Manhole base section for sewer lines

Claim 1

A maNhole base section for sewer lines comprising in combination a tubular form of concrete or the like having a side wall of generally uniform thickness and an imperforate flat bottom wall provided with a U-shaped flow channel for guiding effluent therethrough, an integral reinforcing section of concrete or the like adjacent said bottom wall and at each end of said channel of substantial thickness and extending chord-like across the interior of said tubular form on opposite sides of the respective channel end and outwards toward the open end of said form for greatly enlarging the thickness of said form in the area of each reinforcing section, the outer side of each reinforcing section conforming to the outer side of the tubular form thereby to provide a relatively smooth exterior for said form, there being a lateral passage through each reinforcing section open on the outer end and tapering inwardly to an opening on the inner end of a size approximately equal to the outside diameter of the sewer pipe intended to connect in the respective reinforcing section, the wall at the inner end of each passage being spaced from said channel approximately the thickness of the sewer pipe intended for same, thereby to provide an uninterrupted connection, a plain end sewer pipe of concrete or the like for connection in each of the tapered passages of said reinforcing sections, an elastomeric band snugly fitting the inner end portion of each sewer pipe, and means on said band adapted when crowded into one of said tapered passages to provide a liquid-tight seal between the sewer pipe and the respective tapered passage and to afford limited tilting of the sewer pipe in any direction with respect to said tubular form.