Abstract: Disclosed is a heating apparatus for a cabin of a construction equipment in which hot air ejected from an oil cooler is used for heating in winter while it is ejected out in summer to maximize cooling or heating efficiency of the cabin of the construction equipment. The heating apparatus for a cabin of a construction equipment includes a duct ejecting air ejected from an oil cooler provided inside an automotive body at the rear of the cabin to the outside of the automotive body, and a switching means provided in the duct to open and close, guiding the air inside the duct to the rear of the cabin if it is opened. The heating apparatus is automatically operated depending on its peripheral temperature condition to maximize cooling or heating efficiency of the cabin.

Abstract: A slide table includes an inner member, an outer member fitted at least partly over the inner member, air bearings provided between the inner and outer members, and a motor means having a coil connected to the outer member to drive the same.

Abstract: A lateral hole boring method whereby a lateral hole of a desired length is formed underground by repeatedly performing the following steps. A vertical hole is prepared, and a lateral hole boring apparatus equipped with a leading auger of a smaller length than the diameter of the vertical hole is lowered into the vertical hole to a predetermined position. The apparatus is manipulated from the ground level to advance and rotate the leading auger to bore a lateral hole. When the lateral hole has reached a predetermined length commensurate with the length of the leading auger, the advance movement of the leading auger is stopped, and the lateral hole boring apparatus is manipulated from the ground level to detach the leading auger therefrom, and is lifted above the vertical hole while leaving the leading auger in the lateral hole.

Abstract: A hydraulic circuit system for civil engineering and architectural machinery having at least first and second hydraulic pumps, a plurality of actuators driven by hydraulic fluid from said pumps, and a plurality of directional control valves for controlling the direction and flow rate of the hydraulic fluid supplied from the pumps to the actuators. In the directional control valves, a first boom directional control valve and one of right and left travelling directional control valves are connected to the first pump in parallel with each other, a swing directional control valve, an arm directional control valve and a second boom directional control valve are connected to the second pump in parallel with one another, and the other of the right and left travelling directional control valve is connected in tandem to the swing, arm and second boom directional control valves at a location downstream thereof.