Gijsbert Prast: Solar collector comprising solar tracking means. U S Philips Corporation, Thomas A Briody, William J Streeter, Rolf E Schneider, July 3, 1979: US04159710 (36 worldwide citation)

A solar collector includes a plurality of elongate parallel reflectors mounted for rotation about their respective longitudinal axes, together with mechanism coupled to the reflectors for simultaneously rotating the same. An elongate absorber is arranged parallel to the reflectors for collecting sol ...

Gijsbert Prast, Andries Mijnheer, Jan Mulder: Pressing block for die pressing thermoplastic material. U S Philips Corporation, Frank R Trifari, David R Treacy, April 19, 1977: US04018552 (20 worldwide citation)

A pressing block for a phonograph or video record press in which ducts for cooling and heating media for the die are formed by a thin layer of a porous heat-conducting material provided between two thin metal sheets and bonded thereto. The assembly is connected on its side remote from the die to a s ...

Josephus J M Braat, Jan Haisma, Gijsbert Prast: Single lens having one spherical and one aspherical refractive surface. U S Philips Corporation, Robert J Kraus, November 15, 1983: US04415238 (13 worldwide citation)

A lens having a spherical surface and an aspherical surface curved relative to each other to minimize coma for a large diffraction-limited field and a large numerical aperture.

Gijsbert Prast, Hendrik Jan Rauwerdink: Cold-gas refrigerator, displacer seal to reduce frozen contaminants. US Philips Corporation New York NY, Frank R Trifari, September 5, 1972: US3688512 (9 worldwide citation)

A cold-gas machine includes first and second pistons for varying the volumes of a cold and a warm space; the first piston has a seal and a duct which communicates with a buffer space, the latter communicating via a duct with the warm space, debouching at a place situated between the axial boundaries ...

Gijsbert Prast, Cornelis M G Jochem: Device for performing measurements on a transparent object, method of manufacturing a fiber and fiber manufactured by means of said method. U S Philips, William L Botjer, January 5, 1993: US05176731 (4 worldwide citation)

In a device for performing measurements on at least partly transparent objects such as optical fibres a radiation beam is directed on the object. The radiation deflected by the object is imaged by means of a lens system (321, 322) on a radiation-sensitive detection system (330). As a result of refra ...