US2837260A

US2837260A - Safety device for ladders

Info

Publication number: US2837260A
Application number: US490168A
Authority: US
Inventors: Kinnett Lucian
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-02-24
Filing date: 1955-02-24
Publication date: 1958-06-03
Anticipated expiration: 1975-06-03

Description

June 3, 1958 Filed Feb. 24. 1955 ELIE-3 1.. KINNETT SAFETY DEVICE FOR LADDERS 2 Sheets-Shea:- 1

I ILE=E INVENTOR.

51w m 0155M Km;

4 TTOPNEVJ June 3, 1958 L. KINNETT SAFETY DEVICE FOR LADDERS Filed Feb. 24. 1955 2 Sheets-Shee 2 INVENTOR. ZUC/AN K/NNETT 5M/ TH, 015m M070 United States Patent 2,837,260 SAFETY DEVICE FOR LADDERS Lucian Kinnett, Lincoln Park, Mich. Application February 24, 1955, Serial No. 490,168 4 Claims. (Cl. 228 67) This invention relates to safety devices for ladders.

Such devices are intended primarily to prevent persons from falling from elevated positions on ladders. It is desirable however that such devices not interfere with the free use of the person's hands and body, as for example in using his tools, welding equipment and other apparatus. The safety devices should also be comfortable to the person. One cause of discomfort which it is desirable to eliminate arises because ladders are conventionally constructed with round ladder rungs. round ladder rungs are hard on peoples feet and after a person has been standing on them for extended periods of time the rungs become quite uncomfortable.

- Essentially the problem is one of providing a relatively low cost but comfortable safety device which will prevent the ladder user from falling from the ladder but which will at the same time allow him complete movement of his arms and body. There have been employed as safety devices various types of harnesses or belts but these mechanisms generally do not allow the user free arm and body movements. Also these mechanisms become rather uncomfortable after extended periods of use, and they make no provision for relieving foot discomfort caused by a person standing on the conventional round ladder rungs. Small protected scaffolds have been employed but these mechanisms are generally so constructed as to prevent safe, easy movement of the user up and down the ladder. Their relatively high cost and difficulty of installation also make them objectionable for most uses.

The present invention provides a relatively low cost but comfortable safety device which not only protects a person from falling from a ladder but which at the same time allows him complete 'movement of his arms and body. The safety device is easily positioned on the ladder and adjusted to different longitudinal positions thereon with a minimum of manual efiort. Preferably the safety device is made adjustable in lateral directions whereby to adaptit for installation on varying width ladders.

One object of the invention is to provide asafety device for a ladder which will not only protect a person from falling from the ladder but which will also allow him complete movement of his arms and body.v

These ice 2 Figure 1 is a partial side elevation of a ladder on which is positioned one embodiment of the invention, Figure 2 is a view taken in the direction of arrow B in Figure 1,

Figure 3 is a view taken in the direction of arrow A in Figure 1,

Figure 4 is a view taken on line 44 in Figure 5,

Figure 5 is a view taken on line 5-5 in Figure 4, and

Figure 6 is a view taken on line 6-6 in Figure 4.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also. it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring now to the drawings the illustrated construction will be seen to comprise a ladder 1 on which is positioned the safety device generally designated by reference numeral 2. The ladder may be an extension type ladder comprised of a plurality of adjustable sections or it may be a single section ladder.

Safety device 2 comprises a pair of C-shaped guide members 3 and 4 mounted for adjusting movements up and down on the side rails 5 and 6 of ladder 1. Members 3 and 4 have projecting therefrom a pair of pins 7 and 8 which serve as pivot means for two dog elements 9 and 10. Elements 9 and 10 have anchored thereto at' 11 a cord 12 which runs over the dog element, through a hole 13 therein and down to a connection 14 with a pull cord 15. A lug 16 extends from each of members 3 and 4 into registry with dog elements 9 and 10, whereby when lugs 9 and 10 are in their Figure 4 positionsthey are wedged between lugs 16 and one of the ladder rungs 21 so as to retain guide members 3 and 4 in elevated positions on the ladder.

' vertical positions out of registry with the ladder rungs.

Another object is to provide a safety device which will eliminate the discomfort caused by a person standingfor extended periods of time on the conventional round lad-v der rungs.

Another object is to provide a safety device which can be adjusted for use with varying size ladders. 3

Another object is to provide a safety device which can be easily and quickly adjusted from one position on a ladder to another position thereon.

Another object is to provide a safety device which will allow easy and safe movements of persons up and down whereby to permit lowering movement of guide members 3 and 4 on the ladder side rails. In order to insure that elements 9 and 10 automatically drop into their vertical positions said elements may be weighted at their lower ends or spring means may be provided to urge said elements to their vertical positions. v

A Guide members 3 and 4 are each provided with a pair of ears 22 which, through the media of screws 23 and nuts 24, serve to pivotally mount

arm members

25 and 26 of a generally U-shaped railing 27. The free ends of

arms

25 and 26 are turned inwardly at 39 and 40 to reinforce a backrest plate 52 fixedly secured on plate 3 9. If desired, backrest 52 could be padded so as toform a more comfortable construction.

Members

25 and 26 of railing 27 are provided with pivot means at 28, 29 for the movable mounting of two; depending

bar members

30 and 31. A plate 54 is preferably provided on

members

30 and 31 to prevent said members from buckling downwardly past their dotted line positions shown in Figure 1. The

lower ends

32 and 33 of

members

30 and 31 are turned toward each other whereby to support a fiat foot plate 34 which is fixedly. secured on the upper face of end portion 32. .A pairof; shortchannel sections 35 are secured ,on theloweriface'sl of end portions'32'and 33for positioning plate 34'above' theladder rung. The function of plate 34 is to'provide a comparatively large flat surface on which the ladder user may stand, whereby to eliminate discomfort due to standing on the conventional round ladder rungs. Inprder that the safety'device may be utilized with varying width ladders certain of the laterally extending elements are so constructed as to provide for expansion and contraction of the device in lateral directions. Thus pins 7 and 8 are provided with slots at 36 for reception over

pins

37 and 38 on sleeve 20.

The inwardly extending

portions

39 and 49 of

railing members

25 and 26 are each provided with an internally threaded lugdl. Lugs 41 meshingly engage the threaded portions 42 and 43 of a rod element 44, Portions 42 and 43 are threaded in opposite directions whereby when rod element44 is turned (by the application of a wrench to non-circular portion 45 on rod 44) lugs 41 will moveftoward or away from each other, depending on the direction in which rod 44 is turned. a

The inwardly extending

portions

32 and 33 of depending

members

30 and 31 have projecting therefrom a pair of internally threaded lugs 46 which meshingly engage threaded portions 47 and 48 of a rod element 49. Portions 47 and 48 are threaded in opposite directions whereby when rod element 49 is turned (by the application of a wrench to non-circular portion 50) lugs 46 and their secured elements will move toward or away from each other, depending on the direction in which rod 49 is turned.

Positioning the safety device in the full 'line position (Figure 1) may be effected by initially slipping guide members 3 and 4 over rails and 6 (with the ladder in a lowered easily accessible location) and extending

elements

25, 26, 3t), 31 to their dotted line positions (Figure 1). members 3 and 4 can be adjusted to any desired location on the ladder by manually pulling cords l8 and 12. Manual pull on cord 18 serves to raise members 3 and 4. Lowering of members 3 and 4 is effected by gravity. Manual pull on cord 12 serves to bring dog elements 9 and into engagement with the undersides of lugs 16 As cord 18 is released members 3 and 4 slide down on rails 5 and 6 whereby to bring dog elements 9 and 10 into locking engagement with ladder rung 21. A semi-circular plate 51 is secured on each of

bars

30 and 31 for the purpose of preventing foot plate 34 from striking and catching on the ladder rungs during the periods when members 3 and 4 are being moved up and down on rails 5 and 6. Railing 27 and foot plate 34 may be brought into their full line positions (Figure 1) by the user of the ladder after he has ascended the ladder to a point just below the foot plate. All that is necessary is .to give an upward push on

members

30, 31 and drop channel sections 35 over the desired one of rungs 21. Railing 27 and foot plate 34 may be brought from their full line positions to their dotted line positions by lifting channels 35 clear of rungs 21 and lowering

elements

27, 30, 31 to their dotted line positions.

In its full line position the safety device provides a free space between

arm portions

39, 40 and foot plate 34 through which the user may ascend or descend as desired. Railing 27 prevents the user from falling from the ladder and without any interference to the free use of the users arms and body while he is situated within the confines of the safety device. Foot plate 34 pr0- vides a flat surface on which the user may stand, thereby avoiding the discomfort which a person experiences after standing for extended periods on the conventional round ladder rungs.

Having thus described my invention, I claim:

7 .1. A safety device for a ladder comprising a pair of guide members for slidable reception on the ladder side rails,. means on said members for releasably holding them at varying positions on the ladder, flexible means for After raising the ladder to its elevated position 'actuati'ng' saidholding means from the foot of the ladder, flexible means for manually raising the guide members from the foot of the ladder, a back-engaging railing mounted on said guide members, a foot plate below said back-engaging railing, members depending from the railing into connected positions with the foot plate whereby to position the foot plate adjacent the ladder rungs and the web portion of the railing away from the ladder for the performance of its safety function.

2. A safety device for a ladder comprising a pair of guide members for slidable reception on the ladder side rails, a dog element pivotally mounted on each of said guide members and in registry with the ladder rungs, a stop member extending from each of said guide members and in registry with the associated dog element, flexible means for raising said guide members on the ladder, flexible means for moving said dog elements into contact with the stop members, a U-shaped railing having its ends pivotally mounted on the guide members, two depending members pivotally mounted on the U-shaped railing, and a foot plate interconnecting said depending members. V

3. A safety device for a ladder comprising a pair of guide members for slidable reception on the ladder side rails, a dog element pivotally mounted on each of said guide members and in registry with the ladder rungs, a stop member extending from each of said guide members and in registry withthe associated dog element, flexible means for raising said guide members on the ladder, flexible means for moving said dog elements into contact with the stop members, a U-shaped railing having its endspivotally mounted on the guide members and being extensible in lateral directions whereby to accommodate the safety device to varying width ladders, two depending members pivotally mounted on the U-shaped railing and having inturned end portions, a foot plate supported on said end portions, and adjusting means for varying the distance between said depending members in accordance with dilferent ladder widths.

4. A safety device for a ladder comprising a pair of guide members for slidable reception on the ladder side rails; a U-shaped, back-engaging railing having its ends pivotally connected to the guide members; said U-shaped railing defining a web portion and two parallel arm portions; two spaced depending bar members pivotally connected with the parallel arm portions; a foot plate interconnecting the lower ends of said bar members; said foot plate having a dimension, in directions parallel to the arm portions, approximating the length of a human foot; and positioning means carried by the foot plate for rigidly but removably anchoring the foot plate onto the ladder; the space between the web portion of the railing and intermediate portions of the foot plate being entirely unobstructed to constitute a free space; whereby the device can, be positioned on a ladder with the arm portions and bar members extending along the length of the ladder, and the device can be made operative for its safety function by causing the railing and bar members to buckle upwardly about their pivotal connections, after which the user can ascend the ladder through the aforementioned free space to an upright position with his back adjacent the railing web portion.

References Cited in the file of this patent UNITED STATES PATENTS 764,463 Harrison July 5, 1904 799,782 Ellinger Sept. 19, 1905 1,574,801 Eddington Mar. 2, 1926 2,080,015 Sneddon May 11, 1937 2,103,603 Voigt Dec. 28, 1937 2,151,135 Moberg Mar. 21, 1939 2,341,510 Born Feb. 15, 1944 2,678,243 Masse, May 11, 1954