Patent Description:
Roll containers are a popular means of moving and temporary storage of goods. While there are a variety of different types of roll containers, a nesting type has achieved great popularity. The European standard for roll containers EN12674-<NUM>:<NUM> discloses the five main types of nesting roll containers, namely:.

The "A-frame chassis" type has gained great popularity. As the name suggests, the type employs an A-shaped chassis in plan view. The "A-frame chassis" type may feature a back frame section with a rear wall extending laterally and integral side pieces, which are known as trombones, extending longitudinally, i.e. orthogonally to the rear wall. The rear casters are attached to the trombones and the front casters are attached to the chassis. "A-frame chassis" roll containers also comprise a liftable base which is hinged to the back frame section of the container. Some "A-frame chassis" models, however, do not feature a rear wall or trombones. In such an open rear configuration, the base may be simply carried by the side walls and the side walls are pivotably attached to the forks of the rear casters. In deployed state, the roll container has a prismatic form. In nesting state, the base is either turned back or to the side towards a vertical orientation or removed and potentially suspended from a side wall. With the base removed from the center, the side walls are then pivoted in and towards each other, wherein the front of the roll container is narrower than the rear. The achieved wedge-shaped is used to nest several roll containers to achieve a compact formation for return logistics. The volumetric efficiency of the roll container, on the other hand, serves the purpose of reducing the carbon footprint of logistics through efficiency in return logistics. <CIT> discloses a chassis for a roll container. The chassis has three elements welded together to form an H frame chassis for the purposes of minimizing the number of components in the chassis. <CIT> and <CIT> both disclose an A frame chassis for a roll container with rear hinged side walls.

While the "A-frame chassis" roll container type is very efficient in view of return logistics, there still remains a long standing need to improve to further reduce the carbon footprint of logistics equipment.

A novel chassis for a roll container is therefore proposed. The chassis has a caster assembly, which has a caster with a fork as well as a pin. The pin may be repeatedly attached to and removed from the fork so as to attach the chassis of the roll container to the fork. The pin also acts as the hinge pin of a pivotable side wall of said roll container. The chassis a first arm and a second arm which are attached to the fork of a respective first and second such rigid caster assembly by the pin through a respective hole in the arms.

Further, a roll container is proposed making use of such a chassis. A first side wall of the roll container is attached at one end to a first such caster assembly and at a second end to another caster. A second side wall of the roll container is attached at one end to a second such caster assembly and at a second end to another caster.

Considerable benefits are gained with aid of the present proposition. The modular rigid caster assembly provides for assembly with elementary or no tools close to the end user of the roll container. By avoiding welding, the components of the assembly may be shipped packed efficiently in flat parcels. On the other hand, by assembling the caster assembly with repeatedly attached joints, a damaged rear caster, for example, can be replaced on site without sending the unit for repair welding. This, in turn, improves the overall volumetric efficiency of the life span of the roll container.

In the following certain exemplary embodiments of the present invention are described in greater detail with reference to the accompanying drawings, in which:.

The use and construction of a modular fork assembly is discussed in connection with a roll container that has auxiliary components which are discussed first. The chassis, for example, has been engineered so as to be assembled and disassembled with minimal or no tools and which includes a sacrificial and/or suspending element for improved tolerance for impacts and/or handling.

The appended FIGURES illustrate one embodiment where an H-frame roll container <NUM> is constructed making use of detachably interconnected components forming parts of the chassis <NUM>. While the concept has been described as applied to an H-frame chassis <NUM>, the same principles are equally applicable to other chassis constructions, chiefly to an A-frame chassis.

<FIG> depicts a roll container <NUM> featuring two side walls <NUM>, namely a first side wall 200A and a second side wall 200B, on a chassis <NUM>. The labels A and B are in this context used to distinguish between two different individual but similar components. The side walls <NUM> may feature, as shown, a conventional design with a peripheral frame delimiting a mesh. Naturally, alternative solid or lighter wall constructions are also foreseeable. The side walls <NUM> are spaced apart from each other in a dimension which is in this context referred to as a transversal dimension which is orthogonal to the main intended travelling dimension of the roll container <NUM>. A removable base <NUM> is suspended from the lower frame beams of the opposing side walls <NUM>. The base <NUM> has a mesh structure and hooks for suspending the base <NUM> in a horizontal deployed configuration shown in the FIGURES or in a vertical stored configuration (not illustrated). The base is <NUM> further supported by the chassis <NUM> from below.

The roll container <NUM> further includes four casters. Two of the casters provided to a first end of the roll container <NUM>, which in this context is referred to as the rear end for the sake of clarity, are rigid casters <NUM>, i.e. non-turning casters. A first rigid caster 410A is attached to the rear end of the first side wall 200A and a second rigid caster 410B is attached to the rear end of a second side wall 200B. The other two of the casters provided to a second end of the roll container <NUM>, which in this context is referred to as the front end, are swivel casters <NUM>, i.e. turning casters. A first swivel caster 420A is attached to the front end of the first side wall 200A and a second swivel caster 420B is attached to the front end of a second side wall 200B. The caster configuration may be varied by, for example, having only swivel or only rigid casters or any combination thereof. The first rigid caster 410A and first swivel caster 420A form a first pair of casters which carries the first side wall 200A. The casters 410A, 420A of the first pair of casters are arranged at a distance from one another in the longitudinal dimension of the roll container <NUM>. The second rigid caster 410B and second swivel caster 420B form a second pair of casters which carries the second side wall 200B. The casters 410B, 420B of the second pair of casters are arranged at a distance from one another in the longitudinal dimension of the roll container <NUM>. The second side wall 200B is therefore arranged at a distance from the first side wall 200A in the transversal dimension of the roll container <NUM>.

<FIG> shows the roll container <NUM> from below and reveals the design of the chassis <NUM> which is an H-frame chassis which is a modified version of an A-frame chassis as defined by the standard SFS-EN <NUM>-<NUM> (<NPL>on). Conventional A-frame chassis resembles the letter A in plan view, whereas an H-frame chassis resembles the letter H in plan view. The operating principle of an H-frame chassis roll container <NUM> is that in the deployed state (shown in the FIGURES) the side walls <NUM> extend longitudinally. In the nesting state (not shown in the FIGURES) the side walls <NUM> are pivoted in respect of a vertical rear hinge so as to turn the front ends of the side walls <NUM> closer to one another. Such pivoted the side walls <NUM> form a V shape when viewed from above. This requires removal or turning of the base <NUM> into a vertical orientation. To achieve the nesting option, the roll container <NUM> includes, on the one hand, a rear hinge, which will be discussed here after, and on the other hand swivel casters <NUM> which enable movement in respect to the chassis <NUM>. As shown in <FIG>, the wheel plates <NUM> of the swivel casters <NUM> are elongated in the transversal dimension. The wheel plate <NUM> terminates at the outer end to the side wall <NUM> and at the inner end to a lip for limiting the movement of the side wall <NUM> in respect to the chassis <NUM>. Accordingly, the front end of the chassis <NUM> is supported by the wheel plates <NUM> of the swivel casters <NUM> so as to allow relative sliding movement between the chassis <NUM> and the swivel casters <NUM>. The swivel caster <NUM> is fixed to the front end of the side wall <NUM>. In the shown example the wheel plate <NUM> is fixed to the joint between the front upright and bottom horizontal piece of the frame of the side wall <NUM>. The fork <NUM> of the swivel caster <NUM> is, in turn, rotatably connected to the wheel plate <NUM> and houses the wheel <NUM>.

<FIG> depicts a focused representation of the chassis <NUM>. The chassis <NUM> is to be understood as the stationary components on or to which movable components of the roll container <NUM> are fitted. In the illustrated example, the movable components include the side walls <NUM>, the swivel casters <NUM> and the wheels <NUM> of the rigid casters <NUM>. The chassis <NUM> includes two arms, namely a first arm <NUM> and a second arm <NUM>. The arms <NUM>, <NUM> are arranged spaced apart from one another in the transversal dimension. The arms <NUM>, <NUM> are also arranged non-parallel so as to open in a V angle towards the rear of the roll container <NUM> so as to facilitate the nesting state when the front ends of the side walls <NUM> are pivoted towards one another. The arms <NUM>, <NUM> may have, as illustrated, an elongated quadrangular and hollow profile. Alternatively solid arms having a similar or different profile, such as circular, oval, hexagonal. Also, any combinations of hollow and solid profiles having different shapes are foreseeable. The arms <NUM>, <NUM> may be made of metal, such as steel or an aluminium alloy, plastics, composites, etc..

The arms <NUM>, <NUM> are connected, preferably on the front half of the arms <NUM>, <NUM>, by a crossmember <NUM>. The crossmember <NUM> is formed to be less resistant to mechanical strain than that of the first and second arm <NUM>, <NUM>. This means that the crossmember <NUM> is made to more easily elastically deform than the arms <NUM>, <NUM> or that it is formed as a sacrificial member having lower structural strength than the arms <NUM>, <NUM> or both. It is preferable that threshold for elastic deformation of the crossmember <NUM> is set considerably than that of the arms <NUM>, <NUM> so that the crossmember <NUM> of the chassis <NUM> will flex upon impact rather than the arms <NUM>, <NUM>. It is also preferable that threshold for plastic deformation of the crossmember <NUM> is set considerably lower than that of the arms <NUM>, <NUM> so that the crossmember <NUM> of the chassis <NUM> will distort or break upon impact rather than the arms <NUM>, <NUM>. The difference in mechanical resistance may be established by selecting the material of the crossmember <NUM> to withstand less stress than that of the arms <NUM>, <NUM>. The crossmember <NUM> may be of, for example, a polymer, such as polyamide, or a composite, such as glass or carbon fibre reinforced polyamide, polyethylene, or polypropylene. The material should, however, preferably withstand impacts enough so as to maintain integrity. Alternatively or additionally, the crossmember <NUM> may be made of a thinner profile than the arms <NUM>, <NUM> to achieve the same result. With the crossmember <NUM> made more elastic than the arms <NUM>, <NUM> the roll container <NUM> is improved in two ways. Firstly, the relatively elastic crossmember <NUM> will absorb much of the mechanical strain thus minimizing the risk of replacing the arms <NUM>, <NUM> which may be made from a more expensive material. Secondly, the relatively elastic crossmember <NUM> will enable flexing of the roll container <NUM> on uneven surfaces thus keeping the wheels <NUM>, <NUM> against the supporting surface. According to a further embodiment, the resistance against flexing in one dimension may be different to resistance in another dimension. For example, the crossmember may be made from a composite material having fibres arranged such that flexing may relatively easily occur about one axis and hindered in about another axis. This means that the crossmember may flex about an axis extending horizontally in the main travelling direction of the dolly but be prevented about a vertical axis or vice versa. Additionally or alternatively, the design of the crossmember may include additional supports for establishing the same effect.

According to an alternative embodiment, the materials and/or mechanical properties of the arms and crossmember may be reversed. More particularly, the crossmember may be made of a relatively sturdy material whereas the arms are made of a sacrificial material flexing and/or breaking more easily than the crossmember.

The crossmember <NUM> has three sections, namely a first sleeve <NUM> for receiving the first arm <NUM>, a second sleeve <NUM> for receiving the second arm <NUM>, and a body <NUM> connecting the first sleeve <NUM> to the second sleeve <NUM>. The sleeves <NUM>, <NUM> are therefore aligned with the arms <NUM>, <NUM> with the body <NUM> connecting the sleeves <NUM>, <NUM> in the transversal dimension. The sleeves <NUM>, <NUM> are hollow profiles designed to match that of the arms <NUM>, <NUM> for receiving the arms <NUM>, <NUM> in an enclosed manner. Due to the male-female fit between the sleeves <NUM>, <NUM> and the arms <NUM>, <NUM>, the crossmember <NUM> can be repeatedly attached to and detached from the first and second arm <NUM>, <NUM>. The attachment can be a simple one as shown in the FIGURES, wherein the arms <NUM>, <NUM> are simply slid into the sleeves <NUM>, <NUM> (<FIG>).

When the chassis <NUM> is assembled, it rides at the rear on the rigid casters <NUM> and at the front on the plate <NUM> of the swivel casters <NUM>. To maintain rigidity, it is preferred that connection between the arms <NUM>, <NUM> and the crossmember <NUM> is secured. The attachment of the arms <NUM>, <NUM> to the sleeves <NUM>, <NUM> may be secured by an interlocking coupling interface provided to the crossmember <NUM>, the first arm <NUM>, and to the second arm <NUM>. The coupling interface features a female counterpart provided to the first and second arm <NUM>, <NUM>, which counterpart is an opening <NUM> in the FIGURES. Cooperating with the female counterpart is a respective male counterpart which may be a protrusion (not shown in the FIGURES) provided to the inner space delimited by the sleeve <NUM>, <NUM>. Naturally, the coupling interface may be reversed by adding a male counterpart on the arms and a receptive female counterpart to the sleeves (not shown in the FIGURES). Also, the entire fit between the crossmember <NUM> and the arms <NUM>, <NUM> may be reversed by having pins at both ends of the body of the crossmember extending parallel to the arms and having a receptive opening on the arm (not shown in the FIGURES). The openings may be provided, for example, to the side surface of the arms that face each other when the chassis is assembled. If desired, the connection between the crossmember <NUM> and the arms <NUM>, <NUM> may be further strengthened by a bolt or other detachable fastener (not shown in the FIGURES) in addition to or instead of the interlocking coupling interface. The fastener may, for example, penetrate the assembly through the fit between the crossmember and arms.

The sections of the crossmember <NUM>, whether female (as shown) or male (as not shown), may be formed to be integral with the body, wherein the crossmember is a unitary piece, or the sections may be assembled through joints. It is, however, preferable that the crossmember <NUM> is cast as a unitary piece so as to maintain a continuous structure that provides consistent bending and strength properties.

The illustrated embodiments show the crossmember <NUM> forming part of an H-Frame chassis. It would similarly possible to form an A-frame chassis with a somewhat similar construction, with the modification that the arms <NUM>, <NUM> do not extend through the sleeves <NUM>, <NUM> as in the embodiment according to the FIGURES. In an A-frame embodiment the body <NUM> could be shaped to be slightly convex when viewed from the front. In the shown H-frame embodiment, the body <NUM> is shaped concave when viewed from the front.

The chassis <NUM> may be disassembled by removing the fit between the crossmember <NUM> and the arms <NUM>, <NUM> in a reverse order in respect to assembly. By virtue of the several approaches above described for removably attaching the crossmember <NUM> to the first and second arm <NUM>, <NUM>, the chassis <NUM> may be easily assembled at the end use location with minimal or no tools and/or competence. This means that the components <NUM>, <NUM>, <NUM> of the chassis <NUM> can be shipped to the end use location not attached to each other, which enables efficient packing and thus helps reduce the carbon footprint of the roll container <NUM> as compared to a welded structure. In addition, should the crossmember <NUM> sustain a mechanical failure, it will most likely fail before the arms <NUM>, <NUM> are damaged. Accordingly, the roll container <NUM> may be repaired in situ without shipping the container for welding.

The same goal of reducing the carbon footprint of the roll container <NUM> may be improved additionally or alternatively by considering the hereafter described caster assembly.

At the rear the chassis <NUM> acts as the mounting point for the rear casters <NUM> and for hinge points for the side walls <NUM>. Accordingly, the arms <NUM>, <NUM> are attached at the rear to the rear fork <NUM> and to a hinge pin <NUM>. In the illustrated embodiment, the rear caster <NUM> is a rigid caster, i.e. non-turning caster. It is foreseen to construct a similar rear end of the roll container <NUM> with a swivel caster, i.e. turning caster, whereby it should be understood that the following description is equally applicable to a swivel caster construction. Additionally or alternatively, the front caster <NUM> may be replaced with a rigid caster. A swivel caster is, however, preferred at the front of the roll container so as to assist in the pivoting of the side walls about the rear hinges.

<FIG> depict a focused representation of the caster assemblies attached to the rear of the chassis <NUM>. The caster assemblies may include a rigid caster <NUM> as shown in the FIGURES or a swivel caster (not shown in the FIGURES). For illustrative purposes, the caster assembly is described by showing and referring to a rigid caster even though the same teachings are applicable to swivel casters. Similarly, for illustrative purposes, the interaction between the second arm <NUM> and the second rigid caster 410B is depicted, but the same teachings are applicable to the interaction between the first arm <NUM> and the first rigid caster 410A.

The rigid caster <NUM> includes a fork <NUM> which acts as a housing for the wheel <NUM> which has been omitted from <FIG> and <FIG>. The bottom end of the fork <NUM> includes an opening for receiving the axle of the wheel <NUM>. The fork <NUM> features a top plate <NUM>. The top plate <NUM> serves the purpose of acting as an attachment point for the arm <NUM> and hinge pin <NUM>. The top plate <NUM> is preferably planar for receiving and carrying the planar bottom surface of the arm <NUM>. The top plate <NUM> also has a bracket <NUM> for matching and keeping the therein inserted arm <NUM> attached to the fork <NUM>. Alternatively the connection between the fork and arm may be another connection which allows axial displacement of the arm in respect to the fork but blocks other degrees of freedom. Such alternatives include fishtail and other positively locking shapes (not shown in the FIGURES). Preferably, the bracket <NUM> allows for axial displacement of the arm <NUM> but blocks other degrees of freedom thereof. The bracket <NUM> is therefore a rear sleeve for receiving the arm <NUM>.

A pin <NUM> is attached to the fork <NUM>. In the illustrated embodiment, the pin <NUM> has a dual purpose. Firstly, the pin <NUM> serves the purpose of forming the male counterpart of a hinge formed between the rear of the chassis <NUM> and the side wall <NUM>. Secondly, the pin <NUM> serves the purpose of securing the arm <NUM> to the fork <NUM>. <FIG> best illustrates one exemplary embodiment of the pin <NUM>. The pin <NUM> may have an elongated body extending between a first end and a second end. The body may, for the most part, be cylindrical for promoting rotation around it.

The first end of the pin <NUM> has a tip <NUM> for attachment to the fork <NUM>. The tip <NUM> is shaped to form a first coupling element of an interlocking coupling interface between the pin <NUM> and the fork <NUM>. The second coupling element of the interlocking coupling interface between the pin <NUM> and the fork <NUM> may have several alternative manifestations depending on the first coupling element on the tip <NUM>. The tip <NUM> may, for example, have an opening <NUM> with a male thread as the first coupling element. The top plate <NUM> of the fork <NUM>, on the other hand, may have a corresponding female thread as the second coupling element for attaching the tip <NUM> to the top plate <NUM> through tightening rotation. The threaded connection may also be reversed with a threaded element protruding from the top plate and interconnecting with a threaded female opening at the end face of the tip (not shown in the FIGURES). Alternatively, as shown in the FIGURES, the opening <NUM> of the top plate <NUM> may be blind, wherein the pin <NUM> is attached to the top plate <NUM> with a nut <NUM> provided to the underside of the top plate <NUM> (<FIG>). Alternatively, the pin <NUM> may be secured to the fork <NUM> in the axial dimension of the pin <NUM> by a transversal cotter pin extending through a receptive opening at the bottom end of the tip <NUM> on the underside of the top plate <NUM> (not shown in the FIGURES). Regardless of which of the disclosed or undisclosed interconnecting elements are selected, it is preferable for the fork <NUM> and the pin <NUM> to include cooperating coupling elements <NUM>, <NUM> which form the interlocking coupling interface between the pin <NUM> and the fork <NUM>.

As indicated above, the pin <NUM> blocks also the axial movement of the arm <NUM> in respect to the fork <NUM>. In this context, the axial dimension of an element, such as the pin <NUM> or arm <NUM>, refers to the dimension of greatest extension thereof. The rear end of the arm <NUM> has a through hole <NUM> which is designed to receive the tip <NUM> of the pin <NUM>. The pin <NUM> therefore penetrates the arm <NUM> and the top plate <NUM> thus attaching the arm <NUM> to the fork <NUM> as illustrated by the dashed line of <FIG>.

The pin <NUM> also includes a key <NUM> for rotating the pin <NUM> about its axial dimension. The key <NUM> is a shape which enables engagement with a corresponding tool for tightening the pin <NUM> against a corresponding threaded element which may be a threaded opening <NUM> or nut <NUM>, for example, on the fork <NUM>. According to the shown embodiment, the key <NUM> is located at the second end of the pin <NUM> opposing the tip <NUM>. Alternatively, the key could be arranged somewhere between the first and second end, for example, in the middle of the body in the axial dimension. The key <NUM> exhibits two parallel sides so as to be engaged with a wrench. Alternatively, the second end of the pin <NUM> could feature a screwdriver socket, such as a Philips or torx socket, for engagement with a corresponding screwdriver head.

Returning the illustration of the chassis <NUM> shown by <FIG> it can be stated that both the first and the second arm <NUM>, <NUM> are attached to the forks 411A, 411B of respective first and second rigid caster assemblies. The illustrated embodiment shows the caster assemblies being attached to the rear end of an H-frame chassis.

In addition to the pin <NUM> acting as a fastener for fastening the arms <NUM>, <NUM> to the forks 411A, 411B, they act as hinge pins for the side walls 200A, 200B. For that purpose the first and second side wall 200A, 200B each comprise a hollow vertical profile which is designed to engage with the respective pin <NUM> on the first and second fork 411A, 411B so as to form the rear hinge of the roll container <NUM>. In the illustrated example, the rear upright profile of the frame of the side <NUM> includes a bottom opening through which the pin <NUM> is inserted upon assembly of the roll container <NUM>. Alternatively, the side wall <NUM> could feature a separate hinge block attached to the side of the frame profile.

With the proposed modular caster assembly the end user may assemble or repair the roll container with elementary or no tools. Accordingly, the components of the assembly may be shipped packed efficiently in flat parcels. On the other hand, by assembling the caster assembly with repeatedly attached joints, a damaged rear caster, for example, can be replaced on site without sending the unit for repair welding. This, in turn, improves the overall volumetric efficiency of the life span of the roll container.

Claim 1:
A chassis (<NUM>) for a roll container (<NUM>), the chassis (<NUM>) comprising:
- a first arm (<NUM>),
- a second arm (<NUM>),
- a first and second caster assembly, each of which comprises
∘ a caster (<NUM>) comprising a fork (<NUM>) and
∘ a pin (<NUM>), which is configured to act as the hinge pin of a pivotable side wall (<NUM>) of said roll container (<NUM>),
characterized in that the arms (<NUM>, <NUM>) each comprise a hole (<NUM>), through which the pin (<NUM>) is configured to extend, and in that both the first and the second arm (<NUM>, <NUM>) are attached to the fork (<NUM>) of the respective first and second caster assembly by the pin (<NUM>).