Note: Descriptions are shown in the official language in which they were submitted.
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LADDER STABILIZING DEVICE
BACKGROUND OF THE INVENTION
This invention relates in general to ladder safety devices and deals
more particularly with an improved stabilizing device for a ground-supported
straight ladder.
A ground supported ladder of the type with which the present
invention is concerned is used in an inclined position with its upper end
portion
resting on or against a suitable support. When a downwardly directed force is
applied to the ladder by someone standing on it there is a nature tendency for
the
base of the ladder to move in a horizontal direction away from the supporting
surface. Most serious accidents involving ladders of this type can be
attributed to
failure to provide a sound ladder footing. Long straight ladders and
particularly
extension ladders are inherently unstable when supported on uneven ground.
When such a ladder is used on irregular or sloping surfaces it is common
practice
to block or shim the ladder to compensate for the irregularity of the
supporting
surface. This is an extremely dangerous practice, but in many instances the
practice cannot be avoided. This is particularly true where there is no
provision for
adjusting the effective length of the ladder side rails.
Accordingly, it is the general aim of the present invention to provide an
improved ladder stabilizing device which is geometrically designed to provide
a
wide support base to assure firm footing for a straight ladder. It is a
further aim of
the invention to provide a ladder stabilizing device which may be readily
adjusted
to compensate for irregularities in the ladder supporting surface and may be
collapsed to a storage position for convenient handling and storage.
SUMMARY OF THE INVENTION
In accordance with the present invention, a stabilizing device is
provided for a straight ladder having elongate parallel laterally spaced apart
side
rails including upper and lower ends and a plurality of spaced apart rungs
extending laterally between and connecting the side rails. Such a ladder is
normally arranged in a forwardly and upwardly inclined position with the upper
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end portion resting on a supporting structure. The stabilizing device
comprises a
base member having an upwardly extending front leg and an upwardly extending
rear leg spaced from the front leg. The base member further includes a
forwardly
and upwardly inclined carrying member which is connected to and extends
between the upper ends of the rear leg and the front leg. An elongate support
member is mounted on the base member for pivotal movement about a laterally
extending axis relative to the base member and carries a connecting member
which defines a socket for receiving the lower end of an associated side rail.
A
means is provided for releasably securing the associated side rail to the
connecting member.
BRIEF DESCRIPTION OF THE DRAWING
Fig. 1 is a fragmentary front elevational view of a straight ladder
shown supported on an uneven surface by a pair of stabilizing devices
embodying
the present invention.
Fig. 2 is a somewhat enlarged fragmentary side elevational view of a
ladder stabilizing device embodying the present invention.
Fig. 3 is a fragmentary front elevational view of the device.
Fig. 4 is a fragmentary top plan view of the device shown in Fig. 2.
Fig. 5 is a somewhat enlarged fragmentary sectional view taken
along the line 5-5 of Fig. 1.
Fig. 6 is a fragmentary front elevational view of another ladder
stabilizing device embodying the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
Turning now to the drawing and referring first to Fig. 1 a pair of ladder
stabilizing devices embodying the present invention and indicated generally at
10
and 10' are shown attached to and supporting a straight ladder designated
generally by the letter L. The illustrated ladder L is a conventional
extension
ladder and has a main section M which includes a pair of elongate parallel
laterally spaced apart side rails S, S. The side rails have upper and lower
ends,
but only the lower ends are shown. A plurality of longitudinally spaced apart
rungs
R, R extend laterally between and connect the side rails S, S. The illustrated
ladder L is an extension ladder and also includes an extendible section (not
shown) which is generally telescopically engaged with the main section M. The
ladder L is adapted for use in a forwardly and upwardly inclined position with
the
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upper end portion of the ladder resting upon a suitable supporting structure
{not
shown). The stabilizing devices 10, 10' are adjustable and particularly
adapted to
support a ladder, such as the ladder L, in a stable position both on a level
supporting surface and on uneven ground, as shown in Fig. 1 and as will be
hereinafter evident from the further description which follows.
The illustrated ladder stabilizing devices 10 and 10' are preferable
fabricated from a light weight metal, such as aluminum, and are substantially
identical to each other, but of opposite hand for a reason which will be
hereinafter
evident.
Further referring to the drawings and particularly to Figs. 2-4, the left
hand device 10 is illustrated and essentially comprises a base member
indicated
generally by the numeral 12, a support member pivotally mounted on the base
member and designated generally by the numeral 14 and a connecting member
indicated generally at 16 and adjustably secured to the support member 14.
Considering the ladder stabilizing device 10 in further detail, the
base member 12 comprises a unitary structure and includes an upwardly
extending rear leg 18 and an upwardly extending front leg 20, which is
somewhat
longer than the rear leg, and a forwardly and upwardly inclined carrying
member
22 integrally connected to and extending between the upper ends of the rear
leg
18 and the front leg 20. Preferably and as shown the legs 18 and 20 have
friction
pads 23, 23 attached to the bottom surfaces thereof, as best shown in Figs. 2
and
4.
The support member 14 has a longitudinally upwardly extending
elongate shank 25 and a bifurcated lower end portion or cievis 24 which
straddles
the carrying member 22. The lower end portion of the support member 14 is
pivotally connected to the carrying member 22 by a pivot pin or bolt 26 which
extends laterally through both the bifurcated lower end portion 24 and the
carrying
member 22. Preferably, and as best shown in Fig. 2, the axis of the pivot pin
26,
indicated at 28, is located closer to the front leg 20 than to the rear leg
18. A series
of longitudinally spaced apart cylindrical holes 30, 30 extend transversely
through
the upwardly extending shank 25 for a purpose which will be hereinafter
further
evident.
The connecting member 16 is slidably supported on the shank 25
and is formed as either a right or left handed part, as shown in Fig. 1. It
has a
generally rectangular collar portion 32 and a socket defining portion 34 which
is
both laterally and rearwardly offset relative to the collar portion 32, as
best shown
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in Figs. 3 and 5. The collar portion 32 has a rectangular bore 36 extending
through it which receives and substantially complements the shank 25 on the
support member 14. Laterally aligned cylindrical holes 38, 38 substantially
equal
in size to the holes 30, 30 open through opposite sides of the collar portion
32 for
registry with a selected one of the holes 30, 30 to receive a locking pin 40
for
releasably securing the collar in a selected one of a plurality of incremental
positions of adjustment along the shank 25. The Pocking pin may take various
forms. However, the illustrated locking pin 40 includes a spring ball decent
at its
free end for releasably retaining the pin in assembly with the collar 34.
The socket defining portion 34 includes an upwardly open blind
socket 42 partially defined by a slot 44 in the front wall of the socket
defining
portion 34. The socket has a generally T-shaped cross-section as viewed from
above (Figs. 3 and 5) and is particularly adapted to receive the lower end of
a
metal ladder having side rails S, S of channel shaped cross-section. A
clamping
fastener 46 threadably engaged in the rear wall of the socket defining portion
34
for clampingly engaging the lower end portion of a ladder sidewall S to
releasably
retain the device 10 in assembly with the ladder.
In Fig. 5 the lower end of a side rail of the extension ladder L is
shown clamped within the socket 42, the extendible portion of the ladder being
shown in broken lines. When the device 10 is attached to a ladder of the type
shown the extendible portion of the ladder may be moved to its fully lowered
position without removing the device from the ladder. It is for this reason
that the
socket defining portion is offset relative to the collar portion 32. The
geometry of
the base member 12 and the manner in which the support member 14 is
connected to the base member provide a sound support base for the ladder L.
The support base 12 is pivotally moveable between an active
position wherein the carrying member 22 extends generally transversely of the
support member 14 and a storage position wherein the carrying member is
disposed in generally axially parallel relation to the support member, as it
appears
in broken fines in Fig. 2.
Fig. 6 illustrates another ladder stabilizing device embodying the
present invention and indicated generally at 10a. The illustrated device 10a
is
similar in most respects to the device 10 previously described and parts which
correspond to parts of the previously described device bear the same reference
numeral and a letter a suffix and will not be hereinafter described in detail.
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The device 10a differs from the device 10 in the construction and
arrangement of the support member 14a. Specifically, the support member 14a
has an upwardly extending shank portion 25a which carries the connecting
member 16a, as previously described. The support member 14a also has a
5 bifurcated lower end portion indicated at 24a which is laterally offset
relative to the
shank portion 25a.
The ladder stabilizing device 10a, which comprises the presently
preferred structure, is used in combination with a substantially identical
ladder
stabling device of opposite hand to support a straight ladder in the manner
hereinbefore described. However, because of the laterally offset arrangement
of
the base members 12 the devices provide a somewhat wider support base for a
ladder and provide a greater degree of lateral stability.
