Tiger lock

Rochester Institute of Technology:
Department of Computer Engineering
Senior Design Project - Spring 2008
Jeremy Espenshade & Jason Fay
the device


We encounter combination locks every day - they are in schools, gyms, and many other establishments with general purpose lockers. These devices provide a useful level of security that ensures our belongings remain safe. However, for many people combination locks are not accessible. Those of us who experience a lack of fine motor control can have difficulty gripping and precisely spinning the lock dial, and those of us who are blind or visually impaired may be unable to see the small numbers necessary to successfully enter our combinations. Solutions like asking for assistance are inconvenient as well as insecure, given that a private combination is essential to the security provided by such a lock.


The objective of this project is to design and implement a device that can manipulate a combination lock with minimal fine motor skill and sight requirements from the user. This handheld device will make combination locks accessible to many individuals with limited vision or fine motor control.


The implemented device allows users to input their combination on a telephone-style keypad and receive both visual and auditory feedback via an LCD and embedded speaker respectively. Once the user inputs their combination, the device will spin the lock dial appropriately and allow the user to open the lock. The entire battery powered device fits in your hand with dimensions roughly 5.5" x 7.5" x 2.5".