EP3023047B1

EP3023047B1 - A steam cleaning device

Info

Publication number: EP3023047B1
Application number: EP14194042.9A
Authority: EP
Inventors: Kevin Stones; Derek Muir
Original assignee: Black and Decker Inc
Current assignee: Black and Decker Inc
Priority date: 2014-11-20
Filing date: 2014-11-20
Publication date: 2017-05-31
Anticipated expiration: 2034-11-20
Also published as: EP3023047A1

Description

The present invention relates to a steam cleaning device.
In recent times steam cleaning devices have been used to clean the domestic environment. Many steam cleaning devices comprises a steam generator such as a boiler to convert water in to steam. The steam flows from the steam generators to a nozzle or a floor head and the steam is directed on to a surface to be cleaned. In some circumstances the steam is able to loosen stubborn stains and dirt on a dirty surface.
There has been a trend for the user to demand steam cleaning devices with improved steam generation capacity. This means that the steam generators and the heating elements therein may have a larger thermal capacity. In this way the thermal output increases and some steam cleaning devices may operate at higher temperatures. A steam cleaning device according to the preamble of claim 1 is already known e.g. from US-A-8549697 . When steam cleaning devices operate at high temperatures, the outside temperature of the steam cleaning device must remain at a temperature which is still safe to operate. One such method of cooling is disclosed in US 6,879,776 which describes a steam cleaner having a space between a container and a housing and an air flows in the space. The container encapsulates the steam generator and air flows over the container. A problem with the steam cleaner is that the air holes are on the underside of the device are for both air circulation and water draining purposes. This means that if water is draining out of the holes, cool air cannot circulate around the container or if the steam cleaner. The orientation of the steam cleaner will also affect the efficiency of the air circulation.
Embodiments of the present invention aim to address the aforementioned problems.
In one aspect of the present invention there is a steam cleaning device comprising: a housing; a boiler mounted in the housing; and a floor head in fluid communication with the boiler and coupled to the housing; wherein the housing comprises at least one first air hole and at least one second air hole and an air flow path therebetween, the at least one first and at least one second air holes being positioned either side of the boiler along a longitudinal axis of the steam cleaning device and the at least one first and at least one second air holes being positioned either side of the boiler along a transverse axis of the steam cleaning device such that one of the at least one first or second air holes is above the other of the at least one first or second air holes when the steam cleaning device is in a substantially vertical position or a substantially horizontal position.
In this way cool air is drawn into the housing and flows over the boiler irrespective of whether the steam cleaning device is upright or lying down. This advantageously ensures that the boiler does not overheat the housing.
Preferably the housing comprises at least one third air hole wherein the at least one third air hole and the at least one first air hole are positioned either side of the boiler along a longitudinal axis of the steam cleaning device. Preferably the at least one third air hole and the at least on second air hole are positioned either side of the boiler along a transverse axis of the steam cleaning device. Preferably the housing comprises at least one fourth air hole wherein the at least one fourth air hole and the at least one second air hole are positioned either side of the boiler along a longitudinal axis of the steam cleaning device. Preferably the at least one fourth air hole and the at least one first air hole are positioned either side of the boiler along a transverse axis of the steam cleaning device.
This means that air holes are provided for allowing air flow to cool the boiler irrespective of the orientation or positioning of the steam cleaning device. By placing the air holes on either side of the boiler along both the longitudinal axis and transverse axes of the steam cleaning device, the air convection is still achieved even if the user places the steam cleaning device in an unusual position. For example if the steam cleaning device is carelessly stowed in a cupboard and the steam cleaning device topples over, the arrangement of air holes will still allow a cooling air flow to pass over the boiler.
Preferably one or more of the at least one first air hole, at least one second air hole, at least one third air hole and the at least one fourth air hole are a plurality of air holes. By increasing the number of air holes for allowing air to exit and enter the housing, a greater cooling effect is achieved.
Preferably the plurality of air holes are spaced along an axis transverse to the longitudinal axis and the transverse axis.
Preferably boiler is mounted in a chamber in the housing wherein there is an air gap between the boiler and the wall of the chamber. By providing an air gap between the boiler and the wall of the housing, air flow is encouraged to pass over the outer surface of the boiler. By passing air over the boiler itself, better cooling can be achieved which prevents the housing from overheating.
Preferably the boiler is clad in a thermal insulating layer. By providing a thermally insulating layer over the boiler, the transmission of thermal energy from the boiler to the housing is reduced.
Preferably the boiler comprises a thermal mass for storing thermal energy. A thermal mass that stores thermal energy can be heated to higher temperatures which will provide a longer run time of steam generation when heating elements are not powered. This allows for a longer running steam cleaning device operating without electrical power. Preferably the thermal mass is heated to a temperature exceeding 400 degrees C.
Preferably the steam cleaning device comprises a locking articulated joint between the floor head and the housing arranged to lock the steam cleaning device in a substantially vertical position. This allows the steam cleaning device to be freestanding in the upright position.
Preferably the boiler is mounted on a plurality of ribs projecting from the housing. This means that the boiler is suspended away from the walls of the housing with minimal contact with the housing. This reduces the transmission of thermal energy to the housing and allows the air gap to be created.
Preferably the housing is substantially cylindrical. A cylindrical shape provides an efficient shape for storing thermal energy.
Preferably the steam cleaning device is a steam mop.
Preferably one of the at least one first or second air holes is above the other of the at least one first or second air holes when the steam cleaning device is moved between the substantially vertical position and the substantially horizontal position.
Various other aspects and further embodiments are also described in the following detailed description and in the attached claims with reference to the accompanying drawings, in which:

Figure 1 shows a side view of the steam cleaning device according to an embodiment;
Figure 2 shows a side view of the steam cleaning device according to an embodiment;
Figure 3 shows cross sectional side view of the steam cleaning device according to an embodiment;
Figure 4 shows a schematic cross sectional view of the steam cleaning device in a substantially vertical position according to an embodiment;
Figure 5 shows a schematic cross sectional view of the steam cleaning device in a substantially horizontal position according to an embodiment;
Figure 6 shows a schematic cross sectional view of the steam cleaning device in a substantially vertical position according to an embodiment;
Figure 7 shows a schematic cross sectional view of the steam cleaning device in a substantially horizontal position according to an embodiment
Figure 8 shows an exploded perspective view of the housing of the steam cleaning device according to an embodiment; and
Figure 9 shows a cross sectional diagram across the intersection IX-IX.

Figure 1 shows a side view of a steam cleaning device 10. The steam cleaning device 10 in some embodiments is a steam mop, but will be referred to hereinafter as a steam cleaning device 10. Indeed, the present invention can be applied to other domestic steam cleanings other than steam mops.
The steam cleaning device 10 comprises a body 11 having housing 12 which comprises a clam-shell type construction with a first housing portion 14 and a second housing portion 16. The first and second housing portions 14, 16 are fastened together with screw fasteners. Alternatively the first and second housing portions 14,16 can be fastened together with any means suitable for fastening such as integral clips. The housing 12 in some embodiments is constructed from a plastics material such as acrylonitrile butadiene styrene (ABS) or any other suitable thermoplastics material.
The steam cleaning device 10 comprises a floor head 18 which is coupled to the body 11 via an articulated joint 20. The articulated joint 20 allows movement of the floor head 18 in two degrees of freedom with respect to the body 11. This means that the body 11 can be tilted in a forwards and backwards direction with respect to the floor head 18 about a tilting axis 26. Furthermore the body 11 can be pivoted from side to side with respect to the floor head 18 about a pivoting axis 28. Optionally the articulated joint 20 comprises a locking mechanism (not shown) which locks the articulated joint. The locking mechanism comprises a catch and latch mechanism which releasably fixes the position of the body 11 with respect to the floor head 18. The locking mechanism locks the body 11 with respect to the floor head 18 when the steam cleaning device 10 is substantially in a vertical position.
The steam cleaning device 10 as shown in Figure 1 is in a substantially horizontal position or lying down position. In this case the body 11 has been tilted about the tilting axis 26 in the articulated joint 20 such that the base 22 of the floor head 18 is substantially parallel with a longitudinal axis A-A of the steam cleaning device 10. When the steam cleaning device 10 is in the horizontal position, the steam cleaning device 10 can be laid down on the floor. The floor head 18 and the a floor contact portion 24 of the housing 12 will be in contact with the floor in this position. This means that the user is able to lay the steam cleaning device 10 down when it is not in use. The steam cleaning device 10 is stable in the lying down position because the floor head 18 and the floor contact portion 24 prevent the steam cleaning device from rolling around.
As mentioned above, the floor head 18 is rotatably coupled to the body 11. In particular the floor head 18 is rotatable by a rotation of substantially 90 degrees about the tilting axis 26. Figure 2 shows a side view of the steam cleaning device 10 in a substantially vertical or upright position. In the upright position the steam cleaning device 10 can either be used for steam cleaning when the articulated joint 20 is unlocked or stored when not in use when the articulated joint 20 is locked. It should be noted that the steam cleaning device 10 is normally used with the body 11 tilted to some degree with respect to the floor head 18.
When the steam cleaning device 10 is in the substantially vertical position, the base 22 of the floor head 18 is substantially perpendicular to the longitudinal axis A-A of the steam cleaning device 10. When the floor head 18 being locked in position with respect to the body 11 of the steam cleaning device 10, the base 22 of the floor head 18 provides a stable base for the steam cleaning device 10 and the steam cleaning device 10 remains upright.
In order to use the steam cleaning device, the user grips a handle 30 which is mounted to the body 11. The handle 30 extends along the longitudinal axis A-A of the steam cleaning device 10 as shown in Figure 1.
The internal structure of the steam cleaning device 10 will now be discussed in further detail in reference to Figure 3. Figure 3 shows a cross sectional side view of the steam cleaning device as shown in Figures 1 and 2. The housing 12 comprises a chamber 32 in which a steam generator or boiler 34 is mounted. In some embodiments the boiler 34 is mounted on ribs projecting from the wall creating the chamber 32. This will be discussed in further detail in reference to Figure 8.
The boiler 34 is substantially cylindrical in shape as shown in Figure 3, although the boiler 34 can be other shapes if desired. Advantageously the cylindrical shape provides one of the most efficient shapes for maximum volume to surface area ratio and transferring heat to create steam. The housing 12 is also substantially cylindrical and larger in diameter than the diameter of the boiler 34. An air flow conduit 44 is provided between the inner surface of the chamber 32 and the outer surface of the boiler 34. The air flow conduit 44 provides a volume within the steam cleaning device 10 where air can circulate. The circulation of air within the steam cleaning device will be discussed in further detail in relation to Figures 4 and 5 and Figures 6 and 7.
Turning back to Figure 3, the boiler 34 is fluidly coupled to a water tank 36 and a pump 38. The pump 38 pumps water to the boiler 34 during operation. The operation of the steam cleaning device 10 is controlled with power buttons (not shown) on the handle 30. The boiler 34 comprises a conduit 40 or cooling circuit for receiving water from the water tank 36. The conduit 40 has a flow pathway through the boiler 34. The material surrounding the conduit 40 is heated by electrical resistive elements (not shown) and the thermal energy output from the resistive elements causes the water in the conduit 40 to be converted into steam. The electrical resistive elements are powered from either a mains electricity supply or a battery (not shown). The boiler 34 is in fluid communication with the floor head 18 and steam is output in the floor head at steam outlets 42.
In some embodiments, the resistive elements are optionally also configured to heat a thermal mass 46 which acts a heat store. The thermal mass 46 can be any material suitable for storing thermal energy which can transfer thermal energy to the conduit 40. In some embodiments the thermal mass 46 is mass of metal, metal alloy or a metal eutectic mixture. When the resistive elements have heated the thermal mass 46 up, the resistive elements can be switched off and the thermal energy stored in the thermal mass 46 is sufficient to continue to convert the water into steam. In some embodiments the thermal mass 46 is heated to a predetermined temperature to continue transfer thermal energy to the conduit 40 to convert water into steam for a predetermined period of time. In some embodiments the thermal mass 46 can be heated to over 400 degrees Celsius. As the water is converted into steam, so the thermal energy is dissipated from the thermal mass 46 and the thermal mass reduces in temperature. By using the thermal energy stored in the thermal mass 46 to convert water in to steam after the resistive elements have been switched off, the temperature of the boiler 34 needs to be operating at a much higher temperature than boilers in other domestic steam cleaning devices.
This means that the transfer of thermal energy from the boiler 34 to the housing 12 of the steam cleaning device 10 needs to be reduced to prevent the user from burning themselves on the outside of the housing 12 or damaging or melting the housing 12. This also limits the energy loss rate.
In order to reduce thermal energy being transferred from the boiler 34 or the thermal mass 46 to the housing 12, the boiler 34 is optionally clad in a thermally insulating jacket 48. In some embodiments the thermally insulating jacket 48 is thermally insulating ceramic. The thermally insulating jacket 48 must be able to withstand temperatures of over 400 degrees Celsius. In other embodiments the thermally insulating jacket 48 is any means suitable for thermally insulating the thermal mass 46 from the housing 12.
Further cooling arrangements will now be discussed in reference to Figures 4 and 5. Figures 4 and 5 show a schematic representation of the steam cleaning device 10 in a substantially horizontal orientation and a substantially vertical orientation respectively. The steam cleaning device 10 comprises a first air hole 50 in the housing and a second air hole 52 in the housing. The first and second air holes 50, 52 are apertures in the housing and permit the passage of air in and out of the steam cleaning device.
The first air hole 50 is positioned in the housing 12 at an end of the housing 12 which is closer to the floor head 18. The second air hole 52 is position in the housing 12 at an end of the housing which is closer to the handle 30. The first and second air holes are positioned either side of the boiler 34 along the longitudinal axis A-A of the steam cleaning device 10. Furthermore the first and second air holes are positioned either side of the boiler 34 along a transverse axis B-B of the steam cleaning device 10. The transverse axis B-B is substantially perpendicular to the longitudinal axis A-A of the steam cleaning device 10.
This means that the first and second air holes 50, 52 are located near diametrically opposite corners of the housing 12.
As previously mentioned, the steam cleaning device 10 as shown in Figure 4 is positioned in a substantially horizontal position. If the user lays the steam cleaning device 10 down after use, the boiler 34 will still be hot and heating the air inside the housing 12. The warm air within the housing 12 will naturally rise within the housing 12 due to convection. As the air moves within the housing 12, the warm flows in the air conduit 44 which is between the outer surface of the boiler 34 and the inner surface of the chamber 32.
When the steam cleaning device 10 is lying down in the substantially horizontal position, the second air hole 52 is located above the first air hole 50. As the warm air rises within the housing, at least some of the warm air will escape to the environment outside the housing 12 via the second air hole 52. The convection of the warm air within the housing 12 will draw cool air in from the exterior of the housing 12. In this way the first air hole 50 is an air inlet and the second air hole 52 is an air outlet. The cool air flows around the air conduit 44 and passes over the surface of the hot boiler 34 and cools the exterior of the boiler 34 in the process. The air flows between the first and second air holes 50, 52 and the air flow pathway is such that the cool air will flow over the surface of at least some part of the boiler 34. As can be seen from Figure 4, the air can flow above or below the boiler 34. Of course, the air conduit 44 surrounds the boiler 34 in three dimensions, so the cool air can take a multitude different paths between the first air hole 50 and the second air hole 52. For example the cool air can spiral round the cylindrical boiler 34. By offsetting the first and second air hole 50, 52 along the axis, an increased surface area of the boiler 34 is cooled by the flow of cool air entering from the first air hole 50 and flowing adjacent along the length of the boiler 34.
Figure 5 shows the steam cleaning device 10 as shown in Figure 4 in a substantially vertical position. In this case the second air hole 52 is still located above the first air hole 50. One of the at least first hole 50 or the at least second hole 52 is always located above the other hole when the steam cleaning device is in the vertical position and the horizontal position. Similarly the cool air enters via the first air hole 50 and the warm air exits via the second air hole 52. This means that the arrangement of the air holes ensures that the boiler 34 can be cooled with an airflow when the steam cleaning device 10 is in the substantially vertical position because the warm air can exit the second air hole 52. In this way the warm air can exit the housing 12 when the steam cleaning device 10 is in either the substantially vertical position or the substantially horizontal position.
In some embodiments the second air hole 52 is located on the upper portion of the housing 12 near the handle 30 and the first air hole is located on the lower portion of the housing 12 near the articulated joint 20. This means that when the body 11 is tilted with respect to the floor head 18, the second air hole 52 is above the first air hole 50. As mentioned above, a user will normally operate the steam cleaning device 10 when the body 11 is tilted to some extent with respect to the floor head 18. Since the second air hole 52 is above the first air hole 50, the warm air will be able to more easily escape from the housing 12 and a better cooling air flow is achieved during use.
Further embodiments will now be discussed in reference to Figures 6 and 7. Figures 6 and 7 show schematic representations of the steam cleaning device 10 in the substantially horizontal orientation and the substantially vertical orientation respectively. Figures 6 and 7 are similar to the embodiments discussed in reference to Figures 4 and 5 except that there are additional air holes for allowing increased air flow.
In addition to first and second air holes 50, 52 the housing also comprises a third air hole 54 and a fourth air hole 56. The first and third air holes 50, 54 are respectively positioned on the housing either side of the boiler 34 along the longitudinal axis A-A. The first and fourth air holes 50, 56 are respectively positioned on the housing either side of the boiler along the transverse axis B-B. The second and fourth air holes 52, 56 are respectively positioned on the housing either side of the boiler 34 along the longitudinal axis A-A. The second and third air holes 52, 54 are respectively positioned on the housing either side of the boiler along the transverse axis B-B.
In this way the air holes are positioned on the housing and spaced around the boiler 34 to provide cooling air flow. When the steam cleaning device 10 is lying down, cool air enters in the lower air holes, that is the first air hole 50 and the third air hole 54. The cool air then passes over the boiler 34 and is warmed up. The warm air can then take a number of different flow paths through the housing 12. Air entering via the first or third air holes 50, 54 can exit via either the second or fourth air holes 52, 56.
When the steam cleaning device 10 is in the substantially upright position, the lower air holes are the first and the fourth air holes 50, 56 and the higher air holes are the second and third air holes 52, 54. Cool air enters via the lower air holes, that is the first or the fourth air holes 50, 56. The warm air exits via the upper air holes, that is the second or the third air holes 52, 54. The increased number of flow paths means that a cooling air flow will flow over the boiler 34 whatever orientation the steam cleaning device is positioned in.
In some embodiments each of the first, second, third and fourth air holes can be a plurality of air holes for increasing air flow. Figures 8 and 9 will explain this in more detail. Figure 8 shows an exploded perspective view of the housing 12 with the first and second housing portions 14, 16. The first housing portion 14 comprises a plurality of second air holes 62 and a plurality of fourth air holes 66. The second housing portion comprises are plurality of first air holes 60 and a plurality of third air holes 64. The first, second, third and fourth plurality of air holes are spaced along a third axis substantially perpendicular to the longitudinal axis A-A and the transverse axis B-B. The plurality of air holes 60, 62, 64, 66 are located in the cylindrical surface of the housing 12. Figure 9 shows a cross section of the housing 12 clearly showing the first and fourth plurality of air holes 60, 66. The air holes perform the same function as described in reference to the previous embodiments.
The housing 12 comprises ribs 68 which are projecting inwards from the inner surface of the housing 12. The ribs 68 provide a structure which mounts the boiler 34 remote from the housing 12 to create the air conduit 44 between the boiler 34 and the housing 12.
In some embodiments there are two circumferential bands (not shown) wherein the band comprises an even distribution of air holes around the circumference of the cylindrical housing 12.
Preventing the transfer of thermal energy from the boiler 34 to the housing 12 is particularly applicable where a thermal mass 46 is used to store thermal energy as discussed in reference to the previous embodiments. However the present invention is still applicable to other steam cleaning devices which do not use a thermal mass 46. For example, a simple electric kettle element (not shown) arrangement could be used for a boiler. If the cooling arrangement described in the aforementioned embodiments is used with a different boiler, then less insulation is required. For example the thickness of the walls of the housing 12 can be reduced.
In another embodiment two or more embodiments are combined. Features of one embodiment can be combined with features of other embodiments.

Claims

A steam cleaning device comprising:
a housing;

a boiler mounted in the housing; and

a floor head in fluid communication with the boiler

and coupled to the housing;

wherein the housing comprises at least one first air hole and at least one second air hole and an air flow path therebetween, characterized in that

the at least one first and at least one second air holes being positioned either side of the boiler along a longitudinal axis of the steam cleaning device and the at least one first and at least one second air holes being positioned either side of the boiler along a transverse axis of the steam cleaning device such that one of the at least one first or second air holes is above the other of the at least one first or second air holes when the steam cleaning device is in a substantially vertical position or a substantially horizontal position.
A steam cleaning device according to claim 1 wherein the housing comprises at least one third air hole wherein the at least one third air hole and the at least one first air hole are positioned either side of the boiler along a longitudinal axis of the steam cleaning device.
A steam cleaning device according to claim 2 wherein the at least one third air hole and the at least on second air hole are positioned either side of the boiler along a transverse axis of the steam cleaning device.
A steam cleaning device according to claims 1 to 3 wherein the housing comprises at least one fourth air hole wherein the at least one fourth air hole and the at least one second air hole are positioned either side of the boiler along a longitudinal axis of the steam cleaning device.
A steam cleaning device according to claim 4 wherein the at least one fourth air hole and the at least one first air hole are positioned either side of the boiler along a transverse axis of the steam cleaning device.
A steam cleaning device according to any of the preceding claims wherein one or more of the at least one first air hole, at least one second air hole, at least one third air hole and the at least one fourth air hole are a plurality of air holes.
A steam cleaning device according to claim 6 wherein the plurality of air holes are spaced along an axis transverse to the longitudinal axis and the transverse axis.
A steam cleaning device according to any of the preceding claims wherein boiler is mounted in a chamber in the housing wherein there is an air gap between the boiler and the wall of the chamber.
A steam cleaning device according any of the preceding claims wherein the boiler is clad in a thermal insulating layer.
A steam cleaning device according to any of the preceding claims wherein the boiler comprises a thermal mass for storing thermal energy.
A steam cleaning device according to claim 10 wherein the thermal mass is heated to a temperature exceeding 300 degrees C.
A steam cleaning device according to any of the preceding claims wherein the steam cleaning device comprises a locking articulated joint between the floorhead and the housing arranged to lock the steam cleaning device in a substantially vertical position.
A steam cleaning device according to any of the preceding claims wherein the boiler is mounted on a plurality of ribs projecting from the housing.
A steam cleaning device according to any of the preceding claims wherein the housing is substantially cylindrical.
A steam cleaning device according to any of the preceding claims wherein one of the at least one first or second air holes is above the other of the at least one first or second air holes when the steam cleaning device is moved between the substantially vertical position and the substantially horizontal position.