Tokyo Shibaura Denki Kabushiki Kaisha

Nihon Kogen Concrete Kabushiki Kaisha

Shigeru Suzuki

Takayuki Kobayashi

A static circuit comprising an input transformation circuit responsive to current or voltage derived from an electric power system to be protected for producing a first pair of electric quantities having a phase difference of .theta. and a second pair of electric quantities dephased by .phi. from the first pair of electric quantities respectively, a pair of multipliers for the producing products of the first and second pair of electric quantities, and an adder or subtractor for producing the difference of these products.

Protective relaying apparatus for electric power systems

A device for producing a prestressed concrete member adapted to facilitate the joining of one concrete member to another including a mold having a plurality of panels oppositely disposed, one of the panels being provided with a plurality of fixing metal pieces each having a concaved portion in the top surface thereof, another panel of said panels being provided with cup-shaped guide metal pieces at the corresponding positions to said fixing metal pieces, an anchor plate fixedly disposed transversely and adjacently to the top portions of said fixing metal pieces, tensioning steel members coated with an sliding material each having one end connected with said anchor plate and the other end pierced through the top portion of said guide metal piece into the inside of said guide metal piece, one end of tension steel members each having a head portion for engaging with said anchor plate or the projecting portion formed therein in the shape of a crater so as to be fitted in said concaved portion of said fixing metal piece, the anchor plate being securely clamped to said one panel at a predetermined portion thereof by means of a bolt, the other ends of said tensioning steel members in said guide metal pieces being strained by a tension applying means after the concrete that is poured in said mold is hardened, and being clamped by a nut, whereby prestress is introduced into the concrete.

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Fuchu, Japan

Shigeru Suzuki