An electric drive dump truck travels by contacting, with trolley lines, power collection units configured to be moved up and down by lifting devices and receiving electrical power from the trolley lines. A position detection device is configured to detect a position of the electric drive dump truck; a vehicle speed detection device is configured to detect a vehicle speed of the electric drive dump truck; and a storage section is configured to store a position of the trolley lines and a time (hereinafter referred to as a moving-up time) until the power collection units contact with the trolley lines since the power collection units start moving up. A control device is configured to output a signal indicating that the power collection units can be moved up based on the position and vehicle speed of the electric drive dump truck, the position of the trolley lines, and the moving-up time.

An electric drive dump truck travels by contacting, with trolley lines, power collection units configured to be moved up and down by lifting devices and receiving electrical power from the trolley lines. A position detection device is configured to detect a position of the electric drive dump truck; a vehicle speed detection device is configured to detect a vehicle speed of the electric drive dump truck; and a storage section is configured to store a position of the trolley lines and a time (hereinafter referred to as a moving-up time) until the power collection units contact with the trolley lines since the power collection units start moving up. A control device is configured to output a signal indicating that the power collection units can be moved up based on the position and vehicle speed of the electric drive dump truck, the position of the trolley lines, and the moving-up time.

A pantograph assembly configured to transfer electrical power from an overhead conductor to a machine is disclosed. The pantograph assembly may include a pantograph base detachably mounted to the machine, an articulated linkage assembly having a linkage assembly lower end operatively connected to the pantograph base and a linkage assembly upper end pivotally connected to the linkage assembly lower end, a collector rail assembly operatively connected to the linkage assembly upper end, and a stop member. The stop member may be connected to the pantograph base and engaging the articulated linkage assembly, or connected to the articulated linkage assembly and engaging the pantograph base, to prevent the articulated linkage assembly from being lowered toward the pantograph base below a predetermined down position or lower limit position. A latch assembly may be mounted on the pantograph base and operable to move between a latch locked position and a latch unlocked position.

The invention relates to a current transmission device for stationary charging of electrical energy stores of devices and/or for mobile supplying of electrical drive units of devices having a current transmitter which is embodied as an articulated arm system, and which can swivel between a current-transmitting extended position and a current flow interrupting retracted position, an adjusting drive interacting with the current transmitter as well as a spring system interacting with the current transmitter, wherein the adjusting drive is self-locking-free and has a switchable electromagnetic brake device.

The invention relates to a current transmission device for stationary charging of electrical energy stores of devices and/or for mobile supplying of electrical drive units of devices having a current transmitter which is embodied as an articulated arm system, and which can swivel between a current-transmitting extended position and a current flow interrupting retracted position, an adjusting drive interacting with the current transmitter as well as a spring system interacting with the current transmitter, wherein the adjusting drive is self-locking-free and has a switchable electromagnetic brake device.

A pantograph device of a trolley-type truck includes: a base frame; a bottom frame rockably attached to the base frame; a top frame rockably attached to the vicinity of the top end portion of the bottom frame through a connecting shaft; a collector shoe rockably supported in proximity to the top end portion of the top frame; a hydraulic cylinder for raising and lowering the bottom frame, attached to the base frame; and a spring which acts so as to rotate the top frame upward through the connecting shaft. By erecting the bottom frame by the hydraulic cylinder, the tensile force produced in the spring is increased and the top frame is rotated upward through the connecting shaft. This makes it possible to obtain a wide movable range without use of a long and strong spring and enhance the followability to overhead wires without increasing pressing force.

A pantograph device of a trolley-type truck includes: a base frame; a bottom frame rockably attached to the base frame; a top frame rockably attached to the vicinity of the top end portion of the bottom frame through a connecting shaft; a collector shoe rockably supported in proximity to the top end portion of the top frame; a hydraulic cylinder for raising and lowering the bottom frame, attached to the base frame; and a spring which acts so as to rotate the top frame upward through the connecting shaft. By erecting the bottom frame by the hydraulic cylinder, the tensile force produced in the spring is increased and the top frame is rotated upward through the connecting shaft. This makes it possible to obtain a wide movable range without use of a long and strong spring and enhance the followability to overhead wires without increasing pressing force.

A pantograph assembly configured to transfer electrical power from an overhead conductor to a machine is disclosed. The pantograph assembly may include a pantograph base detachably mounted to the machine, an articulated linkage assembly having a linkage assembly lower end operatively connected to the pantograph base and a linkage assembly upper end pivotally connected to the linkage assembly lower end, a collector rail assembly operatively connected to the linkage assembly upper end, and a stop member. The stop member may be connected to the pantograph base and engaging the articulated linkage assembly, or connected to the articulated linkage assembly and engaging the pantograph base, to prevent the articulated linkage assembly from being lowered toward the pantograph base below a predetermined down position or lower limit position. A latch assembly may be mounted on the pantograph base and operable to move between a latch locked position and a latch unlocked position.

The invention consists of a pantograph (2) comprising a pantograph head (+) with two bows (10), and comprising a low-voltage supply system having at least one transducer (15, 20) that converts the mechanical energy generated by oscillating movements of the pantograph head (4) with at least two bows (10) into electrical energy: each bow (10) is connected mechanically to a suspension arm (26), said suspension arm (26) being connected mechanically to an elastic link (25), and said elastic link (25) being connected by a joint (24) to the end of an upper arm (7) of the pantograph (4), wherein at least one first transducer is connected mechanically on one side to said suspension arm (26) connected to a first bow (10) and on the other side to the joint (24).

The invention consists of a pantograph (2) comprising a pantograph head (+) with two bows (10), and comprising a low-voltage supply system having at least one transducer (15, 20) that converts the mechanical energy generated by oscillating movements of the pantograph head (4) with at least two bows (10) into electrical energy: each bow (10) is connected mechanically to a suspension arm (26), said suspension arm (26) being connected mechanically to an elastic link (25), and said elastic link (25) being connected by a joint (24) to the end of an upper arm (7) of the pantograph (4), wherein at least one first transducer is connected mechanically on one side to said suspension arm (26) connected to a first bow (10) and on the other side to the joint (24).