[0001] The invention relates to a universal ladder.
[0002] Ladders known as "universal ladders" are known and are extremely common; such ladders
comprise two ramps each formed by two longitudinal support members with a plurality
of rungs and are connected at the top by two articulated joints located at the ends
of the adjoining longitudinal members; ladders of this type can be considered to be
present in nearly every family or work group.
[0003] Reverting now to the aforementioned articulated joints in more detail, it can be
observed that such joints each comprise a male shell and a female shell fixed to the
end of each of the adjoining longitudinal members and reciprocally hinged in different
ways, and in the most common form such male and female shells are made of cast aluminum
alloy which ensures a reduced weight and a permanence of surface conditions in a substantially
immutable state for the entire life of the ladder.
[0004] However, aluminum alloy is not optimal in terms of resistance characteristics, and
it is therefore possible for the articulated joints to break, with consequent dislocation
of the structure of the ladders and falling of the user, the weight of whom has determined
the breakage.
[0005] As a result, ladders were devised being fitted with articulated joints made of steel,
therefore having high resistance characteristics, but not sufficient to ensure durability
in environments, such as marine environments, that have particularly corrosive atmospheres.
[0006] The aim of the present invention is to devise a universal ladder that is fitted with
articulated joints that ensure high resistance characteristics, thus being substantially
weatherproof at the surface layer.
[0007] This aim is achieved by a universal ladder, according to the invention, comprising
two ramps connected at the top by two articulated joints each of which in turn comprises
a male shell and a female shell reciprocally hinged and made of cast aluminium alloy,
characterised in that in each shell an insert made of highly-resistant material is provided.
[0008] Further characteristics and advantages will become better apparent from the description
of a preferred, but not exclusive, embodiment of the invention, illustrated by way
of a non-limiting example in the accompanying drawings wherein:
Figure 1 shows a general view of the ladder;
Figure 2 shows the two shells comprised in an articulated joint according to the invention,
with a dotted line indicating the insert, the figure further showing the inserts provided
in each shell;
Figure 3 shows the male shell;
Figure 4 is a sectional view taken along the line IV-IV of Figure 3.
[0009] With reference to the figures, the reference numeral 1 globally indicates a universal
ladder comprising two ramps 2 and 3 connected at the top by two articulated joints
indicated with 4 and 5.
[0010] More specifically, the ramps 2 and 3 each respectively comprise two longitudinal
members 2a, 2b and 3a, 3b that support a plurality of rungs 2c, 3c, and the two articulated
joints 4 and 5 are respectively located at the ends of the pairs of adjoining longitudinal
members 2a, 3a and 2b, 3b.
[0011] The two articulated joints 4 and 5 are identical, and therefore only the articulated
joint 4 will be described in detail.
[0012] The articulated joint 4 comprises a male shell 4a and a female shell 4b fixed to
the ends of the longitudinal members 2a, 3a respectively, and are reciprocally hinged
by means of a stay rod 4c.
[0013] The shells 4a, 4b are made as usual from cast aluminum alloy, and, according to the
main feature of the invention, each has inside it an insert made from highly-resistant
material, which can typically be steel.
[0014] In this way the male shell 4a features the insert 6 which is visible inside the shell
in figures 2, 3, 4, and which, for better comprehension, is also shown outside the
shell, again in figure 2.
[0015] In the same way the female shell 4b comprises an identical insert 7 inside it.
[0016] Such inserts 6 and 7 have holes 6a, 6b which favour the complete coupling to the
surrounding aluminum alloy, and are shaped in such a way as to be congruous with the
functionality of the shells inside which such inserts are enclosed and which, as described
hereinbefore, can be reciprocally hinged in different ways.
[0017] Thus, a universal ladder has been devised being fitted with articulated joints, that
is capable of providing users with maximum safety, while at the same time ensuring
the maintenance of the surface layer at an optimum level.
[0018] The invention thus conceived is susceptible of numerous modifications and variations,
all of which are within the scope of the appended claims.
[0019] The disclosure in Italian Utility Model No.
MI2009U000209 from which this application claims priority are incorporated herein by reference.
[0020] 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 universal ladder (1), comprising two ramps (2, 3) connected at the top by two articulated
joints (4, 5) each of which in turn comprises a male shell (4a) and a female shell
(4b) reciprocally hinged and made of cast aluminum alloy, characterised in that each shell is provided with an insert (6, 7) made of highly-resistant material.
2. The universal ladder according to claim 1, characterised in that the insert (6, 7) inside each shell (4a, 4b) is made of steel.