Abstract:
A sorting apparatus for sorting piece goods ( 12 ), having at least a first moving transport unit ( 22 ) for transporting at least one piece good ( 12 ) in a main transport direction ( 18 ), the first transport unit ( 22 ) has a chassis ( 38 ) for the movement, a transfer unit ( 32 ) which moves the piece good ( 12 ) in a transfer direction ( 50 ), and a drive unit ( 34 ) fixed to the first transport unit ( 22 ) for driving the piece good ( 12 ) in the transfer direction ( 50 ). The sorting apparatus has a coupling device ( 62 ) for coupling the chassis ( 38 ) to the drive unit ( 34 ) at least for a period of time.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a 35 U.S.C. §§371 national phase conversion of PCT/EP2012/068727, filed Sep. 24, 2012, which claims priority of German Patent Application No. 10 2011 083 882.1, filed Sep. 30, 2011, the contents of which are incorporated by reference herein. The PCT International Application was published in the German language. 
     TECHINCAL FIELD 
     The invention relates to a sorting apparatus for sorting individual items. 
     TECHNICAL BACKGROUND 
     A sorting apparatus has at least a first movable transport unit for transporting at least one individual item in a main transport direction. The first transport unit has a chassis for movement in the main transport direction. It has a transfer unit for moving the individual item in a transfer direction, which differs from the main transport direction, during a transfer operation. It also has a drive unit, which is fixed to the first transport unit and is provided for driving the individual item in the transfer direction. 
     Sorting apparatus are known, which convey a chain of coupled transport units along a conveyor section, in particular a closed circulating section, by means of a static, central drive. Linear drives, friction wheels or chain systems are conventional embodiments of such a central drive. Each transport unit also has a local drive unit, which can be used to drive a transfer unit, which has a belt element for example, for an inserting or ejecting operation. 
     The abovementioned central drives give rise to disadvantageous challenges in relation to the geometric and functional configuration of the sorting apparatus. In particular it is necessary to provide a large amount of space. Also such sorting apparatus are cost-intensive in respect of energy requirements. 
     The object of the invention is to provide a generic sorting apparatus, which allows a compact design and low operating costs to be achieved. 
     SUMMARY OF THE INVENTION 
     To achieve the object, it is proposed that the sorting apparatus has a coupling facility for coupling the chassis to the drive unit, at least for a period of time. This means there is no need, either at least largely, or in particular at all, for a central drive for driving the transport unit. There is thus no need for a considerable part of the space usually required for a central drive. Advantageously, direct driving of the chassis by the local drive unit allows energy losses, which result during the conventional transmission or conversion of the drive energy generated by a stationary unit for the onward movement of the transport unit in the main transport direction, to be avoided to the greatest possible degree. 
     The ability of the transport unit to move is defined relative to a stationary reference system, which is fixed to the base of a sorting unit. The movement of the transport unit also expediently takes place relative to at least one stationary input station and at least one stationary output station. During a transfer operation, which is configured as an input operation or an inserting operation, an individual item is transferred from the input station in a transfer direction to a passing transport unit, to be then transported in the main transport direction by means of the transport unit. An output or ejecting operation is a further transfer operation of the sorting apparatus, in which the individual item is transferred from the transport unit in a transfer direction to the output station, in order to be conveyed onward from there. 
     For movement of the transport unit in the main transport direction, the chassis expediently has at least guide elements, e.g. guide wheels, which correspond to corresponding stationary guide elements, e.g. guide rails, and carriage elements, which are actively connected particularly by a drive axle, to drive elements of the drive unit. The guide elements and carriage elements can be formed at least to some degree by identical parts. 
     The “coupling” of the chassis to the drive unit refers in particular to an operation, in which the drive unit and the chassis are coupled to one another for drive purposes. In this process the chassis is preferably connected to the drive train of the drive unit in such a manner that the resulting connection allows transmission of the drive energy generated by the drive unit to the chassis, with a torque of the chassis for example, as required for the onward movement of the transport unit, being generated by said drive energy. 
     The sorting apparatus is particularly suitable for an application as a component of a baggage handling unit, in particular in an airport, for sorting baggage items, and/or as a component of a package handling unit in a distribution center for sorting package units. 
     According to one advantageous embodiment of the invention the sorting apparatus has a control unit, which is provided to activate the coupling facility as a function of a transfer operation. This allows the time period for coupling the drive unit to the chassis to be matched in an efficient and precise manner to the performance of a transfer operation. 
     In this context it is proposed that the control unit is provided to establish coupling of the chassis to the drive unit on completion of a transfer operation, allowing particularly efficient utilization of the available drive power of the drive unit to be achieved. Based on the knowledge that the drive unit of a transport unit is conventionally deployed for transfer operations for approx. 20% of the operating time of the sorting apparatus, said drive unit can advantageously be deployed for up to 80% of the operating time for the onward movement of the transport unit in the main transport direction by means of the coupling of the drive unit to the chassis. 
     The control unit is advantageously a control unit fixed to the transport unit, in that it is coupled in a mechanically fixed manner to the transport unit. This allows short control paths to be achieved. The control unit is expediently connected in an active manner to a central, stationary monitoring unit for monitoring the flow of individual items by way of a data network. 
     In one advantageous development of the invention it is proposed that the sorting apparatus comprises at least a second transport unit for transporting at least one individual item in the main transport direction. The second transport unit is coupled mechanically to the first transport unit, and it has a transfer unit, which is provided to move the individual item it is transporting in a transfer direction, which differs from the main transport direction. During a transfer operation, the control unit assigned to the first transport unit causes the chassis of the first transport unit to be coupled to the drive unit of the first transport unit during a transfer operation of the second transport unit. This allows the drive unit of the first transport unit to be used for the onward movement of the second transport unit, which is coupled mechanically to it, in particular while the second transport unit performs a transfer operation. 
     In this context it is also proposed that the second transport unit has a chassis for movement in the main transport direction, a fixed drive unit, which is provided for driving the individual item it transports in the transfer direction, and a coupling facility, which couples the chassis of the second transport unit to its drive unit at least for a period of time. This allows an advantageous redundancy to be achieved in the drive of the transport units in the main transport direction in the sorting apparatus. 
     If the sorting apparatus has a set or chain of transport units coupled mechanically to one another, it is particularly advantageous if at least the majority of the transport units—in particular all the transport units—are provided with a chassis, a transfer unit, a drive unit and a coupling facility, as described above for the first transport unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An exemplary embodiment of the invention is described in more detail with reference to the figures, in which: 
         FIG. 1  shows a sorting apparatus with a set of transport units, which are conveyed along a circulating section and 
         FIG. 2  shows a detailed view of one of the transport units from above. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
       FIG. 1  shows a schematic view from above of a sorting apparatus  10  for sorting individual items  12 . In the exemplary embodiment, the sorting apparatus  10  is configured as a component of a sorting and distribution center for sorting package units. 
     The sorting apparatus  10  has a conveyor unit  14 , which in the present example is configured as a rotating conveyor. This conveyor unit  14  conveys individual items  12  to be sorted along a closed conveyor section  16 . The direction in which the individual items  12  are moved by means of the conveyor unit  14  along the conveyor section  16  is referred to as the main transport direction  18 , with the individual items  12  conveyed in the main transport direction  18  forming an individual item flow  20 . 
     The conveyor unit  14  comprises a set of transport units  22 , which are driven to move along the conveyor section  16 . Each transport unit  22  is provided with a receiving facility  24 , which receives at least one individual item  12  to be sorted. The receiving facility  24  in particular forms a transport surface  26 , on which the individual item  12  remains as it is conveyed along the conveyor section  16 . 
     The individual items  12  are sorted by means of transfer operations which take place at transfer stations  28 ,  30 . At the transfer station  28  an individual item  12  is inserted into the individual item flow  20  in a transfer operation referred to as an inserting operation, in that it is conveyed to a transport unit  22  with free transport surface  26 . At the transfer station  30  an individual item  12  conveyed by the conveyor unit  14  is removed from the individual item flow  20  in a transfer operation referred to as an ejecting operation, in that it is conveyed from the transport surface  26  to a technical conveyor unit of the transfer station  30 . 
     The movement of the individual item  12  relative to the individual item flow  20  during an inserting and ejecting operation is brought about by means of a transfer unit  32 , with which each transport unit  22  is provided. The transfer unit  32  has a drive unit  34 , configured for example as an electric motor, and a conveyor facility  36 , which can be driven by this and moves the individual item  12  to be transferred in a transfer direction  50 , which differs from the conveyor direction  18  (see  FIG. 2 ). Assigned to the conveyor facility  36  for the purpose of controlling the drive unit  34  is a control unit  35 , which is for example a decentralized control unit in the form of a component of the transport unit  22 . In an alternative embodiment the conveyor facility  36  can be controlled by a central, stationary control unit. 
     One of the transport units  22  is shown more closely in a detailed view in  FIG. 2 . For movement in the main transport direction  18  the transport unit  22  is provided with a chassis  38 . This has at least two drivable rolling bodies  40 . 1 ,  40 . 2 , in particular in the form of drive wheels, which interact with corresponding stationary rails  42 . 1 ,  42 . 2  of the conveyor section  16 . The chassis  38  also comprises a set of guide bodies  44 . 1 ,  44 . 2 , which correspond to corresponding stationary guide elements  46 . 1 ,  46 . 2  of the conveyor section  16 . These guide elements  46 . 1 ,  46 . 2  are in particular each formed here by a surface formed by one of the rails  42 . 1 ,  42 . 2 . The rails  42 . 1 ,  42 . 2  therefore have the function of guide rails. The guide bodies  44 . 1 ,  44 . 2  are each configured as rolling bodies, which have a rotation axis  48  extending vertically and perpendicularly to the main transport direction  18 . 
     As mentioned above, the transport unit  22  has a transfer unit  32 , which is deployed in conjunction with a transfer station  28  or  30  for moving the individual item  12  in the transfer direction  50  during a transfer operation. In the example in question the transfer direction  50  is aligned perpendicularly to the main transport direction  18 . For the purpose of conveying in the transfer direction  50  the transfer unit  32  is provided with the conveyor facility  36 , which in the example in question has a conveyor element  52  configured as a conveyor line or conveyor belt. For the sake of clarity the conveyor element  52  is only shown with a broken line in the figure. To move the conveyor element  52  the conveyor facility  36  also comprises a pair of rollers  54 . 1 ,  54 . 2 , which are aligned parallel to one another and each have a horizontal rotation axis  56  aligned in the main transport direction  18  or perpendicularly to the transfer direction  50 . The roller  54 . 2  is configured as a drive roller, while the other roller  54 . 1  is a running roller. 
     As described above, the conveyor facility  36  has the drive unit  34  configured as an electric motor and the control unit  35 , which is actively connected thereto. The drive unit  34  and the control unit  35  are therefore components of the movable transport unit  22 , in other words they are coupled in a mechanically fixed manner, in particular rigidly, to a base body of the same. The drive unit  34  draws a drive energy required to drive it, in particular by way of the control unit  35 , by means of a current collector  58 , which engages with a stationary power rail  60  of the section  16 . 
     The transport unit  22  is also provided with a coupling facility  62 , which is connected downstream, in particular connected directly downstream, of the drive unit  34 —in relation to the drive train. It is configured as an alternating coupling, which —in a first operating position—establishes a coupling between the drive unit  34  and the conveyor facility  36 , in particular its drive roller  54 . 2  and—in a second operating position—establishes a coupling between the drive unit  34  and the chassis  38 . The alternating coupling can in particular be configured as an electromechanical alternating coupling. 
     The first operating position of the coupling facility  62  is set by means of the control unit  35  during a transfer operation. The drive energy of the drive unit  34  is transmitted by way of further drive elements  64 ,  66  to at least one of the rollers  54 , in particular to the drive roller  54 . 2 . In the exemplary embodiment in question the drive elements  64 ,  66  are configured as a drive axle or drive belts. When the coupling facility  62  is in this operating position, the drive energy is used to drive the conveyor facility  36 , by means of which the individual item  12  transported by the transport unit  22  is moved in the transfer direction  50 . 
     On completion of the transfer operation the drive unit  34  is available for the onward movement of the transport unit  22 . To this end the control unit  35  sets the coupling facility  62  in the second operating position, in which the drive unit  34  is coupled to the chassis  38  for drive purposes. This is brought about by means of a drive element  68 , which is coupled to a drive axle  70  connecting the rolling bodies  40 . 1 ,  40 . 2 . In the example in question the drive element  68  is configured as drive belts. 
     Further transport units  22 —which form either part of the set of transport units  22  or advantageously the entire set of transport units  22  of the conveyor unit  14 —are configured in an essentially identical manner to the transport unit  22  according to the above description. These transport units  22  each have at least a chassis, a transfer unit, a drive unit, a control unit and a coupling facility, by means of which the local drive unit can be coupled to the chassis, as described above. 
     All the drive units  34  of the conveyor unit  14  together form a drive, which has a high level of redundancy. Operation of the conveyor unit  14  can be continued with essentially the same power even if a drive unit  34  fails. 
     This is also true when a transfer operation takes place with one or more of the transport units  22 . During the transfer operation of a transport unit  22  the corresponding drive unit  34  of said transport unit  22  is coupled for drive purposes to its conveyor facility  36 , as described above, with the result that the drive energy of the drive unit  34  is not used for the onward movement of the transport unit  22 . However this drive for onward movement is brought about by way of further transport units  22  coupled mechanically to said transport unit  22 , the drive units  34  of which are each coupled to the local chassis  38 . When a transfer operation is performed with a first transport unit  22 , the control unit  35  of at least a second transport unit  22  coupled mechanically to the first transport unit  22  ensures that the coupling facility  62  of the second transport unit  22  couples the drive unit  34  to the chassis  38 . 
     When its coupling facility  62  is in the second operating position, a drive unit  34  can therefore not only be used for the onward movement of its assigned transport unit  22  but it can also help with the onward movement of further transport units  22 . This is the case in particular for the directly adjacent transport units  22 , which are coupled to the illustrated transport unit  22  in  FIG. 2  by means of mechanical couplings  72 . With these couplings  72  the set of transport units  22  of the conveyor unit  14  forms a chain or train of transport units  22 , which moves along the conveyor section  16 .