US2393048A - Automatic winch control - Google Patents

Description

Jan. 15, 1946. MAHNKE AUTOMATIC WINCH CONTROL Filed Feb. 10, 1944 WITNESSES:

K INVENTOR Karl Ma fun e.

ATTORNEY.

Patented Jan. 15, 1946 AUTOMATIC WINCH CONTROL Kurt Mahnke, Wilkinsburg, Pa., assignor to Westlnghouse Electric Corporation, East Pittsburgh, 1a., a corporation oi. Pennsylvania Application February 10, 1944, Serial No, 521,817

2 .Claims.

My invention relates to electric winch control systems, such as ior towing winches and cargo winches. It is known to provide such systems with a master controller for manual control of the electric winch motor and also with automatic control means for controlling the motor in dependence upon the tension or length, or both, of the winch cable.

It is an object of my invention to provide a winch control system of the Just mentioned type, which affords an improved maneuverability by permitting the operator to change more readily than in known systems from automatic to manual control and vice versa, for instance, for temporarily modifying, accelerating, reversing or otherwise altering an automatic towing performance.

Another object of my invention is to provide a winch control system of the type referred to with an improved master control unit in which a single master controller and a single handle, when placed in one position, serves to set the system for automatic control and, when placed in other control positions, serves also to govern the manually controlled winch operation.

Other objects and advantages of my invention will be apparent from the following description of the winch control system diagrammatically shown in the drawing as an example of the invention.

According to the drawing, the winch motor WM has its armature A connected with a shaft l which drives a reduction gear unit 2 whose output shaft 3 is in driving connection with the winch drum 4 for accommodating the rope or cable 5 to be paid out or reclaimed by the winch drive. The winch drum 4 is provided with an orbit gear meshing with planet gears 6 which, in turn, are in meshing engagement with a sun gear 1. The sun gear is rotatable relative to the drum 4 about an axis coinciding with that of the drum shaft and is firmly connected with a spider 8. The shafts about which the planet gears 6 rotate are mounted on the legs of this spider. The spider is biased by a spring 9 and provided with an electric contact l which cooperates with two stationary contacts H and II. The spring 9 tends to hold the spider 8 in a position where the appertaining contact I0 is in engagement with the stationary contact ll. Whenthe pull of cable increases so that the corresponding drum torque exceeds the driving torque of the winch motor WM to such an extent as to overcome the force of spring 9, the contact In is separated from contact II and engages the stationary contact I2. This has the efiect of controlling the automatic control devicesof the systems so as to cause the motor WM to change its torque in the direction required for reducing the cable pull with the. result of restoring the desired torque and pull conditions as will be apparent from the following description of the operation of the system.

A friction brake BR is provided in order to retard or stop the winch drum 4. This-brake is normally biased by a spring towards its operative position and contains a magnet coil which, when energized, releases the brake.

The reduction gear unit 2 is provided with two limit switch devices. One of these devices has a travelling member i3 which reciprocates to and fro in accordance with the length of cable paid out by the winch drum. This travelling member is so adjusted that it engages and opens a contact l4 only when the safe maximum length of .cable has been paid out, and it engages and opens another contact [5 when cable is heaved in beyond its safe minimum length, The opening of either contact l4 or ii causes the controlsystem to deenergize the winch motor WM and to apply the brake in order to prevent damage to the winch machinery. This control effect of the extreme pay-out limit mechanism will also be understood in detail from the description of the operation of the system given hereinafter. switch S is provided for resetting the winch after an operation of the limit contact l4 or l5,

The second travelling member, when in its operative position engages a switch contact ll so that the switch I! remains open for small departures of the member Hi from its center position in either direction and is closed when this departure exceeds a given limit value. The member I6 is adjustable so that it can be set into its center position for any desired length of cable paid out by the winch drum 4. As will be explained in a later place, the closure of switch contact H has the effect of controlling the winch motor automatically so as to pay out or reclaim an amount of cable sufilcient to restore the original position of member it. As a result, this limit mechanism maintains the paid-out cable length automatically at an adjusted value or between relatively narrow limits. For instance, if during a towing operation, inheavy sea, the pull of the towing cable becomes so great as to force the drum 4 to pay-out an excessive length of cable, the limit switch I! is actuated and causes the winch motor to reclaim enough cable for restoring the original cable length without imposing A normally open undue stress on the cable or the winch machincry.

The winch motor WM has a series field winding SF and a shunt field winding PF and is under control by two selectively operating line contactors IP and IR serving to connect the motor to the supply mains X and Y for operation in the pay out and reclaiming direction, respectively. The pay out contactor IP has two line contacts 3| andtl for performing the Just mentioned switching operation and is also provided with an interlock contact 33, which prevents the reclaim contactor IR from being energized as long as the motor is connected for pay out operation. Other contacts denoted by 34, 35 and 35 serve to tie up the pay out contactor IP with other relays of the systems. Similarly, the reclaim contactor IR has two line contacts 2| and 22, contact 23 for interloclring the contactor IP when the motor is energized for reclaiming operation, and three additional contacts 24, 25 and 28 associated with other control devices of the system.

A dynamic braking resistor RI is arranged in friction brake BR. When relay DH is deenergized,

the dynamic braking resistor RI is connected across the armature and the coil of the friction brake is deenergized so that this brake is also in operation. Conversely, the energization of relay DB renders the dynamic braking resistor RI inefiective and releases the friction brake BR.

The motor WM is further connected with a group of starting resistors R2, R3, R4 and R5, which are under control by respective relays IA, 2A, 3A and 4A. Each of these relays has a main contact 5|, 5|, 1| or III, and. an interlock contact 52, 52 and 12, respectively, with the exception of relay 4A which has no such interlock. Due to the operation of these interlock contacts, each subsequent starting relay can be operated only after the preceding relay has connected its appertaining starting resistor to the motor.

A group of timing relays denoted by IT, 2T, 3T and 4T serve to provide a given minimum period between the subsequent operation of the starting relays and are also associated with the automatic control relays described hereinafter. Each timing relay has an operating coil 9|, IOI, III or I2| and a group of contacts 92, 93, 94 and I02, I03, I04, and H2, H3, H4, and I22, I23, I24, respectively.

The contacts I0 and I2 are connected with the control coil I40 of a relay PR with three contacts I4I, I42 and I43 serving to control the motor operation in response to the occurrence of excessive cable pull. Another relay RR has its coil I30 connected with the limit switch I1 and is provided with contacts, numbered I3I through I39, for controlling the motor in dependence upon the departure of the cable length from the adjusted value, as previously mentioned. The system is further provided with a low voltage relay LV, with a control coil I50 and three contacts I5I, I52 and I53.

A single control unit CU is provided for governing the operation of the system selectively either by hand or automatically. The control unit CU contains a selector switch SS and a master controller MC. The selector switch SS has an off" position, a hand position, and an "auto position. In the off position, the master controller and the feed connections of the control relays are disconnected and, hence, inoperative. When placing the selector switch SS on "hand" position, the automatic control devices of the system remain disconnected while the master controller MC becomes operative so that the system is under control by the master controller MC exclusively. When placing the selector switch SS on "auto," the automatic control devices are prepared for operation but their energizing connections extend through the master controller MC so that the automatic devices are only operative as long as the master controller is in its "of! position.

The master controller has a series of contact positions for pay out operation and for reclaiming operation. Its contact segments, numbered |1I through I13, engage corresponding contact fingers in selected contact positions of the master controller. Two of these segments, namely those denoted by HI and I13 are disposed between the selector switch SS and the automatic control devices for the purpose already mentioned. I

shunt field PF of the winch motor WM is imme diately supplied with excitation. As long as the selector switch SS of the control unit CU is in its "of!" position, the low voltage relay LV remains deenergized.

Moving the selector SS into hand" or "auto" position causes a temporary closure of its contacts I53 and I64, thereby energizing the low voltage relay LV from X through circuit I53, I54. I1I, I4, I5, I50, Y. Relay LV closes contacts I5I, I52, and I53 and seals itself in through contact I5I. If the relay L1] is tripped, for instance by voltage failure, the selector switch S8 must be returned to the "ofl position before the operation can be resumed, and the master controller MC must also be in the 012" position, so that the relay circuit is closed at I1I for resetting the relay LV.

Manual control With SS placed in the "hand" position, the winch is under control by the motor controller MC and operates as follows:

In the 03" position of MC, relay LV is sealed in as described above. The relays IT, 3T, 3T, and 4T are energized. The main coil 30 of IT is excited through X, I5I, IN, 24, 34, 30, Y so that contacts 92 and 03 are closed while contact 34 is opened. Coil I00 of relay 2T is energized through Y, I00, 02, I52, I5I, I53, X so that contacts I02 and I03 are closed while contact I04 is opened. Coil IIO of relay 3T comes in through Y, IIO, I02, I52, I5I, I53, X and closes contacts H2 and II 3 while opening contact II4. Coil I20 of relay 4T is energized through Y, I20, II2, I52, I5I, I83, X and closes contacts I22 and I23 while opening contact I24. The closure of contact I22 energizes the interconnected neutralizing coils 3|, IOI, III, and I2I of the timing relays.

Upon turning M0 to first point "payout," the dynamic braking relay DB becomes energized through Y, 40, I14, I53, I23, II3, I03, 33, I52, I5I, I53, X and opens the circuit of resistor RI at contact 4|. Simultaneously, the line contactor IP is energized through Y, 30, 23, I15, I14, I53, I23, II3, I03, 33, I52, IBI, I63, X and connects the winch motor WM to the line at 3| and 32 through circuit X, SF, 3 I, A, R5, 32. Y. This connection includes the resistor R5. As a result, the motor is started in the payout direction. Both field windings SF and PF are now in operation.

The interlock contact 42 of relay DB energizes the coil of brake BR, thereby releasing the brake. Contact 34 of contactor IP opens the circuit of coil so that the timing relay IT drops out after the elapse of its timing period.

On second point "payout of MC, the coil 50 of contactor IA is energized through Y, 50, 34, I15, I14, I53, 36, II, I6I, I63, X. Relay IA closes contact 5| and thus connects resistor R2 in parallel to R5, thereby reducing the total resistance of the armature circuit. At the same time, coil I00 of timing relay 2T is deenerglzed by opening its circuit at I12 so that 2T falls off upon elapse of its timing period, thereby permitting the relay 2A to be energized on the next payout point of MC.

36, I5I, I6I, I63, X and, at H, connects resistor R4 in parallel to R5, R2, and R3. The circuit of coil I20 is opened at I12 so that relay 4T drops out upon elapse of its timing period thereby preparing relay 4A for subsequent operation.

On fifth point payout of MC, relay 4A is energized through Y, 80, 12, I24, I15, I14, I53, 36, ISI, I6I, I63, X and shorts resistors R2, R3, R4, and R5 at 8|.

In review, the starting resistance in the motor circuit is successively lowered and eventually shorted out when the motor controller is passed from its "Off position through its fifth point payout.

If the master controller is thrown suddenly from "011 to fifth point payout, line contactor IP will close immediately and relay DB will disconnect the braking resistor RI and release the brake BR. After elapse of its timing period, relay IT drops out and energizes relay IA while deenergizing timing relay 2T. The latter, upon elapse of its timing period, will energize relay 2A while deenergizing timing relay 3T and so forth until finally the relay 41%. short clrcults the starting resistors. Thus the minimum "time of an operating sequence is determines -y the adjustment of the timing relays, and the system is in under automatic control. these timing relays when the controller is actuated at high speed.

When placing the master controller from its "Oh position on first point reclaim, relay DB is energized through Y, 40, I14, 33, I23, H3, I03, 93, I52, I'5I, I6i, I63, X and disconnects resistor RI at contact 1I. At the same time, the line contactor IR is energized through Y, 20, 33, I16,I14, I53, I23, II3, I03, 33, I52, iBI, I63, X and connects the winch motor WM to the line at 2I and 22 through circuit X, SF, 2I, R5, A, 22, Y. As a result, the motor is started in the reclaiming direction, the brake BR being released by the closure of contacts 42 and 25. Contact 24 of relay IR disconnects coil 90 or timing relay IT so that the latter drops out after elapse of its timing period, thereby preparing relay IA for operation.

On second point reclaim," coil 50 of relay IA comes in through Y, 50, 04, I16, I14, I53,

in parallel to resistor R6 by closing contact 6|.

These and all subsequent points "reclaim" of the master controller correspond to a control operation similar to the respective payout" point except that the running direction of the winch motor is reversed. The minimum periods of the sequential starting steps are again determined by the time adjustment of the timing relays as described in the foregoing.

Automatic control When the selector switch S8 is placed into "Auto" position and the master controller left in its "OfF position, the winch drive is automatically controlled by the operation of the payout control switch I1, and the tensiometric contacts. In this position of switch SS, relay LV is energized and remains sealed in, and the timing relays IT, 2T, 3T and 4'1 are also energized as described previously.

As long as the paid-out cable length remains within the extreme operating limits, as is normally the case, the travelling unit I6 remains somewhere between the limit switches I4 and I6 so that these two switches stay closed. Upon paying out a desired cable length, by means of the above-described manual control operation, the adjustable member I6 is set so as to engage switch I1. Hence, switch I1 remains open as long as the \paid-out cable remains between relatively narrow operating limits as set by nut I6. Contact I0 of the tension-responsive device engages the contact II as long as the cable pull or tension remains below a given safe limit. If the tension from closing their respective contacts. The 010- sure of contact I42 in relay PR. energizes the brake relay DB through circuit Y, 40, I42, I53, I23, II3, I03, 93, I52, I6i, I63, X so that the dynamic braking resistor R! is disconnected, at 4i,

from the armature A. Contact .2 of relay PR energizes the line contactor IP through circuit Y, 33, its, 5553, Its, while "he I released to the cics'are of co cts and, it of relays DB and iiirespectivel; As a ult, the motor "i i/M will run in the pay out .ction, thereby reducing the cable The torque characteristic of the and r, so operating, corresponds to that of the first point pay-put of the master controller. isince, normally, the paidmut' cable length remains Within the extreme limit determined by limit switch i3, a condition will be reached where the cable tension has dropped suflflciently for disengaging the tension responsive contacts I I and I2 so'that the payout relay PR is deenergized, the motor stopped, and the brake set for operation. In the meantime, nut I6 has left its original position so that contact I1 is closed. Hence, when the cable tension drops to a point where the tensiometer contact I0 engages the contact II the reclaim relay RR.is energized through circuit Y, I30, I1, II, I0, I13, I62, I52, I6I, I63, X. As a result, the line contactor IR is excited via Y, 20, 33, I35, I53, I23, II3, I03, 03, I52, I6I, I63, X and closes its contacts 2I and 22, thereby causing the winch motor to run in the reclaim direction. At the same time, relay DB comes in over Y, 40, I", I53, I23 and disconnects RI from the armature A while releasing the brake BR. The motor accelerates until member l6 reaches its original posi tion and opens contact I! thus stopping the motor and setting the brake.

Combined automatic and manual control It is an essential feature of my invention that the control means described in the foregoing are so interlinked that when the system is set for automatic operation, or during the actual performance of an automatic operation, the control can be taken over by the master controller merely by moving it out of its Off position. This is achieved by the fact that the connections between the automatically operating control elements and the relays controlled thereby extend through contact segments of the master controller which are so designed and located that the automatic control circuits can be completed only when the master controller is in the off position. That is the circuits necessary for the automatic operation are interrupted when the master controller leaves the oil position, while the manuall controllable portion of the system remm'ns operatively connected to the master con troller even if the system is set for automatic operation. Thus, the connection from the tensiometer contact is to the main X extends through the segment "l3 of the master controller, this segment being so arranged that the circuit of pay-out relay PR or reclaim relay RR can be completed only if and as long as the master controller is in the on position.

a result, the operator can at any time inieuve: required by a momentary exigency, or he can modify or temporarily alter the operation of the towing winch system and then resume the automatic control merely by actuating the single handle or other manual of the master controller accordingly. For instance, if during an automatic reclaiming operation as described above, some amount of cable is to be paid out temporarily, the operator need merely turn the master controller in the pay-out direction. This causes the reclaim relay RR to be tripped, by disconnection of its coil I30 at segment H3, and the motor will reverse its direction and gradually accelerate corresponding to the selected controller point. To mention another example,

if an automatic paying out is to be speeded up,

the operator may turn the master controller temporarily on second to fifth point pay-out. In any such case, the automatic operation is resumed as soon as the master controller is returned to its "01! position.

It will be obvious to those skilled in the art. that a system according to my invention can be modified in many respects, especially as to details of the appertaining control devices, without departing from the essential features, objects and advantages of the invention. I, therefore, wish this specification to be understood as illustrative and not in a limiting sense.

I claim as my invention:

1. An electric winch control system comprising, in combination, a winch drum; a reversible motor in driving connection with said drum; automatic means for controlling said motor in response to given conditions of winch operation; a master controller for controlling said motor manually; current supply means; a manual selector switch disposed between said supply means on the one hand and said automatic means and controller on th other hand and having three positions for disconnecting said supply means from both said automatic control means and said master controller, connecting said supply means with said master controller alone, and connecting said supply means with both said automatic means and said master controller, respectively; said switch and said automatic control means being electrically connected with said master controller so that the connection of said automatic control means with said supply means through said switch is completed only when said master controller is in a position wherein the manual control is inoperative, and interrupted when said master controller is in any of its positions wherein the manual control is operative.

2. An electric winch control system comprising, in combination, a winch drum, a reversible motor in driving connection with said drum, automatic means for controlling said motor in response to given conditions of winch operation, a. master controller for controlling said motor manually, current supply means, a manual switch for selectively connecting said supply means to said automatic control means and saidmaster controller, said master controller having a plurality of operating positions in which the manual control is operative and an oil position in which the manual control is inoperative and comprising contact means which are closed only in said off position, said contact means being elec- KURT MAHNKE.

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