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You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION 
     This invention relates to a water dispensing unit for shower baths and the like. 
     As is known, various types of shower bath units are currently available commercially. One of the most widely used such units includes a supporting fork element having protruding lugs adapted to hold the dispensing element. In other instances, the supporting element is merely a wall-mounted hook adapted to fit into a slot purposely formed on the head of the water dispensing element. 
     Such prior shower bath units have the important disadvantage that the protruding lugs of the fork element, or the hang-up hooks, for the dispensing element are potentially hazardous in that, owing to their stand-out configuration, it is quite easy to bump against them and get hurt. 
     Another disadvantage of conventional shower bath units is that they are often expensive to manufacture and, accordingly, uneconomical. 
     SUMMARY OF THE INVENTION 
     It is a primary object of this invention to remove the disadvantages affecting conventional shower bath units by providing a more functional such unit. 
     A further object of the invention is to provide a shower bath unit which is not liable to cause injury to the user by eliminating the hazard of protruding appendages. 
     It is another object of this invention to provide such a shower bath unit, which is simple to manufacture and hence economical. 
     An additional object of the invention is to provide such a shower bath unit which is easy to operate and can fit any type of supporting wall. 
     According to one aspect of the present invention, these and other objects, such as will be apparent hereinafter, are achieved by a water dispensing unit for shower baths and the like, comprising a water dispensing element and a holder element for supporting the dispensing element, said holder element being adapted for wall mounting, characterized in that rabbeted connection means are provided between said dispensing element and said holder element. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further features and advantages will be more apparent from the following detailed description of a water dispensing unit for shower baths and the like, according to the invention, as illustrated by way of example only in the accompanying drawings, where: 
     FIG. 1 is a partly sectional side view of the water dispensing unit, as comprising a first type of holder element; 
     FIG. 2 is a rear view of the unit of FIG. 1, wherein the holder element is shown in section; 
     FIG. 3 is a side and plan view of the holder element shown in FIGS. 1 and 2; 
     FIG. 4 shows a second holder element of the swivel type; 
     FIG. 5 is a front view of the holder element of FIG. 4; 
     FIG. 6 is a front view of the dispensing unit, with the holder element of FIG. 4; 
     FIG. 7 is a partly sectional side view of the shower bath unit, as incorporating the second type of holder element; and 
     FIG. 8 is a detail view of the holder element of FIG. 4, respectively in section, as viewed from above, and in perspective. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Making reference to the drawing figures, the water dispensing unit for shower baths and the like, according to this invention, comprises a water dispensing element or shower head 1 and a holder element or support 2, for mounting to a wall 3. The dispenser element 1 has a first face 4 and a second face 5, which are connected to each other through a lateral surface or portion 6 which, as visible from the drawing figures, circumferentially extends trasversely to said faces 4 and 5 and is formed with a groove or at least partially circumferential recess 7 which defines a grip formation functioning as the handle of the shower head 1. Since the handle of the dispensing element 1 is provided incorporated to it, differently from conventional shower bath units, there is no separate handle, so that the water supply hose 8 will be connected directly to the element 1. 
     On the face 4 of the water dispensing element 1, there are formed spray nozzle defining water outlet holes 9, while on the face 5 a shaped groove 10 is provided which extends from one edge of the face 5 to the diametrically opposite edge. Said groove 10 narrows gradually and parallel to its major dimension direction from the closest edge to the point of connection to the hose 8. Said groove gradually widens from the face 5 towards its bottom so as to define a trapezium in cross-section and constitutes a female member intended to cooperate with a male member 11a or 11b provided on the holder element 2, such as to produce a dovetail type of rabbeted connection. 
     In fact, as best visible in FIG. 2 (doted lines) and FIG. 6, the sidewalls of groove 10 are convergent in a first direction leading from the bottom of the groove and in a second direction extending longitudinally to the groove 10. 
     The holder element 2 may be variously configured. As an example, in FIGS. 1 or 3, it is implemented as a one-piece construction including a cylindrical portion 12 forming a base body and a truncated cone mating portion 11a which constitutes the male member of the rabbet and engages in the groove 10. 
     Also provided is a screw 13 for fastening the holder element 2 to a wall. 
     Another embodiment of the holder element 2 is shown in FIGS. 4-8. Here, the male member 11b comprises an elongate body whose sidewalls 14 (as shown more clearly in the sectional view of FIG. 8) include two mutually parallel portions 14a and two diverging portions 14b, the latter two portions cooperating with the groove 10. Again with reference to FIG. 8, the elongate body 11b is formed, at a lateral surface 15 thereof, with a threaded hole 16 through which the end of a rod 17 is threaded. The lateral surfaces 14, on the opposite side to that adjacent the surface 15, are interconnected by a curved surface 18 such that the inwardly projecting end of the elongate body 11b is made free of any sharp corners potentially hazardous for the user. 
     The rod 17 is connected, through a ball joint system 19, to a base body 20 for securing the holder element 2 to the wall 3. 
     As visible from the drawing figures in both embodiments the transversal dimentions of the mating portion 11a, 14b are smaller than the transversal dimentions of the groove at the first end portion thereof near the hose 8 but bigger than the transversal dimensions of the groove at the opposite end portion thereof. 
     The operation and utilization of the water dispensing unit for shower baths according to this invention is apparent from the foregoing description. In particular, it should be noted that in the embodiment shown in FIGS. 1-3, the holder element is stationary, and, to use the shower, the dispenser element 1 must be removed from the holder element 2, whereas in the embodiment shown in FIGS. 4-8 the dispenser element may be left engaged in the holder element 2 while in use, the swivel element enabling it to be positioned as desired. 
     In both cases, however, to release the connection between the dispenser element and holder element, it is necessary that the former be moved in a parallel direction to the major dimension direction of the groove, until the male member locates at the wider end of the groove, while, to place the dispenser element back into its home position the reverse operation must be performed, until the male member fits into the groove by virtue of the decreasing width of the latter. 
     It may be seen from the foregoing description that the invention fully achieves its objects. In fact, the shower bath unit is extremely functional, thanks to the handle being provided on the water dispensing element itself. 
     Furthermore, the shower bath unit of this invention is in no way hazardous, since any pointed projecting appendages have been effectively eliminated. Also, the water dispensing unit according to the invention is economical and simple to manufacture and use, and adaptable to any type of wall. 
     Lastly, it is important to observe that this water dispensing unit for shower baths is also advantageous in relation to its specific technical aspects as may be inferred from the specification and from the drawings, and as it will be apparent to those skilled in the art. 
     In practicing the invention, the materials, shapes, and dimensions may be any selected ones to meet individual requirements.

Summary:
The dispensing unit comprises a water dispensing element supported by a holder element adapted for wall mounting, between the water dispensing element and the holder element there being provided a dovetail connection system comprising a male element slidably engageable in a female member, the latter being defined by a shaped groove gradually narrowing in a parallel direction to its major dimension direction.