Abstract: To permit adjustment and ready removal of a halogen lamp from an operating room light so that the halogen bulb (3) can be positioned with respect to a dome-shaped reflector (1) to control the light distribution therefrom while being readily removable for bulb replacement and cleaning, a pivot arm (5) is hinged at a circumferential point to the outer circumference of the reflector (1) and held in horizontally extended position across the reflector by a latch (16, 20; 18, 19, 19'; 21, 27). The other end of the latch is in engagement with a vertically positionable adjustment sleeve or rod (7) to adjust the position of the latch arm, and hence of the lamp bulb (3) with respect to the apex of the reflector (1) by pivoting of the pivot arm (5) about its pivot point (6) adjacent the circumference of the reflector. A plurality of such lamps may be combined in a common housing (H), and adjustment can be carried out conjointly, for example by a drive (11, 23) common to all the adjustment elements.

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.