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Expired Canadian patentCanada

Drop manhole precast encasement

CA 1238196 A · Owner: A-Lok Products, Inc. · Inventors: Ditcher, Jack

CIPO record

Overview

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A system of modular precast encasement sections is provided to protect the outside drop of a manhole structure from damage due to weak ground support and to prevent leakage from said outside drop. Said precast encasement sections are stacked on top of a drop manhole base and on top of each other to a height sufficient to surround and support the outside drop tube. The stack of encasement sections is then capped off with a solid collar which has a circular opening of a diameter sufficient to receive the outside drop tube. This circular opening widens to form a shoulder which is adapted to receive and support thereon the lower most opening of a T-coupler for joining a supply line to the drop …

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Granted June 21, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 21, 2005.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledOctober 8, 1985
GrantedJune 21, 1988
Term endedJune 21, 2005
Patent numberCA 1238196 A
Classification (IPC)E21F17/16 +2 more

Timeline

Timeline From CIPO dates

1986198819901992199419961998200020022004Application filedOct 8, 1985Patent grantedJune 21, 1988Term endedJune 21, 2005

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.