DE3018975A1 - Screw and dowel for panel fixing - includes screw with threaded and plain parts forced into dowel by hammer - Google Patents

Abstract

The dowel with a cylindrical top part (2) carrying a flange (6) and a lower expanding part (5) is used with a screw (11) which is forced inside by using a hammer. The screw has a head (13) with a sloping surface which fits against the countersunk mouth (7) of the dowel. This is on top of a plain cylindrical part (12) which matches the interior (3) of the cylindrical part of the dowel. The bottom (14) of the screw carries sawtooth shaped threads (15) which enter a smaller diameter hole (9) in the expanding part of the dowel, forcing its sections outwards. The upper and lower cylindrical interiors (3,9) of the dowel are connected by an intermediate tapered part (8). In another design, the expanding part of the dowel has a zig-zag or corrugated interior, and the outside surface is toothed. The cross section of the expanding part may be square, and compressed against the interior of a circular hole, to match its shape. The flanged top enables a panel to be secured to a surface.

Description

description

The invention relates to a mounting kit consisting of a elastic dowel with neck and spreading part and a matching one for fastening by hammering in a suitable fastening element.

There are already a large number of expanding bibles, especially for driving in known of spreading elements to be driven.

Such spreaders, which are preferably made of plastic, quietly a spreading part, which is usually through a longitudinally extending The slot is divided into two half-shells. The inner cross-section tapers of the expansion part towards the insertion end of the dowel, in such a way that the inner surfaces of the Spreading part on the lateral surfaces of a cone which tapers towards the inlet lie with a weak angle of incline. Can on the outer surfaces of the expansion part be provided transversely to the longitudinal direction of ribs through which a better anchoring and prestressing in the borehole is achieved.

A disadvantage with such dowels is that when they are hammered in an expansion element in the form of a hammer screw, a nail or another wedge-shaped element this through the narrowing inner surfaces of the expansion part a strong frictional resistance is opposed, which with increasing penetration depth increasing can reach a value that leads to the fact that the spreading part of the Dowel tears off, or that there are upsets or with correspondingly short drill holes Buckling of the front end of the expansion part comes.

The suggestion was therefore made to avoid this disadvantage to counter that in the smallest inner cross-section of the expansion sleeve resulting area the inwardly facing transverse ribs, at least the outer cross-section of the expansion sleeve is the same size as in the areas adjoining in the longitudinal direction of the dowel and that the Expanding sleeve in the area of the inwardly pointing transverse ribs over the outer circumference the adjacent areas protruding, also running transversely to the longitudinal direction of the dowel Has outer ribs (DE-OS 2753547).

Even with this known hammer-in expansion dowel, the to eliminate the disadvantages described to the full extent, and this is still liable the disadvantage that after driving in the expansion element a holding control cannot be carried out without endangering the hold. It also prepares the Dismantling greatest difficulties. A non-destructive solution is practically unlikely possible.

A large number of expansion anchors are known and commercially available for which threaded expansion elements are screwed in.

It is often felt to be a disadvantage with such known dowels, that the required holding strength is only achieved if one on the dimensions The screw type precisely matched to the dowel is used as an expansion element.

But even if this condition is met, the disadvantage remains a time-consuming and exhausting assembly, whereby often a holding force is achieved, which is much larger than necessary.

On the other hand, it can, however, be the case if a not optimally suitable one is used Screw and a dimension of the borehole that is outside the tolerance come that the required holding force is significantly undercut, in particular then if the pilot hole on the neck of the dowel in relation to the screw diameter is too big and / or too short.

The object of the invention is to provide one of a elastic Dowel with neck and expansion part as well as a matching one for fastening through Drive in a suitable fastener through the existing fastening kit to optimize appropriate design and coordination of the dimensions in order to as a result to achieve a maximum of holding force with a minimum of assembly effort.

Another important part of the job is getting the job done Holding force through a holding control that can be carried out in a simple manner, that is to say to be able to determine without great effort, as well as to create a possibility Dismantle the mounting kit also avoiding difficulties to be able to.

And finally, the invention seeks to provide a fastening kit to make available the conditions mentioned by economic means and fulfilled in a simple manner, thereby creating a labor and cost-saving mass fastening element to provide.

The task at hand is solved with a mounting kit with the followingN features: a) the fastener has a Leadership with a head at one end and a head at the other end Thread zone with a drive-in thread with thread flanks receding in the direction of impact is arranged, which ends in a conical tip.

b) the neck of the dowel is outside with a flange-like collar reinforced, and has a central guide bore receiving the guide shaft on which adapted in the area of the collar for receiving the head with this Receiving surfaces is provided and at the other end with a conical outlet in the area of the expansion part passes over.

The invention provides a fastening kit in an advantageous manner available, in which by coordinating the design proportions of dowels and Fastening element a surprising functional optimization succeeds through which With a minimum of assembly work, an optimum of holding force is achieved.

Especially where mass fasteners without the unconditional The need for supervisory approvals or individual permits are used, for example when attaching cable clamps, ribbon cables, facade cladding panels, Thermal insulation panels etc. brings the use of the fastening kit according to the invention considerable economic Advantages through labor and cost savings with them.

One embodiment provides that the diameter of the guide shaft is at least equal to the outside diameter of the impact thread.

This results in precise guidance of the fastening element in the dowel, which advantageously prevents the fastener when hammering runs out of the dowel axis. This makes the quality of the hold in easier Way secured.

It is further provided in an embodiment of the invention that the head designed as a pan head and the impact thread profiled with sawtooth-like Thread flanks is equipped.

The advantage of the lens head shape is that it is not exactly axially applied hammer blows counteracted bending of the fastening element is, and especially when with the sawtooth profiled, retreating Thread flanks a very safe and problem-free penetration of the fastening element anyway in the spreading part of the Dowel with exact guidance of the fastening element is guaranteed.

It is further provided that the guide shaft of the fastening element and the guide hole of the dowel has a defined fit such as sliding fit, sliding fit, Form fit-fit, tight fit according to DIN etc. with one another.

By assigning defined fits through qualified tolerances the nested diameter of the shaft and the bore is surprising high level of security and strength of a fastening kit together integrated unit of dowel and fastening element, which is achieved by a Numerous attempts could be proven.

The advantage of such a fit is particularly optimal applies if, as is provided in a further refinement, the fit is a snug fit or a tight fit.

It is also provided that the expansion part of the anchor by flat inner surfaces is formed in wave form.

Such a design in wave form combines the advantage of a relatively uncomplicated design of the production mold in the injection molding process and thus relatively cheap manufacturing costs with optimal spreading and the clamping effect of the dowel, especially in the case of imprecisely drilled holes.

However, similarly advantageous results are also achieved if accordingly Another embodiment, the expansion part of the anchor by flat inner surfaces in Zigzag shape is formed.

In a further embodiment it is provided that the fastening element is designed as a drive-in screw, which has a pan head with cross recess, has a cylindrical guide shaft and a thread zone with impact thread, which ends in a conical tip.

This configuration results in particular in the case of a drive-in screw due to the shape of the lens head with cross recess the advantage that on the one hand how already explained, not exactly centric hammer blows largely without bending endured, including the one provided for engaging a screwdriver Cross recess in the lens head is relatively insensitive to sprains caused by hammer blows is.

The cross recess allows after driving in by means of engagement Screwdriver and a small, for example half or full turn of the Screw in the direction of tightening both if necessary a readjustment on tension, as well as an uncomplicated one that can be determined by torque control Checking the holding strength and, if necessary, a problem-free dismantling.

In an embodiment it is further provided that the tip is at an angle CC with respect to the axis of the fastening element between 10 ° and 30 °, preferably between 12 ° and 15 °.

This slim conical shape of the tip advantageously avoids that the drive-in screw when driving into the expansion part material from the inner surfaces scrapes off the expansion part or pushes it in front of it. In this way there is a risk that the expansion part of the expansion anchor due to increasing entry resistance tears off, avoided with certainty.

Another embodiment provides that the receding flanks of the impact thread an angle P with respect to the axis of the fastening element that is equal to or greater than the angle Ch.

This measure also helps ensure that at a minimum Driving resistance a maximum of holding force is achieved in the end position, in particular because of the exact guidance of the fastening element in the direction of the dowel axis.

Further advantages for a problem-free driving in of the impact screw, as well as to achieve the greatest possible holding forces even in the event of inaccurate compliance the borehole dimensions result from the fact that, according to a further embodiment the pitch of the impact thread approximately half the dimension of the outer thread diameter is equivalent to.

This, as well as the further measure, according to which the core diameter of the impact thread approximately half the dimension of the outer thread diameter corresponds, results in surprisingly good values for the ratio of driving resistance and holding force even under unfavorable conditions such as incorrect dimensions of the drill hole, especially because of the strong formation of the thread flanks.

A fastening set according to the invention is further characterized in that that the guide hole in the area of the expansion part with a taper in a passes through the expanding smaller bore, the diameter of which is preferably equal to or smaller than the core diameter of the impact thread, and which ends in the area of the dowel tip with a further diameter taper.

Through this gradual staggering of the tapered bore diameter is a step-by-step, the conditions of the borehole in an advantageous manner and the base material in a special way causes a spreading process that allows acceptable holding forces even under largely unfavorable circumstances.

In a further embodiment it is provided that the fastening element a nail with a lens head, cylindrical guide shaft, multi-thread, preferably four-start high helix thread and conical tip.

In cases where, as mentioned above, a mass fastener is used without the special requirement of approvals by building supervision, this design of the mounting kit results in an absolute minimum of assembly work and costs with sufficient holding forces.

Both in the case of using a drive-in screw as also a nail with advantage to increase the holding force provided that the guide shaft a diameter aspect ratio between 1: 2 and 1:15, preferably between 1: 3 and 1:10.

An expedient embodiment provides that the leadership and the guide bore have approximately the same length.

Further advantages in the same direction result from the fact that the thread zone has a diameter / length ratio between 1: 5 and 1:15, preferably between 1: 6 and 1:10.

Furthermore, an expedient embodiment provides that the dowel neck a round cross-sectional shape and the expansion part a substantially square Have cross-sectional shape.

The square cross-sectional shape of the expansion part gives a special one elastic, usable and adaptable within wide tolerances of a borehole Dowel, its considerable possibility of deformation during the expansion process in particular when used in structures made of lightweight concrete such as foam concrete, aerated concrete, pumice concrete, Planks, gypsum walls and the like are used to advantage.

And finally, it is provided that the outside diameter of the impact thread with the guide hole forms a tight fit and that dowel and fastening element, with at least part of the impact thread in the guide hole of the anchor Tight fit joined together to form a preassembled fastening unit.

Such a preassembled fastening unit makes it easier for the craftsman Labor and thus advantageously costs.

In addition, there is an uncomplicated guarantee that dowels and fastening element are precisely matched to one another, with confusion are made impossible.

In the following, the invention is illustrated by means of exemplary embodiments in the drawing shown and explained in more detail.

1 shows a dowel according to the invention, in longitudinal section. 2 shows a drive-in screw matching the dowel according to FIG. 1, in view, FIG. 3 a preassembled unit of dowel and fastening element, partly in view, partly in section, FIG. 4 shows a dowel with a zigzag-shaped slot in the expansion zone, Fig. 5a borehole and inserted dowel with a square cross-sectional shape of the expansion part in section, FIG. 5b shows the expansion part according to FIG. 5a in the expanded state, likewise on average.

The dowel 1 in Fig. 1, shown in longitudinal section, has a cylindrical Neck 2 with guide hole 3, as well as an expanding part as a continuation of the tip 4 5. At the end opposite the tip 4, the dowel 1 has a flange-like one Collar 6, which is for receiving the head of a fastener with a this adapted depression 7 is equipped. The guide hole 3 goes in the area of the expansion part 5 with a conical taper 8 in a through the expansion part 5 continuing smaller hole 9 over, which in turn in the area of the tip 4 expires with a further diameter taper 10.

FIG. 2 shows a fastening element belonging to the dowel 1 FIG. 1 11. This has a guide shaft 12, at one end of which a lens head 13 and at its other end a thread zone 14 with a drive-in thread 15 is provided. The drive-in thread 15 is in accordance with the direction of impact Arrow 16 receding sawtooth-like profiled thread flanks 17 equipped. The Ilt thread zone ends n a conical tip 18. Between the dowel 1 and the fastening element 11 an optimal hold is achieved, that the shaft 12 forms a defined fit with the guide bore 3. It can a sliding seat according to DIN, a sliding seat, a snug fit, act a tight fit or other appropriate fits.

The tip 18 forms an angle OC with respect to the axis of the fastening element 11, the amount of which can be between 10 and 30 ° and in the present example has an amount of 12 °. The receding flanks 17 of the impact thread 14 form an angle P with respect to the axis of the fastening element 11 which can be equal to or slightly larger than angle cc and in the present case is 20 °.

Of the other dimensions of the thread, the thread diameter is with "A", the thread core diameter with K and the thread pitch with "S".

The fastening element 11 has a slope in the example shown "S" of the impact thread 15, which is approximately half the dimension of the thread outer diameter "A" corresponds to.

The core diameter K has a dimension which is approximately half that Outer diameter "A" corresponds.

Another coordination of dimensions of the matching unit from dowel 1 and fastening element 11 as a fastening kit results characterized in that the bore 9 penetrating the expansion part 5 is equal to or smaller than the core diameter K. The diameter "D" of the shaft 12 is preferred equal to or at least slightly larger than the diameter "A" of the impact thread. The guide shaft has a diameter / length ratio between 1: 2 and 1: 15, preferably between 1 to 3 and 1:10 and in the example shown Fig. 2 of 1: 4 up. According to the assignment of dowels and fastening elements to one integrated mounting kit is also provided that the guide shaft 12 and the guide bore 3 have approximately the same lengths "L 2 and UL 2", while the length of the thread zone 14 corresponds approximately to the length of the expansion part 5. Here is the diameter / length ratio, which is within the limits between 1: 5 and 1:15, preferably between 1: 6 and 1:10, in the present case Embodiment 1: 6.

A preassembled unit of a fastening set 20 is shown in FIG. 3.

This consists of the dowel 21 and the threaded nail 22. It is here part of the thread 23 with an interference fit in the guide hole shown in dashed lines 24 of the anchor 21 inserted.

In the example shown, the fastening element 22 is a with four-course High helix thread 22 'for driving in a nail equipped with a guide shaft 25 and a lens head 26.

The dowel 21 of the fastening kit 20 is used in the present case the fastening of a plate 27 in the masonry 28.

In this is the hole 29, which the preassembled mounting kit 20 initially receives with unspread dowel 21.

In the present example, the expansion part 30 of the dowel 21 is flat Surfaces formed in wave form 31 and provided with retaining cams 32 on the outside. The direction of impact is indicated by the arrow 33 and symbolized by a hammer head 34.

The attachment of the plate 27 in the masonry 28 is done by means of a or two hammer blows by hammering the threaded nail 22 into the dowel 21 the pre-assembled unit 20 of the mounting kit.

Another form of the anchor according to the invention is shown in FIG. 4.

The neck part 40 of the dowel 39 is similar to those after Fig. 1 and 3 formed. The expansion part 41 differs from the Spreading parts 5 and 30, because the two lungs 42, 42 'are more separating from one another Slot 43 runs in a zigzag shape.

In the area of an accumulation of material formed in each case Tongues 42, 42 'are relief notches 45 to 51 transverse to the longitudinal direction of the dowel 39 provided. This embodiment has the advantage that it is mutually exclusive Have contradicting properties optimized, such as maximum holding force with minimum Workload and elastic adjustment of dowel 39 and fastening element 11, 19 to unfavorable assembly conditions such as tolerance deviations of the drill hole.

In relation to these optimal properties, they are comparative low manufacturing costs of the dowel due to an injection-molded design another advantage.

Another embodiment of the dowel 56 is shown in FIG. 5a with the borehole 55 on average. The dowel 56 inserted therein has the tongues 42, 42 ', which together form an expansion part of approximately square cross-section. Downtown the guide hole 9 can be seen, which provides a secure guidance of the spreading effecting fastener takes over.

In the illustration according to FIG. 5a it can be clearly seen that the expansion part with a square cross-section in the round receiving bore 55 a considerable Has deformation leeway, however, starting from the abutment of the bore 55 four corners 57 to 60 of the dowel 56 an extremely high contact pressure with a corresponding Wall reveal is achieved, as soon as the dowel 56 is hit by a Fastening element 22, as shown purely schematically in FIG. 5b, for the extreme spreading is deformed.

The exemplary embodiments shown in FIGS. 1 to 5b represent only represents a qualified selection of possible embodiments. which correspond to the craftsmanship of the specialist, fall as well as the Examples shown under the invention, provided they are one of the applicable claims suffice.

L e r s e i t e

Claims (19)

Attachment to the patent application for fastening kit claims fastening kit, consisting of an elastic dowel with neck and expansion part and a matching, fastening element suitable for fastening by hammering in, characterized by the features: a) the fastening element (11,22) has a guide shaft (12, 25), at one end a head (13, 26) and at the other end a Thread zone (14,22) with a drive-in thread with receding in the direction of impact Thread flanks (17) is arranged, which ends in a conical tip (18). b) The neck (2, 40) of the dowel (1, 21, 39) is on the outside with a flange-like The collar (6) is reinforced and has a central one that receives the guide shaft (12, 25) SEhrhrungsbohrung (3, 24), which in the area of the collar (6) for receiving the Head (13, 26) is provided with this adapted receiving surfaces (7) and on the other End with a conical outlet (8) merges into the area of the expansion part (5). 2. Fastening kit according to claim 1, characterized in that the Diameter (D) of the guide shaft (12) approximately equal to the outer diameter (A) of the impact thread (15). 3. Fastening set according to one of claims 1 or 2, characterized in that that the head (13, 26) designed as a lens head and the impact thread (15) with sawtooth profiled thread flanks (17) is equipped. 4. Fastening set according to one of claims 1 to 3, characterized in that that the guide shaft (12, 25) of the fastening element (11, 19) and the guide bore (3, 24) of the dowel (1, 21) a defined fit such as sliding fit, sliding fit, snug fit, Form a tight fit according to DIN etc. 5. Fastening set according to one of claims l to 4, characterized in that that the fit is a snug fit or interference fit. 6. Fastening set according to one of claims 1 to 5, characterized in that that the expansion part (30) of the dowel (21) by flat inner surfaces in wave form (31) is formed. 7. Fastening set according to one of claims 1 to 5, characterized in that that the expansion part (42, 42 ') of the dowel (39) by flat inner surfaces in a zigzag shape (43) is formed. 8. Fastening set according to one of claims 1 to 7, characterized in that that the fastening element (11) is designed as a drive-in screw which has a Pan head (13) with a cross slot, a cylindrical guide shaft (12) and a thread zone (14) with impact thread (15), which in a conical Tip (18) runs out. 9. Fastening set according to one of claims 1 to 8, characterized in that that the tip (18) is at an angle d with respect to the axis of the fastening element between 100 and 300, preferably between 120 and 150. 10. Fastening set according to one of claims l to 9, characterized in that that the receding flanks (17) of the impact thread (15), an angle n opposite form the axis of the fastening element (ll), which is equal to or greater than the angle CX is. 11. Fastening set according to one of claims 1 to 10, characterized in that that the pitch (S) of the impact thread (15) is approximately half the dimension of the Outer thread diameter (A) corresponds to (S =). 12. Fastening set according to one of claims l to ll, characterized in that that the core diameter (K) of the impact thread (15) is approximately half the dimension of the outer thread diameter (A) corresponds to (K = A 13. Fastening kit after a of claims 1 to 12, characterized in that the guide bore (3) in the area of the expansion part (5) with a taper (8) in a through the expansion part Continuing smaller bore (9) passes over, the diameter of which is preferably the same or smaller than the core diameter (K) of the impact thread (15), and which runs out in the area of the dowel tip (4) with a further diameter taper (16). 14. Fastening set according to one of claims 1 to 13, characterized in that that the fastening element (19) is a nail with a lens head (26), cylindrical guide shaft (25), multi-start, preferably four-start coarse thread (22 ') and conical tip is. 15. Fastening set according to one of claims l to 14, characterized in that that the guide shaft (12, 25) has a diameter / length ratio between 1: 2 and 1:15, preferably between 1: 3 and 1:10. 16. Fastening set according to one of claims 1 to 15, characterized in that that the guide shaft (12, 25) and the guide bore (3, 24) are approximately the same Have length. 17. Fastening set according to one of claims 1 to 16, characterized in that that the thread zone (14) has a diameter / length ratio between 1: 5 and 1: 15, preferably between 1: 6 and 1:10. 18. Fastening set according to one of claims 1 to 17, characterized in that that the dowel neck (3, 40) has a round cross-sectional shape, and the sprinkling part (42, 42 ') has a substantially square cross-sectional shape. 19. Fastening set according to one of claims 1 to 18, characterized in that that the outer diameter (A) of the impact thread (15) with the guide hole (3) forms a tight fit, and that dowel (1, 21, 39) and fastening element (11, 19) with at least part of the impact thread (15, 22 ') in the guide bore (3, 24) of the dowel (1, 21) joined together with a tight fit to form a preassembled unit.