Domestic steam cleaning appliance

Abstract: A domestic steam cleaning appliance comprises, enclosed within a single casing (13) grippable with one hand, the following means: a water vessel (24), a pump (9) of capacity between 20 and 50 cm³/min, and an elongate boiler (1) of cast light alloy having embedded in its wall a resistance element (2) of between 800 and 2200 Watt; said boiler comprising an entry duct connected to said pump and an exit duct connected to a delivery nozzle (6), operating and control means for said pump and said boiler being provided within the casing.

Description: This patent relates to a steam cleaner for domestic use. Domestic appliances are known consisting of a base, generally mounted on wheels, in which there are positioned a water container, a pump and a small steam generator located downstream of the pump to feed a movable terminal connected to the base by a hose. The terminal comprises a delivery structure from which there emerges a small quantity of steam, used either directly or in combination with a series of accessories. Said structure is made to slide over the surfaces to be cleaned, these being subjected to the emollient action of the steam and possibly to the mechanical action of accessories. Known domestic appliances absorb a power of the order of 1500-2000 W. They have serious operational limits deriving both from their bulk and from the lengthy connection between the boiler and the delivery structure, along which heat is lost and a considerable quantity of the generated steam is condensed. They are substantially of poor manageability and are totally unsuitable for cleaning small spaces such as cooker ovens, and corners, gaps and difficultly reachable surfaces because of the presence of the steam feed hose connected to the wheel-mounted base, which is bulky and difficult to handle. In addition as the water capacity of such devices cannot exceed 30-50 cm 3 /minute depending on the available power, the heat loss along the tube, even if modest, is highly penalizing. The object of the invention is to provide a very small-dimension domestic cleaner which can be manoeuvred with one hand and contains all the means for its operation so as not to need a separate base, and requiring for its operation only an electrical connection cable. This object is attained according to the invention by a cleaner comprising the features of claim 1 and preferably having within a single casing, a small water container having a capacity of the order of 200-600 g, a pump having a capacity of 20-50 cm 3 /minute, a known boiler fed by said pump and consisting of a housing carrying in its wall an electrical resistance element of 800-2200 watt power, and a delivery nozzle positioned in proximity to and as exit from said boiler, and having a hole of between 1 and 2 mm diameter. The casing contains the necessary control and safety means such as thermostats, and operating means such as switches. The casing is preferably of gun shape or a shape equivalent thereto such as to comprise means for comfortably gripping the appliance. As will be seen hereinafter the casing dimensions may be similar to those of a normal hairdryer so that the appliance can be easily operated in proximity to gaps, or inside small spaces such as domestic cooker ovens. The merits and operational and constructional characteristics of the invention will be more apparent from the detailed description of one embodiment thereof given hereinafter by way of non-limiting example with reference to the figures of the accompanying drawings. FR-A-1561817 discloses a steam cleaner having water reservoir, pump and electrically-heated steam boiler in a portable housing as do EP-A-0 586 762 and WO-A-94 24920, which are state of the art under Art. 54(3). Figure 1 shows an arrangement of the operational parts contained within a gun-shaped casing. Figure 2 is a view in the direction II of Figure 1. Figure 3 is a section on the line III-III of Figure 1. Figure 4 shows the electrical schematic of the appliance. Said figures show a cast aluminium boiler 1 having embedded in its wall a U-bent resistance element 2 of total length 300 mm and power 1500 W, its ends being connected to the electrical power line via a main switch 4 and a maximum-temperature thermostat 42. In this manner, on closing the main switch the resistance element is powered until the boiler reaches maximum temperature. The boiler comprises at one end an exit duct 5 in which a nozzle 6 is directly mounted. At its opposite end the boiler comprises an entry duct 7 connected by an elastomer tube 8 to a pump 9. The pump 9, of commercially available type, has a capacity of 50 cm 3 /min. It draws water through the duct 10 provided within a block 11 securely fixed to the outer casing 13 by a circumferential groove 12. The block 11 extends to the outside of the casing 13 as a cylindrical stem 18 provided with a seat and respective annular gasket 14, and with an an annular projection 15. It is therefore able to sealedly receive, by snap-fitting, a container 16 containing a water softening filter of about 70 cm 3 capacity. The container comprises a seat 17 to be mounted on the stem 18 and to remain locked thereon, a hole 19 being provided at the base of the seat in a position corresponding with the duct 10. At its opposite end the container 16 comprises a similar cylindrical seat 20 with its wall provided with a hole 21. The axis of the cylindrical seat 20 is substantially perpendicular to the axis of the cylindrical seat 17. The cylindrical base of a profiled vessel 24 of about 360 cm 3 capacity is inserted into the seat 20 and sealed therein by virtue of the annular gasket 22. This vessel has a half-moon cross-section, as shown in Figure 3, and extends upperly to embrace the end of the casing 13. For this purpose the upper wall of the vessel 24 is semi-cylindrical of horizontal axis and comprises two grooves 25 to be mounted on corresponding projections 26 on the casing (see Figure 2). The grooves 25 are parallel to the axis of the stem 18 so that the block formed by the container 16 and vessel 24 can be withdrawn and separated from the casing 13. This latter is composed of two half-casings held together by screws, not shown. The casing 13 is of gun shape, its handgrip 131 containing the block 11 and the pump 9. It receives the electric power cable 28 via the cable clamp 27, and comprises at its front a switch 29 functioning as a trigger for operating the pump 9 of the appliance. At the top of the handgrip 131 there is the cylindrical part 132 of the casing, containing the boiler 1, the indicator lamp 3 and the main switch 4. The block formed by the container 16 and vessel 24 acts as a hand protector. A flow regulator 30 can be provided between the pump and the boiler 1. An insulation covering 31 is preferably provided about the boiler 1, and a gasket 32 is provided between the nozzle 6 and the casing. As can be seen in Figure 1, said nozzle 6 is positioned at the end of a tube 60 on which a sleeve 61 comprising at least one small radial hole 62 is slidingly mounted. The sleeve 61 can assume the two operating positions shown respectively by full lines and by dashed and dotted lines in Figure 1. The operation of the invention is clear from the electrical schematic of Figure 4. When the switch 4 is closed the resistance element 2 is activated but the indicator lamp 3 remains extinguished until the boiler temperature reaches the minimum scheduled operating temperature. When this temperature is reached, the minimum-temperature thermostat 41 closes the circuit and the lamp 3 lights to inform the operator that the appliance is ready. When the minimum operating temperature is reached, the minimum-temperature thermostat 41 allows power to reach the trigger switch 29 which, when operated by the operator, powers the pump 9 for the time during which it is pressed. It is evident that the pump 9 cannot operate if the boiler has not reached the minimum temperature, ie without enablement by the thermostat 41. During the use of the invention the sleeve 61 can be arranged in the two aforespecified positions. In the first position said at least one hole 62 is closed because it is covered by the tube 60, and the nozzle emits a jet of steam as generated by the boiler. In the second position said at least one hole 62 is open by being downstream of the nozzle, so that ambient air is drawn through said hole to mix with the steam and cause its rapid condensation, so increasing its emollient power. The combination/arrangement of the aforesaid parts can be varied within the gun-shaped casing, without leaving the inventive concept. For example the pump can be positioned in line with the boiler, and the vessel can be provided in the handle. Likewise the boiler can be positioned in the hand protector, instead of the container 16 and vessel 24. These latter can also be formed in a single block. All the aforesaid and further modifications lie within the scope of protection of the following claims.

Claims: A domestic steam cleaning appliance characterised by comprising, enclosed within a single casing (13) grippable by one hand, the following means: a water vessel (24), a pump of between 20 and 50 cm 3 /minute capacity, an elongate boiler (1) of cast alloy, having embedded within its wall a resistance element (2) of between 800 and 2200 watts; said pump being positioned between said vessel and said boiler; said boiler comprising an exit duct connected to a delivery nozzle (6), means for operating and controlling said pump and said boiler being provided within the casing. An appliance as claimed in claim 1, characterised in that on said nozzle (6) there is slidingly mounted a sleeve (61) which has at least one small radial hole (62) and is able to slide between a rearward position in which said at least one hole (62) is closed and lies upstream of the nozzle, and a forward position in which said at least one hole (62) is open and lies downstream of the orifice of said nozzle. An appliance as claimed in claim 1, characterised in that the water vessel has a shape complementary to that of the casing and is removable. An appliance as claimed in claim 1, characterised in that a water softening filter is positioned between the water vessel and the pump. An appliance as claimed in claim 1, characterised in that the pump operation is controlled by a trigger switch enabled by a minimum-temperature thermostat, which enables only when the boiler has reached minimum operating temperature. An appliance as claimed in claim 5, characterised in that enablement by the thermostat causes an indicator lamp to light. An appliance as claimed in claim 1, characterised in that the casing is gun-shaped, its handgrip containing the pump and the trigger switch, its hand protector being formed by the removable vessel and the water softener, and its upper part containing the boiler and the relative operating and control means. An appliance as claimed in claim 1, characterised in that the boiler operating and control means comprise a maximum-temperature thermostat and a main switch. An appliance as claimed in claim 1, characterised in that the boiler is at least partly covered by a layer of insulating material. An appliance as claimed in claim 1, characterised in that the casing comprises a handgrip. An appliance as claimed in claim 1, characterised in that a part of the casing is shaped as a handgrip.

Inventors: LANDINI ERMINIO, LANDINI, ERMINIO
Applicants: GEN TECHNOLOGY S R L, GENERAL TECHNOLOGY S.R.L.
Application year: 1995
Main classification: A47L11
IPC codes: A47L11, A47L5, F22B1