EP0012676B1 - Machine for externally coating objects such as tubes, particularly with concrete - Google Patents

Description

The present invention relates to a machine for coating externally with concrete, parts such as pipes.

The invention applies more particularly to the manufacture of concrete pipes and in particular to the installation of an external coating ensuring the protection of the turns of the hooped pipes.

FR-E-63.001 notably discloses an installation in which the pipe to be coated is supported externally by rotating rollers and situated exactly in line with the outlet orifice of a hopper comprising a vibrating comb. Besides the fact that the rolling areas of the pipe on the rollers cannot be coated with concrete, the fins of the vibrating comb are short and the vibration time of the layer of concrete leaving the hopper is quite short if you want maintain sufficient performance. In another installation known and disclosed by the. FR-E-56.173 or else a wedge-shaped throttle is formed at the exit of the hopper between an oblique wall and the part to be coated, but this throttle is not located above the part to be coated and the benefit the support of the coating material by the part itself is thus lost, or else when the outlet opening of the hopper opens above the part to be coated, the lower front wall of the hopper no longer extends obliquely above said piece so as to form a wedge-shaped space as before.

Thus, according to the techniques currently used, the concrete is poured at the base of a hopper onto a pipe to be coated rotating slowly above it, the concrete being vibrated during its passage through a short area of vibration at the outlet of the hopper, However, we know that, to obtain a good compactness of concrete, it is important to vibrate it for a minimum period of time whose duration is notably a function of the frequency and amplitude of the vibrations. Since, on conventional devices, the vibrating zone is relatively narrow and the vibrations are carried out in an anarchic way, it is necessary to slow down the rotation of the pipe to be coated and to reduce the exit section of the hopper so that the concrete is vibrated long enough. This results in disproportionately long manufacturing times and a noticeable slowdown in production simply because of this simple operation.

US-A-3,036,931 and US-E-1 8,334 are also known in the prior art.

US-A-3,036,931 describes an apparatus for coating, in particular with concrete, the outer part of a cylindrical part like a pipe.

According to this US patent, the product to be applied to the cylindrical part is conveyed by a plurality of conveyor belts from a hopper. The means used do not ensure direct application from the hopper. Different motors are required to drive the conveyor belts and the cost of the device is therefore relatively high.

The patent US-E-18,334 describes an apparatus for coating with several layers the periphery of a cylindrical part. This device comprises a hopper provided with several compartments, an applicator in the form of a roller and a smoothing means. The products spilled from the hopper do not receive vibrations and are simply deposited on the cylindrical part. There is therefore no provision for compaction of the product at the time of its application.

The object of the present invention is therefore to propose a machine for externally coating, with concrete, parts such as pipes, which allows the operation time to be reduced considerably while nevertheless ensuring excellent compactness for the concrete of the coating.

According to the invention, the machine for externally coating, with concrete, tubular pieces of revolution such as pipes, comprises at least two rotating supports intended to support the piece at its ends and to drive it in rotation on itself , a coating product storage hopper having an outlet opening which opens above the space reserved for the part and a bottom wall which extends above said location and vibrating members arranged in the opening outlet of the hopper in the vicinity of the part to be coated, said rotary supports being coaxial rotary drums displaceable in relation to each other and arranged so as to be able to penetrate into the bore of the part tubular to support it, while the outlet opening of the hopper is offset behind the vertical plane passing through the common axis of the drums considering the direction of rotation of these and that the bottom wall of the hopper is inclined e obliquely above the location of the part so as to delimit with it a cross-sectional space in the form of a corner directed in the direction of rotation.

The vibrating members located at the outlet of the hopper may be juxtaposed fins or teeth of triangular shape known per se arranged so as to substantially match a cross-section in the form of a corner of the space delimited between the oblique wall of the hopper and the part to be coated, said fins or teeth vibrating in synchronism parallel to the axis of the drums.

Alternatively, the vibrating members can also be constituted by vibrating needles known per se juxtaposed along the part to be coated, in the space with a wedge-shaped section overcoming it.

Preferably, at the tip of the spout of the hopper is provided an adjustable smoother articulated on the hopper.

The proposed solution essentially consists in combining the effects of organized vibrations developing in a preferred direction and the compaction of the coating material which is literally extruded through an outlet conduit whose section is narrowing.

Finally, so that the covering material is supported longer in a substantially horizontal plane and allows better attachment to the tubular part to be coated, it is planned to deposit said material on the tubular part behind the vertical plane passing through its axis of horizontal rotation.

All of these characteristics, added to the fact that, according to the invention, it is intended to support the tubular part from the inside, makes it possible to obtain a homogeneous coating over the entire extent of the peripheral surface of the part to be put on.

• Fig. 1 représente une coupe transversale de la machine selon l'invention;
• Fig. 2 représente une coupe longitudinale de la machine de la figure 1.

The invention will now be described in more detail with reference to a particular embodiment cited by way of nonlimiting example and represented by the appended drawings in which:

• Fig. 1 shows a cross section of the machine according to the invention;
• Fig. 2 represents a longitudinal section of the machine of FIG. 1.

As shown in the figures, the machine comprises a fixed frame 1 and a movable frame 2 mounted on a slide 3 so that it can be moved away from or close to the fixed frame, the two frames supporting coaxially rotary drums 4 and 5, driven in rotation by drive means housed in said frames. The machine further comprises a hopper 6 supported laterally by lateral frames 7 and 8 adjustable in height above the location between the two frames 1 and 2, the outlet of the hopper being a slot 9 of section adjustable by means , for example, of an articulated or sliding shutter, said slot being open at the lower part of the hopper and extending longitudinally, parallel to the axis of rotation of the drums 4 and 5, slightly behind the vertical plane passing through said axis considering the direction of rotation of the drums (clockwise in Figure 1).

A lower wall (10) of the hopper located forward in the direction of rotation of the drums has a projection or extension in the form of a beak, extending obliquely above the axis of the drums 4 and 5, so to be delimited with the part to be coated which, in this case is a hooped concrete pipe 11, a wedge-shaped space the point of which is directed in the direction of rotation of the pipe. In said space is housed a vibrating comb 12 essentially constituted by a rear plate 13, supporting several juxtaposed teeth 14, of triangular shape, substantially matching a cross section of the wedge space between the pipe 11 and the sheet metal spout of the hopper. The comb 12 has at its ends pins 15 and 16 mounted sliding along their axis in bearings formed in the wall of the lower part of the hopper, the pin 16 being connected to the rod of a vibrating hydraulic cylinder 17 secured to the frame fixed 1.

At the tip of the spout 10 is provided a smoother 18 placed following the extension of the front wall of the hopper 6, this smoother being supported at an adjustable height above the pipe 11 by means of articulated support arms 19 at 20 on said front wall of the hopper.

• La trémie 6 étant relevée en position haute pour dégager les abords des bâtis, le tuyau 11 à revêtir extérieurement est amené par un engin de manutention quelconque entre le bâti fixe 1 et le bâti déplaçable 2 préalablement écarté du bâti fixe par un glissement arrière sur la glissière 3. Le tuyau 11 étant mis en place sous la fente de sortie 9 de la trémie 6, le bâti 2 est rapproché du bâti 1 de telle sorte que le tuyau 11 repose librement sur les deux tambours 4 et 5 pénétrant à l'intérieur de celui-ci à chacune dé ses extrémités. La trémie est ensuite abaissée à proximité du tuyau et les tambours 4 et 5 sont entraînés en rotation, ce qui provoque la rotation dans le même sens du tuyau 11, tandis que la fente de sortie de la trémie est ouverte et laisse couler le béton 21 stocké dans celle-ci, ledit béton s'étalant en une couche superficielle 22 sur la surface extérieure de la paroi du tuyau 11. Au fur et à mesure de son écoulement à la sortie de la trémie, le béton emplit l'espace en coin placé sous le bec 10 où il est soumis à des vibrations parallèlement à l'axe du tuyau. Les effets combinés des vibrations et de la compression radiale auquel il est soumis du fait de la réduction de la hauteur de passage sous la tôle du bec 10 de la trémie améliore très sensiblement la compacité du béton ainsi que l'accrochage sur le tuyau de la couche de revêtement.

The machine according to the invention operates as follows:

• The hopper 6 being raised in the high position to clear the surroundings of the frames, the pipe 11 to be coated externally is brought by any handling device between the fixed frame 1 and the movable frame 2 previously spaced from the fixed frame by a rear sliding on the slide 3. The pipe 11 being placed under the outlet slot 9 of the hopper 6, the frame 2 is brought closer to the frame 1 so that the pipe 11 rests freely on the two drums 4 and 5 penetrating inside of it at each of its ends. The hopper is then lowered near the pipe and the drums 4 and 5 are rotated, which causes the rotation of the pipe 11 in the same direction, while the outlet slot of the hopper is open and lets the concrete flow 21 stored therein, said concrete spreading in a surface layer 22 on the outer surface of the wall of the pipe 11. As it flows out of the hopper, the concrete fills the corner space placed under the spout 10 where it is subjected to vibrations parallel to the axis of the pipe. The combined effects of the vibrations and the radial compression to which it is subjected due to the reduction in the passage height under the sheet metal of the spout 10 of the hopper very significantly improves the compactness of the concrete as well as the attachment to the pipe of the coating layer.

On leaving the spout 10 of the hopper, the compacted concrete layer finally passes under the height-adjustable smoother 18 which laminates it to the desired thickness and smoothes its outer surface.

In addition to improving the compactness and the attachment of the coating to the pipe, the invention offers various other important advantages such as the fact that the hopper is no longer subjected to vibrations as in conventional machines, which increases its duration, the fact that thanks to the use of a vibrating jack, the vibrations no longer develop in an anarchic way in all directions but are on the contrary ordered and oriented all in the same direction where they add their effects and allow a high quality smoothing leading to a better exterior finish of the coating, the fair that, still thanks to the vibrating jack, the sound level is very attenuated and a precise control of the amplitude and the frequency of the vibrations is possible, these being adjustable according to the nature of the concrete to be vibrated, etc ...

Finally, and above all, the extension of the vibrating zone due to the addition of the spout 10 which the concrete leaving the slot 9 of the hopper must pass through increases the time during which the concrete is vibrated compared to conventional machines, which , with equal compaction and quality of coating, makes it possible to increase the speed of rotation of the pipe and consequently the efficiency of the machine.

Of course, the scope of the invention is not limited to the single embodiment described above by way of nonlimiting example, but it also covers any variant which would differ only in details.

Thus it is possible to replace the comb 12 and the vibrating hydraulic cylinder 17 by conventional vibrating needles juxtaposed along the pipe to be coated; this solution no longer offers the advantages arising from a unidirectional vibration, but it is more economical.

Claims (3)

1. Machine for externally coating with concrete tubular parts of revolution such as tubes (11), the said machine comprising at least two rotating supports (4, 5) adapted to support the part (11) at its end and drive it rotationally about itself, a storage hopper (6) for the concrete having an outlet orifice (9) which opens above the location provided for the part (11) and a lower wall (10) which extends above the said location and vibrating members (12, 13, 14) disposed in the outlet orifice (9) of the hopper (6) in the vicinity of the part (11) to be coated, characterized in that the supports are coaxial rotary drums (4, 5) displaceable along a common axis relative to each other, in that the said drums are disposed so as to penetrate inside the bore of the tubular part (11) to support it, in that the outlet orifice (9) of the hopper (6) is rearwardly offset from the vertical plane passing through the common axis of the drums (4, 5) taking into consideration the direction of rotation thereof, and in that the lower wall (10) of the hopper (6) is obliquely inclined above the location of the part (11) so as to delimit therewith a space having a transverse cross section in the shape of a wedge directed in the direction of rotation.

2. Machine according to claim 1, characterized in that the vibrating members located at the outlet of the hopper (6) are juxtaposed fins or teeth (14) of triangular shape, known per se, disposed so as to substantially embrace a wedge-shaped cross section of the space delimited between the oblique wall (10) of the hopper (6) and the part (11) to coated, the said fins or teeth (14) vibrating parallel to the axis of the drums (4, 5).

3. Machine according to claim 1, characterized in that the vibrating members essentially comprise vibrating needles, known per se, juxtaposed along the part (11) to be coated, in the space having a wedge-shaped section surmounting the same.

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