Patent Publication Number: US-2009231853-A1

Title: Surgical light

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to co-pending German Patent Application Serial Number 10 2008 014 128.3, filed 13 Mar. 2008, the entirety of which is incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a surgical light in accordance with the preamble of claim  1 . Such a surgical light is known from DE 101 51 978. 
     Such known surgical lights having a discharge lamp have proven themselves in practice since the desired intensities of illumination can be provided without the environment being excessively heated. Since discharge lamps cannot be dimmed electrically in a conventional manner, pivotable lamellae are provided for the dimming of the light incident onto the surgical field with whose help the light discharge can be shaded. In this respect, the lamellae are produced from light impermeable material and have cut-outs to limit a maximum dimming of the lamp to a value of 30%, for example. 
     On the carrying out of endoscopic or laparoscopic operations, an intensity of illumination in the order of magnitude of 30 to 50 klx is required for the preparation of the operation. However, only an orientation light is required for the endoscopic procedure itself. If, however, complications should arise in an endoscopic procedure, the procedure is aborted immediately under certain circumstances and the full intensity of illumination of up to 160 klx is required without time delay for open surgery. 
     BRIEF DESCRIPTION OF THE INVENTION 
     It is the object of the present invention to improve a surgical light of the initially named kind such that it can also be used in endoscopic procedures. 
     This object is satisfied by the features of claim  1  and in particular in that a light impermeable closure element is provided at least one lamella with which the cut-outs of the lamella can be closed. The intensity of illumination of the surgical light can be further reduced in this manner for an endoscopic intervention without the discharge lamp having to be fully switched off; that is the surgical light is available for emergency operation with full intensity of illumination at all times. By providing closure elements at a plurality of lamellae or at all lamellae, the residual light output by the surgical light with closed lamellae can be reduced so far that only straying scattered light is output by the surgical light which is, however, desirable for an endoscopic procedure. Since the surgical light can be operated at an increased intensity of illumination at any time by opening the closure elements and optionally also the lamellae, there is also no risk for the patent in the event of an emergency procedure since the discharge lamp is not switched off and thus also a few minutes do not pass until it can be restarted again. 
     Advantageous embodiments of the invention are described in the description, in the drawing and in the dependent claims. 
     In accordance with a first advantageous embodiment, the closure element can be provided with openings which correspond to the cut-outs of the lamella. The closure element can in this manner either be aligned with the lamella so that the cut-outs and the openings are aligned so that no shading is caused by the closure element. On the other hand, the closure element can be positioned in front of the lamella so that no light can exit through the cut-outs of the lamella. 
     In accordance with a further advantageous embodiment of the invention, a lamella can have two rows of spaced apart cut-outs of a rectangular shape. A much improved light distribution is hereby achieved in comparison with throughgoing slots or openings and a more uniform light field is thus achieved if the lamellae are in the closed state and the closure elements are in the open state. 
     In accordance with a further advantageous embodiment, a closure element is provided at all lamellae, with all the closure elements being able to be actuated via a common drive. In this manner, the residual light exiting the surgical light can be reduced to approximately 1% with closed lamellae and closed closure elements. Such a residual light is well suited for endoscopic procedures since the present residual light brightens the operating room just sufficiently so that an additional auxiliary light for endoscopic procedures, such as is known from the prior art with surgical lights, can even be dispensed with. 
     The lamellae can be pivoted into a closed position using the surgical light in accordance with the invention so that a residual light portion of, for example, approximately 50% to approximately 30% exits the surgical light with non-closed cut-outs. Good results have been achieved with a residual light portion in an order of magnitude of approximately 30%. If subsequently, with lamellae pivoted completely into the closed position, the cut-outs are fully closed by the closure elements, a residual light portion in an order of magnitude of approximately 5%, in particular of approximately 3% to approximately 1%, can be achieved. Good results have been achieved in practice in that a residual light portion in an order of magnitude of some few percent, for example 1%, exits when both the lamellae and also the closure elements are completely closed. It is, however, also simultaneously advantageous if a residual light portion of at least approximately 1% is ensured since such a residual light portion is desired for endoscopic procedures. 
     So that no unwanted shading takes place by the closure element, in accordance with a further advantageous embodiment, a drive can be provided which only actuates the closure element with a completely closed lamella. 
     A cost-effective manufacture of the surgical light can be achieved in that only one single drive, for example, one single electric motor, is provided for the movement of the lamellae, on the one hand, and for a movement of the closure element, on the other hand. 
     In accordance with a further advantageous embodiment, the closure element can be movable along the pivot axis of the lamellae. A compact construction and a problem-free operation hereby result. 
     In accordance with a further advantageous embodiment, a rotatably journaled guide element can be provided for a movement of the lamellae and of the closure element which first effects a pivot movement of the lamellae and subsequently a stroke movement of the closure element. A purely mechanical dimming device is hereby provided with which not only the lamellae can be opened and closed, but also the closure elements can be activated once the lamellae are located in their completely closed position. 
     In accordance with a further advantageous embodiment, a blocking device can be provided which prevents an activation or actuation of the closure element when the lamellae are not located in a completely closed position. Such a blocking device, which can be formed mechanically or also electronically or by means of software, prevents an accidental shading by the closure element when the lamellae are not yet completely closed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       The present invention will be described in the following purely by way of example with reference to an advantageous embodiment and to the enclosed drawings. There are shown: 
         FIG. 1  a sectional view of a surgical light; 
         FIG. 2  a perspective representation of the diaphragm means with opened lamellae and opened closure elements; and 
         FIG. 3  a plan view from below of a cam guide of the diaphragm means of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a sectional view of a surgical light having a lamp body  10  in which a discharge lamp  12  is arranged which illuminates a surgical field via a paraboloid reflector  14 . The discharge lamp  12  has an approximately cylindrical design and is arranged vertically along the central axis of the surgical light. The light exiting the discharge lamp  12  initially radiates through a hollow cylindrical glass filter  16  and is then incident onto the reflector  14  which guides the light onto the surgical site without shade. 
     A mechanically adjustable diaphragm means  20  is provided for the adjustment of the intensity of illumination of the light exiting the surgical light; it is shown magnified in  FIG. 2  and includes in the embodiment shown a total of twelve approximately rectangular lamellae  22  which are each pivotable around a vertical axis. The lamellae  22  comprise light impermeable material, for example, stamped sheet metal and have a plurality of cut-outs  24 . In the embodiment shown, two rows of spaced part cut-outs  24  are provided arranged next to one another per lamella  22 , with five cut-outs of rectangular shape being provided in each row and the cut-outs of the inner row and of the outer row being of equal size. The cut-outs of the inner row and of the outer row are furthermore arranged slightly mutually offset so that the upper margin of the outer cut-outs  24  is located approximately at the center of the inner cut-outs. 
     The lamellae  22  have a lower spigot  26  and an upper spigot  28  at their radially inner sides, with the lower spigots  26  being set into a lower support ring  30  and the upper spigots  28  being set into an upper support ring  32  so that the lamellae  22  are pivotable around the spigots  26  and  28 , that is around a vertical pivot axis. 
     In the embodiment shown, each lamella  22  is furthermore provided with a light impermeable closure element  34  which has approximately the same outer contour as the associated lamellae and which contacts the respective associated lamella in planar fashion. Each closure element  34  has openings  36  whose size and arrangement correspond to the cut-outs  24  of the lamellae  22 . However, the closure elements  34  have only four openings  36  in a row, whereas the lamellae  22  are provided with a total of five cut-outs  24  lying above one another. The closure elements are in turn somewhat shorter than the lamellae. 
     As  FIG. 2  shows, each lamella  22  has an angled over lower lug  23  at its lower side and an angled over upper lug  25  at its upper side. Respective strip sections  27  and  29  of the associated closure element are guided by these two lugs  23  and  25  so that the closure element  34  can be moved relative to the lamella  22  along the pivot axis of the lamella, that is upwardly and downwardly in  FIG. 2 . In the position shown in  FIG. 2 , all lamellae  22  are in their completely open position in which they are aligned substantially radially and do not block a light exit. At the same time, the closure elements  34  are in their open position in which the openings  36  of the closure elements  34  are aligned with the cut-outs  24  of the lamellae  22 . The two bottommost openings  24  of each lamella are not covered by the respective closure element  34 . 
     As  FIG. 2  further illustrates, a guide button  38  of plastic in molded to each lower strip section  27  of each closure element  34 , said guide button having an approximately circular-cylindrical upper section  40  and an approximately parallelepiped shaped lower section  42 . The guide button  38  serves for the pivoting of the lamellae  22  and for the opening and closing of the closure elements  34  with the help of a cam ring  44  which is shown in  FIG. 3 . 
     The cam ring  44  shown in  FIG. 3  is stamped from sheet steel and has a ring section from which a total of twelve web sections  46  extend radially outwardly at an angle of approximately 30° and each form an inner guide slot  48 . Each guide slot  48  extends from the radially outer end of the web sections  46  in linear fashion up to a radially inwardly disposed turning point W from which the slot  48  extends in the peripheral direction. In this respect, a U-shaped tongue  50  surrounding the slot  48  is stamped out of the cam ring  44  in the section of the slot  48  extending from the turning point W and is angled downwardly at an angle of approximately 30° as shown in the representation B-B. The guide button  38  can hereby slide on the web section  46  from its radially outer end up to the turning point W. If the guide button  38  is moved further within the slot  48 , it slides, from the turning point W onward, on the tongue  50  downwardly through the cut-out  52  formed by the tongue  50 . 
     To be able to rotate the cam ring  44  around the center axis of the surgical light and relative to the support rings  30  and  32 , a cut-out having an elongate hole  54  into which a spigot  56  engages which is fastened to a drive  58  is provided at the cam ring  44  in the region of a web section  46 . The drive  58  has an electric motor  60  which moves a spindle (not shown) so that a holding arm  62  to which the spigot  56  is fastened can be moved to and fro along a linear guide  64 . 
     The operation of the mechanical diaphragm means  20  is as follows: 
       FIG. 2  shows the mechanical diaphragm means  20  in the completely open position in which all lamellae  22  are aligned substantially radially and in which the closure elements  22  are located in their open position in which the cut-outs  24  of the lamellae are not covered. If a dimming of the surgical light is desired, the electric motor  60  is activated so that the holding arm  62  in  FIG. 2  moves to the left along the linear guide  64 , whereby the cam ring  44  is pivoted to the left, that is clockwise, whereas the spigot  56  slides in the elongate hole  54 . In this movement, the guide buttons  38  slide in the guide slots  48  so that the lamellae  22  are pivoted around their vertical pivot axis and close. The lamellae  22  can be pivoted so far by a further rotation of the cam ring  44  so that they are completely closed, that is until the guide button  38  has reached the turning point W. All the lamellae  22  are admittedly closed in this state, but a residual light portion of approximately 30% can exit through the cut-outs  24  and through the openings  36  of the closure elements  34 . 
     If a still further darkening of the operating room is desired, but without switching off the discharge lamp  12 , the electric motor  60  can be activated again so that the cam ring  44  continues to rotate clockwise. In this respect, the guide buttons  38  slide obliquely downwardly on the downwardly angled tongues  50  so that the closure elements  34  move downwardly relative to the lamellae  22  and thereby increasingly cover the cut-outs  24 . When the guide buttons  38  have reached the end of the tongues  50 , they are in their bottommost position in which all the cut-outs  24  are covered or closed by the closure element  34 . in this state, only a straying scattered light portion of approximately 1% can exit the surgical light, which is, however, desired for an endoscopic procedure. 
     Once an endoscopic procedure has been ended or if an emergency operation is required, only the electric motor  60  has to be operated in the opposite direction so that initially the closure elements  34  move vertically upwardly and the lamellae  22  are subsequently pivoted into their open position shown in  FIG. 2 . 
     The reference numeral  66  in  FIG. 1  designates a halogen lamp for emergency operation if the discharge lamp  12  or the power supply should go down.