EP1922787B1 - Double crimping tool - Google Patents

Abstract

A double crimping tool for fastening an electrical conductor with insulation to a contact element, which includes a front crimping unit with a front drive cam plate and front crimping stamps for forming a front press section in the region of the stripped end of the conductor; and a rear crimping unit with a rear drive cam plate and rear crimping stamps for forming a rear press section in the region of the insulation of the conductor. The crimping stamps are displaced by rotation of the drive cam plates. By levers the two drive cam plates are connected to a shared force introduction element such that during the pressing procedure at first optionally the front or the rear drive cam plate is rotated by a predefined initial pressing angle while the other drive cam plate is made to rotate only after the first drive cam plate has attained the initial pressing angle.

Description

The present invention relates to a Doppelcrimpwerkzeug according to the preamble of the appended claim 1 for mounting an electrical conductor with insulation on a contact element.

Such a tool is used to attach a surrounded with an insulating sheath electrical conductor, which may be formed as a single or multi-wire, to a contact element, such as a ferrule, a cable lug or a contact socket. The double crimping tool is intended both to produce an electrically conductive connection between the conductor and the contact element and also to secure an insulation section adjoining the stripped conductor end by a pressing operation on the contact element. The crimping tool can be designed as a hand tool or as a machine-driven tool.

From the US 3,713,322 is a crimping tool for connecting a contact to a wire end known. This tool uses two pairs of press dies, which are displaced in guide slots radially to a receiving cross section in order to press the sleeve positioned in the receiving cross section with the inserted wire end. In this case, the first pair of stamps with flat anvil surfaces is first brought to the contact sleeve in order to press it against an oval shape. During the further crimping process, the pair of punches positioned transversely to the first pair of punches is brought to the pre-pressed contact sleeve in order to complete the crimping process by means of curved anvil surfaces. The four rams are driven by a common cam ring, wherein the feed of the individual ram is determined by the radially changing surface design on the inside of the cam ring. With this known crimping tool only a crimping in the region of the stripped end of the cable is possible. In addition, large forces must be applied during the crimping process by the user of the hand tool.

The US 5,415,015 shows a crimping tool, with which in a single crimping both in the portion of the stripped electrical conductor and in the insulation portion, a press connection can be made with the contact element to be connected. For this, the hand tool described has on two opposing punches in each case two differently shaped, axially one behind the other anvil surfaces which simultaneously attack the contact area and the insulation area during crimping to deform the sleeve-shaped portions of the contact pin. The punches must be specifically adapted to the shape of the contact sleeve. The processing of different cross sections is thereby largely excluded. In addition, can be produced with the known crimping tool no crimps that would meet high safety requirements for continuous load the crimping.

The execution of such a safety requirements sufficient crimp and the basic structure of a suitable tool describes the standard MIL-C-22520/20, March 19, 1976, which calls for the use of four Crimpstempeln, each offset by 90 ° at the periphery of the crimp and perform the pressing process in pairs. The requirements of this standard, for example, of the crimping tool according to the above US 3,713,322 implemented. When designing a standard-compliant crimping tool, the person skilled in the art is therefore limited in his freedom of development, so that until now hardly any leeway was recognizable for further developments.

From the WO 2004/021523 A1 , Which corresponds to the preamble of claim 1, can be seen a crimping tool, with which the simultaneous production of a press connection in the section of the stripped conductor end and in the adjacent insulation section to be made possible. For this purpose, two axially successively arranged crimping units are provided, each having four crimping dies, which are simultaneously displaced radially into the receiving cross section during the crimping process in order there to press the contact sleeve with the conductor. Simultaneous pressing in the conductor and insulation area requires extremely large forces, which can not be applied by the user on a hand tool just for larger cross sections. The heavy stress leads to heavy wear of the press ram. In addition, there may be an unfavorable positional shift of the electrical conductor in the contact sleeve, if in the isolation area already pressing forces act before a sufficient attachment of the conductor has been made in the contact sleeve. Finally, the previously known crimping tool does not allow to process different cross sections without exchanging the individual pressing dies.

The DE 195 07 347 C1 describes a crimping tool for wire end ferrules. This pressing tongs uses six pressing jaws, which are pivotally mounted on bearing pins and are pivoted upon actuation of an annular pivoting lever into the wire end receiving cross-section in order to carry out the pressing operation by the resulting reduction in cross-section. However, this crimping pliers does not allow the simultaneous production of two crimps in axially successive sections and is also not allowed when crimping wire ends according to the above standard with wire end ferrules.

From the DE 40 23 337 C1 is a tool for crimping a double connection of a connector with a conductor on the one hand and insulation on the other hand known. The tool comprises a tool head which has a frame and an axially fixed to the frame pressing jaw and an axially guided on the frame pressing jaw. The axially guided pressing jaw has at least two stamped plates provided with working profiles and is pressed by a drive against the axially fixed pressing jaw, which has there at least two anvil plates provided with working profiles. At least one of the anvil plates or stamp plates is pivotable on the respective other anvil plate or stamp plate about an axis arranged perpendicular to the main direction of extension, so that another Edge with a different trained work profile when pressing the jaws is effective.

From the DE 195 09 442 C2 is a crimping tool for manually attaching a connector to a cable known in which four dies inserts are placed with several crimp nests on two mouth jaws. The four crimp nests are arranged side by side lying in the die inserts, of which at least one is aligned so that the clamping of the strain relief for the cable to be fastened to the connector on opposite sides of the die inserts. The solution known from this document is particularly suitable for crimping plugs to ignition cable.

From the EP 1 598 906 A1 is a crimping tool with a rotatable punch known, which has four different sized crimping profiles on its sides. The rotatable punch is pressed against a fixed pressing jaw, which has two different sized crimp nests. By rotating the rotatable punch, one of the four different crimp profiles can be selected, with the selected crimp profile facing the mating one of the two crimp nests.

The object of the present invention is therefore to provide an improved crimping tool, with which in a single crimping process a double crimp connection can be made in axially offset regions of a contact element in order to connect both the stripped conductor end and the end region of the insulation to the contact element. In cross-sections customary for crimp connections, this should be possible with low forces that can be applied by a user in one-handed operation, so that the crimping tool can also be designed in the form of a hand-held pliers. The crimping tool should be able to be adapted to different contact element types, contact element sizes and cable cross-sections with little effort. After all the crimping tool should open up the possibility, at least in the section of the stripped wire end to produce a MIL standard crimp connection.

This object is achieved by a Doppelcrimpwerkzeug according to the appended claim 1.

In the case of the double crimping tool, a front crimping unit and a rear crimping unit are each actuated by a separate drive cam plate, whereby both cam plates are connected to a common force introduction element via levers such that first one drive cam plate is rotated by a predefined pre-pressing angle during the pressing process and only the second Drive cam plate is set in motion to crimp the insulation area. Depending on the embodiment, it is possible that the crimping in the conductor area is partially or almost completely completed before the crimping process is performed in the isolation area. By this measure, the applied forces reduce considerably. The actuation of the drive cam plates can also be done in reverse order, so that only in the rear pressing area and then crimped in the front pressing area.

Furthermore, the necessary driving force can be reduced, in which a force-displacement conversion is carried out by means of the knee lever technology known per se.

Preferably, the front crimping unit, with which the crimped connection is produced in the stripped conductor section, comprises four crimping dies, which are displaceable radially relative to the receiving cross section. The front crimping unit is thus preferably made in accordance with the above-mentioned MIL standard.

To achieve a good Crimpergebnisses in the insulation area, applying low forces, instead of several crimping dies are used in the rear crimping unit, which are pivotally mounted and with their Swing the anvil surfaces tangentially into the receiving cross section. For the practical implementation of such a construction can be cited on the DE 195 07 347 C1 to get expelled.

Further preferred embodiments are mentioned in the appended subclaims.

Fig. 1

eine perspektivische Ansicht eines Doppelcrimpwerkzeugs in Form einer Handzange;

Fig. 2

eine Explosionsdarstellung des Zangenkopfes der in Fig. 1 dargestellten Handzange.

Details, advantages and embodiments of the present invention will become apparent from the following description of a preferred embodiment, with reference to the drawings. Show it:

Fig. 1

a perspective view of a Doppelcrimpwerkzeugs in the form of a hand tongs;

Fig. 2

an exploded view of the pliers head of in Fig. 1 illustrated hand pliers.

This in Fig. 1 illustrated Doppelcrimpwerkzeug invention is designed as a hand tool, which is suitable for one-handed operation. For this purpose, this hand tool initially comprises two handles 1 in a conventional manner, which can still be covered with hand-shaped molded plastic handles for better ergonomics.

The actual double crimping tool is arranged in the pliers head 2. It comprises a front crimping unit 3 and a rear crimping unit 4. The two crimping units are arranged axially one behind the other relative to a workpiece axis 5. Along the workpiece axis 5, a contact element and an electrical conductor (not shown) to be attached thereto are inserted in a central receiving cross section 6, which continues in the two crimping units when the forceps are open.

Preferably, each crimping unit has its own adjusting element 7, via which different crimping dimensions (cross section of the longitudinal section to be pressed by the respective crimping unit) can be adjusted. The operation of the adjusting elements 7 will be explained in more detail below on a specific embodiment.

In the hand tongs can continue to be installed a closing lock 8, which allows the opening of the pliers again after the start of the crimping process, when the end position of the crimping units has been reached before. This ensures that the desired final dimension when crimping is maintained in any case. In the illustrated embodiment, two toggle lever 9 are further provided, which serve to transmit power from the handles 1 to the crimping units 3, 4.

In Fig. 2 the pliers head with the essential components of the crimping tool is shown in an exploded view. The items are between two retaining plates 10, which may be formed as an extension of a handle 1, enclosed.

The front crimping unit 3 comprises a front drive cam plate 12, on the inside of which a profiled surface profile is formed, so that the resulting distance between the workpiece axis 5 and this surface varies. In the front drive cam plate 12, a guide plate 13 is used with four cross-shaped guide slots 14. The guide plate 13 is stationary relative to the holding plates 10, while the front drive cam plate 12 is rotatable relative to the guide plate 13. The driving force required for this rotation is introduced via the toggle lever 9 and a common drive lever 15.

To the front crimping unit 3 further includes four front crimping dies 16, which are guided in the guide slots 14. In the Fig. 2 the crimping dies are shown in the closed state in which their inwardly directed anvil surfaces are positioned in close proximity to each other. In the open state of the pliers, the crimping dies release the receiving cross section 6 in order to receive the contact element with the inserted electrical conductor. In order to move the front crimping stamp in its rest position, spring elements are arranged in a conventional manner, which are not shown in the drawing.

The relative to the receiving cross-section 6 radially outer actuating surfaces 17 of the front crimping die 16 come to the cam surface of the front drive cam plate 12 to the system and are moved radially inwardly due to the top surface design upon rotation of the front drive cam plate 12 to the stripped portion of the conductor in the contact element to press.

The rear crimping unit 4 comprises a rear drive cam plate 20 with the toggle lever 9 acting on it, which in turn is driven by the drive lever 15. Furthermore, six rear crimping dies 21 are present, which abut with their actuating surfaces 17 on the profiled inner surface of the rear drive cam plate 20.

The rear crimping dies 21 are pivotally mounted on support pins 22, which in turn are fastened in support plates 23. When taking place by-rotation about the workpiece axis 5 operations of the rear drive cam plate 20, each rear crimping die 21 is pivoted about its support pin 22, so that the inner anvil surfaces of the rear crimping plunger 21 engage tangentially in the receiving cross-section 6 to narrow this, causing the positioned there longitudinal portion of the contact element is pressed to the insulation of the electrical conductor. This leads to a hexagonal profile formation in Quarantine. In alternate embodiments, multiple or fewer rear crimping dies could be used, however, the use of six rear crimping dies has proven advantageous.

The support plates 23 serve in conjunction with spring units (not shown) at the same time the forced return of the rear crimping die 21st

The driving forces are transmitted to the front as well as the rear crimping unit via said knee lever 9. These are in their length and their position of the coupling to the drive cam plates 12, 20 on the one hand and on the drive lever 15 on the other hand designed so that upon actuation of the hand tool initially only the front drive cam plate 12 is set in a rotary motion. Only after a predetermined pressing angle of, for example, 15 ° has been passed through, the driving force acts on the rear drive cam plate 20 so that it is also set in motion. The prepressing angle can preferably be selected in the range between 10 ° and 30 ° such that at least partial compression in the front crimping unit is achieved between the stripped conductor end and the contact element or this pressing process is already well advanced. Depending on the embodiment, both drive cam plates are simultaneously rotated over a certain angle section in the subsequent pressing step or there is largely only a rotation of the rear drive cam plate 20 for forming the crimp connection between the insulated conductor section and the contact element.

In the illustrated embodiment, an already mentioned actuator 7 is provided on each drive cam plate, with which in each crimping unit, the cross-sectional dimension can be adjusted, which is to be achieved at the conclusion of the crimping process. In the embodiment shown, an eccentric is used as adjusting element 7, via which the curve path for the respective drive curve can be adjusted. This will be the effective length of the changed lever, wherein after completion of the set curve path, the further rotation of the drive cam plate is stopped, so that the associated crimp not further penetrate into the receiving cross-section.

Due to the separate adjustability, the double crimping tool can be easily adapted to different cross-sectional dimensions, so that different contact elements and conductor cross-sections can be processed with one and the same tool.

The adjustment also allows a wear due to necessary adjustment of the crimp dimensions.

For the adjustment of the crimp gauge block, for example, a revolver stop can also be used in modified embodiments.

LIST OF REFERENCE NUMBERS

1 -

handle

2 -

pliers head

3 -

front crimping unit

4 -

rear crimping unit

5 -

Workpiece axis

6 -

Cross Section

7 -

actuator

8th -

enforcement lock

9 -

toggle

10 -

holding plates

12 -

front drive cam plate

13 -

guide disc

14 -

guide slots

15 -

driving lever

16 -

front crimping dies

17 -

operating surfaces

20 -

rear drive cam plate

21 -

rear crimp stamp

22 -

supporting journal

23 -

support plates

Claims (11)

1. A double crimping tool for fastening an electrical conductor with insulation to a contact element, comprising:

   a front crimping unit (3) with a front drive cam plate (12) and front crimping stamps (16) for forming a front press section in the region of the stripped end of the conductor;

   a rear crimping unit (4) with a rear drive cam plate (20) and rear crimping stamps (21) for forming a rear press section in the region of the insulation of the conductor;

   wherein the crimping stamps (16, 21) of each crimping unit (12, 20) comprise anvil surfaces that are directed towards each other, between which anvil surfaces an receiving cross section (6) for receiving the sections of the contact element, which sections are to be pressed together, with the conductor inserted therein, and wherein the crimping stamps are displaced by rotation of the drive cam plates (12, 20) in order to carry out the pressing procedure by narrowing the receiving cross section (6), characterised in that the two drive cam plates (12, 20) are connected by levers (9) to a shared force introduction element (15, 1) such that during the pressing procedure at first optionally the front or the rear drive cam plate (12 or 20) is rotated by a predefined initial pressing angle so as to, in the associated press region, reduce the receiving cross section (6), while the other drive cam plate (20 or 12) is made to rotate only after the first drive cam plate (12) has attained the initial pressing angle, in order to reduce the receiving cross section in the other press region.
2. The double crimping tool according to claim 1, characterised in that, the front and the rear drive cam plates (12, 20) are rotated together by a predetermined angle when the initial pressing angle has been reached.
3. The double crimping tool according to one of claims 1 or 2, characterised in that, a front end stop is formed by a front adjusting element (7) which when an intermediate angle has been reached stops any further rotation of the front drive cam plate (12), while the rear drive cam plate (20) continues to be rotated until a rear end stop that is formed by a rear adjusting element (7) is reached.
4. The double crimping tool according to claim 3, characterised in that, respectively each one of the adjusting elements (7) is arranged on the front and/or on the rear crimping unit (3, 4), by which adjusting element (7) the effective cam travel of the front and/or of the rear drive cam plate (12, 20) are/is variable so that the crimp dimension can be set.
5. The double crimping tool according to one of claims 1 to 4, characterised in that, the introduction of force is by way of a drive lever (15) that is connected to a front and a rear toggle lever (9) which in turn drive the front or rear drive cam plates (12, 20) respectively.
6. The double crimping tool according to one of claims 1 to 5, characterised in that, the front crimping unit (3) comprises four front crimping stamps (16) that are radially slidable in relation to the receiving cross section (6) and that are arranged so as to be offset by approximately 90° so that their anvil surfaces oppose each other in pairs.
7. The double crimping tool according to one of claims 1 to 6, characterised in that, the rear crimping stamps (21) of the rear crimping unit (20) are mounted pivotably and when activated by the rear drive cam plate (20) their anvil surfaces pivot tangentially into the receiving cross section (6).
8. The double crimping tool according to one of claims 1 to 7, characterised in that it is designed as a hand tool that is suitable for single-handed operation.
9. The double crimping tool according to claim 8, characterised in that the front and the rear crimping unit (3, 4) are arranged between two retaining plates that are connected to one of the handles (1) of the hand tool, while the other handle (2) is connected to a drive lever (15) which in turn establishes an effective connection with the drive cam plates (12, 20).
10. The double crimping tool according to one of claims 8 or 9, characterised in that furthermore, there is an activation detent (8) which makes it possible to open the hand tool only after a predetermined end position has been reached.
11. The double crimping tool according to one of claims 1 to 7, characterised in that, furthermore, it comprises a machine drive.

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