AU603791B2 - A terminal contact cutter for connecting insulated electric wires - Google Patents

Description

FORM 10 FORM 10SPRUSON FERGUSON COMMONWEALTH OF AUTRALIA PATEN ATSAC1 ~g COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE: Class Int. Class Complete Specification Lodged: Accept~ed: Published: Priority: Related Art: This d otirn',nt cont:Jin the =ind in-is niade tpuck Sectio)ii 49 anid is cor,'..ct tih printing. __J Name of Applicant: Address of Applicant: Actual Inventor(s): Address for Servicoe: Complete Specification SIEMENS AKTIENGESELLSCHAPT Wittelsbacherplatz 2, D-8000 Munchen 2, Federal. Republic of Germany HANS SCHOLTHOLT and EWALD STEINER Spruson Ferguson, Patent Attorneys, Level 33 St Martins Tovyer, 31 Market Street, Sydney, New South Wales, 2000, Australia for the invention entitled: "A TERMINAL CONTACT CUTTER FORl CONNECTING INSULATED ELECTRIC WIRES" The following statement is a full description of this invention, including the best method of performing it known to us SBR/na/183F i

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ABSTRACT:

A TERMINAL CONTACT CUTTER FOR CONNECTING INSULATED ELECTRIC WIRES: A terminal contact cutter comprises a central clamping slot between two clamping jaws At their free front ends the clamping jaws are each provided with a bevel (4) which forms an acute angle with the clamping slot When an insulated electric wirr is impressed, its insulation is pierced by the tips of the clamping jaws and is forced outwards, and the metallic core of the wire is clamped between the clamping jaws FIGURE 2 t.

I I t 1A "1A lA A TERMINAL CONTACT CUTTER FOR CONNECTING INSULATED ELECTRIC WIRES The invention relates to a terminal contact cutter for connecting insulated electric wires. One terminal cutter of this kind has been disclosed, for example, in the German Specification No. AS 1 263 130, in which a terminal cutter is described that is formed from flat material, has a central slot into which the metallic core of an insulated electric wire can be impressed, so as to form a terminal contact. The front ends of the side flanks, which delimit the slot, form an acute-angled cutting edge with respect to the inner walls of the flanks, and this acute-angled cutting edge facilitates cutting into the insulation material on the wire. The front ends extend outwards in a concave curve to form a projecting end section after an intermediate clamping portion of the slot, which itself widens adjoining the cutting edge, so that a very acute-angled cutter is formed.

One object of the present invention is to provide an improved terminal contact cutter such that wires having a very hard, tough and thick Pinsulation can be reliably and cost-favourably connected.

accordance with the present invention there is disclosed a cutting clamp for connecting a single insulated electric wire which can be inserted transversely into a clamping slot of the cutting clamp, which consists of Itht= material, where the clamping slot lies between two clamping jaws, between which the core of the insulated electric wire can be clamped so as rort to form a contact, and which, at the f9r=eend of the clamping slot, are provided with cutting edges which cut into the wire insulation, where the 2 5 distance between the cutting edges is approximately equal to the core diameter of the wire, and where the front end of the clamping jaws, which extend obliquely in the region of the cutting edge, forms an acute-angled cutter with the inside of the clamping jaws, and wherein the tip of the flanks is of wedge-shaped flat formation, and that the front end continues obliquely towards the outside of the clamping jaws, and that the insides of the clamping jaws extend in parallel to one another adjoining the cutter so as to pierce the insulation of the wire and force the insulation outwardly during such piercing.

2 clamping jaws, extending obliquely from the cuttingg s forming an acute-angled cutter, the tip of the s being of wedge-shaped flat formation, and the f nd continuing obliquely towards the outside of tl.- .mping jaws, whilst the insides of the clamping Thus, the terminal contact cutter has a simple geometric shape which can be favourably produced by punching technology.

The shaping is such that the wire insulation is not shaved off as the wire is impressed, but is pierced, and in the contacting zone it is pushed outwards by the level front end, without being severed. It's fr, periphery then embraces the terminal contact and thereby increases the clamping force. Piercing of the insulation is less detrimental "to wear than shaving, as the cut surfaces are smaller and as the oblique front end produces an externally-directed force component which relieves the load on the cutting edge. As the insides of the i, 'clamping flanks extend mutually parallel, each cutting edge is better j t supported, which improves its durability. A terminal contact cutter designed in this way is particularly suitable for wires provided with a thick insulation which is difficult to cut, as is the case for example with external connection lines of telephone installations.

t An advantageous further development of the invention, |ij in which the internal width between the two tips of the flanks is somewhat greater than the core diameter of the wire, and the clamping slot has a sharp-edged, stepped constriction arranged between the tips and a clamping zone for the wire, and that the internal width of the clamping slot below the sharp-edged constriction is Ssomewhat less than the diameter of the wire core, serves to further 3 V relieve the load on the cutting edge, as the metal core of the wire slides past the cutting edge. As a result the cutting edge retains its sharpness for subsequent connecting operations. Because of the wider inlet, the wire can be more easily centred, thus reducing the danger of damage. An additional cutting edge is formed at the stepped constriction, and this removes any residual insulating layer from the wire core and thus ensures a reliable contact.

The invention will now be described with reference to the drawings, in which:- Figure 1 is a side view of one exemplary embodiment tt of a terminal contact cutter, together with a cross-section of an insulated electric wire, prior to connection; Figure 2 shows the components shown in Figure 1 following the making of a connection; and Figure 3 is a plan view of the assembled components shown in Figure 2.

In accordance with Figures 1, 2 and 3, a terminal contact cutter 1 is produced from flat material. It includes a central slot 2 arranged between jaws 3. At their free front ends the jaws are provided with a bevel 4 which extends at an acute angle to the inner point of each jaw, where it forms a sharp cutting edge Each bevel 4 extends in a straight course to the outside edge of its jaw 3. The insides of the jaws extend mutually parallel to form a clamping portion.

When an insulated electric wire 6 is inserted, its insulation is pierced by the cutting edges and forced outwards by the bevel 4, which extends at an angle of less than 45'. This insulation section embraces the exterior of the two jaws 3. The 4 metallic core of the wire 6 is clamped in the slot 2 between the two jaws 3, and electrically contacted therewith.

At its outer end the slot 2 is wider than the core diameter of a given wire 6. This insertion zone terminates at a sharp-edged stepped constriction 7, which is adjoined by the actual clamping portion 8. The internal width o the clamping portion 8 is less than the core diameter of the wire 6, so that the wire can be contacted with sufficient force.

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Claims (3)

1. A cutting clamp for connecting a single insulated electric wire which can be inserted transversely into a clamping slot of the cutting clamp, which consists of wtb material, where the clamping slot lies between two clamping jaws, between which the core of the insulated electric wire can be clamped so as to form a contact, and which, at the fte@Aend of the clamping slot, are provided with cutting edges which cut into the wire insulation, where the distance between the cutting edges is approximately equal to the core diameter of the wire, and where the front end of the clamping jaws, which extend obliquely in the region of the cutting edge, forms an acute-angled cutter with the inside of the clamping jaws, and wherein the tip of the flanks is of wedge-shaped flat formation, and that the front end continues obliquely towards the outside of the clamping jaws, and that the insides of the clamping jaws extend in parallel to one another adjoining the cutter so as to pierce the insulation of the wire and force the insulation outwardly during such piercing.

2. A cutting clamp as claimed in claim 1 wherein the internal width between the two tips of the flanks is somewhat greater than the core T diameter of the wire, and that the clamping slot has a sharp-edged, stepped constriction which is arranged between the tips and a clamping zone for the wire, and that the internal width of the clamping slot below the sharp-edged constriction is somewhat less than the diameter of the wire core.

3. A terminal contact cutter substantially as described herein with reference to the drawings. DATED this FIFTH day of APRIL 1990 Siemens Aktiengesellschaft Patent Attorneys for the Applicant SPRUSON FERGUSON IAD/921o