Abstract: An apparatus and method for controlling a lifting magnet (12) of a materials handling machine (10) to eliminate arcing between contacts (70-80) within the magnet controller (26) as is well as is large voltage spikes. The controller (26) selectively excites the shunt field windings (66,68) of a direct current generator (22). The magnitude and direction of the current passing through the shunt field windings (66,68) is varied by the magnet controller (26) to control the magnitude and polarity of the voltage at the generator output (23). The armature (60) of the generator (22) is rotatably driven by a hydraulic motor at an essentially constant speed to minimize voltage variations at the output (23) of the generator (22). At least the drop cycle is controlled through use of a current transducer (200) that senses current flowing to the lifting magnet so that the electronic controller is able to control the flow of current to the lifting magnet based upon the sensed current in the magnet circuit.

Abstract: A hydraulic circuit (124) is defined in a manifold (130) which may be aluminum, steel, or any other suitable material. The circuit (124) regulates the flow of hydraulic fluid to the hydraulic motor (120) and thus ensures that the motor rotates at an essentially constant speed, independent of the speed of the hydraulic pump (122) supplying the circuit. The circuit includes a pressure compensated flow control valve assembly (140) with an adjustable flow control valve (142) that regulates the flow of hydraulic fluid to the motor (120). The assembly (140) also includes a balanced piston-type pressure compensator (144) that ensures a select pressure differential across the flow control valve (142) such that the flow through the valve (142) remains at least essentially constant. This constant flow through the pressure compensated flow control valve assembly (140) ensures an essentially constant rotational speed of the motor (120).

Abstract: An apparatus and method for controlling a lifting magnet (12) of a materials handling machine (10) to eliminate arcing between contacts (70-80) within the magnet controller (26) as well as large voltage spikes. The controller (26) selectively excites the shunt field windings (66,68) of a direct current generator (22). The magnitude and direction of the current passing through the shunt field windings (66,68) is varied by the magnet controller (26) to control the magnitude and polarity of the voltage at the generator output (23). The armature (60) of the generator (22) is rotatably driven by a hydraulic motor at an essentially constant speed to minimize voltage variations at the output (23) of the generator (22). The magnet controller (26) includes a programmable logic controller (40) which selectively opens and closes the contactors (70-80) within the controller (26).

Abstract: A cooling system mounting arrangement includes a platform of an article of construction machinery and an engine enclosure and a cab and cab riser mounted to the platform. The engine enclosure includes an engine and associated engine cooling system. The cab is mounted atop the cab riser, and the cab riser is adapted for ducting cooling air to an auxiliary cooling system disposed in the cab riser separate from the engine cooling system. The auxiliary cooling system includes a heat exchanger and a fan assembly for flowing cooling air across the heat exchanger. The fan assembly is movably mounted to the cab riser for movement between a first position adjacent to the heat exchanger for flowing cooling air across the heat exchanger and a second position spaced apart from the heat exchanger to permit access to the downstream side of the heat exchanger for cleaning and maintenance.

Abstract: An electromagnet having a 360.degree. flux pattern for attracting magnetizable items over the entire surface area of the magnet is disclosed. The electromagnet includes an outer casing having a circumferential portion constructed of non-magnetizable material, a core portion of magnetizable material, and a means for generating magnetic flux lines contained within the casing. The core is disposed generally radially within the coil and includes an inner core portion and a first magnetic pole portion extending axially from the coil. The first magnetic pole comprises a bottom wall depending from the inner core and being radially coextensive with at least a portion of the coil. The core also includes a second magnetic pole portion extending axially from the coil opposite of the first magnetic pole portion and comprising a top wall depending from the inner core which is radially coextensive with at least a portion of the coil.

Abstract: An improved mobile magnetic lifting assembly for providing magnetic pickup and release in response to hydraulic control. A hydraulic drive motor and electric generator are disposed within a housing which includes an electromagnet attached thereto. The motor drives the generator which is electrically coupled to an electromagnet. The housing includes a suspension brakcet for detachably securing the housing to the boom of a lifting apparatus, as a crane. Hydraulic connections extend through the housing to provide hydraulic motor drive control of the electrical power to the electromagnet.

Abstract: A wheeled carrier adaptable for use with material handling equipment comprises a main body and first and second frames adjustably connected to the main body portion. Wheel assemblies are connected to the frames. The width of the carrier is adjustable so the carrier can be easily transported yet provide sufficient stability when used in material handling applications.