Abstract: The present invention relates to solar energy pick-ups composed of a fixed cylindrical mirror having an elliptic transverse section and a heat collector parallel to the generatrices of the cylinder, placed at the bottom of the mirror, in the plane parallel to the large axis of the ellipse in which a heat-carrying fluid circulates.

Abstract: A hydraulic punch press having a base adapted to receive a workpiece and a cylinder axially disposed opposite to the base. The cylinder includes a first and second piston slidable defining within its interior, a first chamber formed between the surface of said first piston and one end of said cylinder and a second chamber formed between the first and second pistons. The pistons have coaxial rods extending outwardly of the other end of the cylinder in opposition to said base. The rod of the first piston extends axially through the rod of said second piston and carries at its end a tool while the rod of the second piston is tubular and is adapted to carry at its end holding means for the workpiece blank.

Abstract: A digit rate reducing method in the transmission of video-telephone signals, wherein each frame is scanned by means of two consecutive fields comprising each the lines of same parity, each frame dot being represented by a word of n, in particular 3, binary digits comprising transmitting a frame every three frames, storing a frame of each parity at the receiving equipment in a frame storage device, systematically freshening-up a stored frame by the next transmitted frame of same parity, and regenerating intermediate frames by interpolating between the stored frames, further comprising forming a pseudo-field I.sub.n with opposite parity to a stored field T.sub.n by interpolating between T.sub.n and the stored field T.sub.n+3 or T.sub.n-3, and regenerating an intermediate field T.sub.n+1 or T.sub.n-1 from I.sub.n and T.sub.n+3 or T.sub.n-3, respectively.