This invention reiates to a filter for filtering a fluid. In particular, the invention relates to a filter for filtering water in a central heating system before it enters a boiler unit forming part of the central heating system.

Known domestic central heating systems comprise a wall-mounted boiler unit for beating water and a system of pipes that transport the water from the boiler unit to radiators distributed throughout the premises and then back to the boiler unit. Over time the internal walls of the pipework and radiators corrode, thereby introducing debris into the water that flows through the system. Modern boiler units comprise intricate heat exchangers with narrow channels for the water to pass through In order to provide high heat transfer rates. However, the intricacy of the heat exchangers makes them vulnerable to debris causing blockages which may reduce the efficiency of the heat exchanger or possibly cause complete failure.

To minimize the amount of debris that enters the heat exchanger in the boiler unit, a filter may be fitted to the central heating system to filter the water before it enters the boiler unit. Typically, water will enter a boiler unit from above or below the unit via a vertically oriented pipe running parallel to the wall on which the boiler is mounted. It is this pipe to which the filter is most commonly attached as it will filter the water almost immediately before it enters the boiler unit, therefore limiting the amount of fresh debris that may enter the water between the filter and the boiler.

Known filters for central heating systems are vertically oriented, that is the filters extend substantially parallel to the pipe that enters the boiler. The orientation of known filters causes them to extend substantially above or below the boiler unit and provides an eyesore to the end user.

According to the invention there is provided a filter for filtering a fluid comprising a filter body and a filter head sealingly and rotatably connectable to the filter body such that a filter volume is defined within the filter head and the filter body, wherein: the filter extends along a first axis; the filter body comprises an inlet port and an outlet port spaced apart from one another and each operatively connectable to the filter volume, the inlet port and the outlet port being orientated such that a second axis extends through the inlet port and the outlet port, which second axis is perpendicular to the first axis; the filter head comprises: a drain port operatively connectable to the filter volume, and a bleed valve comprising an actuation portion and a sealing portion, the actuation portion being configured to extend outwardly from the filter head and facilitate actuation of the sealing portion between a first position and a second position, the sealing portion being configured such that in the first position the sealing portion is engaged with the drain port such that the drain port is sealed from the filter volume and in the second position the sealing portion is disengaged from the drain port such that the drain port is operatively connected to the filter volume.

By means of the present invention a filter is provided that extends along a first axis perpendicular to a second axis which is defined by the inlet to and outlet from the filter. In some embodiments of the invention, in use, the filter may be fitted to a central heating system such that the second axis is parallel to the wall that the associated boiler unit is mounted to. The filter may therefore extend outwardly from the wail along the first axis, which, in such embodiments, is perpendicular to the wall, rather than extending up or down away from the boiler unit. The filter may therefore be positioned close to the top or bottom of the boiler unit such that it is substantially hidden from view rather than extending away from the boiler unit and causing an eyesore.

A filter according to the invention also comprises additional features which may improve its functionality.

Firstly, the filter comprises two main parts, the filter head and the filter body. The filter body comprises the inlet port and the outlet port which are attachable to the central heating system in order to operatively connect the filter to the central heating system. The filter head may be sealingly connected to the filter body such that a filter volume is defined within the filter head and the filter body. When the filter is operational, filtration of the central heating water occurs within the filter volume. However, when maintenance of the filter is required, for example to clean the filter of debris that has built up within it, the filter head may be disconnected from the filter body. Therefore, a user of the filter (such as an installation engineer, a maintenance engineer or an owner of the central heating system and associated premise) may readily access the internal components of the filter for cleaning without being required to remove the filter body from the associated pipework.

Further the filter head may be sealingly and rotatably connected to the filter body. Therefore, when the filter head is sealingly connected to the filter body and the filter volume is sealed within the filter head and filter body, the filter head may be rotated relative to the filter body. The rotation may occur substantially about the first axis along which the filter extends.

The filter head comprises a drain port operatively connectable to the filter volume. The drain port may extend outwardly from the filter and divergent from the first axis. Therefore, the orientation of the drain port may be adjusted by rotating the filter head relative to the filter body.

For example, in embodiments of the invention the filter head may be rotatable between a first configuration and a second configuration when in use. In the first configuration the drain port may be directed downwardly to allow drainage of the filter or the overall central heating system. In the second configuration the drain port may be directed upwardly to allow dosing or venting of the filter or the overall central heating system.

The multi functionality of the drain port provided by the rotatable filter head reduces the number of ports that are required. As well as further reducing the size of the filter, the reduction in ports results in a sleeker design of the filter, thus increasing its aesthetic appeal.

Additionally, by virtue of the filter being able to extend horizontally outwardly from the wall, rather than parallel to the wall, the drain port may be more accessible to the user.

An advantage of the drain port extending divergently from the first axis is that it would therefore be directed away from a user that is opening the drain port and would also direct fluid that exits the drain port away from the user. For example, if there was a fault in the system that caused high pressure water or steam to collect in the filter and a user opened the drain port without knowledge of the fault, the water or steam would be directed away from the user, reducing chance of serious injury. However, if the drain port were configured to extend substantially parallel to the first axis then the drain port would be directed towards the user attempting to open the drain port. If the same fault occurred in this instance, then the user opening the drain port would be at significant risk of injury caused by water or steam rapidly exiting the drain port in the user's direction. Although such a fault may be highly unlikely, the user may have greater confidence in operating the filter in the knowledge that risk of injury caused by a fault in the system is reduced. The filter head also comprises a bleed valve with an actuation portion and a sealing portion. The sealing portion is movable between a first position and a second position wherein in the first position the sealing portion seals the drain port from the filter volume and in the second position the sealing portion is positioned such that the drain port is operatively connected to the filter volume. Accordingly, during standard operation of the filter, the sealing portion may be placed In the first position to seal the drain port from the filter volume, therefore ensuring that water enters the filter volume via the inlet port and exits via the outlet port without leaking. However, when the drain port is to be utilized, such as for draining or dosing, the sealing portion may be placed in the second position such that water may exit the filter volume via the drain port rather than the outlet port, or dosing chemicals may be injected in to the filter volume via the drain port.

The actuation portion is configured to extend outwardly from the filter head and facilitate actuation of the sealing portion between the first position and the second position. In some embodiments of the invention the actuation portion may extend parallel to the first axis such that actuation portion extends away from the wall to which the associated boiler unit is mounted and is therefore readily accessible by a user of the filter when sealing or opening the drain port, even though the drain port may extend in a different direction to the actuation portion of the bleed valve.

In embodiments of the invention the filter further comprises a filter core adapted to fit within the filter volume. In such embodiments of the invention the filter core may filter water that passes through it.

In embodiments of the invention the filter core comprises a magnet. As water passes through the filter volume, past the magnet, magnetic debris may be attracted to the magnet and therefore be held within the filter volume rather than continuing with the flow of water to the boiler unit. The magnetic debris may comprise metal particles that have fallen away from the slowly corroding internal wails of pipework and radiators forming part of the central heating system.

In embodiments of the invention the magnet is positionabie within the filter volume substantially parallel to the first axis. The filter may be configured such that, during typical use, water enters through the inlet port, flows through the filter volume and then exits through the outlet port. As water flows through the filter, the water may flow past the magnet since it extends substantially parallel to the first axis. The magnet and the filter may each have a length sufficient to maximize the efficiency with which magnetic debris is removed from the water,

In embodiments of the invention: the bleed valve is formed in the filter head and comprises a bleed screw and a screw receiving portion; the actuation portion comprises a screw thread engageable with the screw receiving portion such that rotation of the bleed screw causes axial movement of the sealing portion between the first position and the second position; and the sealing portion comprises a first seal, which first seal is sealingly engageable with the drain port when the bleed screw is in the first position,

In such embodiments of the invention a user of the filter may move the sealing potion of the bleed screw between the first position and the second position by rotating the bleed screw such that the screw thread of the actuation portion causes axial movement of the bleed screw. For example, clockwise rotation of the bleed screw may cause the sealing portion of the bleed screw to move towards the first position, wherein the filter volume is sealed from the drain port. Anticlockwise rotation of the bleed screw may cause the sealing portion of the bleed screw to move towards the second position, wherein the filter volume is operatively connected to the drain port. In other words, rotation of the bleed screw clockwise and anticlockwise may open and close the drain port respectively.

The first seal may comprise an 0-ring attachable to the sealing portion and engageable with a wall of the drain port such that the sealing potion prevents the drain port from operatively connecting to the filter volume.

In embodiments of the invention the actuation portion comprises a screw head adapted to receive an actuation tool and to facilitate axial rotation of the bleed screw. The screw head may be adapted to receive any suitable actuation tool, such as at least one of a variety of standard screwdrivers. Therefore, a user of the filter may use a screwdriver to rotate the bleed screw and actuate the sealing portion between the first position and the second position in order to open or close the drain port.

When the sealing portion is in the second position and the filter volume is operatively connected to the drain port, water may flow from the filter volume to the drain port past the sealing portion of the bleed screw and the screw receiving portion. If the screw receiving portion were not sealed, then water may be able to flow into the screw receiving portion. The introduction of water into the screw receiving portion may result in gradual corrosion of the screw thread which may eventually cause the bleed screw to seize up or become too loose. It may also allow water to leak from the screw receiving portion.

Therefore, in order to avoid water entering the screw receiving portion, in embodiments of the invention the first seal is sealingiy engageabie with the screw receiving portion when the bleed screw is in the second position.

Further, to avoid water entering the screw receiving portion when the sealing portion is between the first position and the second position, embodiments of the invention comprise a second seal sealingiy engageabie with the screw receiving portion when the bleed screw is between the first position and the second position inclusively.

In other embodiments of the invention, the bleed valve may be any form of bleed valve that suitably facilitates movement of a sealing portion between a first position and a second position, wherein the sealing portion comprises a first seal which is sealingiy engageabie with the drain port when the bleed screw is in the first position.

Embodiments of the invention may comprise any suitable means for sealingiy and rotatably connecting the filter head to the filter body.

For example, in embodiments of the invention the filter comprises a sealing ring removably connectable to the filter head and filter body such that when the sealing ring is connected to the filter head and filter body, the filter head is sealingiy and rotatably coupled to the filter body.

In such embodiments of the invention, the filter head and filter body may be sealingiy and rotatably abuttable with one another and the sealing ring may be connected to both the filter head and the filter body in order to ensure that they remain in abutment with one another.

In embodiments of the invention the filter body comprises a first threaded portion and the sealing ring comprises a second threaded portion rotatabiy engageabie with the first threaded portion.

In such embodiments of the invention, the sealing ring may be connectable to the filter- body via engagement of the first and second threaded portions. In other words, the sealing ring may be screwed onto the filter body. In embodiments of the invention the filter bead comprises a rim, and the sealing ring is sealingiy abuttab!e with the rim.

In such embodiments of the invention, the sealing ring may be screwed into connection with the filter body until it abuts with the rim of the filter head. The sealing ring may thereby act to maintain the abutment of the filter head to the filter body.

In general use, the sealing ring may be screwed relatively tightly to the filter body so that the filter head abuts the filter body with a level of pressure that does not allow rotation of the filter head relative to the filter body due to friction. The filter bead may therefore be fixed in position relative to the filter body. However, in instances when a user of the filter wishes to rotate the filter head relative to the filter body, the sealing ring may be partially loosened from the filter body so that the first and second threaded portions are only partially engaged with one another and the pressure between the abutting surfaces of the filter head and filter body is reduced to allow the filter head to rotate relative to the filter body.

In embodiments of the invention the filter head or the filter body comprises a seal and the other of the filter head and the filter body is sealingiy abuttab!e with the seal.

In such embodiments of the invention the seal may act as a seal between the filter head and the filter body whenever the filter head is abutted against the filter body, including when the sealing ring is loosened to allow rotation of the filter head relative to the filter body. Therefore, the seal ensures that the filter head is sealingiy connected to the filter body while also being rotatably connected to the filter body.

For example, the seal may be an G-r!ng positioned around a portion of the filter head that abuts against the filter body and configured to facilitate a water seal between filter head and the filter body when they abut one another.

In embodiments of the invention the drain port may comprise an attachment means to enable attachment of one or more additional components that may provide the filter with further functionality.

For example, in embodiments of the invention the filter further comprises a drip cap removably attachable to the drain port. The drip cap may catch any drips of water that are present in the drain port after it has been opened and closed or any drips of water that are able to pass the sealing portion of the bleed valve. The drip cap may therefore be attached to drain port to protect the surrounding area from water that could drip from the drain port.

In embodiments of the invention the filter further comprises a hose connection removably attachable to the drain port. A user of the filter may therefore fit a hose to the drain port. This may advantageously allow the user to drain the filter or the central heating system directly into a sink or drain, for example.

In embodiments of the invention the filter further comprises a pressure gauge removably attachable to the drain port. This may allow a user to check the pressure within the central heating system without having to open the boiler unit.

Further, modern boiler units may comprise an electric pressure gauge which requires a power source to provide a pressure reading. When the central heating system is first installed an electrician may be required to connect the boiler unit to a power source. If the electrician is not present when the engineer is fitting the central heating system, the engineer may not be able to use the in-built pressure gauge of the boiler unit. It may therefore be particularly advantageous for the engineer to be able measure the pressure in the system with an analogue pressure gauge attachable to the filter.

In embodiments of the invention the filter further comprises a rapid dosing point removably attachable to the drain port. In such embodiments of the invention, a user may dose the central heating system via the filter using a standard rapid dosing implement.

In embodiments of the invention the filter body may comprise an attachment means to enable attachment of one or more additional components that may provide the filter with further functionality. The attachment means may comprise the first threaded portion with which the second threaded portion of the sealing ring may be engaged in order to connect the filter head to the body.

In embodiments of the invention the filter further comprises a flush connector removably attachable to the filter body.

In such embodiments of the invention, the user may remove the filter head from the filter body and attach the flush connector in its place in order to flush the associated central heating system. The flush connector may comprise a third threaded portion engageab!e with the first threaded portion of the filter body. The invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a schematic representation of a filter according to an embodiment of the invention.

Figure 2 is a schematic representation of the filter shown in Figure 1 with the filter head rotated through 180°.

Figure 3 is a cross-sectional view of a filter head forming part of the filter shown in Figure 1.

Figure 4 is a cross-sectional view of a bleed valve forming part of the filter shown in Figure 1.

Figure 5 is a schematic representation of a drain port forming part of a filter according to an embodiment of the invention.

Figure 6 is a schematic representation of a drip cap removably attachable to a filter according to an embodiment of the invention.

Figure 7 is a schematic representation of a hose connection removably attachable to a filter according to an embodiment of the invention.

Figure 8 is a schematic representation of a pressure gauge removably attachable to a filter according to an embodiment of the invention.

Figure 9 is a schematic representation of a flush connector removably attachable to a filter according to an embodiment of the invention.

Referring initialiy to Figure 1, a filter according to the invention is generally defined by the reference numeral 2 and comprises a filter body 4 and a filter head 6 sealingly and rotatably connectable to the filter body 4. In this embodiment the filter 2 further comprises a sealing ring 18 removably attachable to the filter body 4 and filter head 6 to facilitate the sealable and rotatable connection of the filter head 6 to the filter body 4. The filter body 4 comprises an inlet port 10 and an outlet port 12 spaced apart from one another and filter head 6 comprises a drain port 14 and a bleed valve 16,

The filter 2 extend along a first axis 20. The inlet port 10 and the outlet port 20 are orientated such that a second axis 22 extends through the inlet port 10 and the outlet port 12, The second axis 22 is perpendicular to the first axis 20.

When fitted to a central heating system comprising a wall-mounted boiler unit, the filter 2 may be removably attached to pipework feeding into the boiler unit via the inlet and outlet ports 10, 12 such that water which has cycled through the central heating system may enter the filter 2 through the inlet port 10, be filtered within the filter 2 and exit through the outlet port 12 before entering the boiler unit. In known central heating systems, the pipe entering the boiler may extend vertically above or below the boiler unit substantially parallel to the wall which the boiler unit is mounted to. Therefore, the second axis 22 may extend vertically towards the boiler unit and the first axis 20 may accordingly extend perpendicularly to the second axis 22 such that the filter extends outwardly from the wall.

The orientation of the filter 2, perpendicular to the second axis 22, results in the filter 2 occupying a smaller footprint with respect to the associated pipework than if the filter was oriented parallel to the second axis as is the case for known filters. The filter 2 may therefore be positioned closely to the boiler unit such that it is substantially hidden from view by the boiler unit, rather than extending more noticeably above or below the boiler unit and being an eye sore for the owner of the relevant premises.

Further, the compact footprint of the filter 2 with respect to the pipework it may be attached to allows the filter 2 to be fitted in spaces that other filters, which occupy more space in the direction of the equivalent second axis 22, may not be able to fit within.

Referring now to Figure 2, the filter 2 shown in Figure 1 is shown with the filter head 6 rotated 180° relative to the filter body 4.

The filter head 6 is sealingiy and rotatably connectable to the filter body 4 such that, when the filter 2 is in use, the filter head 6 may be rotated relative to the filter body 4 while a seal is maintained between the two so that the filter 2 does not leak. For example, this allows the filter head 6 to be rotated between a first configuration (shown in Figure 1) in which the drain port 14 is directed downwardiy and a second configuration (shown in Figure 2) in which the drain port 14 is directed upwardiy.

In this embodiment of the invention, the filter body 4 comprises a first threaded portion (not shown) and the sealing ring 18 comprises a second threaded portion (not shown) rotatably engageabie with the first threaded portion, Additionally, the filter head 6 comprises a rim 19 (shown in Figure 1) and the sealing ring 18 is seaiingly abuttable with the rim 19. Therefore, in order to connect the filter head 6 to the filter body 4, the filter head 6 may be abutted against the filter body 4 and the sealing ring 18 may be passed over an end of the filter head 6 (opposite to the inlet and outlet ports 10, 12) and then screwed to the filter body 4 via the first and second threaded portions. By screwing the sealing ring 18 to the filter body 4, the sealing ring 18 may be caused to abut against the rim 19. The sealing ring 18 thereby acts to keep the filter head 6 in abutment with the filter body 4.

If the sealing ring 18 is screwed tightly (by hand) to the filter body 4, the friction between the abutting surfaces of the filter head 6 and the filter body 4 may prevent rotation of the filter head 6 relative to the filter body 4. However, the sealing ring 18 may be loosened so that the first and second threaded portions are only partially engaged and friction between the filter head and filter body is reduced to allow rotation. Accordingly, the filter head is rotatably connectable to the filter body.

Further, in this embodiment of the invention, the filter head 6 comprises a seal (not shown), and more particularly an G-ring, that is seaiingly abuttable with the filter head 6, The seal ensures that the filter head 6 is seaiingly connected to the filter body 4 while also being rotatably connected to the filter body 4.

In other embodiments of the invention the filter body 4 may comprise a seal that is seaiingly abuttable with the filter head 6 or the filter head 6.

In the first configuration the drain port may be opened to drain the filter 2 or the overall central heating system associated with the drain port. On the other hand, in the second configuration, the drain port may be opened to vent the central heating system or act as a dosing point through which cleaning chemicals, for example, can be injected into the filter and optionally the overall central heating system.

Further, the rotatabiiity of the filter head allows the filter to be adaptable to different, and potentially unconventional, central heating systems. For example, the filter 2 may be fitted to horizontally oriented pipe work and the filter head 6 may simply be rotated such that the drain port 14 is in the desired orientation. The adaptability of the filter 2 is advantageous over known filters on the market which may only be suitable for fitting to conventional central heating systems that provide sufficient space and orientation of pipework for the filter to operate correctly.

Referring now to Figure 3, a filter volume 8 is defined within the filter body 4 and the filter head 6 when they are connected to one another. The inlet port 10 and the outlet port 12 may each be operatively connectable to the filter volume 8 in that water may flow through the inlet port 10 into the filter volume 8 and then out of the filter volume 8 through the outlet port 12.

The filter 2 further comprises a filter core 24 configured to fit within the filter volume 8. The filter core comprises a magnet 26 and a filter mesh 28. The magnet may be positioned within the filter volume 8 substantially parallel to the first axis 20 (shown in Figure 1). As water passes through the filter volume 8, past the magnet 26, magnetic debris may be attracted to the magnet 26 and therefore be held within the filter volume 8 rather than continuing with the flow of water to the boiler unit.

The filter mesh 28 may be configured to filter non-magnetic debris from the water and hold the debris within the filter volume 8 such that it does not flow into the associated boiler unit.

The bleed valve 16 comprises an actuation portion 30 and a sealing portion 32. The actuation portion 30 is configured to extend outwardly from the filter head 6 and facilitate actuation of the sealing portion between a first position and a second position. The sealing portion 32 is configured such that in the first position (shown in Figure 3) the sealing portion 32 is engaged with the drain port 14 such that the drain port 14 is sealed from the filter volume 8. In the second position (not shown) the sealing portion 32 is disengaged from the drain port 14 such that the drain port 14 is operatively connected to the filter volume 8.

Referring now to Figure 4, a bleed valve 16 according to an embodiment of the invention is shown wherein the bleed valve 16 comprises a bleed screw 34 and a screw receiving portion 36 formed in the filter head 6. In this embodiment of the invention the actuation portion 30 comprises a screw thread 38 engageable with the screw receiving portion 36 such that rotation of the bleed screw 34 causes axial movement of the sealing portion 32 between the first position (shown in Figure 4) and the second position (not shown). The actuation portion 30 further comprises a screw head 40 configured to receive an actuation too! and facilitate axial rotation of the bleed screw. Therefore, a user of the filter 2 may rotate the bleed screw 34 by using an actuation tool such as a screwdriver. Rotation of the bleed screw 34 in a first direction (clockwise for example) may cause the sealing portion to move axially towards the first position while rotation of the bleed screw in an opposite second direction (anticlockwise for example) may cause the sealing portion to move towards the second position.

The sealing portion 32 comprises a first seal 42 sealingly engageable with the drain port 14 when the bleed screw 34 is in the first position, In this embodiment of the invention the first seal is a first O-ring fitted to an end of the bleed screw such that an outer edge of the first O-ring is engageable with a wail of the drain port 14 whereby the first seal 42 blocks fluid from travelling between the filter volume 8 and the drain port 14 when the sealing portion 32 is in the first position, as shown in Figure 4.

The sealing portion also comprises a second seal 44 configured to be seaiingly engageable with the screw receiving portion 36 when the bleed screw 34 is between the first position and the second position inclusively. In this embodiment of the invention the second seal 44 is a second O-ring fitted to the bleed screw 34 and spaced apart from the first O-ring such that it is engageable with a wall of the screw receiving portion 36 when the sealing portion 32 is in the first position, the second position and any position in between. The second seal 44 therefore provides a seal that prevents water from entering the screw receiving portion 36, particularly when the sealing portion 32 is not in the first position and the filter volume 8 is operatively connected to the drain port 14 such that water may be flowing past the bleed valve 16. Preventing water from entering the screw receiving portion is advantageous as it stops water from flowing into the screw thread 38 where corrosion could cause the bleed screw 34 to seize or fail, thereby locking the position of the sealing portion and rendering the drain port inoperable.

Referring now to Figure 5, the drain port 14 comprises an attachment interface 50 configured to facilitate the attachment of further components to the drain port 14. For example, a drip cap 52 as shown in Figure 6, a hose connection 54 as shown in Figure 7 or a pressure gauge 56 as shown in Figure 8.

The drip cap 52 may catch any drips of water that be present in the drain port 14 after it has been opened and closed via the bleed valve 16, or any drips of water that are able to pass the sealing portion 32 of the bleed valve 16. The drip cap 52 may therefore be attached to drain port 14 to protect the surrounding area from water that could drip from the drain port 14.

The hose connection 54 may allow a user of the filter 2 to fit a hose to the drain port 14. This may advantageously allow the user to drain the filter 2or the associated central heating system directly into a sink or drain, for example.

The pressure gauge 56 may allow a user of the filter 2 to measure the pressure within the associated central heating system without having to open the housing of the boiler unit.

In this embodiment of the invention the pressure gauge 56 comprises a rapid dosing point 57. Accordingly, a user may dose the associated central heating system via the filter 2 using a standard rapid dosing implement.

In other embodiments of the invention, the pressure gauge and the rapid dosing point may be formed as separate components, each attachable to the drain port 14.

Similarly, to the attachment interface 50 of the drain port 14, the filter body 4 may comprise an attachment means (not shown) that facilitates the attachment of further components, as well as facilitating connection of the filter head 6 to the filter body 4. The further components may provide the filter with additional functionality.

Referring now to Figure 9, a flush connector 58 is removably attached to the filter body 4 rather than the filter head 6, thereby converting the filter 2 into a fixture that facilitates flushing of the associated central heating system.

Preferences and options for a given aspect, feature or parameter of the invention should, unless the context indicates otherwise, be regarded as having been disclosed in combination with any and all preferences and options for all other aspects, features and parameters of the invention.