Abstract:
For lighting equipment for illumination of theatre and show stages and platforms there is designed equipment for quick change of rotary gobos comprising a carrier disc supporting interchangeable segments with the gobos. The individual segments are attached at the carrier disc by springs which register the position of the segment on the gobo carrier while at the same time holding the segment in place.

Description:
RELATED APPLICATION(S) 
       [0001]    This application is a utility filing claiming priority of provisional application 61/165,253 filed on 31 Mar. 2010. 
     
    
     TECHNICAL FIELD OF THE INVENTION 
       [0002]    The invention relates to equipment for a change of rotary gobos furnished with a carrier disc supporting interchangeable segments with the gobos. 
       BACKGROUND OF THE INVENTION 
       [0003]    The expression gobo relates to an image which is to be projected as a slide within a comparatively great distance. Due to a high temperature of the respective light source such an image is typically created on a metal, glass or any suitable base. To increase the achieved effect the gobos rotate, as a moving image attracts more attention than a stationary image. Rotary gobos need not rotate continuously; therefore their rotation depends upon activation of a drive motor. Typically these systems are configured on a circular carrier with a central sun gear surrounded by planetary gears which rotate the gobo when the sun gear rotates. The figures described below illustrate the planetary gears but not the sun gear. In some such systems the planetary gears are rotated by a gear on the periphery of one or more of the planetary gears. In some such systems gears are not employed at all, the rotation is accomplished by friction or belts. In other systems a combination of belts and gears are used. 
         [0004]    Generally speaking there exist two basic types of changeable gobo rotary gobo systems, which are applied with minor or major divergences. By the first system gobos are placed on a carrier disc and the gobos themselves are exchanged. Such a system is technologically simple and cheap, but from a practical point of view it is very cumbersome. In general a lighting equipment designs offer very little working space for any manipulation and often special tools are necessary. This simple design is used preferably for cheap equipment. 
         [0005]    In the second type of system, the carrier disc is furnished with mutually independent segments, one segment for each gobo. In order to change the gobo in these systems complete segments are exchanged. In most cases each segment has a special bearing with grooves matching with counter-pieces on the carrier disc. The design of these systems is very demanding on manufacturability of the system. It is an object of the invention to simplify the design of attachment of gobos at the carrier disc and to simplify and speed up gobo changing procedures. 
         [0006]    The foregoing problems are solved by equipment design for a rotary gobos drive comprising a carrier disc supporting interchangeable gobo holding segments in accordance with the present invention. The individual segments being attached at the carrier disc by central holding means, each segment being provided with means for in a non-fixed manner registering the position of the segment on the carrier disc. Further in accordance with the present invention each segment may be provided with a lamella for attachment in the central holding means. In a preferred embodiment the central holding means comprise a system of flexible fingers in a fan-shaped arrangement. The fingers are at inside ends fixed to the carrier disc and on the outside free ends adapted to allow for insertion of the segment lamellas between the fingers and the carrier disc. The fingers may be at their inside ends integrated into one unit. The number of fingers within the unit corresponds to a number of segments to be supported by the carrier disc. Still further in accordance with the invention each segment is provided with a bearing supporting a driver with a gobo. The bearing inside ring is provided for by the driver outer rim and the bearing outside ring is attached to the segment lamella by dismountable connection means. The driver further comprises a flange with a spur toothing, designed for engaging with a mechanism for rotation of the gobos. Dismountable connection means for attachment of the bearing outer ring on the lamella may be preferably utilized as means for attaching the segment on the carrier disc. The carrier disc may be further provided with circular apertures allowing for lighting of gobos, the apertures having their centres located at a common pitch circle and being along own perimeter provided with means for engaging with means for registering the position of the segments on the carrier disc. 
         [0007]    According the first aspect of the invention provides a simple seating of a segment with gobos on the carrier disc and for changing of the gobos in a very simple and easy procedure. According to another aspect of the invention the presented solution is also technologically simple with little manufacturing costs. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    By way of examples the invention will be now described with reference to the accompanying drawings: 
           [0009]      FIG. 1  illustrates an axonometric view from above on a carrier disc with seven segments, one of which is in an outside position; 
           [0010]      FIG. 2  illustrates an axonometric view from underneath on the carrier disc according to  FIG. 1 ; 
           [0011]      FIG. 3  illustrates an axonometric view on one segment in a disassembled state; 
           [0012]      FIG. 4  illustrates an axonometric view on a carrier disc supporting six segments; 
           [0013]      FIG. 5  illustrates an axonometric view on a carrier disc with five segments; 
           [0014]      FIG. 6  illustrates an axonometric view of a further embodiment; 
           [0015]      FIG. 7  illustrates an axonometric view from underneath the carrier disc shown in  FIG. 6 ; 
           [0016]      FIG. 8  illustrates an axonometric view of a single removable segment with the rotating gobo carriage mounted thereto; 
           [0017]      FIG. 9  illustrates a cross section of a segment and the carrier; 
           [0018]      FIG. 10  illustrates an axonometric view of a further embodiment; 
           [0019]      FIG. 11  illustrates an axonometric view from underneath the carrier disc shown in  FIG. 10 ; 
           [0020]      FIG. 12  illustrates an axonometric view of a single removable segment; 
           [0021]      FIG. 13  illustrates an axonometric view of a single segment mounted on the carrier disc; 
           [0022]      FIG. 14  illustrates an axonometric view of a further embodiment; 
           [0023]      FIG. 15  illustrates an axonometric view from underneath the carrier disc; shown in  FIG. 14 ; 
           [0024]      FIG. 16  illustrates an axonometric view of a further embodiment; 
           [0025]      FIG. 17  illustrates an axonometric view from underneath the carrier disc shown in  FIG. 16 ; 
           [0026]      FIG. 18  illustrates an elevation of a single removable segment; 
           [0027]      FIG. 19  illustrates an axonometric view of a further embodiment; 
           [0028]      FIG. 20  illustrates an axonometric view from underneath the carrier disc shown in  FIG. 19 ; 
           [0029]      FIG. 21  illustrates an axonometric view of a single removable segment in a disassembled state; and 
           [0030]      FIG. 22  illustrates an axonometric view of the single removable segment shown in  FIG. 21 . 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0031]      FIG. 1  illustrates equipment for a change of rotary gobos comprising a carrier disc  1  on which there are arranged interchangeable segments  2  with gobos mounted thereon. On all accompanying drawings gobos are presented simply as blank fields. In the embodiment presented on  FIG. 1  the carrier disc  1  is equipped with seven segments  2  and one free position, which serves for direct illumination by light. 
         [0032]    All segments  2  are by central holding means  10  attached at the carrier disc  1 . A part of each segment  2  is made of a lamella  3 , shaped for attachment of the segment  2  in the central holding means  10 . The gobo is fixed in a rotating gobo carriage driver  6  seated in ball bearing. Fixed connection means, like screws  4  with cylindrical head in the depicted embodiment, serve for securing a ball bearing outside ring  5  on the lamella  3  of each segment  2 . The bearing balls are freely located in the bearing outside ring  5 , while the bearing inside ring is provided for by a driver  6  outer rim. The driver  6  seating is thus of a very simple design when compared with a standard ball bearing arrangement, nevertheless the function of a rotary gobo is fully retained. The driver  6  is provided with a flange  7  having a spur toothing/teeth for engagement with a mechanism for rotation of the gobos. 
         [0033]    The carrier disc  1  is provided with apertures  9 , the centers of which are placed on a common pitch circle. The apertures  9  allow for a light beam to go through the gobos or just through the carrier disc  1 , as the case may be. 
         [0034]    Each segment  2  is provided with means for registering the position of a segment  2  on the carrier disc  1 . Preferably the means for registering the position of a segment  2  on the carrier disc  1  are provided for by the bearing connection means  4  for attachment of a ball bearing outside ring  5  on the lamella  3 . In the discussed embodiment the means for registering the position of a segment  2  on the carrier disc  1  are provided for by the cylindrical heads of the screws  4 . To achieve a proper position of the segment  2  on the carrier disc  1  the screw  4  heads match with recesses  8  made along a perimeter of respective aperture  9  in the carrier disc  1 . In the embodiment shown on  FIG. 1  and  FIG. 2  there are used three screws  4  for each segment  2  and therefore each aperture  9  has three recesses  8  distributed along its perimeter and spaced apart with respect to distribution of the screws  4 . There may be used a different number of the screws  4 , but basically two of them are sufficient. Instead of the above described construction the means for registering the position of a segment  2  on the carrier disc  1  may be provided for also by another means known as such. 
         [0035]    The central holding means  10  comprise a system of radially extending flexible fingers  10  in a fan-shaped arrangement. The fingers  10  are at inside ends attached to the carrier disc  1 , preferably by rivets, and on the outside free ends  11  bent upwards to facilitate insertion of segment lamellas  3  between the fingers  10  and the carrier disc  1  body. The number of fingers  10  corresponds to the number of the segments  2 , but it is possible for one finger  10  to secure position of more than one segment  2 . Preferably the inside ends of all the fingers  10  are integrated into one piece. In a place corresponding to a free position on the carrier disc  1  there is no finger  10  and the space is kept free. To improve pressing forces produced by the central holding means upon the segment  2  lamellas  3  the fingers  10  may be provided with a pressure disc  12  located in their central part common for all the fingers  10 , as presented on  FIG. 4  and  FIG. 5 . 
         [0036]    To further facilitate insertion of the segment lamella  3  under the finger  10  of the carrier disc  1  one of the recesses  8  is carried out in such a way, that a centre of such a recess  8  is located at a radial going through the carrier disc  1  centre, as it is performed by the embodiments illustrated in  FIG. 1 ,  FIG. 2 ,  FIG. 4  and  FIG. 5 . By a larger number of segments  2 , usually seven and more, the driver  6  outside contour edges are cut off, as shown on  FIG. 1  and  FIG. 2 . By a small number of the segments  2 , the inside edge  13  of the lamella  3  is of an arc shape for a better fit under the central holding means. 
         [0037]      FIG. 6  and  FIG. 7  illustrate another embodiment of a rotating gobo carrier wheel where the retention of the segment onto the carrier is achieved through magnetic attraction.  FIG. 6  provides a top perspective view and  FIG. 7  provides a bottom perspective view. The segment  2  is made of a lamella  3 , shaped for registration and attachment of the segment  2  by a magnetic holding means  24 . The gobo is fixed in a driver  6  seating in ball bearing. Bearing connection means, like screws  4  with cylindrical head in the depicted embodiment, serve for securing a ball bearing outside ring  5  on the lamella  3  of each segment  2 . The bearing balls are freely located in the bearing outside ring  5 , while the bearing inside ring is provided for by a driver  6  outer rim. The driver  6  is provided with a flange Z having a spur toothing/teeth for engagement with a mechanism for rotation of the gobos. 
         [0038]    The bearing connection screws serve a second function: to register the position of the segments when installed on a carrier disc. It is important to note that these screws do not hold the segments to the carrier disc. To achieve a proper position of the segment  2  on the carrier disc  1  the screw  4  heads match with recesses  8  made along a perimeter of respective aperture  9  in the carrier disc  1  together serving to register the position of the segment on the carrier. In the embodiment shown on  FIG. 6  and  FIG. 7  there are three registration screw heads  4  for each segment  2  and therefore each aperture  9  has three recesses  8  distributed along its perimeter and spaced apart with respect to distribution of the registration screw heads  4 . There may be used a different number of the registration screw heads  4 , but basically two are sufficient. Instead of the above-described construction the means for registering a segment  2  on the carrier disc  1  may be provided for also by another means known as such—for example pegs or slots and non-concentric inserts. 
         [0039]    The magnetic holding means comprise a ferrous plate  23  mounted underneath the carrier plate  1  with a hole  22  in the carrier plate  1  exposing a portion of the ferrous plate  23 . Carrier plate  1  is typically constructed of a non ferrous non-magnetic material such as aluminum. In addition alignment pins  20  are attached to carrier plate  1 . In the embodiment shown, the number of alignment pins  20  and holes  22  corresponds to the number of segments  2 . Further the segment  2  has a magnet  24  mounted underneath the lamella  3  such that the magnet passes through the hole  22  in the carrier plate  1  and attaches to the ferrous plate  23 . The magnetic attraction between magnet  24  and ferrous plate  23  securely retains the segment in position on the carrier. Magnet  24  may be of the same size and shape as the hole  22  such that there is a close alignment between the magnet  24  and the hole  22 . In an alternate embodiment magnet  24  is smaller than hole  22  such that alignment screws  4  provide alignment of the segment by engaging in recesses  8 . Magnet  24  may be a rare earth magnet or constructed of other magnetic material well known in the art. Lamella  3  may have an indentation  21  at its inner end which serves to engage with alignment pin  20  and assist with the positioning and alignment of the segment onto the carrier. 
         [0040]      FIG. 8  illustrates the detail of the underneath of a single segment with its lamella  3 , position registration screw heads  4 , magnet  24  and alignment indentation  21 .  FIG. 9  is a cross section through the assembly showing how the magnet  24  passes through the hole  22  in the carrier plate  1  to engage with the ferrous plate  23 . 
         [0041]      FIG. 10 ,  FIG. 11 ,  FIG. 12  and  FIG. 13  illustrate a yet further embodiment of the invention. In this variant the segments do not carry gobos but instead carry filter material or other optical device such as lenses, frost or effects glasses. The filter material may be dichroic glass, colored glass or other colored material well known in the art. Filter material  102  is attached to lamella  101  which, in turn, has a magnet  107  attached to its underside. The main carrier plate  103  has a series of holes  106  through which the magnets  107  can pass and attach to the ferrous plate  104  which is affixed to carrier plate  103 . The lamella  101  may have an indentation  108  at its inner end which serves to engage with alignment pin  105  and assist with the positioning and alignment of the segment onto the carrier. This system has the further distinction of not requiring a full size carrier plate  103 . This allows the filter material segments  102  to be mounted adjacent to one another with no frame or border between adjacent segments. The alignment provided by indentation  108  and alignment pin  105  is adequate for this requirement. 
         [0042]      FIG. 14  and  FIG. 15  illustrate a further embodiment  200  where the retention of the segment  202  onto the carrier plate  201  is achieved through magnetic attraction.  FIG. 14  provides a top perspective view and  FIG. 15  provides a bottom perspective view. The segment  202  is made of a lamella  203 , shaped for registration and attachment of the segment  202  through a magnetic holding means  210 . The gobo is fixed in a geared driver seating  206  supported by a ball bearing race (not shown). The bearing balls (not shown) are freely located in the bearing inside ring  205 , while the bearing inside ring is provided for by the outer rim of geared driver seating  206 . The geared driver  206  is provided with a flange  207  having spur gear teeth for engagement with a mechanism for rotation of the gobos. The segment  202  may be aligned and prevented from rotation by optional guide pins  208 . First and second tabs  211  on the sides of lamella  203  engage with a shoulder on guide pin  208 . Although not necessary during normal operation such engagement with first and second tabs  211  serves to both guide and assist insertion of the segment and to prevent excessive movement of segment  202  in both a lateral and vertical direction with respect to carrier plate  201  if the unit is heavily jarred during shipping. In the embodiment disclosed in  FIG. 14  and  FIG. 15  there are the same number of guide pins  208  as apertures  209 . 
         [0043]    Primary lateral alignment is provided by the bearing sleeve  212 . Bearing sleeve  212  protrudes from the underside of the lamella  203  on the rear side of segment  202  and engages with aperture  209  in the carrier plate  201 ; this coupling provides accurate alignment of segment  202  with carrier plate  201  in all lateral directions. The alignment of bearing sleeve  212  with aperture  209  combined with the optional back-up of engagement of first and second tabs  211  with guide pins  208  provides accurate and robust alignment of the segment to the carrier plate in all planes and ensures accurate registration and focus of the gobo image. 
         [0044]    The magnetic holding means comprise a ferrous lamella  203  and a magnet  210  mounted to the carrier plate  201 . Carrier plate  201  is typically constructed of a non ferrous non-magnetic material such as aluminum. In operation the ferrous lamella  203  is attracted to magnet  210  while being further constrained by guide pins  208  and tabs  211  so as to securely retain the segment in position on the carrier. Magnet  210  may be a rare earth magnet or constructed of other magnetic material well known in the art. Magnet  210  may be a single magnet or may be a pair of adjacent magnets  213 ,  215  presented in magnetic opposition such that a magnetic circuit is provided through the ferrous lamella  203  thus providing increased attractive force. 
         [0045]      FIG. 16  and  FIG. 17  illustrate a different class of embodiments of a rotating gobo carrier wheel  300  where the retention of the segment  302  onto the carrier is achieved through a forked spring  214 .  FIG. 16  provides a top perspective view and  FIG. 17  provides a bottom perspective view. The segment  302  is made of a lamella  303 , shaped for registration and attachment of the segment  302  through a forked spring holding means to guide pin  313 . The gobo is fixed in a geared driver seating  306  supported by a ball bearing race. The bearing balls are freely located in the bearing inside ring  305 , while the bearing inside ring is provided for by the outer rim of geared driver seating  306 . The geared driver  306  is provided with a flange  307  having spur gear teeth for engagement with a mechanism for rotation of the gobos. The segment  302  may be aligned and prevented from rotation by optional guide pins  308 . First and second tabs  311  on the sides of lamella  303  engage with a shoulder on guide pin  308 . Although not necessary during normal operation such engagement with first and second tabs  311  serves to both guide and assist insertion of the segment and to prevent excessive movement of segment  302  in both a lateral and vertical direction with respect to carrier plate  301  if the unit is heavily jarred during shipping. In the embodiment disclosed in  FIG. 16  and  FIG. 17  there are the same number of guide pins  308  as apertures  309 . Primary lateral alignment is provided by the bearing sleeve  312 . Bearing sleeve  312  protrudes from the underside of the lamella  303  on the rear side of segment  302  and engages with aperture  309  in the carrier plate  301 ; this coupling provides accurate alignment of segment  302  with carrier plate  301  in all lateral directions. The alignment of bearing sleeve  312  with aperture  309  combined with the optional back-up of engagement of first and second tabs  311  with guide pins  308  and forked spring  314  with guide pin  313  provides accurate and robust alignment of the segment to the carrier plate in all planes and ensures accurate registration and focus of the gobo image. 
         [0046]    The forked spring holding means comprise a two fingered forked spring  314  and a central guide pin  313  mounted to the carrier plate  301 . Guide pin  313  has a central pin surmounted by a cap that is of larger diameter than the central pin. The underside of the cap is separated from the carrier plate  301 . In operation the two fingers of forked spring  314  is slid under the cap and around the central pin of guide pin  313 . Forked spring  314  has a preformed bend towards from the carrier plate such that the fingers of said forked spring require pressure so as to slide under the cap of guide pin  313 . As the segment is slid inwards with the forked spring under the cap of guide pin  313  the bearing sleeve  312  will drop into aperture  309  securely retaining segment  302  by pressure between the underside of the guide pin cap and forked spring  314 . 
         [0047]      FIG. 18  shows an elevation of a removable segment  302  illustrating the forked spring  314  and the bend  315  in the forked spring. 
         [0048]      FIG. 19  and  FIG. 20  illustrate a further embodiment of the invention where the retention of the segment carrying a fixed, non rotating gobo, onto the carrier is achieved through a forked spring.  FIG. 19  provides a top perspective view and  FIG. 20  provides a bottom perspective view. The segment  402  is made of a lamella  403 , shaped for registration and attachment of the segment  402  through a forked spring holding means  414  to guide pin  413 . The gobo is fixed in a seating ring  406 . The seating ring  406  is retained within the curved arms  405  of lamella  403 . The segment  402  is aligned and prevented from rotation by central guide pin  413 . Such engagement prevents movement of segment  402  in both a lateral and vertical direction such that segment  402  is constrained in an accurate position with respect to carrier plate  401 . In the embodiment disclosed in  FIG. 19  and  FIG. 20  there are one less central guide pins  308  than apertures  309  so as to provide a single permanently open aperture. Further alignment is provided by the sleeve  412 . Sleeve  412  protrudes from the underside of the lamella  403  on the rear side of segment  402  and engages with aperture  409  in the carrier plate  401 ; this coupling provides accurate alignment of segment  402  with carrier plate  401  in all lateral directions. The alignment of sleeve  412  with aperture  409  combined with the engagement of forked spring  414  with central guide pin  413  provides accurate and robust alignment of the segment to the carrier plate in all planes and ensures accurate registration and focus of the gobo image. 
         [0049]    The forked spring holding means comprise a two fingered forked spring  414  and a central guide pin  413  mounted to the carrier plate  401 . Guide pin  413  has a central pin surmounted by a cap that is of larger diameter than the central pin. The underside of the cap is separated from the carrier plate  401 . In operation the two fingers of forked spring  414  is slid under the cap and around the central pin of guide pin  413 . Forked spring  414  has a preformed bend towards from the carrier plate such that the fingers of said forked spring require pressure so as to slide under the cap of guide pin  413 . As the segment is slid inwards with the forked spring under the cap of guide pin  413  the sleeve  412  will drop into aperture  409  securely retaining segment  402  by pressure between the underside of the guide pin cap and forked spring  414 . 
         [0050]      FIG. 21  and  FIG. 22  show perspective views of a removable segment  402  illustrating the snap-in attachment of the seating ring  406  into the forked spring  405 . 
         [0051]    It should be appreciated by those skilled in the art that the quick-change gobo changer systems described above can be changed without removing the gobo carrier from the automated luminaire without handling the gobos directly and without the use of tools and can be done very quickly by hand. 
         [0052]    In other embodiments rather than having a slot in the gobo segment spring lamella, the slot(s) is located in the central pin and the gobo segment spring labella slides into and registers in such slot(s) The central pin for each gobo segment may have one or more such slots to mate with one or more lamella extensions. 
         [0053]    While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this invention, will appreciate that other embodiments may be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims. 
         [0054]    The invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as described by the appended claims.