GB2331632A

GB2331632A - Temporary connection tool

Info

Publication number: GB2331632A
Application number: GB9724637A
Authority: GB
Inventors: Gareth Bryn Jones; David Antony Bell
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-11-22
Filing date: 1997-11-22
Publication date: 1999-05-26
Anticipated expiration: 2017-11-22
Also published as: GB2331632B; GB9724637D0

Abstract

A tool for temporary connection to a wire 8 or the like comprises a hollow sleeve 5, a core 2 which moves through the sleeve 5, and an end element 8,13 for engaging the wire 9 so that the core 2 can be moved to pierce the insulation of the wire and contact the wire, characterised in that the sleeve and core are capable of bending in unison. The sleeve may be covered with insulation 10. The sleeve may be formed of curtain spring wire and return to shape after bending or may be formed of ductile metal tube which retains a set bend. The core is pushed against the bias of a spring 6 by pressing a button 4a attached to the core whilst clasping a handle 4b attached to the sleeve.

Description

1 TOOL 2331632

It is frequently necessary in the field of electrical circuitry to be able to enter a circuit and either measure the potential at that point or positively to apply a potential to that point. If the circuit or target wire can be seen but not reached as for instance in a complicated array of closely packed circuits such as might be present in a modern electronics installation the entry to the circuit might prove very difficult. The tool of the present invention is provided to assist in such a situation.

The object of the present invention is to provide a tool which can be adapted to circumvent one or more obstructions lying between an operator and a target circuit or wire and make it possible to enter the circuit or make a connection with the wire for the purpose of measuring or applying a potential thereto.

According to the present invention a tool for assisting in the measurement of potential in or applying a potential to an electrical circuit comprises an elongated core element, an elongated sleeve element closely encircling the core element a shaped locating element fastened to a first end of said sleeve element and adapted to engage and hold a target insulated electrical wire, a sharp end attached to or formed on a first end of said core element being positioned closely adjacent to but spaced lengthwise from said shaped locating element, both of said elements being capable of bending in unison in at least one lengthwise plane at at least one place along the length of the tool, said core element being adapted by connection means to be connected to a meter or a source of potential so that when the sharp end is advanced sufficiently towards the target wire held in the locating element to cut through the insulation of the target wire its potential may be measured or altered as the case my be.

BD1 2 1 1 Preferably both of said elements are capable of bending in unison in any lengthwise plane at any place along the length of the tool. Further, a spring means may be positioned at the second end of the sleeve element and the core element and is operative to bias said locating element away from said sharp end at said first end. The sleeve element may be electrically conductive and in continuous electrical contact with the core element and in this case includes an elongated insulating element closely encircling said sleeve element and fastened thereto.The connecting means is constituted by a wander lead connected either directly to said core element or the sleeve element. The sharp end may be constituted by a spike and the locating element may be constituted by an outwardly presented bifurcation adapted to trap a target wire against an adjacent reactive structure or by a hook-like formation.

The core and sleeve elements may be arranged to return to their former natural relative positions on removal of bending forces applied to the tool, but it may be preferable for them to retain their bent positions on removal of bending forces. To this end one of the core, sleeve or insulating elements is structurally arranged to resist the return to a former shape after bending, though two of those elements may be serve this purpose. An elongated fibre optic viewing element may be incorporated alongside said insulating element there being an objective lens adjacent the said first ends and viewing apparatus at the opposite end.

The preferred embodiments of the invention will now be described with reference to the accompanying drawings of which; Figure 1 represents a cut-away and partially sectioned scheme, Figure 2 is a cross section in the plane II-II seen in Figure 1.

Figure 3 is a view similar to a part of Figure 1 of an BD1 3 alternative end fitting.

Referring to figure I the tool 1 has a elongated steel core wire 2,shown as a single solid line, extending from a spike 3, formed by sharpening the core wire 2, at the first or inner end, to a thumb button 4a at the second or outer end. The core wire 2 is closely encircled by an elongated sleeve 5 in which it can slide longitudinally outwardly under the action of a spring 6 placed between a washer 7a fixed to the top end of the sleeve 5 and a washer 7b fastened to the outer end of the core 2 and the thumb button 4a. A double finger rest 4b is fixed to the washer 7a so that pressure between thumb and fingers will overcome the outward spring bias to move the core 2 and spike 3 longitudinally inwardly. The sleeve 5 terminates at its inner end in a bifurcated locator 8 capable of trapping a target wire 9 in position so that the spike 3 may be advanced to penetrate the target wire insulation and make contact with the target wire 9.

Conveniently the sleeve 5 is made of metal and needs to be insulated. To this end an elongated insulating sheath 10 is provided extending from the washer 7a to the locator 8. In this version also a wander lead 11 is attached electrically to the washer and a plug 12 which may be plugged into or otherwise connected to a measuring instrument I or a source of potential either positive or negative or zero (ground) P.

An important part of the invention is the ability of the core 2, sleeve 5 and sheath 10 to bend in several planes along its length so that the locator can be advanced past immovable or other awkward obstructions. The tool shown in Fig 1 has a steel core 2 and a metal sleeve 5 so they are electrically as one and the wander lead 11 connection can be made to the washer 7a. The sleeve 5 can be of a close spiral construction commonly described as 'curtain' wire and will spring back to the straight condition after the bending forces have been removed. However, the preferred sleeve 5 is made of a ductile metal tube so that the operator may set bends in the tool to BD1 1--- 1 1 1 4 cater for avoidance of the obstructions. The sleeve 5 may be made of non- conducting plastic material which may be set, in which case the wander lead 11 will be connected directly to the core wire 2 by being attatched to washer 7b. In such a case the outer sheath 10 of insulating material may not be needed.

Figure 3 shows a version of the locator in the form of a flattened hook 13, the operating arrangement being that the target wire is trapped by the hook in position to receive the spike 3, when contact needs to be made.

Certain judgments and skills need to be employed by the operator in deciding how to bend or otherwise employ the tool according to the present invention but the tool itself enables the user to perform tasks which might not otherwise be possible.

BD1

Claims

1 A tool for assisting in the measurement of potential in or applying a potential to an electrical circuit comprises an elongated core element, an elongated sleeve element closely encircling the core element and permitting lengthwise relative movement, a shaped locating element fastened to a first end of said sleeve element and adapted to engage and hold a target insulated electrical wire, a sharp end attached to or formed on a first end of said core element and being positioned closely adjacent to but spaced lengthwise from said shaped locating element, both of said elements being capable of bending in unison in at least one lengthwise plane at at least one place along the length of the tool, said core element being adapted by connection means to be connected to a meter or a source of potential so that when the sharp end is advanced sufficiently towards the target wire held in the locating element to cut through the insulation of the target wire its potential may be measured or altered as the case my be.

2. A tool as claimed in claim 1 wherein both of said elements are capable of bending in unison in any lengthwise plane.

3. A tool as claimed in claim 1 or claim 2 wherein both of said elements are capable of bending in unison at any place along the length of the tool.

4. A tool as claimed in claim preceding claim, wherein a spring means is positioned at the second end of the sleeve element and the core element and is operative to bias said locating element away from said sharp end at said first end.

5. A tool as claimed in claim 1 wherein said sleeve element is electrically conductive and is in continuous electrical contact with the core element and includes an elongated insulating element closely encircling said sleeve element and fastened thereto.

6. A tool as claimed in claim 1 or claim 2 wherein said connecting means is constituted by a wander lead connected BD1 6 either directly to said core element as dependent from claim 1 or claim 2 or to said sleeve element as dependent from claim 2.

7. A tool as claimed in any preceding claim wherein said sharp end is constituted by a spike.

8. A tool as claimed in any preceding claim wherein said locating element is constituted by an outwardly presented bifurcation adapted to trap a target wire against an adjacent reactive structure.

9. A tool as claimed in any one of claims 1 to 7 wherein said locating element is constituted by a hook-like formation.

10. A tool as claimed in any preceding claim wherein the core and sleeve elements revert to their former natural relative positions on removal of bending forces applied to the tool.

11. A tool as claimed in any one of claims 1 to 9 wherein the core and sleeve elements retain their bent positions on removal of bending forces applied to the tool

12. A tool as claimed in claim 11 in the case where the tool incorporates an elongated insulating element wherein one of the core, sleeve or insulating elements is structurally arranged to resist the return to a former shape after bending.

13. A tool as claimed in claim 11 in the case where the tool incorporates an elongated insulating element wherein two of the core, sleeve or insulating elements are structurally arranged to resist the return to a former shape after bending.

14. A tool as claimed in any one of the preceding claims wherein an elongated fibre optic viewing element is incorporated alongside said insulating element there being an objective lens adjacent the said first ends and viewing apparatus at the opposite end.

15. A tool substantially as described herein and illustrated by reference to figures 1 and 2 of the accompanying drawings.

16. A tool substantially as described herein and illustrated by reference to figures 1,2 and 3 of the accompanying drawings.

BD1