Abstract: An operator cab for heavy equipment is described to prevent a sliding door mounted on the cab from rocking or rattling in X, Y, and Z-axis directions due to a shock or vibration applied to the cab in a state that the sliding door is fully opened.

Abstract: A hydraulic system for a leveling apparatus in excavator and forestry equipment is provided, whereby an upper frame of the equipment is kept in a horizontal state even if a lower frame of the equipment is on an inclined ground against a horizontal surface H. The hydraulic system a pair of first and second actuators and a pair of third and fourth actuators for rocking the lower part of the upper frame, first leveling control valves for simultaneously controlling extension and contraction of the first and second actuators, second leveling control valves for simultaneously controlling extension and contraction of the third and fourth actuators a reducing valve for discharging a reducing pilot signal pressure, and flow control valves for discharging the pilot signal pressure for the spool shifting of the first and second leveling control valves when a control signal is applied from a preset leveling controller.

Abstract: An axle locking cylinder structure is capable of enabling an operator of heavy construction equipment to stably carry out an axle locking operation since a sudden variation of the flow rate is prevented in the axle locking cylinder by draining a highly-pressurized flow rate slowly at the release of axle locking and supplying a flow rate quickly at the drive of axle locking. A highly-pressurized hydraulic fluid can be steadily drained from a cylinder chamber since an opening region between a poppet valve and a pilot flow path is enlarged so as to open the pilot flow path connected to the cylinder chamber during a relatively long time. A cylinder rod can be quickly expanded according to the manipulation of an axle locking switch by compensating a flow rate supplied to a cylinder chamber when the cylinder rod is expanded.

Abstract: An upper frame for construction equipment mounted to swing on a lower driving structure is provided, in which fixing pins for supporting a boom and a boom cylinder are coupled to left and right side plates that are welded on a base plate to face each other, and a plate-shaped joint connection plate is welded on the left and right side plates and the base plate, so as to support the left and right side plates by exhibiting the rigidity and flexibility against load being transferred to the fixing pins through a working device during working.

Abstract: A method for controlling the gears of a vehicle that has an automatic transmission that is arranged to change gear according to a plurality of gear modes that differ in that changing to a higher gear is carried out at different minimum engine speeds or, if the changing is carried out steplessly, with different degrees of gearing, with the transmission having a forward gear position for driving the vehicle forwards and a reverse gear position for driving the vehicle backwards, comprising detection of an operating parameter and, in response to this production of a parameter signal for a control unit, selection, that is carried out by the control unit, of one of the gear modes on the basis of the parameter signal's value. The parameter signal represents the total distance that the vehicle has been driven during an individual sequence with at least one of the forward gear position and the reverse gear position.

Abstract: A system of wireless electronic devices for construction equipment and a maintenance system thereof are disclosed, in which various information used in an input and output unit, like modules of a construction work vehicle such as a hydraulic excavator, etc., are transmitted and received based on a wireless method, so that the use of wires can be significantly decreased. The wireless electronic system of a construction machine comprises at least one control panel which transmits a wireless signal for controlling each part of a construction machine in accordance with an operator's control; a main control device which receives a wireless signal from the control panel and transmits a wireless control signal for controlling a corresponding device; at least one auxiliary control device which performs input and output control, operation control, error detection, automatic control, etc.

Abstract: A footstep for an excavator is provided, in which the footstep, that is fixed to a track side frame so that an operator can get on/off a cab and so on therethrough, can be prevented from being damaged by rocks and so on during operation of the excavator in an inferior working environment. The footstep for an excavator, mounted on a track side frame of the excavator, includes an upper step composed of side plates formed on left and right sides to face each other, and a front plate formed in a body with the side plates and having through-holes formed on left and right sides thereof, to protect a head part of a fastening member, which fixes the footstep to the side frame, from an external impact; a fixing plate having both ends fixed to inner surfaces of the side plates to fix the upper step to the side frame by the fastening member that is fastened to pass through the through-holes; and a lower step fixed to lower ends of elastic pieces having upper ends fixed to the side plates, respectively.

Abstract: A load support apparatus for a cabin of heavy equipment is capable of overcoming the problems that a vibration absorption apparatus is very efficient for absorbing vibrations transferred from an upper frame to a cabin when heavy equipment runs or does work but is less efficient with respect to the left and right direction vibrations. The load support apparatus of a cabin of heavy equipment comprises a vibration prevention member which is engaged with an outer side of the cabin, a support bracket which is installed on an upper side of the upper frame and receives the vibration prevention member therein, and an elastic member which is installed between an outer side of the vibration prevention member and an inner side of the support bracket and absorbs the left and right direction vibrations which are transferred from the upper frame to the cabin.

Abstract: An operator's seat for heavy equipment having optimized switch arrangements for controlling the equipment is provided, in which arrangements of various kinds of switches and components of operating devices that are frequently used by an operator in the seat due to the characteristic of the equipment are integrated within a radius that an operator's hand reaches (i.e. in a hand arm operation zone), and thus physical inconvenience and fatigue that the operator who repeatedly operates working devices for a long time suffers can be reduced.

Abstract: A hydraulic circuit for a construction machine is disclosed, which can prevent an energy loss of a hydraulic system by automatically reducing revolution of an engine when a working device such as a boom is not driven. The hydraulic circuit includes first to third hydraulic pumps, a first switching valve, a second switching valve, a third switching valve, a confluence switching valve, a first shuttle valve selecting any one of a pressure of a first signal line in which a signal pressure is formed when the third switching valve for working devices connected to the third hydraulic pump is shifted and a pressure of a second signal line in which a signal pressure is formed when a switching valve for traveling devices is shifted, and a second shuttle valve selecting any one of the pressure selected by the first shuttle valve and a pressure of a third signal line in which a signal pressure is formed when switching valves for the working devices connected to the first and second hydraulic pumps are shifted.

Abstract: A fuel supply system for supplying a fuel to an engine mounted on an upper frame of heavy construction/forest equipment is provided. The fuel supply system includes a junction tank unit for interflowing a fuel supply line which is connected to a lower end of a primary fuel tank and a fuel supply line which is connected to a lower end of a secondary fuel tank, the fuel supply lines being connected in parallel to each other, a water separator connected to the junction tank unit via a fuel supply line, a fuel supply line for supplying the fuel to an engine from the water separator, and a fuel recovery line for recovering a remaining fuel from the engine to the primary fuel tank.

Abstract: An armrest for a vehicle seat includes a seat cushion and a backrest. The armrest is intended to be turned around a pivot axis between a first active position and a second folded-away position. The armrest includes an upper part, which in the active position is positioned with its longitudinal axis substantially parallel to a substantially vertical plane through a side surface constituting an outer edge surface of the vehicle seat and intended to support a user's forearm, and at least one lower part provided with a fixing device for attaching the upper part to the vehicle seat. The lower part includes a linking mechanism arranged for setting the upper part in a transverse direction between a first position outside the side surface and an adjustable second position, and a locking device that is arranged to activate a catch that locks the upper part in a set position after it has been moved to the second position. A vehicle seat provided with an armrest and to a vehicle including an armrest are also provided.

Abstract: A sliding door safety device for heavy construction equipment is provided, which includes an outer side wall having a doorway formed thereon, an upper rail and a lower rail formed on an upper part and a lower part of the outer side wall, respectively, a sliding door sliding to move to a front or rear side of a cab by an upper roller and a lower roller engaged with the upper rail and the lower rail, respectively, to open or close the doorway, and first and second door position sensing switches mounted on one side of the outer side wall to sense a door position when the door is in its open position where the door is fully opened or in its closed position where the door is fully closed.

Abstract: A method for preventing overturning a dump vehicle, the vehicle including a forward vehicle section with a forward frame and a wheel axle supported by the frame. The dump vehicle further includes a rear vehicle section with a rear frame and at least one wheel axle supported by the frame. The dump vehicle further includes an articulation joint, which connects the forward frame and the rear frame and allows the forward frame and the rear frame to pivot in relation to each other about an axis extending in a longitudinal direction of the vehicle. During a tilting procedure for unloading material from a container of the dump vehicle, the method includes determining if there is a risk for a pair of wheels of the wheel axle of the forward vehicle section to lose ground contact or if the pair of wheels have already lost ground contact.

Abstract: A hydraulic system for construction equipment is provided, which can increase the driving speed of a corresponding working device by making hydraulic fluid of a hydraulic pump, which is added to the hydraulic system having two hydraulic pumps in the construction equipment, join hydraulic fluid on the working device side, and can intercept the supply of hydraulic fluid from the working device side to a traveling apparatus side when the working device and the traveling apparatus are simultaneously manipulated.

Abstract: A structure of an upper frame for supporting a cabin of construction machinery, whereby, in the event of a rollover accident, an excessive vertical load or rearward load applied to a cabin structure is primarily dispersed by a reinforcing member of the cabin structure, and the dispersed load is supported by a separate cabin supporting structure, so that the plastic deformation of the cabin structure can be minimized.

Abstract: A hydraulic flow sharing system for excavating and pipe laying work is provided, which can prevent the abrupt change of a traveling speed during traveling through compulsory sharing of the flow rate applied to a working device and a traveling apparatus when a combined operation, in which the traveling apparatus and the working device such as a boom are simultaneously driven, is performed.

Abstract: An apparatus for absorbing vibrations of components of heavy construction equipment is disclosed, which comprises an elastic support ring which has a tightening part at both ends of a longitudinally extended body for thereby absorbing and decreasing vibrations transferred from heavy construction equipment to components by connecting and fixing the fixing part and the vibration part as the elastic support ring is tightened wherein the apparatus for absorbing vibrations of components of heavy construction equipment is installed between a fixing part for mounting components of heavy construction equipment such as a handrail, work mirror, etc. and a vibration part which generates lots of vibrations for thereby absorbing and decreasing vibrations of components of heavy construction equipment.

Abstract: A straight traveling hydraulic circuit is provided. In case of performing a combined operation in which a fine operation of a working device and a fine traveling of a traveling device are simultaneously required, the straight traveling hydraulic circuit can allow the working device and the traveling device to operate independently, and thus prevent a declination or sudden traveling of the equipment. In case of performing the combined operation by simultaneously operating the traveling device and the working device, first and second center bypass shifting valves installed on the lowermost stream side of first and second center bypass passages are shifted by a pilot signal pressure that shifts a straight traveling valve installed on an upper stream side of the second center bypass passage, so that the degree of opening of the first and second center bypass passages is reduced to operate the working device and the traveling device independently.

Abstract: Patent An attachment arrangement and a method for attaching a panel to a supporting structure on a vehicle are provided. The attachment arrangement includes a profile with a first section extending outwards from the supporting structure and a second section extending in a plane substantially parallel to the supporting structure, wherein the second section is arranged to extend into a recess in an outer edge along one side of the panel.