Patent Publication Number: US-7712181-B2

Title: Hopper opening mechanism

Description:
The present invention relates to a hopper opening mechanism, in particular for assisting in the cleaning of motorised suction sweeping machines used for clearing dirt and litter from streets and roads. The present invention also provides a method of opening or a method of tipping a suction sweeping machine comprising a hopper. 
   A suction sweeping machine generally comprises front rotary sweepers for gathering the dust and the like, water sprayers for wetting the dust and the like in dry weather, and a vacuum cleaning or suction mechanism for sucking the wetted dust and the like into the machine for collection in a hopper via a suction hose. Once the hopper is full, the machine is emptied and, if required, cleaned. 
   It is known to fit cyclone units into such suction sweeping machines. These cyclone units are provided for removing fine or small dirt and the like from the airflow generated by a main vacuum fan. Larger dirt and litter, which would damage the cyclone unit, is prevented from entering the cyclone unit by a mesh screen. The cleaned air is then vented from the machine, while the dirt and litter that has been extracted from the airflow is thrown by the cyclone unit into the hopper. The hopper, i.e. a container for collecting the dirt ant litter, when full, needs to be emptied. At the end of the day, the hopper is additionally cleaned. The cyclone unit, however, is a sealed unit. Therefore it is difficult to clean. 
   In order for these machines to remain efficient, the cyclone unit must function properly. However, if the mesh screen becomes clogged by the dirt and the like, the airflow into the cyclone unit will be impaired and the cyclone unit, which requires airflow to drive it, will lose efficiency. Therefore it is necessary to clean the mesh screen at least once a day, usually at the end of the day. Further, it is preferred to clean the cyclone unit occasionally. However, cleaning these machines, and in particular the mesh screen or the cyclone unit, is generally unpleasant, undesirable and difficult. It would therefore be desirable to provide a suction sweeping machine or cyclone unit therefore, that is easier to clean. 
   The present invention provides a hopper opening mechanism for a hopper in a suction sweeping machine, the opening mechanism comprising an actuator mechanism for opening the hopper for cleaning of the hopper, wherein the actuator mechanism also rotates a mesh screen for cleaning of an otherwise inaccessible surface the mesh screen. 
   Preferably the mesh screen is a filter for a cyclone unit. 
   The present invention also provides an opening mechanism for a cyclone unit and hopper in a suction sweeping machine, the opening mechanism comprising an actuator mechanism for opening both the cyclone unit and the hopper for cleaning of the cyclone unit and the hopper. Preferably a base of the cyclone unit is moved by the actuator mechanism relative to the rest of the cyclone unit to open the cyclone unit. Preferably the base is rotated. 
   Preferably the base has a portion of a mesh screen attached thereto, the mesh screen forming a filter for the cyclone unit. 
   The present invention also provides a cyclone unit and hopper comprising an opening mechanism for opening both the cyclone unit and the hopper. 
   The present invention also provides a suction sweeping machine comprising a cyclone unit, a hopper and an opening mechanism for opening both the cyclone unit and the hopper. 
   Preferably the actuator mechanism comprises a hydraulic piston. 
   Preferably the actuator mechanism is attached at one end to the inside of the hopper, and more preferably to the roof of the hopper. 
   Preferably the actuator mechanism is attached at one end to a lid or door of the hopper. 
   Preferably the actuator mechanism is attached at one end to a removable base of the cyclone unit. 
   Preferably the actuator mechanism is attached at one end to the removable base of the cyclone unit via a hinged portion of a mesh screen for the cyclone unit, the base being attached to the hinged portion of the mesh screen. 
   Preferably the actuator mechanism is attached to the lid or door of the hopper via a linkage mechanism. Preferably the actuator mechanism is attached to the mesh screen, or the base of the cyclone unit, or both, via a linkage mechanism. Preferably the linkage mechanism is attached to both the mesh screen and the lid or door of the hopper. 
   Preferably the actuator mechanism, upon actuation, will open the lid or door of the hopper by rotating it. Preferably the lid or door is rotated by about 60°. 
   Preferably the actuator mechanism, upon actuation, will rotate the mesh screen and base of the cyclone unit. Preferably they are rotated by about 34.4°. 
   Preferably there is a single actuator in the actuator mechanism. 
   Preferably there is a single lid or door for the hopper. Preferably the lid or door is hinged towards the front of the hopper. Preferably the hopper is positioned towards the rear of the suction sweeping machine. 
   Preferably the mesh screen is attached to the base of the cyclone unit using spacers to provide an air gap between the base of the cyclone unit and the hinged portion of the mesh screen. Preferably the air gap is about 20 mm. 
   Preferably the cyclone unit is inside the hopper. Preferably the cyclone unit is positioned towards the top and front of the hopper. Preferably the cyclone unit comprises an air vent for venting air to the atmosphere, out of the hopper. Preferably the air vent is positioned towards the top of the hopper. 
   Preferably the mesh screen effectively extends across the entire horizontal area of the hopper, just below the top thereof. Preferably the mesh screen is in two parts. Preferably a first part extends substantially horizontally, in its closed position, below the or each cyclone unit. Preferably a second part extends substantially horizontally, in its closed position, below the lid or door of the hopper. Preferably both parts are hinged. Preferably the first part is rotated by the actuator mechanism. Preferably the second part is hinged adjacent the junction thereof with the first part. Preferably the junction extends laterally across the hopper. Preferably the first part is hinged adjacent the front of the hopper, parallel to the hinge of the second part. Preferably a portion of the second part of the mesh screen is provided on the underside of the lid or door of the hopper, so that it is opened as the lid or door of the hopper is opened by the actuator mechanism. 
   Preferably a pair of cyclone units is provided. Preferably the cyclone units are laterally spaced. Preferably the actuator mechanism is positioned between the two cyclone units. 
   Preferably the hopper comprises a tipper mechanism for tipping the hopper about a hinge point for emptying the contents thereof through the lid or door of the hopper once the lid or door of the hopper has been opened by the actuator mechanism. 
   Preferably the lid or door of the hopper is provided at the top of the hopper in its untipped position. 
   Preferably the lid or door opens such that it moves away from the hinge point. 
   Preferably the mesh screen is rotated such that it moves away from the hinge point. 
   The present invention also provides a method for tipping a hopper of a suction sweeping machine comprising:
         providing a suction sweeping machine having a hopper with a lid or door for tipping any contents of the hopper therefrom, the hopper being positioned towards the rear of the suction sweeping machine, the hopper comprising a tipping mechanism; and   actuating the tipping mechanism to tip the hopper about a hinge point positioned substantially towards the top and rear of the suction sweeping machine.       

   Preferably the hopper, to tip out its contents, is rotated up and over the hinge point by about 110°. 
   Preferably, upon starting to tip the hopper, the hopper is moved rearwardly and upwards, while being rotated, to move it out of the suction sweeping machine such that, in its tipped position, it will hang substantially upside down, above and clear of the suction sweeping machine. 
   Preferably the hopper has a cyclone unit therein and an opening mechanism, for example as described above. 
   Preferably the opening mechanism opens a lid or door of the hopper and opens a base of the cyclone unit to move them into a cleaning position prior to tipping of the hopper. 

   
     The present invention will now be described, by way of example only, with reference to the accompanying drawings in which: 
       FIG. 1  shows a detailed perspective view from the top of a preferred cyclone unit for a suction sweeping machine; 
       FIG. 2  shows a perspective view of the cyclone unit of  FIG. 1 ; 
       FIG. 3  shows in elevation a suction sweeping machine incorporating the opening mechanism of the present invention in an opened state; 
       FIG. 4  shows in elevation the hopper and cyclone unit of the machine of  FIG. 3  prior to tipping of the hopper; and 
       FIG. 5  shows in elevation details of a linkage mechanism for operating the opening mechanism of the present invention. 
   

   Referring now to  FIG. 3 , there is shown a small sweeper or suction sweeping machine  10  that uses a centrifugal fan (not shown) to suck up dirt and dust in all weathers. It passes the dirt and dust via a pick up hose (not shown) through the fan, which compacts this material and blows it into a hopper  12 . Once the hopper  12  is full, the hopper is emptied by tipping out its contents. The hopper  12  is shown in its tipping position  20  and its non tipping position  22 . Instead of a fan through which the dirt passes, however, the system may operate using a vacuum source to pull the dirt into the hopper. 
   In dry or damp conditions water is sprayed from the front brushes  14  onto the ground to prevent airborne dust from being created by the brushes, and also into the front of the pick up hose to treat dusty air or to prevent the hose becoming blocked with sticky dirt. Water is also sprayed at the top of the hose before the fan. 
   As dusty material, with the water, enters the casing of the fan, the mixing and compacting properties of the fan agglomerates the majority of the dry/dusty material swept and sucked up off the ground to form heavy dirt before it enters the hopper. 
   A system of baffles in the main body of the hopper spins the material, air and water mixture in the hopper, creating a cyclone effect. The baffles are placed in the corners of the hopper and when air, water, dirt and dust enter the hopper, it does so at the near side of the hopper. Together with the baffles the mixture is set spinning with the heavy dirt being thrown against the walls of the hopper and lighter material settling into the ‘dead’ air area at the centre of the hopper. A sample device incorporating this technology is the original Applied 525 sweeping machine, from the present applicants. Further description of this basic cyclone effect, therefore, is not required. 
   The machine shown in  FIG. 3 , however, comprises a secondary cleaning system not found in the original Applied 525 sweeping machine. Referring in particular to  FIG. 4 , the hopper  12  is again shown, but in more detail. The hopper  12  has therein a pair of cyclone units  16  (one shown). A cyclone unit  16  is provided on each side of the machine  10 . 
   A mesh screen  18  is provided inside the hopper  12  to extend substantially across the entire horizontal extent of the hopper  12 , just below the top  50  of the hopper  12 , but below the cyclone units  16 . In the figures, the mesh screen  18  is shown to comprise multiple component parts  18 ′,  18 ″,  18 ′″. They are all hinged so that they can be opened for cleaning both sides thereof. 
   A first part is positioned below the cyclone units  16 . It is shown in an open or downwardly rotated position  18 ′ as well as the closed position. It can be rotated about a hinge  19  adjacent the front of the hopper  12 . When the cyclone units are operating, however, this part of the mesh screen  18  will be closed (reference sign  30  in  FIG. 5 ). 
   A second part  18 ″ is provided on the underside of the lid or door  24  of the hopper  12 . It is hinged adjacent the hinge  23  of the lid or door  24 . 
   The third part  18 ′″ is hinged about a laterally extending hinge  25  towards the middle of the hopper  12 . 
   The air that has been partially cleaned by the main cyclone formed by the baffles passes through the mesh screen  18  towards the roof of the hopper  12 . These mesh screen entraps material to prevent certain large grades of material from entering the cyclone units  16 . Much of this entrapped material will then fall into the hopper. 
   Depending on conditions of the dirt on the ground, some material will pass through the mesh screen  18 . This is typically light, dusty material that has not been agglomerated by the water dust suppression system. It is this material that then passes through the twin, roof mounted, cyclone units  16 . 
   Cyclone units are normally designed individually to handle a certain flow of air at a certain pressure. The material the cyclones are designed to separate normally does not change. It is either wet or dry and normally of a predetermined size. The material passing through the mesh screens  18  into the cyclone units  16  will be dry or wet depending on the conditions of the street. The cyclone unit shown in  FIGS. 1 and 2  will handle both wet and dry dirt. 
   Referring to  FIG. 2 , each cyclone unit  16  comprises stationary, angled blades (or fins)  32 , a spinner  34  underneath them (shown more clearly in  FIG. 5 ), and a central air venting core. The spinner comprises four arms  40  (one shown having a paddle on the end—each arm, however, will generally have a paddle). The side wall of the cyclone unit  16  has at least one dirt slot  38  therein for the dirt to exit the cyclone unit  16 . The base of the cyclone unit  16  is made of a solid steel plate  39 . The plate  39  can be moved relative to the rest of the cyclone unit  16  to open up the cyclone unit for cleaning it. 
   Referring to  FIGS. 2 ,  4  and  5 , after dusty or dirty air has passed  29  through the mesh screen  18 , the dusty or dirty air will enter  31  the cyclone units  16 . Then it passes through the angled blades  32 . They cause the air to spin at high speed around the cyclone unit  16 . The slot or slots  38  in the external wall of the cyclone units then allows the heavier than air material to pass out of the cyclone unit for collection in the hopper  12 . The spinner  34  (a propeller-like unit) spins with the air causing the ‘boundary’ air in the cyclone unit to be at a higher velocity and so more efficient at displacing the dirt therefrom. The cleaned air will then pass to the inside of the cyclone unit and exit  33  upwards through the central core  36 . 
   The heavier than air material passing out of the cyclone unit for collection in the hopper  12  may pass back through the mesh into the hopper or may collect on the cyclone unit side of the mesh screen  18 . 
   The operation of the cyclone units  16  will be readily understood by a skilled person in the art of cyclone based dirt/air separation units. Therefore further description of the cyclone units  16  is not required. 
   Dirt and dust will build up in and around the area where the cyclone units  16  are housed. Further, if wet or damp material passes through the cyclone units  16 , the centrifugal forces will cause the dirty material to be thrown against the cyclone units inside walls. Although non sticky dirt will pass through the dirt slots into the hopper, glutinous material will stick against the wall of the cyclone (as it does in the hopper area and generally around the sweeping equipment). Therefore, it is useful to be able to wash down the internal mechanisms of the suction sweeping machine  10 , the mesh screen and the inside of the cyclone units regularly and easily to keep the machine  10  operating properly and at maximum efficiency. 
   The present invention provides a mechanism for facilitating the cleaning operation of the internal mechanisms of the hopper and cyclone unit. 
   As shown in  FIG. 5 , the base of the cyclone unit  16  (steel plate  39 ), which is attached to the hinged part  18 ′ of the mesh screen  18 , swings down and away from the rest of the cyclone unit  16  to open up the interior of the cyclone unit  16 . This facilitates the cleaning of the interior of the cyclone unit  16 . 
   In order to operate the opening of the mesh screen, an actuator mechanism  42  is provided. The actuator mechanism  42  comprises a hydraulic cylinder  44  attached at a first end  46  to a bracket  48  on the inside surface  50  of the roof of the hopper  12 . At the other end of the cylinder  44  there is a piston  52 , operable with the cylinder  44  to form a hydraulic ram. The piston  52  connects at its operative end  54 , i.e. the end distal to the first end  46  of the cylinder  44 , to a linkage mechanism  56  that is operatively connected to both a lid or door  24  for the hopper  12  and the hinged part  18 ′ of the mesh screen  18 . 
   The linkage mechanism  56  comprises a link arm that is connected to both a lever arm for the lid or door  24  of the hopper  12  and to a lever arm  60  for the hinged part  18 ′ of the mesh screen  18 . The lengths of the two lever arms are different so that the angles to which the lid or door  24  and the hinged part  18 ′ of the mesh screen  18  will open upon operation of the actuating mechanism will be different. The angles are shown to be 60° and 34.4°, respectively. 
   The linkage mechanism is shown in three separate positions in  FIG. 5  (and in  FIG. 4 ). Reference sign  56  is for the open position. Reference sign  56 ′ represents an intermediate position. Reference sign  56 ″ represents a closed position. 
   The suction sweeping machine also comprises a tipping mechanism for the hopper  12 . Referring to  FIG. 4 , the tipping mechanism comprises a hinge arm  62  that is welded or bolted to the rear wall  64  of the hopper  12 . The hinge arm has a hinge point  66  positioned substantially towards the rear and top of the hopper. A hydraulic ram (not shown) operates against the hinge arm  62  to rotate the hopper  12  up and over the hinge point  66  by about 110° into an inverted and raised position (tipping position  20 ) as shown in  FIG. 3 . 
   To empty the hopper, the suction sweeping machine is first positioned such that it is backed up to a skip, or the like, for receiving the dirt from the hopper  12 . Then a user operates the tipping mechanism to tip out the contents of the hopper  12  into the skip. 
   The actuator mechanism for the door  24  of the hopper and the hinged part  18 ′ of the mesh screen  18  will be operable in conjunction with the tipping mechanism such that the actuator mechanism can be operated either before the tipper mechanism is operated, or as the tipper mechanism is operated. 
   At the end of each day, the hopper  12 , the mesh screen  18  and the cyclone units  16  will need to be washed out. To do this a user, after tipping out the contents of the hopper  12  as best as possible by operating the tipping mechanism while the machine is positioned backed up to the skip, will move the machine  10  forward without untipping the hopper to allow him to stand behind the machine  10 . The user will then wash down the inside of the hopper  12 , for example using a high pressure hose. 
   As shown in  FIG. 3 , in the tipping position  20  the hopper  12  is rotated to be positioned above and behind the suction sweeping machine  10 . Further, the lid or door  24  of the hopper  12  is opened. Further, the mesh screen  18  will also be open. These three features provide for simple access to the dirty parts of the internal mechanisms of the hopper, the mesh screen and cyclone units, thereby facilitating the cleaning process for the hopper, the mesh screen and the cyclone units; access to the inside of the hopper  12  and both surfaces of each part of the mesh screen  18  is provided through the lid or door of the hopper since the mesh screen parts are hinged so that water can be sprayed on the inside surface of the hopper  12  and also the both surfaces  26  of the various parts of the mesh screen  18  to displace any accumulated dirt from the outside surface  28  of the mesh screen  18 —water can push through the mesh screen to force out entrapped dirt. Further, with a hooked hose, the inside of the cyclone unit can also be washed out easily. 
   As the sweeper has to operate in all weathers and be kept clean in order to be at its most efficient it is important that all areas of the sweeper involved in filtration of dirty air can be cleaned. Further, knowing the reluctance of most operators to perform this unpleasant job, it is important that the cleaning is made as easy and accessible as possible. It is for this reason that the present invention makes the cyclone units and the mesh screen, i.e. the filters, split or open automatically whenever the machine is emptied. This facilitates the cleaning of the internal components of the suction sweeping machine  10 , and in particular otherwise inaccessible areas and components of the machine  10 . 
   The present invention has been described above purely by way of example. Modifications in detail, however, may be made to the invention as defined in the claims appended hereto.