Abstract: A light guide with a liquid light transmissive medium is connected to a variable pressure source, such as a controllable pump, and a hydraulic pressure take-off is connected to the light guide, for example adjacent the light exit window, to control the position of a positionable element, typically an optical system, such as a fluid lens, a movable lens, a diaphragm or the like, with respect to the exit light window from the light guide tube as a function of the pressure applied to the light transmitting liquid within the tube. Thus, the light guide can function simultaneously as a light guide and as a hydraulic servo pressure control element, to control the light output or the position of another element linked to the hydraulic servo positioning piston-cylinder arrangement coupled to the light transmitting fluid in the light guide.

Abstract: A pivot support element is fixed in position to extend essentially vertically, and carries a horizontally projecting pivot pin. The movable pivotable member on which the weight is suspended is pivoted and connected to the pin by means of a plate-like pivot rod secured laterally to the pivotable member, so that the pivot pin will form the pivot axis for the plate-like element. The pivot pin additionally has fixedly attached thereto a link element, such as a short plate-like member to which a balance rod is pivotally attached which is connected with an intervening spring, typically a compression spring, to the weight-supporting member. Two plate-like pivot rods may be used, one on either side of the support member to provide for balanced attachment. The entire assembly is readily encapsulated in shell-like housing halves, to be essentially dust and contamination-proof, with minimum handling in assembly, or for cleaning and maintenance.

Abstract: The present invention relates to a surgical operating lamp with mainly cold light radiation, whereby the infrared part of the light radiation from a light source is reflected by means of a concave cold light reflector and by an infrared reflector in the lamp area which reflects the infrared rays toward a heat absorbing body surrounding the lamp body. An outer bell, surrounds said heat absorbing body and forms a space therebetween to allow the passage of air therethrough to facilitate the cooling of the heat absorbing body.