Patent ID: 7837050

Claim:
A collection tank for use in a vacuum operated earth reduction system, said collection tank comprising: a. a closed first end; b. an open second end defining a tank sealing flange; c. a body extending between said closed first end and said open second end; d. a door coupled to said open second end and configured to releasably seal said open second end; and e. a hydraulic powered door closer having (i) a cross bar rigidly attached to a center of said door, said cross bar having a first end and a second end, (ii) a first linkage assembly having a first end coupled to said cross bar first end, a second end coupled to said body and a first pivot point intermediate said first and said second ends, and (iii) a second linkage assembly having a first end coupled to said cross bar second end, a second end coupled to said body and a second pivot point intermediate said first and said second ends, wherein when said first linkage assembly first pivot point rotates to a point below the coupling of said first linkage second end and said body, when said second linkage assembly second pivot point rotates to a point below the coupling of said second linkage second end and said body, said door is in a locked position and will not open until said first and second pivot points are rotated above the coupling of their respective linkage assembly second ends to said body, and said hydraulic powered door closer provides a closing force at said center of said door so that said closing force is equally distributed about a periphery of said door.