Abstract:
A roller cam latching system adapted for securing a door of a storage bin for handling bulk materials includes a roller cam assembly and a latch assembly. The roller cam assembly includes a post and a bushing such that the bushing is rotatably disposed about the post. The latch assembly includes a contact member defining a contact surface and an actuator affixed to the contact member which can actuate the contact member between a first and a second position. In operation, actuation of the contact member from the first position to the second position causes the contact surface of the contact member to engage the bushing to secure the door of the storage bin.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is related to and claims priority from U.S. Provisional Application Ser. No. 60/600,982 filed Aug. 12, 2004, and entitled “Roller Cam Assembly for Side Door Bin”, and is hereby incorporated by reference. 
     
    
     BACKGROUND  
       [0002]     The present invention relates generally to a latching system for a storage bin. More particularly, the present invention relates to a roller cam assembly and roller cam latching system promoting improved storage bin door lockdown.  
         [0003]     Storage bins are a well-known means for handling bulk materials such as pharmaceuticals, foods, plastics, chemicals, and others. Typically, such bins are made from stainless steel or other appropriate materials. These bins generally include some type of door, hinged or otherwise. One common method of maintaining door closure is through use of a latch dog assembly. While use of latch dogs is generally well known, improvements remain to be made in both ease of use and functionality.  
       SUMMARY  
       [0004]     One aspect of the present invention relates to a roller cam latching system adapted for securing a door of a storage bin for handling bulk materials. The roller cam latching system includes a roller cam assembly including a post and a bushing rotatably disposed about the post, and a latch assembly including a contact member defining a contact surface and an actuator affixed to the contact member for actuating the contact member between a first position and a second position. As such, the contact surface of the contact member engages the bushing upon actuation of the contact member from the first position to the second position.  
         [0005]     One aspect of the present invention relates to a roller cam latching system. The roller cam latching system includes a roller cam assembly including a post defining a substantially cylindrical shape and a bushing rotatably disposed about at least a portion of the post, and a latch assembly including a propeller having a sidewall defining a helical contact surface, a shaft defining a first end and a second end, with the first end secured to the propeller, and an actuation member secured to the second end of the shaft such that actuation of the actuation member rotates the propeller. As such, the latch assembly and the roller cam assembly are configured such that rotating the propeller engages the bushing with the helical contact surface to produce rotation of the bushing and a resultant closing force on the latch assembly.  
         [0006]     One aspect of the present invention relates to a roller cam assembly for securing a door of a storage bin. The roller cam assembly includes a post affixed to the storage bin and a bushing rotatably disposed on the post. The post includes a substantially cylindrical head having a top end and a bottom end, and a neck formed at the bottom end of the head, with the neck defining a diameter less than that of the head. The bushing includes an upper body defining a tubular shape and extending from a bottom end to a top end, and a retaining collar formed at the bottom end of the upper body, with the retaining collar defining an inner diameter less than that of the upper body of the bushing. As such, the retaining collar of the bushing interacts with the neck of the post to retain the bushing on the post.  
         [0007]     One aspect of the present invention relates to a storage bin for handling bulk materials. The storage bin includes a body defining an enclosure and an access opening to the enclosure, a door openably secured to the body over the access opening, a roller cam assembly secured to the body, and a latch assembly secured to the door. The roller cam assembly includes a post and a bushing rotatably disposed about the post, and the latch assembly includes a contact member and an actuator affixed to the contact member. The actuator is configured to actuate the contact member from a first position to a second position to engage the bushing of the roller cam assembly with the contact member. As such, the door is secured in a closed position over the access opening upon actuation of the contact member from the first position to the second position. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is an isometric view of an exemplary side door bin in accordance with the present invention.  
         [0009]      FIGS. 2A, 2B , and  2 C are views of the exemplary side door bin of  FIG. 1 .  
         [0010]      FIG. 3  is a side, cross-sectional view through line  3 - 3  of  FIG. 2A  of an exemplary hinge mechanism of the side door bin.  
         [0011]      FIG. 4  is a side, cross-sectional view through line  4 - 4  of  FIG. 2A  of an exemplary roller cam latching system in accordance with the present invention.  
         [0012]      FIG. 5  is a cross-sectional view through a central axis of a post of the roller cam latching system of  FIG. 4 .  
         [0013]      FIG. 5A  is a detail view as indicated in  FIG. 5 .  
         [0014]      FIG. 6  is a cross-sectional view through a central axis of a bushing of the roller cam latching system of  FIG. 4 .  
         [0015]      FIG. 6A  is a detail view as indicated in  FIG. 6 .  
         [0016]      FIG. 7  is an exploded and perspective view of an exemplary roller cam assembly in accordance with the present invention.  
         [0017]      FIG. 8  is a cross-sectional view through a central axis of an exemplary roller cam assembly in accordance with the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0018]     In the following Detailed Description, reference is made to the accompanying figures, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “left”, “right,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of the embodiments of the present invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.  
         [0019]      FIGS. 1, 2A ,  2 B, and  2 C illustrate an exemplary, side door bin  20  as one example of a storage bin in accordance with the present invention. The side door bin  20  generally includes a body  22  defining an enclosure and a door, such as a side door  24 . As shown, the side door  24  is openably secured via a hinge  25  over an access opening (hidden) formed in a lower portion of the body  22 . As shown, the side door  24  covers the access opening.  
         [0020]     With reference to  FIG. 3 , an exemplary embodiment of the hinge  25  is shown in greater detail. As shown, the hinge  25  is configured to facilitate secure closure of the side door  24  to the body  22 .  
         [0021]     With reference to  FIG. 4 , an exemplary embodiment of a roller cam latching system  30  in accordance with the present invention can be described. Generally, the roller cam latching system  30  includes a latch assembly, such as a propeller assembly  32 , as well as a roller cam assembly  34 . More specifically, the latch assembly, or the propeller assembly  32 , defines a central axis X and includes a contact member, such as a propeller  36 , a shaft  38 , and an actuation member  40 .  
         [0022]     The propeller  36  includes a helical wall  42  radially extending partially about a cylindrical body  44  of the propeller  36 . As will be understood in greater detail below, the helical wall  42  defines a contact surface for engaging the roller cam assembly  34 . Depending upon the application, the propeller assembly  32 , including the propeller  36 , can be made of a variety of materials including, for example, aluminum 6061.  
         [0023]     The shaft  38  is generally cylindrical and configured such that the shaft  38  can be rotationally fixed relative to the propeller  36 . Further, the shaft  38  is configured to be fixed relative to the side door  24  in both a direction parallel to the central axis X and in a direction transverse to the central axis X of the propeller assembly  32 .  
         [0024]     The actuation member  40  is configured to interact with the shaft  38  and the propeller  36 , such that rotation of the propeller  36 , and in particular, the helical wall  42 , can be accomplished as desired by actuating the actuation member  40 . In this manner, the propeller  36  can be actuated between a first, open position and a second, closed position. In one embodiment, the actuation member  40  includes a hex head cap  48  fixed rotationally relative to the shaft  38  and consequently, the propeller  36 . Thus, actuating the actuation member  40  includes rotation of the hex head cap  48 . In particular, rotation of the hex head cap  48  results in concurrent rotation of the propeller  36 , including the helical wall  42 . For further reference, the hex head cap  48  is shown in more detail in  FIG. 1 .  
         [0025]     While one exemplary embodiment of the latch assembly  32  has been generally described above, it is to be recognized that a variety of alternatively designed latch assemblies can be utilized without departing from the scope of the present invention. For example, other actuation arrangements such as electric motors, levers, or gears, could be employed within alternative embodiments of the latch assembly  32  without departing from the scope of the present invention.  
         [0026]     With additional reference to  FIG. 4 , an exemplary embodiment of the roller cam assembly  34  can be described. Generally, the roller cam assembly  34  includes a post  50  and a bushing  52 . With reference to  FIGS. 5 and 5 A, it can be understood that the post  50  can be solid and continuously formed from a material such as aluminum 6061. As shown, the post  50  includes a post head  54 , a post neck  56 , a post body  58 , and a post base  60  and defines a central axis Y.  
         [0027]     In one embodiment shown in  FIG. 5 , the post head  54  forms a solid cylinder including a generally vertical head sidewall  62  terminating at a top end or face  63  of the post  50 . In one exemplary embodiment, the head sidewall  62  defines a height of approximately 0.74 inches and a diameter of approximately 0.75 inches. Furthermore, the post head  54  terminates at a crown  64  characterized by a chamfer  65 . In one exemplary embodiment, chamfer  65  defines an angle of approximately 60 degrees from horizontal. Furthermore, in one exemplary embodiment, the crown  64  is chamfered to a diameter smaller than the diameter of the head sidewall  62  by approximately 0.12 inches.  
         [0028]     In one embodiment, the post neck  56  forms a solid cylinder including a vertical neck sidewall  68  having a diameter less than that of the head sidewall  62 . In one exemplary embodiment, the neck sidewall  68  has a diameter of approximately 0.725 inches and extends a height of approximately 0.26 inches. The post neck  56  is coaxially aligned to and integrally formed with the post head  54  at a bottom end of the post head  54  opposite the top face  63 . Furthermore, in one exemplary embodiment, the connection, or transition, between the post neck and the post head  54  defines a chamfer  69  at an angle of approximately 45 degrees.  
         [0029]     In one embodiment, the post body  58  forms a solid cylinder including a vertical body sidewall  70  having a diameter greater than the post neck  56 , or in another embodiment, the post head  54 . In one exemplary embodiment, the body sidewall  70  defines a diameter of approximately 1.25 inches and a height of approximately 0.4 inches. As shown, the post body  58  is coaxially aligned with, and integrally formed with the post neck  56 . The connection between the post body  58  and the post neck  56  can define a round  71 . In one exemplary embodiment, the round  71  has a radius of approximately 0.06 inches.  
         [0030]     In one embodiment, the post base  60  forms a solid cylinder including a substantially vertical base sidewall  72  having a diameter smaller than that of the post body  58 . As shown, the base sidewall  72  originates at a bottom face  74  of the post  50 . As shown in  FIG. 4 , the base sidewall  72  can define a length generally corresponding to a thickness T of the body  22  of the side door bin  20 . In one exemplary embodiment, the base sidewall  72  has a diameter of approximately 0.74 inches and a height of approximately 0.25 inches. As shown, the post base  60  is coaxially aligned with the body  58  and connected thereto. The connection between the post base  60  and the body  58  can form a corner  73 . In one exemplary embodiment, the corner  73  forms an approximately 90-degree angle.  
         [0031]     With reference to  FIGS. 6 and 6 A, an exemplary embodiment of the bushing  52  can be described in greater detail. Generally, the bushing  52  defines a tubular shape and includes a substantially vertical sidewall  76  forming an inner cavity  77  and defining an upper body  78  and a retaining collar  80 , and includes a cap  82 . In one exemplary embodiment, the bushing  52  defines an overall height of approximately 1.188 inches, a retaining collar height of approximately 0.166 inches, an inner diameter of approximately 0.765 inches, and an outer diameter of approximately 1.125 inches. The bushing  52  can be formed from a variety of wear materials including polymeric or metallic materials. In one exemplary embodiment, the bushing  52  is formed of Hydex 4101.  
         [0032]     In one embodiment, the bushing sidewall  76  continuously forms the retaining collar  80  at a bottom end of the upper body  78 . The retaining collar  80  defines an outer diameter substantially the same as that of the upper body  78 , but defines an inner diameter less than that of the upper body  78 . The inner diameter of the upper body  78  can transition to the inner diameter of the retaining collar  80  to define a chamfer  83 . In one exemplary embodiment, the transition is over a height of approximately 0.12 inches. The chamfer  83  can generally match the dimensions, e.g., the angle and a length, defined by the chamfer  69  of the post  50 . In one exemplary embodiment, the chamfer  83  is at an angle of approximately 45 degrees and an inner diameter of the retaining collar  80  is approximately 0.74 inches.  
         [0033]     Additionally, the inner diameter of the retaining collar  80  can transition to an inner diameter of a terminal end  84  of the retaining collar  80  to define a chamfer  85 . The chamfer  85  and the chamfer  65 , and the other chamfers of the post  50  and the bushing  52  can be configured to interact to facilitate positioning of the bushing  52  over the post  50 , to facilitate removal of the bushing  52  from the post  50 , or to prevent the bushing  52  from inadvertently coming off of the post  50 . In one respect, the chamfer  85  can generally match the chamfer  65  of the post  50 . In relative terms, the matching chamfers  65 , 85  are steeper than matching chamfers  69 , 83 . In one embodiment, the matching chamfers  65 , 85  are formed at a relatively steep angle to facilitate installation of the bushing  52  over the post  50 . Conversely, the matching chamfers  69 , 83  are at a less steep angle to reduce the chance of accidental, or otherwise unwanted removal of the bushing  52  from the post  50 . In one exemplary embodiment, the inner diameter at the terminal end  84  is less than the inner diameter of the retaining collar  80  such that the chamfer  85  defines an angle of approximately 60 degrees from the horizontal.  
         [0034]     In one embodiment, a top end of the bushing  52  is topped with a cap  82  that is continuously formed with the upper body  78  and at an opposing end to the retaining collar  80 . The cap  82  can transition from the upper body  78  to define an internal round  86 . In one exemplary embodiment, the round  86  defines a radius of approximately 0.06 inches.  
         [0035]     In one embodiment, the cap  82  defines a top surface  88  of the bushing  52 . In one exemplary embodiment, the top surface  88  is generally dome-shaped defining a radius of curvature of approximately 1.125 inches. However, the top surface  88  can also be generally flat as can be better understood with reference to  FIG. 7 . The top surface  88  transitions to the sidewall upper body  78  to define an external chamfer  87 . In one exemplary embodiment, the external chamfer  87  is at an angle of approximately 45 degrees. In another exemplary embodiment, the external chamfer  87  is alternatively a round  87  having a radius of approximately 0.19 inches.  
         [0036]     While exemplary embodiments, including dimensions thereof, have been described herein, it is to be generally understood that the bushing  52  is configured to be rotatably disposed about the post head  54  and post neck  56 . Furthermore, the bushing  52  and post  50  are manufactured in such a manner that the bushing  52  is removable from the post  50  without damage to the post  50  or the bushing  52 .  
         [0037]      FIG. 7  shows one exemplary embodiment of the post  50  and the bushing  52  prior to assembly. In one embodiment, the bushing  52  is positionable over and removable from the post  50 , as the sidewall  76  of the bushing  52  is at least somewhat flexible and can be deflected outwardly relative to the central axis Z of the bushing  52 .  
         [0038]     As shown in  FIG. 8 , when the bushing  52  is positioned over the post  50 , the retaining collar  80  is configured to interact in a complementary fit with the post neck  56 . Thus, in one embodiment, a flexible property of the bushing  52  permits the retaining collar  80  to be deflected outwardly away from the central axis Z of the bushing  52 , or alternatively central axis Y of the post  50 , in order to secure the bushing  52  about the post head  54  and the post neck  56 . In this manner, the bushing  52  can be removed from the post head  54  and the post neck  56 . In other words, the semi-flexible configuration of the bushing  52  results in a roller cam assembly  34  with the bushing  52  being removably secured to the post  50 .  
         [0039]     Furthermore, the chamfer  85  of the bushing  52  is suited to facilitate removal and replacement of the bushing  52  on the post  50 . As alluded to above, the chamfer  85  can help guide the retaining collar  80  away from the central axis Z of the bushing  52  when it is being maneuvered onto the post  50 . For example, as described above, the chamfer  85  and the chamfer  65  can act in a complementary manner to facilitate assembly of the bushing  52  over the post  50 .  
         [0040]     The bushing  52  is also configured to rotate about the cylindrical head  54  and the post neck  56  of the post  50 . In particular, selective and/or slidable contact exists between the bushing  52  and the post  50 . In one embodiment, an inner surface  90  of the cap  82  slidably contacts the top face  63  of the post head  54 . Additionally, an inner face  92  of the bushing sidewall  76  slidably contacts the post head sidewall  62 . In this respect, an inner face  94  of the retaining collar  80  also slidably contacts the post neck sidewall  68 .  
         [0041]     In one embodiment, the terminal end  84  of the bushing  52  is maintained apart from a body top face  96  of the post body  58 . In this respect, a space between the body top face  96  and the terminal end  84  can be such that a removal tool can be inserted between them. In another embodiment, the bushing  52  can be moved, or lifted, relative to the post  50 , such that a sufficient space for a removal tool is maintained between the body top face  96  and the terminal end  84 . In one exemplary embodiment, the space is approximately 0.08 inches. In yet another embodiment, the terminal end  84  of the bushing  52  slidably contacts the body top face  96  of the post body  58 .  
         [0042]     As indicated above, while certain embodiments include the slidably contacting interactions described above, it should be noted that the embodiments can include selective, slidable contact, or even no contact at all between the surfaces described above. For example, the inner surface  90  of the bushing cap  82  can be separated from the top face  63  of the post  50 . Furthermore, the bushing  52  need not completely enclose the post head  54  and post neck  56 . For example, holes or other features, such as those used to introduce lubrication between surfaces could be incorporated into the bushing  52 .  
         [0043]     With reference to  FIG. 4 , interaction between the propeller assembly  32  and the roller cam assembly  34  can be further described. As shown, the roller cam assembly  34  is affixed to an internal surface  98  of the enclosed body  22  of the side door bin  20  proximate the latch assembly  32 , or the propeller assembly  32 . In particular, the post base  60  of the post  50  is disposed within the internal surface  98  of the side door bin  20  such that the post body  58  abuts a top face  100  of the internal surface  98 .  
         [0044]     In one embodiment, the post  50  is fixed relative to the internal surface  98 . One method of assembling the post  50  with the internal surface  98  includes: drilling a hole in the internal surface  98 ; inserting the post base  60  into the hole; and welding the post  50  to the internal surface  98 . In one exemplary embodiment, the hole is approximately 0.75 inches in diameter. The post body  58  and/or post base  60  can be welded to the internal surface  98 . In one embodiment, welding the post  50  to the internal surface  98  includes welding a fillet weld at the vertical body sidewall  70  and a portion of the surface  98  proximate the vertical body sidewall  70 . In another embodiment, the post  50  includes threads (not shown) such that the post  50  is screwed into the internal surface  98 . However, and as mentioned above, the bushing  52  remains free to rotate about the central axis Y, or alternatively the central axis Z, of the post  50  and the bushing  52 , respectively.  
         [0045]     In one embodiment described above, the propeller assembly  32  is fixed to the side door  24  in both a transverse and axial direction relative to the central axis X. Additionally, the propeller assembly  32  is affixed to the side door  24  such that when the side door  24  is in a closed position (as shown) the helical wall  42  of the propeller  36  can contact the bushing sidewall  76  to “pull” the side door  24  tightly closed as the propeller  36  and more specifically, the helical wall  42 , is rotated. In other words, rotation of the helical wall  42  induces a resultant thrust, or closing, force on the roller cam assembly  34 , thus closing the side door  24 .  
         [0046]     With this arrangement, the helical wall  42  can be moved past the post  50  when the side door  24  is first closed. The propeller  36  can then be rotated via the actuation member  40  such that the helical wall  42  exerts a tangential force on the sidewall  76  of the bushing  52 , as well as an accompanying thrust force. In one embodiment, the bushing  52  rotates about the post  50  in response to the tangential force applied to the sidewall  76 . Rotation of the bushing  52  about the post  50  reduces the friction between the roller cam assembly  34  and the propeller assembly  32 . This reduction in friction, in turn, reduces torque necessary to rotate the helical wall  42  and, therefore, the propeller assembly  32 . The resultant thrust force from contact between the helical wall  42  and the roller cam assembly  34  causes the side door  24  to tighten against the body  22  as the propeller  36  is progressively rotated against the bushing sidewall  76 .  
         [0047]     The capability of the bushing  52  to rotate about the post  50  is advantageous for several reasons. As mentioned, rotation of the bushing  52  decreases the torque needed to rotate the propeller  36  against the roller cam assembly  34 . Additionally, wear on both the propeller  36  and, in particular, the helical wall  42 , is reduced. Furthermore, corresponding wear on the post  50  that would occur in the absence of the bushing  52  is either eliminated or reduced. The bushing  52  can also be readily replaced after substantial wear has occurred, as the bushing  52  is removably secured to the post  50  as described above. Exemplary embodiments of the bushing  52  are also conducive to an operator using a screwdriver, for example, to simply “pop” the bushing  52  off of the post  50 , thus reducing otherwise wasteful bushing/post change-out times. In light of the above discussion and accompanying figures, the present invention supplies a roller cam assembly and roller cam latching system promoting improved side door lock down.  
         [0048]     Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. With that in mind, this application is intended to cover any adaptations or variations of the specific embodiments discussed herein.