AU731547B2

AU731547B2 - Tailgate for vehicles

Info

Publication number: AU731547B2
Application number: AU15174/97A
Authority: AU
Inventors: Gunter Weber
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-03-07
Filing date: 1997-03-07
Publication date: 2001-04-05
Anticipated expiration: 2017-03-07
Also published as: AU1517497A

Description

1

AUSTRALIA

Patents Act 1990 GONTER WEBER

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Tailgate for vehicles The following statement is a full description of this invention including the best method of performing it known to me:- Tailgate for vehicles The invention concerns a tailgate for vehicles which is constructed from extruded aluminium hollow sections extending in the longitudinal direction of the tailgate and joined with each other as well as with transverse extending end sections.

In the construction of a tailgate of this type usually a transversely extending end section is provided at the free ends of the tailgate, which tapers towards its free end, so that the tailgate could be placed on the ground without any problem and a run-on ramp could be formed. A transversely extending end section is provided on the vehicle-facing end also, by means of which section the tailgate is mounted and is engaged by the pivoting and lifting device. These transversely extending end sections are joined with each other by a number of extruded hollow box sections made of aluminium or aluminium alloy which form the actual loading platform. Each of these hollow box sections have one or more chambers and on their longitudinal sides coupling devices for the reciprocal joining of the hollow box sections with each other. The coupling devices consist of a longitudinal rib provided on one open longitudinal side of the section, which rib engages a corresponding longitudinal groove of the respective adjacent section, which groove is provided on the other longitudinal side section, as well as hooking means situated opposite to the longitudinal rib and longitudinal groove.

Usually these tailgates, which have a width of up to 2.5 m, are constructed from similarly constructed hollow box sections, while on the longitudinal sides of the tailgate additional end sections are provided. This construction has the problem that, as time passes, the load on the tailgate leads to buckling and/or sagging of the hollow box section in the transverse direction.

Tailgates are usually classified into specified weight classes, wherein the first weight class is from 500 to 750 kg, the second from 1000 to 1,500 kg and the third one from 2,000 to 3,000 kg.

The object of the invention is to design a tailgate of the type mentioned in the introduction so that it has increased strength against the buckling of the hollow box section in the transverse direction, so that the tailgate can take heavier loads than was the case until now and/or is suitable for the next higher weight class. The tailgate according to the invention is characterised in that the tailgate is constructed symmetrically relative its longitudinal centre from a number of hollow box sections, which, as their distance increases from the longitudinal centre, have increasing widths and an increasing number of chambers, bound by longitudinal walls.

The invention makes it feasible to design the tailgate in a simple manner with regard to the number of the different hollow box sections from the inside to the outside in such a manner, that the specified buckling strength and/or transverse bending ::20 strength of the tailgate in the transverse direction will be achieved.

Preferably each group of sections is constructed from hollow box sections, having one, two or three enclosed chambers.

25 According to a further feature each hollow box section has, as it is known, an enclosed and an open longitudinal side, on which coupling means are provided for reciprocal form- and force-locking joining of the hollow box sections with each other.

According to the invention on the outside of the tailgate end sections are provided, which are provided on their external sides with a mounting surface to accommodate light-reflecting strips or the like and are preferably rounded on their external side.

To increase the resistance to slipping on the top surface of the tailgate, preferably blast-treated hollow box sections are used within the scope of the invention, wherein the overall arrangement is achieved by that, viewed in the transverse direction of the tailgate, usefully at least each second hollow box section has a surface with a slip-resistant treatment. This surface is achieved advantageously by a corundum steel treatment with a coating thickness of 100 to 150 p.

In the following the invention is described in detail on an embodiment by referring to the drawings, in which the hollow box sections intended for the construction of a tailgate according to the invention are illustrated in Figs.l to while Figs.6 and 7 show a schematic top view and a crosssection along line VII-VII, respectively, of a tailgate constructed from various sections.

Figs.l to 5 show schematic cross-sections across hollow box sections having different widths, where in Fig.l a section 1 is illustrated, which is provided in the central region of the tailgate. Section 1 has a chamber 1" enclosed by wall i' and an open chamber As the tailgate has a symmetrical design relative its longitudinal centre X-X, according to Fig.7 six, for example, sections 1 are joined with each other to form a S central tailgate part A; however, this number may be smaller.

To this section 1 as an intermediate parts B, four section 2 each, are joined, which are illustrated in Fig.2, wherein each of these hollow box sections have two enclosed chambers 2", which are separated by walls and a chamber open to one end. Usually between two and four pieces of section 2 are provided per side. Further to the outside the external side C of the tailgate is constructed from two sections 3, which are illustrated in Fig.3, which have three chambers 3"1 each, separated from each other by walls and a chamber open to one end. The longitudinal lateral edge of the tailgate is formed by the single-chamber sections 4' and respectively, which are illustrated in Figs.4 and 5, which are open on one longitudinal side and closed on the other. The sections 4 and have rounded external walls, which are provided with a mounting surface 14 to accommodate light-reflecting strips or the like.

As it is shown in the drawings, the tops of the individual sections 1 to 3 are provided with longitudinal ribs 6, positioned at a distance from each other. To increase the resistance to slipping on the top surface of the tailgate, in the transverse direction at least each second section 1 to 5 is provided with a surface coating of corundum steel, wherein the coating thickness is, for example, 100 to 150 M.

The individual sections 1 to 5 are enclosed on one of their longitudinal sides, whereby one groove 7 and a hooking slot 8 are formed, and are open on the other longitudinal side, while on this longitudinal side a groove engaging bead 9 is provided on the bottom of the section and a protrusion 10 on the top of the section, so that the sections 1 to 3 can be joined by inserting the bead 9 into the groove 7 of the adjacent section and pivoting about this groove as well as snapping the protrusion 10 into the slot 8. The end sections 4, 5 on the longitudinal sides of the tailgate are joined with the associated adjacent sections 3 in the same manner.

ooo 0@*o All sections and the entire tailgate are made of aluminium or an aluminium alloy. The number of the sections 1, provided on the inside of the tailgate and the sections 2 and 3 joining them on the outside is chosen depending from the weight class and/or transverse bending strength of the tailgate to be achieved.

S The transverse section 11, 12 at the end of the tailgate are S. made of a section 11 tapering towards its open end, which section makes a driving-on feasible when the tailgate is placed

S.

on the ground, as well as a transverse section 12, accommodating the lifting and pivoting mounting (not illustrated), which section is complemented with boxes 13, accepting the lifting pistons and welded to the bottom of the tailgate.

The construction according to the invention can, of course, vary with regard to the number of the sections and their chambers as well as the joining means from the illustrated one without abandoning the inventive concept.

a. a. a a a *aa.

Claims

2. A tail gate according to claim 1 characterised in that the hollow box sections have one, two or three enclosed chambers.
3. A tailgate according to claim 1 or 2, characterised in that each of the hollow box sections has, as it is known, an enclosed and an open longitudinal side, on which coupling means are provided for reciprocal form- and force-locking joining of the hollow box sections with each other.
4. A tailgate according to any one of the claims 1 to 3, characterised in that on the outside of the tailgate hollow 25 end sections are provided, which are provided on their o *external sides with a mounting surface to accommodate light- reflecting strips or the like and are preferably rounded on their external side.
5. A tailgate according to any one of the claims 1 to 4, characterised in that the hollow box sections and the hollow end sections are provided on their top surface with longitudinal ribs positioned at a distance from each other S•and that at least each successive second section in the transverse direction of the tailgate is provided on the top surface with a slip-resistant coating, which is achieved by a blast-treatment, preferably by a corundum blasting. -6-
6. A tailgate substantially as hereinbefore described with reference to the accompanying drawings. Dated this twenty-fourth day of January 2001 Gunter Weber Patent Attorneys for the Applicant: F B RICE CO