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US 3,943,713 AGranted
Control arrangement
AssigneeEaton Corporation
InventorErlen B. Walton
Life of this patent
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AssigneeEaton Corporation
InventorErlen B. Walton
Estimating the term…
A hoist system employing a hydraulic motor, a variable displacement reversible flow hydraulic pump for supplying hydraulic fluid to the hydraulic motor, and an electric motor employed as a prime mover for the pump has a control arrangement effective for sensing various indicia of operation as, for example, rate of speed of lifting of an associated load, failure of the hoist system power train and the lifting of maximum loads. Within the overall control arrangement means are provided for comparing the actual rate of speed of lifting to the desired or requested rate of speed of lifting with the differential thereof being directed back to the associated mechanism for varying the output displacement of said hydraulic pump for thereby modifying such output displacement in order to achieve zero differential output. Means are also provided for automatically braking the hoist drum in order to prevent the load carried thereby from dropping in the event of a failure of the said power train. Means are also provided for varying the maximum speed of the hoist system with variations in load.
A control arrangement for a power supply system employing variable displacement hydraulic pump means, a prime mover for driving said hydraulic pump means, hydraulic motor means driven by said hydraulic pump means, and power transmission means driven by said hydraulic motor means, the control arrangement comprising:
A control arrangement for a power supply system employing variable displacement hydraulic pump means, a prime mover for driving said hydraulic pump means, hydraulic motor means driven by said hydraulic pump means, and power transmission means driven by said hydraulic motor means, the control arrangement comprising:
A control arrangement for a power supply system employing variable displacement hydraulic pump means, a prime mover for driving said hydraulic pump means, hydraulic motor means driven by said hydraulic pump means, and power transmission means driven by said hydraulic motor means, the control arrangement comprising:
A hoist mechanism comprising a prime mover, a variable displacement pump driven by said prime mover, a fluid motor receiving the fluid output of said pump, a hoist drum driven by said motor, first means sensing the output speed of said motor and operative to generate a speed signal corresponding to said output speed of said motor, second means supplying a control speed signal, means comparing said speed signals from said first and second means and operative to selectively vary the displacement of said pump in response to sensed differentials in the said compared signals for controlling the speed of said motor, and means for sensing the pump output pressure and operative to vary the maximum obtainable displacement of said pump as a function of said output pressure.
A control arrangement for a power supply system employing variable displacement hydraulic pump means, a prime mover for driving said hydraulic pump means, hydraulic motor means driven by said hydraulic pump means, and rotatable power transmission means driven by said hydraulic motor means, said control arrangement comprising first means effective for indicating the actual speed and direction of rotation of said rotatable power transmission means, second means effective for indicating a desired speed anad direction of rotation of said rotatable power transmission means, and means effective for sensing the occurrence of a reversal in the direction of rotation of said rotatable power transmission means without a corresponding change in said desired direction of rotation or of a sustained difference between said actual speed and said desired speed said difference comprising a certain magnitude of phase shift between the output of said first indicating means and said second indicating means and operative upon such occurrence for applying a braking force to said power transmission means to thereby prevent further rotation of said power transmission means.
A hoist mechanism comprising a prime mover, a variable displacement pump driven by said prime mover, a fluid motor receiving the fluid output of said pump, a hoist drum adapted to be rotated by said motor, braking means operatively connected to said drum and operative upon actuation to prevent rotation of said drum, first means effective for supplying a first signal indicative of the actual speed and direction of rotation of said drum, second means effective for supplying a second signal indicative of a desired control speed and desired direction of rotation of said drum, and means effective for comparing said first signal and said second signal and being operative upon the occurrence of a reversal in the said direction of actual rotation of said drum without a corresponding change in said desired direction of rotation or upon the occurrence of a sustained difference between said actual speed and said desired speed said sustained difference comprising a certain magnitude of phase shift between the outputs of said first and second means to effect actuation of said braking means.
Dependencies are inferred from the claim text.