EP2536478A1

EP2536478A1 - A percolating filter device

Info

Publication number: EP2536478A1
Application number: EP11702453A
Authority: EP
Inventors: Moretto Maurizio
Original assignee: Laica SpA
Current assignee: Laica SpA
Priority date: 2010-02-17
Filing date: 2011-02-04
Publication date: 2012-12-26
Also published as: ITPD20100044A1; TW201143877A; IT1399048B1; WO2011101265A1

Abstract

A percolating filter device (l)of the type with a replaceable cartridge (9) includes a device (10) for indicating the service life cycle of the cartridge (9) for the purpose of indicating the exhaustion of the cartridge (9 ) when the cartridge (9) is due to be replaced and an electrical switch device for selecting and/or activating a function of the indicator device (10), the indicator (10) device including a capacitive proximity switch with an operating electrode fitted on the filter device (1).

Description

A percolating filter device

DESCRIPTION

The present invention relates to a percolating filter device of the type with a replaceable cartridge, according to the preamble of the principal claim.

Filter devices having the aforementioned characteristics are widely used for the filtration of drinking water for domestic use. They are generally made in the form of jugs, kettles, teapots and the like. A typical example of this technology is described in PD2008U000033.

In these devices, the filter cartridge contains a filter bed of active carbon, ion exchange resins or other material, whose capacities are liable to become exhausted with use and/or over a period of time, until the cartridge has to be replaced . Devices are therefore provided for counting one or more operating parameters of the cartridge in order to indicate its exhaustion when the filtering capacity is considered to be insufficient to ensure the subsequent effective filtration of the liquid to be treated . Typically, the parameters monitored by these devices include the period elapsed since the initial activation of the cartridge and/or the quantity of liquid filtered. These parameters can be detected directly or through functions correlated with them such as the number of filling cycles of the filter jug, the pressure of a push button, or the like.

In all cases, at least one switch is generally connected to the indicator device for the purpose of selecting and/or activating a function of the device, typically at least the initial activation of the indicator device. In the prior art, the switches used are of the push button type, generally having rubber protection to make them fluid-tight. These switches have a number of serious drawbacks. In the first place, they require a degree of pressure for their actuation. This creates a state of uncertainty in the user concerning the effectiveness of the actuation, especially since the pressure exerted may be insufficient, the contacts may be oxidized, and/or the repetition of the pressure over a period of time may cause damage to the rubber protection. In order to overcome this drawback, use has been made of membrane switches, in which the contacts are formed by two membranes, at least one of which can be deformed by the pressure of a finger. Even in this case, however, the switch is subject to wear which, over a period of time, may cause damage and may even allow water or moisture to enter the indicator device, thus seriously compromising its operation.

The principal object of the invention is to provide a filter device of the aforesaid type which is structurally and functionally designed to overcome all the drawbacks described with respect to the aforementioned prior art. In the context of this object, a principal aim of the invention is to provide a filter device in which the cartridge monitoring functions are highly reliable. This object and other aims are achieved by the invention by means of a percolating filter device made in accordance with the appended claims.

The features and advantages of the invention will be made clearer by the following detailed description of a preferred, but not exclusive, example of embodiment, illustrated, for the purposes of guidance and without limiting intent, with reference to the appended drawings, in which :

Fig. 1 is a schematic sectional view of a filter device in the form of a jug;

Fig. 2 is a plan view from above of a detail of the device of Fig . 1. In the drawings, the number 1 indicates the whole of a percolating filter device of the type to which the present invention relates. In this case, the device is a filter jug with a replaceable cartridge, but similar considerations are applicable to kettles, teapots, cafetieres and the like.

The jug 1 comprises a housing 2 having a mouth which is closed removably by a cover 3. A funnel-like divider (or "hopper") 6 is inserted into the housing to form within the jug 1 an upper bowl 4 for collecting the water to be filtered and a lower bowl 5 for collecting the filtered water.

A seat 7 is formed in the divider 6 to receive a replaceable cartridge 9 which is positioned in such a way that the water to be filtered flows through this cartridge 9 as it passes from the upper to the lower bowl.

A device 10 for indicating the life cycle of the cartridge 9 is provided on the cover 3 (or on another part of the housing of the jug, for example the handle 11) to indicate the exhaustion of the cartridge when the latter is due to be replaced .

The indicator device 10 includes a housing 12 fitted in a seat 13 in the cover 3, a display 14 for showing a signal indicating the useful life of the cartridge, such as a bar diagram representing the remaining useful life, and an electrical switch device for selecting and/or activating a function of the indicator device, for example in order to activate a counter of the time that has elapsed since the first use of the cartridge. The switch device includes a circuit component with a capacitive proximity switch built into an integrated circuit 15 and an operating electrode 16.

The electrode 16 is formed by a strip of conductive material mounted on the container of the filter device and connected to the circuit 15 by means of conductors which are not shown. Preferably, the electrode 16 is mounted in the proximity of the indicator device 10 on the cover 3 or on the handle 11 of the jug.

It is also preferable for the electrode 16 to be incorporated in the housing 12 of the indicator device in such a way that the latter forms a unit which can be handled separately and is self-contained, completely independent and sealed .

In the operation of the device 1, the electrode 16 acts as the push button member of a conventional switch, with the evident difference that, since it is a capacitive electrode, it actuates the electrical switch of the circuit 15 when the dielectric field around the electrode is disturbed. Thus it is not even necessary to touch the electrode 16 physically in order to activate the switch of the circuit 15; it is sufficient to bring a finger close to it. Because of this arrangement, the electrode 16 can be incorporated into the housing 12 of the indicator device, where it is fully protected from accidental contact with liquids and moisture. This also makes it possible to make the housing 12 completely fluid-tight since it is no longer necessary to have wires passing through it and/or to provide sealing with membranes which are rather unreliable.

Thus the invention resolves the aforementioned problem while providing numerous benefits including complete immunity to wear combined with considerable sensitivity to simple contact, enabling the device 12 to be constructed in such a way as to be fully fluid-tight and reliable over a period of time.

Claims

1. A percolating filter device of the type with a replaceable cartridge, including a device for indicating the service life cycle of the cartridge for the purpose of indicating the exhaustion of the cartridge when the cartridge is due to be replaced and an electrical switch device for selecting and/or activating a function of the indicator device, characterized in that the indicator device includes a capacitive proximity switch with an operating electrode fitted on said filter device.

2. A device according to Claim 1, wherein said electrode is fitted in the proximity of said indicator device.

3. A device according to Claim 1 or 2, including a container in which a first and a second bowl are formed one above the other, and are intended, respectively, to collect the liquid to be filtered and to hold the filtered liquid, wherein said electrode and said indicator device are fitted on a wall of said container.

4. A device according to Claim 3, wherein said wall includes a cover of said container.

5. A device according to any one or more of the preceding claims, wherein said electrode and said switch device are incorporated into a single housing with said indicator device.

6. A device according to Claim 5, wherein said housing of the indicator device is completely fluid-tight.