US1471657A - Brake for rolling ladders - Google Patents

Description

Oct. 23, 1923. 1,471,657

` L. N. HAMPTON BRAKE FOR ROLLING LADDERS Filed Nov. 26 1920 2 Sheets-Sheet l 1920 2 sheets-sheet 2 /m/enfo Leon /M Ham/afan A E ,o m 5 i f if? Afm L. N. HAMPTON BRAKE FOR ROLLING LADDERS Filed Nov. 26

Patented st. 23,A 1923..

' tarima LEON'N. HniirrfrON, or NEW Yoan, N. Y., ,assraNoi-'rro Wns'rnnN n'rno'rnro; corr-` rnNY, INCORPORATED, or Nnweroan, NY., .a CORPORATION yor Naw Yoan.

, nanna ron ROLLING rnnnriias.

' Application rIedNOveinber 26,1920. Serial No. 428,464.

To all whom-t may concern. i

Beit known that LJLEON'N. HAMPTON,

a citizen of the United States, residing at New York, in the county oi'BronX, State' of New`York, have invented certain Anew and useful Improvements in Brakes for Rolling Ladders, of which the following is a full,

` clear, concise, and exact description.`

This invention relates to improvements in rolling ladders, and more particularly, in that class of rolling `ladders which are supported on an overhead trackfor use in telehone exchanges stores and the like where f it is necessary to have ready access to maiii chine parts or shelves normally out of reach.

YThe primary object 0f thel invention'is to provide a ladder with a brake which. is

Y automatically applied by theweight of the *person using the ladder and similarly re-v leased while the ladder is occupied. Fur- Fill leased upon the removal of the weight.

A further object is 'to` provide a means,

operating kindependently ofk the movement ol' the ladder, whereby the brake can be krethermore, thisdesirable feature is brought about insuch a way, that, by using a minimum effort, the brake may be released so that the ladder will be ree'to be rolled from place to place as desired; s ,l p

More specifically, the inventionl consists in thecombination with a track, and a truck 'movable on the track of a ladder depending therefrom, cooperating with a lockingmember or brake which serves to secure the truck' against movement on the track, and which? is actuated by a limited Y downward in ove-A ment of the ladder, the latter having a yielding connectionwith the'braking member.

The braking member is also normally held in its inoperative or released position by a spring or other means to counter-balance .theV weight of the ladder when it is not in y use.

consists in certain combinations of parts all as will be more fully described herein? after, the novel features beingk pointed out in the claimsy appearing at theend of Lthis specification.

To these and other ends the invention,

2 is avvertical sectional view taken onthe lineZ-ZoFig l.

Fig. ,3 is an enlargedA-:vertioal sectional view along the line 3;-3 of Fig. l;

illustrating at modified form-of my invention( -Fign is a side elevation kpartly inA section i Fig. 5 is avertical sectional yview .taken on located in the horizontal section of the dethe slot W, is rmly seated across thetwo brackets K which intheirturn arelike- This movement is ob-V Similar reference letters' ink the several wise rigidly attached to the ladder T von its L upper step. ln orderthat this relative motion of the ladder T to the truckC may be restricted, accordingk to the requirements oit thepresent invention, a restoring tension spring Z isfattaohed tothe ladder T and the dependingtruck C, the connection being obtained in the case of the ladder, by means of a' U'shaped bracket Kpwhich contains the spring Zastened at O' and which islocated on the under side of the top step of the ladder T in alignment with the brackets K holding the pin L, andin thelcase'of. the truck C it 'is obtained atN by an elongated lbrackets securing plates K. This spring spur or projection M formed directly beneath andfintegral with the slotted portion or the truck C and passing through an aper-y ture in the ladder step between the U-shaped i Z' using the 'truck C as its lined support, eX#k ertssniicient Vpull when theladder T is unoccupied to yraise the ladder andthe pin L rigidly seated thereon, until the latter reaches the upper limit of its confining ,slot

W, 'but it does not in the reverse instance,

`exert suilicient pull for the same purpose when the ladder T is occupied, but is in this case overcome by the force resulting from the weight on the ladder, Yso that the ladder is lowered until the pin L reaches the opposite-or lowerlimityof the said slot WV.

. It is this arrangementv which fundamentally controls the operation and release of the braking mechanism which will now be described.

The pin L which connects the ladder T and the depending truck C, so as tor allowvertical play of one in'respe'ctto' the other, also kserves to rigidly hold to the ladder brackets l; in which it is seated, a'cap 'piece lconstructed oitv a U-shapedangle iron,` and provided with shoulders on'its sides which bear against the vertical legs of the ladder bracketsl. Fastened to the top` of this cap piece l is a second tension spring H which for Vconvenience will be called the brakin Spring to distinguish it from the yfio restoring spring Z described in the last parso that there may be constantengagementY between the `inclined surfacesV of the shoes E and those ot the actuating member F, to the end that the outer friction surfacesof .the brake shoes E will be withdrawn from engagement with the track surface `by the actionfoit the springs S when no pressureis being applied from within by the actuating meinberl?. .tssuming that the ladder i T is occupied and the pin L is at'its lower istv - release when the ladder is not occupied will limit in the slot YV, sutlicient pressure is being applied to the actuating member F throiigh the medium of' the braking spring H to` 'torce the shoes E into engagement with the inner surface of the track A and an eii'ective braking action is thus brought about. Having covered the automatic application of the brake when the ladder is in an occupied condition. the voperation of the elements which enter into its automatic next be considered. l Y

The element which plays an important f part in automatically releasing the'braking shoes E when the' restoring spring Z has moved the ladder upward and brought the Lpin L to the upper limit of the slot W, is

a releasing member l which issecuredin the upper face of the cap piece I, and

which has sufficient cross sectional diameter in its upper portion to provide an appreciable bearing surface to engage and abut against the actuating member F, relieving the pressure on the inner faces of the inclined surfaf-es of its head soz that the shoes li, having their inner surfaces simultaneously relieved oi' pressure can be drawn together and out of engagement with the track A by the, actionoi the small springs Si which are speciiically provided Jfor this .position it is naturally in when occupied,

that is, the pin L is at its lower limit, in the slot lV'. ris the actuating member Fis pried upwards, the braking spring H elongates and a separation occurs between the member l? and the member il which normally lunfstions in auton'iaticaily.releasing the brake, so that thedesiied result is obtained without effecting or being ai'ected by the vertical position oli the' ladder. inasmuch as a separation occurs between the actuating member F andthe releasing member l of the mechanism, when the manual release is beingL employed, it is evident that the force required to effect this release,A disregarding the factorL of mechanical. advantage gained bythe lever Q, need only be sufficient to overcome the tension of the spring H, which will be ytor all practical working conditions, a definite, tixedforce in ay given ladder.

Fig. 5 shows a modification of the invention the mechanical elements corresponding to those in Fig. l being referred to by similar letters. In this case the slot lV and pin L connection is similar to that mentioned in the preferred embodiment; but several of the elements employed in obtaining the result are changed. For example.` instead of using as a restoring` or counterbalancing means, a tension spring located under the top step of the ladderl` as is done in the first instance` a compression spring Z which fits snugly within the cap piece or housing l is employed. Then the ladder T" moves downward as the result of a weightplaced upon it the cap piece T compresses the spring Z against the depending yoke or truck C. which has no motion in a vertical plane, and thus stores up energy in the compressed spring Z sufficient to restore the ladder to its elevated position when the Vweight is again removed. Thus an ei'licient and compact means is provided for controlling the motion of thepin L' in its elongated slot W.

The means employed in automatically releasingthe brake upon the upward motion of the unoccupied ladder consists in this instance,of two upturned ears or angle irons J', rigidly attached Ito the .top of the cap piece i actuating member F', provided with a horizontalV section with which the 'ears are adapted to cooperate. Y Y. n

YThe braking mechanism is operated by the actuating member F' ,which receives a tension froma braking spring H', after a manner-similar to that disclosed in Fig. 1. The shoes N' of thek mechanismdn this case, however. are not appliedy directlylto the track-surface,but to the wheels of the roller carriages B' whichsupport the depending truck, eachof vtwoshoes cooperating 'with awheel or roller on eachrcarriage. AThese braking shoes N', which are provided with creseentshaped friction surfaces which approximate the peripheryof the rollers in respect t theirraxes of curvature, are pivotally connected to twov toggle levers E' which are pivotally connected at Oto the vertical portion of the brake actuating member F'. AA tendency kfor the kbrakes to `jam andJ stick must in this instance be Y guarded against, for should the toggle levers approach a horizontal position, vthis condition would lbe the likely result. Accordingly, two angle bars S', provided with set screws X' on their horizontal faces, are rigidly attached to across barGron the depending yoke C', so that the range of movement within which the brake' actuating member. F' is freel to operate can be determined according to the peculiaritiesv .ofl the individual case. v Y Y It willreadily be seen from the operation of these two devicesthat in both 'cases the braking' action is constant, since the coun-kV terbalancing springs namely .thegf tension spring Z in Fig. 2 and the compression spring Z' in Fig. 6 are so adjusted that the weight of aV person is sufficient to make the pin L travel the length of the slot in spirit of my invention as set forth inthe appended claims.

What is claimed is: Y

1. In a device of the class described a track, a truck movable thereon, a ladder supported for movement on the truck, a

, and .which abut against a brakeV braking member movableinto engagement with the track by a movement of the ladder andfmeans .for releasingthe brakingy member independently-of themovementof Y theladder. .v i, f'

2. In a device'gof the class described a track, a truck movable thereon. a laddery depending Afrom the truck and having a linear movement relatively thereto, aloekingkmemmovementrelatively thereto, a member serv-L ing to secure the ladder against movement while the ladder is weighted, andmeans for releasing lthe member while the ladderV is weighted, said means operating independently ofthe movement of the ladder. f

" LlJThe combination with an yoverhead track, of aV truck mo'vablethereon, a ladder v depending fromsaid truck and having a l linear movement relatively thereto, a lockingY member, movable `into. and out `of engagement with the track, an element4 servingto force said member intoengagement with the 'track and means for applying a iiXed, tension to said element. y y 5. The; combination with 'i an overhead track, of a truck movable thereon, a ladder depending fromy said truckand having a limited movement' thereon, a brakey applied and-released bythe movement of the ladder On the truck anda brake release operating independently of thermovement kof the lad-` der. V

6. fThe combination` with an overhead track, of .atruckhaving a linear movement thereon,.a ladder movable relativelyy to the truck. a' lockinglmechanism anda releasing device therefor operating independently of the movement of the ladder. i

.7..The 4combination with an -overhead track, a truck movable thereon, anda braking member Vfor securing the truck against movement,'of a ladder suspended from the truck andhaving ay limitedmvertical movement relatively thereto, means operating to yieldingly support the ladder in its elevated position onV the truck, and a' yieldingconnection between4 the ladder and rbraking member foroperating the latter upon the downward movementy of the ladder. Y n 8. vvThe combination withk an overheadk track,.a truck movable thereon, anda braking member for securing the truck against leo j movement, of a ladder suspended from the *truck* and having a limited vertical Inovementk relatively thereto, .means operating to yieldingly support the'ladder in its elevated position on the truck, anda releasing member onthe ladder arranged to engagel the braking'member to move it into its inoperative position kwhenthe ladder is restored to its normal position.

9. llhe combination with an overhead tubular track, a truck ,having spaced car-A riages movable in ythe track, brake shoes located between the carriages and an actuating member for *moving them into engagement with the .track vand having a limited downward movement, of a ladder suspended tion, and a spring attachedto'thefladder and ysaidac-tuating member for moving it upon the downward movement of the ladder.

l0. The combination with a tubular track having a longitudinal slot in its'low'er side,

a truck movable in the track comprising a I yoke depending through the slot, having a downwardly extending projection, of a ladder having its top step provided with an aperture receiving said projectioma bracket beneath said step and a spring attached to thelatter and to said projection serving to counterbalance theI `weight of the ladder, brackets above s'aidstep embracing the yoke and having a slotand pin connection therewith and a cap 4piece extending upwardly from said brackets, brake shoes within the track, a wedge member for separating them having a'depending portion guided on the yoke, spring connecting the wedge member with the cap piece and a part on the latter positioned to move: the wedge member upwardly and hold it in an inoperative position when the ladder is elevated.

ll. The combination with an overhead track, a truck movable thereon having adepending yoke portion, of aladder supported for limited vertical' movement on the truck a yielding connection between the ladder andthe truck serving to counterbalance the weight of the ladder, a braking member movable into and out ofengagement with the trackl an actuating e-lement guided on the yoke Afor vertical movement kand operating the braking member and a yielding connection between said actuating element and the ladder serving to operate said element upon the downward movement of the ladder on the truck, a pinconnected to the ladder and engaging said actuating element to'move it into its inoperative position upon the upwardmovement ofthe ladder on the truck, av bracket on ysaid truck and aflev'er bar pivoted on the bracket, and engaging said member for ifeleasingit.

` 12.'The combination with an overhead tubular track having fa longitudinal slot in itslowerside, spaced roller carriers movable inthe track, and a truckfsupported by said rollercarriers, a yoke' portion depending nanna? through the slot and a cross bar on said yoke portion, of a ladder supportedior limited movement on the yoke, means cooperating with the yoke and the ladder serving to hold the ladder in its elevated position, separable vbraking shoes `movable into and out of engagement with the track ybetween saidy roller carriers, a member guided onLt-he cross bar serving to separate the shoes, a yielding connection between the member andthe ladder and a pin cooperating with the member to move it intork its inoperative position, a bracket on the cross bar. and a lever pivoted on the bracket.

'13. The combination with a tubular track having'a longitudinal' slot in its lower side, roller Carriers'movable in said track, a truck attached to the roller carriers, a yoke portion for the truck depending through the slot.'of a ladder depending from the yoke and having a movement thereonand a yielding' connection between the ladder and the yoke serving to hold the ladder in its uppermost position on the yoke, braking shoes yielding in respect to each other movable into and out of engagement with the track 7 a member guided on the yoke and cooperating withy said shoes, a yielding lattachment between said member and the ladder allowing the member to be moved downward when the ladder is moved downward and a pinL attached to the ladder to force the member kinto position 'to release the brake shoes whe shoes cooperating with the track, a resilient connection hol/ding saidA brake shoes in an vinoperative position andan actuating member. for separating said brake shoes having a depending end portion, a yielding connection between the ladder and said depending portion'serving to move it in one direction to operate the brake shoes when the ladder moves downward and a pin attached to the ladder to move the actuating member into its inoperative positionY when the ladder moves to its Velevated position.

15. A ladder, a brake for said ladder, applied by a vertical movement of said ladder, andl means for releasing said brake independentlyof the movement of the ladder. I v16. The combination with a track, of a truck movable thereon, a ladder movable relatively to the track, abraking mechanism applied bya movement of the ladder and a releasing device therefor `operating indee pendently of the movement kof the ladder.

LEON N. HAMPTON.

22nd day of November A. D.,

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