. The two-shell casing in this case consists of a deep-drawn inner metal half-shell and an outer plastic half-shell. The metal and plastic half-shells are connected to each other. The metal half-shell of the lower casing part is fitted over the metal half-shell of the upper casing part like a cover, while the upper plastic half-shell of the upper casing part is fitted over or engages with the plastic half-shell of the lower casing part like a cover. This achieves a tight transition between the upper and lower casing parts.

[0006] A disadvantage of the known prior art is that the two-part metal casing has a sealing edge, so a closed outer surface without a sealing edge is not possible, which significantly improves the cleanability and prevents the accumulation of dirt in this area.

[0007] overview SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a weighing device which eliminates or at least reduces the known drawbacks of the prior art.

[0008] This problem is solved by providing an intermediate frame between the upper and lower sections of the weighing device of the aforementioned type. In particular, at least two steps or one, preferably two, stepped notches are provided on the outer periphery of the intermediate frame. The two steps or stepped notches serve as support for the edges of the upper and / or lower sections. Thus, at least one step or at least one stepped notch is provided on the upper and lower surfaces of the intermediate frame, respectively. The outer edges of the intermediate frame, where the upper and lower sections are located, are therefore flush with the upper and lower sections. The screw fastening of all three components creates a sealing effect by pressing the casing section or the upper and lower sections against the intermediate frame in a circumferential manner. This protects the internal components from the intrusion of dirt or high-pressure jets. The connection between the lower section, intermediate frame, and upper section is therefore watertight. In addition to sealing the housing, the intermediate frame also serves as a support for the printed circuit board, the display, and other components. Corresponding cutouts, screw fastenings, and cable guides can be provided in and / or on the intermediate frame. In particular, the intermediate frame can have at least one cutout for the display.

[0009] In another embodiment, the step or step-shaped recess has a width or depth corresponding to the material thickness of the upper and / or lower sections. Preferably, both the upper and lower sections are formed or deep-drawn from a single piece of sheet metal, with a material thickness of at least 0.5 mm to 10 mm, preferably 0.5 mm to 5 mm, and particularly preferably 0.5 mm to 3 mm. Correspondingly, the step has a depth of at least 0.5 mm to 10 mm, preferably 0.5 mm to 5 mm, and particularly preferably 0.5 mm to 3 mm. Due to the small material thickness of the upper and lower sections, a seal cannot be inserted in this area because the sealing surface would be so small that the seal would be cut off or squeezed out on at least one side when the upper section is screwed to the intermediate frame and lower section. This would no longer provide a reliable seal for the housing. Due to the presence of at least two steps and their corresponding depths, a good seal is already achieved according to the present invention. In particular, the edges of the upper and lower parts rest entirely on the steps, and additionally, the inner surfaces of the upper and lower parts rest against the rear edges of the respective steps, the rear edges being higher than the surfaces of the steps on which the edges of the upper and lower parts rest. The edges, like the steps, extend over the entire outer periphery of the intermediate frame. Preferably, the height of the rear edges is 0.1 mm to 30 mm, more preferably 0.2 mm to 20 mm, and particularly preferably 0.3 mm to 10 mm.

[0010] In another configuration, at least one seal is arranged between the intermediate frame and the upper part and / or between the intermediate frame and the lower part. Preferably, one seal is arranged between the upper part and the intermediate frame and one seal is arranged between the lower part and the intermediate frame. The at least one seal ensures that the interior of the casing is completely sealed, so that water cannot reach the interior of the casing even when cleaning with high-pressure jets. This is achieved, in particular, by preventing the high-pressure jets from directly hitting the seal, because the seal is arranged inside the casing and the upper part, intermediate frame, and lower part protect the seal from direct contact with the high-pressure jets.

[0011] In another embodiment, the inner surface of the upper part and / or the inner surface of the lower part have at least one bevel and / or at least one concavely shaped area in the area of the seal, so that the bevel and / or the concavely shaped area at least partially contacts the seal. Therefore, at least the inner surface of the upper part and / or the inner surface of the lower part, particularly the outer surface of the upper part and / or the outer surface of the lower part, in the area of the outer periphery of the upper part and / or the lower part, form an angle with respect to the connecting area of the upper part and / or the lower part, particularly less than 90°, preferably less than 60°, and particularly preferably less than 30°. This, on the one hand, promotes the outflow of liquid, and, on the other hand, allows this area to contact the seal. This area can contact the seal before the upper part and / or the lower part are yet to be screwed to the intermediate frame, or this area only contacts the seal once the intermediate frame is screwed to the upper part and / or the lower part. Furthermore, this fixes the position of the seal and allows a preload to be applied to the seal. For this purpose, the seal preferably has an overdimension. The seal is compressed during assembly of the upper part and the intermediate frame and / or during assembly of the lower part and the intermediate frame. Alternatively, a seal corresponding to an O-ring seal may be deformed and thus compressed.

[0012] In another embodiment, the intermediate frame has at least one first region for receiving the upper and / or lower portions, a second region for fixing at least one seal, and a third region for receiving a display. The intermediate frame thus comprises at least three regions. The three regions are manufactured as a single unit. This allows the intermediate frame to have an internal stepped structure, allowing the insertion and positioning of at least one seal. Preferably, the intermediate frame is made of a molded part, particularly an injection-molded part. Preferably, the second region of the intermediate frame has a stop against which at least one surface of the seal rests, thereby at least partially fixing the seal. The seal is preferably held in a form-locking manner between the stop and the inner surface of the upper portion and / or the inner surface of the lower portion. A step is disposed between the second and third regions. When viewed from the top of the intermediate frame, the second region is located lower than the third region. The upper surface of the intermediate frame faces the upper part. This creates a stop at the edge between the second and third regions. This stop fixes the position of the seal. Furthermore, another seal, in particular a third seal, is arranged between the upper part and the third region of the intermediate frame. This third seal is preferably formed as a flat seal and seals the area between the upper part and the intermediate frame where the display is located. This prevents water from penetrating into the interior of the casing from the display side. Preferably, the seal extends to the inner periphery of the upper part.

[0013] In another configuration, a retaining metal sheet is arranged on the intermediate frame to fix the upper portion. The retaining metal sheet is arranged between the intermediate frame and the upper portion. Furthermore, another seal may be arranged between the upper portion and the retaining metal sheet. The retaining metal sheet also serves to reinforce the intermediate frame in the region of the third region of the intermediate frame. Additionally, the retaining metal sheet also serves to accommodate the membrane keyboard so that the membrane keyboard is fully supported at its outer periphery.

[0014] In another embodiment, a pressure compensation element is arranged in the casing, which serves to prevent positive or negative pressure caused by temperature fluctuations from occurring inside the casing.

[0015] In one alternative embodiment, the intermediate frame is made of an electrically conductive material, in particular an electrically conductive plastic. Furthermore, the electrically conductive material for the intermediate frame ensures a good electrical connection between the two housing parts, thereby contributing to meeting all electromagnetic compatibility requirements. Preferably, the intermediate frame is made of a thermoplastic, in particular PA, POM, LCP, PP, or ABS.

[0016] Further advantageous aspects will become apparent from the following description of the preferred embodiment taken in conjunction with the drawings. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 shows a scale equipped with a display unit. [Figure 2] FIG. 2 is a diagram showing a cross section of the display unit. [Figure 3] FIG. 2 is a schematic diagram showing an intermediate frame.

[0018] Detailed Description of the Embodiments FIG. 1 shows a weighing scale 1 equipped with a display unit 2. The display unit 2 has a separate casing 3. The casing 3 consists of an upper part 4 and a lower part 5, with an intermediate frame 6 arranged between the upper and lower parts 4 and 5. The display unit 2 further comprises a display 12 and a membrane keyboard 7. The membrane keyboard 7 has various keys for operating the display unit 2. A number of bases 10 are arranged on the lower part 5 of the display unit 2. The weighing scale 1 has a balance pan 8. Below the balance pan 8, a load cell and a frame are arranged, which support the balance pan and accommodate the load cell. A base 9 is arranged, which, together with the frame of the weighing scale 1, allows the height and tilt of the weighing scale 1 to be adjusted. The weighing scale 1 is connected to the display unit 2, preferably via a cable 11, which allows the weighing scale 1 to be powered and weighing data to be received from the weighing scale 1.

[0019] Figure 2 shows a cross section of the display unit 2 shown in Figure 1. A seal 13 is disposed between the upper part 4 and the intermediate frame 6 and between the lower part 5 and the intermediate frame 6 near the outer periphery of the intermediate frame 6. A first seal 14 is disposed between the upper part 4 and the intermediate frame 6, and a second seal 15 is disposed between the lower part 5 and the intermediate frame 6.

[0020] The intermediate frame 6 has three regions 16, 17, and 18. The first region 16 accommodates the upper and lower sections 4 and 5, the second region 17 accommodates and fixes the seals 13, 14, and 15, and the third region 18 contains a receptacle 28 for the display 12. The three regions 16, 17, and 18 are manufactured as a single unit. The intermediate frame 6 thus has a stepped structure. The second region 17 includes a stopper 19, which points toward the upper and lower sections 4 and 5, respectively. The seals 13, 14, and 15 are positively secured between the stopper 19 and the inner surface of the upper section 4 or the inner surface of the lower section 5. The stopper 19 is located between the second region 17 and the third region 18. The second region 17 is located lower than the third region 18. "Lower" in this context means that the second region 17 has a greater distance from the upper part 4 than the third region 18. This results in a stop 19 at the edge between the second region 17 and the third region 18. The stop 19, which points in the direction towards the lower part 5 and is a stop 19 for the second seal 15, is formed by an extension of the edge located between the second region 17 and the third region 18. The intermediate frame 6 therefore has a T-shaped geometric shape in cross section in the second region 17.

[0021] The first region 16 is located on the outer periphery of the intermediate frame 6. Two steps 21 are arranged on the outer periphery of the intermediate frame 6, or two step-shaped cutouts 21 are arranged on the outer periphery. The two steps 21 or step-shaped cutouts 21 serve as support for the edges of the upper part 4 and the lower part 5. Thus, at least one step is arranged on the upper surface of the intermediate frame 6 and on the lower surface of the intermediate frame 6. The upper surface is the surface of the intermediate frame 6 facing towards the upper part 4, and the lower surface of the intermediate frame is the surface of the intermediate frame facing towards the lower part 5. Thus, the upper part 4, the intermediate frame 6, and the lower part 5 have flush, closed outer edges 26. This means that the upper part 4, intermediate frame 6 and lower part 5 fit flush with the outer edges 26 where they abut, so that none of these components protrude beyond the other components.

[0022] The second step 21 has a predetermined width or depth. The step 21 on the upper surface of the intermediate frame 6 corresponds to the material thickness of the upper part 4, and the step 21 on the lower surface of the intermediate frame 6 corresponds to the material thickness of the lower part 5. The edges of the upper part 4 and the lower part 5 rest entirely on the step 21, and additionally, the inner surfaces of the upper part 4 and the lower part 5 rest against the rear edges of the respective step 21. In this case, the rear edges are higher than the surfaces of the step 21 on which the edges of the upper part 4 and the lower part 5 rest. The edges of the upper part 4 and the lower part 5, like the step 21, extend around the entire outer periphery of the intermediate frame 6.

[0023] The upper part 4 and the lower part 5 each have at least one bevel 22 in the area of the seal 13, 14, 15. The bevel 22 contacts the seal near the outer periphery of the upper part 4 and the lower part 5. Therefore, the upper part 4 and the lower part 5 have an angle α with respect to the connecting area of the upper part 4 and the lower part 5 near the outer periphery of the upper part 4 and the lower part 5. This angle is particularly smaller than 90°, preferably smaller than 60°, and particularly preferably smaller than 30°. Similarly, the upper part 4 may have a bevel 22, and the lower part 5 has a recessed area 23 with respect to the connecting area of the lower part 5 near the outer periphery of the lower part 5. Both the bevel 22 and the recessed area 23 are abutted against the respective seal 13, 14, 15 in the screwed or assembled state. Thus, in each region, the seals 13, 14, 15 are held in a form-fitting manner between the intermediate frame 6 and the upper part 4 and between the intermediate frame 6 and the lower part 5, and are held in a preloaded manner by the inclined surfaces 22 and / or the concavely shaped regions 23.

[0024] By screwing the upper part 4 to the intermediate frame 6 and screwing the lower part 5 to the intermediate frame 6, the casing part or the upper part 4 and the lower part 5 are pressed against the intermediate frame 6 all around, thereby creating a sealing effect.

[0025] Furthermore, a third seal 20 is arranged between the upper part 4 and the third region 18 of the intermediate frame 6. The third seal 20 is formed as a flat seal. The third seal 20 seals the region between the upper part 4 and the intermediate frame 6 where the display 12 is arranged. This prevents water from entering the inside of the casing 3 from the display side. The third seal 20 extends around the inner periphery of the upper part 4.

[0026] Furthermore, a retaining metal sheet 24 is arranged on the intermediate frame 6, which fixes the upper part 4 in place. The retaining metal sheet 24 is arranged between the intermediate frame 6 and the upper part 4. In other words, the retaining metal sheet is arranged in the third region 18 of the intermediate frame. A third seal 20 is arranged between the upper part 4 and the retaining metal sheet 24. The retaining metal sheet 24 also serves to reinforce the intermediate frame 6 in the region of the third region 18 of the intermediate frame 6. Additionally, the retaining metal sheet 24 also serves to accommodate the membrane keyboard 7, so that the membrane keyboard 7 is fully supported at its outer periphery.

[0027] Additionally, a pressure compensation element 25 is arranged in the casing 3, in particular in the lower part 5. The pressure compensation element 25 serves to ensure that no positive or negative pressure can develop inside the casing 3 due to temperature fluctuations.

[0028] FIG. 3 shows a schematic diagram of the intermediate frame 6. The intermediate frame 6 has a first region 16 located on the outer periphery of the intermediate frame 6. Two steps 21 are arranged on the outer periphery of the intermediate frame 6, or two stepped cutouts 21 are arranged on the outer periphery, one stepped cutout 21 on the upper surface of the intermediate frame 6 and the other stepped cutout 21 on the lower surface of the intermediate frame 6. A second region 17, also having a stepped shape and connected to the first region, is also shown. A third region 18 is connected to the second region 17 and has a cutout 27 for the display 12. A further step is arranged around the cutout 27 for the display 12. This step serves as a receiving section 28 for the display 12. [Explanation of symbols]

[0029] 1 Weighing instrument 2 Display Unit 3 Casing 4 Upper part 5 Lower part 6 Intermediate Frame 7. Membrane Keyboard 8 Balance pan 9 Base, balance pan 10 Base, display unit 11 Cable 12 Display 13 Seal 14 First Seal 15 Second Seal 16 First Area 17 Second Area 18 The Third Region 19 Stopper, second area 20 Third Seal 21 Step / Step notch 22 Slope 23 Concave shaped area 24 Holding thin metal plate 25 Pressure Compensation Element 26 outer edge 27 Notch Display 28 Storage unit Display

Claims

1. A weighing instrument (1) having a balance pan (8), A display unit (2) is coupled to the meter (1), The display unit (2) has a casing (3) consisting of an upper part (4) and a lower part (5) and at least one display (12), An intermediate frame (6) is disposed between the upper part (4) and the lower part (5), The outer edge (26) of the intermediate frame (6) on which the upper part (4) and the lower part (5) are arranged is aligned flush with the upper part (4) and the lower part (5). A weighing instrument (1).

2. 2. A weighing machine (1) according to claim 1, characterized in that at least two stepped notches (21) are arranged on the outer periphery of the intermediate frame (6).

3. 3. The weighing machine (1) according to claim 2, characterized in that at least one stepped notch (21) is arranged on the upper surface of the intermediate frame (6) and on the lower surface of the intermediate frame (6).

4. 4. The weighing device (1) according to claim 2 or 3, characterized in that the stepped notch (21) has a depth that corresponds to the material thickness of the upper part (4) and / or the lower part (5).

5. 5. The weighing instrument (1) according to any one of claims 1 to 4, characterized in that the intermediate frame (6) has at least one cutout for the display (12).

6. 6. The weighing device (1) according to claim 1, wherein at least one seal (13, 14, 15) is arranged between the intermediate frame (6) and the upper part (4) and / or between the intermediate frame (6) and the lower part (5).

7. 7. The weighing device (1) according to claim 6, characterized in that the inner surface of the upper part (4) and / or the inner surface of the lower part (5) have at least one inclined surface (22) and / or at least one concavely shaped area (23) in the area of the seal (13, 14, 15), the inclined surface (22) and / or the concavely shaped area (23) at least partially contacting the seal (13, 14, 15).

8. 8. The weighing instrument (1) according to claim 6 or 7, characterized in that the intermediate frame (6) has at least one first area (16) for accommodating the upper part (4) and / or the lower part (5), a second area (17) for fixing at least one seal (13, 14, 15), and a third area (18) having an accommodating portion (28) for the display (12).

9. 9. The weighing machine (1) according to claim 8, characterized in that the second region (17) of the intermediate frame (6) has a stopper (19) against which at least one surface of the seal (13, 14, 15) abuts.

10. 10. The weighing vessel (1) according to claim 9, characterized in that the seal (13, 14, 15) is held in a form-fitting manner between the stopper (19) and the inner surface of the upper part (4) and / or between the stopper (19) and the inner surface of the lower part (5).

11. 9. The weighing device (1) according to claim 8, characterized in that at least one further seal (20) is arranged between the upper part (4) and the third region (18) of the intermediate frame (6).

12. 12. The weighing machine (1) according to claim 1, wherein the intermediate frame (6) is provided with a holding metal plate (24) for fixing the upper part (4) in place.

13. 13. A weighing device (1) according to claim 12, characterized in that a further seal (20) is arranged between the upper part (4) and the retaining metal sheet (24).

14. 14. The meter (1) according to any one of the preceding claims, characterized in that a pressure compensation element (25) is arranged in the casing (3).

15. 15. The weighing machine (1) according to any one of the preceding claims, characterized in that the intermediate frame (6) is made of an electrically conductive material.

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