The present invention relates to an outlet tube for washing machines in general, in particular dish and linen washing machines.
As is known, a washing machine, for example a dish washing machine, comprises a water conveying tube for conveying the machine water to a drain, which drain may comprise either a sink siphon or trap assembly, or a wall hole connected to a hydraulic or water drain system.
Document
Water is conveyed through a water conveying pump included in the washing machine.
Because of the outlet tube length, and depending on its arrangement path through the machine to the drain, a negative pressure may be generated in the outlet tube and accordingly the pump is caused to operate in a vacuum or a negative pressure condition.
Such a mode of operation of the pump greatly reduces its life.
Moreover, the pump is subjected to operating failures and noise and, as the outlet tube remains in a water-free condition for a time, a disagreeable smell is frequently generated.
Accordingly, it is necessary to prevent a negative pressure condition from being generated in the outlet tube.
Accordingly, the aim of the present invention is to provide a dish and linen washing machine outlet tube for overcoming the above mentioned problems and drawbacks.
Within the scope of the above mentioned aim, a main object of the invention is to provide such an outlet tube which comprises a small number of component pieces and which, moreover, is advantageous from a mere economic standpoint.
Another object of the present invention is to provide such a washing machine outlet tube which, owing to its specifically designed structure, is very reliable and safe in operation.
The above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by an outlet tube for dish and linen washing machines comprising the features of claim 1. Further preferred embodiments of the invention are claimed in the dependent claims.
Further characteristics and advantages of the present invention will become more apparent hereinafter from the following detailed disclosure of a preferred, though not exclusive, embodiment of the invention, which is illustrated, by way of an indicative but not limitative example, in the accompanying drawings, where:
With reference to the number references of the above mentioned figures, the outlet tube for washing machines, such as dish and linen washing machines, according to the present invention, and generally indicated by the reference number 1, comprises a corrugated hollow body 2 having a first end portion including a fitting 3 designed for connection to an outlet 4 of a washing machine 5 including a water discharging or unloading pump 6.
Said corrugated body 2 comprises a second end portion including a fitting 7 for connection to a drain 8, which drain may comprise a sink siphon or trap assembly or a wall outlet, as in the example shown in
According to the present invention, said corrugated body 2 comprises a smooth zone 9 for engaging therein a valve device, generally indicated by the reference number 10.
Said valve device 10 comprises a silicone umbrella valve 11, including a projecting lug 12 engaged in a central hole 13 formed in a support element 14 of said valve.
Said support element 14 comprises moreover a plurality of holes 15 which are radially arranged about the central hole 13.
The support element 14 comprises a cylindric body open on a side thereof wherein is housed the surface 16 of the umbrella membrane, thereby properly holding the latter.
The support element 14 and umbrella valve 11 are housed in an insert 17 including an end piece 18 which is removably engaged in a through hole 19 formed in the smooth zone 9 of the corrugated body 2.
Said insert 17, umbrella valve 11 and support element 14 may be disassembled from one another and from the corrugated body 2.
The washing machine outlet tube according to the present invention operates as follows.
In a normal operation condition, shown in
If a negative pressure is formed in said corrugated body 2, then the environment pressure will press the membrane 16 so as to move said membrane 16 away from the radial holes 15 to allow environmental pressure air to enter the corrugated body 2 thereby compensating the inner pressure of the outlet tube.
It should be apparent that the umbrella valve 11 will be automatically closed as the pressure in said corrugated body will increase to exceed the environment outer pressure.
Thus, the umbrella valve applied to the inventive outlet tube prevents said tube from being fully emptied in a washing machine discharging operation step, since said umbrella valve will be opened to allow environment pressure air to enter the outlet tube.
It has been found that the invention fully achieves the intended aim and objects.
In fact, the invention has provided a washing machine outlet tube allowing the washing machine pump to operate in an optimum operating condition, thereby increasing the operation life of the pump, and preventing a negative pressure from forming in the outlet tube.
It should be apparent that the outlet tube may also be designed as a smooth tube instead of a corrugated one as in the shown and disclosed exemplary embodiment.
It should be also apparent that the outlet tube according to the present invention could also be used for any desired types of dish and/or linen washing machines.
Advantageously, the inventive outlet tube may also be mounted on existing washing machines, in replacement of conventional existing outlet tubes, without the need of modifying the hydraulic fittings and other apparatus.
A further advantage of the outlet tube according to the present invention is that it may be easily serviced, since the valve device 10 may be easily disassembled from the corrugated body and moreover the whole device may also be easily disassembled to its individual components, for cleaning or optionally replacing the latter.
In practicing the invention, the used materials, as well as the contingent size and shapes can be any, depending on requirements.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.