US3331468A

US3331468A - Extension ladders

Info

Publication number: US3331468A
Application number: US504600A
Authority: US
Inventors: James C Redman
Original assignee: Werner Co
Current assignee: Werner Co; RD Werner Co Inc
Priority date: 1965-10-24
Filing date: 1965-10-24
Publication date: 1967-07-18
Anticipated expiration: 1984-07-18

Description

July 1'8, i967 J. c. REDMAN 3,333,458

EXTENS I ON LADDERS Filed Oct. 24, 1965 INVENTOR. James C flea man BYy United States Patent 3,331,468 EXTENSION LADDERS James C. Redman, Hadley, Pa., assignor to R. D. Werner Co., Inc., Greenville, Pa., a corporation of Pennsylvania Filed Oct. 24, 1965, Ser. No. 504,600 6 Claims. (Cl. 182-209) This invention relates to extension ladders and relates more particularly to cable means for use in hoisting the fly section of an extension ladder beyond the base section thereof.

An object of the present invention is to provide cable means of the above type which can be quickly and easily attached to or detached from the fly section to permit separation of the fly and base sections.

Another object of the invention is to provide cable means of the above related type which, when not in use, is carried entirely by the base section and is available for use whenever the need for hoisting a fly section thereon arises.

Still another object of the invention is to provide improved attachment means for an endless hoisting cable of the type referred to.

Yet another object is to provide cable means having the above characteristics wherein the ends of the hoisting cable, carried by the base section are secured to simple clamp means, which clamp means enable the cable to be secured to a rung of the fly member of the extension ladder when said ladder section is stacked on the base section, as in front loading.

A further object is to provide hoisting cable attachment means for fixing the cable in a position substantially beneath the fly section to eliminate any ropes dangling over the ladder as the ladder is ascended.

A still further object of this invention is to permit the placement of the cable in a desired fixed position inside or between the ladder sections.

A further object of the invention is to provide an improved hoisting cable means of the type referred to which is economical in construction and highly eflicient in use.

These and other objects of this invention will become more readily apparent from a purview of the invention as set forth in the appended description and disclosed in the drawings, in which said drawings:

FIG. 1 is a front elevation of an extension ladder comprising base and fly sections having the cable means of this invention attached thereto;

FIG. 2 is a vertical section taken along the line 2-2 of FIG. 1;

FIG. 3 is a vertical section taken along the line 33 of FIG. 1;

FIG. 4 is a vertical section taken along the line 44 of FIG. 1;

FIG. 5 is a perspective view of the attaching clamp in its engaged position;

FIG. 6 is a perspective view similar to FIG. 5 showing the clamp in the disengaged position;

FIG. 7 is a horizontal section taken along the line 77 of FIG. 1; and

FIG. Sis a horizontal section taken along the line 8-8 of FIG. 1.

Referring now to the drawings, in all of which like parts are designated by like reference characters, an extension ladder is generally indicated at 10 which comprises a base section 20 and fly section 40. The base section 20 comprises generally parallel, laterally spaced side 'rails 21 joined together by transverse, uniformly vertically spaced rungs 22. The fly section 40 similarly comprises generally parallel, laterally spaced side rails 41 joined together by transverse, uniformly vertically spaced rungs 42. It will be noted that the side rails 41 of the fly section 40 are more closely laterally spaced than the side rails 21 of the base section 20 and that said side rails 41 are disposed laterally inwardly of the side rail-s 21 against the rungs 22 of said base section (FIGS. 2 and 3). This causes the fly section 40 to be slidably disposed partially between the side rails 21 of the base section 20, said side rails 21 preventing lateral or sidewise displacement of said fly section. It will be understood that the above described arrangement for guiding the fly section is given by way of example only and is not essential to the present invention.

The base and

fly sections

20 and 40, respectively, may be made of any suitable material, such as wood or metal, and may be slidably attached to prevent forward and rearward separation in any suitable manner. As herein illustrated by way of example, the extension ladder 10 is made of a lightweight metal such as aluminum. The side rail-s 21 of the base section 20, as detailed in FIGS. 7 and 8, arec hannel-shaped having substantially flat webs 23 and substantially right angularly inwardly directed flanges 24 whereby the channels of said side rails 21 open toward each other. The free edges of said flanges 24 are, in turn, provided with inturned lips 25 directed inwardly of the associated side rail channel. The side rail-s 41 of the fly section 40 are also channel shaped comprising substantially flat webs 43 and substantially right angularly outwardly directed flanges 44 whereby the channels of said side rails 41 open away from each other. The free edges of said flanges 44 carry inturned lips 45 directed inwardly of their associated side rail channels.

One example of the attaching the

side rails

21 and 41 to each other is illustrated in the sectional views of FIGS. 7 and 8. Adjacent to its upper end, each side rail 21 of the base section 20 carries a guide bracket 26 comprises a flat mounting portion 27 and a right angularly projected hook portion 28. Each said mounting portion 27 is secured in the top of a channel of aside rail 21, and each hook portion 28 projects inwardly to engage a lip 45 of an adjacent side rail 41 of the fly section 40. The lower end portion of each said side rail 41 of the fly section 40 is similarly provided with a guide bracket 46 comprising a flat mounting portion 47 and a right angularly projecting hook portion 48. Each mounting portion 47 is secured in the bottom of a channel of a side rail 41, and each book portion 43 projects outwardly to engage lip 25 of an adjacent side rail 21 of the base section 20. The mounting

portions

27 and 47 are secured to the

webs

23 and 43 in any suitable manner, such as by rivets 29 and 49, respectively. Thus, the top of the base section 20 slidably engages the fly section 40, and the bottom of said fly section slidably engages said base section.

The surface of each web 43 of the side rails 41 adjacent to the rungs 42 is, in the form of the extension ladders illustrated herein, provided with a conventional catch member 51 which is pivoted to said web by suitable means, such as brackets 52 carried by said web. The catch members 51 are adapted to simultaneously engage one rung of each ladder section, in a well-known manner, to maintain the fly section 40 in any selected vertically adjusted position.

In addition to the above features, the base section 20 and the fly section 40 are shown as provided with

upper end caps

30 and 50 carried by the upper ends of the

side rails

21 and 41, respectively. The said

end caps

30 and 50 are oppositely laterally offset to allow free sliding movement between the ladder sections and may be made of a suitable plastic to prevent scratching of the surface against which the ladder is leaned in use. The base section 20 is preferably provided with ladder shoes 31 which are pivoted on transverse pins 32 carried by the lower end portions of the side rails 21.

3 Movement of the fly section on the base section is effected by an endless flexible connection generally indicated at 60 in FIG. 1 comprising an endless rope or cable 61 connected preferably between the uppermost rung of the base section 20 indicated at 22a, and the lowermost rung of said base section, indicated at 22b. The rope ends are secured by a sinuous clamp 70, which is disposed in front of the rungs 22, and the rope passes upwardly therefrom over a pulley 62 carried by the uppermost rung 22a of the base section. From the pulley 62, the rope 61 passes downwardly behind the rungs 22, under the lowermost rung 22b of the base section and upwardly in front of said rungs 22 and beneath the rungs 42 of the fly sections back to the clamp 70.

The clamp 70, as is Well shown in FIGS. 5 and 6, comprises a centrally disposed relatively thick body portion 71 carrying a pair of inturned C-shaped arms 72 on one side of said body portion and a hook 73 on the opposite side thereof. As herein illustrated, the clamp 70 is preferably made of extruded aluminum, and the arms 72 each engage an opposite end portion of the rope 61 by having said arms crimped tightly around said rope ends. The hook 73 is curved and has an opening 74 between its distal end and the body portion 71 of suflicient dimension to readily receive a portion of the rope 61, as hereinafter later described.

The endless rope or cable 61 as illustrated is provided with suflicient slack whereby a portion thereof can be grasped and brought forwardly under a rung, 42 of the fly section 40, after the fly section is stacked on a base section carrying the cable as above described, and the portion grasped is then drawn upwardly and back of the rung 42 disposed through the opening 74 in the hook 73 of the clamp 70 disposed forwardly of the rung 22. As

well shown in FIG. 3, this forms a loop 61a around one rung 42 of the fly section 40 whereby said fly section is secured to the cable means of the base section and may be hoisted or lowered by manipulating the said endless rope 61. When the ladder sections'20 and 40 are assembled as illustrated, the

rungs

22 and 42 thereof are spaced apart in a forward and rearward direction sufficiently to provide adequate clearance for the rope 61 to pass freely between said ladder sections.

If the ladder sections are to be separated or disassembled, the loop 61a is removed from the hook 73 of the clamp 70 and the same drop downwardly and away from the rung 42 which had previously been engaged thereby. Because the entire cable means is carried by the base section 20 when not in use as an extension ladder, the fly section 40 can be easily removed after removal of the clamp.

FIG. 1 illustrates the cable means 60 as being attached to the second lowermost rung 42 of the fly section 40, but said cable means may be attached to any of said rungs.

From the foregoing, it will be readily seen that the present invention provides means for quickly and easily connecting a fly section to a hoisting rope or cable which is carried solely by the base section and which said rope or cable can be just as quickly and easily disconnected from said fly section.

It will be understood that many changes in the details of this invention as herein described and illustrated may be made without, however, departing from the spirit thereof or the scope of the appended claims.

What I claim is:

1. In an extension ladder having a base section and a longitudinally slidable fly section, and endless cable means carried by said base section between spaced rungs of said base section, a portion of said cable means overlying certain of the rungs of said base section and a portion of said cable means underlying said rungs, fastener means carried by said endless cable means at one point thereof for detachably connecting said cable means to itself at another point thereof, there being suflicient slack in said cable means whereby a portion of said base rung overlying cable portion located above a rung of the fiy section and located adjacent to said fastener means can be looped under and over said rung of the fly section and said fastener means attached at said other point, and said cable means being slidable relative to the spaced rungs whereby the fly section can be hoisted or lowered by the cable means carried by the base section.

2. In an extension ladder as set forth in claim 1, said endless cable means comprising a rope poined at its ends by said fastening means, said fastening means comprising clamping means securely engaging the ends of said rope, said clamping means having a hook, there being suflicient slack in said cable means whereby said hook can be passed under and upwardly around a rung of the fly section and hooked over a portion of the slack in the said cable means to engage the fly section.

3. In an extension ladder as set forth in claim 2, said cable means being carried between rungs disposed adjacent to the top and bottom of the base section with said rope passing upwardly in front of said rungs, downwardly behind said rungs, and upwardly again to said clamping means.

4. In an extension ladder as set forth in claim 2; said clamping means having a pair of arm portions each of which is clamped tightly around an end of said rope.

5. In an extension ladder as set forth in claim 2; said clamping means being made of extruded metal and having a pair of arm portions each of which is crirnped tightly around an end portion of said rope.

6. In an extension ladder as set forth in claim 2, said cable means being carried between the uppermost and lowermost rungs of the base section, said clamping means joining said rope in front of the rungs of the base section with said rope passing upwardly in front of said rungs to a pulley carried by the uppermost rung, downwardly behind the other said rungs, and upwardly again to said clamping means, said clamping means being made of. extruded metal and having a pair of arms portions each of which is crimped tightly around an end portion of said rope.

References Cited UNITED STATES PATENTS 46,648 3/1865 Eaton 182-209 153,716 8/1874 Lovell 182210 623,476 4/1899 Jones 182212 REINALDO P. MACHADO, Primary Examiner,

Claims

1. IN AN EXTENSION LADDER HAVING A BASE SECTION AND A LONGITUDINALLY SLIDABLE FLY SECTION, AND ENDLESS CABLE MEANS CARRIED BY SAID BASE SECTION BETWEEN SPACED RUNGS OF SAID BASE SECTION, A PORTION OF SAID CABLE MEANS OVERLYING CERTAIN OF THE RUNGS OF SAID BASE SECTION AND A PORTION OF SAID CABLE MEANS UNDERLYING SAID RUNGS, FASTENER MEANS CARRIED BY SAID ENDLESS CABLE MEANS AT ONE POINT THEREOF FOR DETACHABLY CONNECTING SAID CABLE MEANS TO ITSELF AT ANOTHER POINT THEREOF, THERE BEING SUFFICIENT SLACK IN SAID CABLE MEANS WHEREBY A PORTION OF SAID BASE RUNG OVERLYING CABLE PORTION LOCATED ABOVE A RUNG OF THE FIY SECTION AND LOCATED ADJACENT TO SAID FASTENER MEANS CAN BE LOOPED UNDER AND OVER SAID RUNG OF THE FLY SECTION AND SAID FASTENER MEANS ATTACHED AT SAID OTHER POINT, AND SAID CABLE MEANS BEING SLIDABLE RELATIVE TO THE SPACED RUNGS WHEREBY THE FLY SECTION CAN BE HOISTED OR LOWERED BY THE CABLE MEANS CARRIED BY THE BASE SECTION.