Pop-up, precision lock-cylinder that reveals at once, with visual and tactile cues, who else with a key has sought or gained entry

摘要

Pop-Up Indicator, Replacement Lock-Cylinder with distinctive keys for owner, employee (or acquaintance), and some third party whose right to enter is legitimate only upon notice or in an emergency. The pop-up indicators are brightly and differently colored. The lock cannot be circumvented by pressing a pop-up in and endeavoring to turn the key, because the pop-up's barrel blocks rotation of the lock's core unless the pop-up is fully extended. Once triggered, the pop-up remains visible and in locked position until the lock owner resets it. A tactile indicator of sought entry is transmitted to the owner upon key insertion and rotation, as well. Meanwhile, the employee and/or third party enjoys unimpeded access. The owner will thus know whether the employee has been over—to inspect for termites, walk the dog, etc.—and the third party cannot allege lockout lease breaking. The lock operates quite normally with either or both pop-ups triggered. Since only the employee's key or the third-party key (but not the owner's key) is capable of triggering a pop-up, if these keys have been given out, the owner obtains prima facie proof of sought entry. The owner may wish to leave a pop-up exposed in order to show a witness or possibly the police.