Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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"EXTENSION LEG ASS:13MBLIES FO:R LADDERS"
BACKGROUND OF THE INVENTION
This invention relates to new and useful improve~
ments .in extension leg assemblies usable with the legs of
ladders, or extension ladders, stepladders and the like.
Such ladders are often used on uneven ground sur~
faces or on stairways and the like where it is necessary to
support the lower legs of the ladder at different heights
and with conventional ladders on uneven ground for example,
it is us~lal to insert a packing member such as a piece of
lumber, rock or the like under the leg which needs the ex-
tension, in order that the ladder will extend substantially :
vertically. However, such a practice is extremely dangerous : ~:
asr due to the incllnation of the ladder when leaning against
a building for example, the supported leg often sIlps from ~ ~
the packing materlal. . :
It is also well known that it is difflcult to use
a stepladder on stairs, steps and the like as it is not
possible to extend the front and rear legs of a ~tepladder
unless once again some packing material is placed under the ~-
legsrequiring the extension in order that thP stepladder may ~ ;:
be substantially level. ;:
Attempts have been made in the past to provide ex-
tending leg assemblies for 1adders~ stepladders and the like ~:
but these usually are either extremely involved and include
ratchets and the like or, alternatively J utilize an extending
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leg with an elongated slot therein through which a bolt and
wing nut assembly passes in order to clamp the extension in
the desired relationshlp. Once again such a practice is
dangerous because the extended leg relies on the friction be-
tween the wing nut and bolt assembly and the extending leg
portion.
Other attachments may be suitable for the old fash-
ion wooden ladder or ladders with a smooth outer surface but
difficulty is encountered in attaching many of the known as-
semblies to the outer surface of the legs of an aluminum
ladder due to the fact that the ends of the rungs extend be-
yond the surface of the vertical supports or legs thus making
it difficult to provlde a firm clamping pressure between the
ladder leg and the extending portion.
SUM~RY` OF THE I~VENTION
The present inVention overcomes these disadvantages
by providing~a leg assembly which can readily be attached to ;~
the legs of an aluminum extension ladder, a wooden extension
ladder, a single ladder componentl and stepladder or the like.
In accordance with the invention there is provided
an extension leg assembly for ladders which include at least
two spaced and parallel legs with rungs extending therebetween;
comprising in combination a base portion securable to adjacent
the lower end of the leg of the ladder, a movable portion en-
gageable within said hase portion for lengthwise sliding move-
ment relative thereto and means cooperating between '
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said base portion and said movable portion to selectively : -
lock said portions together in the desired lengthwise re-
lationship with one another, said means coopera.ting between
said base portion and said movable portion to selectively
lock said portions together, including an aperture formed
through saicl base portion, a plurality of selectively matching
apertures formed through said movable portion, pin means
cooperatively engaging the aperture in said base portion
and any one of the apertures ln said movable portion and de~
tachable retaining means cooperating between said pin means
and said leg assembly to deter inadvertent displacement of
said pin means.
Another advantage of the invention is that it can
be secured to the lower end of the legs of any convention-
al ladder or stepladder and will supply an extension leg .
assembly whlch is Elrmly clamped to the ladder and cannot slip
relative thereto and can be extended into a plurality of
positions depending upon the e~tension required, once
again being detachably locked into the desired relationship
so that it cannot slip.
Another advantage of the invention is that thepivotaL lower pad assemblies often found on extension ladders
or the like, can be detached from the legs of the ladder
and reattached to the lower end of the extension leg assembly. .
A further advantage is that the pad assembly
whether it be pivotal or fixed to the base or lower end of
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the extension leg, can be utilized to rest the ladder there-
on when the leg assemblies are fuLly retracted so that the
weight of the ladder is upon the pad assemblies rather than
on the pins assemblies extending between the inner and outer
portions of the extending leg assembly.
A yet further advantage of the invention is to
provide a device of the character herewithin described
which is simple in construction, economical ln manufacture : ~ :
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and otherwise well suited to the purpose for which it is
designed.
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With the foregoing in view, and other advantages as
will hecome apparent to those skilled in the art to which
this invention relates as this specification proceeds, the in-
vention is herein described by reference to the accompanying
drawings forming a part hereof, which includes a description
of the pre~erred typical embodiment of the principles of the
present invention, in which:
DESCRIPTION OF THE DRA~INGS
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Figure 1 is a fragmentary front elevation of the
lower end of a ladder with the invention securea thereto.
Figure 2 is a fragmentary isometric view of one of `~
the extension leg assemblies.
Figure 3 is a side elevation of the lower end of a
ladder leg with the base portion of the invention secured
thereto.
Figure 4 is a fragmentary cross sectlonal view of
one of the leg assemblies showing one method of detachably se-
curing the sections together.
Figure ~A is a partially broken away view of an al-
ternative e~bodiment of the locking pin per se.
Figure 5 is a fragmentary side view of the invention
in the fully retracted position.
Figure 6 is a partially schematic side elevation
showing the invention secured to a stepladder on a schematic ~;
representation of a stairway.
Figure 7 is an isometric view of an alternative con-
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struction of -the lower pad assembly.
Figure 8 is a view similar to Figure 5 bu-t showing
the pad of Figure 7 installed thereon.
Figure 9 is a ragmentary isometric view of the
upper end of the movable portion per se.
In the drawings lilse characters of reference inidicate
corresponding parts in the different figures.
DET~ILED DESCRIPTION
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Proceeding therefore to describe the invention in de-
tail, reference to Flgure 1 will show the lower end of a ladder
collectively designated 10 which may be an extension ladder, or
a single ladder. In this particular embodimentt it includes a
pair of spaced and parallel vertical legs or rails 11 with a
plurality of rungs 12 extending therebetween and in the usual
construction of such a ladder, extruded aluminum is used ~ith
the ends of the rungs extend1ng through the web 13 of the legs ~`
and being swaged over as indicated by reference character 14
in Figure 3 50 that these ends actually extend beyond the sur-
face 13A of the outer sides of the legs.
The lnventlon collectively designated 15 is secured
to the lower ends of the legs 11 and upon the outer sides
thereof as shown in Figure 1.
Each extension leg assembly 15 consists of a base
portion collectively designated 16 and a movable or inner por-
tion collectively designated I7.
The base portion 16 is preferably formed from ex-
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trudedaluminum and includes a base 18 having a pair of side
platesl9 extending one each from the longitudinally extending
edges of the base 18 to form a substantially U-shaped channel.
Inturned retainer flanges 20 are formed on the dis-
tal or outer edges 21 of the side plates 19 as clearly shown ;;
in Figure 2.
Apertures 22 are punched through the base 18 pre- ;~
ferably adjacent the upper and lower ends of the base through
which nut and bolt assemblies 23 may extend and also through
corresponding apertures (not illustrated) formed through the
web 13 of the ladder legs 11, thus securing the base portions
16 to adjacent the lower ends o* the legs 11 and upon the outer
surfaces thereof.
If the rungs 12 are provided with the swaged over
ends 14, then enlarged apertures 24 are punched through the
base 18 and engage over the extending ends 14 o~ the rungs
thus enabling the base 18 to be clamped or secured by bolt
assemblies 23, in interfacial relationship with the outer sur-
face 13A of the webs 13 thus providing~secure attachment.
The movable portion 17 is of a similar configuration
to the base portion 16 but is dimensioned so that it can be
slidably engaged within the base portion as clearly ~hown in
Figure 2~ This movable portion also includes a base 18A~
spaced and parallel side plates l9A and inturned flanges 20A
and the movable portion 17 slidably engages within the base
portion 16 in opposition thereto so that the two bases 18 and
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18~ face one another in spaced and parallel relationship with
the retaining flanges 20 of the base portion being slidably
engaged by the outer vertical edges of the base 18A of the
movable portion as clearly illustra-ted.
Means are prov.ided to detachably secure the movable
portion 17 relative to the base portion 16, said means taking
the form of an aperture 25 punched or otherwise formed through
one side plate 19 of the base portion.
The corresponding side plate l9A of the movable por-
tion is provided with a plurality of spaced apart apertures 26 ~;
anyone of which can be placed in matching relationship with
the aperture 25 as the movable portion is moved lengthwise re-
lative to the base portion. Detachable fastening means are
provided engageable through the aperture 25 and the selected
aperture 26 and the preferred embodiment takes the form of a
cylindrical pln 27 and illustrated ln Figure 4. The inner end
is preferably chamfered as at 28 to assist in engagement of
the pin with the aperture 25 and the selected matching aperture
specifically designated 26A in Figure 4 and a ring or similar
means 29 is pivotally secured adjacent the outer end 30 of the
pin to assist in engaging and disengaging same from the aperture.
Means are provided to prevent inadver-tent disengage-
ment of the end from the apertures once the pin is in place,
for safety reasons, sald means taking the form, in Figure 4, of
a spring loaded ball assembly 31 which is coventional in con-
struction, in the wall of the aperture 25 reinforced by a plate
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32 secured to the side plate 19 engaging within an annular
groove 33 formed around the periphery of the pin 27, when the
pin is fully engaged within the apertures.
An alternative arrangment is shown in Figure 4A in
which a spring loaded ball assembly 31A is situated adjacent
the inner end 34 of the pin 27 which may engage behind the
inner surface 35 of the wall l9A when the pin 27 i5 fully en-
gaged within the apertures 25 and 26A.
Stop means in the form of a plate 36 lS detachably
or permanently secured to the upper end 37 of the movable por-
tion 17 and engages the upper end 38 of the base portion when
the movable portion is fully extended and this stop plate 36
prevents the movable portion from disengagement from the base
portion. ;`
Many extension ladders are provided with a pad assem-
bly 39 pivotally secured to the lower end of the legs 11. When
the extension leg assemblies 15 are secured to the legs 11,
this pad assembly is removed and secured to the lower end 40 of
the movable portion as shown in Figures 1 and 5. The conven-
tional plvoted pad assembly includes a pair of spaced and
parallel side plates 41 together with a base 42 forming a U-
shaped bracket with an anti-skid pad 43 being secured to the
underside of the base 42 and these are pivoted to the lower ends
40 by means of a pivot pin 44.
The upper sides 45 of the side plates 41 are prefer-
ably horizontal as clearly shown in Figure 5 and when the mov-
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able portion 17 is in the fully retracted position shown in
Figure 5, the lower end 46 of the base portion 16 rests on
this horizontal upper edge 45 thus taking the weight of the
ladder and relieving pressure on the pin 27. In this regard,
the uppermost aperture specifically designated 16B, within ~,J
the movable portion, is slightly larger than the other aperture
16 so that the pin 27 may be engaged therethrough in order to
prevent the movable portion form extending inadvertently when
the ladder is lifted yet at the same time permitting the weight
to be taken on the upper edges of the side plates of the pad
assemblies 39.
The above described embodiments can be used on the
majority of ladders and on the legs 47 of a stepladder assem-
bly as shown in Figure 6.
When used upon a stepladder assembly 48, it is not
necessary to provide the clearance apertures 24 but the leg
assembly may be secured by nut and bolt assemblies 23 in a
manner similar to that hereinbefore described.
A similar extension leg assembly may be used on the
other or front legs 49 of a stepladder assembly but may be of
smaller dimensions than those used on the other legs 47 because
they are usually of a smaller or thinner construction.
When used on a stepladder assembly 48, the swivel pad
assemblies / are not present to be used on the lower ends of the
movable portions so that a pad assembly to that shown in Figure
7 may be utilized. This comprises a U-shaped bracket 50 having
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a pair of spaced and parallel side plates51 and a base~plate
or portion 52 with an anti-friction pad 53 secured to the
underside thereof. This U-shaped bracket is engaged over the
lower end of the movahle portlon 40 and secured as by rivets
through apertures 53A and once again the upper horizontal edges
54 may be used to take the weight of the stepladder assembly
when the extension leg assemblies are in the fully retracted ~ :
position.
Since various modifications can be made in my inven-
tion as hereinabove described, and many apparently widely dif-
ferent embodiments of same made within the spirit and scope of
the claims without departing from such spirit and scope, it is
intended that all mat~er contained in the accompanying specifi-
cation shall be interpreted as illustrative only and not in a
limiting sense.
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