Locking manhole cover
OwnerFrank E. Fullerinventor
Life of this patent
Estimating the term…
Abstract
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.
Claims20
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;
- and
- an operator device mounted in said frame member for effecting said pivotal movement of said locking member.
A locking manhole cover including in combination:
- a cover plate having an upper surface and a lower surface and having a diameter greater than a hole to be covered;
- a cylindrical frame member attached to the lower surface of said cover plate and having dimensions selected to fit into said hole and to extend downwardly into said hole from said cover plate, said frame member having at least two sets of diametrically opposed apertures therethrough with said sets of apertures being axially displaced in said frame member;
- movable locking members hingedly attached to said frame members adjacent each of the apertures therethrough for pivotal movement of said locking members through the corresponding aperture from a location within said frame member;
- and
- an operator device mounted in said frame member for effecting said pivotal movement of said locking members through the apertures in said frame member.
Dependencies are inferred from the claim text.