Freyssinet International (stup)

Bernard Amelot

Jose Savall

Claude Parmentier

Carlos De La Fuente

Jean Ducreux

To prepare a split frustoconic jaw intended for the anchoring of a cable, a part is first taken bounded externally by a frustoconic surface and hollowed by a cylindrical axial channel whose inner surface is advantageously striated. This part is sawed into by substantially axial and radial slashes leaving bridges to subsist of small thickness at the bottom of these slashes throughout the central channel. An assembly ring is mounted in an outer annular groove and the whole is subjected to cementation treatment so as to surface harden the jaw while making the bridges fragile.

Frustoconic anchoring jaws for cables and their methods of manufacture

A swiveling device for tensioning a pre-stress bar having a threaded end projecting from an end face of the element to be pre-stressed comprises a jack having a movable part attached to the bar and a fixed part bearing against the element. A first bearing plate is mounted on the end face of the element around the bar and includes an annular spherical cup surface. A swivel joint nut is threaded on the end of the bar and has a spherical ball part seated in the cup surface of the first bearing plate forming a first swivel joint. A second bearing plate is slidably disposed on a face of the first bearing plate and includes a second annular spherical cup surface. The end of the fixed part of the jack proximate the element includes a spherical surface seated in the second annular spherical cup surface forming a second swivel joint.

Device for tensioning pre-stress bars and for determining this tension

Apparatus for releasing the means for gripping a pre-stress cable, to allow the cable to be detensioned. Each strand is usually maintained in the tensioned state by a cone truncated group of gripping means enveloping this strand. According to the invention each of the gripping means of a group surrounding a strand comprises towards the outside an extension which, in the active state of the gripping means, is spaced apart from this strand, all the extensions thus determining a volume of revolution terminating towards the outside by a hooking flange, while the extractor is formed by resilient parts distributed along the generatrices of a cylinder and comprises inwardly turned hooking flanges, the circumference determined by all the inner edges of the projections in the state of rest being of smaller diameter than that of the volume formed by the outer surface of the extensions of the gripping means beyond their hooking flange, when these gripping means are in the active state.

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Epernon, France

Bernard Amelot