Abstract:
A belt conveyor system with a distributing belt conveyor unit having upper and lower movable frame assemblies that are pivotally connected to a gear unit that simultaneously moves the lower movable frame assembly in opposition to the movement of the upper movable frame assembly, therein allowing the belt to track smoothly when transferring the articles between one branch belt conveyor unit and two or more branch belt conveyors units. The construction of the distributing belt conveyor unit allows for easy removal of the belt.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Application No. 61/358,941, filed Jun. 28, 2010. The entire contents of this related application is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    Belt conveyor systems, such as those used in airports to handle baggage or parcels and in industrial facilities to move products, typically include a “junction” for distributing or sorting the articles being transported from one conveyor to another. The distributing and/or sorting may be accomplished using diverters that have arms that are pivotably mounted at the side or adjacent to the conveyor to move articles to branch conveyors. Alternatively, the system may use a moveable conveyor for distributing or diverting the articles being transported onto stationary conveyors. 
         [0003]    Conventional distributing conveyors are mechanically complex with many components that are subject to wear and tear. In addition, to increase the throughput of the articles, it is desirable to have the belt conveyor system operate at high speeds. However, the faster the conveyors are operated, the greater the equipment vibrates, further increasing the wear and tear, and also producing higher noise levels during operation. Moreover, belt conveyor systems typically require tension adjustments and belt replacement over time. In order to adjust and replace the belts, the belt conveyor system has to be disassembled, and if complex, this results in a long system shutdown period for such maintenance and service. 
         [0004]    Accordingly, there is a need for belt conveyor systems with units that have fewer components, are capable of operating at high speeds relatively quietly, while allowing for ease of maintenance; in particular, the replacement of the belt. 
       SUMMARY 
       [0005]    The embodiments generally relate to a belt conveyor system that includes a distributing belt conveyor having a belt, an upper movable frame assembly, a lower movable frame assembly, a base frame, a gear unit attached to the base frame, at least one drive motor, and the upper and lower movable frame assemblies are pivotally connected to the gear unit and have pulleys that support the movement of the belt. The upper movable frame assembly is moved to pre-determined positions corresponding to the positions of the two or more stationary belt conveyor of the system. The gear unit operates to simultaneously move the lower movable frame assembly in opposition to the movement of the upper movable frame assembly, which permits the belt to track smoothly. The distributing belt conveyor can be operated bi-directionally, when transferring the articles between a trunk belt conveyor and the two or more branch belt conveyors. 
         [0006]    In one embodiment, a belt for the belt conveyors that has edge protrusions on its upper surface is disclosed. The pulleys for the belt conveyors will have edge profiles that engage these protrusions. 
         [0007]    A further embodiment of the belt conveyor system relates to the design and construction of the distributing belt conveyor that allows for easy removal of the belt, and in general, to a frame structure for belt conveyors that has removable sections to enable the belt to be more easily removed. 
         [0008]    The embodiments, along with their advantages and features herein disclosed, will become apparent through reference to the following description and the accompanying drawings. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessary to scale, because the emphasis is generally being placed upon illustrating the principles of the invention. In the description below, various embodiments of the present invention are described with reference to the following drawings, in which: 
           [0010]      FIG. 1  is a plan view of an embodiment of a belt conveyor system. 
           [0011]      FIG. 1   a  is a plan view of another embodiment of a belt conveyor system. 
           [0012]      FIG. 2  is a perspective view of an embodiment of a distributing belt conveyor. 
           [0013]      FIG. 3  is a perspective view of an exemplary main conveyor assembly of the distributing belt conveyor. 
           [0014]      FIG. 4  is a perspective view of an exemplary counter assembly of the distributing belt conveyor. 
           [0015]      FIG. 4   a  is an exploded perspective view of a section of the counter assembly. 
           [0016]      FIG. 5  is a perspective view of an exemplary switching gear unit of the distributing belt conveyor. 
           [0017]      FIG. 5   a  is an exploded perspective view of the switching gear unit. 
           [0018]      FIG. 6  is a cross sectional view of an exemplary protrusion for a belt. 
           [0019]      FIG. 7  is a cross sectional views of an exemplary grooved-step profile of the drive pulley and counter pulley. 
           [0020]      FIG. 7   a  is an exploded cross sectional view of the grooved-step profile. 
           [0021]      FIG. 7   b  is a cross sectional view of a belt with an exemplary protrusion engaging the grooved-step profile of a pulley. 
           [0022]      FIG. 8   a  is a perspective view of an exemplary gear drive mechanism for an embodiment of the distributing belt conveyor unit. 
           [0023]      FIG. 8   b  is a perspective view of an exemplary belt drive mechanism for an embodiment of the distributing belt conveyor unit. 
           [0024]      FIG. 9  is a perspective view of a section of an embodiment of the distributing belt conveyor unit showing the vertical frame, spacer and base frame arrangement. 
           [0025]      FIG. 10  is a perspective view showing the replacement position of an exemplary belt removal support. 
           [0026]      FIG. 10   a  is an exploded perspective view of the exemplary belt removal support. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    The embodiments generally relate to a belt conveyor system. The belt conveyor system, called a Flexible Horizontal Conveyor, may be used in many applications, including, but not limited to, airport handling systems for baggage and parcels, industrial production lines for moving and sorting various articles, and other similar uses. The belt conveyor system will have multiple units, including a distributing belt conveyor, for directing the articles to and from multiple locations. 
         [0028]    The distributing belt conveyor is able to perform several functions including: 1) be placed at a confluence of a transportation line to merge the articles into the transportation mainstream by being positioned at either the home position or divert position; 2) be placed at a confluence of a transportation line to divert the articles into the branch stream with assistance of other equipments (e.g. arm pusher) by being positioned at the divert position; 3) to sort the articles from the upstream, in-feed trunk conveyor into two or more downstream branch conveyors by switching between the home position and different divert positions, respectively; and 4) to merge articles from the two or more upstream branch conveyors into one main transportation stream. 
         [0029]    The following description sets forth, without limitation, the various embodiments of the belt conveyor system and, in particular, the distributing belt conveyor, as shown in the accompanying figures. 
         [0030]    As shown in  FIG. 1 , an embodiment of the belt conveyor system  1  includes a trunk stationary belt conveyor A, a distributing belt conveyor  2  and three branch stationary belt conveyors B, C and D. The belt conveyor system is able to move articles to and from multiple locations. Accordingly, the stationary belt conveyors A, B, C and D, as well as distributing belt conveyor  2 , can be operated bi-directionally to transport the articles. 
         [0031]    The distributing belt conveyor  2  employs a movable main conveyor assembly  3  with a movable end  4  and a stationary end  5 , which are aligned, respectively, with the stationary belt conveyors. Located at the stationary end  5  is the pivot point P, which is the vertex for the angles θ 1  and θ 2  (as measured from the centerline a-a), for positioning the main conveyor assembly  3  in alignment with the two branch stationary belt conveyors B and D. The linear alignment along the centerline a-a with the stationary belt conveyor C is considered in a “neutral” or “home” position. The main conveyor assembly  3  operates by switching between the branch stationary belt conveyors, with the movable end  4  following an arc-shaped path about the pivot point P travelling along a roller guide  6 . When three branch stationary belt conveyors are used, the angles θ 1  and θ 2  may be the same or different depending on the layout of the belt conveyor system  1 . The angles may be pre-determined to permit automated positioning of the main conveyor assembly  3 . 
         [0032]    In one embodiment, there are at least two branch stationary belt conveyors.  FIG. 1   a  shows an embodiment of the belt conveyor system that is configured for only two branch stationary belt conveyors, B and C. In this configuration, the distributing conveyor unit may be modified; for example, the roller guide  6 ′ can be shorter. It is within the scope of this disclosure to have more than three branch stationary belt conveyors, depending on the width of the main conveyor assembly and the width of the branch stationary belt conveyors. 
         [0033]    As shown in  FIG. 2 , this embodiment of the distributing belt conveyor  2  includes the movable main conveyor assembly  3  and a movable counter assembly  12 , which are supported by a base frame  7 . The main conveyor assembly moves in opposition to the movement of the counter assembly, which enables a belt  11  to track smoothly. The belt  11 , for example, may include an endless belt, a lacing belt or a zip belt. Other types of belt may also be used. The main conveyor assembly and the counter assembly are shown in an aligned neutral position. The base frame  7  has vertical frames  8   a  and  8   b  at the stationary end  5 . The base frame is wider than the main conveyor assembly to provide greater stability, and together with the vertical frames, is the main support for the distributing belt conveyor unit  2 . 
         [0034]    In a preferred embodiment, a horizontal frame  9  is shown in  FIG. 2  as an arc-shaped, semi-circular structure. The vertical frames  8   a  and  8   b  support the horizontal frame  9 , which is attached proximally to the tops of the vertical frames. The horizontal frame provides support at the stationary end  5  for the main conveyor assembly  3  and for the belt  11 . The arc-shape may be correspondingly fitted to slidably engage the main conveyor assembly. It is within the scope of this disclosure to have alternative embodiments for the semi-circular, solid surface shown for horizontal frame  9 ; for example, the surface may be slats, a lattice or a mesh surface in place of a solid surface, and an arc-shape smaller than a semi-circle or other suitable shape may be used. 
         [0035]    A guide track  10  is shown in  FIG. 2  as an arc-shaped, semi-circular structure. The guide track supports the movement of the counter assembly  12 . The vertical frames  8   a  and  8   b  also support the guide track  10 , which is attached below the horizontal support  9 . The shape of the guide track  10  can be varied, provided it is able to support the movement of the counter assembly, and will depend, in part, on the length of the counter assembly. It is preferred that at least that portion of the guide track  10  supporting the movement of the counter assembly  12  be an arc-shape. 
         [0036]    As shown  FIG. 3 , the main conveyor assembly  3  includes a take-up pulley  13 , a tail pulley  14 , and a drive pulley  16 . The take-up pulley, tail pulley and drive pulley are axially mounted parallel to each other on the frame of the main conveyor assembly. The take-up pulley is adjustably mounted to allow for tightening and loosening of a belt and can be removed when the belt needs to be replaced. Located near the tail pulley  14  is an extension  17 , which serves to bridge the gap between the distributing belt conveyor and the branch stationary belt conveyors. 
         [0037]    In the embodiment shown in  FIG. 3 , a belt drive motor  15  is attached to the drive pulley  16  and is a drum-type motor. It is within the scope of this disclosure for the drive pulley to be motorized by either a direct method, using a drum motor or shaft mounted motor, or an indirect method, using a timing belt coupled with switching drive motor that is horizontally mounted on the main conveyor assembly  3 . 
         [0038]    The main conveyor assembly  3  includes a main frame connector  18  and at least one caster wheel  23  that is attached to the underside of the main conveyor assembly. The caster wheel travels on the roller track  6 , as it supports the weight of main conveyor assembly during the switching movement about pivot point P. The upper surface of roller track  6  is preferably rubberized for noise reduction. The main conveyor assembly  3  is also provided with two side frames that are removable for maintenance, including the replacement of the belt. In one preferred embodiment, each side frame is divided into two removable parts  19   a  and  19   b , which permits the take-up pulley  13  or the tail pulley  14  to individually serviced without the need to disturb the other pulley. 
         [0039]    The upper portion of the main conveyor assembly  3  is provided with a horizontal belt support  20  and side guards  21   a  and  21   b . The horizontal belt support and side guards accommodate the contour of the horizontal frame  9  to allow the main conveyor assembly to move smoothly. It is also preferred that the upper surfaces of the horizontal belt support  20  and the horizontal frame  9  are leveled to be in the same horizontal plane, thereby permitting the transported articles to travel smoothly on the belt, and that edge  22  of horizontal belt support is shaped to correspond closely with the horizontal frame  9 . Alternative embodiments for the horizontal belt support  20  may include a frame with rollers, slats, a lattice or mesh surface rather than a solid surface. 
         [0040]    The side guards  21   a  and  21   b  are positioned to move over the horizontal frame  9  with minimal or no friction. In addition, the lengths of the side guards can be the same or different depending on the number of branch stationary belt conveyors. For example, if only two branch stationary belt conveyors are present, and positioned as B and C as shown in  FIG. 1   a , it can be advantageous to have side guard  21   b  longer than side guard  21   a . However, if the two branch stationary belt conveyors are positioned as C and D, as shown in  FIG. 1 , it can be advantageous to have side guard  21   a  longer than side guard  21   b.    
         [0041]    As shown in  FIG. 4 , the counter assembly  12  is provided with a counter frame connector  24 , bearing wheel  25 , wheel support  26  and counter pulley  27 . The counter assembly is supported by at least one bearing wheel, which moves on guide track  10 . When one bearing wheel is used, the bearing wheel and wheel support is preferably located near the center of the counter pulley (not shown) to provide better weight distribution. In a preferred embodiment having two wheel supports positioned on the sides of the counter pulley  27 , the counter assembly  12  will have at least two bearing wheels. It is preferred that the bearing wheels  25  be made of a polymeric material, which will enable smooth movement on the guide track and reduced noise. 
         [0042]    As shown in  FIG. 4   a , another preferred embodiment provides a wheel support  26  on both sides of the counter pulley  27 , with each wheel support having upper bearing and lower bearing wheels  25 . The guide track  10  is provided with a flange portion  10   a  that is engaged between the upper and lower bearing wheels. In this arrangement, the bearing wheels prevent the counter pulley from disengaging from the guide track. 
         [0043]    As shown in  FIG. 5 , the distributing belt conveyor  2  is provided with two long end pulleys, the lower long end pulley  28  and upper long end pulley  29 , and a switching gear unit  33 , which are positioned at the stationary end  5 . The lower long end pulley  28  and upper long end pulley  29  are mounted parallel to each other. The long end pulleys  28  and  29  rotate when the main conveyor assembly is in the “home” position. When the main conveyor assembly is in a “diverted” position, as shown in  FIG. 1 , both long end pulleys are kept stationary to allow the belt to more easily stay on track. In one embodiment, to keep the long end pulleys stationary, an encoder  30  and brake mechanism  31  are provided at the ends of the long end pulleys, while the other ends of long end pulleys are coupled with a timing belt  32 . The brake mechanism may be placed on either the upper or the lower long end pulley. 
         [0044]    The movements of the main conveyor assembly  3  and the counter assembly  12  are synchronized using a switching gear unit  33 , or “reverse” gear unit. As shown in  FIG. 5   a , the switching gear unit  33  is provided with a counter gear  34 , a main gear  35 , a counter shaft  36 , four flanged mounted bearings (only the top flanged mounted bearings  37  and  38  are shown), at least one eye-turned buckle  39 , two welded plates  40  and  41 , and a main shaft  42 , which embodies the pivot point P. The remaining two flanged mounted bearings are positioned at the underside of the switching gear unit  33  near the bottom ends of counter shaft  36  and main shaft  42 . 
         [0045]    The main frame connector  18  is coupled to main gear  35 , which enables the synchronized movement. The main gear  35  has bearings (not shown) inside and these bearings permit rotation on the main shaft  42 , i.e., each moves independently. The counter frame connector  24  is connected to the top end of the main shaft  24 . The main shaft acts as the pivot point P for the movement of both the main conveyor assembly  3  and counter conveyor  12 . 
         [0046]    The main gear  35  and counter gear  34  are engaged and rotate in opposite directions. The welded plates  40  and  41  are joined by at least on eye-turned buckle  39  and this synchronizes the rotation of main shaft  42  and counter shaft  36 . By means of the opposite rotation of the gears and the shaft synchronization, the reverse swinging movement of main conveyor assembly  3  and counter conveyor  12  is achieved. 
         [0047]    For example, to align the movable end  4  of main conveyor assembly  3  with the branch stationary belt conveyor B (as shown in  FIG. 1 ), the main frame connector  18  is moved in the direction b 1  (as shown in  FIG. 5   a ). As a result, the main gear  35  (which is attached to main frame connector  18 ) is rotated in a clockwise direction and causes a counter-clockwise rotation of the counter gear  34  and counter shaft  36 . Accordingly, the main shaft  42  and the attached counter assembly  12  are rotated in a counter-clockwise direction by the arrangement of the welded plates  40  and  41  and the eye-turned buckle  39 . The synchronized reverse swinging movement of main conveyor assembly  3  and counter assembly  12  thereby enable the smooth movement of the belt  11 . 
         [0048]    For the distributing belt conveyor  2 , the belt  11  extending from the upper long end pulley  29  to the tail pulley  14  is the transporting surface for the articles. In one direction of use, the belt is taken downward by the drive pulley  16  and around the take-up pulley  13  towards the lower long end pulley  28 . From the lower long end pulley  28 , the belt extends around the counter pulley  23 , and continues upward to the upper long end pulley and then to the tail pulley  14 . 
         [0049]    In a preferred embodiment, the belt  11  is provided with protrusions that are proximal to the outer edges of the upper surface of the belt, which engage the drive and counter pulleys. As shown in  FIG. 6 , a protrusion  44 , which is made of a medium hard belt material, is located proximal to the edge of the belt  11 . In another preferred embodiment, the edge protrusion  44  of the belt has cross-sectional shape in the form of a rectangle. It is within the scope of this disclosure and understood that other shapes may be used, including square, semi-circular and triangular. In addition, between the protrusions, a roughened upper surface may be used that prevents transported articles from easily sliding off the conveyor, while the lower surface of the belt is smooth. 
         [0050]    As shown in  FIGS. 7 ,  7   a  and  7   b , in this preferred embodiment, the drive pulley  16  and counter pulley  27  are provided with ends that have a grooved-step profile  43 . The shape of the groove  43  will correspond with the shape of the protrusion  44  to allow the protrusion to fit inside the grooved-step. This arrangement allows the drive and counter pulleys to more easily maintain the position of the belt and prevents the belt from sliding off the pulleys and to the edges of the conveyor. The corners of grooved-step profile  43  are made smooth to mitigate the tearing of the belt  11 . 
         [0051]    In one embodiment, the movement or “switching” between the branch stationary belt conveyors is powered by a motorized drive mechanism. The preferred embodiments for the drive mechanism are: a) belt drive mechanisms; and b) gear drive mechanisms. 
         [0052]    As shown in  FIG. 8   a , an embodiment of the gear drive mechanism provides a switching drive motor  45 , a gearbox  46 , arc gear  47  with arc sprockets  48 , and a sprocket  49 . Switching drive motor  45  is mounted on the base frame  7  under the main conveyor assembly  3 . Gearbox  46  attached to switching drive motor  45  can be a right angle or straight type. Arc gear is preferably attached to the underside main conveyor assembly  3 . The movement of main conveyor assembly  3  is driven by the operation of the switching drive motor  45  via sprocket  49 , as it engages the arc sprocket  48  on the arc gear  47 . In another embodiment, the arc gear may be substituted with pins or a chain to engage the sprocket  49 . 
         [0053]    As shown in  FIG. 8   b , an embodiment of the belt drive mechanism provides a gearbox (not shown), switching drive motor (not shown), two drive pulleys  51  and  52 , a timing belt  53 , connection block  54  and two linear rails  55  and  56 . As with the gear drive mechanism, the switching drive motor and gear box are mounted on the base frame  7 . The gearbox attached to the switching drive motor can be a right angle or straight types. The two pulleys  51  and  52  are mounted at the upper surface of base frame  7  and either one of the pulleys may be connected to and driven by the switching drive motor and gearbox. The timing belt  53  is looped around the two pulleys  51  and  52 , with the connection block  54  attached firmly on the timing belt  53 . The linear rail  55  is mounted on the base frame  7  and is positioned parallel with the section of the timing belt  53  between the pulleys. The linear rail  56  is attached under main conveyor assembly. The connection block  54  is slidably attached to linear rails  55  and  56 . The motor  45  drives the movement of connection block  54  as a result of it being coupled to the timing belt  53 . 
         [0054]    When the pulley  51  or  52  (depending on which pulley is attached with the drive motor) is rotated in clockwise direction, the connection block  54  is driven in the direction c 1  by the movement of the timing belt  53 . The linear guide rail  56  is pulled by connection block  54  and the main conveyor assembly  3  is swung in the same direction. When the pulley  51  or  52  is rotated in counter-clockwise direction, the main conveyor assembly  3  is swung to the direction c 2 . 
         [0055]    The embodiments provide a distributing belt conveyor unit that is simpler to maintain and service; in particular, the removal of the belt is simplified. To that end, with reference to  FIGS. 9 ,  10  and  10   a , it is preferred that the belt removal be performed from the side of the distributing belt conveyor where the timing belt  32  is located. 
         [0056]    To begin, the take-up pulley  13  is loosened and removed, followed by the removal of extension  17  and the main assembly side frames parts  19   a  and  19   b . By removing the take-up pulley, the belt is slackened and the counter pulley  27  can be easily removed by unfastening the counter frame connector  24  from main shaft  42 . Thereafter, the belt  11  can be shifted to the side where the timing belt  32  is located. The belt removal support  58 , which has an inverted L-shape, as shown in  FIG. 10   a , is placed on the base frame  7  on the opposite side of the timing belt  32 , as shown in  FIG. 10 . The belt removal support is positioned to permit the remaining pulleys to be left undisturbed in their original positions. Subsequently, the timing belt  32  and the vertical spacer  57 , as shown in  FIG. 9 , are removed. After completing the steps above, the belt  11  can be removed through the openings created by the removal of the side frames parts  19   a  and  19   b  and the vertical spacer  57 . 
         [0057]    Although the one or more above-described embodiments and implementations have been described in language specific to structural features and/or methodological steps, it is to be understood that other embodiments and implementations may be practiced without the specific features or steps described. Rather, the specific features and steps are disclosed as preferred forms of one or more embodiment and implementation.