iKey® partners with Gamber-Johnson often for forklift mounting projects. Here are a few solutions to look at from Gamber-Johnson. You can find more information at their website, www.gamberjohnson.com
Forklift Low Profile Tablet Keyboard Bracket: # 7160-0984 http://www.gamberjohnson.com/
Other keyboard brackets for forklifts, whether you want to mount horizontally or vertically, they have a solution: http://www.gamberjohnson.com/
The above link also shows the mounting solutions for an iKey numeric pad, Zebra tablet and quick release keyboard tray assembly.