Abstract: A pile driver includes a leader rotation/holding mechanism that can firmly hold a leader in a rotatable state and also reliably rotate the leader using a general-purpose, inexpensive hydraulic motor by keeping the hydraulic motor from action of a bending moment from the leader. The pile driver has a leader revolver that includes a mechanism for rotating a leader. The leader revolver includes an outer tube and an inner tube that is concentrically arranged inside the outer tube via a pair of tapered roller bearings provided at two upper and lower positions. A lower part of the leader is connected, in an integrally rotatable state, to an upper part of the inner tube protruding upward from an upper end opening of the outer tube. A hydraulic motor is placed in a lower part of the leader revolver.

Abstract: A pile driver includes a leader rotation/holding mechanism that can firmly hold a leader in a rotatable state and also reliably rotate the leader using a general-purpose, inexpensive hydraulic motor by keeping the hydraulic motor from action of a bending moment from the leader. The pile driver has a leader revolver 15 that includes a mechanism for rotating a leader 17. The leader revolver 15 includes a fixed-side outer tube 31 and a rotation-side inner tube 32 that is concentrically arranged inside the fixed-side outer tube 31 via a pair of tapered roller bearings 35, 36 provided at two upper and lower positions. A lower part of the leader 17 is connected, in an integrally rotatable state, to an upper part of the rotation-side inner tube 32 protruding upward from an upper end opening of the fixed-side outer tube 31. A hydraulic motor 33 is placed in a lower part of the leader revolver 15.

Abstract: A coated granular fertilizer which makes it possible to independently design the period since its application till 10% dissolution-out and the period since 10% dissolution-out till completion of its dissolution-out is provided, which fertilizer is prepared by coating a granular fertilizer with a coating having a sugar polymer or its derivative dispersed therein, and has a time limit dissolution-out function, the former period till 10% dissolution-out and the latter dissolution-out duration being respectively capable of being controlled to within a range of 26 to 315 days and a range of 29 to 371 days.

Abstract: A granular fertilizer with a coating which is decomposable by soil microorganisms, preferably a coating which is decomposed and degraded both on the surface layer of the soil and in the soil, and a process for producing the granular fertilizer, which coating contains a poly 3-hydroxy-3-alkylpropionic acid as an indispensable ingredient, and if necessary, a resin or a low-molecular resin and further, if necessary, an inorganic or organic powder, and which process comprises adding an organic solvent solution of the poly 3-hydroxy-3-alkylpropionic acid, and if necessary, the resin, and if necessary the powder (dispersed in the solution) to a granular fertilizer in fluided state in the form of spray, and when added, blowing a high speed hot air stream onto the fertilizer to thereby instantaneously remove the solvent and also dry the resulting fertilizer.

Abstract: A coated or encapsulated granular fertilizer which comprises an olefin polymer and/or copolymer and a polyether polyol in a defined amount. The olefin polymer is an ethylene or propylene homopolymer and/or a copolymer of an olefin monomer and a copolymerizable monomer such as olefinic monomers, vinyl acetate and carbon monoxide. The polyether polyol is polymers of ethylene oxide, propylene oxide and mixtures thereof with or without etherification with polyhydric alcohols. By the addition of the polyether polyol, a dissolution rate of the fertilizer can be arbitrarily controlled without a sacrifice of physical properties of the coated film.

Abstract: A fertilizer with a degradative coating wherein the dissolving-out rate of the fertilizer component can be controlled by adjusting the composition of the coating component and the residual capsule after the dissolving out degrades by light is provided, which degradative coating comprises as its active ingredient, at least one member of polyolefin resins and at least one member selected from the group consisting of rubbery resins and ethylene-vinyl acetate-carbon monoxide copolymer.

Abstract: A granular fertilizer with a degradative coating characterized in that after it has been applied to soil and its fertilizer component has dissolved out, the resulting coating part degrades rapidly is provided, which degradative coating comprises an ethylene-carbon monoxide copolymer as its indispensable component and a rubbery resin, an ethylene-vinyl acetate copolymer resin or powder as an optional component.

Abstract: Fertilizers coated with coating layer having a controlled moisture permeability and a controlled temperature dependency of moisture permeability are presented by the production method which comprises ejecting hot drying air to the spout of granular fertilizer and spraying a hot solution of polyolefin type resin, ethylene-vinyl acetate copolymer or vinylidene type resin upon said fertilizer granules and drying said fertilizer granules upon being sprayed with solution having the property capable of forming a solution while it is hot but turning into jelly-like gel when it is cooled but as a most characteristic feature of this method uniformly dispersed fine powder is incorporated in said drying air or in said solution so as to have a coated layer of said resin containing uniformly distributed fine powder.