DIGITALNA ARHIVA ŠUMARSKOG LISTA
prilagođeno pretraživanje po punom tekstu
| ŠUMARSKI LIST 12/1974 str. 55 <-- 55 --> PDF |
— kardanska osovina vrši pogon hidraulične pumpe, koja je u vezi sa hidrauličnim komandama. Putem komandi otvaramo ventile i stavljamo u protok hidraol ulje, — protok ulja pod velikim pritiskom (oko 300 atmosfera) ide putem armirano gumenih crijeva do: a) cilindar a na lijevom i desnom točku, čime vršimo horizontiranje prikolice, odnosno vertikaliziranje svrdla, b) hidromotora, koji svrdlu daje aksijalnu vrtnju, i c) reduktora , koji reducira broj okretaja na željenu brzinu. — Samo svrdlo nalazi se na jednom vertikalnom ramu po kojem se kreće gore-dolje pomoću valjkastog lanca i lančanika (princip čelnog viljuškara). Svrdlo je dužine 3 metra i promjera 12,5 cm, a sastoji se od tri dijela: a) neposredne oštrice (noža) oblika lastinog repa, koja je od specijalnog čelika i zamjenjuje se, b) tijela svrdla (šuplja cijev sa zavojnicama) koje prolazi kroz dva prstena, a kopčano je na reduktor pomoću kardanskog zgloba, c) dio između tijela i oštrice, također radi mogućnosti zamjene. — Osim navedenoga, bušilica ima na postolju veliki hladnjak za ulje i dva ventilatora koji se automatski uključuju u slučaju pregrijavanja ulja. — Bušilica ima 5 komandi za sve potrebne radne operacije, a pomoću jedne od njih svrdlo se diže u zrak u položaj za transport. SUMMARY Deep planting of Poplars on the soils of the Drava-Danube basin This country´s most fertile soils outside of the chernozem zone are normal alluvial soils which, according to their physical-chemical and other characteristics, are in general considered the best when it is a question of Poplar growing. However, as we are concerned here with undeveloped (recent) soils with different horizontal zones and marked vertical layering, those normal alluvial soils are very mosaic-like in their microlocality. On such soils any stereotyped improvisation ought to be eliminated, and it is necessary tentatively to investigate the pedological-hydrological characteristics, and to establish adequate techniques. The paper deals with the problem of deep planting. With the present technological means at our disposal deep plant- i!ng is limited to 3 m when planting holes are machine-drilled, and to 4 m (practically) when they are hand-drilled. As a rule, the required minimum-depth planting is that of the depth of the capillary zone (pedological standard), while 2- or 3-year-old setts areto be planted above the one-year height of the sett (biological- preventive standard). In 1973 and 1974 the Forest Enterprise of Osijek had established 85 hectares of Poplar plantings by manual deep planting, and 35 hectares with the Italian 527 |