US2000959A - Braking mechanism - Google Patents

Description

May 14, 1935. F. A. JIMERSON BRAKING MECHANISM Filed July 1v, 1930A INVENTOR.

idrimena/z 78 H15 A TTORNEY.

Patented May 14, "15935 Y BRAKING MECHANISM Y n y Francis A.l Jimerson, Athens, Pa., Yassigner. t9 Ingersoll-Rand Companys; Jersey City, N.AJ.,Ya.-V corporation of New Jersey, I, I. f r VVApplication July y17, 1930.,"'Serial 2 Clarins.4 (o 1 !v1s8'`s'2 )j V n I'his 'invention relatesto hoists and more particularly to a braking device-for the same,

Y One objectv of the invention is to maintain conftrol of thev load vat all times and prevent it from 5 dropping rapidly when not being raised.' y

y Yi5 j Another object of the invention is jto 'I'nade said braking device automatic and operable as soon as the load begins to drop. i Other objects of the' inventionwill be in part obvious and in part pointed out hereinafter.

[Inithe drawing, l Figure 1 is a longitudinal the vimproved hoist, and Y o,

vFigure 2 'isa sectional View taken on line `22 ofFi'gure1.` v Y j `l This .invention more particularly contemplates ,the v.provision of `a controlling brakemechanism to be applied to a hoist which is driven ,byan' sectional view through electricmotor as distinct yfrom a hoist which is driven byV anhair motor of the piston type. In the 'latter it will be obviousthatV as soon asthepower WhichV was applied'for raising the load was cut off the motor' itself automatically actedv as va powerfulbrake and thus prevented the loadafroin rapidly dropping., When 'a hoist'is driven by an electric motor, however, and the currentis cut off Wh'en the load is' raised,I there is nothing to prevent ftheload from dropping; rapidly except i3d the inertia of the parts. "Ihespeed of the dropping' load would, under these conditions, accelerate very rapidly and easily become sufficient to wreck the armature by centrifugal force.V This-'serious disadvantage has been overcome in my invention by a simple braking device which is automatic in `its action,v and practically instan- ,taneously effectiveaas soon as the loadbegins Vto drop.: y Y u f Referring to the drawing whereinA similar characters of reference denote corresponding parts throughout, II) designates vthe base frame of my improved device which is adapted to support both the hoist I2 and. the motor I4 for driving the holst. The motor I4 may be of the .electric type havingafuniedirectional of othermotion The armature shaft I6 of the motor is supported the usual end cover I8 by means ofthe bearing `20.

Suitable means are provided forcoupling theV hoist I2 `to the motor I4 and inthisinstance the Varmature s'haftffIBv has a projecting end formed with a series of splines 22 extending longitudiandthe splined shaft I 6 enters this coupling'` for ,a short distance. ,Y Intothe otherendoff th1s V-'eorir'iling 24fis securedin asimilarnannerf the A'main' s haft 26 ofth'efh'oist |712', fj j ,Y v Thejother 'end' of the 26 lis-'supportedina y bearing Z8 carried by, a "cover 30 which encloses e "5 'l that endoff the hoist |25 TheimainshaftfZB A driven in this way atthegspeedofgthejmotor due toth'e' direct couplingto the -armature shaft I 6. This speed l is preferably "reduced 'before being Y lapplied'to raise a load byafsystemlof reduction `10 gearing operated by* afpinion A32 suitably `keyed.

to the mainfshaft 26A adjacentthe`V QOVQIIII). Meshing vv'ithfthel pinionV 32V ajrelatively Vlarge y eazr:3ft-with a pinior36 adapted to rotate at similar speed and Aforthis-'p'urpos e `laeingfio'rmed. inthis instance integral withy thelarge gear 34 andjsupported in conjunction vtherewith upon the shaft 38. The shaft" 38 is4 Supported atheney end'in the cover 3B -byra bearing and at theother endV -o by a' bearing j(42 which is securedin afh'ousingjy v20 enclosingthese'qgealrs,r AIhejhousing is secured by focuses mulebasen),`

Meshingwith the pinionl is a `larger gear .46 'whichjis suitably keyedftov a hollow shaftl. t. The vhollow shaft 48 willI therefore be driven 25 through the reduction :gearing atV desired relative Sped t9 thev main" Shaft 12.6 .depending Vupon the chosenratio of-these gears. Thegear46 is maintained in'position on the hollow shaftf'48 ,-5 I oy avr nut Ywhich holds it against a bearing 52 'V30 supporting the hollow shaft 48finthe'housing 4,4. A ange A54 on the housing 44 extends at the'fother side fof the bearing 52 and abutting thsflange' isa braledrum'member 56 supported onvthe d hollow' shaft 48 by abearing'58." o 35 '7"I'he`brake drum member 56'has an 'external vbraking surface lil),` upon :which a brake .band1l62 i isadapted to act and preventits rotation witlzrtheV hollow. @shaft4 4.8.' ,"I'lie brakaband mechanism 54D I comprisesja band lI54fpreferably of metalsecureid Y tofthe brake bandA 62,y which is iprefer'aiblylgo'f a j friction material; and this metalfb'arld"f 64' is Vanchored at'itsiendsto 'A pins 66 rcarried"by sup;Y ports k68Y on the casing "I0, LOne of the supports Vv68Vpreferably has ajleft;V hand thread 1,0 andthe othersupportpreferably has alright hand thread 12." Ajjshaft 'I4Vhaving 'right andleft hand threads thereon is inserted inthe supportsBBand' extends through a bearing 16 vorrthe casinglllwherea handle'l may besecuifedthereto.H Thesupports '68;f`a're arranged.' jslideways vlill soythat they can movetowa'rds aniffa-vvay fromeachothr inithe casing I, 0 when the shaft'j'l4'-zis -rotatleldf 11n Y one direction :or vthe other; "I

A portion of the brake drum 56 extends beyond the braking surface 60 and has aninternal gear 80 formed thereon. Meshing with this internal gear 80 is a drum driver comprising a plurality of pinions 82 arranged in planetary fashion. These pinions 82 mesh with a pinion 84 suitably keyed to the hollow shaft 48.

A winding drum 90, which is adapted to accommodate the Vhoisting rope 9| carrying the load to be raised, is supported upon the hollowy shaft 48 around which it may be driven by the drum driver.

To this end the winding drum Sil-'has a iiange abutting the braking drum 56 and into this flange projects a plurality of stub shafts 92'. Thev other end of each stub shaft is supportedin a hub 94- on a Vcover 95 which is secured to the winding drum by bolts 88.Y Theplanetary drum'rdriver pinions are free to Vrevolve on the stub shafts 92 whereon they are supported by frictionless bearings-86e i f i The. Winding drumli rotates freely. on the hollow shaft 48 and i s -j ournaled at the driven enden a hearing 98. titiller;v abuts a-shoulder.

the Shait-.r ,It Willbe ,Seen from this Construction thatl when` the nut 0wat the end of the hollow shaft 48 isV dl'WIl 11D tightly Vall theparts betweentheshoulderfl 00 and the nut will be held Y seurely in. Desmonf A reduced portion |02 on. the hoisting drum is mended in Order'that the rope 9| may. be wound therearound, andgin order to keepthe rope in A.position asecond-flange |06 isA provided Yat `the oftherend of the reduced. portieri |02. This end Yof the drum-90 having the iiange1|06 is supported ontle *hollow` shaft bya bearing |88 which abuts as edpeisnoulde; :menthe shaft 4 8, Extendingffrom the Harige-|016. is a projecting portion 2 inthe form of a hubhaving threads 4 on its periphery. The threads ||4 in thisk instance *may` be right-hand.. Theinner surface of the Y gagingr the 'thread I I4. The clamping'v member |24"is preferably spaced from the'iian'ge |06 on the, hoisting drum and fbetween these two members is a frictionmember Y|26 having clutch facings '|28 'of some friction material projecting Von l either side thereof and secured in position by the rivets |30. The friction member |26 hasan an- 'nularange ori its periphery forming aA braking "surface '|32'.Q4V The (braking surface |32 is similar tothe braking sufaceBD at the' other side of Athe hoist'ffand has ar similar. brakeband 62 acting thereon, The mechanism for manually operatingthis second brake is Videntical withthat emtljiesame at this point is'` therefore. omitted. e

Thel friction member. |26 is preferably sup- "por-ted ,forfree rotation upon the clampingv member.|24 bymeans'ofa projectinghub |34 vengag- Attached by its. outer end to the clamping member |24 is a spring |36 of the Ldat spiral type, 1186,/-

vforth of the clamping member ing its inner end engaging the hub 2 on the winding drum. This spring is adapted to be placed under an increased tension and released from such by longitudinal movement back and will cause the pinion 84 to rotate the pinions 82 of the planetary drum driver.

If the brake 62 has not been 1tightened upon the bra-ke drum 5S thev drum driver will merely rotate the brake drum 56 Without in any way moving the winding drum 90.

They brake 6.2.- is thereforetightened upon the brakedrum 56 to prevent its rotation, whereupon the pinions 82 of the planetary drum-driver will roll around the internal gear 80 and cause the the rope 9| will wind thereon to raise the` load. VVVThe othervband brake |32 has been tightened upon the frictionl member |26, preventing its rotation with the drum. As the winding drum revolves thvelclutch facings |28.wi1l frictionally engage the clamping Ymember |24 holding it against rotationv andthe thread ||4 being right-handed will move it away from the winding drum against the tension of the spring |38.. The spring |36 will now commence to wind up and at a certain point the increased 4tension thereof will overcome the, friction exerted/by the lclutchffacings |28 upon the. clamping member 24 to permit the winding drum to rotate the clamping member around the clutchv faeings |28.4 The clutch facingsA are, of course; heldimmovable by the tightened brake band. 62 acting .upon the braking Vsurface |32. YTheload can vtlriereiore be hoisted to anviheight. e When the load has stopping rotation of the. windingvdrum ina clockwise direction and permitting the kforce ofgravity toact uponthe load vto move the drum in the opposite direction by meansof the rope 9|. As soon as thedrumstarts torevolvein the opposite direction the vincreased tension on the Aspring |36 will be relaxed thus permitting the clutch facings |2Y8 to gain lcontroland frictionally rotate the clampingmember |24 moving it back longitudinally along the thread |4 inthe direction of the flangeY |06 on the winding drum. longitudinal movementwill continue for a brief instant and then the clamping member |24 will forcefthe clutch `facings .l 2 8 against Vthe flange vv| 06lcreating 4a braking action `which becomes continually greater Vuntil movement of the winding drum ceases It will readily be seen that the braking action of the clutch facings |28upon the winding drum will occur almost instantly Fwith .the dropping of the, load and that thewinding `drum can Y attain no :great speed beforethisv` occurs. ployed foroperatmg the first anda description of If it isdesired to lower the load,` thiscan be done .by gradually .releasing the brake band 62 onthe Africtionmember |26 and `controlling the,

h istsj'h heen.. provided, While .-thegbrakng |24 on the Y y been hoisted to desired:

height the vmotor may be entirely cut off thus Y v Vincorrere device has been described in connection with `an electric motor drive, it will be apparent that 'its use is not confined to this type, but may be applied to other forms of drive with equal facility. The braking action is practically instantaneous with the dropping of the load and is entirely automatic. I claim:

1. A brake for a rotary member, comprisingspiral spring connected to the members and being subjected to tension during rotation of the members and acting upon cessation of rotation or thev members toV eiect frictional locking engagement between the friction means and.` both members. Y

2; A brake for a rotary member, comprising non-rotary Vfriction `means adjacent the rotarymember and movable longitudinally with respect thereto,` a clamping member rotatable with the rotary member and being held released from the friction means upon rotation of the rotary member, a spiralrspring connected to both members Y for clamping the friction means into frictional engagement with both members upon cessation of rotary movement of the members, and brake `means for locking andreleasing the `friction meBlnS.

FRANCISVA. JIMERSON.

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