ADLERSON, Hans (Kobbehallsvägen 7, Askim, S-436 39, SE)
GIBSON, Johannes (Berättelsegatan 36, Hisings Backa, S-422 42, SE)
ANDERSSON, Niklas (Wingärdsgatan 11B, Göteborg, S-416 54, SE)
ADLERSON, Hans (Kobbehallsvägen 7, Askim, S-436 39, SE)
GIBSON, Johannes (Berättelsegatan 36, Hisings Backa, S-422 42, SE)
| C L A I M S 1. A rear deck structure (18) for a vehicle, comprising a rigid deck grating (20) and at least one mounting bracket (24) for securing said deck grating (20) to a vehicle frame structure (10), said vehicle frame structure (10) supporting the deck grating (20) in vertical (Z) direction, characterized in that the mounting bracket (24) provides a flexible portion (30) compensating movements of the vehicle frame structure (10) relative to the rear deck structure (18) wherein the mounting bracket (24) is fixed with one portion (24a) to the deck grating (20) and with one portion (24b) to the frame structure (10). 2. The rear deck structure according to claim 1 , characterized in that flexible portion (30) comprises an elastic portion. 3. The rear deck structure according to claim 1 or 2, characterized that the mounting bracket (24) comprises an interfacial section (32) located between the deck grating (20) and the top (14) of the frame structure (10). 4. The rear deck structure according to claim 3, characterized in that the elastic portion (30) is located in the interfacial section (32) of the mounting bracket (24). 5. The rear deck structure according to any preceding claim, characterized in that the flexible portion (30) of the mounting bracket (24) is formed by a section (34) which is folded vertically in a wavelike manner. 6. The rear deck structure according to any preceding claim, characterized in that the flexible portion (30) of the mounting bracket (24) is formed by a web-like section (34) of zigzag shape. 7. The rear deck structure according to any preceding claim, characterized in that the flexible portion (30) of the mounting bracket (24) comprises a mechanical spring. 8. The rear deck structure according to any preceding claim, characterized in that the flexible portion (30) of the mounting bracket (24) comprises a strip of an elastic material. 9. The rear deck structure according to any preceding claim, characterized in that the mounting bracket (30) is secured to the outside (16) of the vehicle frame structure (10). 10. The rear deck structure according to any preceding claim, characterized in that the mounting bracket (24) is attached with one portion (24a) to the outside (16) of the vehicle frame structure (10) and with another portion (24b) to the bottom (22) of the deck grating (20). 11. A vehicle comprising a rear deck structure (18) according to any preceding claim. |
Rear Deck Structure for a Vehicle
TECHNICAL FIELD
The invention relates to a rear deck structure for a vehicle, according to the preambles of the independent claims. Specifically, the invention relates to rear deck structure for a tractor.
BACKGROUND OF THE INVENTION
Truck-like vehicles, including tractors, customarily comprise a frame structure with a pair of main structural members which run from the front to the rear of the vehicle. These main structural members carry the particular body of the vehicle, auxiliary equipment such as gas tanks and the lake as well as a rear deck structure. The rear deck structure allows the driver or any other person to safely access places situated above the main structural members, for example the space immediately behind the vehicle's cab. For example, on a tractor the rear deck structure is used by the operator to stand on while applying air and electricity connections to the trailer. The rear deck structure usually comprises a grating or a sheet panel surrounded by a rigid frame which is secured to the vehicle's main structural members through the use of bolts or by welding.
US 4,161 ,232 discloses a rear deck structure which is attached to the vehicle frame by means of connecting elements in the shape of J-bolts. Each J-bolt is engaged in a cylindrical sleeve welded to the rear deck structure as well as a resilient sleeve welded to the vehicle's frame structure. The resilient sleeve causes a positive engagement between the connecting element and the frame structure, thus precluding relative movement between the vehicle's structural members and the deck structure once the J-bolt has been fully secured. During operation of the vehicle, the frame structure undergoes bending and twisting motions. In particular, torsions of the vehicle frame structure around the vehicle's longitudinal (X) axis occur whenever the chassis is loaded with heavy components without adequate support. Simulations show that the forces exerted on the connecting elements during bending/twisting motions are directed in the vehicle's lateral (Y) direction. These forces exert strain and stress on the rigid connecting elements which attach the deck structure to the vehicle frame as well as on the deck structure itself. Such bending and twisting of the vehicle frame during operation may result in mechanical fatigue and failure of the connecting elements. Moreover, given that the rear deck is a comparatively weak element, the rear deck may undergo irreversible damage, even breakage, if it is attached to the vehicle frame structure by rigid connection elements.
In order to alleviate this problem, the deck structure may be secured to the frame structure using connecting elements which allow for motions of the deck structure with respect to the frame structure. FIG. 1a and 1b show a perspective view (FIG. 1a) as well as a sectional view (FIG. 1b) of a design according to the state of the art in which a rear deck structure 104 is clamped to a C-shaped longitudinal element 102 of a vehicle frame structure 100 by means of mounting brackets 114 bolted to the deck structure 104 with screws 116. The rear deck structure 104 comprises a deck grating 106 which is secured to a spacer 108 by means of bolts 110. The spacer 108 rests on top of the longitudinal elements 102, while the mounting bracket 114 contacts the longitudinal element 102 from below. Twisting/bending motions of the vehicle frame structure 100 relative to the deck structure 104 are compensated by rubber pads 112a, 112b attached to the bottom of the spacer 108 and to the top of the mounting bracket 114, these rubber pads 112a, 112b allowing sliding motions of the rear deck structure 104 relative to the longitudinal elements 102 of the vehicle frame structure 100. While the design shown in FIG. 1a and 1 b permits the rear deck structure 104 to slide whenever the vehicle frame structure 100 undergoes bending and twisting motions, it comprises a multitude of individual parts which requires a complex assembly sequence and makes its manufacture quite costly. SUMMARY OF THE INVENTION
It is an object of the invention to provide means for attaching a rigid deck structure to the frame structure of a vehicle in such a way as to minimize stress and strain due to bending und twisting motions of the vehicle during operation.
Furthermore, it is an object of the invention to provide means for attaching the deck structure to the vehicle frame structure which facilitate the assembly process.
These objects are achieved by the features of the independent claims. The other claims and the description disclose advantageous embodiments of the invention.
According to the invention, the rear deck structure comprises a deck grating which is secured to the vehicle frame structure by means of mounting brackets which are capable of compensating movements of the vehicle frame structure relative to the deck grating. The mounting bracket provides a flexible portion compensating movements of the vehicle frame structure relative to the rear deck structure wherein the mounting bracket is fixed with one portion to the deck grating (20) and with one portion to the frame structure. Thus, besides allowing the deck grating to slide with respect to the vehicle frame, the mounting brackets will restore the deck grating to its original position once the distortions, twisting and bending of the vehicle frame subside. Since the mounting bracket itself absorbs the vehicle frame's movements, there is no need for additional rubber cushions etc. interleaved between the deck grating and the mounting bracket and/or the vehicle frame structure. This allows for a simplified design of the rear deck structure and for a reduction of parts. Moreover, the assembly of the rear deck structure is made easier, since the mounting bracket can be assembled early in the production process, while the deck grating can be mounted later on.
Preferably, the mounting bracket can comprise rigid portions for securing the mounting bracket to the vehicle frame and to the rear deck structure as well as a flexible portion for compensating relative motion of the vehicle frame relative to the rear deck structure. The flexible portion acts as a spring which is elongated when the vehicle frame undergoes bending and/or distortions and returns to its original length as the vehicle frame relaxes.
Advantageously, the mounting bracket can be secured to the outside of the vehicle frame structure. This allows for a rigid design and an easy assembly.
Preferably, the mounting bracket can comprise an interfacial section which is located between the vehicle frame and the deck grating and which is oriented horizontally. Preferably, the flexible portion of the mounting bracket is located in this interfacial section. The rear deck structure rests upon the vehicle frame; thus, while the mounting bracket balances the forces acting on the deck grating, it does not need to support the deck grating's weight.
In a preferred embodiment of the invention, part of the mounting bracket can be folded in a wavelike manner, thus forming the flexible portion. In an alternate embodiment, part of the mounting bracket has a zigzag shape, thus forming the flexible portion. Moreover, the mounting bracket may comprise a mechanical spring and/or sections formed of an elastic material, thus forming the flexible portion. Of course, the mounting bracket can provide a combination on two or more types of flexible portions.
In a preferred embodiment of the invention, the mounting bracket can be attached on one side to the outside of the vehicle frame structure and on the other side to the bottom of the deck grating. Favourably, the mounting bracket itself acts as a spacer between the deck grating and the frame of the vehicle. The ends of the mounting bracket can be attached to the frame and the deck grating by welding, or attached by screws and bolts.
According to another aspect of the invention a vehicle is proposed comprising a rear deck structure which comprises a deck grating which is secured to the vehicle frame structure by means of mounting brackets which are capable of compensating movements of the vehicle frame structure relative to the deck grating. Preferably, the vehicle is a truck-like vehicle, including tractors. BRIEF DESCRIPTION OF THE DRAWINGS
The present invention together with the above-mentioned and other objects and advantages may best be understood from the following detailed description of the embodiments, but not restricted to the embodiments, wherein is shown schematically:
Fig. 1a, 1b a perspective view of a rear deck structure with mounting brackets according to the state of the art (Fig. 1a) and a sectional view of the rear deck structure of Fig. 1a secured to a vehicle frame structure using mounting brackets according to the state of the art (Fig. 1 b) Fig. 2 a schematic sectional view of a rear deck structure secured to a vehicle frame structure according to a first embodiment of the invention; Fig. 3 a schematic bottom view of a rear deck structure secured to a vehicle frame structure according to a second embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
In the drawings, equal or similar elements are referred to by equal reference numerals. The drawings are merely schematic representations, not intended to portray specific parameters of the invention. Moreover, the drawings are intended to depict only typical embodiments of the invention and therefore should not be considered as limiting the scope of the invention.
FIG. 2 shows a schematic sectional view of a rear deck structure 18 comprising a deck grating 20 which is secured to a vehicle frame structure 10 by means of a mounting bracket 24. The vehicle frame structure 10 comprises C-shaped longitudinal elements 12 which run along the longitudinal (X) direction of the vehicle. The deck grating 20 may be reinforced by stiffening fins and/or a reinforcing frame in order to increase its stability and/or rigidity. The sides of the deck grating 20 rest upon the top flange 14 of the longitudinal element 12 of the vehicle frame 10, e.g. a longitudinal beam. Thus, the deck grating 20 is supported in vertical (Z) direction by the vehicle frame 10. The mounting bracket 24 attaching the deck grating 20 to the vehicle frame 10 is bolted to the outside 16 of the longitudinal element 12 by means of a first set of screws 28, and the deck grating 20 is bolted to the mounting bracket 24 by means of a second set of screws 26. The mounting bracket 24 comprises a flexible portion 30 which absorbs any movements and distortions of the vehicle frame structure 10 and restores the deck grating 20 to its original position once the movements and distortions of the frame 10 subside.
In a first preferred embodiment of the invention, the mounting bracket 24 consists of metal sheet; the flexible portion 30 being formed by a section 34 which is folded vertically in a wavelike manner, thus permitting reversible elongations of the mounting bracket 24. The height 36 of the waves may vary for different vehicle variants, thus adjusting the height of the deck grating 20 over the vehicle frame 10 as desired. The flexible portion 30 is located in a horizontally oriented region 32 of the mounting bracket 24. Preferably, the wavelike structure is flexibly extendable in the vehicle's lateral (Y) direction, corresponding to the principal direction of traction forces acting on the mounting brackets 24 due to bending/twisting motions of the vehicle frame 10 during operation.
FIG. 3 shows a schematic bottom view of a second preferred embodiment of the invention. The deck grating 20 is secured to the vehicle frame 10 with a mounting bracket 24 which is formed of metal sheet, its flexible portion 30 being represented by a web-like section 34 of zigzag shape.
Alternatively, the flexible portion 30 of the mounting bracket 24 may be formed by a (mechanical) spring or by a strip of an elastic material such as a reinforced rubber or plastic.