Abstract:
A squirrel-proof sunflower seed bird feeder is provided which denies feeding access to squirrels by way of a unique connection system between an inner housing member and an outer housing member of the bird feeder.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a squirrel-proof bird feeder and more particularly to a squirrel-proof sunflower seed bird feeder which denies feeding access to squirrels by way of a unique connection system between an inner housing member and an outer housing member of the bird feeder. 
     2. Description of the Related Art 
     Many types of squirrel-proof bird feeders have been previously provided but it is believed that they suffer from certain disadvantages. First, some of the squirrel-proof bird feeders of the prior art are constructed of wood or plastic which may be damaged by an aggressive squirrel. Secondly, it is believed that the mechanisms of the prior art for closing feed ports of a bird feeder if a squirrel moves onto the feeder are not reliable and are difficult to maintain. Third, it is believed that the squirrel-proof feeders of the prior art do not have adequate feed level control devices associated therewith. 
     SUMMARY OF THE INVENTION 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key aspects or essential aspects of the claimed subject matter. Moreover, this Summary is not intended for use as an aid in determining the scope of the claimed subject matter. 
     A squirrel-proof sunflower seed bird feeder is described with the feeder including an outer housing member having an inner housing member positioned therein. The outer housing member is vertically movable with respect to the inner housing member when a squirrel moves onto the outer housing member. 
     The outer housing member of the feeder is elongated and is tubular and has upper and lower ends. The outer housing member has first and second alternating bands of openings or perforations formed therein with the openings in the first bands being smaller than the openings in the second bands thereof. The tubular inner housing member has upper and lower ends and has first and second alternating bands having openings or perforations formed therein with the openings in the first bands thereof being smaller than the openings in the second bands thereof. The outer housing member is vertically movable between first and second positions with respect to the inner housing member. The first and second bands of openings in the outer housing member register with the first and second bands of openings in the inner housing member respectively when the outer housing member is in its first position. The second bands of openings in the outer housing member are positioned below the second bands of openings in the inner housing member when the outer housing member is in its second position. 
     The inner housing member has a feed level control device positioned therein adjacent each of the second bands of openings which maintains a certain amount of feed at that level in the inner housing member even though the main supply of feed has dropped below the feed level control device. A spring means connects the inner and outer housing members to yieldably maintain the outer housing member in its first position but which will permit the outer housing member to move to its second position if a squirrel should move onto the outer housing member. 
     In the preferred embodiment, the openings in the second bands of openings of the outer housing member are larger than the openings in the second bands of openings in the inner housing member and the openings in the first band of openings in the outer housing member are larger than the openings in the first bands of openings in the inner housing member. 
     In the preferred embodiment, the feed level control devices are inverted truncated funnels. In the preferred embodiment, the outer and inner housing members are comprised of a metal mesh material. In the preferred embodiment, a pair of springs interconnect the outer and inner housing members to yieldably maintain the outer housing member in its first position. In the preferred embodiment, the springs are positioned at the outer side of the inner housing member. In the preferred embodiment, the outer housing member has a pair of vertically disposed slots formed therein at the upper end thereof which receive the springs therein and with the inner housing member having a pair of vertically disposed grooves or recesses formed therein which partially receive the springs therein. In the preferred embodiment, the springs are covered by shields to prevent squirrels from damaging the springs. In the preferred embodiment, each of the springs have upper and lower ends with the upper ends of the springs being secured to the inner housing member and the lower ends of the springs being secured to the outer housing member. Thus, if a squirrel moves onto the outer housing member, the registering feed openings between the outer housing member and the inner housing member are no longer in a registering position which denies access of the squirrels to the feed in the inner housing member. 
     It is therefore a principal object of the invention to provide an improved squirrel-proof sunflower seed bird feeder. 
     A further object of the invention is to provide a unique squirrel-proof sunflower seed bird feeder including inner and outer housing members with the outer housing member being movable downwardly with, respect to the inner housing member should a squirrel move onto the outer housing member. 
     Yet another object of the invention is to provide a bird feeder of the type described including inner and outer housing members with each of the inner and outer housing members having alternating first and second bands of openings formed therein. 
     Another object of the invention is to provide a unique bird feeder of the type described which includes feed level control devices positioned in the inner housing of the bird feeder. 
     Yet another object of the invention is to provide a bird feeder of the type described which resists damage thereto by aggressive squirrels. 
     These and other objects will be apparent to those skilled in the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. 
         FIG. 1  is a perspective view of the bird feeder of this invention; and 
         FIG. 2  is an exploded perspective view of the bird feeder of this invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Embodiments are described more fully below with reference to the accompanying figures, which form a part hereof and show, by way of illustration, specific exemplary embodiments. These embodiments are disclosed in sufficient detail to enable those skilled in the art to practice the invention. However, embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. The following detailed description is, therefore, not to be taken in a limiting sense in that the scope of the present invention is defined only by the appended claims. 
     The numeral  10  refers to the squirrel-proof sunflower seed bird feeder of this invention. Feeder  10  includes an outer housing member  12  comprised of a metal mesh material and which has an upper end  14  and a lower end  16 . Outer housing member is comprised of alternating first and second bands or segments  18 ,  20 ,  18 ′,  20 ′,  18 ″ and  20 ″. The bands  18 ,  18 ′ and  18 ″ have perforations or openings formed therein which are of the same size. The bands  20 ,  20 ′ and  20 ″ have perforations or openings formed therein which have the same size. The perforations or openings in bands  20 ,  20 ′ and  20 ″ are larger than the size of the perforations or openings in bands  18 ,  18 ′ and  18 ″. Bands  20 ,  20 ′ and  20 ″ define feed openings. Perches  22  are preferably mounted on housing member  12  as seen in  FIG. 2 . 
     Housing member  12  is provided with a guide slot  24  formed therein at its upper end as seen in  FIG. 2 . Housing member  12  has a pair of vertically disposed slots  26  and  28  formed therein which extend downwardly from the upper end thereof. The numerals  30  and  32  refer to elongated and arcuate shields which are secured to the outer side of housing member  12  outwardly of slots  26  and  28  respectively. 
     Feeder  10  also includes an inner housing member  34  having an upper end  35  and a lower end  36 . Inner housing member  34  is comprised of a metal mesh material and has alternating first and second bands or segments  38 ,  40 ,  38 ′,  40 ′,  38 ″ and  40 ″. The bands  38 ,  38 ′ and  38 ″ have perforations or openings formed therein which are the same size. The bands  40 ,  40 ′ and  40 ″ have perforations or openings formed therein which have the same size. The perforations or openings in bands  40 ,  40 ′ and  40 ″ are larger than the size of the perforations or openings in bands  38 ,  38 ′ and  38 ″. Bands  40 ,  40 ′ and  40 ″ define feed openings. 
     Inner housing member  34  has a pair of elongated recesses  42  and  44  formed therein which register with slots  26  and  28  of outer housing member  12 . Springs  46  and  48  are adapted to be partially positioned in the recesses  42  and  44  respectively and to be partially received in the slots  26  and  28  respectively as will be described hereinafter. The numerals  50 ,  50 ′ and  50 ″ refer to feed level control devices such as disclosed in my U.S. Pat. No. 7,198,004. The devices  50 ,  50 ′ and  50 ″ have a shape of an inverted, truncated funnel and are associated with the bands  40 ,  40 ′ and  40 ″ respectively which maintain a certain amount of feed at that level in the inner housing member  34  even though the main supply of feed has dropped below that feed level control device. 
     Inner housing member  34  is inserted downwardly into outer housing member  12  until the lower end  36  of inner housing member  34  rests upon the lower end of outer housing member  12 . At that position, bands  38 ,  40 ,  38 ′,  40 ′,  38 ″ and  40 ″ of inner housing member  34  will register with bands  18 ,  20 ,  18 ′,  20 ′,  18 ″ and  20 ″ of outer housing member  12  respectively. During the insertion of housing member  34  into housing member  12 , the guide  47  will be received by the guide slot  24 . The lower ends of springs  46  and  48  are connected to the outer housing member  12  and the upper ends of springs  46  and  48  are connected to the upper end of housing member  34  with the springs  46  and  48  being partially received in the recesses  42  and  44  respectively. Shields  30  and  32  are then secured to outer housing member  12  to shield the springs from damage from squirrels. 
     A rain shield or roof  52  is then positioned on the upper end of housing member  12  with the channels  54  and  56  of roof  52  being received by the upper ends of the slots  26  and  28  respectively. Cover or lid  58  with hanger  60  is then secured to the upper end of housing member. 
     In normal use, the birds may feed from the sunflower seeds in the inner housing member  34  by way of the registering feed openings created by bands  20 ,  40 ,  20 ′,  40 ′ or  20 ″,  40 ″. If a squirrel should move onto the outer housing member  12 , the weight of the squirrel will cause the outer housing member  12  to move downwardly against the yieldable force of springs  46  and  48  so that the bands  20 ,  20 ′ and  20 ″ no longer register with bands  40 ,  40 ′ and  40 ″ to prevent the squirrel from gaining access to the feed in the feeder. When the squirrel departs from the feeder, the springs  46  and  48  cause the housing member  12  to return to its normal position so that bands  20 ,  20 ′ and  20 ″ again register with bands  40 ,  40 ′ and  40 ″ respectively. 
     Thus it can be seen that the invention accomplishes at least all of its stated objectives. 
     Although the invention has been described in language that is specific to certain structures and methodological steps, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific structures and/or steps described. Rather, the specific aspects and steps are described as forms of implementing the claimed invention. Since many embodiments of the invention can be practiced without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.