US3768123A

US3768123A - Safety device for an extension ladder and method of mounting

Info

Publication number: US3768123A
Application number: US00285334A
Authority: US
Inventors: F Forte
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-08-31
Filing date: 1972-08-31
Publication date: 1973-10-30
Anticipated expiration: 1990-10-30

Abstract

A safety device for an extension ladder has a lock member with three legs and two loop members connecting said legs, to one of which legs an elongate, resilient hook member is attached. The lock member is mounted on ladder rungs by placing one loop member directly below one ladder rung and rotating the lock member until it is above said rung, while the other loop member is now directly below a rung of another ladder, and raising said hook member to the next rung above either, and hooking it over the latter rung.

Description

United States Patent 1191 l orte l- 30, 1973 [54] SAFETY DEVICE FOR AN EXTENSION 473,852 4/1892 McQuillan 182/209 X LADDER AND METHOD OF MOUNTING 1,375,224 4/1921 MacLewee.... 24/73 CS UX 2,742,679 4/1956 Young 24/73 CS X [76] Inventor: Frank N. Forte, 65 Dale Street,

Boston, Mass. FOREIGN PATENTS R APPLICATIONS 69,873 4/1952 Netherlands 182/209 [22] 1972 815,531 10 1951 Germany 248/361 A [21] Appl. No.: 285,334 25,298 11/1919 Denmark 24/73 HH 52- U.S. c1. 24/73 cs, 182/209 f sgg' g'g gsz [51] Int. Cl A441) 21/00, E066 7/06 v [58] Field of Search 182/207, 209,- 230; 24/73 cs, 73 111-1, 73 R, 81 R, 73 cc, 81 cc, 1 ABSTRACT 73 73 73 73 84 84 A safety device for an extension ladder has a lock 81 81 C1 31 81 T member with three legs and two loop members connecting said legs, to one of which legs an elongate, re- 1 References Cited silient hook member is attached. The lock member is UNITED STATES PATENTS mounted on ladder rungs by placing one loop member 371,453 1887 'l-lawkes 182/209 direct-[Y f" ladder and mulling lock 496,696 5/1893 N h 24/84 UX member unt1l 1t above sald rung, wh11e the other 630,734 8/1899 Ooth0ut.. 24/81 AF UX loop member is now directly below a rung of another 2,841,349 7/1958 Charles '24/73 R X ladder, and raising said hook member to the next rung 3,672,004 /1 Smithm 24/73 HH above either, and hooking it over the latter rung. 3,494,658 2/1970 Maes 248/361 A I 124,940 3/1872 Edmunds 182/209 x 3 Claims, 5 Dr wing Figures 444,632 1/1891 Goosmann 182/209 X 9 g v 0 &

I SAFETY DEVICE FOR AN EXTENSION LADDER AND METHOD OF MOUNTING The principal object of my invention is to lock the two ladder sections of an extension ladder against movement, so that if pawls are used, and they are not in their proper place, or if a rung should loosen or break, neither ladder section can slip or otherwise move away from the other.

Another ojbect is to provide a safety device that is simple and inexpensive to manufacture, and with a lock member that can be readily formed as an integral unit.

A further object is to provide a simple method of mounting my device on two rungs of two ladder sections by rotating a lock member 180 so to bring a first loop member over a rung of one ladder section, and a second loop member under an adjacent rung of another ladder section, and then raising a fastener member with a hook to a higher rund and hooking it on the latter, thus loking the ladder sections against movement.

The foregoing and other objects which will appear as the nature of the invention is better understood, may be accomplished by a construction, combination and arrangement of parts, and a method of mounting, such as is disclosed by the drawing and specification. The nature of the invention is such as to render it susceptible to various changes and modifications, and therefore, I am not to be limited to the construction disclosed by the drawing, nor to the particular parts described in the specificatiom'but am entitled to all such changes therefrom as fall within the scope of my claims.

In the drawing:

FIG. 1 is a perspective view of an extension ladder with my safety device mounted thereon.

FIG. 2 is an enlarged, fragmentary, sectional view, taken on the line 22 of FIG. 1, showing my safety device ready to be moved to position of use on the ladder sections.

FIG. 3 is a sectional view similar to FIG. 2; but shwoing the lock member rotated to an intermediate position on the extension ladder.

FIG. 4 is a viewsimilar to FIG. 2; but showing the lock member in its final mounted position with a hook member extending ter efrom to a rung on the ground of stationary ladder section.

FIG. 5 is an elevational view of my safety device.

As illustrated, my safety device has a lock member that is S-shaped, usually madeof metal. It has an outer leg 12, terminating in a short, inwardly extending, an gular, clinger portion 14. A first loop member 16 extends from said leg 12 to an intermediate leg 18 which extends to another loop member 20. A second outer leg 22 extends from the latter, approximately parallel with said

legs

12 and 18, thus terminating said lock member.

A fastener member 26 has an open ring portion 28 at one end that extends into a'hole 30.at an end extremity portion of said second outer leg 22. A coil spring 32 continues from said ring portion 28, terminating in another ring portion 34 at an opposite end of said spring 32. A hook member 36 has a bent end 38 that receives said other ring portion 34, and from it a handle 40 extends that continues to a hook 42.

My device is used with a well-known extension ladder 46 having a ground or stationary ladder section 48 having the usual rungs 50, and an inner or adjustable ladder section 52 having the usual rungs 54. The side frame extremities of said adjustable section 52 are laterally and slidably within the side extremities of said ground section.

In position of use with my device a said ground section rung which I identify as 50a, is slightly higher on the extension ladder 46 than the nearest rung which I identify as 54a on the adjustable section 52, hence there is a space between a said rung 50a and said rung 54a nearest to it.

In applying my lock member 10 to said ladder rungs 50a and 54a, in my first method step the open mouth of said loop member 16 is placed directly under and adjacent said rung 50a as shown in said FIG. 2, with the other loop member 20 extending laterally away from said

rungs

54a and 50a. Then said lock member 10 is rotated clockwise to move said loop members to final position in wich said loop member 16 is ab and resting on said rung 50a, and the mouth of said loop member 20 is directly under said rung 54a. Then said fastener member 26'is raised upwardly and its hook 42 is placed on a rung 50b directly'above said rung 50a, thus locking said

ladder sections

48 and 52 in place.

What I claim is:

1. A safety device in combination with an extension ladder, the latter having two ladder sections each having rungs, said device having a lock member having a first outer leg, an intermediate leg and another outer leg, said legs extending approximately parallel and laterally opposite each other, a first loop member extending between said intermediate leg and said second outer leg, and a fastener member attached to an end portion of one of said outer legs having a coil spring and a hook extending therefrom, said first loop member'resting on a first-mentioned rung of one said section, said second loop member being directly under a second-mentioned rung of another said section, said fastening member extending from said second outer leg to a rung of one of said ladder sections above said first and second mentioned rungs, and said hook being attached to the latter said rung. 2. A safety device-in combination with an extension ladder, as of claim.1, one of said ladder sections being a ground section 'andthe other of said ladder sections being an adjustable section, the side extremities of which adjustable section are laterally within the side extremities of said ground section, said ground section having said first-mentioned rung, said adjustable section having said second-mentioned rung, said hook being attached to said first-mentioned rung of said ground section.

3. A method of applying a safety device to an extension ladder having a ground section and an adjustable section, each said section having rungs spaced apart, a rung of one'said section being adjacent and slightly higher than the nearest rung of the other said section whereby there is a space between said adjacent rungs when the ladder is in position of use, said safety device having a lock member having a first loop member and a second loop member laterally thereof, said loop members being open in opposite directions, placing said first loop member adjacent and under a first said rung of one said section, with said second loop member positioned outside of said ladder, then rotating said lock member clockwise until said first loop member is above a said first rung and said second loop member is directly below and adjacent a rung of said other section, said device having a fastener member attached to said lock member and having a spring and a hook at the end of said spring, and raising said fastener member to a position above the first-mentioned two rungs and fastening said hook on a higher rung of a said section that is above the said latter two rungs.

* a it

Claims

1. A safety device in combination with an extension ladder, the latter having two ladder sections each having rungs, said device having a lock member having a first outer leg, an intermediate leg and another outer leg, said legs extending approximately parallel and laterally opposite each other, a first loop member extending between said intermediate leg and said second outer leg, and a fastener member attached to an end portion of one of said outer legs having a coil spring and a hook extending therefrom, said first loop member resting on a first-mentioned rung of one said section, said second loop member being directly under a second-mentioned rung of another said section, said fastening member extending from said second outer leg to a rung of one of said ladder sections above said first and second mentioned rungs, and said hook being attached to the latter said rung.

2. A safety device in combination with an extension ladder, as of claim 1, one of said ladder sections being a ground section and the other of said ladder sections being an adjustable section, the side extremities of which adjustable section are laterally within the side extremities of said ground section, said ground section having said first-mentioned rung, said adjustable section having said second-mentioned rung, said hook being attached to said first-mentioned rung of said ground section.

3. A method of applying a safety device to an extension ladder having a ground section and an adjustable section, each said section having rungs spaced apart, a rung of one said section being adjacent and slightly higher than the nearest rung of the other said section whereby there is a space between said adjacent rungs when the ladder is in position of use, said safety device having a lock member having a first loop member and a second loop member laterally thereof, said loop members being open in opposite directions, placing said first loop member adjacent and under a first said rung of one said section, with said second loop member positioned outside of said ladder, then rotating said lock member clockwise until said firSt loop member is above a said first rung and said second loop member is directly below and adjacent a rung of said other section, said device having a fastener member attached to said lock member and having a spring and a hook at the end of said spring, and raising said fastener member to a position above the first-mentioned two rungs and fastening said hook on a higher rung of a said section that is above the said latter two rungs.