DE9014313U1 - Clamp tool in the form of an assembly key for holding branch terminals for insulated conductors - Google Patents

Description

Applicant: REMA Lipprandt GmbH & Co KG
Spichernstrasse 11, 5300 Bonn 2

Representatives: Patent attorneys and lawyers

Dipl.-Phys. Theodor Koch and Partner
Colmantstrasse 20, 5300 Bonn 1

Description: "Clamping tool in the form of an assembly key for holding
Branch terminals for insulated conductors"

The present invention relates to a terminal tool in the form of an assembly wrench, the handle of which is electrically insulated in such a way that it has a dielectric strength of up to 1000 V, for holding fully insulated branch terminals for insulated conductors in a flat steel profile part opening at the side of the handle according to the preamble of claim 1, as well as bare terminals.

Assembly keys of this type are used in particular for connecting insulated overhead line terminals of the 22 series. A fully insulated branch terminal of this type is, for example, in accordance with DE-OS 29 03 960

Connection of the
known, whereby the two upper and lower clamping jaws of the clamp body, made of electrically insulating plastic, are connected by screwing a web-like metal plate resting on the upper clamping jaw with through holes for clamping screws to a metal plate embedded in the lower side of the lower clamping jaw. This metal plate has through holes which are aligned with the through holes of the upper web-like metal plate and are designed in the form of threaded holes.

so that no nut is needed to clamp the two clamping jaws together.

By tightening the clamping screws, not only is the upper clamping jaw clamped together with the lower clamping jaw, but also the branch conductor to be connected to the main conductor is contacted at the same time, as the contact elements in the upper and lower clamping jaw penetrate into the main conductor or branch conductor against each other. This is critical in that in many cases the breaking strength of the conductors and their vibration resistance are impaired. Since such branch terminals are used in particular for connection to insulated overhead lines, a reliable seal against the penetration of moisture into the interior of the branch terminal must be achieved at considerable expense. This is particularly problematic with a compact design of the branch terminal, as sufficiently long creepage distances cannot be provided.

To mount the fully insulated branch terminal on insulated overhead lines, it is therefore necessary to use a clamping tool with increased contact protection. In doing so, it must also be ensured that the clamping screws are tightened to a certain torque, depending on the type of main and branch conductor, so that the contact elements only penetrate the conductor against each other in such a way as to establish electrical contact, without impairing the breaking strength of the conductor or its vibration resistance. To do this, it is necessary to mount the clamping body of the branch terminal firmly against the insulated overhead line, whereby this is particularly important when tightening the clamping screws to clamp the upper and lower conductors together.

lower clamping jaw and for contacting the main conductor with the branch conductor. The branch terminals must be prevented from tilting when the clamping screws are tightened. In conventional assembly wrenches, the clamp body is supported with the metal plate of the lower pressure plate protruding downwards on a flat steel profile part, which extends laterally from an electrically insulated handle. The steel profile part has two longitudinal recesses, the size of which corresponds to the dimension of the protruding rectangular metal plate on the underside of the lower clamping plate.

To assemble the terminal body of the branch terminal with such a known assembly key, two fitters are generally required. One fitter must hold the assembly key on the underside of the terminal body of the branch terminal in such a way that it rests there at a certain height and is held in such a way that when the other fitter tightens the clamping screws on the top of the upper clamping jaw, the terminal body does not become jammed in relation to the main or branch conductor to be connected. This is difficult in that a second fitter can only inadequately prevent the terminal body from becoming jammed when the clamping screw is tightened, and it is also technically difficult in that the known assembly key cannot be used to hold the terminal body directly below the open-end wrench for tightening the clamping screws.

The object of the invention is therefore to create an assembly key which enables safe assembly of the overhead line and branch terminals even under tension without the terminal body becoming jammed, whereby the terminal body is held directly by the assembly key in the upper area of the upper branch terminal. To solve this problem, an assembly key is designed in accordance with the characterizing part of claim 1. The assembly key is then designed with such a flat steel profile part that opens at the side, so that the terminal body can be held directly on the upper clamping jaw below the web-like metal plate that rests there and serves as a pressure plate. The enlarged lever arm, which comes into effect when the terminal body is suspended in this way, effectively prevents the terminal body from becoming jammed when tightening against the conductor of the insulated overhead line. It is possible for a single fitter to simultaneously tighten the clamping screw and hold the clamp in place using the assembly key. An increased lever arm is also achieved when using the assembly key according to the invention in that the flat steel profile of the assembly key, which opens at the side, is arranged at the upper end of the handle. It is possible to store smaller metal plates that serve as pressure plates centrally within the holder of the flat steel profile part of the assembly key, which extends to the right and left. The flanks of this holder, which is designed in the form of a parallel guide, are bevelled inwards towards the underside of the holder in such a way that the steel profile, which opens in a C-shape at the side, with the bevelled flanks, can be pushed laterally under the upper web-like metal plate that serves as pressure plate.

of the clamp body, whereby the clamp body is then finally locked in the steel profile of the assembly key.

In this respect, the opening width of the parallel guide must be slightly smaller than the width of the web-like, rectangular metal plate. The length of the parallel guide is preferably designed to match the length of the metal plate to be locked. The mechanical strength of the steel profile is designed for a tightening torque of the clamping screws of 20 Nm. With the tightening torque of the clamping screws of 15 Nm specified for these branch terminals, this steel part cannot expand. Since neither the upper web-like metal plate acting as a pressure plate nor the clamping screws of the clamp body or the lower metal plate on the underside of the lower clamping jaw with threaded holes for the clamping screws come into contact with live parts during assembly and operation, the branch terminal can also be safely installed under voltage, provided that no leakage currents can occur due to moisture. In this respect, the handle of the assembly wrench is provided with an insulating sheath in a manner known per se. Advantageous external dimensions of the flat steel profile part attached to the upper end of the handle of the assembly wrench are given in claim 2, while advantageous dimensions of the holder of this steel profile part designed as a parallel guide, in particular with regard to the dimensions of the narrowed holder in the area of the inwardly bevelled flanks are given in claim 3.

The drawings show two preferred embodiments of the assembly key and its arrangement relative to the fully insulated branch terminal when clamping the upper clamping jaw against the lower one.

Show it:

Figure 1 a: A first embodiment of the assembly key, in which the steel profile plate is designed as a flat locking plate, in which the receptacle enclosing the clamp body under the upper web-like metal plate opens laterally to the left;

Figure 1 b: A side view of the narrow side of the

Assembly key showing the

Material thickness of the steel profile plate and

the diagonally sloping inward, a

Parallel guidance forming flanks, the side-opening receptacle;

Figure 2: A cross-sectional view through a fully insulated branch terminal for insulated overhead lines showing the terminal body and the elongated web-like pressure plate resting on the top;

Figure 3: The arrangement of the branch terminal on an insulated overhead line with a branch line extending from it, with the assembly key pushed laterally under the upper pressure plate of the branch terminal, whereby the steel profile part of the assembly key locks the terminal body;

Figure 4 a: A side view of a second embodiment of the assembly key with a vertical

to the longitudinal direction of the elongated holder curved locking plate, and

Figure 4 b: A view of the narrow side of the assembly key, seen from the plate wall that is closed at the side opposite the elongated holder;

In the side view and top view according to Figures la and lb of the steel profile plate (4) of the assembly key (1) which opens laterally in a C-shape, its structure can be clearly seen.

The assembly key (1) consists of a handle (2) with an outer insulating casing (3) which is designed for a voltage resistance of up to 1000 V, as well as the steel profile part (4) which opens laterally into a holder (5). The holder (5) is designed in the form of a parallel guide (6), between the parallel side walls (7, 8) of which a web-like metal plate (13) which serves as the upper pressure plate when the upper and lower clamping jaws (25, 26) of the branch terminal (27) are clamped together according to Figure 2 can be inserted laterally and secured there, whereby the metal plate (13) resting longitudinally on the curved surface (28) of the upper clamping jaw (25) is gripped behind on both sides on the back with flanks of the side walls (7, 8) which are beveled downwards and inwards.

The flat plate-like steel profile (4) of the assembly key (1) is thus fixed between the engaged edges of the metal plate (13) and the curved upper side (28) of the upper clamping jaw (25), whereby the assembly key (1) is pushed laterally under the metal plate (13) serving as the upper pressure plate with the opening side of the steel profile (4).

This locks the terminal body of the branch terminal in the steel profile lath (4), so that the main conductor (29) and the branch conductor (30) to be contacted with it are laid through the branch terminal (27) held in this way and then, while holding the assembly key with one hand, the same fitter

with the other hand the clamping screws (31, 32) of the clamp body can be tightened.

This can be done in a precisely controlled manner, for example by means of a torque wrench, so that despite the contact elements (12, 17) being notched through the insulation in the main and branch conductors to be contacted, these do not impair the breaking strength and vibration resistance of the conductor.

Since the clamp body is inserted at the top, directly at the metal plate (13) serving as the upper pressure plate, into the holder (5) that runs laterally into the opening (9), and is pushed onto the flanks of the side walls (7, 8) that are angled towards one another and thus hooked in there, with the clamping screws of the clamp body coming to rest directly above them with their screw heads when tightened, when the clamping jaws and the clamp body holder are clamped together using the elongated handle (2) of the assembly key (1), a larger lever arm is created compared to a clamp body that only rests with its underside in the steel profile plate (4). In this respect, tilting of the branch clamp relative to the insulated overhead line when the clamping screws are tightened is effectively prevented.

In accordance with the usual dimensions of the upper pressure plate of a fully insulated overhead line branch terminal of the 22 series (length of the terminal 20 mm to 54 mm, width of the terminal 34 mm to 56 mm), the holder (5) has an opening width of a = 29.8 mm or b = 31.8 mm and a depth of c = 48.0 mm, measured over the flanks of the side walls (7, 8). The dimensions a and b are shown in Figure Ib in the top view of the front side of the plate-like part with a material thickness of 4 mm.

flat steel profile part (A). The depth c of the holder (5) is greater than the length of the web-like elongated metal plate (13) according to the arrangement of the assembly key shown in Figure 3 in relation to the branch terminal to be mounted.

It is then possible to insert this metal plate (13), which serves as the upper pressure plate, so far into the holder (5) of the steel profile plate, which opens laterally in a C-shape

(4) so that the handle (2) of the assembly key (1) is positioned to the right of the two clamping screws (31, 32) of the terminal body to be tightened. The depth c of the holder (5) of 48.0 mm is well suited to a given length of the insulated overhead line terminals between 20 mm and 54 mm in order to be able to hold all of these different types of branch terminals with one or two clamping screws securely using the same assembly key (1). The dimensions of the key remain compact, and the steel profile plate (4) in particular is not bulky.
The holder (5) forming the parallel guide (6) is arranged perpendicular to the straight-line handle (2). This ensures that the rectangular metal plate (13) serving as the upper pressure plate is optimally locked in the holder (5) during tightening of the clamping screws (31, 32) and rests securely on the flanks of the parallel side walls (7, 8) without coming out of the holder.

(5) to be able to slip out. In order to be able to store both shorter printing plates with just a single clamping screw and longer printing plates safely in the holder (5), the depth (c) of the holder (5) should not be too short and therefore not less than the length of the shortest printing plate of 20 mti.

The structure of the fully insulated overhead line terminal (27) is shown in Figure 2.

The clamp body consists of the upper clamping jaw (25) and the lower clamping jaw (26). The upper clamping jaw (25) is made entirely of an electrically insulating and sufficiently heat-resistant plastic. On both sides of a passage opening (33) for a clamping screw (31, 32), by means of which the two clamping jaws (25, 26) can be clamped together, in the surface facing the lower jaw (26) there is a groove open towards the lower clamping jaw (26), which run parallel to each other and partially form a conductor channel for a main conductor

(29) or a conductor channel for a branch conductor

(30). In order to prevent the contact pressure from being transmitted via the insulation of the conductors, which could lead to the insulation flowing and a reduction in the contact pressure, four cross-cutting edges (12) protrude into the grooves of the upper clamping jaw. These cross-cutting edges (12), which run in the circumferential direction of the conductor channel, are attached to the upper clamping jaw.

(25) is formed. The through-opening (33) of the upper clamping jaw (25) has

(26) has a circular cross-section. Towards its other end, the cross-section becomes an elongated hole with increasing length, which enables the adjustment of the upper clamping jaw (25) relative to the lower clamping jaw (26) to different conductor cross-sections. On the upper side of the upper clamping jaw (25) facing away from the lower clamping jaw (26) is placed a metal plate (13) running in the longitudinal direction of the upper clamping jaw and over the area of the outlet openings (33) and serving as an upper pressure plate, which is provided with a series of circular through holes and on the underside corresponding to the upper side (28) of the upper clamping jaw

is curved in order to enable the head of the clamping screw (31, 32) to rest close to the shaft in all setting positions of the upper clamping jaw (25).

The lower clamping jaw (26), like the upper clamping jaw (25), has a groove (14) or (15) on both sides of its passage channel (20) for the clamping screw (31, 32), which are aligned with the grooves of the upper clamping jaw and together with these form the two conductor channels of the branch terminal. Therefore, the grooves (IA) and (15) also have at least approximately the same radius of curvature as the grooves of the upper clamping jaw. The grooves (14) and (15) are formed by the side zones (16') or (16'') of a plate (16) made of a material that conducts electricity well, which is the only contact bridge. This plate (16) has contact elements (17) formed in one piece with it on the side facing the upper clamping jaw (25) in the sections of its two side zones (16* and 16''). In the example shown, the four corner areas of the plate (16) each have three adjacent rows of four pyramid-like teeth. The contact elements (17) extend into the grooves (14 and 15) and thus into the conductor channels of the upper clamping jaw. When the two clamping jaws (25, 26) are clamped together using the two clamping screws (31, 32), the contact elements (17) penetrate the insulation of the conductors and then contact their metallic core. The large number of contact elements guarantees good contact without affecting the conductor breaking strength and the vibration resistance of the conductors.

With the exception of the surface of the side zones (16* and 16'') facing the upper clamping jaw (25), the plate (16) is completely embedded in the insulating material of the lower clamping jaw (2), which preferably consists of the

the same material as the upper clamping jaw

(25). The plate (16) lies in a plane which is penetrated vertically by the clamping screws (31, 32). The plate (16) is therefore provided with a cylindrical opening (18) in its center for the passage of one of the screws (31, 32). The diameter of the cylindrical opening (18) is larger than the diameter of the passage channel (20) for the shaft of the screw (31, 32), so that the insulating material filling the cylindrical opening (18) up to the passage channel insulates the plate (16) from the clamping screw (31, 32).

An increase in the creepage distance between the shaft of the clamping screw (31, 32) and the exposed surfaces of the plate (16) is achieved by means of a sleeve (19) which covers the passage channel (20) of the lower clamping jaw

(26) for the clamping screw (31, 32) is extended beyond the surface facing the upper clamping jaw (25). The sleeve formed onto the lower clamping jaw (26) is so long that it engages in the through opening (33).

A lower metal pressure plate (21) is completely embedded in the outer surface of the lower clamping jaw (26) facing away from the upper clamping jaw (25), which is provided with a threaded hole aligned with the passage channel (20) for the engagement of one of the clamping screws (31, 32). No nut is therefore required to clamp the two clamping jaws (25, 26) together.

In Figure 3, which shows the arrangement of the assembly key (1) on the upper clamping jaw (25) of the branch terminal (27), one can see the main conductor (29) running through this branch terminal and the

Branch conductor (30) running into the branch terminal on the right side.

The metal plate (13) serving as the upper pressure plate is shown on the top side (28) of the upper clamping jaw (25). The upper clamping jaw (25) is clamped together with the lower clamping jaw (26) using the two clamping screws (31, 32).

The assembly key (1) with its steel profile plate (4) opening to the left is inserted under the two long sides of the metal plate (13) serving as the upper pressure plate. The lower edges of the metal plate (13) rest on the downwardly inwardly bevelled flanks of the parallel side wall (7, 8) of the holder (5).

In this way, the metal plate (13) and thus the clamp body are locked in the steel profile part (4), whereby the clamping screws (31, 32) can be fixed directly above the steel profile plate (4) and the metal plate (13).

The holder (5) of the metal plate (13) has a length (c) which is greater than the length of the metal plate (13), so that the handle (2) of the assembly key (1) in particular comes to rest on the right side at the beginning of the metal plate (13). The metal plate (13) is inserted into the holder (5) over its entire length, so that the clamp body can be optimally locked and held without tilting while the clamping screws are tightened. The holding of the assembly key (1) and the tightening of the clamping screws (31, 32) can be carried out simultaneously by a single fitter.

In contrast to the steel profile plate (4) with the flat outer side walls (7, 8) running parallel to one another, the assembly key (I ¹ ) shown in the side view and front view of Figure 4 a and Figure 4 b according to a second embodiment has a steel profile plate (4 ¹ ) that is curved perpendicularly to the longitudinal direction of the longitudinal holder (5'). Flanks (10') of the side walls (7', 8') slope inwards in the parallel guide (6) to the horizontal support plane (35) indicated by dash-dot lines.

In this embodiment, the flanks (10')

original
in this case, an angle of 90° to the top of the outer side wall (7 ¹ , 8'). In this respect, it is possible to form the steel profile plate (4 ¹ ) together with the projection (34) which projects vertically to the side to form the handle (2) as a one-piece, continuous punched-out profile part, whereby the flanks (10* ) sloping vertically from the side walls are punched between an upper and lower tool at the same time as the curvature to be created from a flat profile.

In contrast to the steel profile plate (4), the flanks (10') of the steel profile plate (4 ¹ ) do not have to be milled off at the sides. Instead, the upper pressure plate resting on the clamp body in the form of the web-like metal plate (13) of Figure 2 can be gripped behind with the simple punched-out holder (5'). Due to the curvature of the steel profile plate (4'), the flank (10') which slopes inwards towards the horizontal support plane (35) below the upper pressure plate of the clamp body acts as a locking mechanism.

The production of an assembly key according to embodiment (I') with a curved steel profile plate (4') is in the manufacturing process and with regard to the

-U-

Manufacturing costs are significantly cheaper than an assembly key (1) which is made with a flat steel profile plate (4), which must therefore also be milled after the actual steel profile part has been punched on the flanks of the holders (5).

Claims (10)

Protection claims Clamping tool in the form of an assembly wrench, the handle of which is electrically insulated in such a way that it has a dielectric strength of up to approximately 1000 V, with an iron or steel profile plate punched from a flat profile, with an elongated receptacle extending to the right and left in the middle of the end of the handle, opening on one side and forming a parallel guide, for holding bare or fully insulated branch terminals for insulated conductors, in particular for insulated overhead lines, while tightening clamping screws of the clamp body, via which the two clamping jaws arranged at a distance from one another, consisting of an electrically insulating material and forming the clamp body are clamped together, with passage channels being created in the upper clamping jaw, which run from the lower end to the upper end and change from a circular cross-sectional shape at the lower end with increasing length towards the upper end into the cross-section of an elongated hole, with perpendicular in the longitudinal direction of the clamp body transversely to the elongated holes running on the top across the width of the upper clamping jaw a web-like, elongated metal plate serving as the upper pressure plate and having a rectangular cross-sectional dimension with a row of elongated or round holes and a hole spacing corresponding to that of the elongated holes, in particular resting so as to be laterally displaceable, which is also curved in the direction of the elongated holes and can be screwed to a metal plate serving as the lower pressure plate, which is fully or partially embedded in the outer surface of the lower clamping jaw facing away from the upper clamping jaw and which is provided with threaded holes aligned with the passage channels of the upper clamping jaw and with passage channels running between the two clamping jaws, . ■· ■ . ■ ·.· ⁱ characterized in that
for locking the clamp body between the rectangular web-like metal plate (13) and the top side (28) of the upper clamping jaw (25), the laterally opening steel profile plate (4, 4') is arranged in the form of a flat locking plate or a locking plate curved perpendicularly transversely to the longitudinal direction of the elongated receptacle (5,5'), wherein the receptacle (5,5') designed as a parallel guide (6) has flanks (10, 10') sloping inwards laterally from its outer side wall (7, 8, 7', 8') to a horizontal support plane, and that the opening width of the parallel guide (6) is slightly smaller than the width of the metal plate (13) serving as the upper pressure plate, and that the minimum length of the parallel guide (6) is greater than or equal to 20 mm (length of the metal plate serving as the upper pressure plate for a single clamping screw (31))
is, and furthermore, the steel profile part (4, 4') has such a mechanical strength that tightening torques of the clamping screws of up to 20 Nm can be absorbed without deformation of the steel profile. 2. Clamping tool according to claim 1,
characterized in that the steel profile plate (4, 4') has a substantially rectangular dimension (length 63 mm and width 56 mm). 3. Clamping tool according to claim 1 or 2,
characterized in that the opening width of the parallel guide (6) installed in the holder (5.5') of the steel profile plate (4, 4') with a thickness of the plate material of 4 mm on the undercut plate side has a size of a = 29.8 mm and on the inwardly bevelled side has a size of b = 31.8 mm. 4. Clamping tool according to one of claims 1, 2 or 3, characterized in that the length of the parallel guide (6) is 48 mm. 5. Clamping tool according to one of claims 1-4, characterized in that the outer plate sides (Ha, Hb) of the flat or curved steel profile plate (4, 4') run parallel or at the same distance over the entire surface. 6. Clamping tool according to one of claims 1-5, characterized in that the inwardly sloping flanks (10, 10') are bevelled over the entire thickness of the steel profile plate (4, 4'). 7. Clamping tool according to one of claims 1-6, characterized in that the curved steel profile plate (4 ¹ ) has flanks (10 ¹ ) sloping vertically inwards laterally from the outer side walls (7 ^f , 8') to these. 8. Clamping tool according to one of claims 1-7, characterized in that the steel profile plate (4, 4') and a projection (34) projecting laterally vertically to form the handle (2) form a one-piece, punched-out profile part. 9. Clamping tool according to one of claims 1-8, characterized in that the handle (2) is provided with an insulating sheath (3) is provided. 10. Clamping tool according to one of claims 1-9, characterized in that the steel profile plate (4, 4') has a uniform material thickness of approximately 4 mm.