After the mayor banned cell phones in public schools five years ago, Bronx-native Vernon Alcoser, 41, decided to figure out how to tap into this new, niche market. So, he bought a truck, equipped it with safe places for kids to store their electronic devices, and called it Pure Loyalty.

Alcoser and his sister Theresa, 34, started off parking one van on East Tremont Avenue directly across from Lehman High School.  They charged $1 a day to keep students’ phones during school hours.

Lehman is one of many city high schools with metal detectors that vigorously enforces the ban on cell phones, iPods, beepers and other communication devices.  Not all do.  The only allowable exception is for students who need cellphones for medical reasons.

The siblings’ cellphone storage business has now expanded to five trucks that park outside additional large schools in Manhattan and Queens.  Theresa Alcoser said Pure Loyalty was the first of its kind and now has competitors.  She did not disclose the school locations for fear of more copycat competition.  Some, she said, are run out of nearby homes and barber shops.

Each competitor cuts into Pure Loyalty’s share of the student clientele.  Still, Theresa said she is happy that her business is staying afloat and employing five people during the recession.

“We are not getting rich, but we are staying alive and are hoping to expand,” said Alcoser. “For right now, we’re okay and I’m proud of our business.”