公开(公告)号：US06599095B1

公开(公告)日：2003-07-29

申请号：US09959515

申请日：2001-10-29

申请人： Noriyuki Takada ,  Takayuki Yamakawa ,  Hidetoshi Ryu ,  Tetsuo Kawano ,  Koji Kawamoto ,  Toshio Miyano ,  Richard L. Pratt ,  Brian Mackinnon

发明人： Noriyuki Takada ,  Takayuki Yamakawa ,  Hidetoshi Ryu ,  Tetsuo Kawano ,  Koji Kawamoto ,  Toshio Miyano ,  Richard L. Pratt ,  Brian Mackinnon

IPC分类号： F04B1924

CPC分类号： F04B47/02 ,  F04B49/065 ,  F04B2201/0202 ,  F04B2203/0201 ,  F04B2203/0204

摘要： A pump off control method comprises detecting the speed of the induction motor and an instantaneous value of secondary current of the induction motor. Down stroke time in every cycle of the pump jack is detected. An average value of instantaneous values of the secondary current of the induction motor in the down stroke time in said every cycle is calculated. An average value reference of the secondary current of the induction motor to be compared with calculated average value of the instantaneous values of the secondary current of the induction motor is set. The calculated average value of the instantaneous values of the secondary current is compared with the average value reference after the down stroke end in each cycle. An occurence of pump off is detected if the calculated average value of the instantaneous values is greater than the average value reference.

摘要翻译： 抽油机控制方法包括检测感应电动机的速度和感应电动机的次级电流的瞬时值。 检测到泵千斤顶的每个周期的下降时间。 计算出所述每个周期中的下行时间内的感应电动机的次级电流的瞬时值的平均值。 设定与感应电动机的二次电流的瞬时值的计算平均值进行比较的感应电动机的次级电流的平均值基准。 将计算出的次级电流的瞬时值的平均值与在每个周期中的下行程结束之后的平均值参考值进行比较。 如果所计算的瞬时值的平均值大于平均值参考值，则检测到泵送的发生。

公开(公告)号：US5938052A

公开(公告)日：1999-08-17

申请号：US750584

申请日：1997-05-15

申请人： Toshio Miyano ,  Takayuki Yamakawa ,  Tetsuo Kawano ,  Richard L. Pratt ,  Frederick C. Lach

发明人： Toshio Miyano ,  Takayuki Yamakawa ,  Tetsuo Kawano ,  Richard L. Pratt ,  Frederick C. Lach

IPC分类号： B66C13/22 ,  B66C13/06

CPC分类号： B66C13/063

摘要： An object of this invention is to provide a high performance and low cost crane rope steadying control method and apparatus for which mechanical or optical swing angle detecting means are not necessary.The invention provides a rope steadying control method for a crane or the like having a trolley driving apparatus for causing a load suspended by a rope of a crane or the like to travel, wherein swinging of a load suspended by a rope is stopped by calculating a swing load signal I.sub.2W * proportional to the rope swing angle and the load by computationally estimating a motor torque estimate signal .tau..sub.M * not including load torque fluctuations caused by swinging of the rope on the basis of gain coefficients and equivalent time constants of the control system and the drive system, and comparing this estimate signal .tau..sub.M * with an actual load torque .tau..sub.M and negatively feeding back to a trolley speed command N.sub.S of the trolley driving apparatus (1) a speed signal N.sub.W produced by carrying out phase lead/lag compensation on the difference between a swing angle detection estimated value .theta..sub.1 * proportional to this swing load signal and a swing angle set value .eta..sub.S.

摘要翻译： PCT No.PCT / JP96 / 01132 Sec。 371日期1997年5月15日 102（e）日期1997年5月15日PCT提交1996年4月25日PCT公布。 公开号WO96 / 33943 日期1996年10月31日本发明的目的是提供一种不需要机械或光学摆动角度检测装置的高性能和低成本的起重机绳索稳定控制方法和装置。 本发明提供了一种用于起重机等的绳索稳定控制方法，其具有用于使由起重机等的绳索悬挂的负载行进的小车驱动装置，其中通过计算一个起重机来停止由绳索悬挂的负载的摆动 基于控制系统的增益系数和等效时间常数，通过计算估计马达转矩估计信号τM *而不包括由绳索的摆动引起的负载转矩波动而与绳索摆动角度和负载成比例的摆动负载信号I2W * 和驱动系统，并且将该估计信号τM *与实际负载转矩τM进行比较，并将其反馈到手推车驱动装置（1）的小车速度指令NS，以通过执行相位超前/滞后而产生的速度信号NW 与该摆动负载信号成比例的摆动角度检测估计值θ1 *与摆动角度设定值eta S之间的差的补偿

公开(公告)号：US5027049A

公开(公告)日：1991-06-25

申请号：US304390

申请日：1989-01-31

申请人： Richard L. Pratt ,  Craig D. Dewey

发明人： Richard L. Pratt ,  Craig D. Dewey

IPC分类号： H02P27/06

CPC分类号： H02P27/06

摘要： A motor control method is disclosed in which a drive motor is connected to an adjustable frequency power supply in which the frequency of the power supplied to the motor can be selectively varied. While the motor is running at a constant speed as determined by the frequency of the power supplied to the motor, the value of the current being supplied to the motor by the power supply is sensed and an actual current signal representative of said actual current value is produced. A reference current signal which is representative of a selected maximum current value and thereby a maximum load at which the motor speed may be increased is also provided. The actual current signal is compared with the reference current signal and if the former is less than or equal to the latter, an output signal is provided. In response to the output signal resulting from the comparison, the value of the actual frequency of the power supplied to the motor is increased to a preselected value so that the motor speed also increases. The acceleration rate of the motor while its speed is increasing may also be changed.

摘要翻译： 公开了一种马达控制方法，其中驱动马达连接到可以选择性地改变提供给马达的功率频率的可变频电源。 当马达以由供给马达的功率的频率确定的恒定速度运行时，检测由电源提供给马达的电流值，代表所述实际电流值的实际电流信号是 生产。 还提供了表示所选择的最大电流值，从而代表电动机速度可能增加的最大负载的参考电流信号。 将实际电流信号与参考电流信号进行比较，如果前者小于或等于后者，则提供输出信号。 响应于比较产生的输出信号，提供给电动机的功率的实际频率的值增加到预选值，使得电动机速度也增加。 电机的速度增加时的加速度也可能发生变化。

公开(公告)号：USD589778S1

公开(公告)日：2009-04-07

申请号：US29261929

申请日：2006-06-22

申请人： Richard L. Pratt

设计人： Richard L. Pratt

公开(公告)号：US4953053A

公开(公告)日：1990-08-28

申请号：US304757

申请日：1989-01-31

申请人： Richard L. Pratt

发明人： Richard L. Pratt

IPC分类号： H02H7/085

CPC分类号： H02H7/085

摘要： A hoist for raising and lowering objects with an apparatus for detecting mechanical overload of the hoist. The system provides a hoist having an alternating current motor connected to an alternating current power supply. The level of current of the power supplied to the motor is compared to a level of power indicative of a mechanical overload condition. If the current signal representative of the actual motor current level equals or exceeds the mechanical overload reference current then an overload output signal is provided.

摘要翻译： 一种用于检测起重机械机械过载的装置升起和降低物体的起重机。 该系统提供具有连接到交流电源的交流电动机的起重机。 将供给到电动机的电力的电流水平与表示机械过载状况的功率电平进行比较。 如果表示实际电动机电流水平的当前信号等于或超过机械过载参考电流，则提供过载输出信号。

公开(公告)号：US4486744A

公开(公告)日：1984-12-04

申请号：US405211

申请日：1982-08-04

申请人： Richard L. Pratt ,  Francis J. Thornton

发明人： Richard L. Pratt ,  Francis J. Thornton

IPC分类号： G08B21/18 ,  G08B21/00

CPC分类号： G08B21/182

摘要： A device for indicating the flow of gases includes a vertically extending conduit section in which is disposed a ball. The ball seats on a lower seat at zero or minimum gas flow, and on an upper seat at maximum sensed gas flow. The upper seat is configured to permit essentially unrestricted gas flow when the ball is seated on it.Electrical means are associated with either the bottom seat and/or the top seat and co-acts with the ball to sense either minimum gas flow or maximum gas flow, and generate a signal responsive thereto.

摘要翻译： 用于指示气体流动的装置包括垂直延伸的管道部分，其中设置有球。 球座位于下部座椅上，零点或最小气流，在最高感测到的气体流量的上部座椅上。 上座椅配置成当球座落在其上时允许基本上不受限制的气体流动。 电气装置与底部座椅和/或顶部座椅相关联，并与球体共同作用以感测最小气体流量或最大气体流量，并产生对其的响应的信号。