[0001] The present invention relates to a portable ladder.
[0002] Portable ladders are known which have at least one pair of stringers which are substantially
parallel and face each other and are mutually connected by a plurality of rungs which
extend transversely to the stringers and are provided, at the end of the stringers
that is designed to be directed downward, with a stabilizing bar, which extends transversely
and is longer than the rungs, so as to protrude laterally, with its opposite end portions,
with respect to the stringers and is provided, at the corresponding ends, with resting
elements, typically constituted by pads made of elastically yielding material.
[0003] According to the background art, in order to fix the stabilizing bar to the stringers,
two through holes are provided in the body of the stabilizing bar so as to obtain
a pair of connecting holes, each of which is designed to be engaged by a respective
screw for connection to a corresponding stringer.
[0004] The drawback of the background art described above resides in that each ladder in
production requires, depending on its ramp width, i.e., the distance between its stringers,
the provision of connecting holes with a different center distance, with an obvious
complication of the work, in addition to requiring considerable store reserves of
stabilizing bars with mutually different holes.
[0005] The aim of the present invention is to provide a portable ladder that is capable
of improving the background art in one or more of the aspects indicated above.
[0006] Within this aim, an object of the invention is to provide a portable ladder that
allows to provide in an extremely practical manner the fixing of the stabilizing bar
to the stringers for different widths of the ramp of the ladder and of the cross-sections
of the stringers.
[0007] Another object of the present invention is to provide a portable ladder that can
be obtained easily with a small number of practical assembly operations.
[0008] Another object of the invention is to provide a portable ladder which, by virtue
of its particular constructive characteristics, is capable of giving the greatest
assurances of reliability and safety in use.
[0009] Another object of the present invention is to provide a portable ladder that can
be provided with a stabilizing bar that can be equipped with accessories and can also
be applied to other ladders of a different size, even already in use.
[0010] Another object of the present invention is to provide a portable ladder which, in
addition to being constructively simple to provide, can be obtained at highly competitive
costs.
[0011] This aim, as well as 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.
[0012] Further characteristics and advantages of the invention will become better apparent
from the description of a preferred but not exclusive embodiment of the portable ladder
according to the invention, illustrated by way of nonlimiting example in the accompanying
drawings, wherein:
Figure 1 is a perspective view of the ladder according to the invention;
Figure 2 is a front view of the ladder;
Figure 3 is a lateral elevation view of the ladder according to the invention;
Figure 4 is a partial perspective view of the ladder according to the invention, shown
exploded in order to show various components thereof;
Figures 5 and 6 are perspective views of a sequence of steps of the assembly of the
ladder according to the invention;
Figure 7 is a sectional view, taken along the line VII-VII of Figure 3;
Figure 8 is a view of the step of the assembly of the stabilizing bar of the ladder
according to the invention.
[0013] With reference to the cited figures, the portable ladder according to the invention,
designated generally by the reference numeral 1, comprises at least one pair of stringers
2a, 2b, which are substantially parallel and face each other and are mutually connected
by a plurality of rungs 3, which extend transversely to the stringers 2a, 2b and are
arranged so as to be mutually evenly spaced along the extension of the stringers 2a,
2b.
[0014] Substantially at one end of the stringers 2a, 2b and more precisely at their end
that is designed to be directed downward, there is a stabilizing bar 4, which extends
substantially at right angles to the stringers 2a, 2b.
[0015] As shown, the end portions of the stabilizing bar 4 advantageously protrude laterally
outward on mutually opposite sides with respect to the stringers 2a, 2b.
[0016] According to the invention, the stabilizing bar 4 comprises a base profiled body
5, preferably made of metallic material, and at least one auxiliary body 6, which
is coupled to the base profiled body 5 and is provided with a plurality of connection
seats 7 which can be engaged selectively by fixing means 8 which allow the connection
of the stringers 2a, 2b to the stabilizing bar 4.
[0017] It should be noted that the connection seats 7 are already formed in the auxiliary
body 6 when it is coupled to the base profiled body 5.
[0018] Advantageously, the auxiliary body 6 is provided by at least one strip 9 which has
an extension that is substantially parallel to the longitudinal extension of the base
profiled body 5 and in which there are at least two pairs of connection seats 7 which
have a mutually different center distance along the extension of the stabilizing bar
4.
[0019] Each one of the pairs of connection seats 7 can be engaged selectively by the fixing
means 8 as a function of the distance between the stringers 2a and 2b, i.e., of the
ramp width of the ladder.
[0020] In practice, the various pairs of connection seats 7 formed in the strip 9 allow
the fixing to the stabilizing bar 4 of stringers 2a and 2b arranged at a mutually
different distances, so as to allow the provision of ladders with different ramp widths.
[0021] Advantageously, the connection seats 7 of each one of the pairs of connection seats
7 that are present on the strip 9 are arranged symmetrically with respect to a central
plane of symmetry of the stabilizing bar 4 that extends substantially at right angles
to the longitudinal axis of said stabilizing bar.
[0022] Advantageously, the strip 9 is made of plastic material by molding, so as to have,
already at the output from the mold, the connection seats 7. The strip 9 can also
be provided by a bar or a plate which is provided with holes beforehand, is made of
metal or other material, and the holes of which provide the connection seats 7.
[0023] Conveniently, the fixing means 8 comprise screws 10 which can be engaged in nuts
11 accommodated in the connection seats 7.
[0024] Conveniently, the base profiled body 5 is crossed axially by at least one longitudinal
channel 12, which is open, by means of a window 13, onto at least one lateral face
5a of the base profiled body 5 and is designed to accommodate actually the auxiliary
body 6.
[0025] More particularly, as in the illustrated embodiment, the strip 9 has at least one
flat face 9a, which is crossed by the connection seats 7 and is arranged, with its
portion provided with the connection seats 7, at the window 13 formed in the base
profiled body 5, so as to allow access from the outside of the base profiled body
5 to the connection seats 7 of the strip 9.
[0026] Conveniently, at least the portion of the flat face 9a of the strip 9 in which the
connection seats 7 are formed is in relief with respect to the longitudinal edges
of said strip and is at least partially inserted through the window 13.
[0027] Advantageously, there are locking means which allow to lock stably the auxiliary
body 6 with respect to the base profiled body 5.
[0028] In particular, as shown, the locking means are conveniently provided by virtue of
means 15 for closing the ends of the longitudinal channel 12 and spacer means which
can be interposed between said closure means of the longitudinal channel 12 and the
auxiliary body 6.
[0029] Advantageously, the closure means 15 are constituted by a pair of closure pads 15a,
which can be coupled to the ends of the base profiled body and are made for example
of rubber or the like and can be provided appropriately with ground resting feet 15b
for the stabilizing bar 4.
[0030] Conveniently, the spacer means comprise at least one pair of spacer bars 16, each
of which can be accommodated in the longitudinal channel 12 between a respective end
of the auxiliary body 6 and the closure means.
[0031] The shape in transverse cross-section of the spacer bars 16 can be substantially
identical to that of the strip 9 and their length will vary as a function of the length
of the base profiled body 5 and therefore of the stabilizing bar 4.
[0032] In particular, the manufacturer of the ladder may use a provision of multiple pairs
of spacer bars 16 of different length which can be interposed selectively, during
the assembly of the ladder, between the auxiliary body 6 and the closure means depending
on the length of the stabilizing bar 4 to be applied to the ladder.
[0033] It should be noted that in the illustrated embodiment two auxiliary bodies 6 are
coupled to the base profiled body 5 and each is provided with respective connection
seats 7 for the engagement of means 8 for fixing to a corresponding portion of the
stringers 2a, 2b.
[0034] More particularly, according to the illustrated embodiment, in the base profiled
body there are two longitudinal channels 12 which are substantially mutually parallel,
each of which is open, by means of a respective window 13, onto the mutually opposite
lateral faces 5a of the base profiled body 5.
[0035] A respective strip 9 is accommodated in each one of said longitudinal channels 12
and is provided with corresponding pairs of connection seats 7 and is locked in a
substantially central position with respect to the longitudinal extension of the stabilizing
bar 4 by a respective pair of spacer bars 16 and by the pads 15a, which, in this case,
allow to close the ends of both longitudinal channels 12.
[0036] Again according to the illustrated embodiment, each stringer 2a, 2b has, at its end
designed to be connected to the stabilizing bar 4, a respective pair of tabs 17a and
17b, which are mutually opposite and face each other and between which the base body
5 is interposed, facing them with its lateral faces 5a.
[0037] Each tab 17a, 17b is crossed by a corresponding through hole 18, which is engaged
by a respective screw 10, which, by means of its head 10a, is designed to abut, appropriately
by means of the interposition of a respective washer 19, against the external face
of the corresponding tab 17a and 17b and which, with its threaded stem, screws into
the nut 11 of one of the connection seats 7 formed in the corresponding strip 9.
[0038] From what has been described above it is evident that the portable ladder according
to the invention allows easy assembly of the stabilizing bar 4 to the stringers 2a,
2b.
[0039] In fact, in order to assemble the stabilizing bar 4 to the stringers 2a, 2b it is
sufficient to couple the auxiliary bodies 6, already provided with multiple connection
seats 7, to the base profiled body 5 and, after locking the auxiliary bodies 6 to
the base profiled body 5, fix the stabilizing bar to the stringers 2a and 2b, engaging
the fixing means 8 in the connection seats 7 which allow the arrangement of the stringers
2a and 2b at the desired mutual distance.
[0040] More particularly, with reference to the illustrated embodiment, in order to assemble
the stabilizing bar 4 to the stringers 2a and 2b one proceeds initially by inserting
in each one of the longitudinal channels 12 of the base profiled body 5 a respective
strip 9 in which the connection seats 7 are predefined and by inserting, as shown
by Figure 8, in the longitudinal channels 12, through their opposite ends, respective
pairs of spacer bars 16, of a suitable length depending on the length of the base
profiled body 5, so as to occupy the space that is present in the longitudinal channels
12 between the strips 9 and the ends of the longitudinal channels 12, which in turn
are subsequently closed, coupling the pads 5a to the ends of the base profiled body
5.
[0041] At this point the base profiled body 5 is inserted between the tabs 17a, 17b of the
stringers 2a, 2b and the through holes 18 of their tabs 17a, 17b are arranged so as
to be aligned with the connection seats 7 that are present in the strip 9 and have
a mutual center distance that corresponds to the mutual distance between the stringers
2a, 2b.
[0042] In order to complete assembly, one then proceeds by inserting, through the through
holes 18 of the tabs 17a, 17b, respective screws 10, which by acting on their head
10a, with an adapted tool, such as for example an Allen key, as shown by way of example
by Figure 6, are screwed into the nuts 11 arranged in the connection seats 7 that
are aligned with the through holes 18.
[0043] In practice it has been found that the invention achieves the intended aim and objects,
providing a portable ladder that does not require providing holes with a different
center distance depending on the width of the ladder itself in order to provide the
fixing of the stabilizing bar.
[0044] The invention thus conceived is susceptible of numerous modifications and variations,
all of which are within the scope of the appended claims.
[0045] Thus, for example, nothing forbids the portable ladder from being provided with two
pairs of stringers which are mutually pivoted at their upper end and/or stringers
that can be folded by means of joints interposed along their axial extension.
[0046] All the details may furthermore be replaced with other technically equivalent elements.
[0047] In practice, the materials used, so long as they are compatible with the specific
use, as well as the contingent shapes and dimensions, may be any according to the
requirements and the state of the art.
[0048] The disclosures in Italian Patent Application No.
102018000001570 from which this application claims priority are incorporated herein by reference.
[0049] 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 pair of stringers (2a, 2b), which face each
other and are mutually connected by a plurality of rungs (3), which extend transversely
to said stringers (2a, 2b) and are mutually spaced along the extension of said stringers
(2a, 2b), and provided, substantially at one end of said stringers (2a, 2b), with
a stabilizing bar (4), which extends substantially at right angles to said stringers
(2a, 2b), characterized in that said stabilizing bar (4) comprises a base profiled body (5) and at least one auxiliary
body (6), which is coupled to said base profiled body (5) and is provided with a plurality
of connection seats (7) which can be engaged selectively by means (8) for fixing said
stringers (2a, 2b) to said stabilizing bar (4).
2. The portable ladder according to claim 1, characterized in that said auxiliary body (6) comprises at least one strip (9) which has an extension that
is substantially parallel to the longitudinal extension of said base profiled body
(5) and forms at least two pairs of connection seats (7), which have a different mutual
center distance along the extension of said stabilizing bar (4).
3. The portable ladder according to one or more of the preceding claims, characterized in that the connection seats (7) of each one of said pairs of connection seats (7) are arranged
symmetrically with respect to a central plane of symmetry of said stabilizing bar
(4) which is substantially perpendicular to the axis of said stabilizing bar (4),
each one of said pairs of connection seats (7) being selectively engageable by said
fixing means (8) as a function of the distance provided between said stringers (2a,
2b).
4. The portable ladder according to one or more of the preceding claims, characterized in that said fixing means (8) comprise screws (10) which can engage in nuts (11) accommodated
in said connection seats (7).
5. The portable ladder according to one or more of the preceding claims, characterized in that it comprises means for locking said at least one auxiliary body (6) with respect
to said base profiled body (5).
6. The portable ladder according to one or more of the preceding claims, characterized in that said base profiled body (5) is crossed axially by at least one longitudinal channel
(12), which is open on at least one lateral face (5a) of said base profiled body (5)
and accommodates axially said at least one auxiliary body (6).
7. The portable ladder according to one or more of the preceding claims, characterized in that said locking means comprise means for closing the ends of said at least one longitudinal
channel (12) and spacer means which can be interposed between said closure means and
said at least one auxiliary body (6).
8. The portable ladder according to one or more of the preceding claims, characterized in that said spacer means comprise at least one pair of spacer bars (16), each of which can
be accommodated in said at least one longitudinal channel (12) between a respective
end of said at least one auxiliary body (6) and said closure means.
9. The portable ladder according to one or more of the preceding claims, characterized in that it comprises a plurality of pairs of said spacer bars (16) of different length which
can be interposed selectively between said at least one auxiliary body (6) and said
closure means as a function of the length of said stabilizing bar (4).
10. The portable ladder according to one or more of the preceding claims, characterized in that said strip (9) is made of plastic material by molding.
11. A method for assembling a portable ladder, characterized in that it comprises the steps of providing a stabilizing bar (4), coupling to a base profiled
body (5) at least one auxiliary body (6) which is already provided with a plurality
of connection seats (7), and fixing said stabilizing bar (4) to a pair of stringers
(2a, 2b) by virtue of fixing means (8), engaging said fixing means (8) with at least
one pair of said connection seats (7) which is selected according to the mutual distance
between said stringers (2a, 2b).