Patent ID: 7165911
Filing Date: 2007-01-23
Classification: E02D

Abstract:
1. A manhole assembly including: a manhole frame having a downwardly extending inner conical surface and an annular horizontal surface extending inwardly from said conical surface and terminating in a generally annular vertical surface; a riser assembly including an annular riser frame having a lower surface for supporting the riser frame on the horizontal surface of the manhole frame and an annular metallic locking ring extending downwardly from the riser frame and along the vertical surface of the manhole frame; and said locking ring includes a plurality of locking projections formed integrally therewith to form a one-piece member with said locking projections protecting upwardly outwardly at an acute angle from said ring and having an upper end extending inwardly toward the ring and engageable with the manhole frame when placed thereon to restrict upward movement of the riser frame.