Abstract:
A load-bearing roller for conveying items includes an outer cylinder and a transmission assembly. The transmission assembly includes a bushing rotatably mounted in an end of the outer cylinder, a transmission member, and a retracting member. The transmission member includes a transmission wheel and a toothed gear non-rotatably coupled to the transmission wheel. The transmission wheel is positioned outside the outer cylinder. The toothed gear is positioned in the bushing. The retracting member is mounted in the bushing. A free end of the retracting member engages with the gear teeth to urge rotation of the bushing and the outer cylinder. When the roller is jammed or prevented from rotating, the retracting member retracts over the teeth of the toothed gear so as to prevent overload of a prime mover. The disclosure also includes a conveying device using the load-bearing roller.

Description:
FIELD 
       [0001]    The subject matter herein generally relates to a roller, and to a conveying device using the roller. 
       BACKGROUND 
       [0002]    A roller, usually with a number of others, is used in a conveying device in order to convey objects. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]    Implementations of the present technology will now be described, by way of example only, with reference to the attached figures. 
           [0004]      FIG. 1  is a isometric view of an embodiment of a conveying device. 
           [0005]      FIG. 2  is a diagrammatic, isometric view of a load-bearing roller of the conveying device of  FIG. 1 . 
           [0006]      FIG. 3  is an exploded, isometric view of the load-bearing roller of  FIG. 2 . 
           [0007]      FIG. 4  is an enlarged, isometric view of a transmission assembly and a cap of the load-bearing roller of  FIG. 3 , from another angle. 
           [0008]      FIG. 5  is a cross-sectional view of the transmission assembly and the cap of  FIG. 4 , taken along the section plane V-V line. 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure. 
         [0010]    Several definitions that apply throughout this disclosure will now be presented. 
         [0011]    The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently connected or releasably connected. The term “substantially” is defined to be essentially conforming to the particular dimension, shape, or other feature that the term modifies, such that the component need not be exact. For example, “substantially cylindrical” means that the object resembles a cylinder, but can have one or more deviations from a true cylinder. The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like. 
         [0012]    The present disclosure is described in relation to a load-bearing roller. The load-bearing roller can include an outer cylinder and a transmission assembly. The transmission assembly can include a bushing rotatably mounted in an end of the outer cylinder, a transmission member, and a retracting member. The transmission member can include a transmission wheel and a toothed gear non-rotatably coupled to the transmission wheel. The transmission wheel can be positioned outside the outer cylinder, and the toothed gear can be positioned in the bushing. The retracting member can be mounted on an inner surface of the bushing. A free end of the retracting member can engage with the toothed gear, thereby allowing the bushing and the outer cylinder to rotate with the toothed gear. When the bushing and the outer cylinder are prevented from rotating under an external force, the retracting member can retract repeatedly over the teeth of the toothed gear, due to an increased rotating torque of the bushing. 
         [0013]    The present disclosure is described in relation to a conveying device. The conveying device can include supporting frame, a plurality of load-bearing rollers rotatably mounted on the supporting frame, a chain, and a driving member. Each load-bearing roller can include an outer cylinder and a transmission assembly. The transmission assembly can include a bushing rotatably mounted in an end of the outer cylinder, a transmission member, and a retracting member. The transmission member can include a transmission wheel and a toothed gear non-rotatably coupled to the transmission wheel. The transmission wheel can be positioned outside the outer cylinder, and the toothed gear can be positioned in the bushing. The retracting member can be mounted on an inner surface of the bushing. A free end of the retracting member can engage with the toothed gear, thereby rotating the bushing and the outer cylinder with the toothed gear. When the bushing and the outer cylinder are prevented from rotating under an external force, the retracting member can retract repeatedly over the teeth of the toothed gear. The chain can couple with the transmission wheels of the plurality of load-bearing rollers. The driving member can be configured for driving the chain to rotate. 
         [0014]      FIG. 1  illustrates a conveying device for conveying objects such as containers or packages. The conveying device can include a supporting frame  10 , a plurality of load-bearing rollers  30 , a chain  50 , and a driving member  70 . The plurality of load-bearing rollers  30  can be rotatably mounted on the supporting frame  10 . The chain  50  can be configured for coupling with the plurality of load-bearing rollers  30 . The driving member  70  can be configured for driving the chain  50  to rotate. 
         [0015]      FIGS. 2-3  illustrate a load-bearing roller  30  in the illustrated embodiment. Each load-bearing roller  30  can include an outer cylinder  32 , a transmission assembly  34 , a mounting base  36 , and a supporting shaft  38 . The transmission assembly  34  and the mounting base  36  can be mounted at opposite ends of the outer cylinder  32 . The supporting shaft  38  can be received in the outer cylinder  32 . The ends of the supporting shaft  38  can be mounted on the transmission assembly  34  and the mounting base  36 . 
         [0016]    In the illustrated embodiment, the outer cylinder  32  can include a roller body  322 , a first cap  324 , and a second cap  326 . The roller body  322  can be a substantially hollow cylinder and define a receiving chamber  3223  passing through opposite ends of the roller body  322 . The first cap  324  and the second cap  326  can be mounted on opposite ends of the roller body  322  in order to cover the receiving chamber  3223 . Also referring to  FIG. 4 , the transmission assembly  34  can include a bushing  342 , a transmission member  344 , and a retracting member  346 . The bushing  342  can be a substantially hollow cylinder and can be rotatably received in the receiving chamber  3223  adjacent to the first cap  324 . The transmission member  344  can be rotatably mounted on an end of the roller body  322  adjacent to the first cap  324 . The transmission member  344  can include a transmission wheel  3442  and a toothed gear  3445  non-rotatably coupled to the transmission wheel  3442 . The transmission wheel  3442  can be positioned outside the roller body  322  and be coupled to and rotated with the chain  50 . The toothed gear  3445  can be located in the bushing  342  and configured to rotate with the transmission wheel  3442 . The toothed gear  3445  can define a central hole  3447  configured for receiving the supporting shaft  38 . Also referring to  FIG. 3 , the transmission assembly  34  can further include a rotating shaft  345 . The rotating shaft  345  can pass through the first cap  324  and be partially located in the bushing  342 . The transmission wheel  3442  and the toothed gear  3445  can be coaxially rotated via the rotating shaft  345 . In the illustrated embodiment, the number of transmission wheels  3442  can be two. The transmission wheels  3442  can be removably fixed on the rotating shaft  345 . The toothed gear  3445  can be integrally formed on an end of the rotating shaft  345  and can be located in the bushing  342 . In other embodiments, the toothed gear  3445  can be detachably mounted on the rotating shaft  345 . 
         [0017]    In the illustrated embodiment, the retracting member  346  can include an engaging tab  3462  and a spring  3464 . One end of the spring  3464  can be mounted on an inner surface of the bushing  342 , and the other end of the spring  3464  can urge against the engaging tab  3462 . A free end of the engaging tab  3462  can be inserted into the valley between two adjacent teeth of the toothed gear  3445 . 
         [0018]      FIG. 5  illustrates the inner surface of the bushing  342 . A guiding groove  3423  is defined therein, configured for guiding the retracting movement of the retracting member  346 . The spring  3464  can be partially received in the guiding groove  3423 . An end of the spring  3464  can be mounted on a bottom surface of the guiding groove  3423 . The engaging tab  3462  can include a resisting portion  3463  protruding around a side surface of the engaging tab  3462 . One end of the engaging tab  3462  can be inserted into the spring  3464  and spaced from the bottom surface of the guiding groove  3423 , the other end of the engaging tab  3462  can be inserted into the toothed slot of the toothed gear  3445 . In the illustrated embodiment, the number of retracting members  346  and of guiding grooves  3423  can be two. The two guiding grooves  3423  can be oppositely located, that is, at 180 degrees from each other, on the inner surface of the bushing  342 . Each retracting member  346  can be mounted in a guiding groove  3423 . 
         [0019]      FIG. 3  illustrates that the mounting base  36  can be mounted on an end of the roller body  322 , adjacent to the second cap  326 . The mounting base  36  can include an elongated portion  362 . The elongated portion  362  can define a mounting hole  364 . The two ends of the supporting shaft  38  can be mounted in the mounting hole  364  and the central hole  3447 . The load-bearing rollers  30  can further include a mounting sleeve  39  mounted in the receiving chamber  3223  adjacent to the second cap  326 . The mounting sleeve  39  can be sleeved on the elongated portion  362 . An annular cavity (not shown) for mounting a bearing (not shown) can be cooperatively defined between the mounting sleeve  39  and the elongated portion  362 . 
         [0020]    In assembly, the toothed gear  3445  can be received in the bushing  342  and the rotating shaft  345  can run through the first cap  324 . Two transmission wheels  3442  can be separately sleeved on the rotating shaft  345  and positioned outside the bushing  342 . Two retracting members  346  can be mounted on the inner surface of the bushing  342  and the free end of the engaging tab  3462  can be inserted into the valley between teeth of the toothed gear  3445 . The bushing  342  can be received and mounted in the receiving chamber  3223 . The first cap  324  can be mounted on an end of the roller body  322  to cover the receiving chamber  3223 . An end of the supporting shaft  38  can be inserted into the central hole  3447  of the toothed gear  3445 . The mounting sleeve  39  can be received and mounted in the receiving chamber  3223  away from the first cap  324 . The mounting base  36  can be mounted on an end of the roller body  322  and the elongated portion  362  can be inserted into the mounting sleeve  39  and sleeved on an end of the supporting shaft  38  away from the first cap  324 . The second cap  326  can be mounted on an end of the roller body  322  away from the first cap  324  to cover the receiving chamber  3223 . 
         [0021]    In use, objects to be conveyed (not shown) can be laid on the load-bearing rollers  30 . The chain  50  can be rotated by the driving member  70 , which allows the transmission wheel  3442  and the toothed gear  3445  to rotate together. The engaging tab  3462  in the valley between two teeth can engage with the toothed gear  3445  and can rotate with the toothed gear  3445 , thus driving the bushing  342  to rotate. The roller body  322  rotates together with the bushing  342  due to a frictional force between the bushing  342  and the roller body  322 , thereby conveying the objects. The plurality of items can jam up or stop moving for some reason on the end portion of the conveying device  100 . Then, a frictional force between the bushing  342  and the roller body  322  is increased, so that the rotating torque of the bushing  342  is increased. The rotating force applied on the retracting members  346  can be therefore increased. Then rotating toothed gear  3445  can still rotate as the retracting members  346  retract as necessary over the teeth running beneath it. The rotational movement of each or any load-bearing roller  30 , positioned at the end portion of the conveying device  100  or at some other location, can be stopped. The transmission member  344  can be idle, preventing the driving member  70  from being overloaded. Other load-bearing rollers  30  of the conveying device  100  can keep rotating independently of the stopped load-bearing rollers  30 . 
         [0022]    In other embodiments, the spring  3464  is not sleeved on the engaging tab  3462  so long as opposite ends of the spring  3464  are mounted on the bottom surface of the bushing  342  and the engaging tab  3462 . The number of retracting members  346  can be one or more than one. The retracting member  346  can be an elastic member. Such an elastic member can be mounted on the inner surface of the bushing  342  and can be inserted into the valleys between teeth of the toothed gear  3445 . 
         [0023]    The embodiments shown and described above are only examples. Many details are often found in the art such as the other features of a load-bearing roller and a conveying device using the load-bearing roller. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, including in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the claims.