US3402788A

US3402788A - Extension ladders

Info

Publication number: US3402788A
Application number: US641176A
Authority: US
Inventors: Redman James Charles
Original assignee: Werner Co
Current assignee: Werner Co; RD Werner Co Inc
Priority date: 1967-05-25
Filing date: 1967-05-25
Publication date: 1968-09-24
Anticipated expiration: 1985-09-24
Also published as: DE1679130A1; ES342888A1

Description

P 1963 J. c. REDMAN 3,402,788

EXTBNS ION LADDERS Filed May 25, 1967 2 Sheets-Sheet 2 INVENTOR. James C o man H. is

A TTORNE Y United States Patent 3,402,788 EXTENSION LADDERS James Charles Redman, Hadley, Pa., assignor to R. D. Werner Co., Inc., Greenville, Pa., a corporation of Pennsylvania Filed May 25, 1967, Ser. No. 641,176 7 Claims. (Cl. 182207) ABSTRACT OF THE DISCLOSURE There is disclosed herein, in conjunction with an extension ladder having a base section and a longitudinally slidable fly section, a pair of spaced pulleys mounted on the outside of one side rail of the base section, a rope engaging said pulleys, a connector adjustably connecting the ends of the rope for taking up slack in the rope, and a bracket carried by the fly section adapted to detachably receive the connector for hoisting and lowering the fly section.

This invention relates to extension ladders and relates more particularly to cable means for hoisting and lowering the fly section of an extension ladder with respect to the base section thereof.

An import-ant object of the invention is to provide cable means for the purpose set forth which is carried entirely by the base section and can be quickly and easily attached to or detached from the fly section of an extension ladder.

Another object of this invention is to provide cable means as set forth above which is completely clear of the ladder rungs in use thereof whereby the entire width of said rungs is clear of the hoisting means.

Still another object of the invention is to provide cable means having the above features and characteristics wherein means is provided for taking up stretch in the hoisting rope and for quickly and easily removing the hoisting rope from the ladder if desired.

Yet another object of the invention is to provide a connector carried by the cable means and a bracket carried by the fly section so constructed that said connector and bracket cannot become accidentally disengaged in normal use thereof, said connector and bracket being easily disengaged upon simple manipulation thereof.

A further object of the invention is to provide an improved hoisting means for an extension ladder which is simple in construction, composed of but few parts, readily assembled and highly efficient in use. v

Other objects of the invention and a number of the advantages thereof will become more readily apparent from the following description of the invention and the accompanying drawings, in which drawings:

FIGURE 1 is a side plan view of an assembled extension ladder comprising base and fly sections and having the cable means of this invention attached thereto;

FIGURE 2 is a front elevation of the base section only as seen from the line 22 of FIGURE 1, a portion of one side rail being broken away;

FIGURE 3 is an enlarged view of a connector and bracket of FIGURE 1 as viewed from the line 33 of FIGURE 2;

FIGURE 4 is a vertical section taken along the line 44 of FIGURE 3;

FIGURE 5 is a horizontal section taken along the line 55 of FIGURE 3;

FIGURE 6 is a perspective view of the bracket which is adapted to be carried by the fly section;

FIGURE 7 is a perspective view of the connector, which is adapted to be carried by the cable means; and

FIGURES 8 and 9 are diagrammatic views showing the manner in which the connector is manipulated with 3,402,788 Patented Sept. 24, 1968 respect to the bracket for quickly attaching the fly section to the cable means.

Referring now to the drawings in all of which like parts are designated by like reference numerals, an extension ladder is generally indicated at 10 which comprises a fly section 20 and a base section 40. The ladder as herein illustrated is preferably of the front loader type disclosed in copending application of James C. Redman, assigned to the assignee of the present application, Ser. No. 504,601, filed Oct. 24, 1965. The ladder may be made of any suitable material such as wood, fiber glass, or metal, and the sections may be slidably attached to each other in any preferred manner to prevent forward and rearward separation thereof. As illustrated in the present application, the extension ladder 10 has extruded aluminum side rails and tubular rungs.

Referring now particularly to FIGURES 1 and 2, the fly section 20 comprises U-shaped side rails 21 which are disposed parallel with each other and are connected by a plurality of evenly spaced tubular rungs 22. Similarly, the base section 40 comprises U-shaped side rails 41 spaced apart the same distance as the side rails 21 and connected by vertically spaced, tubular rungs 42. Said base section may be provided with pivoted shoes 41a attached to the lower ends of the side rails 41 to assist in stabilizing the ladder and providing means for gripping its supporting surface.

As shown in FIGURE 5, each side rail 21 of the fly section 20 has a central web 23 the lateral edges of which are provided with integral, right angularly disposed flanges 24 having slightly inturned lips 25. Similarly, each side rail 41 of the base section 40 has a flat, central web 43, right angularly turned flanges 44, and inturned lips 45. As herein illustrated, all of the side rail flanges project laterally outwardly of the ladder with one of the flanges 24 of the fly section slidably overlying one of the flanges 44 of the base section.

Means for slidably connecting the base and fly sections to each other are provided in the form of identical guide brackets 11 and 11 mounted adjacent to the upper end of the base section 40 and the lower end of the fly section 20, respectively. Each guide bracket 11 or 11' has a flat base portion 12 secured to a

web

43 or 23 by any suitable means such as rivets 13. The base portions 12 are disposed within the channels of the side rails between the flanges thereof, each said base portion having an integral, laterally outwardly stepped, C-shaped portion 14 which is adapted to slidably engage adjacent flanges 44 and 24, and the associated

lips

45 and 25 thereof, whereby the fly section 20 is slidably retained with respect to the base section 40 at both the lower end of said fly section and the upper end of said base section. It will be readily understood that the guide brackets 11 and 11' are provided on both side rails of both said sections.

The cable means for hoisting and lowering the fly section 20 with respect to the base section 40 is disposed within the channel provided by one of the side rails 41 of said base section. Since the channels face laterally outwardly with respect to the ladder, this places the hoisting or cable means completely away from the rungs of the ladder thereby leaving said rungs clear and unobstructed during use. A pair of pulleys 50 and 50' are secured to the web of the left-hand side rail 41, as seen in FIGURE 2, generally adjacent to the upper and lower ends respectively of said side rail. Said pulleys are identical in form each comprising a simple pulley bracket 51 secured in any suitable manner to the rail web 43, such as by means of a rivet 52. Each bracket 51 carries a pulley wheel 5'3 which is disposed in a plane parallel with the adjacent web 43 and mounted upon an axis disposed at right angles to said web.

A hoisting cable in the form of a rope 54 is threaded through and around the pulleys 53 and has its ends connected to a connector 60. The connector 60 is preferably formed from flat, substantially heavy sheet metal and is provided adjacent to one edge thereof, with three preferably

circular openings

61, 62, 63. The opening 61 is disposed uppermost with respect to the connector 60 and receives a downwardly directed portion 54a of the rope 54 which is disposed adjacent to the fly section 40. The end of the rope is threaded through the opening 61 and then secured to itself by having an elongated, C-shaped clamping member 64- of malleable metal crimped tightly thereover. The opposite end portion 54b of the rope 54 which projects upwardly from the lower pulley 50' adjacent to the fly section is threaded first through the opening 63 disposed adjacent to the bottom of the connector 60 and then through the opening 62 disposed midway between the openings 61 and 63. This upwardly projecting end portion 54b is thus adjustably gripped by the connector 60 and held by the friction of the rope against said connector and at the peripheries of the

openings

62 and 63. It will be readily understood that any slack which may develop in the rope 54 due to stretching can be very simply taken up by pulling said rope further through the opening 63 and then pushing any slack at this point as far as possible through the opening 62. It will also be readily seen that by removing the rope end portion 541) from the

openings

62 and 63, the entire rope plus the connector 60 can be quickly and easily removed from the base section 40.

The connector 60 projects forwardly from the base section 46 whereby a forwardly and downwardly tapered portion 65 thereof extends beyond the adjacent flange 24 and 25 of the associated fly section rail 21. The forwardly tapered portion 65 is provided with a vertically elongated, preferably rectangular slot 66 by means of which it is adapted to engage a bracket carried by the fly section 20.

As best shown in FIGURES 5 and 6, the bracket 30 comprises a substantially flat base portion 31 by means of which it is mounted flatwise against the web 23 of the left-hand side rail 21. Said base portion has a circular, outwardly convex portion 32 which is centrally apertured at 33 to allow its riveting to the web 23 by means of a rivet 34. The base portion 31 extends generally toward the base section 40 and is provided with a right angularly outwardly turned arm 35 having a rib 35a which projects beneath the adjacent lip 25 of the side rail 21. The arm 35 extends laterally outwardly beyond the adjacent flange 24 where it is again bent at right angles to provide a backwardly turned flange 36. Said flange 36 is, in turn, provided with an inturned flange portion 37 which is directed toward the base portion 31 and which terminates in a lip 38 turned at right angles in the direction of the base section 40 and disposed parallel with both the base portion 31 and the backwardly turned flange 36 of the bracket 30. As shown in FIGURE 5, the space defined between the outturned arm 35 and the inturned flange portion 37 and between the backwardly turned flange 36 and the lip 38 is adapted to loosely receive that part of the tapered portion 65 of the connector 60 which is disposed in front of the rectangular slot 66 or forwardly in the direction of the fly section 2% In use the connector plate 60, while carried by the rope 54 disposed around the pulley 53. is adapted to be connected to the bracket 30 in the manner illustrated in FIGURE 5.

FIGURES 8 and 9 show in a diagrammatic fashion the manner in which the connector 69 is attached to or removed from the bracket 36. Referring especially to FIG- URE 8, the bracket is first turned to a plane which is generally parallel with the out-turned arm 35 with the slot 66 disposed just beyond the inturned flange portion 37. Said slot 66 is of such size that the connector 64 can be moved to the left in the direction indicated by the arrow in FIGURE 8 and will pass over and clear said inturned flange portion 37 including the lip 38. The connector 60 is then moved over against the out-turned arm 35 and pulled against the backwardly turned flange 36 whereby clockwise rotation thereof as illustrated in FIGURE 9 will rotate the forwardly directed edge a of the tapered portion 65 inwardly behind the lip 38. The slot 66 is so positioned relative to the forward edge 65a that said forward edge just clears the lip 38 when the parts are positioned as shown in FIGURE 9 but is too large to move past said lip 38 when the connector 60 is in the position shown in FIGURE 5. Normally, the tautness of the rope 54 will maintain the connector 60 in the general position shown in FIGURE 5 whereby it cannot become disengaged from the bracket 30 in normal use. Disengagement of the connector from said bracket is effected by stretching or springing the rope outwardly (or downwardly as shown in FIGURE 9), reversing the pivoting motion whereby the edge 65a again clears the lip 38, and reversing the motion illustrated in FIGURE 8.

From the foregoing, it will be readily seen that the present invention provides a cable hoisting means which is disposed completely on the outside of the ladder thereby leaving the rungs free of obstruction. The inven tion further provides a connector means which can be quickly and easily engaged or disengaged with respect to the fly section, .is effectively retained in its connected position in normal use without essentially interfering with its feature of being quickly and easily detachable, has means for readily taking up .any slack or stretch which may develop in the rope, and connects the rope in such manner that it can be entirely removed from the base section if desired.

It will be understood that the term rope or rope means is meant to include any suitable flexible element; such as, a rope, cable, belt, cord, or the like and may be made of any suitable material usable in the manner described; such as, hemp, cotton, plastic, metal, etc.

Many changes in the details of the invention as herein described and illustrated may be made without, however, departing from the spirit thereof or the scope of the appended claims.

What is claimed is:

1. An extension ladder comprising a base section and an overlying fly section; each said section having side rails connected by transverse rungs; means connecting said sections for longitudinal sliding movement of said fly section with respect to said base section; a pair of spaced pulley means carried by one side rail of said base section; rope means carried by said pulley means; a connector; one end portion of said rope means being connected to said connector and the other end portion of said rope means being adjustably attached to said connector for taking up slack in said rope means with respect to said pulley means; a bracket carried by the one side rail of said fly section which is disposed adjacent to said one side rail of said base section; said connector having means detaehably engaging said bracket for hoisting and lowering said fiy section.

2. An extension ladder as set forth in claim 1: said pulley means carried on the outer side of said one side rail of said base section opposite said rungs; said bracket having .an arm portion turned outwardly with respect to said one side rail of said fly section; said connector having means defining an opening therein adapted to be projected over and engage said arm portion.

3. An extension ladder as set forth in claim 2: said connector being asubstantially flat member having means defining a pair of spaced-apart, vertically aligned apertures therein, said other end portion of said rope means being threaded first through one of said spaced-apart apertures and then through the other of said spaced-apart apertures.

4. An extension ladder as set forth in claim 3: said connector having means defining a third aperture disposed vertically above and in line with said pair of apertures, said one end portion of said rope being threaded through said third aperture and secured to itself above said third aperture.

5. An extension ladder as set forth in claim 4: said connector having a portion projecting laterally of said apertures and overlapping a portion of the adjacent side rail of said fly section; said opening being disposed in said projecting portion of said connector.

6. An extension ladder as set forth in claim 5: said arm portion of said bracket projecting outwardly in a plane substantially parallel with the plane of said fly section; the outer end of said arm having a backwardly turned flange directed toward the front of said fly section; an inturned flange portion carried at the end of said backwardly turned flange, said inturned flange portion being directed toward the adjacent side rail of said fly section and disposed parallel with said arm; a lip disposed at the edge of said flange portion and directed toward said arm, said lip being parallel with said backwardly turned flange; said opening being of such size as to allow said flange, flange portion, and lip to pass therethrough when said connector is disposed in a plane substantially parallel with said arm; said lip being spaced from said arm sufliciently to allow the edge of said laterally projecting portion of said connector to clear said lip upon turning said connector back toward the base section to a position parallel with the adjacent side rails of said ladder.

7. In an extension ladder comprising a base section and an overlying fly section, each section having substantially parallel side rails connected by transverse rungs, and means connecting said sections for longitudinal sliding movement of said fly section with respect to said base section; a pair of spaced pulleys carried on the outer side of one side rail of said base section; a rope disposed around said pulleys; a connector member connecting the ends of said rope; .a bracket carried by the one side rail of said fly section which is disposed adjacent to said one side rail of said base section; said bracket comprising an arm directed outwardly with respect to said one side rail of said fly section a backwardly turned flange, an inturned flange portion, and an angled lip disposed at the edge of said flange portion, each recited part being disposed substantially at right angles to the prior recited part and turned in the same direction whereby said arm and said flange portions are parallel and spaced from each other and said backwardly turned flange and said lip are parallel and spaced from each other; said connector member being generally flat and having an opening therethrough disposed adjacent to an edge thereof; said opening being of such size as to allow said backwardly turned flange, flange portion, and lip to pass therethrough when said connector is disposed in a plane substantially parallel with said arm; said lip being spaced from said arm sufliciently to allow said edge to clear said lip upon turning said connector away from said flange portion whereby to dispose said arm through said opening and to dispose said edge between said lip and said backwardly turned flange.

References Cited UNITED STATES PATENTS 75,052 3/ 1868 Pine l82-209 375,250 12/1887 Bailey 182-208 3,337,001 8/ 1967 Huska et al. 182-207 3,347,340 10/ 1967 Huska et al. 182207 REINALDO P. MACHADO, Primary Examiner.