US1447624A - Hoisting apparatus - Google Patents

Description

Mar. 6, w23 ummm@ j A. E. NORRIS .HOISTING APPARATUS Filed Apr. lo,- 1920 5 sheets-sheep 1 Maw, w23., l x ummm l A. E. NO'RRES HOI STING APPARATUS Filed Apr. lo, 1920 V5 Sheenswsheet 4 Maf. ,6, 1923.

Filed Apr. 1o, 192o- A. E. NCRRIS 'HOISTING APPARATUS 5 sheets-sheet 5 @MMW fraiieai'ed Mai. areas., l

unirse srarisa -iearaiar ortica.

ALMON E. N'ORRIS, OE'BRQOKLINE, MASSACHUSETTS] HISTINQ APPARATUS. I

.Applicationiiied A pr'ii '1a-192e. seriai No. 372,936.

To all whom may concer/1 5:

proveinent in Hoisting Apparatus, of which the following description, 1n connectionwith" the accompanying dra-wings, is a specifica.

the; drawings repreA- a trolley-supported bucket .or graby as einployed in connection with a self-propelled bridge, but the invention isi-applicable also i to hoisting apparatus einployediin connection with other structures and otherforms of load-carrying devices. This application is a division of my prior co-pending application Ser. No. 69879, filed V,Jaa 3,1916. y

The invention will be best understood by `referencetothe following description when .taken inA connection with the accompanying illustration of o `ne` specific embodiment -thereoffwhile its scope `will be more parconnected tothe opening and closing drum ticularly pointed out in the'appended claims.

In the drawings:

Figurel is a side elevation showing .the structure of a. bridge selected for illustra-v tion asernbodying one form of the inven tion; 3"

d ruins and devices cooperating-therewith for 46 controlling the I cables for the trolley and the grab; Y

Fig. 3 shows inv sectional plan and on an enlarged scale the governor-controlled brake -valve and the switch for throwing into operation the regenerative b raking F iFig."4 shows more or lessdiagrammati cally vand inside elevation the opening andclosing drums and the-hoisting druin. with the controlling brakes therefor. together with a controlling stand and pressure fluid controlling cylinders:` ,A

Fig. 5 shows on an enlarged scale and 1n horizontal section the governor-controlled conducting pipes connected. to the' brake- Beit known that I, ALMoN E. Noim'is, v Ia citizen ofthe United States, and a resident of Biookline,county of- 'Norfolk, and State 15 of Massachusetts, have invented` an. Im-

aiseie'a fan' embodiment. of the invention as applied to the contiol of f .opening andclosing itsjaws.

Vcable is connected to be wound about or -una plan. showing' the Aropewiinding.

brake valve and the switch in a different position fro'in thatshown in Fig. 3;

Fig. 6 'is a view inside elevation of the parts shown in Fig. 5; and

Fig. 7 isa .wiring diagram showing the electrical connections for the primary and secondary panels of the master controller for`the hoisting'inotor and the electrical connections between the governor and said controller.

Referring to the 'dra-wings, the invention 1s therein shown 'for illustrative purposes as applied to a hoisting and conveying bridge structure (Fig. 1) which supports an overheadtrackway 1, one en'd of which .1s-sustained by a boom 3. A trolley carriage 5 is adlpted to runn said trackway and supportv a grab or 'bucket Tof the well-V known clamshell type.

The holding Ywound `from theholding drum 13, whence it extends over the guide sheaves 15 and 17 to one end ofthe trackway, thence to the trolley carriage andthe bucket and vthence to a dead end or'fixed anchoringpoint atfthe opposite end of the trackway.

The opening and closing cable' likewise is 19. whence it extends over suitable guide.

Vsheaves. including the sheave 21. to one end of the trackway. thence to the trolley and the bucket, and thence to a dead end at the opposite end of the trackway. The trolley is`-tiaversedl by means-of an endless trolley rope 23f"wbich passes around the trolley winding drum 25 and thence over guide v'sheaves at oppositeiendslof the trackwav and thence to the trolley carriage s) its endsare fixedly secured. i The trolley-winding drum may be driven by any suitable means., there being em ployed for tliat' purpose the electric motor 30: but Since the propelling mechanism is not necessaryto an understanding of the piesent'invention. no further description of the same is necessary.

Referring now to the grab 'hoisting and opening niechan'isin. the opening and closing driinir19 is adapted Ito be connected by a to which clutch 31 with a gear 33; and the holding drum 134 is adapted to be connected by a 4 similar clutch 35 to a' gear 37, the gears 33 and 37 being in mesh with and adapted to be .driven by an intermediate pinion 39 fast on the shaft 41 driven by the electric motor 43. The devices for operating theclutches to connect. the two drums to or disconnect them from'the driving gears may be of -any usual type and their specific construction is immaterial to the present invention, it being sufficient to state that they are hereincontrolled by pressure fluid admitted through the respectiveipipes 45 and 47 and hended' in the form of a brake which al1- tomatijcally preventsv unwinding movement of the ,drum except when released, while 13 has a large brake wheel 51 (Figs. 2 .and

I permitting at'all times the windingon movement thereof. As shownherein, the. drum 4) fixed thereto at the endv opposite the Vclutch-35, said Wheel being encircled by a Abrake band 53' connected to a brake lever55 y and a link 56 of a'general construction similarto thatdisclosed in Letters Patent 1,123,786, granted to me Ja-n.5,1915.

closes and applies thebrake irrespective of. a releasing movement of the brake lever 551,

"-'mitted to or exhausted from the'brakecyl- .'.rection draws the link down vtoward they` center line passing .from the axisof thef-V hub to the point of pivotal support of thef- -link, thereby automatically opening or -un-. clasping the band and'leavingthe drum'at The brake may also be positively released. for movement in a contraclo'ckwise direc-l .When the drum tends to unwind the cable bg turning in" a contracloc'kwise direction 35 i tioned by a spring 57 is drawn out by reag. 4); the link, which is normally posison of the' friction on the band. 'This'enforced movement of the link automatically Rotation of the drum 13 in the opposite di all times free for rotation in that direction.

tion' (Fig. 4) by a releasing movement of the lever 55. To .accomplish this, said lever may be connected by a link 59 with one arm I l of a bellcrank 61, the other arm whereof is pivotally connected to the stem 63 'of a pis' lton in a cylinder 65 having a pipe 67 (Fig.

4) connected thereto for' conducting pressure fluid to the cylinderfrom'a pressure fluid supply. The admission of -pressure Huid to the cylinder is under the control of the operator at the controlling stand 49, so

,that While the brake normally prevents re' verse -or unwinding movement of the holding drum and at all times permits the winding movement thereof, it may be released at will to permit the lowering of the grab.

- To assist in stopping the holding drum. motor andto, prevent reversal of the motor shaft, a brake maybe applied 'to'l the motor shaft 41 which isgeared to the drum. This brake comprises a wheel 69 encircled by `a brake band 71 connected to a brake lever v73 by a.. link 75 constructed andl operating "in a manner similarto that described for lthe holding drum brake. To positively release thebrake, there may-*be provided a releasing lever 77 connectedbya stem 79 with a piston inl a, cylinder 81, the latter.

connected byI a pipe with-fafsource of presscribed.

Any suitable such levers and 87. '.lheleverA 85 is 'conf I nected to the shaft of a.A mast-er controller` capable' of` starting the trolleymotor lin 1 either direction at will, while the lever 87 is connected to 'aj master controller .which exercises a suitable controliover thehoist -ing motor 43 vas will more fully appear.

Bothlevers are connectedtoexercis'e a cooperative control over the various valve devices which are yemployed for admitting..

yfluid pressure to the various clutch and brake operating units at the hoistingdrums. Suclf devices are described in detail in my. aforesaid prior application,l Ser. No. 69,879, but

the details there'ofare not necesSarytfo an i understanding of the present, invention, it

being sufficient to state that through the 'control of the lever 87 pressure fluid to control the brakescylinders 65 and 81 ma'yr be admitted to or exhausted from 'a'pipe 89 and, under the controll'of the governor-controlled-brake valve hereinafter described, ad-

inders themselves. i l

Referring now to the control of the lowering ofthe grab by regenerative braking,

when the lever -87 is shifted to release the "brakes .and permit the lowering of the grab; thekunwindingof the cables from .the holding and opening 'and closing drums reverses' the motor 4 3 and when-the latter attainsA synchronous speed .itscircuit is automatically closed and the motor is operatedre-- generatively, thereby returning power to the line from which it receives its circuit The work ofthis regeneration serves to check or limit the speed of fall of the grab and to maintain a substantially constant.

lowering speedtherefor. To produce this f regeneration, the holding motor maybe pro-A- vided with a governor 91 (Figs. 2, 3, 5 and 6) comprising a head `fixed to the outer end 'ofthe holding motor shaft 4l'referred to, and having segments l 95 pivoted thereto. These segments have inwardlyprojecting arms 97 pivoted to a ring 99'fast on a -spindie 101 adapted to slide'in a vprojection 'on iso ing.

said-head. The spindle hasa` rounded endv seated in a similarly shaped depression 103 ein a l c1105. One end of said bar is suitably contains a valve 115 normally urged against said plug by a helical spring 117 in a casing -119 tapped into one end' of thevalve casy The tension of fsaid spring ma-y be varied by an adjusting screw 121.

The'v'alve casing isprovided Wit-h a port 123 connected to the pipe'89 referred to..

for conducting pressure-fluid from the control stand.Y The'valvev casing is also pr0` vided Wit-ha port 125 communicating- -With a pipe 127, referred to, leading to the pipes '37.and 83-x`vhich are connectedto the 'controlling' cylinders .for the brakes -for Athe holding l,drum and its motor. The valve casing is also provided with a. port 129 communicating with anexhaust pipe 131.

113 referred to. A disc 141 of insulation material is mounted. fast on said plunger intermediate its-ends and, carries a contact urged toivard the ring 143 adapted for engagement with contact fingers 145 mounted-bn an ,insulation bar 147secured to one of the upright mem.` bers 139. The vplunger 133 is normally governor by a' spring 149 contained in the casing. 137', the tension of which maybe varied by an adjusting screw 'When the hoisting motor shaft is rotated by the unwinding of the drums, the governor segments 95 will tend to fly outward byv centrifugal `force from their position shown in Fig. .5 to their posit-ion shown -in Fig. 3. This `will cause the spindle-101A to slide outward and press the bar 105 on the valve spindle 107 and cont-act plunger 133 against the resistance of their springs. The spindleis connected with the bar at one side of the center of the bar so that'it op'- erates with greater mechanical advantge on the contact plunger than on the valve.

spindle. y Consequently, dle in moving outward contact ring 143 into engagement with the Contact fingers 145. and may` under certain conditions then shift the brake-controlling the governor spinvalve 115 toward the right of Figs. 3 and 5 to apply the hlding'drum and motor shaft brakes` The connecting of the contact ring with the contact fingers completes a circuit to be described for the holding drum motor.

soon as the motor speed is above synchronous speed the regenerative braking obtained by the vmotor will be cifective .to

Will first thrust the' sufficiently limit ,the speedv of fall of the grab and the spindle bar 105 will remain in its position shown in Fig. 3, holdingthe contact ring 143'a'gainst the finger contacts 145 and completing the circuit to said motor'.

If. however, the regenerative braking should fail to suiiicientlyv limit the fall of the grab7 the speed-fof the thereby increasingv the speed of rotation of the governor and causingV the segments 95 of the latter to vfly Vfurther outward. ,This

will thrust thefs'pindle bar 105 from .its position shown in full lines in Fig. 3 to its y position shown in dotted lines in said-figure,

hoisting motor willincrease7 come effective to apply the same and retard thefall'ofv andbring the grabto rest.

It will be understood that the governorcontrolled yvalve is normally in the'posi- The. spindle bar 105 is also connected toone end of ajplunger 133 adapted to slide 4in a. plug 135 and a spring casing 137 on` uprightmembers 139 rising from the bracket tion shown in Figs. 3 and`l5, thereby placing the pipe. 127 leading to the brake-controlling cylinders of the holding drum and its motor in communication with the pipe 89 f leading from the interlock valve.

The master speed controller for the alternating .current motor for the holding drum may be in its broad aspectof usual construction and therefore need not bev described in detail herein excepting in so far as it may `be necessary to explain the electrical connections vlof ythe therewith. v

Referring to Fig. 7, there, is shown a degoverncr-controlled switch velopement of the master controller cylinder contacts together with ,stationary contacts 'cooperating therewith.

P, P2, P3, designate the three-phase primary conductors leading to the alternating current hoist `motor 43. ,'The conductor P leads directly to said motor, While the con-v ductors P2 and P3 are interrupted by aA switch 161 adapted to'bel closed to complete the primary circuit `for forward driving of `the motor to hoist the grab and by a switch 163 adapted to be closed to complete the pri,-

same. To closethe forward switch 161 it Yhas an armature 165 connectedl thereto adapted to be attracted' by a magnetic coil 167.

The circuit for energizing the forward switch coil 167 comprises a "conductor 173 .mary circuit to the motor for reversing the the reverse switch 163 and adapted 'td be con nected by -a bridge contact,189 with a. fixed contact. 191 by the reverse switch when the latter is open. The fixed Contact 191 is connected by a, conductor 193 with a fixed con-4 tact 195 at the forward switch 161, said fixed .energizesaid coil,and shift the forward i, ther to the right,bridged contact segmentsr217 on the .cylinder will connect aistationary Contact 195 being connected by a conductor 197 with the coil magnet 167 forclosing the forward switch. Said coil is connected by a' conductor 199 with a conductor 201 through a switch203 -controlled by an overload coil 205.l The cdiductor 201 is connected to a conductor 207. through a switch 209v con;

trolled by an overload coil 211. These ove'rload switches and coils are of usual construction and need not be further referred to herein. The conductor207 is connected by the switch 213 Awith the conductor `215lefd into the primary conductor P2. v 'vrom the albove description it will be apparent that when the controller cylinder is shifted to the right-the bridge Contact 181 will-'connect' the stationary contacts 179 `and 183 and thereby complete the circuit-'just de? scribed to the coil magnet 167. This will switch 161 to the left (Fig. 7), thereby coniple'ting the circuit through the primary conductors P2 and P3 to the alternating current motor 43 and lrotating the same in a direcfion for lhoisting the grab. r

/ vAs the controller cylinder is shifted diurcontact 219 with a stationary. cntact y' 221 and thereby cut out some of the resistances 223 on the secondary panel. As Vthe controllercylinder' is 'shifted furtherto the` right, centaetjsegments 225 are progressively brought intov engagement with stationaryl ycontacts 227, thereby progressively cutting r,out additional resistances and increasingthe speed of the motor.4 Since'theseresistances andthecircuits therefor are of usual construction, it is thought unnecessary to describe theml furthervherein.

The circilit for energizing the reverse switch coil 171 comprises a bridge contact' 229 on the controller cylinder .ferronnecting thefstationary contact 179 referred to with a stationary contact 231. The vlatter is connected by a. conductor 233 with one of the finger contacts 145 which, as stated, is adaptv ed to be connected bythe governor-actuated ring contact 143 with a iinger Contact 145.

The latter contact is connected by a conduc torf23 4 with a fixed contact 235 at the forward switch 161 and adapted "to be connected by a bridge contact 237 with a fixed'contact 239 by the forward switch when the latter is open. The. fixed contact 239 is connected by a conductor 241 with the reverse switchl actuating coil 171. referred to. This coil `is connected by a conductor 243 with the magnetic coil 167 for the forwa-rd'switch.

jplete thecircuittothe reverse switch coil sstat'ed, this coil is connected through the ' conductors 199, 201,'207 and 215 with the 4primary conductor P2.

Then the controller cylinder is shifted to the left (Fig. 7'), the bridged contacts'229 will connect the stationary. contact 179 and 231 andthe circuit "will be completed for energizing the reverse switch magnetic coil 171 with the 'exception at the pointwhere the circuit is broken by the governor-controlled switch'143. When the motor is reversed by the drop of the grab and brought above synchro-nous speed, the governor will automatically close theswitch 143 and com- 171, thereby causingthe reverse switch 163 to complete the circuit through' the primary conductors P2 and P3 to the inotorr'fThe regenerative braking will .nowcommence,

The usual current-limiting coilsl 245 "and their .circuits and 'switches may .be provided 'and need not be referred to further herein.

thispoint, asffor'example onfailure of the current, then it will cease to actwith regen- '10Q -erative braking effect andthe governor -will shift thevalve 115 andV permit the pressure fluid on the brakes to exhaust, thereby permitting the automatic brakes to apply to check the lowering of the lgrab and arrest the saine. y

It is desired at times tore-verse the ,inotor and `enable a fewy reverse turns to be imarted to the windingdrums to kick off the cables therefrom to initiateand acceleate the fall ofthe grab or to slacken the cables as desired. To accomplish this the controller4 cylinder is provided with a cony tact 249 adapted to beconnected with a stationary contact 251 when-'the cylinder is 115 shifted to the extreme left, said contact being connected by a conductor 253 with the conductor 234 leading to the magnet coil y171 for controlling lthe reverse switch 163. This vwill serve asashunt across the conductors 233 and 234 leadingA to the governorcontrolled switch and complete the circuit, to

the coil 171- and close the reverse switch 163 independently of the governor-controlled switch.

While l have herein shown and described for purposes of illustration one specific em; bodiment ofthe invention, it is to be undery vstood that the saine is not limited to the mechanical .details or theform of relative ar-l( braking on reversalof said combination, a grab, acable therefor, a drum' for said cable,a motor adapted 'when rotated in=one direction to Wind inv said cable, and

when turned in the opposite direction to pro` duce regenerative braking, a governor ro:

tated' by said motor, and means controlled by said governor for automatically complet,-

ing a circuit thereto for initiating suchbrak- Amg.

'2. A hoisting apparatus comprising, in combination, a grab, a holding cable theres for, a drum for said cable, a motor connected to said drum, analternating current mQtQ'r for driving said drum, a governor driven by said motor, and electrical connections for saidmotor and governor includingal Switch automatically ,closed by said governor for limitingt-he fall`of the grab by regenerative i motor lat synchronous speed. A 'v 3. A hoisting apparatus comprising,V in combination, a grab, a drum, a cable connect-A ing said grab with said drum, an alternating current motor, means connecting said motor with said drum, a governor dri-ven by said vmotor, and a. switch actuated by sald gov .ernor when said motor attains a reverse syn chronous speed to close the circuit to said motorand regenerate the feed lline thereto.

4, A hoisting apparatus comprising, in combination, a carrier, a drum, a cable connecting said carrier vvithsaid drum, a motor for the latter, an automatic brake forA said drum, pressure fluid operated means for re leasing said. brake, a governor driven by said. motor., means Acontrolled by said governor for completing the circuit toA said motor for checking 4the fall of the carrierby regenerative braking, and means for automatically rendering said brake effective toresume the retarding of the fall of said carrier ifthe motor attains an excessive speed.

,5L A hoisting apparatus comprising,r` in combination, a carrier, a drum, a cable coni necting said carrier with said drum, an alternating current motor connected to said drum for driving the same to hoist said carrier, an automatic brake for said drum, means for releasing said brake to permit the drop of said carrier and the reversal of said motor, and means for controlling the circuit to said motor having provision for automatically regenerating the feed line thereof when the motor has been brought up to synchro nous speed by the drop of said carrier.

6. A hoisting .apparatus comprising, in combinatioma carrier, a drum, a cable connecting the Same, an alternating current motor for rotating said drum ito hoist said carrier, an automatic brake for checking the initial drop of said carrier, and means for automatically completingthe circuit to said motor when it attains a predetermined reverse speed to regenerate the feed line to said motor and 'relieve' said automatic brake of the Work of limiting the speed of drop of the carrier.

'7.' A hoisting apparatus comprising, vin

.'combination, 'a-'grab, a Winding drum, a

cable connecting the same, and an alternating-current motorrotatable in one direction .for hoisting the grab and having provision on` reverse` rotation thereof for limiting the fall of the grab to -a substantially constant speed.A y

8. 'A hoisting apparatus comprising, in. combmatlon, 'a carrier, a tvmdmg drum, a

cable connecting Vthe same, an alternating current motor connected to said drum, electrical means for said motor including a controller having means for 'causing saidv motor to rotate in one direction to hoist said carrier, means for causing a few reverse turns of said motor to Vassist the initial drop of the carrier, and means for automatically completing the circuit to said motor when it attains synchronous speed to regenerate the line of feed thereof and thereby limit the speed of fall of the carrier.

Q .A hoisting apparatus coniprising, in combination, a carrier, a Winding drum, a cable connecting the same, an alternating current motor rotatable in one direction for hoisting the carrier and in the opposite di- Vrectionby the fall of the carrier, an automaticbrake for .said drum, pressure fluid controlling means including a valve for advmitting pressure'to release said brake, a governor driven by said motor `for automatically completing the circuit thereto to regenerate its feed line vwhen said motor attains synchronous speed, 'and means controlled by said governor for shifting said brake controlling' valve to release the pres- Vsure on said brake and permit said brake to apply itself to retard the drop of the carrier if the motor attains a. speed greater than synchronous.

combination, a carrier, a` Winding drum, a

cable connecting the same, an alternating current motor rotatable in one direction to hoist said carrier and in the opposite direction by the drop of said carrier, an automatic brake for said drum` means for applying pressure fluid to` release said brake including a valve, a circuit for said motor including a switch, and a governor driven by Said motor having provision for automatically closing said switch to produce regenerative braking on synchronous reverse speed of said motor and for automatically shifting said valve to release pressure from said brake When said motor attains a higher speed'.

l0. A hoistingapparatus comprising, in

z motorf, and a switch-Mractuated by saidy 'matic brake for said drum, means for ap.

11. A hoisting apparatus comprising, inA

combination, a carrier, a winding drum,`a cabley connecting the same, an alternating current motor rotatable in one directionfor hoisting the carrie and in the opposite direction by thedrop of the carrier, an autoplying pressure iuid to said brake to release the same including a valve, a circuit for said motor including a switch, a governor driven by sai-d motor, and means connecting said governor with `said switch and valve for automatically. operating the same.

121A hoisting apparatus comprising, in combination, a carrier, a winding drum, a cable connecting thel same, driving means for said drum'for hoisting the carrier,l a brake ,for said drum, and means operating throughv A13. A hoisting apparatus comprising, in'l said driving means for automatically limitd ing the lowering speed of the carriervfollowing release of said brake.

combination, a carrier 7, a cable 9 therefor,

.a drum 13 for said cable, an alternating current motor, a governor '91' driven by-said governor for completing the. circuit to said `'motor4 when the-latter attains a predeterf rse mined speed 'to retard the lowering of the carrier by regenerative braking.

14,. In a hoisting apparatus, -the combina- 4tio'i'igwith a carrier of a druin and cable for hoisting the same, an electric motor orfrotating said drum, a brake, for' holding'said` ycarrierin elevated position, means cooper# ating'with said motor on releasecfsaid brake and reversal of said motor automatically 'to produce regenerative braking to limit the lowering speed of said carrier, and

.me-ans forautomatically applying said brake if' saidv motor. exceedsv its regenerative braking speed. i

15. 'In a; hoisting apparatus, the combinationwith a carrier of a. drum and cable for hoisting the same, an electric motor for ros tating said drum, a circuit and electrical connections for said motor, a switch in said circuit, and a governor actuated by said motor for; automatically operating said switch'tocomplete said circuit to"produce" regenerative braking on Vreverse rotation off said; vmotor at a predetermined speed and 'limit the,4 lowering speed of said carrier.

electric-motor for driving said drum, and means cooperating, with said motorV on reversal thereof automatically' to produce rgenerative'braking for maintaining a substantially constant lowering speed for said p carrier.

18. In `av hoisting apparatus, the combination with a carrier of a drum and cable for hoisting the same, an electricmotor for rotating said drum', a'brake for said drum,

means cooperating with said motor on re.-l

versal thereof automatically 'to' produce regenerative braking to limit they lowering speed of said carrier, and Huid-pressure re# sponsive meansl for automatically appl ing said brakeon reverse rotation .of said di'um above a predetermined speed. Y

19. In a hoisting apparatus, the combination with a carrier of a drum and cable for hoisting the same, an electric motor for rotating said drum, a brakeo-r saiddrum;v

means including laii electrical circuit, va switch therein, andy a governor; driven by said motor for automatically actuatingsaid Aswitch andiprodu'c'ing regenerative braking to limitthe lowering speedv oit-said carrier 'oli reverse rotation of said drum; andv means operated by said governor for automatically applying'said brake on reverse rotation of said motoi above a predetermined speed.

20. I n a hoisting apparatus, the combination w1th `a carrier of aadrum, a cable con- Vnecting the same, an elestric motor, for rotating said drum to'hoist said carrier, an automaticv brake cooperating with said drum to hold Ithe carrier in elevated position, and

means operable on release of lsaid brakel to I l limit lowering of said carrier'to a substantially constant speed.

21. In a hoisting apparatus, the combinaios tion with a hoisting drum 13 of a'carrie'r 7,

a cable 9 connecting said carrier with said drum, an electric motor 85 for Lrotating said drum. to hoist said carrier, means 51, 53 cooperatin with said drum to hold said carrier in e evated position, and means 91 cooperating with said motor for automatically producing regenerative brakingto limit;the

drop of said carrier to a predetermined. lspeed on release of said holding means;

22. A hoisting apparatiis comprising, in combination, a load-sustainingY device, loadraising mechanism, a motor for drivingsaid load-raising ymechanism to'hoistthe load, circuit-controlling :devices to provide, for regenerative braking of the motor on lowerf ing the load, a brake and a speedresponsive device with means for coordinat'ely! controlling thereby the brake and the circuit-controlling devices. i.

23. A hoisting apparatus 'comprising-in combination, a load-sustaining device, loadraising. mechanism, a motor vfor driving said load-iaising mechanism -to hoist the load, circuit-controlling devices to provide for.

regenerative braking Yof the motor on lower'- ino* the load, and means to. provide for a su stantially constant lowering speed ofthe motor while on the regenerative brakingcircuit. f Y

24. A hoisting apparatus comprising, in combination, a load-sustaining device, loadraising mechanism, a synchronous motor for driving said load-raising mechanism to hoist the load, circuit-controlling devices to provide for regenerative braking of the motor on the lowering of the load, and means for maintaining a substantially constant motor speed during regenerative braking.

25. A hoisting apparatus comprising', in combination, aload-sustaining device, loadraising mechanism, a synchronous motor for driving said load-raising mechanism to hoist the load, circuit-controlling devices to provide for regenerative braking of the motor on the lowering ofthe load, and a brake to maintain a substantially constant motor speed during regenerative braking.

26. A.hoisting apparatus comprising, in combination, a load-'sustaining device, loadraising mechanism, a motor for driving said load-raising mechanism to hoist the load, circuit-controlling devices to provide for regenerative braking of the motor onl the lowering of the load anda brake with means to causel the same to automatically supplement the speed control of the motor during regenerative braking.

27.\A hoisting apparatus comprising: in combination, a load-sustaming device', loadralsing mechanism, an electrlc 'motor for driving said mechanism to raise the load A devices for regeneratively breaking the motor -on descent of the load, and a mechanical brake with means for automatically applyingv it in the event that excess speed is reached during regenerative breaking.

- 28. A hoisting apparatus comprising in' combination, a load-sustai-ning device, loadraising mechanism, a synchronous electric motor for driving said mechanism to raise the load, devices for regeneratively break-` ing the motor on descent of the load effec- 'tive when synchronous speed is reached, and

a mechanical brake with means :for automatically applying itV when synchronous exceeded during regenerative raisin 'mechanism` an electric driving g 7 C motor, a regenerative breaking, circuit for the motor, a controlling switch therefor, a speed controlled governor for moving -said switch, a mechanical brake for holding the load when raised, and speed responsive means for applying the brake.

In'testimony whereof, I have signed my nameJ to this specification,

ALMON E. NORRIS.

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