Abstract:
Apparatus for turning over individual boards assembled as a stack, preferably for leafing the program boards of a music box (juke box) is provided, in which boards may be rotated around mutually parallel pivot axes lying in a plane, pivoting bilaterally with the edge area of one side on mutually straight profile sections which can be moved synchronously in guides of a chassis by a drive in a straight line in both directions. The boards are provided with projections extending beyond the pivots, at which a stay fixed to the chassis engages in such a way that in each case, a diagonally supported board lying in a viewing window of the chassis is turned over to the opposite side, in which position it is supported at an approximately identical, mirror-image angle.

Description:
The invention relates to an apparatus for turning over individual boards assembled as a stack, preferably for leafing the program boards of a music box (juke box). 
     BACKGROUND OF THE INVENTION 
     In an apparatus of this type known from EP 0 441 949 B1, the individual program boards belonging to two stacks are pivoted next to each other in a chassis behind its two viewing windows around pivots located at their rear sides in such a way that they can be turned over individually by a rail movable to and fro by a drive which rail is provided with stops which engage at lug-shaped projections of the program boards extending beyond the pivots. Here, in each case two opened sides of each stack of the program boards become visible which sides lie diagonally on each side of each viewing window. According to the opened sides of the program boards assembled as racks in each case, the center migrates between two opened sides to the left or right in each viewing window because the pivots of the individual program boards are supported in a line next to each other fixed to the chassis and the row of pivots of each stack takes up a length corresponding to the breadth of the stack. Due to the migrating of the centerlines between the opened sides in the viewing windows, an unattractive appearance is created because the symmetry of the opened sides to the relevant viewing window is interrupted. 
     It is therefore the object of the invention to provide an apparatus of the type described above where the centerline between two opened program boards always remains at the same position in the center of the viewing window so that the two sides of the program boards always appear at the same place in the viewing window. 
     SUMMARY OF THE INVENTION 
     This object is solved in accordance with the invention by an apparatus for turning over individual boards assembled as a stack, preferably for leafing the program boards of a music box (juke box), which boards may be pivoted around mutually parallel pivot axes lying in a plane, pivoting bilaterally with the edge area of one side on mutually parallel straight profile sections which can be moved synchronously in guides of a chassis by a drive in a straight line in both directions, and are provided with projections extending beyond the pivots at which a stay fixed to the chassis engages in such a way that in each case a diagonally supported board lying in a viewing window of the chassis is turned over to the opposite side in which position it is supported at an approximately identical, mirror-image angle. In the apparatus in accordance with the invention, the centerline between two opened sides of the program boards always appears at the position in the viewing window at which the stay is located. The stay can therefore be aligned to the viewing window in such a way that the opened sides of the program boards always appear at the same position. 
     For this purpose, the profile sections are provided in a series of flush spindles pointing towards each other, the number of which corresponds to the number of boards. The individual program boards which appropriately consist of plastic injection moldings, thus only need to be provided with flush blind boreholes with which they can be pushed onto the flush spindles for their support. 
     For this purpose, the stay consists of a rod parallel to the flush spindles with each projection exhibiting flanks which are approximately at right angles to each other in accordance with the angle formed by the opened sides of the boards facing each other, with the rod entering over that flank lying in the direction of movement until it abuts the flank located at right angles to it and rotates it in the direction of movement while turning over the board. To have the centerline between two opened sides in the center of the viewing window, the rod appropriately lies in the vertical center plane of the viewing window. 
     One special problem when turning over stacks of program boards in such a way that always two opened sides appear in a viewing window, is to have to opened sides appearing at the same angle to each other. In accordance with a preferred embodiment, it is therefore provided that on at least one of the profile sections two toggle levers are supported in a rotatable manner around pivot axes parallel to the spindles which support themselves in each case with one leg on a guide curve fixed to the chassis and whose other legs support the outside board in each case of a side of the opened board stack, and that the guide curve is shaped in such way that the opened sides lying in the viewing field of the viewing window always form roughly the same angle of opening of preferably 90°. 
     In accordance with a further preferred embodiment, it is provided that the outer sides of the boards protrude in chambers with edges bent from their outsides parallel to the viewing window which always allow only one turning over of the boards visible in the viewing window. In this way, any unwanted turning over of the program boards by hand is prevented. 
     Appropriately, two leafable board stacks identically designed in mirror-image are positioned next to each other whose sides of the boards turned open are visible in windows lying next to each other and whose boards turned over towards each other extend into a common central chamber. 
     To allow the profile sections supporting the pivots of the boards to be moved synchronously, the upper and lower profile sections are appropriately connected by racks which mesh with pinions mounted on a common shaft supported in the chassis with a gear wheel of the gear driving the pinion via a controllable electric motor being provided with markings which can be scanned by a light barrier and which effect a stepped turning over. The light barrier emits signals corresponding to the marks scanned to an electronic control unit which then controls the electric motor in such a way that the program boards are turned over by steps or continuously in following steps. 
     Appropriately, the program boards possess compartments lying on both sides horizontally next to each other to store the title sheets of the content books and the title lists of the playable CD discs. 
     One special problem of the apparatus in accordance with the invention is that the stay engaging at the projections extending beyond the pivots of the program boards is not aligned to the program boards to be turned over so that a breakdown in turning may occur. In accordance with a further embodiment of the invention, it is therefore provided that the stay or the rod is guided in a movable manner in the chassis laterally to the straight profile sections against the force of a spring which attempts to move the rod in the direction of its engaged position at the projections extending beyond the pivots of the boards. 
     If, for example, external intervention is made in the moving title sheets or program boards by hand or by other means, it is possible with the sprung arrangement of the stay or the rod to prevent any jamming of the program boards by the fact that the stays or rods can give way backwards in a sprung manner. If the levers formed by the projections extending beyond the pivots possess at their ends stop surfaces formed by flanks roughly at right angles to each other for the stay or the rod, the rod can give way in a spring-like fashion when it moves over flanks of program boards not to be turned. Only when the rod abuts the flank of a program board to be turned over, is it held tensionally at the angle of engagement in its engagement position in which it effects the turning. Therefore, to be able to leaf a stack of program boards in a synchronized manner, it is only necessary to move the rod so far that it moves over the “incorrectly” lying program boards so that subsequently when the direction of movement of the profile sections supporting the program boards is reversed, the program boards can be turned in a coordinated and synchronised manner. 
     Appropriately, the rod is guided in longitudinal holes of the frame profile sections. 
     A flat spring can be provided moving the rod in the direction of its engagement position. 
     To adjust the leafing mechanism, for example after a change of the program board stack or after replacing individual program boards, it may be necessary to be able to freely move the profile sections supporting the program boards in their guides. However, this is not possible if the profile sections are coupled with the drive. In accordance with another preferred embodiment, it is therefore provided that a coupling is provided by means of which the shaft supporting the pinions can be separated from its drive. 
     As the coupling, a stepped gear consisting of two gear wheels connected to each other can be provided on one axle which stepped gear is supported axially in a movable manner against the force of a spring, from which gear one gear wheel meshes with a gear wheel driven by the electric motor and the other gear wheel meshes with a gear wheel driving the pinion shaft with the stepped gear being disengaged from at least the driving or driven gear wheel by an axial movement and with the spring attempting to maintain the stepped gear in engagement with the driving and driven gear wheels. 
     In order to engage and disengage the coupling, a pull or push strap can be provided with which the stepped gear can be disengaged from the driven and/or driving gear wheel. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     One embodiment of the invention is described below in detail by means of the drawing which shows in 
     FIG. 1 a perspective view of the chassis accepting the board stack with the apparatus for turning over the individual boards of the stack from which the board stacks have been removed for reasons of a better overview; 
     FIG. 2 a perspective view of the central lower chassis part from FIG. 1 in an enlarged view; 
     FIG. 3 a perspective view of the lower rail supporting the programme boards with an inserted program board in an enlarged view 
     FIG. 4 a view in accordance with FIG. 3 of the left part of the profile rail from FIG. 3 without the inserted program board; 
     FIG. 5 a horizontal section through the chassis from FIG. 1; 
     FIG. 6 a section through the chassis along the line VI—VI in FIG. 5; 
     FIG. 7 a top view of the lower frame profile section with the rod guided in a movable manner in a longitudinal hole; 
     FIG. 8 a rear view of the frame profile section with the rod guided in a movable manner in it; 
     FIG. 9 a rear view of the upper frame profile section with the drive for the pinion shaft arranged on it; and 
     FIG. 10 a top view of the arrangement from FIG.  10 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The program display shown in FIG. 1 for music boxes (juke boxes) consists of a chassis  1  which can be manufactured from blanked sheet metal components or as a plastic injection molding. Rectangular chambers  3  which are open towards the middle are connected to the narrow faces of a rear frame  2  consisting of mutually parallel profile sections. Rectangular edge rails  5  are bent towards the frame  2  from the front side walls  4 , which are parallel to the frame  2 , of the chambers  3 . Arranged in the middle between the end chambers  3  is a channel-section web  6 , the legs  7  of which are connected to the angled side edges of the profile sections forming the long sides of the frame  2 . The front end of the channel-section web  6  lies in a plane with the front ends  4  of the chambers  3 . The outer faces of the legs  7  of the channel-section web  6  lie in a plane with the top and bottom faces of the end chambers  3 . Edge strips  9  are inwardly bent at right angles from the rectangular front end  8  of the channel-section web  6 . 
     Secured in an inwardly angled edge strip  11  of the lower long profile section  12  of the frame  2  are guide rails  13  with a C-section profile open at the top, in which guide rails  13  is guided a longitudinally sliding rectangular profile section  14 . 
     A freely rotational shaft  14 ′ is pivot-mounted in the legs  7  of the channel-section web element close to the lower frame profile section  12 . Said shaft  14 ′ features at its top and bottom ends pinions  15  which mesh with a rack  16  riveted to rectangular section rail  14 . 
     The rectangular section rail  14  features pins  17  at its ends, which form the spindles for mounting the program boards. Also mounted in the upper, angled profile section  11 ′ are guide pieces  13 , in which is mounted, in an arrangement mirroring that of the lower profile section  14 , an identical profile section with flush-aligned bearing pins which serves to retain the top end of the suspended program boards, The upper profile rail is also riveted to a rack which meshes with the upper pinion of the shaft  14 ′. 
     To the side of each of the two rows of spindles  17  are mounted on spindles  18  angled levers  19 , of which the shorter arms  20  are located so that they slide on a guide cam arrangement  21  fixed to the frame. The longer arms  22  form support levers for the outer program boards of the opened stack. 
     Secured to the bottom of the upper leg  7  of the channel-section web element  6  is a controllable electric motor  30  which drives, via a worm  31 , a worm gear  33 , this being connected coaxially to a gear wheel  32  which meshes with gear wheel  34 . Gear wheel  34  is rotationally fixed to shaft  14 ′. The pinions  15  mounted on shaft  14 ′ mesh, in the manner described, with the racks  16  which are riveted to the rectangular profile section  14 . The gear wheel  34  is provided with three markings  35 , which are concentric to its rotational axis and of equidistant angular displacement, these being scanned by a photoelectric element  36  which transmits its signals for controlling the motor  30  to an electronic control not illustrated. 
     The program boards  40  comprise fame-like, essentially rectangular injection moldings which are provided at the inner ends of their short sides with blind holes  41 , these being flush with one another with their centerline running through the rear long edge profile section of the program board. The program boards  40  are mounted with these blind holes  41  on the pins  17  of the rail  14  sliding in the guide pieces  13 , so as to provide for their pivot mounting. 
     In an extension of their upper and lower narrow edge profile sections, the program boards  40  are provided with projections which, emanating from a central notch, exhibit flanks  43 ,  44  arranged at right angles to each other. In the center plane of the window formed between the lateral chambers  4  and the center channel-shaped web element  6  are secured between the inwardly angled edges of the long side profile sections of frame  2 , rods  45  which serve as stays to enable the program boards to be turned or “leafed through”. As the rectangular profile rail  14  moves, the rods of each window side slide over one of the flanks  43 ,  44  of the projections  42  into the angled recesses between these until they abut the right-angled flank  43  or  44 , so effecting the turning over of the program board. The outer sides of the program cards  40  protrude into the side chambers  3  with the outer sides of the program boards being overlapped by the bent edge strips  5  of the chambers. The bent edge strips  5  allow the turning over of the program cards whose sides are visible in the windows, but prevent any turning over of the following program cards in the manner visible from FIG.  5 . 
     As can be seen from FIG. 5, the program cards  40  pivoted on the pins  17  on the rail  14  possess on their side serving their support a greater distance to each other than that corresponding to their thickness. The outer sides of the program cards  40 , however, abut each other in the chambers  3  so that the program card stack is wider on the support side than on the outer side. To ensure that the program boards always appear at the same oblique angle in the viewing windows, the legs  22  of the toggle levers  19  always press each side of the opened stack together in such a way that the outer sides of the program boards abut each other. This is achieved by the legs  20  of the toggle levers  19  being provided at their ends with slide pieces  50  which slide on the guide curve  21  whose gradient decreases inwardly in the manner visible from FIG. 5 in such a way that the lever  22  gives way outwardly as the stack height decreases. 
     The central channel web-section part  6  forms a chamber open to both sides in which the program boards turned over to the center of both program stacks lie. The central chamber formed in this way can take up the program boards turned over to the center of both program stacks because as the profile rod  14  is moved to the left or right the same number of program boards is turned into the central chamber which is turned out of it again. 
     To reduce the friction of the movable profile rail in the guide parts  13 , the pins  17  penetrate the profile rail in the manner visible from FIG. 6 so that these slide on the base of the C-shaped groove of the guide pieces  13  with their lower rounded heads  48 . 
     The program boards  40  are provided on both sides in rows arranged above each other with compartments  50  to insert the content books of the CD disks and with compartments  51  to insert the title cards. 
     As can be seen from FIGS. 7 and 8, the rod  45  forming a stay can be guided movably in longitudinal holes  55  of the edge strips  11  bent from the frame profile section  12  which runs laterally to the profile rail  14 . One end of a biased flat spring  56  is riveted to the frame profile  12  and the spring attempts to maintain the rod  45  in its engagement position visible from FIG. 8 at the ends of the longitudinal holes  55  facing the profile rails  14 . 
     For the rod  45 , guides are provided so that it is held in the longitudinal holes  55  in only a laterally movable manner, but cannot be moved in an axial direction. As can be seen from FIGS. 9 and 10, the stepped gear is guided in an axially movable manner with the worm gear  33  and the gear wheel  33  positioned coaxially and next to each other on an axle  60  which is connected at the edge strip  11  or at the connection sheet  61  connected to it of the upper leg  7  of the channel-section web. In the drive position, the stepped gear is held in abutment with a ring  62  which is located at the lower free end of the axle  60 . In this drive position of the stepped gear, the worm gear  33  meshes with the worm  31  and the gear wheel  32  with the gear wheel  34  wedged in a non-turning manner on the shaft  14 ′. The stepped gear  32 ,  33  is held in abutment to the lower ring  62  by a spring not shown. 
     The ring  62  is connected to an angled actuation piece  64  whose leg bent off the ring section  62  protrudes upwards through a slot  65  of the leg  7 . By pulling on the leg of the actuating piece  64  passing through the slot  65 , the stepped gear  32 ,  33  can be moved upwards so that the worm gear  33  and the gear wheel  32  are disengaged from the worm  31  and the gear wheel  34 . This uncoupled position can be fixed by having a borehole  66  provided in the leg of the actuating piece  64  passing through the slot  65  through which borehole a pin, for example a screwdriver, can be pushed through to fix in position. If the leg of the angled actuating piece  64  passing through the slot  65  is released, the spring not shown presses the stepped gear back into a position where the drive is coupled with the pinion shaft  14 ′.