Manhole cover stop mechanism
OwnerDavid Stadlerinventor
Life of this patent
Estimating the term…
Abstract
A stop mechanism advantageously combined with a manhole cover includes a holder body having a passage which slidably receives a stop member able to be cammed in and out upon advance or retraction of a threaded drive member having an enlarged tip engaged with a down sloping channel formed in the stop member. Upper sides of the channel engage the tip upon reversal of the drive member to cam the stop member back into the holder body. The stop member when extends prevents removal of the cover from being blown completely free of the manhole vault structure in the event of an explosion.
Claims15
A mechanism for preventing a cover received in an opening in a surrounding structure from being completely removed from said surrounding structure, comprising:
- a holder body attached to an underside of said cover;
- said holder body formed with a passage extending into said body and slidably receiving a stop member so as to be able to be moved in said passage therein between a retracted position and an extended position with one end protruding out from said body and into alignment with a fixed abutment formed on said surrounding structure to prevent said cover from being completely free of said surrounding structure;
- a drive member having a threaded main portion received into a threaded bore in said holder body extending into said passage and having a tip able to be advanced into engagement with a downwardly angled surface formed on said stop member;
- said stop member surface aligned with an axis of said drive member;
- whereby as said drive member is advanced in said threaded bore, said stop member is cammed to said extended position.
Dependencies are inferred from the claim text.