Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02690504 2009-12-21
"Ladder-Adder" Ladder Stabilizing Device
Field of the invention
The present invention relates to a ladder stabilizer device for an extension
ladder and
provides an improved and simplified design.
Background
The invention relates generally to extension ladders and a means to safely
stabilize them
against a possibility of a sideways collapse during an ascent. This insures
against the
likelihood of great injury or even death from a fall.
The device is specifically used on an extended extension ladder that is
propped against a
vertical surface (such as a tree or roof) for support and whereas the intended
activity is
beyond the reach of a conventional step ladder.
The device entails the use of two hinged wooden stabilizer supports that pivot
to extend
outwards from the frame rails of the ladder and are attached through a hollow
rung at a
predetermined location on the extension ladder base. Because the main hinge
brackets are
also allowed to swivel, as well as pivot, the wooden stabilizer supports can
be better
positioned to an angle that is advantageous to brace the assembly, regardless
of the slope
of the ground.
References Cited
Some examples of similar and complex United States of America patents are as
follows:
6672427 Sheffield, Lance Rodney
6527084 Hrincu, Viorel
4949809 Levi, Avraham Y. / Quarberg, Craig D.
7163084 Blehm, Berle G.
5868222 Charbonneau, Francois
4964488 Stewart, John V.
CA 02690504 2009-12-21
4723629 Vanden Hoek, Vernon M. / Maasdam, Leonard J.
5511632 Ermis, Jerry J.
Although several of these designs are very flexible and adaptable in their
nature, their
cost of manufacture and/or the set-up for the consumer is their biggest
inadequacy.
Summary of the invention
The basis of this invention was to create a very simple, sturdy and economical
platform
for securing the stability of the extension ladder. Most other patent examples
relating to
this design are sometimes extremely complex and probably very expensive to
manufacture.
My design has relatively few parts and is easily reproduced with the principle
of simple
to construct and simple to use.
The use of wood as the material for the main stabilizer support is simply
derived from the
practiced uses of it in fabricating most children's playground sets that you
see in parks
and backyards throughout the country. Also its approved use in construction
does not
even require quoting of its resiliency, adaptability and ease of affordability
& availability
to the consumer.
Another valuable reason for the use of wood as a stabilizer support is the
known fact that
electricity will not conduct easily thru it, therefore making this device
indispensable to
workers of the electrical trade.
CA 02690504 2009-12-21
The entire assembly is not very cumbersome when attached and can be stored or
transported together with the extension ladder to a desired work area with
ease.
The simplicity of the entire design allows for ease of set-up and removal from
the work
area or even detachment of the assembly from the ladder itself, if necessary.
An improvement of the design, compared to most of the prior art, is the
addition of two
leveling indicators to assist with the initial alignment of the extension
ladder. The
indicators reflect the position of the ladder being perpendicular to the
ground (plumb) and
of also having the correct recognized angle of elevation to the ladder peak
(15 ). The use
of this alignment aid, in conjunction with a "ladder leveling device" on the
base of the
ladder, allows for a safer and steadier foundation of the whole assembly. This
is
especially noticeable when the ladder is erected on sideways' sloping ground.
The utilization of two flexible bungee cords to harness the wooden stabilizer
supports to
the correct angular aspect to one another is unique, as opposed to the varied
complex and
elaborate restraints incorporated from previous patents for their stabilizer
support
members.
The stabilizer support hinge design is simple and "self-centering" for use
with most
`hollow rung' extension ladder styles. Mounting the stabilizer support hinges
to the
ladder using an existing hollow `rung' location ensures that no additional
holes will be
drilled into the ladder frame. This preserves the structural integrity of the
ladder and does
no harm to its safety standards and warranty restrictions.
The wooden stabilizer support length is determined by the specific ladder
length that the
consumer owns. Therefore if the consumer decides to purchase a larger or
smaller ladder
in the future, the only item that will require exchange to suit this new
ladder is the
wooden stabilizer supports.
Also to allow flexibility, additional support strut extensions may easily be
fastened with
woodscrews to the stabilizer supports, as needed, to suit any drastic terrain
difficulties.
All hardware fasteners used are of a standardized size and length to enable
the consumer
ease of availability in the case of loss or damage of the aforementioned
mounting
hardware.
Drawings
The invention is described with reference to the following drawings:
Figure #1 is a Representative Drawing (3-D View) of an extended extension
ladder
coupled with the Ladder-Adder device and leaning against a building roofline.
The
device is in the `open' (ready to use) stage of the set-up.
Figure #2 is an Exploded Representative View (3-D View) of the entire assembly
of the
Ladder-Adder device. The extension ladder is not shown.
Figure #3 is a Front View of an extended extension ladder coupled with the
Ladder-
Adder device and leaning against a cinder brick wall. The device is in the
`open' (ready
to use) stage of the set-up.
CA 02690504 2009-12-21
Figure #4 is a Side View of an extended extension ladder coupled with the
Ladder-
Adder device and leaning against a cinder brick wall. The device is in the
`closed' stage
of the set-up.
Figure #5 is a Side View of an extended extension ladder coupled with the
Ladder-
Adder device and leaning against a cinder brick wall. The device is in the
`open' (ready
to use) stage of the set-up.
Figure #6 is a Front & Side View of the main hinge bracket (pair) of the
Ladder-Adder
device assembly.
Figure #7 is a 3-D View of the hardware required to mount the wooden
stabilizer
support to both the main hinge and the ladder frame. It comprises: a length of
threaded
rod, a washer & self-locking nut (pair), and a bolt & self-locking nut (pair).
Figure #8 is a 3-D View of a wooden stabilizer support (pair) and all the
itemized
handiwork procedures entailed to produce it
Figure #9 is a 3-D View of a plastic tie-wrap (pair).
Figure #10 is a 3-D View of a bungee cord (pair).
Figure #11 is a 3-D View of a woodscrew & a steel wire "indicator" (pair) that
has been
bent to the entailed shape.
*Photos* A thru Hare views describing the proper operative set up of an
extension
ladder and the Ladder-Adder device assembly.
Item Reference Numbers
(drawings)
#1 MAIN HINGE BRACKET - STAINLESS STEEL or MILD STEEL
#2 THREADED ROD - STAINLESS STEEL or ZINC PLATED
#3 HINGE MOUNTING HARDWARE (to suit Item #2)
- TWO stainless flat washers
- TWO stainless `nylock' nuts
#4 SUPPORT MOUNTING HARDWARE (to suit Item #3)
- TWO stainless hex bolts
CA 02690504 2009-12-21
- TWO stainless `nylock' nuts
#5 TWO 2x4 or 2x6 WOODEN STABILIZER SUPPORT PLANKS
(Length determined by ladder size)
#6 TWO PLASTIC TIE-WRAPS
#7 TWO FLEXIBLE BUNGIE CORDS
#8 DRILLED HOLES - Thru wooden planks
#9 45 MITRE CUT - Across wooden planks
#10 DRILLED HOLES - Thru wooden planks
#11 45 MITRE CUT - Across wooden planks
#12 2 WOOD SCREWS
#13 2 BENT WIRE "INDICATORS" (clothes hanger material)
#14 LADDER BASE FRAME RAILS
#15 LADDER BASE HOLLOW "RUNG"
Pase 1
Description
To enable the full understanding of the "Ladder-Adder" Ladder Stabilizing
Device, it
will now be described with the assistance of the illustrated drawings,
Figure's #1 thru 11
and Photo's A thru H.
Assembly of the device:
Referring strictly to FIGs. 1 & 2 to fully illustrate the attachment of the
assembly, a
conventional extension ladder raised to an extended position and propped to
the side of a
building is proposed .
CA 02690504 2009-12-21
- A pair of U-channeled steel or hinge brackets 1 are harnessed to this ladder
via the
ladder base section frame rails 14 at a predetemined ladder rung 15 location.
Refer also to
FIG. 6.
- The hinges 1 are mounted to the hollow bore of rung 15 with the installment
of a steel
threaded rod 2 joining thru them, parallel to the ladder rails 14. Refer also
to FIG. 7.
- The embossment of each steel hinge bracket 1 allows for self-centering in
relation to the
hollow bore of the rung 15. Refer also to FIG. 6.
- Hinge mounting hardware 3 is then fastened to both ends of the steel
threaded rod 2 at
a specified torque setting to allow the hinge brackets 1 to pivot as needed.
Refer also to
FIG. 7.
- After determining the overall length of the supplied extension ladder, two
wooden
stabilizer support planks 5 are purchased by the consumer to suit the length
and size
requirements of the device (longer ladders will require longer and possibly
"stiffer"
supports).
- The stabilizer support planks 5 are then sawed at mitre cut locations 9 & 11
and drilled
thru at drilling locations 8 & 10 to the suit the specified requirements of
the design. Refer
also to FIG. 8.
- The stabilizer support planks 5 are then mounted into the hinges 1 using the
support
mounting hardware 4 in the drilled hole locations 10 of the planks 5.
- The support mounting hardware 4 is then fastened to a specified torque
setting to allow
the stabilizer support planks 5 to swivel outwards away from the ladder rails
14 as
needed. Refer also to FIG. 7.
- The clearance gained by sawing the mitre cut 11 allows increased rotation of
the
stabilizer support planks 5 outwards from the ladder rails 14. Refer also to
FIG. 8.
- The mitre cut 9 sawed at the bottom of the stabilizer support planks 5
allows for
improved friction/ penetration of the surrounding terrain that the ladder will
be used on.
Refer also to FIG. 8.
- A pair of plastic tie-wraps 6 are loosely attached to each of the stabilizer
support planks
using the drilled hole locations 8. Refer also to FIG's. 8 & 9.
- A pair of `level and angle of inclination' wire indicators 13 are bent to a
desired shape
and both are fastened loosely to a high location along the outer side of the
stabilizer
support planks 5 with the use of two wood screws. Refer also to FIG's. 4 & 11.
Pau 2
- The outer side of the stabilizer support planks 5 are also inscribed with a
dark line to
visually represent a 15 degree angle at the point where the wood screw 12 is
fastened.
Refer also to FIG. 4.
- A pair of bungee cords _7 are connected to the pair of plastic tie-wraps 6
used near the
bottom of the stabilizer support planks 5 to help maintain the assembly at a
correct
angular aspect. Refer also to FIG. 3.
- This pair of bungee cords 7 can also be used near the bottom of the
stabilizer support
planks 5 to help retain them alongside of the ladder base section frame rails
14 for
storage & transport of the entire assembly. Refer also to FIG. 4.
Erection of the extension ladder:
CA 02690504 2009-12-21
- A suitable location to rest the ladder and device are determined, that are
free of
obstacles (overhead and at ground level).
- Ensure that the terrain is of adequate firmness to allow proper anchoring of
both the
extension ladder base rails 14 and the pair of wooden stabilizer support
planks S (loose
ground or sand may cause failure of the ladder/device operation creating a
possibility of
grave personnal injury - if in doubt, solidify using appropriate means such as
laying
down additional planking or plywood).
- Take notice of any angular variations (slope) of the ground level and be
prepared to
adjust the extension ladder base rails 14 accordingly to suit the ground
profile.
- The assembled device and extension ladder are transported to the worksite
area.
- Lay the "upper" extension ladder section down flat on the ground, ensuring
that the
ladder `foot' is against the base of the wall or vertical structure that you
will be
attempting to ascend (climb). If the foot cannot be anchored in this manner, a
second
person should be used to help secure it. Refer to PHOTO A.
- Lift the ladder's top section (at the peak) and maintain foreward pressure
against the
anchored foot. Refer to PHOTO B.
- Lift the ladder overhead to the highest point of reach with your hands and
raise ladder
towards the wall/vertical structure using a hand over hand method. Refer to
PHOTO C.
- As you reach the mid point of the ladder, remain focused and continue to
raise the top
portion while increasing pressure against the foot/anchored point until the
ladder is
standing straight upright. Refer to PHOTO D.
- Rest the upper portion of the ladder against the wall/vertical structure
while being
careful to avoid any damage to glass or fragile surfaces. Then, lift the
ladder base (foot)
outwards and away from the wall/vertical structure approximately five feet (in
length)
away. Refer to PHOTO E.
- With care, lean back the upper section of the ladder away from the
wall/vertical
structure, until the ladder is standing straight upright again. Refer to PHOTO
F.
- Slowly, while anchoring the bottom rung of the ladder with your foot,
carefully extend
the ladder using its rope and pulley system until a desired length is
established. Refer to
PHOTO G.
NOTE: Ensure the top section (peak) of the extension ladder is to be extended
no less
than three rungs above the top edge of the wall/vertical structure. Refer to
FIGs. 1 & 2.
Page 3
- Carefully lay the top section (peak) of the extension ladder against the top
edge of the
wall/vertical structure. Refer to PHOTO H.
> The ladder is now ready for angular alignment & levelling with the use of
the "Ladder-Adder" Ladder Stabilizing Device
Operation of the device:
- Align the extension ladder frame 14 utilizing the bent wire "indicators" 13
that were
mounted along the outside edge of the wooden stabilizer support planks f of
the
assembly. Ensure that the ladder frame 14 is plumb (perpendicular to the
ground) and that
CA 02690504 2009-12-21
its angle of inclination from foot to peak is set at 15 degrees. Adjust the
ladder frame 14
accordingly determined by the reference of the indicators 13. Refer to FIG's.
1 & 4.
- Ensure that the anchoring of the extension ladder frame 14 is secure. If the
ground is
sloped or uneven,then level it using appropriate means (adjust the uneven
ground, place
wide shims under the floating ladder frame rail 14 or use a ladder levelling
attachment).
Note: All extension ladder bases must be anchored properly prior to attempting
any
ascent.
- Release/remove the two bungee straps 7 from the "storage set up" (of the
device
assembly) and swing outwards the two wooden stabilizer support planks 5 away
from the
extension ladder frame 14. Refer to FIG. 3.
- Then, allow the stabilizer support planks 5 to `pivot' towards the
wall/vertical structure
until they can be lowered down plumb and on a plane parallel with the
wall/vertical
structure. Refer to FIG. 5.
The stabilizer support planks 5 are rotated/pivoted via the mechanics of the
main hinge
bracket 1 and the various fastening components 2, 3 & 4 listed previously in
the
`assembly of the device section'. Refer to FIG's 1, 3 & 5.
- The stabilizer support planks 5 will appear to spread out in a rough V-
formation when
viewed, depending on the slope of the terrain. Refer to FIG's.I & 3.
- If the slope is severe, then simply attach an appropriate extension strut
plank to the
wooden stabilizer support plank 5 that requires lengthening (allow these
additional strut
planks to overlap by a minimum of two feet in length and secure them together
by
fastening long woodscrews through them). Refer to FIG. 1.
- In order to help secure the wooden stabilizer support planks 5 from
slipping, stretch the
two bungee cords _7 together between the plastic tie-wraps 6 (located near the
bottom of
the wooden stabilizer support planks 5) and attach to each other. Refer to
FIG's 1, 2 & 3.
- If the bungee cords 7 are of insufficient length, then simply incorporate a
length of rope
between the cords 7 to help adjust the tension to suit the specific
ladder/assembly
configuration (longer length extension ladders will require additional rope to
be
implemented due to a wider V-formation `spread' of longer wooden stabilizer
support
planks 5 used in the assembly).
- The geometry of the mitre cut tips 9 of the stabilizer support planks 5
allow for
improved penetration/anchoring of the terrain when weight is applied to the
ladder and
device assembly. Refer to FIG's.I & 3.
