Variable-speed load-dependent drive and hoist system
AssigneeMi-Jack Products, Inc.
InventorsDaniel Brian Zakula, Sr., Myron Glickman
Life of this patent
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Abstract
In an embodiment, a crane including a hoisting (i.e., load-lifting) mechanism is provided with a variable-speed load-dependent control system and method for operating functions of the crane. An exemplary control system includes an actuator subsystem for performing at least one function of the crane, a sensor for detecting the magnitude of the load lifted by the hoisting mechanism and a controller that communicates with the sensor, wherein, relative to a load signal from the sensor, the controller transmits a speed signal to vary an operating speed of at least one actuator of the actuator subsystem.
Claims32
A crane for lifting a load, the crane comprising:
- a hoisting mechanism that includes a trolley mechanism at a front of the crane with a first load sensor and a trolley mechanism at a rear of the crane with a second load sensor;
- an actuator subsystem including an actuator for moving at least one component of the crane;
- a sensor for detecting a load lifted by the hoisting mechanism, the sensor providing a load signal indicating a magnitude of the load;
- and
- a controller in communication with the actuator subsystem and the sensor,
- wherein the controller varies a speed of the actuator by comparing the load signals from the respective first and second sensors to a predetermined threshold, causes the actuator to operate at a high speed if both of the load signals from the respective first and second sensors are lower than the predetermined threshold, and causes the actuator to operate at a low speed if either of the load signals from the respective first and second sensors is higher than the predetermined threshold.
A crane including a hoisting mechanism for lifting a load, the crane comprising:
- an actuator subsystem including an actuator for operating at least one function of the crane;
- means for sensing a load lifted by the hoisting mechanism and detecting and indicating a magnitude of the load, said means for sensing including a first load sensor and a second load sensor, the hoisting mechanism comprising a trolley mechanism at a front of the crane to which the first load sensor is mounted, and a trolley mechanism at a rear of the crane to which the second load sensor is mounted, and wherein the controller varies the speed of the actuator by comparing the load signals from the respective first and second sensors to a predetermined threshold, causes the actuator to operate at a high speed if both of the load signals from the respective first and second sensors is lower than the predetermined threshold, and causes the actuator to operate at a low speed if either of the load signal from the respective first and second sensors is higher than the predetermined threshold;
- and means for controlling a speed of the actuator according to the magnitude of the load.
A method for controlling a crane including a hoist mechanism for lifting a load, said hoisting mechanism having a trolley mechanism at a front of the crane and a trolley mechanism at a rear of the crane, and an actuator system having at least one actuator for moving at least one component of the crane, the method comprising:
- receiving an operator input selecting to drive the at least one actuator;
- detecting a load lifted by the trolley mechanism at the front of the crane and detecting a load lifted by the trolley mechanism at the rear of the crane;
- determining if the load detected at either the front or rear trolley mechanisms exceeds a given threshold and a speed for the at least one actuator;
- and
- driving the at least one actuator at the speed determined in the determining step.
A crane including a hoisting mechanism for lifting a load, the crane comprising:
- an actuator subsystem comprised of:
- an actuator for moving at least one component of the crane;
- a hoist subsystem including a hoist actuator for operating the hoisting mechanism;
- and
- a drive subsystem including a drive actuator for rotatably driving a wheel;
- a sensor for detecting a load lifted by the hoisting mechanism, the sensor providing a load signal indicating a magnitude of the load;
- and
- a controller in communication with the actuator subsystem and the sensor, wherein the controller varies a drive speed of the drive actuator by comparing the load signal to a first predetermined threshold, causes the drive actuator to operate at a high drive speed if the load signal is lower than the first predetermined threshold, and causes the drive actuator to operate at a low drive speed if the load signal is higher than the first predetermined threshold, and wherein the controller varies a hoist speed of the hoist actuator by comparing the load signal to a second predetermined threshold, causes the hoist actuator to operate at a high hoist speed if the load signal is lower than the second predetermined threshold, and causes the hoist actuator to operate at a low hoist speed if the load signal is higher than the first predetermined threshold.
A crane including a hoisting mechanism for lifting a load, the crane comprising:
- an actuator subsystem comprised of:
- an actuator for moving at least one component of the crane;
- a hoist subsystem comprised of:
- a hoist actuator for operating the hoisting mechanism;
- a plurality of sheaves;
- and
- a hoist cable reeved about the plurality of hoisting sheaves, wherein the hoist cable connected for movement by the hoist actuator;
- a drive subsystem including a drive actuator for rotatably driving a wheel;
- a sensor for detecting a load lifted by the hoisting mechanism, the sensor being a load pin that supports at least one sheave of the plurality of hoisting sheaves, the sensor providing a load signal indicating a magnitude of the load;
- and
- a controller in communication with the actuator subsystem and the sensor, wherein the controller varies a speed of the actuator as a function of the load signal.
A crane including a hoisting mechanism for lifting a load, the crane comprising:
- an actuator subsystem comprised of
- an actuator for operating at least one function of the crane;
- a hoist subsystem comprised of:
- a hoist actuator for operating the hoisting mechanism;
- a plurality of hoisting sheaves;
- and
- a hoist cable reeved about the plurality of hoisting sheaves, wherein the hoist cable connected for movement by the hoist actuator;
- a drive subsystem including a drive actuator for rotatably driving a wheel;
- means for sensing a load lifted by the hoisting mechanism and detecting indicating a magnitude of the load, wherein said means for sensing is a load pin that supports at least one sheave of the plurality of hoisting sheaves;
- and
- means for controlling a speed of the actuator according to the magnitude of the load.
A method for controlling a crane including a hoist mechanism for lifting a load and at least two actuator subsystem having at least one actuator for moving at least one component of the crane, wherein one of the actuator subsystems is a hoisting subsystem in which the actuator is a hoist actuator and the component is the hoist mechanism, and wherein the other actuator subsystem includes a driving subsystem in which the actuator is a drive actuator and the component is at least one wheel of the crane, whereby the determining step includes determining if the load is greater than a first predetermined threshold associated with the driving subsystem and determining if the load is greater than a second predetermined threshold associated with the hoisting subsystem, the method comprising:
- receiving an operator input selecting to drive the at least one actuator;
- detecting a load lifted by the hoisting mechanism;
- and
- determining a speed for the at least one actuator a function of the detecting step;
- and
- driving the at least one actuator at the speed determined in the determining step.
Dependencies are inferred from the claim text.