초록 ▼

A locking manhole cover which may be made of lighter weight material than conventional iron or steel manhole covers has a cover plate dimensioned to fit over a manhole opening. A cylindrical frame is attached to the underside of the cover plate and extends downwardly into the hole when the cover pla

A locking manhole cover which may be made of lighter weight material than conventional iron or steel manhole covers has a cover plate dimensioned to fit over a manhole opening. A cylindrical frame is attached to the underside of the cover plate and extends downwardly into the hole when the cover plate is in place. Diametrically opposed apertures are located in the side of the frame; and movable locking members are hingedly attached to the frame adjacent the apertures for pivotal movement through the apertures from a location within the frame to a location where a portion of the locking members engage the sides of the manhole in which the device is located. An operator is mounted inside the frame for effecting the pivotal movement of the locking members by means of an interacting cam or gear arrangement.

대표청구항 ▼

[ What is claimed is:] [1.] A locking manhole cover including in combination:a cover plate having a top and an underside and having dimensions greater than the dimensions of a hole to be covered;a frame member attached to the underside of said cover plate having a side extending downwardly from said

[ What is claimed is:] [1.] A locking manhole cover including in combination:a cover plate having a top and an underside and having dimensions greater than the dimensions of a hole to be covered;a frame member attached to the underside of said cover plate having a side extending downwardly from said cover plate and dimensioned to fit into and extend downwardly into the hole, said frame having at least one aperture through the side thereof;a movable locking member hingedly attached to said frame member adjacent the aperture therethrough for pivotally moving said locking member through said aperture from a location within said frame member to a location engaging the hole; andan operator device mounted in said frame member for effecting said pivotal movement of said locking member.