Abstract:
A combination wind direction and wind speed indicating apparatus for providing enhanced visibility at night and under other low visibility conditions is mounted, for example, at an airport landing zone, to rotate in the wind and indicates wind direction with high-intensity colored lights mounted in a specified array about the horizontal periphery of the apparatus; a vertical array of lights is illuminated in response to incremental wind speed variations. The apparatus can include a self-contained source of electrical power such as a rechargeable battery pack connected via appropriate circuitry to a solar power cell.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a wind direction and speed indicator, and in particular, to an improved apparatus design that provides greater visibility of the indicator at night and during other low visibility conditions. 
     2. Description of the Related Art 
     Airplane pilots who are approaching an airport or landing strip need to know the ground wind direction and relative speed in order to safely land their craft. A number of devices are in use, or have been proposed to assist aviators by indicating wind direction and speed. 
     Since antiquity, wind vanes have been used for indicating wind direction and some airports continue to use wind vanes for this purpose. For example, the Whitehorse International Airport in Yukon Territory, Canada, has mounted a retired commercial aircraft, a Douglas DC-3, to serve as a wind vane for the airport. Relative wind speed can be indicated with an anemometer, which is believed to have been invented during the Renaissance by Leon Battista Alberti, when he suspended a flat plate from an edge and discovered that the wind would deflect the plate, with the revolutions depending on the wind speed. The anemometer has been updated in more recent times as a cup anemometer, in which the plate is replaced by three or four cups attached by arms to a vertical rod that catch the wind to rotate the rod. 
     A wind vane and cup anemometer are sometimes positioned on the same vertical rod. Alternatively, another combination of wind vane and anemometer is the aerovane, in which a propeller and a tail are combined on the same horizontal shaft and mounted on a vertical axis for rotation to indicate wind direction. 
     Perhaps the simplest device for indicating wind direction and relative speed is a windsock, a piece of cloth with a frustoconical shape provided with a rigid circular support for the wider end and mounted for rotation on a vertical shaft. In low winds, the cloth droops, but in higher winds the cloth fills and flies horizontally, indicating the direction in which the wind is blowing. For example, if the windsock is pointing east, that means there is a westerly wind (a wind blowing from west to east). The windsock&#39;s angle relative to the ground provides an indication of whether the winds are light, moderate or heavy. Windsocks may be affected by sleet, snow and freezing weather in both their ability to rotate into the wind and also to straighten or extend from a vertical to a horizontal position. 
     The United States Federal Aviation Authority (FAA) Specification for Wind Cone Assemblies, FAA Advisory Circular 150/5345-27D, requires windsocks to indicate wind direction in winds as light as 3 knots, and to be fully extended in the horizontal position (indicating high winds) at 15 knots. Windsocks may be lighted for nighttime observation, either by floodlights illuminating the exterior of the windsock, or with a pole-mounted light illuminating the windsock&#39;s interior. 
     U.S. Pat. No. 1,879,267, “Wind Indicator for Aviators,” discloses an aerovane in which the casing of the device has a triangular shape with a rudder at the point to steer the aerovane. The casing also contains lamps to provide illumination of the aerovane at night. However, the propeller at the front of the aerovane which provides relative wind speed information is not illuminated. Aviators would therefore have a difficult time gauging wind speed at night. 
     U.S. Pat. No. 1,911,169, “Air Navigation Apparatus,” discloses a tubular member through which wind passes, as though it were a rigid version of a windsock. The tubular member pivots to indicate the wind direction. Some of the wind passing through the tubular member is diverted and operates a spring and gear mechanism, which controls a pointer that indicates relative wind speed on a large dial mounted on the top of the tubular member. The spring and gear mechanism complicate this device, and the distance at which the dial may be read is not great. In addition, the apparatus is not illuminated for nighttime use. 
     U.S. Pat. No. 1,953,159, “Means for Indicating the Direction and Velocity of the Wind Near the Ground,” discloses a wind vane with two arms that pivot at different wind speeds, so that a pilot may observe the orientation of the wind vane and the angle of the pivoting arms and determine the wind direction and relative speed. Lights on the vane and arms illuminate for nighttime observation. The design is complicated because of the need to control the pivoting arms. 
     U.S. Pat. No. 1,969,206, “Device for Giving Luminous Signals, Particularly Adapted for Aviation Purposes,” discloses a wind vane with a projection lamp system that projects the wind direction and speed onto a reflective screen or other surface. This design requires a projection surface, and the reflection of the projected light will not be as visible at a distance as direct illumination would be, especially if the surface were dirty or coated with ice or snow. 
     U.S. Pat. No. 4,241,604, “Nighttime Wind Direction and Speed Indicator,” discloses a lamp with a rotatable projection lens that concentrates a portion of the light from the lamp and projects it on the nearby ground. The rotatable projection lens is attached to an external wind vane, so that the lens rotates as the wind vane pivots in the wind, with the projected beam indicating wind direction. A cup anemometer on top of the housing is connected to a rotatable shutter internal to the lamp so that the shutter interrupts the projected beam of light, with the frequency of interruption being proportional to the wind speed. It is not clear how an aviator not familiar with the device would relate the flashing to the ground speed of the wind. 
     U.S. Pat. No. 5,323,649, “Airport Wind Direction and Velocity Indicator,” discloses a housing shaped as a tetrahedron with a triangular cross section that pivots in the wind. The edges of the housing are illuminated, allowing pilots to view the wind direction from a distance at night. In addition, a cup anemometer mounted on the housing measures wind speed, which is projected as large illuminated numerals mounted on the two top sides of the housing. 
     U.S. Pat. No. 7,310,047, “Gas Alarm System with Wind Direction Indicator,” discloses a mechanism that senses the presence of a hazardous gas and provides annunciation to signal and warn personnel of the hazardous gases and to also alert them as to the direction of the wind carrying the toxic gas. 
     The devices of the prior art have limited ability for use in regions that may experience conditions of blowing sand and dust at ground level due to complex mechanical systems that could become fouled and that would require frequent inspection and maintenance to assure their continued reliable operation. 
     Apparatus that display numbers also present problems of deciphering the numerals at a distance as the pilot is approaching the runway or landing strip. 
     It is therefore an object of the present invention to provide an improved wind speed and direction indicator that is highly visible and readily discernable to the pilot or navigator of an approaching aircraft, particularly under conditions of lowered visibility. 
     Another object of the invention is to provide such a wind speed and direction indicator that is of robust and durable construction having low maintenance requirements that will remain operable under harsh conditions including, for example, ice, snow, airborne dust and/or sand, and that can be installed at remote airstrips. 
     SUMMARY OF THE INVENTION 
     The above objects and other advantages are achieved by the present invention which comprehends an improved wind direction and wind speed indicator that provides for greater visibility of both of indications at night and under other conditions of poor visibility. 
     The wind direction indicator portion of the present invention includes: (a) a mast-mounted rotatable central body member; (b) a rudder or windvane attached to the body member; and (c) lights mounted on the edge of the central body and on the sides of the rudder. 
     In a preferred embodiment, the rotatable body member is shaped as a generally circular disk. However, other shapes can be utilized, such as an elliptical disk, an elongated member, or a conical or frustoconical structure. 
     In a preferred embodiment, the rudder is arrow-shaped for ease of identification of its orientation and is attached to the central body by a projecting cantilever mounting assembly displaced from the vertical axis of rotation in order to assure rotational movement of the apparatus in light winds or in the event that the free movement of the rotational bearings are affected by adverse weather conditions, e.g., the accumulation of dirt, ice or the like. However, a variety of planar or other rudder shapes can be used that present sufficient area to wind currents to assure movement of the body assembly. Other known wind vane mounting methods and structures can be used, e.g., the rudder can be attached directly to the central body, or can be an integral part of the central body. 
     Any of various types of lights can be used in the present invention, including, for example, incandescent, fluorescent, xenon, argon, halogen, high intensity discharge (HID), optical cables and gel cables. For convenience and the purpose of describing a preferred embodiment, reference will be made to light-emitting diodes (LEDs). 
     In a preferred embodiment, the anemometer portion of the invention takes the form of a wind activated airfoil or paddle and lever assembly linked electromechanically to an associated vertically arrayed light display to indicate wind speed. 
     In another preferred embodiment, the combined wind direction and speed indicator of the invention is provided with solar panels and one or more rechargeable batteries to provide power for operation and allow the device to be installed in remote areas where an electric power source is limited, unreliable or not available. In this embodiment, operating on battery power, LEDs are especially preferred due to their high efficiency, i.e. high lumen output with relatively lower power consumption. 
     The present invention also has the advantage of extended life as compared to natural or synthetic fabric-type windsocks, while the LEDs of the preferred embodiment allow the device to be seen at a greater distance than a pilot can view a traditional windsock. The apparatus and its components can be constructed of a scale and positioned at a location relative to the landing zone to accommodate the specific type of aircraft that typically utilize the runway. A landing strip or field serving small craft can utilize a device that is smaller in scale than may be desirable for guiding larger aircraft. 
     The present invention can also be utilized to provide a highly visible wind direction indicator to workers evacuating an industrial chemical production facility during an emergency such as a release of hazardous gas, when it would be important to know the prevailing wind direction in order to select the safest evacuation route. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be further described in detail below and with reference to the attached drawings which are provided by way of illustration and example only, and in which: 
         FIG. 1  is a top, front perspective view of one embodiment of the illuminated directional wind speed indicator of the invention having a generally circular central body; 
         FIG. 2  is a front elevation view of  FIG. 1 ; 
         FIG. 3  is a side elevation view of another embodiment of the illuminated directional wind speed indicator having a cone-shaped central body; 
         FIG. 4  is a top view of the embodiment of  FIG. 3 ; 
         FIG. 5  is a perspective view of one embodiment illustrating an interconnection between the airfoil and the switches that control the lights of the wind speed indicator; 
         FIG. 6  is a schematic diagram of another embodiment showing an interconnection between the airfoil and the switches that control the lights of the wind speed indicator; and 
         FIG. 7  is a schematic diagram of one embodiment of a power distribution circuit for the illuminated directional wind speed indicator of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 and 2 , the illuminated directional wind speed indicator  100  includes a rotationally-mounted base member in the form of a rotatable enclosure  110  with top surface  112 , bottom surface  114  (not shown) and side  116 . In the embodiment shown in  FIGS. 1 and 2 , the rotatable enclosure  110  is shaped as a disk or short cylinder of generally circular cross-section. As will be apparent from this description, other non-circular configurations can be employed for the base member. 
     A plurality of high intensity light-emitting diodes (LEDs) of predetermined and readily distinguishable colors are mounted along the periphery or the side of the rotatable enclosure  110 . For example, the right side can be fitted with an array of green LEDs  120  arranged with equal angular spacing and the left side provided with an array of red LEDs  122 . The rotatable enclosure  110  has a forward central portion on which is mounted one or more white LEDs  124  and an aft or rear central portion on which is mounted one or more blue LEDs  126 , as best shown in  FIG. 3 . Other distinctive and readily distinguishable color combinations can be employed. 
     A projecting arm or beam  130  fitted with an arrow-shaped planar rudder or windvane  134  is mounted at the rear central position of the rotatable enclosure  110 . The rudder  134  has a left side and a right side, on each of which is mounted a red LED rudder array  136 . As will be apparent to one of ordinary skill in the art, the rudder and beam can be produced as a single assembly, for example, by a molding or casting process. Furthermore, the base member  110 , rudder  134  and its supporting beam  130  can also be produced as a unitary element. 
     The rotatable enclosure  110  is bearing-mounted at its center of rotation on a supporting post  140 , which terminates in a coupling  142 . The coupling  142  in turn bolts to a vertical post  144  which is permanently secured in the ground, such as by embedding it in concrete. In one embodiment, the coupling  142  is constructed to provide freedom of rotation and also to house the power link. As an added safety feature, the coupling  142  can also be configured to break away in the event that an aircraft or ground vehicle were to strike the indicator  100 . 
     Also mounted towards the rear and extending away from the central position of the rotatable enclosure  110  below the rudder  134  is an anemometer in the form of a lever assembly  150  which is attached to an airfoil or paddle  152 . Mounted on, and extending above the top center of the rotatable enclosure  110  is a vertical bar  160 , which carries an array of three stages or groups of wind speed indicator lights. In one embodiment, vertical bar  160  can be transparent, with lights mounted inside. The lowest stage or array of lights  162  are, for example, green, the middle stage of lights  164  are yellow, and the upper stage of lights  166  are red. In a preferred embodiment, switches and lighting circuits are housed in the rotatable enclosure  110 . 
     The rotatable enclosure  110  rotates as wind strikes the rudder  134 , so that the rudder  134  indicates the wind direction. During the day, an aviator is able to directly observe the rotatable enclosure  110  and rudder  134  and thus discern the wind direction. At night, a photocell or time clock activates the lighting circuits, which illuminate the rudder array  136  on the rudder  134 , as well as the red LEDs  122 , green LEDs  116 , white LED  124  and blue LED  126  on the rotatable enclosure  110 . These illuminate the outline of the rotatable enclosure  110  and rudder  134 , allowing a pilot or persons evacuating an area where hazardous gas is present to determine the prevailing wind direction. Thus, if the white light or lights are flanked by one or more red and green lights, the observer will know that the wind is coming from the general direction of the observer. The relative number of red versus green lights provides the trained observer with more specific information about wind direction. 
     Similarly, the presence of the blue light, or lights flanked by red or green lights, or both red and green lights, indicates that the observer is heading into the wind. If only the array of red or green lights is visible, the observer will understand that a cross wind will be experienced in the vicinity of the indicator. 
     The intensity or speed of the wind causes the airfoil  152  and its lever  150  to rotate in the vertical plane, with linkage internal to the rotatable enclosure  110  activating switches that measure and process the relative rotation of the airfoil  152 . In low wind conditions, there is little or no movement of the airfoil  152  and lever  150 , and the circuitry transmits power to the green (lowest) stage of lights  162  of the vertical bar  160 . In moderate winds, vertical movement of the airfoil  152  and lever  150  is greater, and the circuitry powers the yellow (middle) stage of lights  164 . In the highest winds, the rotational movement of the airfoil  152  and lever  150  is even greater, rotating to its maximum 90 degree position, which is the horizontal position shown in  FIG. 1 , and the circuitry powers the red (upper) stage of lights  166 . 
     Referring now to the embodiment of  FIGS. 3 and 4 , LED wind direction and speed indicator  300  illustrates a rotatable enclosure  320  of frustoconical shape, with photovoltaic arrays  330  mounted to the angled top surface  312 . As with the generally cylindrical rotatable enclosure  110  of  FIGS. 1 and 2 , the frustoconical rotatable enclosure  320  of  FIG. 3  houses a linkage to the airfoil  152  and its lever  150 , which activates switches that correspond to, and process the relative rotational position of the airfoil  152 , which is shown in  FIG. 3  in a vertical, no-wind or not measurable wind position. In addition, rotatable enclosure  320  contains charging circuits and batteries associated with the photovoltaic arrays  330 . In other aspects, LED wind direction and speed indicator  300  is similar to the planar embodiment shown in  FIGS. 1 &amp; 2  and described above. 
     Referring to  FIG. 5 , one embodiment of an interconnection between the airfoil  152  and the switches  580  that control the lights  162 ,  164 ,  166  of the illuminated directional wind speed indicator is illustrated. The airfoil  152  and lever  150  protrude from the housing of the LED wind direction and speed indicator (not shown). The lever  150  connects to a linking/supporting rod  510 , which is supported within the housing by fixed bearings  520 . As the airfoil  152  is lifted by the wind, the airfoil  152 , lever  150 , linking/supporting rod  510 , and a disc  530  on one end of the linking/supporting rod  510  rotate. The rotation is limited to 90 degrees, and as the disc  530  rotates, an angular/linear converter link  540  attached between disc  530  and shaft  550  converts the circular motion of disc  530  into a linear motion for shaft  550 . Shaft  550  then slides linearly through fixed guides  560 . In the embodiment shown in  FIG. 5 , a screen  570  is mounted on the distal end of shaft  550 . The screen  570  interrupts optical signals transmitted and received between the optical electronic switch array  580 . The activation of particular switches within optical electronic switch array  580  is predetermined and calibrated to correspond to the wind speed of the lifting airfoil  152 , and the switch signals are used to control lights  162 ,  164  and  166 . 
       FIG. 6  is a schematic diagram of an alternate embodiment of an interconnection between the airfoil  152  and the switches that control the lights  162 ,  164 ,  166 . In this embodiment, shaft  550  features a cam  610 , which activates position switches  620 . The activation of particular switches within the array of position switches  620  therefore corresponds to the speed of the wind contacting and lifting airfoil  152 , and the switch signals are used to control lights  162 ,  164  and  166 . It will be understood by one of ordinary skill in the art that the switching system can be modified so that the plurality of lights in each different color array are actuated sequentially as the wind speed increases. Thus, if each color array has three separate lights, light wind speeds of 1 to 5 knots will serially illuminate one, two or all three green lights to indicate more accurately the relative wind speed. 
       FIG. 7  is a simplified schematic circuit diagram of the LED wind direction and speed indicator for an embodiment incorporating photocells and rechargeable batteries. The photovoltaic arrays  330  are wired to the chargers/batteries  710 . In the preferred embodiment, the LEDs are powered when ambient light falls below a predetermined level, e.g., in conditions of fog or a sandstorm, and at dusk. When the photocell  720  or, alternatively, a time clock transmits an appropriate signal, the switch closes and power from the batteries is conducted to the lighting circuits. The lighting circuits include the lights on the rotatable enclosure  110 , i.e., red LEDs  122 , green LEDs  116 , white LED  124  and blue LED  126 , and rudder array  136 . As discussed above, wind of sufficient force on the airfoil  152  will rotate the lever  150 , linking/supporting rod  510  and disc  530 , then angular/linear converter link  540  converts the circular motion to a linear motion, sliding shaft  550 , and allowing its distal end to activate the light switches of switch array  730 , which as discussed earlier can be, for example, an optical electronic switch array or an array of position switches. This leads to the illumination of one or more of the green stage of lights  162  of the vertical bar  160  for low winds, the yellow stage of lights  164  for moderate winds, and the red stage of lights  166  for higher winds. 
     In the embodiment illustrated in  FIGS. 5 and 6 , the screen  570  or cam  610  are configured so that less than all of the switches of the switch array will be activated at any one time, so that, for example, at high wind speeds the switches corresponding to the red stage of lights  166  are illuminated, but not the yellow or green stages  164  or  162 . However, in an alternate and preferred embodiment, relays may be used so that when the yellow stage of lights  164  is illuminated, the green stage of lights  162  are also illuminated, and so that when the red stage of lights  166  is illuminated, both the green stage of lights  162  and the yellow stage of lights  164  is illuminated. In yet another alternate and preferred embodiment, the length and position of the screen  570  or cam  610  can be modified so as to activate the switches corresponding to the wind speed and to also maintain activation of the switches corresponding to lower wind speeds, allowing for multiple stages of lights to be illuminated without the need for relay logic. 
     Other types of wind speed indicators and associated electrical circuitry can be employed. A rotating cup anemometer can be substituted and mounted on the base. However, the embodiment described above is of simple and robust construction requiring little maintenance and has the ability to withstand the harsh conditions that are foreseeable in desert installations. 
     The openings in the housing through which the wind speed assembly passes can be provided with appropriate seals (not shown) that are well known to those of ordinary skill in the art. Dust and water vapor seals will preserve the mechanical linkages and electrical contacts from damage. Various integrated circuit devices and processors can also be substituted for mechanical components. Piezo-electric pressure sensing devices can also be employed in conjunction with the wind speed indicator to simplify the mechanical assembly. Other known types of anemometers can be employed using analog or digital signals to actuate the circuits connected to the vertical wind speed indicator lighting array. 
     It will also be understood that observers such as aircraft pilots and navigators, as well as ground personnel and installation employees who will be called upon to rely on the indicating apparatus of the invention will require training in the arrangement and meaning of the various lighting arrays and the significance of the colors and color combinations that are viewed. To this end, illustrative training materials illustrating the specific configuration of the apparatus of the invention will be provided, as well as the position of the variously colored light sources. Existing standards for placement of colored navigational lights, e.g., the United States Federal Aviation Agency can also be employed. 
     The present invention has been described in the foregoing specification with reference to specific embodiments. It will, however, be evident to one of ordinary skill in the art that various modifications and additions can be made without departing from the broader scope of the invention, which is to be determined by reference to the claims that follow. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.