Abstract:
A storage rack with a multiplicity of rack units ( 4, 5 ) comprises a stack of interspaced supporting mounts ( 72 ), arranged paired at opposing sidewalls ( 70 ) of the rack units in forming a storage location ( 3 ) for a tote ( 40 ). The tote ( 40 ) is designed for storage and retrieval in/from storage locations (3) by means of an automated transfer apparatus ( 1 ). The transfer apparatus ( 1 ) comprises a first transfer means ( 10 ) for travelling in a vertical direction (Z). Furthermore it comprises a second transfer means ( 20 ) for travelling in a first horizontal direction (X) supported by and relative to the first transfer means ( 10 ). To allow a simple adaptation of the storage rack to changes in the spatial situation the first transport means ( 10 ) consists of a multiplicity of releasably interconnected modules ( 13, 18, 61 ), the number of which can be varied depending on the number of rack units ( 4, 5 ).

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a storage rack with a multiplicity of rack units comprising a stack of interspaced supporting mounts, arranged paired at opposing sidewalls of the rack units in forming a storage location for a tote, the tote being designed for storage and retrieval in/from storage locations by means of an automated transfer apparatus. The transfer apparatus comprises at least one first transfer means for travelling in the vertical direction and a second transfer means for travelling in a first horizontal direction supported by and relative to the first transfer means. 
         [0003]    2. Description of Related Art 
         [0004]    Known from EP 0 722 894 B1 is a storage rack comprising two interspaced rack units, between which a transfer apparatus is provided, by which a tote can be travelled vertically. Each rack unit features sidewalls oriented parallel to each other, defined at interspaced vertical rack stanchions. Provided at the sidewalls is a multiplicity of stacked and interspaced supporting mounts to form storage locations for the totes. The supporting mounts are configured as supporting ledges integrated and moulded in the sidewalls. Provided at one end of a rack unit is a removal aperture through which the tote can be shifted into the region of the transfer apparatus. Once the tote is on the transfer apparatus it can be vertically travelled to the desired level. After having attained the target level the tote is transversed into its final storage location. 
         [0005]    Prior art storage racks in accordance with the preamble of claim  1  are furthermore known in which a multiplicity of rack units are arranged juxtaposed and the totes can be travelled in all three spatial directions by means of a transfer apparatus comprising a first transfer means for vertical travel featuring a horizontal cross-supporting member. A second transfer means is supported by the first transfer means, relative to which it can be travelled in a first horizontal direction. 
       SUMMARY OF THE INVENTION 
       [0006]    The invention is based on the object of defining a storage rack which can now be simply adapted to changes in the spatial situation. 
         [0007]    To achieve this object a storage rack having the aforementioned features as set forth in claim  1  is characterized in that in accordance with the invention the first transfer means consists of a multiplicity of releasably interconnected modules, the number of which can be varied depending on the number of rack units. 
         [0008]    The storage rack in accordance with the invention is based on having discovered that by engineering a first transfer means modular, a storage rack is now achievable which can be extended or reduced in length to thus permit adapting the storage rack to changes in the spatial situation by simple ways and means. 
         [0009]    Advantageous aspects of the storage rack in accordance with the invention read from the dependent claims. 
         [0010]    To advantage, the first transfer means comprises at least one supporting member extending in the first horizontal direction (X) consisting of a multiplicity of member modules. The member modules are advantageously bolted to each other. Thus adapting the supporting member to the change in the number of rack units by simple ways and means is facilitated. 
         [0011]    In an advantageous aspect the first transfer means comprises at least one biasing member consisting of a multiplicity of biasing modules and at least one tension lock. By means of such biasing, large spans can be attained for the first transfer means. By means of the biasing modules the biasing member can be simply adapted to changes in length of the supporting members. 
         [0012]    It is furthermore of advantage when the biasing member runs at least portionally spaced away from the supporting member of the first transfer means. Such an external bias in which the biasing member is arranged mostly outside of the supporting member cross-section exerts due to the lever formed by the spacing from the supporting member a compression force which can result in overcompression of the tension zone of the supporting member. 
         [0013]    In a further advantageous embodiment the second transfer means can be travelled by means of a rack and pinion drive comprising at least one gear rack consisting of a multiplicity of gear rack modules. Thus the output of the gear rack is enabled to be simply adapted to changes in the number of rack units. 
         [0014]    Advantageously the first transfer means can be travelled by means of a chain drive comprising at least one drive shaft, the length of which is adapted to the width of the storage rack. To adapt to a change in length of the storage rack drive shafts differing in length are employed. 
         [0015]    In one advantageous aspect the multiplicity of rack units consists of interspaced rack end modules between which rack intermediate modules are arranged. By adding or removing rack intermediate modules between the remaining rack end modules, varying the length of the storage rack is made easy. 
         [0016]    In an advantageous further embodiment the second transfer means is guided by wheels on the first transfer means. 
         [0017]    To advantage, the second transfer means features a carrier plate mounted on a carriage relative to which it can be travelled in a second horizontal direction (Y). Travelling the carrier plate of the second horizontal direction (Y) ensures reliable storage and retrieval of the totes. 
         [0018]    To minimize vibrations possibly occurring in movement of the transfer means the first transfer means is guided to advantage by means of at least one wheel on at least one rack unit. 
         [0019]    To achieve a rigid design of the sidewalls the supporting mounts are impressed snaked into the sidewalls. The sidewalls are made in particular of sheet steel and expediently welded to vertical stanchions. 
         [0020]    It is furthermore of advantage when in the region of the bayway a height sensor is provided to sense the height of the articles. The height sensor establishes the number of the height units needed to store the articles. The sensing signal of the height sensor is communicated to a transfer controller which as a function of the assignment of the storage rack and the height of the article concerned travels the tote to a suitable storage location and stores it there. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0021]    The invention will now be detailed with reference to the diagrammatic FIGs. of the drawings in which 
           [0022]      FIG. 1  is a view in perspective of the storage rack in accordance with the invention with a transfer apparatus; 
           [0023]      FIG. 2  is a cross-section taken along the line II-II in  FIG. 1  through the transfer apparatus; 
           [0024]      FIG. 3  is a cross-section taken along the line III-III in  FIG. 1  through the transfer apparatus; 
           [0025]      FIG. 4  is a top-down view of the first transfer means and 
           [0026]      FIG. 5  is a side view of the first transfer means of the transfer apparatus. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0027]    Referring now to  FIG. 1  there is illustrated diagrammatically the configuration of a storage rack in accordance with the invention with eight rack units  4 ,  5 , of which four rack units  4   a ,  4   b ,  4   c ,  4   d  are arranged juxtaposed in a first row and a further four rack units  5   a ,  5   b ,  5   c ,  5   d  are arranged juxtaposed in a second row. Sited between the two rows is a transfer apparatus  1  for the totes  40 . Provided in each of the rack units  4 ,  5  is a multiplicity of stacked storage locations  3  for receiving articles  2  stored on totes  40 . 
         [0028]    To store the totes  40  in the individual storage locations  3  the rack units  4 ,  5  feature sidewalls  70  having pairs of opposed supporting mounts  72 . The sidewalls  70  made of sheet steel are each welded to stanchions  71 , preferably by means of projection welding. 
         [0029]    Referring now to  FIG. 3  there is illustrated how the supporting mounts  72  are connected to each sidewall  70  as an integrated snaked impression or recess in each sidewall. This ensures a relatively rigid configuration of the sidewalls  70 . To achieve facilitated storage of the totes  40  in the storage locations  3  the supporting mounts  72  feature a tapered cross-section (not shown) at the side facing the transfer apparatus  1 . 
         [0030]    Referring again to  FIG. 1  there is illustrated how a bayway  75  permits storing and retrieving the totes  40  in/from the storage rack. To optimize available storage location space a height sensor  76  is provided in the region of the bayway  75  to sense the height of the articles  2 . The height sensor  76  features a multiplicity of photocell switches interspaced in accordance with the stack spacing of the supporting mounts  72  so that the number of height units needed for storing the articles  2  can be determined. 
         [0031]    A controller determines one or more suitable storage locations  3  and directs the totes  40  to the storage locations  3  as predetermined by the controller. 
         [0032]    For transfer of the totes  40  the transfer apparatus  1  is engineered so that the totes  40  can be travelled in a first spatial direction Z, in a second spatial direction X and in a third spatial direction Y. The three spatial directions X, Y, Z are oriented at right angles to each other in the present example aspect. In the following, the spatial direction Z is also termed the vertical direction, the spatial direction X also termed the longitudinal direction and the spatial direction Y is also termed the transverse direction. 
         [0033]    To locate the totes  40  in the vertical direction, longitudinal direction and transverse direction the transfer apparatus  1  comprises a first transfer means  10  and a second transfer means  20 . The first transfer means  10  is travelled by means of a first drive in the first vertical direction Z and comprises two supporting members  11 ,  12  oriented parallel to each other. As evident from  FIGS. 4 and 5  each supporting member  11 ,  12  is composed of three supporting member modules  13  each bolted to the other. This results in a releasable connection between the supporting member modules  13 . 
         [0034]    The first transfer means  10  comprises two biasing members  17  extending at the underside of the supporting members  11 ,  12 . Each biasing member  17  comprises four biasing modules  18  in the form of tie rods. In the middle portion of the biasing member  17  a tension lock  19  is provided for regulating the bias generated by the biasing member  17 . However, adjusting the tension can also be done additionally or alternatively in end portions of the end modules of the biasing member  17 . 
         [0035]    The biasing member  17  is oriented in the middle portion spaced away from the supporting member  11 ,  12 . This results from the lever arm in a torque being generated acting contrary to the torque generated by the dead weight of the transfer apparatus  1  and the totes  40  including the articles  2 . This results in a reduction in the bending of the supporting member  11 ,  12  in thus permitting a higher loading capacity of the supporting member  11 ,  12  as compared to a supporting member  11 ,  12  without a biasing member  17 . 
         [0036]    In assembling the supporting members  11 ,  12  the individual supporting member modules  13  are bolted together, at each joint of the supporting member modules  13  a connecting arm  31  being arranged at the underside of the supporting members  11 ,  12 . At the end portion of the connecting arm  31  the biasing member  17  is defined spaced away from the supporting member  11 ,  12 . Furthermore, the first transfer means  10  features two inclined stiffeners  15  and two crossmembers  14  provided in the end portions of the supporting members  11 ,  12 . 
         [0037]    Referring still to  FIG. 1  there is illustrated furthermore how the first transfer means  10  is fitted with a drive comprising a total of four chain drives each comprising a chain  50  and two drive shafts  51  jutting out horizontally from a drive motor (not shown). To adapt the drive to the change in length of the storage rack, drive shafts  51  differing in length find application. 
         [0038]    To avoid pivoting of the supporting members  11 ,  12  in the transverse direction Y during movement of the first transfer means  10 , a multiplicity of wheels  74  is provided at the supporting members  11 ,  12  and at the struts  16  which run on the vertical supporting members of the rack units  4 ,  5 . 
         [0039]    As evident from  FIGS. 1 to 3 , the second transfer means  20  comprises a carriage  21  supporting the carrier plate  30 . To achieve location of the second transfer means  20  in the first spatial direction X a rack and pinion drive and a multiplicity of wheels  22  are provided supported by the first transfer means  10 . 
         [0040]    The rack and pinion drive comprises a gear rack  60  formed by a multiplicity of gear rack modules  61 , a pinion  62  mating with the gear rack  60  and a motor  63  for powering the pinion  62 . The module configuration of the gear rack  60  also enables this to be adapted to changes in length of a first transfer means  10 . The gear rack modules  61  are mounted on the struts  16  of the first transfer means  10 . The pinion  62  and motor  63  are mounted on the carriage  21  so that the teeth of the pinion  62  can mate with the teeth of the gear rack  60 . 
         [0041]    Serving guidance of the second transfer means  20  are, for one thing, the wheels  22  rotating about an axis oriented parallel to the transverse direction Y and provided for location on the flange of the supporting member  11 ,  12 . For another, additional wheels  23  mate with the vertical oriented flanges of the supporting member  11 ,  12 , rotating about an axis oriented parallel to the vertical direction Z in serving for lateral guidance of the carriage  21  at the supporting members  11 ,  12 . 
         [0042]    The carrier plate  30  is located on the carriage  21  so that it can travel together with the totes  40  located thereon in the second spatial direction Y. To make this possible a gear drive (not shown) is in turn preferably provided. The motor for powering this gear may be fitted besides the motor  63  also on the underside of the carriage  21  as shown in  FIG. 3 , for example. 
         [0043]    In the example aspect as presently explained it is provided for that the carrier plate  30  can be travelled relative to the carriage  21  by a relatively short distance in the second spatial direction Y. This serves substantially to travel the carrier plate  30  from the region of the stored totes  40  (see  FIG. 2 ). In accordance with the example aspect the carrier plate  30  is travelled by a distance of approximately 40 to 50 mm in the second spatial direction Y. Alternatively, this distance can also be much greater, however. 
         [0044]    To convey the tote  40  to the predefined storage location  3  the carrier plate  30  is provided with two chain drives, each comprising a chain  55  and two drive shafts  56 . In this arrangement the chains  55  are arranged upright, i.e. the drive shafts  56  rotate about an axis oriented parallel to the vertical direction Z. Each chain  55  features a driving dog  57  engaging each recess  41  in the tote  40 . When the driving dogs  57  engage the recesses  41  the tote  40  can then be moved with the aid of the chain drive and a slider guide on the carrier plate  30  (not shown) in the second spatial direction Y so that the totes  40  come to rest on a pair of supporting mounts  72 . 
         [0045]    The embodiment as described is characterized particularly in that by inserting or removing rack intermediate modules  4   b ,  4   c ,  5   b ,  5   c  the storage rack is now variable in the longitudinal direction X for facilitated adaptation to changes in the spatial situation. This is made possible particularly by the modular configuration of the first transfer means  10 . To adapt the storage rack to a change in the number of rack units  4 ,  5  the length of the supporting members  11 ,  12  can now be simply varied by means of the supporting member modules  13 . Furthermore, the biasing member  17  and the gear rack  60  can also be varied in length due to their modular configuration. Adapting the drive shafts  51  is achieved by drive shafts  51  differing in length. 
         [0046]    It is emphasized that the example aspect as described merely represents just one possible embodiment and that further embodiments are just as possible by selecting the individual components, particularly of the transfer apparatus. 
       LIST OF REFERENCE NUMERALS 
       [0000]    
       
           1  transfer apparatus 
           2  articles 
           3  storage location 
           4  rack unit 
           5  rack unit 
           10  first transfer means 
           11  supporting member 
           12  supporting member 
           13  supporting member module 
           14  crossmember 
           15  stiffener 
           16  strut 
           17  biasing member 
           18  biasing module 
           19  tension lock 
           20  second transfer means 
           21  carriage 
           22  wheel 
           23  wheel 
           30  carrier plate 
           31  connecting arm 
           40  tote 
           41  recess 
           50  chain 
           51  drive shaft 
           55  chain 
           56  drive shaft 
           57  driving dog 
           60  gear rack 
           61  gear rack module 
           62  pinion 
           63  motor 
           70  sidewall 
           71  stanchion 
           72  supporting mounts 
           73  end face 
           74  wheel 
           75  bayway 
           76  height sensor 
         Z vertical direction 
         X first horizontal direction/longitudinal direction 
         Y second horizontal direction/transverse direction