PATENT AND TRADEMARK OFFICE

I. CROSS REFERENCE TO RELATED APPLICATION

This application is based on and claims priority of United States Utility Patent Application 12/807,091 filed August 28, 2010.

II. BACKGROUND OF THE INVENTION

The present invention relates to an improvement in an air blowing device. Typically such a device incorporates a bladed fan wherein the blades are mounted on a shaft which is fitted into a motor for rotational purposes. The rotation of the shaft rotates the blades in order to create an air flow forward of the blades which rotate, to accelerate the air in front of the blades forward of the blade fan, while suction draws air from behind. Typically, such devices will be provided with grilles or grates surrounding the fan blades to avoid injury to the user. Such grilles or grates will also be provided with vanes or louvers which will direct the air stream from the radial and/or tangential components of the air flow toward the axial flow. It is also well known that the blades may be manufactured from metal, in which case, clearly a grille or grate of some type must be used to surround the blades to protect the user from any type of injury. The prior art similarly shows bladed fans wherein the fan blades are formed of a foam or plastic material, which minimizes injury to the user, and in the case of foam blades, permits the fan to be used without the need of a protective grille. However, all of such prior art devices require that the fan blades be mounted on a shaft which is in turn carried or mounted in a motor of some type, which operates to rotate the shaft, and it turn, the blades to create the air flow. Hence, all of the mechanisms necessary to create the air flow are exposed to the user, in one form or another.

Another form of prior art air blowing devices demonstrated in the prior art is especially shown in patent 2,488,467. The device as demonstrated in the foresaid patent is a motor driven fan and eliminates fan blades. In this instance, the fan consists of a base in which the motor is contained, the motor driving an impeller to create the air flow, the base extends upwardly via a neck portion, which has three distinct nozzles mounted to the upper portion of the neck, and each of which includes a hollow interior chamber, into which the air flow created by the motor's impeller will flow. Each of the nozzles are provided with a slot formed along the outer forward edge thereof, and which functions as an exit port for the air flow generated by the impeller of the motor. As indicated in the aforesaid patent, the device is intended to produce a uniform flow of air which may be regulated without changing the speed of the motor and which moves the moving elements including the motor and the impeller into an enclosed base, providing a safety feature for the user. Further note that the impeller here would spin much faster than the blades of a typical motor driven fan for ventilation. This gives the air flow a greater velocity even if the total flow rate were the same.

The prior art has advanced to a further improvement over the bladeless motor driven fan as shown in patent 2,488,467, as demonstrated by US patent application publication US 2009/0060710. This device makes use of the concept of a nozzle or housing which incorporates a Coanda surface adjacent to the slot opening of the housing or nozzle. As described in the aforesaid publication, the device includes a base which contains the motor and impeller device which creates the air flow, and exits the base into a circular housing or nozzle which has a hollow interior, and exits the housing interior toward the central axis via a slot formed along the periphery of the rear portion of the housing. As described in the aforesaid publication, the air discharge slot is formed adjacent to a curved or Coanda surface which is formed along the wall on the downstrearn side of the slot throughout. As indicated by the specification therein, the Coanda surface is intended to draw air from outside the fan assembly through the opening formed by the housing, by bending in a forward direction the air flow directed over the Coanda surface. As indicated therein, air exiting from the slot hugs the Coanda surface, expands downstream of the slot and this air stream will cause air from outside of the fan device to draw air through the central opening therein to produce an enhanced air flow forward of the air device. Again, as indicated therein, the primary air flow directed over the Coanda surface combined with the secondary air flow entrained by primary air flow acts as an air amplifier and gives a total air flow emitted or projected forward to a user from the opening defined by the nozzle. Hence, the total air flow is sufficient for the fan assembly to create an air current suitable for cooling.

A companion publication describes the relationship between the fan nozzle and the base as described in publication US 2009/006071 1. It is stated therein that the base is no more than twice the depth of the nozzle and width of the base is no more than 75% the width of the nozzle. These relationships appear to permit the device to be made as small and as compact as possible due to space restrictions in domestic environments.

The present invention relates to a further improvement to the design of an air blowing device or ventilating device and acts like a conventional axial bladed fan without exposure to rotating blades in the same manner as the prior art referenced hereinabove. The present invention takes advantage of the principals of induction or entrainment wherein a jet of air directed into a volume of stationary air accelerates adjacent volumes of stationary air to increase or magnify the volume of moving air. However, the present invention avoids having to resort to Coanda effect flow to achieve this magnification, rather, using simpler methods of collimating and redirecting air flows to shape the velocity distribution of the discharged air stream. As demonstrated in the -710 and -71 1 prior art devices, the device employs a Coanda surface. The Coanda effect in fluid flow describes the tendency of a jet of air to appear to be attracted to convex solid surface as the jet passes near. This results in a pressure drop in the region between the jet and the surface drawing the jet toward the surface. The effect is used to bend the discharge of the jet from a nozzle toward an adjacent curved surface and has the effect of directing the stream of air forward. This stream induces the volume of still air within the annulus or open space of the nozzle to move forward by induction, giving the multiplier effect as claimed therein. It will be noted, however, that the single ring disclosed therein includes a slot or opening located toward the rear of the ring and designed with the Coanda surface so that the jet emerges almost parallel to the inside surface of the ring. This construction will cause the still air behind the annulus or opening of the nozzle to be induced to move forward once the air flow emanates from the slot of the nozzle. In the previously mentioned prior art device of the -467 patent, it will be observed that the slot of each of the rings is located at the forward edge of each of the rings. The air jets out through the orifices or slots into an annular pattern of air stream through concentric streams as demonstrated in the aforesaid patent. The air streams will therefore diffuse radially outward and inward and merge forming a more typical bell shape distribution pattern of air flow that varies with radial distance from the center axis of the diffuser. The air flow exiting the nozzle will tend to separate out and not be collimated into a beam of air. The result of this construction is that the user of the fan will not feel a beam of cooi air when utilizing the device.

The problem which exists with respect to the prior art devices is that the air flow may not be strong because there is too much of a transverse or radial flow of air relative to the central axis of the air flow stream. This results in weak air flow and inefficient operation. As far as the device shown in the -467 patent is concerned, the outer diffuser ring or nozzle will spray a good portion of its air stream outward and not forward as it lacks any kind of nozzle, guide or louvers downstream of the nozzles. The more the air stream expands laterally, the less force is felt by the user at a distance in front of the fan. As far as the device shown in the -710 and -71 1 prior art devices, the use of a Coanda effect surface means that the friction losses of the jet flowing along the surface of the air foil shaped diffuser reduces efficiency and the ultimate flow rate of air from the fan. Further, the Coanda effect cannot be scaled up to higher air flows without increasing the size of the diffuser.

Further with respect to the prior art devices mentioned hereinabove, the air flow generated by the impeller must make a sudden almost 90° turn when exiting from the base into the diffuser ring or nozzle and therefore suffers a head loss due to the air having to bend almost 90° to enter into the hollow chamber of each of the nozzles or diffuser rings. If one attempts to put a larger motor in order to move more air, the extra speed and size adds noise so that the motor driving the impeller must be slowed down in order to get into the range of noise accepted by the consumer and hence, a loss of performance in addition to a loss in efficiency.

The present invention is intended to provide an air blowing device which employs a ring or diffuser nozzle, which shall be termed herein as a housing, which is constructed to avoid the problems noted above. The device of the present invention avoids the need for having a Coanda surface, by moving the slot to the forward portion of the housing, and is constructed with a pair of inner and outer walls which are flat, but are constructed in a manner which has the net effect of collimating the air flow emitting therefrom into a beam of air thereby improving the cooling effect observed by the user thereof.

III. OBJECTS AND ADVANTAGES

It is therefore the object of the present invention to provide an air blowing device the type generally described, which is formed by a base which incorporates a motor therein, driving an impeller to create an air flow. A housing is mounted on the top of the base, which incorporates a hollow chamber therein, so that air flow created by the motor and impeller can exit the chamber of the base and enter into the interior chamber of the housing. The housing is designed to be mounted on the base with angled branches so that the air flow emanating from the impeller as it enters the interior housing chamber is bent less than 70°, and preferably approximately 45 °, in order to reduce the loss of the air pressure or air flow as the air enters into the housing chamber.

A further object of the present invention is to design the slot forming the air discharge opening adjacent the forward edge of the housing, the slot being formed by an outer extended side wall, and an inner shortened side wall, both of which are flat surfaces.

A further object of the present invention is to provide a device of the type described, wherein the base is formed as a chamber which contains a motor therein with an impeller to create the air flow, and wherein the base is surrounded by an outer chamber which has air ducts formed therein for feeding outside air into the base interior chamber. The outer chamber is provided with air inlet openings, to permit outside air to be drawn into the device when the impeller is activated. The outer chamber further serves the purpose of reducing the noise which emanates from the motor when in operation.

In conjunction with the foregoing object, a further object of the invention is to provide an air blowing device of the type described wherein the interior chamber of the base may further be provided with a noise reducing filter material mounted to the interior side walls of the chamber, so that the combination of the outer chamber and the noise reduction filter material, will greatly reduce the noise which emanates from the operation of the motor.

A further object of the invention is to provide an air blowing device of the type described wherein the housing mounted to the base takes the form of an inverted triangle having the apex of the triangle forming the two branches mounted to the base, and the base of the triangle forming the top portion of the subject device.

In conjunction of the foregoing object, a further object of the invention is to provide a device as the type described wherein the housing may take the form of a diamond shaped device. It is considered that any geometric configuration may be used so long as the branches when mounted to the base, will bend the air flow entering the housing to bend less than 90 ^° , and preferably more on the order of only 45° when entering the interior chamber of the housing.

Further objects and advantages will best be understood by reference to the accompanying drawings taken in conjunction with the following specifications.

IV. SUMMARY OF THE INVENTION

In summary, the present invention is intended as an improvement over prior art air blowing devices which improves the air flow emanating from the device by collimating the air flow emanating from the device into a beam of air to enhance the cooling effect felt by the user. This is accomplished by providing a device which consists of a base which has an interior chamber housing a motor which drives an impeller to create an air flow, and the base having suitable air inlet openings to take in outside air for the impeller to create an air flow. A housing structure is mounted to the top of the base, the housing structure being mounted at a connecting point. The housing has an internal chamber which is in fluid communication with the chamber of the base through the connection point. The housing is provided with a slot air discharge opening adjacent the forward edge of the housing, the slot being formed by an outer extended flat surface, and an inner shortened flat surface. Further, the housing will take the form of a triangle or other geometric shape wherein the branches of the housing being mounted to the base of the connection point, will form an angle with the base such that the air flow emanating from the impeller of the motor blowing up through the connection point into the housing will bend no more than and preferably around 45 ° ; Hence, the housing will ideally take the shape of triangular structure the apex of the triangle forming the connection to the base at a connection point, and the base of the triangle forming top portion of the air blowing device. Alternatively, the housing may take the shape of a diamond shaped structure. It is to be considered within the scope of the present invention to employ any geometric shape which avoids air having to bend almost 90° when entering the housing or nozzle of the base.

V. BRIEF DESCRIPTION OF DRAWINGS

The invention as illustrated in the following drawings wherein:

Figure 1 is a front elevational view in partial cross section, showing the prior art device described above, formed by a base, a neck extending up from the base, and three concentric nozzles in fluid communication with the air chamber of the base;

Figure 2 represents a cross sectional view taken along the line 2-2 of Figure 1 , showing the construction of the three concentric nozzles including the air discharge slot formed therein;

Figure 3 is a schematic view of the construction of the nozzle as shown in Figures 1 and 2 and the air flow pattern created thereby;

Figure 4 is a front elevational view and partial cross section, showing a further prior art device including a ring nozzle mounted on a base, of the type described hereandabove;

Figure 5 is a perspective view in cross section, showing the construction of the housing or nozzle of the prior art device as illustrated in Figure 4;

Figure 6 is a front elevational view of the air blowing device of the present invention, showing the base, a neck portion extending upwardly from the base, and having a housing formed as a triangular construction mounted to the top of the neck;

Figure 7a is a cross sectional schematic view of a slot air discharge opening in accordance of the present invention, the slot being formed by an outer flat extended surface and a lower shortened flat surface, the slot air discharge opening formed adjacent the forward end of the housing;

Figure 7b is comparison schematic view in cross section, showing a construction of the slot as shown of the device in Figure 1 of the drawings and a comparison of the air flow emanating from the slot air discharge opening therefrom;

Figure 7c is a further embodiment of an slot air discharge opening in cross section, of a possible alternative embodiment of the present invention wherein the outer flat surface wall of the slot is further extended, and the inner shortened flat surface is set further back from the forward edge of the housing;

Figure 8 represents a further alternative embodiment of the present invention, wherein the housing includes a pair of concentric housings mounted to the base via neck portion but incorporating the slot air discharge opening as described with respect to the present invention;

Figure 9 is a front elevational view in cross section, showing the details of construction of the base of the unit having a motor mounted therein, and the construction of an outer chamber surrounding a base chamber which functions as a means for controlling the air flow into the base and into the housing via the opening between the base and the housing and further shows the noise reduction the capacity by the inclusion of filter material mounted to the inside walls of the interior chamber;

Figure 10 is a front elevational view illustrating a further embodiment of the present invention which takes the form of a tower fan blowing device, and functions by the use of a pair of opposed housing members mounted to the base, and creates a beam of collimated air flow there between;

Figure 1 1 is a cross sectional view taken in the direction of the arrows 1 1-1 1 of Figure 10, showing the construction of the two housing members including the slot air discharge opening associated with each of said housing;

Figure 12 is a side elevational view, partly in cross section, showing the construction of the housing of the air blowing device shown is Figure 6;

Figure 13 is a cross sectional view of the housing as shown in Figure 12 of the drawings; and

VI. DETAILED DESCRIPTION OF DRAWINGS

With specific reference to Figures 1 - 3 of the drawings, a prior art device is illustrated therein. As was mentioned in the description of the prior art, Figure 1 represents the device as illustrated in patent 2,488,467. It will be observed that the device is formed by a base 10, which has an air chamber 1 1 formed therein. The base incorporates a motor 12 which drives an impeller 13 in order to create the air flow. An air chamber 1 1 extends upwardly through the neck 14, and enters into each of three rings, 15, 16 and 17 respectively, and noted as "nozzles" in the subject patent. Each of the rings 15, 16 and 17 respectively terminate in annular slot or air discharge opening denoted by the numeral 18. It will therefore be appreciated that the air flow created by the impeller 13 blows upwardly through the neck 14 and into each of the rings 15, 16 and 17 respectively, and exits the device through each of the air discharge openings 18. Hence, an air flow is created forward of the device toward the user thereof.

Figures 2 and 3 denote the construction of each of the rings, 15, 16 and 17 respectively, and the discharge air opening 18. Figure 3 illustrates the construction of the air discharge opening 18 and illustrates in schematic form, the air flow created therefrom. When the device is operational, air jets out through the air discharge openings, into an angular pattern of air stream, that is, three concentric streams in this case. Far from the unit, the air streams diffuse radially outward and inward and merge forming a typical bell shaped distribution pattern of air flow that varies with radial distance from the center axis of the diffuser. It is obvious from the views of Figures 2 and 3 of the drawings, that the air flow exiting the air discharge opening will tend to spread out and not be collimated into a beam of air. The air flow pattern mentioned herein is generally illustrated by the arrows 19 of Figure 3.

Figure 4 illustrates still another prior art device of the type previously mentioned hereinabove, and as depicted in patent publication -710 and -71 1. This device is formed by base 20 which has an interior air chamber 21 and wherein the base 20 houses a motor 22, which drives an impeller 23. A housing 24 is mounted to the base 20 and takes the form of a ring and has a hollow interior 25, which is in fluid communication with the air chamber 21 of the base 20. The ring 24 is provided with a slot or air discharge opening 26 which has the construction as shown in Figure 5 of the drawings. As illustrated in Figure 5 of the drawings, the air discharge opening is constructed with a Coanda surface 28 formed immediately adjacent the opening 26. As was previously mentioned, the Coanda surface provides a Coanda effect fluid flow which describes the tendency of a jet of air fluid to appear to be attracted to convex solid surfaces as the jet of air passes thereover. This results in a pressure drop in the region between the jet and the surface drawing the air jet toward the surface. The effect is used to bend the discharge of a jet from the nozzle or air discharge opening toward an adjacent curved surface. According to the aforesaid prior art description, air from the opening formed in the ring is induced to flow forward. A further problem is caused by the air flow which must make a sudden almost 90° turn as illustrated by arrows 27 in Figure 4, as the air flows from the base air chamber 21 into the housing air chamber 25. This, in effect, can cause a greater loss of air flow pressure than the pattern wherein the air makes a shallower bending angle from the base chamber into the housing chamber. In order to overcome that obstruction, the impeller has to work harder to move air through the closed system than a conventional axial flow fan and hence, the impeller has to be made larger or spin faster to move an equivalent amount of air. The extra speed and size will add noise so that the motor driving the impeller must be slowed to get back into the noise range that would be acceptable by a consumer. Hence, the additional problem that will be presented is the fact that the device would become overly large and cumbersome thereby defeating he purpose as set forth in the aforesaid prior art publication.

Figure 6 represents the preferred embodiment of the present invention. The present invention provides an air blowing device 30 which is formed by a base 31 , which has an upper neck portion 32 associated therewith, and is completed by a housing 34 mounted to the neck portion 32 of base 31 at a connection point 35. It will be observed that the housing 34 takes the shape of an inverted triangle having opposed branches 36 and 37 respectively, with the apex of the triangle formed by the two branches 36 and 37 being the mounting point at the connection point 35. The base of the triangular housing 34 is denoted by the numeral 38 and forms the top of the air blowing device 30. For purposes of the present discussion, the front side of the device 30 is considered to be the side which is forward of the air flow, and the top is referred by the numeral 38, and the bottom consists of the two branches 36 and 37 respectively, mounted to the base neck portion 32 and the connection point 35. The housing 34 forms an open central portion 39, through which air is induced to flow. A slot air discharge opening 40 is formed adjacent the front side of the air blowing device 30 and assumes the shape and configuration as depicted in Figures 7a and 7c of the drawings. With specific reference to Figures 7a and 7c, it will be observed that the air slot discharge opening 40 is formed by an outer extended flat surface 41 , and inner short flat surface 42. The arrows immediately forward of the air discharge opening 40 demonstrate the magnitude of the air velocity vectors across the aperture which are created when the device is operational and the air is being discharged through the opening 40. The lower arrows 43 shows how the air flow is collimated to form a beam of air to the interior side of the device, causing the air stream to be concentrated and draws air from the rear side of the air blowing device 30 forwardly therefrom. The upper arrows 44 illustrate the fact that air from externally of the device will be inducted into the air flow, but not to the same extent that the interior air flow is collimated into a beam of air to impact the user thereof.

Figure 7b illustrates the flow pattern of the slot formed in the rings 15, 16 and 17 of the prior art device illustrated in Figures 1 - 3 of the drawings. The arrows 19 illustrate that the air flow pattern is not collimated, but rather spread out to the upper and lower sides of the upper and lower portions of the air discharge opening 18.

Figure 7c illustrates a further embodiment of the present invention, wherein the outer extended flat surface 41 is further extended than the inner shortened flat surface 42, which has the effect of having even more of the air flow to the interior side of the housing 34.

Figure 7b represents the construction of the nozzle or housing of the air blowing device of the Figures 1 - 3 of the drawings. As was indicated, the nozzle or ring 15 has an air discharge opening 18 through which the air is discharged during use. The discharged air has a flow pattern as demonstrated by the arrows 19. It will be observed that the air pattern is not collimated but rather, will radiate outwardly.

Again with a view in Figure 6, an advantage of the present invention is derived from the triangular configuration of the housing 34. As previously indicated, the housing 34 takes the shape of a triangular configuration, with the triangle base 38 forming the top of the device 30, and the branches 36 and 37 forming the connection to the neck portion 32 of the base 31 at the connection point 35. With respect to Figure 6, the arrows 46 show the air flow that emanates from the base interior chamber into the housing chamber assuming an angle of less than 70 ^° .

The construction of the base interior and the related upper housing is more clearly shown in Figure 9 of the drawings. The base 31 includes an interior chamber 51 , and accommodates the mounting of a motor 52 therein which drives an impeller 53. In the embodiment illustrated in Figure 9, the base 31 is provided with an outer chamber 54 which surrounds the base 31. The outer chamber 54 includes an outer wall 55 which is provided with air inlet openings 56 to allow outside air into the device. The outer chamber 54 is constructed with at least one or more air ducts 57 which will direct the air flow into the interior chamber 51 of the base and provide a source of air for the motor 52 and impeller 53. The air flow is illustrated by the arrows 59, and is created by the air flow emanating by the impeller 53. The air flow enters into the housing 34 via the opening 61 which exists between the base interior chamber 51 , and the housing interior chamber 48.

It will be appreciated that the outer chamber 54 not only directs the air flow into the interior chamber 51 of the base, but also serves the purpose of deadening the noise created by the motor 52. A further feature that helps in the noise deadening capacity of the device is the provision of the filter material mounted along the walls of the base interior chamber 51. The filter material 63 is porous in nature, and hence, may be mounted over the air duct 57 and affords the device to have the opportunity to still have an inflow of air to feed air to the impeller 53 when it is operational.

From the above description it will be appreciated that the air blowing device 30 of the present invention operates in much the same manner as prior art devices, but improves upon the same by the construction of the housing, which takes the form of either a triangular configuration, or another geometric shape such as a diamond shape configuration. As will be appreciated from Figures 6 and 9 of the drawings, the efficiency of the air blowing device is maximized by using a geometric shape for the housing 34 which minimizes the angle of the bend of air as it flows from the base chamber into the housing chamber. Hence, an angle of 45" or even less results in an efficient air flow.

Figure 8 represents a further alternate construction of the present invention. In this embodiment, the air blowing device 90 is formed by a base 91 which houses the motor (not shown) and is connected to the housing by a neck 92. The housing takes the form of a pair of triangular shaped outer housing 93 and inner housing 94. The inner housing 94 is connected to the outer housing 93 by a series of three braces 95. The construction of the outer and inner housings 93 and 94 respectively is the same as described with respect to the device of Figures 6 and 9. Each of the braces 95 has a hollow interior thereby to provide an air flow path from the base chamber via the outer housing chamber to the inner housing chamber. Further, each housing is provided with an air discharge opening 96 and 97 respectively, constructed in accordance with Figure 7a. Hence, it is contemplated that an air blowing device having multiple concentric housings falls within the scope of the present invention.

Figures 10 - 1 1 represents still a further embodiment of the present invention. The present invention may take the form of what is commonly referred to as a tower fan. A tower fan is generally an elongated structure, which is typically rectangular in configuration. As shown in Figure 10 of the drawings, the tower air blowing device 75 is again formed with a base 76 and includes a pair of opposed housings 78 and 79 respectively mounted thereon. As shown in Figure 11 , each of the housings 78 and 79 are formed with a housing interior chamber 81 and a slot air discharge opening 83. The air discharge opening 83 is again formed in the same manner as illustrated previously with respect to Figures 7a and 7c of the drawings, and as clearly shown in Figure 1 1 , will create an air flow pattern which collimates the air to form an air beam represented by the arrows 85. It will further be clear that the air flow emanating from the air discharge opening 83 will induce air from the rear side of the tower air blowing device 75 to flow through the central space 87 forward part of the device, and create the beam of collimated air as illustrated in Figure 1 1. It is contemplated that while Figure 10 shows two separate housings 78 and 79 mounted to the base 76 the housing may take the form of a single housing connected at the top by a loop in the nature horseshoe shaped housing. Figures 12 and 13 illustrate the details of construction of the housing 78 mounted on the base 76 at a connection point 80. Once again, it will be observed that th4e slot air discharge opening 83 is formed by an outer extended flat surface 82 and an inner shortened flat surface 84. The air which discharges through the slot 83 is collimated to form a beam of air to the interior side of the device 75, as was described relative to figure 7A. hence, the user will feel a stream of air when positioned in front of the device 75.

It will be appreciated from the above description that the present invention further improves upon the construction of an air blowing device which eliminates fan blades from the external portion of the device, and relies upon an internally housed motor with an impeller, to create an air flow and is formed with an air discharge opening formed near the portion of the fan device so that a beam of collimated air is formed to increase the effect of cooling upon the user.

While there has been described what is at present considered to be the preferred embodiment of the invention, further variations may be made without departing from the true spirit and scope of the invention and the claims appended hereto.