Patent Publication Number: US-9420900-B1

Title: Mobile inventory rack apparatus and inventory rack system

Description:
BACKGROUND 
     The manufacturing and assembly process for vehicles requires workers to install various parts to the vehicle as the vehicle moves along an assembly line. The supply of these parts, or inventory, must be replenished during the assembly process, with some parts requiring replenishment more often than others. The frequency of replenishment can depend on the storage area allotted to the parts adjacent to the installation location along the assembly line, the size of the parts, the quantity of the parts used per vehicle, and how many vehicles traveling the assembly line require use of the specific parts. 
     Traditional part-replenishment systems can include delivery of inventory according to a detailed schedule or delivery of inventory upon specific request by workers on the assembly line. Parts can be delivered, for example, by forklift drivers or automated guided vehicles (AGVs) traveling between an inventory storage location and the various stations of the assembly line requiring the specified parts. Schedule-based delivery systems can be overly complicated to manage, and request-based delivery systems can cause delays along the assembly line. A better part-replenishment system for supplying inventory is thus required to improve the manufacturing and assembly process. 
     SUMMARY 
     A mobile inventory rack apparatus serving as part of an inventory rack system is disclosed. The mobile inventory rack apparatus can receive articles of inventory on an as-needed basis from a stationary supply rack apparatus and deliver articles of inventory on an as-needed basis to a receiver rack apparatus located adjacent to the assembly line for a vehicle. The mobile inventory rack apparatus can include an inventory conveyor designed to receive an article of inventory when a requirement indicator has an inventory required state as denoted by the lack of contact with an article of inventory. The mobile inventory rack apparatus can also supply articles of inventory by repositioning a set of paired stoppers that prevent translation of the articles of inventory to allow at least one article of inventory to be removed from the inventory conveyor when a supply lever is contacted by a requirement pin extending from a receiver rack apparatus. 
     In one implementation, a mobile inventory rack apparatus is disclosed. The mobile inventory rack apparatus includes an inventory conveyor configured to translate articles of inventory and a receiving system including a requirement indicator disposed along the inventory conveyor. The requirement indicator has an inventory required state when not in contact with an article of inventory. The mobile inventory rack apparatus further includes a supply system including a pair of spaced stoppers disposed along the inventory conveyor. Each stopper has an extended position preventing translation of the articles of inventory and a retracted position allowing translation of the articles of inventory. The inventory conveyor is configured to receive at least one article of inventory when the requirement indicator is in the inventory required state and to allow removal of at least one article of inventory when one of the stoppers is in the retracted position. 
     In another implementation, an inventory rack system is disclosed. The inventory rack system includes a supply rack apparatus and a mobile inventory rack apparatus. The supply rack apparatus includes a supply system. The supply system includes a pair of spaced stoppers disposed along a supply conveyor, each stopper having an extended position preventing translation of articles of inventory and a retracted position allowing translation of the articles of inventory. The supply system also includes a supply lever extending from the supply rack apparatus configured to switch the positions of both of the spaced stoppers. The mobile inventory rack apparatus includes a receiving system. The receiving system includes a requirement indicator disposed along an inventory conveyor, the requirement indicator having an inventory required state when not in contact with an article of inventory. The receiving system also includes a requirement pin extending from the mobile inventory rack apparatus when the requirement indicator is in the inventory required state. The inventory conveyor is configured to receive at least one article of inventory from the supply conveyor in response to the requirement pin of the mobile inventory rack apparatus being contacted by the supply lever of the supply rack apparatus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein: 
         FIG. 1  is a side view of a mobile inventory rack apparatus; 
         FIG. 2  is an end view of the mobile inventory rack apparatus of  FIG. 1 ; 
         FIG. 3  is another side view of the mobile inventory rack apparatus of  FIG. 1 ; and 
         FIG. 4  is a side sectional view of an inventory rack system including a supply rack apparatus, the mobile inventory rack apparatus of  FIGS. 1-3 , and a receiver rack apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     A mobile inventory rack apparatus and an inventory rack system including the mobile inventory rack apparatus are described below. The mobile inventory rack apparatus can include at least one inventory conveyor configured to translate articles of inventory. The mobile inventory rack apparatus can deliver the articles of inventory from an inventory source to a line-side storage location for use in a vehicle assembly process. To accomplish delivery on an as-needed basis, the mobile inventory rack apparatus can include a receiving system including a requirement indicator that has an inventory required state only when not in contact with an article of inventory and a supply system preventing translation of articles of inventory until a supply lever on the mobile inventory rack apparatus is contacted by a requirement pin on a receiver rack apparatus located at the line-side storage location. 
       FIG. 1  is a side view of a mobile inventory rack apparatus  100 . The mobile inventory rack apparatus  100  described below can move through an assembly plant, either automatically if controlled by an AGV or manually if controlled by an operator. The mobile inventory rack apparatus  100  can be driven adjacent to a stationary supply rack apparatus in order to receive new inventory as needed and be driven adjacent to a stationary receiver rack apparatus to deliver inventory as needed to various stations on an assembly line. The mobile inventory rack apparatus  100  thus facilitates part delivery to the assembly line without the need for either scheduling deliveries or manually requesting parts. 
     To facilitate receipt of new inventory on an as-needed basis, the mobile inventory rack apparatus  100  includes a requirement indicator  102  as part of an upper conveyor receiving system  104  shown in an inventory required state and a requirement indicator  106  as part of a lower conveyor receiving system  108  shown in an inventory not required state. The upper conveyor receiving system  104  of the mobile inventory rack apparatus  100  (including the requirement indicator  102 ) is disposed along an upper inventory conveyor  110 , and the lower conveyor receiving system  108  (including the requirement indicator  106 ) is disposed along a lower inventory conveyor  112 . 
     The two inventory conveyors  110 ,  112  are configured to translate articles of inventory within containers, such as boxes  114   a - c , from one side of the mobile inventory rack apparatus  100  to the other side. In this example, the boxes  114   a - c  are designed to hold vehicle parts, i.e. inventory, for use in the vehicle assembly process. Though the mobile inventory rack apparatus  100  is described here in the context of part delivery for a vehicle assembly line, it is also possible to use the mobile inventory rack apparatus  100  in other delivery contexts, such as in grocery stores or warehouses. Further, though two inventory conveyors  110 ,  112  are shown, any number of inventory conveyors can be included as part of the mobile inventory rack apparatus  100  since the design is scalable. Each inventory conveyor  110 ,  112  can be configured to deliver different types of parts on an as-needed schedule given the design of the delivery mechanisms described below. 
     The inventory conveyors  110 ,  112  can be sloped in order to use gravity to assist in translation of the boxes  114   a - c  and can optionally include spaced roller channels to further assist in translation. The requirement indicators  102 ,  106  can be disposed between the spaced roller channels and are designed to collapse beneath the boxes  114   a - c  upon contact with the boxes  114   a - c  in order to indicate the inventory not required state. The requirement indicators  102 ,  106  can include rollers at distal ends for ease of collapse upon contact. In the example shown in  FIG. 1 , the requirement indicator  106  has an inventory not required state, i.e., no inventory is required to be added to the lower inventory conveyor  112 , since the requirement indicator  106  is in contact with and has collapsed beneath the box  114   b . The requirement indicator  102  is not in contact with anything and is positioned upright between the spaced roller channels of the upper inventory conveyor  110 . Thus, the requirement indicator  102  has an inventory required state, that is, the upper inventory conveyor  110  is ready to receive an additional article of inventory, e.g. another box of parts. 
     The upper conveyor receiving system  104  further includes a requirement pin  116  configured to extend from the mobile inventory rack apparatus  100  when the requirement indicator  102  is in the inventory required state as shown. The extension of the requirement pin  116  is based on the upright position of the requirement indicator  102  and the lack of contact with an article of inventory. The requirement pin  116  and the requirement indicator  102  can be joined, for example, by a cable and/or lever system as part of the upper conveyor receiving system  104 . The upper inventory conveyor  110  can be designed to receive at least one article of inventory, for example, another box of parts, from a supply rack apparatus in response to the requirement pin  116  being contacted by a supply lever extending from the supply rack apparatus when the mobile inventory rack apparatus  100  passes by the supply rack apparatus. 
     The lower conveyor receiving system  108  also includes a requirement pin  118 , the requirement pin  118  having a retracted position shown in dotted line based on the requirement indicator  106  having an inventory not required state. The retracted position of the requirement pin  118  is thus based on the collapsed position of the requirement indicator  106  below and in contact with the box  114   b . Since the requirement pin  118  is in the retracted position, a corresponding supply lever on a supply rack apparatus will not be able to contact the requirement pin  118 , and no parts will be transferred to the lower inventory conveyor  112  when the mobile inventory rack apparatus  100  passes by the supply rack apparatus. 
     The mobile inventory rack apparatus  100  also includes stoppers  200 ,  202  at the end of the inventory conveyors  110 ,  112  forming part of an upper conveyor supply system  204  and a lower conveyor supply system  206 . When in an extended position as shown, the stoppers  200 ,  202  prevent translation of articles of inventory. The upper conveyor supply system  204  includes the stopper  200  as part of a pair of spaced stoppers  200 ,  208  disposed along the upper inventory conveyor  110 . Similarly, the lower conveyor supply system  206  includes the stopper  202  as part of another pair of spaced stoppers  202 ,  210  disposed along the lower inventory conveyor  112 . Each of the stoppers  200 ,  202 ,  208 ,  210  has an extended position preventing translation of articles of inventory and a retracted position allowing translation of articles of inventory. 
     For example, the extended position of the stopper  200  in the upper conveyor supply system  204  is preventing the box  114   a  from sliding off of the upper inventory conveyor  110 . Similarly, the extended position of the stopper  202  in the lower conveyor supply system  206  is preventing the box  114   c  from sliding off of the lower inventory conveyor  112 . In the example shown in  FIG. 1 , the stoppers  200 ,  208  are paired, or coupled, in that the extension of the stopper  200  leads to the retraction of the stopper  208 . Similarly, the stoppers  202 ,  210  are paired, and the extension of the stopper  202  leads to the retraction of the stopper  210 . The paired extension and retraction can be accomplished using a lever system and common axes of rotation for the connected pairs of stoppers  200 ,  208  and  202 ,  210 . The mechanisms shown are similar in function to a see-saw, though other mechanical, hydraulic, or electric mechanisms for paired extension and retraction are also possible. 
     The upper conveyor supply system  204  further includes a supply lever  212  configured to switch the positions of both of the spaced stoppers  200 ,  208  when contacted by a requirement pin extending from a receiver rack apparatus. Similarly, the lower conveyor supply system  206  further includes a supply lever  214  configured to switch the positions of both of the spaced stoppers  202 ,  210  when contacted by a requirement pin extending from a receiver rack apparatus. Once the supply levers  212 ,  214  are contacted by the applicable requirement pins, the stoppers  200 ,  202  can be retracted, and the boxes  114   a,c  can be automatically released from the respective inventory conveyors  110 ,  112 . The spacing between the paired stoppers  200 ,  208  and  202 ,  210  is such that a single article of inventory can be positioned along the inventory conveyors  110 ,  112  between the sets of paired stoppers  200 ,  208  and  202 ,  210 . However, the spacing can be such that any number of articles of inventory can be designed to be released from the respective inventory conveyors  110 ,  112  upon retraction of the respective stoppers  200 ,  202 . 
       FIG. 2  is an end view of the mobile inventory rack apparatus  100  of  FIG. 1 , more specifically, a right-end view of  FIG. 1 . In this view, the supply levers  212 ,  214  are shown in a stacked vertical condition, with the supply lever  212  directly above the supply lever  214 . The boxes  114   a - c  are shown in dotted line so that the details of the conveyor receiving systems  104 ,  108  and the conveyor supply systems  204 ,  206  located along the inventory conveyors  110 ,  112  are visible. This right-end view is included to show that additional inventory conveyors (not numbered) can be present as part of the mobile inventory rack apparatus  100 , for example, in the form of another column of two inventory conveyors located to the right of the inventory conveyors  110 ,  112 . Thus, the example in  FIG. 2  is a mobile inventory rack apparatus  100  capable of receiving and supplying four different types of inventory. The remainder of the description refers only to the left side of the mobile inventory rack apparatus  100  of  FIG. 2  for simplicity, but it is understood that the mechanisms associated with the inventory conveyors  110 ,  112  can also be implemented with additional inventory conveyors forming a larger mobile inventory rack apparatus  100 . Thus, the design is scalable. 
       FIG. 3  is another side view of the mobile inventory rack apparatus  100  of  FIG. 1 . In this example, the requirement indicators  102 ,  106  of both the upper conveyor receiving system  104  and the lower conveyor receiving system  108  have an inventory not required state. As compared to  FIG. 1 , another box  114   d  of parts has been received on the upper inventory conveyor  110 , thus both the upper inventory conveyor  110  and the lower inventory conveyor  112  are full, with the boxes  114   a  and  114   d  located on the upper inventory conveyor  110  and the boxes  114   b  and  114   c  located on the lower inventory conveyor  112 . 
     Once received on the upper inventory conveyor  110 , the box  114   d  makes contact with the requirement indicator  102 , moving the requirement indicator  102  beneath the box  114   d  as shown. The box  114   b  remains in contact with the requirement indicator  106 . Given the presence of the boxes  114   b ,  114   d  in contact with the requirement indicators  102 ,  106 , both of the requirement pins  116 ,  118  are in the retracted state, indicating that no additional inventory is currently required by the mobile inventory rack apparatus  100 . If the mobile inventory rack apparatus  100  passes a supply rack apparatus in this configuration, no articles of inventory will be transferred from the supply rack apparatus to the mobile inventory rack apparatus  100 . 
     In  FIG. 3 , the stopper  202  in the pair of spaced stoppers  202 ,  210  in the lower conveyor supply system  206  has a retracted position allowing translation of an article of inventory, i.e. box  114   c , from the lower inventory conveyor  112 . The supply lever  214  has been contacted by a requirement pin extending from a receiver rack apparatus, leading to the rotated state of the supply lever  214  as shown. In response to the supply lever  214  being contacted and rotated, the stopper  202  was retracted at the same time that the stopper  210  was extended. This coordinated motion is achieved by coupling the motion of the paired stoppers  202 ,  210  to the motion of the supply lever  214 , using, for example, a combination of cables and levers. Once the stopper  202  is retracted, the box  114   c  can slide from the lower inventory conveyor  112  to, for example, a receiver rack apparatus. The sliding motion of the box  114   c  is indicated by an arrow. 
     At the same time that the box  114   c  is released by the retraction of the stopper  202 , the box  114   b  is halted by the extension of the stopper  210 . In this example, the stopper  210  extends into the space between the boxes  114   b  and  114   c  to stop the motion of the box  114   b , but if no space is present between the boxes  114   b  and  114   c , the stopper  210  can be designed to impact the bottom of the box  114   b  to stop its motion while the box  114   c  slides off of the lower inventory conveyor  112 . Thus, the spacing of the paired stoppers  202 ,  210  controls the number of articles of inventory that are released from the lower inventory conveyor  112  upon contact with the supply lever  214 . 
     The paired stoppers  202 ,  210  can also include a counter-weight return mechanism. Once the appropriate number of articles of inventory is released, in this example, just the single box  114   c , the stopper  202  can return to its extended position and the leftmost stopper  210  can return to its retracted position, allowing the box  114   b  to slide down the lower inventory conveyor  112  to rest at the stopper  202 . In turn, the requirement indicator  106  will be released from contact with the box  114   b  to return to the inventory required state extending up through the lower inventory conveyor  112 , and the requirement pin  118  will be triggered to extend from the mobile inventory rack apparatus  100 . 
     The same supply mechanisms described in respect to the lower inventory conveyor  112  are present on the upper inventory conveyor  110 . That is, the paired stoppers  200 ,  208  are coupled to the supply lever  212 . Contact made with the supply lever  212  will retract the stopper  200  and allow removal of the box  114   a  while at the same time extending the stopper  208  and stopping translation of the box  114   d  just until removal of the box  114   a  is complete and the counter-weight mechanism returns the stopper  200  to the extended position and the stopper  208  to the retracted position. At this point, the box  114   d  will be free to slide into contact with the stopper  200  and the requirement indicator  102  will be released, allowing extension of the requirement pin  116  indicating the inventory required state for the upper conveyor receiving system  104 . The mobile inventory rack apparatus  100  described in the preceding figures is further described as part of an inventory rack system below. 
       FIG. 4  is a side sectional view of an inventory rack system including a supply rack apparatus  500 , the mobile inventory rack apparatus  100  of  FIGS. 1-3 , and a receiver rack apparatus  502 . The supply rack apparatus  500  includes a pair of supply systems  504 ,  506  each disposed along a supply conveyor  508 ,  510  and including a pair of spaced stoppers  512 ,  514  and  516 ,  518 . Each stopper  512 ,  514 ,  516 ,  518  has an extended position preventing translation of articles of inventory and a retracted position allowing translation of articles of inventory. The upper pair of spaced stoppers  512 ,  514  is coupled to a supply lever  520  extending from the supply rack apparatus  500  and the lower pair of spaced stoppers  516 ,  518  is coupled to a supply lever  522  extending from the supply rack apparatus  500 . The supply levers  520 ,  522  are configured to switch the positions of the respective spaced stoppers  512 ,  514  and  516 ,  518  upon contact, for example, between retracted and extended positions. 
     In the example shown in  FIG. 4 , the supply lever  522  is being contacted by the requirement pin  118  of the mobile inventory rack apparatus  100 , and the stopper  516  is consequently retracted, allowing box  114   e  to move from the supply rack apparatus  500  to the mobile inventory rack apparatus  100 . At the same time, the stopper  518  is extended, impeding the motion of box  114   f  until the transfer of the box  114   e  is complete. The supply lever  520  is not contacted by the corresponding requirement pin  116  because the requirement pin  116  is retracted based on the presence of the box  114   d  in contact with the requirement indicator  102  on the upper inventory conveyor  110  of the mobile inventory rack apparatus  100 . 
     The receiver rack apparatus  502  includes a pair of receiving systems  524 ,  526  each disposed along a receiver conveyor  528 ,  530  and including a requirement indicator  532 ,  534 . The requirement indicators  532 ,  534  have inventory required states when not in contact with an article of inventory and inventory not required states when in contact with an article of inventory. The receiving systems  524 ,  526  further include requirement pins  536 ,  538  configured to extend from the receiver rack apparatus  502  when the requirement indicators  532 ,  534  are in the inventory required state. In this example, the box  114   c  was previously transferred to the receiver conveyor  530  by the mobile inventory rack apparatus  100  and is now in contact with the requirement indicator  534 . Consequently, the related requirement pin  538  is retracted and does not contact the supply lever  214  of the mobile inventory rack apparatus  100 . Thus, no articles of inventory will be transferred between the lower inventory conveyor  112  and the receiver conveyor  530 . 
     The example shown in  FIG. 4  has the requirement indicator  532  in a position extending upright through the receiver conveyor  528 , making no contact with any articles of inventory. Thus, the requirement pin  536  is extended from the receiver rack apparatus  502  and can contact the supply lever  212  when the mobile inventory rack apparatus  100  travels by the receiver rack apparatus  502 . Upon contact between the requirement pin  536  and the supply lever  212 , the stopper  200  located on the upper inventory conveyor  110  is retracted, and the box  114   a  can transfer between the upper inventory conveyor  110  and the receiver conveyor  528 . At the same time, the stopper  208  extends to impede motion of the box  114   d  until the transfer of the box  114   a  is complete. Once the box  114   a  transfers from the mobile inventory rack apparatus  100  to the receiver rack apparatus  502 , the box  114   a  will contact the requirement indicator  532  which in turn will retract the requirement pin  536 , indicating that the receiver conveyor  528  is full. 
     The mobile inventory rack apparatus  100  described in the preceding figures allows for as-needed supply of inventory between an inventory source, such as the stationary supply rack apparatus  500 , and assembly stations on the assembly line that include limited storage for inventory, such as the receiver rack apparatus  502 , each shown in  FIG. 4 . Though not shown in the figures, the mobile inventory rack apparatus  100  can also be designed to receive receptacles for articles of inventory, for example, empty boxes, from the assembly stations and return the empty boxes back to the inventory source to be refilled using either the same receiving systems and supply systems described above, or simplified receiving systems and supply systems designed for empty box return, but designed in a reverse direction. 
     The foregoing description relates to what are presently considered to be the most practical embodiments. It is to be understood, however, that the disclosure is not to be limited to these embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.