Latching arrangement for manhole cover

A latching arrangement, said arrangement comprising:

• a cover formed with a cavity and upper and lower throughgoing apertures opening into said cavity and both lying on a cavity axis;
• a latching member rotatable in said cavity about said axis and having a lower end projecting through said lower aperture, and an upper end underneath said upper aperture and formed at said axis with a socket opening toward said upper aperture, said socket and said upper aperture being of similar shape and having like radial extensions;
• a support having a seat snugly engageable with said cover and including means having a formation cooperating with said lower end of said latching member for locking said cover and support together in a locking angular position of said latching member relative to said axis and for permitting separation of said cover and support in an angularly offset freeing position of said latching member relative to said support, said extensions being axially and angularly aligned only in said locking position;
• and
• a key having a tip of substantially the same cross-sectional shape as said upper aperture and said socket and engageable through said upper aperture into said socket only in said locking position, said support having a throughgoing hole through which said lower end of said latching member is engageable, and at said hole is provided with ramps engageable with said lower end, said support being a rim circumferentially surrounding said cover, said rim having an upper face turned toward said cover and a lower face turned away from said cover and having said ramps.

A latching arrangement, said arrangement comprising:

• a cover formed with a cavity and upper and lower throughgoing apertures opening into said cavity and both lying on a cavity axis;
• a latching member rotatable in said cavity about said axis and having a lower end projecting through said lower aperture and an upper end underneath said upper aperture and formed at said axis with a socket opening toward said upper aperture, said socket and said upper aperture being of similar shape and having like radial extensions;
• a support having a seat snugly engageable with said cover and including means having a formation cooperating with said lower end of said latching member for locking said cover and support together in a locking angular position of said latching member relative to said axis and for permitting separation of said latching member relative to said support, said extensions being axially and angularly aligned only in said locking position;
• and
• a key having a tip of substantially the same cross-sectional shape as said upper aperture and said socket and engageable through said upper aperture into said socket only in said locking position,
• a plug having an upper portion complementary to said upper aperture and a lower portion complementary to said socket, and having a height generally equal to the axial distance between the base of said socket and the upper surface of said cover at said upper aperture, whereby said plug can simultaneously fit in said upper aperture and said socket and rotationally lock said latching member in said cover.