[0001] The present invention relates to a device for weighing rubbish-collecting bins, comprising:
at least one lifting arm having a first end oscillatably in engagement with a bearing
structure; a hooking element disposed at a second end of said lifting arm and having
a rest seating for a lifting pin carried by a bin.
[0002] It is known that modern rubbish-collecting systems involve use of appropriate bins
suitably distributed on the urban ground, that are periodically emptied by automatic
devices provided on motor-vehicles designed for collection and transportation of the
waste material to the rubbish dumps or other disposal places.
[0003] Such an automatic gripping and emptying device for rubbish bins is described in the
European Patent EP 776835 in the name of the same Applicant. This device essentially
comprises a pair of lifting arms parallel to each other, each having a first end rotatably
linked to a bearing structure, and a second end carrying a gripping member arranged
to engage a bin at a lifting pin laterally projecting from said bin. Appropriate actuating
means activated by fluid-operated cylinders carry out the simultaneous displacement
of the lifting arms between a rest condition in which they are substantially oriented
downwardly and contained in the overall dimensions of the vehicle, and an overturned
position in which they are substantially oriented upwardly. Identified between the
rest position and the overturned position is a grip position in which the arms bring
the respective gripping members completely level with the bin-lifting pins to enable
the bins to be picked up from the ground and lifted until reaching of the overturned
condition in which the bin is turned upside down over a loading hopper associated
with the motor-vehicle.
[0004] In order to check the rubbish amounts collected in the different areas of the urban
territory, many users ask for the possibility of weighing the individual bins as they
are picked up from the ground.
[0005] The solutions generally adopted to meet this requirement presently involve arrangement
of a load cell in an engagement seat suitably defined along each of the lifting arms.
In particular, the engagement seat of each load cell is arranged at an interruption
point of the longitudinal extension of the lifting arm, formed halfway on the arm
length, so as to divide said arm into a first and a second portions. The first and
second portions terminate at the first and second ends respectively of the lifting
arm and are mechanically interconnected by the stiff body of the load cell. Under
this situation, each load cell is interlocked with the load applied to the second
end of the arm by effect of the weight of the bin raised from the ground, the value
of which can be therefore detected in order to go back to the weight of the rubbish
contained therein.
[0006] In accordance with the present invention, the Applicant has perceived that in the
embodiments of the above described type presently adopted, positioning of the load
cell at an intermediate point of the lifting-arm development involves many drawbacks.
In particular, it has been found that a positioning spaced apart from the load cell
relative to the application point of the bin load causes transmission of high loads
to the cell itself and the structural parts dedicated to its connection to the arm
portions. All these parts are therefore required to be conveniently sized in order
to support the high loads applied thereto, which will bring about an increase in the
weight, costs and structural complexity of the assembly. In addition, these circumstances
make it economically inconvenient to make devices having arms set to receive the load
cells in all cases in which a weighing function, and therefore the presence of the
load cells themselves, is not required. Presently, in these cases use of arms of one
piece construction is preferred and consequently drastic modifications to the lifting
device will be compulsorily required when the user asks for the installation of the
weighing device after some time.
[0007] The Applicant has also perceived that in the present embodiments reading of the load
can be conditioned and/or hindered by external factors such as the mechanical resistance
offered by the hydraulic and/or pneumatic connection pipes leading to the gripping
members and the mechanisms interlocked therewith.
[0008] In accordance with the present invention it has been found that these problems can
be brilliantly overcome by arranging a hooking element removably in engagement with
the second end of the lifting arm, so that the load cell can be mounted to such an
end.
[0009] Accordingly, it is an object of the present invention to provide an automatic lifting
and emptying device for rubbish-collecting bins, characterized in that said hooking
element is disposed on the second end of the lifting arm, being removably in engagement
therewith.
[0010] Further features and advantages will become more apparent from the detailed description
of a preferred but not exclusive embodiment of an automatic lifting and emptying device
for rubbish-collecting bins in accordance with the present invention. This description
will be set out hereinafter with reference to the accompanying drawings, in which:
- Fig. 1 is a front view of a lifting device in accordance with the invention;
- Fig. 2 is a side view of the device shown in Fig. 1;
- Fig. 3 shows an enlarged and interrupted detail of Fig. 1.
[0011] With reference to the drawings, a device for automatic lifting and emptying of bins
for rubbish collection in accordance with the present invention has been generally
identified by reference numeral 1.
[0012] In a manner known per se, device 1 lends itself to be mounted on a side of a truck
(not shown) or other motor-vehicle used for rubbish collection and transportation
to the rubbish dumps or other disposal places. To this aim, device 1 has a bearing
framework 2 in engagement on the motor-vehicle side.
[0013] Associated with the bearing structure 2 is a pair of lifting arms 3 each having a
first end 3a oscillatably connected with the bearing structure itself and a second
end 3b carrying a gripping and handling member 4 for a bin 5 diagrammatically and
only partly shown.
[0014] In known manner, the bearing structure 2 is movable away from the motor-vehicle side
to enable the lifting arms 3 to take a position alongside opposite sides of the bin
5 to be emptied. The lifting arms 3 are in turn movable close to each other to come
near the side walls of bin 5 and enable the respective gripping and handling members
4 to operatively engage the bin itself. In more detail, for the purpose each gripping
and handling member 4 is provided to be equipped with a hooking element 6 having a
rest seating 6a with an arched profile the shape of which substantially matches that
of a lifting pin 5a projecting from the side wall of bin 5.
[0015] Said rest seating 6 is adapted to receive the lifting pin 5a to cause engagement
of bin 5 and allow lifting of same by arms 3 above a loading hopper arranged on said
motor-vehicle.
[0016] With each gripping and handling member 4 auxiliary devices can be also associated
such as an overturning lever 7 driven by a first actuator 7a to cause overturning
of bin 5 over the hopper, an auxiliary lever system 8 driven by a second actuator
8a to cause opening of the bin lid upon overturning of said bin, as well as a safety
device 9 to be driven by a third actuator 9a to prevent accidental disengagements
of pin 5a from the rest seating 6a during lifting and overturning of bin 5.
[0017] The overturning member 7, auxiliary lever system 8 and safety device 9 are diagrammatically
shown and they are not further described as they are not of importance to the aims
of the present invention.
[0018] Advantageously, each lifting arm 3 can be essentially defined, at least at its second
end 3b, by a pair of holding plates 10 disposed in mutual and parallel side by side
relationship, so that at least part of said auxiliary devices 7, 8, 9 associated with
the gripping member 4 can be housed in a space defined between the holding plates.
In particular, in the embodiment shown, housed in the space defined between plates
10 is the overturning member 7 with the first actuator 7a and the safety device 9
with the respective third actuator 9a.
[0019] An attachment base 11 is fastened between the holding plates 10 and it is preferably
made up of a plate-like element disposed in a plane perpendicular to the holding plates
10. Removably fastened to the attachment base 11 is the hooking element 6. In more
detail, the hooking element 6 essentially comprises an anchoring portion 12 fastened
to the attachment base 11 by first threaded elements 13, and a suspended portion 14
carrying the rest seating 6a. In a possible embodiment, not shown in the drawings,
the suspended portion 14 can be formed unitary with the anchoring portion 12, or rigidly
engaged with the latter in any manner.
[0020] If it is required, as in the example shown, that the weight of bin 5 raised by device
1 should be detected, it is provided that at least one load cell 15 would be associated
with each lifting arm 3; said load cell is not further described because it can be
made in any known and conventional manner. Advantageously, as better viewed from Fig.
3, the load cell 15 is fastened to the anchoring portion 12 of the hooking element
6. More particularly, the load cell 15 for the purpose has a first portion 15a housed
in a first seat 16 defined between the anchoring portion 12 and the attachment base
11, and fastened thereto by one or more of the first threaded elements 13 used to
obtain locking of the anchoring portion itself. The suspended portion 14 of the hooking
element 6 is made as a distinct part separated from the anchoring portion 12 and is
fastened to a second portion 15b of the load cell 15, by one or more second threaded
elements 17, for example.
[0021] Advantageously, each of the holding plates 10 has a perimetric edge that, as better
shown in Fig. 3, defines a recess 18 disposed close to the rest seating 6a and extending
concentric with the arched profile of the rest seating itself, according to a radius
of curvature slightly greater than said seating. Beyond the recesses 18, the holding
plates 10 further extend forming respective end portions 19 mutually connected at
the respective upper edges 19a by a connecting plate 20 adapted to define a lead-in
surface to facilitate insertion of pin 5 in the rest seating 6a.
[0022] The present invention achieves important advantages.
[0023] It should be noted in fact that the present invention enables device 1 to be adapted
for execution of the weighing function in a very simple and cheap manner, by merely
replacing the hooking element of one piece construction with a hooking element 6 made
of two distinct parts associated with the respective load cell 15, without further
interventions on the lifting arm 3 being required.
[0024] The possibility of installing the load cell 15 directly on the second end 3b of the
lifting arm 3, which is obtained simultaneously with the manufacture of the hooking
element 6 as a removable component mounted to the end itself enables important advantages
to be achieved in terms of structural simplification, costs, lightening of the parts
and reliability.
[0025] In particular, the invention enables the load cell to be installed at a distance
that just as an indication does not exceed 200 mm, preferably included between 70
and 110 mm, from the rest seating 6a of pin 5a, i.e. at a very close position relative
to the technical solutions of the known art. In this circumstance, the load cell is
submitted to greatly lower stresses than in known embodiments, in which the load cells
were spaced apart a distance greater than 500 mm from the rest seating of the pin.
[0026] The reduced stresses enable use of load cells of smaller sizes, less structural strength
and, consequently, less cost than in the known art.
[0027] The dimensional structure of the members designed for engagement of the load cell
15 is also greatly simplified as compared with the known art, due to the reduced efforts
transmitted.
[0028] Positioning of the load cell 15 at the free end of the lifting arm 3 further ensures
greater reliability and accuracy in detecting the bin weight, because reading is not
affected by the structural strength of the accessory components applied to arm 3 such
as, for example, hydraulic and/or pneumatic pipes interlocked with the actuators 7a,
8a, 9a of the auxiliary devices.
[0029] In addition to the above, the invention improves safety of use in device 1, by eliminating
any risk of the bin 5 falling in case of structural yielding of the load cell or other
components of the hooking element 6. It should be noted in fact that in case of structural
yielding of the load cell 15, the lifting pin 5a of the bin 5 would find a support
on the recesses 18 arranged on the upper edges of the holding plates 10, so as to
prevent the bin from falling. This circumstance cannot be found in the known art,
where breaking of the load cell takes place upon structural yielding of the lifting
arm thereby giving rise to falling of the bin to the ground.
1. An automatic lifting and emptying device for rubbish-collecting bins, comprising:
- at least one lifting arm (3) having a first end (3a) oscillatably in engagement
with a bearing structure (2);
- a hooking element (6) disposed at a second end (3b) of said lifting arm (3) and
having a resting seat (6a) for a lifting pin (5) carried by a bin (5);
characterized in that said hooking element (6) is disposed on the second end (3b) of the lifting arm (3)
being removably in engagement therewith.
2. A device as claimed in claim 1, wherein said hooking element (6) comprises an anchoring
portion (12) fastened to the lifting arm (3) and a suspended portion (14) carrying
the resting seat (6).
3. A device as claimed in claim 2, further comprising at least one load cell (15) associated
with the lifting arm (3) to detect the weight of a bin (5) lying on the rest seating
(6a) of the hooking element (6), said load cell (15) being fastened to the anchoring
portion (12) of the hooking element (6), whereas said suspended portion (14) is separated
from the anchoring portion (12) and fastened to the load cell (15).
4. A device as claimed in claim 1, wherein the second end (3b) of the lifting arm (3)
comprises a pair of holding plates (10) disposed in parallel side by side relationship
and an attachment base (11) fastened between the holding plates (10), said hooking
element (6) being fastened to the attachment base itself (11).
5. A device as claimed in claim 4, wherein each of said holding plates (10) has a perimetric
edge defining a recess (18) disposed close to the rest seating (6a).
6. A device as claimed in claim 3, wherein the load cell (15) is spaced apart a distance
not exceeding 200 mm from the rest seating (6a) of the hooking element (6).