Length-adjustable anti-falling testing pen for narrow space
By designing an adjustable-length and drop-proof test pen, the problem of inconvenient operation of traditional test pens in confined spaces is solved, providing flexible testing and safe one-handed operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANDONG DAIYIN TEXTILE GROUP SHARE CO LTD
- Filing Date
- 2025-08-14
- Publication Date
- 2026-07-24
AI Technical Summary
Traditional test pens have a fixed length, making them difficult to operate flexibly in narrow spaces. They also lack a tail-end anti-drop structure, making them easy to drop when used with one hand.
A length-adjustable, anti-drop test pen for confined spaces was designed. It adopts a rotatable adjustment knob and a sleeve structure, combined with a conductive ring and a warning light, to achieve length adjustment of the test pen and prevent it from falling.
It enables flexible detection in confined spaces, has an adjustable length to adapt to different depth requirements, and provides a force application point to prevent falling through the conductive ring, thus improving operational safety.
Smart Images
Figure CN224553357U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of test pen equipment, specifically relating to a test pen with adjustable length in confined spaces that prevents it from falling. Background Technology
[0002] As a basic tool for electrical maintenance, the test pen is widely used in voltage testing of power distribution equipment. It is an indispensable safety tool for electricians to detect whether conductors are live during electrical work, ensuring the safety of operators. A traditional test pen typically consists of a pen-shaped insulated handle, a built-in current-limiting resistor, a neon bulb or LED, and a metal tip at the front.
[0003] In practical applications, especially in confined spaces such as complex distribution cabinets, dense wiring harnesses, or the interior of equipment, traditional voltage testers exhibit significant shortcomings: Their fixed length makes them difficult to maneuver and reach in narrow spaces, while their limited length prevents them from reaching deeper or more distant test points, leading to testing difficulties and requiring the use of additional extension tools, which is cumbersome and poses safety hazards. Furthermore, existing voltage testers lack a drop-proof mechanism at the tail, making them prone to falling when used with one hand in confined spaces due to a lack of leverage.
[0004] Therefore, a drop-proof test pen with adjustable length in confined spaces is proposed. Utility Model Content
[0005] The purpose of this utility model is to provide a test pen with adjustable length in confined spaces to prevent it from falling. It has the functions of adjustable test pen length and preventing falling in confined spaces, which solves the problems of fixed length of existing test pens, which are inconvenient to use and difficult to test when too long or too short, and lack of tail anti-fall structure, which makes them easy to fall when used with one hand in confined spaces due to lack of a point of force to hold them.
[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This utility model provides an anti-drop voltage tester with adjustable length in confined spaces, including a handle, a warning light at the center of the bottom of the handle, a conductive ring at the bottom edge of the handle, an opening at the top of the handle rotatably connecting an adjustment knob via a bearing, an internal thread on the inner wall of the adjustment knob, a sleeve inserted into the top of the adjustment knob, an external thread on the bottom outer wall of the sleeve that engages with the internal thread of the adjustment knob, an internal thread at the top opening of the sleeve, a voltage tester tip at the front end of the sleeve, and an external thread on the bottom outer wall of the voltage tester tip that engages with the internal thread at the top of the sleeve.
[0007] Preferably, the bearing is a stainless steel miniature deep groove ball bearing, with the inner ring of the bearing pressed into the top of the handle and the outer ring of the bearing interference fit onto the bottom of the adjustment knob.
[0008] Preferably, the handle's internal cavity is encapsulated with a current-limiting resistor, with the front end of the current-limiting resistor connected to the inner ring of the bearing and the rear end connected to the warning light and the conductive ring.
[0009] Preferably, the conductive ring is made of metal, and the exposed end of the conductive ring is machined into a flat shovel-shaped structure.
[0010] Preferably, the test pen tip, sleeve, and adjustment knob are all made of metal, and the outer wall of the adjustment knob is provided with an insulating layer.
[0011] Preferably, an adjustment rod is inserted into the opening at the bottom edge of the handle, the end of the adjustment rod is set as a bent head, and a round hole is provided in the middle of the test pen tip, the diameter of the adjustment rod is the same as the diameter of the round hole.
[0012] Compared with the prior art, the advantages and positive effects of this utility model are as follows:
[0013] 1. This utility model is designed for confined spaces, intuitively displays the electrical status, flexibly adapts to different depth detection needs, and the protruding conductive ring at the bottom of the handle makes it easy for the user to pinch it with their fingertips to prevent accidental dislodgement during operation;
[0014] 2. This utility model has an adjustable length for the test pen and a drop prevention function in confined spaces, which solves the problems of the fixed length of the existing test pen, which is inconvenient to use and difficult to test due to being too long or too short, and the lack of a drop prevention structure at the tail, which makes it easy to fall when used with one hand in confined spaces due to the lack of a point of force to hold it. Attached Figure Description
[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 This is a structural diagram of a drop-proof test pen with adjustable length in a confined space, according to one embodiment.
[0017] Figure 2 An exploded view of an embodiment of an adjustable-length anti-drop test pen for confined spaces;
[0018] In the above figures, 1. handle, 2. warning light, 3. conductive ring, 4. adjustment knob, 5. bearing, 6. sleeve, 7. external thread, 8. test pen tip, 9. round hole, 10. adjustment rod, 11. bending head, 12. internal thread. Detailed Implementation
[0019] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.
[0020] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed in the following specification.
[0021] Example 1, as Figure 1-2 As shown, a drop-proof voltage tester with adjustable length for confined spaces includes a handle 1. The handle 1 has a main insulated structure, providing a gripping area. Circuit components are encapsulated inside the handle 1 to ensure safe current transmission. It is ergonomically designed for easy one-handed operation, and the insulating material ensures user safety. A warning light 2 is integrated into the center of the bottom of the handle 1, indicating the electrified state of the object being tested. The warning light 2 uses a low-power LED, offering high brightness and fast response.
[0022] A conductive ring 3 is provided at the bottom edge of the handle 1. The conductive ring 3 serves as a current loop contact point, forming a complete circuit when the user's finger touches it. It also provides a force point to prevent slippage, as the user's finger can grip the front end of the conductive ring 3 to prevent slippage in confined spaces. An adjustment knob 4 is rotatably connected to the top opening of the handle 1 via a bearing 5. The inner wall of the adjustment knob 4 has an internal thread 12. A sleeve 6 is inserted into the top of the adjustment knob 4. The outer wall of the bottom of the sleeve 6 has an external thread 7 that engages with the internal thread 12 of the adjustment knob 4. The top opening of the sleeve 6 has an internal thread 12. The adjustment knob 4 drives the sleeve 6 to extend and retract through the internal thread 12. The bearing 5 enables the rotational connection between the adjustment knob 4 and the handle 1. When the handle 1 is not rotating, rotating the adjustment knob 4 causes the sleeve 6 to move up and down.
[0023] The sleeve 6 has a test pen tip 8 at its front end. The bottom outer wall of the test pen tip 8 has an external thread 7 that engages with the internal thread 12 at the top of the sleeve 6. The external thread 7 engages with the internal thread 12 of the opening at the top of the sleeve 6. The telescopic structure enables length adjustment. The test pen tip 8 directly contacts the conductor being tested and introduces current. The pointed and conical front end design is suitable for narrow contact points.
[0024] The specific design of the aforementioned key components will be discussed in detail below:
[0025] The bearing 5 is a stainless steel miniature deep groove ball bearing 5. The inner ring of the bearing 5 is pressed into the top of the handle 1 and physically fixed by interference fit. The outer ring of the bearing 5 is interference fitted to the bottom of the adjustment knob 4. The adjustment knob 4 rotates freely and the outer ring of the bearing 5 moves accordingly while the inner ring of the bearing 5 is fixed.
[0026] The handle 1 has an internal cavity encapsulating a current-limiting resistor. The front end of the current-limiting resistor is connected to the inner ring of the bearing 5, and the rear end is connected to the warning light 2 and the conductive ring 3. The equivalent circuit relationship is: test pen tip 8 → sleeve 6 → adjustment knob 4 → outer ring of bearing 5 → ball bearing 5 → inner ring of bearing 5 → current-limiting resistor → warning light 2 → conductive ring 3 → human body ground. After the test pen tip 8 receives current, the current forms a circuit along the above path.
[0027] Bearing 5 is a conductive bearing, which is an existing technology product. Refer to CN110118227B for a related structure of a conductive bearing. The balls of bearing 5 simultaneously perform current conduction and mechanical rotation functions, eliminating the need for additional wires and avoiding the risk of torsional breakage. The resistor is encapsulated with epoxy resin with an IP54 protection rating, providing moisture and shock resistance. The resistance value ranges from 1-5MΩ, meeting the IEC61010 safety standard.
[0028] The conductive ring 3 is made of metal, and its exposed end is machined into a flat, shovel-shaped structure. The shovel-shaped edge forms a mechanical stop, making it easy to pinch with a single fingertip and preventing slippage. The conductive ring 3 is preferably made of 316 stainless steel. The test pen tip 8, the sleeve 6, and the adjustment knob 4 are all made of metal, preferably beryllium bronze, which has both high conductivity and bending resistance. The outer wall of the adjustment knob 4 is provided with an insulating layer, which has a double-layer structure: an inner layer of epoxy resin and an outer layer of silicone rubber.
[0029] An adjusting rod 10 is inserted into a hole at the bottom edge of the handle 1. The end of the adjusting rod 10 is set as a bending head 11, which facilitates the removal of the adjusting rod 10. The adjusting rod 10 is a rigid cylindrical structure. A circular hole 9 is provided in the middle of the test pen tip 8. The diameter of the adjusting rod 10 is the same as the diameter of the circular hole 9. By inserting the adjusting rod 10 into the circular hole 9, the test pen tip 8 can be easily rotated using the lever principle, which allows for quick assembly and disassembly of the test pen tip 8 and adjustment of its length.
[0030] All standard parts used in this utility model can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art. In addition, the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here. The contents not described in detail in this specification belong to the prior art known to those skilled in the art.
[0031] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.
Claims
1. A drop-proof voltage tester with adjustable length for confined spaces, comprising a handle, wherein a warning light is disposed at the center of the bottom of the handle, characterized in that, A conductive ring is provided at the bottom edge of the handle. An opening at the top of the handle is rotatably connected to an adjustment knob via a bearing. The inner wall of the adjustment knob is provided with an internal thread. A sleeve is inserted into the top of the adjustment knob. The outer wall of the bottom of the sleeve is provided with an external thread that engages with the internal thread of the adjustment knob. The opening at the top of the sleeve is provided with an internal thread. A test pen tip is provided at the front end of the sleeve. The outer wall of the bottom of the test pen tip is provided with an external thread that engages with the internal thread at the top of the sleeve.
2. The anti-drop test pen with adjustable length in confined spaces according to claim 1, characterized in that, The bearing is a stainless steel miniature deep groove ball bearing. The inner ring of the bearing is pressed into the top of the handle, and the outer ring of the bearing is interference-fitted to the bottom of the adjustment knob.
3. The anti-drop test pen with adjustable length in confined spaces according to claim 2, characterized in that, The handle has an internal cavity encapsulated with a current-limiting resistor. The front end of the current-limiting resistor is connected to the inner ring of the bearing, and the rear end is connected to the warning light and the conductive ring.
4. The anti-drop test pen with adjustable length in confined spaces according to claim 1, characterized in that, The conductive ring is made of metal, and the exposed end of the conductive ring is machined into a flat shovel-shaped structure.
5. A test pen with adjustable length in confined spaces to prevent falling, as described in claim 4, is characterized in that... The test pen tip, sleeve, and adjustment knob are all made of metal, and the outer wall of the adjustment knob is provided with an insulating layer.
6. The anti-drop test pen with adjustable length in confined spaces according to claim 1, characterized in that, An adjustment rod is inserted into a hole at the bottom edge of the handle. The end of the adjustment rod is set as a bent head. A round hole is set in the middle of the test pen tip. The diameter of the adjustment rod is the same as the diameter of the round hole.