DE29824254U1 - Fastening device - Google Patents

Description

G3623
08.06.2000 Su/De

MEFA fastening and assembly systems GmbH; 74635 Kupferzei l

Fastening device

State of the art

The invention is based on a fastening device for anchoring a structural part to a base component by means of an anchor part according to the preamble of the main claim. With such fastening devices, other structural parts are fastened to profile rails with a C-shaped cross section, in which the free legs of the C point inwards towards the base side of the C, via anchor parts that are available in the profile rails and engage behind these free legs, by clamping them to the profile rails via the shaft of the anchor part. After loosening the anchor part, it can be moved within the rail and thus the position of the structural part in relation to the profile rail can be changed and then tightened again. Such fastening devices are available in a wide variety of designs, with profile rails with a C cross section being used preferably, which serves as a through opening.

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The anchor part is inserted with its broad side through this slot and then twisted, whereby the arms of the anchor head grip the free legs of the profile rail

In practice, it is a problem to ensure that after turning and adjusting the anchor part on the base component and before fastening the superstructure part to the anchor part or base component, the anchor part remains in the specified position until the shaft of the anchor can be mounted, for example in the form of a screw bolt, after which the fixation can then take place by tightening the superstructure part on the base component using the shaft.

In a known fastening device of the generic type (DE-OS 44 21 252), an axial spring element is arranged between the anchor head and an intermediate body resting on the clamping surface, which is connected on the one hand to the intermediate body and on the other hand to the anchor head. This connection is rotationally locked so that after the anchor head has been inserted, it can be rotated by the intermediate body into the position in which the anchor head engages behind the abutments, i.e., for example, the free legs of the profile rail. The axial spring effect of the spring part pulls the anchor head towards the intermediate body, which results in the desired self-locking of the anchor head to the base component. This self-locking is improved by tooth profiles on the opposing surfaces of the abutment on the one hand and the arms of the anchor head on the other. A disadvantage of this known fastening device is, on the one hand, that the spring preload is achieved by turning the anchor head, in which the anchor head is axially displaced from a starting position given after insertion to a clamping position given after turning via ramps or other insertion aids, while at the same time preloading the spring part. As soon as

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08.06.2000 Su/De

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If the anchor head is not precisely guided when it is turned, it gets caught in the abutment area, and it is difficult to change the turned position once it has been turned to the left of the through-opening, since for this to happen, with the tooth profiles in place, the teeth would first have to be lifted apart, which can only be done via the shaft of the anchor, which is not yet installed at this early stage. This also limits the use of this known fastening device. A further disadvantage is that with such connections in the direction of tension of the spring between the spring part and intermediate body on the one hand and the spring part and anchor head on the other hand, this connection can come loose or wear out relatively easily, which then not only makes it impossible to turn it back for disassembly, but also generally changes the position of the anchor head in the base component. Last but not least, the intermediate body has a minimum thickness in order to be able to attach the spring part to it, which leads to a minimum distance between the base component and the superstructure part.

In another known fastening device (DE-OS 44 32 996), the fastening anchor is connected to a retaining insert via a rotationally locked connection, which dips into the through-opening in sections, rests on its edge and allows a certain amount of movement in the axial direction. Since this retaining insert is flat at the top, it has projections that protrude outwards to enable the rotational movement during installation, which are pressed inwards into the through-opening when the structural parts are attached. Apart from the fact that the retaining insert could fall through or become jammed if it is installed slightly one-sidedly, the connection between the spring part and the anchor head is problematic and the adjustment projections get in the way during installation.

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The invention and its advantages

The fastening device according to the invention with the characterizing features of the main claim has the advantage that the anchor head can be easily inserted through the through-opening and can be easily rotated after slightly overcoming the leaf spring force and can then be adjusted and adjusted by gently pressing the flange and thus overcoming the spring force in the through-opening. Due to the effect of the leaf springs on a flat clamping surface, the position of the anchor head can be pre-adjusted and thus rotation can be carried out without getting caught. Since the spring is arranged outside the base component, it can always be observed and its position corrected if necessary. Last but not least, this type of design is extremely inexpensive.

According to an advantageous embodiment of the invention, the flange is connected to the structural part so that, particularly in the case of structural parts of smaller dimensions, the engagement with the flange takes place via the structural part.

According to a further advantageous embodiment of the invention, the flange is clamped between the mounting part and the support surface after the mounting part has been tightened, for example via the shaft. If the clamping is then loosened by partially unscrewing a shaft designed as a screw bolt, for example, the spring effect is created again when the leaf spring is shaped accordingly.

According to a further advantageous embodiment of the invention, the spring part is made of plastic. Depending on the material,

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08.06.2000 Su/De

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This is the desired intermediate layer when the base component and the superstructure are made of hard materials, especially metal.

According to a further advantageous embodiment of the invention, recesses are provided in the superstructure on the side facing the support surface, into which the corresponding nubs of the spring part or flange serving for the connection engage. These nubs can also serve as a pre-adjustment of the superstructure parts to the base component, since the anchor part is already adjusted in the base component.

According to a further advantageous embodiment of the invention, the spring part has a basket or the like for receiving the anchor head, which is connected by connections such as the flange that run in the direction of action of the shaft. The basket and these connections can be designed in a variety of ways. All that is required is that there is rotational locking between the flange and the anchor head and that the arm of the anchor head rests on the abutment.

According to a further advantageous embodiment of the invention, the flange has a flat central section with a through hole for the shaft, which is adjoined by two side sections on which the leaf springs are arranged. This also ensures that any effects on one side section have little or no influence on the other and that, in addition, the connecting devices to a structural part can be provided on the central section.

According to a further advantageous embodiment of the invention, the anchor head and its arms are designed as an elongated plate. In addition to manufacturing advantages, this also

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08.06.2000 Su/De 6

also a simplified introduction both into the connection to the flange and into the through opening.

According to a further advantageous embodiment of the invention, the plate has ramps or rounded edges as an insertion or twisting aid.

According to a further advantageous embodiment of the invention, tooth or friction profiles are present on at least one of the mutually facing surfaces of the abutment or arm of the head.

Further advantages and advantageous embodiments of the invention can be found in the following description, the drawings and the claims.

drawing

An embodiment of the invention is shown in two variants in the drawing and described in more detail below. They show:

Fig. 1 a spring part in perspective view,

Fig. 2 an anchor head,

Fig. 3 the anchor head inserted in the spring part,

Fig. 4 + 5 Variations of the spring part all in

perspective view and

Fig. 6, 7,8 a profile rail in cross section with

inserted spring part.

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Description of the embodiment

Fig. 1 shows the spring part 1 of a fastening means with which a structural part can be fastened to a base component, for example a profile rail, wherein, as shown in Figs. 6 to 8, an anchor head 2, as shown in Fig. 2, can be mounted by means of this spring part 1 to carry out the fastening. This spring part 1 has a flange 3 on which fastening studs 4 are arranged, which has a central bore 5 for the passage of a retaining bolt and which has two side sections 6, each with two leaf springs 7, as well as a central section 8 arranged between the side sections, on which the fastening studs 4 are arranged.

A basket 11 is attached to the underside of the flange 3 via connections 9, whereby when the flange is rotated in its plane, this basket 11 is also rotated accordingly, since the connections have a rotationally locking effect. The spring part is made of plastic and is manufactured in one operation, in particular in an injection molding process.

The anchor head 2 shown in Fig. 2 has a central threaded hole 12 and a toothing 14 on the top of its arms 13. In addition, two edges 15 facing away from each other are rounded. Otherwise, the anchor head 2 has a substantially rectangular cross-section.

In Fig. 3, the spring part 1 is shown with the anchor head 2 inserted into the basket 11, wherein the basket 11 has rounded walls 16 corresponding to the rounded edges 15 and wherein the axis of the threaded bore 12 coincides with the axis of the bore 5 of the flange 3.

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While in the embodiment shown in Fig. 1 the leaf springs 7 have a cross-section with a curvature downwards, in the first variant according to Fig. 4 the leaf spring 17 is flat and parallel to the flange 3, while in the second variant according to Fig. 5 the leaf spring 18 is bent downwards.

In Fig. 6, 7 and 8, the spring part 1 including anchor head 2 is shown in different positions during installation. In Fig. 6, a profile rail 19 is shown in its C-shaped cross-section with free inwardly projecting legs 21 and upwardly pointing clamping surfaces 22. The spring part 1 is inserted from above into the opening created by this in this slot between the free legs 21, with the anchor head 2 shown in section being arranged in the basket 11, the width of this anchor head plus the wall thickness of the basket 11 being less than the distance between the two free legs 21. In the position shown in Fig. 6, the spring part 1 rests with its leaf springs 7 on the clamping surfaces 22 of the profile rail 19, transversely to the longitudinal course of these clamping surfaces 22. In this position, the toothing 14 of the anchor head 2 is higher than the side 23 of the legs 21 which serves as an abutment and which also has a toothing.

In the position shown in Fig. 7, the spring part 1 is pushed downwards in the direction of arrow I by the distance made possible by the leaf spring 7, whereby the teeth 14 of the anchor head 2 come under the side 23 of the free legs 21 of the profile rail 19. The fastening studs 4 can be advantageous in this assembly process. As soon as the position shown in Fig. 7 is reached, the spring part 1 is rotated by 90°, the rounded walls 16 on the two opposite corners enabling such a rotation between the free legs 21.

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08.06.2000 Su/De

In Fig. 8, the spring part 1 is shown in this twisted position, in which the anchor head 2 with its upper toothing 14 lies under the sides 23 of the legs 21 and is pulled into the toothing of these sides 23 by the leaf springs 7. In order to carry out the twisting movement, the anti-twisting device provided by the connections 9 between the flange 3 and the basket 11 serves.

After the spring part 1 and thus the anchor head 2 assume the position shown in Fig. 8, the structural parts serving as the shaft of the anchor can be screwed to this anchor or anchor head 2 by means of threaded bolts (not shown), whereby the anchor head 2 is firmly clamped to the legs 21 from below with its arms 13. The knobs 4 can serve as adjustment pins for the structural part.

All features presented in the description, the following claims and the drawings can be essential to the invention both individually and in any combination with one another.

Claims (10)

1. Fastening device for anchoring a superstructure part to a base component ( 19 ) by means of an anchor part ( 2 ), - wherein the base component ( 19 ) has an elongated through-opening in a clamping surface ( 22 ) and an abutment ( 23 ) on the opposite side thereof, - wherein the superstructure part can be clamped to the base component ( 19 ) by a shaft of the anchor part ( 2 ) and - wherein at least one arm ( 13 ) of an anchor head ( 2 ) of the anchor part, which can be connected to the shaft, passes through a spring part ( 1 ) connected to the anchor head ( 2 ) in a rotationally locking manner to the abutment ( 23 ) after being inserted through the through-opening and rotated about the axis of the shaft, after which the anchor head ( 2 ) is drawn onto the abutment by the spring action ( 7 ) for its self-locking, characterized , - that the spring part ( 1 ) has a flange ( 3 ) running transversely to the shaft, the respective surface dimensions of which are larger than the width of the through opening, - that leaf springs ( 7 , 17 , 18 ) acting in the shaft direction are arranged on the flange ( 3 ), - so that after rotation of the anchor part ( 2 ) the leaf springs ( 7 , 17 , 18 ) act on the clamping surface ( 22 ). 2. Fastening device according to claim 1, characterized in that the flange ( 3 ) is connected to the structural part. 3. Fastening device according to claim 1 or 2, characterized in that the flange ( 3 ) is clamped between the structural part and the support surface after the structural part has been tightened via the shaft. 4. Fastening device according to one of the preceding claims, characterized in that the spring part ( 1 ) is made of plastic. 5. Fastening device according to claim 4, characterized in that recesses are provided in the structural part on the side facing the support surface ( 22 ), into which recesses engage knobs ( 4 ) of the spring part ( 1 ) which correspond in position and serve for the connection. 6. Fastening device according to one of the preceding claims, characterized in that the spring part ( 1 ) has a basket ( 11 ) or the like for receiving the anchor head ( 2 ), which is connected to the flange ( 3 ) by connections ( 9 ) running in the direction of action of the shaft. 7. Fastening device according to one of the preceding claims, characterized in that the flange ( 3 ) has a flat central section ( 8 ) with a through hole ( 5 ) for the shaft and two adjoining side sections ( 6 ) on which the leaf springs ( 7 ) are arranged. 8. Fastening device according to one of the preceding claims, characterized in that the anchor head ( 2 ) and its arms ( 13 ) are designed as an elongated plate. 9. Fastening device according to claim 8, characterized in that the plate has ramps or rounded edges ( 15 , 16 ) as an insertion or twisting aid. 10. Fastening device according to one of the preceding claims, characterized in that tooth or friction profiles ( 14 ) are present on at least one of the mutually facing sides of the abutments ( 23 ) or arms ( 13 ) of the anchor head ( 2 ).