US237616A - Fire-escape ladder - Google Patents

Description

(Model.) l A a sheets-sheet 1.

' 0. SHBRWOOD, Jr.

Fire Escape Ladder.

No. 237,616. Pateted Feb. 8, 188|.v

umldlgllllllmuyy WIK( E, INVENToz/r f7 wkgy, v ATTORNEYS N.PETERs, PHOTO-LITHOGRAFNER. WASHXNGTON. D C.

3 Sheets- Sheet 2.

(Medel.)

` 0. SHERWOOD, J1. Pire Escape Ladder.

Patented Feb. s,

M25-liasses NFETERS, PHOT0LITHOGRAPHER, WASHINGTON. D. C.

(Model.) 3 Sheets-Sheet 3. O.'SHBRWOOD,J1. Pire Escape Ladder; No. 237,616. u 'Patented Feb. 8,1881.

N. PETERS. PNDTO-IJTHOGRAPNER. WASHINGTON, D. C.

, @Nimm STATES ArtNr ricrea.

OBADIAH SHERWOOD, JR., OF EAST FAIRFIELD,VERMONT.

`FIRE-ESCAPE LADDER.

SPECIFICATION forming part of Letters Patent No. 237,616, dated February 8, 1881.

Y Appneanmnled November 27,1880. (Moda.)

To all whom it may concern:

Be it known thatl, OBADIAH SHERwooD,

Jr., of East Fairfield, in the county of Franklin and State of Vermont, have invented certain new and useful Improvements in Exten-y sion Fire-Escape Ladders; and I do herebyde-` clare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art towhich it appertains to make and use the same, refer#v view of the adjustable extension-,prop with its grooved incline.

Similar letters ot' reference indicate corresponding parts in all the gures.

My invention contemplates certain improvements .in portable extension-ladders or tireescapes, having for its object to constructa ladder ot' this class which can .be raised or lowered in a fewmoments and with little la# bor, which shall be strong and safe, and yet comparatively light in weight, and adapted for a short truck, so thatit can readily turn corners and be used in narrow streets, where a long truck could not well be managed.

To this end my invention consists in the detailed construction and combination otl parts of atruck, a turn-table, and extension-ladder composed of three or more sections, an adjustable extension-prop for supporting the lowermost ladder-section when raised in an upright position, a brake device for preventing motion of the truck .when the ladder is in use, a safety-hook attachment to theseveral extensible laddersections,and mechanism for operating the extensible sections and their adjustable. extensionprop, z substantially as hereinafter fully described, and particularly pointed out in the claims.

In the annexed three sheets of drawings, A

is a truck-frame, made as light as is consist- `ent with strength, and supported upon axles and wheels B B. This truck carries a turntable, C, which may be adjusted at right angles to the truck, as shown in dotted lines in Fig.

3 of the drawings, or at any other desired .angle thereto, and is held in any given position upon the truck by a lock-pin, a.

At the rear end of the turn-table C are two vertical uprights, b b, united by a cross-piece, c, which forms aprop or support for the grooved incline D, one side of which has a series ot' notches, d d,for the purpose hereinafter stated, while its outer or upper end is provided with a sheave or pulley, E, over which passes a rope, e, one end of which is attached to and wound by the windlass E', while the other end is secured in the lower end of the sliding extensionprop F, a short distance above a caster or small wheel,vf, which runs in the grooved incline or way D and forms the foot of the prop.

g is a pawl, which engages with the notches d in way D, to prevent the prop from slipping back after it has been hoisted up by the windlass E and rope e to the proper position. This prop or support consists ot two parts-fviz., a

lower beam, F, having the caster or roller j' 4and pawl g, and an upper part or section composed ot' two beams, F', which said upper part slides upon the lower section, and is opera-ted by a rope, h, passing over a pulley in the upper end ofthe lower section, F, one end of the rope being connected to a strap orfeyebolt in the lower end of the upper sliding part, while the other end is attached to a windlass, z', upon the lower end'ot' section F. By turning this windlass and winding up the rope the prop F F may be extended to its full length and prevented from slipping back by a pawl, k, which engages with a ratchet-wheel on the windlas's, as usual. y

To the forward end of the turn-table Gis hinged the lower ladder-section, G, one side of which has a laterallyfprojectin g bracket, Z, through which is inserted a screw, m, the lower end of which bears against the hinge-,block n. By turning this screw the ladder may be adjusted laterally upon its turn-table, so as to stand in a perpendicular position at all times,- when in use, without respect to the inclination IOO to one side orto the other of the truck and turntable, caused by unevenness in the ground.

In the present illustration of my invention I have shown three ladder-sections, G G G2, the two upper ones of which are provided at their lower end with hinged safety hooks or catches I-I, the construction and operation ot' which willreadily be understood byreferenccto the detail view, Fig. 5, of the drawings. Each of these hooks is composed of a shank, 0, the lower end ofwhich is pivoted in the side piece of the ladder, (one on each side,) while its upper end, which is inserted through a staple or keeper,p, to control its play, has a head,q, rounded on its upper side, and forming a projecting hook, r, at one end and a lip, s, at the end opposite. Above each ofthe hooks H is pivoted a stop, t, which may be turned down against lip s, so as to prevent the hook from turning. In vextending the ladder these several stops t are turned up and out of the way, so as to give free play to the hooks, and as the ladder-seetions are slid up one upon another, the rounded head q of each of the hooks, striking the rungs or steps of the section next behind, causes the hook to be tilted back out of the Way, when it will immediately again fall back into position and hook onto the ladder rung'or step just passed. Thus, if the tackle should break or slip while the ladder is being extended, the several sections could not slide back, but would be held in the positions to which they had been raised by their self-operatin g safetyhooks H. When the ladder has been extended to its full length, the hooks may be locked in place, to prevent accidental slipping out, by turning down the stops t.

Hinged to both sides of the lower laddersection, G, is a bracket, I, having hinged braces K, the lower ends ot' which may be stepped into sockets u, provided a little lower down on each side of the ladder. Bracket I has eyes o, through which are inserted the stays or guyropes L L, and to the upper end of the intermediate ladder-section, G', are attached similar guy-ropes, M M, reaching down to the rear end of the turn-table, on opposite sides of which they are made fast.

To the forward end of the turn-table is hinged a short ladder, N, to facilitate lreaching the foot of the main ladder in ascending, or the ground in descending; and this also serves, in connection with the hinged prop O at the rear end of the turn-table, to keep the truck steady on the ground and preventirocking or swaying ot' the turn-table.while-theladder is being operated and ascended.

After the lower or main ladder-section Ghas been raised in position the sliding sections G G2 are extended by ropes P P', operated 4by a windlass, Q, in a manner well understood, as that iscommon to all extension-laddersot` this class; but prior to the hoisting and extendingV ot' the ladder the truck is xed on the ground by a brake device consisting of the shoes R R, of which there is a pair for each of the hind wheels, secured at the lower end of curved arms S S, the upper ends of which are pivoted a short distance above the hind axle on each side. The opposite pairs of curved arms are united by beams or bars T T, one for each side of the axle, so as to move in unison with each other, and upon one of these cross-bars is hinged a curved rod or circle-bar, U, having two offsets, w w', and a stop-pin a0. This curved bar is inserted through a staple or keeper, y, on the opposite cross-bar T, passing under the axle, so that the brake-shoes R t may beloeked upon the wheels at their under side, close to the ground, by slippingthe circle-bar U through staple g/till lthe inner offset or shoulder, w, catches over har T, thus keeping the two bars with their respective brake arms and shoes together. When it is desired to let go77 the -brakes preparatory to lnoving the truck, the

circle-bar is unshipped from har T, with which it'engages, and this bar is pushed up above the second oii'set, w, and held in place by a hook, 2, which is hitched into a staple secured in the axle.

From the foregoing description, taken in vconnection with the drawings, the operation of my improved extension-ladder will readily be understood. To extend the ladder from the `folded position shown in Figs. l and 2 to that represented in the perspective view, Fig. 3,the first step is to loosen the guy-ropes, (the upper ends of which may have hooks, so that they may he quickly fastened to their respectiveladder-sections when required.) Next, the bracket I is raised and its braces K K stepped into their sockets. After this, (all the guy-ropes being east loose,) turn the crank of windlass E', to draw the lower end of the extension-prop up the incline. Next, turn the crank ot' windlass i to extend the prop to its full length, care being taken to see that the pawl is down to hold the prop in position when extended. After this7 turn up the stops or buttons t, that hold the safety-hooks II back and out ot' the way while the ladder is being folded, but allow them to operate as the sections are being extended one upon another. Next, turn the crank of the ladder-windlass Q until the ladder is extended to the proper height.; and, tinally, tighten the guy-ropesand fasten to the turn-table, as described. The guy-ropes may, however, be dispensed with when the ladder leans against and is supported by a wall or building, and are only required when the ladder is to be ascended standing alone and without support to brace its upper end.

A seventy-foot ladder composed of three sections, and constructed according to my description, may be operated and extended to its -full length, ready for use, by one man within the spaceof one and one-half minute, or with two men -this may be done in less than one minute.

In eonstructingvery long ladders, gears may be used to operate the several windlasses and IOO y 23mm cranks, for the purpose of economizing power and facilitating the operation of raisin g and eX- tending the ladder.

Having thus described my invention, I claim and desire to secure by Letters Patent of the United Statesl. The combination of the ladder-truck A B, adjustable turn-table G, having grooved and notched incline D, provided with the pulley E, windlass E', and rope e, hinged extensionprop F F', having rope h and windlass i, and hinged ladder-section G, substantially as set forth.

2. In combination, the ladder-truck A B, turn-table G, hinged ladder-section G, having the hinged bracket I K K and sliding eXtension-sections Gl G2, sai'ety-hooksH, with their stops t, and guy-ropes L LM M, substantially as and for the purpose herein shown and specified.

3. The combination, with the truck-wheels B B, of the brake mechanism or attachment, composed ot' two pairs of hinged arms, S S, having brake blocks or shoes (R R, parallel cross-bars T T, and hinged segmental bar U,`

windlass Q, and adjusting` or balancing screw en', hinged bracket I K K, and guy-ropes or stays L L M M, all constructed and combined substantially in the manner and for the purpose herein shown and set forth.

In testimony that I claim the foregoing as my own I have hereto affixed my signature .in presence of two witnesses.

OBADIAH SHERWOOD, JR. Witnesses: A

FOREST J. SULHAM,

HENRY MITCHELL.

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