US 4,175,517 A · Cat proof pigeon trap

Abstract

A pigeon trap including a two-level walkway and a locking mechanism barring entry of animals such as house cats and other predatory quadrupeds of comparable size. The upper level walkway is or is covered by a hinged deck plate which remains in a tilted, off-horizontal position as long as there is no weight on it, and in this position it exerts an upward force on one end of a pivoted balance beam through a rod connecting the two members. This causes the opposed end of the balance beam to be depressed, thereby freeing the lower ends of the pivotally mounted bobs which would otherwise be locked in place by the balance beam. In this position of the members, a pigeon standing on the lower level walkway can push the bobs out of his way and fly into the loft. The hinged deck plate will be depressed when any animal weighing less than the average pigeon walks on it, depressing the adjacent end of the balance beam and causing the far end to be raised, in which position the lower ends of the bobs enter registering holes in the far end of the beam, locking the bobs in place. This creates no problem for the pigeon, because as soon as he jumps to the lower level, the hinged plate springs upward, again freeing the bobs. The lower level is too small, however, to accommodate the full weight of a house cat, who can get his forelegs onto the lower level but must keep the rest of his body on the upper level, thus keeping the plate depressed and keeping the bobs locked in place like the bars of a prison cell.

Claims4

Dependent claims

A pigeon trap comprising a walkway divided into an outer walkway having an outer end open to the atmosphere and an inner walkway having an inner end open to an aviary except for the usual bobs pivotally suspended from a horizontal pin disposed above such inner end, such bobs normally hanging approximately vertically and having free lower ends,

a balance beam extending below both said walkways and pivotally mounted proximate its midpoint with an outwardly extending portion having its end connected to said outer walkway by a connecting rod and its inwardly extending portion having an end provided with a number of through openings registering with and adapted to receive the lower ends of said bobs,
said outer walkway being pivoted and having a normally raised position when no weight rests on it and a depressed position when a weight less than that of the average pigeon does rest on it,
whereby when there is no weight on the outer walkway it assumes its raised position and it acts on said balance beam through the connecting rod to raise the outer end of the beam and depress the inner end of the beam to keep such inner end spaced away from the lower ends of the bobs and allow a pigeon standing on the inner walkway to push the bobs out of its way so that it can pass by them into the aviary, and when a pigeon or other animal rests a portion of its weight on the outer walkway, such outer walkway assumes its depressed position and rotates the balance beam so that its outer end is depressed and its inner end is raised to engage said lower ends of the bobs and lock said bobs against rotation.

Dependencies are inferred from the claim text.

Cat proof pigeon trap

Life of this patent

Cat proof pigeon trap

Life of this patent

Abstract

Claims4