US1806185A - Extension ladder - Google Patents

Description

y 9, 1931. H. E. SKEELS 1,306,135

\ EXTENSION LADDER Filed Aug. 10, 1928 2Sheets-Sheet l INVENTOR All; ATTORNEY May 19, 1931. H. E. SKEELS EXTENSION LADDER Filed Aug. 10

2 Shets-Sheet 2 Patented May 19, 1931 .5,;

UNITED STATES- V PATENT OFFICE 3 11 HENRY E. SKEELS, OF ROCHESTER, NEW YORK, ASSIGN'OR OF ONE-HALFiTO WILLIAM R,

nuenns t nxrnnsronrnnnnn Application as August 0, .1928. Serial No. 298.703;

. The present invention relates to extension ladders and an object thereof is to provide a construction in which any desired number of sections may be added to the lower end of 5 a sliding section to increase the length of the ladder. Another object of theinvention is to provide an improved latch or detent for holding a sliding section in adjusted position. Still another obj ect of the invention is to pro- '10 vide for controlling the latch anda movable section through an endless cable or'flexible connection. A further object of the invention is to provide for removing sections of the ladder by the actionof gravity.

To these and other'ends, the invention consists of certain parts and combinations of parts, all of which will be hereinafter described: the novel features being pointed out in the appended claims.

'7 2o In the drawings:

' in rear elevation;

Fig. 3 is a fragmentary view showing the ladder adjusted to make the step ladder;

Fig. 4 is a fragmentary perspective view of the connection'between the uprights'oftwo sections of the ladder;

Fig. 5 isa fragmentary view in front elevation with parts in section, showing the latch of detent holding the slidable section in elevated position; c

Fig. 6 is asection onthe line 6-6, Fig. 5;

Fig. 7 is a view similar to Fig. 5 of the rear face of the ladder; V

Fig. 8 shows the latch or detent, shifted by the controlling cord to permit the low'ering of the upper v section; and I l 1 Fig.9 is a section on the line 99, Fig; 5.

In the illustrated embodiment/of the invention, a ladder of three' sections is shown. The lower section comprises uprights 1 connected by rungs 2. The second section is sub stantially the same length as the lower section i and embodies uprights 3 connected by rungs 4, the rungs being shorterthan the rungs 2 so that the uprights 3 may slide between the g9 uprights 1 of the lower section; The other extension section embodies uprights 5 connected Icy-rungs 6 the distance betweenthe uprights 5 being the same as between the uprights 3 so that the uprights 5 may be connected to the lower ends of the uprights 3 in line therewith. The height of the uprights 5 is less'than the height of the uprights 1 and 3.

In order to make connection between the uprights 3 and 5, the upper ends of the up-' rights 5 may have socket members 7 secured thereto to receive the lower ends of the uprights 3. These sockets members 7 are in the form of sleeves and are of such length that they extend about the upright 5beyond the first rung 6 of the ladder so as to strengthen the upright adjacent the rung. Their upper ends are slotted at 8 in their opposed faces so that the'lower rung 4, connecting the up rights 3, may be received in'order that the socket member may extend above such rung 4 and strengthen the upright'adjacent thereto.

With the end in view of guiding the extensible sections on the lowermostsection, the latter has guide members 9 projected rearwardly from both uprights thereof, their end portions being turned'inwardly at 10, the ends being curved or beveled at 11 so as to permit a free sliding of the uprights 3 and 5 between the guide'member'and the rear face of the rungs 2 of the lower sections. These guide members 9 are positioned adjacent the upper end of the lower member so that when the two members are resting on the ground on end'in interlocked relation by raising the lowermember upwardly it may be slipped off the sliding section. 1 7

Movement of the slidable sections on the lower section may be effected by an endless flexible connectionlQ in the form of 'a rope which is guided over a pulley 13 on the uppermost rung 2 of the lower sectionand which carries a hook 14 adapted to be engaged either with an eye 15 on the lowest rung of the section comprising the uprights 3 and, the rungs 4 orwith a1} .63? 167 qn the lows Strung of the section comprising the artists a and. the west este t use necting it with one of the arms of the U shaped member. This U shaped member is arranged 1n inverted positlon and is mounted to swing freely about the pintles 18 as an,

axis. Projecting upwardly from the upward portion of the U shaped member are lugs 20 and also two lugs 21. These lugs 20 and 21 act as limiting stops for the swinging movement of thedetaining means 17 by "cooperating with opposite sides of one of the rungs 2 of the lower ladder section. The de tentis adapted to swing so that it may lie in the path of travel of the ladder sections guided on the lower section so as to engage one of the rungs 4 or 6, the lugs 21 cooperating with such rung and holding the detent against swinging while .at the same timesupporting the extension section or sections of the ladder in adjusted position.. The arms of the detent are bevelled or inclined @at 22 'so that, when-theextension sections are elevated through the endlessoperating connection, the rungs 4 or 6 will engage the portions 22 and shift the detent out of the path of the'rung so that it may again fall back into such path by gravity to preventithe descent of the section or sections, provided, of course, the lower ladder section is inclined in the proper direction. If the lower ladder section is inclined in the opposite direction, then the detent will fall by gravity in such direction .and out of the path of the rungs 4 or 6, thereby permitting the descentof the extension sections without' interference by the detent. In some instances, however, it is desirable to extend the ladder whilethe detent normally lies in the path of the rungs 4 or6 and this is accomplished by providing the detent with a guide in the formof a perforated ear 26 through which the flexible endless connection 12 passes. By producing tension on this flexible connection and pulling outwardly with reference to the front of the lower section, it is possibleto swing this detent outwardly or forwardly away. from the path of the rungs 4 and 6 while the descent of the latter is controlled by the cable. I

WVith the end in view of making a step ladder out of the extension ladder, the slid ing section embodying the uprights3 and the rungs 4 is fitted beneath the upper pair of guide brackets 10 to rest upon the upper rung 2, as shown in Fig. 3, of thelower section and abut the guide brackets 9. Two supports 27 are provided which are 'removably and adjustably secured to the inner faces of the upper'ends of the..uprights 3, of the first v upper section and extend over the uppermost rung 4, their outer ends having lateral projections, in this instance in the form of roof hooks to engage under the rung 2.

Assuming thatlit is desired to attach the first upper section to' the lower section, the upper section is raised on end and tilted forwardly simultaneously with the lower section and-then the lower section is raised upwardly to permit the guides to be slipped over the upper section, the forward tilting throwing the latch forwardly so that the lower section may slide freely onto the upper section. The

hook14 is now attached to the eye on the lower rung of the first upper section andthe upper sectionis pulled upwardly-onthe lower section, the rungs of the upper section sliding past the latch by cooperating with the beveled portions 22. .Should it be desired I to lower the upper section, tension is placed on the operating-cord or cable, pulling the latch forwardly out of the path of the rungs of the upper section and permitting the upper section todescend. To detach the upper section, the two sections are tilted forwardly so that the latch swingsout of the path of the rungs of the upper section after which the lower moving the lower section upwardly. Assuming that it is desired to add a third section to the ladder while said ladder is standing, the first upper section is raised upwardly on the lower section until its lower end is above the upper end of the upper section tobe added, the latter being shorter than the lower section and also shorter than the first upper section. The sleeves 7 are now fitted onto the, lower ends of the uprights 3 and are-held in this position while the cable is detached from the lower rung 4 and attached tothe lower rung-.-6.'= By pulling on the cable, the two sliding upper sections are now elevated. Still other sliding sections like-that comprisingthe uprights 5 and the rungs'6 may be added to the lower ends of theuprights-5 so that a desired length of-the ladder'may be obtained. Assuming that it is desired to disconnect the sliding section'comprising the uprights 5 and the rungs 6 from the sliding sections comprising theuprights 3 and the rungs 4, the sliding sections'are lowered until the uprights 5 rest on the ground after which the hook 14 is connected to the lowermost upright rung-4 so that the controlling cable does notlconnect with the extension sections formed by the uprights .5 and the rungs 6. A slight pull upwardly will disconnect the slidingsection comprising the uprights 5 andthe rung 6 from the slidingsec 'tion comprising the uprights 3 and rungs 4. lnlother words, the lower sliding section will drop by gravity off the ends of the upper sliding section. The endless-cable being the convat";

section may be liftedofi the upper section'by 3F trolling connection cannot become accidentally disconnected from the ladder. 7

It will thus be seen that the ladder permits an extension to be added thereto at the lower end of the lowermost sliding section. The sockets at the upper end of the extensions not only tend to strengthen the uprights adjacent the upper rung of the extension but also tend to strengthen the uprights of the extension which is fitted in said socket members. The latch is of novel construction and has two stops which limit the swinging of the latch in two directions for cooperating with that rung above the pivot of the latch. The latch is beveled so that the rungs of the sliding sections shift the latch out of their paths as the sliding sections are elevated.

What I claim as my invention and desire to secure by Letters Patent is:

An extension ladder comprising a lower section, a sliding section guided on the lower section and a latch pivotally mounted on the lower section and extending upwardly from its pivotal axis, said latch carrying means cooperating with the rung to limit the swinging movement of the latch in two directions, and a controlling cable for efiecting the raising and lowering of the sliding section, slidably connected with the latch to move and hold the latter-out of latching position.

HENRY E. SKEELS.

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