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.

Date of Patent:
Jun. 20, 1989

Filed:

Feb. 20, 1987
Applicant:
Inventors:

Heinrich Zenhausern, Urdorf/Zurich, CH;

Robert Weber, Oakville, CA;

Assignee:

Other;

Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B29C / ;
U.S. Cl.
CPC ...
264254 ; 264263 ; 264274 ; 425116 ; 425120 ; 4251261 ; 4251291 ;
Abstract

A climbing rung for anchoring to the wall of a manhole shaft. The climbing rung has a generally U-shaped core of two parallel legs spaced apart by a central tread. Each leg is sheathed in a pre-formed protective sleeve, closed at one end, by inserting the leg into the mouth of the sleeve. An injection moulded protective coating is bonded to the core of the tread and the core of each leg, extending to proximate the mouth of each pre-formed sleeve when a leg is sheathed therein, forming a sealing interface proximate the annular lip circumferentially defining the mouth of each sleeve. A method includes gripping the climbing rung only proximate the pre-formed protective sleeves when both legs are sheathed therein, so as to permit positioning the core of the tread and legs, extending only to proximate the mouth of each pre-formed protective sleeve, in an injection moulded cavity radially spaced equidistant the surface of the mould cavity. Advantageously, positioning pins inside the injection mould cavity for radially spacing the core of the climbing rung from the surface of the mould cavity are thereby not required. The method also includes alternatively gripping at least two oppositely spaced portions of the core of the climbing rung and alternately coating the portion of the climbing rung opposite the end which is being gripped.


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