Patent Publication Number: US-2022219637-A1

Title: Roll cage

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of German Patent Application No. DE 10 2021 100 189.7, filed Jan. 8, 2021, the disclosure of which is hereby incorporated herein in its entirety by reference. 
     FIELD OF THE INVENTION 
     The invention relates to a roll cage for a motor vehicle with Isofix attachment points in the rear of an automobile interior. The Isofix attachment points in a motor vehicle are used in particular for attaching a child seat. They comply with the ISO 13216 standard and are composed of two mounts that are 6 mm thick, located at a spacing of 280 mm in the gap between the backrests and seat cushions of each seat in the rear part of the vehicle interior. They are now standard attachment points in passenger automobiles. 
     BACKGROUND OF THE INVENTION 
     A roll cage is normally formed by a rollbar with at least four mounting points for securing the rollbar to the motor vehicle. In the case of an accident, in particular in which the vehicle rolls over, the passenger compartment is reinforced such that it does not become deformed in a manner dangerous for the driver and passengers. In particular, racecars and sportscars are currently equipped with such roll cages for safety reasons. 
     Rollbars are normally attached to the vehicle chassis and/or the vehicle framework. Because this involves an engagement in the structure of the vehicle, in some jurisdictions these rollbars must be registered in the licensing office. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to create a roll cage that can be installed in a vehicle after production, and preferably does not have to be registered. 
     This object is achieved according to the invention by a roll cage according to the claims. Further advantageous aspects, details, and designs of the invention can be derived from the description, and the drawings. 
     The roll cage according to the invention is formed by a rollbar that is attached to and/or supported in the vehicle with at least four mounting points. The roll cage is designed for vehicles that have Isofix attachment points in the rear of the automobile&#39;s interior. Of the four mounting points, two are designed as clamp elements that engage with at least two of the Isofix attachment points. Two of the other mounting points are designed as support elements that brace the rollbar against the passenger compartment, in particular the floor thereof. 
     The invention has the advantage that the roll cage can be quickly and easily installed in the vehicle, and is not permanently attached to the vehicle&#39;s chassis. The use of the roll cage therefore does not require approval and/or registry in the vehicle title according to the current approval provisions of some jurisdictions. 
     The roll cage is nevertheless able to absorb forces acting on the passenger compartment in the case of an accident, thus preventing a life-threatening deformation of the passenger compartment. 
     As explained above, the Isofix attachment points in the vehicle are composed of two mounts that are 6 mm thick on each seat, which are spaced 280 mm apart in the gap between the backrest and the seat in the rear of the vehicle. If the normal Isofix attachment points are provided on the two outer rear seats in the vehicle then there are four mounts in the rear of the vehicle interior, wherein the spacing between the mounts for the two outer rear seats may vary, and depends on the size of the vehicle. 
     The spacing between the two first mounting points can therefore be adjusted precisely to a specific type of vehicle, e.g. a VW Golf IV. A greater range of use and variability is obtained for different types of vehicles if the spacing between the first mounting points can be adjusted. This adjustability can be obtained, for example, in the adjustable receivers on the rollbar for the first mounting points. In this manner, production tolerances can also be accounted for in a vehicle with regard to the spacing between the outermost Isofix attachment points. 
     In principle, the roll cage can have just two first mounting points, in particular for the outermost mounts on the Isofix attachment points in the vehicle. If the rollbar is to be securely attached to the vehicle in a particularly robust manner, there can also be four first mounting points on the rollbar, which are then attached to all four Isofix attachment points in the vehicle for the two outer rear seats. 
     It should be noted that the roll cage also has an aesthetic value, and the roll cage according to the invention does not provide the same level of vehicle safety that is obtained with a roll cage that is permanently attached to the chassis of the vehicle. 
     In general, it is possible that the rollbar simply has feet plates at the bottom that are basically the same size or slightly larger than the tubes forming the rollbar, such that the end of the tube is simply closed with a plate, for example. This may be necessary for some vehicles due to the available space therein. 
     The supporting elements preferably have support plates, however, which are designed to fit in the vehicle at the side of the passenger compartment and/or on the floor thereof. 
     These support plates should be of a minimum size for this, in order to absorb the forces acting on the chassis in the rollbar in the case of an accident, and thus prevent perforation of the floor where the plates press against it. An appropriate minimum size would be 100 mm×100 mm, preferably 200 mm×200 mm, and ideally 200-250 mm×250-350 mm in the case of a rectangular surface of the support plate, for example, depending on which size fits best on the floor in the rear of the passenger compartment. 
     According to a preferred embodiment, the support plates weigh between 5 and 15 kg, in particular 8 to 10 kg. As a result, the rollbar remains in place on the floor of the vehicle due to the weight of the support plates. 
     In an advantageous development of the invention, the support plates have flanges that can be attached to the lower ends of the tubes forming the rollbar. The support plates can thus be attached to the rollbar after the rollbar has been positioned in the vehicle. This significantly simplifies the installment of the roll cage in the vehicle. The attachment can preferably be obtained using screw clamps, which connect the lower ends of the tubes of the rollbar to the flanges. 
     The clamp elements are preferably made of two oblong clamp parts, in particular metal brackets that can be connected to one another by at least one threaded bolt, where at least one of the clamp parts has at least one recess on its side facing the other clamp part for a mount on the Isofix attachment point. 
     A first clamp part is preferably welded to the rollbar, and the second clamp part is preferably screwed to the first clamp part. This design can be produced easily, and simplifies installation. 
     Because the mount is formed by a web that has a diameter of 6 mm, the receiver of clamp element is preferably formed by the semicylindrical channels in both clamp parts facing one another. Alternatively, the recess can be formed entirely in one of the clamp parts, in which case the recess formed in the one clamp part is simply covered by the other clamp part. 
     In a very stable and easily produced embodiment of the invention, the two clamp parts are made of metal strips or brackets that are 4 to 10 mm thick, in particular 5 to 8 mm thick. This has the advantage that forces can be effectively transferred due to the thickness of the materials. The materials are also thick enough that a 3 mm channel can be formed therein for the 6 mm thick mount, without deforming it, such that the two half-channels in the two clamp parts face one another, thus forming a cylindrical hole for the mount with a 6 mm diameter. 
     The two clamp parts therefore preferably have a cylindrical channel or groove on their sides facing one another, with a diameter of at least 5 mm, in particular 5.5 mm to 6.5 mm. The trough is transverse to the longitudinal axis of the clamp part in each case. The troughs face each other on the two clamp parts that are screwed together, thus forming the receiver for the mount. 
     The mount on the Isofix attachment point is preferably clamped between the two clamp parts, such that any play is eliminated. The diameter of the recess in at least one of the clamp parts can therefore be slightly smaller than the diameter of the mount, e.g. 5.9 mm. 
     To attach the two clamp parts securely but releasably, they can be connected to one another by at least one, preferably at least two threaded bolts, placed successively in the longitudinal direction. The two clamp parts are first screwed together when the rollbar is placed correctly in the vehicle, and the mount lies in the trough or recess of at least one clamp part. The installation is thus simplified in this embodiment. 
     If the distance between the holes for the bolts is at least 3 cm, preferably at least 5 cm, the tightening area is not affected by the seat cushions in the rear, and the installation is easier. 
     In order to be able to withstand the potentially strong forces that may act on the roll cage in the case of an accident, the rollbar and/or the mounting points are made of metal, in particular steel. Preferably, both the rollbar and the mounting points are made of steel. As a result, the forces acting on the passenger compartment can be effectively transferred by the roll cage to the Isofix attachment points and the vehicle chassis. 
     The following expressions are used synonymously: first mounting point—clamp element; clamp part—metal strip, metal bracket; second mounting point—support element. 
     It is clear to the person skilled in the art that the embodiments described above can be combined arbitrarily with one another, as long as the embodiments are not mutually exclusive. 
     Developments, advantages and application possibilities of the invention can be derived from the following description of exemplary embodiments and from the drawings. All of the features described and/or illustrated in the drawings are fundamentally part of the invention in and of themselves or in arbitrary combinations thereof, independently of their descriptions in the claims or the references made thereto. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention shall be described in greater detail below on the basis of exemplary embodiments in conjunction with the schematic drawings. Wherein: 
         FIG. 1  shows a side view of a roll cage according to an embodiment of the invention in a motor vehicle; 
         FIG. 2  shows a rear view of the roll cage shown in  FIG. 1 ; 
         FIG. 3  shows a detailed view of the support element in a fragmentary, side view; 
         FIG. 4  shows a top view of the support element; 
         FIG. 5  shows a top view of a clamp element; and 
         FIG. 6  shows a longitudinal cut through the clamp element shown in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION 
       FIG. 1  shows a schematic and very simplified illustration of a passenger compartment  10  in a motor vehicle, with a windshield  12 , steering wheel  14 , front seats  16 , rear section  18  behind the front seats, and a back seat  20 . 
     A mount  26  for an Isofix attachment point is located in the known manner on the back seat  20  in the gap between the seat  22  and the backrest  24 . These attachment points are usually used for securing child seats. 
     A roll cage  30  is located in the rear section  18  of the passenger compartment  10 , which shall be explained in greater detail in reference to  FIGS. 1 and 2 . 
     The roll cage  30  contains a rollbar  32 , which, seen from the side, has an A-frame structure with a front leg  36  and rear leg  33 , connected by a horizontal connecting web  39 . The rear leg  33  has a horizontal web  37  at its lower end, which has two first mounting points  34   a ,  34   b , each of which can be secured to a mount  26  on an Isofix attachment point, preferably on both sides at the outermost Isofix attachment points. 
     The front leg  36  extends into the footwell in front of the back seat  20 , and is supported by two supporting elements  38   a ,  38   b  on the floor  41  of the passenger compartment  10 . Each supporting element  38   a ,  38   b  is composed of a support plate  40  with a flange  42 , which is connected to the lower end  46  of the front leg  36  of the rollbar  32  by a screw clamp  44 . 
     The support elements  38   a ,  38   b  are shown in greater detail in  FIGS. 3 and 4 . They are composed of the support plate  40 , which is preferably 150 milimeters (mm)×250 mm to 200 mm×350 mm, and therefore supported with a large surface area on the floor  41  of the passenger compartment. The weight is preferably numerous kilograms, preferably 5 to 15 kg, such that the weight of the support plates  40  keeps the rollbar  32  securely on the floor  41  of the passenger compartment  10 . 
     The flange  42 , i.e. a tube flange, is welded to the support plate  40 . The flange  42  preferably has the same diameter as the lower end  46  of the front leg  36  of the rollbar  32 . It is then connected via the screw clamp, or tube screw clamp  44 . The tube screw clamp  44  is composed of two half-clamps  48 ,  50 , which are tightened to one another by two screws  52  that pass through the flange  42  and the lower end  46  of the front leg  36 , thus securely connecting the lower end  46  and the flange  42  to one another. 
     The clamp elements  34   a ,  34   b  are shown in greater detail in  FIGS. 5 and 6 . The clamp elements  34   a ,  34   b  are composed of a first clamp part  54 , which is welded to the horizontal web  37  of the rollbar ( FIG. 2 ). The first clamp part  54  forms an oblong metal bracket with a material thickness of preferably at least 5 mm. 
     The first clamp part  54  has a cylindrical trough  56 , transverse to the longitudinal axis, at its front end, which encompasses the mount  26  on the Isofix attachment point over approximately 180°. A second clamp part  60  is secured by two screws  58  to the first clamp part  54 , which also forms an oblong metal bracket with a thickness of preferably at least 5 mm. The second clamp part  60  also has a complementary trough  62  at its front end, lying opposite the trough  56  on the first clamp part  54 , such that the two troughs form a cylindrical hole  64  that entirely encompasses the mount  26 , thus securing the rollbar  32  to the mount  26  on the corresponding Isofix attachment point. 
     There can be two or four first mounting points in the form of these clamp elements  34 , which are secured to a corresponding number of mounts  26  in the rear section  18  of the vehicle&#39;s interior. 
     The rollbar  32  is securely anchored to the Isofix attachment points in this manner, and it is also supported on the floor  41  of the passenger compartment. The roll cage  30  can thus be quickly installed, without having to be registered, and it is also robust and functional. 
     It is clear to the person skilled in the art that the invention is not limited by the description of the drawings, and can be varied within the scope of protection of the subordinate claims. 
     LIST OF REFERENCE SYMBOLS 
     
         
           10  passenger compartment in the vehicle 
           12  windshield on the vehicle 
           14  steering wheel 
           16  front seat 
           18  rear section of the passenger compartment 
           20  back seat 
           22  seat part of the back seat 
           24  backrest on the back seat 
           26  mount on the Isofix attachment point 
           30  roll cage 
           32  rollbar 
           33  rear leg of the A-frame rollbar 
           34   a, b  first mounting point—clamp element 
           36  front leg of the A-frame rollbar 
           37  lower horizontal web of the rear leg for attaching the first mounting point 
           38   a,b  second mounting point—support element 
           39  connecting web between the front and rear leg 
           40  support plate of the support element 
           42  flange welded to the support plate of the support element 
           44  screw clamp—tube screw clamp for attaching the support element to the lower end of the front leg 
           46  lower end of the front leg of the rollbar 
           48  first half-clamp of the screw clamp 
           50  second half-clamp of the screw clamp 
           52  screws for tightening the two half-clamps 
           54  first clamp part—metal bracket 
           56  cylindrical trough in first clamp part, transverse to the longitudinal direction for clamping the mount 
           58  screws for tightening the clamp parts to one another 
           60  second clamp part—metal bracket 
           62  cylindrical trough in first clamp part, transverse to the longitudinal direction, for clamping the mount 
           64  cylindrical hole for receiving the mount, formed by the troughs in the two clamp parts facing one another