Post device formed from a mouldable material

Abstract

The invention relates to a method for manufacturing a post device (10) comprising a tubular plastic element (1) and a post (2) formed from a mouldable material and arranged in the tubular plastic element (1), this method comprising a step of pressure injection moulding the mouldable material into the tubular element (1), wherein the tubular element (1) is arranged, during the pressure injection moulding step, in a direction inclined relative to a horizontal plane (21).

Description

Moldable material pole device

[0001] The present invention relates to posts made of moldable material, such as concrete, encased in a plastic tube, particularly a thermoplastic tube. It also relates to methods and systems for manufacturing such posts.

[0002] Such poles are commonly used in various applications, including but not limited to lamppost bases, flagpoles, signposts, streetlights, traffic signs, power line pylons, fence posts, and candelabras. The use of plastic tubing, most often PVC, allows for slender poles and provides a protective coating against corrosion, enhancing the safety and longevity of the concrete pole. The PVC tubing acts as a barrier between the concrete and external elements, such as water and chemicals, which could otherwise cause corrosion and reduce its lifespan.

[0003] These poles are made by pouring concrete into a cylindrical or truncated conical plastic tube. The plastic tube can have a constant or variable cross-section (decreasing from the base to the top of the pole), and its interior serves as a mold. Methods and systems for hot-forming a tube with a variable cross-section from a tube with a constant cross-section made of thermoplastic material are known in the prior art. The concrete pole is most often reinforced with metal rebar. If necessary, a conduit (a hollow tube) can be provided inside the concrete pole to run a power cable, for example.

[0004] The posts are then transported, often horizontally or at a slight angle, to the installation site to be driven vertically into the ground or a base. A load can be attached to the post. In its various applications, the post is located outdoors, exposed to the elements.

[0005] Throughout all these phases, the structural integrity of the pole is constantly tested. Shocks during handling, accelerations / shocks during transport, vibrations (especially repeated ones), or expansion / contraction of the plastic tube can weaken, or even detach / break, the bond between the concrete core and its plastic casing, at least in some places. The slightest break in the bond between the concrete core and the plastic tube can cause vibrations and noise, especially when the pole is supporting a load (such as a flag or a sign), thus amplifying this phenomenon. This results in premature wear that compromises the integrity of the pole.

[0006] These risks are considerably exacerbated when voids or air pockets remain in the concrete core, or at the interface between this core and the plastic tube. Similarly, uneven or inhomogeneous filling of the plastic tube, whether in density or continuity, compromises the overall structural integrity. Such manufacturing defects, often difficult to avoid with currently known processes and systems, represent points of weakness that can permanently compromise the column, particularly under mechanical stress or environmental conditions.

[0007] These defects are more likely when the plastic tube is long (typically 4 meters or more) and / or has a variable cross-section (for example, decreasing from the base to the top of the post). Indeed, current manufacturing processes for this type of post do not always guarantee homogeneous and perfectly compact filling of the tube, particularly along its entire length.

[0008] It is known in the prior art to use a chemical bonding agent to promote the adhesion of concrete to the inner surface of the plastic tube. However, besides being expensive, this solution presents several risks, resulting, for example, from an insufficient quantity of the agent, inconsistent distribution of the agent in the concrete in contact with the inner surface of the plastic coating, loss of agent effectiveness due to environmental factors (temperature or UV rays from the sun, for example), or load borne by the pole. Furthermore, such a chemical bond may lack flexibility, making it brittle and susceptible to repeated vibrations, and therefore prone to cracking.

[0009] One object of the present invention is to remedy the aforementioned drawbacks.

[0010] Another object of the present invention is to improve the lifespan and mechanical reliability of a moldable material post encased in a plastic tube.

[0011] To this end, it is proposed, firstly, a method for manufacturing a post device comprising a tubular plastic element, a post made of moldable material in said tubular plastic element, this method comprising a step of molding the post made of moldable material in the tubular element, this method comprising a step of pressure injection molding of the moldable material in the tubular element, the tubular element being arranged, during the pressure injection molding step, in a direction inclined with respect to a horizontal plane.

[0012] Various additional features may be provided, alone or in combination: - the tubular element arranged in an inclined direction extends longitudinally between a lower end and an upper end, the moldable material being injected under pressure through the lower end of the tubular element; - the tubular element forms an angle of inclination with the horizontal plane of between 30 degrees and 60 degrees or between 40 degrees and 50 degrees or substantially equal to 45 degrees.

[0013] Secondly, a post device is proposed comprising a tubular plastic element, a post made of moldable material in said tubular plastic element, this post device being manufactured according to the process presented above.

[0014] Various additional features may be provided, alone or in combination: - an inner face of the tubular element intended to be in contact with the moldable material post includes at least one protruding relief element and / or one recessed relief element; - the relief element includes at least one helical thread; - the tubular element is of frustoconical shape or of variable cross-section; - the tubular element has a longitudinal length greater than or equal to 4 meters.

[0015] Thirdly, a system for manufacturing a pole device is proposed, comprising a tubular plastic element, a pole made of moldable material in said tubular plastic element, this system integrating a pressure injection machine for injecting the moldable material in its fresh state into the tubular element, an injection ramp allowing the tubular element to be held in support during the pressure injection of the moldable material in its fresh state into this tubular element, in an arrangement inclined relative to a horizontal plane.

[0016] In one embodiment, the injection ramp forms an angle of inclination with the horizontal plane of between 30 degrees and 60 degrees or between 40 degrees and 50 degrees or substantially equal to 45 degrees.

[0017] Other features and advantages of the invention will become clearer and more concrete upon reading the following description of embodiments, which is made with reference to the accompanying drawings in which:

[0018] The figure schematically illustrates in perspective a post device with a part cut out according to various embodiments;

[0019] the figure schematically illustrates in perspective a tubular element with a part cut out according to various embodiments;

[0020] The figure schematically illustrates the steps in a manufacturing process for a post device according to various embodiments;

[0021] The figure schematically illustrates elements of a manufacturing system for a post device according to various embodiments.

[0022] With reference to the figure shown, a pole device 10 comprises a tubular plastic element 1 wrapping or encasing a moldable (i.e., moldable) pole 2 molded into the tubular element 1. The pole device 10 extends longitudinally between a first end or base intended to be fixed in the ground or, more generally, in a baseplate, and a second end or top intended to be free or to support a load (such as a flag, a lighting device, or a sign).

[0023] The tubular plastic element 1 is a hollow part forming a protective outer casing for the moldable material post 2. This tubular element 1, inside which the moldable material post 2 is molded, is, in particular, a tube made of thermoplastic material such as PVC, polypropylene, or polyethylene. In one embodiment, the tubular element 1 is preferably made of rigid PVC stabilized against ultraviolet radiation and chemical agents. In other words, the tubular element 1 includes, in one embodiment, fillers that stabilize it against light and are resistant to chemical agents. The outer surface of the tubular element 1 is preferably smooth and glossy for better weather resistance.

[0024] The tubular element1 can have any suitable cross-section, such as a circular or polygonal section. In the example shown in the attached figures, the cross-section of the tubular element1 is circular, but this embodiment is not limiting; other profiles with hexagonal or, more generally, polygonal cross-sections are also possible.

[0025] In one embodiment, the tubular element1 is cylindrical in shape, in other words, of constant cross-section.

[0026] In another embodiment, the tubular element1 is frustoconical in shape or, more generally, has a variable cross-section. The cross-section of the tubular element1 can, in fact, vary along the length of the column assembly10, for example, decreasing (or strictly decreasing) between a larger cross-section at the base of the column assembly10 and a smaller cross-section at the top of the column assembly10. Advantageously, such a shape of the tubular element1 allows for more slender columns and provides them with greater stability.

[0027] The pole device10 has a length, measured along its longitudinal axis, greater than or equal to 4 meters.

[0028] The tubular plastic element 1 has an inner face 11 intended to be in contact with the moldable material post 2. This inner face 11 includes at least one relief element 12. A "relief element" is defined as a protruding and / or recessed relief element present on the inner face 11 of the tubular element 1. A recessed relief element 12 refers to any depression, concavity, indentation, groove, or channel present on the inner face 11 of the tubular element 1. A protruding relief element 12 refers to any elevation, convexity, or protrusion present on the inner face 11 of the tubular element 1. More generally, a protruding or recessed relief element 12 refers, in this context, to any local deformation where a portion of the inner face 11 of the tubular element 1 extends above or below the surrounding level of that inner face 11.A relief element12 thus forms an exception (in projection or in depression) to the uniform character of the inner face11 of the tubular element1.

[0029] In one embodiment, the relief element 12 comprises a rib, a helical groove (a rib or protrusion that follows a spiral or helical path around the longitudinal axis of the tubular element 1, as illustrated in Figure 1), a clamp, an indentation, a pattern, or a helical groove. A plurality of projecting and / or recessed relief elements 12 may be envisaged. A projecting relief element 12 advantageously avoids local thinning of the tubular element 1. A recessed relief element 12 advantageously saves material and thus reduces the weight and manufacturing cost of the tubular element 1.

[0030] In one embodiment, a relief element 12 comprises a first portion extending in a first direction and a second portion extending in a second direction different from the first (for example, a first longitudinal direction and a second transverse direction of the tubular element 1). In another embodiment, the inner face 11 comprises at least one first relief element 12 and a second relief element 12 that intersect or, more generally, a first and second relief element 12 that are not parallel. The inner face 11 of the tubular element 1 is, in one embodiment, grooved or fluted, that is, decorated with inward / outward flutes. In another embodiment, the inner face 11 of the tubular element comprises a plurality of helical fillets or a plurality of ribs centered on the longitudinal axis of the tubular element 1.

[0031] The tubular element 1 can be obtained, for example, by extrusion or injection molding of thermoplastic materials. In one embodiment, the tubular element 1 comprises a rigid outer sleeve and a flexible inner sleeve having at least one raised element 12. In another embodiment, the tubular element 1 is formed of a rigid PVC outer sleeve and a plasticized PVC inner sleeve having raised elements 12 on its inner face, in particular helical threads.

[0032] The moldable column 2 is, in one embodiment, made of concrete or any other similar material that can be molded into the tubular element 1. It should be noted that the term "concrete" here encompasses any material suitable for the same function, namely a cementitious material or a moldable material suitable for forming a column, such as heavyweight concrete, lightweight concrete with or without the addition of a bonding agent or fibrous material, or a moldable synthetic material. A predefined concrete mix of cement, fine sand, and water is preferably adapted for the production of reinforced concrete. For example, a concrete mix comprising one part cement, two to four parts fine sand, and one-third water can be used. A metallic reinforcement 3, comprising longitudinal and / or transverse reinforcing wires, advantageously strengthens the moldable column 2 (reinforced concrete).

[0033] The moldable material is poured or injected into the tubular element 1 (serving as a mold) where it is left to harden (solidify) in order to form the moldable post 2. In one embodiment, a conduit 4 is provided in the post device 10. The latter can thus be solid or hollow.

[0034] A raised element 12 on the inner face 11 of the tubular element 1 advantageously increases the contact area between the tubular element 1 and the moldable material post 2. This results in an improved bond between the tubular element 1 and the moldable material post 2. A raised or recessed element 12 acts as a locking or securing device, giving a monolithic effect to the assembly formed by the tubular element 1 and the moldable material post 2.

[0035] A combination of protruding and recessed relief elements on the inner face of the tubular element limits the relative movements between the tubular element and the moldable material post, thereby reinforcing the monolithic appearance of the post assembly. Additionally, non-parallel relief elements, or relief elements extending in at least two different directions, work together to limit the degrees of freedom of the tubular element and the moldable material post relative to each other. This advantageously results in a moldable material post that is integrally bonded to the tubular element.

[0036] The presence of raised or recessed relief elements 12 on the inner face 11 of the tubular element 1 advantageously prevents the propagation of any gaps or air pockets that might form between the tubular element 1 and the moldable material post 2.

[0037] A monobloc column assembly 10 advantageously avoids vibrations, formwork removal (even localized), and / or slippage of the tubular element 1 relative to the moldable column 2, and vice versa. This results in reduced wear on the column assembly 10 and any noise that may be its source.

[0038] Referring to the figure, a manufacturing method for the pole device 10 comprises, in one embodiment, a step of arranging a metal reinforcement 3 within the tubular element 1, substantially centered on the longitudinal axis of the tubular element 1. The tubular element 1 is, for example, of variable cross-section, in particular frustoconical, the inner face 11 of which has at least one raised or recessed relief element 12. Such a tubular element 1 is, in one embodiment, hot-formed from a tubular blank made of thermoplastic material (in particular, PVC) of constant cross-section, having on its inner face 11 at least one relief element 12 such as a protrusion or a helical groove.

[0039] During a molding step 31 of the column 2 in moldable material within the tubular element 1, a moldable material, in particular concrete, is injected under pressure into the tubular element 1. This pressure injection molding step 31 uses an injection machine 40 for injecting the moldable material in its fresh state (i.e., still sufficiently fluid to be injected into the tubular element before it begins to set or harden). Preferably, the injection machine 40 is equipped with a device for regulating the injection pressure and / or the flow rate of the injected moldable material. In one embodiment, the injection machine 40 is a mixer-sprayer for a pumpable, fresh moldable material.

[0040] As illustrated in the figure, the tubular element1 is positioned, during the pressure injection molding step31, in a direction inclined relative to a horizontal plane21. In other words, the tubular element1 is oriented, during the pressure injection molding step31, along an axis inclined relative to the horizontal plane21. The longitudinal axis of the tubular element1 thus forms a non-zero angle of inclination with the horizontal plane21. For example, the tubular element1 forms an angle A with the horizontal plane21 of between 20 degrees and 70 degrees or, preferably, between 30 degrees and 60 degrees, or between 40 degrees and 50 degrees, or approximately equal to 45 degrees.

[0041] In one embodiment, the tubular element 1 is supported, during the pressure injection molding step 31, by an injection ramp 20. This injection ramp 20 allows the tubular element 1 to be held in support during the pressure injection of the fresh moldable material into this tubular element 1, in an inclined position relative to the horizontal plane 21.

[0042] The injection ramp 20 serves as a support for the tubular element 1, which it holds in an inclined position relative to the horizontal plane 21. The bearing surface of the injection ramp 21 is preferably smooth, so as not to damage the tubular element 1. Fastening means, preferably shaped to at least partially conform to the external form of the tubular element 1—that is, having a geometry complementary to that of the element—are provided to fix the tubular element 1, particularly a frustoconical one, to the injection ramp 20. These fastening means ensure stable and reliable support of the tubular element 1, at least during the molding stage, while preventing any deformation, marking, or alteration, so as to preserve a smooth, regular (or uniform), and glossy external surface. In one embodiment, the fastening means are PVC shims.The post device 10 is preferably kept on the injection ramp 20 during the hardening of the moldable material molded in the tubular element 1.

[0043] An inclined (or oblique) arrangement of the tubular element 1, i.e. according to a distinct orientation of the vertical and horizontal axes, on the injection ramp 20 advantageously avoids deformation of the tubular element such as ovalization or swelling, particularly when the tubular element 1 has a significant longitudinal length (for example, greater than or equal to 4 meters) and / or when the tubular element 1 is frustoconical in shape or has a variable cross-section.The tests carried out by the applicant have demonstrated that such an oblique arrangement, in particular at an angle A between 30 degrees and 60 degrees, preferably between 40 degrees and 50 degrees, or ideally substantially equal to 45 degrees with respect to the horizontal plane21, also makes it possible to avoid the formation of air pockets as well as the segregation of the moldable material, i.e. the non-homogeneous accumulation of granules or laitance in a localized area of ​​the tubular element, which could compromise the structural integrity of the core.It follows that the moldable material is densely and homogeneously compacted, so that it perfectly conforms to the inner surface of the tubular element 1 along its entire length (including, in particular, any raised elements 12), thus ensuring firm and continuous contact across this entire surface, without risk of deformation or alteration (e.g., ovalization or swelling) of the apparent external shape of the tubular element 1. Once the moldable material has hardened within the tubular element 1 for a predetermined drying time, the result is advantageously a post 2 made of moldable material intimately bonded to the tubular element 1, so as to form together a compact and coherent whole, capable of preserving the initial shape of the tubular element 1, particularly when it is conical in shape.

[0044] The tubular element 1, positioned at an angle to the horizontal plane 21, extends longitudinally between a lower end (located at the bottom) and an upper end (located at the top). When the tubular element 1 is conical or, more generally, has a variable cross-section, its cross-section at its lower end is larger than its cross-section at its upper end. The moldable material is injected under pressure through the lower end of the tubular element 1, that is, from the bottom of the tubular element 1. This injection method ensures better compaction of the formed core, while guaranteeing that the moldable material remains firmly in contact with the inner surface of the tubular element 1. This prevents the formation of air pockets or any gaps between the tubular element 1 and the moldable material post 2.

[0045] The result is, advantageously, a post device10 that meets the most demanding specifications in terms of integrity and rigidity.

Claims

Method of manufacturing a pole device (10) comprising a tubular plastic element (1), a pole (2) of moldable material in said tubular plastic element (1), this method comprising a step of molding the pole (2) of moldable material in the tubular element (1), this method being characterized in that it comprises a molding step (31) by pressure injection of the moldable material in the tubular element (1), the tubular element (1) being disposed, during the molding step (31) by pressure injection, in a direction inclined with respect to a horizontal plane (21). Manufacturing method according to the preceding claim, characterized in that the tubular element (1) arranged in an inclined direction extends longitudinally between a lower end and an upper end, the moldable material being injected under pressure through the lower end of the tubular element (1). Manufacturing method according to the preceding claim, characterized in that the tubular element (1) forms an angle of inclination with the horizontal plane (21) between 30 degrees and 60 degrees or between 40 degrees and 50 degrees or substantially equal to 45 degrees. Pole device (10) comprising a tubular plastic element (1), a pole (2) made of moldable material in said tubular plastic element (1), this pole device (10) being manufactured according to the process of any one of the preceding claims. Post device (10) according to the preceding claim, characterized in that an inner face (11) of the tubular element (1) intended to be in contact with the moldable material post (2) comprises at least one protruding relief element (12) and / or a recessed relief element. Post device (10) according to claim 4 or 5, characterized in that the relief element (12) comprises at least one helical thread. Pole device (10) according to any one of claims 4 to 7, characterized in that the tubular element (1) is frustoconical in shape or has a variable cross-section. Pole device (10) according to any one of claims 4 to 9, characterized in that the tubular element (1) has a longitudinal length greater than or equal to 4 meters. A manufacturing system for a pole device (10) comprising a tubular plastic element (1), a pole (2) made of moldable material in said tubular plastic element (1), this system being characterized in that it integrates a pressure injection machine (40) for injecting the moldable material in its fresh state into the tubular element (1), an injection ramp for maintaining the tubular element (1) in support, during the pressure injection of the moldable material in its fresh state into this tubular element (1), in an arrangement inclined with respect to a horizontal plane (21). Manufacturing system according to the preceding claim, characterized in that the injection ramp (20) forms an angle of inclination with the horizontal plane (21) between 30 degrees and 60 degrees or between 40 degrees and 50 degrees or substantially equal to 45 degrees.

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