Abstract: A control system for a bucket hoist includes a two-axis master switch configured to generate a first and a second command signal responsive to motion along each axis. Each command signal is provided to one of a pair of motor controllers configured to control one of a pair of motors. The two motors are controlled to raise/lower and open/close the load handling member. When the two-axis master switch is moved to the close position, the closing motor controller is commanded to control its respective motor to begin closing the load handling member. The holding motor controller is configured to generate a current to its respective motor to generate torque at a predefined level. The predefined level of torque is selected such that the load handling member lowers into the material in which it is digging as it is being closed.

Abstract: A control system is provided for one or more chain drives. The control system includes a automation control system or control device in communication with a control board installed on one or more chain drives. The control board can include a microprocessor and a memory device. The memory device stores one or more computer programs or algorithms executable by the microprocessor to generate a plurality of commands to control the operation of a component, e.g., a motor, of the chain drive in response to receiving an operational command from the automation control system or control device.

Abstract: A winch comprises a cable roll; a cable having one end fixed to the cable roll and another end configured to electrically connect an electric device to the cable, wherein the cable is further configured to provide the electric device with electric power and/or with data; a framework to which the cable roll is mounted; measuring means connected to the framework and configured to provide data related to the length of an unwound part of the cable; and processing means configured to control winding and unwinding of the cable based on data provided by the measuring means. The cable has a predetermined reference state at which a predetermined fixed reference point is at a reference position in relation to a coordinate system, wherein the length of unwound cable is defined as the distance measured along the cable, between the location of the predetermined fixed reference point and the reference position.

Abstract: A puller is provided with a number of advantages. Pullers are described that have a high power to weight ratio, and a high power to volume ratio. Examples of pullers and pulling systems include harmonic drive gear reduction elements and configurations that provide high cable friction in a small device volume. Examples of pullers and pulling systems also include constant force pulling which is desirable in particular for small diameter pipe replacement. Using pullers and pulling systems as described, minimally invasive pipe replacement operations are possible. Reversible pullers are also provided that decrease the amount of time needed to burst or split multiple segments of pipe.

Abstract: Single networkable fault monitoring system for monitoring electrical parameters on at least one electrical phase on at least one interconnected electric chain hoist for various fault conditions. When at least one fault signal is generated, at least one kill signal is generated in the fault monitoring system, causing generation of at least one kill function in at least one chain hoist motor controller. The generated kill function causes a power disconnection to all connected electric chain hoists and/or the entire network of fault monitoring systems. When a fault has been generated, each individual fault signal outputs fault specific diagnostic data from the fault monitoring system to help an operator identify the fault specific electric chain hoist(s) and the specific fault type(s). This data is intended for the purpose of interfacing with an operator monitoring device, LED indicators, data logger, and/or any other user-defined application or combination thereof.

Abstract: A preferred embodiment of a lifting device includes a mounting column having a first major portion extending in a first direction, and a second major portion fixedly coupled to the first major portion and extending in a second direction. The lifting device also comprises a lifting arm rotatably mounted on the second major portion of the mounting column and having a first hole formed therein for receiving a pin, a bracket fixedly coupled to the second portion of the mounting column and having a second hole formed therein for receiving the pin so that the pin restrains the lifting arm from substantial rotation about the second major portion of the mounting column, and a retaining member secured to the second major portion of the mounting column so that the bracket and the retaining member restrain the lifting arm from substantial movement in the second direction.

Abstract: A hoist synchronization apparatus and method using a master controller operating software that provides a pulse reference to a slave controller. The slave commands its motor to rotate at the speed conveyed by that pulse reference. The slave controller monitors the pulse feedback from both the master encoder and the slave's encoder and compensates for any position error by adjusting its motor output speed. In addition, the slave controller includes the capability to automatically resynchronize the hoists. Resynchronization is accomplished by storing position error generated when either the master or the slave is run independently and correcting for the error when both units are operated at a later time.

Abstract: A cable winch hoisting device for theatrical stages, whereby a plurality of elongated, rod-like holding girders are suspended on cables, and these holding girders are adjustable in height by varying the free cable length between the cable suspension and the holding girder, which determines the position of the respective holding girder. The holding girders are adjustable in height between two end positions without any mutual interference in the clearance spaces which do not overlap with one another and are provided for the holding girders. At least two cables which are uniformly adjustable by the same cable-operating device act on the holding girders and are distributed over the length of the girders. The cable-operating devices are each electrically driven cable drums. The cables acting on the same holding girder can be wound up side by side onto the cable drum of the respective cable-operating device with the same change in free cable length, which determines the position of the holding girder.

Abstract: A hoist synchronization apparatus and method using a master controller operating software that provides a pulse reference to a slave controller. The slave commands its motor to rotate at the speed conveyed by that pulse reference. The slave controller monitors the pulse feedback from both the master encoder and the slave's encoder and compensates for any position error by adjusting its motor output speed. In addition, the slave controller includes the capability to automatically resynchronize the hoists. Resynchronization is accomplished by storing position error generated when either the master or the slave is run independently and correcting for the error when both units are operated at a later time.

Abstract: An elevating system especially designed for raising and lowering battens used in stages. The elevating system preferably uses two or more winch assemblies with synchronous motors coupled together in parallel to an AC inverter to provide smooth, ramped starting and stopping of the winch assemblies as well as torque boost, speed boost, and electric braking. Each winch assembly is provided with numerous safety features such as overload and underload protection, automatic releveling of the batten, thermal overload protection and cable drum lock protection.

Abstract: The device comprises two winches (12, 12') fastened to the outer surface of a hollow body (2) having a vertical channel (3) in which the load (4) is displaced. Each of the winches (12, 12') comprises two drums (13a, 13b) driven by a common motor (14). The drums (13a, 13b) of a first winch (12) are each arranged opposite a drum of the second winch (12') in relation to the axis of the channel (3). The device comprises two cables (15a, 15b) which are common to two drums located opposite one another around the body (2). The cables (15a, 15b) are wound with their end part on the drums located opposite one another and on their run between the drums pass over deflecting pulleys (16a, 16b), the axis of which is stationary, and over load-supporting pulleys (34a, 34b), the axis of which is movable and accompanies the load. The device ensures that the load is held and displaced in the event of a failure of one of the motor assemblies (14) and in the event of a break of one of the cables.

Abstract: A hoist drive for a double hoist carrying member having a hold hoist drum, a hold rope connected to the hold hoist drum and from which the carrying member is suspended, and a hold motor for rotating the hold hoist drum to raise and lower the carrying member. The hoist drive further includes a close hoist drum, a close rope connected to the close hoist drum and from which the carrying member is suspended, and a close motor for rotating the close hoist drum to raise and lower the carrying member. During raising of the carrying member, the hold and close motors are each supplied with a.c. power at different preselected frequencies. The hold and close motors each operate along a first pair of intersecting frequency to torque curves during a raising operation in which the hold motor curve is steeper than the close motor curve.

Abstract: An apparatus for the motorized control of theatrical sets connected to manual lift units each comprising upper and lower pulleys upon which a line runs to raise and lower a counterweight operatively connected to a set on the stage by a plurality of lift lines is comprised of a series of upper and lower sheaves for support of an independent control line connected to the counterweight. The sheaves are positioned as to not interfere with the manually-operated lines. A drive drum and motor drive unit is associated with each upper and lower sheave, and runs the control line. The drive drums and motor drive units are arranged in a spaced array such that the drive units may be connected and discounted to the drive drums as necessary and required by a particular set configuration, thus eliminating the need for all drums of the array to be coupled to drive units at all times.

Abstract: A drum and piston drive system incorporates within the interior of a drum used for reeling cable in and out, a reversible electric motor which drives the drum from the inside through a gearset. Also carried within the drum is a manifold structure including a gear pump driven directly from the opposite end of the reversible motor operating in a closed hydraulic circuit to supply hydraulic pressure to reversibly move a piston in a cylinder. The manifold includes check valves limiting the pump output pressure, and a pair of accumulators which maintain a desired pressure on both sides of the pump to avoid cavitation. Relief valves in the manifold limit the pressure to the piston and check valves in each line to the cylinder block reverse flow. The system operates to control and coordinate drum rotation movement and direction with the direction and movement of the piston.

Abstract: The cable puller employs a conically tapered capstan and self-contained motor both carried on a readily collapsible and portable frame. The puller is adapted for placing inside of a manhole where the capstan is aligned with the duct through which the cable is to be pulled. Several such cable pullers may be operated in concert to pull a theoretically endless fiber optic cable at a controlled speed and without exceeding the tensile strength of the cable. Tension on the cable effects the frictional gripping force between the capstan and the cable looped there around and this gripping force controls the extent to which the cable is permitted to climb up and slip down the conical incline of the capstan to a point where equilibrium is reached. A radio-controlled sensor is provided at each pulling station to signal cable stoppage faults and to respond to faults signaled by other pulling stations by shut down of all stations until the fault is corrected.

Abstract: A payload can be transferred between two relatively movable stations for example two ships using a winch system having an inhaul winch and an outhaul winch. The barrel of the outhaul winch is driven by an outhaul motor through a torque convertor such that the outhaul winch provides pull on the trolley 16 regardless of the sense of rotation of the outhaul winch barrel. A control system is used to control the speed of the inhaul winch barrel either to retrieve cable or to pay out cable. Thus, the speed of the trolley 16 is controlled by the speed at which the inhaul winch barrel is driven. The outhaul winch either can be at the same station as the inhaul winch or can be at the opposite station to the inhaul winch.

Abstract: A cable drive mechanism wherein a cable member comprising a plurality of individual cables disposed in side by side relation to form a flat member is successively wrapped around at least one cable wheel in one rotational direction and around at least one tension wheel in an opposite rotational direction, the tension wheel being mounted on pivot arms and connected to drive motors such that rotation of the tension wheel induces an angular moment in the pivot arms to urge the tension wheel toward the cable wheel in order to provide gripping friction on the cable member between the cable wheel and the tension wheel sufficient to overcome the inertia of the cable during start-up.

Abstract: A patient positioning device characterized by a horizontal support beam, a pair of motors coupled to the support beam, a first cable and hook assembly associated with a first motor, a second cable and hook assembly associated with a second motor, and a motor controller operative to selectively actuate the first motor, the second motor, or both motors simultaneously. Rigid, body contoured supports and/or flexible slings are coupled to one or both of the motors to selectively lift portions of a patient's body from a bed.

Abstract: The invention relates to electrical drive apparatus for a vertically displaceable blackboard. In order to obtain synchronous operation of such drive apparatus either one motor, one shaft, or two motors connected by means of an electrical shaft were employed. The apparatus according to the invention operates with an electric motor which is combined with a worm drive, a drive sheave, and a slip coupling to a unit which is mounted at the top inside the guide beams of the blackboard, with the motor arranged vertically and having a hollow shaft through which the drive cable is guided. One such drive apparatus is mounted in each guide beam at its top, with simultaneous switching on and switching off without an electrical shaft.