[0001] The present invention relates to a stacker for a machine for sorting postal articles.
[0002] Postal articles can be sorted by machines that have a plurality of output stackers,
each of which accumulates the sorted postal articles so as to form a stack in a respective
housing. These housings are accessible from the above and, when substantially full,
are emptied by a robotized system or by hand. In particular, the stacks of postal
articles are transferred to containers or trays to be transported to their respective
destinations.
[0003] In some sorting machines, the stackers are arranged on two levels, at different heights.
In solutions of this type, the stackers on the upper level at least partially overlay
the stackers on the lower level and therefore, due to the space they occupy, make
picking stacks of postal articles from the lower level stackers difficult, especially
if this picking is performed by hand. In fact, the operator, especially if of above-average
height, must bend down in order to entirely see the postal articles in the lower level
stacker and to pass his/her arm beneath the upper level stacker when he/she must pick
these articles.
[0004] To resolve this problem, the upper level stackers are usually shorter and, in consequence,
can accommodate a smaller number of postal articles with respect to the lower level
stackers, so as to obstruct emptying the lower stackers as little as possible.
[0005] In addition, the upper level stackers are sometimes moved towards the inside of the
machine in order to overlap lower level stackers as little as possible. As a rule,
the capacity of the upper level stackers is reduced in this case as well, otherwise
the operator, hindered by the lower level, would have to stretch his/her limbs too
much and lean forwards to reach the upper level.
[0006] The need is therefore felt to perfect the above-described known solutions, so as
not to excessively reduce the accumulation capacity of the upper level stackers, and
so that the emptying of the lower level is as ergonomic as possible.
[0007] The object of the present invention is that of providing a stacker for a machine
for sorting postal articles, that enables the above-described needs to be met in a
simple and inexpensive manner.
[0008] According to the present invention, a stacker for a machine for sorting postal articles
is provided, as defined in claim 1.
[0009] The present invention also relates to a machine for sorting postal articles, as defined
in claim 9.
[0010] The invention shall now be described with reference to the attached drawings, which
illustrate a non-limitative embodiment, where:
- Figure 1 is a perspective view of a preferred embodiment of the stacker according
to the present invention, for a machine for sorting postal articles shown with parts
removed for clarity;
- Figure 2 is a side view of the sorting machine in Figure 1, with parts sectioned along
a vertical section plane;
- Figure 3 is a perspective view from above, on an enlarged scale, of the stacker of
the present invention; and
- Figure 4 is an enlargement of a detail of Figure 2.
[0011] In Figure 1, reference numeral 1 indicates, as a whole, a sorting machine (partially
illustrated) comprising a structure 2 and a conveyor system 3, of known type and not
described in detail, which is supported by the structure 2 and is controlled so as
to sort a series of postal articles towards a plurality of stackers. In particular,
the sorting is performed as a function of the addresses or delivery destinations indicated
on the postal articles. The stackers are arranged side by side and on two levels,
which are parallel to a horizontal direction D. As shown in Figure 2, the upper level
stackers are arranged at a greater height and are indicated by reference numeral 5,
while the lower level stackers are indicated by reference numeral 6 and, preferably,
are made according to the known art.
[0012] Each stacker 6 is aligned with an above respective stacker 5 along a horizontal direction
E, orthogonal to direction D.
[0013] The inlets to the stackers 5 are substantially aligned in a vertical direction with
the inlets of the stackers 6, so as to allow an operator 7 (Fig. 2), even if of below-average
height, to easily reach the postal articles on the upper level.
[0014] The stackers 5 and 6 accumulate the sorted post and are manually emptied by the operator
7, or by means of a robotized system, not illustrated, when the filling level of the
stackers 5 and 6 reaches a given threshold and/or at predetermined time intervals.
[0015] The upper level stackers 5 are all the same, and therefore the following disclosure
will refer to just one of them. According to what shown in Figures 3 and 4, the stacker
5 comprises a base 10 defining a lower plane 11 of a housing 12 able to accommodate
a stack of postal articles (not illustrated). These postal articles are transferred
by the conveyor system 3 in a known manner and not described in detail and are stacked
in the housing 12 whilst vertically arranged, i.e. with a lower edge resting on the
plane 11.
[0016] The conveyor system 3 comprises a roller device 14, of known type, which is configured
to stack the postal articles along an axis 15 orthogonal to direction D. In the particular
example illustrated, the axis 15 is slightly inclined with respect to horizontal direction
E. The housing 12 has an inlet 16, defining an area where the postal articles are
inserted, one at a time, by the roller device 14, with an orientation orthogonal to
axis 15.
[0017] The stacker 5 comprises a movable shoulder 20, which is aligned with the inlet 16
along axis 15, to define the front end of the housing 12, i.e. the end opposite to
the inlet 16. The movable shoulder 20 has a face 21 orthogonal to axis 15 and defining
a support for the first postal article of the stack, is preferably made with a blade-like
shape and is known in the jargon as a "knife". The movable shoulder 20 is connected
to a guide 22 (fig. 3) parallel to axis 15, so that it can move along axis 15 with
respect to the structure 2 according to the amount of postal articles stacked in the
housing 12. In particular, two end-of-stroke elements are provided: one to define
a rest position (shown with unbroken lines in Figure 4), where the movable shoulder
20 is located at the inlet 16, and the other to define a forward position (shown with
broken lines in Figure 4), where the movable shoulder 20 is located at a front end
25 of the base 10.
[0018] The movable shoulder 20 is connected to the guide 22 by a support 26 comprising:
a slide 27 engaging the guide 22; an arm 28 extending upwards with respect to the
slide 27; and a connection device 29 that couples the movable shoulder 20 to the arm
28 and enables the movable shoulder 20 to be raised with respect to its normal position
where it is aligned with the inlet 16. In this way, the movable shoulder 20 can be
moved away from the stack resting on the plane 11. Preferably, the connection device
29 is defined by a hinge having a rotation axis 30 parallel to axis 15.
[0019] The stacker 5 further comprises a stop surface 31, which is substantially vertical
and is arranged is a fixed position at the front end 25 of the base 10. In particular,
when the movable shoulder 20 is located in its forward position, the stop surface
31 is vertically between the plane 11 and the movable shoulder 20 (Figure 3). Preferably,
the stop surface 31 is defined by a handle 32, which can be gripped to longitudinally
translate a front portion 10a of the base 10 with respect to a rear portion 10b of
the base 10.
[0020] Indeed, according to the present invention, the base 10 is of the extensible type,
and autonomously lengthens according to the number of stacked postal articles in the
housing 12. In particular, the rear portion 10b is fixed with respect to the structure
2, while the front portion 10a is coupled to a guide device 33 so that it can translate
parallel to axis 15 between a retracted end-of-stroke position, where it is close
to the inlet 16, and a forward end-of-stroke position, where it is spaced apart from
the inlet 16.
[0021] Preferably, the guide device 33 is arranged beneath the plane 11 and, in particular,
comprises two guide members 34 parallel to axis 15 and transversally set apart from
each other. As shown in Figure 4, each guide member 34 comprises a rod 35, fixed with
respect to one of the parts 10a or 10b, and a metal tube 36, which is fixed with respect
to the other of the two parts 10a or 10b and is slidingly engaged by the respective
rod.
[0022] Still with reference to Figure 3, parts 10a and 10b conveniently have a comb-like
or fork-like shape, so as to have respective fingers 37 and 38 that are parallel to
axis 15, alternate with each other parallel to direction D and engaged so as to slide
in seats defined by the fingers 38 or 37 of the other part 10b or 10a. Preferably,
the shapes and sizes and the maximum translation of the fingers 37 and 38 are such
as to avoid gaps in the plane 11 in all operating positions of the front portion 10a.
[0023] According to a preferred aspect of the present invention, the stacker 5 comprises
a return device 40 (Figures 2 and 4) exerting an elastic action that tends to automatically
return the front portion 10a towards the inlet 16, i.e. towards its retracted end-of-stroke
position. Preferably, the stacker 5 also comprises a return device 41, exerting an
elastic action on the support 26 that tends to automatically return the movable shoulder
20 towards the inlet 16, i.e. towards its rest position. In particular, the return
devices 40 and/or 41 are defined by belt or cable devices.
[0024] According to a preferred aspect of the present invention, the guide 22 is fixed with
respect to the front portion 10a and the end-of-stroke element defining the forward
position of the movable shoulder 20 is also fixed with respect to the front portion
10a.
[0025] In the particular embodiment shown, this end-of-stroke element is a check plate that
is placed at the end of the guide 22 and enables the base 10 to automatically lengthen
as a function of the stacked postal articles in the housing 12. In fact, the creation
of the stack of postal articles first makes the movable shoulder 20 translate towards
its forward position against the action of return device 41, while return device 40
keeps the front portion 10a in its retracted end-of-stroke position. When the movable
shoulder 20 arrives to its end of stroke, the stacking of further postal articles
makes the movable shoulder 20 and the front portion 10a move as one against the action
of the return devices 40 and 41, until the front portion 10a reaches its forward end-of-stroke
position. Advantageously, as shown in Figure 3, the guide 22 is arranged laterally
and/or constitutes part of one of the fingers 37, and/or the guide members 34 are
aligned with the fingers 38.
[0026] To pick the postal articles, the movable shoulder 20 can be raised, leaving the stack
on the stop surface 31. At this point, the return device 41 returns the support 26
with the movable shoulder 20 back towards the inlet 16, so as to give free access
to the housing 12. The stack of postal articles can then be picked and transferred
to a container or tray (not illustrated).
[0027] Preferably, during removal of the postal articles from the housing 12, an interlock
(not illustrated) keeps the front portion 10a at a standstill with respect to the
rear portion 10b. When this interlock is, automatically or manually, deactivated,
the return device 40 automatically returns the front portion 10a to its retracted
end-of-stroke position. Lastly, the movable shoulder 20 must be returned to the position
aligned with the inlet 16, for the further stacking of postal articles.
[0028] With reference to Figure 2, immediately after having emptied stacker 5, it is possible
to easily empty the underlying stacker 6. In fact, when stacker 5 is empty, namely
when the base 10 is arranged in a minimal length configuration, stacker 6 protrudes
forwards along direction E, i.e. in the opposite direction to the position of the
conveyor system 3, with respect to the front end 25 of stacker 5. In this configuration,
the space occupied by stacker 5 is quite modest. The operator 7 can therefore access
stacker 6 in an ergonomic manner, as it is not necessary to bend down or perform particular
manoeuvres to grasp the postal articles housed in stacker 6.
[0029] Thus, from the foregoing, it is evident how stacker 5 allows access to the underlying
stacker 6 without any difficulty, yet at the same time it can have a relatively high
accumulation capacity thanks to the fact that the base 10 is of the extensible type.
In particular, stackers 5 have a capacity substantially equal to that of stackers
6 when the bases 10 are arranged in a maximum length configuration.
[0030] The fact of making the base 10 in two parts enables achieving a relatively simple
solution and of maintaining stable support on the plane 11 despite the elongation
of the base 10. The characteristics of the guide 22 and, in particular, of the end-of-stroke
element defining the forward position of the movable shoulder 20 permit obtaining
high compactness and, at the same time, simple and automatic operation for lengthening
the base 10. The special constructional characteristics of parts 10a and 10b of the
guide device 33 and of the support 26 also permit obtaining high compactness and,
at the same time, extreme simplicity in the use and/or in the assembly of the various
components.
[0031] Finally, from the foregoing, it is evident that modifications and variants can be
made to the stacker 5 and to the machine 1 described with reference to the attached
figures without departing from the scope of the present invention, as defined in the
appended Claims.
[0032] In particular, the base 10 could include a different system for rendering it extensible;
or parts 10a and 10b could have different shapes from those illustrated by way of
example.
[0033] The return devices 40 and/or 41 could be absent and, for example, be replaced by
friction or snap-action retention devices that impede the translation of the front
portion 10a and the movable shoulder 20, without exerting any return action towards
the inlet 16, for which return to the inlet 16 must be performed by intentionally
pushing after emptying the housing 12.
[0034] Furthermore, the movable shoulder 20 could have a slide independent of that of the
front portion 10a: in this case, for example, the elongation of the base 10 could
start when the stack of postal articles makes contact with the stop surface 31.
[0035] In addition, the return devices 40 and 41 could be of a different type from the belt
ones, indicated by way of example; and/or the guide device 33 could be shaped differently
and/or arranged in a different position with respect to the illustrated preferred
embodiment.
1. A stacker (5) for a machine for sorting postal articles; the stacker comprising:
- a base (10) having a plane (11) defining a support for a lower edge of said postal
articles;
- an inlet (16) for stacking postal articles along a longitudinal axis (14) on said
plane (11);
- a movable shoulder (20), which is aligned with said inlet (16) along said longitudinal
axis (14) at least during stacking;
said base (10) comprising a fixed rear portion (10b) and a front portion (10a), which
is coupled to first guide means (33) to translate in a direction parallel to said
longitudinal axis (15) between a retracted end-of-stroke position, where it is close
to said inlet (16), and a forward end-of-stroke position, where it is spaced apart
from said inlet (16); shoulder means being provided to automatically translate said
front portion (10a) as a function of the amount of stacked postal articles;
characterized by comprising second guide means (22) that guide a translation of said movable shoulder
(20) along said longitudinal axis (15) from said inlet (16) with respect to said front
portion (10a) and said rear portion (10b) as a function of the amount of stacked postal
articles.
2. The stacker according to Claim 1, characterized in that said shoulder means comprise an end-of-stroke element, which is fixed with respect
to a front end (25) of said front portion (10a) and defines, for said movable shoulder
(20), a forward position, in which said movable shoulder (20) is located at said front
end (25).
3. The stacker according to Claim 1 or 2, characterized in that said shoulder means comprise a handle (32) arranged in a fixed position at a front
end (25) of said front portion (10a).
4. The stacker according to any of the preceding Claims, characterized by comprising elastic means (40) exerting an action that tends to bring said front portion
(10a) towards its retracted end-of-stroke position.
5. The stacker according to any of the preceding Claims, characterized in that said second guide means (22) are fixed with respect to said front portion (10a).
6. The stacker according to any of the preceding Claims, characterized in that said rear portion (10b) and said front portion (10a) comprise respective fingers
(38, 37) which are parallel to said longitudinal axis (15) and are alternated.
7. The stacker according to Claim 6, characterized in that said second guide means (22) form part of one of said fingers (37).
8. The stacker according to any of the preceding Claims, characterized in that said first guide means (33) are arranged below said plane (11).
9. A machine for sorting postal articles, comprising a lower level of stackers (6) and
an upper level of stackers (5); the upper level stackers (5) being made according
to any of the preceding Claims.
10. The sorting machine according to Claim 9, characterized in that the stackers (5) of the upper level have inlets which are substantially aligned in
a vertical direction with respective inlets of the lower level stackers (6).
11. The sorting machine according to Claim 9 or 10, characterized in that the lower level stackers (6) project forwards with respect to the bases (10) of the
upper level stackers (5) when said bases (10) are arranged in a minimal length configuration.
12. The sorting machine according to any of claims 9 to 11, characterized in that the upper level stackers (5) have a capacity substantially equivalent to that of
the lower level stackers (6) when the bases (10) of the upper level stackers are arranged
in a maximum length configuration.