US1229984A - Electrically-controlled hoist. - Google Patents

Description

S. H. LlBBY.

ELECTRICALLY CONTROLLED HOIST.

APPLICATION FILED MAY i. 1914.

Patemm'i 3mm 12, 3/937.

2 SHEETSSHEET l 1mm; rwtm Sam M. migh- EQMRE UHY, A COLsPUYEtATIQIli- 015 Application filed May 1, 1914. Serial its.

aZZ whom it may concern Be it known l, SAM H. LIBBY, a citi-- Zen oi the United States, residing at East provision of improved means whereby certain loading and conveying operations may be performed a reliable and etlicient manner with a minimum amount of apparatus.

My invention relates more specifically to hoisting mechanism oi the type known as grab bucket hoists, although my invention is not necessarily limited to this specific type of apparatus. In the construction of grab bucket hoists, two winding drums are necessary, one for closing or lacing the bucket and the other for holding the bucket while the opening (and under some circumstances the closing) operation is going on; Here" tofore where these grab bucket hoists were operated electrically two motors have been generally required, one for operating each drum. One of the objects of my invention is to provide means whereby the two drums may be operated by a single motor and controller to perform all the necessary operations connected with the use of a grab bucket hoist without the use of manually operated clutching brakcs. In one specific embodiment of my invention the lacing drum is geared to the motor so as to be positively driven whenever the motor operates. The holding drum is driven by the motor through electromagnetic friction clutch mechanism under the control of the operator. The arrangement is such that the power transmitted through the friction clutch will depend upon whether or not the electromagnetic mechanism is energized. Under one condition, say for instance when the mechanism is energized, a light friction clutch will be on, whereby a small amount of power will be transmitted to the holding drumenough to keep the cables taut, but when the mechanism is denergizcd a heavy friction clutch will be on which will transmit to the holding drum all the power received from the motor. A friction brake is also applied. to the holding drum so that the bucket will not overhaul the drum dur- Specification of Letters Patent.

fatented ing the opening or closing in air operations. Since the lacing drum is operated for every movement of the hoist, and the ho] drum is only operated during he sting and lowering, the single mom arranged as do scribed performs all the nor ry tunetions. Other objects and purposes of my invention will appear in the course of the following specification in which l have shown my invention embodied in concrete form for purposes of 'llustration.

In the accomp anying crawing showing one embodii ent of my invention,igureli an outline view in elevation of grab bucket hoist; Fig. 2 is a sectional view through the gear casing and the friction clutch and brake mechanism; l 3 is a sectional view on line 3+3 of Fig. 2; and Fig. is a diagram of the circuit connections.

Ref rring first to Fig. 1, it-will be seen that I have shown an ordinary grab bucket hoist consisting of a conveyor housing; 10 carried by two trucks l1 and 12 mounted upon the track 13 and getting power for operating the same from two trolley wires, only one of which, 14, and one trolley 15 is shown. drums, that is, the lacing drum 16 and the holding drum 1?. The lacing drum has a single cable 18 which runs downward to the grab bucket 19 and closes the bucket as the cable, on being drawn upward, turns the power wheel 19 in a clockwise direction and allows it to open, as the cable is lowered The holding drum has two cables, 20, 21, which are attached to the cross arm or upper center casting 22 on the grab bucket. Thesecables 20 and 21 support the bucket while certain operations are taking place as hereinafter described, and cooperate with the cable 18 to lift the bucket.

Referring now to Fig. 2, the pinion 23 is for driving the lacing drum 16, and the pinion it drives the holding drum 17. These pinions are geared to their respective drums as shown in Fig. The motor shaft 25 is located between these two gears. The gear case 26 forms a bearing for the shafts upon which the gears 23 and are mounted and also for the motor shaft 25. The motor shaft drives the lacing drum directly and positively through the gears 26, 27 and .23, so that the lacing drum is always operated whenever the motor is operated. 'lhe hold- This conveyor carries the two ing drum however, is not positively geared to the motor, but driven from the motor shaft through a friction clutch. This is accomplished through a. sleeve 28 carrying a pinion 9,9 which meshes with the gear 30 which in turn drives the pinion 2i and drum 1?. This sleeve is driven from the motor shaft through a friction clutch mocha nisai consisting of friction disks lil on the mot r shaftand friction rings 32 carried by the sleeve. 'lhcse friction surfaces are pix-sod, together either by light or heavy spr ng presscrs depending upon whether or not the electromagnet P18 is energized. 1n the specific arrangement shown when the magnet energized the light spring pres sure is applied through spring 84: so that the sleeve is only lightly clutched to the motor shaft, but when the magnet is del nergizcd the heavy pressure is applied by springs in addition to the light pressure and the sleeve is clutched strongly to the motor shaft. lhe sleeve .28 is elongated, and the shaft 253 which extends through the sleeve has bearings 28 at each end thereof. The end of the sleeve is formed into a flange 2-36 which cooperates with the friction disks 3i splined to a hub 31 on the motor shaft and the friction rings 1-32. The friction rings are strung upon bolts 37 passing through the flange 36 so that they may move toward and away from the flange but must turn with it. A. plate 38 also mounted upon the bolts 37 receives at its center the pressure of spring 3i which produces the light driving friction The spring 34': is made adjustable by means of the plug l. Another plate having a central opening for permitting the spring M to pass through it, is pressed against the plate 38 by springs 35. This plate 4.0 acts as the armature for the electromagnet 3 the arrangement being such that when the magnet is energized, the plate --'l-U will be attracted and. compress the springs 35. thereby relieving the friction surface of the pressure of sprin 35. ll hen the magnet is det nergized, the friction surfaces are pressed together by all the springs. The spring -E-t presses against "the plate 258, and the springs 35 press against the plate ita through the plate -l-U.

ihe net result is that when the magnet- 33 is dei nergized the friction surfaces-are pressed strongly together so as to clutch the sleeve tightly to the motor shaft. llnder this condition the clutch will transmit to the sleeve and hence to the holding drum all "the power received from the motor. lint when the magnet is energized the friction surfaces are pressed together less strongly so that the clutch will not transmit all the power received from the motor, but will slip, thereby giving to the sleeve a certain turning tendency which keeps the rabies on the holding drum taut. A. friction brake consisting of the fri tion disks 1,229,.eea

and rings pressed together by springs -11 is arranged to apply a brake to the slee e. This brake operates between the sleeve and the hub l) of the gear casing, and is similar to that just described. Magnet windings 43 control this brake so that when the windings are energized the brake is released and when the windings arc tit-energized the brake is applied to the holding drum. it will be seen, therefore, that when the motor operates, it drives the lacing drum positively through gearing, but whether or not it will drive the holding drum will depend upon whether or not the clutch magnet 33 is energized. The holding drum will be braked or free, depending upon whether or not the brake magnet is energized.

In Fig. l 1 have shown 'a diagrammatic view of the motor connected to the drums and clutch mechanism and have also shown the circuit connections for the motor clutch, magnetic brake, etc.

The circuit connections will be understood by following through the various steps as they occur in actual practice. Assume that the bucket is openv and resting on the pile, say of coal, to be loaded. The first opera ing position of the controller (position a) energizes the brake magnet so as to take the brake off th motor. In this position of the controller the clutch magnet 33 is also energized through wires l5 and slip rings 46 (Fig. 2), thereby taking off the heavy friction clutch between the motor shaft and holding drum. In the next position (b) the circuit of the motor M is closed through the resistance sections R and series field F. The motor will now operate the lacing drum to close the bucket in the usual manner, and the holding. drum will simply put a tension on the holding cables 20 and 21 and keep them taut. In the next two positions (0 and d) of the controller the resistance sections are cutout of the armature and series field circuit and the motor operates at a greater speed to close the bucket. In the next movement of the controller (position a), the clutch magnet 33 is dei nergized by the contact finger 47 passing off its segment. This throws on' the heavy friction clutch, whereby the motor drives the holding drum, one section of the resistance R being in circuit with the motor. Both drums now start to operate and 'aise the bucket by the three cables 18 20 and 21, the latter two cables only being taut enough to keep them from fouling. In the next position the resistance R is cut out of the armature and series field circuit and the motor comes up to full hoisting speed. When the hoisting operation is accomplished the operator turns the controller to position (it) in which all circuits are opened and the brake is applied to hold the bucket in its upper position by the ie/energizing of winding 4x3. The hoist is "by the motor through the ieoirsg dr'e i.

iower the bucket,

iii desired bosition, t

-i i heii the bucket has opened and iris iooci is dumped the ogeretor turns the con-iroiier book no position (ii) and trowerses the hoist back "so Hie loading station, after which he turns oontroiier to posiizioii to in. abiiis position the some magnet is'rieenergiseii so that homing; drum Wiii operate with the motor as W811i as the drum aiici lower ifne bucket, i ie broke beiiig reiesseri. The motor is out o f I in this position and connected in a dynamic brake c i. h the resistance smi one c t-ion of the resist-once R. In the next position of the coiitroiier the remainder of ie resists-rice ii is connected in circuit so "he oucket cie soends more rapidly. the position (m) of the controiier, the brake is applied to the motor, sensing oo ois being oi? and the oontroiier iieiidie having made oompie'te revolution being now resciy to again compieixe the cycire of operation. iiii some, cases, as, for instance, Where there is 110%., room to Withdraw the open boeko from a space which it hos entered, ihe bucket must first be 'cioseoi. Under these circuiiistarises after the bucket has opened the coii'tiioiier is turned back to position in which the bucket is closed The bucket must s rwermi be opener} and the operation continued as above ciesoribed. It will thus be seen with my arrangement s sin gie motor i sense to perform oil the operations incl 5- iosding and imiooiding, hoissmg mic ing of e grab bucket or simiizuhOiSii, all operations being" performed by e single coriiroiier sod xvii-bout the use foot brakes hand brakes or meiioeiiy opereteri eiiiizciies. 'Wiiiie i have ciesorioool myioveoibi i as em bodied in ootooreie form onci operif io s syeciiic mariner purposes iiii tie i it siiouid oe iiiriciersizoo that do not ET inversion f ere'zo, si" e arious riselvos to siiose skilled in from. the s airit; of my inversion. the em oe oi which is forth in the annexe-r1 c .s.

2 e to secure by Letters Patent of the Uniteri is,

A grab bucket hoist or *biieii re core- Esing i racing cirusio on electric Thor hovriving connectionstherewith, i1oiiin drum and means whereby she motor op erases time hoiciiog cirum so as to suop bucket during ioociiiig and lift ii hoisting,

9. A grab bucket hoist or ithe iiire prising eiecing oirum our; hoioii an eieofirio motor boring am positive our connection. with one of ssici (iiUIllS eiee, mognetiooiiv controlled. friction eiu mechanism between the motor and o drum, and means whereby the frici' iieotioii transmits more or less power pending upon whether or 'not he eier-Lro magnetic mechanism is ener iizedi ii. gmio bucket hoist or HR iiirnju m prising o. isoing drimi are. eirr A moiur {5,1 iim 'ijog positive driving commotion there with, o. holding drum, and. an. electromagneticeii y controlled driving connection for transmitting more or less power from ike motor the holding ii-om His will oi the 1 operebor" A. grab ouciet most or the hire com" prising a iaci'ng drum, on iotor hei "mg adriving connection fisher uh, o

- prising drum, on eieeizric mo'iaor new will of the operator, and 2111 ing a posii'l've driving conneoiion iii 2L ildiiillg drum, frictional (ii 611;; coon-ootiers "the motor o'oc'i the holding}; drum, and eieotromogneiio means controT. oi? 01 M01 for power or (:5, through. iiie .v RBCtiGl'l.

grab brisket iioisi; or ii prising so lacing drum, heviiig' cor iioiciiiig (13711111 iiieeins amount of power WilBEfii" may from the motor $0 the 110101 ceiiy actuated broke on the no 8. A bucket hoist or prising 2i lacing drum, o o r .iiPoVilfigl s driving coneotioir o, iioiriing drum fission ciu all provided with iiiosiis for effecting the transmission oi. meii amount of power between the i'noror i iii the holding drum at s1]. times and :i grea amount under the control of ihe operate and on eieotromogneiiioaiiy not-fiuoizeii .5 tion brake on the holding cirumi 9 A bucket hoist or 1 we prising a lacing drum, an electric motor ha ing a positive driving connection therewith, a holding drum, elect-rtunagnetically controlled friction clutch mechanism hetween the holding drum and the motor. and means whereby the friction connection transmits more or less power depending upon whether or not the electromagnetic mechanism is energized.

10. it grab bucket hoist or the like coniprising a lacing drum, an electric motor having a positive driving connection therewith, a holding drum, electromagnetieally controlled friction clutch mechanism between the holding drum and the motor, and means whereby the friction connection transmits more power when the electromagnetic mechanism is deenergized than when it is energized.

1.1. A. grab bucket hoist or the like comprising a lacing drum, an electric motor having its shaft connected to positively drive the. same, a holding drum, a sleeve on the motor shaft geared to the holding drum,

magnetic clutch mechanism connecting the motor shaft and the sleeve so as to transmit a greater or less amount of power from the motor to the holding drum at the will of the operator, and an electromagnetically controlled friction brake upon the sleeve for braking the holding drum.

12. A grab bucket hoist or the like coniprising a lacing drum, an electric motor having a driving connection therewith, a hold ing drum, a friction clutch connecting the holding drum and the motor shaft, means for exerting a small ainount of pressure 'at all times on the friction clutch, and electrz magnetically controlled means for exerting a greater pressure on the friction clutch at the will of the operator.

Inwitness whereof, I have hereunto set my hand this twenty ninth day of April,

' SAM H. LIBBY.

Witnesses:

ROGER H. BUTTERWORTH, FREDERICK KEYLER.

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