Abstract: A tractor includes a hydraulic lifting and lowering driver to lift and lower a three-point linkage, a load detector to swing according to a traction load of an implement, and a mechanical linkage to transmit a swing amount of the load detector to the lifting and lowering driver. The mechanical linkage includes a first linkage on one side in a right-left direction of a vehicle body frame and interlockingly linked with the load detector, a second linkage on the other side in the right-left direction of the vehicle body frame and interlockingly linked with the lifting and lowering driver, and an operation cable interlockingly linking the first linkage and the second linkage.

Abstract: A filter element, including a pair of filter plates that are each made of a nonwoven fabric or felt of a polymeric material shaped into a plate having a corrugated cross section and which are positioned in such a way that the grooves in one filter plate are opposed to those in the other filter plate, is reinforced with reinforcements that are placed across the width of the filter element. The reinforcements and the filter element are secured at their respective ends by means of bolts. The reinforcements are similar in cross-sectional shape so that they can circumscribe the corrugated cross section of the filter plates such that a pair of the reinforcements can hold the filter element therebetween.

Abstract: In a method for continuously burning particles in a gas or oil heated vertical furnace in which the particles are charged from an uppermost part of the space, and the particles bed fluidized by a burning gas flow is formed in a vertically successive downward arrangement and then the burned particles are discharged out of the bottom of the furnace after cooling, the improvement comprises the steps of: providing the furnace with a plurality of downwardly vertically successive zone, including a precipitation zone of the particles at an uppermost part in the furnace, a lower upward flow velocity zone having low upward stream of the burning gas (referred to as "rich fluidized bed", hereinafter) and a higher upward flow velocity zone having high upward stream of the burning gas (referred to as "lean fluidized bed", hereinafter) underneath the precipitation zone wherein the lean fluidized bed is formed beneath and adjacent to the rich fluidized zone, and feeding the particles, burning them successively through the z