The invention relates to a device for conveying grains, in particular to a device for conveying seed grains individually using a moving device which is part of a machine for precision sowing.

State of the Art

State of the art machines for accurate sowing contain a device for individual seed metering. The means for individual seeding may be in the form of a drum, disc, or similar rotating geometrical equipment with a perforated surface. Different air pressures on either side of the perforated surface cause the seeds to be caught. Seeds are held to the perforations in the direction of the air pressure gradient.

There are various means for conveying seed grains for individual sowing. The most advanced solution is the fluidized bed shown in Patent Document EP 1754406. The device there described has the disadvantage that the seed is thrown directly against the metering unit and there is great turbulence and throw back of seed from the metering unit. Another disadvantage is that the movement of grains towards the metering unit is disorderly and does not lead to synchronised individual metering of the seeds or to a significantly reduced difference between the speed of various seeds and the rate of the metering unit, resulting in inferior adhesion of the seeds to the metering unit.

Another device for conveying grain seed for individual sowing is shown in Patent Document DE 10140773. This device also does not lead to synchronisation of speed between the seeds and the metering unit, which also results in inferior adhesion of the seeds to the metering unit.

From the above mentioned state of the art technology, it is obvious that the main disadvantage is that there is no device existent which demonstrates regulation of the movement of seeds towards the metering unit or which at least partially equalises the speed of seeds and the peripheral speed of the metering unit.

The aim of the invention is the construction of a device which will be able to create an orderly movement of seed grains towards the metering unit, so that there will be a partial or full synchronisation of the velocity of seed grains and the peripheral speed of the metering unit.

Principle of the invention

The mentioned deficiencies are to a large part removed and the aim of the invention is fulfilled by a device for conveying grains, especially for conveying seed grains to a moving metering unit, according to the invention characterized in that it comprises of at least one injector arranged to create an orderly movement of the grain, which includes an air jet, a mixing area, and a diffuser. The air jet, mixing area, and diffuser are advantageously arranged along a common axis. The metering device may be, for example a drum, disc, or belt.

It is advantageous that the injector is arranged approximately tangent to the metering device. This significantly increases the success rate of positioning of the grains on the body of the metering unit.

It is further advantageous that the injector has an output speed approximately the same as the peripheral speed of the metering unit, and in the most advantageous arrangement, the device further includes a mean for controlling the amount of air supplied to the injector, synchronising the speed of the grains with the peripheral speed of the metering unit. This significantly increases the success rate of grain positioning on the body of the metering unit. The aforesaid again increases and at the time stabilises the successful placement of individual grains on the body of the metering unit.

It is advantageous that the injector and mixing area are joined by an antechamber, which is connected to a hopper and an area of suspension. This enables firstly individual grains to be guided to the metering unit and secondly, in the case of failed delivery of a grain to the metering unit, its return to the injector.

The hopper is connected to a source of pressurized air, which is most advantageously a fan.

The air jet is connected to another source of pressurized air, which is most advantageously a fan.

To advantage, the injector is circular or elliptical or oval or square or rectangular in cross-section. According to the invention, the advantage of the device for conveying grains is that the difference between the speed of the grain and the peripheral speed of the metering unit is completely equalised or is at least considerably reduced, while there is significantly better adhesion of the grains to the metering unit. Another advantage is that, by gravity, grain which does not adhere to the metering unit falls back into the antechamber of the injector, where it is again thrown in a tangential direction to the metering unit. Thus, additional equipment to circulate the seeds is not needed.

Overview of the Figures

The invention will be further elucidated using drawings, in which Fig.1 illustrates the device for conveying grains in a schematic side sectional view and Figu. 2 is an axonometric view with a semi sectional view of the general arrangement of the apparatus for conveying grain.

Example of the Performance of the Invention

The device (Fig. 1 , Fig. 2) for conveying seed grains 2 to the moving device with a metering unit 4, is a vacuum drum 3 with peripherally positioned openings 5 for receiving seed grains 2, contains a number of injectors1 to keep the grains airborne.

The injectors are circular or elliptical or oval or square or rectangular in cross- section.

The injectors 1 are positioned approximately tangent to the metering unit 4, with an output rate of grain 2 approximately equal to the peripheral speed of the metering unit 4.

The device for conveying seed grains further comprises a mean not shown for regulating the amount of air supplied to the injectors 1_, which equalizes the speed of the grains 2 with the peripheral speed of the metering unit 4.

Individual injectors 1 contain an air jet 8, mixing area 12, and diffuser 13.

The mixing area 12 is connected to the antechamber 14, which is joined to the hopper 7 and an area 16 of suspension.

The hopper 7 is connected to the source 6 of pressurized air, which is a fan. . The air jet 8 is connected to an additional source 10 of pressurized air, which is a fan.

The device for conveying seed grains 2 to the moving metering unit 4 further includes an instrument 15 for removing double seed grains 2.

The device for conveying seed grains 2 works so that individual grains 2 fall by gravity from the hopper 7 to the air jet 8, where they are accelerated by a current of air from another source 10 of pressurized air, against the direction of gravity tangent to the circumference of the metering unit 4. In this way the accelerated and streamlined grain 2 has the speed and direction of movement the same as or very close to the direction and peripheral 9 speed of the metering unit 4, which is easily accepted by perimeter openings 5 positioned on the vacuum drum 3 of the metering unit 4.

The speed of movement of the seed grains 2 is regulated by the amount of air from the source 10 of pressurized air and the shape of the air jet 8.

Seed grain 2 which does not adhere to the metering unit 4 falls by gravity back into the antechamber 14 of the injector 1, where it is again thrown in a tangential direction to the metering unit 4.

Industrial Application

The device for conveying grains can especially be used for precision sowing.