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EP-4735850-A1 - WEIGHING PAN ASSEMBLY AND ELECTRONIC BALANCE

EP4735850A1EP 4735850 A1EP4735850 A1EP 4735850A1EP-4735850-A1

Abstract

Provided is a weighing pan assembly, which includes a weighing pan and a weighing pan support that are stacked, and further includes a clump weight arranged between the weighing pan and the weighing pan support in a replaceable manner, wherein the clump weight includes a notched portion and a non-notched portion that are located on the clump weight; and the weighing pan support includes an elastic limiting structure, wherein the notched portion is configured to accommodate the elastic limiting structure to limit the clump weight, and the non-notched portion is configured to squeeze the elastic limiting structure to allow the clump weight to be movable. The above weighing pan assembly can realize stable mounting of the clump weight, and may further cause the clump weight to feature being replaceable. An electronic balance including the above weighing pan assembly is further included.

Inventors

  • WANG, Heqiao
  • CHEN, XINGHONG
  • ZHANG, HUI
  • ZHOU, MI
  • YU, Yanqing

Assignees

  • Mettler-Toledo Instruments (Shanghai) Co., Ltd.

Dates

Publication Date
20260506
Application Date
20240228

Claims (18)

  1. A weighing pan assembly (30) , which comprises a weighing pan (301) and a weighing pan support (306) that are stacked, characterized in that the weighing pan assembly further comprises: a clump weight (302) arranged between the weighing pan (301) and the weighing pan support (306) and comprising a notched portion (3021) and a non-notched portion (3022) that are located on the clump weight; and the weighing pan support (306) comprises an elastic limiting structure (304) , wherein the notched portion (3021) is configured to accommodate the elastic limiting structure (304) to limit the clump weight (302) , and the non-notched portion (3022) is configured to squeeze the elastic limiting structure (304) to allow the clump weight (302) to be movable.
  2. The weighing pan assembly of claim 1, characterized in that the elastic limiting structure (304) comprises an elastic member (3041) and a limiting member (3042) connected to the elastic member (3041) .
  3. The weighing pan assembly of claim 2, characterized in that a bottom surface of the non-notched portion (3022) is configured to be capable of squeezing the limiting member (3042) to apply a pressure to the elastic member (3041) in an axial direction of the clump weight (302) .
  4. The weighing pan assembly of claim 2, characterized in that an outer side surface of the non-notched portion (3022) is configured to be capable of squeezing the limiting member (3042) to apply a pressure to the elastic member (3041) in a radial direction of the clump weight (302) .
  5. The weighing pan assembly of any one of claims 2-4, characterized in that the elastic member (3041) is an elastic cantilever beam.
  6. The weighing pan assembly of any one of claims 2-5, characterized in that the notched portion (3021) comprises an inlet channel (3029) and an internal chamber (3028) , and a maximum width of a cross section of the inlet channel (3029) is less than a minimum width of the limiting member (3042) , so that the limiting member (3042) is capable of engaging with the internal chamber (3028) via the inlet channel (3029) .
  7. The weighing pan assembly of any one of claims 1-6, characterized in that the notched portion (3021) comprises an arc-shaped surface that comes into contact with the limiting member (3042) .
  8. The weighing pan assembly of any one of claims 1-7, characterized in that the weighing pan support (306) further comprises a positioning structure (305) that is located above the clump weight (302) supported on the weighing pan support (306) and is configured to fix the clump weight (302) together with a bottom surface of the weighing pan support (306) .
  9. The weighing pan assembly of claim 8, characterized in that the positioning structure (305) has a shape complementary to that of the notched portion (3021) , or a cross-sectional area of the positioning structure (305) is less than a notch cross-sectional area of the notched portion (3021) .
  10. The weighing pan assembly of claim 9, characterized in that the positioning structure (305) is arranged on a path of mounting the clump weight (302) to the weighing pan support (306) , and designed to guide the mounting of the clump weight (302) by cooperation between the positioning structure (305) and the notched portion (3021) during the mounting.
  11. The weighing pan assembly of any one of claims 1-10, characterized in that the weighing pan support (306) further comprises a fixing structure (307) , and the fixing structure (307) is configured to apply a pre-tightening force to the weighing pan (301) to keep the weighing pan (301) and the weighing pan support (306) in a relatively stable state.
  12. The weighing pan assembly of claim 11, characterized in that the fixing structure (307) applies a radial pre-tightening force to a circumferential side surface (3013) of the weighing pan (301) .
  13. The weighing pan assembly of claim 11, characterized in that the weighing pan (301) comprises a horizontal disc surface (3012) , the circumferential side surface (3013) , and an inclined side surface (3014) , the circumferential side surface (3013) is connected to the horizontal disc surface (3012) by the inclined side surface (3014) , and the fixing structure (307) applies a pre-tightening force to the inclined side surface (3014) .
  14. The weighing pan assembly of claim 11, characterized in that the fixing structure (307) comprises an elastic portion (3071) and a limiting portion (3072) , and the limiting portion (3072) comprises a cambered surface for matching a surface of the weighing pan (301) .
  15. The weighing pan assembly of claim 14, characterized in that the elastic portion (3071) is a cantilever beam, and the limiting portion (3072) is a limiting bead.
  16. The weighing pan assembly of claim 14, characterized in that the weighing pan (301) further comprises a groove (3011) with which the limiting portion (3072) engages to limit the movement of the weighing pan (301) .
  17. The weighing pan assembly of any one of claims 1-16, characterized in that the weighing pan assembly comprises a batch of clump weights with different shapes and/or thicknesses and/or materials, and any one of the clump weights is arranged between the weighing pan (301) and the weighing pan support (306) in a replaceable manner.
  18. An electronic balance, which comprises an air shield system (10) and a balance shell (20) , characterized in that the electronic balance further comprises a weighing pan assembly (30) according to any one of claims 1 to 17.

Description

WEIGHING PAN ASSEMBLY AND ELECTRONIC BALANCE BACKGROUND OF THE INVENTION Technical Field The present invention relates to the field of weighing, and in particular, to the field of electronic balances. Background Art An electronic balance includes an air shield system, a balance shell, and a weighing pan system. Different balance sensors require weighing pans and weighing pan supports that have different weights. Usually, a specific balance sensor needs a specific weighing pan and weighing pan support structure. Weighing pan supports and weighing pans of state-of-the-art balances are fixed by pasting glue, wherein some balances further meet weighing requirements of balance sensors by pasting balance weights. The above method has various drawbacks. For example, there is a proneness to disconnection of elements fixed to each other by use of an adhesive due to chemical decomposition, so that there is insufficient reliability. Further, there is need for a special tooling fixture when using an adhesive process, which leads to low production efficiency and also increases labor costs. Finally, a weighing pan and a weighing pan support can only adapt to one type of balance sensor if an adhesive process is used, and hence are not universal and inconvenient to use, resulting also in a waste. SUMMARY An objective of the present invention is to provide a weighing pan assembly in which a clump weight can be mounted in a reliable and stable manner, wherein the clump weight is replaceable nevertheless. To achieve the above objective, the weighing pan assembly includes a weighing pan and a weighing pan support that are stacked, and further includes a clump weight arranged between the weighing pan and the weighing pan support in a replaceable manner, wherein the clump weight includes a notched portion and a non-notched portion that are located on the clump weight; and the weighing pan support includes an elastic limiting structure, wherein the notched portion is configured to engage with the elastic limiting  structure to limit the clump weight, and the non-notched portion is configured to squeeze the elastic limiting structure to allow the clump weight to be movable. In one or more embodiments, the elastic limiting structure includes an elastic member and a limiting member connected to the elastic member. In one or more embodiments, a bottom surface of the non-notched portion is configured to be capable of squeezing the limiting member to apply a pressure to the elastic member in an axial direction of the clump weight. In one or more embodiments, an outer side surface of the non-notched portion is configured to be capable of squeezing the limiting member to apply a pressure to the elastic member in a radial direction of the clump weight. In one or more embodiments, the elastic member is an elastic cantilever beam. In one or more embodiments, the notched portion includes an inlet channel and an internal chamber, and a maximum width of a cross section of the inlet channel is slightly less than a minimum width of the limiting member, so that the limiting member is capable of engaging with the internal chamber via the inlet channel. In one or more embodiments, the notched portion includes an arc-shaped surface that comes into contact with the limiting member. In one or more embodiments, the weighing pan support further includes a positioning structure that is located above the clump weight supported on the weighing pan support and is configured to fix the clump weight together with a bottom surface of the weighing pan support. In one or more embodiments, the positioning structure has a shape complementary to that of the notched portion, or a cross-sectional area of the positioning structure is less than a notch cross-sectional area of the notched portion. In one or more embodiments, the positioning structure is arranged on a path of mounting the clump weight to the weighing pan support, and designed to guide the mounting of the clump weight by cooperation between the positioning structure and the notched portion during the mounting. In one or more embodiments, the weighing pan support further includes a fixing structure, and the fixing structure is configured to apply a pre-tightening force to the weighing pan to keep the weighing pan and the weighing pan support in a relatively stable state. In one or more embodiments, the fixing structure applies a radial pre-tightening force to a circumferential side surface of the weighing pan. In one or more embodiments, the weighing pan includes a horizontal disc surface, the circumferential side surface, and an inclined side surface, the circumferential side surface is connected to the horizontal disc surface by the inclined side surface, and the fixing structure applies a pre-tightening force to the inclined side surface. In one or more embodiments, the fixing structure includes an elastic portion and a limiting portion, and the limiting portion includes a cambered surface for