Dustbin with improved wheel unit

Abstract

A dustbin (10) comprises a container body (1); an axle (2) supported by the container body (1) and equipped with a geometric axis (5); at least one wheel (3) mounted on the axle (2) and equipped with a tubular hub (8); and interconnecting means (9) for interconnection of said at least one wheel (3) to the axle (2). The dustbin (10) is equipped with interconnecting means (9) which are integrated in the structures of the wheel (3) and of the axle (2), where they form a rolling support (14) wherein the wheel (3) and the axle (2) are interconnected with the freedom to rotate relative to each other around the geometric axis (5) of the axle (2).

Description

[0001] DUSTBIN WITH IMPROVED WHEEL UNIT

[0002] Technical field

[0003] This invention relates to a dustbin, with improved wheel unit , for facilitated mounting and recovery, for recycling, of the materials of which it is made up . Background art

[0004] The prior art , relative to dustbins made of plastic by injection moulding and provided with wheels for movement , already includes dustbins which have a wheelholder support composed of a cylindrical, tubular metal axle, equipped with two wheels placed at its opposite ends . The wheels have a rim made of plastic material with a band of rubber tread .

[0005] For the axle-rim connection, on the axle there is , at each of its ends , a circumferential channel made by means of permanent deformation, on a press , of the axle or by means of an equivalent knurling working process .

[0006] The rim is provided with a substantially cylindrical hub in which one end of the axle is inserted . A radial steel pin, separate from the hub and from the axle is inserted in the channel of the axle after passing through the rim of the wheel .

[0007] Once the rim is mounted on the axle, the pin inhibits the freedom of translation of the rim and the axle relative to each other along the line longitudinal to the axle .

[0008] After the rim has been fixed to the axle, a tread cover, surrounding the rim, and made of rubber, is fitted with circumferential elastic interference on the rim, covering the metal pin, made of steel, which as a consequence of that becomes practically unreachable, without first disassembling the tread cover .

[0009] Although that construction method is extensively used in the sector, it is not without disadvantages .

[0010] In fact , a first , economic disadvantage is a high industrial cost of the wheel-holder support , which costs practically as much as the entire container body of the dustbin .

[0011] The second and even more critical disadvantages is the fact that the dustbin which has reached the end of its useful life cannot be sent directly for grinding to recover the plastic material of which it is made and to recycle that material in the process of manufacturing a new dustbin or other manufactured article .

[0012] In fact , before being able to get to the grinding step preliminary operations are required for disassembly and selective separation of the metal materials from the plastic material, in particular removal of the metal pins and separation of the plastic materials of the wheels and of the metal materials of the axle .

[0013] Given the build structure of such wheel-holder supports , the relative disassembly involves the use of complex and expensive forced disassembly equipment , whose use largely nullifies the economic benefits of recovering the modest economic value of the plastic material .

[0014] On the other hand, there also exist , for this type of products strict regulatory requirements which require such products to be able to have a minimum resistance performance, without damage, meaning that the products must be able to withstand impact against the ground, as a result of free falling from a predetermined height and with a minimum excess weight , also predetermined, and finally with the entire reaction to the impact force concentrated on a single wheel . Attempts to apply wheels to the dustbin independently and without the use of a connecting axle, that was not made of metal material, provided completely unsatisfactory results in terms of the mandatory minimum resistance capacity required by sector regulations for the dustbin .

[0015] Disclosure of the invention

[0016] The main aim of this invention is therefore to overcome these disadvantages by proposing a dustbin wherein - while still meeting all of the performance requirements of the regulations for the sector - the wheelholder support can be sent for grinding together with the body of the dustbin without any preliminary work involving disassembly and selection of its component parts .

[0017] A further aim of this invention is to reduce the number of component parts of the dustbin, in such a way as to reduce the production costs and make the product manufacturing process less expensive .

[0018] In accordance with the invention, those aims are achieved by a dustbin with improved wheel unit , whose technical features are defined in the appended claims .

[0019] Brief description of the drawings

[0020] Further technical features and advantages of the invention will be more apparent below in this text with the description of an embodiment of the invention, nonlimiting and by way of example only, with reference to the accompanying drawings in which :

[0021] - Figure 1 is an axonometric view of a dustbin according to the invention;

[0022] - Figure 2 is an exploed3ed view of a wheel unit of the dustbin of Figure 1 ;

[0023] - Figures 3 and 4 are two axonometric views of a wheel according to the invention seen from two different viewpoints ;

[0024] - Figure 5 is an axial section of the wheel of Figures 3 and 4 ;

[0025] - Figure 6 is an axonometric view of an axle according to the invention;

[0026] - Figure 7 is an axial view of the axle of Figure 6;

[0027] - Figure 8 is an axial section, of the axle according to the plane of line A-A of Figure 7;

[0028] - Figure 9 is a partial view, in axial section, of the wheel unit of the dustbin;

[0029] - Figure 10 is a partial view of the wheel unit of Figure 9;

[0030] - Figure 11 is an axonometric partial view of the assembled dustbin and wheel unit .

[0031] Preferred embodiments of the invention

[0032] With reference to Figures 1-4 of the accompanying drawings the numeral (10) is used to label in its entirety a dustbin, made of plastic material, preferably by injection moulding.

[0033] The dustbin (10) basically comprises a container body (1) with relative lid (16) , and a wheel unit labelled (15) in its entirety.

[0034] The wheel unit (15) comprises: an axle (2) with its own geometric axis labelled (5) ; and a pair of wheels (3) , preferably with a disk (3a) , provided with a relative circumferential rim (17) and a central tubular hub (8) . A set of fins (18) (or spokes) , equally distributed around the hub (8) , monolithically connects the hub (8) and the rim (17) to each other.

[0035] The dustbin (10) further comprises interconnecting means (9) for interconnection of the wheels (3) to the axle (2) , which are integrated in the structures of the wheel (3) and of the axle (2) , where those interconnecting means (9) form a rolling support (14) , constituted of only- two component parts, in which the wheel (3) and the axle (2) are interconnected with the freedom to rotate independently relative to each other around the geometric axis (5) of the axle (2) .

[0036] The interconnecting means (9) comprise, in particular, at least one projection (6) jutting out, and projecting radially towards the geometric axis (5) shared by the axle (2) and by the wheel (3) , and a circumferential groove (7) , in which the projection (6) is engaged in a guided way with circumferential freedom of movement relative to said axis (5) .

[0037] Preferably, the projections (6) are supported by the hub (8) of the respective wheels (3) , whilst the circumferential groove (9) is borne by end stretches of the axle (2 ) .

[0038] The coupling of the projections (6) of the wheels (3) to the grooves (7) of the axle (2) is performed by means of elastic snap-in engagement, which is obtained when a stretch of the axle (2) is inserted in the corresponding hub (8) of the wheel (3) .

[0039] The projections (6) of each hub (8) have a longitudinal extent that is geometrically congruent with an arc of a circle of the groove (7) . Preferably, each projection (6) affects an arc with length substantially equal to one third of the entire circumferential extent of the groove (7) . Obviously, a number of projections (6) greater than or less than three, may be chosen partly depending on the rheological properties of the materials used to make the hub (8) and the axle (2) .

[0040] Regarding the geometric shape of the projections (6) and grooves (7) , Figures 5 to 9 show that the projection (6) has a lateral face (11a) with substantially rightangle orientation and a lateral face (12a) with substantially oblique orientation, relative to the geometric axis (5) of the axle (2) . Similarly, the groove

[0041] (7) has a lateral face (lib) with substantially rightangle orientation and a lateral face (12b) with substantially oblique orientation, relative to the geometric axis (5) of the axle (2) .

[0042] The oblique faces (12a, 12b) favour the elastic snap- in coupling of projections (6) and grooves (7) , whilst the right-angle faces (11a, 12b) in contrast favour stable retaining of the coupling in independently stable engagement conditions.

[0043] The hub (8) is also provided with an end wall (13) , suitable for acting as a front stop for the axle (2) . That end wall (13) , in combination with the projections (6) on the same hub (8) , helps to limit, as an abundant constraint, the freedom of axial translation, of said axle (2) and said wheel (3) relative to each other, already guaranteed by the connecting means (9) .

[0044] Preferably, the axle (2) is provided with an elongate tubular body (4) , with thickness variable along its length, as well as a diameter variable along its line of extension.

[0045] Prudent selection of the local thicknesses and diameters of the body (4) of the axle (2) , relative to the geometric and rheological properties of the hub (8) of the wheels (3) , advantageously allows modulation of both local and general stiffnesses and resiliencies, in order to obtain the optimum coupling conditions: for interconnection stability; for mobility of the parts moving relative to each other; as well as for the structural strength of the dustbin (10) ; all of that in complete compliance with what is required by the regulations for the sector.

[0046] Preferably, all of the component parts of the dustbin (10) and more specifically, all of the component parts of the wheel unit (15) , including a layer (19) covering the rim (17) which acts as tread, are made of plastic material.

[0047] As a consequence of that, a dustbin (10) which has reached the end of its useful life, can be sent directly for grinding, to recover and recycle the relative materials of which it is made up, without the need for any preliminary activities for disassembly and / or selection of the materials. That is undoubtedly an advantage for protection of the environment and for reducing costs, in complete compliance with the dictates of a circular economy .

[0048] Where particular unspecified situations and / or needs make it necessary to use a metal material to make the axle (2) , the features of the invention would be equally advantageous .

[0049] In fact, observing Figure 10 of the accompanying drawings, it can be seen how the disk (3a) of the wheel advantageously has several arc-shaped through slots (20) , located in a circle at the end wall (13) of the hub (8) . So, if the wheel (3) must be disassembled from the axle (2) in advance, said slots (20) may form an element for facilitated breaking of the wall (13) , whose removal then facilitates the quick release of the axle (2) from the wheel (3) with the aid of only a hammer or a small manual mallet, without the need for complex and expensive special equipment .

Claims

CLAIMS1. Dustbin comprising a container body (1) ; an axle (2) supported by the container body (1) and equipped with a geometric axis (5) ; at least one wheel (3) mounted on the axle (2) and equipped with a tubular hub (8) ; and interconnecting means (9) for interconnection of said at least one wheel (3) to the axle (2) ; said dustbin (10) being characterised in that said interconnecting means (9) are integrated in the structures of the wheel (3) and of the axle (2) , where they form a rolling support (14) wherein the wheel (3) and the axle (2) are interconnected with the freedom to rotate relative to each other around the geometric axis (5) of the axle (2) .

2. Dustbin according to claim 1, characterised in that said interconnecting means comprise at least one projection (6) jutting out, and projecting radially towards the geometric axis (5) of said axle (2) and of said wheel (3) , and a circumferential groove (7) , in which the projection (6) is engaged in a guided way with circumferential freedom of movement relative to said axis (5) .

3. Dustbin, according to claim 2, characterised in that said projection (6) is supported by the hub (8) of the wheel (3) and said circumferential groove (7) is borne by the axle (2) .

4. Dustbin according to claim 2 or 3, characterised in that said at least one projection (6) and said groove (7) are coupled to each other by means of elastic snap-in engagement triggered when a stretch of said axle (2) is inserted in said at least one hub (8) .

5. Dustbin, according to claim 2 or 3 or 4, characterised in that said at least one projection (6) has a profile congruent with an arc of a circle of said groove (7) .

6. Dustbin according to one of claims 2 to 5 characterised in that said at least one projection (6) has a lateral face (11a) with substantially right-angle orientation and a lateral face (12a) with substantially oblique orientation, relative to the geometric axis (5) of the axle (2) .

7. Dustbin, according to one of claims 2 to 6, characterised in that said groove (7) has a lateral face (lib) with substantially right-angle orientation and a lateral face (12b) with substantially oblique orientation, relative to the geometric axis (5) of the axle (2) .

8. Dustbin, according to claim 1 or 2 or 3, characterised in that the hub (8) has an end wall (13) , suitable for acting as a front stop for said axle (2) , that end wall (13) in combination with said at least one projection (6) helping to limit the freedom of axial translation of said axle (2) and of said wheel (3) relative to each other.

9. Dustbin, according to claim 1, characterised in that said axle (2) is provided with an elongate tubular body (4) , with thickness variable along its length.

10. Dustbin, according to claim 9, characterised in that the elongate body (4) of said axle (2) has a diameter variable along its line of extension.

11. Dustbin, according to claim 8, characterised in that said wheel (3) has, at a relative disk (3a) , slots (20) for facilitated breaking of said end wall (13) of the hub (8) of the wheel (3) .

12. Dustbin, according to one of the preceding claims, characterised in that said axle (2) is made of plastic material .

13. Dustbin, according to one of claims 1 to 11, characterised in that said axle (2) is made of metal material .

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