Hand-held DC resistance tester

Abstract

The invention discloses a handheld direct-current resistance tester, and relates to the field of direct-current resistance testing. At present, a wire clamp needs to be manually fixed on an equipment column head, so that the operation complexity is increased. The tester comprises a tester host, a take-up and pay-off unit is slidably assembled on the back surface of the tester host, a test wire is wound on the take-up and pay-off unit through a take-up column, and joints and wire clamps are assembled at two ends and the other two ends of the test wire respectively; through the wire clamp, the take-up and pay-off unit and the extension unit, the test wire is wound, the test wire can be integrally carried with the tester host, the test wire can be mounted at the front end of the host for use during use, and meanwhile, the wire clamp can be driven to move towards equipment at a high position or a far position by extending the extension unit; a tester can connect the tester host with the to-be-tested equipment through the wire clamp without other tools, meanwhile, after the wire clamp makes contact with the column head of the to-be-tested equipment, the wire clamp can be clamped on the surface of the column head through the control rope, and the worker does not need to get close to the equipment for manual clamping.

Description

Technical Field

[0001] The invention relates to the field of direct current resistance testing, and in particular to a handheld direct current resistance tester. Background Art

[0002] The DC resistance tester is a high-precision replacement product that replaces the DC single-arm and double-arm bridge. The DC resistance fast tester adopts advanced switching power supply technology and displays the measurement results on a dot-matrix LCD, overcoming the shortcoming of other similar products that the LED display value is inconvenient to read under the sun. It also has an automatic arc extinguishing function.

[0003] In order to facilitate carrying, a handheld DC resistance tester is designed and is widely used in the electrical field and electrical equipment maintenance.

[0004] Due to the structural design of the handheld DC resistance tester and the long test wire it is equipped with, the test wire cannot be stored inside the tester and needs to be carried separately. This not only increases the inconvenience of carrying, but also causes the problem of crisscrossing of the test wires in actual operation. In this case, the tester must carefully check whether the connection between the connector and the wire clamp is accurate, and the wire clamp needs to be manually fixed on the device column head, which greatly increases the complexity of the operation. In particular, when faced with a device to be tested that is located at a high place or a long distance and blocked by obstacles, it is often difficult for the tester to complete the test quickly without approaching the device, which further limits the test efficiency and safety. Summary of the invention

[0005] The purpose of the present invention is to solve the problem that the wire clamp needs to be manually fixed on the device column head, which greatly increases the complexity of the operation. In particular, when faced with a device to be tested that is located at a high place or a long distance and blocked by obstacles, it is often difficult for testers to quickly complete the test without approaching the device, which further limits the test efficiency and safety. A handheld DC resistance tester is proposed.

[0006] In order to achieve the above-mentioned object, the present invention adopts the following technical scheme: a handheld DC resistance tester, comprising a tester mainframe, a retracting unit is slidably mounted on the back of the tester mainframe, the retracting unit is wound with a test line through a reeling column, two ends of the test line are jointly equipped with connectors, the other two ends of the test line are jointly equipped with a wire clamp, a control rope for driving the wire clamp to tighten is wound on the reeling column through a plug-in key column, and an extension unit for driving the wire clamp to move toward the far end is slidably mounted on the outer wall of the tester mainframe; The extension unit includes a main rod on the main body of the tester that is slidably assembled, and at least three extension sections are inserted in the main rod, and the three extension sections are the first extension section, the second extension section and the third extension section from the outside to the inside, and a screw rod for driving the extension section to extend outward is rotatably connected to the middle part of the inner bottom wall of the main rod, and a connecting piece for installing a wire clamp is inserted in the third extension section, and a transmission assembly for driving the retractable unit to rotate synchronously is installed on the main rod; The three extension sections in the main rod are driven by the screw rod to drive the wire clamp installed on the connecting piece to move closer to or away from the column head of the device to be tested at a distance, and at the same time, the test line and the control rope are driven to loosen or reel in through the transmission component, and when approaching the column head, the wire clamp is driven to clamp on the column head in a contactless manner after continuing to reel in the control rope.

[0007] As a further description of the above technical solution: The extension unit also includes an internal thread sleeve threadedly sleeved on the screw rod, the top end of the internal thread sleeve is connected to the first extension section, a vertical tube is fixed on the inner bottom wall of the first extension section, and one end of the screw rod passes through the first extension section and is inserted into the vertical tube; A mounting plate is fixed to the top of the vertical pipe, a first pulley is mounted on the mounting plate, a first pulley is provided with a first pull rope, one end of the first pull rope passes through the mounting plate and is fixed to the inner bottom wall of the second extension section, and the other end of the first pull rope is fixed to the inner bottom wall of the main rod.

[0008] As a further description of the above technical solution: A second pulley is installed at the edge of the lower surface of the first extension section, and a second pulley is provided with a second pull rope. One end of the second pull rope passes through the first extension section and is fixed to the lower surface of the second extension section, and the other end of the second pull rope is fixed to the inner top wall of the main rod.

[0009] As a further description of the above technical solution: A third pulley is mounted on the inner bottom wall of the second extension section, and a third pulley is provided with a third pull rope. One end of the third pull rope that passes through the third extension section is fixed to the lower surface of the mounting plate, and the other end of the third pull rope is fixed to the lower surface of the third extension section.

[0010] As a further description of the above technical solution: A fourth pulley is mounted on the inner top wall of the second extension section, and a fourth pull rope is arranged on the fourth pulley. One end of the fourth pull rope is fixed to the portion extending outward from the bottom end of the third extension section, and the other end of the fourth pull rope is inserted into the first extension section and fixed to its inner bottom wall.

[0011] As a further description of the above technical solution: The connecting member includes an extension rod inserted in the third extension section, one end of the extension rod is rotatably connected to a connecting rod, an extension rod is inserted in the connecting rod, and a threaded groove for connecting a wire clamp is provided on the front and one side of the connecting rod and the extension rod.

[0012] As a further description of the above technical solution: The wire clamp comprises a connecting seat, one end of which is equipped with a fixed side clamp by means of bolts, a movable side clamp is equipped on the fixed side clamp by means of a sliding groove, one end of the control rope is fixed to an end of the movable side clamp inserted into the sliding groove, a first spring is sleeved on the outer surface of the control rope, one end of the first spring is fixed to a side wall of the sliding groove, and the other end of the first spring is fixed to an end of the movable side clamp inserted into the sliding groove; The other end of the control rope is fixed on the keyed column, and the other two ends of the test line are respectively connected to the fixed side clamp and the moving side clamp. The front and lower surfaces of the connecting seat are fixed with threaded columns that are compatible with the threaded groove, and the connecting seat is fixed in the threaded groove through the threaded columns.

[0013] As a further description of the above technical solution: The retracting unit comprises a bottom box slidably mounted on the main body of the tester, the bottom box is provided with two partition chambers, the reeling column is rotatably connected to the inner bottom wall of the partition chamber, and the top fixed sleeve of the outer wall of the reeling column is provided with a lower limit plate for limiting the test line; The middle part of the winding column is provided with an insertion hole adapted to the key column, the bottom of the inner bottom wall of the insertion hole is provided with a plurality of key columns, the bottom of the outer wall of the winding column is provided with a plurality of key slots adapted to the key columns, so that the key column can rotate with the winding column after being fully inserted into the insertion hole, and an upper limit plate for limiting the control rope is fixed to the top of the key column; A limiting slide bar is fixed on the outer wall of the bottom box, and a limiting slide groove matched with the limiting slide bar is opened on the top of the tester host, so that the bottom box can be assembled on the top of the tester host.

[0014] As a further description of the above technical solution: The transmission assembly includes an external cover fixed on the main rod, a motor is mounted on the inner bottom wall of the external cover, a first bevel gear is fixed to the end of the main rod that penetrates into the external cover, an output end of the motor is fixed to one end of the first bevel gear, a bearing seat is fixed to the back of the main rod, a shaft rod is inserted into the bearing seat, and a second bevel gear meshing with the first bevel gear is fixed to one end of the shaft rod.

[0015] As a further description of the above technical solution: A first pulley is fixed to one end of the winding column that passes through the bottom box, and a first transmission belt is meshed together on two of the first pulleys. A second pulley is fixed to the lower surface of one of the first pulleys and the other end of the shaft, and a second transmission belt is meshed together on two of the second pulleys.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: By setting the wire clamp, the retracting unit and the extension unit, the test wire can be reeled up through the retracting unit, and can be carried together with the tester host, and can be installed at the front end of the host for use. At the same time, by extending the extension unit, the wire clamp can be driven to move toward the high or distant equipment, so that the tester can connect the tester host with the device to be tested through the wire clamp without the help of other tools. At the same time, after the wire clamp contacts the column head of the device to be tested, the wire clamp can be clamped on the surface of the column head through the control rope, without the need for personnel to approach the device for manual clamping; At the same time, after the test is completed, while the extension unit drives the wire clamp to retract, the transmission component can drive the winding column to reel in the test wire, and the test wire can be reeled in separately, so that the test wire can be directly wound up after use, and the test wire will not be entangled, thereby ensuring normal use next time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional schematic diagram of the present invention.

[0018] Figure 2 It is a schematic diagram of the planar structure of the extended unit of the present invention after being cut open.

[0019] Figure 3 It is a schematic diagram of the three-dimensional structure of the extended unit of the present invention after being cut open.

[0020] Figure 4 It is a schematic structural diagram of the connecting piece of the present invention.

[0021] Figure 5 It is a front structural schematic diagram of the wire clamp of the present invention in the first usage state.

[0022] Figure 6 It is a schematic diagram of the back structure of the wire clamp of the present invention in the first usage state.

[0023] Figure 7 It is a schematic structural diagram of the wire clamp of the present invention.

[0024] Figure 8 It is a structural schematic diagram of the retractable unit of the present invention.

[0025] Fig. 9 It is a schematic diagram of the internal structure of the winding column after being cut open.

[0026] Fig.10 The present invention Figure 6 Schematic diagram of the structure enlarged at point A in the middle.

[0027] Fig.11 It is a structural schematic diagram of the wire clamp of the present invention in the second usage state.

[0028] Fig.12 It is a partial structural schematic diagram of the third use state of the wire clamp of the present invention.

[0029] Fig.13 It is a partial structural schematic diagram of the wire clamp of the present invention in the fourth usage state.

[0030] Legend: 10. Tester host; 20. Test line; 30. Wire clamp; 31. Connecting seat; 32. Bolt; 33. Fixed side clamp; 34. Moving side clamp; 35. Control rope; 36. First spring; 40. Retractable unit; 41. Bottom box; 42. Retracting column; 43. Keying column; 50. Extension unit; 51. Main rod; 52. First extension section; 53. Second extension section; 54. Third extension section; 55. Screw rod; 56. Connector; 561. Extension rod; 562. Connecting rod; 563. Extension rod; 564. Threaded groove; 57. Internal threaded sleeve; 58. Vertical pipe; 59. First pulley; 510. First pull rope; 511. Second pulley; 512. Second pull rope; 513. Third pulley; 514. Third pull rope; 515. Fourth pulley; 516. Fourth pull rope; 60. Transmission assembly; 61. External cover; 62. Motor; 63. Second bevel gear; 64. First pulley; 65. Second pulley. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Embodiment 1 like Figure 1 - Fig.13 As shown, the present invention provides: A handheld DC resistance tester includes a tester main body 10, a retracting unit 40 is slidably mounted on the back of the tester main body 10, a test line 20 is wound around the retracting unit 40 via a reeling column 42, two ends of the test line 20 are jointly equipped with connectors, and the other two ends of the test line 20 are jointly equipped with a wire clamp 30, a control rope 35 for driving the wire clamp 30 to be tightened is wound around the reeling column 42 via a plug-in keying column 43, an extension unit 50 for driving the wire clamp 30 to move toward a distal end is slidably mounted on the outer wall of the tester main body 10, and preferably, the handheld DC resistance tester is equipped with a storage box.

[0033] The extension unit 50 includes a main rod 51 that is slidingly assembled with the tester main body 10, and at least three extension sections are inserted in the main rod 51. The three extension sections are the first extension section 52, the second extension section 53 and the third extension section 54 from the outside to the inside. The middle part of the inner bottom wall of the main rod 51 is rotatably connected with a screw rod 55 for driving the extension section to extend outward, and a connecting piece 56 for installing the wire clamp 30 is inserted in the third extension section 54. The main rod 51 is equipped with a transmission assembly 60 for driving the retractable unit 40 to rotate synchronously.

[0034] The three extension sections in the main rod 51 drive the wire clamp 30 installed on the connecting piece 56 to move closer to or away from the column head of the device to be tested at a distance under the drive of the screw rod 55. At the same time, the test line 20 and the control rope 35 are driven to loosen or reel through the transmission assembly 60, and when approaching the column head, the control rope 35 is continuously reeled and the wire clamp 30 is driven to clamp on the column head in a contactless manner.

[0035] like Figure 1 , Figure 5 , Figure 8 and Fig. 9 As shown, the retracting unit 40 includes a bottom box 41 slidably assembled on the tester main body 10, and two partition chambers are opened on the bottom box 41. The reeling column 42 is rotatably connected to the inner bottom wall of the partition chamber, and the top fixed sleeve of the outer wall of the reeling column 42 is provided with a lower limit plate for limiting the test line 20.

[0036] A limit slide bar is fixed on the outer wall of the bottom box 41 , and a limit slide groove matching the limit slide bar is provided on the top of the tester host 10 , so that the bottom box 41 can be assembled on the top of the tester host 10 .

[0037] In fact, when not in use, the bottom box 41 is installed on the back of the tester main unit 10 and keeps it parallel to the tester main unit 10. When it is needed for testing, the bottom box 41 is slid outward and then assembled on the top of the tester main unit 10. At the same time, it is worth noting that when the winding column 42 and the typing column 43 rotate clockwise, the test line 20 and the control rope 35 can be wound up. When the winding column 42 and the typing column 43 rotate counterclockwise, the test line 20 and the control rope 35 will be gradually loosened, releasing the wound and fixed state of the two.

[0038] like Figure 7 and Figure 8 As shown, the wire clamp 30 includes a connecting seat 31, one end of the connecting seat 31 is equipped with a fixed side clamp 33, and a movable side clamp 34 is equipped on the fixed side clamp 33 by opening a slide groove, one end of the control rope 35 is fixed to the end of the movable side clamp 34 inserted into the slide groove, and the outer surface of the control rope 35 is sleeved with a first spring 36, one end of the first spring 36 is fixed to a side wall of the slide groove, and the other end of the first spring 36 is fixed to the end of the movable side clamp 34 inserted into the slide groove, and the other end of the control rope 35 is fixed to the keying column 43, and the other two ends of the test line 20 are respectively connected to the fixed side clamp 33 and the movable side clamp 34.

[0039] A socket matched with the typing column 43 is opened in the middle of the winding column 42, and a plurality of key columns are opened at the bottom of the bottom wall of the socket, and a plurality of key grooves matched with the key columns are opened at the bottom of the outer wall of the winding column 42, so that the typing column 43 can rotate with the winding column 42 after being fully inserted into the socket, and an upper limit disk for limiting the control rope 35 is fixed to the top of the typing column 43.

[0040] Specifically, after the fixed side clamp 33 moves to one side of the column head of the device to be tested, the keying column 43 is pulled upward to separate the keying groove at its bottom end from the key column. At this time, the upper limit plate is manually rotated to rotate the keying column 43 clockwise, thereby winding the control rope 35, so that the movable side clamp 34 is gradually pulled close to the fixed side clamp 33 through the control rope 35, so that the fixed side clamp 33 and the movable side clamp 34 are abutted against the outer wall of the column head, so that the fixed side clamp 33 and the movable side clamp 34 are fixed on the column head, and at this time, the keying column 43 is pushed downward again. The bottom end is reinserted into the keying groove, so that the position of the movable side clamp 34 is fixed. It is worth noting that after the test is completed, the keying column 43 needs to be pulled upward again. At this time, the movable side clamp 34 is driven by the elastic force of the compressed first spring 36 to move away from the fixed side clamp 33 again, thereby releasing the clamping of the column head. At this time, the keying column 43 is pressed again, so that the keying column 43 can rotate with the winding column 42, and after the control rope 35 is wound, the wire clamp 30 can be placed in the bottom box 41 for storage.

[0041] When the fixed side clamp 33 and the movable side clamp 34 are used to clamp the column head, the clamping force will not weaken as the use time increases, ensuring that the column head can always maintain a good clamping force to avoid loosening during testing due to weakened clamping force. In addition, the tester does not need to directly contact the equipment, reducing the possibility of electric shock or other safety risks.

[0042] like Figure 2 , Figure 3 and Figure 5 As shown, the extension unit 50 also includes an internal threaded sleeve 57 threadedly sleeved on the screw rod 55, the top of the internal threaded sleeve 57 is connected to the first extension section 52, vertical guide blocks are fixed to the front and back sides of the internal threaded sleeve 57, and a vertical guide groove matched with the vertical guide block is opened on the inner wall of the main rod 51 to prevent the internal threaded sleeve 57 from rotating. A vertical pipe 58 is fixed on the inner bottom wall of the first extension section 52, and one end of the screw rod 55 passes through the first extension section 52 and is inserted into the vertical pipe 58.

[0043] A mounting plate is fixed to the top of the vertical tube 58, and a first pulley 59 is mounted on the mounting plate. A first pull rope 510 is arranged on the first pulley 59. One end of the first pull rope 510 passes through the mounting plate and is fixed to the inner bottom wall of the second extension section 53. The other end of the first pull rope 510 is fixed to the inner bottom wall of the main rod 51. A second pulley 511 is mounted on the edge of the lower surface of the first extension section 52. A second pull rope 512 is arranged on the second pulley 511. One end of the second pull rope 512 passes through the first extension section 52 and is fixed to the lower surface of the second extension section 53. The other end of the second pull rope 512 is fixed to the inner top wall of the main rod 51. A third pulley 513 is mounted on the inner bottom wall of the second extension section 53, and a third pull rope 514 is arranged on the third pulley 513. One end of the third pull rope 514 that penetrates into the third extension section 54 is fixed to the lower surface of the mounting plate, and the other end of the third pull rope 514 is fixed to the lower surface of the third extension section 54. A fourth pulley 515 is mounted on the inner top wall of the second extension section 53, and a fourth pull rope 516 is arranged on the fourth pulley 515. One end of the fourth pull rope 516 is fixed to the portion extending outward from the bottom end of the third extension section 54, and the other end of the fourth pull rope 516 penetrates into the first extension section 52 and is fixed to its inner bottom wall.

[0044] The transmission assembly 60 includes an external cover 61 fixed to the main rod 51, and a motor 62 is installed on the inner bottom wall of the external cover 61. It is worth noting that the battery installed in the tester host 10 can power the motor 62. The end of the main rod 51 that penetrates into the external cover 61 is fixed with a first bevel gear, and the output end of the motor 62 is fixed to one end of the first bevel gear. A bearing seat is fixed to the back of the main rod 51, and a shaft is inserted into the bearing seat. A second bevel gear 63 meshing with the first bevel gear is fixed to one end of the shaft. The winding column 42 passes through the end of the bottom box 41 and is fixed with a second bevel gear 63 meshing with the first bevel gear. A pulley 64, two first pulleys 64 are jointly meshed with a first transmission belt, a second pulley 65 is fixed to the lower surface of one of the first pulleys 64 and the other end of the shaft, and the two second pulleys 65 are jointly meshed with a second transmission belt, a fixing stud is threadedly penetrated on the inner wall of the external cover 61, and a threaded hole matched with the fixing stud is opened on the outer wall of the tester main body 10, when the main rod 51 slides upward to the top, the fixing stud is tightened to fix the external cover 61 to the tester main body 10, thereby fixing the position of the main rod 51.

[0045] Specifically, when the extension unit 50 is extended, the screw rod 55 is driven to rotate clockwise by starting the motor 62, so that the internal threaded sleeve 57 can drive the first extension section 52 to extend outward, and at the same time, with the cooperation of multiple pulleys and pull ropes, the second extension section 53 and the third extension section 54 are driven to extend outward together, so that they can approach the distance. At the same time, the second bevel gear 63 is driven to rotate counterclockwise by the first bevel gear, so that the winding column 42 and the keying column 43 are driven to rotate counterclockwise under the action of the pulley and the transmission belt, and the test line 20 and the control rope 35 are gradually loosened, so that the wire clamp 30 at one end can follow the extension unit 50 to extend to the distance, thereby adapting to the equipment to be tested in different positions. When not in use, the second transmission belt can be removed and placed in the bottom box 41 for storage.

[0046] like Figure 2 , Figure 4 and Figure 5As shown, the connecting member 56 includes an extension rod 561 inserted into the third extension section 54, one end of the extension rod 561 is rotatably connected to the connecting rod 562, and the extension rod 563 is inserted into the connecting rod 562. The front of the connecting rod 562 and the extension rod 563 are both provided with a threaded groove 564 for connecting the wire clamp 30, and a threaded column matched with the threaded groove 564 is fixed on the lower surface of the connecting seat 31, and the connecting seat 31 is fixed in the threaded groove 564 through the threaded column. Preferably, a positioning seat is fixed on the top of the outer wall of the third extension section 54, and a knob stud is threaded through the positioning seat, and a positioning screw hole matched with the knob stud is opened on one side of the connecting rod 562, so that the connecting rod After 562 is rotated to be perpendicular to the third extension section 54, it can be fixed together with the third extension section 54 by means of a knob stud. At the same time, a plurality of equally spaced positioning holes are provided on the upper and lower surfaces of the extension rod 563, and mounting holes are provided on the inner top wall and the inner bottom wall of the connecting rod 562. A second spring is fixed in the mounting hole, and a positioning spherical column matching the positioning hole is fixed at one end of the second spring. After the extension rod 563 is pulled outward for a certain distance according to the required spacing between the two wire clamps 30, the positioning spherical column is driven to engage in the corresponding positioning hole under the action of the second spring, so that the extension rod 563 can be fixed in the connecting rod 562 after being pulled outward for a certain distance.

[0047] Specifically, before extending, first pull the connecting piece 56 out from the third extension section 54, then rotate the connecting rod 562 so that its side is against the top of the third extension section 54, and then fix the two together through the knob stud. At this time, the wire clamp 30 is installed on the front of the connecting rod 562 and the extension rod 563 through the threaded column at the bottom. At the same time, the extension operation can be performed by the motor 62, so that the wire clamp 30 is extended to the device to be tested that is located at a high or distant place, so that the tester can operate the tester at a safe distance. At the same time, during use, the connecting rod 562 and the extension rod 563 can stably support the wire clamp 30 and ensure good contact between the wire clamp 30 and the column head of the device to be tested, especially when performing low resistance measurements, which helps to improve the precision and accuracy of the test.

[0048] Embodiment 2 like Figure 4 , Figure 5 , Figure 7 and Fig.12 As shown, a thread groove 564 for connecting the wire clamp 30 is formed on one side of the connecting rod 562 and the extending rod 563 , and a thread column matched with the thread groove 564 is fixed on the front side of the connecting seat 31 .

[0049] Specifically, according to the placement of the device to be tested, the wire clamp 30 is fixed to one side of the connecting rod 562 and the extension rod 563. At this time, the wire clamp 30 can be used in the case where the device is located at a high place and the column head is located at the top of the device.

[0050] Embodiment 3 like Fig.11 and Fig.13 As shown, one end of the connecting seat 31 is assembled with a fixed side clamp 33 through a bolt 32; After the wire clamp 30 is installed in different thread grooves 564 according to the specific position of the equipment, the bolt 32 is loosened. At this time, the angle of the fixed side clamp 33 can be adjusted according to actual use needs. After adjusting to a suitable angle, the bolt 32 is tightened again. At this time, the positions of the adjusted fixed side clamp 33 and the movable side clamp 34 are fixed, so that the wire clamp 30 can be used for more equipment.

[0051] Specifically, when this handheld DC resistance tester is working / in use: First, before use, take out the retractable unit 40 from the back of the tester main body 10, and then assemble it on the top of the tester main body 10, then move the main rod 51 upward so that it is at the top of the outer wall of the tester main body 10, and then tighten the fixing stud to fix the position of the main rod 51, and then pull the connecting piece 56 out from the third extension section 54 until the connecting rod 562 is exposed, and then rotate the connecting rod 562 so that its side is against the top of the third extension section 54, and then tighten the knob stud to fix the two together, and then install the wire clamp 30 on the front or one side of the connecting rod 562 and the extension rod 563 through the threaded column at the bottom according to the use requirements, and after installation, adjust the angle of the fixed side clamp 33 together with the movable side clamp 34 as needed.

[0052] After the adjustment is completed, the motor 62 is started to drive the screw 55 to rotate clockwise, so that the internal threaded sleeve 57 drives the first extension section 52 to extend outward, and at the same time, with the cooperation of multiple pulleys and pull ropes, the second extension section 53 and the third extension section 54 are driven to extend outward together, so that they can get close to the equipment at a distance or a high place. At the same time, the second bevel gear 63 is driven to rotate counterclockwise through the first bevel gear, so that the winding column 42 and the key column 43 are driven to rotate counterclockwise under the action of the pulley and the transmission belt, and the test line 20 and the control rope 35 are gradually loosened, so that the wire clamp 30 can smoothly follow the connecting piece 56 to get close to the equipment. When the fixed side clamp After 33 moves to one side of the column head of the device to be tested, turn off the motor 62, then pull the keying column 43 upward to separate the keying groove at its bottom end from the key column, then manually rotate the upper limit disk to rotate the keying column 43 clockwise, and then reel in the control rope 35, so that the movable side clamp 34 is gradually approached to the fixed side clamp 33 by pulling the control rope 35. In the process, the first spring 36 is driven to compress, so that the fixed side clamp 33 and the movable side clamp 34 are abutted against the outer wall of the column head, so that the fixed side clamp 33 and the movable side clamp 34 are clamped on the column head, and then push the keying column 43 downward again to reinsert its bottom end into the keying groove, so that the position of the movable side clamp 34 is fixed.

[0053] Then carry out the test. When the test is finished, first pull the keying column 43 upward again. At this time, the movable side clamp 34 is driven by the elastic force of the compressed first spring 36 to move away from the fixed side clamp 33 again, thereby releasing the clamping of the column head. At this time, press the keying column 43 again, so that the keying column 43 can rotate with the winding column 42, and then start the motor 62 to drive the screw 55 to rotate counterclockwise, so that the extension section shrinks, and the winding column 42 and the keying column 43 rotate clockwise to wind up the test line 20 and the control rope 35. After the winding is completed, the wire clamp 30 is removed and put back into the bottom box 41, and then the second transmission belt is removed and placed in the bottom box 41, and then the connecting piece 56 is reset, and finally the bottom box 41 and the main rod 51 are reset.

[0054] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A handheld DC resistance tester, comprising a tester host (10), characterized in that: The back of the tester mainframe (10) is slidably equipped with a retracting unit (40), the retracting unit (40) is wound with a test line (20) via a reeling column (42), two ends of the test line (20) are jointly equipped with connectors, the other two ends of the test line (20) are jointly equipped with a wire clamp (30), a control rope (35) for driving the wire clamp (30) to be tightened is wound on the reeling column (42) via a plug-in key column (43), and an extension unit (50) for driving the wire clamp (30) to move toward the far end is slidably equipped on the outer wall of the tester mainframe (10); The extension unit (50) comprises a main rod (51) slidably assembled with the main body (10) of the tester, at least three extension sections are inserted into the main rod (51), and the three extension sections are, from the outside to the inside, a first extension section (52), a second extension section (53) and a third extension section (54), a screw rod (55) for driving the extension section to extend outward is rotatably connected to the middle part of the inner bottom wall of the main rod (51), a connecting piece (56) for installing the wire clamp (30) is inserted into the third extension section (54), and a transmission assembly (60) for driving the retractable unit (40) to rotate synchronously is assembled on the main rod (51); The three extension sections in the main rod (51) are driven by the screw rod (55) to drive the wire clamp (30) installed on the connecting member (56) to approach or move away from the column head of the device to be tested at a distance, and at the same time, the test line (20) and the control rope (35) are driven to loosen or reel through the transmission assembly (60), and when approaching the column head, the control rope (35) is continuously reeled in, and the wire clamp (30) is driven to clamp on the column head in a contactless manner.

2. A handheld DC resistance tester according to claim 1, characterized in that: The extension unit (50) further comprises an internal threaded sleeve (57) threadedly sleeved on the screw rod (55), the top end of the internal threaded sleeve (57) being connected to the first extension section (52), a vertical tube (58) being fixed on the inner bottom wall of the first extension section (52), one end of the screw rod (55) passing through the first extension section (52) and being inserted into the vertical tube (58); A mounting plate is fixed to the top end of the vertical pipe (58), a first pulley (59) is mounted on the mounting plate, a first pulley (59) is provided on the first pulley (59), one end of the first pull rope (510) passes through the mounting plate and is fixed to the inner bottom wall of the second extension section (53), and the other end of the first pull rope (510) is fixed to the inner bottom wall of the main rod (51).

3. A handheld DC resistance tester according to claim 2, characterized in that: A second pulley (511) is mounted on the edge of the lower surface of the first extension section (52), and a second pull rope (512) is disposed on the second pulley (511). One end of the second pull rope (512) that penetrates into the first extension section (52) is fixed to the lower surface of the second extension section (53), and the other end of the second pull rope (512) is fixed to the inner top wall of the main rod (51).

4. A handheld DC resistance tester according to claim 2, characterized in that: A third pulley (513) is mounted on the inner bottom wall of the second extension section (53), and a third pull rope (514) is disposed on the third pulley (513). One end of the third pull rope (514) that passes through the third extension section (54) is fixed to the lower surface of the mounting plate, and the other end of the third pull rope (514) is fixed to the lower surface of the third extension section (54).

5. A handheld DC resistance tester according to claim 2, characterized in that: A fourth pulley (515) is mounted on the inner top wall of the second extension section (53), and a fourth pull rope (516) is disposed on the fourth pulley (515). One end of the fourth pull rope (516) is fixed to a portion extending outward from the bottom end of the third extension section (54), and the other end of the fourth pull rope (516) is inserted into the first extension section (52) and fixed to the inner bottom wall thereof.

6. A handheld DC resistance tester according to claim 2, characterized in that: The connecting member (56) comprises an extension rod (561) inserted into the third extension section (54); one end of the extension rod (561) is rotatably connected to a connecting rod (562); an extension rod (563) is inserted into the connecting rod (562); and a threaded groove (564) for connecting a wire clamp (30) is provided on the front side and one side of the connecting rod (562) and the extension rod (563).

7. A handheld DC resistance tester according to claim 6, characterized in that: The wire clamp (30) comprises a connecting seat (31), one end of the connecting seat (31) is equipped with a fixed side clamp (33) by means of a bolt (32), a movable side clamp (34) is equipped on the fixed side clamp (33) by means of a slide groove, one end of the control rope (35) is fixed to one end of the movable side clamp (34) inserted into the slide groove, a first spring (36) is sleeved on the outer surface of the control rope (35), one end of the first spring (36) is fixed to one side wall of the slide groove, and the other end of the first spring (36) is fixed to one end of the movable side clamp (34) inserted into the slide groove; The other end of the control rope (35) is fixed to the keyed column (43), and the other two ends of the test line (20) are respectively connected to the fixed side clamp (33) and the movable side clamp (34). The front and lower surfaces of the connecting seat (31) are fixed with threaded columns that match the threaded groove (564), and the connecting seat (31) is fixed in the threaded groove (564) through the threaded columns.

8. A handheld DC resistance tester according to claim 1, characterized in that: The retracting unit (40) comprises a bottom box (41) slidably mounted on the tester mainframe (10), the bottom box (41) being provided with two partition chambers, the reeling column (42) being rotatably connected to the inner bottom wall of the partition chamber, and a lower limit plate for limiting the test line (20) being provided on the top fixed sleeve of the outer wall of the reeling column (42); The middle of the winding column (42) is provided with a plug hole matched with the key column (43), the bottom of the bottom wall of the plug hole is provided with a plurality of key columns, and the bottom of the outer wall of the winding column (42) is provided with a plurality of key slots matched with the key columns, so that the key column (43) can rotate with the winding column (42) after being fully inserted into the plug hole, and an upper limit plate for limiting the control rope (35) is fixed to the top of the key column (43); A limit slide bar is fixed on the outer wall of the bottom box (41), and a limit slide groove matching the limit slide bar is provided at the top of the tester mainframe (10), so that the bottom box (41) can be assembled on the top of the tester mainframe (10).

9. A handheld DC resistance tester according to claim 8, characterized in that: The transmission assembly (60) comprises an external cover (61) fixed on a main rod (51), a motor (62) being mounted on an inner bottom wall of the external cover (61), a first bevel gear being fixed to one end of the main rod (51) that penetrates into the external cover (61), an output end of the motor (62) being fixed to one end of the first bevel gear, a bearing seat being fixed to the back of the main rod (51), a shaft being inserted into the bearing seat, and a second bevel gear (63) meshing with the first bevel gear being fixed to one end of the shaft.

10. A handheld DC resistance tester according to claim 9, characterized in that: A first belt pulley (64) is fixed to one end of the winding column (42) passing through the bottom box (41), and a first transmission belt is meshed with two of the first belt pulleys (64). A second belt pulley (65) is fixed to the lower surface of one of the first belt pulleys (64) and the other end of the shaft, and a second transmission belt is meshed with the two second belt pulleys (65).

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