US3174086A - Multi-function plural motor control for material handling apparatus - Google Patents

Description

March 16, 1965 H. A. GORJANC MULTI-FUNCTION PLURAL MOTOR CONTROL FOR MATERIAL HANDLING APPARATUS Flled Aprll 12, 1960 INVENTOR. HENRY A. GORJANC [:0 L BY ATTORNEYS United States Patent 3,174,686 MULTI-FUNCTION PLURAL MOTQR CONTROL FOR MATERIAL HANDLING APPARATUS Henry A, Gorjanc, Wicklifie, Ohio, assignor to The Cleveland Crane dz Engineering Company, Wiclrliife, Ohio,

a corporation of ()hio Filed Apr. 12, 1960, Ser. No. 21,744 7 Claims. (Cl. Slit-51) This invention relates to material handling apparatus including electrically operated cranes, trolleys, carriers and the like having a plurality of operational functions such as forward and reverse motion, and/ or up and down hoist operation, etc. More particularly this invention is directed to apparatus of the character mentioned including a control apparatus for effecting control of a plurality of operations or functions from a remote position through conductors and wherein such apparatus can be effected without requiring an inordinate amount of conductors.

It is a principal object of the invention to provide a novel and improved alternating current electrically powered material handling apparatus having movable carrier means supplied with alternating current electric power from conductor bars and having remote multifunction control means which is particularly simple and efficient in operation and which utilizes the phase differences of the alternating current to provide a plurality of function contactor actuating circuits, portions of which circuits are common to more than one such circuit, whereby a number of function effecting contactors can be selectively actuated or energized to produce their respective functions, and which circuits include only one control conductor bar in addition to the power supplying conductor bars.

Another object of this invention is the provision, in an alternating current electrically powered material handling apparatus of the character mentioned, of a multi-function control circuit comprising a sending portion and a receiving portion connected by conductor bar and current collector means and utilizing the alternating current phase characteristics of the electric power to provide rectified or polarized control current for selectively energizing switching means to complete circuits for energizing electrical actuators, such as, motor means, from the alternating current power supply, and whereby as many as four ditfercnt function contractors may be selectively actuated in response to remote control switches in the sending portion of the circuit.

Other objects and advantages of the invention, not specifically set forth above, will be apparent from the following detailed description of the presently preferred embodiment thereof, illustrated in the accompanying drawing forming a part of this specification, and in which:

P16. 1 is a fragmentary clevational View of an electrified, overhead, monorail, carrier-type material handling apparatus forming part of an exemplary embodiment of the invention; and

FIG. 2 is a diagrammatic illustration of a four function control circuit for operating the carrier of FIG. 1.

This invention is particularly applicable to material handling apparatus having carriers in the form of bridge crane trolleys, overhead monorail cranes, overhead monorail carriers, and the like which are electrically operated and have motor means for performing a plurality of functions, such as, forward and reverse travel along a runway, bridge or track, and up and down hoist operations.

As one embodiment of the invention, a portion of a material handling system, including a trolley or carrier ll adapted to travel along an overhead monorail track or rail ll, is shown in FIG. 1. The carrier 1!) is provided with a drive motor 12 for propulsion thereof along the rail 11 and a hoist motor 13 for raising or lowering a hook block 14, or the like, forming a part of a hoist mechanism 15. The system includes a plurality of conductor bars, such as a bar 20, associated with the rail structure ll and adapted to provide current or electric power to the carrier 10 through a plurality of current collectors, such as the collector 21, mounted on the carrier and in sliding engagement with the conductor bars.

The four functions previously mentioned, namely forward, reverse, up and down, are representative of the type of functions that may be effected through the use of the control apparatus or circuit described hereafter, and per units the remote control of the functions through the conductor 'bars usually required for providing electric power and a single additional conductor bar. The functions are effected in response to operation of control switches which may be mounted in the cab of a bridge type crane for controlling the trolley thereof, or on a wall bracket or the like for controlling a carrier, such as the carrier ll), of a monorail system. In these instances the control switches are manually operable, however it will be recognized that in automatic dispatch systems, or the like, the control switches may be in the form of limit switches associated with the rail ill and operable by the carrier 1t) itself. It will also be recognized that the control system may be employed to perform operations off the carrier, such as, operation of a track switch.

A four function control circuit is illustrated in FIG. 2 and comprises a sending portion 22 and a receiving portion 23. The receiving portion 23 is carried by the trolley or carrier it? and is connected to the sending portion through current collectors 21a, 21b and 210 in engagement with conductor bars Zita, 20b, and 20c forming a part of the sending portion 22. The circuit operates on alternating current supplied through power lines L1 and L2 connected to the power conductor bars Ella, 2th: and includes a control line C connected to the control conducto-r bar sec. The power lines L1 and L2 may be two lines of a three phase system the third line which is designated L3 or may be the two lines of a single phase system.

The sending portion 22 comp-rises four diode type rectifiers 25, 26, 27 and 2S and push button switches Bil, 31, 32 and 33 for effecting the aforesaid forward, reverse, up and down functions, respectively. These control switches complete circuits, which will be more particularly described hereafter, to energize and actuate a plurality of solenoid actuated relays or function contactors 35, 36, 37 and 38 in the receiving portion 23 for completing motor energizing circuits of the type which are well known to those skilled in the art to which the invention pertains and which operate the motors l2 and 13 to carry out the listed functions.

The power lines L1 and L2 carry alternating current and exhibit opposite potentials at each half-cycle thereof, that is, during one half-cycle the line L1 is positive with respect to L2, and during the other half-cycle L2 is positive with respect to L1. The control line C is adapted to be connected to one or the other of the power lines L1, L2 by depressing the appropriate push button switch 30, 31, 32 or 33.

The receiving portion of the circuit 23 comprises conductors 40, 41 and 42 which are connected to the current collectors 21a, 21b and 21c, respectively, and the conductors 4d and 42 thereof continuously exhibit the same potentials as the power lines L1 and L2 from which they are energized. The forward and reverse function relays or contactors 3S and as are connected across the conductors it} and 42 in series relation with diode type rectificrs 466 and 47, normally closed contacts 48 and 49 of the contactors 35 and 36, and a pair of resistors 59 and 51. The up and down function relays or contactors 37 and 38 respectively, are similarly connected across the conductors 4t) and 42, in series relation with diode type rectifiers 56 and 57, normally closed contacts 58 and 59 of the contactors 37 and 38 and a pair of resistors 60 and 61. The conductor 41 which is connected to the control line C by the current collector 21b is connected commonly between the resistors 50, 51 and the resistors 60, 61.

The contactors 35, 36, 37 and 38 are provided with normally open contacts 62, 63, 64 and 65 respectively, which contacts when closed serve to complete conventional circuits for energizing the motor means 12 and 13. The contacts 62 are connected in series circuit between line 40 and a line 66 connected to L3 by the conductor 26c and the collector 21d with the forward solenoid e7 of the reversing motor controller for the travel motor 12 and the contacts 63 are connected in series circuit between the same lines with the reverse solenoid 68 of the motor controller. The contacts 64, 65 are connected to the up and down solenoids, respectively, of the reversing controller for the hoist motor 13 in a similar manner.

The rectifiers as and 47 are oriented so as to conduct current from the conductor 40 to the conductor 42 when the former is positive with respect to the latter, and to lock current flow when the conductor 42 is positive with respect to the conductor 49. It will be recognized that because of the above described series relationship of the contactors and 36 that there will normally be a rectified or polarized current flow from the conductor through the contactors 35 and 36 to the conductor 42 and that a potential will appear across each of the contactors of a value something less than one-half of the potential existing between the conductors 40 and 42. Likewise, there will appear across each of the contactors 3'7 and 33 a potential which is something less than one-half of the potential which exists between conductors 42 and 40. The potentials across the contactors are less than onehalf because of the voltage drops introduced by the series connected resistors 51, and 61, and by the rectifiers 4e, 47, 5s and 57.

The contactors 35, 36, 37 and 38 are chosen to have such operating characteristics that they will not be actuated or pick up at half the potential between conductors 40 and 42, but will be actuated at more than half of that potential. Therefore, although a small current is normally flowing through each set of contactors 35, 36, 37 and 38, they will not be actuated thereby.

In order to energize the drive motor 12 in a sense to propel the carrier 10 in a forward direction the push button 39 is depressed, thereby closing the normally open contacts thereof and opening the normally closed contacts 71 thereof. The closing of the contacts 70 completes a circuit which may be traced from the power line L1 through a conductor 75, normally closed contacts '76 of the push button switch 31, a conductor 77, the now closed contacts 70, the diode type rectifier 25, to the control line C and the conductor bar Ztlb, the current collector 21b, conductor 41, the resistor 51, normally closed contacts 49 of the reverse contactor 36, a diode type rectifier 46 and the actuating solenoid 78 of the forward contactor 35 to the conductor 42 connected to the current collector 210 which is in conducting engagement with the conductor bar 20b connected to the power line L2. The conductor 41 is thereby brought to the same potential as the conductor 40, with the effect of shorting out the reverse contactor 36, rectifier 4'7 and resistor 50.

The forward function contactor 35 therefore has almost the full line voltage impressed thereacross and is energized, opening its normally closed contacts 48 and closing its normally open contacts 62. The now closed contacts 62 are connected in a suitable manner to complete a circuit for energizing the forward solenoid 67 of the motor controller which in turn causes the drive motor 12 to operate in the direction to effect forward movement of the carrier 10.

It will be recognized that the rectifier 46 will permit current flow therethrough only during the half-cycle in which conductors 4t 41 are positive with respect to conductor 42, and therefore a smoothing capacitor is connected directly across the solenoid 78 of the contactor 35. The capacitor 80 is charged during current flow through the rectifier 46 and discharges through the solenoid 78 when the rectifier blocks current flow from the conductor 42. The resistance 51 serves to slow the charging of the capacitor 80 and, as mentioned before, to assure that the contactor 35 normally has less than half the line voltage thereacross and will not pick up unless the control switch 30 is depressed.

if the forward control switch 39 is now released, opening the contacts 76 thereof, the current flowing in the solenoid '78 of contactor 35 will fall to zero because the normally closed contacts 48 thereof are open. With the loss of current thereto the contactor 35 will drop out or release its armature to close the contacts 48, and to open the contacts 62 for de-energizing the motor 12. The contacts 48 are positioned between the conductors 40, 41 because, although the contactor 35 will not pick up at half potential, there is a possibility that it would not drop out on a mere reduction of potential from full line voltage to half potential as would occur if the contacts 48 were positioned between conductors 41 and 42, which would permit current to flow from the conductor 40 through the contactor 36 and resistor 5t) to the contactor 35 immediately upon switch 39 being released.

If it is now desired to run the carrier along the rail 11 in a reverse direction, the push button control switch 31 may be depressed, closing the normally open contacts thereof and opening the normally closed contacts 76 thereof. Closing of the contacts 85 completes a circuit which may be traced from the conductor ill through the solenoid 86 of the reverse contactor 36, the rectifier 47, the normally closed contacts 48 of the contactor 35, the resistor 5t conductor 4-1 and the current collector 21b to the conductor bar 20b, the conductor or control line C, the rectifier 2e and now closed contacts 85 of the control switch 31, a conductor 88, contacts 1 of the forward control switch 30, and a conductor 5.9 to the power line L2.

This circuit shorts out the resistor 51 and the solenoid 78 of the forward contactor 35, thereby increasing the current flow through the solenoid 36 to a level where the reverse contactor 36 is actuated, drawing in its armature to open the normally closed contacts 4-9 thereof and to close the normally open contacts 63 thereof. The latter, contacts 63, serve to complete a circuit for energizing the motor 12 in a sense to propel the carrier 10 in a reverse direction along the rail 11.

A smoothing condenser or capacitor 9% is connected across the solenoid 86 and serves to store electricity during the half-cycle during which current flows to the solenoid 85 and to give up electricity therethrough during the other half-cycle.

In order to halt the reverse movement of the carrier 10, the switch 31 is released, thereby reducing to zero the potential across the contactor 36 and causing the contacts 63 thereof to open.

Operation of the up and down functions is accomplished through portions of the control circuits similar to those described with respect to the forward and reverse functions, and is described hereafter. When it is desired to raise the hook 14, the up push but-ton or control switch 32 is depressed, closing the normally open contacts 92 thereof and opening the normally closed contacts 93 thereof.

Closing of the contacts 92 completes a circuit which may be traced from the conductor 42, through the actuating solenoid 95 of the up contactor 37, the rectifier 56, normally closed contacts 59 of the down contactor 38,

the resistor 61 and the conductor 41 to the current collector 21b, and from the conductor bar 20b through the control line C, the rectifier 27, the now closed contacts 92 of the up control switch 32, a conductor :97, normally closed contacts 98 of the down control switch 33, and a conductor 99 to the power line L1. This circuit serves to short out the down contactor 38 and the resistor 60, thereby increasing the current fiow through the solenoid d5 to a level where the armature thereof is drawn in.

Drawing in of the armature opens the normally closed contacts 53 thereof and closes the normally open contacts 6 thereof. The latter, contacts 64, complete a circuit which is effective to energize the hoist motor 13 in a sense to operate the hoist mechanism 15 to raise the book block 14. The opening of the contacts 58 prevents the likelihood of the contactor 37 remaining drawn in upon releasing the control switch 32 and opening the contacts 92 thereof.

in order to lower the hook block 14, the push button control switch 33 may be depressed, opening the normally closed contacts 98 thereof and closing the normally open contacts 106 thereof. Closing of the contacts 100 effects the completion of a circuit which may be traced from the power line L2 through a conductor lfil, the normally closed contacts 93 of the up control switch 32, a conductor 1%, the now closed contacts 1% of the switch 33, the rectifier 28, the control line C and conductor bar Ztlb, the current collector 21b, the conductor 41, resistor 6d, contacts 58, the rectifier 57, and the actuating solenoid 1&5 of the down contactor 38 to the conductor 4t). This circuit serves to energize the contactor 38 by increasing the current flow therethrough, drawing in the armature thereof to open the normally closed contacts 59 and to close the normally open contacts 65. The

latter, cont-acts 65, complete a circuit which is effective to energize the motor 13 in a sense to operate the hoist mechanism for lowering the hook block 14.

Again, it will be noted that the contactors 37 and 38 are provided with capacitors lit and 111 respectively, for storing up electricity during that half-cycle when the conductor 42 is positive with respect to the conductor 4t) and for discharging current through the solenoids 95 and 1% during the other half-cycle.

The control switches 30 and 31 are electrically interlocked so that depressing of both switches at the same time cannot cause a short circuit from the line L1 to the line L2. Likewise, the control switches 32 and 33 are electrically interlocked to prevent the possibility of creating a short circuit from line L2 to line L1 in the event both switches are depressed. The electrical interlock in each case is effected by providing each switch with normally closed contacts and normally open contacts, with the normally closed contacts of each switch connected in series with the normally open contacts of another switch. In the instance described above where the control switch 30 was depressed to actuate the forward contactor 35, for example, the normally closed contacts '76 of the switch 31 are in series with the contacts 70 of the switch Sfi. Had the switch 31 been depressed at the same time as the switch 36, no circuit would have been completed.

Because the forward and reverse switches 30, 31 are interlocked, and the up and down switches 32, 33 are interlocked, the circuit is ideal for controlling reversing motors such as the motors 12 and 13 since each is only capable of running in one direction at a time.

The motors 12 and 13 can, however, be operated simultaneously without regard to direction because of the orientation of the rectifiers in pairs, with the rectifiers 46, 4'7 and 25, 26 arranged for permitting current fiow in one direction and the rectifiers 56, 57 and 27, 28 for permitting current fiow in the opposite direction.

The invention can be used to perform merely two functions such as forward and reverse, up and down, or the like, and the interlock referred to omitted and the wiring thus simplified by omitting one or the other pairs of contactors 35, 36 and 37, 38 and the control elements associated therewith including the pairs of switches 30, 31 and 32, 33, respectively.

From the foregoing detailed description of the preferred embodiment of the invention, and a modification thereof, it will be recognized that there has been provided thereby a particularly economical multi-function electrical control systems and/ or material handling system having improved control means for effecting a plurality of motor functions or the like from a remote position and using the power conductors thus requiring the inclusion of but one additional conductor. The system is particularly rugged and simple in construction yet flexible and adaptable in use.

Although the invention has been described in considerable detail and with reference to specific embodiments thereof, it is understood that the invention is not limited thereby but rather the invention includes such changes, modifications and uses thereof as are reasonably embraced by the scope of the claims hereof.

Having described my invention, I claim:

1. In a multi-function control circuit, first and second conductors adapted to be connected to an alternating current source, a first contactor connected in series with a first rectifier means between said first conductor and a third conductor, a second contactor connected in series with a second rectifier means between said third conductor and said second conductor, said contactors connected in series across said first and second conductors drawing insufiicient current to actuate the same, a first control switch connected between said first conductor and said third conductor, and a second control switch connected between said third conductor and said second conductor, said first rectifier means being oriented to conduct current in a direction from said first conductor toward said third conductor, and said second rectifier means being oriented to conduct current in a direction from said third conductor toward said second conductor whereby closing of said first control switch shorts out said first contactor to effect actuation of said second contactor and closing of said second control switch shorts out said second contactor to effect actuation of said first contactor, said first and second control switches each having normally open contacts and normally closed contacts, the normally closed contacts of each control switch being connected in series relation with the normally open contacts of the other control switch.

2. In a multi-function control circuit, first and second conductors adapted to be connected to an alternating current source, a first contactor connected in series with a first rectifier means between said first conductor and a third conductor, a second contactor connected in series with a second rectifier means between said third conductor and said second conductor, said contactors connected in series across said first and second conductors drawing insuficient current to actuate the same, a first control switch connected between said first conductor and said third conductor, and a second control switch connected between said third conductor and said second conductor, said first rectifier means being oriented to conduct current in a direction from said first conductor toward said third conductor, and said second rectifier means being oriented to conduct current in a direction from said third conductor toward said second conductor whereby closing of said first control switch shorts out said first contactor to eitect actuation of said second contactor and closing of said second control switch shorts out said second contactor to effect actuation of said first contactor, and means to prevent simultaneously establishing a circuit through said first and second control switches.

3. In a multi-function control circuit; first and second power conductors adapted to be connected to an alternating current source; a control conductor; a first contactor and a first rectifier connected in series relation between said first conductor and said control conductor; a second contactor and a second rectifier connected in series relation between said control conductor and said second conductor; a third contactor and a third rectifier connected in series relation between said first conductor and said control conductor; a fourth contactor and a fourth rectifier connected in series relation between said control conductor and said second conductor; said contactors connected in series across said first and second conductors drawing insufiicient current to actuate the same, a first control switch and a fifth rectifier connected in series relation between said control conductor and said second conductor; a second control switch and a sixth rectifier connected in series relation between said first conductor and said control conductor; a third control switch and a seventh rectifier connected in series relation between said control conductor and said second conductor; and a fourth control switch and an eighth rectifier connected in series relation between said first conductor and said control conductor; said first, second, fifth and sixth rectifiers being oriented to pass current in one direction and said third, fourth, seventh and eighth rectifiers being oriented to pass current in the opposite direction whereby actuation of said control switches will operate said contactors selectively.

4. A circuit as defined in claim 3 and wherein said first contactor includes normally closed contacts in series with said second contactor; said second contactor includes normally closed contacts in series with said first contactor; said third contactor includes normally closed contacts in series with said fourth contactor; and said fourth contactor includes normally closed contacts in series with said third contactor.

5. A circuit as defined in claim 3 and wherein said control switches each comprise normally open contacts and normally closed contacts, the normally open contacts of each control switch being connected in series with the normally closed contacts of another of the control switches.

6. In a material handling system including a carrier and having electric motor means for effecting at least four functions: first, second, third, and fourth solenoid actuated contactors to which said motor means are responsive to selectively effect said four functions; said system having alternating current transmitting means including first, second, and third sets of cooperating relatively fixed and movable conductive elements; said first contactor being connected in series with a first rectifier means between a conductive element of said first set and a conductive element of said third set; said second contactor being connected in series with a second rectifier means between a conductive element of said third set and a conductive element of said second set;-said third contactor being connected in series with a third rectifier means between a conductive element of said first set and a conductive element of said third set; said fourth contactor being connected in series with a fourth rectifier means between a conductive element of said third set and a conductive element of said second set; said contactors connected in series across said first and second conductors drawing insufiicient current to actuate the same; a first control switch and a fifth rectifier means connected in series between a conductive element of said i3 0 first set and a conductive element of said third set; a second control switch connected in series with a sixth rectifier means between a conductive element of said third set and a conductive element of said second set; a third control switch connected in series with a seventh rectifier means between a conductive element of said first set and a conductive element of said third set; and a fourth control switch connected in series with an eighth rectifier means between a conductive element of said third set and a conductive element of said second set; said first, second, fifth and sixth rectifier means being oriented to pass current in one direction and said third, fourth, seventh and eighth rectifier means being oriented to pass current in the opposite direction.

7. In a material handling system including a carrier having electric motor means for effecting at least four functions and having current collector means for receiving electric power from conductor bar means: first, second, third and fourth solenoid actuated contactors to which said motor means are responsive to selectively effect said four functions; first and second conductor bars adapted to carry alternating current; first and second current collectors for engagement with said first and second conductor bars; a third conductor bar and a third current collector for engagement therewith; said first contactor being connected in series with a first rectifier means between said first current collector and said third current collector; said second contactor being connected in series with a second rectifier means between said third current collector and said second current collector; said third contactor being connected in series with a third rectifier means between said first current collector and said third cu"- rent collector; said fourth contactor being connected in series with a fourth rectifier means between said third current collector and said second current collector; said contactors connected in series across said first and second conductors drawing insufficient current to actuate the same; a first control switch and a fifth rectifier means connected in series between said first conductor bar and said third conductor bar; a second control switch connected in series with a sixth rectifier means between said third conductor bar and said second conductor bar; a third control switch connected in series with a seventh rectifier means between said first conductor bar and said third conductor bar; and a fourth control switch connected in series with an eight rectifier means between said third conductor bar and said second conductor bar; said first, second, fifth and sixth rectifier means being oriented to pass current in one direction and said third, fourth, seventh and eighth rectifier means being oriented to pass current in the opposite direction.

References Cited in the file of this patent UNITED STATES PATENTS 1,463,168 Kintzing July 31, 1923 2,401,358 Lazar June 4, 1946 2,418,806 Reeves et al. Apr. 8, 1947 2,892,132 Mallory June 23, 1959 2,941,638 Hoover June 21, 1960 2,943,255 Fresne et al June 28, 1960

Claims (1)

1. IN A MULTI-FUNCTION CONTROL CIRCUIT, FIRST AND SECOND CONDUCTORS ADAPTED TO BE CONNECTED TO BE ALTERNATING CURRENT SOURCE, A FIRST CONTACTOR CONNECTED IN SERIED WITH A FIRST RECTIFIER MEANS BETWEEN SAID FIRST CONDUCTOR AND A THIRD CONDUCTOR, A SECOND CONTACTOR CONNECTED IN SERIES WITH A SECOND RECTIFIER MEANS BETWEEN SAID THIRD CONDUCTOR AND SAID SECOND CONDUCTOR, SAID CONTACTORS CONNECTED IN SERIES ACROSS SAID FIRST AND SECOND CONDUCTORS DRAWING INSUFFICIENT CURRENT TO ACTUATE THE SAME, A FIRST CONTROL SWITCH CONNECTED BETWEEN SAID FIRST CONDUCTOR AND SAID THIRD CONDUCTOR, AND A SECOND CONTROL SWITCH CONNECTED BETWEEN SAID THIRD CONDUCTOR AND SAID SECOND CONDUCTOR, SAID FIRST RECTIFIER MEANS BEING ORIENTED TO CONDUCT CURRENT IN A DIRECTION FROM SAID FIRST CONDUCTOR TOWARD SAID THIRD CONDUCTOR, AND SAID SECOND RECTIFIER MEANS BEING ORIENTED TO CONDUCT CURRENT IN A DIRECTION FROM SAID THIRD CONDUCTOR TOWARD SAID SECOND CONDUCTOR WHEREBY CLOSING OF SAID FIRST CONTROL SWITCH SHORTS OUT SAID FIRST CONTACTOR TO EFFECT ACTUATION OF SAID SECOND CONTACTOR AND CLOSING OF SAID SECOND CONTROL SWITCH SHORTS OUT SAID SECOND CONTACTOR TO EFFECT ACTUATION OF SAID FIRST CONTACTOR, SAID FIRST AND SECOND CONTROL SWITCHES EACH HAVING NORMALLY OPEN CONTACTS AND NORMALLY CLOSED CONTACTS, THE NORMALLY CLOSED CONTACTS OF EACH CONTROL SWITCH BEING CONNECTED IN SERIES RELATION WITH THE NORMALLY OPEN CONTACTS OF THE OTHER CONTROL SWITCH.

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