EP0330000A1 - Semi-automatic sieving apparatus for aggregates on the building site - Google Patents

Abstract

The invention relates to a sieve (X) arranged inside the mouth of a concrete mixer (Y), the upper part of the sieve resting temporarily on the rim of the mouth of the drum and benefitting from the rotation of the latter in order to perform its function. Starting from raw sand (F), the shovel loads are deposited in the descending part of the sieve, trajectory B. As the sieving function takes place in the ascending part, the sieved sand falls into the drum (D), trajectory (A), ready for use. The large aggregates roll to the lower part of the sieve, are superimposed on the following shovel load and are discharged into the wheelbarrow (E), trajectory (C). The device according to the invention, very simple to make and to use, is particularly intended for building sites of structures and of public works. Working safety is particularly effective because the sieve is integrated at 1 in the inside of the drum of the concrete mixer. <IMAGE>

Description

The present invention relates to the use of a semi-automatic device for screening aggregates on site.

Certain masonry work on site requires the sieving of sand to have a homogeneous product. The present invention makes this work less strenuous, increases its output and this with effective work safety.

Currently this work is carried out using a sieve composed of a wooden hoop surrounding a mesh and the whole is handled by hand. It is strenuous work, with a low yield and which requires several sand handling operations. For better performance, an inclined rectangular screen is used which rests on the ground but which also requires several sand handling operations. It is a bulky and fragile device, not very suitable for its transport. In both cases, two piles of sand are obtained on the ground, one sieved and the other containing the aggregates of large diameter which have not passed through the sieve. Another means is the transport of sieved sand from a sieving plant, but in most cases the quantities required on site are not sufficient to justify the costs of transport by truck.

According to the invention, the use of a semi-automatic device characterized by the temporary introduction of a cylindrical sieve inside the mouth of the rotating tank of a concrete mixer eliminates all these drawbacks. The yield is improved, a single handling with the shovel of aggregates is enough the sieved sand being found inside the concrete mixer ready for use, the large aggregates being loaded automatically in the wheelbarrow to transport them to the area of storage. The operation consists of loading the aggregates into the concrete mixer in normal use but through a sieve.

• La figure 1 représente une vue en coupe du modèle simple de tamis associé a une bétonnière traditionnelle.
• La figure 2 représente la zone d'évolution des agrégats à l'intérieur du tamis.
• La figure 3 représente toutes les phases de cheminement des agrégats pour le tamisage.

The accompanying drawings illustrate the invention:

• Figure 1 shows a sectional view of the simple model of sieve associated with a traditional concrete mixer.
• FIG. 2 represents the zone of evolution of the aggregates inside the sieve.
• FIG. 3 represents all the phases of the path of the aggregates for sieving.

The device according to the invention allows the screening of aggregates As shown in FIGS. 2 and 3 the device comprises the cylindrical screen (X) introduced into the tank of the concrete mixer (Y). The inclination of the tank is carried out at around 45 ° for optimum performance. The speed of rotation of the tank being that of its normal use which is between 25 and 30 rpm. The assembly rotates in the direction of the arrow (I). Starting from the pile of raw sand (F) and following the trajectory (B) we load the sieve (X) by depositing the shovels of raw sand to be sieved in the region (G) of the sieve. This sand then occupies the area (H) therefore the grains of sand of caliber smaller than the mesh of the mesh pass through and fall into the tank of the concrete mixer along the path (A). The aggregates with a diameter greater than the mesh of the mesh roll up to the lower part of the sieve, superimposed on the next shovel, and pour into the wheelbarrow (E) following the path (C).

The device shown in Figure 1 includes the screen (X) composed of a rigid cylindrical body with in its lower internal part and fixed thereto the sieving fabric composed of a mesh. The sieve is incorporated entirely inside the tank. It has a working surface equal to the surface of the mouth of the concrete mixer (Y). This sieve will be economical, simple in shape, without fixing because the friction force of the rolled edge of the sieve on the rolled edge of the mouth of the concrete mixer is sufficient to avoid any slipping. The center of gravity of the sieve, empty or loaded, located inside and below its lift surface prevents it from tipping over.

This sieve is reserved particularly for traditional concrete mixers for mason craftsmen and masonry enthusiasts.

The device according to the invention highlights the advantages of this sieve: easy and rapid implementation of the assembly, sieving of aggregates just in the quantity required, a single manipulation of the sand with a shovel is sufficient, therefore saving of time, of trouble, of aggregates. All while having maximum job security due to its integration and the absence of projecting parts.

The device, object of the invention, can be used in all cases where sorting of aggregates is required.

Claims (2)

1. A semi-automatic sieving device for aggregates on site, characterized in that the sieving part of the sieve (X) has a diameter equal to the diameter of the mouth of the concrete mixer tank (Y). 2. Device according to claim 1 characterized in that the cylindrical body of the screen (X) is temporarily incorporated inside the mouth of the concrete mixer tank (Y).

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