US3847251A - Control apparatus for a powered hoist - Google Patents

Control apparatus for a powered hoist Download PDF

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Publication number
US3847251A
US3847251A US00343047A US34304773A US3847251A US 3847251 A US3847251 A US 3847251A US 00343047 A US00343047 A US 00343047A US 34304773 A US34304773 A US 34304773A US 3847251 A US3847251 A US 3847251A
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Prior art keywords
electrical signal
responsive
torque
drum
brake
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US00343047A
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English (en)
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J Binns
K Ellis
D Craven
P Maltby
S Glaze
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Northrop Grumman Properties Ltd
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Lucas Aerospace Ltd
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C13/00—Other constructional features or details
    • B66C13/18—Control systems or devices
    • B66C13/22—Control systems or devices for electric drives
    • B66C13/23—Circuits for controlling the lowering of the load

Definitions

  • FIG. 1 showsas a block a pair of powered hoists together with associated control apparatus
  • FIG. 2 is a diagram of a control apparatus
  • FIG. 3 is a circuit diagram of a part of the control apparatus.
  • a pair of powered hoist arrangements l0, 11 each comprises a winch drum 12 coupled by means of a shaft 13 to a gas turbine 14.
  • a brake assembly 15 is mounted on the shaft 13 to arrest the drum in a manner later to be described.
  • the turbines l4 and brake assemblies 15 are substantially as described in our co-pending application No. 1404/72.
  • Brake assemblies 15 are spring-biased to arrest rotation of the drums 12 and are movable to release drums 12 by a gas pressure from a source 16 which also acts to drive turbines 14.
  • Gas supply to each brake assembly 15 is under control of an associated solenoid valve 140 ('FIGJZ) responsive to electrical signals on lines 19 from-a pair of control apparatuses 17, 18 respectively associated with the hoist arrangements 10, 11.
  • 'FIGJZ solenoid valve 140
  • Each turbine 14 includes a control valve operable by means of an electric motor to reverse the direction of rotation of the turbine and also to control the amount of gas flow through the turbine, and hence the turbine power output. Electrical signals to control the motors are supplied from the associated control apparatus via lines 20. The positions of the control valves are fed back to the associated control apparatus via lines 21.
  • shut-off valve 22 Between each turbine 14 and the gas supply 16 is a shut-off valve 22 which is spring-biased to a shut position and which is operable to open by gas pressure from supply 16 under control of a solenoid valve 23. Valves 23 are responsive to signals on lines 24 from the associated control apparatus to open valves 22.
  • Each drum 12 is arranged so that associated cables 25 are laid up on drums 12 in a single layer only.
  • the torque applied to each drum 12 by a given load W thus remains constant.
  • the brake assemblies 15 respectively include a load-sensing elements 26, 27 which are operable, when the associated brake assembly 15 is holding the drum 12, to supply a voltage signal corresponding to the torque on the drum 12 to the control apparatus via lines 27a.
  • Brake assemblies 15 also include microswitches 40, 41 (FIG. 2) operable, when the associated brake assembly 15 is holding its drum 12, to provide an electrical signal via line 28 to the control apparatus as soon 2 as the torque supplied by turbine 14 overcomes the torque due to load W.
  • each drum 12 Associated with each drum 12 are microswitches 29, 30 (FIG. 2) which apply voltage control signals-to the associated control apparatus via respective lines 31, 32 when the drum 12 is at opposite extremes of its travel, that is when the cable 25 is respectively wound fully in and fully out.
  • Potentiometers 183, 184 (FlG. 2) associated with the respective drums 12, provide signals on lines 33 indicating the positions of the drums l2, and hence the amounts by which cables 25 are wound in or out.
  • 35 conveniently comprise hand-held units arranged so that control may be effected using one hand only.
  • control apparatuses l7, 18 are interconnected in a manner later to be described, whereby both hoist arrangements 10, 11 may, if required, be controlled from a single one of the panels 34, 35.
  • Each control apparatus 17, 18 incorporates a plurality of NAND gates whose input connections are such that both a +5 volt potential and an open circuit to these connections are logically equivalent to l and an earth potential applied to the connections is logically equivalent to 0. 1
  • control apparatus 17 includes pair of switches 36, 37 which are respectively connected between positive and negative voltage sources and a common terminal 38.
  • the winding of a potentiometer 39 is connected between terminal 38 and earth.
  • Switches 36, 37 and potentiometer 39 form part of the control panel 34.
  • Apparatus 17 includes an end stop circuit 54 to which terminal 38 is connected.
  • Circuit 54 includes a diode 42 having its cathode connected to terminal 38 and its anode connected via a resistor chain 43 and an inverter 44 to one input 45a of a NAND gate 45.
  • An intermediate point of resistor chain 43 is connected via a diode 46 to earth so that a current can flow from earth via diode 42 to terminal 38 when the latter is at a negative potential.
  • Input 45b of gate 45 is connected via line 32 and microswitch 30 to a +5 volt supply, and via a resistor 47 to earth.
  • Tenninal 38 is also connected to the anode of a diode 48 whose cathode is connected via a resistor chain 49 to one input 50a of a NAND gate 50.
  • An intermediate point on resistor chain 49 is connected to earth viaa resistor 9.
  • a second input 50b of gate 50 is connected via line 31 and microswitch 29 to a +5 volt supply, and also via a resistor 8 to earth.
  • NAND gates 45, 50 provide two of the inputs of a three input NAND gate 51, whose third input is provided in a manner later to be described.
  • An inverter 52 has as an input the output of gate 51, the output of inverter 52 being connected to an output line 66 for the end stop circuit 54.
  • the wiper of potentiometer 39 is connected via a resistor 55 to the input terminal of an amplifier 56.
  • the output tenninal of amplifier 56 is connected, via resistors 57, 58 in series, to the input terminal of a further amplifier 59.
  • the common point 60 of resistors 57, 58 is connected, via diodes 61, 62 respectively. to negative and positive reference voltages of predetermined values.
  • the arrangement of diodes 61, 62 is such that if the magnitude of the voltage at point 61 exceeds that of the reference voltages, current flows in the appropriate diode to maintain point 60 at the reference voltage.
  • the output terminal of amplifier 59 is connected to one input terminal of each pair of differential amplifiers 63, 64 whose other input terminals are respectively connected to negative and positive voltages.
  • the output terminals of amplifiers 63, 64 are commonly connected to the third input of NAND gate 51 via a line 53.
  • Amplifiers 56,59, 63, 64 and the associated resistors and diodes form, in conjunction with end-stop circuit 54 a speed and direction selector circuit 65, having an output line 67 provided by the output of amplifier 59, and whose manner of operation is as follows. Assuming that the associated drum 12 is not at either end of its travel, switches 29, 30 are open. Then if switch 36 is closed to select an upward direction for the asso ciated hoist, a 1 will appear at input 50a of gate 50.
  • the input of inverter 44 is earthed, i.e., volts providing a l at input 45a of gate 45. Since, however, inputs 45b and 50b are both at 0, both gates 45, 50 have a 1 output.
  • gate 45 will have an 0 output when switches 30, 37 are both closed, and will have a 1 output in other conditions.
  • a l signal thus appears on an output line from circuit 65 only when a speed and direction isfseleeted and the hoist is also free to move in theselected direction; If both switches 36, 37 are open, then both gates 45, 50 will have a 1 output. lnthis circumstance a l on line 53 derived in a manner to'be described later, will result in a 1 output on line 66 from end stop circuit 54.
  • Lines 68, 69 are connected to the input terminals of amplifiers 56,59 respectively.
  • Lines 68, 69 carry signals which are more or less positive or negative when the selected direction is respectively up or down.
  • Microswitch 40 is connected between a 5 volt supply and the signal line 28.
  • a brake indicator latching circuit 70 comprises NAND gates 71, 72.
  • Line 28 is connected to one input 71a of gate 71.
  • Input 71a is also connected via a resistor to earth.
  • the output of gate 71 is connected to an input 72a of gate 72, whose other input 72b is connected to a latching circuit reset line 73.
  • the output of gate 72 is connected to an input 71b of gate 71.
  • Microswitch 40 is operated by brake 15, when the latter is engaged with the associated winch drum 12, so that when a torque applied by the turbine 14 overcomes the torque due to load W, microswitch 40 opens.
  • Circuit thus has an 0 output only Switching circuit 78 forms part of a power-demand indicating circuit 79 and has a pnp transistor 80 with its base connected to connection 77, via a resistor 81. The emitter and collector of transistor 80 are respectively connected to a +5 volt supply and, via a resistor 82, to a 12 volt supply.
  • the collector of transistor 80 is also connected via a resistor 83 to the gate of a field effect transistor 84.
  • the source of transistor 84 is connected to earth.
  • a positive potential at connection 77 cuts ofi' transistor 80, applying l2 volts to the gate of transis tor 84, which then becomes non-conductive.
  • an earth potential at connection 77 causes transistor 84 to conduct.
  • Circuit 79 also includes an amplifier 85 which receives an input from the load sensing device 26 on the associated brake assembly 15.
  • the output terminal of amplifier 85 is connected to the drain of transistor 84.
  • a tacho-generator 86 is responsive to the speed of the associated drum 12.
  • the drain of transistor 84 and tacho-generator 86 are connected by respective resistors 87, 88 to an output terminal 89 of circuit 79.
  • the output line'67 of circuit'65 is connected via resistors 90, 91 to the output terminal 89 of circuit 79.
  • Terminal 89 also forms the input terminal of a position control circuit 93 for a synchro motor 94, which operates the direction and speed control valve in the turbine 14.
  • Circuit 93 includes an amplifier 95, to the input terminal of which the terminal 89 is connected.
  • the out I common point of resistors 102, 103 is connected to earth via a switching circuit 104, identical with circuit 78 previously described.
  • a latching circuit 105 identical with latching circuit 70, is responsive both to the output from gate 75 and to the signal on line 73.
  • a signal on a line 106 between the output of circuit and a control connection 107 for switching circuit 104 is thus maintained at l when there is an 0 output from gate 75.
  • a pair of switches 110, 111 are included in the respective control panels 34, 35.
  • Panels 34, 35 also respectively include potentiometers 112, 113 and associated respective spring-loaded switches 114, 115.
  • Switch 114 is connected between a +5 volt supply and an inverter 116 which forms part of a synchronising control circuit 117.
  • the input of inverter 116 is also connected via a resistor to earth.
  • Switch 114 and potentiometer 112 may be adjusted, in a manner later to be described, to obtain a condition in which both drums 12 are moved in unison but with different amounts of their associated cables wound out.
  • Switches 110, 111 are connected between a +5 volt supply and one input of a NAND gate 118 whose other input is connected to the output of inverter 116.
  • the output of gate 118 is connected via inverter 119 to one input of aNAND gate 120.
  • the output of gate 120 is connected to one input of a NAND gate 121 and the output of gate 121 is connected via an inverter 122 to a line 123 which provides an output connection for synchronising circuit 117 as a whole.
  • Circuit 117 also includes an inverter 124 which is connected between output line 74 from latching circuit 70 and a second input of gate 120.
  • a NAND gate 125 has one input also connected to the Output of gate 124 and a second input connected to the output of gate 118.
  • a further output line 126 for circuit 117 extends from the output of inverter 119.
  • Synchronising circuit 117 also includes a latching circuit 164 identical with circuit 70 and including NAND gates 165, 166.
  • One input of gate 165 is connected to earth via a resistor and also via one of lines 28 and microswitch 41 to a +5 volt supply.
  • a reset line 167 for circuit 164 is connected to control apparatus 18 and corresponds to line 73 in apparatus 17. Signals on lines 73, 167 are obtained in a manner later to be described.
  • the output of latching circuit 164 is connected via an inverter 129 to a third input of gate 120, and also via a line 163 to one input of a gate (not shown) in apparatus 18 and corresponding to gate 75 above described.
  • Line 123 is connected via an inverter 130 to one input of a NAND gate 131, whose other input is connected to the output line 66 from circuit 65.
  • the output of gate 131 is connected via an inverter 132 to the control connection 133 of a switching circuit 134 which is identical to switching circuit 78.
  • Circuit 134 is operable to connect the common point of resistors 90, 91 to earth, and circuit 134, together with inverters 130, 132 and gate 131, comprises an output control circuit 135 for signals on line 67 from speed selection circuit 65.
  • End stop circuit 54 and circuit 135 together comprise a switching arrangement for isolating a speed and direction demand signal from the position control circuit 93.
  • a solenoid 140 for the gas control valve for the brake is responsive to a brake control circuit 141, comprising a NAND gate 142, an inverter 146, a latching circuit 147, identical with circuit 70, and power stage switching circuit 148, identical with circuit 78.
  • Control circuit 141 has as its inputs the lines 66 and 123 and a third input provided by a differential amplifier 145 responsive to the output of the tacho-generator 86.
  • Amplifier 145 is biased so as to provide a 1 output when the drum 12 is stopped, and an 0 output when drum 12 is rotating.
  • a reset circuit 128 is also responsive to an output signal from amplifier 145 and comprises NAND gates 144, 154, 155, 157 159, and inverters 143, 153, 158, 160, 169.
  • Line 66 is connected to one input of gate 142 and via inverter 143 to one input of gate 144.
  • Gates 142, 144 also have inputs provided by differential amplifier 145.
  • Line 123 is connected via inverter 146 to a third input of gate 142.
  • the output of gate 142 is connected, via latching circuit 147, to a control connection of the power stage 148.
  • Stage 148 is in series with relay contacts 149 to control current flow from a 28 volt supply through solenoid 140.
  • the turbine 14 includes a gas shut-off valve 22.
  • the shut-off valve 22 is controlled by a servo-valve 23 operable by a solenoid 150 which is connected in parallel with solenoid and stage 148. Solenoid is not, however, responsive to control circuit 141, but to operation of relay contacts 149 as a result of operation of a relay 151 by either of a pair of emergency stop switches 138, 139 on the respective panels 34, 35.
  • the output of gate 144 is connected via inverter 153 to one input of each of gates 154, 155.
  • Output line 126 from circuit 117 is connected to the other input of gate 155, to one input of gate 157 and via inverter 158 to an input of gate 154.
  • the outputs of gates 154, 155, 157 provide inputs for gate 159.
  • a further input for gate 159 is provided from a +5 volt supply when either of switches 138, 139 in panels 34, 35 respectively are made.
  • the output of gate 159 is connected via inverter 160 to the reset line 73, which forms an output line from reset circuit 141. Line 73 provides an input into one gate of each latching circuit 70, 105 and 147, as described above.
  • a switching circuit 161 identical to circuits 78, 104, 134 is operable, when an earth potential is applied to its control connection 162, to connect the common point of resistors 98, 99 to earth.
  • Connection 162 is connected to the output of inverter 132 in circuit 135.
  • a line 168 is connected, via an inverter 169 to a second input of gate 157.
  • Line 168 is connected, in apparatus 18, to the output of a gate which corresponds to gate 144 as described above.
  • the output gate 144 is similarly connected, via a line 179 to an inverter in apparatus 18 corresponding to inverter 169.
  • the parts of the control apparatus 17 so far described are these necessary to effect control of the associated hoist arrangement 10 only, by means of the control panel 34, in which cases switches 110, 111 will not be made, and there will always be a 0 on line 126.
  • the amplifier 145 Before starting operation the amplifier 145 has a 1 output, and if speed and direction have not been selected there is a 0 on line 66 from circuit 65. Both inputs of gate 144 are therefore at l and the resulting 0 at the output is inverted to provide a l at one of the inputs of gate 154. The other input of gate 154 is also at l as a result of the inverted 0 on line 126.
  • the output of gate 154 is thus at 0 producing a l at the output of gate 159 and a 0 on reset control line 73.
  • the outputs of all the latching circuits 70, 105, 147 are thus at l, irrespective of the states of the other inputs of these latching circuits.
  • the 0 on line 66 causes the output of gate 142, and hence that of latching circuit 147, to be 1 causing the switching circuit 148 to de-energise brake solenoid 140.
  • the brake assembly 15 is thus holding the shaft 13.
  • Selection of a speed and direction provides a l on line 66 which, by applying an to one input of gate 144, causes the output of the latter to become 1. An 0 is thus applied to one input of gate 154, causing its output to become 1. The states of gates 155, 157 remain unchanged, and the output of gate 159 therefore becomes 0. The signal on line 73 is thus l, whereby the states of latching circuits70, 105, 147, may be changed.
  • the 0 on line 74 is inverted by gate 75 and is applied to latching circuit 105, which does not, however, change its state.
  • Switching circuit 104 thus remains in its closed circuit condition and amplifier 97 continues to integrate.
  • the 1 from gate 75 is again inverted and switching circuit 78 earths the output from load sensing element 26.
  • the 0 on line 123 causes both inputs to gate 131 to be 1 and the resulting 1 output from inverter 132 places switching circuits 134, 161 in their open circuit condition.
  • the speed and direction demand signal from circuit 65 can thereby pass to terminal 89 to be summed with the output of tacho-generator 86 to provide a speed error signal.
  • the amplified signal from terminal 89 can also pass via resistors 98, 99 to amplifier 100.
  • a potentiometer 181 is responsive to the position of the air control valve for turbine 14 in hoist arrangement 10. The voltage on the wiper of potentiometer 181 is supplied via line 21 and a resistor to the input of amplifier 100.
  • the input signal to amplifier is thus a positionerror signal for the air control valve.
  • a speed-error signal corresponding to a downward movement of the load similarly causes the input signal to amplifier 100 to be reduced, and motor 94 moves the air control valve so that the torque output of the turbine falls below that imposed by the load W. The winch is thus rotated by the load against the reduced lifting torque of the turbine.
  • inverter 76 At the same time the output of inverter 76 is set to 0 and switching circuit 78 conducts, earthing the output of load-sensing element 26.
  • the l on line 123 operates via output control circuit 135 to cause switching circuit 134 to earth the junction of resistors 90, 91, and also operates to cause switching circuit 161 to earth the junction of the resistors 98, 99.
  • the l output from latching circuit renders switching circuit 104 non-conductive, and amplifier 97 ceases to act as an integrator. The signal level from amplifier 97 thus disappears.
  • Apparatus 17 is thus set to its pre-start condition, from which it cannot depart until there is once again a 1 from end-stop circuit 54.
  • the input of amplifier 56 is connected via a resistor 170 to earth via a switching circuit 171 which is identical to circuit 78.
  • the control connection of circuit 171 is connected to a volt supply via the switches 110, 111.
  • the common point of resistor 170 and circuit 171 is also connected via a resistor 172 to a line 173 which extends to the wiper of a speed demand potentiometer 174 forming part of control panel 35.
  • Apparatus 18 is identical to apparatus 17 as above described, except that apparatus 18 has no equivalent of synchronising control circuit 117.
  • a synchronising circuit 180 is connected to apparatuses 17, 18, to control panels 34, 35 and via lines 33 to the potentiometers 183, 184 respectively associated with the drums 12.
  • latching means indicated at 189, 190, for retaining these wipers in required positions. Operation of the latching means 189, 190 to disengage the respective wipers 112a, 113a causes'the associated switches 114, 115 to be closed.
  • Summing junction 188 provides an input connection for an amplifier 191 whose output terminal is connected to earth via a resistor 192 and a switching circuit 193, identical to switching circuit 78.
  • the common point of resistor 192 and circuit 193 is connected via a line 206 and a resistor 207 to the input of amplifier 59.
  • the output terminal of amplifier 191 is also connected to earth via a resistor 194, an inverting amplifier 195 a further resistor 196 and a further switching circuit 197.
  • the common point of resistor 196 and circuit 197 is connected via a line 208 to a part of control apparatus 18 corresponding to resistor 207 and amplifier 59.
  • Load sensing element 26 is connected via an amplifier 198 to one input of a differential amplifier 199.
  • Load sensing element 27, associated with hoist arrangement l l, is connected via an amplifier 200 to the other input of amplifier 199.
  • Amplifier 199 is such that when the loads are equal or that sensed by element 26 is the greater there is, an 0 at the output of amplifer 199, and when the load sensed by element 27 is the greater there is a l at the amplifier output.
  • the output of amplifier 199 is connected to one input of a NAND gate 201 and via an inverter 202 to one input of a NAND gate 203.
  • the other inputs of gates 201', 203 are connected to the +5 volt supply via switches 110, 111.
  • the output of gate 201 is connected via an inverter 204 to the control connection of switching circuit 193.
  • the output of gate 203 is connected via an inverter 205 to the control connection of switching circuit 197.
  • a switching circuit 209 forming part of control apparatus 18 has its control connection connected to the +5 volt supply via switches 110, 111.
  • a pair of resistors 210, 211 also form part of apparatus 18 and are connected in series in a line 212 between the wiper of potentiometer 39 and the input connection of an amplifier 213 which also forms part of apparatus 18 and corresponds to amplifier 56 in apparatus 17.
  • Resistors 170, 172, 210, 211 have the same value. This value is twice that of resistors 55 in apparatus 17 and also twice that of a resistor 214 at the input of amplifier 213 in apparatus 18.
  • the impedance between the wiper of potentiometer 39 and the amplifier 56 is the same as that between potentiometer 39 and amplifier 213, when switching circuit 171 is open. Similarly the impedance between potentiometer 171 and amplifiers 56 and 213 are the same when switching circuit 209 is open.
  • both switching circuits 171, 209 are rendered open-circuit.
  • the inputs of amplifiers 56 and 213 in apparatus 17 and 18 respectively are thus inter-connected via resistors 170, 172, 210, 211.
  • a speed and direction selected on either of control panels 34, 35 will be applied to both of control apparatuses 17, 18.
  • a speed and direction signal at the inputs of amplifiers 56, 213 applies a l to line 53 and to the corresponding line in apparatus 18, thereby causing the output signal from the associated end-stop circuits to be 1.
  • Neither of hoist arrangements 10, 11 will, however, start up until the torque load on both has been overcome, as described above in connection with the synchronising circuit 117 of apparatus 17.
  • drum 12 in arrangement 10 With both hoists operating to lift their loads, and the load on hoist arrangement 1 1 being the heavier, it is to be expected that drum 12 in arrangement 10 will lead the drum of arrangement 11.
  • the wiper of potentiometer 183 thus becomes more positive than that of potentiometer 184.
  • the input of amplifier 191 becomes negative and a negative signal is applied via line 206 to the input of amplifier 59. This negative signal opposes the signal from control panel 34 by an amount dependent on the amount by which the drum arrangement 10 leadsthat of arrangement 11.
  • a control apparatus for a powered hoist having a winch drum, a motor capable of variable output for driving the drum and a brake for the drum said control apparatus comprising means for detecting a first torque applied by the drum to the brake when the latter is en gaged to arrest the drum, control means for causing a second torque supplied by said driving motor to be increased, brake control means responsive to movement of said drum by said second torque, said brake control means for releasing said brake only when the second torque exceeds the first torque, and further control means, operative only when the brake has been released, for modifying the second torque.
  • a control apparatus for a powered hoist having a winch drum, a motor capable of variable output for driving the drum and a brake for the drum said control apparatus comprising means for generating a first electrical signal dependent on a first torque which is applied by the drum to the brake when the latter is engaged to arrest the drum, means responsive to the magnitude of said first electrical signal to generate a second electrical signal, said motor supplying a second torque, means for increasing said second torque at a rate dependent on the magnitude of said second electrical signal, means for releasing said brake only when the second torque exceeds the first torque, and furthercontrol means, operative only when the brake has been released, for modifying the second electrical signal.
  • An apparatus as claimed in claim 2 which includes a synchro motor responsive to said second electrical signal to vary said second torque from said driving motor.
  • said means for releasing the brake comprises afirst'switching means, operable by the brake, when a part-thereof is urged against said first torque by said second torque, to provide a third electricalsignal, said brake being released in response to said third electrical signal.
  • An apparatus as claimed in claim 4 which includes second switching means responsive to said third electrical signal to provide a fourth electrical signal, and an electro-magnet device responsive to said fourth electrical signal to release said brake.
  • An apparatus as claimed in claim 5 which'includes third switching means responsive to said third electrical signal to isolate'said first electrical signal from said second electrical signal generating means.
  • An apparatus as claimed in claim 5 which includes means for generating a fifth electrical signal dependent on the rotational speed of said drum, said means for generating the second electrical signal being responsive to said fifth electrical signal.
  • said means for modifying the second torque includes means for generating a sixth electrical signal dependent on a desired speed and direction-of rotation of said drum, said means for generating the second electrical signal being responsive to said sixth electrical signal.
  • An apparatus as claimed in claim 8 which includes fourth switching means operable when said drum has reached a permitted limit of its rotation in either direction, for isolating said sixth electrical signal from said second electrical signal generating means.
  • said second electrical signal generating means includes means for summing said fifth and sixth electrical signals and a first amplifier responsive to the output of said summing means to provide an eighth electrical signal.
  • said second electrical signal generating means includes a further amplifier responsive to said eighth electrical signal and to the output of said summing means to provide said second electrical signal.
  • An apparatus as claimed in claim 11 which includes means for generating a feedback signal dependent on the rotational position of said synchro motor, said further amplifier also being responsive to said feedback signal.
  • An apparatus as claimed in claim 12 which includes fifth switching means responsive to said third electrical signal to isolate said further amplifier from the output of said summing means, whereby said further amplifier is responsive only to said eighth electrical signal only when said first switching means is not operated by said brake.
  • An apparatus as claimed in claim 11 which includes a feedback arrangement associated with said first amplifier to cause the latter to operate as an integrator, and sixth switching means responsive to operation of said sixth electrical signal generating means and to operation of said fourth switching means to render said feedback arrangement operative, whereby said first amplifier acts as an integrator when said sixth electrical signal is present and when said drum is not at one of its limits of angular rotation.
  • An apparatus as claimed in claim 14 which includes a logic circuit responsive to said fifth electrical signal and to operation of said fourth switching means and said sixth electrical signal generating means, to generatev a ninth electrical signal, whereby said ninth electrical signal is present only in the presence of said sixth electrical signal and when said drum is not at one of its limits of rotation, and a plurality of latching circuits responsive to said ninth electrical signal to cancel said third and fourth electrical signals and to cause said sixth switching means to render said feedback arrangement inoperative.
  • a combination as claimed in claim 16 which includes seventh switching means operable to provide a tenth electrical signal, said interconnection arrangement being responsive to said tenth electrical signal to cause said control apparatuses to coact.
  • said interconnection arrangement includes a second logic circuit responsive to said third electrical signal and to said tenth electrical signal to provide an eleventh electrical signal, said fourth switching means and a corresponding switching means in said further control apparatus being responsive to said eleventh electrical signal, whereby, when said seventh switching means is operated, and said first switch means and a corresponding switching means in said further apparatus is operated, said sixth electrical signal, and a corresponding arrangement inoperative.
  • said interconnection arrangement includes first and second means responsive to the rotational positions of the respective drums to provide thirteenth and fourteenth electrical signals, second summing means responsive to said thirteenth and fourteenth electrical signals to provide a fifteenth electrical signal, and first and second modifying means for respectively modifying said sixth electrical signal, and a corresponding signal in said further control apparatus, in accordance with said fifteenth electrical signal.
  • a combination as claimed in claim 20 which includes means for generating a sixteenth electrical signal dependent on the torque applied by the drum of said further hoist to the brake thereof when the latter is engaged, and ninth and tenth switching means responsive to said first and sixteenth electrical signals and to said tenth electrical signal and respectively operable to isolate said fifteenth electrical signal from said sixth electrical signal and from the corresponding signal in said further control apparatus.
  • a combination as claimed in claim 20 which includes means for modifying said thirteenth and fourteenth electrical signals in accordance with a desired difference in the rotational positions of said drums.
  • a combination as claimed in claim 17 which includes means for interconnecting said sixth electrical signal generating means and the corresponding generating means in said further control apparatus, and eleventh switching means responsive to said tenth electrical signal to render said interconnecting means inoperative.

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  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Mechanical Engineering (AREA)
  • Safety Devices In Control Systems (AREA)
  • Control And Safety Of Cranes (AREA)
  • Stopping Of Electric Motors (AREA)
  • Braking Arrangements (AREA)
US00343047A 1972-03-21 1973-03-20 Control apparatus for a powered hoist Expired - Lifetime US3847251A (en)

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GB1321372A GB1419641A (en) 1972-03-21 1972-03-21 Control apparatus for a powered hoist

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US3847251A true US3847251A (en) 1974-11-12

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US00343047A Expired - Lifetime US3847251A (en) 1972-03-21 1973-03-20 Control apparatus for a powered hoist

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US (1) US3847251A (de)
JP (1) JPS4912559A (de)
DE (1) DE2313893A1 (de)
FR (1) FR2176986B1 (de)
GB (1) GB1419641A (de)
IT (1) IT979910B (de)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4337848A (en) * 1980-04-21 1982-07-06 Inventio Ag Start control device, especially for an elevator
US4739969A (en) * 1985-11-04 1988-04-26 Johns Perry Industries Pty. Ltd. Lift sheave
US4754850A (en) * 1987-07-29 1988-07-05 Westinghouse Electric Corp. Method for providing a load compensation signal for a traction elevator system
US4793442A (en) * 1987-11-05 1988-12-27 Schindler Elevator Corporation Method and apparatus for providing pre-travel balancing energy to an elevator drive
US5049793A (en) * 1986-04-10 1991-09-17 Kabushiki Kaisha Yasakawa Denki Seisakusho Method of controlling V/F inverter for machines having mechanical braking systems
US5424498A (en) * 1993-03-31 1995-06-13 Otis Elevator Company Elevator start jerk removal
US6758356B1 (en) * 1989-10-10 2004-07-06 Manitowoc Crane Companies, Inc. Liftcrane with synchronous rope operation
WO2013060120A1 (zh) * 2011-10-28 2013-05-02 上海三一科技有限公司 多卷扬同步控制装置及控制方法及包括该装置的起重机
US10308230B2 (en) * 2015-11-13 2019-06-04 Igarashi Electric Works Ltd Electric parking brake device

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2033511B (en) * 1978-11-10 1982-09-02 Coal Industry Patents Ltd Brake control equipment for a vehicle with drive means
GB2082227B (en) * 1980-08-15 1984-03-07 Coal Industry Patents Ltd Brake equipment for underground mining machines

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3244957A (en) * 1959-09-02 1966-04-05 Spiess Gustav Starting arrangements of electric drives with mechanical holding brakes
US3486101A (en) * 1965-04-01 1969-12-23 Inventio Ag Jolt-free starting arrangement for electrical drive having a mechanical brake
US3614996A (en) * 1968-11-29 1971-10-26 Mitsubishi Electric Corp Elevator control system

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3510107A (en) * 1968-01-11 1970-05-05 United Aircraft Corp Multiple hoist synchronization system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3244957A (en) * 1959-09-02 1966-04-05 Spiess Gustav Starting arrangements of electric drives with mechanical holding brakes
US3486101A (en) * 1965-04-01 1969-12-23 Inventio Ag Jolt-free starting arrangement for electrical drive having a mechanical brake
US3614996A (en) * 1968-11-29 1971-10-26 Mitsubishi Electric Corp Elevator control system

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4337848A (en) * 1980-04-21 1982-07-06 Inventio Ag Start control device, especially for an elevator
US4739969A (en) * 1985-11-04 1988-04-26 Johns Perry Industries Pty. Ltd. Lift sheave
US5049793A (en) * 1986-04-10 1991-09-17 Kabushiki Kaisha Yasakawa Denki Seisakusho Method of controlling V/F inverter for machines having mechanical braking systems
US4754850A (en) * 1987-07-29 1988-07-05 Westinghouse Electric Corp. Method for providing a load compensation signal for a traction elevator system
US4793442A (en) * 1987-11-05 1988-12-27 Schindler Elevator Corporation Method and apparatus for providing pre-travel balancing energy to an elevator drive
US6758356B1 (en) * 1989-10-10 2004-07-06 Manitowoc Crane Companies, Inc. Liftcrane with synchronous rope operation
US5424498A (en) * 1993-03-31 1995-06-13 Otis Elevator Company Elevator start jerk removal
WO2013060120A1 (zh) * 2011-10-28 2013-05-02 上海三一科技有限公司 多卷扬同步控制装置及控制方法及包括该装置的起重机
US10308230B2 (en) * 2015-11-13 2019-06-04 Igarashi Electric Works Ltd Electric parking brake device

Also Published As

Publication number Publication date
DE2313893A1 (de) 1973-10-04
FR2176986B1 (de) 1977-12-30
GB1419641A (en) 1975-12-31
FR2176986A1 (de) 1973-11-02
JPS4912559A (de) 1974-02-04
IT979910B (it) 1974-09-30

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