Folding roof for vehicles, especially passenger motor vehicles

A folding roof for vehicles, especially passenger motor vehicles, is detachably secured at a windshield frame and at a roll bar bridging the passenger space and is essentially composed of laterally disposed longitudinally extending girders, of a plurality of struts arranged between the longitudinal girders extending generally parallel to the girders and a flexible roof covering, connected to and supported by the longitudinal girders and the struts. In order to create a folding roof which, with lowest possible weight, has a high form rigidity, i.e., strength, and which when folded-together requires as low as possible a structural height and which is also utilizable more individually, alternately form-rigid struts and elastic struts are arranged to extend in the longitudinal direction of the vehicle in such a manner that nonreinforced sections of the covering between the struts are minimized.

The present invention relates to a folding roof for vehicles, especially 
passenger motor vehicles, which is detachably secured at a windshield 
frame and at a roll bar bridging the passenger space. The folding roof is 
essentially composed of laterally disposed longitudinally extending 
girders, a plurality of struts arranged between the longitudinally 
extending girders extending generally parallel thereto, and a roof 
covering, the longitudinally extending girders and the plurality struts 
forming a frame to which the roof covering is connected. 
A known folding roof (German Offenlegungsschrift No. 14 55 743) generally 
of the aforementioned type includes several form-rigid struts between 
oppositely disposed longitudinally extending girders. However, these 
struts are constructed relatively narrow leaving substantial nonreinforced 
roof sections disposed therebetween so that the folding roof has an 
inadequate support for the top covering. All of the struts of the folding 
roof have, in this known installed condition, a similarly directed 
curvature which when the roof is in a folded condition have the 
disadvantage that the respectively adjacent struts lie one above the other 
with oppositely directed curvatures. Especially with passenger motor 
vehicles which exhibit a pronounced roof curvature, the folded-together 
roof assumes a relatively large structural height, as a result of which 
the accommodation in the vehicle is made more difficult. 
Additionally, by reason of the relatively wide unreinforced roof sections, 
no defined folding movement is possible which, accordingly, causes the 
installation and disassembly of the folding roof to require a large amount 
of time. Furthermore, this construction permits driving with or without 
the folding roof and does not make possible an opening of the folding roof 
over only half of the vehicle, i.e., one side only. 
It is the aim of the present invention to provide a folding roof which with 
lowest possible weight exhibits a high form-rigidity, i.e., strength, 
which requires as little structural height as possible when 
folded-together and which permits each side of the vehicle roof to be 
utilized individually. 
The underlying problems are solved according to the present invention in 
that the support frame for the flexible covering of the folding roof 
alternately includes form-rigid struts and elastic struts extending in the 
longitudinal direction of the vehicle, in such a manner that unreinforced 
sections of the covering between the struts are minimized. 
The advantages primarily achieved with the present invention reside in that 
as a result of the construction of the folding roof with alternately 
arranged form-rigid and elastic struts, between which only narrow sections 
of nonreinforced roof covering exist, a high form-rigidity and stiffness 
of the folding roof is achieved. Additionally, a light-weight folding roof 
is created by the construction of the elastic struts of plastic material, 
especially with a hollow chamber-like cross section. The possibility 
exists, by the use of a form-rigid strut which is arranged in the vehicle 
longitudinal center plane and which has a greater width, of utilizing the 
folding roof more individually, i.e., the possibility of folding the 
folding roof on only one side of the vehicle while the other section of 
the passenger space can remain covered by a part of the folding roof. 
With a closed folding roof, the elastic struts assume the shape of the 
adjacent form-rigid struts whereas during the folding of the roof, the 
elastic struts adapt themselves to the shape of the form-rigid struts 
disposed therebelow and thus a smallest possible structural height of the 
folded-together package is achieved. Conditioned by the relatively narrow 
sections of nonreinforced roof covering, the struts forcibly assume a 
position lying flush one above the other, as a result of which a defined 
folding movement is achieved which assures a rapid disassembly as well as 
a rapid installation.

Referring now to the drawing wherein like reference numerals are used 
throughout the various views to designate like parts, the motor vehicle, 
partially illustrated in FIG. 1, generally designated by reference numeral 
1 includes a windshield frame 2 with a windshield 3, a roll-bar 5 bridging 
the passenger space 4, a rear window 6 and doors 7. The roll-bar 5 is 
assembled in a known manner of pressed-out or stamped-out sheet metal 
parts that form a box-shaped hollow body. 
A groove or recess in the windshield frame 2 for abutment of a sealing body 
9 thereagainst, generally designated by reference numeral 8 (see FIG. 4), 
extends in the vehicle transverse direction. Ideally, a similar groove or 
recess (not shown) is provided at the roll-bar 5 for abutment of a sealing 
body 9 thereagainst. 
A folding roof 10 is detachably secured between the windshield frame 2 and 
the roll-bar 5, which extends in the transverse direction between the two 
doors 7 of the vehicle 1, and which in the longitudinal direction of the 
vehicle abuts with the sealing bodies 9'. The fastening of the folding 
roof at the windshield frame 2 and at the roll-bar 5 takes place by means 
of conventional retaining elements, not illustrated in detail herein (the 
fastening means may be of the form as described, for example, in German 
Offenlegungsschrift No. 14 55 743). 
The folding roof 10 includes laterally disposed longitudinally extending 
girders 11, a plurality of struts 12 arranged between the longitudinal 
girders 11 extending generally parallel to the longitudinal direction of 
the vehicle and the longitudinally extending girders 11, and a roof 
covering generally designated by reference numeral 13 (FIG. 3). A 
laterally disposed longitudinally extending girder 11 extends adjoining 
each of the doors 7 of the motor vehicle 1 and are made as cast parts from 
light-weight metal. The roof covering 13 is formed by a flexible outer 
skin 14 and by a flexible foldable inner covering 15. The inner covering 
15 includes two layers which are sewed together in the vehicle 
longitudinal direction on either side of each of the struts 12. The 
thus-resulting hollow spaces formed by the sewed-together layers serve for 
the accommodation of the struts 12 and fix the same in position relative 
to another. 
The struts 12 arranged between and extending generally parallel to the 
longitudinal girders 11 are constructed in alternate sequence as 
form-rigid struts 16 and as elastic struts 17, and more particularly in 
such a manner that nonreinforced roof sections 18 remain between the 
struts 16 and 17. The struts 12 extending adjacent the longitudinal 
girders 11 are preferably constructed as elastic struts 17. 
The form-rigid struts 16 are formed by pressed-out sheet metal parts 19 and 
are shaped both in the vehicle longitudinal direction as also in the 
vehicle transverse direction corresponding to the curvature of the roof 
contour. For purposes of increasing the rigidity, the form-rigid struts 16 
have a profiling 20 in cross section. 
The elastic struts 17 are made from a suitable plastic material such as 
fiberglass reinforced polycarbonate, polyamide, polyacetal, or the like. 
For reasons of weight-saving, preferably a hollow chamber-like profile 21 
of polycarbonate is used for the elastic struts 17 (FIG. 6). Layers 22 of 
foam-rubber or the like are provided above and below the form-rigid-struts 
16 and possibly the elastic struts 17. 
The elastic struts 17 possess in their original condition a rectilinear 
contour. They are not bent either in the vehicle longitudinal or in the 
vehicle transverse direction. However, with a closed folding roof 10, 
conditioned by the form-rigid struts 16 adjoining on both sides and the 
tension of the roof covering 13, the elastic struts 17 assume the contour 
of the form-rigid struts 16. A further advantage of the alternate 
arrangement of form-rigid struts 16 and elastic struts 17 is that the 
folding roof 10 produces a slight structural height in the folded-together 
condition since the elastic struts 17 can assume the shape of the 
form-rigid struts 16 disposed therebelow in the folded-together condition. 
According to FIG. 3, a form-rigid strut is arranged in the vehicle 
longitudinal center plane A--A which has a greater width than the 
remaining struts 12 and which serves as a base bearer for the two roof 
halves 24 and 25 of the folding roof 10. The two roof halves 24 and 25 are 
adapted to be folded together accordion-like with the struts 12 lying one 
above the other. The base bearer 23 has preferably a somewhat greater 
width than the two roof halves 24 and 25 of the folding roof 10 disposed 
adjacent one another in the folded condition. 
The two roof halves can be folded together independently of one another. 
This construction makes it possible to fold together only one roof half, 
for example, the roof half 24, whereas the other roof half 25 continues to 
cover off a part of the passenger space 4. For fixing the installed roof 
half 25, retaining means (not illustrated in detail) are provided in a 
center section of the windshield frame 2 and of the roll-bar 5 which 
cooperate with support sections of the base bearer 23. When, for example, 
roof half 24 is folded together and disposed on the base bearer 23, it is 
retained thereat in position by means of clamping elements (not shown in 
detail). 
For storing the folded-together folding roof 10 in the luggage space, the 
folding roof 10 is provided with a casing or covering 26 (see FIG. 7). To 
facilitate storage, clamp-like retaining members 27 are attached to the 
inside of this casing or covering 26, into which engage sections 28 of the 
longitudinal girders 11 to thereby hold the roof in position. 
The nonreinforced roof sections 18 between the struts 16 and 17 have a 
width such that during the folding operation, a positive stacking of the 
struts 16 and 17 lying flush one above the other takes place. This 
forcible folding movement enables a rapid installation and disassembly of 
the folding roof. 
Within the area of the sealing bodies 11 arranged at the windshield frame 2 
and at the roll-bar 5, all struts 16 and 17 include form-rigid support 
sections 29, as a result of which a good sealing effect is achieved. The 
support sections 29 and the form-rigid struts 16 are made in one piece 
(FIG. 4) whereas in connection with the elastic struts 17, the support 
sections 29 are formed by separate structural parts 30 which are connected 
with end sections 31 of the elastic struts 17 (FIG. 5). 
The cross section of the support sections 29 is thereby identical with all 
struts 12, as viewed in the vehicle longitudinal direction, so that within 
the area of the struts 16 and 17, a constant sealing surface is achieved. 
For fastening each structural part 30, an aperture 32 tapering in the 
downward direction is provided at corresponding end sections 31 of the 
elastic strut 17, into which is inserted a connecting member 33 made of 
elastic material (rubber). The connecting member 33, elongated as viewed 
in plan view, is supported in the opening 32 exclusively along its end 
areas 34 and 35 and is provided with a slot-shaped opening 36 as well as 
with a support section 37 (FIG. 5). A retaining tongue 38 formed as part 
of the structural part 30 and bent up is extended through the slot-shaped 
opening 36 and is folded over and supported at the support section 37. The 
connecting member 33 is provided with a circularly shaped aperture 39 
adjacent the support section 37. This aperture 39 as well as the sections 
40 and 41 remaining free laterally adjacent the connecting member 33 
represent a space for the connecting member 33, whence the different 
longitudinal expansions of the elastic struts can be compensated for 
without changing the position of the support sections 29. 
While I have shown and described only one embodiment in accordance with the 
present invention, it is understood that the same is not limited thereto 
but is susceptible of numerous changes and modifications as known to those 
skilled in the art, and I therefore do not wish to be limited to the 
details shown and described herein but intend to cover all such changes 
and modifications as are encompassed by the scope of the appended claims.