A wire winding structure for a grounding continuity resistance tester calibration device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-19
- Publication Date
- 2026-08-14
AI Technical Summary
[0004]上述装置中,虽然通过转动提手带动第一圆板转动,能够对外界导线缠绕收纳,但是,上述装置将导线收卷完成之后并不能对导线进行固定,在转运该装置的过程中,导线容易从导线缠绕组件上散落下来,影响后期的使用,为了解决上述问题,本申请设计了一种接地导通电阻测试仪检定装置用导线收纳缠绕结构
1)、本装置在滑块、弹簧和推动杆的共同作用下,压线板能持续将导线压紧在导线缠绕组件上,防止在转运该装置时,导线从导线缠绕组件上散落下来,便于后期的使用。
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Figure CN224632995U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of wire storage technology, and specifically relates to a wire storage and winding structure for a grounding continuity resistance tester calibration device. Background Technology
[0002] Grounding resistance testers are commonly used instruments for testing and measuring grounding resistance. They are also indispensable tools for electrical safety inspections and the final acceptance of grounding projects. However, during use, wires are required for connection and testing, which can easily lead to tangling and make the wires knotted and difficult to store.
[0003] A search revealed a patent application with application number 202020264449.X, which discloses a grounding continuity resistance tester calibration device. The device includes a calibrator with a display screen mounted on its top. The left end of the lever engages with a left-side cover plate via a slot, and the top of the terminal block is equipped with an anti-detachment component. This grounding continuity resistance tester calibration device, through the cooperation of the calibrator, display screen, cover plate, lever, spring, slot, and anti-detachment component, allows the cover plate to be tightly closed when not in use, thus protecting the components on the top of the calibrator and reducing the probability of damage. During use, the terminal block can be quickly secured to the external wire by rotating the handle, preventing loose connections during testing. Furthermore, the cooperation of the calibrator, display screen, cover plate, lever, spring, slot, and anti-detachment component allows the device to rotate during use by turning the handle, thereby winding and storing the external wire.
[0004] In the above-mentioned device, although the first circular plate can be rotated by rotating the handle to wind and store the external wires, the device cannot fix the wires after winding them. During the transportation of the device, the wires are prone to falling off the wire winding assembly, which affects the later use. In order to solve the above problems, this application designs a wire storage and winding structure for a grounding continuity resistance tester calibration device. Utility Model Content
[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a wire storage and winding structure for a grounding continuity resistance tester calibration device. Under the combined action of the slider, spring and push rod, the pressure plate can continuously press the wire onto the wire winding assembly, preventing the wire from falling off the wire winding assembly when the device is transported, thus facilitating later use.
[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A wire winding structure for a grounding continuity resistance tester calibration device includes an upper box and a lower box, which are hinged on one side. A resistance tester is installed inside the upper box, and a partition is installed inside the lower box. A wire winding assembly and a wire pressing assembly are installed on the partition, and the wire pressing assembly cooperates with the wire winding assembly. The wire pressing assembly includes a bracket, a wire pressing plate, and a push rod. The bracket is fixedly mounted on a partition plate and has a slotted hole. A guide rod, a slider, and a spring are disposed in the slotted hole. The two ends of the guide rod are fixedly mounted on the inner wall of the slotted hole. The slider is slidably mounted on the guide rod. The spring is sleeved on the guide rod to provide power to the slider. The end of the wire pressing plate is rotatably mounted on the bracket. A connecting rod is disposed on one side of the push rod, and a fixed shaft is disposed at the end of the connecting rod. The two ends of the push rod are connected to the fixed shaft and the slider, respectively.
[0007] Preferably, the bracket includes a fixed plate and several support rods, with the support rods arranged in an array around the circumference of the fixed plate. The strip-shaped holes are provided on the support rods, and a column is provided at the end of the support rod. The column is fixedly installed on the partition plate and is used to support the pressure plate to ensure that the pressure plate can rotate normally.
[0008] Preferably, at least two support rods are provided, and the two support rods are evenly distributed around the circumference of the fixed plate. The support rods are provided to ensure the normal operation of the slider, guide rod and spring.
[0009] Preferably, the end of the pressure plate is rotatably mounted on the column, and the pressure plate cooperates with the wire winding assembly. The pressure plate can press the wire onto the wire winding assembly to prevent the wound wire from becoming loose, thus ensuring the safety of the wire.
[0010] Preferably, the wire winding assembly includes a driving component and winding rollers symmetrically arranged on both sides of the partition centerline. The driving component is located at the bottom of the partition, and the winding rollers are located at the top of the partition and connected to the driving component. The end of the pressure plate presses on the winding rollers, and the driving component drives the winding rollers to rotate, thereby achieving the purpose of winding and storing the wires. The winding rollers symmetrically arranged on both sides of the partition centerline can simultaneously store two wires, improving the wire storage efficiency of the device.
[0011] Preferably, the winding roller is also provided with a wire clamping groove to facilitate fixing the end of the wire. The wire clamping groove facilitates fixing the movable end of the wire and ensures that the wire can be wound normally on the winding roller.
[0012] Preferably, the driving component includes a fixed base, a rotating shaft, a vertical shaft, a first bevel gear, a second bevel gear, a worm gear, and a worm. The fixed base is fixedly installed at the bottom of the partition, the rotating shaft is rotatably installed on the fixed base, the vertical shaft is rotatably installed on the partition, the winding roller is fixedly installed on the vertical shaft, the first bevel gear is fixedly installed on the vertical shaft, the second bevel gear is fixedly installed on the rotating shaft, the first bevel gear and the second bevel gear mesh with each other, the worm gear is fixedly installed in the middle of the rotating shaft, and the worm is located above the worm gear, and the worm gear meshes with the worm. One end of the worm extends through the lower housing to the outside of the lower housing. The driving component is used to provide power for the rotation of the winding roller, ensuring the normal rotation of the winding roller, thereby achieving the purpose of winding and storing the wire. Rotating the worm drives the worm gear to rotate, the worm gear rotates to drive the rotating shaft to rotate, the rotating shaft rotates to drive the second bevel gear to rotate, the second bevel gear rotates to drive the first bevel gear to rotate, the first bevel gear rotates to drive the vertical shaft to rotate, the vertical shaft rotates to drive the winding roller to rotate, and the rotation of the winding roller achieves the purpose of winding and storing the wire.
[0013] Preferably, the drive unit further includes a handle, which is located on the outside of the lower housing and mounted on the worm gear. The handle facilitates the operator to rotate the worm gear, thereby ensuring that the device can store the wire.
[0014] Preferably, a wire splitting assembly is also provided on the partition plate. The wire splitting assembly includes a wire splitting plate with a through hole in the middle. A wire splitting roller is provided in the through hole. The wire splitting roller is located in the middle of the through hole. The wire splitting plate can separate two wires that are wound together, ensuring the efficiency of wire winding.
[0015] Preferably, countersunk grooves are provided on the other side of both the lower and upper boxes, and handles are provided in the countersunk grooves. The handles make it easy for workers to lift the device, and the countersunk grooves protect the handles and ensure their safety when not in use.
[0016] Preferably, the lower and upper boxes are provided with buckles, which are symmetrically arranged on both sides of the countersunk groove. The buckles are used to fix the lower and upper boxes together, ensuring that the device is always in a closed state during transportation and transfer, thus ensuring the safety of the device.
[0017] The beneficial effects of this utility model are: 1) Under the combined action of the slider, spring and push rod, the pressure plate of this device can continuously press the wire tightly onto the wire winding assembly, preventing the wire from falling off the wire winding assembly when the device is transported, thus facilitating its later use.
[0018] 2) The uprights of this device are designed to support the pressure plate and ensure that the pressure plate can rotate normally.
[0019] 3) This device has at least two support rods, which are evenly distributed around the circumference of the fixed plate. The support rods are used to ensure the normal operation of the slider, guide rod and spring.
[0020] 4) The pressure plate of this device can press the wire onto the wire winding assembly to prevent the wound wire from becoming loose, thus ensuring the safety of the wire.
[0021] 5) The drive unit of this device drives the winding roller to rotate, thereby achieving the purpose of winding and storing the wire. The winding rollers symmetrically arranged on both sides of the center line of the partition can simultaneously store two wires, improving the storage efficiency of the device for the wire.
[0022] 6) This device is also equipped with a wire clamping groove on the winding roller to facilitate the fixing of the end of the wire. The wire clamping groove is designed to fix the movable end of the wire and ensure that the wire can be wound normally on the winding roller.
[0023] 7) The drive mechanism of this device provides power for the rotation of the winding roller, ensuring its normal rotation and thus achieving the purpose of winding and storing the wire. The rotation of the worm gear drives the worm wheel to rotate, which in turn drives the rotating shaft to rotate. The rotating shaft drives the second bevel gear to rotate, which in turn drives the first bevel gear to rotate. The rotation of the first bevel gear drives the vertical shaft to rotate, which in turn drives the winding roller to rotate. The rotation of the winding roller achieves the purpose of winding and storing the wire. The handle facilitates the operator's rotation of the worm gear, thus ensuring that the device can store the wire.
[0024] 8) The device is also equipped with a wire splitting assembly on the partition plate. The wire splitting assembly includes a wire splitting plate with a through hole in the middle. A wire splitting roller is installed in the through hole. The wire splitting roller is located in the middle of the through hole. The wire splitting plate can separate two wires that are wound together, thus ensuring the efficiency of wire winding.
[0025] 9) The handle of this device is designed to facilitate the lifting of the device by the staff, and the countersunk groove is designed to protect the handle and ensure its safety when not in use.
[0026] 10) The buckle of this device is used to fix the lower box and the upper box together, ensuring that the device is always in the closed state during transportation and transfer, thus ensuring the safety of the device. Attached Figure Description
[0027] Appendix Figure 1 This is a schematic diagram of the structure of this utility model.
[0028] Appendix Figure 2 This is a schematic diagram of the internal structure of this utility model.
[0029] Appendix Figure 3 This is a structural schematic diagram of the medium voltage line assembly of this utility model.
[0030] Appendix Figure 4 This is a schematic diagram of the support structure in this utility model.
[0031] Appendix Figure 5 This is a schematic diagram of the wire winding assembly in this utility model.
[0032] Appendix Figure 6 This is a schematic diagram of the installation structure of the driving component in this utility model.
[0033] Appendix Figure 7 This is a schematic diagram of the driving component in this utility model.
[0034] Appendix Figure 8 This is a utility model Figure 2 Enlarged view of point A in the middle.
[0035] In the picture: 1. Lower box; 2. Upper box; 3. Buckle; 4. Wire pressing assembly; 401. Bracket; 402. Wire pressing plate; 403. Connecting rod; 404. Fixed shaft; 405. Push rod; 406. Strip hole; 407. Spring; 408. Slider; 409. Guide rod; 4010. Column; 4011, Support rod; 4012, Fixing plate; 5. Resistance tester; 6. Separating assembly; 601. Separating plate; 602. Through hole; 603. Separating roller; 7. Wire winding assembly; 701. Drive component; 702. Winding roller; 703. Wire clamping groove; 704. Fixed base; 705. Rotating shaft; 706. Second bevel gear; 707. First bevel gear; 708. Vertical shaft; 709. Worm gear; 7010. Handle; 7011. Worm wheel; 8. Partition; 9. Countersunk groove; 10. Handle. Detailed Implementation
[0036] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0037] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0038] like Figure 1 As shown, a wire winding structure for a grounding continuity resistance tester 5 calibration device includes an upper housing 2 and a lower housing 1, which are hinged on one side. The resistance tester 5 is installed inside the upper housing 2, and a partition 8 is installed inside the lower housing 1. A wire winding assembly 7 and a wire pressing assembly 4 are installed on the partition 8. The wire pressing assembly 4 cooperates with the wire winding assembly 7. The wire winding assembly 7 is used to wind the wire, and the wire pressing assembly 4 is used to press the wound wire onto the wire winding assembly 7 to ensure that the wound wire is always in a safe state during transportation.
[0039] In this embodiment, as Figure 3 , Figure 4 As shown, the wire pressing assembly 4 includes a bracket 401, a wire pressing plate 402, and a push rod 405. The bracket 401 is fixedly installed on the partition plate 8. A strip hole 406 is opened on the bracket 401. A guide rod 409, a slider 408, and a spring 407 are arranged in the strip hole 406. The slider 408 is slidably installed on the guide rod 409. The spring 407 is sleeved on the guide rod 409 and is used to provide power to the slider 408. The end of the wire pressing plate 402 is rotatably installed on the bracket 401. A connecting rod 403 is provided on one side of the push rod 405. A fixed shaft 404 is also provided at the end of the connecting rod 403. The two ends of the push rod 405 are respectively connected to the fixed shaft 404 and the slider 408. The wire pressing assembly 4 is used to press the wire onto the wire winding assembly 7 to ensure that the wire is always in a safe state during the transfer process.
[0040] Spring 407 provides power to slider 408, which in turn pushes one end of push rod 405 to move. The other end of push rod 405 provides power to fixed shaft 404 on connecting rod 403, ensuring that connecting rod 403 and pressure plate 402 can rotate around column 4010, so that the end of pressure plate 402 is always in close contact with winding roller 702, ensuring that pressure plate 402 can press the wire onto winding roller 702, thus ensuring the safety of the wire.
[0041] In this embodiment, as Figure 3As shown, the two ends of the guide rod 409 are respectively fixedly installed on the inner wall of the strip hole 406. The guide rod 409 can support the slider 408 and prevent the slider 408 from falling out of the strip hole 406 during movement, thus ensuring the normal operation of the slider 408.
[0042] In this embodiment, as Figure 4 As shown, the bracket 401 includes a fixed plate 4012 and several support rods 4011. The several support rods 4011 are arrayed around the circumference of the fixed plate 4012. The strip hole 406 is provided on the support rod 4011. A column 4010 is provided at the end of the support rod 4011. The column 4010 is fixedly installed on the partition plate 8. The column 4010 is provided to support the pressure plate 402 and ensure that the pressure plate 402 can rotate normally.
[0043] In this embodiment, as Figure 3 , Figure 4 As shown, take three support rods 4011 as an example.
[0044] In this embodiment, as Figure 4 As shown, at least two support rods 4011 are provided, and the two support rods 4011 are evenly distributed around the circumference of the fixed disk 4012. The support rods 4011 are provided to ensure the normal operation of the slider 408, the guide rod 409 and the spring 407.
[0045] In this embodiment, as Figure 4 As shown, the end of the pressure plate 402 is rotatably mounted on the column 4010, and the pressure plate 402 cooperates with the wire winding assembly 7. The pressure plate 402 can press the wire onto the wire winding assembly 7 to prevent the wound wire from becoming loose, thus ensuring the safety of the wire.
[0046] In this embodiment, as Figure 5 As shown, the wire winding assembly 7 includes a driving member 701 and winding rollers 702 symmetrically arranged on both sides of the center line of the partition 8. The driving member 701 is located at the bottom of the partition 8, and the winding rollers 702 are located at the top of the partition 8. The winding rollers 702 are connected to the driving member 701. The end of the pressure plate 402 presses on the winding rollers 702. The driving member 701 drives the winding rollers 702 to rotate, thereby achieving the purpose of winding and storing the wire.
[0047] In this embodiment, the winding rollers 702 symmetrically arranged on both sides of the center line of the partition 8 can simultaneously accommodate two wires, thereby improving the wire accommodating efficiency of the device.
[0048] In this embodiment, as Figure 5As shown, a wire clamping groove 703 is also provided on the winding roller 702 to facilitate fixing the end of the wire. The wire clamping groove 703 facilitates fixing the movable end of the wire and ensures that the wire can be wound normally on the winding roller 702.
[0049] In this embodiment, as Figure 6 , Figure 7 As shown, the driving component 701 includes a fixed base 704, a rotating shaft 705, a vertical shaft 708, a first bevel gear 707, a second bevel gear 706, a worm gear 7011, and a worm 709. The fixed base 704 is fixedly installed on the bottom of the partition 8. The rotating shaft 705 is rotatably installed on the fixed base 704. The vertical shaft 708 is rotatably installed on the partition 8. The winding roller 702 is fixedly installed on the vertical shaft 708. The first bevel gear 707 is fixedly installed on the vertical shaft 708. The second bevel gear 706... The first bevel gear 707 and the second bevel gear 706 are fixedly installed on the rotating shaft 705. The worm gear 7011 is fixedly installed in the middle of the rotating shaft 705. The worm 709 is located on the upper side of the worm gear 7011 and the worm gear 7011 meshes with the worm 709. One end of the worm 709 extends through the lower housing 1 to the outside of the lower housing 1. The driving component 701 is provided to provide power for the rotation of the winding roller 702, ensuring the normal rotation of the winding roller 702, thereby achieving the purpose of winding and storing the wire.
[0050] Rotating the worm gear 709 drives the worm wheel 7011 to rotate, which in turn drives the rotating shaft 705 to rotate. The rotating shaft 705 then drives the second bevel gear 706 to rotate, which in turn drives the first bevel gear 707 to rotate. The rotation of the first bevel gear 707 then drives the vertical shaft 708 to rotate, which in turn drives the winding roller 702 to rotate. The rotation of the winding roller 702 serves the purpose of winding and storing the wire.
[0051] In this embodiment, as Figure 7 As shown, the drive unit 701 also includes a handle 7010, which is located on the outside of the lower housing 1 and is mounted on the worm gear 709. The handle 7010 facilitates the rotation of the worm gear 709 by the operator, thereby ensuring that the device can store the wire.
[0052] In this embodiment, as Figure 2 As shown, a wire splitting assembly 6 is also provided on the partition 8. The wire splitting assembly 6 facilitates the separation of two wires, preventing the two wires from tangling together when they are wound and rolled up at the same time, thus improving the winding quality of the wires.
[0053] like Figure 8As shown, the wire splitting assembly 6 includes a wire splitting plate 601, with a through hole 602 in the middle of the wire splitting plate 601. A wire splitting roller 603 is provided in the through hole 602. The wire splitting roller 603 is located in the middle of the through hole 602. The wire splitting plate 601 can separate two wires that are wound together, ensuring the efficiency of wire winding.
[0054] In this embodiment, as Figure 6 As shown, countersunk grooves 9 are opened on the other side of both the lower box 1 and the upper box 2. A handle 10 is provided in each countersunk groove 9. The handle 10 is designed to facilitate the lifting of the device by the staff. The countersunk groove 9 is designed to protect the handle 10 and ensure the safety of the handle 10 when it is not in use.
[0055] In this embodiment, as Figure 1 As shown, buckles 3 are provided on the lower box 1 and the upper box 2. The buckles 3 are symmetrically arranged on both sides of the countersunk groove 9. The buckles 3 are used to fix the lower box 1 and the upper box 2 together, ensuring that the device is always in a closed state during transportation and transfer, thus ensuring the safety of the device.
[0056] Its working process is as follows: When winding is required, the wire is passed through the through hole 602 and the end of the wire is placed in the wire clamping groove 703. Rotating the handle 7010 drives the worm gear 709 to rotate, the worm gear 709 drives the worm wheel 7011 to rotate, the worm wheel 7011 drives the rotating shaft 705 to rotate, the rotating shaft 705 drives the second bevel gear 706 to rotate, the second bevel gear 706 drives the first bevel gear 707 to rotate, the first bevel gear 707 drives the vertical shaft 708 to rotate, the vertical shaft 708 drives the winding roller 702 to rotate, and the rotation of the winding roller 702 can wind the wire onto the winding roller 702. During the winding and coiling process, the spring 407, slider 408 and push rod 405 provide power to the pressure plate 402, ensuring that the pressure plate 402 is always in close contact with the winding roller 702. This prevents the wire from becoming loose during the winding and coiling process and ensures the safety of the wire during transportation.
[0057] The above content is merely an example and illustration of the structure of this utility model. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the scope defined by the structure of this utility model, they should all fall within the protection scope of this utility model.
Claims
1. A wire winding structure for a grounding continuity resistance tester calibration device, comprising an upper housing and a lower housing, the upper housing and the lower housing being hinged on one side, a resistance tester being disposed inside the upper housing, and a partition being disposed inside the lower housing, characterized in that... The partition is provided with a wire winding assembly and a wire pressing assembly, wherein the wire pressing assembly cooperates with the wire winding assembly; The wire pressing assembly includes a bracket, a wire pressing plate, and a push rod. The bracket is fixedly mounted on a partition plate and has a slotted hole. A guide rod, a slider, and a spring are disposed in the slotted hole. The two ends of the guide rod are fixedly mounted on the inner wall of the slotted hole. The slider is slidably mounted on the guide rod. The spring is sleeved on the guide rod to provide power to the slider. The end of the wire pressing plate is rotatably mounted on the bracket. A connecting rod is disposed on one side of the push rod, and a fixed shaft is disposed at the end of the connecting rod. The two ends of the push rod are connected to the fixed shaft and the slider, respectively.
2. The wire winding structure for a grounding continuity resistance tester calibration device according to claim 1, characterized in that, The bracket includes a fixed plate and several support rods. The array of support rods is distributed around the circumference of the fixed plate. The strip-shaped holes are provided on the support rods, and the columns are provided at the ends of the support rods. The columns are fixedly installed on the partition.
3. The wire winding structure for a grounding continuity resistance tester calibration device according to claim 2, characterized in that, At least two support rods are provided, and the two support rods are evenly distributed around the circumference of the fixed plate.
4. The wire winding structure for a grounding continuity resistance tester calibration device according to claim 2, characterized in that, The end of the pressure plate is rotatably mounted on the column, and the pressure plate cooperates with the wire winding assembly.
5. The wire winding structure for a grounding continuity resistance tester calibration device according to claim 4, characterized in that, The wire winding assembly includes a driving component and winding rollers symmetrically arranged on both sides of the center line of the partition. The driving component is located at the bottom of the partition, and the winding rollers are located at the top of the partition. The winding rollers are connected to the driving component, and the end of the pressure plate presses on the winding rollers.
6. The wire winding structure for a grounding continuity resistance tester calibration device according to claim 5, characterized in that, The winding roller is also equipped with a wire clamping groove to facilitate fixing the end of the wire.
7. The wire winding structure for a grounding continuity resistance tester calibration device according to claim 5, characterized in that, The driving component includes a fixed base, a rotating shaft, a vertical shaft, a first bevel gear, a second bevel gear, a worm gear, and a worm. The fixed base is fixedly installed at the bottom of the partition, the rotating shaft is rotatably installed on the fixed base, the vertical shaft is rotatably installed on the partition, the winding roller is fixedly installed on the vertical shaft, the first bevel gear is fixedly installed on the vertical shaft, the second bevel gear is fixedly installed on the rotating shaft, the first bevel gear and the second bevel gear mesh with each other, the worm gear is fixedly installed in the middle of the rotating shaft, the worm is located above the worm gear, and the worm gear meshes with the worm, with one end of the worm extending through the lower housing to the outside of the lower housing; it also includes a handle, which is located on the outside of the lower housing and is installed on the worm.
8. The wire winding structure for a grounding continuity resistance tester calibration device according to claim 1, characterized in that, A line-separating assembly is also provided on the partition plate. The line-separating assembly includes a line-separating plate with a through hole in the middle. A line-separating roller is provided in the through hole, and the line-separating roller is located in the middle of the through hole.
9. The wire winding structure for a grounding continuity resistance tester calibration device according to claim 1, characterized in that, Countersunk grooves are provided on the other side of both the lower and upper boxes, and handles are provided in the countersunk grooves.
10. The wire winding structure for a grounding continuity resistance tester calibration device according to claim 9, characterized in that, Buckles are provided on the lower and upper housings, and the buckles are symmetrically arranged on both sides of the countersunk groove.
Citation Information
Patent Citations
Calibrating device for grounding on-resistance tester
CN212060547U