Strut, especially floor supporting strut in building construction

DESCRIPTION

PLUMB, NAMEDLY PLUMBED TO SUPPORT CEILINGS

IN CIVIL CONSTRUCTION

The invention relates to a plumb, namely a plumb to support ceilings in civil construction, with two plumb elements, of which one can perform a telescopic movement in relation to the other, which elements can be blocked in relation to at least a direction of load incidence through a pin-hole connection, so that the soffit of the hole of at least one of the plumb elements is widened in the connection zone in relation to the neighboring wall thickness of that plumb element. The invention further relates to a process according to claim 4 and a device for carrying out the same according to claim 8.

The plumbs of the type in question are constituted in the vast majority of cases by an interior plumb element of tubular shape and an outer plumb element of also tubular shape, within which the interior plumb element can carry out a telescopic movement. At the outer periphery of the outer plummet element, a thread is formed at least in some parts of it, in addition to two long holes arranged face to face and with the respective axes arranged parallel to the thread axis. A support ring is screwed onto the thread, which serves to support a bolt threaded through both long holes. The inner plummet element has holes with a certain spacing between them, through which it is possible to insert the pin. The fine adjustment of the entire plumb is then carried out by rotating the support ring. In this type of plumb line there are two factors that play a decisive role. On the one hand, it is intended to construct the plumbs in a way that

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as light as possible so they can be easily handled. On the other hand, the problem arises in the context in question that the maximum load exerted on the soffit of the holes, in which the pin is inserted, should be supported as far as possible in such a way that there are no unacceptable deformations. To take this conditionality into account, it has already been proposed by the patents DE-A-29 35 187 and DE-A-44 00 360 to increase the thickness of the profile of the holes in the interior plumb element along its entire length, thereby widening the soffit of the holes. This widening is in the great majority of cases obtained by an appropriate choice of the profiles of which the pipe is made or by the application of a reinforcement by a welding operation. Although a configuration of this type alone provides great weight savings, combined with a sufficiently high resistance to the bottom of the hole, there is nevertheless the purpose of achieving an even greater improvement.

The aim of the present invention is to provide a plumb of the type of beginning referred to, which provides a sufficiently strong resistance in the area of ​​the holes, combined with the least possible weight of the profiles.

According to the invention, this objective is achieved by configuring the widening of the soffit of the hole by molding by stamping a support nose shaped on one side of the hole, which is the side of the load incidence, the nose of which The support surface is essentially perfectly adapted, in terms of its shape, to a corresponding area on the bottom of the hole.

This means that, according to the invention, a repression is created artificially in the load area of ​​the bottom of the hole, a repression that would otherwise be created during the use of plumbs whenever the pressure exerted on the bottom of the hole is too high or else as a result2

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normal aging process. In addition, the invention has the enormous advantage that the widening of the soffit of the hole can only be carried out on the side of the hole where the force transmission takes place. In the ceiling support posts for civil construction, with only one direction of load incidence, this is usually seen at the top of the hole, since this is the part that exerts pressure on the bolt, due to the load that is exercised from the top side. Distinguishing itself from a damage of this type in which the hole over time takes on an oval shape, so that the pin starts to have play, the hole according to the invention has a precise circular shape configuration, which allows a pin fitting with less clearance. Instead of reinforcing the hole area along the entire length of the plumb element, the solution according to the invention does not require the use of supplementary material, since the support nose is molded from the material made available during punching the hole. This makes it possible to obtain significant weight savings. In addition, the widening of the soffit of the hole is located only at the place where such widening is really necessary.

A shape of the holes that is given special preference provides that they are circular and that the support nose has the shape of a sickle adapted to the circular shape of the hole, this being the easiest way of making it from the point of view of production technology and the most advantageous for the type of cargo in question.

The easiest way to manufacture the plumb line is to provide for its construction a metal, preferably steel, since in this case there is the possibility of producing the support element from the material in the form of band, through operations stamping molding and bending or winding operations.

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In the following, protection is claimed for a hole forming process for a bolt and hole connection that can be requested from the load in a certain direction, namely for a plumb line according to any of claims 1 to 3. This process distinguishes itself through the following steps:

a) punching a hole with a certain gap between the molding punch and the die in the area on the soffit side of the hole that will later be subjected to the load, thus forming a burr of predefined dimensions;

b) molding of the burr by a stamping operation, to form a support nose with a support surface that is essentially exactly adapted to a corresponding area of ​​the bottom of the hole.

process is distinguished by its simplicity. By deliberately choosing too large a gap between the die opening and the impression punch in the area of ​​the supporting nose to be configured, burr formation is consciously achieved. This burr, which protrudes laterally, can then be compressed in a subsequent stamping operation in order to obtain the desired shape of the support nose. The actual idea of ​​this invention lies in the fact that it is consciously created at a point in the hole to punch out disadvantageous punching conditions, which lead to the formation of a burr that would otherwise be undesirable.

Advantageously, steps a) and b) of the process can be performed by the same molding punch, so that the forming of the hole with the support nose is carried out in a single work step.

To increase the quality of the hole and the accuracy of the measurements of the support surface of the support nose, it is possible, according to

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with a process variant, carry out a bore calibration in another process step, at least in the area of ​​the load side and the support surface.

A simplification of the process can be obtained advantageously, making steps a), b) and c) to be carried out by the same impression punch. Thus, a hole with a support nose that has a very high measurement accuracy is performed in a single work step.

In addition, protection is required for a device for carrying out the process according to any of claims 4 to 7.

The device comprises a die and a molding punch that enters an opening in the die, a punch that serves to punch a hole in a workpiece, which between the opening and a punching zone of the molding punch is provided in the zone on the future side the load of the soffit of the hole to punch a certain gap that allows to form a burr of predefined dimensions, also comprising a stamping device for shaping the burr in order to transform it into a support nose with a support surface that is essentially adapted, in terms of its shape, to a corresponding area of ​​the bottom of the hole. The impression punch, which in principle can be inserted into the die opening with a perfect fit, has a purposeful gap in a single well-defined area. Because a large part of the periphery of the impression punch is guided inside the opening, the punch cannot deviate from that periphery, which causes a well-defined burr to be created.

Advantageously, the embossing device can have the configuration of a embossing zone integrated in the embossing punch and located above the embossing zone. That zone of u

During the stamping operation, the embossing compresses the burr into a molding cavity arranged in the matrix near the upper edge of the opening, which cavity serves to conform the supporting nose. In these conditions, there is the possibility, by reducing the gap between the die opening and the molding punch, to perform the stamping operation. The burr can then be pressed into the molding cavity, which precisely defines the outer contour of the support nose. Advantageously, the clearance reduction can be carried out gradually.

To improve the accuracy of the measurements, a calibration device can be provided, which calibrates at least the hole in the workpiece located on the side of the load and on the support surface.

In this context, it has been found advantageous that the calibration device has, according to yet another variant of the invention, the configuration of a calibration zone with a cutting edge arranged in the molding punch above the embossing zone. In a configuration of this type, all three molding operations (punching, stamping and calibration) are carried out in a single operation and by means of one and the same molding punch.

In order for a clean stamping and calibration to be carried out, resulting in a correspondingly clean configuration of the support nose and the support surface, both the stamping zone and the calibration zone can be inserted in the die opening with an adjustment that essential is perfect and with a reduced clearance.

Since the holes are mainly circular holes, the molding cavity may, seen from the front, have the shape of a scythe, which is adapted to the shape of the opening. This shape is especially easy to conform and guarantees a clean fit of the support nose in relation to the hole.

In yet another embodiment of the invention, the impression punch is supported on a guide plate subjected to spring pressure and disposed above the die. Due to the load exerted by the springs, the guide plate ensures a perfect incidence of pressure on the workpiece, even if it presents some differences in thickness. By properly relocating the springs, it is possible to advance the part to be machined, namely the material in the form of a band.

In the following it will be explained in more detail, by means of a drawing, an example of realization of the present invention. The figures in the drawing show:

Fig. 1 is a partial cross-sectional view of the plumb line according to the invention,

Fig. 2 is a perspective view of the interior plumb element,

Fig. 3 is a cross section along line III-III of the cutout in fig. 2,

Fig. 4 is a cross section of the cutout of fig. 2 along line IV-IV,

Fig. 5 a device for making a hole according to the present invention, in a cross-sectional view,

Fig. 6 the device of fig. 5 in a cross-sectional view, rotated 90 °,

Fig. 7 the impression punch of fig. 5,

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Fig. 8 the impression punch of fig. 7, in a 90 ° rotated view,

Fig. 9 the impression punch of fig. 7, in a view from the bottom side,

Fig. 10 the matrix of fig. 5, in a cross-sectional view,

Fig. 11 is a section of the matrix of fig. 10, in a top view,

Fig. 12 a hole punching operation according to the present invention,

Fig. 13 the stamping operation and

Fig. 14 the calibration operation.

The part of a plumb line that fig. 1 shows a cross-section, the plumb line that is used to support formwork in civil construction, shows its essential components. The plumb comprises an outer plumb element 1 in a tubular shape, which rests on the floor by its foot not shown in the figure and has a threaded section 2 in its upper terminal area, an inner plummet element 3 in a tubular shape, which can perform a telescopic movement in relation to the previous element, projecting outwards from the upper end of the lower plumb element 1 and which can be brought into contact with the element to be supported by means of a support head not shown in the figure and arranged at its upper end and still a pin 4 that can be threaded through the support elements 2, 3 in a direction perpendicular to them. In order to insert the bolt 4, the lower plumb element 1 has in its threaded section 2 two long holes 5 arranged face to face. The interior plumb element 3 has several holes 6, with two of these holes always aligned face to face, and the distance between holes 6 in relation to the pair of holes.

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following holes, seen in the axial direction, less than the length of the threaded section 2. In the threaded section 2, a support ring 7 is also screwed in, against which the pin 4 rests in relation to the lower plumb element 1 .

The holes 6 are provided only on the side 8 of the load incidence, which is predefined by the load direction A, of a support nose 9 that widens the soffit of hole 6. Fig. 2 to 4 now show in detail the configuration of a hole 6 formed in the upper plumb element 3. The support nose 9 protrudes into the inside of the plumb element 3 and shows a front configuration over the hole 6. sickle shape, adapted to that hole. Seen in cross-section, the support nose 9 is approximately in the shape of a triangle. By configuring a support surface 10, which follows with perfect fit to hole 6, the soffit of the hole on the side of the load incidence 8 is increased. It is quite possible to obtain, through the configuration of the support surface 10, a duplication the width of the soffit of hole 6.

In the following it will be explained in more detail the way of acting and functioning of the embodiment described above.

The user places the plumb in a suitable place on a lower foot not shown in the figure and removes, while simultaneously holding the upper plumb element 3, the pin 4. Through a telescopic movement of one plumb element 1 in relation to the other 3, a rough preset. For this purpose, an appropriate pair of holes 6 is chosen. Then, the pin 4 is inserted through the long hole 5 and the holes 6 to block the position of the plumb elements 1, 3. 0 remaining stroke to the headrest not shown in the figure on the element to be supported is overcome by a rotating movement of the support rim 7. This operating mode is similar to that of the uprights

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which is why the description of the plumb as a whole is dispensed with.

It is now verified that the plumb is subject to a load in the direction of incidence of the load A, so that the force is transmitted through the load side 8 of the hole 6 on the pin 4 and from there, through the support ring 7, on the lower plummet element 1. In order that the top plummet element 3 may be of a light construction, with a relatively thin wall thickness, the load side 8 of the hole 6 has been reinforced by the support nose 9. 0 The size of the support surface 10 has been chosen in such a way that the wide soffit of the increased width can withstand the high pressures exerted at this point. This prevents hole 6 from aging, so its perfectly circular shape and perfect fit is maintained. For this reason, the clearance between pin 4 and hole 6 is approximately uniform, even if the plumb is used frequently. It should be noted that in this type of construction the use of material for the creation of the support nose 9 is relatively low, so that it is possible to substantially reduce the weight, if we compare it with the plumbs used so far.

Using figs. 5 to 14, an embodiment of a device will be explained in more detail below, as well as a process for making a hole 6 with a supporting nose 9.

The embodiment of the device essentially comprises a die 11 with a hole 12, a guide plate 14 whose movement is aided by the pressure springs 13 and a molding punch 16, which is moved and guided inside the guide hole 15 of the guide plate 14. Because the guide plate 14 can be raised in relation to the matrix 11, it is possible to position and advance web-shaped material 17 between those two parts. The band-shaped material 17, which preferably consists of 10

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by steel plate, it is then rolled up at a later stage of manufacture, so as to form the corresponding plumb element 1, 3. The molding punch 16 has at its lower end a punching zone 18 with an inclined surface, a zone stamping 19 located directly above the former and still above the latter a calibration zone 20. The punching zone 18 has a cross section with a section that is slightly recessed on one side, but which is also adapted with a perfect fit of its shape to the diameter D_Mof the hole 12 of the die 11. The width a of the punching zone 18 therefore has a clearance S = D_M-a with respect to hole 12. At the upper edge of hole 12, a scythe-shaped molding pit 21 is provided, which essentially corresponds to the shape of the support nose 9 to be created.

In the stamping zone 19 there is a gradual annulment of the recessed section, until the molding punch 16 reaches a diameter D, which essentially corresponds to diameter D_M of the hole 12. The gap S essentially shrinks to the minimum necessary to be able to insert the molding punch 16 into the hole 12.

In the calibration zone 20 there is a recess 22, which could also be called a chip lifting groove. This groove profiles a cutting edge 23 for calibration, which is also essentially adapted to diameter D.

In the guide zone 24 of the impression punch 16, two sliding surfaces 25 are provided facing each other, which in an opening 15 of the guide plate 14 in a complementary way to that of the punch define the precise angular position of that punch.

Then and using figs. 12 to 14, an embodiment of the process will be explained in more detail, using for 11

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such a device according to the embodiment described above.

In fig. 12 sees how the punching zone 18 of the molding punch 16 penetrates the material in the form of band 17, having already partially punched the material to obtain the hole 6. Simultaneously and due to the gap S existing between the punching 18 and diameter D_M from the hole 12 a burr 26 is formed, which is partially pressed into the molding pit 21. On the opposite side and due to the negligible gap between the punching zone 18 and the hole 12, a clean punching is obtained without significant burr formation.

When the molding punch 16 then continues to enter the hole 12, as seen in fig. 13, the embossing zone 19 comes into contact with the burr, that burr 26 being pressed with an essentially perfect fit into the molding pocket 21 for configuration of the support nose 9, due to the reduction of clearance S. At this point the section of material 27 is already completely separated from the material in the form of band 27.

Then and during the continuation of the downward movement of the molding punch 16, the calibration zone 20 slides with its calibration edge 23 in order to pass the burr 26 already molded to form the supporting nose 9, so that it becomes It is possible to configure a support surface 10 with the best possible precision, which is located following the remaining hole 6 and which fits perfectly. The calibration cutting edge 23 makes, as usual in calibration operations, a small cut of metal chip.

After forming the support nose 9, the impression punch 16 slides back to its raised position so that it completely comes out of the area where the band-shaped material 17 is located. Simultaneously, the pressure 13, so that the guide plate 14 is also raised. 0 band-shaped material 17 can then proceed appropriately to configure another hole 6 with support nose 9, then tightening the band again using the guide plate 14 and with the aid of pressure springs 13.

This process allows the making of a hole 6 with a support nose 9 in a single work step, so the time required to configure the hole according to the invention is not different from the time required to configure the holes of plumb elements already known. The band-like material 17 is then rolled up to take the form of the plumb element 3. It should be emphasized here again that the weight savings, which this configuration allows to obtain, is very high.

The present invention does not apply only to props for civil construction, but in principle to all metallic components that are intended to be connected to another component by means of a pin and hole assembly.