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:
Aug. 17, 1976
Filed:
Apr. 22, 1974
John Ditcher, Langhorne, PA (US);
A-Lok Corporation, Trenton, NJ (US);
Abstract
Method and apparatus for forming steps in manhole structures. Manhole assembly is comprised of pre-cast concrete sections. Each such section is formed in an appropriate mold typically comprised of inner and outer mold shells. The inner shell is provided with pairs of openings arranged in a predetermined fashion. Plastic core members are snap fittingly inserted into the openings and are provided with resilient pairs of flanges which cooperate with the marginal edges of each opening to retain the core in proper position and alignment. The concrete is placed in the mold. One set and cured, the section is removed from the mold. The plastic core members are snapped free from their locked position with the mold inner shell and remain as an integral part of the cured section. U-shaped stepped sections are force fittingly inserted into the cores which serve to retain each step member in position.