[0001] This invention refers to a new fold-up ladder.
[0002] The fold-up ladders presently known on the market consist of sections of several
treads which are almost of the same length as that of the main" strut of the portable
ladder itself, to which it backs. These addition sections are linked by clamps to
the couple of main struts between which the treads are placed.
[0003] These clamps secure the struts of the main and secondary sections allowing the longitudinal
extension of this secondary section along the main one to the allowed length and its
securing required by means of anchorage of one section in relation to the other. Another
design consists in linking both sections, main and secondary, on their ends by a hinged
joint. Nevertheless, this other solution is less reliable for the use of the ladder,
as the securing lugged nut has to exert a great pressure in the aligned position in
order to avoid the collapsing of the end of the ladder once it has been subject to
the load of the person stepping on the additional top section, the effect of which
load is still aggravated by the increase originated by the lever arm of the lengthening
section itself. Therefore, this design is still less safer than the first one. Nevertheless,
both designs show the drawback of the difficulty of handling of collapsible ladders,
as well as that of their weightness and that of requiring too much space when not
in use, specially if they have to be carried from one working site to another, as
they usually do not fit into small cars.
[0004] To avoid this drawback, the subject of the present invention has been designed, thanks
to which the ladder consists of as many different sections as treads compose it, being
hinged one to that immediately following it upwards in dimensions, all of them being
inscribed in the lowermost tread or section of dimensions greater than all the remaining
components of the ladder. In this manner, when the ladder has been folded down, the
same consists of a multiplicity of tread sections inscribed the ones inside the others,
the whole constituting an assembly easy to taking on shoulders by passing the arm
through the central orifice in the same manner as a roll of rope is borne.
[0005] On the other hand, this design also allows it to place the folded-down ladder inside
the luggage compartment of passenger cars. In order to allow a better understanding,
a practical embodiment is described beneath, as an example only, with no limitative
character, of the new fold-up ladder, with reference to the annexed drawings. Figure
1 shows diagrammatically a ladder built in accordance with the invention, unfolded
so that every section is aligned with respect to the foregoing one, being fixed through
the corresponding rectractable securing fasteners, whilst figure 2 shows the same
ladder, after having capsized its sections and folded them down completely, being
carried by the user on his shoulder.
[0006] The invention consists in the ladder being made up of a multiplicity of "U"-shaped
modules, showing the shape of a rectangular frame lacking of one of the smaller sides
(2), each of which frames has its two arms hinged in (3) to both arms of the following
smaller module, for wwhich reason, in the folded position, every module (1) of the
ladder is inscribed inside the frame of the foregoing one, except the largest (lA)
corresponding to one end of the ladder, and by swinging them, the modules (1) become
alternatively placed in such a position with respect the ones the others that the
ends of the arms of one group of modules face the ends of the arms of the other group
of modules, all them becoming placed in the same plane, out of which they are taken
at the user's will by pulling the last smallest module (lB) upwards, so that the assembly
of modules (2) advances up to a certain limit, after which every module (1) is swung
around itself for 180° with reference to the former, so that all the modules (1) become
aligned to each other, by keying elements (4) arranged on each module so that in the
aligned position of the greater lateral struts, the keying elements of one of the
individual frames introduce in the orifices arranged in the lateral struts of the
aligned opposite module, the treads of the latter therefore forming the own bases
(5) of every "U"-shaped module.
[0007] It is understood that in the present case, every detail of construction and finish,
that shall not alter, change or modify the essentially of the invention, shall be
considered as variants.
New fold-up ladder, characterized by consisting of a multiplicity of "U"-shaped modules
in the manner of a rectangular frame lacking of one of its smaller sides (2), each
of which frames has its two arms hinged in (3) to both arms of the following smaller
module, for which reason, in the folded position, every module (1)of the ladder is
inscribed inside the frame of the foregoing one, except the largest (lA) corresponding
to one end of the ladder, and by swinging them, the modules (1) become alternatively
placed in such a position with respect the ones the others that the ends of the arms
of one group of modules face the ends of the arms of the other group of modules, all
them becoming placed in the same plane, out of which they are taken at the user's
will by pulling the last smallest module (lB) upwards, so that the assembly of modules
(1) advances up to a certain limit after which every module is swung around itself
for 180° with reference to the former, so that all the modules become aligned to each
other, by keying elements (4) arranged on each module so that in the aligned position
of the greater lateral struts, the keying elements of one of the individual frames
introduce in the orifices arranged in the lateral struts of the aligned opposed module,
the treads of the ladder therefore forming the own bases (5) of every "U"- shaped
module.
