EP0732779B1 - Pliers for pressing wire end ferrules - Google Patents

Abstract

The crimping tool has a crimping head (4) incorporating a number of crimping plates (18) , with respective profiled crimping surfaces, cooperating to define a variable cross-section crimping opening. The crimping plates are operated by peripheral pivot levers (16), coupled via a knee-lever mechanism (12,13) to the manually-operated pivoted crimping handle (5). The profiled crimping surfaces of the crimping plates cooperate to form a regular polygonal cross-section crimping opening, with sliding surfaces adjacent the crimping surfaces lying in flat contact with the sliding surfaces of the adjacent crimping plates. The fixed crimping handle (6) incorporates a compensation spring lever cooperating with the knee-lever mechanism.

Description

The invention relates to a pressing tongs for pressing wire end sleeves, contact sockets or cable lugs onto electrical conductors, with pressing jaws arranged in the pliers head part, surrounded by a pivoting lever and centrally movable relative to one another by its swiveling drive movement effected via a toggle lever drive, which can be brought into and in the return stroke out of the pressing position, whose partially butting jaw surfaces together with the adjacent press jaws form an adjustable press cross-section, bridging different sized press profiles and the resulting different press paths an automatically acting during the pressing process, elastic, spring-loaded compensation between the Power transmission members is created.
The balancing of the pressing paths present in each case by means of different large-sized pressing profiles within the drive mechanism of the pressing tongs between the handles and the pressing jaws is therefore necessary in order to be able to guarantee high uniformity and quality of the pressing within a predetermined size range of wire end ferrules and electrical conductors to avoid breakage of pliers links due to possible overloading. It is particularly advantageous to make this compensation resilient and elastic, for example by means of a spring member, which experience has shown that work with the pliers is considerably improved and facilitated.
The pliers are secured against any premature opening of the press jaws by a ratchet lock known in its type and purpose, so that in any case the working stroke that has been initiated is completed for the respective pressing.

For pressing tongs with scissor-type opening pressing jaws is relevant the compensation of baling path differences have been operated so that only the one jaw rigid, while the other jaw resilient Zone, also in the form of a separate spring member, on the associated Handle with the interposition of the actuators, e.g. one Toggle lever drive is articulated (DE-PS 3109 289).

In the case of pressing tongs of the generic type, on the other hand, the compensation of the pressing path differences can be carried out in such a way that an elastically acting support is arranged at least on one of the force transmission members, which is expediently formed by a separate spring member. (EP-PS 0158 611). In this case, one of the toggle levers belonging to the power transmission system is designed to be displaceable at its outer articulation point against the action of a tension spring and can, together with a ratchet mechanism, adjust within certain limits to the size of the profile to be pressed. This type of indirect resilient support of the swiveling lever receiving the press jaws must be assessed as disadvantageous in various respects, because any press errors that occur with regard to the degree of perfection of the pressing cannot be noticed and therefore cannot be excluded.
Crimping pliers according to the generic features for crimping wire end sleeves onto electrical conductors, with pressing jaws arranged in the pliers head part, enclosed by a pivoting lever formed by the pliers limb and pivotable in relation to one another, thereby being able to be moved centrally and thereby being brought into and out of the pressing position, are known (US Pat. No. 3,203,078). .
In this type of pliers, the pivot lever is operatively connected to the press jaws via a spline profile, and the pivot lever is centered and movable on the peripheral outer surface of the press jaws. The press jaws are pivotally mounted on the lower base plate of one pliers part on continuous bearing bolts and axially fixed.

The pliers proposed here are of the type and shape of the Press profile and also after the execution of the functional Construction elements not for crimping ferrules suitable. In these it comes to an all-round, if possible over the entire cross-section is evenly procured and dimensionally accurate Pressing that cannot be achieved with such pressing tongs.

Other known tool designs for pressing electrical conductors are described in U.S. Patents 5,261,263; U.S. Patent 3,199,335; GB-PS 886 259; GB-PS 1324 253; shown and described. This too Tool designs are not suitable to meet the modern demands of Connection or compression technology in power electronics precise, non-destructive and fixed pressings correspond and also suitable for multi-range pressing as well to be simple and easy to use. While partly the function-determining design features sometimes complicated have been designed and a relatively high technological effort on the other hand, it is precisely these elements that make up the functional Properties of these pliers with regard to high working accuracy and impair in terms of low functional susceptibility to malfunction.

It is also the case that such multi-range pressing tongs, especially with the small and smallest press dimensions, for example in the size below 1 mm ² cross section, require a very precise movement of the press jaws and, in addition, an equally precisely operating drive or power transmission and cushioning system between the moving ones Pliers parts necessary.

• das kinematische System der Preßbacken zu verbessern und zu verfeinern,
• den zwischen den Kraftübertragungsgliedern zur Anwendung vorgesehenen Kraft-Weg-Ausgleich zu vereinfachen und zu vervollkommnen und
• die Preßbacken mit einem wirkungsvolleren Preßprofil auszustatten.

The known constructions of this type of pliers are currently unable to meet these expectations, or can only be met incompletely.
The purpose and object of the present invention result from these circumstances.
The purpose of the invention is the further technical-functional perfection of this type of tool concerned here and leads to the task of this crimping pliers, while maintaining a toggle lever for driving the pivoting lever

• to improve and refine the kinematic system of the press jaws,
• to simplify and perfect the force-displacement compensation provided between the power transmission elements and
• to equip the press jaws with a more effective press profile.

This object is achieved according to the in the associated Patent claims characterized technical features for design a new type of pliers construction. The in the subclaims The technical means mentioned are essential to the invention advantageous additions to the design of essential construction details this pressing tongs.

The invention is intended below with the aid of the associated drawing images are illustrated and explained in more detail using an exemplary embodiment.

Fig. 1

die Gesamtansicht der Preßzange mit allen wesentlichen Funktionsteilen,

Fig. 2

eine Einzelheit zur Ausführung der Federelemente im teilweisen Schnitt des rechten Zangenhandgriffes;

Fig. 3 und 4

eine Darstellung der geometrischen Verhältnisse zur Ausbildung und Anordnung der Preßbacken und ihrer Kinematik; bei 6-eck- und 4-eck-Pressung;

Fig. 5

einen Preßbacken in Ansicht seiner Preßflächenausführung;

Fig. 6 und 7

eine darstellende Erläuterung der möglichen Arten von Verpressungen an Aderendhülsen;

Fig. 8

einen teilweisen Querschnitt durch das Preßprofil eines Preßbackens.

Show

Fig. 1

the overall view of the pressing tongs with all essential functional parts,

Fig. 2

a detail for the execution of the spring elements in partial section of the right pliers handle;

3 and 4

a representation of the geometric relationships to the formation and arrangement of the press jaws and their kinematics; with 6-corner and 4-corner pressing;

Fig. 5

a press jaw in view of its press surface design;

6 and 7

a descriptive explanation of the possible types of crimping on ferrules;

Fig. 8

a partial cross section through the press profile of a press jaw.

The pliers body 1 is made in a known manner from two base plates 2; 3 joined together, which form a head part 4 and part handle parts 5 and 6.
In the right-hand grip part 6, an outer spring zone 8 is expediently formed by a constriction 7 in the middle section, which, under the corresponding, yet to be shown, action of force, is able to spring in and out relative to the adjacent head part 4 and grip part 5.
Approximately in the same section there is also an inner or inner spring 9, designed to be movable as a spring lever and held at one of its ends, which has a common articulation point 10 or clamping area 10 with the outer spring zone 8 of the right handle part 6.
With its other free-standing end, which is designed as an open bearing shell 11, this spring 9 is in a positive connection with the toggle lever 12 mounted in the left grip part 5, which, as can be seen in FIG. 1, consists of a toggle lever drive in a known manner from the levers 12 and 13, as well as the handle part 5, which forms the function-determining element of this pliers drive. The other of the two toggle levers, here bearing reference number 13, is formed between the common bearing point 14 and the bearing point 15, the bearing point 15 belonging to the pivot lever 16 to be driven.
The pivot lever 16 is arranged between the two base plates 2 and 3 of the pliers body 1 and, as has already been indicated, is connected to the toggle lever drive in the bearing point 15 in a drive-effective manner by a tab 17 provided on the pivot lever 16. He is resiliently supported on the spring members 8 and 9 according to the proposal of the invention via the lever cable of the toggle lever.
Towards the driven side, the swivel lever 16 is connected to the press jaws 18 of the press tool. This connection is based on a positive connection, which is produced by a spline 19.
1 and especially FIGS. 3 and 4 show this detail clearly, for which it should be emphasized that the pivot lever 16 is guided by this arrangement, but is otherwise freely movable.
The press jaws 18 are, as has already been proposed, connected to the lower base plate 3 with the aid of a continuous bearing pin 21 and are pivotably mounted thereon.
The spatial arrangement, the storage and the working profile of the pressing jaws 18, as is part of the inventive solution, meet the following geometric conditions:
The profile to be formed by the swiveling press jaws 18, as shown in the drawing plane, is in each case by the profile surfaces 22; 23, formed. See FIGS. 3 and 4. The profile surfaces 22 and 23 can be designed for a polygonal pressing, preferably for a square or hexagonal pressing, the geometric configuration and mechanical adjustment of which, as shown in FIG. 1, being carried out in a rosette-like manner .
The pivot point 24 of the press jaws 18 is in each case on that perpendicular perpendicular 25 which is formed between one of the corner points of the largest possible press profile and its profile center point 26. With regard to the arrangement and mounting of the pressing jaws 18, it should also be noted that the distance between the bearing pins 21 and the center of the profile is decisive for the size of the translation which is effective here and also for the size of the pressing area.

In the exemplary embodiment of the present invention, the translation is advantageously 1: 1.

The two resilient elements 8 and 9, one according to the invention novel, simple and advantageous technical solution of the such pressing pliers existing problem to bridge the represent different pressing areas are in the rear end section of the right handle part 6 by transverse bolts 27 and longitudinally shaped knobs 28 firmly joined together and act there like a compact whole, what circumstance for the function and Property of the springs 8 and 9 on their common pivot point 10th is also important.

Some more that determine the functional properties of this pressing tongs Design features exist in the embodiment of the invention Press jaws 18. These are on their actual profile or press surfaces 22 profiled, such that the pressed surfaces 29 of the ferrules 30 optionally a rotating press profile, as shown in FIG. 7, or a offset press profile, as shown in Fig. 6 results.

The profile advantageously has a triangular basic shape 31 like that 8 is intended to illustrate. The profile tips 32 are rounded.

The pressing tongs work as follows:
With the handle parts 5 and 6 open and the knee lever 12 folded; 13, the press space 32 provided between the press jaws is also open. The parts to be pressed together can be inserted and brought into their pressing position.

For pressing the parts, the handle parts 5; 6 closed. Doing so the toggle lever 12; 13 moved to its extended position "A-B" and thus pivots the pivot lever 16 in the direction of arrow "C" until the under the influence of this pivoting movement via the spline-form locking likewise moving press jaws 18 into their pressing position on the workpiece have arrived. If the pliers handles 5; 6 takes place shape-forming pressing of the parts, which is continued until the The toggle lever reaches its end position, approximately shortly before its extended position, that Jack ratchet was overrun and thus deactivated again is so that the pliers can open.

When pressing relatively large cross-sections or at all when pressing cross-sections of different sizes, since the way to work on the handles and also on the toggle lever mechanism always remains the same, a force-travel compensation must be brought about inside the pliers.
As is known, this compensation is necessary in order to be able to close the pliers partly with different pressing cross-sections with the manual force that is usually to be used and partly to cancel the effect of the ratchet mechanism.

For this, expediently elastic compensation in the power transmission system provide the springs 8 and 9 which, if necessary Direction of arrow "B" can evade. Depending on the power requirement in the Press zone, the spring characteristics of the two spring elements in it makes sense to add a perfect compression to one part guarantee on the parts and on the other hand a corresponding one enable easy and convenient handling of the pressing tongs.

Claims (3)

1. A crimping tool for crimping lead end sleeves, contact sockets or lugs onto electrical conductors, having pivoting jaws which bear the die profile and perform the crimping arranged in the head end 4,

   which are axially fixed by and pivot on through bearing pins 21,

   which jointly form a crimping aperture of adjustable cross-section, and are enclosed in a ring lever 16 which drives them,

   whose outer peripheral surfaces mechanically hold and center the ring lever 16 in a splined profile 19, while the rotating motion of the ring lever, actuated by a toggle joint mechanism driven by the handles 5, 6 moves them into and out of their crimping position,

   and whereby an automatically actuated power/stroke compensation is created between the parts of the power transmission system, as by spring action, incorporated in the crimping tool and situated between the handles 5, 6 and the jaws 18, in order to compensate for crimping cross-sections of various dimensions and the resulting variable crimping stroke; and whereby the crimping portion of the jaws 18 is formed of a die surface 22 and a sliding surface 23, such that the die surfaces 22 of all the jaws 18 together form a die of a closed shape (e.g. a square or hexagon) in all crimping positions within their crimping range, to which purpose the rotational or pivot axis of the jaws 18 is defined by a line 25 bisecting at right angles the line from the respective corner of the crimp cross-section toward the center 26 of the crimp cross-section, together with the circle chosen for the bearing pins 21; and whereby the sliding surface 23 of each jaw 18 is in planar contact with the die surface 22 of the adjacent jaw 18, extending the plane of the adjacent die surface, and whereby the fixed handle 6 is constructed as a compensating spring for force/stroke compensation by means of a reduction in its cross-section in the form of a waist 7 in its middle section, together with an elastic lever 9 integrated in the handle 6 and mechanically linked with one lever arm of the toggle joint mechanism 12.
2. A crimping tool as recited in Claim 1, wherein said jaws 18 have a profile on their die surface 22 such that the crimped surfaces 29 of the lead end sleeves 30 are formed with a profile that may be either continuous around the sleeve or offset from one crimped surface to another, whereby the profile is formed by a basic triangular shape whose profile points 32 are rounded.
3. A crimping tool as recited in Claim 1, wherein said elastic lever 9 is constructed as part of the handle 6 and has both a positive and a friction connection with said handle 6 at its rear section by means of bolts 27 and splines 28.

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