WO2004000633A1

WO2004000633A1 - Platform made of fiber reinforced plastic for bus

Info

Publication number: WO2004000633A1
Application number: PCT/HU2003/000045
Authority: WO
Inventors: Nimród PAIS; József PETROVICS; Balázs LÁNYI; Ben Van Der Linden
Original assignee: NABI Autóbuszipari Rt.
Priority date: 2002-06-21
Filing date: 2003-06-19
Publication date: 2003-12-31
Also published as: AU2003244882A1; HU225709B1; HU0202043D0; HUP0202043A2

Abstract

The invention relates to a platform (1) made of fiber reinforced hardening plastic for bus, with enclosed load bearing support members and frame structures, which are designed as a single unit using overlapping fiber reinforcing layers that have different volumes and structures. According to the invention said platform (1) has hollow enclosed load bearing support members are made of cavity-filling enclosed fiber reinforced fabric and/or mat, a hardening plastic, the platform (1) is designed with the rear side axle and/or transmission support members (53, 54) and it extends to the front of the body including the front wall (6) up to the front rail (76), the side walls (46, 47) up to the window rails and to the lower confining surface of window openings, where adjoining members and pieces (69, 70, 71) are arranged for each window column and an end wall (10) is arranged in or adjoined to the floor section located close to (in front of or behind) the rear axle, which end wall (10) is normal or approximately normal to the floor plate (5).

Description

Platform made of fiber reinforced plastic for bus

In designing and making cars, it is general practice that a single plate is used for stamping a bottom plate, which is then turned into a platform by welding thereon some strengthening transversal and/or longitudinal force introducing parts. When different body side walls, i.e. wheel drums, front and rear walls are welded thereon, various types of vehicles can be produced, e.g. saloons, sedans, station wagons, high top or single-volume cars, station wagon/saloon combinations, etc.

There are proposals according to which the platform is to be fitted with the engine and the transmission, so that the platform hence equipped can be transported to the car manufacturer which installs a body thereon, thereby using the very same platform for making different types of cars as mentioned, above.

In prior art, it was suggested to use a fiber reinforced plastic platform for a small size garden vehicle with a short wheel base. The top part - also made of plastic - is bonded to the bottom part. The vehicle has a seat for the driver only and it is not fitted with an enclosed cabin as shown in the patent specification US-5.314.23. The top member is made of a weaker plastic, and the loading of the implement is allowed by the bottom platform, but the loading requirement is very low indeed, because this low speed vehicle or implement is only designed to carry a single person, and it is not roadworthy, consequently there is no need to meet impact regulations.

In making buses, a practice followed for several decades has been the making and selling of a self-propelled chassis, which holds a body built by the body manufacturer, thereby producing a complete bus. The so-called self-propelled chassis features the axles, the transmission equipment and the brake units, consequently the assembly is ready to operate and is self- propelled. It is usual practice to apply a ladder chassis or a lattice structure 'chassis' and when a body with similar latticework is fitted thereon, a bus with a unitary or semi-unitary lattice body construction is produced.

When creating this invention, our objective was the designing of a platform suitable for making a bus, using fiber reinforced plastic as a result of its well-known advantages, including but not limited to small weight and no corrosion as well as the fact that preparation activities are not required - even on the outside - prior to painting.

Our objective is achieved by a tray-shaped platform made of fiber reinforced hardening plastic resin only, without embedding into the fabric any metal-based force introducing members as integral parts of the platform, which has fitting and adjoining surfaces for bonding other body members to the former, and which are furthermore fitted with force introducing adjoining components for connecting the axle and transmission units, which all have bearing surfaces for supporting the loadable members/plates located on the two opposite sides, and for receiving the bolts with nuts that pass through them for clamping purposes. In accordance with general practice, in order to increase the bending inertia of load bearing parts, hollow support members are fitted, with a foamed plastic or balsa wood core in the cavity.

The platform embodying our invention is especially suitable for building a so-called low floor body or bus without access steps, using fiber reinforced hardening plastic resin.

Our invention relates to a bus platform made of fiber reinforced hardening plastic, which platform has enclosed load bearing members and frame structures. These are designed as a single unit through the use of overlapped fiber reinforcing layers that have fibers in different volumes and structures, making use of hollow enclosed load bearing members with self- enclosed fiber reinforced fabric for filling the cavities and/or a mat reinforced hardening plastic, with the platform featuring the backmost axle and/or transmission support components, and expanding to the front of the body with the front wall, including the front wall up to the front rail, the side walls up to the window frames or up to the bottom confining surface of window apertures, where adjoining members and pieces are. arranged for each window column and where a rear wall is used in or adjoined to the floor section close to (before or behind) the rear axle, which said end wall is normal or very similarly positioned to the floor plate.

In a preferential embodiment of our invention, the core of load bearing members is made of foamed plastic or balsa wood blocks and their external surface is coated with the fiber reinforced hardening plastic. The fiber arrangement and fiber volume of fiber reinforcing fabrics are selected in a way that they absorb the mechanical/strength load, and layers with different fiber arrangements and fiber volumes as well as fabrics are overlapped.

In a further preferential embodiment of our invention, there are adjoining members made of multilayer fabric and featuring cores, to be used at the force introducing and adjoining points of the axle and transmission. These members are fitted with through holes, and each adjoining member has opposite surfaces with several through holes, which surfaces are designed as adjoining surfaces for supporting and bonding multi-bolt clamping members, and the platform has at least two multibolt adjoining members with adjoining surfaces for fixing the front bumpers, and the said adjoining surfaces include an angle of roughly 45 degrees from opposite sides with the longitudinal axis of the platform.

The low-floor bus platform can be used expediently for a rigid front axle, where two upper and two lower radius rods can be fitted for guiding the axle. For adjoining the upper longitudinal radius rods, rectangular brackets can be fixed to the arched front side of the wheel drum and to the aisle side inner part by through bolts with nuts. The said brackets can be bonded using their bearing surfaces, and they hold the journals of the rubber couplings of the radius rods. When projected to the platform plane, the lower radius rods are slanted, and they converge towards the front of the platform, therefore both can be screwed by means of the journals of their rubber couplings to a double clamping rib each fitted on a common steel support plate, which has through holes aligned with through holes in the floor, consequently the support plate can be fixed to the floor by bolts and nuts passing through these holes. The whole surface of the support plate is designed as an adjoining surface that matches the adjoining opposite face of the floor and they can be bonded together by an adhesive. The surface on the other side of the floor is also designed in a way that the washers of bolt heads are not resting separately on it, but the surface is suitable for the use on an underlay of principally identical size with the support plate, and the former can be bonded to the latter. In the wheel drum, on the upper horizontal section close to the side wall and next to the aisle, a bearing surface for supporting the air spring armature is fitted with round holes for the fixing bolts. On the other external side of the wheel drum wall, a bearing surface principally identical with the other bearing surface is situated with round holes in identical positions, in this case for the clamping disc having bores, on which the clamping bolts/nuts can be supported. The clamping disc can be bonded to the bearing surface with an adhesive. A similar bearing surface with a round hole therein is located in the wheel drum for fitting the telescopic shock absorber.

The platform is suitable for the installation of an air spring type rear axle, and in the case of a bus falling into a lower weight category, a similar appropriate design for connecting the air spring and the shock absorber is used as described for the front wheel drums, and in the case of a platform suitable for a heavier category bus the installation of such a rear axle is considered, which has two air springs and shock absorbers on each side. The fixing points for these can be provided within the wheel drum, directly before or behind the front and rear arches of the wheel drum where the members appropriate for force introduction rest on the air springs. Before the rear wheel drum, for adjoining the shock absorber, there is a thicker part with an overlay in the floor featuring a round hole and a bearing surface on both floor sides, and disc shaped support members can be bonded to the bearing surfaces. An adjoining point is fitted in the vicinity of side walls for securing the shock absorbers. Regarding the width of the platform, the adjoining surfaces suitable for holding the air springs are located within these points. A round bearing surface for holding the armature of air springs in front of the wheel drum is situated at the bottom of a frame-type platform section, the front side of which is formed by the front wall or the extended wall of the step fitted in the aisle, while at the intersection of the rear and side walls of the frame-type section there is a U-shaped fitting piece, into which the front edge of the longitudinal rib member is bonded. The upper edge of the longitudinal rib member is bonded to the floor, and the side surface of the transversal rib is bonded to the rear confining edge thereof. The upper edge of the transversal rib is bonded to the floor. The transversal rib extends to the side walls, and its front edges are bonded thereto; both side surfaces are bonded to the edges of semi-cylindrical air spring support members, and the upper front edges are bonded to the floor. The lower front edges are bonded to discs with an increased thickness, the front surface of which is designed for supporting and fixing the armature of air springs. An adjoining point between the air spring support members and the side walls is available for fixing each shock absorber, in a similar design than those in front of the wheel drum.

It has been mentioned above that in the aisle in front of the wheel drums there is a step, and the front wall of the step and the floor of the aisle represent the platform floor. On these two members there are adjoining surfaces and fixing points for the connection members of the radius rods guiding the rear axle. For adjoining the right and left hand side radius rods, a double adjoining bracket made of metal plate is fitted, which has two corner members with bolt connection points for fixing the journal of the radius rod rubber coupling, and which also has surfaces and fixing members for securing by bolts to the above mentioned step front wall of the platform and to its floor. A connecting rib links the two corner members, which are bonded to the platform.

Behind the rear wheel drums, at the end of the aisle the platform has another step, the vertical wall of which represents the front wall of the engine compartment, and the same item is the bottom part of the passenger compartment's rear wall from the side of the aisle. In the floor in front of the step and also in the engine compartment front wall, there are adjoining and fixing members fitted or arranged for securing the front engine suspension brackets). These fixing points are designed for the comer members,~which are supported both by the front wall of the engine compartment and by the floor in front of it.

As shown in the discussion above, when designing the platform we have used structural parts at the force introduction points which take all the substantial forces, where two or more fiber reinforced plastic members arranged in different planes have an intersection, where however the fabric sheet is the same between structural parts including an angle, which ensures a proper loading capacity, distributes in different and several directions the forces absorbing the loading forces and influences the progress of an eventual crack in a way that a sudden breakage and ripping of the load bearing part does not occur.

The invention is detailed by way of example of figures showing a platform suitable for a low floor bus, where

Fig. 1 shows the front and top views of the platform,

Fig.2 shows the rear and bottom views of the platform,

Fig. 3 shows the platform as per Fig. 2 with the front axle connection members, and

Fig. 4 shows the platform as per Fig. 2 with the rear axle connecting and transmission fixing members.

The platform 1 is suitable for constructing a low floor, primarily city bus. Since the platform 1 has a tray shape, this design determines the door arrangement of the bus that can be built thereon. The platform 1 is suitable for a left hand side steering rear engine bus, which has two passenger doors, one in front of the front axle and the other between the front and rear axles.

The platform 1 does not include an integral metal component, which can only become part of the platform 1 by being bonded to a surface or after being fitted there with a releasable joint.

The construction material of the platform 1 is fiber reinforced plastic; several types of glass fiber mat and fabric are fitted, and depending on the thickness and fiber arrangement of the fabric, and the differences of the fabric surface, at the points subjected to heavy loads, the reinforcing fabric sheets may also include carbon fiber layers. The applied synthetic resin is epoxy vinyl ester in a vacuum procedure, epoxy polyester in the no vacuum procedure; for bonding and combining the various members, methyl methacrylate can be applied. The platform 1 can be made in a so-called negative mold, as a result of which the smoothness of the external mold side surfaces (skin) is of such an extent that it can be suitable for prompt coating with a paint spraying technology. In a vacuum procedure, the fabric sheets are placed into a negative mold, a sealed vacuum bag is placed over it along the edges of the mold, which the vacuum sucks onto the fabric sheets and then through feeder channels the fabric sheets are filled up with the hardening plastic mentioned above. Such a building block is called composite material in trade literature, consequently it is laminated and mostly includes glass fiber layers. In the given case these sheets encapsulate the core which is mostly a polyurethane foam or balsa wood, and the laminated layers are impregnated with vinyl ester resin, which becomes hard within a short period and thereby turns into a solid building block.

Fig. 1 shows the front and top views of the platform 1. The platform 1 is a tray shaped, single fiber reinforced, fabric sheet structural unit in which the fabric sheets continuously pass between walls that generally include 90 degrees or a different angle between them, i.e. the same fabric sheet is arranged in both walls to ensure the high strength of the adjoining point. To accomplish the required bending inertia and torsion strength required for each structural part, wall, etc., the fabric reinforced hardening epoxy vinyl ester synthetic resin encapsulates or encloses tightly a core consisting of balsa wood or foamed polyurethane.

Each load bearing part and member of the platform 1 is of such a design, and wherever possible the transition of the fabric sheet is continuous everywhere from one geometrical formation to the other, i.e. for example as mentioned above the very same fabric sheet is located in the panels that include a 90-degree angle with each other.

In its whole length and width - except for recess 4 which houses a retractable ramp at the central passenger door aperture 3 - the floor 2 of the platform 1 is designed as a solid member encapsulating the cores, as a single plate of different thicknesses, without unfilled hollow parts. The floor 2 has many sections, the first represents the floor section 5 from the front wall 6 to the inner step 7, the second floor section 8 extends to the front wall 10 holding the last row of seats 9, and the support for the last row of seats 9 has a similar loading capacity than the second floor section 8, it is approximately flat and then comes the structural part which is . parallel with the first floor section 5 and adjoins the engine space front panel 11. The latter has a similar loading capacity and structure, is fitted with the same fabric sheet, and includes an angle of almost 90 degrees with support 9 of the last row of seats. Adjoined to the engine compartment front panel 11 is the engine compartment lid 12, which has a similar loading capacity and structure and is fitted with the same fabric sheet. In the first floor section 5, the platform 1 is fitted with the front wheel drums 13, in the second floor section 8 it has the rear wheel drums 14, and the side walls 15 of the latter and the side walls 16 of the wheel drums 13 confine the aisle 17 from both sides. On the top of the arched part 18 of the front wheel drums 13 there is a flat section 19 and an indented adjoining section 20. Each part of the wheel drums 13 and 14 is designed as a load bearing element encapsulating a core. In the adjoining section 20, for supporting the armature of the front axle air spring, the adjoining point 21 is located with reinforcement 22 and adjoining surface 23, on which a load distributing adjoining member can be installed, bonded and fixed by a through bolt and nuts. To connect the shock absorbers of the axle, a similar adjoining point 24 is designed with reinforcement 25, through-hole 26 and adjoining surface 27. The reinforcements 22 and 25 and the adjoining points 21 and 24 do not include a balsa wood or polyurethane foam core, because they would be crushed by the bolts. The reinforcements 22 and 25 only include a glass fiber fabric sheet made of thick filament sheets, the external surfaces of which contain jointing fibers, so that when the two filament sheets are placed on each other, they already establish a weak contact by an interconnection between the filaments. In the front wheel drums 13, for the connection of longitudinal radius rods guiding the axle, adjoining points 28 are established in a way that the radius rod can be fixed by a corner element, therefore in the practically vertical section of the arched section 18 of the wheel drum 13, which section faces the front of the platform 1, and on its side wail 16 the adjoining point 28 is divided with the adjoining surfaces 29, which are suitable for bonding and are fitted with the through holes 30 for receiving the fixing through-bolts with nuts.

For connecting the lower radius rods of the front axle, in floor section 5 immediately in front of the wheel drums 13, a large oblong size adjoining point 31 is designed on the bottom side 32 of the floor 2, with adjoining surface 33 suitable for bonding, and featuring some sixteen round openings 34 for receiving the through bolts with nuts for the floor 2. On the upper side 35 of the floor 2, an identical adjoining point 36 and adjoining surface 37 similar to those on the bottom 32 are designed for supporting a load distributing plate, and ready for bonding with an adhesive. The rear wheel drums 14 protrude from the floor section 8 of the floor 2, and this floor section 8 with the step 7 is located higher than the floor section 5, consequently the force introducing members and pieces suitable for supporting the armatures of shock absorbers and air springs are at this point inherent with floor section 8. The platform 1 is suitable for the installation of such a rear axle where on each side there are two air springs and two shock absorbers to carry the load. For connecting the shock absorbers, an annular adjoining point 38 with the circular opening 39 in the floor 2 is available both in front of and behind the wheel drum 14. The adjoining point 38 has an adjoining surface 40 reinforced with additional glass fiber filaments and ready for bonding; this adjoining surface is featured on both sides of the floor 2, and there are round openings 41 for through-bolts with nuts playing a clamping role within the adjoining surfaces 40. For supporting the air springs, several structural members are fitted or assembled. Below the side wall 16 of the wheel drums 14 a stiffening rib 42 is fitted, designed as a multilayer sheet having cores, and then bonded to the rear side 43 of the step 7, and also to a transversal rib 44 which is bonded directly behind the wheel drum 14 to the floor section 8, at edges 45 to the side walls 46 and 47. To both sides 48 of the transversal rib 44, the semi- cylindrical air spring supports 49 are bonded vis-a-vis the longitudinal center line and with their front edges 50 they are bonded to the floor section 8. The air spring supports 49 have a fully circular front panel 51, which is suitable for supporting the armature of air springs and has fitting/fixing members for the same. Similar air spring supports 49 are fitted in front of the wheel drums 14, and they are fixed by bonding to the bottom side 32 of the floor 8, as well as to the rear side 43 of the step 7. The front panels 51 are designed as adjoining points and not as bonding points for the air springs.

For connecting the two lower and two upper radius rods of the rear axle, a large size unit welded from a common steel plate is envisaged, the two L-shaped parts of which are adjoined by a web plate. For fixing the unit, there are circular openings 52 for the platform 1 in the step 7, and in its direct vicinity in the floor section 5. The circular openings 52 - for receiving three times 6 through-bolts and nuts - are featured in the adjoining points 53 and 54, the adjoining surfaces 55 and 56 of which are suitable for bonding. The adjoining surfaces 55 and 56 are designed on both sides of the step 7 and of the floor section 5.

Suitable adjoining points are designed for suspending the rear engine of the bus based on platform 1. Two L-shaped metal members are envisaged for the front suspension in front of the center of gravity of the transmission consisting of the engine and the gearbox, and two adjoining points 57 for fixing the said members, are located in the front wall 10 of the rear support 9 of the last row of seats, and the said adjoining points have round openings 58 for receiving the through-bolts and nuts. They are arranged in adjoining surfaces 59 ready for bonding, and adjoining surfaces 59 are available on both sides of the front wall 10. On the surface facing the passenger compartment, the fitting and bonding of a load distributing clamping plate is envisaged. For fixing the lower leg of the L-shaped engine support member, immediately in front of the front wall 10 in floor section 8 the adjoining point 60 is located and features the round openings 58 for receiving the through-bolts with nuts. They are arranged in the adjoining surfaces 61 which are ready for bonding; the adjoining surfaces 61 are on the bottom and top sides of the floor section 8, and it is envisaged to fit and bond a load distributing clamping plate on the top one.

For suspending the transmission unit behind its center of gravity, two connection points 62 are available, fitted at the intersection of the engine compartment front panel 11, engine compartment lid 12 and side walls 46 and 47. The adjoining point 62 is situated on the engine compartment lid 12 with a brick-shaped strengthening overlay 63, which includes several layers of glass fabric sheet in the epoxy resin, integral with the engine compartment lid 12. At the adjoining point 62 there is a large through-hole 64 to hold the engine support suspension rod designed for a tensile load. The upper adjoining surface 65 of the adjoining point 62 is designed to be ready for bonding, and the engine support member can be bonded thereto.

The tray-shaped platform 1 comprises the bottom parts of the bus side walls to be fitted thereon, up to or confined by the lower window sash or up to the lower rail side of the side windows or window rails, and in the case of the latter design it also includes the adjoining points of the window columns, namely the lower door and window column stubs.

The platform 1 has side walls 46 and 47, extending to the lower rail side 66 of the side windows, and from this line the window column stubs 67 and the door column stubs 68 slightly protrude. The external surfaces 68 of the side walls 46 and 47 come out of the negative mold without the need for any finishing, in a status ready to be painted. The strengthening glass fabric sheets 69 of the side walls 46 and 47 and the. floor 2 are joined in the vicinity of the corners, i.e. the very same strengthening glass fabric sheet 69 continuously passes from one to the other, offering favorable strength characteristics. For combining the platform 1 and the bus roof, adjoining points 69 are available in the window column stubs 67 and in the door column stubs 68, ready for bonding. These adjoining points 69 are designed as vertical channels 70, into which the leg of the other piece will go. The narrow end surface 71 of the window column stubs 67 and the door column stubs 68 is also an adjoining surface with a finish ready for bonding with an adhesive.

The side walls 46 and 47 are fitted with a horizontal strengthening rib 72, to which the frame of passenger seats can be secured. The wheel cut-outs 73 of the side walls 46 and 47 are designed with strengthening edges 74 on the inner side within the wheel drums 13 and 14, integrated with side walls 46 and 47, because the very same reinforcing glass fiber fabric sheet is fitted in their neighboring parts. In the side wall 46, confined by the door columns 68, a passenger door opening 3 is situated between the front wheel drum 13 and the rear wheel drum 14.

The platform 1 comprises the front wall 75 of the bus up the bottom of the windscreen, i.e. to the lower rail side, which can be bonded to the adjoining surface 77 of the narrow upper edge 76 of the front wall 75, which has a divided design with various compartments, front light recesses etc. for increasing strength and impact security. In the front wall 75, starting from the floor 2, clamping surfaces 78 are located for fixing the bumper. The clamping surface 78 on the right and left hand sides includes an angle of approx. 45 degrees with the geometrical center line of the platform 1. For fitting the driver's seat between the front wheel drum 13 on the left hand side and the front wall 75, the seat platform 79 is provided, including the fixing piece 80 for securing the driver's seat. The seat platform 79 is integrated for load bearing purposes with the neighboring load bearing members like the floor 2, the wheel drum 13, the side wall 47 and the front wall 75.

On the opposite side of the seat platform 79, the passenger door opening 80 is situated, therefore the door column 68 is fitted at this edge of the front wall 75. The platform 1 does not have a bus rear wall or the side wall sections in the vicinity of the rear wall. The rear edge 81 of the side walls 46 and 47 is designed with such a width that the item 82 represents an adjoining surface for the bonding of another side wall section, and similarly the edges 83 of the engine compartment lid 12 represent an adjoining surface 84 to make sure that side wall and rear wall sections can be bonded with an adhesive thereto. assembled. Below the side wall 16 of the wheel drums 14 a stiffening rib 42 is fitted, designed as a multilayer sheet having cores, and then bonded to the rear side 43 of the step 7, and also to a transversal rib 44 which is bonded directly behind the wheel drum 14 to the floor section 8, at edges 45 to the side walls 46 and 47. To both sides 48 of the transversal rib 44, the semi- cylindrical air spring supports 49 are bonded vis-a-vis the longitudinal center line and with their front edges 50 they are bonded to the floor section 8. The air spring supports 49 have a fully circular front panel 51, which is suitable for supporting the armature of air springs and has fitting/fixing members for the same. Similar air spring supports 49 are fitted in front of the wheel drums 14, and they are fixed by bonding to the bottom side 32 of the floor 8, as well as to the rear side 43 of the step 7. The front panels 51 are designed as adjoining points and not as bonding points for the air springs.

Suitable adjoining points are designed for suspending the rear engine of the bus based on platform 1. Two L-shaped metal members are envisaged for the front suspension in front of the center of gravity of the transmission consisting of the engine and the gearbox, and two adjoining points 57 for fixing the said members, are located in the front wall 10 of the rear support 9 of the last row of seats, and the said adjoining points have round openings 58 for receiving the through-bolts and nuts. They are arranged in adjoining surfaces 59 ready for bonding, and adjoining surfaces 59 are available on both sides of the front wall 10. On the surface facing the passenger compartment, ^■ the fitting and bonding of a load distributing clamping plate is envisaged. For fixing the lower leg of the L-shaped engine support member, immediately in front of the front wall 10 in floor section 8 the adjoining point 60 is located and features the round openings 58 for receiving the through-bolts with nuts. They are arranged in the adjoining surfaces 61 which are ready for bonding; the adjoining surfaces 61 are on the bottom and top sides of the floor section 8, and it is envisaged to fit and bond a load distributing clamping plate on the top one.

For suspending the transmission unit behind its center of gravity, two connection points 62 are available, fitted at the intersection of the engine compartment front panel 11-, engine compartment lid 12 and side walls 46 and 47. The adjoining point 62 is situated on the engine compartment lid 12 with a brick-shaped strengthening overlay 63, which includes several layers of glass fabric sheet in the epoxy resin, integral with the engine compartment lid 12. At the adjoining point 62 there is a large through-hole 64 to hold the engine support suspension rod designed for a tensile load. The upper adjoining surface 65 of the adjoining point 62 is designed to be ready for bonding, and the engine support member can be bonded thereto. The tray-shaped platform 1 comprises the bottom parts of the bus side walls to be fitted thereon, up to or confined by the lower window sash or up to the lower rail side of the side windows or window rails, and in the case of the latter design it also includes the adjoining points of the window columns, namely the lower door and window column stubs. The platform 1 has side walls 46 and 47, extending to the lower rail side 66 of the side windows, and from this line the window column stubs 67 and the door column stubs 68 slightly protrude. The external surfaces 68 of the side walls 46 and 47 come out of the negative mold without the need for any finishing, in a status ready to be painted. The strengthening glass fabric sheets 69 of the side walls 46 and 47 and the floor 2 are joined in the vicinity of the corners, i.e. the very same strengthening glass fabric sheet 69 continuously passes from one to the other, offering favorable strength characteristics. For combining the platform 1 and the bus roof, adjoining points 69 are available in the window column stubs 67 and in the door column stubs 68, ready for bonding. These adjoining points 69 are designed as vertical channels 70, into which the leg of the other piece will go. The narrow end surface 71 of the window column stubs 67 and the door column stubs 68 is also an adjoining surface with a finish ready for bonding with an adhesive.

On the opposite side of the seat platform 79, the passenger door opening 80 is situated, therefore the door column 68 is fitted at this edge of the front wall 75. The platform 1 does not have a bus rear wall or the side wall sections in the vicinity of the rear wall. The rear edge 81 of the side walls 46 and 47 is designed with such a width that the item 82 represents an adjoining surface for the bonding of another side wall section, and similarly the edges 83 of the engine compartment lid 12 represent an adjoining surface 84 to make sure that side wall and rear wall sections can be bonded with an adhesive thereto.

Claims

1. A platform made of fiber reinforced hardening plastic for bus, with enclosed load bearing support members and frame structures, which are designed as a single unit using overlapping fiber reinforcing layers that have different volumes and structures, characterised in that the hollow enclosed load bearing support members are made of cavity-filling enclosed fiber reinforced fabric and/or mat, a hardening plastic, the platform III is designed with the rear side axle and/or transmission support members /53, 54/ and it extends to the front of the body including the front wall 161 up to the front rail /76/, the side walls /46, 47/ up to the window rails and to the lower confining surface of window openings, where adjoining members and pieces /69, 70, 71/ are arranged for each window column and an end wall /10/ is arranged in or adjoined to the floor section located close to (in front of or behind) the rear axle, which end wall /10/ is normal or approximately normal to the floor plate 151.

2. The platform defined in Claim 1, characterised in that the core of load bearing support members is made of foamed plastic or balsa wood blocks and their external surface (skin) is coated with fiber reinforced hardening plastic.

3. The platform defined in Claim 1, characterised in that the fiber arrangement and fabric volume of the fiber reinforcing fabrics are selected in a way that they are suitable for absorbing the mechanical and strength loads, and in which layers of different fiber arrangements, fabric volumes and fabric materials are overlapped.

4. The platform defined in Claim 1, characterised in. that adjoining members made of a multilayer fabric encapsulating a core are fitted at the force introducing and adjoining points of the axle and transmission, which said adjoining members have through-holes, opposite surfaces - featuring several through-holes - of each adjoining member are designed as adjoining surfaces for supporting and for being bonded to the multi- bolt clamping members.

5. The platform defined in. Claim 1, characterised in that the platform 111 has at least two multi-bolt adjoining members with adjoining surfaces /78/ for fixing the front bumpers, which said opposite adjoining surfaces include /78/ an angle of approximately 45 degrees with the center line of the platform 111.