Abstract:
A bird feeder having a gated feed access opening, and a squirrel or other undesired animal detector and repulsion devices is presented. The structure may have a rotating perch or landing area to throw off animals having a greater weight than an adjustable set point in addition to shutting the feed access gate. The structure may also have smooth sidewalls to prevent non flying animals from gaining access to the feed access openings.

Description:
TECHNICAL FIELD 
       [0001]    This disclosure relates generally to methods and structures for wild animal feeding, and more specifically to preventing squirrels from accessing bird feeders. 
       BACKGROUND 
       [0002]    Certain persistent animals, such as squirrels, empty bird feeders rapidly, resulting in lost feeding opportunities for desirable bird. Fewer feeding resources may result in fewer birds remaining in the general area of the feeder, and thus loss of desirable visual and auditory experiences, and potential increase in local insect population, which may lead to health concerns. 
         [0003]    There have been many attempts to prevent animals such as squirrels from gaining access to the bird feeders, including the use of overhanging roofs, slippery sides, closing doors or gates, and rotating devices. However, squirrels can jump great distances, and do not need to be able to hold on to any portion of the feeder, since the disruption of the stable position of the feeder may typically result in a portion of the feed spilling out onto the ground, where the squirrels may feed at their leisure. 
         [0004]    A potential issue with the use of a rotating feeder is that the rapid rotation needed to cast the undesired animal off of the feeder may typically be sufficient to partially empty the feeder due to centrifugal force acting upon the feed. Thus, the potential solutions to undesired animal access to bird feeders may reduce the amount of lost feed, but a great deal of feed is still lost and wasted. 
         [0005]    What is need in response to the above noted problems, is a method that prevents a squirrel or other undesired animal from remaining in the vicinity of the feeder, and reduces the amount of feed spilled during repeated attempts to access the feed container. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  illustrates a feeder device according to various embodiments of the invention; and 
           [0007]      FIG. 2  illustrates a feeder device, according to various alternative embodiments of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0008]    When an undesired animal attempts to access a feeder station intended to for certain birds, a device to reduce or prevent the loss of bird or other animal feed includes, a support structure connected to a food container, with a number of feed openings providing access to the interior of the food container. The interior may have a number of independent food containers, with each one connected to a different feed opening. There may be a circular landing area or perch located outside the food container next to one or more of the feed openings. There may be a number of different perches, perhaps with one located next to each of the openings, but a circular perch may provide a place for birds waiting for a vacant feed opening. In either event, the landing area or perch is capable of rotating relative to the feed openings. The perch may rotate around a long symmetrical axis of the bird feeder, and may rotate at about sixty revolutions per minute in response to an undesired animal&#39;s presence. There may be a switch connected to the perch, which responds either to a selected weight on the perch, or a variation in the slope of the feeder away from vertical with may indicate an animal or high wind, or to movement of the perch. The activation of the switch causes a movable gate or door to close the feeder opening by activation of a motor, relay or solenoid, and activates a motor connected to the circular perch to rotate the landing area or perch away from the feeder openings and to cause the animal to leave the landing area. 
         [0009]      FIG. 1  illustrates a feeder device  100  according to various embodiments of the invention, from both a side view and a top view. The feeder  100  has a feed container tube  102 , a landing area  104  that is set at a height appropriate for the size of the desired type of bird or other animal. The landing area  104 , or perch may typically have a number of spokes connecting the landing area  104  to a central symmetry axis of the feed tube  102 , to enable rotation of the landing area  104  with respect to the feed tube  102 . In other embodiments, both the landing area  104  and the feed tube  102  rotate both with respect to each other, and to a support structure. 
         [0010]    The feed tube  102  contains a number of feed openings  106 , which may have various opening sizes to encourage certain types of birds and discourage the presence of other types of birds. The feed openings  106  each have a movable gate  108  positioned to close the opening  106  at selected times. The movable gates may slide in a ring on the inside of the feed tube  102  as shown, or may be positioned on the outside of the tube  102  to avoid potential jamming of the slide mechanism by especially small bird feed types, such a thistle seed. The movable gates may alternatively swing shut from the outside on hinges, drop from the top to cover the feed opening, of be raised from the bottom, among other easily understood methods to close an opening, including an iris type shutter. 
         [0011]    The landing area  104  may include a switch  110  that responds to a weight on the landing area  104 . The switch may respond to a radio signal, a clock or timer, a moisture sensor, to variations in the angle of the landing area  104  from horizontal, or to motion of the landing area, in addition to a weight limit. The switch  110  may typically be located at the attachment point between the landing area  104  and a shaft of a motor  112 . The actuation of the switch  110  initiates the rotation of motor  112  causing the landing area to rotate with relation to the feed opening  106 , and dislodging the undesired animal from the landing area. The weight limit for operation of the switch  110  may be made low enough to prevent larger birds from using the feeder  100  as well as preventing squirrels from remaining in the vicinity of the feed opening  106 . The rotation of the landing area  104  and the rocking of the feed tube  102  may allow some of the feed to be expelled from the feed opening  106 . This loss of feed is reduced by the operation of sliding gates  108  to close the feed opening  106  in response to activation of the switch  110 . The gate  108  may be operated by the rotation of the landing area under the drive of the motor  112 , or it may be independently operated by a solenoid, relay or a separate motor. 
         [0012]    The feeder  100  may typically be hung from a pole or other support from a top portion of the feeder by a support  114 , which may also be an overhang to render more difficult a non flying animal&#39;s access to the landing area  104 . In addition, the vertical side walls  116  of the feed tube  102  may be smooth and slippery to further obstruct the non flying animal. 
         [0013]      FIG. 2  illustrates a feeder device  200  according to various alternative embodiments of the invention, from both a side view and a top view. The numbers of the elements are similar to those given in  FIG. 1 , and nonessential portions have been removed for simplicity of understanding. The illustrated embodiment includes the feed tube  202  being internally partitioned to allow for different types of feed to be dispensed, each from its own group of feed openings  206 , each opening potentially having a different size to favor a selected type of bird along with the selected type of feed. The illustrated embodiment also includes several non rotating, fixed landing areas or perches  218 , illustratively shown as being at a higher level than the rotating landing area  204 . 
         [0014]    The rotating landing area is shown has having a number of feed openings  206 , and a number of sliding gates  208  to close the feed openings  206  when the switch is actuated. The multiple gates may be formed as a number of spaced openings in a circular sleeve located either inside or outside the feed tube  202 . The sleeve may be operated by a relay and returned to the non activated position by a spring. The illustrated embodiment includes a sonic and/or optic generator  220 , which may produce loud noises and bright flashes of light in response to activation of one of the landing area, or perch, switches, which may be located in the rotating landing are  204  or the fixed perch  218 , or both. In such a fashion the desired bird types may be allowed to easily obtain food, while discouraging undesired large birds or mammals from feeding at the feeder. 
         [0015]    The detailed description refers to the accompanying drawings that show, by way of illustration, specific aspects and embodiments in which the present disclosed embodiments may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice aspects of the present invention. Other embodiments may be utilized, and structural, logical, and electrical changes may be made without departing from the scope of the disclosed embodiments. The various embodiments are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. 
         [0016]    The terms “bird feeder” and “perch” as used in the description may include any structure for providing food to flying animals and having a landing area for the flying animals to utilize while accessing the feeder. 
         [0017]    The term “horizontal” as used in this application is defined as a plane parallel to the conventional plane of the surface of the earth wafer, or to a plane perpendicular to a symmetry axis of the feeder, regardless of the orientation of the feeder. The term “vertical” refers to a direction perpendicular to the horizontal as defined above. Prepositions, such as “on”, “side”, “higher”, “lower”, “over” and “under” are defined with respect to the conventional plane or surface, regardless of actual static or momentary dynamic orientation of the feeder. 
         [0018]    Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments shown. This application is intended to cover any adaptations or variations of embodiments of the present invention. It is to be understood that the above description is intended to be illustrative, and not restrictive, and that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Combinations of the above embodiments and other embodiments will be apparent to those of skill in the art upon studying the above description. The scope of the present disclosed embodiments includes any other applications in which embodiments of the above structures and fabrication methods are used. The detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.