Patent Application
20060093463
This invention relates to air moving appliances. More specifically, the present invention relates to a vertical tower fan.
Portable, free standing fans of various sizes have been used for many years. The normal use of a portable fan is to provide a cooling sensation to the body of the user. This is accomplished by the current of air generated by the fan passing over the skin of an individual. The current of air that passes over an individual serves to increase the convective heat loss of the body through the natural evaporative process of moisture (e.g. sweat) on the skin. The greater the amount of evaporation the greater the sensation of cooling. Further, the greater the portion of the body that can be effected by the current of air the greater the cooling sensation to the user.
Conventional portable fans using axial impellers have been utilized to achieve these desired cooling effects. However conventional axial impeller have several disadvantages. The axial impeller is normally large and requires even larger protective grills. These types of devices not only produce an air stream but may also produce a significant volume of air movement. The shape of the air stream produced by the conventional portable fan utilizing an axial impeller is conical. As the air stream travels away from the fan the area of coverage grows in diameter. The significant volume of air combined with the growth in the coverage area of the air stream may cause objects, (such as papers for example) to be dislodged from their intended place. Further, the volume and growth of the coverage area as described increases the possibility that dust, pollen, dander, etc. will be disturbed and induced to become airborne. Airborne dust and debris can be detrimental to, for example, respiratory conditions.
The volume of air produced by a conventional fan utilizing an axial impeller also requires a predetermined amount of power to produce the volume of air. A greater volume of air requires more power from the electric motor of the fan. More power from the electric motor normally requires that the motor utilize more materials such as lamination steel and copper wire. The increased material usage increases the cost of the conventional fan for both the manufacturer and the end user.
The volume of air produced by a conventional portable fan using an axial impeller also may contribute to increased thrust. Increased thrust is detrimental to the stability of the fan. This thrust must be counteracted by utilizing a large base to stabilize the device. The thrust and stability problem can be exacerbated if the device is elevated above its support surface. The large components (blades and protective grills) of axial fans along with the increased thrust and corresponding stability problems do not allow these types of devices to be easily transportable (portable) or to have space saving characteristics.
The large base and grills of the conventional portable fan, as described, require a significant amount of packaging material as well as space for shipment. In an effort to conserve space requirements for shipping these fans are often disassembled and require customer assembly. If the customer fails to follow the assembly instructions properly the fan may not be stable, safe and/or may be returned to the manufacturer. This may causes extra cost for the manufacturer, retailer and be the cause of a poor customer experience.
In view of the deficiencies of the prior art the following description is of a vertical tower fan that overcomes several if not all of the prior art deficiencies.
According to one aspect of the invention, the device is portable and includes an air blower assembly, and a vertically oriented elongate housing having a longitudinal length extending substantially upward from a support surface.
According to another aspect of the invention, the elongate housing defines an interior space having an air blower assembly disposed within.
According to another aspect of the invention, the air blower assembly includes at least one motor, and at least one air impeller rotated about a vertical axis of rotation by the motor.
According to yet another aspect of the invention, the housing includes at least one air inlet allowing intake air to enter the interior space and an elongate air outlet allowing an exhaust air stream generated by the air blower assembly to exit the interior space of the housing.
According to another aspect of the invention, the device includes an air guide within the interior space. The air guide is positioned within the interior space to extend along the axial length of the air impeller.
According to another aspect of the invention, the device includes an air cut-off within the interior space. The air guide is positioned within the interior space to extend along the axial length of the air impeller.
According to another aspect of the invention, the device includes a base for engaging the support surface.
According to yet another aspect of the invention, the air impeller has an axial length greater than about 24 inches;
According to another aspect of the invention, the overall height of the device, defined as the distance from where the base engages the support surface to a maximum vertical extent of the device is greater than about 44 inches.
According to another aspect of the invention, the air impeller is a transverse type air impeller.
According to another aspect of the invention, the air guide includes a concave form when referenced from the axis of rotation of the air impeller and the air cut-off includes a convex form when referenced from the axis of rotation of the air impeller.
According to another aspect of the invention, the interior space includes an intake portion in fluid communication with the air inlet and defined by portions of the elongate housing, the air guide, the air cut-off, and the air impeller.
According to yet another aspect of the invention, the interior space includes an exhaust portion in fluid communication with the elongate air outlet and defined by portions of the air guide, the air cut-off, and the air impeller.
According to another aspect of the invention, the elongate housing includes a vertical aspect ratio greater than about 3 to 1 defined by the longitudinal length being greater than a maximum width of the elongate housing.
According to another aspect of the invention, the device includes a maximum exit elevation of the exhaust air stream greater than about 36 inches and a minimum exit elevation of the exhaust air stream less than about 15 inches. The maximum exit elevation is defined by a distance from the support surface to the highest vertical exit elevation of the exhaust air stream. The minimum exit elevation is defined by the distance from the support surface to the lowest vertical exit elevation of the exhaust air stream.
According to another aspect of the invention, the vertical length of the exhaust air stream as it exits the housing is greater than about 24 inches.
According to another aspect of the invention, the air impeller includes a maximum diameter of less than about 4 inches.
According to another aspect of the invention, the air impeller is constructed of fiber-reinforced polymer utilizing a polymer matrix and fibers and/or filaments.
According to another aspect of the invention, the air impeller is located substantially above the motor with respect to the base and an upper impeller bearing assembly supports an impeller shaft as the air impeller rotates about it's vertical axis of rotation.
According to another aspect of the invention, the impeller bearing assembly includes a spherical bearing. Preferably, the spherical bearing is constructed of porous material and includes an oil cup, capillary media physically contacting the spherical bearing and substantially covering the inside circumferential area of the oil cup, oil, and a slinger that rotates in conjunction with the air impeller.
According to another aspect of the invention, the oil cup extends below the spherical bearing toward the support surface allowing the capillary media to return the oil to the bearing after the oil migrates along the impeller shaft toward the oil slinger.
Additional features of the present invention are set forth below.
The invention is best understood from the following detailed description when read in connection with the accompanying drawing. It is emphasized that, according to common practice, various features of the drawings are not to scale. On the contrary, the dimensions of various features are arbitrarily expanded or reduced for clarity. Included in the drawings are the following Figures:
The present invention is directed to a vertical tower fan that includes a vertical aspect ratio relative to a support surface. The air stream produced by the device also has a vertical aspect ratio. The vertical aspect ratio of the device and air stream allow the generated air stream to better conform to the human form without the need to produce large volumes of air.
The lower volume of air generated by the device has a velocity sufficient to impinge upon the user, which accelerates evaporation and the cooling effect on the user. The lower volume of air also requires less power to produce, thus reducing the cost of the electric motor within the device. The lower volume of air produced also lowers the thrust and increases the stability of the device. The increased stability of the device reduces the requirement for a large base.
The device is also able to more precisely direct the generated air stream at the user than the prior art, which also accelerates evaporation and the cooling effect on the user. A more precise direction of the generated air stream also reduces the possibility that object, dust, pollen, dander, etc. will be disturbed.
The vertical tower fan also offers a space saving design over conventional fans. The use of a transverse impeller, (cross flow blower) eliminates the need for large protective grills typically required on, for example, axial type fans. The decreased base size, resulting from the reduced thrust, as well as the elimination of the large protective grills minimize the space required to operate, store and ship the device. The minimization of space significantly enhances the space saving aspects of the device. The minimization of space may also allow the device to be shipped with little or no customer assembly. Little or no customer assembly increases customer satisfaction and may decrease returns to the retailer and manufacturer.
The present invention includes various combinations of one or more of the above characteristics and features at a desirable retail cost for the consumer.
In one exemplary embodiment, housing 102 is an elongate housing having a vertical aspect ratio. The vertical aspect ratio of housing 102 is defined as the vertical height H of housing 102 being greater than a maximum horizontal width W of housing 102. In one embodiment the vertical aspect ratio of said elongate housing is greater than about 3 to 1.
Vertical tower fan 100 includes at least one air inlet 110 and at least one air outlet 112. As shown in
Vertical tower fan 100 also includes at least one control assembly 170. Control assembly 170 controls a function of vertical tower fan 100. Also shown is power cord 178, utilized to connect vertical tower fan 100 to an electrical power source (i.e. wall outlet). The electrical component connections of vertical tower fan 100 are integrated within the device, such as for example between control assembly 170 and blower assembly 106. The integration of the electrical component connections within the device eliminates the need for the user to make such connections. In the exemplary embodiment shown, for example, only the connection of power cord 178 to an electrical power source is required for operation of the device. The integration of all the electrical component connections within the device also enhance the portability of vertical tower fan 100.
As shown, housing 102 also includes handle 114. Handle 114 is used to increase the convenience of portability of the device. It is contemplated that handle 114 may be an integral part of housing 102 as shown, or alternatively, handle 114 may be formed as a separate piece or pieces (not shown) that are attached to vertical tower fan 100.
Disposed within interior space 104 is air blower assembly 106. Air blower assembly 106 includes motor 116 and at least one air impeller 120 connected to motor shaft 118. Motor 116 rotates air impeller 120 about axis of rotation Z. Motor 116 may be mounted to housing 102 via a bracket (not shown) or through other conventional means. In a preferred embodiment air impeller 120 is a transverse type impeller. As shown in
Also shown in
In the exemplary embodiment shown, air guide 122 and air cut-off 124 are discrete parts. It is contemplated that one or both air guide 122 and/or air cut-off 124 could be designed so as to be integral with another component of vertical tower fan 100, such as, for example, housing 102. It should be noted that the use of air guide 122 and air cut-off 124 as discrete parts may allow better control of form and shape of these components and thus increase the possible efficiency of blower assembly 106.
Also shown in
Preferably, protective grill 136 is located proximate air outlet 112. Protective grill 136 is designed to protect interior space 104 from the penetration of foreign objects. Protective grill 136 is also designed to minimize it's impedance to exhaust air stream exiting vertical tower fan 100. Incorporated with protective grill 136 may be air directing devices, such as, for example, adjustable louvers (not shown). Adjustable louvers allow additional directional control capabilities of the high velocity air stream. Protective grill 136 may be attached to housing 102 through an assembly device, (not shown), such as for example; screws, adhesives or snaps.
Intake grills 111 is preferably located proximate at least one air inlet 110. Intake grills 111 is designed to minimize their impedance to the flow of air into vertical tower fan 100 while at the same time protecting vertical tower fan 100 from the penetration of foreign objects into interior space 104. As shown, intake grill 111 may be an integral part of housing 102, specifically body half 102a.
Although the exemplary embodiment shown in
In one exemplary embodiment, housing 102 rotates with respect to base 160 and/or a support surface (not shown). Such rotation may be accomplished either in an oscillatory fashion, a stepwise positioning of housing 102 (either manually or under automated control), or in a constant rotation, either in a clockwise or counter-clockwise direction. In one example the rotational range of housing 102 is between about 0 degrees and about 360 degrees. In another exemplary embodiment the rotational range is between about 0 degrees and about 90 degrees.
Control assembly 170 is used to control a function of vertical tower fan 100, such as, for example, the speed of air blower assembly 106 and/or rotation or oscillation of housing 102. As shown control assembly may include control cover 172, button plate 174 and electronic components 176. In a preferred embodiment, electronic components 176 are located within control cover 172. Electronic components 176 may include, for example, switches, power control boards and LED indicators. In one preferred embodiment control assembly 170 is mounted on top 103 housing 102. The position of control assembly 170 on the substantially vertical and upright structure of vertical tower fan 100 benefits the user in that the height of control assembly 170 above a support surface (floor) allows convenient accessibility for visual inspection and manual adjustment of the controlled functions. Alternatively, a remote control unit (not shown) may accomplish the control of vertical tower fan 100 in conjunction with, and/or as a replacement for control assembly 170.
It is contemplated that vertical tower fan 100 may be constructed with material such as polymers, sealed motors, sealed switches and other components, such as for example rain sensors that could optimize a weather proof construction. This would facilitate the use of vertical tower fan 100 on decks, boats and other areas that might be exposed to varying weather conditions.
Functionally, as shaft 123 rotates about axis Z causing a hydrodynamic oil film to develop between shaft 123 and the internal diameter of bearing 152. Gravity will naturally cause the oil film to migrate down the shaft along a first path 160. Oil contacts oil slinger 153 that is rotating with shaft 123. Centrifugal force is imparted to the oil film and causes the oil film to be “slung” radially out along second path 161. Oil film is then absorbed into capillary media 151 and moves via capillary action along path 162 making contact with bearing 152. The oil film is then absorbed into bearing 152 and recirculates through the hydrodynamic process again.
The use of bearing assembly 150 as described increases the life of bearing 152 and shaft 123, increasing in turn the overall functional life of vertical tower fan 100. If the oil film is allowed to dissipate from bearing 152 without recirculation as described, the friction between shaft 123 and bearing 152 will cause pre-mature failure.
Preferably air guide 122 and air cut off 124 segregate interior space 104 of housing 102 into intake portion 104a and exhaust portion 104b. The position of air guide 122 and air cut off 124 relative to air impeller 120 allow the free rotation of air impeller 120 around axis Z while simultaneously preventing the recirculation of exhaust air 302 from exhaust portion 104b toward intake portion 104a within interior space 104. The impedance of air recirculation within interior space 104 encourages a more efficient movement of intake air 300 and exhaust air stream 302 through vertical tower fan 100. Air guide 122, in this example, is concave when referenced from axis of rotation Z of air impeller 120. Air cut-off 124, in this example, is convex when referenced from axis of rotation Z of air impeller 120.
The shape and form of both air guide 122 and air cut-off 124 allow a rotation of air impeller 120 about axis of rotation Z to efficiently develop a first pressure differential between intake portion 104a and the atmosphere exterior to housing 102. This first pressure differential induces intake air 300 to enter intake portion 104a through air inlet 110. The shape and form of both air guide 122 and air cut-off 124 also allow a rotation of air impeller 120 about axis of rotation Z to efficiently develop a second pressure differential between exhaust portion 104b and the atmosphere exterior to housing 102. This second pressure differential induces exhaust air stream 302 to exit exhaust portion 104b through air outlet 112.
Air guide 122 and air cut off 124 divide air impeller 120 into intake side 120a and exhaust side 120b. Intake side 120a is defined as a first distance measured in a direction of rotation of air impeller 120 along the circumference of air impeller 120 from air cut off 124 to air guide 122. Exhaust side 120b is defined as a second distance measured in a direction of rotation of air impeller 120 along the circumference of air impeller 120 from air guide 122 to air cut off 124. Intake side 120a of air impeller 120 is in direct fluid communication with air inlet 110 via intake portion 104a of interior space 104. In a like manner exhaust side 120b of air impeller 120 is in direct fluid communication with air outlet 112 via exhaust portion 104b of interior space 104.
Located proximate air outlet 112 is protective grill 136. Protective grill 136 is designed to minimize it's impedance to exhaust air stream 302 as it exits housing 102, while yet protecting air impeller 120 from the penetration of foreign objects.
Also shown in
In one embodiment, dimension H is greater than about 44 inches, dimension AH1 is greater than about 36 inches and dimension AH2 is less than about 15 inches. In one preferred embodiment, exhaust air stream 302 has an elongate vertical aspect ratio. The elongate vertical aspect ratio of exhaust air stream 302 is defined as dimension AL being greater than dimension AW. In one embodiment, Dimension AL of exhaust air stream 302 is greater than about 24 inches. In one embodiment the vertical aspect ratio of exhaust air stream 302 is about 10 to 1 or greater.
As described and shown, the dimensional aspects of vertical tower fan 100 combined with the dimensional aspects of exhaust air stream 302 and air impeller 120 allow the generated exhaust air stream 302 to better conform to the elongated form of the human body. The dimensional aspects of air exhaust air stream 302 and air impeller 120 have been designed to effectively generate exhaust air stream 302 with an ability to reach the user at a predetermined distance from vertical tower fan 100 at a predetermined velocity thus delivering the desired cooling effect. The air flow characteristics of exhaust air stream 302 may be stated:
Q/A=V
Where: Q is the volume (cubic feet per minute) of air generated by air impeller 120. V is the desired velocity (feet per minute) of exhaust air stream 302. A is the area of exhaust air stream 302 as it exits housing 102. area A can also be expressed:
A=AL×AW
The air flow characteristics of exhaust air stream 302 therefore may be stated:
Q/(AL×AW)=V
The dimensional aspects of vertical tower fan 100 consider the following: The velocity V of air stream 302 is predetermined to effectively reach the user and deliver the desired cooling effect. The desired volume of air flow Q generated by air impeller 120 is also predetermined in that Q is limited to allow the use of a low power electric motor. A lower Q requires less power to produce than a higher Q. AL is also predetermined to sufficiently conform to the desired elongate form of the human body. Therefore AW remains to be manipulated to achieve the predetermined velocity characteristics V of exhaust air stream 302. In one embodiment AW of exhaust air stream 302 is about 3 inches or less.
The volume of air Q generated by air impeller 120 is influenced by dimensions AID of air impeller 120 and dimension AIL of air impeller 120. Dimension AIL of air impeller 120 is predetermined to conform to the desired elongate form of exhaust air stream 302. Therefore, an effective way to limit air volume Q of impeller 120 is to reduce dimension AID. One advantage of a reduced dimension AID of air impeller 120 is that it more easily fits within elongated housing 102 of vertical tower fan 100, thus maintaining the desired vertical aspect ratio. Another advantage of the reduced dimension AID of air impeller 120 is that any uneven weight distribution within the structure of air impeller 120 is less likely to effect the rotation of air impeller 120, thus reducing possible vibrations due to impeller imbalance. In one embodiment dimension AIL of air impeller 120 is greater than about 24 inches. In one embodiment dimension AID of air impeller 120 is less than about 4 inches. In another embodiment dimension AID of air impeller 120 is within a range between about 2.5 inches and about 3.75 inches.
The desired length AIL of air impeller 120 increases the possibility of distortion and force balance problems in the structure of air impeller 120. The structural problems may occur in the fabrication or assembly of air impeller 120. The desired length AIL of air impeller 120 also increases the distance between bearing support areas (not shown) at the opposite extents of length AIL. Increased distance between bearing support areas augment the possibility of vibration and dynamic imbalances during the rotation of air impeller 120. The possible structural distortion of air impeller 120 will further contribute to vibration and dynamic imbalances during the rotation of air impeller 120.
One manner to mitigate the possible structural distortion is to construct air impeller 120 of a fiber-reinforced polymer utilizing a polymer matrix, such as, for example, acrylonitrile-butadiene-styrene (ABS) and fibers, filaments and/or fillers, such as, for example; glass, ceramic, textile and/or steel. The use of such a material increases the structural strength and dimensional stability of air impeller 120. The increased strength and dimensional stability of air impeller 120 further enhance the balance and precision of air impeller 120 during the operation of vertical tower fan 100 thus maintaining better designed performance characteristics.
Another manner to obtain the balance and structure desired is to construct air impeller 120 from multiple sections of impeller fins 502, impeller ends 504 and support structures 506. The multiple sections of air impeller 120 may be assembled together utilizing conventional assembly techniques, such as, for example: adhesives, chemical reactive welding, ultrasonic welding, etc. The use of multiple sections decrease the size of a the molded parts enhancing the ability of a fiber-reinforced polymer to fill the tool cavity during the injection molding process. The use of multiple sections also adds support structures 506 throughout the length AIL of air impeller 120. The distribution of support structures 506 throughout the length AIL of air impeller 120 increases the structural strength and dimensional stability of air impeller 120. In one embodiment air impeller 120 includes about 6 or more sections of impeller fins 502. In another embodiment air impeller 120 is constructed of between about 7 and about 12 sections of impeller fins 502. In another embodiment the axial length of one section of impeller fins 502 is less than about 5 inches. In yet another embodiment the axial length of one section of impeller fins 502 is between 2.5 inches and about 4.5 inches.
An impeller with the aforementioned material, size and structure characteristics minimizes unwanted vibration and dynamic imbalances during a rotation of air impeller 120. In turn minimizing the need for extensive dynamic or static balancing of impeller 120. If limited balancing is needed, it has been found that the balance of air impeller 120 is improved if the rotational speed (RPM) of air impeller 120 during a dynamic balancing process is substantially equal to the maximum operational rotational speed of air impeller 120. The maximum operational rotational speed of air impeller 120 is defined as the maximum rotational speed which air impeller 120 will experience within the normal operational parameters of vertical tower fan 100.
As shown in
Another advantage to the minimization of thrust is that motor 116 of the vertical tower fan 100 does not require the power, (measured in work per minute, e.g. watts) that would be needed to move a large volume of air. This allows the needed motor torque to be reduced and decreases the heat generated by motor 116. Motor 116 may therefore utilize fewer materials and be less expensive while yet producing the required air stream velocity. This in turn yields cost savings for the manufacturer and the consumer. In one embodiment the maximum torque motor 116 is capable of generating is less than about 22 in-oz.
In one exemplary embodiment exhaust air stream 302 has a maximum velocity V of about 400 feet per minute or greater when measured at a distance of about 8 feet from housing 102. The maximum velocity of exhaust air stream 302 is measured by locating an anemometer 8 feet from air outlet 112 of portable air moving device 100. The anemometer is moved vertically up and down and horizontally while maintaining the 8 feet of distance until the maximum velocity within exhaust air stream 302 is located.
In another exemplary embodiment the maximum thrust generated in a direction opposite the direction of the flow of exhaust air stream 302 is about 0.5 lbs or less. The maximum thrust is measured using a certified thrust table as specified by AMCA (Air Movement and Control Association). In another exemplary embodiment the ratio of the velocity V of exhaust air stream 302 when measured at a distance of about 8 feet from housing 102 divided by the maximum thrust generated in a direction opposite the direction of the flow of exhaust air stream 302 is about 800 to 1 or greater.
Axis of rotation Y of axial impeller 704 is oriented horizontally on conventional portable fan 700. In contrast, axis of rotation Z of air impeller 120 of vertical tower fan 100 is oriented vertically. This difference reduces the effects of gyroscopic precession during the oscillation of housing 102 and increases the stability of vertical tower fan 100 when compared to the effects of gyroscopic precession during oscillation of fan assembly 702 of conventional portable fan 700.
The reduced effects of gyroscopic precession during oscillation and the lower thrust characteristics of the vertical tower fan 100, (best shown in
As shown in
As shown in
As shown in
Vertical tower fan 100 as described produces exhaust air stream 302 having a vertical aspect ratio. The vertical aspect ratio of exhaust air stream 302 conforms to the human form without the need to produce large volumes of air. Exhaust air stream 302 has a velocity sufficient to impinge upon the user and accelerate evaporation and therefore the cooling effect for the user. The lower volume of exhaust air stream 302 produced by blower assembly 106 requires less power to produce and also lowers the thrust generated as exhaust air stream 302 exits interior space 104 of housing 102. The lower power requirement reduces the cost of electric motor 116 while the lower thrust increases the stability of vertical tower fan 100 thus reducing required size of base 160. The decreased size of base 160 combined with the elimination of the large protective grills of the prior art minimize the space required to operate, store and ship vertical tower fan 100. The minimization of space significantly enhances the space saving aspects of vertical tower fan 100. The minimization of space also allow vertical tower fan 100 to be shipped with little or no customer assembly requirements which can result in increases customer satisfaction and may decrease returns to the retailer and manufacturer.
Although the invention has been described with reference to exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed to include other variants and embodiments of the invention, which may be made by those skilled in the art without departing from the true spirit and scope of the present invention.
