US3724592A

US3724592A - Adjustable ladder and scaffold

Info

Publication number: US3724592A
Application number: US00157866A
Authority: US
Inventors: H Fleischer
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-06-29
Filing date: 1971-06-29
Publication date: 1973-04-03
Anticipated expiration: 1990-04-03

Abstract

A ladder having one or more of its legs individually extensible so as to enable it to stand or be supported on an irregular surface. The ladder can be converted into a scaffold whose height may be varied utilizing the extensible legs. A standard ladder can be converted for use on irregular terrain by the addition of a novel single leg supported by the lower rung of the ladder and movable therealong.

Description

United States Patent [191 Fleischer I {54] ADJUSTABLE LADDER AND SCAFFOLD [76] Inventor: Henry Fleischer, l8 Notch Park Road, Little Falls, NJ.

221 Filed; June 29,1971

[21] Appl. No.: 157,866

[52] U.S. Cl ..182/27, 182/203 [51] Int. Cl. ..E06c l/383, E04g 1'/3O [58] Field of Search ..l82/27, 205, 203

[56] References Cited UNITED STATES PATENTS l,245,073 10/1917 Walter ..l82/25 [451 Apr. 3, 1973 476,897 6/1892 Ripp v.182/27 3,071,204 l/l963 Piltingsrud 2,152,895 4/l939 Longtin ,.l82/205 Primary Examiner-Reinaldo P. Machado Attorney-Lawrence l. Lerner et al.

[5 7] ABSTRACT A ladder having one or more of its legs individually extensible so as to enable it to stand or be supported on an irregular surface. The ladder can be converted into a scaffold whose height may be varied utilizing the extensible legs. A standard ladder can be converted for use on irregular terrain by the addition of a novel single leg supported by the lower rung of the ladder and movable therealong.

5 Claims, 10 Drawing Figures PATENTEDAPR 3 m5 SHEET 1 BF 2 I NVE NTOR.

HENRY FLEISCHER i'WEWEDAPR 3 I973 SHEET 2 [IF 2 FIG.7

HE N RY FLEISCHER INVIEN'I'OR.

ADJUSTABLE LADDER AND SCAFFOLD BACKGROUND OF THE INVENTION extension leg can be selectively positioned at a:

predetermined vertical position with respect to the ladder leg to which it is secured to steady the ladder or uneven terrain. However, in each of these patents, the extension leg is secured to one leg or the other; none of the extension legs being capable of being shifted from one leg to the other. U.S. Pat. No. 898,973 has taught the use of vertically adjustable ladder attachments with respect to both legs of a ladder. U.S. Pats. Nos. 199,922; 1,424,934; and 2,971,602 have taught ladder leg leveling devices which include generally semi-circular elements which are pivoted with respect to the bottommost rung of the ladder in order to level the ladder on uneven terrain. U.S. Pats. Nos. 1,272,551 and 2,663,283 also teach leveling and equalizing support for ladders which are generally vertically adjustable with respect to the bottom rung of the ladder.

Thus, prior art leveling devices have generally been of two classes. The first class of device generally include a vertically adjustable memberrsecured to one or both legs of the ladder; the second class involve a semicircular attachment from which the ladder can be pivoted with respect to unequal terrain. None of the leveling devices taught by the prior art are movable in a selected horizontal direction between the legs of the ladder so that one selected leg can be made vertically adjustable to compensate for uneven terrain with respect to the other. This type of device would allow for attachment to an existing ladder.

Further, none of the prior art leveling devices are useful in adopting a ladder for conversation into a scaffold..

FIELD OF THE INVENTION This invention relates to leveling devices for ladders, ladders which may be converted into scaffolds, and leveling devices for a ladder so converted into a scaffold. The devices of the present invention are meant to be sold as a separate attachment to be mounted on existing or as an item to be incorporated in the manufacture of ladders.

SUMMARY OF THE INVENTION In the present invention, there are two basic embodiments. The first embodiment is a ordinary step ladder wherein the back legs are each individually extensible to be varied in accordance with the terrain. The cross members joining the ladder with the back legs are also adjustable in accordance with the position of the ladder. The cross members are separable from the back legs to become the upstanding-legs of a scaffolding with the ladder portion becoming the horizontal portion of the scaffolding when erected. The cross members are substantially equal in length to the back legs of the ladder so that they can form equal legs each individually adjustable to the terrain in which the scaffolding will be placed. On the side walls of the step ladder rung portion there are placedremovable cross braces which are attachable to the vertical members of the scaffold to provide bracing for the scaffolding when 1 fully erected.

In the second embodiment, there is provided a single extensible leg longitudinally movable on the bottom rung of a ladder. The extensible leg is slidable from one side of the rung to the other in accordance with the needs of the user. This is especially useful for extension ladders wherein the ladder cannot be reversed without creating safety problems. The extensible leg attached to the rung of the ladder can be incorporated in the manufacture of the ladder or added to existing ladder.

DESCRIPTION OF THE DRAWINGS I FIG. 1 is a perspective view of a step ladder built in accordance with the principles of the present invention.

FIG. 2 is an enlarged showing of one of the cross members of the ladder of FIG. 1.

FIG. 3 is a cross-sectional view of the cross member of FIG. 2 taken along lines 3-3 thereof.

FIG. 4 is a top plan view of the cross member shown in FIG. 2.

FIG. 5 is a perspective view of the step ladder in FIG. I converted into a scaffolding.

FIG. 6 is a plan view of one of the crossmembers at tached to the side leg of FIG. 1.

FIG. 7 is a drawing of a standard ladder to whichhas been attached an extensible leg in accordance with the second embodiment of the present invention.

FIG. 8 is an enlarged view of the mounting of the extension leg shown in FIG. 7.

FIG. 9 is a cross-sectional view taken along lines 9- 9 of FIG. 8.

FIG. 10 is an expanded view of the manner in which the attachment shown in FIG. 7-9is made to the lowermost rung of a ladder.

DETAILED DESCRIPTION In FIG. 1, there is shown a step ladder built in accordance with the principles of the present invention generally designated by the numeral 10. Step ladder 10 comprises a front ladder portion 12, a back leg portion 14 and cross member 16. The front ladder portionl2 comprises two

front legs

18 and 20 joined by rungs 22. The

legs

18 and 20 have each connected at the bottom end thereof

front cleats

24 and 26 respectively. At the top of front ladder portion 12 there is provided a platform 28 .pivotally connected to

legs

18 and 20 and spring biased into place by means of the spring 30.

The back leg portion 14 consists of two

back legs

32 and 34 joined at their upper ends to

front legs

18 and 20 respectively. Each of the

back legs

32 and 34 has, at its lower end, ratchet connected telescoping

extensional legs

36 and 38 respectively. The

back legs

32 and 34 are joined by a cross member 44 to give lateral stability to the back leg portion 14. The

extension legs

36 and 38 may be moved with respect to the

back legs

32 and 34 by means of ratchet locking means 46 and 48 which engage

teeth

50 and 52 respectively on the

extension legs

36 and 38. The operation of the

ratchet members

46 and 48 will be described in detail hereinafter.

The cross member portion 16 consists of two

cross member legs

54 and 56 joined by a bar 58. Each of the

cross members legs

54 and 56 has a

telescoping extension leg

60 and 62. The

legs

60 and 62 have

hooks

64 and 66 which engage pins 68 and 70 on the inside surface of

back legs

32 and 34 respectively.

Cleats

72 and 74 are pivotally connected to the ends of the

extension legs

60 and 62; and at the other end of cross member 16,

legs

54 and 56 are pivotally connected to the bottom ends of the siding of ladder

front legs

18 and 20. It will be appreciated that the connection of said cross member portion to the front and back portion of the ladder may be reversed.

The

legs

60 and 62 are made extensible with respect to cross

member legs

54 and 56 by reason of ratchet locking means 76 and 78 respectively which engage

teeth

80 and 82 on

extension legs

60 and 62 respectively. Ratchet member 76 will be described in detail, it being understood that it is similar in operation to ratchet

members

78, 46 and 48.

With further reference to FIGS. 2 and 3 ratchet member 76 includes a handle 84 pivotally mounted between

side plates

86 and 88 on pin 90. Handle 84 has a pin 92 therethrough to which is linked (by link 93) a wedge shaped tooth 94 which engages the teeth 80 of extension leg 60. Movement of handle 84 to the position shown in dotted lines at 84 lifts wedge shaped tooth 94 out of the tooth 80 and allows the extension leg 60 to telescope inwardly or outwardly with respect to the hollow leg 54. Upon movement of handle 84 back to the solid line position shown in FIG. 2, the wedge shaped tooth 94 is wedged into position within teeth 80 locking the leg 60 in place.

It can thus be seen that the step ladder can have the length of one or both of its

back legs

32 and 34 extended by moving the

extension legs

36 and 38 downwardly or upwardly with respect to it associated hollow

back leg

32 or 34. It is thus possible to level the ladder 10 with respect to the irregularities in the ground surface. It is further possible to vary the span between front and back by varying the length of the

legs

54, 60; 56, 62 of the cross member 16.

Each of the

legs

18 and 20 carries thereon a pair of cross braces 96, 98 and 100, 102 respectively. Cross brace 96 is shown in FIG. 6 and has a hole 104 on one end thereof and a hook 106 at the other end thereof. The hole 104 in

braces

96 and 98 is placed over a pin 108 located on the outer surface of the bottom end of leg 18. The hook 106 of

braces

96 and 98 is placed over a pin 110 at the upper end of leg 18. Similarly, the cross braces 100 and 102 are mounted on

pins

112 and 114 positioned on the outer surface of leg 20.

When the step ladder 10 is intended to be used as a scaffolding, this is accomplished in the manner shown in FIG. 5. That is, the cross members 116 are lifted off the pins 68 and 70 and extended downwardly. The cross braces are mounted as follows: cross brace 96 has its hole 104 mounted on a pin I07 and its hook end connected over a pin 116 on the inner surface of back leg 32. Brace 98 is connected between pin 118 on the inner surface of leg 54 and pin 120 on the outer surface of leg 32. Brace 100 is connected between pin 122 on the outer surface of leg 34 and pin 124 on the surface of leg 56. Finally, brace 102 is connected between pin 123 on the outer surface of leg 56 and pin 126 on the inner surface ofleg 34.

Thus, in place, the scaffolding shown in FIG. 5 is rigid, fully braced, and is capable of being placed on any irregular surface by merely adjusting the height of the individual legs of the scaffold utilizing the ratchet locking means 76, 78, 46 and 48. Thus the step ladder 10 has been shown to be adjustable both as a step ladder and a scaffold and may be easily converted from one to the other. The

hooks

64 and 66 have proved to be detatchable connecting means attachably connected to the back legs and pivotally connected to the ladder legs and thus easily convertable from the ladder into the scaffold arrangement. The platform 28 is spring biased out of position, and the

cleats

24 and 26 are gravity biased out of position so as not to interfere with the use of the ladder of the scaffolding. If desired a board can be supported on the ladder when used as a scaffolding.

In FIG. 7-10, there is shown a second embodiment of the present invention. In FIG. 7, there is shown a ladder 130 having

side legs

132 and 134 joined by rungs 136. The lowermost rung 138 of the rungs 136 is adopted to have connected thereto the extension attachment of the present invention generally designated by the numeral 140. Although the ladder 130 has been shown as a simple one piece ladder, the invention is especially useful for extension ladders of the type generally known and the invention will be so described. As shown, the extension attachment 140 is adopted to give additional length to one of the

legs

132 or 134 so that the ladder may stand on an uneven terrain such as a hill in the manner shown in FIG. 7.

The extension attachment 140 consists of a cross member 142 fixedly secured between the

legs

132 and 134 by screw members l44'and 146. Screw member 144 is secured to the leg 132 so that the cross member 142 is in a fixed position immediately below the lowest rung 138 and spaced therefrom by means of a spacing means 148 (FIG. 10). The screw 144 passes through a hole 150 in the side wall of the leg 132 which hole 150 can be drilled in the situation where leg attachment 140 is to be added to an existing ladder, or hole 150 can be prepunched in the situation where a ladder is being manufactured with the adjustable leg attachment 140. Other means for attaching the leg attachment 140 can be utilized within the scope of the present invention, such as clamp means or the like.

The extensible leg attachment 140 further includes an extensible leg generally designated by the numeral 152. The extensible leg 152 comprises an upper hollow leg154, a middle hollow leg 156 and a lower leg 158 with a suitable pivotally connected cleat 160 at the bottom thereof. The lower leg 158 has teeth 161 thereon which are engaged by suitable ratchet member 162 mounted at the lower end of middle leg member 156. Ratchet 162 controls the relative vertical position of lower leg 158 with respect to middle leg 156. Middle leg 156 has teeth 164 on the outer surface thereof. The upper hollow leg 154 has a suitable ratchet member 166 mounted at the lower end thereof for engaging the teeth 164 of middle leg 156. This allows middle leg 156 to be vertically positioned relative to upper leg 154. The use of the three

legs

154, 156 and 158 provides a variation in the overall length of the extensible leg 152.

The extensible leg 152 has, at its upper end, inwardly directed

flanges

168 and 170, which flanges are fitted within horizontally extending

grooves

172 and 174 in cross member 142. The position of the leg 152 relative to the cross member 142 is determined by the operator by merely sliding leg 152 along leg 142 with the

flanges

168 and 170 fitting within the

grooves

172 and 174. When a desired position is reached, a suitable locking cam 176 is locked into position in the manner shown in FIG. 7. It is thus possible, utilizing a single adjustable leg 152 to extend one or the other of the

legs

132 or 134 as desired. By compressing the leg 152 to its shortest position, the ladder 130 can be used in the ordinary manner since leg 152 would then have a length-merely equal to the length of the ladder leg 132.

I claim as my invention 1. A combination extensible ladder and scaffold comprising:

a ladder portion having ground engaging means at the bottom end thereof; a first leg portion having ground engaging means at the bottom end thereof, means for pivotally connecting said ladder portion to said first leg portion at the top ends thereof, a second leg portion pivotally connected to the bottom end of one of said ladder portion and first leg portion and having a free end detachably connected to the other of said first leg portion ladder portion, said free end having ground engaging means at the end thereof,

detachable scaffold bracing means detachably connectable between said second leg portion and said first leg portion to form a scaffold, and said first and second leg portions having extensible legs, whereby in a first position an extensible ladder is formed with said second leg portions bracing said ladder portion and said first leg portion, and in a second position an extensible scaffold is formed with said detachable scaffold bracing means bracing said first and second leg portions in a parallel upright position. 1 I t 2. The combination extensible ladder and scaffold of claim 1 wherein said one of said ladder portion and first leg portion is said ladder portion;

and said other of said first leg portion and ladder portion is said first leg portion. 3. The combination extensible ladder and scaffold of claim 1 wherein said first leg portion has two extensible legs independently extensible relative to each other.

4. The extensible ladder and scaffold of claim l wherein said detatchable scaffold bracing means includes cross members detatchably connected to the side wall of said front ladder portion when said detatchable scaffold bracing means are not used to form a scaffold.

5. The combination extensible leg and scaffold of claim 1 wherein said first leg portion includes hollow legs with said extensible first leg portion legs being telescoped within said hollow legs and ratchetmeansfor locking said extensible legs into a fixed position relative to said hollow legs.

Claims

1. A combination extensible ladder and scaffold comprising: a ladder portion having ground engaging means at the bottom end thereof; a first leg portion having ground engaging means at the bottom end thereof, means for pivotally connecting said ladder portion to said first leg portion at the top ends thereof, a second leg portion pivotally connected to the bottom end of one of said ladder portion and first leg portion and having a free end detachably connected to the other of said first leg portion ladder portion, said free end having ground engaging means at the end thereof, detachable scaffold bracing means detachably connectable between said second leg portion and said first leg portion to form a scaffold, and said first and second leg portions having extensible legs, whereby in a first position an extensible ladder is formed with said second leg portions bracing said ladder portion and said first leg portion, and in a second position an extensible scaffold is formed with said detachable scaffold bracing means bracing said first and second leg portions in a parallel upright position.

2. The combination extensible ladder and scaffold of claim 1 wherein said one of said ladder portion and first leg portion is said ladder portion; and said other of said first leg portion and ladder portion is said first leg portion.

3. The combination extensible ladder and scaffold of claim 1 wherein said first leg Portion has two extensible legs independently extensible relative to each other.

4. The extensible ladder and scaffold of claim 1 wherein said detatchable scaffold bracing means includes cross members detatchably connected to the side wall of said front ladder portion when said detatchable scaffold bracing means are not used to form a scaffold.

5. The combination extensible leg and scaffold of claim 1 wherein said first leg portion includes hollow legs with said extensible first leg portion legs being telescoped within said hollow legs and ratchet means for locking said extensible legs into a fixed position relative to said hollow legs.