×

Personal alarm apparatus

  • US 5,512,881 A
  • Filed: 08/27/1993
  • Issued: 04/30/1996
  • Est. Priority Date: 08/27/1993
  • Status: Expired due to Fees
First Claim
Patent Images

1. Alarm apparatus comprising electrical circuit means including controller means for generating a variable frequency repetitive sound wave having at least two different predetermined frequencies which occur within a predetermined interval of time, and a resonator for generating a predetermined clock frequency for the sound wave.

View all claims
  • 3 Assignments
Timeline View
Assignment View
    ×
    ×