The present invention relates to a vehicle chassis in accordance with the preamble to the main claim.

State of the art

Vehicle chassis of this kind are previously known and are usually intended to have bus bodies mounted on them. In many cases a bus purchaser wishes to have a special bus body which is manufactured by a separate body builder, in which case the complete chassis has to be transported to the selected independent body builder to enable the vehicle body to be mounted on it.

A known practice in the manufacture of bus chassis for subsequent delivery to independent body builders is to make the chassis in the form of a front module and a rear module which are connected together by a standard intermediate section (a transport frame) which keeps the modules together during the journey to the body builder. The latter then has in a suitable manner to separate the modules and join them together so as to achieve the desired spacing between axles. If the bus is to be provided with a continuous baggage space or a large low-floor section between its axles, its body is used as a self-supporting linking element between the front and rear axle modules.

A known practice if the bus chassis is intended to be provided with a body supported by the chassis frame between the axles is chassis manufacture in a number of predetermined frame lengths. If the body requires some other frame length, the body builder has to cut the fixed frame, create in it configurations of holes corresponding to the desired axle spacings and fasten extension elements between the modules before the mounting of the body can commence. The whole operation requires precision and is time-consuming, since the parts concerned are relatively heavy and difficult to handle. As they will also be largely purpose- made for the respective type of body, the operation as a whole will be relatively expensive to carry out. This known technology involves the chassis manufacturer

in expensive manufacturing and stockholding of numerous frame members manufactured in relatively short production runs.

One object of the present invention is to enable body builders to adapt chassis to desired frame lengths. A further object is to provide a cost-effective solution for the chassis manufacturer. The invention has particularly advantageous applications in chassis with full-length frames for heavy buses in that a large number of body variants with different axle spacings can be derived from a given type of chassis.

Brief description of the invention

This solution is distinguished by what is indicated in the characterising part of the main claim, and involves using an intermediate frame and associated connecting elements to join together the front and rear modules. This provides the body builder with the possibility of choosing axle spacings freely from among the dimensions most commonly arising for this type of vehicle. The chassis manufacturer can thus achieve a standardised cost-effective solution at relatively low cost.

In one advantageous embodiment the intermediate frame is so designed as to exhibit the same frame height as the front and rear modules. This makes it possible to mount on the chassis a bus body which has the same floor height along much of the frame.

In another advantageous embodiment the linking elements are mutually identical, with a number of pairs of holes situated symmetrically along the waist of a channel section. This results in cost-saving standardisation of the constituent parts. In a further advantageous embodiment the linking elements are telescopically insertable in the channel-section side members of the respective module, thereby substantially facilitating not only the fitting and positional adjustment of the linking

elements in the frame side members but also evenly distributed transmission of forces between the various parts.

Other features distinguishing the invention are indicated in the attached patent claims and in the description below of an embodiment of the invention.

List of drawings

An advantageous embodiment of the invention is described below with reference to the attached drawings, which are as follows: Figure 1 depicts schematically a vehicle chassis according to the invention with front and rear modules connected by an intermediate frame and linking elements, and

Figure 2 shows a perspective view of the chassis frame in a position in which the cooperating parts result in a longer vehicle chassis variant than the chassis according to Figure 1.

Description of an embodiment

A vehicle chassis according to the invention and intended for the subsequent mounting of a bus body on it is depicted schematically in Figure 1. The chassis has a front section 1 and a rear section 2 which are connected by an intermediate section 3. The front section 1 has a driving compartment unit 4 and a front axle unit 5, while the rear section 2 incorporates a rear axle unit 6 and a drive unit 7. The front and rear sections each have two frame side members 8, 9 running in the longitudinal direction of the vehicle on either side of its longitudinal symmetry plane.

The intermediate section 3 consists of an intermediate frame 10 and linking elements 11. In this embodiment four linking elements 11 are used to connect the intermediate section 3 to the front section 1 and the rear section 2.

The intermediate frame 10 also incorporates two frame side members 12, 13, which with advantage have channel sections with the same cross-sectional

dimensions as the frame side members 8, 9 of the front and rear sections. The frame side members 12, 13 of the intermediate frame 10 thus form direct extensions of the respective frame side members 8, 9 of the front and rear sections 1 and 2, and all the frame side members 8, 9, 12, 13 have upper limiting surfaces which are situated in a single horizontal plane. The result is a substantially planar section between the axle units 5, 6 which facilitates the subsequent mounting of a vehicle body.

The intermediate frame 10 is further provided with at least one cross-member 14 (there are two of them in the embodiment depicted) enabling the intermediate frame 10 to serve as a fully operative part of a subsequent vehicle complete with body.

The frame side members 12, 13 of the intermediate frame 10 are each provided at their ends with at least one pair of holes 15, preferably in the form of two holes situated in the same vertical plane. Correspondingly, each of the frame side members 8, 9 of the front and rear sections are provided, at their ends directed towards one another, with at least one pair of holes 19. One advantageous embodiment incorporates at least three pairs of holes situated in the waist of the channel section at each of the aforesaid ends of members.

The linking elements 11 each take the form of channel-section members with cross-sections which make it possible for the linking elements to be telescopically inserted into, or pushed onto the outside of, the ends of the front and rear sections and the frame side members 8, 9, 12, 13 of the intermediate frame 10. In the chassis depicted in the drawings the channel sections of the linking elements 11 have a smaller cross-section than the frame side members 8, 9, 12, 13 of the front and rear sections and the intermediate frame 10. The linking elements 11 are accordingly inserted in the aforesaid ends of the frame side members, and the respective channel sections are adapted to cooperate in the transmission of forces.

Each linking element 11 is further provided with a number of pairs of holes 16 which are with advantage situated along the whole of its length so that the linking elements are consequently identical in appearance, thereby creating a cost- effective solution for the chassis manufacturer. The pairs of holes 16 are dimensioned and positioned so that when the linking elements 11 are inserted in the ends of the frame side members of the intermediate frame 10 and the front and rear axle sections they reach a position halfway between the respective pairs of holes 15 and 19 in the aforesaid frame side member ends. This means that when two or more of the pairs of holes 15, 19 and 16 are accommodated by the respective frame side member ends and linking elements 11 , they then have the same between-centres spacing in the longitudinal direction. Alternatively the pairs of holes 16 in the linking elements may have a between-centres spacing which is an even multiple of the between-centres spacing between the pairs of holes 19 at the ends of the frame side members of the intermediate frame 10 or the front or rear sections 1 , 2. The ratio between the between-centres spacings of the pairs of holes may of course also be the inverse. It is advantageous to adopt a between-centres spacing of 50 mm for the pairs of holes 16, which is found to result in good flexibility for achieving most of the axle spacings which may arise in the subsequent vehicle body mounting operation.

The length of the linking elements 11 is with advantage substantially the same as the minimum distance between two successive cross-members 20, 14 in the bus chassis version which has the minimum axle spacing, i.e. the version depicted in Figure 1. The forces acting on the linking elements 11 do of course have to be distributed as evenly as possible, which makes it advantageous for a maximum of a middle third of their length to be clear of the ends of the frame side members when the chassis has the maximum length.

Conventional fastening connections 17, e.g. bolted connections, may then be used to connect the linking elements 11 , the intermediate frame 10 and the front and rear sections 1 , 2 together, preferably at three successive pairs of holes 15, 16, 19. Bolted connections result in a standard form of chassis for transporting to

body builders. It will be easy for the latter to release the bolted connections 17 in order to adjust the chassis length to the desired dimension before mounting the body on the chassis. The body builder need neither make accurately located holes nor fit separate parts to the chassis to make it ready for mounting the body on.

Within the scope of the inventive step, the linking elements 11 may also be joined to an undepicted cross-member to make them easier to handle during chassis manufacture and during the body builder's chassis length adjustment work.