JPH0415992B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a screw clamp for a conductor, comprising:
It has a cylindrical clamp body formed by bending a thin plate, and the wall on the opposite side of the clamp body from the wall into which the clamp screw is screwed overlaps the both side walls of the clamp body vertically. Relates to the type formed by the Department.

DE-OS No. 1 of the applicant's application for the present invention
According to document 1805804, a screw clamp of the same type is known in which the screws are screwed into two folds located one above the other. Although this construction type has been in production for several years and has been well received by those skilled in the art, the following points were already suggested in the above-mentioned specification DE-OS 1805804.

That is, its construction type is particularly suitable for implementation in small-sized screw clamps, especially when trying to make the clamp body as thin as possible (this does not make sense, however, if the screw clamp is to be used as a row-type clamp in a circuit device). (This is extremely important in some cases)
has its limits. That is, the distance between the side walls of the clamp body has been reduced to the point where it almost touches the outer diameter of the screw, so that the width of the inner bent portion for drilling the screw hole is no longer sufficient to effectively support the screw. This is because the threads of the outer bent portion somehow effectively support the screw.

Furthermore, the form mentioned in the introduction, e.g.
In the screw clamp described in OS No. 1790153 or DE-GM1876079,
It has become known to design the clamp body to be narrow. According to this configuration, in order to produce a sufficiently long and durable thread, a collar-shaped hole is provided in the central part of the starting workpiece before the bending process,
A female thread is machined in the outer hole. Other types of thread collars are known for the same purpose. For example DE-AS 1091168. With this configuration, a reasonably durable screw thread was obtained, but the connection of the leg wall or side wall of the clamp body on the side opposite to the thread of the screw was insufficient. It is. The folding structure described in the above specification not only involves a very complicated manufacturing process, but also consumes a large amount of material. This is because the cut shape of the material ceases to be rectangular, but becomes a laterally protruding or T-shaped strip.

As a result, tension-molded clamp bodies have come to be used when clamp bodies with as small a width as possible are required. Such a clamp body is obtained by cutting a single piece of molded tube that has been precisely molded in multiple manufacturing steps. However, the cost of such shaped tubes is extremely high, and at their ends, for reasons of manufacturing technology, a considerable amount of material was wasted.

The object of the invention is to provide a cost-effective method which, in particular, contributes to material savings and has a simple manufacturing process, while also guaranteeing safety against damage to the clamping body even when the clamping screw is fully tightened. Another object of the present invention is to provide a screw clamp of the type mentioned in the introduction.

This problem is achieved according to the invention in that one of the folds has a supporting tongue which engages in the window of the other fold. has been done.

With this arrangement, very thin clamping bodies can be produced not from stretch-formed tubes, but from strip material, which is particularly cost-effective.

The cutting shape of the material of the clamping body is rectangular, so that in principle no material is wasted when processing a strip-shaped starting material. For window punching and partial punching of supporting tongues at folds:
As with the pushing of the support tongue into the window, there is no technical difficulty; therefore, after the bending of the clamping body, the two folds, one above the other, are at right angles to the screw axis. To reliably prevent the side wall of a clamp body from expanding in the lateral direction.

According to a further advantageous embodiment of the invention, the window is provided in the inner fold and the supporting tongue is provided in the outer fold, and the supporting tongue is provided vertically in the outer fold. It faces away from the edge and its tip abuts the window edge adjacent to the longitudinal edge of the inner fold. Advantageously, the supporting tongue is then pushed into the window of the inner fold from the outside. Although other contour shapes are conceivable, in the present invention the window and the supporting tongue have a rectangular contour that fits inside and outside of each other, advantageously with the long sides of the rectangle folded. oriented vertically.

It has been found experimentally that if the clamping screw or screws are tightened until the screw head ruptures, the supporting tongue can withstand the compressive stress acting on it and also, e.g. He never deviated from the correspondence established by him. A further advantage of the invention is that the conductors or cords to be connected, preferably copper, are better held immovable by the window edges against tensile forces. The corners of the window serve a similar function to the transverse serrations provided at the bottom of known lamp bodies. It has also been found that there is no risk that the conductor, which has been pushed into the window due to the deformation, will push the support tongue open from the inside and release it.

The invention will now be explained with reference to the illustrated embodiment.

The illustrated clamping body of rectangular cross section consists of a top wall 1, two side walls 2, 3 and a bottom formed by two folds 4, 5 of the side walls which overlap one another. The upper wall 1 has three collar-shaped holes 6 whose edges project upward and each have an internal thread 7 into which a clamp screw 8 is screwed. The clamping screw is provided with a wire protection curved piece 9, one of which is shown in dotted lines, and is known per se.

Two rectangular windows 10 are punched out in the inner bent portion 4 on the extension line of the clamp screw 8. The outer bent part 5 has two square support tongues 11, which are located below the window 10, and three U-shaped sides of the square are separated. and is bent diagonally upward with respect to the plane of the bent part 5, and the edge opposite to the vertical edge of the bent part 5 is the window 1.
0, the edge of the window 10 extends parallel to and adjacent to the longitudinal edge of the fold 4.

When the connecting wire is firmly tightened by the clamp screw 8, pressure is generated between the upper wall 1 and the bent portions 4, 5. However, this pressure merely causes the effect of pushing the side walls 2 and 3 apart and separating the bent portions parallel to each other. Such a load is completely taken up by the upwardly bent support tongue 11.

[Brief explanation of drawings]

Fig. 1 is a partial cross-sectional view of a clamp body according to an embodiment of the screw clamp of the present invention, Fig. 2 is a side view of the same clamp body, and Fig. 3 is a horizontal longitudinal cross-sectional view of the clamp body of Fig. 1. It is. 1...Top wall, 2...Side wall, 3...Side wall, 4...
Bending portion, 5...Bending portion, 6...Collar hole, 7...Female thread, 8...Clamp screw, 9...
...Wire protection curved piece, 10...Window, 11...Support tongue piece.

Claims (1)

[Claims] 1. A screw clamp for a conductor, comprising a cylindrical clamp body formed by bending a thin plate,
In the case where the wall of the clamp body opposite to the wall into which the clamp screw is screwed is formed by bent portions of both side walls of the clamp body that overlap each other vertically, one of the bent portions 5 has a support tongue 11 which engages into the window 10 of the other fold 4. 2. Screw clamp according to claim 1, characterized in that the bend-joint formed by the support tongue (11) and the window (10) is formed on an extension of the clamp screw axis. 3 The support tongue 1 is attached to the folded part 4 on the inside of the window 10.
1 is provided on the outer folded part 5, and the support tongue-like piece 11 faces in a direction away from the longitudinal edge of the folded part 5, and its tip is attached to the longitudinal edge of the inner folded part 4. 2. A screw clamp according to claim 1, which abuts an adjacent edge of the window. 4. Screw clamp according to claim 1, characterized in that the window (10) and the support tongue (11) have a rectangular profile that fits inside and outside of each other.