Patent Document

BACKGROUND 
     The present invention relates to baggage conveyor systems, such for use in a transportation terminal. More particularly the invention concerns drive mechanisms and configurations for facilitating various radii of the drive mechanisms. 
     In most airports, particularly high traffic facilities, baggage handling involves an extensive array of conveyors that carry luggage, packages, and other items, hereinafter collectively referred to as luggage, from various sources to various destinations throughout the airport, including luggage carousels for incoming luggage. A typical incoming luggage system includes a conveyor for transferring incoming luggage from an airplane to a conveyor surface of the carousel. 
     The carousel typically has an oval shape and includes overlapping pallets that move luggage around the oval shape, with each pallet traveling a complete revolution around the oval. The pallets are driven by a drive mechanism that may be a central mechanism or a modular mechanism. An example of a modular drive mechanism is provided in U.S. Pat. No. 7,621,392 to Langsdorf et al., where a motor rotates a drive wheel that is configured to come in contact with a drive chain connected to pallets in order to move the drive chain and thereby the pallets. 
     However, there is an interrelationship between load carrying capability of the drive chain (measured in lbs), and the frictional engagement between the drive wheel and the drive chain (measured in lbs) including a friction factor. The friction factor is in part based on material selections for the drive wheel and for the drive chain. For example, if the drive mechanism is designed and dimensioned to move 1500 lbs, with a friction factor of 0.5, the wheel must be capable of driving 3000 lbs (1500/0.5=3000). However, a single drive wheel capable of driving 3000 lb with a 0.5 friction factor may be expensive, noisy, and wear quickly. It is desirable for the drive mechanism to drive a large load, e.g., 1500 lbs, quietly and without excessive wear. 
     Once luggage makes contact with the conveying surface of the carousel, it continues to travel around the carousel until the luggage is picked by a person. The luggage capacity of the usual oval-shaped carousel is limited by the length of its perimeter. Therefore, airport terminals are designed to provide sufficiently large perimeters for the oval carousels to accommodate a large number of passengers. It may be desirable to provide a carousel with varying non-oval shapes, including inside and outside turns, in order to accommodate a large number of passengers in a terminal. 
     Therefore, it is desirable to provide improvements in carousel designs to meet challenges faced in an airport terminal. 
     SUMMARY 
     In accordance with one aspect, a luggage conveyor system is provided. The luggage conveyor system includes a frame, a plurality of pallets movably supported by the frame each having a load carrying surface configured to convey luggage thereon, and a drive assembly. The drive assembly includes a chain formed by a plurality of chain links connected to each other. At least one chain link of the plurality of chain links is coupled to one of the plurality of pallets. The drive assembly further includes a motor-driven drive wheel, and a plurality of driven wheels coupled to and driven by the drive wheel. The plurality of driven wheels are arranged such that at least two of the driven wheels simultaneously contact the same one of the plurality of chain links to frictionally drive the chain. 
     In accordance with another aspect, a luggage conveyor system is provided. The luggage conveyor system includes a plurality of pallets configured to convey luggage, a drive mechanism, and a chain coupled between the drive mechanism and the plurality of pallets to move the pallets. The chain is formed by a plurality of chain links connected to each other. The chain is movably coupled to the drive mechanism. At least one chain link is configured to adjust the length thereof while the chain is coupled to the drive mechanism and the at least one chain link is contiguous with the chain. 
     In accordance with yet another aspect, a luggage conveyor system is disclosed. The luggage conveyor system includes a frame having a length which includes at least one linear section, at least one inside turn and at least one outside turn. The luggage conveyor system further includes a plurality of pallets movably supported by the frame. Each pallet has a first end, a second end, and a load conveying surface between the first end and the second end configured to carry luggage thereon. The luggage conveyor system further includes a drive assembly coupled to the plurality of pallets to move the pallets relative to the frame, and a plurality of bumpers. Each bumper coupled to a corresponding one of the plurality of pallets at the second end of the pallet. The plurality of bumpers are configured to overlap each other to provide a substantially continuous surface as the plurality of pallets move along the frame, the surface projecting upward from the load conveying surface to abut luggage. 
    
    
     
       DESCRIPTION OF THE FIGURES 
         FIG. 1  is a plan view of an oval-shaped luggage transfer conveyor system including a cutout depicting a drive mechanism, a plurality of pallet assemblies, and a cutout depicting a chain, according to one embodiment of the present disclosure. 
         FIG. 2  is a fragmentary cross sectional view of a section of the luggage transfer conveyor system of  FIG. 1 , depicting a pallet assembly coupled to a chain link that is driven by a drive mechanism. 
         FIG. 3  is a top view of the drive mechanism shown in  FIG. 2 . 
         FIG. 4  is an elevation view of a chain link shown in  FIG. 2 , depicted in a first position. 
         FIG. 5  is an elevation view of a chain link shown in  FIG. 2 , depicted in a second position. 
         FIG. 6  is a top view of another embodiment of a drive mechanism that can be used in the luggage transfer conveyor system shown in  FIG. 2 . 
         FIG. 7  is a top view of yet another embodiment of a drive mechanism that can be used in the luggage transfer conveyor system shown in  FIG. 2 . 
         FIG. 8  is a top view of a luggage transfer conveyor system, according to another embodiment of the present disclosure. 
         FIG. 9  is a top view of a luggage transfer conveyor system, according to another embodiment of the present disclosure. 
         FIG. 10A  is a top view of three pallets positioned in a linear section of the luggage transfer conveyor system shown in  FIGS. 8 , and  9 . 
         FIG. 10B  is a fragmentary cross sectional view of a section shown in  FIG. 10A . 
         FIG. 11A  is a top view of three pallets positioned in an outside turn section of the luggage transfer conveyor system shown in  FIGS. 1 ,  8 , and  9 . 
         FIG. 11B  is a fragmentary cross sectional view of a section shown in  FIG. 11A . 
         FIG. 11C  is a fragmentary cross sectional view of another section shown in  FIG. 11A . 
         FIG. 12A  is a top view of three pallets positioned in an inside turn section of the luggage transfer conveyor system shown in  FIGS. 8 and 9 . 
         FIG. 12B  is a fragmentary cross sectional view of a section shown in  FIG. 12A . 
         FIG. 12C  is a fragmentary cross sectional view of another section shown in  FIG. 12A . 
         FIG. 13  is a deflection chart of pallet plate deflections shown in  FIGS. 10B ,  11 B,  11 C,  12 B, and  12 C. 
         FIG. 14  is a top view of two bumpers, each coupled to a pallet assembly, for an outside turn that can be used in the luggage transfer conveyor system shown in  FIG. 8 . 
         FIG. 15  is a top view of two bumpers each coupled to a pallet assembly, for an inside turn that can be used in the luggage transfer conveyor system shown in  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains. 
     In accordance with one aspect, the present disclosure contemplates a luggage conveyor system  100 , as shown in  FIG. 1 . The system  100  in this embodiment is oval shaped, although other configurations are contemplated as described herein. The system includes an upper frame  102 , a lower frame  103 , and a plurality of pallet assemblies  104  supported by and extended between the upper frame  102  and the lower frame  103 . Each pallet assembly  104  is terminated with a corresponding moving bumper assembly  106  adjacent the lower frame  103 . 
       FIG. 2  is a fragmentary cross sectional view of the luggage conveyor system  100  showing one of the plurality of pallet assemblies  104 . Depicted in  FIG. 2  are a drive mechanism  200  and a chain  302  that drive the pallet assemblies  104 . The chain  302  is proximate the lower frame  103  and extends around the circumference of the conveyor system  100 , operably parallel to the lower frame  103 . The chain  302  includes a plurality of chain link assemblies  300  with each pallet assembly  104  connected to a particular chain link assembly  300 , as will be described in greater detail below. The chain  302  is coupled to and driven by the drive mechanism  200 . 
     The pallet assembly  104  includes a pallet plate  105 , an upper roller assembly  110 , a lower roller assembly  120 , and a pallet beam  113 . The upper roller assembly  110  includes upper roller&#39;s  112  and an upper roller bracket  114  connected to the pallet beam  113  proximate an upper end  107  of the pallet plate  105 . The upper roller bracket  114  carries the upper rollers  112  that rest on, and are movable along, the upper frame  102  to provide support for the upper roller assembly  110  and the pallet plate  105 . Each pallet plate  105  is connected to a pallet beam  113  at one side of the pallet plate  105 , in a cantilever manner, as further described below with reference to  FIGS. 10A , and  10 B. Similarly, the lower roller assembly  120  includes lower rollers  122  and a lower roller bracket  124  connected to the pallet beam  113  proximate a lower end  109  of the pallet plate  105 . 
     The pallet beam  113  is terminated at the lower end  109  with the bumper assembly  106 . The bumpers assembly  106 , described in greater detail below, may be coupled to a portion of the lower roller bracket  124 . The pallet beam  113  is terminated at the upper end  107  with an upper guard  128  mounted to braces  130  by a bearing plate in sliding contact with end  107  of the pallet plates  105 . The upper frame  102  and the lower frame  103  orient the pallet beam  113  to have an angular relationship with respect to the lower frame  103 , e.g., 20 degrees. 
       FIG. 3  is a top view of a drive mechanism  200  in greater detail. In one embodiment a number of drive mechanism  200  are provided about the luggage conveyor system  100 . For instance, the drive mechanism  200  may be uniformly distributed around the conveyor system  100 , shown in  FIG. 1 . Preferably, a drive mechanism  200  is provided every three feet of length of the conveyor to provide optimum drive capability. The drive mechanism  200  includes a fixed frame  202 , that is fixedly attached to the lower frame  103  (connection not shown) or is a part of the lower frame  103 , and a floating frame  204 . The floating frame  204  provides support for various components of the drive mechanism  200  that are used to drive a plurality of driven wheels  208   n  (where n=1, 2, 3, or 4). For instance, the floating frame  204  supports a motor  224 , a drive member  226 , a drive wheel  206 , the plurality of driven wheels  208   n , and idler wheels  212 . The motor  224  is coupled to the drive wheel  206  by the drive member  226  and causes rotation of the drive wheel  206  which causes rotation of driven wheels  208   n  and the idler wheels  212  by coupling to these wheels with the flexible linkage  210 . The floating frame  204  is adjustably coupled to the fixed frame  202  by a tension adjustment assembly  222  which includes tension brackets  216  connected to the floating frame  204 , tension adjusters  218  threadedly connecting the fixed frame  202  and the floating frame  204 , and springs  220  to bias the floating frame  204  away from the fixed frame  202 . 
     The flexible linkage  210  may be a chain or a belt. For the purpose of interfacing, the drive wheel  206 , the driven wheels  208   n , and the idler wheels  212  each have an associated sprocket interface that couples with the flexible linkage  210 . Each sprocket interface may include a single sprocket or a double sprocket. 
     The biasing forces of the springs  220  bias the driven wheels  208  toward backup rollers  214  to frictionally engage the chain  302 , disposed therebetween. The backup rollers  214  are fixedly coupled to the fixed frame  202 . 
     As discussed above, four driven wheels  208  are depicted in the embodiment of the drive mechanism  200  in  FIG. 3 . It should be appreciated that more than one driven wheel reduces frictional engagement requirement of the driven wheel with the chain  302  as a result of load sharing. Referring to the example provide in the background of the present disclosure, if a drive mechanism is designed and dimensioned to move 1500 lbs, with a friction factor of 0.5, the wheel of a single-wheel drive mechanism must be capable of driving 3000 lbs (1500/0.5=3000). However, as a result of load sharing, each of the four wheels of the embodiment depicted in  FIG. 3 , only has to be capable of driving 750 lbs (1500/0.5/4=750), based on the same friction factor. The lower drive requirement for each wheel may result in less wear of each wheel which may results in a layer of material deposited on the chain  302  which can also result in clogging of the chain. 
       FIGS. 4 and 5  are elevation views of the chain link assembly  300  in different positions. The chain link assembly  300  includes a link body  301 . The link body includes a tongue portion  303  and a groove portion  307 . The tongue portion  303  is configured to fit within the groove portion  307  and be secured therein. A link plate  304  is connected to the link body  301  by fastener assemblies  306 , (i.e., bolts and nuts). The link plate  304  includes holes which are aligned with through-holes  305  provided in the link body  301 . The bolts of the fastener assemblies  306  extend through holes provided in the pallet beam  113  at the pallet-chain interface  111  (see  FIG. 2 ), and further extend through the link plate  304  and through-holes  305 , in order to securely connect the pallet beam  113  to the chain link assembly  300 . 
     The tongue portion  303  has a through hole which is configured to receive a pin  309  of an adjustable roller fastener  314 . The adjustable roller fastener  314  includes an eccentric bolt and nut assembly  308  to provide adjustability of position with respect to the link body  301 . The adjustable roller fastener  314  is also coupled to the link body  301  by a linkage  324  and a fastener  325  which extends through a slotted hole in the linkage  324  and threadedly engages the link body  301 . 
     The eccentric bolt and nut assembly  308  and the adjustable roller fastener  314  are configured to adjust spacing between one chain link assembly  300  and another. The eccentric bolt and a nut assembly  308  and the adjustable roller fastener  314  are depicted in a first position ( FIG. 4 ) and a second position ( FIG. 5 ). A centerline of the pin  309  is depicted in different positions with respect to the first and second positions, defining a spacing  322 . Thereby, the chain link assembly  300  can be shortened or elongated by the spacing  322  by placing the eccentric bolt and nut assembly  308  and the adjustable roller fastener  314  in the first and second positions. Since the aforementioned adjustability of the chain link assembly  300  is independent of its coupling with the pallet beam  113 , each chain link assembly  300  can be shortened or elongated while the chain  302  is extended around the luggage conveyor system  100 , thereby eliminating the necessity to disassemble the chain  302  from the respective pallet assemblies  104 . 
     The chain link assembly  300  is configured so that the length of each chain link assembly is larger than the distance between two consecutive driven wheels  208   n  in the same drive mechanism  200 . According to this relationship, at least two driven wheels  208  contact each chain link assembly  300  within the same drive mechanism  200 . This relationship may result in a quieter operation and less wear on the components making up the chain link assembly. 
     As described above, each chain link assembly  300  is coupled to another chain link assembly by the tongue and groove portion  303  and  305  combinations. Specifically, the link roller  318  of one chain link assembly  300  couples with the tongue portion  303  of another chain link assembly and is secured in place by the adjustable roller fastener  314 . The link roller  318  is configured to rotate on a track (shown in  FIG. 2 ) to provide support for the chain link assembly  300 . 
       FIGS. 6 and 7  are top views of alternative embodiments for the drive mechanism  200 , thereby identified as  200 ′ and  200 ″. In the embodiment of  FIG. 6 , two driven wheels  208   1 ′ and  208   2 ′ are used with one idler wheel  212 ′ and two backup rollers  214 ′. The flexible linkage  210 ′ couples the driven wheels  208   1 ′ and  208   2 ′ with the idler wheel  212 ′. In the embodiment of  FIG. 7 , three driven wheels  208   1 ″,  208   2 ″, and  208   3 ″ are used with two idler wheel  212 ″ and three backup rollers  214 ″. The flexible linkage  210 ″ couples the driven wheels  208   1 ″,  208   2 ″, and  208   3 ″ with the idler wheels  212 ″. The particular drive mechanism, i.e.,  200 ,  200 ′, or  200 ″, that is used in a luggage conveyor application may depend on several factors including but not limited to the loading requirement of objects that the conveyor is designed to convey, the construction and size of the driven wheels, and the size and construction of the chain link assembly. 
     As discussed above, while the luggage conveyor system  100  depicted in  FIG. 1  is oval shaped, the reader should appreciate that other non-oval shapes may also be implemented.  FIGS. 8 and 9  are top views of other non-oval shaped embodiments for the luggage conveyor system, identified as  100 ′ and  100 ″. In  FIG. 8 , the luggage conveyor system  100 ′ includes linear sections  150 ′, a section including a partial inside turn  152 ′, sections including partial outside turns  154 ′, and sections including complete outside turns  156 ′. The chain  302 ′ is disposed near the outside perimeter. In  FIG. 9 , the luggage conveyor system  100 ″ includes linear sections  150 ″, sections including partial outside turns  154 ″, sections including complete outside turns  156 ″, and one section including a complete inside turn  158 ″. The chain  302 ″ is disposed near the outside perimeter. 
       FIG. 10A  is a top view of three consecutive pallet plates  105  connected to three pallet beams  113  and three bumper assemblies  106  oriented in a linear section  150 ′ or  150 ″ as depicted in  FIGS. 8 and 9 , respectively. Also depicted is the chain  302  proximate the bumper assemblies  106 . The perimeters of the three pallet plates  105  are depicted with dotted lines, and the plates are identified as P 1 , P 2 , and P 3 . The pallet plates  105  overlap, and the overlap is depicted as the shaded areas and are identified as OL. 
       FIG. 10A  shows the cantilever relationship between the pallet plate  105  and the pallet beam  113 . The pallet plate  105  is connected to the pallet beam  113  at one side of the plate  105  and from there cantilevers out until it comes in contact with another pallet plate  105  which is supported by another pallet beam  113 . This relationship is also depicted in  FIG. 10B . 
       FIG. 10B  is a fragmentary cross sectional view of the pallet plates  105  and the pallet beams  113  about a section line A-A depicted in  FIG. 10A . Each pallet plate  105  overlaps another pallet plate  105 . Due to the cantilever action, each pallet plate  105  deflects downward away from the pallet beam  113 . The deflection has an inverse function to the distance from the pallet beam  113 , as will be described in greater detail below. 
       FIG. 11A  is three pallet plates  105  coupled to three pallet beams  113  in a partial/complete outside turn  154 ′/ 156 ′ as depicted in  FIG. 8 . The perimeters of the three pallet plates  105  are depicted with dotted lines, and the plates are identified as P 1 , P 2 , and P 3 . The pallet plates  105  overlap, and the overlap is depicted as the shaded areas. 
       FIG. 11B  is a fragmentary cross sectional view of the pallet plates  105  and the pallet beams  113  about a section line A-A depicted in  FIG. 11A .  FIG. 11C  is a fragmentary cross sectional view of the pallet plates  105  and the pallet beams  113  about a section line B-B depicted in  FIG. 11A . An exemplary embodiment is provided below in which relationship between deflections of pallet plates  105  as a function of distance from the pallet beams  113  is provided. 
       FIG. 12A  is three pallet plates  105  coupled to three pallet beams  113  in a partial/complete inside turn  152 ′ and  158 ″ as depicted in  FIGS. 8 and 9 , respectively. The perimeters of the three pallet plates  105  are depicted with dotted lines, and the plates are identified as P 1 , P 2 , and P 3 . The pallet plates  105  overlap, and the overlap is depicted as the shaded areas. 
       FIG. 12B  is a fragmentary cross sectional view of the pallet plates  105  and the pallet beams  113  about a section line A-A depicted in  FIG. 12A .  FIG. 12C  is a fragmentary cross sectional view of the pallet plates  105  and the pallet beams  113  about a section line B-B depicted in  FIG. 12A . An exemplary embodiment is provided below in which relationship between deflections of pallet plates  105  as a function of distance from the pallet beams  113  is provided. 
       FIG. 13  is a deflection schematic that depicts the cantilever of pallet plates  105  as a function of distance from the pallet beams  113  for different circumstances shown in  FIGS. 10A ,  10 B,  11 A,  11 B,  11 C,  12 A,  12 B, and  12 C. Table 1, below, provides exemplary values for parameters identified as X 1 , X 2 , X 3 , X 4 , B 1 , B 2 , B 3 , B 4 , B 5 , and B 6 . The parameters X 1 , X 2 , X 3 , and X 4  indicate different distances away from the edge of the palate plates  105  which is connected to the pallet beam  113 . In the exemplary embodiment provided below X 1 , is 5.375 inches, X 2  is 10.750 inches, X 3  is 13.625 inches, and X 4  is 16.500 inches. The maximum pallet plate width in this exemplary embodiment is 17.75 inches. The parameter B 1  indicates the maximum defection of the pallet plate in a relaxed position, i.e., without interference from another pallet plate. The parameter B 2  indicates the maximum deflection of the pallet plates shown in  FIG. 10B  relative to B 1 , B 3  indicates the maximum deflection shown in  FIG. 11C  relative to B 1 , B 4  indicates the maximum deflection shown in  FIG. 11B  relative to B 1 , B 5  indicates the maximum deflection shown in  FIG. 12B  relative to B 1 , and B 6  indicates the maximum deflection shown in  FIG. 12C  relative to B 1 . The maximum radius of the outside turn, shown in  FIGS. 8 ,  9 , and  11 A, and the maximum radius of the inside turn, shown in  FIGS. 8 ,  9 , and  12 A, is 102 inches from a center position to the outside perimeter of the luggage conveyor system  100 . The maximum deflection of the pallet plates in the relaxed position is 0.705 inches. Also, the chain  302  is 15 inches from the outside perimeter. 
                                                                     TABLE 1                   Deflections (in inches) as a function of distance from       the edge (in inches) for different configurations                X1   X2   X3   X4                            DISTANCE   5.375   10.750   13.625   16.500           B2   0.125   0.439   0.652   0.880           DISTANCE   5.375   10.750   13.625   16.500           B3   0.035   0.125   0.185   0.250           DISTANCE   5.375   10.750   13.625   16.500           B4   0.048   0.169   0.252   0.340           DISTANCE   5.375   10.750   13.625   16.500           B5   0.206   0.723   1.075   1.450           DISTANCE   5.375   10.750   13.625   16.500           B5   0.163   0.573   0.852   1.150                        
The worst case deflection is 1.450 inches for the configuration depicted in  FIG. 12B . For the exemplary configurations discussed above, a force required to generate the latter deflection is 14.5 lbs. This amount of force does not generate excessive stresses on the interface between the pallet plate  105  and the pallet beam  113 .
 
       FIGS. 14 and 15  are top views of two consecutive bumper assemblies  106  oriented about partial/complete outside turns  154 / 156  and partial/complete inside turns  152 / 158 , respectively. Also depicted are the pallet beams  113  coupled to each bumper assembly  106  by the lower roller bracket  124 . Each bumper assembly includes a flexible member  160  and a roller  162 . The flexible member  160  is designed and dimensioned to provide a continuous surface about the perimeter of the luggage conveyor system with the pallets positioned in the partial/complete outside turns  154 / 156 . Similarly, the flexible member  160  is designed and dimensioned to avoid interference about the perimeter of the luggage conveyor system with the pallets positioned in the partial/complete inside turns  152 / 158 . The flexible members  160  are provided to cushion the impact of the luggage sliding from the first end  107  of the pallet plate  105  to the second end  109  of the pallet plate  105 . The roller  162  is configured to make contact with the pallet plate  105  proximate the end  109 . The roller  162  provides a smooth rolling action of the bumper assembly  106  as the pallet plates  105  slide with respect to one another as the pallet assemblies  104  move around the luggage conveyor system. Furthermore, the bumper assemblies may be pivotably coupled to the pallet beams  1113  by pivotably connecting to the lower roller brackets  124 , to further improving the sliding ability of the bumper assemblies  106  with respect to each other. The flexible members are configured to overlap a maximum of 3.774 inches which occurs in a partial/complete inside turn as depicted in  FIG. 15 . 
     While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.

Technology Category: b