US475935A - Extension-ladder - Google Patents

Description

(No Model.) 3 Sheets-Sheet 2.

D. H. CREWS.

EXTENSION LADDER.

No. 475,935. Patented May 31, 1892.

(No Model.) 3 Sheets-Sheet 3. D. H. OREWS. EXTENSION LADDER.

lPatented May 3l, 1892.

1 5 s, E m 2 um e. A H ,m om# m. s. U nll A Ar UNITED STATES ATENT trici-..

DAYTON H. CREVS, OF LADONIA, TEXAS.

EXTENSION-LADDER *SPECIFICATION forming part of Letters Patent No. 475,935, dated May 31, 1892.

Application filed December 29, 1891. Serial No.416,4l3. (No model.)

To all wiz/0771, it may concern;

.Se it known that I, DAYTON Il. CREWS, a citizen of the United States, residing at Ladonia, in the county of Fannin and State of Texas, have invented a new and useful Extension-Ladder, of which the following is a specitication.

rlhis invention relates to ladders, and more especially to that class thereof known as extension-ladders, and the object of the same is to produce certain improvements therein.

To this end the invention consists in the details of construction, substantially as hereinafter more fully described and claimed, and as illustrated on the three sheets of drawings, wherein- Figure l is a perspective view of this ladder in its extended position. F-ig. 2 is a similar view of the ladder with its sections telescoped, and its braces in the act of being folded against the ladder. Fig. 3 is a central longitudinal section showing the catch in position when one section of Lheladder is being raised. Fig. 4 is a similar section showing how the catch supports the section raised. Fig. 5 is an enlarged perspective detail of one of the hooks. Fig. G is a side elevation, on an enlarged scale, of the lower end of one side of the lower ladder-section. Fig. 7 is a crosssection on the line 7 7 of Fig. 6, and Fig. 8 is a vertical section on the line 8 8 thereof. Fig. 9 is a side elevation of the lower end of one of the braces. Fig. 9 is a central vertical longitudinal section thereof. Fig. 9b is a section through the extension device for the brace, taken at right angles to the section of Fig. 9. Fig. 9C is al perspective detailof one of the struts. Fig. lO is a front elevation of the upper end of one ladder-section. Fig. ll is a perspective detail showing one of the'inelined braces out of use. Fig. l2 is a crosssection of two ladder-sections, showing one of the guiding-straps.

Referring to the said drawings, the letter L designates the ladder-sections;.R, the raising-rope; W', the windlass; C, the supportingcatch; P, the friction pulleys or rollers; H, the hooks; B, the braces; E, the extension devices for said braces; S, the struts; I, the inclined braces, and F the extension-feet for the lower ladder-section, these parts being preferably of the following construction:

"same and extended.

The ladder L is made in a number of sections, in the present instance three, designated by the numerals l, 2, and 3, (although there may be more, if desi red,) the second seetion sliding upon the rungs and just inside the side bars of the first, and so on to the top ef the ladder, and they are guided under angular metallic straps 5, as seen in Fig. l2, the straps permitting the side bars of an upper section to slide over the rungs of the section below and preventing the displacement of the sections. The uppermost rung` 3l of each section is preferably of iron, Fig. l0, having a square body and `reduced rounded ends 7, which are secured in the side bars of the ladder and form bearings for friction-rollers or wheels 6, which guide the ladder-section abovein its vertical movements, strap-braces 3l preferably connecting this rung near its ends with the side bars, in order to brace the ladder. At the upper ends 0f the laddersections there are preferably arranged guidewheels 8, which travel against the face of a dead-wall, if the ladder is leaned against t-he -l is a small platform mounted on angular brackets 9, which have hooks 9', adapted to engage two contiguous rungs on any section, so as to hold the platform approximately level, whereby a bucket of water or other article may be supported thereon.

The means for extending this ladder consists of a windlass lV, journaled in bearings at the rear of the lowermost section l, and this windlass comprises a main shaft l0, having crank-handles ll and a ratchet-wheel l2, large gears i3 on this shaft meshing with smaller gears l-i on a second shaft l5 in the bearings 16, above mentioned. Thus when one or both of the cranks ll are turned the shaft l5 is rapidly revolved and this winds the rope R, which is used for raising the several sections of the ladder. The rope itself is in several sections, the lowermost section 2O being connected to the shaft l5 of the windlass, passing thence upwardly over a friction-pulley P, connected to the upper rung 3l of the lower section l and leading thence down to a hook ll, which is connected with one of the lower rungs of the second laddersection 2. The second rope-section 2l is connected in a similar manner to the lower rung IOO of the first ladder-section, passes over another pulley P on the upper rung 3l of the second ladder-section, and is connected by a hook ll to one of the lower rungs of the third laddersection. Thus When the windlass is operated the second ladder-section is raised over the first, and this raises the center of the second rope-section; but as the lower end of this ropesection is secured to a stationary rung it cannot move, and hence the other end rises with twice the speed of the center, which therefore raises the third ladder-section.

Each of the hooks II, just mentioned, is preferably of the construction shown in Fig. 5that is to say, the body 42 of the hook is straight, having its upper end turned over, as at 47, into a large hook and its lower end 45 curved around under the rung 46,10 which it may be bolted, as at 4l. To the extremity of the large hook 47 is pivoted, as at 43, atongue 40, which stands within this hook, and 44 is an eye of any suitable pattern secured to the rope R and ot' proper size to pass over the pivot 43. As the eye rises the tongue moves to the dotted position, and after the eye has passed the tip of the tongue the latter falls back to its full-line position and prevents the displacement of the eye.

In Fig. 4 is shown one of the friction-pnlleys P in section, and Fig. l0 shows it in elevation. The same comprises a strap-hook 30, extending over the rung 3l, to which it may be connected by a bolt 32, and the lower end of this hook is divided, as at 33, its extremity being formed into eyes 34. Through these eyes extends a transverse bolt or pin 35, and on the pin is journaled a grooved sheave or pulley proper 36, as shown.

The catch C, which I preferably use, is best seen in Figs. 3 and 4. This catch comprises a body 50, secured at its lower end to the lower rung 4G of any ladder-section but the lower one, and at its upper end at 5l to the rung next above. A second member is pivoted at 57 to the body, from which it is borne by a spring 54, a chain 52 limiting its rearward movement to just such point that a face 56 at its lower end will come over one of the rungs of the ladder-section next below, as seen in Fig. 4. The upper section being raised this catch slides over the rungs of the lower section, and when the uppersection is brought back a little the lower end 5G of the member 53 rests on one of the rungs, whereby7 the upper ladder-section is supported. Then it .is desired to lower the extension-section, the member 53 of the catch is carried past the rungs of the lower stationary section by an automatically operating pivoted lever 55, which is pivoted at the lower end of a depending hanger 58 and which is arranged so that it will assume normally aposition shown in Fig. 4, with its end 5l) in alignment with the rungs of the lowerstationarysection, whereby when the extension-section is lowered the pivoted lever 55 will be raised and will cngage thc member 53 and will carry the latter inward clear of the rnngs. In raising an extension-section the pivoted lever 55 will swing to a vertical position when it strikes the run gs and will pass the same, and to prevent it entirely rotating by contact with the rungs a stop 59L is provided. Preparatory to lowering an extension-section it is slightly elevated to bring the pivoted lever 55 above the rung on which the member 53 has been supported.

In Fig. 9 is shown to best advantage one of the braces B, which I preferably employ for supporting this ladder when it is to be used at a point where the upper end of the upper section will not rest against a support. Each et' these braces consists of a main or stationary section GO, whose lower end rests on the ground, andan upper or sliding section Gl, adapted to be moved over the lower section bythe extension devices E, this upper section being` pivoted at (52 to the lower laddersection l near its upper end. The lower end of the upper section has a strap G3, which embraces and slides on the body of the lower section, and the upper end of the lower section has a similar strap 64, loosely engaging tbe body of the upper section. It will be seen by Fig. l that each section is in duplicate and the rear ends of the two straps G4 are extended, as at 65, and connected by braces GG with the upper end of the members of the lower section. At the lower end ofthe extension device is a plug G7, let intothe same and havingholes 67through itsbody,and GSis apin moving through a spring G0 in asmall keeper titl and removably engaging one of such holes. By this means the plug can be drawn out the proper extent at the lower end of either member of the lower section to causo the brace to properly rest on inclined or uneven ground, as will be clear. The extension devicesE for this brace are preferably of the following construction: 70 is a shaft journaled in the rear ends (35 of the two straps G4 and having a crank-handle 7l. 72 is a ratchet on this shaft engaged by a pawl 73, and 74 is a rope or chain leading from the shaft 70 over a wheel 75, mounted within the slotted upper end 7G of the lower section 60, led down the groove Gl of the section 6l (l should have said that the adjacent faces of the sections of the brace preferably have tongue and groove) and connected at its other end to the lower end of the upper section. i 77 is a vertical series of holes formed in the upper section 61, and 78 is a stout staple supported by a chain 79 from the section (30 and adapted to be passed astride the upper strap 64 and into a pair of theholes when the two scctionshave been properly adjusted, by which means thebrace .is locked against a possible retrograde movement in case the pawl 73 should slip or the rope or chain 74 should break.

Then the ladder is set up and the braces run out to hold it raised, struts S are used to hold the braces the proper distance from the ladder, and each strut preferably comprises an eyebolt 80, taking through the side bar of IOO the lower ladder-section l, a long rod 8l, linked placement when it does not rest against a wall. Each brace I has a stout pole 84 forits body, with a spike 85 in its lower end, adapted to embed the earth, and a laterally-projecting eye 8G at its upper end. 87 is a bracket secured to the outside of the side bar of the lower ladder-section l, which bracket has an enlargement SS near its lower end and has its two extremities Si) fastened to the said side bar. When not in use each inclined brace is moved so that its eye 8G travels to the upper end of the body S7 of the bracket; but when in use, Fig. ll, the eye is slipped down into the enlargement SS, at which time the body of the brace is longer than the side bar of theladder below said enlargement, and hence the brace must stand oblique. Its spike 85 is embedded in the earth and the ladder is held against all lateral displacement.

In order that the lower section of the ladder may be adj usted to accommodate it toinequalities in the ground, I provide the adjustable feet F. (Best seen in Figs. 6, 7, and S.) Each foot comprises a toothed body 90, with an enlarged lower end 91, the body sliding vertically through eyes 92 in the side bar of the ladder.

93 is acatch slidingr under staples 9-l, laterally of the body 90, and 95 is a spring normally drawing an enlargement 9G of this catch into place in rear of the body, so as to prevent a vertical movement ot' the body by engaging the teeth with a lug 92 in one of the eyes. The lower ends or extremities 97 of the side bars of the ladder are sharpened, as seen in Fig. G, and usually embed the earth for at least a short distance or until the enlarged lower end 91 strikes the earth; but when it is desired to make either side bar longer the catch 93 is moved through the staples 94E until its enlargement 9G disengagcs the teeth of the body. The latter is then set vertically through the eyes 92, as may be necessary, and the catch is returned to itsposition.

`With the above construction of parts the ladder in its extended condition, Fig. l, may be used for any desired purpose, and the braces B and inclined braces I may be omitted entirely if the ladder is to be used against a house or other similar support. The sections of the ladder may be extended by the windlass XV, and the catches C will hold them positively raised, and these catches can be thrown out of operative position by their hooks 55 when it is desired to again lower the ladder. Vhen the braces B are used, they may be extended by their extension devices E, or in lieu of such devices I might have other means for extending them-such, for instance, as shown in my patent, No. 462,240, granted November 3, 1891.

Parts of this device may be used without the whole, and considerable change in and elaboration of details may be made without depart-ing from the spirit of my invention.

What is claimed as new is-- l. A ladder having aligned eyes in its side bars near their lower ends, a foot sliding vertically through said eyes and having an cnlarged lower end, the body of the foot being toothed, and a spring-actuated catch sliding horizontally through staples and having an enlargement normally causing the teeth on said foot to engage with one of the eyes, as and for the purpose set forth.

2. A ladder having on each side bar abracket with an enlargement near its lowerend, in combination with an inclined brace having a. spike in its lower end and a laterally-projecting eye in its upper end loosely engaging said bracket, the brace being longer than the portion of the side bar below said enlargement, as and for the purpose set forth.

3. The combination, with a ladder made in several sections sliding over each other and means for extending and telescopin g said sections, of a brace in two members pivoted to the lower ladder-section near its upper' end, each member comprising two sections sliding` over each other and having straps loosely embracing the other sect-ions, the upper section having a vertical series of holes, means for extending said sections, and a staple adapted to pass over the strap on the lower section and take into two of the holes of said series, as and for the purpose set forth.

Il. The combination, with a ladder made in several sections sliding over each other and means for extending and telescopin g said sections, of friction-wheels journaled on the upper rung of each ladder-section but the uppermost, the side bars of the sections next above moving over said wheels, strap-braces 3l', connecting the rungs supporting the frictionwheels with the side bars of the ladder, and angular metallic straps on the side bars of one section loosely embracing the side bars of the other, substantially as described.

5. The combination, with a ladder, a brace made in two sections, the upper one of which is pivoted to said ladder, and guides causing the sections to slide on each other, of a crankshaft journaled in an extension of the guide on the lower section, a pawl and ratchet on this shaft, a wheel journaled in the slotted upper end of this section, and a rope leading from the shaft over the wheel and connected with the lower end of the upper section, substantially as described.

6. The combination, with a ladder, a brace made in two sections, the upper one of which IOO IIO

is pivoted to said ladder and has a longitudinal series of holes, and a guide on the lower section,through which the upper section slides, of a crank-shaft journaled in an extension of said guide, a wheel journaled in a slot in the upper end of the lower section, a rope leading from the shaft over the Wheel and connected with the lower end of the upper section, and a staple adapted to stand over said guide and removably engage two of the holes in said series, as and for the purpose set forth.

7. In a ladder, the combination, with the ladder proper and means for lengthening` either of its side bars at its lower ends, of a pair of braces pivoted to the upper end of the ladder, a plug seated in the lower end of each brace and having a series of holes through its body, and a spring-actuated pin moving through a keeper on the brace and adapted to engage one of said holes, as and for the purpose set forth.

S. The combination, with a ladder, a brace pivoted to the upper end thereof and made in two members, and a rod connecting said members, of an eyebolt through the side bar of the ladder, a rod linked into the eye at one end and having a hook at its other end adapted to embrace said rod,and a spring-tongue normally closing said hook, as and for the purpose set forth.

9. In an eXtensible ladder, the combination, with a lower section having a pulley secured to its upper rung,awindlass,and a rope leading from the windlass over the pulley to an eye, of a second section sliding on the first and a hook comprising a bent lower end secured to the lower rung of this section, a large hooked body, and a tongue pivoted to the extremity of the body and normally closing it, said eye being of a size to pass over the pivot and tongue, substantially as described.

l0. In an extension-ladder, the combination, with a lower ladder-section and an upper laddersection sliding thereover, of a catch comprising a body secured to two rungs of the upper section, a member pivoted at its upper end to the body and having a curved face at its lower end, a spring bearing the -member to the rear, and a chain limiting its movement so as to bring said face over a rung of the lower section, substantially as described.

1l. In an extension-ladder, the combination, with a lower ladder-section and an upperladder-Section sliding thereover, of a catch comprising a body secured to two rungs of the upf per section, a member pivoted at its upper end to the body and having a curved face at its lower end, a spring bearing the member to the rear, a chain limiting its movement so as to bring said face over a rung of the lower section, and a pivotallymounted lever arranged to be engaged by the ru n gs of the lower section and adapted to engage the pivoted member of the catch, as and for the purpose set forth. p

12. In an extension-ladder, the combination, with a lower section, a metallic rung at the u pper end thereof having reduced ends seated in the side bars,strapbraces connecting said bars with the body of this rung, a pulley carried by the rung, wheels journaled on said reduced ends, and an upper ladder section whose side bars slide over said Wheels, of a windlass on the lower section, a rope leading therefrom overthe lower pulley and connected with a lower rung of the upper section, and guide-wheels journaled in the upper ends of the side hars of the ladder-section, all substantially as and for the purpose set forth.

In testimony that I claim t-he foregoing as my own I have hereto aiixed my signature in the presence of two Witnesses.

DAYTON Il. CREWS.

Witnesses:

M. G. COTTRELL, W. R. CRocKETT.

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