Electrically Focused Surgical Light
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Patentamt êJEuropaisches European Patent Office © Publication number: Q 056 505 Office européen des brevets g *] ® EUROPEAN PATENT SPECIFICATION (g) Dateof publication of patent spécification: 22.07.87 (jjj) Int. Cl.4: F 21 M 1/00 (fl) Application number: 81300165.8 (22) Dateoffiling: 15.01.81 (54) Electricallyfocusedsurgical light. (43) Date of publication of application: ® Proprietor: AMERICAN STERILIZER COMPANY 28.07.82 Bulletin 82/30 2222 West Grandview Boulevard EriePA 16512 (US) (45) Publication of the grant of the patent: 22.07.87 Bulletin 87/30 Inventor: Fisher, Kenneth J. 3020 McKee Road Erie,PA. 16506 (US) (m) Designated Contracting States: Inventor: Miller, William R. AT DE FR GB SE 4950 Wolf Road Erie, PA. 16505 (US) (§) Références cited: GB-A-704409 (74) Représentative: Newens, Léonard Eric et ai US-A-2 005 194 F. J. CLEVELAND & CO. 40/43 Chancery Lane US-A-2 896 066 London WC2A 1JQ (GB) US-A-3493 806 US-A-4 025 778 US-A-4037 096 m o m <o in o note: vvitmn nme months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall CL be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been LU paid. (Art. 99(1 ) European patent convention). ^ouner Press, Leamington Spa, England. activate one filament or the other. This provides a means for the pattern size to be changed by This invention relates to filament type electric remote control without anyone having to physi- lamps and particularly but not exclusively to cally touch the lamp itself. surgical lamps or lights. The present invention is summarised in the A known filament type electric lamp is sum- characterising portion of Claim 1. By switching on marised in the precharacterising portion of Claim the light sources at different distances from the 1 and is known from US-A-3 493 806. reflector, the pattern of light from the lamp on to In US-A-3 493 806 there is described an an object on a surgical table can be changed. incandescent light for use in automobiles, By energizing one or the other of the filaments, including a tubular bulb having a main filament the focus and, therefore, the pattern size can be and a dipping filament, the main filament being changed electrically. As a side benefit to this positioned at the focal point of a single fixed arrangement, in the event a filament should burn parabolic reflector with corresponding light rays out during a surgical procedure, the light could be projected as a horizontal beam, the dipping fila- switched over to another filament and the surgi- ment being axially spaced from the main fila- cal procedure continued without having to pause ment. Screen means are located on the exterior to relamp the light. (In particular, there are some surface of the bulb so as to prevent those rays countries that require such standby lighting capa- from the dipping element which would be bility in surgical lighting.) reflected upwards, from striking the reflector. The present invention envisages the use of a It is also known from US-A-4 037 096 to have bulb with two or more filaments spaced a pre- an illuminator for surgical lighting comprising a determined controlled distance apart relative to single light source contiguously located along the the axis of the optical system. Since two or more axis of symmetry of the illuminator, and multiple filaments can be placed within the lamp, a reflectors arranged such as to project light rays in multiple of patterns can be achieved by expand- a converging light pattern of uniform light inten- ing the number of lamps. The design allows for sity. dual filament capability in small lamp envelope In the specialized lighting utilized for surgical packing configurations. Previous designs were of procedures, it is frequently desirable to be able to the standard incandescent variety, which were adjust the pattern size of the light pattern on the bulky and suffered from shortcomings of lumen wound site depending upon the particular proce- depreciation and reduced life. The lamps dure being used and/or the progress of the oper- employed herein are the frosted, low voltage type ation during the surgical procedure. using the multiple filament technology to over- The light disclosed herein provides an improve- come these negative attributes. Also, the asso- ment over the surgical lamp shown and United ciated small envelope approximates a point States Patent No. 4 037 096 and United States source and allows it use in multi-reflective Patent No. 4 025 778. The latter patent shows a systems offering a greater range in pattern/focus plurality of lights that are arranged mechanically selection. The curvature of the reflector may be to change the position of the focus of the lights. parabolic with the filaments located between the This requires complex apparatus and con- reflector and the focal point of the reflector, so siderable physical effort. that the rays of light come to focus at a finite Thus the conventional means of accomplishing point. a change in focus and/or a change in pattern size A cluster of lights could contain one or more is by mechanical movement of the bulb relative to multi-filament lamps within the cluster. There- the reflector or reflectors of the optical system. fore, by switching to the rearmost filament on the This normally involves utilization of a lever or multi-filament lamps and switching off some of levers located on the light itself in order to initiate the lamps, a small pattern of high intensity can be physical lamp source displacement. Since the obtained. By switching to the other filament and lever or levers are not sterilized prior to the switching on additional lamps, a large pattern of surgical procedure, it would be a break in tech- high intensity can be formed. This design com- nique if any of those individuals who are scrub- pares with hitherto multicluster systems which bed and gloved should touch such levers to vary decrease overlap of fixed light projections from focus or pattern. Thus, such focus means are in- the various lamps and hence pattern size by convenient. To provide for remote operation of switching off lamps. Consequently intensity is focus would require a very cumbersome motor decreased as the pattern becomes smaller. drive being mounted on the light. A derivative of this system has applicability to It is an object of the present invention to pro- the field of photographic lighting. It is well known vide a means for controlling the pattern size and/ that the two principal types of lighting used by or focus of such surgical lighting without the photographers are "Flood" and "Spot". At requirement for mechanical movement thereby present, the photographer has to buy two differ- facilitating remote operation and control. ent bulbs for these two applications and change It is a further object of the present invention to bulbs when the lighting requirements or the provide a means of electrically controlling the subject change. pattern size of a surgical light by the utilization of With the present invention having two light a multiple filament bulb with suitable means to sources displaced a certain distance apart, the lamp can be switched from Spot to Flood and those skilled in the art and will be referred to back to Spot again electrically. Thus, a means is herein generally as filaments. The tungsten halo- disclosed of electrically switching a bulb from gen material has been found to be a desirable "Flood" to "Spot" for maximum flexibility in type filament because of its compact size, photographic lighting. approximating a point source with two or more The invention will now be described by way of filaments spaced a controlled distance from each example only with particular reference to the other. It will be noted that the first light source 15 accompanying drawings, wherein: is spaced from the first reflector 12 between Figure 1 is an illustrative view of a surgical light reflector 12 and focal point 20 and spaced from embodying the present invention in use. the second light source 16. The second filament Figure 1A is a view of a surgical light with a 16 is shown spaced from the first filament 15 and multi-filament lamp embodying the present the focal point 20. invention. The multi-filament lamp 12' may have a frosted Figure 2 is a side diagrammatic view of a cluster glass envelope, to obtain patterns which are free of multi-filament lights. of voids or shadows and preclude filament imag- Figure 3 is a top view of the cluster of lights ing at the pattern site. A clear lamp may also be shown in Figure 2. employed in conjunction with faceted reflector 12 Figure 4 is a diagrammatic view of the lights of and/or variable stepped Fresnel lenses to provide Figures 2 and 3 with the lamps energized to form the desired diffusion of light. a small pattern of light. The handle 17 may be a removable, sterilizable Figure 5 shows the lights of Figures 2 and 3 handle of a type familiar to those skilled in the art energized to form a large pattern of light. which may be grasped by the hand of the Figure 6 is a schematic wiring diagram of an operator to adjust the surgical light to the desired example of switching connections to the several position. filaments. When the first filament 15 of the surgical light of Now with more particular reference to the Figure 1A is energized, a typical light ray 26 will drawings, Fig.