US3365023A - Ladder extension and mounting means therefor - Google Patents

Description

Jan. 23, 1968 T. R. NAGLE 3,365,023

LADDER EXTENSION AND MOUNTING MEANS THEREFOR Filed July 6, 1966 2 Sheets-Sheet 1 T. R. NAGLE 3,365,023

LADDER EXTENSION AND MOUNTING MEANS THEREFOR Jan. 23, 1968 2 Sheets-Sheet 2 Filed July 6, 1966 INVENTOR.

United States Patent Ofiice 3,355,,fi23 Patented Jan. 23, 153%8 3,365,023 LADDER EXTENSION AND MOUNTING MEANS THEREFOR Thomas R. Nagle, 642 Minor St., Emmaus, Pa. 18049 Filed July 6, 1966, Ser. No. 563,155 8 Claims. (Cl. 182-211) ABSTRACT OF THE DISCLOSURE A ladder extension and associated mounting brackets including rigid brackets fixed to one ladder guide rail and hinged brackets fixed to the other ladder guide rail. By opening the hinged brackets, removal of an extension is easily accomplished. To each extension section guide rail is mounted a slidable sleeve to which is attached a pivotally connected locking hook for cooperation with a chosen ladder rung. In addition, a chosen locked rung is latched into a notch contained within the sleeve wall for added stability and protection.

The instant invention is generally concerned with ladders, and more specifically relates to an auxiliary extension section particularly adapted for selective use in conjunction with conventional extension ladders.

It is a primary object of the instant invention to provide a ladder extension or extension section which is capable of being releasably mounted upon the lower section of an extension ladder in a manner whereby a sliding movement therebetweeu can be effected in the manner of a conventional extension ladder with the extension being selectively fixed relative to the lower section in any of a plurality of adjusted positions so as to in effect extend the working height of the ladder.

In conjunction with the above object, it is a significant object of the instant invention to provide an extension which, in light of its readily mountable and demountable nature, avoids the necessity of maintaining different length extension ladders in that a single extension ladder, for example a 32 foot ladder, can be, through the extension of the instant invention, quickly, easily, and temporarily converted into, as an example, a 40 foot ladder. By the same token, the 40 foot ladder defined with the addition of the extension of the instant invention is of a type which can be easily erected and handled by a single person, as compared to the conventional two-section 40 foot extension ladder.

Other objects of the instant invention involve the utilization of a ladder extension in defining three-section ladders which possess a greater structural stability than the conventional equal length extension ladders and the provision of a ladder extension which is of greater Width than the lower ladder section to which it is attached so as to define a wider support base for the ladder.

Basically, the extension of the instant invention is to involve a ladder section incorporating side rails and transversely extending ladder rungs, rail mounted brackets which are adapted to slidingly engage the lower section of a conventional extension ladder, and a pair of section locking hooks releasably mounted upon the lower extension ladder section and cooperatively engaging the rungs of the extension.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of the ladder extension of the instant invention mounted in operative position;

FIGURE 2 is a perspective view of the upper end portion of the extension illustrating the mounting brackets thereon;

FIGURE 3 is an enlarged cross-sectional view taken substantially on a plane passing along line 33 in FIG- URE 1;

FIGURE 4 is a perspective view of one of the mounting brackets;

FIGURE 5 is a perspective view of a cooperating mounting bracket;

FIGURE 6 is an enlarged cross-sectional view taken substantially on a plane passing along line 66 in FIG- URE 1;

FIGURE 7 is a perspective view of the releasably mountable section lock;

FIGURE 8 is a top plan view of the extension with the movable mounting bracket illustrated in a released position;

FIGURE 9 is a cross-sectional view taken substantially on the plane passing along line 9-9 in FIGURE 6;

FIGURE 10 is an elevational view of one of the section locks with a portion broken away for purposes of illustration;

FIGURE 11 is a partial cross-sectional view similar to FIGURE 3 illustrating a modified form of releasable mounting bracket; and

FIGURE 12 is a perspective view of the bracket of FIGURE 11.

Referring now more specifically to the drawings, reference numeral 20 is used to generally designate the ladder extension comprising the instant invention. This extension 20, as will be appreciated from FIGURE 1, is particularly intended for use with a conventional two-section extension ladder 22 through a releasable engagement with the lower section 24 thereof.

The extension 20, including elongated side rails 26 and cross rungs 28, is to be of a width greater than the Width of the lower extension ladder section 24 which is to be received between the rails 26 for sliding adjustment and a selective extension and retraction of the extension 20 relative to the section 22.

The mounting of the extension 26 on the lower ladder section 24 is effected through the use of cooperating brackets 30 and 32, two such sets of cooperating brackets being affixed to the extension 20 toward the upper end thereof in spaced relation to each other as illustrated in FIGURES 1 and 2. The bracket 39 of each set of brackets constitutes a fixed bracket and is defined by a rigid strap stepped so as to define a pair of seats for both one of the extension rails 26 and the corresponding rail 34 of the section 24 to which'the extension 20 is engaged. The seat which receives the rail 34 includes a first elongated leg 35 overlying the outer side face 38 of the rail 34 and being fixedly attached, as by a screw or bolt 40, thereto. The second leg 42 of the seat overlies the front face 44 of the rail 34 and projects inwardly thereof beyond the inner side face 46 of the rail 34. The seat which receives the extension rail 26 continues integrally from the inner end of the leg 42 and projects forwardly so as to define a leg 48 seated against the outer side faces 54 of the rail 26 with the leg 48 in turn terminating in an integral laterally directed leg 52 which overlies the front edge or face 54 of the rail 26.

The cooperating bracket 32, also formed of an elongated n'gid flat plate, differs from the bracket 34 in that a leaf hinge 56 is secured thereto. This hinge 56 includes a first leaf 58 permanently afiixed to the rail engaging leg 36, and a second leaf 6% which overlies the rear face or edge 62 of the corresponding rail 26 and is permanently aifixed thereto whereby an outward swinging of the bracket 32 relative to the corresponding rail 26 can be effected. The significant dilference between the bracket leg 36f and the bracket leg 36 is that. the leg 36 includes an enlarged aperture 64 therethrough for the releasable reception of a locking bolt 66 which also .extends through a suitable transverse aperture in the side rail 26, the side leg 36 being releasably and rigidly locked to the corresponding outer side face of the rail 26 through means of a butterfly nut 68 or the like threaded on the outer end of the bolt 66. The remaining legs of the bracket 32 are formed and utilized in the same manner as the legs of the bracket 30 so as to define seats for the rails 26 and 34.

By pivotally mounting the two mounting brackets 32 so as to enable an outward swinging of these brackets as suggested in FIGURE 8, provision is made for the mounting of the extension 24 in a simple manner which requires only a positioning of the extension 20 behind the lower section 24 and a slight lateral movement of the extension 20 so as to engage the rail 34 of the section 24 within the fixed brackets 3t and a swinging of the movable brackets 32 over the second section rail 34 and the locking of the brackets 32 through the bolt means associated therewith. There is no necessity for longitudinally sliding the extension 20 and section 24 into engagement with each other such as is required between the two sections of a conventional extension ladder. Further, by being able to laterally engage the extension 20 with the section 24 at any desired location, it will be appreciated that the extension 20 can be mounted even when the extension ladder 22 is extendedand positioned in an erected position.

Attention is now momentarily directed to FIGURES ll and 12 wherein a modified form of the bracket 32 is illustrated, this bracket being generally referred to by reference numeral 32. The bracket 32' differs from the bracket 32 in that, rather than the hinge 56, an integrally formed inwardly directed rigid flange or leg 70 is provided, this leg overlying the rear face or edge 72 of the adjacent extension rail 26 so as to in effect snugly conline the side rail 26 between the legs 70 and 42. As in the case of the bracket 32, a mounting bolt 66 and clamping nut 68 are also provided so as to lock the bracket 32 in position. It will of course be appreciated that when mounting the extension 20 utilizing the bracket 32, the bracket 32', also provided in pairs, is completely removed from the rail 26 until the ladder section 24 is positioned.

The instant invention also contemplates that the extension 20 be longitudinally adjustable relative to the ladder section 24, the cooperating brackets 30 and 32 enabling this longitudinal sliding movement while at the same time effectively preventing a lateral disengagement of the extension 20 and ladder section 24. In order to lock the section 24 and extension 26 in a longitudinally adjusted position, a pair of removable lock units 74 are provided, these units 74 bein temporarily mountable upon the lower end of the lower outer section 24 for selective locking engagement with an aligned rung 28 of the extension 20. Two such locking units 74 are to be provided with each of the units 74 including a U-shaped mounting base 76 and a spring-biased locking hook and guide device 78. The mounting base 76 includes laterally spaced fiat parallel walls 8% and 82 which receive the corresponding rail 34 of the section 24 therebetween, the base 76 also including a fiat bight portion84 interconnecting the side walls 89 and 32 and engageable against the forward edge or face 54 of the rail 26. The bracket wall 82 which is to overlie the inner side face of the corresponding rail 26 includes a downwardly and inwardly directed rung-receiving notch 88 therein in conjunction with a retaining latch 99 pivoted to one side of the notch 88 for swinging move-.

ment across the open end thereof so as to retain one of the rungs 92, preferably the lowermost rung, thereby effectively locking the unit 74 to the ladder section 24. It will be noted that the latch 93 includes an inwardly directed recess 94 therein which seats against the received rung 92 and cooperates with the arcuate inner end of the notch 88 so as to define an annular seat for the rung 92. In addition, the latch is provided, on a lower end thereof, with a locking lug 96 which is received within a keeper notch 93 in the side wall 82 immediately below the notch 88 so as to prevent an accidental release .of the latch 90 and necessitate an actual slight outward flexing of the latch 90 so as to disengage the lug 96 from the keeper notch 98. A suitable handle or gripping means 100 may be provided on the latch so as to facilitate the manipulation thereof. I

With a pair of the locking units 74 mounted in position on the lower end of the ladder section 24, the extension 29 can be locked in any desired vertically adjusted position through the pair of locking elements 78 which are afilxed to the outer faces of each of the outer sidewalls 80 for positioning between the outer side face 50 of the corresponding rail 26 and the inner side face 46 of the corresponding rail 34, the element receiving space therebetween being defined by the inward extension of the bracket leg 42 of each of the brackets. The element or unit 78 is generally conventional in construction and includes an elongated hook member 102 having a cannning head 104 thereon and a pivotally mounted guiding device or latch 106 mounted below the receiving end of the hook recess 108 for a selective closing thereof when longitudinally collapsing the sections. The lower end of the hook member 102 is pivoted to the side wall 80 within a housing sleeve 110 which also internally mounts a biasing spring 112 for constantly and resiliently biasing the hook portion 102 toward the underlying ladder section, in this instance the extension 20, for engagement with the rungs thereof in the manner of a conventional extension ladder positioning hook. Upon the engagement of the two laterally orientated hook members 162 with a rung of the subjacent extension 20, it will be appreciated that the extension 20 will be fixedly locked relative to the lower ladder section 24 inasmuch as the base 76 of each unit 74 is itself fixedly locked to the lower section 24.

From the foregoing, it will be appreciated that a highly unique structure has been devised for increasing the effective length of ladders, and in more particular, extension ladders. This device is in the nature of a ladder extension section which incorporates mounting brackets for locking the extension to a ladder section in a manner which enables a relative longitudinal sliding movement therebetween, much in the manner of the two sections of an extension ladder. In addition, the attachment of the instant invention includes a pair of locking units which are releasably mounted upon the section which is to receive the extension, with these locking units being selectively activated so as to fix the longitudinal position of the section relative to the extension. In this manner, the efiective length of an extension ladder can be increased simply and in a matter of minutes, thus in effect reducing to a minimum the number of extension ladders which might be necessary to reach different heights on any par ticular job.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. Means for extending the effective length of a ladder comprising. an extension slidably mountable upon a section of the ladder, said extension including a pair of laterally spaced elongated side rails, transversely extending rungs engaged between the inner sides of said rails, first.

bracket means rigidlyfixed to a first one of said rails and pro ecting laterally forward therefrom for engagement with a superimposed ladder section, second bracket means, and means for releasably fixing said second bracket means to the second of said rails in a position so as to project laterally forward therefrom for engagement with the superimposed ladder section, and locking means releasably mountable on the superimposed ladder section and selectively engageable with selected rungs of said extension for preventing relative movement therebetween, said first bracket means comprising at least one rigid strap, said strap being angularly formed so as to define a first leg fixed across the outer side of the first rail, a second leg integral with the forward end of said first leg and extending perpendicularly therefrom inwardly across the forward face of said first rail and beyond the inner side thereof, and a forwardly projecting rail seat integral with the inner end of said second leg, said second bracket means comprising a plurality of rigid straps, each strap being angularly formed so as to define a first leg positionable against the outer side of the second rail, a second leg integral with the forward end of said first leg and extending perpendicular therefrom inwardly across the forward face of said second rail and beyond the inner side thereof, and a forwardly projecting rail seat integral with the inner end of said second bracket second leg, means releasably fixing said second bracket means comprising an elongated clamping bolt projectable through said second rail and the first leg of the second bracket means, and a locking nut operatively associated with said bolt, an integral flange on the rearward end of said second bracket first leg, said flange projecting perpendicularly inward behind the rear face of said second rail, hinge means engaged between the rearward end of the second bracket first leg and the rear portion of said second rail, said hinge means pivotally fixing said second bracket strap to said second rail for movement toward and away from said second rail.

2. A demonntable ladder section lock unit comprising a base and a lock element, said base including a pair of laterally spaced parallel side walls, a transversely extending end wall extending between and interconnecting a pair of corresponding edges of said side walls so as to define a rail receiving pocket, said lock element being movably mounted on the outer face of a first one of said side walls, the second of said side walls having a rung receiving notch defined therein through the unconnected edge thereof, said notch downwardly inclined having a first closed end oriented below a second open end, and a rung retaining latch movably fixed to the second side wall and selectively projectable across the open end of the notch for the locking of a ladder rung therein.

3. The construction of claim 1 wherein said locking means includes a demountable ladder section lock unit comprising a base and a lock element, said base including a pair of laterally spaced parallel side walls, a transversely extending end wall extending between and interconnecting a pair of corresponding edges or" said side wall so as to define a rail receiving pocket, said lock element being movably mounted on the outer face of a first one of said side walls, a second of said side Walls having a lung receiving notch defined therein through the unconnected edge thereof, said notch downwardly inclined having a first closed end oriented below a second open end.

4. The construction of claim 3 including a rung retaining latch movably fixed to the second side wall and selectively projectable across the open end of said notch for the locking of a ladder rung therein, said latch provided with a locking lug on the lower end thereof and wherein said lug is received within a keeper notch adjoining said receiving notch.

5. The construction of claim 2 wherein said latch is provide-d with a locking lug on the lower end thereof and wherein said lug is received within a keeper notch adjoining said receiving notch.

6. Means for extending the effective length of a ladder comprising an extension slidably mountable upon a section of the ladder, said extension including a pair of laterally spaced elongated side rails, transversely extending rungs engaged between the inner sides of said rails, first bracket means rigidly fixed to a first one of said rails and projecting laterally forward therefrom for engagement with a superimposed ladder section, second bracket means, and means for releasably fixing said second bracket means to the second of said rails in a position so as to project laterally forward therefrom for engagement with the superimposed ladder section, and locking means releasably mountable on the superimposed ladder section being selectively engageable with a selected rung of said extension for preventing relative movement therebetween, said second bracket means comprising a plurality of rigid straps, each being angularly formed so as to define a first leg positionable against the outer side or" the second rail, a second leg integral with the forward end of said first leg and extending perpendicularly therefrom, inwardly across the forward face of said second rail and beyond the inner side thereof, a forwardly projecting rail seat integral with the inner end of said second bracket second leg, means releasably fixing said second bracket means comprising an elongated clamping bolt projectable through said second rail and the first leg of the second bracket means, a locking nut operatively associated with said bolt, and hinge means engaged between the rearward end of the second bracket first leg and the rear portion of said second rail, said hinge means pivotally fixing said second bracket strap to said second rail for movement toward and away from said second rail.

7. The construction of claim 6 wherein said locking means includes a demountable ladder section lock unit comprising a base and lock element, said base including a pair of laterally spaced parallel side walls, a transversely extending end wall extending between and interconnecting the pair of corresponding edges of said side walls so as to define a rail receiving pocket, said lock element being movably mounted on the outer face of a first one of said side walls, the second of said side walls having a rung receiving notch defined therein through the unconnected edge thereof, said notch downwardly inclined having a first closed end oriented below a second open end.

8. The construction of claim 7 further including a rung retaining latch movably fixed to the second side wall and selectively projectable across the open end of said notch for the locking of a ladder rung therein, said latch provided with a locking lug on the lower end thereof and wherein said lug is received within a keeper notch joining said receiving notch.

References Cited UNITED STATES PATENTS 733,269 7/1903 Pope 182210 1,045,165 11/1912 Moulton 182-211 1,461,952 7/1923 Walchi 182-209 1,746,643 2/ 1930 Foss 182-209 2,564,411 8/1951 Shinneman 248211 2,670,119 2/1954 Spluvak 182207 FOREIGN PATENTS 69,873 4/ 1952 Netherlands.

1,157,910 1/1958 France.

RElNALDO P. MACHADO, Primary Examiner.

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