MODULAR MAGNETIC ASSEMBLY

Abstract

A magnetic filter (10) for a central heating system comprises a filter body (12) and an external magnetic assembly (18). The magnetic assembly is in the form of a belt which is made up of multiple modules. The modules may be identical to each other. The number of modules in the belt can be selected according to the size of the filter body, allowing various different sizes of filter to be produced from a small number of different parts. The filter body may be the body of an air-and-dirt separator, so that an existing air-and-dirt separator can be upgraded to include a magnetic capturing capability.

Claims

1. A modular magnetic belt assembly for fitting around the external surface of a filter housing, the magnetic belt assembly comprising: a plurality of modules, each module including a housing and at least one magnet, the modules being connected to each other to form the belt and each module being hinged to its adjacent modules, a means of joining the ends of the magnetic belt to each other to form an endless loop for fitting around the external surface of the filter housing, the magnet of each module being movable relative to the module housing and within the module housing between an in-use position for the magnet to contact the external surface of the filter housing, and an out-of-use position for holding the magnet in a position spaced from the external surface of the filter housing, when the magnetic belt assembly is fitted around the external surface of the filter housing.

2. The modular magnetic belt assembly of claim 1, in which each module is hinged to its adjacent modules by means of a hinged connection, the hinged connection between modules being in the form of a pin and a sleeve.

3. The modular magnetic belt assembly of claim 1, in which each module is hinged to its adjacent modules by means of a hinged connection, the hinged connection between modules including a strip of flexible webbing between modules.

4. The modular magnetic belt assembly of claim 3, in which the joining means includes adjustable tightening means.

5. The modular magnetic belt assembly of claim 4, in which the joining means are incorporated into the modules, the modules at the ends of the belt being joined directly to each other.

6. The modular magnetic belt assembly of claim 1, in which a mechanism is provided for moving the magnet of each module, the mechanism providing a mechanical advantage of greater than one at least when moving the magnet from the in-use position to the out-of-use position.

7. The modular magnetic belt assembly of claim 6, in which the mechanism includes a screw thread.

8. The modular magnetic belt assembly of claim 6, in which the mechanism is manually operable with an operating handle.

9. The modular magnetic belt assembly of claim 1, in which two magnets are provided in each module, the magnets each being mounted to a ferromagnetic carrier.

10. The modular magnetic belt assembly of claim 9, in which the north pole of one magnet faces the filter housing in use, and the south pole of the other magnet faces the filter housing in use.

11. The modular magnetic belt assembly of claim 10, in which modules of a first type and modules of a second type are provided, the modules of the second type having the magnets positioned with reverse polarity relative to the modules of the first type.

12. The modular magnetic belt assembly of claim 11, in which modules of the first type and modules of the second type are disposed alternately along the length of the assembled belt.

13-14. (canceled)

15. A magnetic filter for a central heating system comprising: a modular magnetic belt assembly having a plurality of modules, each module including a housing and at least one magnet, the modules being connected to each other to form the belt and each module being hinged to its adjacent modules, a means of joining the ends of the magnetic belt to each other to form an endless loop for fitting around the external surface of the filter housing, the magnet of each module being movable relative to the module housing and within the module housing between an in-use position for the magnet to contact the external surface of the filter housing, and an out-of-use position for holding the magnet in a position spaced from the external surface of the filter housing, when the magnetic belt assembly is fitted around the external surface of the filter housing; and a filter housing, in which the magnetic belt assembly is disposed around the filter housing, the magnets of each module being in contact with an external surface of the filter housing in an in-use position and being spaced from the external surface of the filter housing in an out-of-use position.

16. (canceled)

17. The magnetic filter of claim 15, in which the filter housing is substantially in the form of a cylindrical pipe.

18. (canceled)

19. The magnetic filter of claim 15, in which the filter housing is a body of an air-and-dirt separator.

20. A method of making a magnetic filter having a filter housing for connection into a central heating system circuit, and an external magnetic assembly, the method comprising the steps of: assembling a modular magnetic belt from a plurality of modules, each module having a module housing and a magnet, the magnet of each module being movable relative the module housing and within the module housing between an in-use position for the magnet to contact the external surface of the filter housing, and an out-of-use position for holding the magnet in a position spaced from the external surface of the filter housing, the modules of the belt being connected to each other and each module being hinged to its adjacent modules, the number of modules in the belt being selected according to a length of a path around an external surface of the filter housing; wrapping the magnetic belt around an external surface of the filter housing; and joining the ends of the belt to each other to form an endless loop which is fixed in place around the external surface of the filter housing.

21. The method of making a magnetic filter of claim 20, in which the joining means includes adjustable tightening means, and the step of joining the ends of the belt to each other includes tightening the belt around the filter housing to retain the belt in place around the filter housing.

22. The method of making a magnetic filter of claim 20, in which the belt is assembled from the modules of a first type and the modules of a second type, the modules of the second type having magnets positioned with their polarity reversed relative to the modules of the first type, and where the belt is assembled with modules of the first type alternating with modules of the second type along the length of the belt.

23. The method of making a magnetic filter of claim 22, in which the filter housing is a body of an air-and-dirt separator.

24. The method of making a magnetic filter of claim 23, in which the air-and-dirt separator is already fitted to the heating system before being upgraded to include a magnetic filtration capability according to the steps of the method.

Description

DESCRIPTION OF THE DRAWINGS

[0022] For a better understanding of the present invention and to show more clearly how it may be carried into effect, example embodiments will now be described with reference to the accompanying drawings, in which:

[0023] FIG. 1 is a perspective view of a magnetic filter including a modular magnetic belt according to the invention;

[0024] FIG. 2 is a cross section of a module, part of the magnetic belt in the filter of FIG. 1;

[0025] FIG. 3 is a perspective view of several of the modules of FIG. 2, detached from each other;

[0026] FIG. 4 shows a perspective view from another angle of the modules of FIG. 3, attached to each other; and

[0027] FIG. 5 shows an alternative embodiment of a magnetic filter, in the form of an air and dirt separator fitted with a modular magnetic belt according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENT

[0028] Referring firstly to FIG. 1, a magnetic filter for a central heating system is indicated generally at 10. The magnetic filter comprises a filter body 12, which is in the form of a substantially cylindrical section of stainless steel pipe. Inlet and outlet ports 14, 16 are provided for connection into a central heating system circuit. Flanges surround the inlet and outlet ports 14, 16, for fixing the magnetic filter 10 to similar flanges on central heating system pipework. The magnetic filter 10 may be produced in various different sizes, for fitting to central heating system pipework having a diameter from around 2 inches (50 mm) upwards.

[0029] This particular embodiment does not include any valves or a drain port, but these can be interposed between the filter body 12 and the central heating system pipework, using off-the-shelf valve and drain components.

[0030] This embodiment is designed for fixing to 2 inch (50 mm) pipework, the bore diameter at the inlet and outlet 14, 16 is therefore nominally 2 inches/50 mm. However, a major extent of the filter body 12 has an enlarged diameter, for example of 3 inches/75 mm. This allows for magnetic debris to be attracted and retained against the internal walls of the filter body 12, without causing a restriction in the central heating system circuit.

[0031] Modular magnetic belts 18 are wrapped around the filter body 12. In this embodiment, four identical belts 18 are provided. Each belt is constructed of multiple modules, and each is joined together to create an endless loop around the filter body 12.

[0032] The individual modules 20 will now be described in more detail with reference to FIG. 2. Each module has a housing 22. In this embodiment the housing 22 is made from plastics. A magnetic element 24 is movable within the housing 22, from an in-use position in which the magnetic element 24 is in contact with the external surface of the filter body (12) (it is the in-use position which is shown in FIG. 2), to an out-of-use position in which the magnetic element 24 is spaced from the external surface of the filter body (12). The out-of-use position is not illustrated in the drawings, but with reference to FIG. 2, the magnetic element 24 would be further towards the top of the drawing in the out-of-use position, rather than level with the bottom edge of the housing 22. The magnetic element is movable by means of an externally screw-threaded shaft 26 which passes through and engages an internally screw-threaded aperture 28 in the magnetic element 24. A spring 30 urges the magnetic element 24 towards the filter body (12) (i.e. downwards in FIG. 2). The screw-threaded shaft 26 is fixed to and operated by a handle 32. The screw-threaded shaft 26 is a conventional right-hand screw, so when the handle 32 is turned clockwise, the magnetic element 24 is drawn away from the filter body (12), against the action of the spring 30 and also against any magnetic attraction between the magnetic element 24 and the filter body (12) or magnetic debris retained on the internal wall of the filter body (12).

[0033] The side of the handle 32 where it meets the module body 22 (i.e. the lower side of the handle 32 in FIG. 2) preferably has a convex surface. This results in a pivoting bearing about which all components inside the module 20 can move. This allows the magnetic element 24 to make good contact with the outside surface of the filter body (12), irrespective of the shape or curvature of the filter body, or of any imperfections/irregularities on the surface.

[0034] Referring now to FIG. 3, a row of three modules 20, 20 is shown. In this embodiment, the modules 20 are entirely identical to each other, and each one includes a hinge pin 34 on one side of the module body 22, and a hinge barrel 36 on the other side. The module 20 on the far left of FIG. 3 is slightly different, in that a slotted pin 38 is provided in place of the hinge pin. This module is designed to go at one end of a belt, formed with one module 20 at an end, multiple modules 20 in the middle, and then another end module (not illustrated) which has a slotted pin similar to the slotted pin 38, but in place of the hinge barrel 36.

[0035] The hinge pins 34 slot into the hinge barrels 36 to make articulated joints between adjacent modules. In this embodiment, the hinge barrel is designed to allow only around 90 degrees of rotation in the hinge, to allow enough flexibility to use assembled belts on a variety of different diameter filter bodies, but to prevent unwanted snapping of modules against each other when the belt is detached.

[0036] In a simple embodiment, the modules at either end of the belt, which have the slotted pin 38, may be joined to each other for example with a cable tie, which allows the belt to be tightened around the filter body. In other embodiments, a buckle or similar may be provided for joining the ends together, or alternatively all modules could be identical, each one having a small amount of adjustability to tighten the belt of modules around the filter body.

[0037] FIG. 4 shows the underside of the modules 20, 20, when attached and in a row to form part of a belt. The side of the magnetic assembly 24 which would in use be against the external surface of the filter body is visible in this figure. Each magnetic assembly includes two magnetic billets 40, attached to a ferromagnetic (mild steel) carrier 42. In the figure, the topmost billet of each magnetic assembly is oriented with its north pole facing towards the filter body (i.e. out of the page in FIG. 4), and the lower billet of each magnetic assembly 24 is oriented with its south pole facing the filter body. Each magnetic assembly 24 is in effect a horseshoe magnet, with the north pole towards the top of the drawing.

[0038] In this embodiment, the polarity of the magnetic assemblies is the same in each module 20, 20. However, in some embodiments the polarity may alternate. This would mean providing an A type module and a B type module with the modules alternating ABABABA etc. along the belt. In this case, the A type module could have (for example) two hinge pins 34, and the B type module could have two hinge barrels 36. In this way, the modules can only be connected together in a way which alternates the polarities.

[0039] FIG. 5 shows an alternative embodiment of a magnetic filter, in that the filter body 12 is the body of an air and dirt separator of known design. The air and dirt separator may already be present in the system, and is likely to already be fitted with isolating valves. A drain port 44 is provided already as part of the air and dirt separator. The air and dirt separator can therefore be upgraded to add magnetic capturing capability, simply by installing a modular magnetic belt 18 according to the invention around the circumference of the air and dirt separator. Because the belt is modular, belts can be assembled to fit a wide variety of air and dirt separators, including those suited for different sized heating systems and including a wide variety of different makes and models of air and dirt separator. Preferably, several belts may be installed for enhanced magnetic capture.

[0040] The modular magnetic belt of the invention allows for a low-cost and straightforward magnetic filter suitable for commercial sized heating systems, for example with a bore of around 2 inches (50 mm) or greater. Filters can be made in many different sizes, the whole range of products only requiring a small number of different parts, since the modules in each case are identical, only the number of modules joined together in a belt will differ. Kits can be provided for upgrading air and dirt separators to include a magnetic capture capability.

[0041] It will be apparent that modifications may be made to the embodiments described, which are only examples of how the invention may be put into effect. The invention is defined in the claims.