Patent Publication Number: US-8540101-B1

Title: Filter housing with liftable lid

Description:
BACKGROUND 
     Large volume filtration vessels are very useful for filtering large amounts of fluid and, due to high pressures within such a vessel, the parts can be quite heavy. The heft of the parts can make changing individual filter elements within the vessel very difficult. Often, a lid or other cover must be lifted to reveal the individual elements within a filter vessel. The cover may be hundreds of pounds and, due to size, be quite awkward. Some large filter vessels may employ external means to lift the cover from the vessel such as an external crane. Frequently chains are used to attach a crane to the lid for lifting. This can cause injury if the chains are improperly installed, or if the chains slip off of the lid during its removal. Ideally, a system for lifting the lid would be integrated into the filter housing itself. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a filter housing. The filter housing has a vessel portion and a lid which mates with the vessel portion. An arm is secured to the lid and is movable with respect to the vessel portion. The arm has an inclined feature. A rotational member engages the inclined feature. The rotational member is rotatable with respect to the vessel portion and restrained from longitudinal movement with respect to the vessel portion so that rotation of the rotational member relative to the arm causes longitudinal movement of the arm and separation of the lid from the vessel portion. 
     In one aspect of the invention, the inclined feature on the arm may be threads. In this case, threads on the rotational member mate with the threads on the arm. 
     In another aspect of the invention, a slot may be located apart from the threads so that a pin rides in the slot. The slot having an aligned portion that is aligned with respect to the longitudinal axis of the arm, and having an inclined portion that is inclined with respect to the longitudinal axis of the arm. The pin being fixed with respect to the housing so the pin may prevent rotation when in the aligned portion, and facilitate rotation when the pin is in the angled portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the filter housing; 
         FIG. 2  is a perspective view of the filter housing shown in  FIG. 1  with the lid in the lowered position; 
         FIG. 3  is a perspective view of the filter housing shown in  FIGS. 1 and 2  with the lid in a raised position, and the lid not being turned with respect to the vessel portion of the housing; 
         FIG. 4  is a perspective view of the filter housing shown in  FIGS. 1-3  with the lid in a raised position, and the lid being turned with respect to the vessel portion of the housing; 
         FIG. 5  is an exploded perspective view of the filter housing shown in  FIGS. 1-4 ; 
         FIG. 6  is a top view of the ratchet housing and ratchet gear; 
         FIG. 7  is a view showing the slot in the arm; 
         FIG. 8  is side view of the arm shown in  FIG. 7  taken ninety degrees to the view shown in  FIG. 7 ; and 
         FIG. 9  is a sectional view taken about the line  9 - 9  in  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION OF INVENTION 
     The filter housing  10  of the present invention has a vessel portion  12  and a lid  14  that is sealingly matable to the vessel portion  12 . The lid  14  is typically made of steel and, depending on the size of the housing, can be extremely heavy. The lid has retainer brackets  16  around the periphery that are designed to accept clamps  18  that are used to secure the lid  14  to the vessel portion of the housing  10  when it is in use. The lid has an arm  20  that is secured to a mounting bracket  24  on the lid  14 . The arm  20  may be joined to the bracket  24  by use of a press fit and bolt  26 , or may be mounted with a bolt  26  and/or pin  28 . The arm  20  and lid  14  are movable relative to the vessel portion  12  and both move together. The arm  20  is typically made of steel pipe and has an inclined feature which are threads  29  along a threaded portion of the arm  20  near its lower end. 
     The arm  20  includes a slot  30  that is above the threads  29 . The slot  30  has an aligned portion  31  and an angled portion  32 . The aligned portion  31  of the slot  30  is aligned with the longitudinal central axis  33  of the arm  20 . The angled portion  32  is inclined with respect to the central axis  33  of the arm  20 . The arm  20  is held adjacent to the vessel portion  12  by upper and lower brackets  34 ,  36 . The upper and lower brackets  34 ,  36  are welded to the side of the vessel portion  20  and have bushings  38  fastened to their upper surfaces as can be seen in  FIGS. 1-4 . The bushings  38  have an inner diameter that accepts the arm  20  and allows movement of the arm  20  within the bushings  38 . Thus, longitudinal and rotational movement of the arm  20  is possible with respect to the vessel portion  12 . The upper bracket  34  has holes through which a pin  39  is inserted. The pin  39  passes through the upper bracket  34  and through the slot  30 . The pin  39  is adapted for riding in the slot  30  during longitudinal movement of the arm  20  with respect to the brackets  34 ,  36 . 
     A rotational member  46  rests against the bushing  38  on the lower bracket, as shown in  FIG. 1 . The rotational member  46  includes a ratchet housing  47  that contains a ratchet gear  48 . The ratchet gear  48  has a threaded bushing  50  that is mounted to the ratchet gear  48  with bolts  49 . The threaded bushing  50  has internal threads that match the threads  29  on the arm  20 . The ratchet housing  47  includes a reversible spring loaded pawl  52 . A spring  53  urges the pawl  52  into teeth  54  on the ratchet gear  48 .  FIG. 6  shows how the pawl  52  is angled to catch within the teeth  54  in one direction and slide over the teeth  54  in the opposite direction. A knurled thumb wheel  58  is attached to the pawl  52  and has a rib  60  for engaging a notch  62  in the ratchet housing  47 . When the wheel is turned 180 degrees, the direction of the pawl  52  is reversed and, as can be seen by one skilled in the art, the direction the ratchet gear  48  will turn will be reversed. A handle  66  extends from the ratchet housing  47 . 
     When the handle  66  is used to turn the ratchet housing  47  with the pawl  52 , as shown in  FIG. 6 , the ratchet gear  48  and threaded bushing  50  will be rotated in a clockwise direction as viewed in  FIG. 6 . Rotating the ratchet housing  47  in a ratcheting motion will move the entire rotational member  46  downward on the arm  20 . Thus, the arm  20  will be urged upward because the rotational member  46  rests against the lower bracket  36  that is fixed to the vessel portion  12 . As the arm  20  is urged upward, the pin  39  rides in the slot. When the lid  14  is in its fully lowered position, the pin  39  is in its uppermost position in the aligned portion  31  of the slot  30 . This is shown in  FIG. 2 . As the arm  20  is urged upwardly to the point that the pin  39  is in the angled portion  32  of the slot  30 , rotation will be imparted in the arm  20  and therefore the lid. The lid  14  and arm  20  are restrained from rotation for a predetermined distance equivalent to the length of the aligned portion  31  of the slot  30 . While the pin  39  is in the aligned portion  31  of the slot, the lid  14  will be lifted vertically. Upon entry of the pin  39 , in the angled portion  32  of the slot, the lid will continue to lift, and will rotate at the same time.  FIG. 3  shows the lid  14  being lifted to its height just before rotation, the lifted height being the length of the aligned portion  31 .  FIG. 4  shows the lid  14  being rotated toward the right of  FIG. 4 . It is contemplated that the angled portion  32  of the slot  30  could be angled the opposite way as that shown in the FIGS, and in such case the lid  14  could be made to rotate in the opposite direction as that shown in  FIG. 4 . If standard right hand threads  29  are used for the threaded portion of the arm  20 , friction will tend to assist in rotation of the lid in the direction shown in  FIG. 4  during upward movement of the lid. Likewise, with standard right hand threads  29 , friction will tend to assist in rotating the lid the opposite direction during lowering of the lid. 
     For a user to lower the lid, he will first pull back on the knurled thumb wheel  58  and rotate the pawl  52 , 180 degrees to the position shown in  FIG. 6 . This will cause the ratchet gear  48  and threaded bushing  50  to be rotated counterclockwise when the handle  66  is pulled. As mentioned above, friction from the threads will assist in rotating the arm  20  so that the pin  39  moves from the angled portion  32  into the aligned portion  31 . 
     The invention is not limited to the details given above, but may be modified within the scope of the following claims.