WO2001002237A1

WO2001002237A1 - Trailer chassis

Info

Publication number: WO2001002237A1
Application number: PCT/SE2000/001317
Authority: WO
Inventors: Ove Sers
Original assignee: Trailergruppen I Jönköping Ab
Priority date: 1999-07-01
Filing date: 2000-06-21
Publication date: 2001-01-11
Also published as: SE514632C2; AU6035100A; SE9902522D0; SE9902522L

Abstract

The invention concerns a trailer chassis with a frame and tubular shaft (4, 5). The chassis is primarily intended as part of a boat transport trailer. According to the invention each tubular shaft (4) is attached to the frame by a detachable support unit (9, 11, 12, 13). By the detachable support unit it is possible to choose the location for each tubular shaft (4) so that an adaptation to different load and operation circumstances can be achieved.

Description

TRAILER CHASSIS

The present invention concerns a trailer chassis of the kind described in the descriptive part of claim 1 . Trailers are used for many different purposes, such as house trailers, freight trailers, animal transport trailers, boat transport trailers etc. Normally, their chassis has a carrying frame, which is rigidly assembled and comprises a tubular shaft, unto which the wheel axles are fastened. Different types of trailers require different locations of the tubular shafts, often a choice of several. Each type of trailer is also made in different sizes and variations, which also implies differences in the optimal location of the tubular shaft. From the manufacturers viewpoint this is a disadvantage, since a very great number of chassis have to be available, where the only difference is the location of the tubular shafts. Alternately, some of the chassis will not be optimal for their task because of the compromise needed to restrict the variations. Even for one selected trailer the work tasks may vary so much that a single position of the tubular shaft is not always optimal. This may occur when one boat trailer is used for boats of different types and sizes. The trailer must then either be made oversize or may become unstable for certain loadings.

From FR 2 760 704 is previously known a boat transport trailer, the length of which can be varied by having a front and a rear chassis part telescopically dis- placeable relative to each other. The tubular shaft unto which the wheel axles are fastened is then necessarily displaceable relative to both chassis parts. This design allows a limited stability and there is a risk of dislocating the tubular shaft attachment to the chassis. With this background, the purpose of the present invention is to achieve a trailer chassis, which permits adjustment of the tubular shaft position relative to the chassis frame in a secure and stable way.

According to the invention, this is achieved by providing a trailer chassis of the kind described in the descriptive part of claim 1 with the special features men- tioned in the characterizing parts of the claims.

By having each tubular shaft fastened to the chassis frame in a releasable way, a single basic frame model can be used for several types of trailers, since the tubular shafts according to the invention can later be located in a position adapted to the intended use. The user of a trailer according to the invention also has a possibility to adjust the position of the tubular shaft to a location optimal for the actual circumstances, such as the size and weight of the load or the evenness of the road. If there should be a need to provide extra wheels this would also be easily done according to the invention. A trailer chassis according to the invention thus offers great advantages in manufacture, stock keeping and use. Since each support unit can be attached in a number of distinct predetermined positions along each main beam of the frame with clamping means, the tubular shaft will be effi- ciently clamped to the chosen locations. This ensures a safe and stable attachment.

In the context of this application, trailer refers to any kind of vehicle designed for being coupled to and pulled by another vehicle except railway vehicles. It refers to single axle, multiple axle or bogie truck equipped vehicles, designed to carry any kind of load as mentioned above. Directions mentioned refer to directions when the vehicles are moving forwards.

According to one preferred embodiment, the tubular shaft is rigidly joined to support blocks, where each support block has a contact surface arranged to be in contact with a corresponding support surface on a main beam of the chassis frame. This constitutes a disconnectable but stable connection with favourable stress distribution.

Preferably, each support block is elongated in the direction of the main beam to create a large contact surface and to spread the stresses over a larger area. According to another preferred embodiment, each support block is extended in one direction, preferably to the rear. This constitutes a reinforcement of the main beam and improves the ability to carry a rearwards overhanging load.

The support blocks are advantageously attached to each main beam with a couple of U-shaped clamping units, forming a reliable and easily detachable connection. This is another preferred embodiment. Each support unit could advantageously be provided with brackets for attachment of mudguards. This will ensure that the mudguards are always correctly located relative to the wheels.

The advantages of the invention are especially valuable if the trailer is a boat transport trailer. That is thus a preferred embodiment.

The above-preferred embodiments of trailers according to the invention and others are mentioned in the claims dependent upon claim 1.

The invention is further explained in the following detailed description of one embodiment of a trailer according to the invention. Figure 1 is a schematic drawing of a trailer according to the invention

Figure 2 is a lateral view from the inside of a support unit for a trailer according to the invention Figure 3 is a section along the line III - III in figure 2

Figure 4 is a section along the line IV - IV in figure 2 Figure 5 is a lateral view of a first detail of the support unit of figure 2

Figure 6 is a lateral view of a second detail of the support unit of figure 2

Figure 7 is an end view of the detail of figure 5

Figure 8 shows the detail of figure 5 from the opposite side

Figure 9 is an end view of the detail of figure 6 Figure 10 is a partial section along the line X - X in figure 2

In figure 1 is shown a schematic drawing of a trailer, preferably a boat trailer pulled by a vehicle (8). Part of the trailer chassis is shown and comprises a frame (1) including two longitudinal main beams (2, 3). A number of tubular shafts (4, 5) are attached to these, and to each main beam is a pair of wheels (6, 7) at- tached in a conventional manner. On trailers according to prior art, the tubular shafts are solidly attached to the frame (1) by welding or similar. At the trailer described here, the tubular shafts (4, 5) are detachably attached to the main beams (2, 3) and may when detached be relocated to any chosen position along the entire length of the main beams (2, 3). Figure 2 further explains how the detachable connection is designed. The figure is a lateral view of the main beam (2) in a region where the rear tubular shaft (4) is attached, as seen from the inside of the chassis of figure 1. The sup- port unit comprises a support block (9) which is elongated in the direction of the main beam (2) and has a contact surface (18) in contact with a support surface (23) of the main beam (2) to support the latter. One end of the tubular shaft (4) is welded to a recess (16) in the support block (9). The support block is also pro- vided with one rear (14) and one front (15) recess for one clamping unit each. Each such clamping unit comprises a U-shaped arch (1 1 ) straddling the main beam (2) and the support block (9) from above, as well as a yoke (12) enclosing both shanks of the arch (1 1 ). The shank ends are threaded and provided with nuts (13) for tightening of the yoke (12). The tubular shaft (4) is connected to the other main beam (3) in a corresponding way. If the nuts (13) are loosened, the support blocks (9) can be longitudinally displaced along the main beams (2, 3) to adjust the location of the tubular shaft along the chassis according to the actual load and transport circumstances. The support block (9) is asymmetrically shaped with a rearward extension. The rear overhanging part of the main beam will thereby be reinforced by the support block to improve the load capacity of the overhanging part.

Figure 3 shows in more detail the region at the arch (1 1 ). As shown there, the support block is made as two parts, one inside part (9a) and one outside part (9b), but naturally it could also be made as one unitary part. The contact surface (18) is as shown one upper surface of a horizontal portion (17) of the inside part (9a). The outside part (9b) is shown with a bracket (19) extending outward for attachment of a mudguard.

Figures 2, 3 and 4 show the main beam (2), the tubular shaft (4) and the yoke (12) as solid elements. They could, however, preferably be realised as profile elements such as hollow beams or U-beams.

Figure 4 shows how the tubular shaft (4) is welded to a recess (16) in the support block (9). The inside part (9a) may have stiffening inside folding (20). At its outside end, the tubular shaft has a bracket (21 ) for attachment of a wheel axle (22). Figures 5, 7 and 8 show in more detail the shape and dimensions of the inside part (9a) of the support block (9). Figures 6 and 9 show correspondingly the outside part (9b). The support block (9) should be attached to the main beam (2) at one of a number of predetermined locations. Those can be arranged as shown in figure 10 by providing a short tap (24) on the upper contact surface (18) on the horizontal portion (17) of the inside part (9a) of the support block. Along the main beam (2) there are a number of holes (25) fitting to insert the tap (24). The support block (9) can then attached only at locations determined by the holes (25).

Claims

1. Trailer chassis comprising a frame (1) and at least one tubular shaft (4, 5) each for a pair of wheels (6, 7), said tubular shaft being attached to the frame (1) with detachable support means comprising two support units (9, 1 1 , 12, 13) each connected to one main beam (2, 3) of the frame (1), where the support units can be relocated along each main beam (2, 3) when detached, characterized by each support unit (9, 1 1 , 12, 13) being attachable to a number of distinct predetermined locations along each main beam (2, 3), and by each main beam (2, 3) at each such predetermined location being provided with a gripping means (25) which can co-operate with a complementary gripping means (24) at the support unit (9, 1 1 , 12, 13).

2. Trailer chassis according to claim 1 , characterized by each support unit (9, 11 , 12, 13) comprising a support block (9) with a contact surface (18) designed for contact with a support surface (23) on the corresponding main beam (2, 3) of the frame (1 ), said support block being solidly attached to the tubular shaft (4, 5).

3. Trailer chassis according to claim 2, characterized by each support unit (9, 1 1 , 12, 13) being attached to a main beam (2, 3) extending in a longitudinal direction of the trailer, and by each support block (9) being longitudinally elongated parallel to the corresponding main beam (2, 3) and having a contact surface (18) over generally its whole length.

4. Trailer chassis according to claim 3, characterized by the support block

(9) being longitudinally extended in at least one direction, enough to improve the strength of the main beam (2, 3), preferably extended in a rearward direction.

5. Trailer chassis according to claim 3 or 4, characterized by each support unit (9, 1 1 , 12, 13) comprising at least one U-shaped arch (11 ) made to straddle the support block (9) and the adjoining portion of the main beam (2, 3), and com- prising a yoke (12) extending between the free ends of the shanks of the arch (11) and being easily detachable from at least one of said ends.

6. Trailer chassis according to claim 5, characterized by each of said ends being threaded and the support unit including a detachable threaded nut (13) screwed on to each thread.

7. Trailer chassis according to any of claims 1 - 6, characterized by each support unit (9, 11 , 12, 13) being provided with brackets (19) for attachment of mudguards.

8. Trailer chassis according to any of claims 2 - 7, characterized by the support block (9) consisting of at least two separate parts, one inside part (9a) and one outside part (9b), where the contact surface (18) of the support block (9) is horizontal and located on the inside part (9a) and the outside part (9b) is in contact with the main beam (2, 3) along a vertical plane.

9. Trailer chassis according to any of claims 1 - 8, characterized by being part of a boat transport trailer.