DE1248357B - Screening device for threshing machines, especially combine harvesters - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

AOIf

German class: 45 e-7/34

Number: 1 248 357

File number: D 51072 HI / 45 e '

Filing date: September 10, 1966

Opened on: August 24, 1967

The invention relates to a screening device for threshing machines, in particular combine harvesters, with a short straw sieve and under this a fine sieve with collecting bottom, one above the collecting bottom protruding short straw screen extension, one from the short straw screen extension to one Return conveyor extending return floor and a fan for generating a from below upward air flow through the short straw sieve. To ensure an optimal Sorting and cleaning in the coarse screening device is recommended with a strong as possible Airflow to work. There are of course limits to the strength of the air flow, as there is too much strong air flow there is a risk that significant quantities of grain over the short straw sieve extension be blown out and thus lost. The invention has the purpose of a particularly strong air flow to avoid an increase in the loss values. This is according to the invention achieved in that behind the short straw sieve extension of the sieve device a removable Additional sieve and under this a collecting plate leading to the return tray is provided and that a device is provided in the area immediately in front of this additional screen, which from the Area between the short straw sieve and the fine sieve, blown air flowing out to the rear like this guides upwards so that the blower air does not get under the additional sieve.

With the help of such an additional sieve, a zone is obtained even with a very strong blower air flow. in which a substantial part of the material conveyed beyond the short straw screen extension can be deposited reasonably in peace, so that the accumulate on the additional sieve Grains due to the shaking movement of the additional sieve, which takes part in the movements of the sieve box, gradually fall down through the sieve holes.

Husks and other waste are of course removed through the short straw sieve Extension and the additional sieve sweeping away air while outside the grains larger and heavy parts, for example smaller ear parts, slide down through the holes in the additional sieve and in the same way as the material coming from the short straw screen extension to the be returned to threshing again. The material can either go to the short straw sieve or to be returned to a previous operation of the threshing and cleaning process, for example even run back to the threshing cylinder.

Sieve device for threshing machines,
especially combine harvesters

Applicant:

Dronningborg Maskinfabrik A / S,

Dronningborg, Randers (Denmark)

Representative:

Dr. E. Wiegand, Dipl.-Ing. W. Niemann,
Dr. M. Kohler and Dipl.-Ing. C. Gernhardt,
Patent Attorneys, Hamburg 50, Königstr. 28

Named as inventor:
Ingeman Damgaard Nielsen,
Thyge J0rgensen,
Dronningborg, Randers (Denmark)

Claimed priority:

Denmark September 25, 1965 (4951)

This return as such does not belong to the invention and is therefore not described in more detail.

It is advisable to design the additional sieve as a bubble sieve. The design of the additional sieve as well its sieve hole sizes and dimensions can be adapted to the material to be threshed. The sieve plate as such, it can be exchangeable, if not the entire additional sieve according to claim 1 removable is designed so that the combine harvester with or depending on the circumstances affecting the operation can work without an additional sieve.

The means for forcing the air upwards, which prevent the air from flowing under the additional screen can flow, according to the invention from one attached to the rear fine screen edge, obliquely upwards directed baffle or from a shielding plate protruding downward from the rear edge of the sieve box exist. In many cases it is advisable to provide both of these devices, so that one Upstream of air through the holes of the additional screen is prevented with security.

The invention is explained in more detail below with reference to the drawing, which schematically shows a Represents a longitudinal section through the screening device according to the invention.

709 638/136

Claims (3)

The screening device consists of a nose-shaped short straw screen 1 and an extension part 2 connected downstream of this, which in the embodiment shown has adjustable lamellae. A fine sieve 3 is provided under the lamellas, at the rear edge of which there is a baffle 4 directed obliquely upward. A collecting base 5, which feeds the cleaned grains to a conveyor 6, is arranged under the fine sieve. A return material collecting plate 7 arranged under the collecting base 5 extends from the area below the short sieve extension 2 to a return material conveyor 8. Behind the short straw sieve extension 2 there is also a nose-shaped additional sieve 9, under which a collecting plate 10 is provided, which extends to the return material collecting plate 7. At the front edge of the additional screen 9, d. H. At the rear end of the short straw sieve extension 2 there is provided a shielding plate 11 which is directed downwards at an angle and extends approximately as far as the collecting plate 10, so that the material conveyed with the help of the collecting plate 10 of the return material collecting plate 7 can be passed under the lower edge of the shielding plate, which is also supported by the guide plate 4 controlled air under the short straw sieve extension 2 can not get under the additional sieve 9, but is passed through the short straw sieve extension and through the rear part of the short straw sieve itself upwards. The air flow directed upwards through the short straw sieve, its extension and through the fine sieve is generated by means of a blower 12 which is provided with a double blower neck 13, 14 each with an adjustable control flap 15 and 16, respectively. The two air flows are indicated by arrows. The material to be treated is passed down from the straw shaker (not shown) onto the short straw sieve 1, on which the pure grains are separated out by the shaking movements of the sieve box and with the aid of the air flow from the fan 12, which fall through the openings of the short straw sieve. Not enough threshed material is passed over the short straw sieve extension 2, where larger constituents fall through the openings of the extension, while the blower air transfers lighter parts to the additional sieve 9. The shield plate 11 prevents the blower air from acting through the openings of the additional sieve on the material lying on this. Entrained grains or smaller ear pieces fall through the openings, while only very light waste parts are removed partly due to the shaking movements and partly by the air flowing over the additional sieve. The material falling through the additional sieve is passed over the collecting plate 11 of the collecting plate 7 for the return material coming from the short straw sieve extension 2 and fed together with this return material to the return screw 8, which feeds the material to an appropriate point for repeated treatment, for example the threshing mechanism. Paterite claims: 1. Sieving device for threshing machines, in particular combine harvesters, with a short straw sieve and under this a fine sieve with collecting base, a short straw sieve extension protruding beyond the collecting base, one extending from the short straw screen extension to a return conveyor Return bottom and a blower to generate a bottom-up directed Air flow through the short straw sieve, thereby characterized in that behind the short straw screen extension (2) a removable additional screen (9) and under this a collecting plate (10) leading to the return floor is provided and that a device (4, 11) is provided in the area immediately in front of this additional sieve, which from the area between the short straw sieve (1) and the fine sieve (3) to the rear directs outflowing fan air upwards in such a way that the fan air does not go under the additional screen got. 2. Sieving device according to claim 1, characterized in that said device is a baffle plate attached to the rear edge of the fine sieve (3) and pointing upwards at an angle (4). 3. Sieving device according to claim 1 or 2, characterized in that said device a shielding plate protruding downwards from the rear end of the short straw screen extension (2) (11). 1 sheet of drawings 709 638/136 8. 67 © Bundesdruckerei Berlin