A device for weighing rubbish-collecting bins

Abstract: In an automatic lifting and emptying device for rubbish-collecting bins, weighing of the bin (5) takes place by means of a hooking element (6) removably fastened to a second (3b) of a lifting arm (3) the first end (3a) of which is linked to the bearing stucture (2) mounted on a side of a motor-vehicle. The hooking element (6) is formed into two distinct portions (12,14). An anchoring portion (12) is removably fastened to the lifting arm (3) and causes fastening of a load cell (15) to the arm itself for detection of the bin weight. A suspended portion (14) is fastened to the load cell (15) and carries a rest seating (6a) for a lifting pin (5a) laterally projecting from the bin (5).

Description: The present invention relates to a device for weighing rubbish-collecting bins having laserally extending lifting pins comprising the features recited into the preamble of claim 1. Document DE-A-1 937 400 discloses a device having the above referred features. More particularly, such a device provides lifting arms each exhibiting a hooking element removably engaged at one end of a lifting arm, so as to allow replacement with hooking elements having different geometrical and dimensional structure. 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. An automatic gripping and emptying device for rubbish bins is described in the European Patent EP-B-776835. 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. 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. 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. 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. 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. In accordance with the present invention it has been found that these problems can be brilliantly overcome by a hooking element having the features of the characterising part of claim 1. 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 comprising a weighing device 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 the weighing 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. 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. 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 structure 2 in engagement on the motor-vehicle side. 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. 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. Said rest seating 6a 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. 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. 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. 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. 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. 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. Advantageously, each of the holding plates 10 has a perimetric edge that, as better shown in Fig. 3, defines a recess 10a 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 10a, the holding plates 10 further extend forming respective end portions 19 mutually connected at the respective upper edges by a connecting plate 20 adapted to define a lead-in surface to facilitate insertion of pin 5 in the rest seating 6a. The present invention achieves important advantages. 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. 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. 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. The reduced stresses enable use of load cells of smaller sizes, less structural strength and, consequently, less cost than in the known art. 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. 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. 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.

Claims: Device for weighing rubbish-collecting bins (5) having laterally extending lifting pin (5a), comprising: at least one lifting arm (3) having a first end (3a) oscillatably in engagement with a bearing structure (2) and a second end (3b) carring a removably fastened hooking element (6) having a rest seating (6a) for a lifting pin (5a) of the bin (5), characterised in that said hooking element (6) comprises an anchoring portion (12) fastened to the lifting arm (3) and a suspended portion (14) carrying the rest seating (6), and least one load cell (15) to detect the weight of the 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). 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 abase (11) fastened between the holding plates (10), said anchoring portion (12) of the hooking element (6) being fastened to the attachment base itself (11). Device as claimed in claim 2, wherein each of said holding plates (10) has a perimetric edge defining a recess (18) disposed close to the rest seating (6a), for supporting the lifting pin (5a) in case of structural yelding of the load cell(15). Device as claimed in claim 1, wherein the load cell (15) is spaced apart a distance not exceeding 200 mm from the rest seating (6a) of the hooking element (6). Automatic lifting and emptying device (1) for rubbish - collecting bins, (5) characterized in that it comprises a weghing device according to anyone of claims 1 to 4.

Inventors: OTTOLINA VITTORIO, SAVOLDI FRANCO, OTTOLINA, VITTORIO, SAVOLDI, FRANCO
Applicants: O M B BRESCIA S P A, O.M.B. BRESCIA S.P.A.
Application year: 2001
Main classification: B65F3
IPC codes: B65F3