Let us take a look at this vision. A larger door handle but moved to the centre of the door where a lock mechanism will push iron pins into three sides of the frame (the top and both sides). The pins are hidden inside the door and the lock could be formed to push each pin simutaneously(sp?)into guard plates inserted into the door frame.

What would one think of this? A sprinkler type head that pops out of the lawn and clips the grass off at a certain height. Make sure someone is not on the -grass- before throwing the switch, okay-right. Each head would cover a radius and by a flick of a switch the job would be done.