Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K13/00—Structural associations of current collectors with motors or generators, e.g. brush mounting plates or connections to windings; Disposition of current collectors in motors or generators; Arrangements for improving commutation
  • H02K13/006—Structural associations of commutators
• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47K—SANITARY EQUIPMENT NOT OTHERWISE PROVIDED FOR; TOILET ACCESSORIES
  • A47K10/00—Body-drying implements; Toilet paper; Holders therefor
  • A47K10/48—Drying by means of hot air
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K23/00—DC commutator motors or generators having mechanical commutator; Universal AC/DC commutator motors
  • H02K23/40—DC commutator motors or generators having mechanical commutator; Universal AC/DC commutator motors characterised by the arrangement of the magnet circuits

Definitions

• the present invention relates to airflow systems, and also apparatus and methods for airflow systems, in particular, appliances adapted to produce air movement, such as for example, air dryers adapted to produce a stream of sterilised air for 'clean' drying conditions.
• the present invention is suitable for use in hand dryers and it will be convenient to hereinafter describe the invention as it relates to sterilising hand dryers that produce a stream of sterilised, heated air, particularly for drying hands, where airflow inside the apparatus may be decelerated by one or more filters through which the airflow passes.
• the invention is not limited to that use, only.
• Hand dryers may be used to emit a stream of heated or warm airflow to dry a user's hands. These hand dryers are typically used in public toilets, and in environments, such as in the medical profession, where the user hopes to retain maximum cleanliness by avoiding contact with potential bacteria-sources such as paper towels, cloth towels or tissues.
• At least one response to this problem may be to solely rely on a larger, more powerful fan motor in the dryer that can provide higher torque and faster fan-speed.
• a larger, more powerful fan motor in the dryer that can provide higher torque and faster fan-speed.
• designers wished to have faster exit airflow speed, there may be a tendency to use a faster, more powerful fan motor.
• problems with this approach of solving the problem by solely using a larger fan motor for example, as follows:
• faster fan-motors tend to be more expensive, and can tend to have a greater amount of internal wear and tear, tending towards shorter lifespan of the motor.
• larger fan-motors can run hotter, and can tend to produce more noise.
• faster fan-motors tend to be larger, leading to motors burning out, which may require the apparatus-housing of the dryer to be larger to accommodate the larger motor.
• the inventor has identified that, in motors that may be used for appliances adapted for air movement, the carbon brush life may not be sufficient to meet the specification of the appliance. Further, the inventor has identified that the speed of motors in such appliances may be too low to overcome back pressure that may build up. This has been particularly noted by the inventor with respect to appliances that make use of the present applicant's bactericidal filter system, with respect to impeded air flow through an appliance. Further, commutators used for motors in such applications as the above noted appliances may be normally 'shell type' commutators. Shell type commutators are generally manufactured from a copper strip and moulded material such as phenolic thermoset moulding material.
• the copper strip may be blanked and fo ⁇ ned, the formed copper shell is then moulded with the thermoset moulding material such as phenolic as noted. After moulding, the copper shell is separated into the required individual bars or segments.
• This type of commutator is suitable for low to moderate operating speeds and low electrical currents. However, at higher speeds and higher electrical currents the risk exists of individual segments or bars moving or lifting. The reason for this effect may be attributed to the fact that the material used to mould the commutator (eg Phenolic Thermoset and equivalent materials) may not adhere to the copper and, as the inventor has identified, the bond may be only mechanical in nature.
• testing and operating conditions may often tend to be opposite in their specifications. For example, it may be a requirement that the testing of a motor for providing air movement in an appliance is performed with the motor under continuous operation. In direct contrast, in normal operating conditions for the appliance, the motor may be required to work in short intervals, such as about 30 seconds, at full performance or in other words, up to full load for short intervals over a relatively long expected lifetime.
• An object of the present invention is to overcome or at least ameliorate one or more of the problems in the related art, or to provide an improved alternative.
• an object of the present invention is to provide at least an improved alternative to the option of simply providing a larger fan-motor, when confronted by the problem of one or more filters decelerating the airflow through a hot air hand drying apparatus.
• an airflow system adapted to enhance airflow in a hand-drying apparatus which expels a stream of substantially sterilised, hot air that is heated by a heating-means for drying of hands, where the airflow inside the apparatus is decelerated by one or more filters through which the airflow passes, wherein the system, downstream of the heating-means, is provided with an airflow- pathway that is progressively smaller along its pathway in respect of flowthrough cross-section, such that, in use, the airflow is enhanced by flowing initially through a larger part of the airflow-pathway, and subsequently through a smaller part of the airflow-pathway after which the airflow exits the apparatus.
• the airflow-pathway may include at least a part that has a degree of taper.
• the degree of taper is able to be selectively varied by the user.
• the degree of taper of the airflow-pathway may be able to be selectively varied by the user substituting a replacement airflow-pathway device of different size preferably selected from a range of passageways of differing degrees of taper.
• the airflow-pathway may include parts that are not tapered.
• the hand-drying apparatus in which the system is adapted to be used, may comprise a completely sealed apparatus-housing that includes therein a fan-casing containing a fan.
• all airflow enters the apparatus-housing through initial main-inlet-means on the apparatus-housing, and all airflow subsequently enters the fan-casing through final main-inlet-means on the fan-casing, wherein the initial main-inlet-means is larger than the final main-inlet-means such that, in use, the airflow is enhanced by flowing initially through the larger initial main-inlet-means, and subsequently through the smaller final main-inlet-means.
• the larger initial main-inlet-means and the smaller final main-inlet-means may have flowthrough cross-sections which have a ratio of around 1.38 relative to one another.
• the fan may be a dual-fan comprising two fan-halves each of which is adapted to draw in airflow into the fan-casing.
• the airflow inside the apparatus is decelerated by a plurality of filters
• the airflow through the system may be driven by a fan apparatus that is activated by a universal commutator motor.
• a method of enhancing airflow through a hand-drying apparatus that expels a stream of substantially sterilised, hot air that is heated by a heating-means for drying of hands, where the airflow inside the apparatus is decelerated by one or more filters through which the airflow passes
• the method includes providing the apparatus with an airflow system which, downstream of the heating-means, includes an airflow-pathway that is progressively smaller along its pathway in respect of flowthrough cross-section, and, in use, enhancing the airflow by causing the airflow to flow initially through a larger part of the airflow-pathway, and subsequently through a smaller part of the airflow-pathway after which the airflow exits the apparatus.
• a hand-drying apparatus airflow system adapted to enhance airflow in an apparatus that expels a stream of substantially sterilised, hot air that is heated by a heating-means for drying of hands, where the airflow inside the apparatus is decelerated by one or more filters through which the airflow passes, wherein the hand-drying apparatus comprises a completely sealed apparatus-housing that includes therein a fan-casing containing a fan, wherein the fan is a dual-fan comprising two fan-halves each of which is adapted to draw in airflow into the fan-casing.
• a universal commutator motor adapted to drive an appliance for providing air movement, the motor comprising: magnetic field generating means for generating a magnetic field; a rotating armature adapted for rotational motion in operative association with the magnetic field; wherein a ratio of magnetic field strength at the armature to the magnetic field strength within the magnetic field is less than about 1 to 1.
• the ratio of magnetic field strength may be about 0.9 to 1.
• the armature may comprise: a lamination armature structure having an arc of winding of about slot 1 to about slot 11 and about slot 12 to about slot 22, respectively.
• the motor may further comprising: at least two carbon brushes; at least two brush holders operatively associated with the at least two carbon brushes; wherein flexible conducting material is adapted to provide electrical connection to a commutator under variable operating conditions.
• the flexible conducting material may comprise braided copper wire.
• the motor may further comprise: a commutator comprising a reinforcing ring located within the body of the commutator such that it is isolated from conducting segments and adapted to substantially reduce bar to bar movement.
• a universal commutator motor adapted to drive an appliance for providing air movement, the motor comprising: magnetic field generating means for generating a magnetic field; a rotating armature adapted for rotational motion in operative association with the magnetic field, wherein a ratio of magnetic field strength at the armature to the magnetic field strength within the magnetic field is less than about 1 to 1; wherein the armature comprises a lamination armature structure having an arc of winding of about slot 1 to about slot 11 and about slot 12 to about slot 22, respectively; at least two carbon brushes ; at least two brush holders operatively associated with the at least two carbon brushes wherein flexible conducting material is adapted to provide electrical connection of the carbon brushes to a commutator under variable operating conditions; and, the commutator comprises a reinforcing ring located within the body of the commutator such that it is isolated from conducting segments and adapted to substantially reduce bar to bar movement.
• the appliance for providing air movement may comprise an air dryer.
• a method of operating a universal commutator motor the motor adapted to drive an electric appliance for providing air movement, the method comprising the steps of: generating a magnetic field within the motor; operatively associating a rotating armature of the motor with the magnetic field; maintaining a ratio of magnetic field strength at the armature to the magnetic field strength within the magnetic field at less than about 1 to 1.
• the ratio of magnetic field strength may be about 0.9 to 1.
• the method may further comprise the step of: providing an increased magnetized area for the armature corresponding to a lamination armature structure having an arc of winding of about slot 1 to about slot 11 and about slot 12 to about slot 22, respectively.
• the method may further comprise the steps of: providing at least two carbon brushes; providing at least two brush holders operatively associated with the at least two carbon brushes; provide electrical connection to a commutator under variable operating conditions by use of flexible conducting material adapted to provide electrical connection to a commutator under variable operating conditions.
• the flexible conducting material may comprise braided copper wire.
• the method may farther comprise the steps of: providing a commutator comprising a reinforcing ring located within the body of the commutator such that it is isolated from conducting segments and adapted to substantially reduce bar to bar movement.
• a method of operating a universal commutator motor comprising the steps of: operatively associating a rotating armature of the motor with the magnetic field; maintaining a ratio of magnetic field strength at the armature to the magnetic field strength within the magnetic field at less than about 1 to 1 ; providing an increased magnetized area for the armature corresponding to a lamination armature structure having an arc of winding of about slot 1 to about slot 11 and about slot 12 to about slot 22, respectively; providing at least two carbon brushes; providing at least two brush holders operatively associated with the at least two carbon brushes; providing electrical connection to a commutator under variable operating conditions by use of flexible conducting material adapted to provide electrical connection of the carbon brushes to a commutator under variable operating conditions; and, providing a commutator comprising a reinforcing ring located within the body of the commutator such that it is isolated from conducting segments and adapted
• the appliance for providing air movement may comprise an air dryer.
• the appliance for providing air movement may comprise a hand-drying apparatus airflow system as described.
• an airflow system adapted to enhance airflow in a hand-drying apparatus which expels a stream of substantially sterilised, hot air that is heated by a heating-means for drying of hands, where the airflow inside the apparatus is decelerated by one or more filters through which the airflow passes, wherein the system is provided with an airflow-pathway that is progressively smaller along its pathway in respect of flowthrough cross-section, such that, in use, the airflow is enhanced by flowing initially through a larger part of the airflow-pathway, and subsequently through a smaller part of the airflow-pathway after which the airflow exits the apparatus.
• the airflow-pathway that is progressively smaller along its pathway, may be provided downstream of the heating-means.
• Figure IA is a front view of an embodiment of a sterilising hand-drying apparatus which has a internal airflow that is decelerated by several filters, and which incorporates an embodiment of an improved airflow system that enables enhanced airflow through the apparatus;
• Figure IB is a side view of the hand-drying apparatus of Figure IA;
• Figure 1C is an underside view of the bottom of the hand-drying apparatus of Figure IA;
• Figure 2 is a rear perspective view of the hand-drying apparatus of Figure IA, when the apparatus-housing is opened to reveal its interior, and when viewed from the perspective of arrow A in Figure IB;
• Figure 3 shows a perspective view of an embodiment of four main filter holders that hold filters, with the first holder shown with its filter withdrawn, being filters that decelerate airflow in the embodiment of Figure IA;
• Figure 4A shows a perspective view of an embodiment of a fan-casing and a fan motor, with a pair of subsequent filter holders and filters which are attached to the fan-casing;
• Figure 4B shows an exploded view of the apparatus of Figure 4A, showing an embodiment of a dual fan that is contained inside the fan-casing;
• Figure 4C shows a further exploded view of the apparatus of Figure 4A, showing more details of the dual fan;
• Figure 4D is a side, cross-sectional view of the dual-fan of Figures 4B and 4C;
• Figures 4E and 4F are side views of the dual-fan of Figures 4B, 4C and 4D, each viewed from a different side of the fan respectively;
• Figure 4G is a section view of the embodiment of the dual-fan in Figures 4B, 4C, 4D, 4E and 4F.
• Figure 5 shows three different embodiments of exit-passageways that can be used interchangeably in the embodiment of Figures IA to 2, each embodiment have a different degree of taper through which airflow leaves the fan-casing and exits the hand-drying apparatus;
• Figure 6A shows a plan view of an example arc winding in relation to a lamination arm in an electric motor in accordance with at least one related art technique identified by the inventor;
• Figure 6B shows a plan view of arc winding in an electric motor in accordance with a preferred embodiment
• Figure 6C is a plan view of a field assembly of a universal motor with an exploded view of its components in accordance with a preferred embodiment
• Figure 6D is a component parts listing for the field assembly of Figure 6C
• Figure 6E is plan view of a brush commutator housing assembly of a universal motor with an exploded view of its components in accordance with a preferred embodiment
• Figure 6F is a component parts listing for the brush commutator housing assembly of Figure 6E;
• Figure 6G is plan view of an a ⁇ nature assembly of a universal motor with an exploded view of its components in accordance with a preferred embodiment
• Figure 6H is a component parts listing for the armature assembly of Figure 6G;
• Figure 61 is a plan view of a drive end housing assembly of a universal motor with an exploded view of its components in accordance with a preferred embodiment
• Figure 6 J is a component parts listing for the drive end housing assembly of Figure 61;
• Figure 6K(a) shows a commutator of a preferred embodiment of the present invention in top plan view;
• Figure 6K(b) shows a cross sectional side view of the commutator of Figure 6K(a) taken along the direction of line A-A in Figure 6K(a);
• Figure 6K(c) is an expanded view of section B in Figure 6K(b).
• Figure IA shows a front view of a sterilising hand-drying apparatus in the form of a hand dryer 1.
• Figure IB shows a side view of the dryer 1
• Figure 1C shows an underside view of the same dryer 1.
• Figure 2 shows a rear perspective view of the dryer 1 when it is opened, showing its interior.
• the dryer 1 draws in ambient air. Bacteria in the airflow is killed and preferably removed. The airflow is heated, and then expelled from the dryer, typically directly onto the user's hands for drying.
• the hand dryer 1 has an apparatus-housing 10, 11 which includes a main hood 10 and a baseplate 11.
• the hood 10 is mounted to the baseplate 11 by hinges 12.
• FIG. 1 shows the hood 10 arranged in a closed position, installed ready for use, for example, mounted on a wall.
• the hand dryer 1 is adapted to expel an airflow or stream of substantially sterilised, hot air for drying hands.
• the operational range of the heated air is around 55 to 65 degrees Centigrade.
• Figure IA is a front view, whereas Figure 2 is a rear view.
• Figure IA the airflow
• the incoming airflow 200A enters the dryer in the region of the left hand side of the diagram. Whereas, in Figure 2, the incoming airflow 200A would enter the dryer 1 in the region of the right hand side of the drawing).
• the incoming air 200A passes through a main-filter assembly 410.
• this main filter assembly includes four main filter holders 410A, 410B, 410C, 410D (seen in more detail in Figure 3).
• the function of these main filter holders and their filters is to kill and remove bacteria particles, to the extent that in the embodiment, the airflow can be made substantially bacteria-free, and preferably 100% bacteria-free.
• the features of an example o the filters, and their role in killing bacteria, is described in the present inventor's earlier corresponding International Patent Application PCT/AU2005/001803 (filed in the name of Panache Global Holdings Pty Ltd), which is incorporated herein by reference into this present description merely as a non-limiting example of the function of these filters.
• the information in PCT/AU2005/001803 explains how an exemplary embodiment of a dryer is able to expel a substantially bacteria-free airflow, preferably a 100% bacteria-free airflow.
• the airflow is drawn towards a fan-casing 400A, 400B that contains a fan.
• Part of the airflow enters the fan-casing through one 400A of the sides of the casing, passing through the filters of some subsequent filter holders 420A, 420B.
• the purpose of these subsequent filters is to effuse and add beneficial substances to the airflow.
• the filters of one of these subsequent filters 420A or 420B can effuse another anti-bacterial substance into the airflow.
• This subsequent anti-bacterial substance effused from the filters of the subsequent holders 420A or 420B, stays in the airflow until it is expelled from the dryer 1 in the exit airflow 200E, where the substance can become coated onto the hands of the user.
• any one or more of the filters from either the main holders, preferably the latter ones 410C, 410D, or from the subsequent holders 420A, 420B, can be used to effuse a beneficial substance into the airflow.
• That substance can be ultimately coated onto the hands of the user when it exits the dryer 1 , or alternatively the substance can spread into the ambient air surrounding the hand dryer 1.
• a fragrance can be effused into the airflow so that the washroom atmosphere smells pleasant.
• an anti-bacterial substance can be effused into the washroom atmosphere to minimise airborne bacteria.
• Many people that use public toilets, after washing their hands, are slightly uneasy about having to touch the bacteria-laden doorhandles of the toilet door. It almost defeats the purpose of washing hands, if bacteria will return immediately by touching the dirty toilet door handle. Some users try to open the door with the feet, to avoid touching the door handle.
• the airflow coats the user's hands with a small amount of the expellable-substance.
• the user's hands can be coated with a small amount of an anti-bacterial substance.
• the amount is sufficient to provide a greater degree of protection for the user's hands when touching the bacteria-coated handle of the toilet door.
• the effused substance on the hands of user may be of a sufficient amount to feel like a cream on the hands. This gives the user tangible evidence that something beneficial has been coated onto the hands.
• the expellable-substance is preferable to effuse from a subsequent filter (420A or 420B) that is located on the fan-casing 400A, 400B, rather than from the earlier main filters holders 410A, 410B, 410C, 410D. This ensures that substantially all the expellable-substance will enter the fan-casing. If, on the other hand, the expellable-substance were to be effused primarily using one of the main filters in the main filter holders 410A, 410B, 410C, 410D, then a portion of the expellable-substance may otherwise deposit on internal surfaces of the housing 10, 11.
• the number of filters, used in practice, is determined by a user of the dryer 1 who may be responsible for installation and/or maintenance.
• Figures 3 and 4C show that the filters can be removed from their holders 41 OA, 41 OB ,
• filters can contain different active ingredients that are intended to be infused into the airflow, hence, the maintenance user can purchase different filters to suit the particular need.
• the substance that are effused into the airflow for use by medical staff such as surgeons, might differ from different substances that are effused in dryers used in public toilets, for example.
• the dryer 1 is provided with an electric heating element 4 (not shown in detail).
• the heating element is located at a heating means location 5 which is close to an opening of the fan-casing 400A, 400B, behind a protective grille 15.
• the heating element includes a grid of wires or plates adapted to be heated up electrically when the dryer 1 is emitting the hot airflow 200E.
• the housing 10, 11 of the dryer 1 is completely sealable, for instance with rubber gasket seals.
• the complete sealing of the housing is achieved by providing seals at all points of contacting between the main hood 10 and the baseplate 11.
• the sealing is to such a degree that, when the housing 10, 11 is closed, absolutely all air entering the dryer 1 must pass through an initial-main-inlet in the form of the initial main aperture 405 A. This ensures that all incoming air will be filtered by the filters in the main filter holders 410A, 410B, 410C, 410D. If not, then any air that were to leak into the housing, other than through the initial- main-inlet, would not be subjected to filtration through the filters in the main holders 410A, 410B, 410C, 410D.
• the initial opening can be divided into several openings, provided that the combined area of the plurality of initial -main-inlets is larger than the area of the f ⁇ nal-main-inlet on the fan-casing. The air then enters into a chamber area inside the completely-sealed, closed housing.
• the apparatus has a cut-off switch so that the airflow cannot be generated when the housing is open).
• the airflow is drawn, from the chamber, into the fan-casing 400A, 400B.
• Part of the airflow enters the fan through the final-main-inlet in the form of final main apertures 405B, which is the part 400A of the fan-casing that is filtered by the filters in the subsequent filter holders 420A, 420B.
• Another part of the airflow is drawn into the fan-casing through another portion of the fmal-main-inlet in the form of final main apertures 405C, which is the part 400B of the fan-casing that is not filtered, and which is closer to the fan motor 430.
• the airflow through the dryer 1 is created by a fan 401, shown in Figures 4B, 4C and 4D.
• the fan rotates inside the fan-casing 400A, 400B.
• the rotation of the fan 401 is operated by a motor 430.
• the motor may be a universal motor capable of up to or greater than a speed of 7500 rpm under operating conditions and is discussed further herein.
• the fan blade 401 is made of injection-moulded plastic.
• the fan should not be made of a material that would readily shatter of extremely high rotation speeds. Also, the fan should not be so flexible that it would warp at high rotation speeds.
• the fan of the embodiment is made of a nylon composite material, although other suitable materials can be used.
• a feature that at least ameliorates this problem is to make the fan 401, in the embodiment, to be a dual-fan, seen in Figures 4C and 4D.
• the dual-fan has two regions that each has a similar function to a no ⁇ nal single fan. In other words, one fan item acts as if it were two fans.
• the fan 401 is manufactured as a single item, it is regarded as a dual-fan, because it has two separate fan regions, which are separated by a central web 403 that extends from a central, axial spindle 404.
• the spindle 404 is connected to the drive shaft (not shown) of the motor 430.
• the dual-fan consists of two fan-halves.
• Figure 4D shows a cross-sectional view of the two halves of the fan-halves 402A, 402B in cross-section.
• Figure 4E shows a side view of the fan 401, showing the fan-half 402A that is closer to the final main aperture 405B that is filtered.
• Figure 4F shows the other side of the same fan, showing the fan-half 402B that is closer to the opposite final main aperture 405C which is nearer the fan-motor 430.
• Figures 4E and 4F show that the circumferential rim of the fan 401 is provided with a series of fan-blades 406 evenly disposed around the circular rim. When these fan-blades 406 rotate, air is draw into the fan-casing, thereby also causing ambient air to be sucked into the dryer 1.
• Figure 4G is similar to Figure 4D, except that the present Figure 4G shows a section view, or "slice view", of the dual-fan 401, when a slice is taken along the dotted line 407 in Figure 4E.
• the embodiment of the dual-fan could be described roughly as having a cylindrical outer rim, which carries the fan blades, where the cylinder has a central partition or central web 403. The central web divides the cylinder roughly into two halves.
• the use of the dual-fan lessens the degree of turbulence in the airflow that is expelled from the fan. It is believed that the airflow, coming out of the dual-fan, is more streamlined, with less turbulence, compared to the airflow that would come from a single, non-dual fan. It is believed that an advantage of having less turbulence is that there would be less likelihood of back-pressure building up particularly inside the fan and the exit nozzle 14. Therefore, the dual-fan is able to contribute to the enhanced airflow, for example, by minimizing the occurrence of internal turbulence in the airflow that is expelled from the fan via the exit nozzle 14.
• back-pressure can, amongst other things, slow down the exit airflow and/or increases the level of noise.
• the fan is slightly tapered, in the sense that the diameter of the first fan-half 402A is slightly smaller than the diameter of the second fan-half 402B.
• the cross-section of the dual-fan is slightly frusto-conical.
• the filters in the filter holders 410A, 410B, 410C, 410D and 420A, 420B have a detrimental effect of decelerating the airflow through the dryer.
• a feature that at least ameliorates this problem is to provide the airflow system, of the dryer 1, downstream of the location 5 of the heater, with an airflow-pathway that is progressively smaller along its pathway in respect of flowthrough cross-section.
• the airflow-pathway is in the form of the exit nozzle 14 that is downstream from the heater location 5.
• the nozzle 14 is tapered, so that it fulfils the criteria of being progressively smaller along its pathway in respect of flowthrough cross-section.
• the airflow is enhanced by flowing initially through a larger part of the nozzle, and subsequently through a smaller part of the nozzle.
• Airflow velocity tends to increase, when it is forced to flow through progressively smaller flowthrough cross-sections of the nozzle 14.
• Providing the exit-nozzle 14 with a tapered passageway enables a faster speed of the exit airflow 200E, without, at the same time, necessarily requiring a larger and faster fan-motor, which may result in the associated problems, as discussed in the above preamble of this specification.
• the exit nozzle 14 has a taper of around 7 degrees to the vertical, however, the degree of taper in other embodiments can be modified.
• Figure 5 shows several other alternative embodiments 14 A, 14B, 14C of nozzles with different degrees of tapering.
• each end-use situation may have different requirements. Another criteria is that the degree of taper can affect the noise level as airflow rushes through the nozzle 14.
• the user requires the exit airflow to be as fast as possible.
• the need is to spread that beneficial substance as far as possible into the ambient environment outside the dryer 1.
• the exit airflow 20OE to be as fast as possible, so that it can have a chance to reach the furthest reaches of the washroom.
• This application can benefit from a narrower nozzle 14C in Figure 5.
• the end-user may prefer to have a wider size of airflow to ensure that his hands are fully or effectively coated with the beneficial substance that is in the exit airflow 200E.
• This application can benefit from a slightly wider nozzle 14A in Figure 5.
• the optimum taper was found to be about 7 degrees to the vertical, however, some experimentation may be required when the dryer is modified in terms of its shapes of the internal chamber, the design and power of the fan-motor, the diameter of the fan, the length of the nozzle, the number of filters, the degree of internal surface smoothness of the nozzle, and other variables that affect the overall speed of airflow through the dryer. All these factors can influence the optimum degree of taper for a particular embodiment of a dryer. Modifications of the Nozzle
• the nozzle can consist of an initial non-tapered region having a larger flowthrough cross-section, which is followed by a subsequent non-tapered region having a smaller flowthrough cross-section.
• this feature is not limited to embodiments that have tapering.
• the degree of tapering of the nozzle is not only defined in terms of slope, but can also be defined in terms of the transition from, for example, a square cross-section at one end of the nozzle, can transition to a circular or differently-shaped aperture at the other end of the same nozzle.
• the notion of enhanced airflow does include the concept of having faster airflow, however, the notion of enhanced airflow also includes the concept of maintaining a suitable airflow through and out of the dryer 1, in spite of the decelerating effect of the filters. In other words, the enhancement comes from overcoming the deceleration that normally would occur when one or more filters would otherwise impede the airflow inside the dryer to a detrimental degree. Hence, in some embodiments, the invention is able to, but not necessarily limited to, achieving faster airflow.
• the invention may include cases where the airflow speed is not substantially reduced, even with the use of one or several impeding filters, compared to a situation where none of the improved features of the present embodiments were incorporated in the dryer.
• the airflow that flows through the airflow system in the hand dryer 1, is driven by the fan 401.
• the fan is rotated and thus activated by a universal commutator motor.
• the inventor has identified a need to establish a relationship between the stationary field of preferably a universal motor and its rotating armature.
• the failing of motors of this type is very often the result of the failing of the bearing due to overheating which may result in the leaking out of lubricant resulting in at least one of the following: noisysy Bearing; Higher Friction; More Heat generated to overcome the friction and the final result may be the burning out of the motor. Accordingly, the magnetic relationship has been established to achieve a relatively cooler Armature.
• the traditional design of universal motors attempts to keep the magnetic force (or magnetic field strength) at a ratio of 1 to 1 between armature and stationary field. In the magnetic relationship established in accordance with a preferred embodiment, a ratio of less than 1 to 1 is provided. Preferably, the ratio is about 0.9 to 1.
• At least one Carbon Brush and Brush Holder may be modified to provide good electrical connection and flexible conductor is preferably used to ensure a positive electrical connection at all times.
• two carbon brushes and brush holders i.e. two carbon brushes each with a brush holder, may be modified to provide the good electrical connection and flexible conductor.
• flexible braided copper wire inserted into the carbon brush at one end thereof the brush and have the copper attached, for example, soldered or crimped, at the other end to the terminal connecting to the field wiring.
• suitable materials for the flexible conductor may be silver, brass or other conducting materials which would be recognised by the person skilled in the art.
• a commutator of high performance grading with a reinforcing ring may be used to substantially eliminate any Bar to Bar movement at high speed.
• a solution provided in preferred embodiments is to use a commutator 610 with individual copper segments 611 and a conducting reinforcing ring 612 that is positioned or located within the commutator body 613 at a distance from the conductive segments 611 and moulded within the moulding material 614 of the commutator 610.
• the conducting material used for the reinforcing ring 612 may be a metal with sufficient strength to provide suitable reinforcement under high speed operation and durability to the commutator, for example, steel or aluminium.
• the commutator 610 of Figure 6K has the following advantages which may ensure that the commutator bars or segments 611 do not lift or move even at high speeds:
• the solid and rigid copper segment 611 will not get distorted or bend even in elevated temperatures.
• the reinforcing ring 612 which is moulded into the commutator 610 acts like a reinforcing as in concrete.
• the reinforcing ring 612 being made of a strong material to provide rigidity to the commutator 610 and may be useful where individual copper segments 611 are used in the commutator 610. It is noted that the commutator of Cooper et al mentioned above may not be applicable to such commutators.
• the universal motor of preferred embodiments also comprises a thermal fuse/protector as a useful safety and failsafe addition.
• the advantages provided with the above noted features of the universal motor in combination are as follows.
• the motor performs at lower armature temperature
• the motor has a longer life expectancy
• the motor is serviceable
• the motor is suitable for short interval operation as well as continuous operation
• the motor can operate in higher ambient temperatures.
• a preferred embodiment of the universal motor with suitable components and example construction is illustrated in Figures 6C to 6J.
• these enhancing features include: the use of a dual fan, and/or provision of the tapered exit nozzle and/or use of a suitable constant speed motor.
• the exit airflow 200E can be around 72 m/s.
• a single nozzle can be designed with a mechanism that allows the user to mechanically adjust the shape of the taper of the nozzle, so that this one single user-variable nozzle can be used in all environments.
• the apparatus can be provided with multiple exit nozzles that incorporate the principles of faster airflow, described herein.
• the reference to a downstream exit airflow-pathway includes the option of more airflow-pathways.
• the system can be used with dryers that have one or more filters, although the benefits of the system are best seen in dryers that have a plurality of filters.
• the embodiment in Figure 2 has potentially six filters that can each decelerate the speed of the airflow.
• the embodiments have been advanced by way of example only, and modifications are possible within the scope of the invention as defined by the appended claims.
• upstream of the heating-means is provided with the airflow-pathway that is progressively smaller along its pathway in respect of fiowthrough cross-section, i.e. in this embodiment, a or the heater is provided at the end of the tapered nozzle.

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• 2008
  • 2008-03-12 WO PCT/AU2008/000338 patent/WO2008109942A1/en active Application Filing
  • 2008-03-12 US US12/531,250 patent/US20100209080A1/en not_active Abandoned
  • 2008-03-12 TW TW097108673A patent/TW200916038A/zh unknown
  • 2008-03-12 AU AU2008226326A patent/AU2008226326A1/en not_active Abandoned
  • 2008-03-12 CN CN2008800157443A patent/CN102316779A/zh active Pending
  • 2008-03-12 EP EP08733267A patent/EP2182830A1/en not_active Withdrawn

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