A removable door locking device having a strong, flexible, resilient, elastic loop capable of absorbing instantaneous force applied to the door. One end of the loop fits tightly around the door knob and the other end of the loop has multiple attachment points to a wall member for adjustment of tight...http://www.google.ca/patents/US5908213?utm_source=gb-gplus-sharePatent US5908213 - Elastic door locking device
