GB2376212A

GB2376212A - Vehicle roll cage

Info

Publication number: GB2376212A
Application number: GB0113546A
Authority: GB
Inventors: Michael Christopher Peck
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-06-05
Filing date: 2001-06-05
Publication date: 2002-12-11
Anticipated expiration: 2021-06-05
Also published as: GB2376212B; GB0113546D0

Abstract

A vehicle roll cage is disclosed which is detachably connected only to existing mounting points within a vehicle, so that the roll cage may be removed to restore the vehicle interior to its original specification and appearance. The roll cage may be connected to seat belt anchoring points, seat fixing points, or the vehicle suspension turrets, and may comprise a hoop section (12 in figure 2), a diagonal brace section (14) and cross braces (16,18). The roll cage may be formed of interconnected separate tubular pieces which are bent in only one plane so as to be easier to store, and may be made from metals such as aluminium and steel, or a carbon fibre material. The roll cage may also have feet intended to spread any loads over a larger area, and the roll cage may provide mounting points for race harnesses and for a fire extinguisher.

Description

Roll Cage This invention relates to roll cages for motor vehicles.

Conventionally, vehicles used for motorsport are required to be fitted with internal roll cages. These consist of tubular cages of aluminium or steel which are welded or bolted to additionally installed welded captive mounts in place within the vehicle. Although the cage improves the rigidity of the chassis, its primary purpose is to maintain the vehicle's integrity should the vehicle roll, in order to protect the driver and any passenger from injury. The roll cage also provides a strong base for the attachment of harnesses which, unlike inertial reel seat belts, allow no slip before locking.

The fitting of roll cages has conventionally presented a problem in that it required substantial and irreversible modifications to be made to the interior of the vehicle, such as welding plates to the door sills, A, B and C pillars, for receiving the cage which was itself welded/or bolted to the interior of the vehicle.

Conventional motor sport vehicles are often stripped of all interior trim such as plastic mouldings, dash board, and carpets, and thus the fitting of the roll cage does not interfere with the interior trim, as it has mostly been removed. It is often the case that once installed, the roll cage remains in place for the life of the vehicle, and as such is not intended to be removed.

Recently, a trend has developed for drivers of road going vehicles, often family saloons, to take their vehicles on race tracks. Since these are private events, there are no guidelines requiring a minimum safety level for the vehicle itself, though most tracks require the use of crash helmets.

Some road vehicles have power and speed far in excess motorsport vehicles regulated by guide lines, but such vehicles when used legitimately at track days have no improved means of roll protection.

The present invention provides a roll cage for protecting the occupants of a motor vehicle, which roll cage is dismountably connectable only to existing mounting points in the vehicle, so that the roll cage may be removed from the vehicle to restore the vehicle interior substantially to its original specification.

The roll cage of the invention provides improved safety to drivers during occasional track events. However, because it is dismountable, it need not detract from the functionality of the vehicle during normal road use.

Furthermore, as the cage is connected in use to existing mounting points, it need not even detract from the appearance of the interior of the vehicle once it has been removed.

Such mounting points will obviously require strength and as such can be mountings points whose original function is one requiring strength. Such points include the front and rear seat belt anchoring points, as well as the seat mountings themselves.

It is advantageous for the frame to be tubular in construction, for the purposes of rigidity and weight, the tubes being fabricated from any suitable material such as aluminium, steel or carbon fibre.

The preferred embodiment of the present invention, uses a cage constructed inside the car from sections bent in one plane. This means that each section of the deconstructed roll cage is only the depth of the diameter of the tube from which the frame is made, thereby occupying very little space.

The strength of the roll cage comes from the shape and layout of the cage itself and not from the vehicle. It is only important for the cage to be prevented from moving within the vehicle. It is preferred to arrange for the cage to be formed of several sections each in the form of a triangle. Such a structure will act to prevent racking of the assembled cage in any direction.

The invention will now be described further by way of example with reference to the accompanying drawings in which Figure 1 is a side view of the preferred embodiment when installed in a vehicle, showing the position of the mountings and seats, Figure 2 is a side view of the preferred embodiment when assembled, Figure 3 is a front perspective view of different embodiment when assembled, Figure 4 is a top perspective view of the preferred embodiment when assembled, Figure 5 is a side view of a bracket used for joining different sections of the roll cage to one another, Figure 6 is a front view of the bracket of Figure 5, Figure 7 is a side view of a different bracket used to secure the roll cage to a vehicle fixing point, such as a seat belt anchoring point, and Figure 8 is a front view of the bracket of Figure 7 with the seat belt cut away.

In the preferred embodiment, the roll cage 10 as shown in the Figures is made of four interconnected sections, namely a hoop section 12, diagonal brace section 14, and cross brace sections 16 and 18. Each section is of tubular construction for rigidity in compression and formed of a suitable material for example steel or carbon fibre.

The strength of the assembled cage originates from the triangular shapes formed between sections 12 to 18.

Triangular frame structures are accepted as a way of producing strength with little weight. The structure makes the cage rigid and strong in its own right, and hence does not rely on its location in the car to provide roll protection.

It is intended that the cage is assembled inside a vehicle 20 as shown in Figure 1. The design of the cage is model specific in that it varies between vehicles depending on their internal layout such as location of fixing points,

and shape of roof. These do not however prevent the general idea of the cage from being described here.

Hoop section 12, is a squared-off arch of tubular material and is first attached behind the front seats of the vehicle providing a rollover bar which runs parallel to the B-pillar of the vehicle across the roof lining and down, parallel to the opposing B-pillar. It is secured to the vehicle 20 by bolting it via bracket 30 to the seat belt anchoring points at the bottom of each B-pillar. The tubular structure of the hoop section 12 is flattened at its ends 38and a hole 22 drilled therethrough for receiving the seat belt attaching bolt (not shown) or alternatively a bracket 30 may be permanently (yet removably) installed to facilitate easy assembly and disassembly.

Figures 7 and 8 show how bracket 30 is bolted to a seatbelt mounting point 32. Bracket 30 has a flat end, allowing it to be inserted between the vehicle body and seat belt fixing bracket 42, the other end of bracket 30 having two plates 40 separated by a gap 34, such that the flattened ends (in this case 38) of the tubular sections 12 and 14 may be inserted into the gap and bolted in place by captive bolts 36.

The hoop section 12 may further be provided with feet (not shown), which extend from the tubular structure to rest on the floor of the vehicle 20, thereby spreading the forces exerted on the cage over a larger area for example, the rear passenger foot wells or indeed the doorsills or transmission tunnel. These locations are all ideal, as they are inherently structurally very strong.

With hoop section 12 secured to the motor vehicle 20, diagonal brace section 14 must then be attached. Diagonal brace section 14 is made from welding a diagonal tube 24 between two parallel tubes 26 and 28, forming an N-shape. To provide further rigidity it is possible to weld in to opposing diagonals to form an X shape.

One end of each of tubes 26 and 28 is bolted to hoop section 12 at the squared off corners, corresponding to the

region just behind the drivers and passengers head restraints. This is achieved by use of a brackets 44 similar to brackets 30, but differing in that they are welded to one section of the cage to allow another section to be bolted thereto, rather than bolting the cage itself to the seat belt anchoring points. Brackets 44 are shown in Figures 5 and 6 The other end of each of the tubes 26 and 28 is bolted to bracket 30 which is permanently (but removably) secured to the rear passenger seat belt mounting point normally found in the gap between the base 46 and upright 48 of the rear seat cushion.

This ensures that hoop section 12 is rigidly attached to the vehicle's floor and also diagonally attached to approximately the boot floor area by means of the diagonal brace section 14.

Further strengthening is provided by attaching cross brace sections 16 and 18 between diagonal brace section 14 and hoop section 12, again, by use of brackets 44. The attachment of these sections, forms the structural triangles mentioned previously and shown clearly in figures 1 to 4.

Figure 3 shows an alternative hoop section 12, which also features horizontal strut 50 positioned behind the front seats parallel to the top crossing beam of the hoop section. This which incorporates mounting points for supporting race harnesses and a fire extinguisher, both useful additions to any vehicle intended for use on a race track.

It should be noted that the fixing of the roll cage to the vehicle is not limited to seat belt anchoring points 32.

Any mounting points that are inherently strong such as seat locating points, or suspension turrets will provide adequate support. Suspension turrets are viable since they are located just behind the rear seats, and as such, with the right shaped brackets, can be utilised as a mounting point, reached through the gap, between the rear seat cushions 46 and 48.

Claims

1. A roll cage for a motor vehicle, the roll cage being dismountably connectable only to existing mounting points in the vehicle, so that the roll cage may be removed to restore the vehicle interior substantially to its original specification.

2. A roll cage as claimed in claim 1, wherein the existing vehicle mounting points include seat belt anchoring points.

3 A roll cage as claimed in claim 1 or 2, wherein the existing vehicle mounting points include seat fixing points.

4. A roll cage as claimed in any preceding claim, wherein the existing vehicle mounting points include suspension turrets.

5. A roll cage as claimed in any preceding claim, wherein the cage is formed of connected sections, secured to one another by locking means.

6. A roll cage as claimed in claim 5 wherein the sections which make up the roll cage are formed of a tubular stock that is bent in only one plane.

7. A roll cage as claimed in claim 5 or 6 wherein the locking means are captive bolts.

8. A roll cage as claimed in any preceding claim, wherein the cage provides mounting points for seat belts.

9. A roll cage as claimed in any preceding claim, wherein the assembled roll cage relies on triangular frame construction to provide racking resistance.

10. A roll cage as claimed in any preceding claim, further comprising a fire extinguisher and means for supporting a fire extinguisher.

11. A roll cage as claimed in any preceding wherein the cage sections incorporate feet which rest on the vehicle floor, thereby spreading the load across a larger area in the event of a roll.

12. A roll cage constructed, arranged and adapted to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.