Patent Publication Number: US-8123260-B2

Title: Latching device for a grain bin door

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to large bulk storage containers. More specifically this invention relates to a latching apparatus for closing and opening a door cover used for closing and opening an access in a bulk storage structure. 
     Bulk storage structures such as grain bins are well known. Typically a grain bin has an access opening that is enclosed by a cover member. These cover members fit over pins that are attached to a door jamb. Typically, a latching apparatus is used to open and close the cover. 
     One known latching apparatus is disclosed in U.S. Pat. No. 4,913,478 to Grossman. Grossman teaches a latch bar with a hook means that receives a stud to lock the cover in a closed position. To open the cover the latch bar is lifted to disengage the hook means from the stud. As the latch bar continues to pivot, manual pressure is applied to the cover member to open. As no limitation is placed on the rotation of the latch bar, a user&#39;s knuckles can become pinched between the latch bar and the cover causing injury. 
     Another latching device is disclosed in U.S. Pat. No. 5,135,271 to Bestwick. While similar to Grossman, the Bestwick Patent added a cam surface to assist in opening the cover member. More specifically, as the latch bar was raised the cam surface would engage the catch and provide a mechanical advantage in opening the cover. The Bestwick latch device was more complex and difficult to manufacture. 
     A third latching device is manufactured by Sukup Manufacturing. The Sukup device has a latching device on each side of the cover that has a handle section, a vertical section, and a locking section that extends outwardly from the vertical portion and is received in a U-shaped or L-shaped channel to lock the cover in a closed position. To open, the handle section is first raised such that the locking section disengages the U-shaped or L-shaped channel. Once disengaged, the device is slid inwardly, away from the U-shaped or L-shaped channel which restricts rotation of the latch. Once the U-shaped or L-shaped channel is cleared, the latch is rotated upwardly until an arcuate portion of the vertical section engages the cover to open the cover. While the arcuate portion assists in preventing injury to a user&#39;s knuckles, the operation of the Sukup device is complex requiring multiple movements. Therefore, a need exists in the art for a latching device that addresses these deficiencies. 
     An object of the present invention is to provide a latching apparatus for a bulk storage structure that reduces injuries. 
     Another object of the present invention is to provide a latching apparatus for a bulk storage structure that facilitates the opening of a cover on the structure. 
     Yet another object of the present invention is to provide a latching apparatus that is easier to manufacture and operate. 
     These and other objects, features and advantages will become apparent from the specification and claims. 
     BRIEF SUMMARY OF THE INVENTION 
     A latch apparatus for releasably securing a cover member over an access opening in a bulk storage structure. The latch apparatus having a pair of latch members with an extension that extends away from the receptacle and engages the cover member when the latch member is moved from a locked position to an unlocked position so that the extension prevents further rotation of the latch member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side plan view of a bulk storage structure; 
         FIG. 2  is a side perspective view of a cover member of a bulk storage structure; 
         FIG. 3  is a perspective view of a latch member; 
         FIG. 4  is a side plan view of a latching apparatus; 
         FIG. 5  is a side plan view of a latching apparatus in a locked position; 
         FIG. 5A  is a side plan view of a latching apparatus in an unlocked position; and 
         FIG. 6  is a side plan view of a latching apparatus. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION 
       FIG. 1  shows a bulk storage structure  10  that in one embodiment is a grain bin. The bulk storage structure  10  has an access opening  12  that is closed by a cover member  14 . As shown in  FIGS. 2 through 6 , a latch apparatus  16  is used to open and close the cover member  14 . 
     As best shown in  FIG. 2 , as is conventional in the art, a plurality of integrating means  18  are secured to the bulk storage structure  10 . The integrating means  18  are pin members, bolts, protuberance means or the like. Specifically the cover member  14  has a plurality of openings or bores that receive the integrating means  18 . 
     The latch apparatus  16  includes a pair of latch members  20  having a latch bar  22  that is secured to and extends between the latch members  20 . The latch apparatus  16  is pivotally mounted to the cover member  14  by brackets or eye bolts  24  that are attached to the cover member  14 . 
     The latch members  20  have a first section  28  and a second section  30  that are generally transverse or angled in relation to one another to generally form a J or an L-shape. The first section  28  has an opening or aperture  32  that receives a pivot pin  33  mounted to bracket or eye bolt  24 . The first section  28  has an inner edge  35  and an outer edge  36  that extends from end  37  toward second section  30 . Preferably, outer edge  36  has an outwardly extending portion  38  and an inwardly extending portion  39 . The outwardly extending portion  38  is of any size or shape such as arcuate as shown in  FIGS. 5 and 5A  or hammerhead as shown in  FIG. 6 . The inner edge  35  of section  28  extends from end  37  to a receptacle  40  that is formed to receive a catch member  26 . Preferably, inner edge  35  is angled inwardly in relation to the longitudinal axis of section  28  from end  37  to receptacle  40 . 
     The second section  30  extends from the first section  28  and terminates in a flange  42  that is used to connect the latch bar  22  to the latch members  20 . The second section  30  has an outer edge  41  and an inner edge  43 . Preferably, the outer edge  41  has two portions  45  and  47  that generally extend outwardly in relation to the central axis of section  30  to a transition point  48  from portion  38  and flange  42  as shown by example in  FIGS. 5 and 5A . Likewise, preferably, inner edge  43  extends outwardly in relation to the central longitudinal axis of section  30  from flange  42  toward receptacle  40 . Alternatively, inner edge  43  is partially arcuate as shown in  FIG. 6 . 
     The catch member  26  is mounted to a door jamb  44 . The catch member  26  is of any size, shape, and structure that is received within receptacle  40 . Preferably, the catch member is comprised of a bolt  41  having a head  50  and a shaft  45 . The shaft  45  of the bolt  41  extends through a pair of flange nuts  48  and slot  46  in door jamb  44 . The flange nuts  48  have a plurality of serrations on their bottom surface that engage the door jamb  44 . The shaft  45  of the bolt  41  is received within receptacle  40  between the head  43  of the bolt  41  and a flange nut  48 . In one embodiment, the catch member  26  is mounted to the door jamb  44  through an elongated slot  46  so that the position of the catch member  26  may be adjusted within the length of the slot  46  to align with receptacle  40 . Alternatively, the eye bolt  24  attached to the cover member  14  is adjusted so that the receptacle  40  aligns with the catch member  26 . 
     To close the cover member  14  the latch bar  22 , which is in an upward or raised position, is pulled toward the user such that the cover member moves toward a closed position and the latch members  20  are positioned above the catch member  26 . Once in this position, the latch bar  22  is lowered such that the catch member  26  engages the second portion  30  of the latch member  20  and is guided toward and received within receptacle  40 . The inner edge  43  of section  30  assists in guiding the catch member  26  toward receptacle  40 . The downward motion of the latch bar  22  combined with the engagement with second section  30  provides a mechanical advantage that assists in pulling the cover member to a closed position that is locked once the catch member  26  is received within receptacle  40  as shown in  FIG. 5 . 
     To open the cover member  14 , the latch bar  22  is raised until the portion  38  of first section  28  engages the cover member  14  which provides manual force to open the cover member  14 . The rotation of the latch bar  22  permits greater acceleration resulting in greater manual force to open the cover member  14 . The portion  38  permits adequate spacing between the cover member  14  and the latch bar  22 , as well as prevents rotation of the latch bar  22  to a point where a user might injure their hands or their knuckles against the cover member  14 . 
     Thus presented is a latching assembly  16  that both improves use and provides a safer bulk storage structure  10  than is currently known in the art. Consequently at the very least all of the stated objectives have been met. 
     It will be appreciated by those skilled in the art that other various modifications could be made to the device without the parting from the spirit and scope of this invention. All such modifications and changes fall within the scope of the claims and are intended to be covered thereby.