Abstract:
A conveyor is disclosed herein. An embodiment of the conveyor comprises an upper side, an under side, a first end, a second end, and a frame comprising a first side and a second side. At least one roller is located in the underside, the at least one roller extends between the frame first side and the frame second side. A belt extends between the first end and the second end, wherein the belt contacts the at least one roller. A bracket connects the first side of the frame to the at least one roller. The bracket comprises a first portion that is pivotally connected to the first side of the frame and a second portion pivotally connected to the roller, the bracket enables the roller to pivot relative to the first side of the frame.

Description:
[0001]    This application is a continuation of patent application Ser. No. 61/095,523, filed on Sep. 9, 2008 for BELT CONVEYOR. This application claims the benefits of the prior application, which is incorporated by reference for all that is disclosed therein. 
     
    
     BACKGROUND 
       [0002]    Conveyors use a belt to convey items between points. The belt moves about two pulleys or rollers located at endpoints of the conveyor. One problem with conveyors is that the belt wanders as it moves. The wandering is typically caused by one edge of the belt being a different length than the opposite edge. 
         [0003]    This wandering may cause the belt to move relative to the conveyor, which may cause the belt to wear, tear, or otherwise disable the conveyor. In order to overcome the wandering, conventional conveyors use devices that steer the belt to the correct location. However, these devices may cause extra wear on the belt and require a lot of time to adjust. The devices may also be noisy and may limit the speed in which the belt moves. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  is a top perspective view of a conveyor. 
           [0005]      FIG. 2  is a top perspective view of the conveyor of  FIG. 1  with the belt removed. 
           [0006]      FIG. 3  is a bottom perspective view of a portion of the conveyor of  FIG. 2 . 
           [0007]      FIG. 4  is an enlarged view showing the association of a roller to a frame of the conveyor of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0008]    An example of a conveyor  100  is shown in  FIG. 1 . The conveyor  100  includes a first end  112  and a second end  114 . The conveyor  100  has a frame  116  extending between the first end  112  and the second end  114 . A continuous belt  120  is able to move relative to the frame  116 . When viewed from the top of the conveyor  100 , the belt  120  moves in a direction  124 . Although, the conveyor  100  may be able to move the belt  120  in an opposite direction. The belt  120  serves to move items, such as the item  130  from the first end  112  to the second end  114 . A motor  122  moves the belt  120  in a conventional manner. In the embodiment of the conveyor  100  of  FIG. 1 , the motor is located proximate the second end  114 ; however, the motor  122  may be located in other locations and may or may not be attached to the frame  116 . 
         [0009]    For reference purposes, the conveyor  100  is referred to as having an upper side  134 , which is sometimes referred to as a first side, and an underside  136 , which is sometimes referred to as a second side. The frame  116  has a support mechanism, not shown in  FIG. 1 , that supports the belt  120  as it travels on the upper side  134 . Gravity causes the belt  120  to sag as the belt  120  travels on the underside  136 . The belt path relative to the underside  136  is sometimes referred to as the return or return path of the belt  120 . As described in greater detail below, rollers serve to support the belt  120  on the underside  136 . The rollers also serve to maintain the belt  120  in a fixed location relative to the frame  116 . 
         [0010]      FIG. 2  shows the second end  114  of the conveyor  100  with the belt removed. The upper side  134  of the conveyor  100  has a bed  140  on which the belt slides. In other embodiments, the bed  140  may have rollers or the like located thereon that facilitate the movement of the belt. The end  114  has transition devices that transition the belt from traveling on the upper side  134  to traveling on the underside  136 . These transition devices may include rollers, pulleys, and belt tensioning devices. 
         [0011]    One problem with conveyors is that the belts and/or the conveyors are not exactly straight. For example, one side of the belt  120 ,  FIG. 1 , may be slightly longer than the other side. In other embodiments, the belt  120  may not be perfectly flat and may have a ripple or the like in it. Either condition may be caused by imperfections during manufacture or wear. Because the belt is slightly crooked, the belt wanders as it moves. This wandering may cause the belt to move on, or relative to, the transition devices. In order to overcome the wandering, conventional conveyors use devices that steer the belt to the correct location. However, these devices may cause extra wear on the belt. The devices may also be noisy and may limit the speed in which the belt moves. 
         [0012]    Additional reference is made to  FIG. 3 , which is a bottom perspective view of the conveyor  100  showing the underside  136 . As shown in  FIG. 3 , the frame  116  has two sides, a first side  150  and a second side  152 , wherein the belt  120  is located substantially between the first side  150  and the second side  152 . The conveyor  100  described herein uses movable rollers  160  to guide the belt  120  in order to keep the belt  120  from wandering.  FIG. 3  shows two rollers  160 , which are referred to individually as a first roller  162  and a second roller  164 . As shown, the belt  120  lays on and is supported by the rollers  160  when the belt is in the return path. As described below, the rollers  160  are pivotally attached to each side  150 ,  152  of the frame  116 , wherein the pivoting causes the belt  120  to realign should it wander. 
         [0013]    Reference is made to the first roller  162 , which is substantially similar to the second roller  164 . The first roller  162  has a first end  168  located proximate the first side  150  of the frame  116  and a second end  170  located proximate the second side  152  of the frame  116 . The second roller  164  has similar ends.  FIG. 4  is an enlarged view of the first end  168  of the first roller  162  and the first side  150  of the frame  116 . A bracket  170  serves to connect the first end  168  of the roller  162  to the first side  150  of the frame  116 . The second end  170  of the roller  170  has a bracket similar to the bracket  170  connecting the second end  170  to the second side  152  of the frame  116 . Thus, the description of the bracket  170  applies to all the brackets connecting the rollers  160  to the frame  116 . 
         [0014]    The rollers  160  have bearings or the like located proximate their ends. For example, the first roller  162  has bearings or the like located proximate the first end  168  and bearings located proximate the second end  170 . The bearings enable the rollers  160  to rotate relative to the brackets  170 . It is noted that the bearings have some friction. 
         [0015]    The bracket  170  serves to pivotally connect the first end  168  of the first roller  162  to the first side  150  of the frame  116 . In summary, the bracket  170  enables the first roller  162  to rotate about an axis AA. In addition, the bracket  170  enables the first roller  162  to swing or pivot in a direction  172  relative to the first side  150  of the frame  116 . A first connector portion  176  of the bracket  170  rotatably connects the bracket  170  to the first roller  162  and enables the first roller  162  to rotate about the axis AA. As described above, bearings within the first roller  162  may enable this rotation. The mounting of the first roller  162  to the bracket  170  also enables to the first roller  162  to move slightly along the axis AA in the direction  174 . In addition, the first roller  162  may move so that the axis AA is not normal to the bracket  170  while the roller  162  continues to be able to rotate. The movement enables the ends  168 ,  170 ,  FIG. 3 , of the first roller  162  to pivot in different directions as described in greater detail below. 
         [0016]    A second connector portion  178  serves to pivotally or rotatably connect the bracket  170  to the first side  150  of the frame  116 . A pin or other fastener connects the second connection portion  178  of the bracket  170  to the second side  150  of the frame  116 . Therefore, the bracket  170  can rotate in the direction  172  relative to the frame  116 . 
         [0017]    Having described the conveyor  100 , the operation of the conveyor  100  will now be described. In summary, the rollers  160  serve to support the belt  120  on its return path. The pivoting of the ends  168 ,  170  of the rollers  160  causes the belt  120  to stay on the rollers  160  and in proper alignment with respect to the chassis  116 . As stated above, the belt  120  is likely not perfectly straight. For example, one side is typically a little longer than the other side. The imperfections in the belt  120  may be due to wear and heating. The imperfections in the belt  120  may be in the form of ripples in the belt wherein a small section of the belt may have one side that is longer than the other side. These imperfections in the belt  120  cause the belt  120  to wander out of alignment relative to the conveyor  100 . As described below, the pivoting of the rollers  160  counters the wandering of the belt  120  and realigns the belt  120 . 
         [0018]    Referring to  FIG. 3 , as the belt  120  moves along the return path, it is supported by the rollers  160 . The belt  120  may wander along an axis  180  in a first direction  182  or a second direction  184  opposite the first direction. The directions  182 ,  184  may be substantially normal to the sides  150 ,  152  of the frame  116 . As described above, the wandering is caused by the belt  120  being longer on one side than the other side. 
         [0019]    Referring to the first roller  162 , when a longer portion of the belt  120  contacts an end  168 ,  170  of the first roller, more force is exerted on the roller. The increased force increases the friction on the corresponding side of the first roller  162 , which reduces its ability to rotate due to friction. This side of the first roller  162  then pivots along the direction  172 . The pivoting causes the return path associated with the longer side of the belt  120  to be slightly longer than the other side. Therefore, the pivoting compensates for the different belt length, which maintains the belt  120  in a proper position in the conveyor  100 . 
         [0020]    The belt correction will now be described with reference to an example. In this example, a portion of the belt  120  corresponding to the first end  168  of the first roller  162  is slightly longer than the other side of the belt  120 . As this portion of the belt  120  may appear as a light sag on the side of the belt when this portion is in the return path of the conveyor  100 . When the sag contacts the first roller  162 , the sag, which is located proximate the first end  168  of the first roller  162  causes additional frictional force to be applied to the first end  168  of the first roller  162 . This additional force is greater than the frictional force applied to the second end  170  of the first roller  162 . The additional frictional force applied to the first end  168  of the first roller  162  causes the first end  168  of the first roller  162  to pivot in the direction  172 . The second end  170  of the first roller  162  does not pivot. Therefore, the return path proximate the first end  168  of the first roller  162  is longer than the return path associated with the second end  170  of the first roller. This longer return path compensations for the ripple in the belt  120  and maintains the belt  120  in proper alignment within the conveyor  100 .