US2468092A - Electric hoist and winch control - Google Patents

Description

Filed Nov. 29, 1947 INVENTOR Kuri Mahrzke.

Cum.

ATT RNEY Patented Apr. 26, 1949 ELECTRIC HOI-ST AND WINCH CONTROL K-urt Mahnke, Pittsburgh, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, 'Pa., a corporation of Pennsylvania Application November 29, 1947., Serial No. 788,951.

7 Claims. 1 .My invention relates "to electric controls for winches and the like devices'for operating is hope mr cable and deals particularly, though not exclusively, with :marine deck equipment 01' this lrind. More specifically, my invention is manned with rope operating: equipment which, dhen 'at rest; isl'ocked by latching bolts, ratchetantl pawl rdevlces',1clu tches or other locking means that must released before the equipment can operate in the lowering or .pay out direction.

There are electric systems for controlling mechanically Blocked -b'oom Stopping winches so thstthe qcni'rviil of a "locking ratchet is eletromagreleased "when the operator :actuates the appertaining master control means in the mroper'manner. In these systems, the release of ithe ratchet, previous tolowering, occurs during nn initial interval in which the winch motor is energized for hoisting to relieve the load on the ratchet n'i'echanism while "immediately thereafter the motor is reversed 'or reconnected for lowering. Two reversing contactors and a number of associated control relays are provided in the known system in order to perform the justmentioncd switching and reversing operations;

"It is an object "of my invention to provide contrdl systems for mechanically latched winches *thatsecure are'lia'ble unla'tc'hingperformance for hoisting as'wellas loweringwiththe aid of con- ;trolmean's df utmost simplicity, with a reduced number 'of component parts, "and under correseemingly reduced space requirements as compared with the above-mentioned systems heretofore available for this type 'of equipment.

linotherobject of my invention, relative to the *foregoing, is to provide latch-releasing controls that are economically applicable for marine deck winches, such .as co-at winches, relatively small load capacity, operating with correspondingly small electric motors. These .and other objects as well as the means provided Boy the invention ior achieving them will lbeapparentzfromthe following description o'f the embodiments illustrated in the drawing.

Figs. .1 and 2 show two different modifications 'o'i samelectric control system 'for a boom topping winch, both figures -representing schematically theselectriccircuit diagram in conjunction with ,partsof ,the winch structure essential for the invention; :and

'50 Fig.3 showsschematically.a-relaycf the kind employed in the embodiments of Figs. 1 and -2.

In .bothembodiments, .as illustrated, the strucailure of :3, :boom topping winch zasa whole is delift-ing and lowering the boom is denoted by M, a control .contactor' by 3,211 overload relay by C, a timing relay by D, and the appertaining master controller by E. Most of the reference munerals applied tofFig. 2-.are the same as those used inFig. l for corresponding e1ements,. except that the prefix I or ll) is added to respective numerals of Fig. .2. Forinstance, the denoted by 3 and 10 in Fig. 1 correspond to those denoted by I03 and I ll], respectively, in 13:..2. Consequently, to a large extent, the following description of Fig. 1 is also applicable to Fig. v,2

Referring to the control-system of Fig. 1,, the boom l of the winch structure A is lifted and lowered by means of a cable .or rope which is wound up one, winch drum .2. A ratchet gear 3 is firmly attached to the drum 2 or the appertaining drum shaft and cooperates with a latching pawl 4 which is springer gravity biased into engagement with the ratchet teeth in order to normally prevent lowering of the .boom l. A solenoid .5 serves to release the pawl .4 in onposition to its spring The winch drum is equipped with a spring-set friction brake '6 which is released when the appertaining magnet coil "l .is energized.

The armature .8 of the motor ,M is-mechanically connected with drum Z'bya suitable transmission or gearing here schematically represented .by a broken line denoted by 9. The motor has two field windings l0 and it. Motor armature and field windings receive excitation from the mains X and Y of a suitable direct-current source under control by the above-mentioned relays B, C and D and subject to the operator-controlled adjustment 0f the master controller .E.

The control relay B has a main coil l2 and a lockout coil I 3. The main coil l2 controls four contacts l4, l5, l6 and I1 and receives excitation from the mains X and Y in a manner described below. The lockout coil I3 is permanently connected across the motor armature 8. con I 3, even if energized-is -ineflective to change the condition of relayB-a'ftertherelayis picked up by the main coil 12, coil I3 is effective to look only when it is suiliciently energized after relay B has dropped out. Then the energized coil 13 secures suilic'ient contact pressure at contact Hand prevents-therela-yiB from again picking up as long as the regenerative armature voltage :of motor M remains above :a given minimum value. In order to secure this lockout action, the relay B in its actual design may have ran armature of the type-denoted .by 20 in Fi 3.

meted .by A, the appertaining :electric motor for 355 Whenthe main coil 12, accordil'ig to Fig. 3, is

energized, it moves the armature 20 and closes contact l5 (as well as contacts l6 and I! which are not shown in Fig. 3), while opening the contact l4. As a result, the airgap between armature and the core of coil l3 becomes so large that the subsequent energization of coil l3 produces no armature movement. However, when thereafter the main coil I2 is deenergized so that armature 20 drops back to the illustrated position, the coil I3, when energized, holds contact l4 safely closed and locks the relay in the dropped-01f position as long as the energization of coil I3 remains above the above-mentioned minimum.

The overload relay C has a main coil 18 to be traversed by the motor load current and is equipped with a lookout coil l9. Contact 2| of relay C is opened only when the load current in coil l8 exceeds a. predetermined maximum value. The performance of the lockout coil I9 is similar to that of coil l3 of contactor B as discussed in conjunction with the schematic illustration of Fig. 3.

The timing relay D has a main coil 22 and a short-circuited winding 23. When coil 22 is energized, the appertaining relay contacts 24 and 25 close immediately, while, after deenergization of coil 22, a given timing interval'due to the effect of the short-circuited winding 23, elapses before the contacts 24 and 25 drop into open position.

The master controller E is shown as a'drum type switch. The handle, to be actuated by the operator, is denoted by 26. This handle as well as the drum contactor are normally held in the 'oif position by means of biasing springs '21. The master controller has a hoist position and a lower position and must be held by the operator in one of these positions as long as the winch is to operate. The master controller has a number of stationary contact fingers or brushes to cooperate with movable contact segments denoted by 28, 29 and 3| to 31. Three resistors appertaining to the control system are denoted by 28, 39 and 4|. 7

The system of Fig. 1 operates in the following manner: When the master controller E, by actuation of its handle 26, is moved from "013 to hoist position, it passes through an intermediate position in which the contact segments 29,131 and 33 prepare the respective circuit connections. When the hoist position is reached, the main coil of relay B is energized in the circuit:

X35--l2--2|-Y (1) Relay B picks up. Its contact I5 energizes the brake coil 1 in parallel to the motor field winding In in the circuit: 1

Consequently, motor M operates in the hoist direction.

When the master controller is released and moves'back to the illustrated ofPpOsition, relay permits the pawl 4 to drop into the ratchet, the

winch is already at rest or its speed is sufficiently reduced to avoid a jarring stop.

For performing lowering operations, the master controller E must first be moved to the hoist position and then quickly moved through the off position to the lower position. Any other way of operating the master controller will not result in lowering performance because the release of ratchet pawl A and brake 6 as well as the operation of the motor M depend upon picking up of the timing relay D, and the circuit conditions for causing relay D to pick up exist only in the .hoist position of the master controller.

When the lowering performance is properly initiated by moving the master controller temtporarily to hoist position, the brake and pawl are released and the motor M is started in the hoist direction in the same manner as described in the foregoing. The short winch movement in the hoist direction relieves the load and frictionon the pawl and hence prepares proper conditions for the pawl release. When the master controller is rapidly switched over to lower positiomcoil 22 of timing relay D becomes temporarily dc;-

energized due to the temporary opening ofcontact ll, but the relay D remains picked up during the subsequent timing interval. This interval is long enoughto be still running when the master controller reaches lower position. Then, coil l2 of relay B becomes reenergized .in the circuit X-36-24-i 22 l--Y (5) Consequently, relay B recloses the armature and field circuits of the motor which, in the meantime, has been reconnected for reversed operation, and also closes at contact H the circuit for coil 22 in timing relay D. As a result, this relay remains picked. up during the entire switching-over performance as well as thereafter, so that the coil 5 remains energized and the pawl 4 lifted out. of the ratchet 3. v

As mentioned, the motor M is now connected for reverse operation. Its armature 8 is .now energized in series with resistor 38 in the circuit:

otherwise affecting the operation of the systeni.

When the master controller is returned to 011 position, the brake 6 is set and relay B drops off immediately, while the timing relay D remains escapee gized by regenerative voltage from armature "8 .and prevents the opening ofthe dynamicbraking circuit ("7) before the motor armature'hasrreached 'suificiently .low speed.

It :will the recognized :that .in this example the operation of the dynamic braking circuit iszrelied :upon only for stopping the winch at the end of a lowering performance, :1. e., when the winch load tends to acceleraterather than-to retard the winch.

51f -d.uring;a hoisting or lowering performance an "excessive overload occurs, "the main coil 1810f reilay C becomes sufliciently energized toopen the :contact 24. This has the eifect of opening the COilzCiICllil; (1) of relay :3. As a result, the brake coil lisdeen'ergized at contact l5 (duringlow- I :ering periorrnance'the-coilfiz of relay D is-also deenergized for a subsequent settingofrthe ratchet :pawl 4) and the motor'armature and field cir- 'cuits :become 'd'eenergized .due to the opening of contact lfi,.so that the winch is stopped. The lockout coil 1.8 then prevents the overload relay 'C from dropping out until the master controller xis'firstmoved back'to o. position. In this manner, the occurrence .of pumping acticnyi. e., an

alternate picking up and dropping out of relays =3 and C under excessive overloadsissafely prevented.

The control :system :shown in illlig. '2 is similar to that :of Fig. :1 in 'that the :master controller must be operated for lowering by :p'lacingait itemmorarily into hoist position and then switching it through the on position to'the .-lower:posi- :tion :as described in :the foregoing. The system according to Fig. 2 differs from that of :Fig. 11. essentiallyinthe provision of different motorccon- :nections so that the lowering performance, which according'to'Fig. 1 occurs un'dera dynamic :lowciting characteristic, is effected as a shunted armature lowering. Thisdifferencein the mo- :tor energizing circuits requires :assoinewhat dif- .ference:arrangement'ofzth-e master controller segments which :in Fig.2 are denoted .by 136, 13? and 1 415 through I153, respectively. The uresistors .appertaining :to the motor circuit of Fig. :2 are 'de- :noted by M2 sthrough 145, respectively.

When the :winch system according to Fi ;2 :is set ;for hoisting, :the motor armature .408 :and main field winding @I-Jl'l are energized :in the-cir- .cuit

X|48--l08 |43 -l46 lllll'6-l'l8-Y (8) Aside from the just m entioned difference in the motor energizing circuits and the corresponding difference in speed-torque characteristic, the system of Fig. 2 has the same small number of component elements and secures .elso

the above-mentioned functions and advantages.

It will thus -be seen that the particular design and operating 1 characteristic of the motor armature'and field-circuits is-notessential to theinvention and can be modified invarious ways with outdeparting from the essential .features.

W'hile I-have illustrated--a:master control means c ned 'as'a drum type contactor, itis obvious that other forms of known and available master control means may be used instead. For :instance, "the master control means may'comprise two spring biased push button contacts, one for operating the motor in the hoist direction and the other for operating in the lowering direction, the -off" position being established when 'both push buttons are released, The individual relays, contacters and circuit connections can also be modified in various ways. It will be recognized, therefore, that the invention permits being can ried out in=a mannerdi-iferent from the embodiments specifically illustrated and described in this disclosure, without departing from'the essence of the invention and within the scope of its essential features as set forth in the claims annexed hereto.

I claim as my'invention:

1. A winch control system, comprising winch locking means-2a winch motor, operator-actuable master control means normally in offp0sition and selectively adjustableto hoist and lower" positions respectively, a current supply circuit attached to said motor and connected with said master control means to operate in different directions when said master control means is in lhoisff and lower positions respectively, a con- 'tactor having a coil and contact means disposed in said circuit 'for completing said circuit only when said coil-is energized, said master control means "having .a first contact and a second contact individually connected with said coil for energizing said coil only when said control means is in hoist andlowerpositionsrespectively, a delayed drop-out relay connected with said locking means for releasing the latter only when said relay is in picked-up condition and connected with said second contact and with said coil to "permit said coilto be-energized through said second contact when said relay is in picked-up condition only, said relay having a pick-up coil connected with said master control means and with said contactor so'as tobe energized through said master controlmeanswhen the latter is in hoist position only and through said contactor when said-contactor coil is energized.

:2. LA winch control system, comprising winch loc in means, a winch motor, operator-actualcle master control :"rneans normally in off position and selectively adjustable to hoist and lower positions respectively, a current supply circuit attached to said motor and connected with said master control means to operate in different direction-s when said master control means is in hoist and lower positions respectively, a contactor having a coil and 'contact means disposed in said circuit for completing said circuit only when said coil is energized, said master control means having a first contact'closed only in hoist 'hoist position and having a relay contact closed only when said relay is in picked-up condition, a contactorhaving a coil connected to said relay contact and tosaidsecond. contact to be energized when said relay is in picked-up condition while said master control means is in lower" position, said contactor having a holding contact connected with said relay coil circuit for holding said relay picked up when said contactor coil is energized, said contactor being connected with said current supply circuit for controllin said motor to permit its operation only when said contactor coil is energized, and said relay being connected with said locking means for releasing it when said relay is in picked-up condition.

3. A winch control system, comprising winch locking means, a winch motor, operator-actuable master control means normally in off .position and selectively adjustable to hoist and lower positions respectively, a contactor having a coil circuit controlled by said master control means to be energized when said control means is in one of said hoist and lower positions and having contact meanscontrolled by said coil circuit, said master control means and said contact means being connected with said motor for operating said motor, when said coil circuit is energized, in different directions corresponding to the hoist" and lower positions respectively of said master control meansya delayed drop-out relay 1 connected to said locking means for releasing the latter when said relay is in picked-up condition, said relay having a :pick-up coil connected with said master control means so as to be placed into pick-up condition only when said master control means is adjusted into hoist position, and a holding circuit associated with said pickup coil and controlled by said contactors for thereafter holding said relay picked up as long as said contactor coil circuit is energized, the delay interval of said relay being rated to permit switching said master control means from hoist to lower position during said interval in order to then maintain said locking means continuously released. i

4. A winch control system, comprising winch locking means, a winch motor, operator-actuable master control means normally in off :position and selectively adjustable to hoist and lower positions respectively, a contactor having a coil circuit controlled by said master control means to be energized when said control means is in one of said hoist and lower positions and having contact means controlled by said coil circult, said master control means and said contact means being connected with said motor for operating said mot-or, when said coil circuit is energized, in difierent direction-s corresponding to the hoist and lower positions respectively of said master control means, a delayed drop-out relay connected to said locking means for releasing the latter when said relay is in picked-up condition, said relay having a pick-up coil connected with said master control means so as to be :placed into pick-up condition only when said master control means is adjusted into hoist position, a holding circuit associated with said pick-up coil and controlled by said contactor for thereafter holding said relay picked up as long as said contactor coil circuit is energized, and braking means associated with said motor and connected to said contactor to be controlled by the latter to retard said motor during the delay interval of said relay so that, when said master control means is switched to o position, said motor is subjected to braking before said relay permits said locking means to set.

5. A winch control system, comprising winch locking means, a winch motor, operator-actuable master control means normally in "off position and selectively adjustable to "hoist and lower positions respectively, a contactorhaving a coil circuit controlled by said master control means to be energized when said control means is in one of said hoist and lower positions and having contact means controlled by said coil circult, said master control meansand said contact means being connected with said motor for operating said motor, when said coil circuit is energized, in diiferent; directions corresponding to the hoist and lower positions respectively'of said master control means, a delayed drop-out relay connected to said locking means for release ing the latter when said relay is in picked-up condition, said relay having a pick-up coil connected with said master control means so ast-o be placed into pick-up condition only when said master control means is adjusted into hoist position, a holding circuit associated with said pick-up coil and controlled by said contactor for thereafter holding said relay picked up as long as said contactor coil circuit is energized, and braking means associated with said motor and connected to said contactor to be controlled by the latter to retard said motor during the delay interval of said relay, braking means associated with said motor and controlled by said contact-o1 to be effective when said contactor coil circuit is 'deenergized, and a lock-out coil magnetically as sociated with said contactor and connected across said motor for preventing said contactor from picking up regardless of the condition of saidcited by regenerative voltage from said motor.

6. A winch control system, comprising winch locking means, a winch motor, operator-actuable master control means normally in off position and selectively adjustable to "hoist and lower positions respectively, a contactor having a coil circuit controlled by said master control means to be energized when said control means is in one of said hoist and lower positions and having contact means controlled by said coil circuit, said master control means and said contact means being connected with Said motor for operating said motor, when said coil circuit is energized, in different directions corresponding to th hoist and lower positions respectively of said master control means, a delayed drop-out relay connected to said locking means for releasing the latter when said relay is in picked-up condition, said relay having a pick-up coil connected with said master control means so as to be placed into pick-up condition only when said master control means is adjusted into hoist position, a holding circuit associated with said pick-up coil and controlled by said contactor for thereafter holding said relay picked up as long as said contactor coil circuit is energized, and braking means associated with said motor and connected to said contactor to be controlled by the latter to retard said motor dur" ing the delay interval of said relay, and an overload relay having a contact disposed in said contactor coil circuit for opening the latter in response to excessive overload current, said relay having a main coil connected with said motor to respond to said current and a lock-out coil for preventing said latter contact from reclosing when said lock-out coil is energized, saidlock-out coil being connected to said master control means to be energized only when said master control means is in hoist and "lower positions respectively.

'7. A winch control system, comprising winch locking means, a winch motor, operator-actuable master control means normally in "ofP position and selectively adjustable to hoist and lower positions respectively, a contactor having a coil circuit controlled by said master control means to be energized when said control means is in one of said hoist and lower positions and having contact means controlled by said coil circuit, said master control means and said contact means being connected with said motor for operating said motor, when said coil circuit is energized, in different directions corresponding to the hoist and lower positions respectively of said master control means, a delayed drop-out relay connected to said locking means for releasing the latter when said relay is in picked-up condition, said relay having a pick-up coil connected with said master control means so as to be placed into pickup condition only when said master control means is adjusted into hoist position, a holding circuit associated with said pick-up coil and controlled by said contactor for thereafter holding said relay picked up as long as said contactor coil circuit is energized, and braking means associated with said motor and connected to said contactor to be controlled by the latter to retard said motor during the delay interval of said relay, braking means associated with said motor and controlled by said contactor to be effective during the delay interval of said relay in response to 'deenergization of said contactor coil circuit, and an overload relay having a, contact disposed in said contactor coil circuit for opening the latter in response to excessive overload current, said relay having a. main coil connected with said motor to respond to said current and a lookout coil for preventing said latter contact from reclosing when said lock-out coil is energized, said lock-out coil being connected to said master control means through said relay so as to be energized only when said relay is in picked-up condition while said master control means is in one of said hoist and lower" positions.

KURT MAHNKE.

No references cited.

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