Valve apparatus

A valve apparatus comprises at least one valve device having a chamber, an inlet and an outlet. A moveable member in the chamber is arranged to displace a membrane such that the membrane is rolled against the wall of the chamber between a closing position at which the membrane covers the opening of the outlet and an opening position at which the opening of the outlet is uncovered. A flow passage is formed for a fluid to flow from the inlet to the outlet. The moveable member is provided with an entrainment member arranged to extend into and be displaced in the flow passage during at least a substantial part of the displacement of the membrane between closing and opening positions.

The present invention relates to a valve apparatus, comprising at least one 
valve device having a valve housing, which forms a chamber with a wall, an 
inlet to the chamber, and an outlet from the chamber, an elongated 
flexible membrane with two ends, one end of the membrane being attached to 
the valve housing, and a movable member situated in the chamber, the other 
end of the membrane being attached to said movable member. The movable 
member is arranged to displace the other end of the membrane back and 
fourth in the chamber, so that the membrane is rolled against the wall of 
the chamber between a closing position, at which the membrane covers the 
opening of the outlet in the chamber, and an opening position, at which 
the opening of the outlet in the chamber is uncovered. A flow passage is 
formed between the wall of the chamber and the movable member, for a fluid 
to flow from the inlet to the outlet, when the opening of the outlet is 
uncovered. 
A valve apparatus of this kind is known from for instance WO 82/01924. In 
the known valve apparatus the movable member has to be activated by means 
of a driving device of some kind for providing the movement of the 
membrane by the movable member between said closing and opening positions. 
Such a driving device consumes a certain amount of energy, which for each 
adjustment of the membrane has to be supplied to the driving device from a 
separate source of energy. 
The object of the present invention is to provide a valve apparatus of the 
kind discussed above, which for its operation only requires a relatively 
small energy supply from a separate source of energy. 
This object is obtained by means of a valve apparatus of the kind initially 
described, which mainly is characterized in that the movable member is 
provided with an entrainment member arranged to extend into and be 
displaced in said flow passage during at least a substantial part of the 
displacement of said other end of the membrane between said closing and 
opening positions. 
This results in the advantage that for the uncovering of the opening of the 
outlet in the chamber of the valve device, energy from a separate source 
of energy only needs to be supplied to the valve apparatus until the 
entrainment member is influenced by a fluid which starts streaming in said 
flow passage from the inlet to the outlet, as the membrane is displaced 
from said closing position, so that the opening of the outlet is partly 
uncovered. Under the influence of said fluid the entrainment member then 
entrains the movable member, so that the membrane is completely displaced 
to said opening position. 
Preferably, the entrainment member is arranged to be in said flow passage 
when the membrane just starts uncover the opening of the outlet during the 
displacement of said other end of the membrane, whereby the influence of 
the entrainment member on the movable member for entrainment of the latter 
can be utilized as soon as said fluid starts streaming through the flow 
passage. 
According to an embodiment of the valve apparatus according to the 
invention an electro-magnetic stepping motor is connected to the movable 
member for the displacement of said other end of the membrane. Further, a 
current source is connected to the electro-magnetic stepping motor and 
adapted to activate the latter to displace the membrane from said closing 
position, such that the membrane at least is displaced to the extent that 
it starts uncover the opening of the outlet in the chamber. 
Said current source advantageously comprises an electric accumulator, for 
instance a capacitor. In consequence the electro-magnetic stepping motor 
can be operated as a generator for charging the electric accumulator 
during the entrainment by the entrainment member. As a result, the energy 
for the operation of the valve apparatus substantially can be taken from 
the flow energy of said fluid, when this flows through said flow passage 
in the chamber, provided that before the membrane is displaced back from 
the opening position to the closing position, the flow has ceased in the 
flow passage in the chamber. 
The valve apparatus may for instance comprise one single valve device and 
be utilized for connection of a source of vacuum to a closed space, the 
source of vacuum being connected to the outlet of the valve device while 
the closed space is connected to the inlet of the valve device. The flow 
which in this case occurs in the flow passage, as the membrane is 
displaced to said opening position, ceases when vacuum prevails in said 
closed space. Then the membrane can be displaced without flow resistance 
back to said closing position. 
According to a further embodiment of the valve apparatus according to the 
invention, the valve apparatus comprises two valve devices, the outlet of 
one of the valve devices communicating with the chamber of the other valve 
device and the movable members of the valve devices being arranged to 
displace said other ends of the membranes, such that the outlet of said 
one valve device is closed when the outlet of said other valve device is 
opened and vice versa. Such a valve apparatus with two valve devices may 
be utilizes as a three way valve. 
Suitably, the movable members of said two-valve devices are connected to 
each other. In consequence, the advantage is obtained that under influence 
of flow of fluid the entrainment member of one of the valve devices also 
will entrain the moveable member of the other valve device, so that the 
latter displaces its membrane towards closed position, and vice versa. 
Thus, this valve apparatus could be designed totally self-running, i.e. 
energy enough from a source of pressure connected to the valve apparatus 
could be transformed to the electric energy required for total operation 
of the valve apparatus.

The valve apparatus 1 shown in FIGS. 1-6 comprises a valve device 2 having 
a valve housing 3, which forms a chamber 4 with circular cross-section. 
The chamber 4 has an inlet 5 and an outlet 6, which is situated in front 
of the inlet 5. (However, it is not necessary that the inlet 5 and the 
outlet 6 are situated in front of each other). A circular cylindrical body 
7 is by means of a shaft 8 pivotally arranged in the chamber 4 coaxially 
with the latter. An elongated flexible membrane 9, the breadth of which 
has the same extension (alternatively less extension) as the axial 
extension of the body 7, has one of its ends attached to the valve housing 
3 and its other end attached to the body 7. The membrane 9 is bent 
180.degree., so that a part of the membrane 9 abuts against the mantle 
surface of the body 7, whereas another part of the membrane abuts against 
the circular wall surface of the chamber 4. By turning the body 7 back and 
forth 90.degree. the end of the membrane 9, which is attached to the body 
7, is displaced so that the membrane is rolled against the wall of the 
chamber 4 between a closing position, at which the membrane 9 covers the 
opening of the outlet 6 in the chamber 4 (FIG. 6), and an opening 
position, at which the opening of the outlet 6 in the chamber 4 is 
uncovered (FIG. 4). At said opening and closing positions the body 7 abuts 
against shoulders on the valve housing (not shown in the drawings), which 
prevent further turning of the body 7. 
The pivoted body 7 is provided with an entrainment member in the form of a 
wing 10 having the same axial extension as that of the body 7 and 
extending radially outwards from the body 7 to the close proximity of the 
circular wall surface of the chamber 4. The wing 10 is oriented on the 
body 7, so that it at said closing position is right between the inlet 5 
and the outlet 6 in the flow passage formed between the mantle surface of 
the body 7 and the circular wall surface of the valve housing 3 (FIG. 6), 
and at said opening position substantially has passed the opening of the 
outlet 6 in the chamber 4 (FIG. 4). 
The shaft 8 has an end portion 11 extending into a chamber 12 of the valve 
apparatus 1. The end portion 11 is connected to a permanent magnet 13, 
which constitutes a rotor of an electro-magnetic stepping motor 14 
arranged in the chamber 12. The stepping motor 14 is connected to a 
control means 15, which in turn is connected to a rechargeable battery 16 
and a capacitor 17. 
The valve apparatus 1 functions in the following way: 
The outlet 6 is connected to a source of vacuum (not shown) while the inlet 
5 is connected to a closed space (now shown) to be evacuated of air. 
Initially the valve apparatus 1 is at a closed position, as shown in FIGS. 
2b, 5 and 6. To adjust the valve apparatus to the opening position shown 
in FIGS. 2a, 3 and 4, the control means 15 first charges the capacitor 17 
with energy from the battery 16. Then the control means 15 activates the 
stepping motor 14 with a pulse of current from the capacitor 17, so that 
the rotor 13 is turned clockwise towards the position shown in FIG. 3. The 
turning of the rotor 13 also results in that the body 7 is turned 
clockwise by means of the shaft 8. In consequence, the membrane 9 is 
rolled off successively from the circular wall surface of the chamber 4. 
When the membrane 9 starts uncover the opening of the outlet in the 
chamber 4, air from said closed space starts streaming through the inlet 5 
in the chamber 4 towards the outlet 6. The air flow in the chamber 4 
forces the wing 10 against the outlet 6, whereby the wing 10 entrains the 
body 7 to the opening position shown in FIG. 4. During the entrainment of 
the body 7 by the wing 10 the stepping motor 14 acts like a generator, the 
control means charging the capacitor 17 with electric energy generated by 
the stepping motor 14. 
When said closed space has been evacuated of air the air flow through the 
chamber 4 ceases, and the valve apparatus 1 can be adjusted back to the 
closing position shown in FIG. 2b, 5 and 6 by activating the stepping 
motor 14 by the control means 15 with a pulse of current from the 
capacitor 17, so that the rotor 13 and the body 7 are turned 
anti-clockwise a quarter of a revolution back to the closing position 
shown in FIGS. 2b, 5 and 6. After the adjustment of the valve apparatus 1 
to this closing position the capacitor 17 may still have a certain amount 
of energy left, which means that only a relatively small amount of energy 
needs to be transferred from the battery 16 to the capacitor 17 at next 
adjustment of the valve apparatus 1 to the opening position according to 
FIGS. 2a, 3 and 4. In certain applications it may occur that the capacitor 
17 receives so much electric energy generated by the stepping motor 14 
that the capacitor 17 can charge the battery 16, whereby the valve 
apparatus 1 will be selfrunning after an initial adjustment to opening 
position. 
The valve apparatus 18 shown in FIGS. 71.varies.14 consists of a valve 
apparatus 1 according to FIGS. 1-6, which is provided with a further valve 
device 19. This is formed analogous to the valve device 2 and thus has a 
chamber 20 with an inlet 21 and an outlet 22, a body 23, which is 
pivotally arranged in the chamber 20, a membrane 24, and a wing 25 on the 
body 23. The shaft 8 is extended by a shaft portion 26, to which the body 
23 is attached. The bodies 7 and 23 are oriented relative to each other so 
that the valve device 2 is closed (FIG. 1) when the valve device 19 is 
open (FIG. 11), and vice versa. The outlet 6 of the valve device 2 
communicates with the chamber 20 of the valve device 19. 
The valve apparatus 18 may be utilized as a three way valve in the 
following manner: 
The inlet 5 is connected to atmosphere and the outlet 21 is connected to a 
source of vacuum (not shown), while the inlet 22 is connected to a closed 
space (not shown), in which atmospheric pressure and vacuum are to prevail 
alternately. In the positions of the bodies 7 and 23 shown in FIGS. 7-11 
said closed space communicates with the source of vacuum, since the outlet 
6 is closed while the outlet 21 to the source of vacuum is open. In order 
to adjust the valve apparatus 18 to the position of the bodies 7 and 23 
shown in FIGS. 8b, 12-13, so that said space communicates with atmosphere, 
the control means 15 activates the stepping motor 14 in the same manner as 
described above in connection with the function of the valve apparatus 1. 
As a result, the body 7 is entrained by the wing 10 to the position shown 
in FIG. 13. Simultaneously the body 23 is turned by the shoulder portion 
26 to the position shown in FIG. 14. With the bodies 7 and 23 in the last 
mentioned positions said closed space thus communicates with atmosphere, 
since the outlet 21 is closed while the outlet 6 to atmosphere is open. 
During the adjustment of the valve apparatus 18 back to the positions of 
the bodies 7 and 23 shown in FIGS. 8a, 9-11, it is the body 23 which is 
entrained by the wing 25, whereby the body 7 simultaneously is turned by 
means of the shaft 8. As a result the capacitor 17 is always charged 
during each adjustment of the valve apparatus 18. Thus, this will be 
totally self-supporting of the required electric energy. 
The embodiments of the valve apparatus according to the invention shown in 
the drawings have movable members in the form of pivoted circular 
cylindrical bodies. However, as an alternative each movable member of a 
valve apparatus according to the invention may be arranged reciprocatingly 
.