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:
Sep. 06, 1988
Filed:
Jun. 11, 1987
Hochtief AG Vorm. Gebr. Helfmann, Essen, DE;
Abstract
For continuously lining a tunnel with extruded concrete a pumping device for feeding the concrete and a form having an interior form member and a forwardly movable form front are employed. The extruded concrete is put into place without clump formation, when it is provided in equal-sized segments in a plurality of equal constant amounts which are fed in succession one after the other circumferentially in a time interval which is small compared to the hardening time of the concrete. For this purpose the form front is provided with a plurality of concrete input ports uniformly distributed circumferentially and connected with the pumping device, while the pumping device is designed to service the concrete input ports in succession one after the other circumferentially.