The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 21, 1988
Filed:
Jul. 09, 1986
Jack Ditcher, Langhorne, PA (US);
James Westhoff, Langhorne, PA (US);
Eric Ditcher, Bensalem, PA (US);
A-LOK Product, Inc., Tallytown, PA (US);
Abstract
Method and apparatus for providing liners in manhole assemblies, which liner is comprised of a plurality of liner sections joined together to form the inner corrosion resistant surface of each manhole member. The liner section define the inner surface of the manhole member being molded. Cast material is poured into the mold and allowed to set. The liner surface engaging the cast material contains integral substantially T-shaped projections which anchor the liner sections to the cast member. The tops and bottoms of each liner section extend around the surface of the section engaging the next adjacent section joined thereto to prevent toxic materials from reaching a cast material. The liner sections are theroplastic vacuum formed whereby the sheet forming the liner section is drawn against substantially T-shaped strips arranged upon the mold member within the vacuum thermo-forming equipment to provide the aforementioned integral T-shaped anchoring projections.