[0001] The present invention relates to a portable ladder.
[0002] As is known, portable ladders are generally constituted by at least one section which
provides at least one ramp, normally formed by a pair of side rails that are substantially
parallel and mutually laterally spaced apart and which are mutually joined together
by a plurality of steps or rungs, which are arranged transversely to the side rails
and are uniformly mutually spaced apart along the longitudinal extension of these
side rails.
[0003] The lower end of the side rails is typically provided with rubber pads that act as
an element for resting the ladder on the ground or on the floor during its use.
[0004] Likewise, double portable ladders are known, also called stepladders, which have
a pair of mutually opposing sections, at least one of which is constituted by a ramp.
[0005] In this case, the sections of the ladder are mutually articulated in an upward region,
so as to allow the transition of the ladder from an extended condition for use, in
which the two sections are mutually spaced apart, so as to render the ladder stable,
thus allowing ascent, to a folded condition for storage, in which the two sections
are mutually brought together, in order to allow convenient transport and storage
after use of the ladder, and vice versa.
[0006] It is also known that, in order to ensure a greater stability for ladders of this
type, cross-bars are usually mounted in the lower part of the sections of the ladder,
in place of the more usual rubber pads, and protrude laterally with respect to the
side rails so as to widen the resting zone of the ladder on the floor with respect
to the transverse dimension of the sections themselves, until it reaches the dimensions
required by European regulations.
[0007] However, cross-bars are rather cumbersome and relatively inconvenient to use, if,
for example, the floor or the ground on which the ladder is placed is uneven.
[0008] In fact, with their intermediate portion, cross-bars occupy the space between the
lower ends of the side rails, thus constituting an obstacle to the free placement
of the ladder, if there are height differences on the ground or on the floor, as well
as an obstacle for the feet of the user, which can easily collide with the cross-bars
when moving the ladder.
[0009] The aim of the present invention is to provide a portable ladder that is capable
of improving the known art in one or more of the above mentioned aspects.
[0010] Within this aim, an object of the invention is to provide a portable ladder that
is capable of offering the highest guarantees of stability using elements with reduced
encumbrance.
[0011] Another object of the invention is to provide a portable ladder that is of practical
use even with uneven floors.
[0012] Another object of the invention is to provide a stabilizer device for portable ladders
that can also be used on existing ladders, in substitution of the traditional resting
elements fitted to those ladders, in order to make the ladders according to the invention
more stable during their use.
[0013] A further object of the invention is to provide a portable ladder that can comply
fully with meet the latest regulations on ladders.
[0014] A still further object of the present invention is to overcome the drawbacks of the
background art in a manner that is alternative to any existing solutions.
[0015] Another object of the invention is to provide a portable ladder that is highly reliable
and easy to implement, and which can be produced at low cost.
[0016] This aim and these and other objects which will become better apparent hereinafter
are achieved by a portable ladder according to claim 1, optionally provided with one
or more of the characteristics of the dependent claims.
[0017] Further characteristics and advantages of the invention will become better apparent
from the detailed description that follows of a preferred, but not exclusive, embodiment
of the portable ladder according to the invention, which is illustrated for the purposes
of non-limiting example in the accompanying drawings wherein:
Figure 1 is a perspective view of a portable ladder according to the invention;
Figure 2 is an enlarged-scale perspective view of the lower part of the ladder according
to the invention;
Figure 3 is a partially transparent perspective view of a portion of the ladder according
to the invention, with a stabilizer device applied;
Figure 4 is a partially transparent perspective view of a portion of the ladder according
to the invention, with the stabilizer device shown cut away;
Figure 5 is a front elevation view of the stabilizer device applied to the ladder
according to the invention;
Figure 6 is a side view of the stabilizer device applied to the ladder according to
the invention;
Figure 7 is a cutaway side view of the stabilizer device applied to the ladder according
to the invention;
Figure 8 is a partially exploded perspective view of a portion of the ladder according
to the invention;
Figure 9 is a partially exploded front elevation view of a portion of the ladder according
to the invention;
Figure 10 is a cross-sectional view taken along the line X-X of Figure 9.
[0018] With reference to the figures, the portable ladder according to the invention, generally
designated by the reference numeral 1, comprises at least one section 2 which has
a pair of side rails 3a, 3b which are mutually laterally spaced apart and are mutually
joined by a plurality of steps 4, which are arranged mutually spaced apart along the
longitudinal extension of the side rails 3a, 3b.
[0019] The portable ladder comprises at least one stabilizer device 5 which can be associated
with the lower end of a respective side rail 3a, 3b and which is provided with a coupling
portion 5a, which can be fixed to the respective side rail 3a, 3b, and with a resting
portion 5b, which is designed to be rested on the ground or the floor on which the
ladder is used and extends from the coupling portion 5a, laterally outward with respect
to the respective side rail 3b, from the side opposite from the side on which the
steps 4 are arranged.
[0020] Also according to the invention, the stabilizer device 5 further comprises at least
one interconnection portion 5c, which preferably is shaped like a bridge or buttress
or, more generally, like an arch, and which extends above the resting portion 5b,
substantially between the free end of the resting portion 5b, opposite the end connected
to the coupling portion 5a, and the respective side rail 3a, 3b, in such a way as
to be able to transmit at least partially the loads bearing down on the free end of
the resting portion 5b to the corresponding side rail 3a, 3b, thus conferring greater
rigidity on the stabilizer device 5 and, as a consequence, greater stability on the
ladder itself.
[0021] In particular, the interconnection portion 5c acts, conveniently, on a region of
the corresponding side rail 3a, 3b that is, in an upward region, spaced apart from
the connecting region between the coupling portion 5a and the resting portion 5b of
the stabilizer device 5.
[0022] Preferably, the ladder according to the invention is provided with at least one pair
of stabilizer devices 5, each one of which can be associated with the lower end of
a respective side rail 3a, 3b of that ladder.
[0023] In more detail, the coupling portion 5a of the or of each stabilizer device 5 has
a male shape structure and can be inserted into a correspondingly shaped female receptacle
6 which is defined axially in the corresponding side rail 3a, 3b and, in practice,
is constituted by the inner cavity of the profiled element that forms the side rail
3a, 3b.
[0024] In particular, the coupling portion 5a has an elongated extension along a direction
substantially parallel to the corresponding side rail 3a, 3b, so that, inserted in
the female receptacle 6, it can engage a longitudinal portion of the corresponding
side rail 3a, 3b.
[0025] Conveniently, the coupling portion 5a and, correspondingly, also the female receptacle
6 have, in transverse cross-section, a substantially polygonal shape, open or, optionally,
closed, so that, with the coupling portion 5a inserted in the female receptacle 6,
the relative rotation is prevented of the coupling portion 5a with respect to the
corresponding side rail 3a, 3b about an axis parallel to the axis of the side rail
itself.
[0026] To ensure the axial locking of the coupling portion in the female receptacle 6 of
the corresponding side rail 3a, 3b of the ladder, so as to prevent the extraction
thereof, there are one or more fixing elements 7, which can engage with the coupling
portion 5a and with the corresponding side rail 3a, 3b.
[0027] These fixing elements 7 are, conveniently, each provided by a screw 7a which can
be locked, using a corresponding lock nut 8, in respective holes 9 provided in the
side rail 3a, 3b and in a respective accommodation seat 10, which is defined in the
coupling portion 5a, in a position substantially coincident with the holes 9, and
which extends substantially transversely to the longitudinal extension of the coupling
portion.
[0028] Conveniently, each stabilizer device 5 has, between the coupling portion 5a and the
interconnection portion 5c, an accommodation interspace 11 for the wall of the corresponding
side rail 3a, 3b that is directed outward with respect to the steps 4 of the ladder.
[0029] Advantageously, protruding inward into the interspace 11 from the face of the coupling
portion 5a that is directed toward the interconnection portion 5c is a longitudinal
ridge 12, which extends upward from the resting portion 5b and is designed to be inserted
in a longitudinal slit 13 defined in the corresponding side rail 3a, 3b, starting
from the lower end of the latter.
[0030] Preferably, each stabilizer device 5 is constituted by a body made of plastic material
14, inside which a metal reinforcement core 15 is embedded.
[0031] Conveniently, the reinforcement core 15 has a substantially plate-like structure
with defined portions designed to be arranged at the coupling, resting, and interconnection
portions 5a, 5b, 5c of the stabilizer device 5, and is provided with through openings
16 and edges 17 that are folded back in order to increase the grip thereon of the
plastic material that makes up the body 14 of the stabilizer device 5.
[0032] Advantageously, at least at the resting portion 5b, each stabilizer device is provided
with a covering 18 made of elastically yielding material, in order to ensure a greater
friction with the surface of the ground or of the floor on which the ladder is used.
[0033] Conveniently, the body 14 made of plastic material can be provided by injection molding
around the reinforcement core 15 and the covering 18 can, in turn, be provided by
co-molding with the body 14.
[0034] It should be noted that the ladder according to the invention can optionally comprise
a pair of mutually opposite sections 2, which are mutually articulated in an upward
region, so as to permit the transition of the ladder from an extended condition for
use to a folded condition for storage and vice versa, via a book-like movement. One
of the two sections 2, or indeed both, are provided with steps so as to make a respective
ramp of the ladder.
[0035] As shown in Figure 1, it is also possible for the ladder to comprise, for example,
four sections 2, of which two are lower and are intended to be placed on the floor
and at least one of these is provided with at least one stabilizer device 5, and two
are upper and are mutually articulated and each one is mounted so that it can slide
on a corresponding lower section 2.
[0036] Conveniently, the side rails 3a, 3b of the lower sections 2 of the ladder can have,
in turn, lower portions that mutually splay, proceeding downward from above.
[0037] Use of the ladder according to the invention is the following.
[0038] If greater stability of the ladder is required, at least one of the rubber pads present
at least at the lower end of the side rails 3a and 3b of the lower section 2 of the
ladder which forms a ramp is removed, in order to replace it with a stabilizer device
5.
[0039] The coupling portion 5a of the stabilizer device 5 is then inserted axially in the
female receptacle 6 defined in the corresponding side rail 3a, 3b, so as to insert,
in turn, the wall of the side rail 3a, 3b that is directed outward in the interspace
11 and the ridge 12 in the slot 13 provided in the side rail 3a, 3b.
[0040] At this point, the screws 7a are inserted in the respective holes 9 of the side rail
3a, 3b and in the corresponding accommodation seat 10, defined in the coupling portion
5a, and the corresponding lock nuts 8 are tightened, so as to ensure the locking of
the stabilizer device 5 to the corresponding side rail 3a, 3b, thus rendering the
ladder ready to be used in total safety.
[0041] During use of the ladder, the actions exerted on the resting portion 5b of the applied
stabilizer devices 5 and in particular on the free end thereof can positively be transmitted
to the side rails 3a, 3b by way of the interconnection portion 5c, thus ensuring an
excellent stability of the ladder.
[0042] Furthermore, even with the stabilizer devices 5 applied on both the side rails 3a,
3b of a lower section 2 of the ladder, the space between the lower ends of the side
rails 3a, 3b is still kept free, in this manner facilitating the use of the ladder
even on very uneven ground or floors.
[0043] In practice it has been found that the invention fully achieves the intended aim
and objects by providing a ladder that is capable of ensuring, by virtue of the peculiar
stabilizer devices with which it is provided, ease of use and excellent stability
even on very uneven ground or floors, as well as complying with the dimensional requirements
of European regulations.
[0044] The invention thus conceived is susceptible of numerous modifications and variations,
all of which are within the scope of the appended claims. Moreover, all the details
may be substituted by other, technically equivalent elements.
[0045] In practice the materials employed, provided they are compatible with the specific
use, and the contingent dimensions and shapes, may be any according to requirements
and to the state of the art.
[0047] Where technical features mentioned in any claim are followed by reference signs,
those reference signs have been included for the sole purpose of increasing the intelligibility
of the claims and accordingly, such reference signs do not have any limiting effect
on the interpretation of each element identified by way of example by such reference
signs.
1. A portable ladder comprising at least one section (2) which has a pair of side rails
(3a, 3b) which are mutually laterally spaced apart and are mutually joined by a plurality
of steps (4) which are arranged mutually spaced apart along the longitudinal extension
of said side rails (3a, 3b), characterized in that it comprises at least one stabilizer device (5) which can be associated with the
lower end of a respective side rail (3a, 3b) and is provided with a coupling portion
(5a), which can be fixed to the respective side rail (3a, 3b), and with a resting
portion (5b), which extends from said coupling portion (5a), laterally outward with
respect to the respective side rail (3a, 3b), said stabilizer device (5) comprising
at least one interconnection portion (5c), which extends above said resting portion
(5b), substantially between the free end of said resting portion (5b) and the respective
side rail (3a, 3b), in order to transmit at least partly the loads bearing down on
the free end of said resting portion (5b) to the corresponding side rail (3a, 3b).
2. The ladder according to claim 1, characterized in that it comprises at least one pair of stabilizer devices (5), each one associable with
a lower end of a respective side rail (3a, 3b).
3. The ladder according to one or more of the preceding claims, characterized in that said interconnection portion (5c) is shaped like a bridge or buttress.
4. The ladder according to one or more of the preceding claims, characterized in that said coupling portion (5a) has a male shape structure and can be inserted into a
correspondingly shaped female receptacle (6) which is defined axially in the corresponding
side rail (3a, 3b).
5. The ladder according to one or more of the preceding claims, characterized in that it comprises at least one fixing element (7) which can engage said coupling portion
(5a) and the corresponding side rail (3a, 3b) for the locking of said coupling portion
(5a) in said female receptacle (6).
6. The ladder according to one or more of the preceding claims, characterized in that said stabilizer device (5) has, between said coupling portion (5a) and said interconnection
portion (5c), an accommodation interspace (11) for the wall of the corresponding side
rail (3a, 3b) that is directed outward.
7. The ladder according to one or more of the preceding claims, characterized in that each stabilizer device (5) comprises a body (14) made of plastic material in which
a metal reinforcement core (15) is embedded internally.
8. The ladder according to one or more of the preceding claims, characterized in that each stabilizer device (5) has, at least at said resting portion (5b), a covering
made of elastically yielding material.
9. The ladder according to one or more of the preceding claims, characterized in that it comprises a pair of mutually opposite sections (2), which are mutually articulated
in an upper region.
10. A stabilizer device for portable ladders, which comprises a body which is configured
to be associated with a lower end of a side rail (3a, 3b) of a portable ladder, characterized in that it comprises a coupling portion (5a), which can be fixed to said side rail (3a, 3b),
and a resting portion (5b), which is designed to engage the ground and extends from
said coupling portion (5a) laterally outward with respect to said side rail (3a, 3b),
there being at least one interconnection portion (5c), which extends above said resting
portion (5b), substantially between the free end of said resting portion (5b) and
said side rail (3a, 3b), in order to transmit at least partly the loads bearing down
on the free end of said resting portion (5b) to said side rail (3a, 3b).