Abstract:
A bulk bag unloading station wherein a bulk bag is suspended above a discharge receptacle. An assembly is provided for securing a spout extending from the bag to a discharge tube. The assembly comprises a clamp ring which defines a channel configured to receive the free edge of the tube therein. An actuator assembly is moveable between a first position where the clamp ring is spaced from the free edge and a second position where it overlies the tube free edge.

Description:
BACKGROUND 
     The present invention relates to the unloading of bulk bags used as containers for dry or moist particulate materials. The present invention more particularly relates to the unloading of bulk bag containers fabricated from cloth like material, such as woven polyester material, which is usually sewn in a cubical configuration. 
     Bulk bags made of heavy cloth material have been known in the art for sometime. It has also been known to provide the bag with heavy corner straps which support the bag when it is hung in a tower like support frame. The opposite end of the bag typically has an outlet spout which is aligned with the discharge unit of a receptacle, for example a conveyer, hopper or the like, through which the material is intended to be discharged. 
     To discharge the bag, the bag is hung in the support frame and material flows via gravity through the spout to the discharge unit. It is a characteristic of some particulate materials contained in a bag to resist or stop flowing out of the spout when the material remaining in the bag reaches the material&#39;s angle of repose or bridges over the spout. Since the bottom of the bag, where it is attached to the spout, is typically not at angle greater than the material&#39;s angle of repose, not all of the material will be discharged through the spout by gravity. 
     To address such, U.S. Pat. No. 5,184,759, commonly assigned with the present invention, discloses an apparatus which attaches to the spout and elongates the bag as material flows from the bag. As a result, the bottom of the bag forms more of a funnel shape, with the walls at an angle greater than the material&#39;s angle of repose, and the material flows more freely through the spout. 
     While the apparatus disclosed in U.S. Pat. No. 5,184,759 has proven successful at promoting freer flow from bulk bags, the manner in which the bag spout is attached to the moveable spout member has not always been the most desirable. With that devise, material may build up about the outside portion of the moveable spout. When the spout is released, the built-up material, particularly if it is a powdery material, may spill and contaminate the work environment. 
     U.S. Pat. No. 5,341,959 issued to Ellis discloses a means of connecting a bag spout to a moveable spout member with an internal securing configuration. However, this configuration is complex to manufacture and difficult to use. Due to the internal connection, an operator may have insufficient clearance to effectuate a proper connection inside the moveable spout member, particularly if the bag spout is short. 
     Accordingly, there is a need for a bulk bag unloading apparatus which includes a simpler, cleaner attachment arrangement. 
     SUMMARY 
     The present invention relates to a bulk bag unloading station wherein a bulk bag is suspended above a discharge receptacle. An assembly is provided for securing a spout extending from the bag to a discharge tube. The assembly comprises a clamp ring which defines a channel configured to receive the free edge of the tube therein and define a bag spout securing area. An actuator assembly is moveable between a first position where the clamp ring is spaced from the free edge and a second position where it overlies the tube free edge. In a preferred embodiment of the invention, the discharge tube is moveably mounted such that it extends the bag spout as the bag empties. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an elevation view of a bulk bag unloading station incorporating the present invention. 
     FIG. 2 is a top plan view of the preferred embodiment of the spout securing apparatus of the present invention. 
     FIG. 3 is a side elevation view of the spout securing apparatus of FIG.  2 . 
     FIG. 4 is a partial cross-sectional view of a preferred moveable spout member of the present invention. 
     FIG. 5 is a top plan view of a clamp ring useable with the preferred spout member of the present invention. 
     FIG. 6 is a cross-sectional view along the line  6 — 6  in FIG.  5 . 
     FIG. 7 is a side view and FIG. 8 is a front elevation of a preferred clamp actuator, useable with the present invention, in an extended position. 
     FIG. 9 is a side view and FIG. 10 is a front elevation of the preferred clamp actuator in transition. 
     FIG. 11 is a side view and FIG. 12 is a front elevation of the preferred clamp actuator in a closed position. 
     FIG. 13 is a partial cross-sectional view of an alternate embodiment of the preferred moveable spout member of the present invention. 
     FIG. 14 is a top plan view of a clamp ring useable with the alternate embodiment of the present invention. 
     FIG. 15 is a cross-sectional view along the line  15 — 15  in FIG.  14 . 
     FIGS. 16,  17  and  18 A progressively illustrate the clamping of a bag spout to the moveable spout member of FIG.  4 . 
     FIG. 18B is an enlarged view of the indicated portion of FIG. 18A showing the clamped position of the bag spout. 
     FIGS. 19,  20  and  21 A progressively illustrate the clamping of a bag spout to the moveable spout member of FIG.  7 . 
     FIG. 21B is an enlarged view of the indicated portion of FIG. 21A showing the clamped position of the bag spout. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The preferred embodiments of the present invention will be described with reference to the drawing figures where like numerals represent like elements throughout. 
     An exemplary bulk bag unloading station  5  incorporating the present invention is shown in FIG.  1 . The bulk bag unloading station  5  generally includes a support frame  6  from which a bulk bag  2  is suspended by the suspension assembly  8 . A hoist mechanism is illustrated, but other suspension assemblies may be used. The suspension assembly forms no part of the invention. A discharge receptacle  10 , for example a hopper, is positioned within the support frame beneath and in general alignment with the bulk bag  2 . A spout adapter  20  is positioned between the bulk bag spout  4  and the discharge receptacle  10 . 
     The preferred embodiments of the spout adapter  20  will be described in more detail with reference to FIGS. 2-15. Referring to FIGS. 2 and 3, the spout adapter  20  generally comprises a moveable discharge tube spout member  30 , a clamp ring assembly  50  and a control assembly  80 . The preferred control assembly  80  includes vertical mounting bracket  82  secured on the support frame  6 . Trolley assembly  86  is mounted to and moveable along the vertical mounting bracket  82  by the plurality of roller assemblies  88 . Opposed mounts  84  and  100  extend from the vertical mounting bracket  82  and the trolley assembly  86 , respectively. A fluid actuator  96 , including an extendable rod  98 , is mounted between the opposed mounts  84  and  100 . 
     The support frame  90  extends from the trolley assembly  86  toward the moveable spout member  30 . In the preferred embodiment, the support frame  90  includes a cross-bar  92  which supports a pair of opposed brackets  94  that connect to the moveable spout member  30 . The cross-bar  92  and opposed brackets  94  are preferred as they provide a balanced attachment for the spout member  30  about the center-line thereof, however, other attachment means may be utilized. 
     Referring to FIG. 3, movement of the moveable spout member  30  corresponds to movement of the actuator rod  98  as translated through the trolley assembly  86 . Downward movement of the moveable spout member  30  may occur either by positive actuation of the fluid actuator  96  to drive the rod  98  downward or by gravity. 
     Referring to FIG. 4, a first embodiment of the moveable spout member  30  is illustrated. The moveable spout member  30  preferably comprises a cylindrical tube  32  having an inlet end  36  and an outlet end  38  and connected by the brackets  94 , shown in phantom, to the control assembly  80  (not shown). The tube  32  is preferably manufactured from sheet metal, plastic or the like and is preferably cylindrical to complement the most common bag spout  4 . Transition tube  34  extends from the outlet end  38  of the cylindrical tube  32  and communicates with the discharge receptacle  10 . In the preferred embodiment, the transition tube  34 , manufactured from a flexible, accordion folded material, is secured at opposed ends thereof to the cylindrical tube  32  and the discharge receptacle  10 . The preferred material allows the transition tube  34  to expand and contract uniformly in response to movement of the cylindrical tube  32 . Alternatively, the end of the transition tube  34  addressing the receptacle may be unattached, similar to the means described in U.S. Pat. No. 5,184,759. 
     Referring to FIGS. 5 and 6, the preferred clamp ring  52  is illustrated. Clamp ring  52  includes a ring or plate  54  which defines an aperture  56  having a diameter less than or equal to the inside diameter of the tube  32 . A pair of spaced walls  58 ,  60  depend from the plate  54  to define a channel  62  configured to receive an upper edge of the spout tube  32 . See FIG. 18. A gasket  64 , manufactured from rubber or some other pliable material, is preferably positioned within the channel  62  adjacent to the plate  54 . A pair of opposed support brackets  66  extend from the plate  54 . 
     Referring to FIGS. 2 and 3, the moveable spout member  30  and the clamp ring  52  are preferably interconnected by a pair of clamp actuators  70 . The preferred clamp actuators  70  will be described with reference to FIGS. 7-12. Each preferred clamp actuator  70  includes a mounting bracket  71  which is securable either directly to the spout tube  32  or to the brackets  94 . An apertured guide block  72  is attached proximate the top of the mounting bracket  71  and a pair of pivot mounts  69  extend from a lower portion of the mounting bracket  71 . A rod  73  extends through the aperture in the guide block  72  for slidable movement therethrough. A first end  73 a of the rod  73  is configured for connection with a respective support bracket  66  on the clamp ring  52 . In the preferred embodiment, the rod end  73   a  is threaded and extends through an aperture  68  in the support bracket  66  and is secured thereto with bolts (not shown) or the like. Other connection arrangements may also be utilized. The other end  73   b  of the rod  73  is configured for pivotal connection to a first pair of links  75  via pivot pin  74  or the like. The first pair of pivot links  75  are in turn pivotally connected to link  77  via pivot pin  76  or the like. Link  77  is pivotally connected to the mounting bracket mounts  69  via pivot point  78 . A handle  79  is preferably secured to link. 
     In an initial position, as shown in FIGS. 10 and 11, the links  75  and  77  are in substantial vertical alignment with the rod  73  is in an extended position. This position maintains the clamp ring  52  spaced from the moveable spout member  30  such that the bag spout  4  can be passed through the aperture  56  and positioned about the spout tube  32 . It is preferable that the links  75  and  77  are not in complete alignment, but instead slightly offset toward the mounting bracket  71  (See FIG.  10 ). With such an alignment, the likelihood that the links  75 ,  77  will inadvertently rotate and lower the clamp ring  52  is reduced. Referring to FIGS. 12 and 13, to lower the clamp ring  52 , the handle  79  is moved along an arcuate path whereby link  77  rotates about pivot pin  78  and correspondingly, through pivot point  76 , links  75  rotate downward thereby, through pivot point  74 , retracting the rod  73 . Referring to FIGS. 14 and 15, the handle  79  is moved until link  77  is substantially horizontal and the links  75  are at an approximately forty-five degree (45°) angle thereto. The further downward travel of links  75  further retracts the rod  73 . The links  75  and  77  are configured such that the stroke of the rod  73  causes engagement of the clamp ring  52  with the spout tube  32  and the linkage is effectively locked with the clamp ring  52  in a closed position. To release the clamp ring  52 , the handle  79  is rotated back along its arcuate path. Other actuation means, for example a fluid actuator, may also be used. 
     Referring to FIG. 13, an alternative embodiment of the moveable spout member  130  is shown. Moveable spout member  130  includes an external tube  134  mounted about tube  32  by brackets  136  or the like. The control assembly  80  (not shown) is secured to the external tube  134  in a manner similar to the previous embodiment. Transition tube  34  extends from, and about, both tubes  32  and  134 . External tube  134  includes an aperture  138  through which a vacuum apparatus  140  may be connected. The vacuum apparatus  140  extrudes fine particulate material which may attempt to escape the spout member  130 . 
     Referring to FIGS. 14 and 15, clamp ring  152  is similar to clamp ring  52  and includes a plate  54  with an aperture  56  therethrough. Two pairs of spaced walls  58 ,  60  and  158 ,  160  depend from the plate  54  to define two channels  62  and  162 . One channel  62  is configured to receive an upper edge of the spout tube  32  and the other channel  162  is configured to receive an upper edge of the external tube  134 . A gasket  64  is preferably positioned in each of the channels  62  and  162 . Again, a pair of opposed support brackets  66  extend from the plate  54  for interconnection to the actuators  70 . 
     Having described the preferred components of the system, its operation will be further described with reference to FIGS. 16,  17 ,  18 A,  18 B,  19 ,  20 ,  21 A and  21 B. 
     Referring to FIG. 16, the spout adapter  20  is set in an initial position with the ring clamp  52  aligned above the moveable spout member  30 . A bulk bag is positioned with its spout  4  aligned with the aperture  56  in the clamp ring  52 . Referring to FIG. 17, the bag spout  4  is passed through the aperture  56  and positioned about the spout tube  32  without any extraneous preparation of the bag spout  4 . Referring to FIG. 18A, the clamp ring  52  is lowered via the clamp actuators (not shown) until the upper edge of the tube  32  seats within the clamp ring channel  62 . The bag spout  4  is thereby secured between the tube  32  and the clamp ring channel  62 , as shown in detail in FIG.  18 B. The gasket  64  provides resiliency to prevent excessive pinching of the bag spout  4  and to provide a more thorough seal. As can be seen in FIGS. 18A and 18B, the bag spout  4  is effectively sealed to the moveable spout member  30  with an unobstructed material path defined. 
     Referring to FIGS. 19,  20 ,  21 A and  21 B operation of the double wall embodiment is illustrated. As shown in FIG. 20, the bag spout  4  is again passed through the clamp ring aperture  56  and positioned about the spout tube  32 . The brackets  136  are preferably positioned such that they do not interfere with the bag spout  4 . Referring to FIG. 21A, the clamp ring  52  is lowered via the clamp actuators (not shown) until the upper edge of the tube  32  seats within clamp ring channel  62  and the upper edge of the external tube  134  seats within clamp ring channel  162 . The bag spout  4  is thereby secured between the tube  32  and the clamp ring channel  62  and the external tube  134  seals against the clamp ring  152 , as shown in detail in FIG.  21 B. With the external tube  134  sealed by the clamp ring  152 , any particulate remaining in the moveable spout member  130  can be extruded through the vacuum apparatus  140 .