JPS63221254A - Circuit test apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention generally relates to a circuit testing apparatus having a conductive probe for penetrating any insulation covering a wire to be tested. Such devices are generally operated manually.

Known electrical circuit testing devices of this general type are typically held in the hand and have a needle in contact with a wire. The wire is held in one hand while the tip of the needle is pushed through the insulation. A suitable signal generating device, such as a light bulb, buzzer or visual reader, is connected in circuit with the probe and a signal is generated when the circuit is closed by contact of the probe with the wire being tested. , a conductive wire extends from the test device.

Clamped or clipped to another point in the circuit to ground or close the circuit to determine if there is a disconnect or short and, if so, where to locate it for repair. becomes possible. Some devices of this type have a hook to hold the wire while the probe is advanced toward the wire.

The problem with such test equipment is that users often have to use both hands to operate it accurately;
The problem is that the probe does not always line up exactly with the wire when it makes contact with the wire. In other words, if the tip of the probe does not pierce the center of the insulated wire,
There is a risk that the probe and wire may not make contact at all, giving a false signal that the circuit is open, and can also damage the insulation and corrode the wire.

An example of a hook-type insulation puncture test device is disclosed in U.S. Patent Nos. 3 and 3.
No. 63,171. The device has an anchor-shaped external case in which a conductive probe is slidably mounted. The case has a hook at one end for hooking the wire and a trigger at the other end for pushing the probe into contact with the wire fixed by the hook. If the wire is not properly centered in the hook, or if the wire shifts to one side during operation, the probe will completely dislodge the wire. No. 511 and Laux, US Pat. No. 1,768,005.

Another test device is disclosed in French published application no. 2.444,940. However, this device necessarily requires a hole in the jaw opposite the probe to allow the probe to extend outwardly from the device.

The presence of holes makes it impossible to test small diameter wires. This is because, without the solid support provided by the hole, small wires can be cut by the probe or forced into the hole where good electrical contact is difficult or impossible. Furthermore, this device locks in only one position.

It is an object of this invention to provide an improved circuit testing apparatus.

In accordance with the present invention, a circuit testing apparatus includes a hollow outer sleeve having first and second jaw members movable relative to each other for sandwiching a wire between opposing jaws. is provided. The probe is movable relative to one of the jaw members and can contact wires of any size held between the jaws. Because the portion of the jaw member facing the probe is a solid surface without holes, even very small diameter wires can be held firmly during testing. The probe and jaws can be locked in various positions.

In a preferred embodiment of the invention, one of the jaws includes a hook extending from one end of the sleeve for engaging onto the wire to be tested. The other jaw member is slidable in the sleeve between a retracted position and an extended position, in which the jaw member faces the hook and is engaged by the hook between the opposing jaws. Clamp any combined wires. The slidable jaw member preferably has two separate V-shaped jaws and the hook has an opening aligned with the jaws. The jaws slide into the opening and allow small sized wires to be clamped. The portion of the jaw between the apertures and facing the probe is rigid and provides support for the wire. This ensures that the wire is accurately centered and held while being supported above. The conductive probe is axially slidable in the jaw member between a retracted position and an extended position, and is held between an opposing hook and the jaw member in the extended position. Contact with wires of any size. The probe has a pointed tip or point to pierce any insulation covering the wire. A suitable manual drive member acts to continuously expel the jaw member and probe into their extruded positions such that the jaw member first grips and holds the wire centrally, and then the probe advances and contacts the wire exactly without moving from the center position. This ml can thus accurately test wires of all sizes.

In yet another configuration, the hook is slidably mounted on the sleeve and engages a first location remote from an end of the sleeve and an opposing jaw member to clamp the wire and then clamp the wire. It is movable between a second position in which the opposing jaws are pushed rearward until the probe pierces the covering insulation and contacts the wire.

A suitable signal generating device can be circuited to indicate the presence or absence of current through the probe. The signal generating device includes a wire connected to a suitable removable electrical tether extending from the test device and connected to a selected point on the circuit and contacted by the probe with said selected point on the circuit. The circuit is tested for open or short between the points. Batteries can also be provided for circuits without a power source.

The hook and opposing jaw members preferably have V-shaped opposing jaws for pinching and centering the line to be tested.

The opposing jaw members preferably have one flat side and move within correspondingly shaped channels so that the jaws and hooks are always properly aligned.

The drive member in a preferred embodiment of the invention has a slidable plunger projecting from the end of the sleeve opposite the hook. The plunger is pushed into the sleeve and forces the jaw member and probe into the pushed out position; the plunger is preferably releasable to push the pushed out jaw member and probe into any desired pushed out position. Lockable, freeing the operator's hands while the circuit is tested. In one embodiment of the invention, the through-hole of the sleeve and the locking portion of the plunger have corresponding eccentric cross-sections, so that when the plunger is rotated or twisted within the through-hole,
The eccentric portions are locked together out of alignment, restricting sliding movement within the plunger throughbore and locking the probe in a contact position. In another embodiment, the plunger movement is mounted within the housing.

It is controlled by a screw that supports the plunger and hooks it at any desired point of its travel.

Preferably, a finger grip is provided on the sleeve so that the operator can grasp the finger grip of one hand and push the plunger inside with the thumb or palm of the same hand. This allows the device to be easily operated with one hand while leaving the other hand free. In locations such as under the dash board of a car, it is common to not be able to easily place both hands on the point that requires testing. In a preferred arrangement, the signal generating device includes a light bulb or similar device mounted in a sleeve, one end of which is connected to a conductive probe, the other end of which is connected to a suitable point for clamping another circuit point. It is releasable and connected to the lamp.

In a preferred embodiment of the invention, a first elastic device pushes the jaw member towards its retracted position, while a second, stronger elastic device pushes the probe towards its retracted position. , these devices suitably have springs. Therefore, the drive member or plunger must first be
The stronger spring force is overcome to push the jaw member toward its pushed position, and the stronger spring force is then overcome to advance the probe. This ensures that the wire is clamped and held centered before the sharp tip of the probe pierces the insulation.

Thus, the circuit test device of the present invention is relatively easy to operate and aids in accurately aligning wires for contact with probes. Therefore, the consistency of the device has been greatly improved.

1 and 2 illustrate a circuit tester M10 of a preferred embodiment of the invention for testing a wire or line 12 for open or short circuits. The housing 10 has a hollow outer case or sleeve 14 of essentially non-conductive material, with one end 1 of a through hole 20 of the sleeve.
A hook 16 protrudes from 8. The hook 16 is for hooking around the wire 2, as shown in FIGS. 1 and 3. A clamp or jaw member 22 is slidably attached to one end 18 of the through hole as shown in FIGS. 2 and 3 and has a V-shaped head portion 24 opposite the hook 16 and also has a cross section. It is also approximately V-shaped.

The jaw member is movable between a retracted position shown in FIG. 2 and an extended position shown in FIG. 3, in which it faces the hook 16. The wire is firmly gripped between the jaws 24 and the hooks 16. As shown in FIG. 5, the opening end 18 of the through hole
has a non-circular cross section, and the clamp member 22 has a non-circular cross section.
The 0gR surface, which has a corresponding profile as shown in the figure and ensures that the head portion 24 is accurately centered with respect to the sleeve through-bore, may be square, but is preferably as shown in FIG. and as shown in FIG. 10, the two opposing sides are rounded to ensure proper alignment of the jaws 24 with the hooks 16 when assembled. The clamping member and hook have opposed first and second jaw members which are arranged between an open position shown in FIGS. 2 and 7 and an extended, wire grasping position shown in FIG. is relatively movable.

A conductive probe 26 having a sharpened tip 28 extends axially into a central open-ended throughbore 27 in the clamp or jaw member 22 and is retractable as shown in FIG. 2 with the sharpened tip within the throughbore. position and the opposing V shown in Figure 3.
The hook is movable between a position in which it protrudes from the through-hole for contacting a wire grasped between the jaws of the shaped hook and the clamping member. A probe drive plunger 30 that is slidable in the axial direction is inserted into the sleeve through hole α and the opposing end portion 32.
The clamping member and probe are continuously pushed into their extruded positions as will be explained in more detail below.

The central portion 17 of the probe 16 is rigid, as shown in FIGS. 3, 5, and 8, and the end 28 of the probe 26 is
There are no holes or other openings in the part opposite the , which allows very small diameter wires (such as 66)
can be fixed and tested accurately. Because it is solidly and fully supported. in contrast,
Conventional equipment that accommodates probe holes cannot test such small wires because the probe forces the wire into opposing holes in the portion that supports the wire. In this way the wire is cut, or at least the probe cannot properly contact the wire and the test becomes inaccurate or cannot be performed.

Both the probe and clamp member have larger diameter flange portions 34 and 36, respectively, at their respective inner ends. A first spring 38 acts between flange portions 34 and 36 to urge the probe toward its retracted position.

A second weaker spring 40 is attached to the clamp member flange portion 3
6 and the rim 42 at the end of the through-bore to push the clamping member towards its retracted position, such as a light bulb or, for example, a buzzer, as shown in FIGS. 2, 7 and 8. A light bulb 44 is in contact with probe 7 flange 34 at one end and non-contact at its opposite end, as shown in FIG. The inner end of conductive plunger 30 contacts conductive button 45 . Butane 45 is connected to a conductive ground wire 48. The casing 14 is preferably a transparent plastic or other non-conductive material, at least in part of the bulb, so that the bulb is visible to the user. The plunger, made of a non-conductive material such as plastic, has an axial through hole 4.
6, through which a ground wire 48 extends to connect the light bulb 4.
4 and a conventional external clip 50. External clip 50 connects the line or mainframe ground point in the circuit to be tested to t! as in the prior art. This is for continuing.

Instead of the clip 50 it is also possible to use a banana jack 51 which is inserted into the socket end 49 of the alligator clip 53. This allows the wire 48 to be connected to various types of ground by the clip 43, or by the probe 55 of the jack 51 after the banana jack 51 is removed from the socket. Probe 55 also. It is also possible to plug it into a voltmeter to measure the voltage quantitatively.

As best shown in FIG. 2, the plunger 30 has a wide boss or butane 52 at its outer end that projects outside the casing, is generally cylindrical in cross-section, and has dimensions similar to that of the casing. The size is such that it can freely slide through the through hole 20. The plunger has a first large diameter portion 54 that snaps into a diametrically opposed projection 56 (see FIGS. 4 and 5) at the end 32 of the casing throughbore. These protrusions 56 are separated from each other and act as a detent to retain the plunger in the through hole unless it is intentionally withdrawn by the user, for example when a light bulb needs to be replaced. A protrusion 56 on the catch 59 inhibits accidental passage of the plunger 30 by pressing against a collar 57 (FIG. 7) slidably fitted onto the outside of the casing 14. Collar 57 can be moved up and down to remove catch 59.

Large diameter portion 54 preferably has an outer diameter with an eccentric cross section and the inner diameter of one through hole 20 has a corresponding eccentric cross section as shown in FIG.

Accordingly, the plunger can be locked by rotating the plunger so that the opposing eccentric surfaces of the throughbore and plunger portion 54 are brought into frictional contact with each other.

The plunger can therefore be easily locked into position within the throughbore by simply twisting into locking engagement with the eccentric surface of the throughbore. In one particular example, the eccentric portions of the plunger and throughbore are 0.474 and 0.47 inches, respectively, while
The maximum diameter of the eccentric part is 0.481 and 0.48, respectively.
It is 4 inches.

In another preferred embodiment, shown in FIGS. 7 and 8, a restraining spring loaded screw 63 is mounted in a threaded hole 67 in a boss 69 on the side of the casing 14. screw 6
At the inner end of 3 it can support the plunger 30 and restrain the movement of the plunger 30 at any desired point during its travel. By tapering the plunger 30 at 73, the tendency of the brush jar to return and loosen probe contact is avoided.

The casing or barrel 14 has diametrically opposed finger grips or projections 58 for an operator to grasp while pushing the plunger into the throughbore. Therefore, the operator can hold the protrusion with the fingers of one hand while pressing the boss 52 of the plunger 30 with the thumb or palm, and can easily operate the device with one hand.

The operation for testing the wire will be explained in detail.

The operator first grasps the zero wire 12, which conventionally connects the clip 50 to one side of the WX or circuit to be tested, with the hook 16, and the operator presses the boss while grasping the finger grip 58. When the plunger moves inward, the weaker spring 40 is first compressed and pushes the clamping member 22 outward until the clamping member 22 reaches the pushed-out position opposite the hook. As shown in FIG. 3, a line 12 is captured between the hook and the V-shaped jaws 24 of the clamp member. Opposing V-shaped jaws aligned with the central axis of the sleeve serve as plunger 3
Hold the wire centered against 0.

As shown in FIG. 6 and FIG.
It consists of two parts, effectively forming two separate jaws. The hook 16 has a corresponding slot 6 aligned with the separate jaws, so that the device has a small diameter opening as shown in FIG. The wire 66 can be clamped. The slots 65 also have the function of keeping the mold pins in aligned position when the casing is manufactured by injection molding.

As soon as the stronger force of the spring 38 is overcome by the plunger, this spring is also compressed and the plunger 30
moves outward. This occurs before the clamp member is fully extended or after member 22 reaches the fully extended position. As the plunger moves outward, its pointed tip covers the insulator 60 covering the wire 62.
and makes contact with the centrally held wire as shown in FIG. At this point, the plunger can be locked by twisting the plunger 9 into engagement with the eccentric surface of the inner diameter of the through hole, or by using the screw 63, resulting in a plunger lock.

The operator's hands are free throughout testing the circuit. In this way, the drive member or plunger advances the clamping member and the probe sequentially into its operating position, so that the wire is initially held firmly centrally and then the probe advances into contact therewith.

When the plunger contacts the conductive wire 62 of line 12 as shown in FIG. 3, any current in the circuit under test will cause light bulb 44 to light up.

Thus, a lit bulb 44 indicates that the circuit being tested is conducting current, whereas a non-lit bulb indicates a possible circuit break.

In another embodiment of the invention (not shown), instead of fixing the hook 16 while the jaws or clamping member 22 and probe 26 successively exit the through hole 27,
The hook 16 itself may be slidable at the end of the sleeve member 14. In this case, the jaws or clamping member project out from the open end of the sleeve, while the probe, which may be fixed, projects into an axial throughbore in the clamping member, as in the illustrated embodiment.

A drive member is provided for pulling the hook back towards the open end of the sleeve so that the wire located in the hook is initially clamped between opposing jaws on the hook and the clamping member. Further retraction of the hook also pulls the spring-loaded clamp member into the sleeve, exposing the sharp tip of the probe, which can penetrate the insulation overlying the wire and make contact with the wire. Both the jaws or clamp members and the hooks are spring biased toward the open position. Thus, instead of providing a drive member that pushes the first jaw outwardly, the drive member in this embodiment pushes the second jaw or hook inwardly against the first jaw.

The circuit testing device described above can be used to test bare circuit lines and insulated lines, and is simple and convenient to use. Accuracy is improved because the wire is centrally clamped to the probe while the probe advances to contact the wire. Thus, the probability that the sharp tip of the probe will dislodge the wire due to incorrect alignment and generate a false signal that the circuit is open is substantially reduced or eliminated. This makes contact or accuracy more accurate than with traditional insulation-puncture probes, where the wire may not be properly centered or the wire may move during probe advancement, causing the probe to completely dislodge the wire. Be consistent.

Although preferred embodiments of the invention have been described by way of example, it is understood by those skilled in the art that modifications may be made to the disclosed embodiments without departing from the scope of the invention as defined in the claims. It is understood.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating a preferred embodiment of the circuit testing apparatus of the present invention with a wire held by the apparatus of the present invention partially cut away to disclose that the probe penetrates the insulation covering the wire; FIG. . 2 is a longitudinal cross-sectional view of the apparatus of FIG. 1 showing the wire clamp and probe in a retracted position; FIG. Figure 3 grasps and contacts the wire held by the device. FIG. 2 is an exploded view similar to FIG. 2 showing the wire grasping end of the test apparatus of the invention with the wire clamp and probe in the pushed-out position; FIG. 4 is a sectional view taken along line 4--4 of FIG. 2; FIG. 6 is an end view of the outer sleeve of the test device as seen from above in FIG. 2 with the plunger, probe and clamping member removed; FIG. 6 shows the clamp grasping a small diameter wire; FIG. 3; A diagram showing the hook end of a similar device. FIG. 7 is a front view of a side part showing a partial cross section of another embodiment of the present invention, FIG. 8 is a sectional view taken along line 8--8 in FIG. 7, and FIG. 9 is a 9--9 in FIG. FIG. 10 is a perspective view of the movable jaw member. 12... Wire, 16... Hook, 22... Jaw member, 26... Probe, 30... Plunger,
44...Light bulb, 50...Clip

Claims (16)

[Claims] (1) a hollow outer sleeve; and first and second opposing jaw members attached to one end of the sleeve, one of which
one jaw member in a retracted position, away from the other jaw member, and in an extruded position, opposite the other jaw member and sandwiching a wire of any size centrally held therebetween; an electrically conductive probe attached to the one end of the sleeve and extending axially into the first jaw member; and the one jaw member and the probe. manually operated drive means for continuously pushing the probe into its pushed position; and signal generating means connected to the probe for indicating the presence of an electric current through the probe; a first jaw member: a retracted position in which the probe is within the jaw member;
probes projecting from the ends of the jaw members and movable relative to each other between an extruded position in which they contact a wire held between opposing jaw members, said probes penetrating any insulation covering the wire; circuit testing, wherein the portion of the jaw member facing the probe is not provided with an opening to firmly support the wire while it is pierced by the probe; Device. 2. The apparatus of claim 1, wherein the second jaw member has a hook projecting from the one end of the outer sleeve for hooking the wire to be tested. (3) the first jaw member is in the retracted position at the end of the sleeve, facing the hook and sandwiching the wire between opposing surfaces of the hook and the first jaw member; 3. The apparatus of claim 2, wherein the probe is axially slidable to and from an extended position, and wherein the probe is axially slidable within the first jaw member. (4) the first jaw member has two separate jaws on either side of the probe, and the hook has a slot that is aligned with the jaws and receives the jaws for clamping wires of various diameters; An apparatus according to claim 3. (5) first elastic means for pushing the first jaw member towards its retracted position; and second elastic means for pushing the probe towards its retracted position. and said second elastic means are stronger than said first elastic means, so that the drive means first overcomes the first elastic means and forces the first jaw member into its pushed position, and then the second elastic means 4. A device according to claim 3, overcoming elastic means to push the probe into its pushed-out position. (6) The sleeve has an open through hole, the hook projects from one end of the through hole, the driving means projects from the other end of the through hole, and the first elastic means connects the first jaw member to the through hole. 6. The probe according to claim 5, comprising a first spring acting between the first jaw member and the probe, and the second elastic means comprising a stronger second spring acting between the first jaw member and the probe. Device. (7) The sleeve has an open through hole, the second jaw member has a V-shaped hook member that protrudes from the first end of the through hole, and has its opening surface facing inward; 2. The device of claim 1, wherein the jaw member is axially slidable within the first end of the throughbore and has a corresponding V-shaped jaw at its outer end facing the hook member. 8. The device of claim 7, wherein the first end of the throughbore and the outer surface of the first jaw member have corresponding square cross-sections. (9) the first jaw member has a through hole passing through in the axial direction;
a probe is slidable relative to the first jaw member and extends within an inner end of one of the jaw member through holes in a retracted position;
8. The apparatus of claim 7, further comprising a probe member having a pointed tip projecting outwardly through the other end of the through hole in the pushed-out position. (10) The first jaw member and the probe member each have a larger diameter inner end portion, and the first spring connects the inner end of the first jaw member and the first end of the sleeve through hole. a second stronger spring acting between the inner end of the first jaw member and the probe member to push the probe member inwardly; The device according to paragraph 9. (11) A drive means is slidable within the sleeve at the end of the sleeve opposite the hook for pushing the first jaw member and the probe toward said one end of the sleeve to reach the pushed position. 4. The device of claim 3, including a plunger. 12. The apparatus of claim 1, further comprising locking means for maintaining said movable jaw member and said probe in either pushed-out position. 13. The apparatus of claim 12, wherein the locking means includes cooperating twist locking means on the sleeve and plunger for locking the plunger in the pushed out position in the sleeve. 14. The device of claim 13, wherein the twist locking means has an inner diameter and an outer diameter on at least a portion of each of the sleeve and plunger with corresponding eccentric cross-sections. (15) The locking means includes a screw that moves laterally relative to the sleeve within an opening through the sleeve, the screw being in contact with an outer surface of the drive means as it moves inwardly, 13. A device as claimed in claim 12, for restraining axial movement within the axial direction. 16. The apparatus of claim 14, wherein the screw is located in a boss extending outwardly from the side of the sleeve.