US1457100A - Extension ladder - Google Patents

Description

May 29, 1923.

R. S. BOLGER EXTENSION LADDER Filed Sent. 26. 1921 A WORN-E75 Patented -May 29, 1923.

ROBERT s. BOLGER, OF rNEW YORK, 1v. Y., As sIGivoa To Malawian-n :MoTon] COMPANY, on NEW YORK, N, Y.,

.-A oonr onnrrron or nntnwnnn' Y ExrEn'sIoN LnDDE t 1 Application filed se ms as, 1921; Seria1 No.i503,'3 56. i

To all whom it concem:

Be it known that I, RoB RTs. Bdrm,

a citizen of the United States, residing in theborough of Manhattan, of, thecit of New York, in the Stateof New York, ave invented certain new and useful Improvements in Extension Ladders, of which the following is a specification, referencebeing had to the accompanying drawmg, form ng apart hereof. 1

Extension ladders as 'i now generally .con-' structed comprise a bed'ladder, a fiy ladder movable thereon and af ladder lock which holds the fly ladder in adjusted position on the bed ladder at any elevation. :This look, no matter what'its form, occupies certain space on thefly ladder which would ordinarily be devoted'to a round." The omission of this round'at thispoint has proven very inconvenient and, indeed, dangerous, since it requires an abrupt change without wa'rn- "i a 7 a r V lllustrated herein to lnsur'e an un'derstandlng to the rounds of the fly ladder which are offset several inches, or vice versa, requires care and thought unless the change comes at a natural and expected time. Where the round is provided, as in accordance with the present invention, adjacent to the end of thefly ladder and in proper spaced relationship'to the next round, and "in spite of the ladder lock, an additional factor of safety and convenience is. introduced which is of substantial importance in this art.

In the preferred embodiment of the invention advantage is taken of the fact that ladder locks are now usually housed; this housing is formed with a hub in which may be supported a suitable round of usual construction. These locks, being placed opposite on another, will thus afford a convenient and secure support for such an additional round.

The invention will be described in greater detail hereinafter in connection with one illustrative embodiment thereof, although it will be understood as the description proceeds antageous resultsimay'be employedwitlrout departingffrom 5 the spiritof'the invention. 1 In the drawing- Figure- Iis' a view in'p'ers-pective of an ex tension "ladder of conventional construction showing the"v relation of the bed ladder, fly ladder and ladder" lock with theadditiona l round supported bythe casing thereof.

igure' 2 is a fragmentary view in trans 'ver'se' section through';' the bed ladder-and broken away "in the interfl 0f the object of the present invention, appears in Figure 1. The bed ladder a with its 1 spaced rounds at has arranged forsliding movement thereon afly ladder I) having spaced rounds I), the raising and'lowering of the fiyladder being accomplished by'any suitable mechanism, indicated conventionally as a rope '0 secured at oneend tothe fly ladder and passing over a block csecured to the bed laddenf The invention is not concerned with the form of the ladder lock employed for maintaining the fly'ladder in any desired relationship to the bed ladder, but

in the preferred embodiment advantage has been taken of the fact that it is now the best practise toemploy only enclosed ladder locks. Of course, heretofore, the very use of ladder locks has precluded the provision of a round on the fly ladder at the points where the ladder locks are mounted, since it has notbeen apparent as to how a round might be mounted in the space allotted to such ladder locks. It is the principal object of the present invention to meet this deficiency by providing at its properplace in spaced relation to the next round, a round on the fly ladder in proximity to the ladder lock and that,too, without sacrificing any of the advantages or purposes. In the drawing a suitable type of lock is illustrated, the parts thereof including a hook d, springe, and release latch f, alldisposed in proper relation within the lockhousing g secured to,

* UNITED the fly ladder b by means of bolts 9, all in a manner with which the present invention is not concerned. One such housing 9 with its locking mechanism is disposed at each side of the fly ladder Z), usually adjacent to the lower end thereof and usually spaced at about the distance of a round from the next round 011 the fly ladder. \Vith the space thus occupied by the ladder lock, he climber in going up or down the extension ladder has found it necessary ,to change his feet from the rounds a" to the rou-nds b, or vicearersa, practically without indication, and since these rounds lie in planes which are several inches apartthis change has been found to be both inconvenient and dangerous. To meet this deficiency the present invention provides an, additional round B which is on thesame level as one of the upper rounds a of the bed ladder and is in properspaced relation to the next round 6 of the fly ladder Z) and, generally speaking, in the space where the ladder lock is found. The round B is illustrated as a hollow steel tube supported in split pinch hubs integral with the housing g of the ladder lock. To hold this round B against displacement a bolt h .is passed through the split hub g and engaged by a retaining nut It. Further, this bolt Z;- may rest within a tangential groove 13 foigmed in the periphery of the round B. The mounting at either end of the round may be the .same with respect .to each housing g. From a manufacturing and mechanical standpoint there are many advantages in forming the supporting hub g for the round B integral with the housing 9', but it is obvious that the in'vention'iis not to be limited in this one respect since supporting devices for the round independent of the housing might be employed.

In use, it will 'be evident that the climber When reaching the expected place for the round- .13 will regulatehis progress accordingly and transfer his teet at the proper time from the rounds a, of the bed ladder to the round B ,'or vice atersa; the fly ladder being complete in vso far .as concerns itstier of rounds. v i

hat Iclaini is: y

In an extension ladder, a bed ladder, a fly ladder, the lowermost round of which is provided with a tangential groove at one end, ladder locks carried'atthelosver end of the fly ladder, said locks serving to support the lowermost round of the fly ladder on a level with oneof the upper rounds ,of the bed lad der, oneofi said locks being provided with a split hub and a nut and .bolt for tightening up said hub, the bolt being adapte'd to en age in said tangential groove.

This specificat'on signed this 23rd day of September, A, D. 51,9721.

, ROBERT 'S. 'BOLG-ER.

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