Tester rod

Abstract

To provide a tester rod which enhances convenience and efficiency of measurement work using a tester to enable safer and more reliable measurement work.SOLUTION: A tester rod to be connected to a tester via a lead wire for electrical measurement is provided, the tester rod being an elongate conductive member comprising a contact for contacting a measurement target site with a tip thereof, and a rod-like holder for holding the contact, where the contact can be removably screwed into the holder.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a tester rod for connecting to a tester used for electrical measurements such as current, voltage, and resistance measurements and continuity tests, and for contacting a measurement target portion or component. [Background technology]

[0002] A tester rod (also called a test lead) is a tapered conductive member that connects to a tester (sometimes called a multimeter or circuit meter) via a conductor (lead wire). The tip of the tester is brought into contact with the part to be measured, and the tester performs electrical measurements such as current, voltage, and resistance measurements. As a configuration for improving the convenience and work efficiency of tester rods, for example, Patent Document 1 discloses a tester rod in which an extension probe can be detachably attached to the tip of the probe to further extend the probe. Patent Document 2 also discloses an illuminated tester rod equipped with an illumination optical fiber to illuminate the tip of the tester rod.

[0003] Figure 13 shows a conventional tester rod, showing an example of an alligator clip (plug-in type) that can be attached by inserting it onto the tip of a currently available tester rod. With this type of attachment method, the tester rod tip (contact) and the alligator clip's receptacle (a pipe-shaped part) are held in place by the frictional force between them, so the tension generated when the tester rod's lead wire is routed can cause the clip to come loose. This phenomenon becomes more pronounced the more frequently the clip is attached and detached. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-128226 [Patent Document 2] Japanese Utility Model Application Publication No. 2-118264 Summary of the Invention [Problem to be solved by the invention]

[0005] At various sites where electrical measurements are performed, it is necessary to prepare multiple types of tester rods in advance to match the shape and size of the area to be measured, which can sometimes reduce the convenience and efficiency of measurement work using a tester.

[0006] Furthermore, when an alligator clip attached to the negative tester rod is fastened to the earth terminal and the voltage relative to it is measured at multiple locations, the measurement operator's attention is focused on the contact position of the positive tester rod and the voltage displayed on the tester, and the operator may not notice, or may notice late, that the alligator clip attached to the negative tester rod has come off.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a novel tester rod that improves the convenience and efficiency of measurement work using a tester, and that enables safer and more reliable measurement work. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the tester rod of the present invention is a tester rod that is connected to a tester for electrical measurement via a lead wire, and is characterized in that it comprises a contactor (also called a test pin) that is an elongated conductive member and whose tip is brought into contact with the part to be measured, and a rod-shaped holder that holds the contactor, and the contactor is attached to the holder by screwing it in a removable manner.

[0009] Preferably, the contactor is further characterized in that a first external thread is provided at the rear end thereof, a first internal thread having conductivity is provided at one end of the holder, and the contactor is attached to the holder by screwing the first external thread into the first internal thread.

[0010] Preferably, the connector further comprises a cap that covers the contact, and the cap is detachably attached to the contact by screwing.

[0011] Preferably, a second external thread is provided at a position adjacent to the tip end side of the first external thread provided on the contactor, and a second internal thread is provided on the inner peripheral surface of the opening of the cap, and the cap is attached to the contactor by placing the cap over the contactor and screwing the second external thread into the second internal thread.

[0012] Preferably, the holder is a rod-shaped member having a hollow interior, and the lead wire passing through the hollow interior is connected to the first internal screw within the hollow interior.

[0013] Preferably, the first internal thread is formed as a metal fitting embedded in the hollow interior of the rod-shaped member.

[0014] Preferably, the contacts are probes of a plurality of types having different lengths and tip shapes, any one of which can be attached to the holder in an interchangeable manner.

[0015] Preferably, the contactor is a needle-shaped probe, an alligator clip, a banana-shaped tip, or an arrow-shaped tip, any of which is replaceably attached to the holder. [Effects of the Invention]

[0016] According to the tester rod of the present invention, the holder and contacts are designed to be interchangeable (detachable) by means of a screw connection (thread engagement), making it possible to use various types of contacts interchangeably depending on the situation and application at the site, thereby dramatically increasing the convenience and work efficiency of measurement work using the tester and enabling safer and more reliable measurement work.

[0017] Additionally, there are already products on the general market that connect alligator clips or similar devices to the contacts at the tip of test probes in a plug-in style. With this type of connection, the connection between the test probe contacts and the alligator clips is maintained only by friction, so tension applied to the lead wires during measurement can often cause the electrical and mechanical connection between the contacts and the alligator clips to come loose. This phenomenon becomes more pronounced the more frequently the connection is repeated.

[0018] In contrast, in the present invention, the alligator clip is screwed directly onto the tester bar without going through a contact, which has the great advantage that the alligator clip will not come off the tester bar even with the tension applied to the lead wire during measurement work. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 2 is a diagram schematically illustrating the appearance of a tester rod connected to a tester. [Figure 2] 1 is a diagram showing a first configuration example of a tester bar 20 according to an embodiment of the present invention. [Figure 3] 10 is a diagram showing the detailed shape of a probe-type contactor 21 having a probe shape. FIG. [Figure 4] 3A and 3B are diagrams showing a second configuration example of a tester bar 20 according to an embodiment of the present invention. [Figure 5] 10A and 10B are diagrams showing examples of shapes of metal fittings that form a first external thread 211. FIG. [Figure 6] 2A and 2B are diagrams showing an example of the configuration of a holder 22 of a tester rod 20. FIG. [Figure 7] 10A and 10B are diagrams showing examples of shapes of metal fittings that form the first internal thread 221. FIG. [Figure 8] 1 is a diagram illustrating a cap (insulating cover) 23 that is placed over the contact 21. FIG. [Figure 9] 9A and 9B are diagrams showing detailed examples of the shape of the cap 23 in FIG. 8. [Figure 10] 10 is a diagram illustrating another cap (insulating cover) 23' that is placed over the contact 21. FIG. [Figure 11] FIG. 10 is a diagram showing a detailed shape of another cap 23' of FIG. 9. [Figure 12] 10A and 10B are diagrams showing a third configuration example of a tester bar 20 according to an embodiment of the present invention. [Figure 13] FIG. 1 is a diagram showing an example (prior art) of an alligator clip (plug-in type) that can be attached by inserting it onto the tip of a tester rod that is currently on the market. DETAILED DESCRIPTION OF THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. However, the technical scope of the present invention is not limited to these preferred embodiments.

[0021] 1 is a diagram showing a schematic view of the appearance of a tester rod connected to a tester. Tester 1 is a device for measuring the continuity and electrical characteristics of an object under test, and is equipped with, for example, a power switch 11, a DC voltage analog meter 12, a digital measurement value display 13, and a polarity display LED 14 in a housing 10. Tester 1 may also be a small, portable oscilloscope capable of displaying current or voltage waveforms.

[0022] A tester rod 20 is electrically connected to the tester 1 via lead wires 2 that connect to predetermined connection terminals. The tester rod 20 is an elongated conductive member and includes a contactor 21 whose tip contacts the measurement target portion and a rod-shaped holder 22 that holds the contactor 21. In the example of FIG. 1, the tester rods 20 are a positive electrode tester rod 20a in which the contactor of the conductive member that contacts the measurement target portion is formed as a probe-shaped probe 21a, and a negative electrode tester rod 20b in which the contactor of the conductive member that contacts the measurement target portion is an alligator clip 21b. The probe 21a of the positive electrode tester rod 20a is covered with a cap (insulating cover) 23a with its tip exposed. The alligator clip 21b of the negative electrode tester rod 20b is also covered with a cap (insulating cover) 23b with its tip exposed, including a portion of the holder 22b of the alligator clip 21b.

[0023] FIG. 2 is a diagram showing a first configuration example of a tester rod 20 according to an embodiment of the present invention. The tester rod 20 includes a contactor 21, which is an elongated conductive member and whose tip is brought into contact with a measurement target portion, and a rod-shaped holder 22 that holds the contactor 21. The contactor 21 is detachably attached to the holder 22. FIG. 2(a) shows the contactor 21 removed from the holder 22, and FIG. 2(b) shows the contactor 21 attached to the holder 22. The example in FIG. 2 also shows a configuration example of a tester rod 20 in which the contactor 21 is a needle-shaped probe. FIGS. 2(c) and 2(d) show the configuration of the holder 22. The body 220 of the holder 22 is a rod-shaped insulating member having a cylindrical hollow interior. A lead wire 30 passes through the hollow interior and is connected to a first internal thread 221 provided at one end of the holder 22. The first internal thread 221 is formed as a metal fitting (conductive member) with an internal thread, and the first internal thread 221 is embedded in one end of the holder 22. The configuration of this holder is the same for both the positive electrode and the negative electrode.

[0024] 3 is a diagram showing the detailed shape of a probe-type contactor 21 having a probe shape. In FIGS. 2 and 3, a first external thread 211 is provided at the rear end of the contactor 21, and a first internal thread 221 having conductivity is built into one end of the holder 22. The first external thread 211 is threadedly engaged with the first internal thread 221, thereby allowing the contactor 21 to be detachably attached to the holder 22. This allows various contactors 21 to be interchangeably used depending on the shape of the measurement target portion and the application. Preferably, the first external thread 211 is molded integrally with the entire contactor 21, but a configuration in which a metal fitting provided with the first external thread 211 is later fixed to the rear end of a commercially available probe-type contactor may also be used.

[0025] Furthermore, a second external thread 212 is provided at a position adjacent to the tip side of the first external thread 211 provided on the contactor 21, and a second internal thread (internal thread 222 in FIG. 9) is provided on the inner circumferential surface of the opening of a cap (cap 23 in FIG. 8) described below, and the cap 23 is attached to the contactor 21 by placing the cap 23 over the contactor 21 and threading the second external thread 212 into the second internal thread 222. The cap 23 is a protective cover that prevents the contactor 21 of the tester rod 20 from coming into contact with conductors that are not the object of measurement, and is made of an insulating material such as vinyl chloride or polypropylene.

[0026] Fig. 4 is a diagram showing a second configuration example of tester stick 20 in accordance with an embodiment of the present invention. In comparison with the first configuration example, in the second configuration example, contactor 21 is formed as an alligator clip, and Fig. 4(a) shows contactor 21 removed from holder 22, Fig. 4(b) shows contactor 21 attached to holder 22, and Fig. 4(c) shows alligator clip contactor 21 with its tip exposed and cap (insulating cover) 23 covering it and part of holder 22. Alligator clip cap 23 is a known flexible cover made of vinyl chloride.

[0027] In the configuration example of Figure 4, a first external thread 211 is also provided at the rear end of the contactor 21, and specifically, the contactor 21 is formed by attaching a metal fitting that serves as the first external thread 211 to the rear end of an alligator clip.

[0028] 5 is a diagram showing an example of the shape of the metal fitting that is the first external thread 211. The first external thread 211 is fixed to an alligator clip by, for example, soldering.

[0029] 4, a first internal thread 221 having conductivity is provided at one end of the holder 22, and the first external thread 211 is threaded into the first internal thread 221, thereby detachably attaching the contactor 21 to the holder 22. This allows various contactors 21 to be interchangeably used depending on the shape of the measurement target portion and the application.

[0030] 6 is a diagram showing an example of the configuration of holder 22. Main body 220 of holder 22 is a rod-shaped insulating member having a cylindrical hollow interior, and a lead wire (not shown) passes through the hollow interior and connects to a first internal thread 221 provided at one end of holder 22. First internal thread 221 is formed as a metal fitting (conductive member) with an internal thread, and first internal thread 221 is disposed by being embedded in one end of holder 22.

[0031] Figure 6(a) shows the front and side of the main body 220 of the holder 22 and the metal fittings that form the first internal thread 221, and Figure 6(b) shows a cross-sectional view of the holder 22 in which the first internal thread 221 is embedded in the main body 220.

[0032] 7 is a diagram showing an example of the shape of a metal fitting that forms the first internal thread 221. The metal fitting that forms the first internal thread 221 is a cylindrical pin fitting, and has a recess (slit) in which the first internal thread 221 is provided, which is concentric with the central axis.

[0033] Fig. 8 is a diagram illustrating an example of a cap (insulating cover) 23 that is placed over the contactor 21. Fig. 9 is a diagram illustrating an example of the detailed shape of the cap 23 in Fig. 8. The tester rod 20 may be provided with a cap 23 that is placed over the contactor 21, and the cap 23 is detachably attached to the contactor 21 by screwing. As an example, Fig. 8(a) illustrates the tester rod 20 with the cap 23 removed from the contactor 21, and Fig. 8(b) illustrates the tester rod 20 with the cap 23 attached to the contactor 21. A second external thread 212 is provided at a position adjacent to the tip end side of the first external thread 211 provided on the contact 21, and a second internal thread 222 is provided on the inner peripheral surface of the opening of the cap 23. The cap 23 is attached to the contact 21 by placing the cap 23 on the contact 21 and threading the second external thread 212 into the second internal thread 222. The cap 23 is placed on the contact 21 so that the contact 21 is exposed from the top of the cap 23.

[0034] Fig. 10 is a diagram illustrating another cap (insulating cover) 23' that is placed over the contact 21. Fig. 11 is a diagram illustrating the detailed shape of the another cap 23' in Fig. 9. The another cap 23' has a longer shape compared to the cap 23 in Fig. 9, and when placed over the contact 21, the another cap 23' extends to a part of the holder 22, forming a protective cover that covers the contact 21 and a part of the holder 22.

[0035] Fig. 12 is a diagram showing a third configuration example of a tester rod 20 according to an embodiment of the present invention. The third configuration example shows a tester rod 20 having a different alligator clip shape compared to the second configuration example shown in Fig. 4. Fig. 12(a) shows a holder 22 with a first internal thread 221 fitted into a body 220 and an alligator clip contact 21 (detached) with a first external thread 211, Fig. 12(b) shows a state in which the contact 21 is attached to the holder 22, and Fig. 12(c) shows a state in which a cap (insulating cover) 23 is placed over the alligator clip contact 21, including part of the holder 22, with the tip of the contact exposed.

[0036] A plurality of types of probe-shaped probes with different lengths may be prepared as contactor 21, any of which may be interchangeably attached to holder 22. Contactors may also be of various shapes, such as a probe-shaped probe, alligator clip, banana-shaped tip, or arrow-shaped tip, any of which may be interchangeably attached to holder 22. By retrofitting a metal fitting with an external screw to a commercially available contactor, it can be used as a tester rod of the present invention.

[0037] The tester rod in the above embodiment of the present invention has a simple structure that combines an external thread and an internal thread, allowing for a wide variety of interchangeable contacts, thereby improving the convenience and efficiency of tester measurement work. Furthermore, a structure that allows for interchangeable holders and contacts through a simple screw connection also reduces manufacturing costs. Furthermore, by connecting the holder and contacts with screws rather than a plug-in type, a more secure connection can be achieved.

[0038] The present invention is not limited to the above-described embodiments, and it goes without saying that the present invention also includes design changes that do not deviate from the gist of the invention, including various modifications and alterations that would occur to a person with ordinary knowledge in the field of the present invention. [Explanation of symbols]

[0039] 1: tester, 10: housing, 20: tester rod, 21: contact, 22: holder, 23: cap, 23': cap, 30: lead wire, 211: first outer screw, 212: second outer screw, 221: first inner screw, 222: second inner screw

Claims

1. A tester rod for connecting via lead wires to a tester for electrical measurements, a contactor which is an elongated conductive member and whose tip portion is brought into contact with a measurement target portion; a rod-shaped holder for holding the contact, The tester rod is characterized in that the contacts are detachably attached to the holder by screwing.

2. 2. The tester rod of claim 1, wherein the contact has a first external thread at a rear end thereof, a first conductive internal thread at one end of the holder, and the contact is attached to the holder by threading the first external thread into the first internal thread.

3. a cap to be placed over the contact, 3. The tester rod according to claim 1, wherein the cap is detachably attached to the contact by screwing.

4. The tester rod described in claim 3, characterized in that a second external thread is provided at a position adjacent to the tip side of the first external thread provided on the contactor, a second internal thread is provided on the inner surface of the opening of the cap, and the cap is attached to the contactor by placing the cap over the contactor and screwing the second external thread into the second internal thread.

5. 3. The tester rod according to claim 2, wherein the holder is a rod-shaped member having a hollow interior, and the lead wire passing through the hollow interior is connected to the first internal thread within the hollow interior.

6. 6. The tester rod according to claim 5, wherein the first internal thread is formed as a metal fitting embedded in the hollow interior of the rod-shaped member.

7. 6. The tester rod according to claim 5, wherein the contacts are probes of a plurality of types having different lengths and a probe shape, any one of which can be attached to the holder in an interchangeable manner.

8. 6. The tester rod according to claim 5, wherein the contacts are needle-shaped probes, alligator clips, banana-shaped tips, or arrow-shaped tips, any of which is replaceably attached to the holder.

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