Abstract:
A trolley suitable for aircraft or use in all space constraint situations comprising a waste compactor comprising a metal horizontal plate driven by an electric motor reducer that, by a mechanical reducer, drives two telescopic screws responsible for pushing the horizontal plate onto the waste, compacting it.

Description:
TECHNICAL FIELD 
   This invention relates to a waste compactor. More specifically, it relates to a waste compactor for compacting trash produced on civil aviation aircrafts during flights and a trolley for housing said waste compactor. 
   The waste compactor can handle items such as plastic or paper plates and cups, plastic cutlery, aluminium drink cans, aluminium food containers, Tetrapak-type cartons, paper napkins, etc. 
   BACKGROUND ART 
   Waste compactors, like all the other accessory equipment used onboard aircrafts, must comply with specific, strict requirements provided for by aeronautical regulations. Specifically, the dimensions and structural characteristics of all civil aircraft accessories must be able to support the loads specified in the applicable regulations in force; furthermore, the accessories must be suitable for being housed and stored in safety during travel in specific aeroplane compartments. Finally, the accessories must be as light as possible. 
   Reducing the in-flight weight by about one kilogram leads to significant savings in energy and running costs over the useful life of the aircraft. 
   The operating principle of the compactors available on the market today is not particularly suited for aviation applications. The compactors suffer from several problems, notably: the large dimensions of the waste compactor, the high electrical power required, the use of significant amounts of a pressurized oil fluid, and the use of structurally complex and costly operating and control systems in terms of construction and maintenance. 
   To resolve the above drawbacks, research efforts have focused on doing away with the hydraulic system for safety and cleanliness reasons: components that work under pressure are a potential source of hazards, especially in an aeroplane. One proposed solution was to switch to an electromechanical system. Document U.S. Pat. No. 5,263,412 describes a compactor comprising a horizontal plate driven by an electric motor, which generates a rotary motion, and mechanisms—specifically, a pantograph system—to convert rotary motion into translational motion for moving the horizontal plate. 
   Unfortunately, although this system resolves the problems related to the hydraulic system, it has a serious drawback: it requires the application of very high forces to execute a complete compaction cycle due to the high multiplication ratio of the pantograph. Consequently, this system requires the use a very powerful motor adding bulk, weight, and generating high mechanical stress on the upper structure of the trolley. 
   SUMMARY OF THE INVENTION 
   It is an object of this invention to provide a waste compactor that resolves the aforementioned problems. 
   It is a main object of this invention to provide a waste compactor that is operated by an electromechanical system, has compact dimensions, and requires a reasonably low electrical input. 
   It is another object of this invention to provide a cart, the so-called “trolley”, that comprises said waste compactor and meets the specific requirements for use in environments with space and weight constraints and, in particular, for aviation applications. 
   The trolley in accordance with the present disclosure has the additional advantage of facilitating handling, movement, and removal of the waste containers deformed by the compacted waste after compaction. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other advantages and features of the invention shall be readily apparent from the more detailed description of preferred embodiments of a waste compactor, given by way of non-limiting examples and in conjunction with the following accompanying figures: 
       FIG. 1  shows a longitudinal, vertical, sectional view of a trolley comprising a waste compactor in accordance with the invention; 
       FIG. 2  shows a longitudinal, vertical, sectional view of a trolley comprising a waste compactor in accordance with the invention during compaction; 
       FIG. 3  shows a plan view of the top of a trolley comprising a waste compactor in accordance with the invention; 
       FIG. 4  shows a front view of a trolley comprising a waste compactor in accordance with the invention; 
       FIG. 5  shows a detail view of a vertical section of a trolley comprising a waste compactor in accordance with the invention; 
       FIG. 6  shows a plan view of the moving part of a trolley comprising a waste compactor in accordance with the invention, during different operating stages; 
       FIG. 7  shows a longitudinal, vertical, sectional view of a small trolley, the so-called “half size trolley”, comprising a waste compactor in accordance with the invention; 
       FIG. 8  shows a plan view of the top of a half size trolley comprising a waste compactor in accordance with the invention. 
   

   DESCRIPTION OF THE INVENTION 
   The figures show the preferred embodiments of a trolley  1  comprising a waste compactor  2  attached to a structure consisting of a moving part or drawer  3  moving from the inside to the outside of the trolley  1 , a fixed part  4 , and an outer casing  5 . The dimensions of the trolley are typical of an aeronautical “full size trolley” or, depending on the case, “half size trolley”. In an alternative embodiment of the trolley, the fixed part  4  and the outer casing  5  comprises a single structure carrying out both functions. 
   The waste compactor  2  comprises an electric motor  18 , preferably a motor reducer, that generates rotary motion and is connected to mechanisms comprising a reducing unit  19  and two telescopic screws  15 ,  15 ′. The telescopic screws drive the horizontal, metal, compaction plate  16  by means of vertical, translational motion. For improved mechanical stability, the system should preferably consist of two paired screws  23 ,  23 ′ driven by a single electric motor. Preferably, a twin system of telescopic, ball bearing screws  23 ,  23 ′ should be used to optimize performance close to 100%. 
   The moving part or drawer  3  houses two waste containers or boxes  6 ,  6 ′. A recess is machined from the base or the bottom  7  of the drawer  3  and is covered with a grate designed to collect any fluids flowing from the waste containers. The front and back of the trolley are equipped with a door  10  and  10 ′, respectively provided with a spring latch and safety catch for locking. The moving part  3  slides on prismatic guides  8 ,  8 ′ secured to the base or bottom  9  of the fixed part  4 . The drawer contains two compartments or chambers  12 ,  12 ′ separated by a central openable partition  11  dividing the front chamber  12 , wherein compaction takes place, so-called “compaction chamber”, from the rear chamber  12 ′, wherein the box of compacted waste is pushed from the front chamber when full, so-called “storage chamber”. 
   An advantageous alternative embodiment of the trolley  1  in accordance with the invention features means designed to facilitate the handling, movement, and removal of the waste containers  6 ,  6 ′. A moving side wall  13  of the drawer  3  is hinged to the top of the drawer structure by a horizontal hinge  25  so that said side wall moves outward toward the drawer  3  and the fixed part  4  when the bottom part of said moving side wall  13  is rotated. 
   The moving side wall  13  is preferably limited only to the compaction chamber to obtain more space inside the compaction chamber  12 . On the vertical walls of the rear chamber  12 ′, two side guides placed horizontally compensate for the thickness of the moving wall  13 . This compaction is ideal for preventing the boxes full of waste, which tend to deform during compaction, from getting stuck when pushed in either direction. 
   Normally, persons wishing to dispose of waste throw the waste into the front box  6  of the drawer  3 . To do so, all persons must turn the handle fitted onto the outside of the front door  10 , pull out the drawer, throw the waste into the container, and, finally, push the drawer  3  back into the trolley  1 . 
   The invention includes a specific electromechanical system for retaining the drawer not shown in the Figures to prevent the drawer from opening unexpectedly during the compaction cycle. 
   Thus, to release the drawer, the specific button must be pressed first. 
   Only after said button is pressed will the control system, after making sure that the status of the waste compactor is okay, release the drawer. 
   An appropriate spring latch system is provided to lock the closed drawer. 
   The central partition  11  is opened with a lever  21  placed in the top part of the drawer; the lever can only be pulled when the front door  10  is open. 
   Once the lever is released and the box is pushed, the central openable partition  11  opens and is stowed away at the side of the rear chamber  12 ′. A return spring not shown in the Figures allows this door to close automatically when there is no box to prevent movement. 
   In an advantageous embodiment of the trolley in accordance with the invention, the same type of device used to open the central openable partition  11  is used to operate the moving side wall  13 , which is hinged to the top of the drawer structure, of the compaction chamber of the drawer. 
   The moving side wall  13  solution is conveniently designed to change the internal transversal dimensions of the compaction chamber, effectively facilitating sliding in both directions. This resolves the problem that occurs when the box full of compacted waste bulges enough to hinder movement. 
   When the device is operated by pulling the lever, the entire moving wall  13  rotates around the axis of the hinge and the bottom part moves outward when facing the rear of the trolley, counterclockwise rotation if the moving wall is on the right of the trolley or clockwise rotation if the moving wall is on the left. 
   Once the boxes  6 ,  6 ′ have been removed, when the lever is pushed both the central openable partition  11  and the moving side wall  13  are locked again; in this way the partition and wall return to their vertical position in their initial configuration. 
   The fixed part  4  comprises two bearing side walls joined together at the bottom by means of a plate, which forms the base or the bottom  9  to which the prismatic guides  8 ,  8 ′ are attached. 
   The top part of the fixed part  4  houses the box  14  containing the reduction gears  19  and an electric motor reducer  18  for driving the telescopic screws  15 ,  15 ′. The telescopic screws  15 ,  15 ′ are connected to the horizontal compaction plate  16 , which is pushed in the vertical direction. 
   Essentially, the rotary motion generated by the motor reducer  18  is transferred to the reduction gears  19  and converted to extend the telescopic screws  15 ,  15 ′, causing the metal plate  16  to move down or up through vertical translation motion. The movement of the compaction plate  16  compacts the waste found in the container  6  housed in the chamber  12  above the grate placed on the base or bottom  7  of the drawer  3 . In turn, the drawer rests on the bottom  9  of the fixed part  4  on which the guides  8 ,  8 ′—on which the drawer slides—are fitted. 
   Both the telescopic screws  15 ,  15 ′ and the gear box  14  are anchored to the fixed part  4 . The gear box houses the reduction gears  19  to which the electric motor  30  reducer  18  and the components of the electronic control, not shown in detail in the Figures, are connected. 
   The gear box  14  is a weight-bearing structure through which the compaction load, generated by the action of the telescopic screws  15 ,  15 ′, is absorbed by the fixed part  4  through the following load path: the two side walls, the horizontal plate  9  that acts as base for the fixed part  4 . Only these items are subjected to the mechanical stress generated by the compaction cycle; the other parts of the drawer and casing are not affected. The total weight of the trolley  1  is also reduced thanks to this innovative type of construction. 
   As was already mentioned, all persons wishing to dispose of waste, normally the flight attendants, throw the waste from above top-loading system into the front area of the trolley. Before doing so, the handle on the trolley must be turned to release the locking system of the front door  9  and allow the drawer  2  to be pulled outward by a predetermined amount. Once the waste is thrown away, the drawer must be secured by turning said handle once again, reactivating the internal locking system of the drawer. 
   For the proper and effective operation of the system, the front of the fixed part  4  is fitted with a control panel  17  that interfaces with an electronic unit managed by a microprocessor with software. In this way, it is possible to manage the different operating phases of the compactor  2  appropriately coordinating the functions of compaction, opening the drawer  3  for changing the boxes  6 ,  6 ′, cleaning the interior, and so forth. Furthermore, the control display is a useful tool for viewing information such as the number of cycles and the hours of operation and/or other useful information for the maintenance of the trolley  1  and the compactor  2 . 
   The inside of the trolley  1  is fitted with different types of sensors—which can be microswitches, optical, magnetic, etc.—that are used to enable/disable compaction and assure safety at all times. Specifically, at least one optical sensor checks for the presence of the box in the compaction area; a microswitch makes sure that the front  10  and rear  10 ′ doors of the trolley, and possibly also the central openable partition  11 , are closed; and other sensors may be present to control any other function deemed necessary. 
   A red emergency button is fitted for added safety, advantageously, on the control panel at the front of the trolley  1 . 
   When the second box  6 ′ is also full, the compaction unit must be emptied before reuse. To make box changing/removal and trolley  1  cleaning operations easier, the trolley can be easily removed from the galley or from other area of the aircraft vehicle where it is stowed. 
   To remove the boxes  6 ,  6 ′ from the chambers  12 ,  12 ′, the front door  10  must be opened and the central openable partition  11  must be released; a rear door  10 ′ is also included for easier maintenance and cleaning of the compactor. 
   To clean the inside of the trolley, the front control panel features a button for placing the compaction plate at a height suitable for cleaning, using a cloth, the top from any remains produced during compaction. This operation is made easier thanks to the presence on the top of the compaction plate  16  of only slender or small elements such as the telescopic screws  15 ,  15 ′ and any protective devices. Cleaning the top part of the walls of the fixed part is also facilitated by the use of the telescopic screws  15 ,  15 ′ in accordance with the invention: these become shorter in length compared with other known systems. 
   As previously mentioned, there is a recess covered by the removable grate in the base plate  8  of the drawer or in the moving part  3 . This recess collects any fluids flowing from the boxes and can then be emptied by the personnel. 
   The outer casing  5  consists of a frame to which the fixed part is attached by means of appropriately placed screws or other fastening means. The casing is made of extruded sections, forming the framework, that are joined with aluminium angle bars; sandwich panels are used for the side walls and the top. The side plates completely cover at least the compaction area and are joined to the framework of the outer casing  5 . 
   Six wheels  20  for moving the trolley are fastened to the bottom part of the base of the casing  5 . 
   Another advantageous embodiment of the invention, see  FIGS. 7 and 8 , where the components are identified with the same reference numbers as the ones used for the already described embodiments, is the smaller trolley  1 , the so-called “half size trolley”. This comprises the waste compactor  2  joined to a structure consisting of a moving part  3 —equal to approximately half the length of the previously described embodiment of the trolley—that can contain only one box  6  where the compaction takes place, in addition to a fixed part  4  and a casing  5 . 
   The moving part or drawer  3  is the item of the structure that houses the single waste container  6  and is equipped with a single door  10  at the front. This door has a spring latch and safety catch for locking. The central openable partition is not included in this embodiment of the invention. 
   The use of the trolley in accordance with the invention is not limited to the aviation industry; the trolley can also be used on coaches, trains, and ships or in the civil sector in general whenever it is necessary to compact this type of waste and there are space constraints. 
   The trolley is made of materials particularly suited for use on aircraft for example, Aluminium alloys; however, other materials can be used if the trolley is employed on vehicles where there are not the same structural and weight constraints. 
   The particular embodiments described in this document do not limit the scope of this patent application, which covers all the embodiments of the invention defined in the claims.