Abstract:
In order to increase the grip of a hand wheel ( 4 ) which is especially intended for a roller file, said hand wheel consists of a base body ( 6 ), an outer shell ( 9 ) and a rubber-elastic insert ( 12 ) disposed between the base body ( 6 ) and the outer shell ( 9 ). Said insert is provided with protuberances ( 11 ) which jut out in the outer shell ( 9 ).

Description:
TECHNICAL FIELD 
   The invention relates to a hand wheel for initiating a rotational movement in the end of a shaft-like or roller-like component, in particular in the end of a holder for a revolving card index. 
   PRIOR ART 
   Hand wheels of the above mentioned type which consist of plastic and have a more or less smooth surface are known. 
   DESCRIPTION OF THE INVENTION 
   The object of the invention is to provide a hand wheel which is provided, in the region of its actuating surface, with means which make it easier to rotate the hand wheel by countering any occurrence of the hand which is gripping the hand wheel slipping on the hand wheel. This object is achieved according to the invention, in the case of a hand wheel of the type in question, in that the hand wheel has a basic body, an outer shell, which can be pushed onto the basic body, can be arrested by latching elements in the pushed-on state and has openings distributed over its circumference, and an elastomeric insert, which is arranged between the basic body and the outer shell and forms protuberances which project through the openings of the outer shell and enhance the grip of the hand wheel. 
   The hand wheel according to the invention is easy to operate. In contrast to a solution in which the hand wheel is in one piece and is provided with integral soft/resilient protuberances, the three-part configuration of the hand wheel according to the invention has the advantage that the tooling expense which is necessary for producing the hand wheel is comparatively low. 
   Further details and features of the invention can be gathered from the subclaims and the following description of an embodiment of the invention illustrated in the attached drawing, in which: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a stand for a revolving card index with two hand wheels, 
       FIG. 2  shows the perspective view of the basic body of one of the hand wheels according to  FIG. 1 , 
       FIG. 3  shows a side view of the basic body according to  FIG. 2 , 
       FIG. 4  shows the end view of the basic body according to  FIG. 2 , 
       FIG. 5  shows the perspective view of the outer shell of one of the hand wheels, 
       FIG. 6  shows the perspective view of an insert which ends up located between the basic body and the outer shell, and 
       FIG. 7  shows a section through the end of the holder which can be made to rotate by the hand wheels and belongs to the stand of a revolving card index which is illustrated in  FIG. 1 . 
   

   METHODS OF IMPLEMENTING THE INVENTION 
   The stand of a revolving card index which is illustrated in  FIG. 1  is provided with a holder  3  which is mounted in a rotatable manner between two supports  1  and  2  and is intended for information carriers (not illustrated). Two hand wheels  4  and  5  are arranged at the opposite ends of the holder, and the construction of these hand wheels can be gathered from  FIG. 2 . 
   Each of the two hand wheels has a basic body  6  which, in the region of its circumference, has cutouts  8  which are separated from one another by supporting ribs  7 . An outer shell  9  can be pushed onto the basic body  6 , and this outer shell  9  is provided, in the region of its circumference, with openings  10  through which protuberances  11  of an insert  12  made of elastomeric material project beyond the outer surface of the outer shell  9 . 
   As can be seen from  FIG. 6 , the insert has a disk-like central part  13 , which serves for covering an opening  14  of the outer shell  9 , said opening being located in the region of the end side of the basic body  6 . The disk-like central part  13  is adjoined, via film hinges  15 , by extension arms  16  which bear the protuberances  11 . The protuberances  11  are enclosed all the way round by supporting flanges  17  which, in the installed state, position themselves against the inner surface of the outer shell  9 . In order for it to be possible for the outer shell  9  to be positioned correctly on the basic body  6 , the latter is provided with guide ribs  18  which fit in guide grooves  19  on the inner wall of the outer shell  9 . 
     FIG. 7  shows the connection between the hand wheel  4  and the holder  3  of the stand according to  FIG. 1 . Projecting into a central shaft  20  of the basic body  6  are two resilient retaining tongues  21 ,  22  which, at their ends, have latching protrusions  23 ,  24  which engage behind two latching stops  25 ,  26  located on mutually opposite shaft walls. In order for it to be possible to separate the hand wheel  4  from the holder  3 , the outer shell  9 , together with the insert  12 , is drawn off from the basic body  6 , on which it is normally retained by a latching connection which is indicated at  27 .