Fastening of a strip to a rearwardly accessible carrier part

A fastening of a strip to a rearwardly accessible carrier part has arranged opposite one another on the longitudinal edges of the strip, pairs of holding tongues which are inserted through long holes arranged in the carrier part. At their free ends, the holding tongues are provided on the sides facing one another with respective hooks which themselves have a clamping face extending approximately parallel to the rear side of the carrier part. Arranged on the rear side of the carrier part for each pair of holding tongues is a double-winged rotary bolt which is pivotable about an axis of rotation perpendicular to the rear side and arranged between the respective mutually opposite pair of long holes. To lock the strip, the wings are pivoted inwards with their end regions between the rear side of the carrier part and the clamping faces of the hooks on the holding tongues, so as bear tautly against the clamping faces.

BACKGROUND AND SUMMARY OF THE INVENTION 
The present invention relates to a fastening of a strip to a rearwardly 
accessible carrier part. 
German Patent Document 2,751,158 discloses an endpiece for fastening an 
anti-ram strip to a vehicle body, in which there is inserted at the end of 
the antiram strip, rectangular in cross-section and having a longitudinal 
slot, a tenon of an endpiece, of which the cap arranged on the end face 
encloses the anti-ram strip completely on the outer circumference. 
Arranged in the tenon itself is a long hole extending in the push-in 
direction of the tenon. Inserted into the long hole from the rear side of 
a panel part of the body is a holding pin which, at its outer end facing 
the strip, has two diametrically projecting holding tongues which engage 
behind the tenon within the clear space of the anti-ram strip. A head is 
arranged on the rear end of the holding pin, so that, when the holding pin 
inserted into the long hole of the tenon is rotated, a clamping of the 
tenon between the head and the holding tongues of the holding pin and 
consequently of the anti-ram strip against the panel part becomes 
possible. However, this type of fastening is advantageous only in narrow 
anti-ram strips, since the force necessary for the clamping rotation of 
the holding pin otherwise becomes too great. Furthermore, if only a small 
free space which can be used for assembly is available in the region of 
the head of the holding pin, for example on account of constructional 
parts which follow at the rear, then the holding pin can be rotated hardly 
at all or only under difficult conditions- Moreover, the outlay for the 
fastening in terms of assembly and the corresponding dismounting is high, 
since it comprises a large number of individual parts. 
European Patent Specification 150,804 discloses a fastening of an anti-ram 
strip made of plastic, which, in its cross-section, has a centrally 
arranged guiding and fastening strip of T-shaped clear cross-section. The 
cross-section of the guiding strip corresponds to that of the anti-ram 
strip previously described. Arranged displaceably in the guiding strip of 
this anti-ram strip are heads of fastening screws which are inserted 
through a bore arranged in the panel part and which are screwed to the 
rear side of the panel part. However, metallic constructional parts which 
are therefore susceptible to rust are used for this. Furthermore, where 
thin-walled anti-ram strips injection-molded from plastic are concerned, 
small indentations form on their visible side in the region of attachment 
of the guiding strip to the anti-ram strip, and these impair the 
appearance of the anti-ram strip and, where appropriate, have to be 
hidden. Also, the outlay in terms of assembly and the time required are 
high, since the threads have to be laboriously slipped in and the screws 
tightened. 
An object of the present invention is to develop a fastening which allows a 
simple assembly and dismounting of a thin-walled strip injection-molded 
from plastic, which permits a tolerance compensation of the strip, at 
least in its direction of extension, and a flush gap-free fastening of 
high holding force, while for fastening purposes the strip does not have 
to be provided with material appendages which are either apparent (or are 
so placed as to become apparent) on the front side in the form of material 
indentations. 
This and other objects are achieved by the present invention which provides 
a fastening arrangement of a strip to a rearwardly accessible carrier 
part, comprising long holes in the carrier part, and at least one pair of 
holding tongues which are arranged opposite one another on longitudinal 
edges of the strip. Each holding tongue is insertable through an 
associated one of the long holes so as to extend beyond a rear side of the 
carrier part. The holding tongues have free ends with sides facing one 
another and hooks. These hooks have clamping faces that extend 
approximately parallel to the rear side of the carrier part. The long 
holes have a longitudinal extension in a longitudinal direction of the 
strip that is longer than a corresponding width of the holding tongues. An 
overall distance between a pair of mutually opposite holding tongues 
corresponds to a distance between outer edges of two of the associated 
long holes. A clearance width of the long holes, as measured transversely 
to the longitudinal extension, is larger than or equal to a corresponding 
largest outer dimension of the individual holding tongues including the 
hook. The arrangement further comprises at least one double-winged rotary 
bolt arranged on the rear side of the carrier part and assigned to the 
pair of holding tongues. The rotary bolt is pivotable about an axis of 
rotation perpendicular to the rear side and arranged between a respective 
mutually opposite pair of long holes. The rotary bolt has wings that are 
pivotable inwards with end regions between the rear side of the carrier 
part and the clamping faces of the hooks on the holding-tongues so as to 
bear tautly against the clamping faces. 
Interlocking takes place by means of the holding tongues, arranged on the 
longitudinal edges of the strip, and the rotary bolt, subjected radially 
to a pivoting force, on the rear side of the carrier part. The strip can 
consequently be produced with a virtually uniform wall thickness and 
therefore without irregularities or material indentations on the visible 
side, this being advantageous in thin-walled strips injection-molded from 
plastic. At the same time, the holding tongues located at the edge, in 
conjunction with the long holes arranged in the carrier part, allow a 
large tolerance width in the direction of extension of the long holes and 
a simple assembly, since the holding tongues can be introduced into the 
long holes without much effort. Furthermore, the dimensions of the holding 
tongues and of the long holes are selected so that the strip bears flush 
against the carrier part in a gap-free manner and with a high holding 
force. Moreover, a further simplification of assembly and dismounting is 
obtained by means of the rotary bolt which can be subjected to a radial 
pivoting force and which can at the same time pivot inwards under the 
respective clamping face of the hooks of mutually opposite holding 
tongues, thereby engaging behind the clamping faces with a clamping effect 
and pressing them inwards, with the result that the strip is pressed 
against the carrier part. The space required between a possibly following 
constructional part and the rear surface of the carrier part can thus be 
restricted to the diameter of a part initiating the pivoting movement or 
to the transverse distance of the holding tongue from the rear side of the 
carrier part. 
Other objects, advantages and novel features of the present invention will 
become apparent from the following detailed description of the invention 
when considered in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE DRAWINGS 
FIG. 1 is a perspective view of a strip 1 constructed in accordance with an 
exemplary embodiment of the present invention. The strip is designed as an 
anti-ram strip and is fastened to a rearwardly accessible motor-vehicle 
bumper forming the carrier part 2. Arranged opposite one another on the 
longitudinal edges 3 of the strip 1 are holding tongues 6 which are 
provided at their free ends with hooks 7 facing one another. The hooks 7 
themselves have clamping faces 8 which are arranged facing the carrier 
part 2 and which extend approximately parallel to the rear side 5 of the 
carrier part 2. 
For fastening the strip 1 to the carrier part 2, the holding tongues 6 are 
inserted through long holes 4 provided in the carrier part 2 and extending 
in the longitudinal direction of the strip 1 and which are assigned to 
respective holding tongues 6. In the fully inserted state, the holding 
tongues 6 extend beyond the rear side 5 of the carrier part 2. So that a 
simple introduction of the hooks 7 arranged on the holding tongues 6 into 
the long holes 4 becomes possible and, furthermore and to make the long 
holes 4 invisible from outside, the individual constructional parts have 
the following dimensions: 
a) as measured in the longitudinal direction of the strip 1, the long holes 
4 are longer than the corresponding width A of the holding tongues 6; 
b) the overall distance B between the respective pair of mutually opposite 
holding tongues 6 corresponds to the distance C between the outer edges 9 
of two associated long holes 4; and 
c) the clearance width D of a long hole 4, as measured in the direction of 
the overall distance B, is larger than or equal to the corresponding 
largest outer dimension E of an individual holding tongue 6 including hook 
7. 
The fastening has, for each pair of holding tongues 6, a double-winged 
rotary bolt 10 (see FIG. 3) which is arranged on the rear side 5 of the 
carrier part 2 and which is pivotable about an axis of rotation 11 
perpendicular to the rear side 5 and arranged between the respective 
mutually opposite pair of long holes 4. The wings 12 of the rotary bolt 10 
can pivot inwards with their end regions 13 between the rear side 5 of the 
carrier part 2 and the clamping faces 8 of the hooks 7 on the holding 
tongues 6. A tolerance compensation and a taut bearing of the end regions 
13 against the clamping faces 8 is needed in the direction of extension of 
the holding tongues 6, (that is to say transversely to the clamping faces 
8). To this end, the bearing faces, opposite the clamping faces 8, of the 
end regions 13 and the wings 12 are expediently at a distance from the 
rear side 5 of the carrier part 2 which corresponds at least to the 
maximum tolerance-related distance of the clamping faces 8 from the rear 
side 5. 
To allow the end regions 13 of the rotary bolt 10 to pivot inwards under 
the clamping faces 8 of the hooks 7 in a simple way, it is advantageous to 
provide the end regions 13 with a run-on face 14 at the edge located at 
the front in the interlocking pivoting direction. 
It is of particular advantage, at the same time, to select the distance of 
the starting edge of the runon face 14 in such a way that it is at a 
shorter distance from the rear side 5 than the minimum tolerance-related 
distance between the clamping faces 8 and the rear side 5. 
The transfer of the rotary bolt 10 into its blocking position is carried 
out in an easy way by means of a pivoting tool 16 which is inserted into 
an insertion orifice 15 arranged radially relative to the pivot axis 11 of 
the rotary bolt 10. 
Since the fastening is always subject to vibration, especially when used on 
motor vehicles, it is expedient to secure the rotary bolt 10 against 
unintentional release in its closing position by a releasable interlock. 
The fastening of the strip 1 to the carrier part 2 therefore takes place by 
an interlocking of the holding tongues 6 arranged on the longitudinal 
edges 3 of the strip 1 with the rotary bolt 10 which is arranged on the 
rear side of the carrier part 5 and which can be subjected radially to a 
pivoting force. Furthermore, as explained above, the constructional design 
of the rotary bolt 10 allows a tolerance compensation not only in the 
direction of extension of the strip 1, but also in the direction of 
extension of the holding tongues 6, thereby making it possible to produce 
the strip more cheaply. A high production accuracy is consequently needed 
only in the direction of the overall distance B between the pairs of 
holding tongues 6, which can be implemented relatively simply; this 
accurate production relates to the long holes 3 and to the strip 1. 
As regards the distance C between the outer edges 9 of the long holes 4, a 
tolerance compensation is also possible if the length of the rotary bolt 
10 is selected to be larger than the distance between a pair of holding 
tongues 6. 
It is expedient, furthermore, for the rotary bolt 10 to be assigned, both 
in the open position and in the blocking position, a blocking stop 17 and 
an open stop 17', so that the rotary bolt 10 cannot be pivoted at random. 
It has proved advantageous, here, to have the pivoting travel restricted 
to 15.degree., since the possibility of easy access for the rotary tool 16 
is afforded thereby. 
Although the invention has been described and illustrated in detail, it is 
to be clearly understood that the same is by way of illustration and 
example, and is not to be taken by way of limitation. The spirit and scope 
of the present invention are to be limited only by the terms of the 
appended claims.