Longitudinally sliding accordion door

An accordion door includes two half-wings hinged along innermost vertically extending sides thereof, and pivotally supported at upper and lower ends of the outermost vertically extending sides of the door by arms which project from respective trucks slidably engaged with respective upper and lower guide members. The trucks also include three pairs of wheels disposed on three axes orthogonal to each other. The wheels of each pair are fairly spaced apart and engage parallel and opposite surface of longitudinal elements making up the guide members. The trucks are thus confined to slide freely along only a horizontal axis defined by the guide members and cannot deviate from such an axis or from horizontal and vertical axes orthogonal thereto. The accordion door is supported at its lower part on arms of lower ones of the trucks and is suspended from arms of upper ones of the trucks which are quite elastic and are provided with an adjustment device that allows that part of the weight of the door loading the upper trucks to be adjusted. The trucks are also provided with spreading apart devices actuated by the same half-wings during the opening movement thereof, which spread apart the edges of the outermost sides of the accordion door from fixed surfaces which, at the closed position thereof, are adjacent thereto. Finally, the trucks include fixed spacer elements which space the trucks fairly far apart when the door is in the open position.

BACKGROUND OF THE INVENTION 
The present invention relates to an accordion door, which can slide 
longitudinally and which can be fitted to furniture, particularly lockers, 
as well as to other various frames such as windows and the like. 
As it is known, particularly in the field of furniture, e.g. for lockers 
and the like, so-called accordion doors are vertically divided into two 
half-wings identical to each other and hinged together at their central 
part. The central part thereof is shifted outwardly during the opening 
movement thereof, while the outermost sides of the two half-wings slide 
toward one another. 
Normally, one of the two sides of the door is fixed and adequately pivoted 
in the piece of furniture, while the other side is slidingly supported 
thereon and appropriately guided by guide members fitted to the piece of 
furniture at the upper and lower parts of the door. Therefore, the two 
half-wings may be moved from a first position corresponding to the closed 
position of the door, in which they are disposed coplanar, to a second 
position corresponding to the opening position of the door in which the 
hinged central part thereof is shifted outwardly and the two half-wings 
confront one another, so as to expose the previously covered part of the 
piece of furniture. 
Such doors are clearly limited in number in application to a piece of 
furniture, although it would be desirable and profitable to employ many 
doors which not only form a bellows structure but which are also able to 
translate longitudinally. 
Several solutions for this problem have been attempted. However, such 
solutions result in doors which are all known to be complicated and quite 
unstable. 
In fact, a considerable vertical instability of the single doors is always 
present when they are slid in their opened position and particularly in 
such doors having wings extending a remarkable amount in the vertical 
direction, such as the doors of lockers. 
SUMMARY OF THE INVENTION 
An object of the present invention is to obviate these drawbacks by 
providing simple and reliable single or multi-accordion doors which can 
translate longitudinally in a stable and safe manner along the front of 
the piece of furniture, and which can also have a considerable vertical 
dimension such as the doors of lockers and the like. The accordion doors 
are formed in a per se known way by two half-wings hinged along respective 
vertically extending sides thereof, so as to be movable from a closed 
position in which said half-wings are coplanar at the front of the piece 
of furniture to an opened position in which the half-wings are folded 
along the hinged axis thereof while being arranged fairly spread apart. 
The invention is characterized in that said half-wings are pivotally 
supported at upper and lower ends of the outermost sides thereof to arms 
which project from respective support elements slidably engaged with upper 
and lower guide members fitted to the front of the piece of furniture. The 
support elements are trucks each provided with three groups of two wheels, 
disposed on three axes orthogonal to each other. The wheels of each group 
are fairly spaced apart from one another and engage parallel and opposite 
surfaces of respective longitudinal elements constituting a longitudinal 
guide member. Such an arrangement permits the trucks to slide freely along 
a horizontal axis defined by the respective longitudinal guide member 
while preventing the trucks from deviating from the horizontal axis as 
well as from horizontal and vertical axes orthogonal thereto. The 
accordion door is also supported at its lower part on respective lower 
arms extending from lower trucks and connected thereto by elements 
providing a hinged connection. The upper part of the door, on the 
contrary, is suspended from upper arms projecting from the upper trucks, 
such upper arms additionally being fairly elastic and provided with 
adjusting means for allowing that part of the weight of the door exerting 
a load on the upper trucks to be varied. The support elements are also 
provided with spreading apart devices which are actuated by the half-wings 
during the opening thereof to spread apart the edges of said outer 
vertical sides of the accordion door from fixed surfaces which, at the 
closed position of the door, are adjacent thereto. The support elements 
further include fixed spacer elements which position the half-wings fairly 
spaced apart from one another when the half-wings are disposed in their 
opened position.

In such figures, common elements are marked with the same reference 
numerals. And, elements which have completely or partially identical 
structure but which differ by only being disposed opposite one another at 
the lower or upper part of the door, are marked with the same reference 
numerals followed, respectively, by the delineating letter "i" or "s". 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
With reference to the figures, and particularly to FIGS. 1 and 2, accordion 
door 1 is formed by two half-wings 11 pivotally connected with a hinge 12 
extending vertically along respective first sides thereof at an internal 
part of the door. 
Moreover, the two half-wings 11 are hinged at the outer ends thereof (upper 
and lower ends), adjacent their respective other sides, with the studs 14i 
and 14s. The studs 14i, 14s connect respective lower and upper brackets 
13i and 13s to corresponding arms 21i and 21s of respective trucks 20i and 
20s. The trucks 20i, 20s in turn engage respective lower and upper 
longitudinal guide members 30i and 30s. As clearly shown in FIGS. 6-13, 
said lower and upper longitudinal guide members 30i and 30s are identical 
and the lower and upper trucks 20i and 20s are identical, except for the 
parts thereof connected to the door, which parts will be described later 
in detail. 
Further, as clearly shown in FIGS. 1, 2, 8, 9 and 11, the trucks fitted at 
the right side of the door are symmetrical to those fitted at the left 
side thereof. 
More specifically, the longitudinal guide members 30 are constituted by a 
section (see FIGS. 3, 6 and 7) comprising a planar strip 31 and four 
flanges orthogonally extending therefrom. These flanges include two 
internal flanges 32 and two external flanges 33, adequately spaced from 
each other. The two external flanges 33 extend from the sides of said 
planar strip 31. Each external flange 32 terminates with a further flange 
34, facing the two internal flanges 32 and extending parallel to said 
planar strip 31. Each truck 20 is so shaped as to form an element that is 
able to slide only along the horizontal x-axis, which axis is defined by a 
respective longitudinal guide member 30, without being able to move at all 
along the horizontal and vertical axes y and z extending orthogonally to 
the horizontal x axis. 
This is all clearly shown in FIGS. 3, 4 and 5, which schematically 
illustrate, in three sectional views taken orthogonally of one another, a 
truck 20 and an associated guide member 30. 
In these figures the three orthogonal axes x, y, z are shown with dashed 
lines, while a pair of wheels and the associated guide surfaces, 
preventing the truck from deviating in its longitudinal movement with 
respect to said three axes x, y, z, are shown with heavy dark lines. 
It is to be noted that such pairs of wheels are advantageously identical to 
each other. 
Referring to FIG. 3, a first pair of coaxially spaced wheels R1 and R2 
engage corresponding longitudinal grooves defined between the planar strip 
31, external flanges 33 and terminal flanges 34. 
Such wheels R1 and R2 each have a diameter practically identical to the 
distance between the opposite internal surfaces of said planar strip 31 
and the flanges 34, so that any rotational movement of the truck 20 about 
said x axis is clearly prevented. 
More particularly, the load P determined by the weight of the door and 
acting on the free end of the arm 21, tends to rotate the truck 20 around 
the axis x as indicated by the arrow M. Therefore, wheel R1 is pushed 
downwardly while the wheel R2 is pushed upwardly and bears respectively 
against the planar strip 31 and the flange 34, which clearly prevent the 
truck 20 from being rotated around such x axis. It is to be noted that a 
force exerted in an opposite direction would cause the impact of the wheel 
R1 against the corresponding flange 34 and the impact of the wheel R2 
against the planar strip 31, so that it follows that the truck 20 is also 
prevented from rotating around the axis x in said opposite direction. 
FIG. 3 clearly indicates the prevention of the rotation of the truck 20 in 
the two opposite directions represented by the arrows N on the y-axis. 
On the other hand, referring to FIG. 4, a second pair of wheels R2 and R3 
are spaced from each other and are aligned in the rear groove of the guide 
member 30, which is bounded at its upper part by the rear flange 34 and at 
its lower part by the planar strip 31. The wheels R2 and R3 bear against 
rear flange 34 and planar strip 31 thus preventing the truck 20 from 
rotating around the horizontal y-axis, which is transverse to the 
longitudinal guide member 30 and orthogonal to the horizontal x-axis. 
Advantageously, one of the wheels of the second pair of wheels may be 
constituted by a wheel of the above-described pair of wheels R1, R2. 
More precisely, in the illustrated embodiment, the wheel R2 is employed in 
common with respect to both pairs of wheels. Finally, referring to FIG. 5, 
the wheels of a third pair of wheels R4 and R5 fitted to the truck 20 are 
rotatably supported about vertical axes and are adequately spaced from 
each other as aligned along the horizontal x-axis defined by the guide 
member 30. The wheels engage a groove bounded by the inner surfaces of the 
internal flanges 32 of said guide member 30, wherein the distance between 
such walls is practically equal to the diameter of the wheels R4 and R5. 
The third pair of wheels R4 and R5, therefore, is guided by such internal 
flanges 32 which clearly prevent the truck 20 from rotating around the 
vertical axis z. 
In summary, the longitudinal translation of the truck 20 is facilitated 
along the associated guide member 30 while, on the contrary, any deviation 
thereof with respect to the three orthogonal axes x, y and z is prevented. 
Consequently, the projecting arm 21 of truck 20, at the end of which the 
door 1 is engaged as described later, acts as a cantilever which, 
particularly when said door 1 is fitted thereto with a hinged joint, 
inhibits moments from being exerted which could cause vertical stresses on 
the door. 
Therefore, the application of four trucks of the described kind to an 
accordion door 1, and more precisely of two trucks at the sides of its 
upper end and of two trucks at the sides of its lower end, permits the 
door to freely translate in a very steady and reliable way along the front 
part of an associated piece of furniture. As already specified, the 
accordion door 1 is pivoted vertically at the sides of its lower and upper 
ends, i.e., at the ends of respective arms 21i and 21s extending from 
corresponding trucks 20i-20s. 
If the door is pivotally supported in correspondence with or in front of 
the front surface thereof, when the door 1 is opened and the half-wings 11 
thereof rotate around their pivotal axes, there is little concern that 
side edges of the door will touch and thus rub a wall or of the edge of a 
door adjacent thereto. On the contrary, if the door is pivotally supported 
behind the front surface thereof, the corners of the side edges of the 
door 1 while rotating around the pivotal axes thereof would intercept 
edges of elements adjacent thereto, so that it is necessary for these 
corners to be progressively moved away from the edges of adjacent elements 
during rotation of the half-wings 11. 
This may be obtained by providing the upper and lower trucks 20s and 20i, 
having the arms 21 at which the two half-wings 11 are pivotally supported, 
with spacer elements 28 which, when actuated by the rotational movement of 
the half-wings as the accordion door 1 is shifted toward its opened 
position, are withdrawn from the trucks 20 by the half-wings while pushing 
the correspondent trucks 20 and therefore the correspondent pivotal axis 
thereof away from the trucks of an adjacent door. The trucks 20 using 
spacer elements 28 are clearly illustrated in FIGS. 12 and 13 a well as in 
FIGS. 6, 7, 8, 9, 10 and 11, which also illustrate the practical 
application thereof to an accordion door 1 as well as the operation 
thereof described in more detail below. 
In the preferred embodiment to which reference is made, such trucks 20 
comprise elements of sheet metal having an adequate thickness, which 
elements are simply sheared, bent and assembled together. 
Referring particularly to FIG. 12, the structure of a lower truck 20i and, 
more precisely, of a truck which will be fitted to the left side of an 
accordion door 1 will be described. The truck to be fitted to the right 
side of the door is substantially identical thereto. 
As is clearly seen from the figure, truck 20i is formed by a lower 
rectangular plate 22i at the left and front part of which a lug 221 
projects. Lug 221 is provided at the center of its free end with a hole 
222 in which the stud 14i of a half-wing 11 is engaged. Truck 20i also 
includes two rectangular plates 231 and 232 disposed over the plate 22i at 
the sides thereof, two additional rectangular plates comprising a front 
plate 241 and a rear plate 242i which are disposed orthogonally over the 
plates 231,232 at the front and rear of the thus resulting structure, 
respectively, and finally an upper rectangular plate 25i identical to the 
lower rectangular plate 22 with the exception of lug 221. This group of 
plates is assembled by means of adequate bolts, extending through 
respective holes defined at the four corners of the structure referred to. 
The two plates 231-232 define a rectangular groove 233 between the 
underlying lower rectangular plate 22i and the overlying rectangular 
plates 241-242i, within which groove 223 a shaped plate 27 which will be 
hereinafter described in more detail is disposed and is able to be 
translated. 
Also the rectangular plates 241-242 define a further rectangular groove 
243, in which the movable spacer element 28 is disposed and is able to be 
shifted and guided. In addition, a lug 244 provided with a central hole 
245 in which a rubber plug 246 is fitted, extends upwardly from and 
orthogonally to the front part of the right side of the rear plate 242i. 
The movable spacer element 28 is formed by a rectangular tongue 281, bent 
at one end to form a short lug 282 directed orthogonally upwards. The lug 
282 is identical to the lug 244 and is provided with a central hole 283 in 
which a correspondent rubber plug 284 identical to the plug 246 is fitted. 
A return spring 4 (FIGS. 8, 9 and 11) is arranged between lug 282 and the 
lug 244. Moreover, from the lower surface of said tongue 281 extends a 
short pin 285 which cooperates, as described later, with a further pin 225 
projecting from the upper surface of said lower rectangular plate 22i. At 
the lower part of plate 22i is fixed a "U"-shaped section having a front 
vertical flange on which the wheel R1 is pivotally supported, a rear 
vertical flange on which the wheels R2, R3 are pivotally supported, and a 
central flange on which wheels R4, R5 are pivotally supported, thus 
providing the already described truck 20. 
Finally, referring particularly to FIGS. 8 and 11, said shaped plate 27 has 
a first part 271 provided at its end with a hole 272 for facilitating the 
securement of plate 27 to the half-wing 11. Such first part 271 ends at 
the location at which said pins 285-225 are disposed, where it has a width 
equal to the distance existing between the pins, when the door is disposed 
in its close position. 
The first part 271, additionally, is contiguous with a second part 273 
having diverging sides which form the maximum width portion of plate 27 at 
a position corresponding to the position of said pins 285-225 when the 
door is disposed in its opened position. 
As is particularly shown in FIG. 13, the upper truck 20s is substantially 
identical in structure to the above-described lower truck 20i and is 
different therefrom in that it is rather longer and has some different 
elements. 
Therefore, in FIG. 13 the elements which are completely identical to those 
of FIG. 12 will be marked by the same reference numerals and those 
differing therefrom in dimensions only will be marked by the literal 
reference "s" added to the reference numeral. Those elements not included 
in the truck shown in FIG. 12 (not provided in the lower trucks 20i) will 
be marked by respective reference numerals. Some features that distinguish 
the trucks from one another include: the lower rectangular plate 22s isn't 
provided with a lug 221 and the upper plate 25s is provided with an 
inclined raised part 251, projecting from the upper part thereof and whose 
function will be described hereinafter. 
Finally, a resilient plate 26 is fitted to the upper part of the truck 20s, 
and a device for allowing adjustment of the elasticity thereof is provided 
and will be described later. 
Said resilient plate 26 is constituted by a rectangular plate of the same 
size as those of the underlying plates. Plate 26 is bent at its back side 
so as to form a depressed back edge 261 permitting it to be fixed to the 
underlying plates and is also folded at its front side so as to form a 
flange 262 turned downwards, from the left end of which a lug 263 
identical to the lug 221 projects towards the front part thereof. Lug 221 
is provided with a hole 264 in which the stud 14s for connecting the 
associated half-wing 11 is inserted. 
Said lugs 221 and 263 practically form the elements which were previously 
called, respectively, lower arm 21i and upper arm 21s. 
Moreover, a hole 265 is provided in said flange 262. The hole 262 is 
aligned with the inclined raised part 251 provided in the underlying plate 
25. A screw 5 engages a pin 6, disposed between the resilient plate 26 and 
the inclined part 251, and extends through the hole 265, thus providing 
the device for allowing adjustment of the elasticity of the resilient 
plate 26. As the screw 5 is rotated (refer to FIG. 6), pin 6 is moved up 
or down inclined part 251 to add tension to a relax resilient plate 26, 
respectively, so as to bear more or less of the load exerted on arm 21s by 
door 1. 
The assembly operates as follows. 
Firstly, the accordion door 1 is hung at its upper part to the associated 
arms 21s, while being supported at its lower part on the arms 21i and the 
connection to the latter is effected preferably by means providing a 
hinged joint. Such an arrangement and the use of the device for allowing 
adjustment of the elasticity of the resilient plate 26 of the upper trucks 
20s, permits that part of the weight P of the door loading the upper 
trucks 20s to be adjusted, which fact allows the distribution of the load 
between these trucks and the lower trucks 20i to be optimized, whereby a 
soft and reliable movement of the accordion door during the opening, 
closing and translating operation thereof can be realized. 
This is all obtained basically by utilizing the above-described trucks 20 
which, as already stated, may freely slide along a rectilinear trajectory 
determined by the guide members 30 without any deviation from such 
trajectory being effected. The opening of a door occurs in a very simple 
way when one of its sides is pushed towards the other. FIGS. 1 and 2, to 
which reference is made hereinafter, clearly illustrate such an operation. 
By way of example, in such figures the door shown at the center thereof has 
been opened by shifting the right-side wing thereof leftwards. In fact, as 
the right side of the door 1 is pushed to translate leftwards, it is 
guided by the associated right-side trucks 20s-20i which are sliding on 
the correspondent longitudinal guide members 30s-30i and such trucks 
20s-20i are able to provide, owing to the already specified reasons, a 
very regular rectilinear movement. 
In practice, slight oscillations with respect to the vertical line of the 
door, which oscillations however are rapidly dampened, may occur but only 
when improper, very irregular and intense strains are in effect. 
While the right side is shifting leftwards, the two half-wings 11 are 
folded together about the axis defined by the hinge 12, and the central 
part of the door 1 is shifted outwards. 
The movement thereof may be continued until the door is fully opened (see 
FIG. 2), which operation occurs when the rubber plugs 246 of the 
right-side trucks 20s-20i bear against the plugs 246 of the left-side 
trucks 20s-20i, which are still since the associated plugs 284 fitted to 
their movable spacer elements 28 are abutting the correspondent plugs 284 
of the left-side trucks 20s-20i of the door 1 adjacent thereto, which door 
is still. 
The various plugs 246-284 act for deadening the impacts which occur when 
moving parts are stopped by still parts. 
It is noted that, as clearly illustrated in FIG. 2, due to the presence of 
the trucks 20, the two half-wings 11 of the door 1 remain rather spread 
apart at the opened position thereof. Such an arrangement is quite 
advantageous as the vertical stability of the half-wings 11 at this 
position, as clearly ensured by the trucks 20, is considerably increased 
owing to the fair amount of separation existing between the two lower 
trucks 20i and the two upper trucks 20s. 
Obviously, when the door 1 is disposed in its opened position, it may 
translate freely transversally along the front part of the piece of 
furniture. 
Moreover, it is noted that when a plurality of doors 1 are provided, it is 
possible to dispose all or at least some of such doors in the opened 
position, whereby such doors may translate freely transversally along the 
opening provided at the front of the piece of the furniture. 
Finally, with particular reference to FIGS. 8, 9, 10 and 11, the operation 
of the device for spreading apart the trucks 20 will be described. 
FIGS. 8 and 11 show, respectively, the group of trucks 20i and 20s fitted 
to the ends of two half-wings 11 of adjacent doors 1 disposed in their 
closed positions, as also illustrated at the left in FIG. 1. Likewise, 
FIG. 11 shows the right-side door 1, corresponding to the central door 
shown in FIGS. 1 and 2, at the open position thereof. 
For clarity, reference is made hereinafter to FIGS. 9 and 11 illustrating 
the upper part of the door, because the action effected at the upper part 
is likewise effected at the lower part thereof, too. 
Therefore, when the door 1 is disposed in its closed position (FIG. 8), 
both the pin 285s connected to the movable spacer element 28s and the pin 
225s connected to the truck 20s are positioned at the sides of the first 
part 271 of the shaped plate 27s, adjacent the beginning of the divergent 
sides 274-275 of the second part 273. 
When the door is shifted to its opened position, the half-wing 11 rotates 
around the stud 14s, and therefore also the stud 15s connecting the shaped 
plate 27s to the bracket 13s fixed to the half-wing 11, thereby causing 
the shaped plate 27s to be pulled outwardly from truck 20s. 
Consequently, the sides 274 and 275 of said second part 273 of the shaped 
plate 27s which, as already stated, are divergent, slide against the 
associated pins 285-225 while wedged therebetween, thus moving the 
correspondent trucks 20s away from the respective trucks 20s adjacent 
thereto (which are situated at the left thereof in FIGS. 1, 2, 9 and 11 
and remains still). 
It follows also that the stud 14s of the half-wing 11 and, therefore, the 
correspondent side edge thereof are progressively moved away from the 
adjacent door 1 so that the front corner of such side edge which would 
contact the side edge of the door 1 adjacent thereto if it were not for 
the above-described device, passes along a trajectory which in fact does 
not intercept such side edge. 
While the half-wing 11 referred to is rotating around the associated studs 
14, the other half-wing 11 of the same door 1 rotates around the hinge 12 
towards the former. The movement thereof is continued until the trucks 
20s-20i situated at the right part of the door 1 cause, owing to the 
engagement of the corresponding elastic plugs 246 of the trucks 20s-20i at 
the left part of said door 1 with the elastic plugs 246 thereof, the 
component parts of the unit to be all stopped in the open position thereof 
clearly illustrated in FIGS. 2 and 9. 
As already stated and clearly shown in FIGS. 2 and 9, the left and right 
trucks 20 thus disposed side by side make it possible for the half-wings 
11 to be quite spread apart at the open position thereof, so as to obtain 
a considerable vertical stability of the door in this position. 
When the door 1 is at the open position thereof and said shaped plate 27 is 
shifted outwardly, the pins contact the convergent parts 276-277 of the 
plate 27 extending from the respective divergent sides 274-275 thereof. 
In this manner, as soon as the portion of plate 27 having the greatest 
divergency in width has passed pins 285-225, the pins which are biased by 
the action of the return spring 4 towards one another engage such 
convergent parts 276-277 so that the half-wings 11 remain locked in 
position. The door 1 may be closed again by exerting a suitable thrust 
causing plate 27 to become unlocked by forcing pins 285-225 apart. 
Clearly, the return of the door to its closed position occurs exactly in a 
way opposite to that way in which the door is opened. 
The shaped plate 27 has a raised tooth 278 at the same side thereof as the 
divergent side 274, which tooth bears against the pin 285 when the 
associated door is disposed in its closed position, thus ensuring the 
correct positioning of the two half-wings 11 in the desired coplanar 
state. Moreover, instead of the two divergent sides 274-275 of said second 
part 273 being rectilinear, they may be curvilinear having an initial part 
with a high divergency curving into two subsequent parts with limited 
divergency so that the corner of the side edge of the door is moved away 
from the adjacent edge just at the beginning of the opening movement of 
the door 1. Such a trajectory is considered to be more safe and to 
completely space apart the adjacent edges of the doors. 
Still referring to FIGS. 1, 2 and 9, at the end of the closing movement of 
the door, the plugs 284 of the right-side trucks 20s-20i bear against the 
corresponding elastic plugs 284 of the trucks 20s-20i of the left part of 
the door 1 adjacent thereto, whereby the door 1 is stopped and positioned 
between two laterally adjacent doors 1. 
The function of the various elastic plugs 246, 284 is to deaden the blows 
upon impact and hence, stop the respective parts which are being moved 
against corresponding still parts. 
It is clear that the door 1 disposed in the open position thereof, as 
illustrated by the FIG. 2, may freely translate laterally along the front 
of the piece of furniture. 
Obviously, also a group of doors 1 all disposed in the open position may 
freely translate in a likewise manner. Finally, also the doors disposed in 
their closed position may translate laterally when the adjacent doors are 
disposed away therefrom. 
It is also to be noted that the accordion doors may be formed by three 
panels instead of by two panels constituting the two half-wings 11. This 
further possible embodiment is indicated by wa of example with a dashed 
line in FIG. 2. In this case, the third panel marked with the reference 
numeral 11a is supported, at the ends of the vertically extending side 
thereof which is adjacent to the side of an adjacent door, on trucks 20a 
identical to the already described trucks and whose movable spacer 
elements 28a abut the movable spacer elements 28s (28i) of the half-wing 
11 adjacent thereto or form a single element with the same. 
As clearly illustrated in FIG. 2, in order for the third panel 11a to be 
disposed at least orthogonally to the piece of furniture, when the thus 
formed door is opened, the shaped plates 27a of the associated trucks 20a 
must be relatively long. And, more precisely, the divergent sides of the 
second part thereof will also have to be adequately long. 
From this detailed description, the particular structural and operative 
features as well as the utility of the accordion door are clear, together 
with the advantages facilitated thereby with respect to the manufacturing 
and assembling thereof. 
It will be understood that different variants of the various elements and 
devices of the door referred to herein may be adopted without departing 
from what is claimed, and therefore all such variants are seen to be 
within the true spirit and scope of the present invention.