A multi-port valve mechanism for fluids, especially compressed air, comprises a cylindrical (ring-like) housing. A motor drives a shaft centered in the housing which is rotatably supported by the housing walls. The shaft carries an arm having one, or two, rollers which pinch close a flexible and resilient elongated tube, which tube is secured to the inside wall of the housing. A series of port orifices are aligned and spaced along the tube; so that an inlet port is connected to outlet ports, one after the other, in sequence, as the pinch roller is moved along the tube by the arm.

FIELD OF THE INVENTION 
The present invention relates to fluid valves and more particularly to 
mechanically operated air valves with multi-outlet ports. 
BACKGROUND OF THE INVENTION 
There is a need in certain industrial and medical fields for a valve system 
for fluids, specially air, in which a fluid under pressure is supplied to 
a plurality of ports in a selected sequence. Although the embodiment 
described below is a valve system for compressed air in the range of 1-20 
pounds per square inch (psi) it is applicable to air at other pressures, 
to other gases and to liquids, i.e., to all fluids. For example, a 
sequence of valves is operated in a multi-port valve system as follows: a 
valve is opened and air pressure is supplied to outlet port 1, after 10 
seconds, a second valve is opened and air pressure is supplied to outlet 
port 2, and so on until air is supplied, in timed sequence, to all of the 
outlet ports. In this example, the air pressure is relatively constant, 
the valves are operated so that the air is supplied to the outlet ports in 
a fixed and timed sequence and each valve is opened at a selected time. 
It is possible to construct a suitable multi-port valve system which opens 
each port in sequence using electrically controlled fluid valves, for 
example, a system using a solenoid fluid valve at each outlet port. 
However, such electrically controlled valves may be expensive, complex and 
may fail, especially in a dusty or humid environment. They should not be 
used if the fluid is a gas which may leak and explode. If there are many 
outlet ports, for example, 50-100, the cost and complexity of control of 
solenoid valves presents a detriment to the practical use of devices 
employing such valve systems. 
One use of multi-ports which are supplied with air, in sequence, is in 
connection with the inflation of sets of balloon cuffs (inflatable 
circumferential tubes). Generally the cuffs surround a limb of a person 
and are inflated, in timed sequence, starting from the cuff furthest from 
the trunk. The inflation sequence, in effect, acts as a parastaltic pump 
and moves blood toward the trunk. That type of device has been used 
following surgical procedures to move the blood in the legs of 
hospitalized patients, as an aid for patients with angina, and as a blood 
exercise system. 
In Apstein U.S. Pat. No. 3,811,431 entitled "Programmed Venous Assist 
Pump", at FIGS. 2-4D, a multi-port valve is connected to a set of 
inflatable cuffs. The valve has a motor-driven cylindrical rotor having 
flats (channels) which connect different ports in the housing as the rotor 
is turned. 
In Rosett U.S. Pat. No. 1,608,239 entitled "Therapeutic Device", at FIGS. 
2-4, a multi-port distributing valve mechanism is connected to inflatable 
circumferential tubes (cuffs). The valve mechanism has a motor driven 
rotor with grooves which connects an inlet port, having compressed air, in 
sequence, to outlet ports connected to the cuffs. Each cuff is inflated 
and deflated in sequence. 
In Bullard U.S. Pat. No. 4,865,020 entitled "Apparatus And Method For 
Movement Of Blood By External Pressure", each cuff is connected to an 
individual valve, shown in FIGS. 7A-7B. In each valve a piston is slid 
within a housing to open and close ports. 
Bullard Patent Application PCT/US91/03021 (WO 92/19206) entitled "Apparatus 
And Method For Movement Of Blood", FIG. 10, shows a multi-port valve in 
which a motor-driven flat rotor rotates in a cylindrical housing to 
connect outlet ports, in sequence, to a supply of compressed air. 
Weinberg U.S. Pat. No. 2,781,041 shows a valve device for sequential 
inflation of bladders (cuffs), with the inflated bladders being held 
inflated. 
The patents cited above are incorporated by reference herein. 
SUMMARY OF THE INVENTION 
A multi-port valve mechanism includes a motor having an output shaft, such 
as a step motor, and an arm carried by the motor output shaft. The arm has 
a free end with a pair of rollers. The rollers act to pinch an elongated, 
flexible and resilient tube against the inside wall of a cylindrical 
housing. The pinching of the tube by the rollers acts as a closing valve 
which is moved along the length of the tube. 
An entry port, connected to a source of compressed air, leads to one end of 
the tube and a series of outlet ports, each connected to an inflatable 
cuff, are connected to the tube along its length. As the rollers move 
along the tube, first the inlet port is opened to the tube and then, in 
sequence, each of the outlet ports is opened (connected) to the inlet port 
through the tube. 
Preferably at the moment the roller has passed the inlet port, the outlet 
ports are first connected to atmosphere (to release the pressurized air) 
and then closed to atmosphere and connected to the series of cuffs 
(balloons) (to inflate the cuffs in sequence).

DETAILED DESCRIPTION OF THE INVENTION 
FIG. 1 shows a single multi-port valve mechanism and FIGS. 3 and 4 show a 
gang of such valve mechanisms side-by-side in a unitary housing. 
As shown in FIG. 1, the single multi-port valve 10 has a cylindrical casing 
11, which is ring-like (circular) in cross-section. The casing may have 
end walls (not shown) to enclose the valve mechanism. The casing 11 is of 
a suitable material, such as brass or aluminum, or formed of an 
engineering plastic. 
The casing 11 has a series of ports 20-30. The ports 20-30 may have formed 
integrally with the casing 11, as in FIGS. 3 and 4, which is preferred 
when the casing 11 is injection-molded. Alternatively, as shown in FIG. 2, 
the ports may be separate members. As shown in FIG. 2, each port comprises 
a bushing 12 having an exterior outer hose connector 15 with V-shaped 
grooves adapted to receive a flexible hose 14 thereon. Each bushing 12 
also has an exterior screw thread which is screwed into a screw thread in 
a through-hole 17 of the casing 11. A flexible hose 14 is connected on the 
hose connector 15. 
A source of air pressure 16, preferably an air pump and tank, is connected 
to a hose 14A leading to the inlet port 20. Preferably the air is at 1-20 
pounds per square inch above atmospheric pressure (1-20 psi or 70.3-1406 
gms/sq cm) and most preferably 5-10 psi (351.5-703 gns/sq cm). 
The air enters through the orifice of the inlet port into an elongated, 
flexible and resilient tube 31. The tube is of a suitable rubber or an 
elastomer plastic. The tube 31 is hollow and has a series of orifices 32 
and an air-tight coupling at each of its orifices which couples the 
orifice to a port 20-30, see FIG. 2. 
The outlet ports 21-30 are of the same construction as the port structure 
shown in FIG. 2, or alternatively the port structure shown in FIGS. 3 and 
4. 
Each outlet port 21-30 is connected to an outlet hose. For example, the 
hoses may be connected to a supply of pressurized air to inflate a series 
of cuffs (balloons) positioned about a subject's limbs. Each cuff also has 
an outlet hose which is connected to a single solenoid-operated valve. 
When that valve is opened the air pressure is simultaneously released from 
all the cuffs. Alternatively, the cuffs' outlet hoses may be connected to 
a multi-port valve mechanism of the type shown in FIGS. 1, 3 and 4, in 
which the "inlet port" is open to atmosphere and the outlet ports are 
connected, in sequence, to atmosphere through the tube and inlet port. 
Such a multi-port valve permits the cuffs to be deflated in a selected and 
timed sequence. 
A rotatable shaft 40 is positioned at the center of the casing 11. The 
shaft is rotated in one direction (clockwise in FIG. 1) by a motor. For 
example, the motor may be an AC or DC motor which slowly rotates the shaft 
40 through a gear box (transmission), a computer controlled step motor, an 
air motor or a hydraulic motor. An arm 42 is fixed to the shaft and 
rotates with it. The arm 42, at its outer end (free end) carries a tube 
pinch means, preferably a pair of rollers. Specifically arm 42 carries two 
rollers 43, 44 which pinch tube 31 against the casing 11 in an air-tight 
fashion. The pinch action of the rollers 43, 44 acts as a pinch valve 
closure which is rotated along the inner surface of the casing 11. The 
outlet ports 21-30 are connected, in a selected timed sequence, to the 
inlet port 20. Generally, but not necessarily, the shaft would be rotated 
uniformly so that the sequence is evenly timed. For example, outlet port 
21 is connected to inlet port 20 and each port 22-30 is also connected, in 
sequence, each after 10 seconds, to the inlet port 20. 
In the embodiment of FIGS. 3 and 4, a series of five tubes 50-54 are 
positioned on the inside wall of a cylindrical casing 11A (housing) having 
end walls. A motor 41 is connected to the housing 55 by bolts 56. For 
example, motor 41 may be a step motor which is controlled from a simple 
and low-cost computer or timer. The motor 41 has an output shaft which is 
fixed to shaft 40A which is rotatable within bearings 58A, 58B at the 
opposite end walls of the housing 55. 
The shaft carries a flat paddle arm 59 and a series of pinch rollers 60A, 
60B-64A, 64B which are rotatably mounted on the outer end of the paddle 
arm 59. The pinch rollers 60A, 60B pinch and close tube 50 against the 
inner cylindrical wall of the housing 55. Similarly, each of the tubes 
51-54 is pinched and closed by its respective pinch rollers, 62A, 62B-64A, 
65B respectively. The roller 65 operates button 66 of switch 67 which is 
used for timing. 
In the embodiment of FIGS. 3 and 4, as in the embodiment of FIG. 1, each of 
the tubes 50-54 is connected, in an airtight seal, with an inlet port 
leading, via a hose, to a source of compressed air, and a series of outlet 
ports, each leading, via a hose, to an inflatable cuff. 
Modifications may be made to the above-described embodiments of the present 
invention within the scope of the sub-joined claims. For example: (1) the 
housing may be flat and the arm and its pinch roller may be carried by a 
rack which is moved along the top of the tube by a motor-driven pinion 
gear; (2) the tube may be positioned on the outer wall of a cylindrical 
housing and the roller moved along the outer face of the tube by a 
U-shaped arm carried by a motor-driven shaft which is centered in the 
housing; (3) the shaft may be rotated at different and selected speeds 
between each port so that the ports are opened with different time periods 
between each port opening, although the ports are evenly spaced; (4) the 
ports are unequally spaced along the tube so that the ports are opened 
with different time periods between such port openings, although the shaft 
is rotated at a constant speed; (5) the casing is provided with two tubes 
arranged end to end with, for example, 5 ports connected to the first tube 
and 5 ports connected to the second tube. In this example the first 5 
ports may be used to inflate 4 cuffs and the second 5 ports may be used to 
deflate the same 4 cuffs or the first 5 ports may be used to inflate a 
first set of 4 cuffs and the second 5 ports may be used to inflate a 
second set of 5 cuffs; (6) the inlet ports of a gang of values are 
supplied with air pressure at different pressures; for example, in the 
embodiment of FIGS. 3 and 4 the five inlet ports are supplied with air at 
2, 4, 6, 8 and 10 lbs/sq.in., respectively, and each of the air lines to 
those inlet ports has a solenoid-operated valve.