US2334295A

US2334295A - Crane

Info

Publication number: US2334295A
Application number: US453936A
Authority: US
Inventors: Harry F Stofflet
Original assignee: Individual
Current assignee: Individual
Priority date: 1942-08-07
Filing date: 1942-08-07
Publication date: 1943-11-16
Anticipated expiration: 1960-11-16

Description

Nov. 16, 1943. H. F. `error-FLE'r 2,334,295

CRANE Filed Aug. '7, 1942 IIIIIIIIIII gk wr k Karr A: f 5gg/3f Patented Nov. 16, 1943 PATENT o1-Fisica Y 'GRAN-n. y n v `miplica-elmu-nuglist 7, lsrasriaziivo. 453;936 i "7 crains. (vol. '21e-$27). if'

The objects of the inventipnlare to `provide a crane havingminimum overhead andend clear'u ances" so as to serve a maximum floorjar`ea`l with maximum hoisting height44 forau 'given' height of building or'supportihg structure; togive-a greater flexibilityfin handling loads; and Ato sojsimplify the constructiorr'and so` locateI andl s'osimplify the power drivev asl-to materially' reduce thecost of construction; operation and maintenance.

These objects are accomplished bymy invention, one preferred embodimentof Which-isshown in the accompanyingdrawing, in which- Fig. 1 is a planview of the crane. f

Fig. 2 is a longitudinalsection on thetlin'e 2-2 ofFigl'; 1 Fig. 3"'i`s a crossseotion, omitting the eridtruclr,r on the line 3-3 ofFig. 1'.' 1

Fig. 4 is a detail side view of a onefofftheftrolley sheaves andy itsv braking mechanism.

Supporting opposite ends'v ofthe bridge beams ma are the-en`d trucksb, l'1), movable oriltli'e side s rails e; of the'supporting-structure. V Supported on one of the bridge beams, ateach enjd thereof,

is affra'mec'oarrying amot'ord. At eachfenfdzoi thebridgeis a cablewinding drum e; the endsof which turn in bearings-gicarried-by the' beamsla. Each motor d drives its corresponding through reduction gearing f and f. l

The wheels of the trolley framelc-runon-v rails h onvthe beams a. Turnablev on `an axleo'arried by the-trolley are two pairs of'sheaves m,;1z, -Yand o, p. Two wire ropes or Cables randls connect the drums `eat opposite ends of the bridge,` the ends vof the ropes being wound uponwthel two drums. One rope r extends from one drum-e successivelyfaround sheave m, asheave t on a sheave .block t2. carrying the -li-ftinghook tj and sheavefn tothe 'other drum e.'r The other cable extends-from one drum e successively-around sheave o, another sheaveon the `sheave block` v t2 and sheavep to the other drum e. AIt will beunderstood .that there may be any number of bi'ghts inthe wireropes r ands .betweenv the. sheaves car'- ried by the trolley .and the sheaves lon the lifting hook andtherefore any corresponding number of `sheaves on the trolley k; the four sheaves shown being adequate for `alsmall crane orior light loads.-

Carried. by ,each sheave m, 1L,ioand p isa brake drum u (see Fig. 4). Each brake drumlcarries a strap o `one `end of which is secured tola frame w and the other end of which is secured to a bell crank'lever pivoted on the frame wandl-operableY by a'fso'lenoid'y. The `form Aof sheave 'brake shown'fis yConventional "and any `suitable known brakes irlocking the ,sheaves against rotation may be substituted or"'br.akes of' the construction shown. j f L luisA the operators cage and Il the'footwalks. The electric connections to the motors d and solenoids' y" are` notshovvn', as these are conventionahy The :movements that itis desirable to impart to` the load are the following: Lifting orlowering the load at f ull speed; lifting or lowering the load at half speed; moving the trolley along the bridge in eitherv directionwith no lifting or lower-` ingof the load; moving the trolley along the bridge in either direction with simultaneous lifting or lowering of the load. i

If it is'desiredto lifnt the load at full speed with normoveme'nt of `the trolley, thevbr'akes are not applied to any of the sheaves 'and both motors are actuated to turn the drums 'e in the direction required to wind the ropes thereon. y The sheaves n, o andpbeing free to revolve, the shortening of the rope lengths between the drums will' be whollytaken up by shortening the bights inthe ropesj-between the trolley sheaves and the load, andthe load will'ilift lat hi'g'hspeed` with no' movem'entof'the trolley. j4 f ,Byv actuating only one motor towind the rope on only -oneA drum e, witlinoapplicationor the brakes,` theload will be lifted `at half'speed, the trolley' remaining `stationary. Y

f If `it is desired' to move the trolley to the right, withno` vertical movement of the load, the brakes are ap'plied to allthe sheaves m, n, o 4and p' and the right-hand motor is actuated to wind the ropes on the right hand drum, the left-hand drum being meanwhile allowed to unwind.` Similarly with all`v thebrakes applied', by 4actuating the left-*hand motor to wind up the ropes and the right-hand drum being, allowed to unwind,th`e trolley will moveto the' left, with no vertical movement of the load. 1 AIl? only `sheaves `m and n, arebraked and the drum at the right turned to wind the ropes thereon, theftrolleywill moveto the right and atthe same time thev sheaves o and p will turn to lift the load. By brakingonly sheaves lo .and p and turning the drum at the left to wind the ropes thereon, the trolley will move to the left and at the same time the sheaves m and n will turn to lift the load.`

speed lift, giving'fa greaterg'range of hoistingV speeds and a greater iiexibility in handling loads.

Shi-ft from half speed or "less to full speed maybe n the sheave block. v

instantly effected. This capacity is a very desirable feature, especially in serving machine tools, assembling parts, or'loading and unloading machinery.

Theheight of the carriage or trolleylc need be substantially no greater than the diameter of the trolley wheels h. The sheaves carried by the trolley may have their axes just high enough to .clear the track. The trolley carries no motor.

Therefore, the head room, that is, the height from rail to required clearance for'moving parts,

` is reduced to a minimum, thereby obtaining a.

greater hoisting height. This close overhead clearance is of importance, since the Vrequired height of hoist can be obtained with a minimum height of building or crane` supporting structure.

The construction shown andv described, and particularly the location of the drums egat the extreme ends of the bridge beams, enable the load carrier to approach very close to the sides of the building vor vcrane-supporting. structure.. These close end clearancesy enable the cran'e'tor serve a substantially maximum' floor area.

The Weight of the motors. and driveb'eing on the end trucks, excellent traction is Secured.

The construction shown andV described permits the elimination of the usual slide bars, current collectors, electrical equipment, wires and other block, and means to brake the trolley sheaves; whereby, with the trolley sheaves unbraked, the load may be lifted at high speed without moving the trolley by winding the ropes on both drums or at low speed by winding the rope on only one drum, and whereby by braking the trolley sheaves and winding the rope on only one or the other drum the trolley may be moved in one .direction or the other without vertical movement of the load., .y

- 3. In a crane, the combinationwith a support-y ing structure comprising 'end trucks and connecting bridge beams, of a trolley adapted to travel along the bridge beams, two sets of sheaves carried by the trolley, a hoisting-hookcarrier and` sheaves thereon, drums at each end of and sup'- "ported on i the supporting structure, ropes en A gaging and extending between the drums, interl. In a'crane, thecombinationwith asupport'-` i 'ing structure comprising end ltrucks andcorm'e'cting bridgebeams; of two drumsvone at each end of, and carried by, the supporting structure,` two motors, one for.v1 each drum, driving lconnections between each .motor and'its corresponding drum; a trolley spanning and movable along, the bridge beams, two setsof sheaves carried by vthe trolley, aV sheave block, a hoisting hoolg thereon and sheaves carried by the sheave block, and ropes each having their opposite kend portions WOllIld 'upon the .two drums and extending between the drums, one rope extending. around one set'of sheaves and a sheave or sheaves on the sheave block and the other. rope extending aroundv the other set of sheavesv and Ya sheave orsheaves on 2. In a crane, the combination with a supporting structure comprisingl end trucks and connecting bridge beams; of two drums one at eachend of, and carried by, the slvlpportingv structure, two

motors, one for each drum,.dri`ving connections between each motor and its corresponding drum;

a trolley spanning andmovable along the bridge v beams, two sets of sheaves carried' by the trolley, a sheave block, a hoisting hook thereonv and sheaves carried by the sheave block, ropes each having their oppositeend portions wound upon the two drums and extending between thedrum's,

one rope extending aroundone set of sheaves and a sheave o r sheaves on the sheave block and the other rope extending around the other set of sheaves'and a sheave or sheavesnon the sheave mediate parts of which engage the two setsv of sheaves respectively and sheaves on the hoisting hook carrier, and means tooperate either drum independently or both drums simultaneouslyto thereby turn theA trolley Asheaves at dilerent speedsv and thereby control the load lifting speed.

4. In a crane, the combination witha support-l ing structure comprising end trucks and connectv ing bridge beams, of a trolley adapted to travel along the bridge beams,.two sets of sheaves carried bythe trolley, a hoisting-hook carrier and sheaves thereon, drums at each end of and supported on` the supporting structure, ropes engaging and'` extending between the drums, inter-` mediate parts of whichengagethe twosets of sheaves respectively and sheaves on the hoisting hook carrier,- stationary motors, one for each drum, supported onr the `supporting structure, Aand driving connections from each motor to its cor,-A

respondingrdrurn.- .l K y l. u t 5. In a crane, the combination with a supportmgl structure comprising end'trucks and connecting bridge beams, of a `trolley adapted to travel p along the bridge beams, two sets of sheaves carried lby the trolley, a hoisting-hook carrier and sheaves thereon, drums at, each endV of and su ported on the supportingstr'ucture ropesengaging and extending between the drums, intermediatel yparts vof which engage the two ,sets of sheaves respectively and .sheaves on the hoisting ,hook carrier, means tobrake the trolleyv sheaves, andpower meansvto operate thedrums whereby whenthe brakes are applied to thetrolley sheaves the trolley may bemoved along thev bridge beams and whereby by unbraking the trolley sheaves the hoisting hookfmay be lifted wtihout movement of the trolley. Y v l 6. In a crane, the combination with a supporting structure comprising end trucks and connectin g bridge beams, of a trolley adapted to Atravel along the bridge beams, two sets of sheaves carried by thetrolley, a hoisting-hook carrier and sheaves thereon, drumsat each end of and vsup-A ported on the'supporting structure, ropes engag-v ingand extending between the` drums, intermef.

diate. parts of Vwhich engage the-two sets'of sheaves respectively and sheaves onthe .hoisting hookcarrier, two stationary motors one: at each end of the supporting structure, driving connections between each motor and the corresponding drum, and,meansrto independently brake each set oftrolley sheaves. i'

'7. In ,a crane, the combination withI a supporting structure comprisingend trucks and con,- necting bridge beams, of a trolley adapted -to sheaves thereon, drums at eachv end of and supported on the supporting structure, ropes engaging and extending between the drums, intermediate parts of which engage the two sets of sheaves respectively and sheaves on the hoisting hook carrier, means to brake the two sets of trolley sheaves independently, and power means to operate the drums independently; whereby, with the trolley sheaves unbraked, the load may be lifted at high speed without movingthe trolley by winding the ropes on both drums or at low speed by winding the rope on only one drum, and wherebyby winding therope on only one drum the trolley may be moved in one direction and the load simultaneously lifted or not dependent on Whether the trolley sheaves of only one set or the trolley sheaves of both sets are braked.

HARRY F. STOFFLET.