GB2359122A

GB2359122A - Electrically-operated pneumatic valve

Info

Publication number: GB2359122A
Application number: GB9930080A
Authority: GB
Inventors: Robert Harrison; Michael Sturmey; Graham Rogers
Original assignee: CRYDOM MAGNETICS Ltd
Current assignee: CRYDOM MAGNETICS Ltd
Priority date: 1999-12-20
Filing date: 1999-12-20
Publication date: 2001-08-15
Also published as: GB9930080D0

Abstract

An electrically-operated pneumatic valve 5 comprises a body 10 which contains an air passage 12 with an inlet inside the body and an outlet outside the body, in which the air passage 12 contains a fixed metal tube 22. The body 10 contains a movable magnet 20. Outside of the body 10 is substantially covered by a set of electrical coils (24, figure 1b). When no electrical current flows the magnet 20 is held against the metal tube 22 blocking the air passage 12 and when current flows the magnet 20 is moved away from the tube 20 such that the tube 20 is unblocked and air can flow through the air passage 12. In use air flows in through branch passages 13 and out through projection 14 to the top of a liquid chamber (29, figure 2) liquid to drain from outlet (32). Liquid cannot drain from outlet (32) when the valve 5 is closed. Coils (24) may filter the air flowing through the valve.

Description

An Electrically-onerated Pneumatic Valve 2359122 The present invention

relates to an electricallyoperated pneumatic valve.

Valves, especially pneumatic valves are well known as means of controlling the pressure or flow ofair within a system. In previously proposed systems these valves have been used to control the flow of fluid from a chamber. Such a valve when open admits air to the top of the chamber allowing fluid to flow from an orifice in the bottom of the chamber. When the valve is closed the flow of fluid from the chamber is prevented. Systems incorporating such valves are preferably portable and battery operated. Such previous systems have disadvantages in that the size of the valve has been considerable therefore adding to the weight of the system. Furthermore, large valves require more power to operate them. Furthermore, such systems also have the problem that air flowing into the top of the chamber can carry contaminants and damage the quality of the fluid contained therein.

It is an aim of the present invention to address these disadvantages.

Accordingly the present invention is directed to an electrical lyoperated pneumatic valve comprising a body which contains an air passage with an inlet inside the body and an outlet outside the body, in which the air passage contains a fixed metal tube, the body further contains a movable magnet, and the outside of the body is substantially covered by a set of electrical coils which are connectable to an electrical supply source, such that 2 when no electrical current flows the magnet is held against the metal tube blocking the air passage and when current flows the magnet is moved away from the tube such that the tube is unblocked and air can flow through the air passage.

This provides the advantage that the valve remains shut unless electrically operated upon. Furthermore the electrical windings act as a filter for the air flowing through the system. This results in the removal of the filter component from such a system. Furthermore it allows the miniaturisation of the device due to the small size of the components necessary.

Preferably the mass of the moveable magnet is such that the magnitude of the gravitational force acting on it is substantially less than the magnitude of the magnetic force. This provides the further advantage that the operating characteristics of the valve are then relatively insensitive to mounting orientation.

An example of the present invention will now be explained in more detail with reference to the accompanying drawings in which:

Figure 1 shows a valve made in accordance with the present invention in side view, side sectional view and cross-section; and Figure 2 shows a schematic side view of operating a liquid containing chamber the valve In Figure 1 shows a valve 5, which has a cylindrical shape. From the sectional view in Figure la it can be seen that the valve 5 has a body 10 made of a non 3 - magnetic material such as plastics. The body 10 has an air passage 12, which protrudes from one end to provide an outlet. The air passage 12 has projections 14 at its outlet end for securing to the device with which it is used. The body 10 has two collars 16a and 16b, which project perpendicularly from the air passage 12. The air passage 12 passes through the collar 16a. The collar 16b furthest away from the outlet end of air passage 12 has coil pins 18 projecting through it for connection to an outside electrical system. At the collar 16b the air passage 12 is split such that a T-shape is created with the collar 16b providing one wall of the side air passages 13. A moveable magnet 20 is provided at the top of the T with a seal 28. A metal tube 22 is contained within the air passage 12. As shown more clearly in the side view in Figure 1b electrical coil windings 24 are tightly wound around the outside of the body 12, between the two collars 16a and 16b, such that they cover the whole area between the two collars 16a and 16b and the entrances of the side air passages 13. Figure ic shows a cross section of the valve 5 along the line XX in the Figure la. As can be seen the side air passages 13 in fact have four branches when viewed in cross section; this Figure also shows side supports 26 of the body 10 which run between the two collars 16a and 16b to support the coils 24.

The valve 5 operates as follows: when no electrical current is passing through the windings the magnet 20 is held against the seal 28 on the metal tube 22. When the coils 24 are energised the magnet 20 is moved away from the metal tube 22 and the flow of air is allowed through the air passage 12. As can be seen clearly in Figure lb air flows in through the coils 24 which act as a filter 4 - for the air by being so close together. This shows clearly the advantage of not needing an extra filter section for the valve 5. Air can then f low out of the air passage 12 to the attached system. Figure 2 shows clearly how the valve 10 is used. In Figure 2a the valve 5 is closed and is attached to a chamber 29, which contains liquid 30 and has a bottom outlet 32. When the valve 5 is open as shown in Figure 2b the air is allowed to flow into the top of the chamber 28 and the fluid 30 flows out through the outlet 32.

Claims

Claims:
2.

body whic inside the which the Accordingly the present invention is directed to an electrically-operated pneumatic valve comprising a contains an air passage with an inlet body and an outlet outside the body, in air passage contains a fixed metal tube, the body further contains a movable magnet, and the outside of the body is substantially covered by a set of electrical coils which are connectable to an electrical supply source, such that when no electrical current flows the magnet is held against the metal tube blocking the air passage and when current flows the magnet is moved away from the tube such that the tube is unblocked and air can flow through the air passage.

An electrically-operated pneumatic valve according to claim 1, in which the mass of the moveable magnet is such that the magnitude of the gravitational force acting on it is substantially less than the magnitude of the magnetic force.

An electrically-operated pneumatic valve substantially as described herein with reference to the accompanying drawings.

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