DE1084337B - Method for establishing an electrical connection between a cylindrical clamp and an inserted conductor - Google Patents

Description

GERMAN

The invention relates to a method for production an electrical connection between a cylindrical ferrule and an inserted conductor or inserted ladders.

It is already known to manufacture an electrical Connection between a cylindrical ferrule, e.g. B. that of a cable lug, and the electrical conductor inserted therein to deform the clamp by notching from the outside in such a way that that creates an intimate connection between the inner wall of the ferrule and the electrical conductor and the release of the ferrule from the conductor is prevented.

According to a known embodiment, the cylindrical clamp by means of a two-part The die is deformed in places so that the clamp on the affected parts has a polygonal, for example, assumes a hexagonal cross-sectional shape. Although the conductor is clamped at these points, but retains essentially the same cross-sectional area.

According to another known embodiment, the cylindrical clamp with the one located therein The ladder is also shaped in a two-part die in such a way that half of the clamp, seen in cross-section, remains semicircular and forms a trough or bead from the opposite side is, whereby the conductor preferably composed of a plurality of wires is compressed and the individual wires are deformed with the elimination of their interstices so that the overall conductor cross-section assumes an approximately sickle-shaped cross-sectional shape.

It is also a tool for making substantially parallel, elongated impressions into a ferrule surrounding a wire known, by means of which the ferrule while maintaining a semicircular Wall part is deformed from the opposite side so that the clamp two adjacent receives deep indentations, as a result of which it forms two lateral upright vertices and a middle, less raised crest remains between the indentations. Even when machining with this tool, the inner conductor is compressed and forms at the pressed points a conductor cross-section of approximately sickle-shaped shape with a cross-sectional projection in the middle.

The invention creates an even better connection method compared to the known. The known method for making an electrical connection between a cylindrical Clamp and an inlaid conductor by notching in a two-part die in which Method of manufacture

an electrical connection

between a cylindrical ferrule

and an inserted conductor

Applicant:

AMP Incorporated,
Harrisburg, Pa. (V. St. A.)

Representative: Dr.-Ing. H. Ruschke, Berlin-Friedenau,

and Dipl.-Ing. K. Grentzenberg,
Munich 27, Pienzenauer Str. 2, patent attorneys

Claimed priority:
V. St. v. America 6 July 1954

Norman Edwin Hoffman, Rutherford Height, Pa.

(V. St. Α.),
has been named as the inventor

three forces are exerted on three surfaces of the clamp to force these surfaces against the conductor press is improved according to the invention in that a first force by direct radial notch and a second and third force through, on the counter die arranged cams are exerted, these forces arising from the reaction to the first force result and squeeze the head in three apices roughly evenly distributed around the circumference, and that after the notch has been made, the clamp and the conductor by pressing on all sides. to an essentially massive triangular focm when taking place in the longitudinal direction Metal extrusion can be deformed.

The inventive method is not only a connection with very high quality electrical and mechanical properties created, but it also possesses characterized by the Deformation increased strength in order to increase tension, vibration and torsion. resist, it is corrosion resistant and can maintain high electrical conductivity for long periods of time.

A particular advantage of the present method is that the connections are made with lower maximum pressures and smaller forces than before, with a higher tensile strength and higher resistance to torsion

009 548/315

3 4

claims is achieved compared to connections Fig. 5 is a cross section along line 5-5 in Fig. 4,

comparable dimensions. This lower Fig. 6 is a vertical longitudinal section

Pressures and forces allow the use of line 6-6 in Fig. 5,

Ferrules with thinner walls. Fig. 7 shows a cross section through a two-part structure

In addition, there is also the possibility of using a countersunk in the open position with an inserted

given ferrule the connection with a wide ferrule and a solid conductor inside,

Manufacture size and type range of conductors, Fig. 8 is a view similar to Fig. 7 of the die in

namely with massive and twisted wires partly closed position,

as with wires with polygonal or round transverse Fig. 9 is a view similar to Figs. 7 and 8 of the

cut or combinations thereof. Furthermore, io die can be in an almost closed position,

a single set of tools for many different lines

ter can be used. Line 10-10 in Fig. 9,

One can also see larger isolated connections from Fig. 11 in an enlarged schematic diagram

the way in which one of an isolation of the outline one according to the invention for example

sleeve surrounded ferrule is present, the 15 connection established according to FIG. 2,

Deformation forces through this insulation cover - Fig. 12 an enlargement of the upper apex

come through to apply. This is possible part of the outline in Fig. 11,

because of the lower forces and the thinner FIGS. 13 and 14 enlarged views of the die-clamp walls, the parts applied according to the invention or the patrix,
can be. 20 In FIG. 1, one is designated generally by 20

The method is excellently suited not only for electrical connection with a clamp part 22

when using ordinary electrical copper, shows the over the stripped end 24 of an insulated

but also with other metals, including electrical conductor 26 striped and fixed on it.

Aluminum, brass, phosphor bronze, beryllium is pressed. A connector 28, which is from the

Copper, hard-drawn copper, iron, etc. 25 Ferrule from extends, consists of one piece with it

An important advantage of the invention is and is shown here as an eyelet. As Fig. 2 shows, that when deforming the curve of the required force becomes a one-piece connection by notching as a function of the tool stroke, the very desirable of the ferrule 22 against the bare end 24 of the conductor Characteristic of a gentle decline during the 26th and the compression by three in approximately Has the largest part of the tool stroke, whereby 30 equidistant elongated, longitudinally the notches 30, 30 and 32 extending to close the tool or die are formed, During this large part of the tool stroke, as shown, these notches are parallel Required force is low, while suddenly pages with rounded ends 34 and rounded increased waste only occurs when the connec- tion bottoms, and they become so in the wall of the ferrule This is pressed together to form a solid cross-section in order to engage it with the conductor 24 is forged, thereby bringing the normal operation and the metal of the ferrule with the of the tool is also the desired actuation. Conductor metal to an essentially massive, if to squeeze the tool or die through a force-piece body. As known, can multiplying toggle device is operated, compressing the metal up to the stage whereby the mechanical advantage (and thus the gears are driven further, where the cross-section is free from exerted force) during most of the work- empty spaces before the mechanical strength tool stroke is only small, but increases sharply when and durability of the connection on any part the knee lever is at its dead center and the work is seriously impaired. Two of these notched pieces approaching the fully closed position, so gen 30 are the same size, while the third the result is essentially a constant force 45, notch 32 is somewhat wider. It is in many during the entire stroke of the handles. The felling has been found advantageous to this third strong increases in force near the full indentation about 15 to about 40% wider The closed position then acts as a limit to make than the other two, and with most of them Preventing excessive deformation in mechanical applications becomes a very high-quality connection Driven tools with a 50 achieved by making the width of the notch 32 µm The resilient link in the power transmission is made about 25 to 30% wider than the others are, as well as with hydraulic tools, which is in front.

have adjusted overflow valves, which at an It is in many cases desirable that the

certain force can be triggered. Length of these notches, something more or something

In the following description and the drawings, 55 less than the outer diameter of the clamp

The invention is based on implementation. For many applications, a very important

Examples explained, on which the invention, however, achieved peaceful connection when the length of the

should not be restricted. In the drawings shows notches just a little smaller than that

Fig. 1 is a perspective view of an end ferrule outer diameter. Furthermore, the

a wire conductor attached ferrule in the form 60 rounded ends of the notches, preferably in

a cable lug, a small distance from the relevant ends

Figv 2 is a cross section through the connection of the ferrule held so that the inside of the not

according to line 2-2 in Fig. 1, notched ends of the ferrule extending from the three-

3 shows a cross section through one of the angular cross-sectional shapes shown in FIG. 1 for such a shape Connection similar connection, in the 65 broader, which is largely the original, round however, a larger conductor retains its shape with the same size ferrule. The non-notched ends make so and the same tool has been used, a reinforcing flange at both ends of the

4 is a perspective view of an electrical clamp. When you get to the end of the ferrule to the ladder

insulated clamp, which leaves undeformed on several wire conductors, results in a bell-shaped

is pressed, -....- 70 opening which the conductor strands at the exit of the

5 6

Ferrule protects against sharp bending. This shows, as shown in Figures 2 and 3, it is another

z. B. Fig. 6. Advantage that the rounded vertices 35

The body shown in cross-section in Fig. 2 and the ribs formed by the ferrule, a reinforcement of the ferrule and the conductor, have a generally triangular shape adjacent to the two sides of each of the notches in the form of an externally curly 5 30 and 32 form. These ribs. 35 and 36 reinforce triangles with concave sides formed by the notches 30 and 32 ge the connection in the area of the connection, which are delimited transversely by circular arcs vertices 40 and 42 in order to accommodate the above with radii of, for example, R ₂ (FIG. 11) contribute to the spoken torsional stresses,
and have vertices 35, 35 and 36, respectively, which by It has been determined that in a connection

Circular arcs with smaller radii, for example 2 ^ ₁ io dung, as described here, a substantial and .R ₃ , are rounded and tangential to the con-thinner wall thickness of the clamp are used kaven arcs. can be compared to earlier connections with

The two apexes 35, in addition to the greater anchoring, good strength with regard to twisting and tensile stress 32 are more pointed than the third vertex 36, so that cracks. With such a connection you can the overall cross-section of the connection generally use a clamp wall thickness, for example, has my isosceles triangular exterior. How that is much lower than it normally is at results from a comparison of FIGS. 1 and 2, be connections between a clamp and a Also an advantage of the present invention is wire common. The use of the thinner in that, for example, in a connection with the wall of the clamp not only saves material one End tongue of the outline of the connection in the 20 cost, but also gives the opportunity to substantially Tongue part 28 passes. to use less force than with such connections

In the compound according to the invention, the fertilizer can generally be required. Also is Notches 30 and 32 in any position, even with a clamp wall of normal thickness Aligning a seam in the clamp requires 20 to 25% less force than before the. In Fig. 3, for. B. shown that the connection 25 known articulation devices. The total profit with a seam 38 which has been made in the economic viability through the use of the dar-proximity the center of the wider, notch 30 made connections with the thinner ferrules. This is the case with a continuous design (butt walls enable further essential or parallel connector) or the so-called glans reduction of the force, although a connection is coarse (End connector) particularly advantageous. The 30 ßerer strength is created. At the same time they are Seam 38 is generally brazed, but the total cost and weight of the equipment is a factor Invention also with butt seams 38 of tools and dies used for notching lower, Advantage. and the wear is less because of the lower

Figure 3 shows a cross section of a joint, forces exerted.

with the same dies and with a ferrule 35. In Fig. 4, an insulated end connection is shown with four 22 of the same size as shown in Figs. 1 and 2, insulated conductors 26, 26a of different sizes, but with one conductor 24a, the before, as shown in FIGS. 5 and 6, contains the user deformation approximately double the cross-section dete clamp 20 a, a metal clamp 22 a, which had that of the conductor 24 over the area. stripped conductor ends 24 is striped. The ferrule

The metal of the ferrule 22 and the conductor 24 a is 40 22 a- is thereby of an insulating sleeve 50 with a in Fig. 3 as well as in Fig. 2 surrounded by the notch an end part of smaller diameter, which the Forged together in pieces to tightly encompass the connection outside of the metal ferrule 22a and to achieve great tensile and torsional strength. has an open shell part of larger diameter,

One of the reasons for the high torsional strength which can surround and protect the ends of the insulation on the conductors 26, connection as shown in FIGS. 2 and 3, is 45 26 a. The insulation sheath that the notch method both the shape of 50 is determined on the metal ferrule 22 α either by friction ferrule and the shape of the conductor, to bungshaftung due to the elasticity of the sheath 50, the forged bond 39 between the or by suitable fastening putty or in on-ladder and the ferrule that fastened a high one of those ways. The connection is possessed by resistance to torsional loads. 50 Application of notch forces through the insulation

Another reason for the high torsional strength of the sheath 50 through to the ferrule therein The connection described is the one that the pressed and the conductors are made.

Conductor cross-section a generally triangular shape

Has shape with concave sides. The result of the invention and the beneficial effect of the dre relatively sharp, possible sink between the surfaces 55 when closing against the insulating sleeve Vertices 40, 40 and 41 of the bond 39 have lent smaller forces that a larger one form abutments, which can be deformed almost radially outwardly insulated ferrule than before was essentially well known from the axis of the connection. In addition, the effect is such that it is angular to extend the torsional stresses to rend the last stage of notching when the to withstand the latter. For illustration, pressures increase in 60, the pressure essentially above 3 shows a dashed line 42 from the axis which is distributed over the entire circumference of the insulating sleeve, Connection by an interfacial causing serious weakening or tearing lay vertex 40 drawn. It can be seen that one of these is avoided.

Tangent 43 to one of the abutments is almost parallel if the insulation sleeve 50 is not after the notching

to line 42. In addition, these resistors have 65 bonded to the metal, they can be in the Pull back the bearing surfaces a little near the interfacial apex area of the notches and points 40 and 42 largest radial distance from the, for example, thin crescent-shaped cavities 52 Axis of the connection, whereby they leave maximum effective- under the insulation, what an additional moment lever in the resistance against lending protection against short-circuit and a longer one form rotation. 70 creepage distance to the clamp results, if the insulation

should be damaged once. As the insulation, cover the crescent-shaped cavities. 52 can give way to a shock, but such damage is very unlikely.

The direction of the notch after the ferrule seam 38 is not critical, but generally is advantageous. In the isolated ferrules of the type shown in Figs. 5 and 6, the deformation of the circular to triangular shape take place at every suitable angle setting.

As shown in Figs. 7, 8, 9, 13 and 14, a die set for making the one described includes Connection, as is known, a die 60 and a patrix 62. The die part 60 has a guide part, generally designated 63, which can receive the ferrule in the longitudinal direction and substantially has straight sides 64 which are at a slight angle to the one indicated by the dashed line 66 (see Fig. 8) shown closing direction are inclined inward. The bottom of the guide part 63 is bounded by a longitudinal central protrusion which has an arched boss 68 between the forms concave indentations 69, which indentations have a small radius and are tangential to the straight sides 64 and to the boss 68.

The male part 62 includes a pair of longitudinally extending side engaging jaws 70 with polished ones Curved surfaces 72 and a longitudinally extending forming flute therebetween 73.

The ferrule with the conductor located therein is in the guide part 63 (Fig. 7), which is an average Has width that is only slightly larger than the outer diameter of the clamp, inserted.

The die parts close (Fig. 8) in the direction 66 which, although they are about to be used is shown for tools with a straight stroke, also curved for pliers and others Tool types can be. So where it is said that parts are "parallel" to the stroke of the die, this includes this also a "concentric" alignment for arcuate operation.

The jaws 70 enter the guide with their outer sides 74 parallel to the direction 66 extend and slide in contact with or only a short distance from the relevant sides 64 of the guide part. The sides 64 advantageously converge somewhat (see also FIG. 13), as a result of which the clamp can be compressed a little. This slight convergence is advantageous because it provides an inevitable lateral support through the action of the sides of the guide part, when the male part drives the ferrule into the female part.

As the male part 62 enters the guide portion, the jaws 70 result in a duplication of the Force and a distracting effect and thus squeeze the ferrule in such a way that it is essentially with coincides with the cooperating forming surfaces of the die and that the conductor is essentially identical coincides with the inside of the deformed ferrule. When the fillet 73 is filled is, the main force on the ferrule and the conductor is due to a direct pressure effect as a result of the Force of. The male part driven into the female part is exercised in order to produce a solid cross-section.

During insertion and final compression, the jaws 70 are laterally removed from the sides 64 of the die supported, so that an unnecessary stress on the groove 73 of the die part 62 is avoided.

The sides of the guide part can advantageously follow from the direction 66 by a small angle be inclined on the outside, for example in the range from V2 to 3 °. A slope of about 1 ° for each side is to be regarded as the best value in many cases.

While the jaws 70 reach into the cavity of the die, their inner curves first contact the clamp tangentially at points 76 on opposite sides of the clamp axis. The lines 77 indicate that the points 76 are less than a quarter of the width of the guide member 63 from the sides thereof. When surfaces 72 first meet the ferrule at points 76, the effective portions of that surface are inclined with respect to direction 66. Therefore, the engagement activity generates notch forces F ₂ and F _it which act perpendicular to the wall of the clamp and which are much greater than the forces exerted .F ₁ and F _s . This effect of the die is advantageous because as the deformation forces increase there is an accompanying increase in the area of the ferrule wall which is used to transmit the forces to the conductor, so that the pressures on the outside of the ferrule are not excessively increased at any point and a crack or objectionable weakening of the ferrule wall is avoided. This is particularly advantageous with isolated clamps.

During the last part of the notching process the ferrule and conductor completely enclosed, and a longitudinal (i.e., axial) Pushing out the metal of the ferrule and the conductor, resulting in a reduction in the total Cross-sectional area of the metal in the notch area after completion of the connection results.

If, during this last part of the notching process, the dies move past that shown in FIG Move position, ends the engagement by the die surface 72, and the required applied force increases sharply, whereby the beneficial results of generating a stopping effect, as mentioned above. When the drive mechanism of the dies is a resilient Contains member or a force reducing member, this stopping effect is used to achieve the desired The amount of deformation in each of many individual connections, regardless of changes in the Size of each ladder and clamps used to achieve.

The heavy line 90 in Fig. 11 shows the outline of an enlarged cross section of an example of one according to the invention curved-triangular notch connection. Let this curve 90 be "curly-isosceles" Called curve. Curve 92 shows an example of another curly triangular shape according to the invention Notch connection. This curve 92 is called a "curly-equilateral" curve.

The distance between opposing side walls above the boss 68 is designated by Z.

ABC, AED, BFE, CDF and DBF are equilateral, enlarged triangles. R ₁ , R ₂ and R _s are radii shown enlarged.

In various connections according to the invention, the relative sizes of these radii are changed, and their respective center points then lie either inside and / or outside equilateral points, for example points A, B, C, D, E and F.

In the curly isosceles curve 90, the position of the center point P for the radius R _{3 is} at a small angle β below the line BC. The angle β can, for example, be in the range from 10 to 30 °, with R _{3 being} slightly larger than R ₁ . For example, R ₃ can range from about 1.2 to about 1.7 times that of R ₁ , and R ₂ can be, for example, about 6 to 9 times that of R ₁ . In many cases a notch connection according to the invention is wider than it is high; For example, H ₁ can be about 0.5Z to about 0.8Z.

An advantage of the invention, as already said, is that it enables a wide Size range of clamps and ladders can be deformed with a single die tool because the connection gives high strength regardless of large changes in the relative reduction in size Cross-section of the metal in the notch area. This relative reduction can be anywhere in the range of 15 to 48%.

The term "conductor" is intended to mean any type of solid conductor or stranded wire or groups of them or comprise any conductor regardless of its cross-sectional shape.

Claims (4)

Patent claims: 10 characterized in that a first force through direct radial notch and a second and third force through arranged on the counter die Cams are exerted, these forces resulting from the reaction to the first force and squeeze the head in three apices roughly evenly distributed around the circumference, and that after made notch the clamp and the conductor by pressing on all sides to one essentially massive triangular shape with metal extrusion in the longitudinal direction will. 2. The method according to claim 1, characterized in that the metal longitudinal extrusion to one Reduction in the total cross-sectional area of the clamp plus conductor between 15 and 48% leads. 3. The method according to claim 1 or 2, characterized in that between the second and third force generated vertex tamper than the other two vertices. 4. The method according to any one of the preceding claims, characterized in that the by the notch created by the first force is wider than those created by the second and third forces be generated. 1.Method of making an electrical document under consideration: Connection between a cylindrical clamp USA patents No. 2 587 095, 2 280 352, and an inlaid conductor by notching 30 2 467 012, 2 109 837. in a two-part die in which three forces Applied on three faces of the ferrule, Legacy Patents Considered: to press these surfaces against the conductor, German Patent No. 965 644. 1 sheet of drawings © 009 548/315 6.