The invention is directed towards a filter external to a tank and, in particular, although not exclusively, to an aquarium.
In order to keep the water in a tank in a satisfactory state of cleanliness it is necessary to filter it. The filtering of the water can be carried out either by a filter mounted inside the tank or by a filter external to the latter and connected to the tank by pipes, one for conveying water and one for returning water, a pump circulating the water and the tank being closed in a sealed manner during periods of use.
A filter external to a tank has a certain number of advantages over a filter contained in the tank. Thus, access for maintenance is easier, and maintenance is performed less frequently in that the filter is generally larger. Furthermore, the external filter has advantages in terms of cleanliness because, when it is being cleaned, impurities are not returned to the inside of the tank as is the case when cleaning a filter integrated into the tank.
A filter external to a tank comprises a vessel closed in a sealed manner by a lid equipped with couplings, one for the entry of water from the tank and one for returning water to the tank. The vessel contains a basket in which there are several layers of materials with different functionalities. These are a foam with physical action on filtration, components made of porous material which have a biological action during filtration, and components such as active charcoal, which have a chemical action on the filtration. All these various functions yield crystal-clear water. The water enters at the bottom and rises up vertically through the baskets containing the various components, and leaves again at the lid.
In general, there is a valve on each pipe, namely the pipe for conveying water to the vessel and the pipe for returning water. There is also a lever for attaching the lid to the vessel. To carry out an operation of cleaning the filter, the two valves need to be closed before the lever which catches the couplings on the lid of the vessel is unlocked. The vessel can then be taken away to a sink where the filter can be cleaned.
One essential disadvantage with this device is that there is no safety feature. It is therefore possible to forget to close a valve, or alternatively to accidentally open a valve when the coupling with which this valve is equipped is not yet locked onto the lid of the vessel. The use of such a filter therefore entails preceding with great caution.
A filter external to a tank is provided, comprising a device for connecting to the water conveying and water return pipes, which is of a simple structure and guarantees complete safety of use, making sure that, when the couplings are detached from the vessel, the valves equipping them have of necessity to be closed.
To this end, in the filter to which it relates, of the type comprising a sealed vessel containing various filtration components and consisting of a vessel closed by a lid equipped with a removable connector for a pipe for conveying water from the tank and a pipe for returning water to the tank, each of the couplings for connecting the two pipes to the connector being equipped with a valve which either does or does not allow water to pass, and the connector being equipped with means of fixing to the lid, is characterized in that the connector is equipped with a single means allowing, on the one hand, simultaneous actuation of the valves mounted on the two pipes and, on the other hand, actuation of the means of fixing the connector to the lid.
The single means in a first movement closes the valves then releases the means of fixing the connector to the lid and in a second movement fixes the connector to the lid then opens the valves. This filter is therefore very practical to use, because actuation of a single means allows the valves to be operated, on the one hand, and the connector to be fixed to the lid, on the other. Furthermore, the operator cannot make handling errors, in that the movements for actuating the valves and for actuating the means of attachment to the connector are always offset in time and performed in the appropriate order.
Advantageously, the single means is equipped with a safety member preventing it from being actuated when the connector is not positioned on the lid of the vessel. This characteristic is advantageous in that it prevents any operation of the single means when the connector is not positioned on the lid of the vessel. It is thus impossible to open the valves when the connector is not positioned on the vessel.
Advantageously, the single means comprises a pivoting lever.
According to one embodiment, the lever can pivot about an axis which is parallel to the plane of the lid of the vessel, is arranged between the couplings for connecting the two pipes and drives the spherical plugs of the two valves which also pivot about the same axis, the connector comprising on its underside two portions of piping intended to be engaged with sealing in two portions of piping belonging to the lid allowing liquid to pass between the vessel and the pipes, the lever comprising an actuating part protruding from the upper face of the connector and a catching part consisting of at least one ramp intended to catch behind a finger integral with the lid.
In practice, in order to remove the connector, the lever is actuated in one direction of pivoting, during which movement the two spherical-plug valves are rotated to the closed position, after which each ramp secured to the lever disengages from the finger behind which it was engaged, allowing the connector to be released from the lid.
According to another feature of this filter, the safety member preventing actuation of the lever when the connector is not positioned on the lid consists of at least one elastic tongue one end of which is integral with the turning part or hub of the lever and the other end of which tends to pivot outward under the effect of the elasticity of the material, this tongue being guided while the lever pivots in a groove made in a cheek integral with the connector, this groove being open and allowing the free end of the tongue to emerge and bear against a wall delimiting the groove, when the lever is in the valves-closed position, this wall being situated forward in the direction of rotation toward the opening of the valves, a finger integral with the lid being provided which, when the connector is positioned on the lid, presses on the free end of the tongue to retract it and allow the lever to be pivoted in the direction of opening of the valves. In practice, the connector needs to be positioned on the lid in order to retract the free end of each locking tongue, before the lever is pivoted to attach the connector to the lid and open the valves.
It may be noted that the pressure exerted on the safety tongues may be very light in order to avoid pushing the connector too far in with respect to the lid before turning the lever. Indeed, the shape of the ramps and of the fingers, forming cams, may improve the engagement of the connector on the lid.
According to one possibility, the valves are in the closed position when the lever is in the vertical position, the free end of each safety tongue then being in the bottom position of the hub, and the finger integral with the lid and intended to press against the tongue being vertical and facing upward.
To make the connector easier to position with respect to the lid, the upper wall of the lid of the vessel has a recess into which the connector can fit.