Load cell with transport drop-proof mechanism and electronic balance equipped with same

Abstract

The present invention provides a load cell with a mechanism for preventing drops during transportation, and an electronic balance equipped with the load cell. The load cell includes a base, a core shaft, an elastic body, a sleeve, a limit pin, a weighing pan support, and a weighing pan connector. The base includes a mounting recess, the weighing pan support includes a through hole, and the sleeve extends into the mounting recess through the through hole. The core shaft is disposed so as to penetrate the sleeve, the elastic body is attached between the core shaft and the sleeve, the weighing pan connector is attached to an end portion of the core shaft, the limit pin is attached to the end of the core shaft and is disposed outside the sleeve, the end of the sleeve includes a plurality of limit notches, and a limit baffle is provided on the inner wall surface of the mounting recess. According to the present invention, the load cell can be switched between a non-transport protection state, an overload protection state, and a transport protection state, thereby improving drop impact resistance during transportation. The force applied to a delicate part is controlled by the amount of compression of the elastic body so as not to exceed the yield strength of the delicate part.

Description

[Technical Field]

[0001] The present invention relates to the field of load cells, and more particularly to a load cell having a mechanism for preventing dropping during transportation, and an electronic balance equipped with such a load cell. [Background technology]

[0002]

[0002] Existing electronic balances, particularly high-precision electronic balances using electromagnetic force balance load cells, can easily be damaged by dropping or impact during transportation. The scale or electronic balance can be damaged not only during transportation from the manufacturer to the purchaser, but also by accidentally dropping it during transportation and cleaning within the user's facility.

[0003]

[0003] Furthermore, if the electronic balance is accidentally dropped during operation, or if an unbalanced or excessive load is applied to the weighing pan of the electronic balance that exceeds its operating capacity, this can result in damage to the load cell and its function.

[0004]

[0004] In patent document CN202123259807U, a suction assembly is provided to suck the electronic balance onto the platform to avoid damage caused by collision or dropping, but this method does not work during transportation.

[0005]

[0005] In patent document CN200720071516U, a Z-shaped plate is pressed with screws to prevent damage to the load cell during transportation. The load cell in this patent is a strain gauge load cell. Because the structure and operating principle are different from those of an electromagnetic force balance load cell, the method of pressing the Z-shaped plate with screws may damage the fragile and sensitive parts of the load cell (flexible joints). This method is not suitable for an electromagnetic force balance load cell and requires additional fasteners and parts such as a Z-shaped plate.

[0006]

[0006] In patent document CN207798246U, a load cell assembly is provided with a floating overload protection structure that can disengage when subjected to an impact when placed upside down, thereby reducing the impact on the load cell, but cannot reduce the impact when placed upside down.

[0007]

[0007] Therefore, there is a need to improve the shock resistance of high precision electronic balances that use electromagnetic force balance load cells to avoid damage when the electronic balance is dropped during transportation or is overloaded.

[0008]

[0008] In order to overcome the above technical problems, the inventor of the present application has designed a load cell having a mechanism for preventing dropping during transportation and an electronic balance equipped with the load cell. Summary of the Invention

[0009]

[0009] The technical problem solved by the present invention is to provide a load cell having a drop-resistant mechanism during transportation, and an electronic balance equipped with the load cell, in order to overcome the drawback of the prior art that the load cell is susceptible to impact and damage.

[0010]

[0010] The present invention solves the above technical problems by a load cell having a mechanism for preventing dropping during transportation, which comprises a base, a core shaft, an elastic body, a sleeve, a limit pin, a weighing pan support, and a weighing pan connector, wherein the base comprises a mounting recess, the weighing pan support has a through hole, the sleeve extends into the mounting recess through the through hole, the core shaft is arranged to penetrate into the sleeve, the elastic body is attached between the core shaft and the sleeve, the weighing pan connector is attached to an end portion of the core shaft, the limit pin is attached to the end of the core shaft and is arranged outside the sleeve, and the end of the sleeve has a plurality of limit notches, and the load cell is characterized in that a limit baffle is provided on the inner wall surface of the mounting recess to limit the position of the upward movement of the limit pin, and the load cell can be switched between a non-transport protection state, an overload protection state, and a transport protection state by the engagement between the limit pin, the corresponding limit notch, and the limit baffle.

[0011]

[0011] The load cell has a moving part having a predetermined position, and when the weighing pan connector is subjected to a downward force that exceeds the pre-compression force of the elastic body, the load cell enters an overload protection state, the limit pin moves downward, disengages from the corresponding limit notch, and contacts the base, and the base is subjected to a load that exceeds the compression force of the elastic body, resulting in the position of the moving part of the load cell being fixed.

[0012]

[0012] When the load cell is in a transport protection state, the limit pin contacts the limit baffle to limit the position of the limit pin so that it can enter the corresponding limit notch, and the elastic body applies a fixed load to the moving part of the load cell to fix the position of the moving part.

[0013] According to an embodiment of the present invention, the moving part comprises delicate parts such as a lever 110, an upper connection joint 140, a lower connection joint 150, and a flexible joint 160.

[0014]

[0014] According to an embodiment of the present invention, the limit baffle extends horizontally outward along the inner wall surface and is positioned above the limit pin.

[0015] According to an embodiment of the present invention, the limit notch is a U-shaped notch.

[0015]

[0016] According to an embodiment of the invention, the end of the sleeve is provided with four symmetrically distributed U-shaped notches.

[0017] According to an embodiment of the present invention, the U-shaped notches include at least a pair of first U-shaped notches and at least a pair of second U-shaped notches arranged opposite each other, and when the movable part of the load cell can move, the limit pin is arranged in the first U-shaped notch and has a certain distance from the base, and when the load cell is in a transport protection state, the limit pin is arranged in the second U-shaped notch and has a certain distance from the bottom of the second U-shaped notch.

[0016]

[0018] According to an embodiment of the present invention, a first rotation baffle is further provided on the inner wall surface of the mounting recess to limit the rotation angle of the core shaft when the load cell is switched from the overload protection state to the transportation protection state.

[0017]

[0019] According to an embodiment of the present invention, a second rotation baffle is further provided on the inner wall surface of the mounting recess to limit the rotation angle of the core shaft when the load cell is switched from the transport protection state to the non-transport protection state.

[0018]

[0020] According to an embodiment of the present invention, the first rotating baffle and the second rotating baffle are connected vertically below the limit baffle.

[0021] The present invention further provides a load cell having a mechanism for preventing drops during transportation, the load cell comprising a base, a core shaft, an elastic body, a sleeve, and a weighing pan support portion, the base comprising a mounting recess, the weighing pan support portion comprising a through hole, the sleeve extending through the through hole into the mounting recess, the core shaft being arranged to pass through the sleeve, the elastic body being attached between the core shaft and the sleeve, the axial end of the core shaft comprising a male-threaded connecting member, the bottom of the mounting recess comprising a female-threaded hole, the core shaft being fixedly connected to the base by fitting between the male-threaded connecting member and the female-threaded hole, and the elastic body applying a fixed load to the moving portion of the load cell to fix the position of the moving portion.

[0019]

[0022] The present invention further provides an electronic balance comprising a load cell having the above-described mechanism for preventing a drop during transportation.

[0023] The present invention has an advantage that the structure for improving the impact resistance of the electromagnetic force balance load cell is designed to allow the load cell to be switched between a non-transport protection state, an overload protection state, and a transport protection state, and a load exceeding the compressive force of the elastic body can be directly transmitted to the base, thereby protecting delicate parts from collision impact.

[0020]

[0024] By using such a structure, the force applied to the delicate parts is controlled by the amount of compression of the elastic body and does not exceed the yield strength of the delicate parts, thereby improving drop impact resistance during transportation and in the event of overload.

[0021]

[0025] The above and other features, characteristics, and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, in which like features are always designated by the same reference numerals. [Brief explanation of the drawings]

[0022] [Figure 1A] 1 is a schematic diagram showing an electronic balance equipped with a load cell according to the present invention. [Figure 1B]1 is a perspective view of a load cell having a transport drop resistance mechanism according to the present invention; [Figure 2] 1 is a schematic structural diagram of a first embodiment of a load cell having a mechanism for preventing dropping during transportation according to the present invention; [Figure 3] FIG. 3 is an enlarged view of part A in FIG. 2. [Figure 4] 1 is a schematic diagram showing the internal structure of a first embodiment of a load cell with a transport drop protection mechanism according to the present invention when in an unprotected transport state; FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along line BB in FIG. [Figure 6] 5 is a schematic view taken along direction C in FIG. 4. FIG. [Figure 7] 1 is a schematic view showing the internal structure of a mounting recess in a first embodiment of a load cell having a mechanism for resistant to drops during transportation according to the present invention. FIG. [Figure 8] FIG. 8 is a schematic plan view of part D in FIG. 7. [Figure 9] FIG. 9 is a cross-sectional view taken along line EE in FIG. 8. [Figure 10] 1 is a schematic diagram showing the assembly of the core shaft, sleeve, and limit pin of the first embodiment of the load cell with a transport drop-resistant mechanism according to the present invention when in a non-transport protected state; FIG. [Figure 11] FIG. 11 is an enlarged view of part F in FIG. [Figure 12] 1 is a schematic diagram illustrating the principle of a first embodiment of a load cell with a transport drop protection mechanism according to the present invention when in a non-transport protected state; [Figure 13] 1 is a schematic diagram showing the internal structure of a first embodiment of a load cell having a transport drop resistance mechanism according to the present invention when in an overload protection state; FIG. [Figure 14] FIG. 14 is a cross-sectional view taken along line GG in FIG. [Figure 15] 14 is a schematic view taken along direction H of FIG. 13. FIG. [Figure 16]1 is a schematic diagram showing the assembly of the core shaft, sleeve, and limit pin of the first embodiment of the load cell with a transport drop-proof mechanism according to the present invention when in an overload protection state; FIG. [Figure 17] FIG. 17 is an enlarged view of part I in FIG. [Figure 18] 1 is a schematic diagram illustrating the principle of a first embodiment of a load cell having a mechanism for preventing drops during transportation according to the present invention when in an overload protection state; FIG. [Figure 19] 1 is a schematic diagram showing the assembly of the core shaft, sleeve, and limit pin of the first embodiment of the load cell with a transport drop protection mechanism according to the present invention when switched from an overload protection state to a transport protection state; FIG. [Figure 20] FIG. 20 is an enlarged view of part J in FIG. 19. [Figure 21] 1 is a schematic diagram showing the internal structure of a first embodiment of a load cell with a transport drop protection mechanism according to the present invention when in a transport protection state; [Figure 22] FIG. 22 is a cross-sectional view taken along line KK in FIG. 21. [Figure 23] 22 is a schematic view taken along the direction L of FIG. 21. FIG. [Figure 24] 1 is a schematic diagram showing the assembly of the core shaft, sleeve, and limit pin of the first embodiment of the load cell with a transport drop-proof mechanism according to the present invention when in a transport protection state; FIG. [Figure 25] FIG. 25 is an enlarged view of part M in FIG. 24. [Figure 26] 1 is a schematic diagram illustrating the principle of a first embodiment of a load cell with a transport drop protection mechanism according to the present invention when in a transport protection state; [Figure 27] 1 is a schematic diagram illustrating the principle of a second embodiment of a load cell having a mechanism for preventing dropping during transportation according to the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0023]

[0026] To make the above objects, features, and advantages of the present invention more apparent and easier to understand, specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

[0027] DETAILED DESCRIPTION OF THE INVENTION

[0013] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. The same reference numbers used throughout the accompanying drawings refer to the same or like parts wherever possible.

[0024]

[0028] Furthermore, the terms used in the present invention are selected from well-known general terms, but some of the terms mentioned in the description of the present invention may be selected by the applicant at the applicant's discretion, and their detailed meanings will be explained in the relevant sections described in this specification.

[0025]

[0029] Furthermore, the present invention should be understood not only by the actual terms used, but also by the meaning encompassed by each term.

[0030] 1A to 12, the first embodiment of the present invention discloses a load cell 1 with a mechanism for preventing dropping during transportation, which includes a base 10, a core shaft 20, an elastic body 30, a sleeve 40, a limit pin 50, a weighing pan support part 60, and a weighing pan connector 170. The load cell 1 further includes a lever limit notch 100, a lever 110, a parallel guide sheet 120, a lifting protrusion 130, an upper connection joint 140, a lower connection joint 150, and a flexible joint 160.

[0026]

[0031] The base 10 shown in FIG. 5 has a mounting recess 11, a weighing dish support portion 60 has a through hole 61, and the sleeve 40 extends through the through hole 61 into the mounting recess 11. The core shaft 20 is disposed so as to penetrate into the sleeve 40, an elastic body 30 (preferably a spring) is attached between the core shaft 20 and the sleeve 40, and a weighing dish connector 170 is attached to the upper end of the core shaft 20. The limit pin 50 is attached to the end of the core shaft 20 and is disposed outside the sleeve 40, and the end of the sleeve 40 has a plurality of limit notches 41. The limit baffle 12 is provided on the inner wall surface of the mounting recess 11 to limit the position of the upward movement of the limit pin 50.

[0027]

[0032] When the weighing pan connector 170 is subjected to a downward force that exceeds the pre-compression force of the elastic body 30, the load cell 1 enters an overload protection state, the limit pin 50 moves downward, disengages from the corresponding limit notch 41, and contacts the base 10, and the base 10 is subjected to a load that exceeds the compression force of the elastic body 30, resulting in the position of the moving part of the load cell 1 being fixed.

[0028]

[0033] When the load cell (1) is in a transport protection state, the limit pin 50 contacts the limit baffle 12 to limit the position of the limit pin 50 so that the limit pin 50 can enter the corresponding limit notch 41, and the elastic body 30 applies a fixed load to the moving part of the load cell 1 to fix the position of the moving part.

[0029]

[0034] The moving part includes delicate parts such as a lever 110, an upper connection joint 140, a lower connection joint 150, and a flexible joint 160, and the weighing pan support part 60 sequentially drives the lower connection joint 150, the upper connection joint 140, the lower connection joint 150, the flexible joint 160, and the lever 110 to rotate the lever 110 and press it against the top of the lever limit notch 100.

[0030]

[0035] The limit notches 41 may preferably be U-shaped notches. For example, the end of the sleeve 40 may preferably be provided with four symmetrically distributed U-shaped notches.

[0031]

[0036] The load cell 1 is switched among a non-transportation protection state, an overload protection state, and a transportation protection state by the engagement between the limit pin 50, the corresponding limit notch 41, and the limit baffle 12. The non-transportation protection state refers to a state in which the moving part of the load cell 1 is not fixed and the load cell 1 is not being transported. The overload protection state refers to a state in which, when the load received by the weighing pan connector 170 of the load cell 1 exceeds the pre-compression force of the elastic body 30, the overload protection structure (including the core shaft 20, elastic body 30, sleeve 40, limit pin 50, etc.) is activated and transmits a load exceeding the compressive force of the elastic body 30 to the base 10. The transportation protection state refers to a state in which, during transportation of the load cell 1, the load on the weighing pan connector 170 is removed and the transportation protection structure (including the core shaft 20, elastic body 30, sleeve 40, limit pin 50, etc.) applies a fixed load to the moving part by controlling the compression amount of the elastic body (e.g., a spring), thereby fixing the position of the moving part.

[0032]

[0037] For example, as shown in FIG. 11, the U-shaped notches may preferably include at least a pair of first U-shaped notches 411 and at least a pair of second U-shaped notches 412 arranged opposite each other.

[0033]

[0038] When the moving part of the load cell 1 can move, the limit pin 50 is disposed in the first U-shaped notch 411 and has a certain distance from the base 10. When the load cell 1 is in the transport protection state, the limit pin 50 is disposed in the second U-shaped notch 412 and has a certain distance from the bottom of the second U-shaped notch 412.

[0034]

[0039] Furthermore, the limit baffle 12 extends horizontally outward along the inner wall surface of the mounting recess 11 and is disposed above the limit pin 50 .

[0040] Furthermore, a first rotation baffle 13 is further provided on the inner wall surface of the mounting recess 11 to limit the rotation angle of the core shaft 20 when the load cell 1 is switched from the overload protection state to the transportation protection state.

[0035]

[0041] In addition, more preferably, a second rotation baffle 14 is further provided on the inner wall surface of the mounting recess 11 to limit the rotation angle of the core shaft 20 when the load cell 1 is switched from the transport protection state to the non-transport protection state.

[0036]

[0042] Preferably, the first rotating baffle 13 and the second rotating baffle 14 are connected vertically below the limit baffle 12 .

[0043] 4 to 12, the load cell 1 having a transport drop-proof mechanism is in a non-transport protection state (hereinafter referred to as State 1). In the electromagnetic force balance load cell mechanism in State 1, the lever 110 has a degree of rotational freedom, and the lever 110 can rotate within the limited range of the lever limit notch 100.

[0037]

[0044] Therefore, the lifting lug 130, the weighing pan support 60, the elastic body 30, the core shaft 20, the sleeve 40, and the weighing pan connector 170 are all movable within a certain range. If the load cell 1 is in this state during transportation, the movable parts will move and collide with the lever limit notch 100, generating an impact load. Sensitive parts such as the upper connection joint 140, the lower connection joint 150, and the flexible joint 160 will deform or break if the impact load exceeds their yield strength, thus affecting the performance of the load cell 1 or rendering the load cell completely inoperable.

[0038]

[0045] In state 1, the limit pin 50 is pressed upward against the sleeve 40, which has a first U-shaped notch 411, and in this state the limit pin 50 is located within the first U-shaped notch 411 to limit the rotation of the limit pin 50 and the core shaft 20. There is no contact between the limit pin 50 and the base 10.

[0039]

[0046] As shown in Figures 13 to 18, the load cell 1 with a transport drop-proof mechanism is in a state where the overload protection state is activated (hereinafter referred to as State 2). The operating principle of the overload protection mechanism is as follows: The sleeve 40 and the core shaft 20 form a sliding pair. The upper end of the core shaft 20 is firmly connected to the weighing pan connector 170 to receive the gravity of the object to be weighed on the electronic balance 2. The lower end of the core shaft 20 is firmly connected to the limit pin 50. The elastic body 30 has an upper end that contacts the core shaft 20 and a lower end that contacts the sleeve 40, and the elastic body has a pre-compression force. When the downward load on the weighing pan connector 170 exceeds the pre-compression force of the elastic body 30, the weighing pan connector 170, the core shaft 20, and the limit pin 50 move downward until the limit pin 50 contacts the base 10 of the load cell 1. In this case, a load exceeding the compressive force of the elastic body (30) is transmitted directly to the base 10, thereby protecting delicate parts such as the upper connection joint 140, the lower connection joint 150, and the flexible joint 160.

[0040]

[0047] In State 2, the weighing pan connector 170 is subjected to a downward force that exceeds the pre-compression force of the elastic body, and the core shaft 20 and limit pin 50 move downward. The limit pin 50 disengages from the first U-shaped notch 411 of the sleeve 40, contacts the base 10, and is subjected to a load that exceeds the compression force of the elastic body 30. In Figure 16, "I" indicates the position of the limit pin 50 relative to the first U-shaped notch 411 of the sleeve 40.

[0041]

[0048] 19 to 26, the load cell 1 with a transport drop-proof mechanism is in a transport protection state (hereinafter referred to as state 3). In state 2, after the limit pin 50 is rotated a certain angle (in FIGS. 19 and 20, a 90-degree rotation is shown), the load on the weighing pan connector 170 is removed, resulting in state 3 in FIG.

[0042]

[0049] That is, this state is achieved by rotating the core shaft 20 and limit pin 50 through a specific angle (90 degrees as shown) after the limit pin 50 has disengaged from the first U-shaped notch 411 of the sleeve 40 in state 2.

[0043]

[0050] In this case, the upper end of the limit pin 50 contacts the limit baffle 12, limiting the upward movement of the weighing pan connector 170, core shaft 20, and limit pin 50, and exerting a downward force on the weighing pan connector 170. This force is transmitted through the mechanism, rotating the lever 110 and pressing against the upper end of the lever limit notch 100.

[0044]

[0051] In contrast to State 1, in State 3, the lifting protrusion 130, the weighing pan support 60, the elastic body 30, the core shaft 20, the sleeve 40, and the weighing pan connector 170 do not move freely, thus avoiding collision shock. This can improve drop shock resistance during transportation. In addition, the force applied to delicate parts such as the upper connection joint 140, the lower connection joint 150, and the flexible joint 160 is controlled by the compression amount of the elastic body and does not exceed their yield strength.

[0045]

[0052] 19 and 20, after the load on the weighing pan connector 170 is removed, State 3, i.e., the transport protection state, shown in FIGS. 21 to 26 is obtained. The limit pin 50 contacts the limit baffle 12 of the base 10, restricting the limit pin 50 from moving upward. The limit pin 50 is located within the second U-shaped notch 412 of the sleeve 40, and the upper end of the limit pin 50 does not contact the second U-shaped notch 412. As a result, the limit pin 50 and the core shaft 20 are restricted from rotating only left and right. "M" in FIG. 24 indicates the position of the limit pin 50 relative to the second U-shaped notch 412 of the sleeve 40.

[0046]

[0053] The base 10 is provided with a first rotation baffle 13 to limit the rotation angle of the core shaft 20 when the load cell 1 is switched from state 2 to state 3, thereby ensuring that the limit pin 50 moves to the second U-shaped notch 412 of the sleeve 40 after the load on the weighing pan connector 170 is removed. Similarly, the base 10 is provided with a second rotation baffle 14 to ensure that the limit pin 50 moves to the first U-shaped notch 411 after the core shaft 20 is rotated when the load cell 1 is switched from state 3 to state 1.

[0047]

[0054] During transportation, switching the load cell 1 of the electronic balance 2 to state 3 can effectively improve drop impact resistance and ensure that the load cell 1 is less likely to be damaged during transportation. After transportation, the load cell 1 is switched to state 1, allowing the electronic balance 2 and load cell 1 to operate normally. In addition, in the event of weighing an overload, the load cell 1 is switched to state 2 to enter an overload protection state.

[0048]

[0055] 27, the second embodiment of the present invention further provides a load cell 1 having a mechanism for preventing a drop during transportation, and the load cell 1 includes a base 10, a core shaft 20, an elastic body 30, a sleeve 40, a weighing pan support portion 60, and a weighing pan connector 170. The base 10 includes a mounting recess 11, the weighing pan support portion 60 includes a through-hole 61, and the sleeve 40 extends into the mounting recess 11 through the through-hole 61.

[0049]

[0056] The core shaft 20 is disposed so as to pass through the sleeve 40, the elastic body 30 is attached between the core shaft 20 and the sleeve 40, the axial end of the core shaft 20 is provided with a male-threaded connecting member 70, and the bottom of the mounting recess 11 is provided with a female-threaded hole 80. The core shaft 20 is fixedly connected to the base 10 by the engagement between the male-threaded connecting member 70 and the female-threaded hole 80, and the elastic body 30 applies a fixed load to the moving part of the load cell 1 to fix the position of the moving part. This load cell 1 is in a transport protected state.

[0050]

[0057] In the load cell 1 with a transport drop-resistant mechanism, the axial end of the core shaft 20 further includes a male-threaded connecting member 70, and the base 10 further includes a female-threaded hole 80. During transport, the male-threaded connecting member 70 can be screwed into the female-threaded hole 80. The screw can be self-locking and will not automatically disengage after being screwed in, thereby securing the lifting protrusion 130, the weighing pan support 60, the elastic body 30, the core shaft 20, the sleeve 40, and the weighing pan connector 170 and providing protection during transport. Furthermore, the compression amount of the elastic body can be adjusted by controlling the screw-in depth, thereby achieving the advantage of selecting different compression forces to suit various transport conditions.

[0051]

[0058] Furthermore, the present invention further provides an electronic balance 2 including a load cell 1 having the above-described mechanism for preventing a drop during transportation.

[0059] According to the above structure description, the load cell 1 with transport drop-proof mechanism according to the present invention has the following improvements: I. The overload protection structure and transport protection structure of the load cell 1 are combined with each other. II. The elastic body 30 exerts a compressive force on the moving part that is below the overload force of the weighing system and is ensured by the elastic body 30, so that this force is controllable and does not damage sensitive components. III. The elastic body 30 and screw structure allow the force to be adjusted to suit various transport environments.

[0052]

[0060] In conclusion, in the load cell 1 having a mechanism for preventing drops during transportation and the electronic balance 2 equipped with the load cell 1 according to the present invention, the structure for improving the impact resistance of the electromagnetic force balance load cell 1 is designed so that the load cell 1 can be switched between a non-transport protection state, an overload protection state, and a transport protection state, and a load exceeding the compressive force of the elastic body 30 can be transmitted directly to the base, thereby protecting delicate parts from collision impacts.

[0053]

[0061] This structure improves resistance to drop impacts during transportation, and the force applied to the delicate parts is controlled by the amount of compression of the elastic body, which does not exceed the yield strength of the delicate parts.

[0054]

[0062] Although specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely examples, and the protective scope of the present invention is defined by the appended claims. Various changes or modifications may be made to these embodiments by those skilled in the art without departing from the principles and essence of the present invention. However, all such changes and modifications fall within the protective scope of the present invention. [Explanation of symbols]

[0055] 1 load cell 2 Electronic balance 10 base 11 Mounting recess 12 Limit Baffle 13 First rotating baffle 14 Second rotating baffle 20 Core shaft 30 Elastic Body 40 sleeve 41 Limit Notch 50 limit pin 60 Weighing pan support 61 through hole 70 Male threaded connector 80 female threaded hole 100 Lever limit notch 110 Lever 120 Parallel guide sheet 130 Lifting protrusion 140 Upper connecting joint 150 Lower connecting joint 160 Flexible Joint 170 Weighing pan connector 411 First U-shaped notch 412 Second U-shaped notch

Claims

1. A load cell (1) having a mechanism for preventing a drop during transportation, comprising a base (10), a core shaft (20), an elastic body (30), a sleeve (40), a limit pin (50), a weighing pan support portion (60), and a weighing pan connector (170), wherein the base (10) has a mounting recess (11), the weighing pan support portion (60) has a through hole (61), and the sleeve (40) extends through the through hole (61) into the mounting recess (11); The core shaft (20) is disposed so as to penetrate into the sleeve (40), the elastic body (30) is attached between the core shaft (20) and the sleeve (40), the weighing dish connector (170) is attached to an end portion of the core shaft (20), the limit pin (50) is attached to an end of the core shaft (20) and is disposed outside the sleeve (40), and the end of the sleeve (40) is provided with a plurality of limit notches (41), a limit baffle (12) is provided on the inner wall surface of the mounting recess (11) to limit the position of the upward movement of the limit pin (50); The load cell (1) has a transport drop-resistant mechanism that can be switched between a non-transport protection state, an overload protection state, and a transport protection state by fitting the limit pin (50), the corresponding limit notch (41), and the limit baffle (12).

2. A load cell (1) having a transport drop resistance mechanism according to claim 1, The load cell (1) has a moving part having a predetermined position, and when the weighing pan connector (170) receives a downward force exceeding the pre-compression force of the elastic body (30), the load cell (1) enters an overload protection state, the limit pin (50) moves downward, disengages from the corresponding limit notch (41), and contacts the base (10), and the base (10) receives a load exceeding the compression force of the elastic body (30), resulting in the position of the moving part of the load cell (1) being fixed.

3. A load cell (1) having a transport drop resistance mechanism according to claim 1, A load cell (1) having a mechanism for preventing drops during transportation, characterized in that when the load cell is in a transport protection state, the limit pin (50) comes into contact with the limit baffle (12) to limit the position of the limit pin (50) so that the limit pin (50) can enter the corresponding limit notch (41), and the elastic body (30) applies a fixed load to the moving part of the load cell (1) to fix the position of the moving part.

4. A load cell (1) having a transport drop resistance mechanism according to claim 2, The load cell (1) has a mechanism for preventing dropping during transportation, characterized in that the moving part comprises delicate parts such as a lever (110), an upper connection joint (140), a lower connection joint (150), and a flexible joint (160).

5. A load cell (1) having a transport drop resistance mechanism according to claim 1, The limit baffle (12) extends horizontally outward along the inner wall surface of the mounting recess (11) and is positioned above the limit pin (50).

6. A load cell (1) having a transport drop resistance mechanism according to claim 1, A load cell (1) having a mechanism for preventing a drop during transportation, characterized in that the limit notch (41) is a U-shaped notch.

7. A load cell (1) having a transport drop resistance mechanism according to claim 6, A load cell (1) with a mechanism for preventing drops during transportation, characterized in that the end of the sleeve (40) is provided with four symmetrically distributed U-shaped notches.

8. A load cell (1) having a transport drop resistance mechanism according to claim 7, The U-shaped notches include at least a pair of first U-shaped notches (411) and at least a pair of second U-shaped notches (412) arranged opposite each other; A load cell (1) having a mechanism for preventing drops during transportation, characterized in that when the moving part of the load cell (1) can move, the limit pin (50) is arranged in the first U-shaped notch (411) and has a certain distance from the base (10), and when the load cell is in a transport protection state, the limit pin (50) is arranged in the second U-shaped notch (412) and has a certain distance from the bottom of the second U-shaped notch (412).

9. A load cell (1) having a transport drop resistance mechanism according to claim 1, A load cell (1) having a mechanism for preventing drops during transportation, characterized in that a first rotation baffle (13) is further provided on the inner wall surface of the mounting recess (11) to limit the rotation angle of the core shaft (20) when the load cell (1) is switched from the overload protection state to the transportation protection state.

10. A load cell (1) having a transport drop resistance mechanism according to claim 9, A load cell (1) having a mechanism for preventing drops during transportation, characterized in that a second rotation baffle (14) is further provided on the inner wall surface of the mounting recess (11) to limit the rotation angle of the core shaft (20) when the load cell (1) is switched from the transport protection state to the non-transport protection state.

11. A load cell (1) having a transport drop resistance mechanism according to claim 10, A load cell (1) having a mechanism for preventing a drop during transportation, characterized in that the first rotating baffle (13) and the second rotating baffle (14) are connected vertically below the limit baffle (12).

12. A load cell (1) having a mechanism for preventing a drop during transportation, the load cell (1) comprising a base (10), a core shaft (20), an elastic body (30), a sleeve (40), and a weighing dish support portion (60), the base (10) comprising an attachment recess (11), the weighing dish support portion (60) comprising a through hole (61), the sleeve (40) extending through the through hole (61) into the attachment recess (11), The core shaft (20) is disposed so as to penetrate into the sleeve (40), the elastic body (30) is attached between the core shaft (20) and the sleeve (40), the axial end of the core shaft (20) is provided with a male threaded connecting member (70), and the bottom of the mounting recess (11) is provided with a female threaded hole (80), A load cell (1) having a mechanism for preventing drops during transportation, characterized in that the core shaft (20) is fixedly connected to the base (10) by fitting between the male-threaded connecting member (70) and the female-threaded hole (80), and the elastic body (30) applies a fixed load to a moving part of the load cell (1) to fix the position of the moving part.

13. An electronic balance (2) comprising a load cell (1) having a mechanism for preventing a drop during transportation according to any one of claims 1 to 12.

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