Abstract:
A closure member for a top opening of a storage bin wherein the storage bin includes a roof with a top opening through which the bin can be filled by material discharged downwardly through the opening; the closure member comprising: a sleeve for engagement with the bin at the opening, the sleeve having a peripheral wall surrounding an axis of the sleeve; the sleeve being arranged to be mounted on the bin at the opening so as to hold the axis to stand substantially upright from the opening with the sleeve extending upwardly from the opening; the sleeve defining an open top end for pouring material through the sleeve into the bin; a cover plate for movement between a closed position covering the open top end and an open position in which the open top end is exposed; the sleeve having a plurality of openings therethrough at angularly spaced positions therearound for allowing vent air to pass between the interior and the exterior of the bin.

Description:
[0001]     This invention relates to a top closure member for a storage bin.  
       BACKGROUND OF THE INVENTION  
       [0002]     Storage bins for particulate materials are well known and widely used. Conventionally the storage bin comprises a metal wall mounted on a suitable base with a metal wall having vertical cylindrical section together with a top conical section which converges upwardly and inwardly toward a top opening through which the bin is intended to be filled.  
         [0003]     Such bins are primarily but not exclusively used for storing harvested crop and it is well known that crop materials require careful storage to ensure suitable moisture content. Thus the bin should provide a top closure member over the opening which prevents the penetration of moisture from rain or snow. In addition it is often desirable to provide vents for the bin so as to allow injected air at the base of the bin to rise through the stored crop materials to vents at the top of the bin. Commonly such vents are provided at spaced positions around the conical roof section in a similar manner to roof vents used on dwellings. Such roof vents are thus designed generally to inhibit or prevent the penetration of moisture while allowing air to escape. However such vents require additional elements to be purchased and installed thus increasing the cost.  
         [0004]     In addition a cover panel for a top of the closure member of the top opening requires to be opened to fill the bin and closed to provide the necessary closure.  
         [0005]     It is common that the top closure member is a hinged flap which can pivot about a horizontal hinge at one edge to be raised and lowered. It is desirable that such opening and closing is effected using a cable from the ground so as to avoid a person climbing dangerously to the top of the bin, particularly in the unsuitable weather conditions which can be found in winter when the bin is use.  
         [0006]     In U.S. Pat. No. 4,747,244 (Christianson) issued May 31, 1988 is provided such an arrangement in which a hinged cover panel is operated by a lever system from the ground.  
         [0007]     In U.S. Pat. No. 4,267,936 (Pavlicek) issued May 19, 1981 is disclosed a storage bin of this type which utilizes a cover panel which slides horizontally on guide tracks from a closed position over the opening to one side of the opening. The cover panel is in the for of a flat plate thus making sealing around the edges of the plate difficult relative to the opening and requiring a particular construction of the plate and sealing edges. The horizontal sliding action prevents the use of a conventional cover plate which has a depending protective flange around the outside edge of the cover plate. Cover plates of this type can include a circular top cover plate together with a cylindrical or annular band or flange which projects downwardly from the outside edge of the plate so that this can engage over a collar at the top of the bin.  
       SUMMARY OF THE INVENTION  
       [0008]     It is one object of the invention to provide a closure member for a storage bin.  
         [0009]     According to one aspect of the invention there is provided a closure member for a top opening of a storage bin:  
         [0010]     wherein the storage bin includes a roof with a top opening through which the bin can be filled by material discharged downwardly through the opening;  
         [0011]     the closure member comprising:  
         [0012]     a sleeve for engagement with the bin at the opening, the sleeve having a peripheral wall surrounding an axis of the sleeve;  
         [0013]     the sleeve being arranged to be mounted on the bin at the opening so as to hold the axis to stand substantially upright from the opening with the sleeve extending upwardly from the opening;  
         [0014]     the sleeve defining an open top end for pouring material through the sleeve into the bin;  
         [0015]     a cover plate for movement between a closed position covering the open top end and an open position in which the open top end is exposed;  
         [0016]     the sleeve having a plurality of openings therethrough at angularly spaced positions therearound for allowing vent air to pass between the interior and the exterior of the bin.  
         [0017]     The sleeve is not necessarily cylindrical and may be partly tapered or wholly tapered with the narrower end at the top or bottom and the term “sleeve” is not intended to be so limited.  
         [0018]     Preferably the sleeve includes a cylindrical portion defining a vertical wall and wherein the openings are arranged in the cylindrical portion.  
         [0019]     Preferably there is provided an overhanging cover surface surrounding the sleeve above the openings and extending outwardly from the sleeve to inhibit penetration of rain through the openings.  
         [0020]     Preferably there is provided a depending flap member over the openings which is arranged such that it flexes away from the sleeve when air flows from the interior to the exterior through the openings and is pressed onto the sleeve when air tends to flow from the exterior to the interior thus inhibiting penetration of exterior materials.  
         [0021]     Preferably the flap member comprises a surrounding band of a flexible material which is slit from the bottom and attached at a top edge above the openings.  
         [0022]     Preferably the sleeve includes a bottom tapered portion which tapers downwardly and inwardly from a cylindrical portion to a bottom edge and wherein the tapered portion is arranged to fit in a bin opening having a smaller diameter than the cylindrical portion.  
         [0023]     Preferably the cover plate has a depending lip for surrounding an outer surface of the sleeve at the open top of the sleeve, wherein there is provided a track extending generally horizontally from the open top of the sleeve to one side therefor for carrying the cover plate from the closed position to the open position at the one side  
         [0024]     Preferably the track is shaped to lift the lip over the open top end to allow the cover plate to move to the side.  
         [0025]     Preferably the track includes a pair of track rails spaced by a width of the cover plate and arranged to engage respective sides of the cover plate.  
         [0026]     Preferably there is provided a latch member actuable to hold the cover plate in the closed position and in the open position.  
         [0027]     Preferably the latch member is carried on the cover plate and is operable to engage and release stops provided on the track.  
         [0028]     Preferably the cover plate is pulled from the closed position to the open position by a cable attached to the latch member.  
         [0029]     Preferably the track is arranged to rise slightly from the closed position to the open position such that the cover plate returns to the closed position under gravity by running down the track.  
         [0030]     According to a second aspect of the invention there is provided a closure member for a top opening of a storage bin:  
         [0031]     wherein the storage bin includes a roof with a top opening through which the bin can be filled by material discharged downwardly through the opening;  
         [0032]     the closure member comprising:  
         [0033]     a sleeve for engagement with the bin at the opening, the sleeve having a peripheral wall surrounding an axis of the sleeve;  
         [0034]     the sleeve being arranged to be mounted on the bin at the opening so as to hold the axis to stand substantially upright from the opening with the sleeve extending upwardly from the opening;  
         [0035]     the sleeve defining an open top end for pouring material through the sleeve into the bin;  
         [0036]     a cover plate for movement between a closed position covering the open top end and an open position in which the open top end is exposed;  
         [0037]     wherein the cover plate has a depending lip for surrounding an outer surface of the sleeve at the open top of the sleeve,  
         [0038]     wherein there is provided a track extending generally horizontally from the open top of the sleeve to one side thereof for carrying the cover plate from the closed position to the open position at the one side;  
         [0039]     and wherein the track is shaped to lift the lip over the open top end to allow the cover plate to move to the side.  
         [0040]     According to a third aspect of the invention there is provided a closure member for a top opening of a storage bin:  
         [0041]     wherein the storage bin includes a roof with a top opening through which the bin can be filled by material discharged downwardly through the opening;  
         [0042]     the closure member comprising:  
         [0043]     a sleeve for engagement with the bin at the opening, the sleeve having a peripheral wall surrounding an axis of the sleeve;  
         [0044]     the sleeve being arranged to be mounted on the bin at the opening so as to hold the axis to stand substantially upright from the opening with the sleeve extending upwardly from the opening;  
         [0045]     the sleeve defining an open top end for pouring material through the sleeve into the bin;  
         [0046]     a cover plate for movement between a closed position covering the open top end and an open position in which the open top end is exposed;  
         [0047]     wherein the sleeve includes a cylindrical portion and a bottom tapered portion which tapers downwardly and inwardly from the cylindrical portion to a bottom edge and wherein the tapered portion is arranged to fit in a bin opening having a smaller diameter than the cylindrical portion. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0048]     One embodiment of the invention will now be described in conjunction with the accompanying drawings in which:  
         [0049]      FIG. 1  is a top plan view of a closure member for storage bin of the present invention.  
         [0050]      FIG. 2  is a side elevational view of the closure member of  FIG. 1 .  
         [0051]      FIG. 3  is an exploded view of the closure member of  FIG. 1 .  
         [0052]      FIGS. 4 and 5  are similar views to that of  FIG. 2  showing the cover panel in an initial opening position and in a completed opened position.  
         [0053]      FIG. 6  is a side elevational view similar to that of  FIG. 2  showing a modified construction for use as a retro fit on existing bins.  
         [0054]      FIG. 7  is a side elevational view on an enlarged scale of the cylindrical section of the sleeve showing the moisture flap arrangement. 
     
    
       [0055]     In the drawings like characters of reference indicate corresponding parts in the different figures.  
       DETAILED DESCRIPTION  
       [0056]     A storage bin comprises a base  10  and a cylindrical wall  11  of a conventional nature. At the top of the cylindrical wall is provided a conical roof section  12  which extends upwardly and inwardly converging to a top opening generally indicated at  13  through which the bin can be loaded. At the opening  30  is mounted a collar  14  which attaches to an upper edge  15  of the conical roof  12  to define a central opening through which air can pass and through which the material to be stored can be poured to fill the bin. Around the opening is provided the collar or ring  14  which attaches in conventional manner by a flange  14 A to the top of the wall  15 .  
         [0057]     The collar  14  attaches to a sleeve  16  which defines a cylindrical wall extending from a bottom edge  16 A to a top edge  16 B. The cylindrical wall forming the sleeve  16  has a series of holes  16 C at angularly spaced positions around the sleeve. Each hole extends from a bottom edge  16 D to a top edge  16 E spaced from the top edge  16 B. The holes are rectangular preferably but may be of different shapes. Each hole is spaced from the next by a strip  16 F of the sleeve. The holes are relatively large so that the majority of the sleeve in the area of the holes between the top and bottom edges of the holes is perforated.  
         [0058]     A rain shield  17  is attached to the sleeve  16  across the top edges  16 E of the holes  16 C. The rain shield  17  is in the form of a frusto-conical surface extending from a top edge  17 A welded or otherwise attached to the sleeve  16  to a bottom edge  17 D which is spaced outwardly from the sleeve  16  and at a position approximately halfway down the holes  16 C. Thus the rain shield  17  tends to prevent rain falling vertically or at an angle less than an angle of the order of 45° to the vertical from penetrating directly through the holes  16 C.  
         [0059]     In some situations the rain shield  17  may be sufficient to prevent the penetration of moisture by rain and/or snow. In some areas snow, which tends to be more buoyant in the air and thus move at higher angles to the vertical may not be a problem so that the rain shield  17  is sufficient.  
         [0060]     As shown in  FIG. 7  an additional alternative moisture penetration system is shown mounted on the sleeve  16 . In this case there is provided a band  20  of a flexible fabric material which is wrapped around the sleeve  16  and covers the holes  16 C. The band  20  has a top edge  20 A just above the top edges of the holes and a bottom edge  20 B approximately at the bottom of the sleeve  16 . The band  20  is held in place by a suitable fastening mechanism at a position above the holes  16  and in the embodiment shown the fastening mechanism comprises a surrounding clamping band  21  which is fastened to the sleeve  16  by suitable fasteners  21 A. Other fastening arrangements may be provided for the band as will be well known to one skilled in the art.  
         [0061]     The band  20  has a plurality of slits  20 C with each slit extending from the bottom edge  20 B to a top  20 D at a respective slit which is located partway up the band  20 . The top edge can be located directly at the clamping band  21  or may be lower as required. It will be appreciated that the slits  20 C separate the band  20  into individual flaps which can open up under pressure from air attempting to exit through the holes  16 C by hinging about a line across the top of the slits. Thus all of the flaps can pivot outwardly if the pressure inside the storage bin is elevated for example by an internal fan which draws external air and passes it through the stored material. Thus the fan pressure presses against the flaps defined by the band  20  forcing them open.  
         [0062]     In the event that it is desired to clamp the flaps closed, a cable  22  wrapped around the flaps adjacent the bottom edge of the flaps can be pulled tight from a cable portion extending to the ground to ensure that the flaps are prevented from pivoting outwardly against the holding force of the cable. The cable can be attached to the band  20  by loops  23  attached to the outside of the band so that the cable remains in place when loosened allowing the flaps to pivot outwardly.  
         [0063]     Thus the sleeve  16  provides air vents to release pressure from the interior of the storage bin thus avoiding the necessity for additional vents at positions spaced around the roof. All the necessary airflow vents can thus be provided in the single sleeve mounted at the center of the bin. The vents can be protected from penetration by moisture by the rain shield  17  and/or by the band  20  depending upon environmental conditions.  
         [0064]     The open top of the sleeve  16  is covered by a cover panel  25 . The cover panel  25  includes a central circular flat portion  26  and a slightly inclined portion  27  extending downwardly from the central portion  26  to an outer edge  28  t which there is provided a depending lip  29 . The lip  29  is circular and can surround the outside edge of the top  16 B of the sleeve  16  so as to inhibit the penetration of moisture under the cover  25  and into the open top of the sleeve  16 . The cover panel can thus sit in place on top of the sleeve closing the sleeve while leaving the vent opening  16 C available for the discharge of air.  
         [0065]     The cover panel  25  can be moved from the closed position sitting on top of the sleeve  16  to an open position at one side of the sleeve  16  on a track  30  including a pair of track rails  31  and  32 . The track rails  31  and  32  are parallel and spaced by the width of the cover panel so that each track rail is arranged at an edge of the cover panel  25  and carries that edge generally horizontally from the closed position to the open position as shown by comparing  FIGS. 1, 4  and  5 . At the edges of the cover panel  25  is provided a pair of carriages  33  and  34  each of which is attached around the edge  28  and each of which provides a pair of wheels  35  and  36  which run on a respective one of the tracks. Each of the tracks, as best shown in  FIG. 3  is straight and generally horizontal along its main part from an outer end  37  to a position  38  along its length. At the position  38  the track curves downwardly and rearwardly to a bottom end  39 . Each of the tracks is attached to the sleeve  16  by a bracket  40  which is fastened to the sleeve at a respective side of the sleeve and is bolted to the track by bolts  41 . This mounting supports the track in fixed position relative to the sleeve so that it can carry the cover plate  25  from the closed position to the open position without the necessity for additional supports. In the open position, therefore, the cover plate is cantilevered on the tracks  31  and  32  at a position spaced outwardly from the sleeve  16 .  
         [0066]     The brackets  33  and  34  are shaped so that the wheel  35  is supported at a position on the bracket which is lower than the position of the wheel  36 . This position corresponds to the position of the lower end  39  of the track so that when the wheels are located on the track with the wheel  35  at the end  39  and a wheel  36  at a position along the length of the track corresponding to the spacing between the wheels  35  and  36 , the cover is in position sitting on top of the open end of the sleeve  16  with the flange  29  surrounding the top of the sleeve.  
         [0067]     As shown in  FIG. 2 , the flange at the position beyond the end of the track projects outwardly from the edge of the sleeve as indicated by comparing the point  29 A of the flange relative to the point  16 X at the top of the sleeve. By comparing  FIGS. 1 and 4 , it will be noted that movement of the cover panel  25  along the tracks causes the wheel  35  to move along the curved portion of the track from the end  39  along the track toward the point  38 . During this movement the wheel  35  moves upwardly as well as moving toward the right which thus acts to lift the point  29 A of the cover panel  25  upwardly so that it clears the point  16 X of the edge of the sleeve while the cover panel begins to open. Once the edge  29 A has cleared the edge  16 X, the cover panel can then move to the right carried along the tracks  31  and  32  in a generally horizontal direction. It is advantageous if the tracks rise slightly toward the right so that the wheels  35  and  36  are lifted as they moved toward the right so as to more effectively clear the bottom edge of the flange  29  relative to the top edge  16 . Thus as shown in  FIG. 5  the cover panel  25  has moved to its cantilevered position beyond the edge of the sleeve  16  thus exposing the opening in the sleeve  16  for filling of the bin through that opening.  
         [0068]     As shown in  FIGS. 1 and 3 , there is provided a latch  45  pulled by a cable  46  which acts to locate the cover panel  25  in both of its closed and open positions as required. The latch  45  includes a pin  46  which hangs into the track  31 . Within the track is provided a pair of shoulders  47  and  48  which engage the pin  46 . The shoulder  47  engages the pin  46  when the cover panel is in the closed position so that the pin holds the cover panel against movement toward the right in view of the abutment between the pin  46  and the shoulder  47 . The pin can be spring biased downwardly into the track so as to be maintained against a shoulder  47 . Similarly the shoulder  48  is located at a position which engages the pin  46  to prevent the cover panel from moving toward the left when it is in the open position.  
         [0069]     In order for the pin to clear these shoulders  47  and  48 , each shoulder is associated with a respective ramp  47 A and  48 A. Thus as the cover panel moves toward the right toward the open position, the spring biased pin  46  slides up over the ramp  48 A to the end of the ramp when it drops over onto the shoulder  48  to prevent backward movement of the cover panel to return to the closed position. Similarly when the cover panel is moved toward the closed position, the pin slides over the ramp  47 A until it reaches the shoulder  47  when the pin drops down to engage the shoulder  47  and hold the cover panel in the closed position. The pin  46  and the latch  45  are mounted for pivotal movement and this pivotal movement is effected by pulling on the cable  45 A which extends to the ground. The cable  45 A passes through a loop  45 B on the cover panel  25  so that it is maintained in a suitable position relative to the latch  45 . Thus a person pulling on the cable  45 A firstly releases the latch from its respective shoulder whereupon the cover panel can be move from its latch position to the required position of open or closed. The preferable slight incline of the track provides a gravity return of a cover panel from its open position to its closed position once the latch has been released. Movement upward of the tracks from the closed position to the open position is effected by pulling on the cable which passes over an edge of the roof of the storage bin to provide a pulling action along the direction of the track  30 .  
         [0070]     In  FIG. 6  is shown a further closure member including the sleeve  16  and a cover panel  25  mounted on track  30 . The sleeve, track and cover are substantially as previously described. In this embodiment, however, the bottom edge of the sleeve as indicated at  16 A is attached to a conical section  50  which is welded or otherwise attached to the bottom edge  16 A at an upper edge  51  of the conical section. From that upper edge, the conical section tapers inwardly and downwardly to a bottom edge  52  which is narrower than the top edge  51 . In this way the conical section can be inserted within a collar  53  of an existing bin generally indicated at  54 .  
         [0071]     It is common that existing bins have a relatively small filling opening at the top defined by the collar  53 . In order that the sleeve  16  may be manufactured as a common size for different types of bins, the sleeve  16  is manufactured to the maximum diameter of filling openings of commercially available bins. In order that the sleeve  16 , which is of greater diameter than the opening of the bin to which it is to be attached, can fit the collar  53 , the conical section  50  is inserted into the collar  53  as far as is necessary to match the diameter of the collar  53 .  
         [0072]     In addition the manufacture of a sleeve  16  at the maximum diameter ensures that there is sufficient air space defined by the vent openings  16 C to allow the exit of air. It will be appreciated that the sum of the areas of the vent openings is preferably approximately equal to the area of the opening  53  so that there is no restriction to air flow. For this purpose while minimizing the height of the sleeve  16 , it is preferable that the sleeve  16  has maximum diameter.  
         [0073]     Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.