AU670203B2

AU670203B2 - Tool head for a joining tool

Info

Publication number: AU670203B2
Application number: AU68986/94A
Authority: AU
Inventors: Klaus-Dieter Dip.-Ing. Burmeister
Original assignee: Quante GmbH
Current assignee: 3M Deutschland GmbH
Priority date: 1993-08-27
Filing date: 1994-08-09
Publication date: 1996-07-04
Anticipated expiration: 2014-08-09
Also published as: EP0641048B1; ES2099517T3; MD940014U; MD1084C2; AU6898694A; DE59401586D1; MD950268A; EP0641048A1; MY111295A; DE9312883U1

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT 0 S Name of Applicants: Actual Inventor: Address for Service: Invention Title: QUANTE AG Dipl.-Ing. Klaus-Dieter

BURMEISTER

CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

TOOL HEAD FOR A JOINING TOOL S

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The following statement is a full description of this invention, including the best method of performing it known to us Tool head for a ioining tool The present invention relates to a one-piece tool head for a joining tool for the strip-free contacting of a wire in a connecting contact which is supported in a housing.

Such joining tools for contacting strip-free connecting contacts are known in the state of the art in various forms. Thus, for example, patent CH 669 284, DE-OS 34 32 028, utility model DE-GM 80 13 494 and patent DE 38 03 969 respectively describe joining tools in which a wire overlength is removed by means of a shears-type cutting apparatus during the strip-free contacting of the wire in 15 the connecting contact. On account of their complicated mechanics, such tools have a complex multi-part structure i and are therefore relatively expensive in manufacture.

A tool head is known from DE-OS 36 23 258. In this known tool head, a knife is provided as a separating means for separating the wire overlength at a forward end of a limb. This knife separates the wire overlength at the end of the contacting process, a further movement of the e contacted wire through the housing of the connecting S• 25 contact being prevented in the cutting step.

:It is the problem (object) of the present invention to provide a tool head for a joining tool (wiring tool) which can be produced cheaply and in a material-saving manner and is free of wear, wherein a quick and reliable contacting should be simultaneously guaranteed.

According to a first embodiment of the present invention there is provided a method of strip-free contacting a wire in a connecting contact, which is supported in a housing, with a joining tool. having a tool head, the wire being pressed by forward movement of the tool head into S the connecting contact and thus being stripped, contacted and clamped, characterized in that at the end of the contacting step, the wire overlength is sheared off at an edge of the housing by a shearing edge which is formed by a shearing surface and an inner surface of the tool head wherein the shearing is performed by this housing edge in co-operation with the shearing edge of the tool head.

According to a further embodiment of the present invention there is provided a one-piece tool head for use in the method described above the tool head having a tool axis, two limbs extending parallel to the tool axis which respectively for a ram, an opening between the limbs, a separating means provided at a forward end of a limb for separating off a wire overlength at an edge of the housing, a guiding groove for the wire is respectively 15 provided at the forward ends of both limbs, the guiding groove of the limb without a separating means is deeper as seen in the direction of the tool axis than the guiding groove of the limb with the separating means, the groove bases of both guiding grooves respectively form a S 20 ram, and the base groove of the guiding groove of the 0 limb with the separating means forms the shearing surface with shearing edge.

0 .In accordance with a preferred embodiment of the invention, a guiding groove for the wire is provided at the forward ends of both limbs of the tool head, both of these guiding grooves being flush and perpendicular to 2 the tool axis. Thus, the wire to be contacted can be inserted in a convenient manner into the flush guiding grooves when contacting the end of the wire to be contacted so that the wire end can be guided into the desired connecting contact by means of the wiring tool. On account of the fact that the wire end is fixed in the guiding grooves, this can be securely inserted into the respective connecting contact. Thus, the wire does not first need to be guided to the respective connecting contact and the wiring tools then subsequently applied, rather the wire can be guided together with the wiring tool to the connecting contact. This ensures a substantially quicker and safer mode of operation, since a slipping of the'wire end out of the connecting contact to be assembled can no longer occur.

Further, in accordance with the invention, the guiding groove of the limb without a separating means is deeper, as seen in the direction of the tool axis, than the guiding groove of the limb with the separating means. Simultaneously, the groove bases of both guiding grooves form a ram, the groove base of .20 the guiding groove of the limb with the separating means 0 1 forming a shearing surface with a shearing edge. These features according to the invention not only result in the wire being 0. securely guidable upon contacting with the wiring tool, but in addition to this, on account of the guiding grooves of different depth, a shearing off of the wire overlength behind o* the connecting contact by means of the shearing edge provided in the tool head also ensues at the end of the contacting step.

In this case, the shearing means is not a knife known from the state of the art which, on the one hand, is difficult to manufacture and, on the other hand, subject tu wear, but in accordance with the invention, the shearing off of the wire overlength ensues by means of the shearing edge of the tool head in cooperatio-a with an edge of the housing of the connecting contact. On account of this special design, a shearing member is provided which is not subject to any wear, since the shearing-off ensues by means of cooperation of one edge of the groove base with an edge of the housing. Further, in the case of the tool head according to the invention, additional shearing or cutting separation means are no longer needed, i.e. the tool head according to the invention can be manufactured in a particularly materialsaving manner.

Advantageous embodiments of the invention are characterized in the dependent claims and described below.

Thus, the shearing surface can form an angle to the tool axis of between 900 and 1200 as seen in the operating direction. In this manner, an obtuse angle is formed between the shearing surface and the operating direction, i.e. the tool axis, which guarantees a good shearing-off of the wire overlength. This obtuse angle also ensures that in contrast to a knife edge no wear occurs at oe the shearing edge.

ol In accordance with a further preferred embodiment of the invention the opening provided between the limbs of the tool head can be substantially U-shaped. This ensures that the tool head can be securely guided over the connecting contact to be wired.

.555.5 S 25 According to a further preferred embodiment of the invention, recesses are provided to both sides of the opening which receive a guiding contour of the housing.

In particular, these recesses can also expand conically from the forward end of the tool head in the direction of its rearward end. This again makes a precise operation easier, as a good positioning of the tool head is possible on account of the relatively narrow entry of the openings. It is also ensured by means of the conic expansion that the wiring tool does not cant during the contacting step, rather a certain (small) play is provided so that the shearing-off of the wire can ensue A AQ quickly, Particularly good guidance of the tool head in the connecting contact housing is achieved if the recesses to both sides of the opening extend arcuately at its rearward end.

According to a further preferred embodiment of the invention, two guiding webs can be formed by the opening between the limbs of the tool head and the recesses to both sides of the opening, the webs

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C C o* e o S C C o eo o*oo I extending parallel to the tool axis. Such guiding webs again increase the ease of operation, since the tool can be purposefully inserted into the respective contacts.

According to a preferred embodiment in this case, the forward end of at least one guiding web can form an additional ram which mechanically secures the wire to be contacted in the housing of the connecting contact. In this case, a pressing down of wire into the connecting contact initially ensues by means of the rams which are formed by the groove base of both guiding grooves of the limbs. However, an additional ram is formed by means of the forward end of the one guiding web which secures the wire in the housing behind the contacting contact after shearing off of the wire overlength at the end of the contacting step. On account of this, exceptionally reliable clamp fits are achieved.

According to a furtherkembodiment, the edges of the groove walls facing the opening can be chamfered in the case of at least one of the guiding grooves. This design again simplifies the insertion of the tool head into the connecting contact.

According to an even further embodiment, the tool head can consist of metal. This provides an exceptionally robust and simultaneously easily manufacturable tool head which is subject to practically no wear 0 When the tool head according to the invention is secured to a grip part, this provides a joining tool with the previously described advantages. The grip part of this joining tool can consist of plastic.

The present invention is described in the following in a purely exemplary manner with reference to a preferred embodiment as well as by means of the enclosed drawings, in which:

I-

Fig. 1 shows a partly sectioned side view of a tool head according to the invention as well a part of the connecting contact housing; Fig. 2 shows a view of the tool head according to Fig. 1 as seen in the direction II; and Fig. 3 shows a view of the tool head according to Fig. 1 as seen in the direction III.

As Fig. 1 shows, the tool head 10 has two parallel limbs 12 and 14 which form an opening 16 therebetween. The limbs 12 and 14 are parallel to the tool axis X. A separating means is formed by a shearing surface 18 and a shearing edge 24 at the forward end of the limb 12.

As shown in Fig. 2, the shearing surface 18 is formed by the groove base of a guiding groove 20 formed at the forward end of the limb 12.

Fig. 1 shows that the shearing surface 18 forms a shearing edge 24 together with an inner surface 22 of the limb 12. The angle between the shearing surface 18 and the tool axis X or the inner surface 22 of the limb 12 parallel thereto is approximately 1050 as seen in the operating direction B of the joining tool.

9 As Fig. 1 shows, the edges of the guiding groove 20 facing the opening 16 are provided with a chamfering 26, which simplifies the operation of the joining tool.

The upper limb 14 of the tool head 10 as seen in Fig. 1 is also provided at its forward end with a guiding groove 28 which is flush with the guiding groove 20 of the lower limb 12, although as seen in the direction of the tool axis X the guiding groove 28 of the limb 14 is deeper than the guiding groove of the limb 12. As a comparison of Figs. 2 and 3 show, a groove base 19 (Fig. 3) of the guiding groove 28 is more distant from the forward end of the tool head than the groove base 18 (Fig.

2) of the guiding groove 20. However, both guiding grooves and 28 extend perpendicularly to the tool axis X.

The edges of the groove walls of the guiding groove 28 facing the opening 16 are also provided with chamferings 30 to simplify the insertion of the tool head.

The opening 16 between the limbs 12 and 14 of the tool head is substantially U-shaped. Provided in this case to both sides of the opening 16 are recesses 32 and 32' (cf. Figs 2 and 3) which can receive a guiding contour of a housing 72 of a connecting strip 70. In this case, the recesses 32, 32' expand (as seen from the side in Fig. 1) from the forward end of the tool head 10 in the direction of its rearward end. The rearward ends 33, 33'of the recesses 32, 32' are arcuate in this case so that the recesses 32, 32'form a drop-like contour as seen from the side.

As Fig. 1 shows, respectively formed by the opening 16 and the recesses 32, 32' are a guiding web 34 on the limb 12 and a guiding web 36 on the limb 14. These guiding webs 34 and 36 extend parallel to the tool axis X. In this case, the forward end 38 of the web 34 together with the groove base 19 form an additional ram which clamps the wire 76 in the housing 72 of the connecting strip As Figs. 2 and 3 show, the tool head is tapered at its forward end.

The right-hand part of Fig. 1 shows the structure of the connecting strip 70 which includes the housing 72 as well as a connecting contact 74. A wire 76 which is to be contacted and the overlength 77 of which is to be sheared off is inserted in the shown example into the connecting contact 74.

-I I I The procedure of contacting and shearing-off when using the tool head according to the invention is described in the following.

At the beginning of the contacting step, the wire 76 can be inserted into the connecting contact, as shown in Fig. 1.

However, the wire 76 can also be advantageously inserted into the guiding grooves 20 and 28 at the beginning of the contacting step, on account of which a precise positioning of the wire in the connecting contact is ensured. In this step, both the groove base 18 of the guiding groove 20 as well as the groove base 19 of the guiding groove 28 serve as a ram. At the end of the contacting step, the wire overlength 77 is sheared off by the shearing edge 24 at an edge 78 of the connecting strip 70. Simultaneously, the forward end 38 of the web 34 acting as an additional ram presses the wire 76 into a clamp S[ opening of the connecting strip 70, not shown in more detail.

In this manner, an optimal contact is guaranteed.

On account of the fact that the recesses 32, 32" conically expand, a certain play is simultaneously provided which simplifies shearing-off and prevents a canting of the tool.

After the overlength 77 has been sheared off, the wire 76 is secured and contacted in the best possible manner in the connecting contact 74 and the housing 72 of the connecting strip 70, the wire overlength having been sheared off at the same time. Thus, the tool head 10 can be pulled out again against the operating direction B.

On account of the inventive design of the tool head, only a small application of force is required for contacting and shearing.

Additionally, the tool head 10 is secured to a grip part (not shown) which consists of plastic. This provides a very easily opertable joining tool.

Claims

1. A method of strip-free contacting a wire in a connecting contact, which is supported in a housing, with a joining tool having a tool head, the wire being pressed by forward movement of the tool head in to the connecting contact and thus being stripped, contacted and clamped, characterized in that at the end of the contacting step, the wire overlength is sheared off at an edge of the housing by a shearing edge which is formed by a shearing surface and an inner surface of the tool head wherein the shearing is performed by this housing edge in co- operation with the shearing edge of the tool head.

2. A one-piece tool head for use in the method according to claim 1, the tool head having a tool axis, 15 two limbs extending parallel to the tool axis which respectively form a ram, an opening between the limbs, a separating means provided at a forward end of a limb for separating off a wire overlength at an edge of the housing, wherein a guiding groove for the wire is S. 20 respectively provided at the forward end of both limbs, the guiding groove of the limb without a separating means is deeper as seen in the direction of the tool axis than the guiding groove of the limb with the separating means, the groove bases of both guiding grooves respectively forming a ram, and the base groove of the guiding groove of the limb with the separating means forming the shearing surface with the shearing edge.

3. A tool head according to claim 2, wherein the shearing surface forms an angle of between 90 and 120 to the tool axis as seen in the operating direction.

4. A tool head according to claim 2 or claim 3 wherein the opening is substantially U-shaped. A tool head according to any one of claims 2 to 4 wherein two recesses for receiving a guiding contour of the housing are provided, one recess on each side of the opening.

6. A tool head according to claim 5, wherein the recesses expand conically from the forward end of the e~< tool head in the direction of its rearward end.

7. A tool head according to claim 4 or claim S S *5 S S S S *5 S S S S .55. 5 S S 5.5. Se .5 S S SSS S 5* S S S wherein the rearward end of each recess is arcuate.

8. A tool head according to claim 5, wherein two guiding webs are formed parallel to the tool axis by the opening and the recesses.

9. A iocl head according to claim 8, wherein the forward of the guiding webs form rams which mechan.i' i'.imp the wire in the housing. 'l head according to claim 2, wherein the edges he groove walls facing the opening are cha;fer; in the case of at least one of che guiding grooves.

11. A tool head according to any one of claims 2 to characterized in that it consists of metal.

12. A tool head substantially as herein described 15 with reference to the accompanying drawings. S.13. A joining tool comprising a tool head according to one of the preceding claims and a grip part to which the tool head is secured.

14. A joining tool according to claim 13, characterized in that the grip part consists of plastic. DATED this SEVENTEENTH day of NOVEMBER 1995 QUANTE AG By their Patent Attorneys CULLEN CO *4 4 e* e I I L- d C Abstract of the disclosure A one-piece tool head for a joining tool for strip-free contacting a wire in a connecting contact includes a tool axis as well as two limbs (12, 14) which extend parallel to the tool axis and respectively form a ram. An opening (16) is provided between the limbs, and a separating means for separating off a wire overlength (77) is provided at the forward end of one of the limbs Both forward ends of the limbs (12, 14) respectively have a guiding groove (20, 28) for the wire Both guiding grooves (20, 28) are flush and extend pe.pandicular to the tool axis. The guiding groove (28) *i of the one limb is deeper than the guiding groove (20) of the other limb The groove base of the guiding groove (20) of Sthe limb (12) forms a shearing surface (18) with a shearing edge (24). (Fig. 1) 020 e a too* e