Multiple valve with automatic sequential operation
INTRODUCTION 
     This invention has for an object to provide a multiple valve with automatic sequential operation. One field of application of such a valve, given by way of example, is that of irrigation systems and especially of irrigation systems for gardens where the available quantity of water is not sufficient for simultaneous operation of all irrigators, or more than one, and therefore it is necessary to provide for a sequential operation of same, that is to say, to make the irrigators operate singly or in groups. 
     Such a sequential operation of a plurality of irrigators, either singly or in groups, is obtained, prior to this invention, with expensive electronic control apparatus or with clock-mechanisms. The multiple valve according to the present invention solves the problem of sequential operation of irrigators in a simple and functionally safe manner, with much less expense than the known control apparatus. 
     Besides the control of irrigators, the multiple valve according to this invention can be employed also in other fields of application, as for instance machine tools, which must perform several operations, one after the other. 
     The embodiment of the invention, as hereafter described and as shown in the annexed drawings, refers to a multiple valve for sequential operation of six irrigators. It can be connected to one feeding duct and to six irrigators. 
    
    
     DESIGNATION OF FIGURES 
     FIG. 1 shows the multiple valve in longitudinal section, in a starting position; 
     FIG. 2 is a similar view at the end of a downward stroke of the control piston; 
     FIG. 3 is a similar view with the valve in an intermediate position during the operation of the first irrigator; 
     FIGS. 4 to 9A show details of separate parts of the valve, each &#34;A&#34; figure being a sectional view of the part of which a face is shown in the adjacent view; and FIG. 5 being a developed view. 
    
    
     GENERAL DESCRIPTION 
     The illustrated valve is composed of the following parts: 
     A = connector head for six irrigators (FIGS. 9 and 9A); 
     B = upper selection disc (FIGS. 8 and 8A); 
     C = piston (FIGS. 4 and 4A) with control groove Ca (FIG. 5); 
     D = lower selection disc (FIGS. 7 and 7A); 
     E = regulator head (FIGS. 6 and 6A); 
     F = guide pin running in the control groove Ca of the piston C; 
     G = throttling screws forming bleed valves; 
     K = spring for the piston C; 
     L = spring for the shaft of the cycle-control valve; 
     M = valve closure of a cycle-control valve; 
     N = guiding tube for the shaft of the cycle-control valve; 
     O = external tube; 
     P = guide rods for the piston. 
     The connector head (FIG. 9) has six openings 2 1  to 2 6 , to which the feeding tubes (not shown) of six irrigators can be connected, and which are to be operated, one after the other, for separately adjustable times, by means of the multiple valve with automatic sequential operation according to the invention. 
     In the middle of the head A there is the opening 1 for the water supply tube (not shown). 
     Beginning from the position shown in FIG. 1 as the starting position, the pressure of the water entering through opening 1 acts on the surface H of the piston C; and thus the piston C (together with its closed control valve M) is pushed downwards to the position shown in FIG. 2, since the force which acts on the piston surface H and on the valve head M is greater than the forces of the springs K and L. During this movement, water keeps the expanding chamber 3 filled, and flows through the hole 7 of the upper selection disc B, and through the first connector opening 2 1  of head A, since these two openings are aligned in the rest position of the multiple valve. It would, however, be possible to set the opening 7 initially for any other of the openings 2 1  to 2 6 . The speed of the downward movement of the piston C together with the valve closure M from the rest position of FIG. 1 towards the position of FIG. 2, and therefore the duration of the operation of the irrigator connected to opening 2 1 , depends from the exit of the medium (initially air or usually water) from chamber 4. This exit takes place through the single selector opening 5 in the disc D (FIG. 7) and through the hole 6 (FIG. 6) and the adjustable throttle G 1  of regulator head E (FIG. 6A) forming a bleed valve for the chamber 4. 
     Nearly at the end of the downward movement of piston C, a sloping surface S of groove Ca engages guide pin F to nudge the piston C angularly, so that when the piston reverses, guide pin F will follow a sloping part of groove Ca. 
     At the end of this downward movement of the piston C together with the valve closure M, the shaft Ma of the cycle-control valve is stopped by the middle dead hole Da of the disc D (FIG. 7) and as a consequence the valve closure M is lifted slightly from the seat I (FIG. 4) on the piston, and now the water can enter from chamber 3 into the chamber 4. When the pressure in the chamber 4 approaches the pressure in chamber 3, then the spring L pushes the cycle-control valve M upwards so that it will not close until piston C reaches the end of its return or upward stroke (FIG. 3). At the same time the spring K begins to push the piston C upwards and during this upward movement, the piston is made to rotate about its axis, by an indexing means which comprises the guide pin F running in a sloping leg T of the guide groove Ca in the outer piston wall. The piston completes an angular movement through an angle which corresponds to the angular distance between the openings 2 1  and 2 2 . When the piston has reached its upper position, the cycle-control valve M closes again against the seat I on the piston and a new cycle, like that described, can begin, but now the irrigator which is connected to opening 2 2  is operated, since the whole unit consisting of the piston C and the discs B and D, has been rotated through an angle from 2 1  to 2 2 . 
     The angular movement of the piston due to the guide pin F running in the groove Ca of the piston is transmitted to the discs B and D through the guide rods P of the piston, so that the opening 7 of the disc B is now aligned with opening 2 2  of head A, while the opening 5 of disc D is now aligned with hole 6 2  for throttle G 2  of disc E. The disc B along with the head A form a sequencing valve for determining which outlet opening 2 is placed in communication with inlet 1. Similarly the disc D along with regulator head E form a sequencing valve for determining which of the bleed valves G is placed in communication with the chamber 4. 
     The throttles G 1  to G 6  can be adjusted for equal or different durations of the cycles they control, so that the duration of operation of the irrigators which are connected to the opening 2 1  to 2 6  may be equal or different.