Abstract:
A mobile industrial rack system which includes a flue spacer, a carriage spacer, and a synchronous motor control that individually and collectively allows the rack system to be used on unleveled surfaces. The industrial rack system is therefore well suited for storage facilities in which it is not possible or not desired to level an otherwise unleveled floor.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates generally to industrial storage systems and, more particularly, to a mobile industrial rack system for use on unleveled flooring. 
         [0002]    Industrial rack systems are commonly used in storage facilities to store products until those products are shipped either directly to a consumer or to a retailer. Typically, the industrial racks store loaded pallets that are placed on and removed from the racks using a forklift. The industrial racks are spaced from one another in a manner to form relatively wide aisles to allow sufficient room for the forklift to load and remove the pallets. Since each industrial rack has a fixed position, each industrial rack must have a dedicated aisle. Moreover, since each aisle is typically as wide, if not wider than, the rack itself, more than half the floor space occupied by the industrial rack system may be occupied by aisles and thus not usable for product storage. 
         [0003]    Mobile industrial rack systems, however, are designed to reduce the number of fixed aisles and, as a result, increase the amount of floor space used for product storage. More particularly, in a typical configuration, a single aisle may be allocated for the entire industrial rack system. The position of that single aisle can be changed by moving the industrial racks along a track or rail that is mounted or otherwise secured to the storage facility flooring, which is typically a concrete slab. While in some configurations each industrial rack is moved independently, it is common for back-to-back industrial racks to be coupled using a rigid flue spacer connector and moved as a single unit by a single mobile carriage supporting both racks. To access a forward rack of a given back-to-back configuration, the racks are moved such that an aisle is formed immediately forward of the back-to-back configuration. To access a rearward rack of the given back-to-back configuration, the racks are moved such that an aisle is formed immediately rearward of the back-to-back configuration. Mobile industrial rack systems provide nearly twice the storage capacity of a similarly sized fixed rack system. 
         [0004]    Conventional mobile industrial rack systems must be mounted on a level floor such that the heavy loading of the industrial racks does not create an undesired imbalance as the racks are being moved. Thus, in a typical implementation, the existing concrete floor of a storage facility, which is generally not level within the specifications required for the mobile industrial rack system, must be leveled by applying a thin coat of concrete material to the concrete floor. The rails along which the racks move are then anchored through the thin coat of concrete material and to the concrete floor. Alternately, footings may be anchored to the concrete floor and the rails anchored through the footings to the concrete floor. When footings are used, grout or similar material is typically placed between the rails and the concrete floor. In both instances, measures must be taken to provide a level surface for the rails along which the racks move, which are generally quite costly,. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0005]    The present invention is directed to a mobile industrial rack system usable on unleveled flooring surfaces. The mobile rack system includes a flue spacer connector having a play feature that allows the industrial racks arranged in a back-to-back configuration to move relative to one another when the back-to-back configuration is being moved across an unleveled floor surface. 
         [0006]    The present invention is also directed to a mobile industrial rack system in which industrial racks of a back-to-back configuration are independently supported by a respective carriage. The pair of carriages is coupled to another by a carriage spacer that allows the carriages to move independently of one another while maintaining a union of the two carriages. 
         [0007]    The present invention is also directed to a mobile industrial rack in which an industrial rack is translated by a series of carriages each having a motor driven roller. An encoder is associated with each motor and provides feedback to a synchronous motor control that adjusts the speed by which each motor drives its respective roller. In this regard, the motors are controlled independently, but are synchronized such that each motor drives its roller at approximately the same speed. 
         [0008]    Therefore, in accordance with one aspect of the invention, a mobile industrial rack system includes a first industrial rack and a second industrial rack. A mobile carriage is adapted to ride along a rail and support the first industrial rack and the second industrial rack. A flue spacer interconnects the first industrial rack and the second industrial rack and allows the first industrial rack and the second industrial rack to move relative to another when the mobile carriage translates along the rail. 
         [0009]    In accordance with another aspect of the invention, a mobile industrial rack system includes a rail adapted to be mounted to a concrete slab, a first industrial rack adapted to support a load such as a plurality of pallets, and a second industrial rack adapted to support a load such as a plurality of pallets. A flue spacer interconnects the first industrial rack and the second industrial rack to form a back-to-back configuration. A first mobile carriage is adapted to ride along the rail and support the first industrial rack, and a second mobile carriage is adapted to ride along the rail and support the second industrial rack. A carriage spacer interconnects the first mobile carriage and the second mobile carriage and is adapted to allow the first and second carriages to move independently of one another when the racks are translated together along the rail. 
         [0010]    According to another aspect of the invention, a mobile industrial rack system includes a series of rails arranged parallel to and spaced from one another along a concrete slab. An industrial rack is designed to be translated along the rails by first and second motors. A synchronous motor control is communicatively linked with the first and second motors to synchronize operation of the first and second motors. 
         [0011]    Other objects, features, and advantages of the invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The drawings illustrate the best mode presently contemplated for carrying out the invention. In the drawings: 
           [0013]      FIG. 1  is an isometric view of a representative embodiment of a mobile industrial rack system incorporating the features of the present invention; 
           [0014]      FIG. 1A  is top schematic plan view of the mobile industrial rack system of  FIG. 1 ; 
           [0015]      FIG. 2  is a top plan view of a carriage incorporated into the mobile industrial rack system of  FIG. 1 ; 
           [0016]      FIG. 3  is a side elevation view of the carriage shown in  FIG. 2 ; 
           [0017]      FIG. 4  is a section view of the carriage taken along line  4 - 4  of  FIG. 2 ; 
           [0018]      FIG. 5  is a section view of the carriage taken along line  5 - 5  of  FIG. 2 ; 
           [0019]      FIG. 6  is an end view of a surface mounted rail incorporated into the mobile industrial rack system of  FIG. 1 ; 
           [0020]      FIG. 7  is an isometric view of a flue spacer incorporated into the mobile industrial rack system of  FIG. 1 ; 
           [0021]      FIG. 8  is a side elevation view of the flue spacer shown in  FIG. 7 ; 
           [0022]      FIG. 9  is an isometric view of a carriage spacer incorporated into the mobile industrial rack system shown in  FIG. 1 ; 
           [0023]      FIG. 9A  is an exploded view of the carriage spacer shown in  FIG. 9 ; and 
           [0024]      FIG. 10  is a schematic representation of a synchronous motor control incorporated into the mobile industrial rack system shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    Referring now to  FIGS. 1 and 1A , a mobile industrial rack system  10  is comprised of a series of industrial racks  12  that are movable along a series of spaced and parallel rails  14 . The industrial racks  12  are arranged in pairs so as to form multiple back-to-back configurations  16 , with each back-to-back configuration  16  having a forward rack  12   a  and a rearward rack  12   b , and being movable as a single unit. Each back-to-back configuration  16  is associated with a control interface  18  that controls movement of the industrial racks  12  along the rails  14 . Either through an input directly to the control interface  18  or using suitable remote controls, the back-to-back configurations  16  can be translated along the rails  14  to move the location of an aisle  20  between adjacent back-to-back configurations  16 , based on the industrial rack  12  that is to be accessed. In a preferred embodiment, the racks  12  are moved such that aisle  20  is sufficiently wide to accommodate a forklift  22 . One skilled in the art will appreciate that if the forward rack  12   a  of a back-to-back configuration  16  is to be accessed, the industrial racks  12  are moved such that aisle  20  is formed immediately forward of the forward rack  12   a.  On the other hand, if the rearward rack  12   b  of the back-to-back configuration  16  is to be accessed, the industrial racks  12  are moved such that aisle  20  is formed immediately rearward of the rearward rack  12   b.    
         [0026]    Additionally, in a preferred embodiment, the mobile industrial rack system  10  may include a pair of stationary industrial racks  24  that bookend the movable industrial racks  12 , as shown in  FIG. 1A . The stationary industrial racks  24  are aligned with rails  14  but do not translate along the rails  14 . One skilled in the art will appreciate that stationary industrial racks  24  may be mounted proximate a wall (not shown) such that access to the racks  24  is available only if an aisle  20  is formed between a stationary rack  24  and a movable rack  12  or, alternately, each stationary rack  24  may be positioned such that an aisle (not shown) is formed between the stationary rack  24  and the wall. 
         [0027]    Each industrial rack  12 ,  24  is comprised of vertical posts  26  of generally equal height connected to one another by a series of bars  28 . In a preferred implementation, each industrial rack  12 ,  24  will include multiple sets of bars  28  that are connected to the vertical posts  26  such that multiple storage bays  30  are defined for each industrial rack  12 ,  24 . In a preferred embodiment, each storage bay  30  is adapted to support a load such as at least one pallet (not shown). 
         [0028]    Referring now to  FIG. 2 , each movable industrial rack  12  is translated along rail  14  by a carriage that includes a series of carriage drive units  32 , each of which includes a drive roller  34  and a driven roller  36 . Each carriage drive unit  32  further includes a pair of support members  38  of length generally equal to the depth of the industrial rack that it supports. The support members  38  couple to two vertical posts  26  using a suitable connection. In addition to being joined indirectly through the coupling of the vertical posts  26 , the support members are interconnected by a drive roller axle  40  and a driven roller axle  42 . In a manner as is known, the carriage drive units  32  are secured together by a suitable frame structure the supports the industrial racks  12 . 
         [0029]    As further shown in  FIG. 3 , the drive roller  34  includes a drive wheel  44  that is caused to rotate about axle  40  by a belt and gear assembly  46 . The belt and gear assembly  46  includes a gear  48  centered about axle  40  and designed to rotate in either a clockwise or counterclockwise direction based on the translational direction of belt  50 . Alternately, belt  50  may be a chain. The belt  50  is trained about gear  48  and a drive gear  52  that is centered about drive shaft  54 . When drive shaft  54  is caused to rotate, the drive gear  52  also rotates and translates belt  50  about its trained path thereby causing drive wheel  44  to rotate and thus travel along rail  14 . The drive shaft  54  is caused to rotate by a motor assembly  56 . 
         [0030]    Referring back to  FIG. 2 , the driven roller  36  includes a driven wheel  58  that, in a preferred embodiment, is not forcibly driven like drive wheel  44  of the drive roller. In this regard, driven wheel  58  is not directly caused to rotate, but will only rotate when the carriage drive unit  32  as a whole is caused to move by rotation of drive wheel  44 . 
         [0031]    Referring now to FIGS.  2  and  4 - 6 , rail  14  includes a base plate  60  that, in a preferred embodiment, is anchored to the floor  62  using suitable anchors  64 , such as concrete screws. In this embodiment, the rail  14  is surface mounted to the floor  62 ; although it is contemplated that rail  14  could be recessed mounted. In a preferred embodiment, the upper surface of the base plate  60  is shaped to define a pair of end sections  66  and a center section  68 . A pair of channels  70  are defined between end sections  66  and the center section  68 . The channels  70  are designed to mirror the tread pattern of wheels  44 ,  58 . More particularly, each wheel  44 ,  58  has a tread pattern  72 ,  74 , respectively, defined by a centered recess  76 ,  78 , respectively, formed between a pair of flanges  80 ,  82 , respectively. The flanges  80 ,  82  are designed to ride along the channel  70  and the centered recesses  76 ,  78  are designed to ride along the center section  68  of rail  14 . 
         [0032]    As further shown in  FIG. 4 , the driven wheel  58  is coupled in a known way to a hub  84  defining a central bore  86  through which axle  42  extends between the pair of support members  38 . Axle spacers  87  position the driven wheel  58  between the pair of support members  38 . As further shown in  FIG. 5 , the drive wheel  44  also has a hub  88  defining a central bore  90  through which axle  40  extends between support members  38 . Gear  48  is supported by a gear plate  92  that is mounted to an exterior surface of drive wheel  44  and is designed to rotate around axle  40 . Axle spacers  93  position the drive wheel  44  between support members  38 . Gear  48  further includes a pair of pins  94  that interconnect the gear  48  and the drive wheel  44 . The interconnection couples the gear  48  and the drive wheel  44  to one another so that rotation of the gear  48  by belt  50  causes rotation of the drive wheel  44 . 
         [0033]    Referring now to  FIGS. 7-8 , a flue spacer  96  according to one aspect of the invention is shown interconnecting the forward rack  12   a  and the rearward rack  12   b  of a back-to-back configuration  16 . The flue spacer  96  includes a forward mounting plate  98   a  and a rearward mounting plate  98   b.  The forward mounting plate  98   a  is coupled to a vertical post  26  of the forward rack  12   a  and the rearward mounting plate  98   b  is coupled to a vertical post  26  of the rearward rack  12   b  using suitable connectors (not shown), such as bolts. Each mounting plate  98   a,    98   b  carries an extension member  100   a,    100   b , respectively, that is sized such that extension member  100   a  at least partially shrouds extension member  100   b.  In this regard, extension member  100   a  is designed to slide within extension member  100   b.    
         [0034]    Extension member  100   a  has a vertical slot  102  whereas extension member  100   b  has a horizontal slot  104 . When the extension members  100   a ,  100   b  are properly aligned, a portion of the vertical slot  102  is aligned with horizontal slot  104  such that bolt  106  may extend through the vertical slot  102  and the horizontal slot  104  along an axis that is transverse to both the vertical slot  102  and the horizontal slot  104 . 
         [0035]    More particularly, extension member  100   a  includes a top plate  108  and a pair of downwardly extending side plates  110 ; only one of which is visible in the figures. The vertical slot  102  is formed in one of the side plates  100  whereas a second vertical slot (not shown) aligned with vertical slot  102  is formed in the other of the side plates. Extension member  100   b  also includes a top plate  112  and a pair of downwardly extending side plates  114 , with each side plate  114  having a horizontal slot  104  formed therein. Bolt  106  has a length sufficient to extend through the horizontal slot  104  of each side plate  114 . 
         [0036]    In operation, the flue spacer  96  is designed to allow relative movement of the industrial racks  12   a,    12   b  when the industrial racks  12   a,    12   b  are moved along an uneven surface. Specifically, as the forward rack  12   a  is moved in the forward direction and encounters an area of rail  14  that is on a non-level portion of the underlying floor, the forward rack  12   a  will experience an angular displacement relative to the rearward rack  12   b.  The flue spacer  96  allows the forward rack  12   a  to play in two different directions relative to the rearward rack  12   b  as a result of the change in floor incline. More particularly, the vertical slot  102  allows the forward rack  12   a  to ride upward relative to the rearward rack  12   b  as a result of the change in floor incline. Thus, extension member  100   a  will move upward relative to bolt  106 . 
         [0037]    Additionally, the flue spacer  96  will permit the forward rack  12   a  to slide forward or rearward relative to the rearward spacer  12   b.  More particularly, the extension member  100   a  may slide along the top plate  112  and side plates  114  of extension member  100   b  without the extensions members  100   a ,  100   b  disconnecting from one another. The bolt  106  extending through the vertical and horizontal slots  102 ,  104  maintains the interconnection of the extension members  100   a ,  100   b  and thus racks  12   a,    12   b  but allows a limited displacement or play of the racks  12   a,    12   b  relative to one another. The ends of the slots  102 ,  104  define the range of relative vertical and horizontal movement between the racks  12   a,    12   b , to accommodate a desired degree of angular displacement between the racks  12   a ,  12   b.    
         [0038]    Flue spacers such as  96  are provided on selected ones of posts  26  and at one or more locations along the height of the posts  26 , according to the length and height of the industrial racks  12 , in order to securely maintain the racks together when the racks  12  are moved together in a back-to-back configuration  16 . 
         [0039]    Referring now to  FIGS. 9 and 9A , the racks  12   a ,  12   b  of a back-to-back configuration  16  are also joined by a carriage spacer  116  that includes a pair of braces  118  arranged parallel to another with a pin connection  120  interconnected therebetween. The carriage spacer  116  is mounted in a conventional manner to carriage drive unit  32  of the forward industrial rack  12   a  and the carriage drive unit  32  of the rearward rack  12   b.  As illustrated in  FIG. 9 , mounting brackets  122  are interconnected between the carriage spacer  116  and the carriage drive units  32 . The mounting brackets  122  include legs  124  that are designed to mate against the lower surface of a vertical post  26  and secured to the vertical post  26  by inserting bolts (not shown) through holes (not shown) formed in the vertical post  26  that are aligned with slots  126  formed in the legs  124 . 
         [0040]    Referring particularly to  FIG. 9A , braces  118  are each comprised of a pair of wall members  128 , a top plate  130 , and a bottom plate  132 . Holes  134 , which are aligned with one another, extend through the pair of wall members  128 . The braces  118  are both fastened in a known way to end plate  136  that is fastened to the mobile carriage drive unit  32  of the rearward rack  12   b . The carriage spacer  116  further includes a mounting plate  138  that is fastened in a known way to the carriage drive unit  32  of the forward rack  12   a.  The mounting plate  138  has a pair of projections  140  each of which is defined by a narrow plate  142  having a hole  144  formed therethrough. When assembled, the mounting plate  138  is positioned relative to the braces  118  such that holes  134  and  144  are aligned. Pivot pin  146  is then inserted through both sets of holes  134 ,  144  and retained therethrough by ring  147 . The pivot pin  146  provides a pivot against which the racks  12   a ,  12   b  may move relative to another when the racks  12   a ,  12   b  are being moved along rail  14 . 
         [0041]    In a preferred embodiment, holes  144  are slightly larger and more elongated than holes  134 . Thus, holes  144  effectively form slots in which the pivot pin  146  may move vertically relative to the mounting plate  138  when the racks  12   a ,  12   b  are being moved in the rearward direction. Alternately, holes  144  allow the mounting plate  138  to move relative to the pivot pin  146  when the racks  12   a ,  12   b  are being moved in the forward direction. Thus, when variations in the incline of the floor are encountered, the carriage spacer  116  will maintain connection of the back-to-back racks  12   a ,  12   b  but permit limited displacement so as to reduce the impact of the unleveled floor. 
         [0042]    In a preferred embodiment, each back-to-back configuration  16  will have multiple carriage drive units  32  to translate the racks along rails  14 . As described above, each carriage includes a drive wheel and a driven or follower wheel; although, it is contemplated that each wheel may be motor driven. Each motor driven wheel is driven independently by a dedicated motor; however, in a preferred embodiment, the operation of each motor is synchronized so that the motors for a given back-to-back configuration  16  operate at approximately the same speed. 
         [0043]    As shown in  FIG. 10 , each motor assembly  56  includes a drive shaft  148  driven by a motor  150 . Each motor  150  includes an encoder  152  that counts rotations of the motor  150 . The encoder counts are provided to an encoder interface  154  that outputs the encoder counts to control board  156 . The control board  156  associated with each motor assembly  56  includes software that causes a processor  158  to compare the encoder count value of each motor  150  and then provide command signals to the motor  150  to synchronize motor speed for all the motors  150  for a given rack  12  or back-to-back configuration  16 . More particularly, each processor  158  compares the encoder count for each motor and adjusts operation of its associated motor  150  such that the encoder count differential between motors approaches zero. The encoder count values are communicated between processors  158  through a high-speed link  160 . Thus, while the motors  150  are controlled independently, their operation is synchronized to reduce racking or skewing during translation of the racks  12  over an unleveled surface. 
         [0044]    While the present invention has been described with respect to industrial racks, it is understood that the invention may also be used in other mobile rack systems where it is desirable to account for, rather than replace or modify, an unleveled floor. Additionally, while the invention has been described with respect to an industrial rack system having flue spacers, carriage spacers, and a synchronous motor control, it is understood that these structural components operate independent of another and thus a given rack system may incorporate less than all these features to account for an unleveled floor. Also, it is understood that the rack system may include other features not specifically described herein to provide additional rack stability such as load distribution sensors, tip rails, and the like. 
         [0045]    Many changes and will modifications could be made to the invention without departing from the spirit thereof. The scope of these changes will become apparent from the appended claims.