| 摘要 |
A bird feeder comprising a feed container having a side wall and a plurality of feed openings therein, a shroud extending about the feed container, the shroud having feed openings therein, the feed openings being spaced from the top of the shroud by a distance equal to between 20% and 80% of the total height thereof, a cover, a base, a center tube and a center rod within the center tube, the center rod being secured to the base and the shroud resting on the base, a spring mounted about the center rod, the arrangement being such that the feed openings in the shroud and the feed openings in the side wall are either aligned or misaligned depending on the weight on the shroud. |
| 主权项 |
1. A bird feeder comprising:
a feed container having a side wall, a plurality of feed openings in said side wall; a shroud extending about said feed container, said shroud having feed openings therein, said feed openings being located between a bottom of said shroud and a top of said shroud, said feed openings being spaced from said top of said shroud by a distance equal to between 20% and 80% of the total height of said shroud; a cover secured to an upper portion of said shroud; a base, a center tube, and a center rod within said center tube, said center rod being secured to said base, said shroud resting on said base; a spring mounted about said center rod, said spring being biased at an upper end against a moveable stopper secured to said center rod, said spring being biased at a lower end against a fixed stopper secured to said center tube, an upper portion of said center rod being threaded, a non rotatable nut forming said upper movable stopper, said center tube having vertical grooves formed on an interior surface, said nut having flanges fitting within said grooves to prevent rotational movement of said nut and permit vertical movement of said nut; and the arrangement being such that said feed openings in said shroud and feed openings in said side wall of said feed container are normally aligned to permit access to feed within the container, said feed openings of said shroud moving out of alignment with said feed openings in said side wall when a predetermined weight is present on said shroud or cover. |
