Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~203S20
FIELD OF THE INVENTION
. .
This invention relates generally to extension
ladders and more particularly to extension ladders comprising
two separable sections which may readily be coupled together
to constitute an extension ladder.
BACKGROUND OF THE INVENTION
In the past various extension ladders comprising
separable sections have been provided, Typical are the
ladders disclosed in U.S. Patent 1,555,344 to Whitney issued
September 29, 1925; Australian Patent 289,370 to Paynter
of March 4, 1969 and French Patent 1,252,593 to Roth issued
December 19, 1960. In each of these patents the ladders
comprise separable base and extension sections which are
coupled together at longitudinally spaced locations by
means of co-operating rung and slot couplingswhereby
rungs and extensions of rungs are received in longitudinally
extending slots.
These prior art extension ladders all suffer
a major disadvantage that to couple the two separable
sections of the ladder together requires the two sections
to be precisely positioned with respect to each other in
longitudinal alignment so that the slot and rung coupling
means at the two spaced locations may be concurrently
engaged. Suitable positioning of the ladder sections
may be extremely difficult particularly by a single person
when the ladder sections are heavy or when no suitably
flat terrain is available on which to lay both of the ladder
sections. When used outdoors,vegetation, mud and snow
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may catch on the sections or partially block the slots
increasing the difficulty of coupling the sections together.
Further in frigid wintery conditions protective clothing
such as mitts and gloves impair the ability of an
individual to precisely locate the ladder sections as is
required for coupling.
Servicemen working for utility companies such
as hydro electric suppliers, cable television suppliers and
telephone companies require ladders for day-to-day use,
For example in Canada, telephone company servicemen require
almost daily a ladder which can extend to 17 feet. Less
frequently they will require a ladder which extends to 21
feet. In the past these servicemen have been provided with
a *wo piece telescoping extension ladder which is 12 feet.
in length when unextended and may extend to 21 feet, Recently,
however, telephone servicemen have been provided with several
automobiles of smaller size than previously, with the
result that the existing 12 foot ladders are longer than the
new automobiles and present a safety hazzard, To overcome
this problem new ladders were proposed comprising a
telescoping two piece ladder of 10 foot length unextended
which may extend to 17 feet, To provide the ladder with
the capability to extend 21 feet when necessary a third
detachable section has been proposed. The disadvantagesof
the prior art extension ladders have made the use of known
separable extensions unsatisfactory particularly in regard
to difficulties in coupling the separable section to the
rest of the ladder by a single serviceman in the field,
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Another disadvantage of the known separable extension
ladder is the absence of any provision for positive locking
of the separable extension to the rest of the ladder as
is required to ensure safe use of the ladder.
SUMM~RY OF THE INVENTION
Accordingly, it is an object of the present
invention to at least partially overcome these disadvantages
of the prior art by providing a ladder comprising two
separable sections to be coupled together in longitudinally
overlapping relation by first coupling means coupling a
portion of a first ladder section proximate one end there-
of to the second section so as to permit the first
ladder section to be rotated with respect to the second
ladder section to a position where second coupling means
are aligned in position for engagement, preferably with stop
means being provided to stop rotation of the first ladder
section at a position where the second coupling means are
aligned for engagement.
Another object is to provide a ladder comprising
two separable sections which is easy to assemble by a single
person even under adverse field conditions,
Another object is to provide a ladder comprising
two separable sections which provides means to positively lock
together the sections when assembled into an extension
ladder.
To this end, in one of its aspects the present
invention provides a ladder comprising two separable
secti.ons, a ladder extension section and a base ladder
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section to be coupled together in longitudinally over-
lapping relation to constitute an extension ladder;
each section comprising rails and rungs,
portions of each rail of the extension section at the lower
end thereof being spaced to be received between rails of
the ladder section and having complementary primary
slots formed therethrough to slidably receive one rung of
the base section therein;
each primary slot having a blind end proximate
the lower end of the extension section, the primary slots
extending from the blind end longitudinally away from the
lower end of the extension section to an open end permitting
entrance of the one rung therein; wherein with the one
rung received in the primary slots at the blind ends, the
extension section being rotatable with respect to the ladder
section about the one rung;
first coupling means on the extension section
spaced longitudinally from the slot on the remote side of
the slot from the lower end of the extension section;
secondly coupling means on the ladder section
spaced longitudinally from the one rung on the remote
side of the one rung from the lower end of the ladder
section;
stop means on one of the extension section and
ladder section, wherein with the one rung received in the
slots at the blind ends, on rotation of the extension
section about the one rung, the stop means stopping rotation
of the extension section about the one rung at a position
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wherein the first and second coupling means are in align-
ment for coupling,
the first and second coupling means engaging
to couple together by sliding the extension section from
the position in a substantially longitudinal direction with
- respect to the ladder SectiQn to slide the one rung in the
primary slots away from the blind ends, the primary
slots being of sufficient longitudinal extension that with
the first and second coupling means coupled together
the- one rung being retained within the primary slot;
the first and second coupling means on
coupling preventing further sliding of the extension section
in the direction, and, with the first and second coupling
means coupled together and the one rung retained within
the primary slots, relative rotation of the extension section
with respect to the longitudinal section is prevented.
In another of its aspects, the present invention
provides a ladder comprising two separable sections, a
first section and a second section to be coupled together
in longitudinally overlapping relation to constitute an
extension ladder with a first end of each section overlapping
with the other section and the other, second,end of each
section to be remote from the respective other section,
each section comprising rails and rungs, the
first end of the first section coupling to the second
section by means of complementary primary slots in the
ails of one of the first and second sections to slidably
receive one rung of the other of the first and second sections;
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the primary slot having a blind end and extending
longitudinally away from the blind slot directionally
away from the first end of the first or second section
provided with the primary slot to an open end permitting
entrance of the one rung therein; wherein with the one rung
received in the primary slots at the blind ends, the
first section being rotatable with respect to said second
section about said one rung
first coupling means on the first section spaced
longitudinally from the one of the primary slots and the
one rung provided on the first section on the remote side
thereof from said first end of the first section;
second coupling means on the second section
spaced longitudinally from the one of the primary slots and
the one rung provided on the second section on the remote
side thereof from the second end of the second section,
stop means on one of the first section and
second section, wherein with said one rung received in the
primary slots at the blind ends, on rotation of the first
section about the one rung, the stop means stopping
rotation of the first section about the one rung at a posi-
tion wherein the first and second coupling means are in
alignment for coupling,
the first and second coupling means engaging
to couple together by sliding the first section from the
position in a substantially longitudinal direction with
respect to the second section to slide the one rung in the
primary slots away from the blind ends, said primary slots
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being of sufficient longitudinal extension that with the
first and second coupling means coupled together the one
rung being retained within the primary slot;
the first and second coupling means on coupling
preventing further sliding of the first section in the
direction, and with the first and second coupling means
coupled together and the one rung retained within the
primary slots relative rotation of the first section with
respect to the second section being prevented.
BRIEF DESCRIPTION OF THE DR~WINGS
Further objects and advantages of the invention
will appear from the following description taken together
with the accompanying drawings in which;
Figure 1 is a pictorial view of an extension
ladder in accordance with a first embodiment of the invention
shown with two separable ladder sections losated relative
to each other in a first position to initiate a coupling
sequence.
Figures 2 and 3 are partial pictorial views of
the ladder of Figure 1 with the two separable ladder
sections located relative to each other in second and third
positions during a coupling sequence.
Figure 4 i8 a partial pictorial view of the
ladder of Figure 1 with the two separable ladder section
located relative to each other in a fourth coupled position.
Figure 5 and 6 are similar cross-sectional views
through section line V~V~ of Figure 4 showing a locking
means in an unlocked and locked position, respectively.
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Figure 7 shows a schematic pictorial view of two
ladder sections coupled to from an extension ladder in
accordance with a second embodiment of the invention similar
in many respects to the ladder shown in Figure 1.
Figures 8, 9 and 10 show schematic pictorial
views of two ladder sections coupled to form extension
ladders in accordance with third, fourth and fifth embodi-
ments of the invention,
Figure 11 shows a pictorial view of an extension
ladder in accordance with a sixth embodiment of the invention
in a position similar to that shown in Figure 1,
DESCRIPTION OF THE PREFERRED EMBODIMENTS
- Reference is made first to Figure 1 showing a
first preferred embodiment in accordance with the present
invention. The extension ladder comprises two seperable
ladder sections, a first or extension section 10 and a
second or base section 20, Each of the first and second
ladder sections have a first end 12 and 22, respectively,
and a second end 14 and 24, respectively. The first ends
are designated so that as shown in Figure 4 when the two
sections are coupled together to comprise an extension
ladder, the first end of each section is the end overlapping
with the other section whereas the second end of each section
is the end shown to be remote from the respective other
section.
Each ladder section comprises rails and rungs
with the rails of the first and second sections designated
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16 and 26, respectively. The rungs of the first section 10
are designated 18 while the rungs of the second section are
generally designated 28 with the exception of the one rung
closest to the first end 22 of the second section 20 which
is designated 29,
Rails 26 of the second section 20 are shown as
parallel, cross-sectionally U-shaped members with an end
cap 30 at the first end 22 to be described later. The rails
16 of the first section 10 are shown to comprise two rails
portions, 32 and 34, with rail portions 32 closest to the
second end 14 of the first section 10 being parallel
cross-sectionally U-shaped members similar to rails 26.
Rail portions 34 proximate the first end 12 of the first
section 10 comprise a pair of hook-like members fixedly
secured as, for example, by rivetting to inside surfaces
36 of rail portions 32 and extend longitudinally beyond
the ends of rail portions 32,
Rails 26 of the second section are provided
spaced the same distance as rail portions 32 of rail 16
of the first section, Rail portions 34 of the first section
are spaced so as to be received between rails 26 of the
second section.
Each rail portion 34 appears as a hook-like member
by reason of primary slots 38 transversely therethrough
in the direction of extension of rungs 18. Primary slot
38 extends from a blind end 40 longitudinally with respect
to rails 16 away from first end 12 of the first section 10
to a slot opening 42. As best seen in Figure 3, surfaces
_g_
44 of rail portion 34 bordering these slot openings 42 are
suitably shaped to assist in guiding rung 29 of the second
section 20 into primary slot 38 as is described later.
Primary slot 38 is sized so as to closely receive
rung 29 yet to permit rung 29 to enter slot opening 42 and
to be slidable longitudinally in the slot to contact and
engage blind end 40.
As best seen in Figure 3, each rail portion 34
is provided with a post 50 which extends transversely
outward from the outside surface 48 of rail portion 34.
As seen in Figures 3, 5 and 6, an internally threaded
locking member 56~is provided co-axially on post 50,
threadably engaging external threads on the post and with
a snap-locking ring 58 preventing withdrawal of the locking
member 56 off the outwardmost end of post 50, Locking
member 56 hasa conical end portion 60 and a handle
portion 62 facilitating manual turning of the locking member
56 for a movement axially with respect to post 50 by co-
operative engagement of the threaded portion of post 50.
Referring now to Figures 2 and 3, end cap 30
on the second section 20 at its first end is provided with
a secondary slot 64 extending transversely of the rail
therethrough in the direction of extension of rungs 28.
Secondary slot 64 extends from a blind end 66 longitudinally
of rail 26 towards the first end 22 of the second section
(and therefore away from the second end 24 of the second
section) to slot opening 68 providing an open end to slot
64.
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The end cap extends as a longitudinal extension
70 on one side of slot opening 68 longltudinally farther
from second end 24 than on the other side of slot opening
68 for the purpose of acting as a stop means in a manner
to be described later,
With the major elements of the first and second
sections now defined, the interaction of these elements will
now be described with reference to Figures 1 to 4 which
show successive steps in a sequence of coupling the first
section to the second section. For the purpose of
illustration, the second section 20 is assumed to stay in
one position and the first sectlon 10 is to be moved with
respect to the second section 20,
The first section 10 is first moved so that both
primary slots 42 will receive rung 29, As shown in Figure
1, first section 10 is preferably positioned so that surfaces
44 proximate slot opening 42 contact rail 29 of the
second member, and then by sliding first section 10 in
the direction of arrow A shown in Figure 1, surface 44
may effectively act as a cam surface to guide rung 29
into slot opening 42. Further sliding in the direction
of arrow A permits rung 2g to slide from slot opening 42
through the slot until further relative sliding of the
first and second portions is prevented by rung 29 engaging
blind ends 40 of primary slot 38 and locating these sections
in their relative positions shown in Figure 2,
With the first and second sections in the position
shown in Figure 2, and with rung 29 maintained in engagement
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with blind slot 40, the first section may be rotated with
respect to the second section about rung 29 in the direction
indicated by arrow B until posts 50 engage extensions 70
on the first end 22 of the second section preventing further
rotation and resulting in the first and second sections
being located in their relative positions shown in Figure 3.
With the locking member 56 being withdrawn towards the
outermost end of post 50 as seen in Figure 5, the upper
surface 72 of extension 70 of the second section contacts
post 50 to stop rotation at the position shown in Figure 3.
With the first and second sections in the
position shown in Figure 3~ the post 50 is in engagement
with extension 70 and post 50 is in a position in alignment
for coupling with secondary slot 64 by sliding longitudinally
in the direction of arrow C until the first and second
sections assume their relative positions shown in Figure
4. In sliding the first section in the direction of arrow
C, post 50 slides longitudinally along the upper surface
72 of extension 70 to enter slot opening 68 and slide along
secondary slot 64 until the post engages blind end 66.
Concurrently with this sliding, the relative position of
rung 29 will be changed with respect to primary slot 38
so as to change from the position shown in Figure 3 with
rung 29 engaging blind end 40 by relative sliding of rung
29 in primary slot 38 away from blind end 40, to a position
as shown n Figure 4,with rung Z9 disposed in primary slot
38 at an intermediate location between blind end 40 and
slot opening 42.
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The longitudinal extent of primary slot 38 is
chosen so as to be greater than the longitudinal extent of
secondary slot 64 so that when the posts 50 engage blind
ends 66 preventing further relative sliding of the first
and second sections in direction C, rung 29 will remain
disposed within primary slot 38. As is to be appreciated,
the relative longitudinal positions of rung 29, slot opening
68, blind end 66 and extension 70 on the second section
must be chosen having regard to the relative positioning of
post 50,and blind end-40 on the first section, For example,
as seen in the figures, the longitudinal distance between blind
end 66 and the far side of rung 29 on the second section
20 may be equal to the longitudinal distance between post
50 and blind end 40 on the first section 10 less the longi-
tudinal distance from slot opening 68 to blind end 66 onthe second section 20,
With the first and second ladder sections engaged
as shown in Figure 4, the extension ladder is satisfactorily
assembled for use. Longitudinal compression of the assembled
ladder is prevented with post 50 engaging on blind end 66.
With post 50 engaging blind end 66 while rung 29 is disposed
in primary slot 38, relative rotation of the first section
10 with respect to the second section 20 is prevented,
Preferably also, the ouside surfaces 48 of rail portions
34 may closely engage the inside surfaces of rails 26 of
second section 20 to provide additional stability.
The preferred embodiment of Figure 1 also includes
an optional locking mechanism whereby locking member 56
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may securely lock post 50 to end cap 30 of the second section.
As described and best shown in Figures 5 and 6, locking
member 56 has a truncated conical end portion 60 co-axially
located about post 50, End cap 30 carrying secondary
slot 64 is formed at blind end 66 to have a conical recess
complementary to conical end portion 60. As seen in Figures
5 and 6, blind end 66 proximate the inside surfaces
of rail 26 has a diameter marginally larger than that of
post 50. As the blind end extends transversely towards
the outside surfaces 78 of rails 26 it opens into a conical
recess 80 having conical walls 82. Conical recess 80 is
co-axial with respect to post 50 when post 50 is engaged
with blind end 66.
The operation of the locking mechanism is now
described. In coupling the first and second sections
together as described by the sequence with reference to
Figures 1 to 4, the locking member 56 should be screwed
to be withdrawn to the outermost end of post 50 so that
post 50 may engage and cam on extension 70 to slide into
secondary slot 64 and to engage blind end 66. With the
first and second sections coupled in their relative
positions shown in Figure 4, then the post 50, locking
member 56 and end cap 30 will be in the relative position
shown in Figure 5 being a cross-section through Figure 4
on section line V-V'. The engagement of post 50 with
blind slot 66 will axially align post 50 and conical end
portion 60 with respect to conical recess ~0 of end cap
30. Turning handle portion 62 of locking member 56 will
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move locking member ~6 from the retracted or unlocked
position shown in Figure 5 to the locked position shown
in Figure 6 engaging conical walls 82. AS best seen
in Figure 3, the conical walls 82 extend more than 180
about the conical recess whereby with the complementary
conical end portion 60 engaged in conical recess 80,
the first and second sections are positively locked
together.
The first embodiment of this invention provides
two sections for an extension ladder which facilitates
easy coupling together of the two sections in assembly into
a complete extension ladder. For example, a single
individual may lay the second ladder section 20 on the
ground. The first ladder section 10 may then be manipulated
~5 to the position shown in Figure 1. With the surfaces 44
near slot opening 42 on the first section serving to cam
and guide rung 29 into primary slot 38, the initial engagement
of rung 29 into slot 38 does not require precise manual
control of the two ladder sections. Once rung 29 is engaged
in primary slot 38, by further pulling the first section
in direction A as shown in Figure 1, rung 29 is caused to
slide down the primary slot to engage blind end 40. Next,
simple manual rotation of the f irst section about rung
29 until rotation is stopped by post 50 engaging extension
70 will place the two sections in two positions to be
slid longitudinally for engagement of post 50 in secondary
slot 64 and contact with blind end 66 thereof, Finally,
locking member 56 may be.manually turned to cause the
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locking member to enter conical recess 80 and securely
lock the two sections together. Thus, as described, the
particular embodiment shown in Figure 1, the first section
need only be roughly manipulated into place in order to
accomplish a positive coupling of the two sections toyether.
Cooperating slots and grooves on the two sections provide for
the adequate relative positioning of the sections for
coupling once rung 29 has been positioned to enter primary
slot 38.
Reference is now made to Figures 7 to 10 which
show second, third, fourth and fifth embodiments in accordance
with the present invention, In each of Figures 7 to 10,
two ladder sections are shown, a first ladder section 110 and
a second ladder section 120. Throughout Figures 7 to 10
like numerals are used to refer to similar elements~
In each of Figures 7 to 10, the first and second
ladder sections are shown coupled together in a position
ready for use as an extension ladder. The first and
second sections are coupled together at two longitudinally
spaced junctures, as shown in Figures 7 to 10, an upper-
most juncture at U and a lowermost juncture at L. Each
juncture comprises a longitudinally extending siot in the
rails of one of the sections and a rung or extension of
a rung from the other of the sections to be received in
that slot.
As in the case of Figure 1, the first end 112
and 122 of the first and second sections 110 and 120,
respectively, are designated as the end of each section
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which is in overlapping relation with the other ladder
section while the second ends 114 and 124 of the first and
second sections respectively are the ends remote from the
other section.
The lowermost juncture L of each of the
embodiments shown in Figures 7 to 10 comprise a primary
slot 138 provided in one of the first section and the second
section. The primary slot has a slot opening 142 and a
blind end 140. Each primary slot extends longitudinally
away from the blind end 140 in a direction away from the
first end 112 or 122 of the first or second section pro-
vided with the primary slot, Adapted to be received in
the primary slots 138 is a primary rung 109 or lateral
e~tensions thereof on the other of the first and second
sections to that on which the primary slot 138 is provided.
One of the primary slots 138 and the primary rung 109 is
located sufficiently proximate the first end 112 of the
first section that with the primary rung 109 recelved in
the primary slot so as to engage blind end 140, the first
2a section 110 is rotatable with respect to the second section
120 about primary rung 109.
The uppermost juncture U of each of the embodi-
ments shown in Figures 7 to lQ comprises a secondary slot
164 provided in one of the first section and the second
section. The secondary slot has a slot opening 168 and a
blind end 166 and extends longitudinally away from the blind
end 166 in a direction away from the second end 114 or 124
of the first or second section provided with the secondary
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slot. Adapted to be received in the secondary slot 164
is a secondary rung 107 or extension 107' thereof on the
other of the first and second section to that on which
the secondary slot is provided.
The one of the secondary slot 164 and secondary
-rung 107 provided on each of the first sections 110 is
shown to be located on the rails 116 of the first section
spaced longitudinally from the elements of the lower juncture
L on the remote side of the lower ~uncture L from the
first end 112 of the first section, Similarly, the one of
the secondary slot 164 and secondary rung 107 provided on
each of the second section 120 is located on the rails 126
of the second section spaced longitudinaLly from the element
of the lower ~uncture L on the remote side of the lower
juncture L from the second end 124 of the second section.
The coupling sequence of each of the embodiments
of Figures 7 to 10 is substantially the same as that
described with respect to the first embodiment. Firstly,
the primary rung 109 is engaged in primary slot 138 and
the sections are moved longitudinally with respect to each
other so that primary rungs 109 engages the blind end 140
of the primary slot~ Secondly, the first section is then
rotated about primary rung 109 until rotation is stopped
by secondary rung 107 contacting stopping surfaces designated
generally as 105 proximate the slot opening 168 of secondary
slot 164. Rotation is stopped in a position in which rung
107 is in alignment to enter secondary slot 164 by substan-
tially longitudinal sliding of the two sections, Thirdly,
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the first section is slid su~stantially longitudinally with
respect to the second section in a direction to move the
primary rung 109 away from engagement with blind end 140
whereby secondary rung 107 enters secondary slot 164 and
becomes in engagement with blind end 166 thereof preventing
further longitudinal sliding of the first section with
respect to the second section in that direction. As may
be seen in each of Figures 7 to 10, with the secondary
rung 107 engaging blind end 166 of the secondary slot,
the primary rung 109 remains within primary slot 138 so
as to prevent relative rotation of the first section 110
with respect to the second section 120.
In discussing the embodiments of Figures 7 to 10,
the terms upper and lower junctures have been used. It is
to be appreciated however that each of the embodiments
illustrated may be used in an inverted position from their
orientations shown in the figures. Further, in each of
Figures 7, 8 and 10, the rails 126 of the second section
120 have been shown to be spaced wider than the rails 116
of the first section 110, By the use of suitable rung
pro~ectionson any of rungs 107 and 109, the rails of the
first section may be provided in modified embodiments to
be spaced wider than the rails 126 of the second section.
Similar changes could be made regarding the embodiment
of Figure 9. For the purpose of clear illustration, the
embodiments of Figures 7 to 10 has been shown schematically
and preferably the inside surfaces of one set of the rails
would closely engage the outside surfaces of the other set
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of the rails to provide additional stability.
Reference is now made to Figure 11 which shows
a sixth embodiment in accordance with the present invention.
The embodiment of Figure 11 is similar in many respects
to that of Figure 1 and like numerals are used to refer
to similar elements. The second section 2~ of Figure 11
differs from the second section of Figure 1 only in the
elimination of end cap 30 as shown in Figure 1 leaving
a simple squared end cap 31 on the first end 22 of the
second section 20 of Figure 11. The first section 10 of
- Figure 11 is identical to the first section of Figure 1
with the exception that post 50 has been replaced by a
socket means generally designated 90. The socket means
90 comprises a slot-like socket recess 92 sized to permit
entry therein of square end cap 31, The socket recess 92
has a blind end provided by end plate 94 and an open
end. Near the open end, a stop plate 98 is provided.
The sequence of coupling the embodiment of
Figure 11 is substantially the same as that for Figure 1.
With rung 29 engaging the blind end 40 of primary slot 38,
the first section 10 may be rotated about rung 29 until
stop plate 98 contacts end cap 31 stopping rotation at a
position in which end cap 31 is in alignment for sliding
into socket recess 92, The first section is then slid
longitudinally with respect to the second section with
end cap 31 to slide into socket recess 92 until end cap
31 contacts end plate 94 preventing further longitudinal
movement.
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Only the first embodiment shown in Figures 1 to 4
has been illustrated with a locking mechanism. While the lock-
ing mechanism of the first embodiment is preferably, many
other locking mechanisms may be used. For example, in the
embodiment of Figure 11, complementary transversely extending
holes could be provided through socket means 90 and end
cap 31 so that in a coupled position a pin or bolt could
be insertea therein to lock the sections together, Further,
the pin could be permanently mounted on the socket means
90 and be biased to a locking position by means of a spring,
possibly with a cam-like ramp being provided on end cap 31
to permit automatic movement of the biased pin into the
hole in the end cap 31 on end cap 31 being slid longitudinally
into socket means 90,
Preferably, the ladder sections as shown in all .
the embodiments of this application may be constructed from
fiberglass or fiber reinforced resin, Many other materials
are suitable for example wood and aluminum, Suitable
frictional engaging means may be provided on the ends of
the ladder section to provide frictional engagement with
surfaces to be contacted, for example the ground and the
side of a building to assist in preventing a ladder
from sliding in use~ For example, if end cap 30 comprises
fiberglass a rigid rubber pad may be attached to the under-
surface of extension 70, Possibly this underpad may extend
laterally beyond each rail 26 internally thereof to provide
increased contact surface and in which case in some embodi-
ments the rubber pad may double as stop means to contact
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rails 16 and stop rotation thereof at a positi.on for coupling,
Although the disclosure describes and illustrates
preferred embodiments of the invention~ it is to be under-
stood that the invention is not limited to these particular
embodiments. Many variations and modifications will now
occur to those skilled in the art, For a definition of the
invention reference is made to the appended claims.
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