INVERTED POWER AND FREE STORAGE SYSTEM

Abstract: A conveyor system provides a series of storage aisles for receiving articles in a plurality of storage lanes. A selected article moving along the conveyor line can be directed to a shuttle station where it is loaded onto a shuttle for movement along a storage aisle. The article is then moved along the storage aisle for placement in one of many storage lanes. The article can be retrieved from the storage lane and again placed on the conveyor system for discharge.

Description: INVERTED POWER AND FREE STORAGE SYSTEM TECHNICAL FIELD This invention relates to conveyor systems. In particular, the invention relates to conveyor systems capable of storing and retrieving articles. BACKGROUND Conveyor systems that move articles along a path are known. It is often desired to store the articles in such a manner that the articles can be selected for reentry to the conveyor path. Prior systems that have attempted this have required excessive use of driving chains and the like, which results in complicated and expensive systems. SUMMARY OF THE INVENTION According to the invention, a prior conveyor system known as an "inverted power- and- free" system is modified to provide storage and retrieval features, but the concepts of the invention could be applied to other types of conveyor systems. Further, while this invention finds particular relevance in the automotive industry where it is often desirable to store incoming automobile bodies, perhaps of different colors, in such a manner that a particular body can be retrieved and provided on an outgoing conveyor track, it will be useful in other industries also. The conveyor system of the invention utilizes a known conveyor system to move a carrier having, for example, an automobile body thereon, along a fixed rail in generally known fashion. In accordance with the invention, one or more shuttle stations is provided along the conveyor path for storing or retrieving the articles. Each shuttle station includes a separate, movable section of the rail, the movable rail section being aligned initially with the fixed rail. The movable rail is mounted on a traveling carriage, and the traveling carriage is, in turn, mounted on one or more floor rails that extend in a direction transverse to the direction of the fixed rail. Positioned on one or both sides of the path defined by the floor rail are storage lanes, each lane being defined by a respective one of a series parallel conveyor rail sections. By this arrangement, known conveyor components can be used to provide a conveyor system having an overall plan that includes an input conveyor line, one or more storage aisles defined by a plurality of storage lanes, and a shuttle station associated with each storage aisle. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of a conveyor system in accordance with the invention. Figure 2 is a plan view of a shuttle station. Figure 3 is a side view of the shuttle station of figure 2 showing a carrier with an automobile body thereon. Figure 4 is an end view of the shuttle station shown in figure 3. Figures 5a through 51 schematically illustrate operation of the shuttle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to figure 1 , a conveyor system in accordance with the invention adapted to transport, store, and retrieve automobile bodies includes an input station 2 and a plurality of storage aisles 4. The input station includes one or more fixed conveyor rails 6, which are known in the art. In the preferred embodiment, the fixed rails are the "free" rail sections of an inverted "power-and-free" conveyor system. The power chain for the system is located below the fixed rails and are not illustrated. The articles to be conveyed, shown here as automobile bodies 8, are secured to carriers in known manner. The rail lines 6 connect with an input rail line 10 by a series of switches 12, as known in the art, whereby the automobile bodies 8 are directed to travel along the input rail line 10. The input rail line 10 connects with one or more shuttle stations 14. By-pass rail lines 16 are provided to allow a selected automobile body to be directed around any particular shuttle station by operation of switches, as is known in the art. Figure 1 illustrates operation of the by-pass in the first aisle. Figure 1 illustrates operation of the storage feature of the invention in the second aisle. There, an automobile 8' is shown moving along the aisle toward a selected one of the storage lanes 17 after having been loaded on a movable conveyor rail, as will be described below with reference to figures 2 through 5. Figure 1 also illustrates operation of the retrieval feature of the invention in the first aisle. There, automobile body 8" is shown at a second shuttle station 18, where the automobile is being passed to an output conveyor rail 20 after having been retrieved from a storage lane. It will be appreciated that the output rail includes by-pass lines 22, which are similar in function to by-pass lines 16. In operation, the conveyor system in accordance with the invention allows the automobile bodies arriving at the input station 2 to be stored in a selected one of the storage lanes 17 and an automobile body to be retrieved from a selected one of the lanes and passed to the output line 22. The operation of the shuttle stations will now be described with reference to figures 2 through 5. Each shuttle station 14 is provided with a movable conveyor rail 26, which is mounted on a traveling carriage 28. The traveling carriage 28 is mounted on floor rails 30, which are shown as parallel rails, but which may be a single rail or other configurations. The floor rails extend transverse to the input rail line 10 to define the storage lanes 4. Operation of the storage feature is initiated when a carrier 32 on input rail line 10 is moved onto a movable rail 26, the movable rail at that time being aligned with the input line 10. After the carrier has been positioned on the movable rail 26, the carriage can be moved along the floor rails, thereby moving the carriage and the automobile body attached thereto along an aisle for storage. The carriage may be moved in any known fashion, an electric motor drive 34 being illustrated here. After the movable rail has been aligned with a selected storage lane 17, the carrier is moved onto the lane similarly to that described with respect to figure 2 through 4, and the carriage and movable rail are moved to another position to continue this operation. Retrieval of a carrier from a lane and onto the movable rail is essentially the reverse of that described with respect to the loading of a carrier onto the movable rail. The preferred method for movement of the carrier with respect to the movable rail will be described with reference to figures 5a through 51. Figure 5a illustrates the situation when a carrier has been moved onto the movable rail 26. The carrier is moved onto and off of the movable rail 26 by operation of two auxiliary pushers 36 and 38. These are arranged on opposite sides of the rail 26 and overhang the ends of the rail to allow the pusher elements to engage the carrier trolleys 40 when the carrier is on the fixed rails 10 or the lane rails 17. As illustrated in figure 5a, a carrier is parked on the movable rail 26 and is aligned with a fixed rail 10 or a storage lane 17. The pusher elements of the pusher 38 engage the intermediate trolley to move the carrier to the left and onto a rail 10 or 17, as shown in figure 5b. Figure 5c shows the slowing of the pusher elements and figure 5d shown the wipe off of the pusher elements from the intermediate trolley. Figure 5e shows the pick up of the rear trolley by the pusher elements and figure 5f shows the carrier fully moved onto the line 10 or 17. Figure 5g illustrates how the movable rail 26 is rotated in order to obtain the necessary clearance for the overhang of the pushers 36 and 38. This rotation is accomplished in the preferred embodiment by providing a pivotal connection between the rail 26 and the carriage 28. When in the rotated position shown i figure 5g, the movable rail can be moved along the aisle to the desired position and then rotated to align with a lane rail 17 or a rail 10 as shown in figure 5h. Retrieval of a carrier is illustrated in figure 5i, where, pusher elements have engaged the rear trolley to pull the carrier out of a storage lane 17. Then, the pusher elements engage the intermediate trolley to complete movement of the carrier onto the movable rail 26, as shown in figure 5j. The carrier is then parked on the movable rail as illustrated in figure 5k. Figure 51 illustrates rotation of the movable rail with an automobile body thereon for movement along an aisle to a storage position or to a second shuttle station for discharge. It will be appreciated that the operation of the second shuttle station is essentially the same as that of the shuttle station 14. Also, the shuttle stations 22 and output lines 22 can be eliminated, their functions being assigned to the line 10. That is, the shuttle stations 14 would be used as both input and output stations. Further, the structure by which the carriers are moved onto or off of the movable rail 26 need not be limited to the pushers 36 and 38. Alternative arrangements, such as rack and pinion structures, hydraulic pushers, screw arrangements, and the like can be employed. An alternative arrangement that does not require an overhang will dispense with the necessity of rotating the rail for movement along a storage aisle. Other modifications within the scope of the appended claims will be apparent to those of skill in the art.

Claims: What Is Claimed Is: 1. A conveyor system having a conveying line including a free track, a power track and a plurality of carriers, the carriers driven along the free track by a drive on the power track, characterized by: a) a plurality of storage aisles; and b) a movable shuttle station linking the conveyor line and at least one of the storage aisles, the shuttle station including: i) a track adapted to align with the free track of the conveyor line and each storage aisle; ii) a pusher/puller assembly mounted to the movable shuttle station and adapted to move a carrier between the conveyor line and the track of the shuttle station and between the track of the shuttle station and one of the storage aisles for either storage of a load on the carrier in one of the storage aisles or retrieval of a load on a carrier stored in one of the storage aisles. 2. The system of claim 1, wherein the movable shuttle station is mounted on rails, the rails extending along the storage aisles. 3. The system of claim 1, wherein the carrier includes a plurality of trolleys, the pusher/puller assembly engaging at least one of the trolleys for movement between the conveyor line and the track of the shuttle station and between the track of the shuttle station and one of the storage aisles. 4. The system of claim 1, wherein the movable shuttle station is mounted on rails, the rails extending along the storage aisles, the storage aisles arranged on either side of the rails. 5. The system of claim 1, wherein the conveyor line includes a switch to direct a carrier to a shuttle station. 6. The system of claim 1, wherein the conveyor line has at least one input line and at least one output line, the storage aisles arranged between the input and output lines. 7. The system of claim 1, wherein each storage line has a track in alignment with the track of the movable shuttle station, whereby a carrier can travel between the track of the shuttle station and a track of a storage aisle using the pusher/puller assembly. 8. A method of conveying carriers on a conveyor line, the carriers driven on a free track on the conveyor line by means of a drive on a power track of the conveyor line, characterized by: a) shuttling one or more carriers between the conveyor line free track to a track of a movable shuttle station; and b) shuttling one or more carriers between the track of the movable shuttle station and one of a plurality of storage aisle for either storage of a carrier of retrieval of a carrier. 9. The method of claim 8, wherein the carrier is pushed from the track of the movable shuttle station to an empty storage aisle for storage or pulled from a storage aisle to an empty track on the shuttle station for retrieval. 10. The method of claim 8, including driving the movable shuttle station on rails along the storage aisle. 11. The method of claim 8, wherein the carriers are shuttled from the conveyor line at one location for storage and shuttled to the conveyor line at another location when retrieved. 12. The method of claim 8, wherein the carriers are shuttled to and from the conveyor line at one location for storage and retrieval.

Inventors: REES PHIL, REES, PHIL
Applicants: REES PHIL, WEBB CO JERVIS B, JERVIS B. WEBB COMPANY, REES, PHIL
Application year: 2000
Main classification: B62D65
IPC codes: B62D65, B65G1, E04H6